Planar array stack design aided by rapid prototyping in development of air-breathing PEMFC

The polymer electrolyte membrane fuel cell (PEMFC) is one of the most important research topics in the new and clean energy area. The middle or high power PEMFCs can be applied to the transportation or the distributed power system. But for the small power application, it is needed to match the power requirement of the product generally. On the other hand, the direct methanol fuel cell (DMFC) is one of the most common type that researchers are interested in, but recently the miniature or the micro-PEMFCs attract more attention due to their advantages of high open circuit voltage and high power density.     

The fate of stacking

The impending doom of CMOS scaling has semiconductor mavericks scrambling for alternative solutions to continue increasing the device density per chip. One serious candidate is 3D integration in which the planar manufacturing technology extends skyward into the third dimension, much like skyscrapers. Similarities between chip architecture and building architecture are plentiful, and the author draws some parallels between the two.     

Particle Size Effect on the Packaging Performance of YAG:Ce Phosphors in White LEDs

The synthesis of cerium-doped yttrium aluminum garnet (YAG:Ce) phosphor of different sizes with uniform size distribution was carried out using solid-state reaction followed by grinding and sieving method. The effect of particle size distribution of YAG:Ce phosphors on the photoluminescence (PL) properties was investigated. The results demonstrate that the uniform size distribution and particle size affects the packaging performance in white light emitting diode (LED) applications. The YAG:Ce phosphors with different particle sizes were packaged in white LEDs using different amounts of each phosphors in order to get similar efficiency as that of commercially available YAG:Ce phosphors. It was observed that minimum amount of phosphor material is required for smaller particle size for getting the similar efficiency as that exhibited by commercially available YAG:Ce phosphors. The results are particularly interesting in view of reducing the cost of current LEDs by lowering the amount of phosphors without compromising the efficiencies of final LED package. A systematic study of YAG:Ce phosphors on the packing performance in white LEDs is reported.     

Influence of nonprotein nitrogen and protein of low rumen degradability on nitrogen flow and utilization in lactating dairy cows

Four lactating cows, each fitted with a rumen cannula and duodenal and ileal t-cannulae, were used to measure flow and digestion of nitrogenous compounds in the digestive tract. Dietary dry matter contained 17% crude protein and 50:50 forage:concentrate. Treatments were: 1) corn silage-soybean meal; 2) corn silage-heated soybean meal; 3) ammonia-treated corn silage-soybean meal; and 4) ammonia-treated corn silage-heated soybean meal. Flow of organic matter to the duodenum was overestimated when lanthanum or chromium ethylene-diaminetetraacetate was used as an indigestible marker. This resulted in low estimates of ruminal digestion of organic matter and high estimates of nitrogen flow to the duodenum. However, calculations using lanthanum or lignin as markers yielded similar organic matter flow to ileum and feces. With acid-detergent lignin as a marker, estimates of dietary nitrogen degraded in the rumen were: corn silage-heated soybean meal, 55.0% ammonia-treated corn silage-heated soybean meal, 58.8%; ammonia-treated corn silage-soybean meal, 63.3%; and corn silage-soybean meal, 66.0%. Digestion in the small intestine of nonammonia nitrogen was equal for all treatments suggesting that availability of heated soybean meal in the intestine was not different, although ruminal degradability tended to be lower. Feeding diets containing nonprotein nitrogen did not decrease available nitrogen at the duodenum.     

