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Vernon Hills, IL, United States

Hwang S.S.,Incheon National University | Han S.S.,Biz Tech | Lee P.H.,Incheon National University | Park B.I.,Incheon National University
Journal of Thermal Science and Technology | Year: 2010

A single-phase, fully three-dimensional transient numerical simulation was performed to analyze the dynamic response of a proton exchange membrane fuel cell (PEMFC) with single serpentine flow channels. In addition, the effects of the membrane and gas diffusion layer thickness on current density transient behavior were investigated using numerical simulation. An overshoot of current density is observed for all thicknesses of the membrane and gas diffusion layer at an abrupt change of operating voltage from 0.7 V to 0.5 V. The peak of the overshoot and the elapsed thickness time to reach to the steady state value increase with decreasing membrane thickness. It is thought that the thin membrane facilitates the transport of water and ions through the membrane, resulting in an increase in current density and humidification of the membrane. The elapsed time to reach steady state voltage become shorter and the peak of the overshoot decreases as the thickness of the gas diffusion layer decreases. We suggest that this occurs because a thick gas diffusion layer increases the distance between the current collector (as heat exchanger) and catalyst layer (as heat source), resulting in a low transport rate of heat generated by the electrochemical reaction at the catalyst layer. © 2010 by JSME. Source

Mutebi M.S.,Biz Tech
1st EAGE Eastern Africa Petroleum Geoscience Forum - Sharing Lessons Learned: What's Next? | Year: 2015

My abstract talks about the offshore and onshore exploration history and discoveries of Eastern Africa to date. Source

Li T.W.,University of Southern California | Yang H.,University of Southern California | Peng H.,University of Southern California | Xia M.,University of Southern California | And 2 more authors.
Carcinogenesis | Year: 2012

Chronic inflammation is an underlying risk factor for colon cancer. Tumor necrosis factor alpha (TNF-α) plays a critical role in the development of inflammation-induced colon cancer in a mouse model. S-adenosylmethionine (SAMe) and its metabolite methylthioadenosine (MTA) can inhibit lipopolysaccharide-induced TNF-α expression in macrophages. The aim of this work was to examine whether SAMe and MTA are effective in preventing inflammation-induced colon cancer and if so identify signaling pathways affected. Balb/c mice were treated with azoxymethane (AOM) and dextran sulfate sodium to induce colon cancer. Two days after AOM treatment, mice were divided into three groups: vehicle control, SAMe or MTA. Tumor load, histology, immunohistochemistry, gene and protein expression were determined. SAMe and MTA treatment reduced tumor load by ∼40%. Both treatments raised SAMe and MTA levels but MTA also raised S-adenosylhomocysteine levels. MTA treatment prevented the induction of many genes known to play pathogenetic roles in this model except for TNF-α and inducible nitric oxide synthase (iNOS). SAMe also had no effect on TNF-α or iNOS and was less inhibitory than MTA on the other genes. In vivo, both treatments induced apoptosis but inhibited proliferation, β-catenin, nuclear factor kappa B activation and interleukin (IL) 6 signaling. Effect of SAMe and MTA on IL-6 signaling was examined using Colo 205 colon cancer cells. In these cells, SAMe and MTA inhibited IL-6-induced IL-10 expression. MTA also inhibited IL-10 transcription and signal transducer and activator of transcription 3 activation. In conclusion, SAMe and MTA reduced inflammation-induced colon cancer and inhibited several pathways important in colon carcinogenesis. © The Author 2011. Published by Oxford University Press. All rights reserved. Source

Biz Tech | Date: 2007-12-21

Computer software development, Information technology consultant.

