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There has been a buzz around the fitness and health world of the new diet called Whole30. The Whole30 is a 30-day diet that emphasizes whole foods and during which participants eliminate sugar, alcohol, grains, legumes, soy, and dairy from their diets. There is a big emphasis on fruits and vegetables completely eliminating the junk food world.
Today I took a turn from the typical veggie omelet with a sweet twist on an American classic. With help from a Coconut Chocolate RX bar (Whole30 approved), I completed this cinnamon apple nut crisp. This is super easy and only requires 4 ingredients. Apple, cinnamon, nuts, and coconut oil.
1 apple
1 teaspoon of cinnamon
1teaspoon of coconut oil
2 tablespoons of chopped nuts
heat oil in a saucepan
chop apple
add apple to pan
add cinnamon and nuts
cook until golden


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Houston Scrap Metal
We serve the greater Houston area with a drive thru Scrap Metal off-loading area!
We provide Commercial Roll-Off containers – dumpsters for your commercial construction scrap as well. Call us today for pricing…. 713-690-6777
Houston Scrap Metal Recycling!
Coastal Metal Recycling
Houston Scrap Metal
The Wave of The Future™
Monday- Friday 8AM- 5PM
14002 Hempstead Hwy.
Houston, TX 77040
713-690-6767 office
713-690-1313 fax
Se Habla Espanol!
Houston Scrap Metal
Houston scrap metal recycling – Our metal recycling facility has proudly served our local commercial and residential customers for 30 years. We offer a full-service, indoor drive-thru facility. We purchase non-ferrous metals, including aluminum, copper, brass, stainless, nickel alloy, lead and much more. We also purchase scrap iron steel.
At Coastal Metal Recycling, we make it easy to sell your scrap metal. We offer a clean, indoor drive-thru facility where our knowledgeable staff will unload, and weigh your scrap metal and pay you cash in a matter of minutes.
We offer roll-off containers/dumpsters to our commercial and industrial customers for larger quantities of scrap iron/steel. Call us today for details.
Industrial Scrap Metal Containers/Dumpsters
We provide roll-off containers or dumpsters including pick-up and delivery services for commercial and Industrial accounts for easy on-site loading. We offer this service for long-term & lage projects in and around the Houston area as well.
We strive to serve you in a prompt and courteous manner for all of your scrap metal & scrap iron roll-off needs.
Call today for more information!
Metal We Accept:

subset: commoncrawl


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Creamy Mozzah Cheez Wheel
Our mozzarella style cheese wheels are made with real ingredients you can pronounce! Allergens? No worries! Our products are dairy, soy, gluten, & tree nut free so all can enjoy. These creamy mozzah wheels can be sliced, shredded, and melted onto all your favorite foods like pizzas, panini's, caprese salads, philly cheez fakes, lasagna, and many other dishes! Be sure to check out our recipes under products for easy meals everyone can enjoy.


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Symptoms of Endometriosis: 1 of 5 things you really need to know about endometriosis
A Comprehensive Guide to Understanding Endometriosis
(Dr Eric Daiter, Board Certified in Reproductive Endocrinology and Infertility)
- What is endometriosis?
- Problems caused by endometriosis: its symptoms
- Diagnosing endometriosis
- Treating endometriosis
- What to expect after treatment for endometriosis
Symptoms of Endometriosis:
Endometriosis causes inflammation, which can in turn cause symptoms such as lower pelvic pain (anywhere from mild discomfort to killer cramps) and the subsequent development of scar tissue (adhesions) in response to this recurring inflammation. The inflammation that results from endometriosis can also cause the involved organs to malfunction. Endometriosis most commonly grows in the female pelvis around the uterus, fallopian tubes, ovaries, bladder and colon so the symptoms that endometriosis most often causes include female lower pelvic pain, irritable bowel symptoms (painful bowel movements, diarrhea or constipation) or urinary frequency (especially during the time of a menstrual flow). All stages of endometriosis can cause female infertility and endometriosis increases the risk of ectopic pregnancy.
Endometriosis," including actual surgical photographs of endometriosis taken by Dr. Daiter (warning: some consider these photos graphic or gross).
If you like what you have been reading then download your entire free copy of "A Comprehensive Guide to Understanding Endometriosis," including actual surgical photographs of endometriosis taken by Dr. Daiter (warning: some consider these photos graphic or gross).
A video testimonial that expert treatment of endometriosis can truly accomplish remarkable results!
These brave "real life" stories present examples of the kind of care that Dr. Daiter provides for his patients.


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God's Many-Splendored Image
Theological Anthropology for Christian Formation
- Buy 10+ and save 35%
Product Details
- Publisher
- Baker Academic
- Format
- Paperback
- Language
- eng
- Publication Date
- 06/01/2010
- Pages
- 220
- Dimensions
- 8.4" x 5.5" x 8.5"
- 9780801034718
Early Christian Insights Concerning What It Means to Be Human
"Sister Nonna writes as an expert in the early Christian world and its literature, but she presents the fruits of her learning in a form that is readily accessible to every reader. Her style is simple yet profound, vivid yet never overstated. . . . Here truly is a work that I can recommend with all my heart."--Metropolitan Kallistos (Ware) of Diokleia (from the foreword)
"A straightforward account of ancient Greek anthropology and spirituality that shows other, non-Augustinian methods for understanding the human condition before God. This side of patristic theological development deserves to be heard."--D. H. Williams, Baylor University
"Clarity, simplicity, beauty, and depth--these are the gifts offered to the reader in this distillation of all that the Christian tradition has signified by claiming that humanity is created in the image of God and may grow into God-likeness. This book is a model of how to appropriate the church fathers for Christians today."--Frances Young, University of Birmingham, England
"This book is a gift, written in a voice that is inviting, deeply personal, and generous. Yet the lucidity and accessibility of Harrison's presentation never compromises the profundity and genuineness of its content, which is always true to the early Christian sources on which she draws. This book is also a rarity: comprehensible, practical, embodied theology. It is founded upon the author's decades of study but also reflects a life lived in alertness to the Word of God spoken in a painfully broken world. It deserves, and will richly repay, the wide audience to which it is addressed."--Peter C. Bouteneff, St. Vladimir's Orthodox Theological Seminary
"This is a wonderful book. Sister Nonna Harrison provides a masterful guide for Christian formation that is based on God's love and care from the very act of creation to the eschaton. She opens for us the Eastern part of early Christianity, providing an alternative to the expected--for Western readers--understanding of postlapsarian 'human nature' as inherently 'bad,' and shows how early Christians, from theologians to desert mothers and fathers, understood the divine image as inherent in who we are."--George Kalantzis, The Wheaton Center for Early Christian Studies, Wheaton College
Nonna Verna Harrison, Author
NONNA HARRISON, Author
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With ILLUSTRATED CLASSICS in mind, the cartoonist Lennart Moberg has written and drawn a dramatic event in Norrköping's history. The Russians' ravages in 1719 have become a comic book.
The book is at present not printed in English Any request or proposal on printing of the English ready version, can be made by e-mail: email@example.com
SAGA:Sweden was often in conflict with Russia, and countless were the battles that was fought between the countries. Even today Sweden looks upon Russia with suspicion (and vice versa of course). This is exemplified in an illustrated book, the exciting topic when the Russians in the early 1700s devastated and burned large parts of the Swedish Baltic coast line. Norrkoping, in particular, was hit hard since practically the whole town disappeared in the flames. The basic story (the summary) are historically accurate with names and places and people that were prominent. However, the story itself a fiction with exciting and dramatic events.The story is structured as a so-called. "Illustrated Classics" series (comics) without the balloons, but with the book text in compressed form.


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BC Awaits Proportional Representation Results
Santanna Hernandez, Chairperson of Selkirk College Students' Union, along with thousands of young voters, returns her referendum ballot at a local Service BC Location
| Chantelle Spicer |
With the deadline to submit all mail-in ballots on the proportional representation referendum having come and gone, British Columbians now wait to see how our democracy will proceed. As of December 7, Elections BC had received an estimated 1,356,000 returned ballots, or roughly 41% of registered voters with the highest returns coming from Vancouver Island.
The No BC Proportional Representation Society faced criticism in its campaign for inciting fear of neo-nazi and fringe party politics emerging in BC due to proportional representation, which led to an ad being temporarily pulled and edited.
Following the deadline, Bill Tieleman, Vote No spokesman, along with Andrew Wilkinson and many of the BC Liberals, have stated that returns under 50% of eligible voters should mean that the referendum be deemed illegitimate.
Torrence Costa, campaigner for the Wilderness Committee, believes a lower return on the referendum is indicative of disenfranchisement with the current first-past-the-post system.
Many municipal elections throughout the province receive far less than 40% voter turnout and remain binding and supported by their communities.
Ann Remnant of Fair Vote – Kootenays chapter states the protestations of Wilkinson and Tenneman regarding returns "have everything to do with trying to undermine the process and nothing to do with the actual turnout. Judging by their NO campaign, they will say anything to discredit the process, the turnout, the results."
For students like Kim Pham, Secretary of the Selkirk College Students' Union, this as "a great opportunity for students to have their voice heard at the decision-making table. It means a more democratic and fairer government, especially for students which are usually considered or consider themselves a minority group."
In her work advocating for proportional representation on campus, she observed that many students she interacted with assumed their votes mean nothing. She states "many students get excited knowing that with this new voting system, their vote would actually get counted. This referendum brings hope to many people, especially students."
During the campaigning period, many rallies and town halls from both sides of the campaign took place throughout the Kootenay region to educate voters on the referendum and what it could mean for rural areas.
Remnant states proportional representation could mean the Kootenays would "be part of a regional group that can work together on issues which affect all of us. I see this as a positive, we are linked by roads, waterways, industry, tourism, and more."
Once the results are finalized, Elections BC states they will be released to the Speaker of the B.C. Legislature and to the public via the Elections BC website, social media channels, and a news release. Elections BC spokeswoman Rebecca Penz said final turnout numbers will continue to be reported into early next week, with the hopes of releasing the results by Christmas.


text: Our doctors, along with our team, invite you to take a virtual tour of our fun, friendly, and comfortable dental office in San Diego, California, from the comfort of your own home! We strive to provide an environment where patients feel welcome and cared for, and we look forward to making you part of our dental family. Please feel free to contact Scripps Rock Dental today to learn more and schedule a visit with our dentists.