An EGF-pseudomonas exotoxin A recombinant protein with a deletion in toxin binding domain specifically kills EGF receptor bearing cells

We constructed two chimeric toxins; one composed of epidermalgrowth factor (EGF) and pseudomonas exotoxin A (PE), designatedEGF-PE and the other composed of EGF and PE with a deletionof the Ia domain (cell-binding domain), designated EGF-PE (Ia).Both chimeric toxins reacted with anti-EGF and anti-PE antibodies.The cell-killing experiments showed that EGF-PE, but not EGF-PE(Ia),was cytotoxic to the murine fibroblast cell line NR6, whichcarried the PE receptor, but not the EGF receptor. However,after NR6 was transfected with DNA for the expression of humanEGF receptor, the transfected cell line, designated NRHER5,overexpressed human EGF receptors and became sensitive to EGF-PE(IA).The cytotoxicity of EGF-PE(Ia), but not EGF-PE, to NRHER5 canbe completely blocked by an excess amount of EGF. To completelyreverse the cytotoxicity of EGF-PE on NRHER5, both the EGF receptorpathway and the PE receptor pathway need to be blocked. Theseresults suggest that EGF-PE exhibits both EGF and PE bindingactivities, while EGF-PE(IA) possesses only EGF binding activity.Thus, EGF-PE(Ia) may be a better chimeric toxin than EGF-PEin terms of target specificity to EGF receptor bearing cells.We, therefore, examined the cytotoxicity of EGF-PE(Ia) to varioushuman cancer cell lines. We find that human cancer cells containingmore EGF receptors are more sensitive to EGF-PE(Ia).     

Neonatal medication surveillance by the pharmacist

Data on prenatal, labor and delivery, and postnatal medication exposure to neonates were collected. During an 11-week period, 100 neonates consecutively admitted to a hospital were studied. The pharmacist obtained a social and medication history from the mothers and reviewed maternal anesthesia records and the charts of the neonates. Fifteen definite and possible adverse medication reactions were detected in 13 neonates. The median number of different medications ingested prenatally was 4.7. The four most commonly ingested prenatal medications were vitamins (97%), iron preparations (90%), headache/pain/arthritis medications (68%) and antinausea/vomiting medications (40%). The most commonly used medications during labor and delivery were oxytocin (73%), meperidine (33%) and promazine (25%). The use of strong narcotics during this period produced neonatal respiratory depression in some cases. The four most commonly prescribed postnatal medications were vitamin K1 (100%), gentamicin (10%), ampicillin (8%) and Poly-Vi-Sol (6%). The maternal interview indicated that most mothers were unaware of the influence that many medications can play upon the fetus. It is recommended that the pharmacist conduct a maternal medication interview prior to labor and delivery.     

PET in breast cancer

In mid-summer 1997, just as the United States National Cancer Institute was acknowledging that the nuclear bomb tests at the Nevada Test Site may ultimately cause up to 75,000 cases of thyroid cancer in people who were living in the USA in the 1950s and 1960s, the Australian authorities were mooting the possibility that the Maralinga test sites in South Australia should become a tourist attraction. Some Aboriginal tribal leaders welcomed this proposed use when the 20 million Pounds 'clean-up' being paid for by the United Kingdom government as some compensation for using the area for its weapons tests in the 1950s and 1960s is completed. This paper surveys the attempts to clean up the site of UK nuclear weapons tests in the 1950s, not least by attempting to vitrify vast tracts of desert.     

A Two-Channel Picture Coding System: I--Real-Time Implementation

The two-channel system previously reported has been implemented in hardware using system parameters appropriate to consumer television. The basic system divides the spectrum into lowand high-frequency spatial components. The lows are coarsely sampled and finely quantized and the highs finely sampled and coarsely quantized using a companded, randomized quantizer. The purpose of this experiment was to demonstrate the potential of the system for low-cost practical application, to study the effect of the character of the randomizing noise, and to ascertain that there were no deleterious effects due to interlace, motion, or input noise. Theoretical noise calculations were qualitatively confirmed.     

A new method for calculating and correcting molecular weight distributions from gel permeation chromatography

A new method for calculating and correcting molecular weight distributions of polymer samples from GPC chromatograms is presented. The integral equation which relates the true molecular weight distribution of polymer sample to the chromatogram is reformulated into an equivalent variational problem of quadratic functional. The method of steepest descent in the function space is then applied to the minimization problem to obtain the true molecular weight distribution. This method is efficient and reduces some of the oscillation problems encountered in the previous methods. Examples are given.