News Article | May 27, 2009
Site: www.techhive.com

Everybody loves a bargain, and some people can spend hours hunting for deals on sites like eBay, Overstock.com and Amazon. But did you know some sale makers are migrating to Twitter? United Airlines recently started offering Twiter-only flight deals called ‘Twares' on @unitedairlines, last week Starbucks gave away five $100 Starbucks Cards to its Twitter followers, and many other mainstream companies are using their Twitter accounts for the occasional give-away and last-minute deal. That got me wondering how many Twitter accounts are out there for tech bargain hunters? It turns out there's quite a few. Some are mainstream companies you know, while others are smaller outfits looking to get the word out any way they can. I should warn you that Twitter is a frontier region in the world of social networking. Anybody can sign up for a Twitter account under any name, so it's hard to tell if some Twitter accounts are the real thing or just a fan whose passion for a particular company borders on the obsessive. But even if the account's authenticity is questionable, the deals they're tweeting about are the real thing. Here are my picks for the 10 best tech deal follows on Twitter: @tigerdirectcom: The online computer bazaar uses Twitter to broadcast its deal of the day and other sales you want to know about. I wasn't able to confirm directly with Tiger Direct that this account is actually managed by the online retailer. However, all links lead directly to Tiger Direct so it's a safe bet this is the real thing. Tweetrate: 3-4 per day. Followers: 1,336. @CheapTweet: CheapTweet offers a mix of all kinds of deals pulled from the Tweet-o-sphere. There's even a Website at CheapTweet.com with sections for Fashion & Beauty, Tech, Entertainment & Travel and Food. CheapTweets also lets you rate the cheap deals with a Digg-style "It's cheap" button or you can vote a deal down with "It's lame." CheapTweet is still a work in progress, so occasionally noncommercial tweets with the word "sale" make it onto its Website. But there are enough legitimate deals here to make a follow worthwhile. Tweetrate: 3-7 per day. Followers: 10,396. @DaddyoDeals: DaddyoDeals is another deal site with its own Twitter extension. Mixed in with deals for Steve Madden shoes and Avon products are tweets for MP3 players, HDTVs, and digital cameras. Beware: Daddyo is a bit of a Twitter addict, so this is a follow for hardcore bargain hunters only. Tweetrate: well over 10 a day. Followers: 3,650. @ComputerGeeks: Tech deals are courtesy of Geeks.com. Based in Oceanside, California, Geeks.com has been doing business online for almost 13 years, according to its Website. Follow these guys for deals on everything from HDTV's to cameras and laptops. Tweetrate: 1-6 per day. Followers: 2,772. @DellOutlet: Coming to you from Dell computers, @delloutlet offers refurbished and previously ordered tablet PCs, laptops, and more. Dell will also answer outlet-related questions on this account. Tweetrate: 2-6 per day. Followers: 550,685. @TekServeNYC: New York City's favorite independent Mac shop tweets about the occasional deal mixed in with information about in-store events, advice, and customer service. Tweetrate: 2-4 per day. Followers: 338. @ea: The video game maker Electronic Arts recently made headlines by promising to make Ashton Kutcher's millionth Twitter follower a featured character on The Sims 3. Nothing that exciting has popped up recently, but EA's tweets are a great source for product announcements and game demos, as well as the occasional giveaway and deal. Tweetrate: 4-6 per day. Followers: 13,425. @amazongames: All video game deals all the time from Amazon. Another questionable identity, but again, all links take you to the purported source -- Amazon -- so it's worth the follow to track gaming deals. Tweetrate: 1 per day. Followers: 3,549. @officedepot: One of the few big box stores currently on Twitter, Office Depot's tweets are all about bargains. If you're a regular Office Depot customer, then this is the follow for you. This is another account that may not be the real thing, but all links lead to Office Depot so at least the information is legitimate. Tweetrate: less than 1 per day. Followers: 452. @mygearstore: Another online retailer from California. Find deals on accessories for all your tech gear including the iPhone, iPods, laptops, and more. Tweets are a mix of deals, answers to customer service questions, and the occasional contest. Tweetrate: 3-6 per day. Followers: 1,213. So there you have it: ten Twitter follows to help you find great tech deals. But remember that while Twitter can be a great place to find deals, the microblogging service attracts many spammers and charlatans. So keep yourself safe by only clicking on links from tweeps you trust, and never hand over your credit card information on Twitter. But if you're a bargain-hunter looking for the latest tech deal, Twitter might just be the social networking service for you.

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