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What should you see when you visit Morganton, GA? The city has attractions to entertain visitors of all ages and many popular sights. Have a look at the list below and get inspired for your next trip.
Adventure Trail Rides
Beautiful scenic horse trails in the mountains that are great for adults and children alike. They offer scenic and fun rides for both beginners and experienced riders.
The Blue Ridge Community Theater
The black box theater seats 132, complete with lobby, box office, and backstage area. Along with four exciting main stage shows, they have planned some very special events this year, and you are invited to come out and join them for a great time!
Morganton Music Park
The Park was established for entire families to have a place in Northern Georgia to go to dance, socialize, eat great food, and listen to live country and western music. So bring the kids, grandma, and even uncle Joe for a great source of good clean family fun.
Pickin' In The Park
An effort to encourage communities and groups across the nation to provide a place for acoustic musicians to gather weekly to play music in unstructured, low pressure venues. Live music jams and pickin' on the banks of the Toccoa River at the Horseshoe Bend Park in McCaysville, GA. Free Admission and the park is wheelchair accessible. Come out, bring the whole family to enjoy the experience. Scattered picnic tables available, nice grassy lawn but you are also welcome to bring a blanket or chair. Encourage your community to start a weekly Pickin' In The Park.
The Blue Ridge Mountain Adventure Race
The Annual Blue Ridge Mountain Adventure Race takes place in the spring and is a challenging contest with lots of surprises and some of the most stunning scenery anywhere — plus the famous Blue Ridge hospitality racers have come to expect and enjoy.
Gorilla Haven
While not open to the public, educational visits, by appointment, will be encouraged. Gorilla Haven provides a safe "haven" and/or temporary holding facility for zoo gorillas in need. In addition, the property can be used for educational camps or programs in conjunction with schools or universities.
The Swan Drive In
One of four drive-in theatres in the state of Georgia that is still operating. The Swan operates year round with first run movies. Come out and enjoy a bit of the past.
Blue Ridge Scenic Railroad
Enjoy a train ride alongside the beautiful Toccoa River from Blue Ridge to McCaysville. The rail adventure is a 3 1/2 hour 26 mile round trip, with a 1 1/2 hour layover to explore.
Ocoee River Rafting
Guided whitewater rafting adventures. No experience is necessary to enjoy the adventure of Ocoee River rafting on the World Class Ocoee River, so let them take you on your next river adventure!
Toccoa River Adventures
An owner operated family run business in their 4th year of operation on the Toccoa River. They try very hard to give each customer personal attention to make sure their rafting trip is one they will fondly remember for years to come.
Rolling Thunder River Company
Whether you are a novice, an experienced paddler, young, or simply young at heart you can enjoy the family friendly Nantahala River and the adventure packed Ocoee River. Just bring your spirit of adventure, a desire to get wet and they will provide the rest of the ingredients for an invigorating one-of-a-kind outdoor experience.
The Lilly Pad Village
The Lilly Pad Village offers Mini Golf, Hiking, Fishing, and Gem Mining. One of the few Mountain Mini Golf Courses in the Country, the Lilly Putt has a 9-hole challenging course that is well lit For Your Night Time Putting Pleasure. Their Flume is located on the upper level of the Lilly Pad. You can mine for Emeralds, Sapphires, Rubies, Tigers Eye, and Moonstones just to name a few. Fishing in their 1/2 acre beautiful pond, which is full of catfish, brim, and small mouth bass, is always a good time. Take a guided hike to a great water fall with hiking gear, light lunch/snacks provided. Your entire family will enjoy this experience, so visit the Lilly Pad Village soon.
Reel Job Fishing, LLC
Offers professional guided conventional and fly fishing trips in North Georgia. Take a guided float trip down one of the local rivers to fish for Rainbow and Brown Trout, or you may prefer a waded fly fishing trip on a public or private watershed to fish for wild rainbow trout, brown trout, brook trout, or even trophy trout. They also offer Bass fishing trips on local lakes for Small Mouth, Large Mouth, Spotted, and Striped Bass, and Carp. Reel Job Fishing can even help you all your outfitting needs.
Unicoi Outfitters
Providing you with an experienced and friendly fly fishing guide for their own Nacoochee Bend trophy trout section of the Chattahoochee, and many other trophy trout streams and rivers in the area. They offer wade and float trips, and classes tailored to all skill levels, along with two full-service fly shops stocked with the best gear from R. L. Winston, Sage, Simms, Orvis, Abel, Lamson, Ross, and more. All guides provided by Unicoi Outfitters have a U.S. Forest Service permit and are fully insured.
Reel Angling Adventures
Offering fully equipped half-day, full-day and multi-day fishing trips on the finest public and private trout and bass fishing waters in the southern highlands. The guide team of Reel Angling Adventures combines more than 120 years of fishing experience in the Appalachian Mountains and the Southeastern US to bring you the region's widest package of angling destinations culled from the most exciting and adventurous fishing locations in the area.
Dave Seay Progressive Horsemansship
Dave Seay helps horses and humans overcome difficulties, fears and frustrations. His experience and expertise have taken him to the most respected equine schools and events in the country. His soft touch, perfect timing and clear communication methods can help bring out the best in you and your horse. Dave works with hunter/jumpers, dressage riders, and active trail riders. His methods help horses in the show ring improve their flatwork and perform better jumps. On the trail, the horses are confident and fun to ride. Visit Dave to take your equestrian experience up a notch.


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A little bit of everything Ann! Just whatever is on my mind...family friendly places to visit, money saving tips, household tips, places to visit, giveaways, freebies, green cleaning, healthy living tips, honest reviews and more! I want to help families so they can spend their money more wisely. I love to save money so I have more to spend! PR pitches welcome and ad space available, just contact me.
Wednesday, June 15, 2011
Really Cute FREE Printable Father's Day Cards
Tip Junkie has done it again (can you tell I am a junkie for Tip Junkie?)! Here are several really cute printable Father's Day cards for FREE! Just use card stock in your printer for a great card. Check out all the cute designs HERE.
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text: << Back to category RW Steele Builders Ltd rwsteelerwsteele1 Builder Category: Canterbury and ChristchurchBuilder Tags: Builder Profile Photos ReviewsR. W. Steele Ltd is a family business first established in 1965 and we subsequently became a limited company in 1974. Directors, Ray and Heather Steele, run the company while Ray and son Sam, qualified builders, actively work on site. Braden in his final stages of apprenticeship completes the team. Work is undertaken to a high professional standard and Ray believes customer satisfaction is the utmost, with immense attention being paid to detail, and a high level of communication necessary. All types of work are undertaken, whether this be a new home, alterations or additions to existing homes, repairs and maintenance, kitchen and bathroom upgrades, decks and pergolas. We have the ability to see your job through from start to finish, arranging sub contractors as necessary. No job is too big or too small; do not be afraid to call for a free quotation. Previous Next Read more... SHARE THIS PAGE


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Cognitive Control clinical trials at UC Health
1 research study open to eligible people
Measuring Plasticity in SFC/dACC Following Theta-Burst-Stimulation Using TMS
open to eligible people ages 18-40
This is a study to determine whether particular forms of brain-stimulation, applied to superior frontal cortex/preSMA can affect cognition and associated frontal theta oscillations. To perform this study, the investigators will first measure brain activity/cognitive performance using "BrainE", a rapid series of cognitive tests measuring sustained attention, behavioral inhibition, working memory and interference/distractor processing. Next, the investigators will apply brain-stimulation over a mid-frontal region most strongly associated with these tasks (mid-line frontal activity overlying superior frontal cortex/pre-SMA area). Finally, human subjects will perform BrainE assessments again immediately after the brain-stimulation. The investigators will compare the effects of brain stimulation on frontal activity evoked on the cognitive tasks, and on behavioral performance across these tasks. The investigators will further compare two types of brain-stimulation against each other: continuous Theta-Burst-Stimulation (a stimulation protocol designed to inhibit brain activity) and intermittent Theta-Burst Stimulation (a protocol designed to excite brain activity).
at UCSD
Last updated:


