"After September 11, the Red Cross started thinking about developing multiple storage depots across the U.S. for frozen red blood cells," says Colonel Thomas Reid, chief of the department of Blood Research at the Walter Reed Army Institute of Research (Silver Springs, MD). "The problem we have is that when the blood ships during times when the temperature dips, the bags containing the blood become brittle," he says. Once the bags break, sterility is compromised and the blood becomes a loss. "In some conditions, our loss rate is 50 to 80% of the entire shipment." Reid and his colleagues investigated the physical and thermal properties of several commercially available blood storage bags. The bags were made from polyvinyl chloride (PVC) with diethylhexylphthalate (DEHP) or trimellitate (TEHTM) plasticizer; polyolefin (PO); polyethylene-co-vinyl acetate (EVA); or fluorinated ethylene propylene (FEP). Bags containing EVA were more shock resistant, giving the lowest rate of breakage (10%) compared to PO or PVC, according to Reid's research. Blood product storage bags made of EVA appear better suited for shipping frozen blood products on dry ice and are cost effective replacements for PVC and other bags, reports Reid. For more information on the research, call (202) 782-3501 or go to www.wramc.amedd.army.mil.
In this new Design News feature, "How it Works," we’re starting off by examining the inner workings of the electronic cigarette. While e-cigarettes seemed like a gimmick just two or three years ago, they’re catching fire -- so to speak. Sales topped $1 billion last year and are set to hit $10 billion by 2017. Cigarette companies are fighting back by buying up e-cigarette manufacturers.
Microchip recently released the 3D TouchPad, the first USB PC Peripheral device that couples 2D multi-touch input with 3D air gesture technology. The company seeks the help of developers to further enhance the capabilities of the technology.
To give engineers a better idea of the range of resins and polymers available as alternatives to other materials, this Technology Roundup presents several articles on engineering plastics that can do the job.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.