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Thanks to author Resa Nelson for this guest post and for letting us be a part of her blog tour. At the end of this post there is a link for a free ebook along with other site information.
Even though I write fantasy, I'm a big believer in doing my homework! First, I do a lot of library research. For example, I modeled my Dragonslayer series on the beginning of the Viking era. Even though I see my series as taking place in a world parallel to ours, I like the idea of making it as realistic as possible. I want people who read my books to feel like they're really in that world and in the thick of everything that's going on. One way for me to do that was to research the Viking era (which I already loved) and the Middle Ages. I wanted to learn things like how houses were made and what type of clothing people wore and lots of other details to make the world feel real.
But my main character Astrid is a female blacksmith, so I decided I needed some hands-on experience. When I was trying to figure out how to do that, I happened to go out to dinner with a large group of friends I'd run into at a science fiction convention. I mentioned wanting to learn blacksmithing to a friend who had a friend (who had come to dinner with us) that had recently taken a course in blacksmithing. So we talked about it, and I decided I needed to take that course. It turned out to be a pretty significant commitment, but I was up for it. The course lasted for 10 weeks, and there was one class each week – each class lasted for 4 hours, which meant 4 hours of standing at an anvil hammering iron or steel. Classes were held on Thursday nights, so I had to figure out how to avoid traffic jams. The commute to where the course was held was about 90 miles. Each class ran from 6 to 10 pm, so I didn't get home until nearly midnight! And when I got home, I reeked of smoke and had to take a shower because my skin was covered in black, sooty smudges.
But I didn't mind. Taking that blacksmithing course was so much fun! I learned how to build a fire and keep it going. I learned how to read the changing colors of the smoke and what they meant. I learned the special things I had to do in order to keep up with my all-male, brawny classmates. I learned what different tools were for and how to use them. And I learned about heating iron and the meaning of the different colors it takes when heated and how to make the best use of them.
I put not only all the wonderful details I learned and experienced from my blacksmithing course into my novel, but I poured my own feelings in as well. I gained a whole new appreciation for who Astrid is and what her daily life is like. Despite the traffic and the long class hours and my smelly, sooty skin, taking that blacksmithing course turned out to be one of the best adventures of my life.
And oddly enough, after I took the course I found out I come from a long line of blacksmiths. Right now there are three generations in my extended family who are blacksmiths!
Author Bio
Resa Nelson has been selling fiction professionally since 1988. She is a longtime member of SFWA (Science Fiction and Fantasy Writers of America) and is a graduate of the Clarion SF Workshop.
Resa was also the TV/Movie Columnist for Realms of Fantasy magazine for 13 years and was a contributor to SCI FI magazine. She has sold over 200 articles to magazines in the United States and the United Kingdom.
Her first novel, The Dragonslayer's Sword, was nominated for the Nebula Award and was also a Finalist for the EPPIE Award. This medieval fantasy novel is based on a short story first published in the premiere issue of Science Fiction Age magazine and ranked 2nd in that magazine's first Readers Top Ten Poll. The Dragonslayer's Sword is Book 1 in her 4-book Dragonslayer series. Book 2, The Iron Maiden, was published last December, Book 3 was published in May, and the final book in the series is scheduled for publication in November.
Resa Nelson's 4-book Dragonslayer series:
Synopsis for The Dragonslayer's Sword (Book 1)
For Astrid, a blacksmith who makes swords for dragonslayers, the emergence of a strange gemstone from her body sets in motion a chain of events that threaten to
destroy her life. Her happiness is shattered when her lover--the dragonslayer--disappears without a trace, and the life that she knows and loves implodes without warning.
Astrid lives in a world of shapeshifters whose thoughts have the power to change not only themselves but others. Everything Astrid knows to be true is called into question when she learns the truth about her past and the mysterious family from which she was separated as a child.
Reality turns inside out as Astrid gradually learns the truth about the people she loves as well as those she disdains. With the fate of dragons, ghosts, and slaves in foreign lands resting on her shoulders, Astrid faces the challenge of deciding who she is and how she will stand up inside her own skin. Will she withdraw and hide from the world that has disappointed her so much...or will she rise to lead others to freedom and peace?
Synopsis for The Iron Maiden (Book 2)
Astrid is reluctant to travel the winter route beyond the Northlands, even though it's her duty. She'd rather stay home in her village, surrounded by friends and neighbors. Ignoring the bonds of tradition, she decides to spend the cold winter months in the
warmth of her blacksmithing shop. Why should she leave the comfort of her cottage to serve and protect foreigners who might raid and harm her native Northlands?
Everything changes when a traveling merchant steals Starlight, the first dragonslayer's sword Astrid forged and her last link to her sweetheart DiStephan. Having no time to alert her friends, Astrid races in pursuit of the merchant, determined to reclaim Starlight as her own and return home in time for dinner. Instead, her quest leads her to new lands, unexpected friendships with foreigners, and a harrowing encounter with the damage done by the followers of a new god that considers women as nothing more than servants to men. All the while, she must be ready to face any dragon traveling the winter route.
In Book 2 of the Dragonslayer series, Astrid must learn that deciding who she is isn't a decision she can make just once. It's a decision she must make every day.
Synopsis for The Stone of Darkness (Book 3)
In Book 3 of the Dragonslayer series, Astrid accepts her duty and follows the winter route--until she's bitten by a dragon. Everyone knows dragon bites are poisonous and deadly, so she reluctantly accepts her impending death. In a twist of fate, she survives. Desperate for an explanation, Astrid believes she has somehow been protected by the black stone she keeps with her at all times, a stone that emerged from the sole of her foot a year ago.
Determined to find out what the stone is and what kind of powers it possesses, Astrid begins a journey that leads her to alchemists and an army of men under the rule of the powerful warrior, Mandulane, the acting lord of the Krystr army. Mandulane's mission is to spread the word of the new god Krystr, which preaches the evil intent of women and the danger they pose to all men, who are entitled to dominate the world. Rumors about this new god and army have spread, but Astrid is the first Northlander to encounter them.
Soon, she stumbles upon a secret of a far-reaching and mind-numbing plot that will impact the entire world. Astrid must find a way to spread the news of this threat and protect her people and everyone else at risk. She's convinced the answer lies inside the Stone of Darkness, and she must find a way to understand the stone and the powers she's convinced it must hold before it's too late.
Book 4 will be published in November 2012
Links for further infomation
Free Mini Ebook
Goodreads Giveaway
Ebooks ($4.99 each) are available directly from Mundania Press here(get a 10% discount at checkout with the coupon code MP10)
Paperbacks are available from Mundania Press, Amazon, and Barnes&Noble:here(get a 10% discount at checkout with the coupon code MP10)


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Our Eczema Story
This handy little eBook covers all of the basics of eczema, a common skin condition affecting up to 20% of children. Many will grow out of the condition but for some people it can mean lifelong changes. Eczema cannot be cured but with some simple adjustments can be very easily managed. While the experience of this common skin condition is different for every sufferer, there are many similarities. We have compiled all of the best, modern advice for sufferers or parents of eczema sufferers in this easy to read guide. Filled with clear-cut tips, recipes for natural treatments and the answers to all of your questions.


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Check out the latest from the Zoo York family. All flow riders. Skateboarding is on a whole other level when dudes this good are just flow.
Archive for April, 2010
Zoo York Field Agent ReportPosted: April 28, 2010 in Uncategorized
Tags: Ams, Field Agent Report, Skateboarding, Zoo York
Josh Keough Is Down For Sideways DecksPosted: April 28, 2010 in Uncategorized
Tags: Decks, Dru Kennedy, Josh Keough, Kickflip, Sideways, Skateboarding, Skateboards
Skating rocks? Nah, Skating Rocks! Josh Keough Kickflip Photo: Dru Kennedy
Click the pic for the full view.
Josh Keough representing the Sideways. He loves them 7 3/4″ white ones. Decks just $49.95 with free grip and a mag, dvd, sticker or something else you'll like.
With all the lights and flashes in that photo do Dru and the crew have something big planned? A video maybe? Hit him up on Facebook and tell him you want a full West Coast video.
New Lakai Telford Colorway Now InstockPosted: April 28, 2010 in Uncategorized
Tags: Black Turquoise, Footwear, Lakai, New, shoes, Telford
Just arrived this morning, a new colorway of the Lakai Telfords. Already priced and on the wall, these won't last for long. Come by and grab a pair, get a second pair of kicks from Fall 09 for 1/2 price.
Lakai AppPosted: April 28, 2010 in Uncategorized
Tags: 3gs, App, Apple, Crailtap, Footwear, ipad, iphone, ipod touch, Itunes, Lakai, news, shoes, Skateboarding, Videos
Bout a week or two late on this one, but whatever. Lakai has released an App for the iPhone, iPod Touch, and iPad. It features news, videos, products, team pages, ads and other stuff. And it's free! Free stuff is awesome. Lakai is awesome. We also just received a new colorway of the Telford. Post it up later today. Here's some screen shots of the app in action. Download it now!
fourstar Crew Ripping the Crail ParkPosted: April 27, 2010 in Uncategorized
Tags: Anderson, Break Room, Carroll, Chocolate, Crailtap, Fourstar, Girl, Howard, Lakai, parking blocks, Sam Smyth, Skateboarding, Skatepark, Talent Management, Trujillo
Nixon WIRE HeadphonesPosted: April 27, 2010 in Uncategorized
Tags: Coldplay, Headphones, ipod, Nixon, Skateboarding, Slayer, Walking the dog, Wire
The WIRE headphones are just what you'd expect from Nixon. Simple and stylish. They sound great too. Don't believe me? Bring in your iPod and test 'em out. 8mm or 10mm with or without mics. Buncha colors. Pick up a set, plug them in, put on a Slayer mix and bomb some hills. Or walk the dog and listen to Coldplay or something.
Zoo York in JapanPosted: April 21, 2010 in Uncategorized
Tags: Brandon Westgate, DVD, Eli Reed, Skateboards, Zered Basset, Zoo York
Kinda old, but if you haven't seen it yet here ya go. Featuring New Pro Eli Reed, Zered Basset, and Brandon Westgate who can ollie/grind/slide whatever most think is too high/long/hard. Remember, all Zoo York decks come with a free copy of "State Of Mind" while supplies last. That goes for both decks and dvds, Zoo products don't last for long. Few sick decks left instock, all with great shapes. Come by and check 'em out.


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CARE Humanitarian | Home
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Join CARE in our effort to accelerate the end of poverty this generation.
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They looked a little like banana breads... but tasted yummy :)
After munching on our baked goods, we went to Lee's parent's house to get the spare key in exchange for 4 banana muffins. While we were there, we were introduced to fairy cakes! We took two of them home to my house. Awesome! So commences the Baked Goods Exchange Programme!
They looked good and tasted yum!
So I'm thinking. A Baked Goods Exchange Programme could really happen. A group of friends could all bake some cakes or muffins on the same day but not all of them can leave home that day due to commitments and such, so one those who are mobile can visit each of the friends and swap cakes. It could be pretty awesome.
There might be some kinks to work out.
Wow, I'm super tired.
Morgan Leichter-Saxby of Pop-Up Adventure Play has won the Playwork Writer Award from the Eastbourne Playwork Conference! I blogged about it here a little while back, and we all can't quite believe that she's been given the award over playwork giants like Bob Hughes and Marc Armitage! She's absolutely stoked, and so am I! I'm so happy for her! She absolutely deserves it, and everyone should go and visit her blog immediately! :)
It's been a good day. I'm very excited but very tired. Largo for Pop-Up Adventure Play tomorrow - I can't wait to be excited from 4000 miles away. :)


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DEFINITION of Verge XVG (Cryptocurrency)
Verge is an open source, decentralized cryptocurrency that claims to offer completely anonymous transactions by obfuscating the location and IP address of the transacting participants using TOR and I2P network layers. Verge trades on leading cryptocurrency exchanges with the symbol XVG.
BREAKING DOWN Verge XVG (Cryptocurrency)
Verge emerged in 2016 as a rebranded version of Dogecoindark, a fork of Dogecoin that came into existence in the year 2014.
Verge Is a Rebranding of Dogecoindark, Claiming to Offer Anonymous Transactions
Verge focuses on anonymity and obfuscates users' IP addresses which makes transactions completely untraceable. IP stands for internet protocol, a unique identity in the form of numbers that is assigned to every device or computer connecting to the internet. Using an IP address, it is possible to trace the user and the online activities they performed on the connected device.
Since popular public ledgers and common cryptocurrencies like bitcoin often face challenges in protecting participants' complete anonymity, cryptocurrencies like Verge that offer unique ways to hide users' identities have led to increased use and popularity of such private ledgers.
Verge ensures anonymity by use of multiple anonymity-centric networks such as The Onion Router (TOR) and Invisible Internet Project (I2P). TOR protects users' identities by bouncing their communications over a distributed network of relays and tunnels run by volunteers spread across the globe, while I2P encrypts user data and sends it through a volunteer-run anonymous peer-to-peer globally distributed network.
While anyone can view the various transactions occurring on the Verge public ledger, use of TOR and I2P network layers hide the location as well as IP addresses of the transacting participants. The Core Verge wallets have built-in TOR integration, additionally supported by SSL-encryption, adding an extra level of security.
While there are many other cryptocurrencies, like Monero and Dash, which also claim to offer higher levels of privacy and anonymity, they rely on cryptography techniques and implementation. Though such cryptocurrencies have achieved varying levels of success in securing user anonymity, their implementation has also made their respective public ledgers secure but less transparent. This tradeoff at times makes it difficult to publicly verify transactions, a core requirement of decentralized cryptocurrency. (See also, What Is Monero (XMR) Cryptocurrency?)
Verge tries to tackle this problem technically. It does not rely heavily on cryptography; rather it banks on the existing and tested technology of TOR and I2P network to achieve its goals of user identity protection. Verge's founders say that an open ledger is mandatory for the participants to verify their transactions, and for other participants to publicly authenticate and verify the overall developments occurring on the blockchain without the need for participant's identity. Verge's implementation helps it achieve both.
The anonymity of Verge was quoted as the primary reason for an adult website network to start accepting cryptocurrency payments exclusively in the Verge cryptocurrency in April 2018. As of April 2018, Verge is ranked 23rd in the list of cryptocurrencies by market-cap.


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Junior has an enormous walk stride. He has long, slow moving hind legs with an overstep of 24 inches. Most people are happy with an overstep of 3-4 hoof prints, but I'm blessed/cursed with 2 feet or more. He has an extended walk for a "9", but a collected walk for a "6". Why? Because rather than shortening and quickening his steps, he simply slows those huge strides down. He braces his neck and back and can become irregular if I'm not really careful. Occasionally, I've received "7's" and an "8" for the collected walk, but those were from judges that tend to love Junior in general and look past his faults.
Of course, with a big, slow moving walk, comes a big, slow moving canter. I've tried many things to get his hind legs moving more quickly with the most effective being countless canter to trot, back to canter transitions. That also improves the swing in his back and makes him quick to my aids. However, the canter pirouettes elude him to this day. I used to think it was just me and that I couldn't train the pirouette, but I can ride them on other horses and I understand the mechanics...so why can't Junior do the pirouette? We can go from medium canter to pirouette canter, but the turn is a disaster. In competition, he's a steady "5" or "6", but that's not good enough. If I try to make the turn small, he's been known to switch leads or stop and rear (that will get me a "2" of course and crush the score for submission). If I make the turn too big, the comment is "more like a circle" and I get a "5". If the judge likes Junior, it's a "6". Unfortunately, pirouettes have a double coefficient, so they absolutely must improve!!
It's very frustrating, because now that we are working on piaffe, Junior can do half steps all day long, but to attempt to come back just a bit more towards piaffe, he's doing the same thing he does in the collected walk and canter pirouette. He braces his neck and back and slows his hind legs down even more than they normally go. Everything needs to get quicker and Junior's tension makes them slower. A ground person causes major upset, work in hand doesn't work either, causing the same amount of mental turmoil. We are looking at the same predicament in all 3 gaits, the highest form of collection (collected walk, piaffe, and pirouettes) all have the same issue.
For 3 years, Pam has told me "you need to get his hind legs closer together." That's a lot of lessons over 3 years. She's given me visual ideas using her own body and demonstrated foot placement, she's given me exercises to use during my training. Get his hind legs closer together!!
Once you have an idea in your head, it's stuck there. For years, I've worked to get his hind legs closer together in the canter. Laterally. I've done countless travers in canter, I've worked half-pass to half pirouette until I was blue in the face and Junior was asleep at the wheel. I've done travers on a circle, spiraling in to pirouette and out again. Nothing changes other than sometimes he ends up crossing his legs in the pirouette and has to leap out of it so he doesn't fall down.
A couple weeks ago, I was working the piaffe. I'm aware it looks as though Junior is half-stepping on a tight rope when I do the half-steps, but his hind legs are laterally closer together, so I leave it alone. Unfortunately, I rarely have the opportunity to watch myself ride since I am usually alone when I'm training. Kelly asked if I wanted her to video me, and I gladly accepted. Since I had her there with the camera, I rode a canter pirouette in both directions as well. Get his hind legs closer together. As I watched the video, I was disappointed to see the half-steps just look like slow trot, with the hind legs moving way underneath his center (like the walk). Then came the pirouettes. Oh my gosh...lightbulb ON! I watched as Junior's inside hind leg came way forward underneath his belly. The outside hind had no place to go because his inside hind is completely unable to support his weight where he placed it. His hind legs are completely spread apart, front to back, not side to side. Get his hind legs closer together meant longitudinally, not laterally! How stupid could I have been all these years??? By watching one 10 minute video, I now understand my mental block that has wasted 3 years of training. For crying out loud!!!
I can't wait to tell Pam how foolish I've been. It was stuck in my head and I never asked the question! Even with everything she showed me, I'd let nothing work its way into my confusion. If you're not sure you understand what your trainer is saying, ask the question. Watch videos of your training sessions as much as you possibly can. A picture is worth more than a thousand words (and dollars!).
Leave a Reply.
Jamie Fell
Co-owner of Fell-Vallee Equestrian Center. Head-trainer and instructor following the German theories of horsemanship.
September 2012


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Denver's Popular Passport Program Returns for Winter
After a successful summer, Denver's Passport Program is back with a new Winter Warmer program of drink specials at the city's best watering holes. Hit the cocktail trail for the holidays and get over $300 in savings.
The Passport Program is a booklet that drinkers can purchase and receive 2-for-1 drink specials if you bring a friend or enjoy half off one drink if flying solo. After visiting, get the booklet stamped, just like an actual passport. It's your passport to taste!
Passports are on sale now for $20 per city and can be purchased online. The books are good for 2-for-1 libations at bars, wineries, breweries and restaurants. Denver bars include Bear Creek Distillery, Blackbird, Blue Island, Call to Arms Brewing, Colt & Gray, FIRE, Humboldt, Jax Fish House, Lola, Lucky Cat, Nocturne, Our Mutual Friend Brewing, Postino, Punch Bowl Social, Ratio Beerworks, Satchel's on 6th, SugarMill, Telegraph Bistro, Vesta, and The Way Back.
Purchase a passport for yourself, give as a gift or both. Also, $1 of every passport sold will go to We Don't Waste, a nonprofit that collects excess food from venues, caterers, restaurants and other food venders and distributes the food to under-served communities in Colorado. The program runs through March 15, 2017. The Passport Program will also be available in Boulder, Fort Collins, and Kansas City, MO.
Photos via Two Parts
Tags: Beer, Cocktails, Gifts


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Something about pizza never fails to please, so we've put together this gluten free pizza crust recipe. But why gluten free?
For many people, grains (especially gluten-containing grains) can cause problems affecting everything from nutrients, gut health, adrenal function to mood, sleep, stress and ultimately your hormones.
Most of the functions that our body performs happen as a result of a hormone! I use a systems biology approach, looking at the body as a whole. Due to the way that hormones are regulated, they are at the bottom of the systems cascade, which means any of the health areas mentioned above, could impact them.
We know going gluten free can be a challenge, which is why it's great to have this easy gluten free pizza recipe on hand. It's simple to make, incredibly delicious and one the kids will love.
The base is made with buckwheat flour, and while the name suggests 'wheat', buckwheat is actually a gluten free seed related to rhubarb. It is a complete protein and contains several polyphenolic acid-oxidants (rutin, tannis and catechin) which have been found to have anti-inflammatory and antioxidant properties that help prevent platelet clot formation inside blood vessels.
Pizza Crust:
You could use any toppings - opt for local seasonal produce. We used the following:
Disclaimer: This blog post is for educational purposes only. It is not designed to diagnose, treat or cure. We are all unique, for your individual health concerns it is important to discuss these with a BePure Holistic Health Consultant or relevant health professional.


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Ivan Perišić joins FC Bayern on loan!
FC Bayern have signed Croatia international Ivan Perišić. The 30-year-old World Cup runner-up joins Bayern from Inter Milan with immediate effect. The two clubs have agreed a one-year loan deal until 30 June 2020, with the option for FC Bayern to sign the player on a permanent deal after that.
► #MiaSanMia - Subscribe & hit the bell🔔: fc.bayern/DEkeysAbo
Facebook: facebook.com/FCBayern
Twitter: twitter.com/fcbayern
Instagram: instagram.com/fcbayern
Snapchat: fc.bayern/FCBayernSnaps
Website: fcbayern.com
FC Bayern.tv: fcbayern.com/fcbayerntv
FC Bayern.tv live: fcbayern.com/fcbayerntv/de/fcbayerntvlive


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There's nothing sadder than a neglected animal. And believe it or not, it really hits them hard. This neglected parrot found himself abandoned a few months ago.
He had passed through several foster families and they all returned him because he had some serious aggression issues.
Over time, this adorable looking creature became so stressed and overwhelmed that he started to pluck out his feathers.
Undeterred by his brutish behavior and slightly harrowing exterior, a kind-hearted woman decided to take him in. And surprisingly, his new mom managed to bond with him!
The little bird, which she lovingly named Chicken Man, has found a forever home with her and the pair couldn't be happier.
Though Chicken Man was anxious at first, he started to warm to his new home and bonded with the family. Not only that, but his feathers started to grow back too!


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A sulfur-rich formula to calm acne flare-ups
Kate Somerville believes that everyone deserves beautiful skin and promises to guide you there. She has bottled Hollywood's best-kept secrets for you to use in your own home.
Active Ingredient: Sulfer 10%
Inactive Ingredients: Isopropyl Alcohol, Zinc Oxide, Camphor, Magnesium Aluminum Silicate, Salicylic Acid, Iron Oxides


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The color you're looking for is unavailable. Here's the next best color in the same style.
Up to50%off sale | Prices as shown | In-store & online
For a limited time, ALDO is offering a wallet valued at $25 for only $10 with any purchase of $40 or more. This offer is valid on the SILENCER wallet only between December 4, 2019 and December 8, 2019, 11:59 PM (EST).
For a limited time, ALDO is offering up to 50% off the original price on sale. Valid online on www.aldoshoes.com and in ALDO stores and ALDO Outlet stores from December 4, 2019 until December 18, 2019 11:59PM EST. Details
I read the reviews before my purchase of these beautiful shoes, and so many said they were comfortable. To my surprise, they actually do feel surprisingly good! I get so many complements on these shoes and I can wear them all day.
Happy hour, Night Out / Party, Work / Professional
These are really pretty in person! They are comfortable too! I am surprised.
Happy hour, Night Out / Party
I just picked them up today from the store, after ordering them online, can't wait to wear them.
Happy hour, Formal / Wedding / Prom, Night Out / Party
These boots do not disappoint, not only are they gorgeous on but the leather is so soft and their really comfy. Definitely recommend them.
Night Out/Party
Never thought that I would say any 4" stilleto would be comfortable ...but here we have it! These shoes are amazing!! They run true to size but narrow because of the point. If you like wide shoes you probably will need to size up half a size and get inserts. They are very versatile, can wear casually with jeans or dressed up for an event. I bought in red (which is a true hot red) and intend on getting the other colors as well.
Happy hour, Wedding /Prom /Formal, Night Out/Party, Casual
I tried these on with no expectation of buying them as I don't typically buy stilettos since I'm on my feet all day. That being said- they fit perfectly, are comfortable, & SO sexy, that I did in fact purchase them! Don't forget your instep cushions - I've been complimented many times already! Thank you ALDO- they're my new favorites !
Happy hour, Night Out / Party, Work / Professional, Everyday wear
This is the one pair theset even when you walk in the store just to kill the time, it will make you buy it! That's what happened today. They fit so well and are super elegant. Very comfortable, too
Absolutely in love with my beautiful new shoes, classy, sexy and oh so chic, welcome to my closet full already of Aldo shoes, who else makes a sexy stiletto you can literally wear for hours on end at such an affordable price point???? Aldo has it down to a T.


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Our Sponsors
WITH THANKS TO ALL OF OUR SPONSORS FOR THIS YEARS HULL DAILY MAIL'S SPORTING CHAMPIONS AWARds
Sponsorship of events that are attractive to your target audience is one of the most effective ways of communicating to your customers. By utilising this type of marketing activity, you can increase and build on your brand awareness whilst informing and introducing new customers. Effective sponsorship can compliment your existing advertising and communication strategy whilst raising your company profile to the community at large.
Hull Culture & leisure
Hull Culture and Leisure Ltd provide a vast range of facilities, services and events for you and your family and friends to enjoy. From a stroll in the park, a night at the opera, relaxing with a good read, exploring the past, dinner for the Queen to an ice hockey game, we cater for all interests and abilities. We want you to have fun, be active and stay healthy.
Smailes goldie
Our clients include sole traders, partnerships, start-ups, SMEs, family businesses, large corporates, charities, not for profit organisations and educational establishments.
We invest our time with the aim of building long lasting relationships. This approach leads to a deeper understanding of the issues you face and enables us to support your aspirations.
Providing business mobile and fixed line solutions for businesses of all sizes, nationwide, we are here to help you save money on your communications spend. Working closely with your organisation to understand your exact requirements, we will create a fully managed, value-added package designed to help you cut the time, effort and cost associated with business communications.
It's a place where all the family can come to have fun and spend quality time together. Young children can dodge pirates and sharks on our Pirate Adventure Golf course or the full family can head out on the Footgolf course for a round then finish the day in The Premier Lounge with a few drinks and bite to eat.
Accredited civil engineering expertise for the construction industry since 1988.
A family-owned business, based in Hull, PBS work across the North of England for both commercial and public sector clients.
Engineering quality is at the heart of what we do. Delivering the highest professional quality and expertise in the construction industry is our number one priority, which is why many of our clients have been working with us for over 20 years.
Roses of Beverley is a family-run business, originally set up in January 2000, successfully selling fitted kitchens to Hull, East Yorkshire and the surrounding areas.
Over the past 10 years we have grown and are now considered to be the leading provider of high-quality kitchens with excellent service both locally and nationally.
active humber
Active Humber is a charitable company whose purpose is to help people of all ages and backgrounds to improve their health and well-being by taking part in regular physical activity and sport.
Active Humber is also one of the 43 County Sports Partnerships (CSPs) located across England and as such receives funding from Sport England to carry out several functions to help achieve the Sport England strategy 'Towards an Active Nation' at a community level.
nationwide diamond group
Established in 2003, Nationwide Concrete Flooring in Goole, East Yorkshire is part of the Nationwide Diamond Group.
The philosophy behind the company's ethos is simple Design, Build, Clean and maintain.
Their customers describe them as the most versatile industrial concrete-flooring contractors in the UK, stating that they are the only concrete flooring contractor that carries out and manages all of the concrete flooring process in-house without the need for sub-contractors.
Nationwide Diamond Group have invested heavily in the most modern concrete flooring equipment and this enables them to carry out concrete floor repairs and new cast in situ concrete floor slabs for blue chip companies such as Prologis, Superdrug, Clugston Group and Leggett & Platt. They do not claim to be the cheapest concrete flooring contractor, but we aspire to offer the best service and quality, which in turn provides benefits for our clients.
headline sponsor
Bishop Burton is one of the UK's leading land-based colleges and has a national reputation for quality.
We're the only college in the UK to hold Centre of Vocational Excellence status in both Agriculture and Equine and in 2017 accrediting body Pearson declared us the Outstanding BTEC College of the Year.
Our excellent success rates, unrivalled facilities and innovative teaching were all factors in receiving the highly coveted national accolade


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As more and more American workers are making the shift to a home office setting, it's imperative that corporate furniture providers offer ergonomic support for these new office spaces. If you are working from home, it doesn't mean that you need to be working from the dining room table, or worse – the bed! Set up a space for yourself in your home that is dedicated to your work. You'll find that you're more productive and can maintain a better work/life balance. At TrueNorth, we have designed a series of ergonomic office furniture that contributes to the overall health, happiness, and productivity of office employees. Here are the 4 best TrueNorth motorized standing desks for your home office:
Depending on your family dynamics and the location of your home office, you might find that your standing desk wears a lot of hats. It might be more than your workspace, and instead include house bills and family to-do lists. The TrueNorth Odyssey offers a large, spacious desktop that proves to be multi-functional. The Odyssey provides maximum space to spread out and create, and it's made for the person who needs room to work on multiple projects at once. Its angled design allows for naturally divided workspaces, but its lines are soft enough that the two arms can flow artfully into each other. Research shows that standing for 3 to 5 hours each workday can dramatically decrease risk of cardiovascular disease, obesity, and diabetes. The TrueNorth Odyssey helps users maintain a healthy lifestyle from their home office.
If you have a smaller home office and need to save space, we recommend the TrueNorth Aspire. The Aspire is unique with separately-adjusting dual levels for a superior standing workstation. The two separate workspaces can be raised and lowered independently of each other, creating endless options for productivity, creativity, and style. The two desk tops can remain flush with each other, or they can separate to create two levels for dual screens or multi-tasking. Change it up throughout the day and watch the TrueNorth Aspire transition from computer desk to drawing board to lunch table and back.
With fewer features and a cleaner design, the TrueNorth Celebrity is our simplest standing desk. For those looking for zero frills but outstanding results, the TrueNorth Celebrity is a great addition to the home office. The Celebrity is a clean, simple workstation that provides ample room to support creativity and productivity. Perfect for the individual who wants a sit to stand desk that provides room to spread out without inviting a crowd, the Celebrity is a bold and simple presence that rises to meet your needs. The Celebrity, Odyssey, and Aspire all hold up to 300 pounds as they shift positions.
For those looking for a more affordable option to a standing desk, consider the Desktop Riser. This riser sits on top of your existing home office desk, but rises and lowers to your preferred standing heights. It costs less than other TrueNorth adjustable height desks, and holds only 35 pounds. However, for those who want something more mobile and less of a commitment, the Desktop Riser is for you. It adjusts smoothly and quietly on twin gas springs through an infinite number of height adjustments, taking you from your desktop to 20" above.
At TrueNorth, we have created a line of motorized sit to stand desks that offer ergonomic support to office workers around the world. Born and built in the USA, our standing desks can hold up to 300 pounds and adjust to preset heights for optimal comfort and support. We have a wide range of standing desk selections so you can choose the right desk for your workspace. Contact us today to learn more about our ergonomic office furniture and to get started on your order.


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Placing fixed water quality monitoring stations in a water distribution system can greatly improve the security of the system via prompt detection of poor water quality. In the event that a harmful substance is injected into a water distribution system, large populations can be put at risk of exposure to the contaminant. Promptly detecting the presence of a contaminant will reduce the number of people put at risk of exposure. However, to protect against a wide variety of possible contaminants, a water quality monitoring station will need to identify contamination via recognition of anomalous changes in a suite of surrogate water quality indicators (chlorine, pH, etc.). This work attempts to place water quality monitoring stations within the water distribution at locations that best detect contamination events via surrogate water quality signals. Networks of water quality monitoring stations are designed to minimize the population affected prior to contamination event detection, and simultaneously minimize the expected number of false positive detections, under uncertain water quality conditions. Solutions generated in this study are compared to solutions designed via classical detection methods. Results show the sensor networks designed without consideration to detection via surrogate water quality parameters have higher false positive detection rates.
Within a water distribution system (WDS), water quality is monitored and maintained at or near the sources, i.e. water treatment plants, desalination plants, etc. Throughout the WDS, downstream water quality is then assumed to be satisfactory given that the pipe network is closed and secure, and that the inlet water quality is adequate for the hydraulic travel times between the sources and the consumers. In a system that is perfectly understood and perfectly secured, the assumption that water quality management at the inlet is sufficient may be valid. However, in real-world WDSs the rate of water quality deterioration will not be perfectly known, and network intrusions and/or backflows can dramatically reduce water quality within a WDS. An intrusion of a harmful substance can expose downstream populations to potential ingestion, and infection or poisoning by harmful contaminants.
Placing water quality monitoring stations (WQMSs), or sensors, within a water distribution system has shown to improve a managing authority's ability to detect a contamination, and reduce the potential size of a population put at risk. Although it is beneficial to monitor a large number of water quality parameters, budget, space, and accessibility constraints will limit the number of parameters a WQMS can measure. Instead of attempting to identify a contamination via detecting the presence of some contaminant, a contamination will be identified by observing anomalous readings in a small suite of water quality parameters as a response to the presence of a contaminant.
Typically, the performance of an early warning system (EWS) composed of water quality sensors is highly sensitive to the locations at which sensors are placed. Initial studies in WQMS placement identified the best locations to place WQMSs according to demand based coverage, and assumed that water upstream from a WQMS was also considered 'safe' (Lee & Deininger 1992; Kumar et al. 1997). Later methods explicitly placed sensors to detect contamination intrusion events (Kessler et al. 1998) by defining a minimum allowable volume of contaminated water delivered prior to detection, termed the 'level of service'. A network of WQMSs was then designed to meet the prescribed level of service. More advanced optimization methods were later applied to identify WQMS locations according to water quality simulation results, including mixed integer programing (MIP), genetic algorithms, and greedy heuristic algorithms. Ostfeld & Salomons (2004) proposed a genetic algorithm to determine the locations to place WQMSs. Performance of each WQMS network was evaluated against a large number of randomly generated contamination events. By evaluating solutions against a large number of random contamination events, the solutions are expected to perform well against any single contamination event. Berry et al. (2006) cast the sensor placement problem as an MIP to minimize the mass consumed following a contamination event. A large number of teams attempted to solve the sensor placement problem during the Battle of the Water Sensor Networks (BWSN) (Ostfeld et al. 2008). A set of 5 and 20 sensors was placed to minimize the: 1. time required to detect a contamination event, 2. population affected prior to detection of a contamination, 3. mass delivered prior to detection of a contamination event, and to maximize the likelihood of detection of a contamination event. Methods of the BWSN included genetic algorithms, mixed integer programing, a greedy algorithm, a demand based heuristic, an engineering strawman approach, and population based heuristic evolutionary algorithms. Specifically, the greedy algorithm proved highly effective, and was further studied (Krause et al. 2008) for sensor placement on large WDSs. Krause et al. (2008) structured the population affected objective function as a submodular function reporting the population 'protected' as opposed to the population affected as a function of the sensor network. Doing so allowed the proposed greedy algorithm to efficiently solve the sensor placement problem to near optimality, even on large water distribution systems. Later studies further evaluated sensor unit performance by assuming 'imperfect' detection (Berry et al. 2009), incorporated risk based objective functions for sensor placement (Weickgenannt et al. 2010), and uncertainties in the sensor placement problem (Xu et al. 2010; Comboul & Ghanem 2013).
In parallel, research examined the task of detecting anomalous changes in water quality measurements to identify a contamination in the system. Numerous algorithms have been developed and tested to identify true contamination events from realistic water quality data including: basic incremental outlier detection algorithms, and linear filters (Mckenna et al. 2008); artificial neural networks (Perelman et al. 2012; Arad et al. 2013); multi-variate classifiers (Oliker & Ostfeld 2014); and model based event detection algorithm incorporating variable contamination event injection concentration and durations, as well as uncertain consumer demands (Yang & Boccelli 2016b). Event detection studies have also considered a system wide event detection algorithm (EDA), where water quality signals from different locations are integrated to better identify true positives and reduce false positives (Koch & Mckenna 2011; Oliker et al. 2016; Yang & Boccelli 2017). Integrating the water quality signals across multiple sensors improved the performance of event detection algorithms, and provided the best performing methods for contamination event detection to date. However, no studies have attempted to place water quality sensors to best perform specifically with respect to the water quality parameters observed at those locations.
Budget constraints are expected to limit the number of sensors that can be deployed, and accordingly, water quality data will be sparsely distributed throughout the WDS. As shown above, this issue has catalyzed a large amount of research to determine what methods can be used to best place WQMSs within a WDS. However, a majority of previous work has placed sensors within the WDS based on the presence of a contaminant, not based on the response of water quality parameters that a WQMS would observe, due to the presence of a contaminant. This limitation may lead to a large gap in the expected performance and the true performance of a WQMS used for contamination detection as a location that may be best for detecting a contaminant, may not be the best for detection of anomalous water quality signals.
This study aims to determine how WQMS locations influence the performance of an early warning system for contamination event detection, specifically when WQMSs observe surrogate water quality signals. This method allows the system design phase to incorporate the effects of background water quality uncertainty into the contamination detection task. Placing sensors under deterministic operating conditions and with conservative contaminants has provided strong baselines for sensor placement, however, these systems may not perform well in a real-world scenario where uncertainties are present. As shown in Figures 1 and 2, following injection the contaminant itself is often propagated throughout the WDS relatively evenly, however, the water quality signals can vary throughout the WDS as a function of operational conditions, and WDS system design. By incorporating background water quality uncertainty into the sensor placement task, we expect that sensors will be placed at network locations that provide water quality signals most indicative of a contamination, and least sensitive to changes in the background water quality signals.
Water quality simulations were performed within EPANET-MSX (Shang et al. 2007). EPANET-MSX uses the hydraulic simulation data calculated within EPANET 2 (Rossman 2000) and then solves the multi-species chemical equilibrium and reaction equations throughout the simulated water distribution system for a defined simulation time. Nicotine was used as a contaminant to be injected into the network for optimizing WQMS locations. To analyze the sensitivity of the WQMS placements to the water quality model used for optimization, a second water quality model was applied and a different contaminant was simulated to be injected into the network, Parathion. Water quality monitoring stations were assumed to monitor three water quality parameters, free chlorine, pH, and alkalinity. Accordingly, the respective reaction and equilibrium equations governing an intrusion of Nicotine and Parathion were applied from the previous studies of Yang & Boccelli (2016a), and Schwartz et al. (2014), respectively, described in the section below.
Water quality simulations
For both water quality models, chlorine input was defined at a source location to simulate chlorination in the water distribution system. Preliminary simulations showed the chlorine concentrations throughout the network to be cyclical with respect to time and correlated with pumping schedules changing the hydraulic regime of the WDS. To reduce the cyclical nature of the chlorine concentration throughout the simulation, water quality simulations were modeled for 12 days, allowing background chlorine levels to reach a relatively steady state. In the baseline model, after the 12-day simulation, contamination events were defined to take place at any point between the 15th and 16th day of the simulation at any node in the network as an instantaneous injection of 5 kg of contaminant. To reduce the computational burden of the water quality simulations, the water quality parameters at the end of the 12-day simulation were saved and a 5-day simulation was initialized with the water quality parameters calculated at the end of the 12-day simulation. To further test the solutions developed using the baseline Nicotine model, a sensitivity analysis was performed by setting the contamination injection duration to 12 hours. A 15-minute water quality timestep was defined for the water quality simulations. It is important to note that the water quality models for the two contaminants are different; the Nicotine model uses a two species second order decay model, and the Parathion model uses a first order decay model. This difference leads to discrepancies in the background chlorine levels in the two models, and thus, Nicotine was considered as the main contaminant of interest for this study. The Parathion injection was used in a sensitivity analysis to compare the sensor networks against a contaminant and water quality models that were not used during the optimization phase.
Nicotine model
|Reaction coefficient
|Reaction coefficient
Parathion model
Parathion was chosen as a second contaminant, used to test the sensitivity of the sensor network to a contamination and a water quality model 'unknown' during the optimization phase. Opposed to Nicotine, Parathion injections affect the background pH and alkalinity signals; combined with its effects on the background chlorine signal, Parathion is expected to provide a stronger signal in surrogate water quality parameters indicative of a contamination. Parathion is also a more toxic substance; while Nicotine has a of roughly 9.7 mg/kg (Mayer 2014), Parathion is highly toxic, with a of 2 mg/kg (Schwartz et al. 2014). Parathion should present a case in which the EWS will receive a strong, combined signal from all water quality parameters, however, given the low the system will require especially prompt detection to reduce the population affected. For a single EDA however, the two contaminants require parameterizing an EDA such that it will recognize either contamination signal, while still maintaining a low false positive detection rate for both the Nicotine and Parathion contaminations.
|Parameter name
|Reaction rate coefficient between PA and HOCl
|Hydrolysis rate coefficient for PA
|Hydrolysis rate coefficient for PAO
|Reaction rate coefficient between PA and OCl
|Hydrolysis rate coefficient between PAO and OCl
|First order chlorine decay rate
|Parameter name
|Reaction rate coefficient between PA and HOCl
|Hydrolysis rate coefficient for PA
|Hydrolysis rate coefficient for PAO
|Reaction rate coefficient between PA and OCl
|Hydrolysis rate coefficient between PAO and OCl
|First order chlorine decay rate
Event detection algorithm
SPSA algorithm
|Contaminant type
|Network condition
|Nicotine intrusion events
|Deterministic background water quality
|Nicotine intrusion events
|Uncertain background water quality
|Nicotine intrusion events
|Nicotine signal for detection
|Nicotine and Parathion intrusion events
|Uncertain background water quality
|Contaminant type
|Network condition
|Nicotine intrusion events
|Deterministic background water quality
|Nicotine intrusion events
|Uncertain background water quality
|Nicotine intrusion events
|Nicotine signal for detection
|Nicotine and Parathion intrusion events
|Uncertain background water quality
Objective functions
To incorporate uncertainty in the background water quality, the objective function initially proposed by Babayan et al. (2005), to optimize WDS design under demand uncertainty, was amended to incorporate background water quality variability and the population affected following a contamination event. Babayan et al. (2005) transformed a stochastic chance constrained optimization problem into an equivalent deterministic problem by calculating the standard deviation of WDS junction pressures due to junction demand uncertainty. The standard deviation of junction pressures was then used to characterize the effect of demand uncertainty, and as a 'safety factor' for system designs. For example: ensuring that a junction's pressure was above a minimum threshold pressure plus two times the calculated standard deviation of that junction's pressure was equivalent to meeting a 95% chance constraint, as two standard deviations describe 95% of a value's variability.
Minimizing the PA objective (Equation (19)) requires that a sensor network promptly detects contaminations emanating from locations; and at times that place large populations at risk of exposure. Conversely, contamination events with more benign input locations and times are proportionally less important for the sensor network to detect promptly. With a limited number of WQMSs to place in a WDS, there is an inherent tradeoff between quickly detecting contamination events and detecting all possible contamination events. Minimizing the population affected objective implicitly considers this trade off by attempting to quickly detect the contamination events that quickly affect large populations, and allows longer detection times for contamination events that take a longer time to infect large populations.
An efficient noisy multi-objective messy genetic algorithm (GA) was employed to identify the set of network junctions that best detected contamination events. The employed GA used adaptive population sizing, and generational contamination event suite re-sampling to improve the efficiency of the GA. Messy GA operators were chosen to allow the GA to add or remove sensors according to the best system performance. Unlike previous WQMS placement studies, no defined number of WQMSs, number of allowable WQMSs, or solution cost objectives were defined that actively constrained or minimized the number of WQMSs placed in the network. By minimizing the expected number of false positive detections, optimization removed sensors that did not reduce the population affected, and only added false positive detections. Adaptive population sizing, as in Kollat & Reed (2006), improved efficiency in search, and 're-stimulated' search by initializing new populations throughout the GA run, and re-sizing the new populations according to the size of the current Pareto optimal set. Generational re-sampling was incorporated to improve the ability of solutions to generalize and perform well against uncertainty in contamination event characteristics. During each generation of the GA, candidate solutions were evaluated against a suite of randomly generated contamination events, and the mean performance across all contamination events was reported. This method is sensitive to the size of the contamination event suite used. A small contamination event suite may not appropriately characterize the true expected behavior of any single contamination event according to the law of large numbers (i.e. the mean of all possible contamination events). In this case, the generated solutions are likely to perform poorly against contamination events not included in the contamination event suite (overfitting). Using a large contamination event suite will lead to better solution generalization, however, it will greatly increase the computational burden of the algorithm because every solution will need to be evaluated against a large number of contamination events. Prior to the optimization phase, a suite of 400 random contamination events was randomly sampled; and during each generation of the GA, 100 contamination events were randomly sampled from the initial 400 contamination events, and used for evaluation during the GA. This method permitted the use of a relatively small evaluation suite during each GA generation, while the re-sampling operator continuously exposed the GA to a diverse set of contamination events.
Messy GAs (Goldberg et al. 1989) are partitioned into two distinct phases: the primordial phase, and the juxtapositional phase. During the primordial phase, all possible combinations of variables are defined (up to some number of variables, k) and each combination is evaluated. The initial population used by the GA is generated by sampling combinations of variables generated during the primordial phase, according to their relative performance. This method initializes the GA with an initial population 'primed' with high performing variable combinations (building blocks). In this study k was set to one, such that the primordial phase of the GA would evaluate every single sensor location. During the primordial phase the SPSA algorithm was run for each sensor location before evaluating the performance of a sensor at that location. A single value was required to score the performance of each single sensor location prior to sampling building blocks into the GA's initial population. The heuristic loss function proposed above, Equation (16), was used to score the single sensor location performances.
During the juxtaposition phase the GA operates similarly to a traditional GA, evaluating a population of solutions, sampling solutions according to their relative performance, crossing solutions together and mutating individual solutions, and lastly placing the newly generated solutions into the population of the next generation. However, in the case of a messy GA, crossover is replaced with a 'cut and splice' operator. Cut and splice either cuts two solutions at some point within their respective solution strings, and exchanges the portions of the string around the cut point; or splice simply merges two solutions together end to end. For this study, the probability of a solution to be cut was 0.9, and the probability that a solution would be spliced was 0.1. Mutation was defined to redefine, add, or remove one value of a solution string following cut and splice (i.e. one WQMS within the solution string). The mutation rate was defined according to the size of the current population, such that a single instance of mutation was expected for each generation, and equal probabilities were defined to add, remove, or re-define the value of a solution. A dominance based tournament of size 2 was chosen to select new solutions from the current GA populations. Tournament participants were compared to the current non-dominated set of solutions, and a solution that was non-dominated with respect to the current 'optimal' non-dominated set was assigned to 'win'. In the event of a tie (both solutions 'win' or both solutions 'lose') a sharing function was used to calculate the density of nearby solutions (a sharing radius was set to 0.25), and the solution with the lowest local solution density was chosen as the tournament winner.
Figure 4 provides a schematic overview of the entire methodology.
The methodology proposed above was tested on two distinct WDSs: the EPANET Net3 network (Rossman 2000), composed of 92 junctions, 2 reservoirs, 3 tanks, 2 pumps, and 117 pipes; and the Ky7 network (Jolly et al. 2014) composed of 481 junctions, 1 reservoir, 3 tanks, 1 pump, and 603 pipes. The Net3 network represents a network with primarily one-directional flow from sources towards consumers, while the Ky7 network represents a network with large amounts of mixing and multi-directional flow in the center of the WDS; and the network is more branched along the periphery. For each WDS, chlorine was input and varied at the source of the WDS. Figure 5 shows a plot of the respective WDSs, the chlorine input locations, and the daily average network-wide chlorine concentrations following the 12-day simulations. For the Net3 network, the mean chlorine concentration across all network junctions was 2.55 mg/L with a standard deviation of 0.32 mg/L, and for the Ky7 network, the mean chlorine concentration across all network junctions was 2.374 mg/L with a standard deviation of 0.497 mg/L.
For each network, the optimization scenarios defined in Table 4 were conducted. Following optimization, final evaluation was conducted against 1,000 newly generated contamination events. Each contamination event can take place at any junction in the network, at any time of the day, with a total mass input ranging from 0 to 5 kg instantaneously input into the system. Each proposed WQMS network was exposed to the contamination events, and the population affected prior to detection was reported. If the affected population was less than 0.5% of the total population served, the solution was deemed to 'pass,' and otherwise was deemed to fail. Solutions were compared based on the percentage of the 1,000 contamination events where the solution 'passed.' For the previously developed solutions, the EDA parameters calculated using the SPSA algorithm were assigned to the sensors for evaluations. Supplementary data including all Matlab files and EPANET files can be found at: https://www.dropbox.com/sh/8iitq658g547t1o/AABH61Ak1LHR3nn_k4GTucpWa?dl=0.
The proposed optimization method (proposed GA) proved successful to develop a network of WQMSs for contamination event detection using surrogate water quality parameters. Water quality monitoring stations were placed at locations which reduced the expected population affected, while simultaneously reducing the expected number of false positive detections. These two objectives proved effective in also governing the number of sensors placed in the network. Traditionally, sensor placement has been performed under the paradigm of a network coverage problem, where more sensors equals better event detection performance. Given that sensors also provide false positive detections, more sensors may not equate directly to better system performance. Although more sensors are likely to improve the detection capabilities of a contamination early warning system, more sensors are also susceptible to more false positive detections, due to non-contamination event anomalies in the water quality signals, and thus reduce the dependability of the contamination signal. Increased false positive detections may be overcome through proper EDA parameterization, however, it is an important factor to consider in the design of an early warning system. In general, the solutions developed that provided the fewest false detections had the fewest number of sensors in the network.
Final evaluation of the solutions developed herein and from previous studies showed discrepancies in performance between the solutions designed as a part of this study, and classical solutions developed via detection of a conservative contaminant (TEVA-SPOT and the Ohar et al. (2015) solutions). In many cases, the classical solutions provided the best performance with respect to the fraction of contamination events that were detected before an allowable population was affected, however, these solutions led to unreliable false positive detection rates, often around 0.2. When evaluated against Nicotine (the same contaminant used during optimization) the solutions developed without considering background chlorine uncertainty provided performance roughly equal to the classical solutions, as shown in Figure 6(a), indicating that the variability in background water quality leads to false positive detections. In this work, only solutions developed with consideration given to background water quality variability were able to achieve reliable false positive detection rates (Figure 6(a)–(c)). When considering a second contaminant (Parathion), the systems generally performed worse (Figure 6(b)). As expected, incorporating both contaminants into the optimization phase proved to improve the solution quality, for both Nicotine and Parathion contamination intrusions. However, caution should be taken in considering the generalizability of the sensor networks, given the two contaminants used different water quality models. The increase in false positive detection rates observed in the Parathion evaluations is caused by different background water quality levels, which were expected to have arisen from the water quality model's characteristics, as opposed to background water quality. Sensor layouts are presented in Figure 7, with respect to the performance of each sensor layout.
The SPSA algorithm proved highly efficient for determining good parameterization for the del threshold value and window size. As seen in Figure 8 the solution ROC (receiver operator curve) plots were developed by varying the del threshold from 1% of the original del value, to 100% more than the original del value assigned by the SPSA algorithm (at 10% increments, i.e. 10%, 20%, 30% …. 190%, 200%). The ratio of true positive detections (y-axis) and the ratio of false positive detection (x-axis) was then plotted for each instance of the del threshold. The ROC plots show the difficulty in contamination event detection in WDSs. Ideally, a ROC plot will have an area beneath the curve of 1, with the optimal points located in the upper left portion of the ROC curve (true positive detection ration of 1, with a false positive detection of 0). In many cases, the SPSA parameterization corresponds to a point far from what would be expected optimal; however it is a 'near-optimal' point for the respective ROC plot.
Similar results were observed for the Ky7 network (Figure 9), where sensors were again placed to best detect a Nicotine contamination according to the response in chlorine, pH, and alkalinity. Again, the solutions developed to incorporate water quality uncertainty performed best when evaluated against random contamination events with potentially uncertain water quality (Figure 9). The solutions developed to detect only Nicotine performed worst, with solutions developed according to deterministic surrogate water quality parameters performing better than the Nicotine detection case, but worse than the case incorporating background water quality uncertainty. Unlike the Net3 case study, in the Ky7 network the deterministic optimization case led to a larger number of potential solutions than the uncertain optimization case. Many of the solutions developed in the deterministic case performed quite well during evaluation with respect to the uncertain solutions. Interestingly, only during the deterministic optimization phase were solutions developed which allowed high false positive detection rates, >0.5. This is indicative of the deterministic optimization case being able to develop sensor networks that result in lower population affected than the uncertain case, however, the solutions are highly sensitive to potential background water quality uncertainty. Figure 10 provides the sensor layouts calculated for the Ky7 network alongside the respective layout's performance.
Receiver operator curves were generated for the Ky7 solution, similarly to the solutions evaluated from the Net3 network. Opposed to the Net3 network, the analysis showed very difficult ROC curves for the solutions generated for the Ky7 network, and the EDA parameters chosen using the SPSA algorithm were often located at sub-optimal points along the curve. Interestingly, the ROC curve shows that the parameters assigned using the SPSA algorithm are often located at the worst possible parameterizations, points that provide the worst performance with respect to the likelihood of false positive detection with zero benefit to the likelihood of contamination event detection (Figure 11). As a secondary analysis, the EDA parameters were varied and evaluated with respect to the affected population, shown in Figure 12. This analysis showed the effectiveness of the SPSA method, as the SPSA parameterizations were best able to span the entire solution space. All other assigned parameterizations cluster solutions within specific reigns of the solutions space, for example, a del value of ½ the SPSA value leads to worse detection performance, and a del value of ¼ the SPSA value leads to a large number of false positive detections regardless of the sensor layout. Increasing the SPSA del value by a factor of 1.5 and 2 leads to worse event detection performance, with relatively no benefit in the false positive detection rate. The discrepancy in performance, according to Figures 11 and 12, is believed to be due to the non-trivial relationship between ROC evaluation measures, event detection likelihoods, and the evaluation measures used in sensor network design. Care should be taken in evaluating event detection algorithms with standard ROC curves, as optimal performance with respect to a ROC curve may not lead to optimal performance with respect to contamination event detection metrics.
A number of sensitivity analyses were performed for the Net3 solutions to determine how the solutions developed within this study under naïve conditions would perform in a more realistic scenario. Accordingly, all solutions were evaluated under conditions of: continuous 12 hour contaminant injection with a total mass input equal to the baseline instantaneous contamination input; consumer demands randomly sampled within 15% of the deterministic model's demand level for each instantaneous contamination event; and an EDA observing only Nicotine and pH water quality data. The results of these evaluations are shown below in Figure 13.
The results of these sensitivity analyses provide valuable insight into the proposed systems. First, the detection performance of the sensor networks generally decreases when considering longer, lower mass input rate contamination events and uncertain demands. Specifically, uncertain demand conditions are shown to greatly increase the number of false positive detections of all solutions, and are important to consider when using surrogate water quality parameters for event detection. Using only the chlorine and pH water quality signals greatly reduces the false positive detection rates of all solutions. Simplifying the EDA to use as few water quality data streams as possible can reduce system complexity, and improve performance, however, it may limit the detection capabilities to a fewer number of reactive contaminants.
The simulations herein have provided an initial investigation into the influence of uncertain water quality on the placement of water quality monitoring stations. Using surrogate water quality parameters to identify a contamination event combines the signal-processing task of detecting the presence of a contamination, with the sensor placement task of best exposing sensors to potential contaminations. The sensor networks developed herein have been optimized to best detect a contamination event under conditions of background water quality uncertainty.
The method proposed herein successfully placed sensors to best detect contamination events. Minimizing the population affected greater than an allowable affected population while minimizing the expected number of false positive detections for a contamination event provided efficient sensor solutions for contamination event detection. Because no constraint was imposed on the number of sensors within a sensor network, the proposed GA only placed a sensor if it reduced the affected population, with a minimal increase in the potential for false positive detections. This framing of the sensor placement problem provides a unique method to best ensure that only the most efficient sensors are placed in the water distribution system.
Recent developments in event detection in water distribution systems have shown the desire to reduce the rate of false positive detections provided by an event detection algorithm. Identifying the best locations to place water quality monitoring stations by explicitly considering the water quality signal observed at each location in the WDS has been shown to provide lower false positive detection rates and strong performance with respect to the population affected by the contamination, even when employing a basic local EDA. However, using surrogate water quality signals to place sensors in a WDS places a large amount of dependence on the fidelity of the water quality model used. In this study, the solutions developed using the Nicotine water quality model were shown to outperform previous benchmark solutions, deterministic solution models, and contaminant based sensor placements; and although the solution performance degrades when evaluated against a second water quality model, the same trends are observed.
As a preliminary study in EDA based sensor placement there are numerous limitations to this study, and directions to consider in future work. To begin with, of the three water quality parameters chosen, pH and alkalinity are highly correlated, and this correlation can be observed in Figure 3. In the future it would be beneficial to incorporate either the pH or the alkalinity and employ a third measure that is not correlated with the free chlorine or the pH, or to simplify the model and only use free chlorine and pH or alkalinity, which has been shown to provide strong performance for Nicotine detection (Figure 13). Secondly, the EDA used herein is quite naïve; state-of-the-art integrated system wide EDA algorithms or more intelligent algorithms which recognize water quality anomalies caused by normal operation from 'unknown' anomalies (Hart & McKenna 2009; Romano et al. 2014) should be incorporated into the proposed framework. Given the modularity of the proposed method, any event detection algorithm can be incorporated for the event detection task. An integrated system wide EDA used during the sensor placement phase would be expected to place sensors at locations that even better detect contamination with reduced false positive rates given the water quality signal observed. This EDA can facilitate intelligent recognition of false positive events caused by normal operation to reduce the false positive rate. In this study, sensor networks were designed and EDA parameters were prescribed based only on instantaneous contamination event simulations. It would be valuable to consider variable contamination event characteristics in future work, specifically for prescribing EDA parameters. Considering longer duration contaminations may improve the system wide total event detection performance when contaminations do not travel through the WDS as a clear contaminant 'pulse.' Secondly, uncertainty in consumer demands should be integrated in the contamination event simulations, and system design phase to ensure that the sensor networks are robust to variable network hydraulics, and thus variable contaminant transport times. Demand uncertainty can be easily integrated in to the proposed methodology using the proposed objective function (Equation (19)) by simultaneously simulating uncertain demand realizations alongside uncertain chlorine input realizations. Lastly, new objectives can be incorporated into the optimization framework for additional design criteria. For example, an additional objective could be incorporated to best locate a contamination event following detection, integrating the contamination event detection and localization problems into the sensor network design phase. Given the widespread availably of high-powered computing, fully integrating event detection and event localization tasks within the sensor placement task, even with complex water quality simulations and incorporation of uncertainties, has become more feasible.
This study was supported by the United States – Binational Science Foundation (BSF), by the Technion Funds for Security research, by the joint Israeli Office of the Chief Scientist (OCS) Ministry of Science, Technology and Space (MOST), and by the Germany Federal Ministry of Education and Research (BMBF), under project no. 02WA1298.