Raney Cobalt: An Effective and Recyclable Catalyst for the Pauson–Khand Reaction

Commercially available Raney cobalt is broadly applicable as a catalyst in intra‐ and intermolecular Pauson–Khand reactions (PKR). The activity of Raney cobalt compares favourably with that of previously described heterogeneous or heterogenised cobalt systems. The major reaction pathway appears to occur at the solid catalyst which can be efficiently separated and reused by filtration and/or exploiting its ferromagnetic properties.     

Single-insertion temperature testing of semiconductor ICs

This paper presents a preliminary-design study considering the feasibility and conceptual implementation of single-insertion temperature testing of any type of semiconductor integrated circuit (IC): memory, microcontroller, microprocessor, or application specific IC. Analyses are presented that establish the necessary thermal response rate of a device under test to make single-insertion testing comparable in throughput performance to a conventional test method. Modeling with ideal conditions to obtain the fastest device response shows that single-insertion testing in testing plastic packaged parts (or slow responding devices) will only be applicable when the test parallelism is very high (>32) and lot overhead times are long (⩾1 h). Given that actual lot overhead times are generally less than 1 h and the trend is for decreasing lot overhead times, the test method is likely more applicable to testing die-exposed type devices, since the test parallelism can be much lower for a given lot overhead time     

Application of fiber optic reflectance spectroscopy for the detection of historical glass deterioration

Historical alkali silicate glass is prone to deterioration over time due to the uptake of atmospheric water and subsequent hydrolysis of the silicate matrix. Recent studies of historical glass have provided insight into the mechanism of alteration; however, few techniques can assess early onset glass alteration noninvasively. Herein, we present fiber optic reflectance spectroscopy (FORS) as an invaluable tool to analyze historical glass alteration. We study a series of artificially aged model potash glasses and assess the nature of the alkali-depleted alteration layer by microscopy, scanning electron microscopy (SEM) with energy dispersive spectroscopy, and FORS. We find that the model glass FORS spectra demonstrate peaks associated with hydroxide, liquid-like water, and bound water. FORS was able to detect an alteration layer as thin as 0.66 µm. The model glass data were then used to generate a hydration thickness prediction curve in order to predict the alteration layer thickness of twenty-one 19th-century glass flutes of similar composition. In the one case that an actual flute sample was available, the predicted value was in good agreement with previous SEM measurement. The results indicate the ability of FORS to noninvasively assess glass deterioration and to understand the nature of absorbed water in historical glass objects.     

Diamond X-ray Photodiode for White and Monochromatic SR beams

High purity, single crystal CVD diamond plates are screened for quality and instrumented into a sensor assembly for quantitative characterization of flux and position sensitivity. Initial investigations have yielded encouraging results and have led to further development. Several limiting complications are observed and discussed, as well as mitigations thereof. For example, diamond quality requirements for x-ray diodes include low nitrogen impurity and crystallographic defectivity. Thin electrode windows and electronic readout performance are ultimately also critical to device performance. Promising features observed so far from prototype devices include calculable responsivity, flux linearity, position sensitivity and timing performance. Recent results from testing in high flux and high speed applications are described.     

Effect of exogenous bovine somatotropin on mammary lipid metabolism and milk yield in lactating dairy cows

Eight lactating Holstein cows were used to study the effect of bovine somatotropin on mammary lipid metabolism, milk production, and milk composition. Eight cows were injected with either excipient (n = 4) or 50 IU somatotropin/d (n = 4). A 2-wk adjustment period preceded a 10-d period when treatments were administered. On d 9, serial blood samples were collected from 2 to 5 h post-injection to determine concentrations of somatotropin and metabolites in plasma. Mammary tissue biopsies were obtained 2 to 3 h after a.m. milking on d 10 to determine lipoprotein lipase activity and in vitro rates of acetate incorporation into fatty acids and acetate oxidation by mammary tissue slices. Activity of lipoprotein lipase in milk and mammary tissue and rate of acetate metabolism by mammary tissue were not affected by treatment. The following means for placebo and somatotropin, respectively, were: milk production (21.5 and 24.8 kg/d), milk fat (3.8 and 4.0%), and 4% FCM (20.7 and 25.1 kg/d). Plasma concentrations of somatotropin (3.0 and 43.4 ng/ml) and free fatty acids (105.6 and 219.5 mu eq/L) were significantly elevated with somatotropin. The injection of somatotropin into lactating dairy cows did not affect the mechanisms of fatty acid synthesis or metabolism evaluated in this study.     

In Vitro and Mouse Evaluation of Methods for Protecting Whey Protein and Casein from Ruminal Degradation

A series of in vitro buffer (protein solubility) and rumen fermentation (ammonia production) studies were conducted to evaluate varying formaldehyde (.25, .5, 1, and 3%) and tannic acid (.5, 1, 2, 3, and 6%), and three heating times (1, 2, and 3 h at 104 C) on protection of whey protein concentrate and casein from ruminal degradation. Subsequent trials of mouse growth were conducted to evaluate the effectiveness of protection of treated proteins. Formaldehyde (.25 to 3%) reduced solubility of whey protein and casein to less than 10% of the untreated in pH 6.8 buffer and approximately 30% of the untreated in pH 2.5 buffer plus pepsin. Formaldehyde reduced ammonia production, indicating protection and reduced solubility of whey protein and casein under rumen conditions in vitro. Tannic acid (.5 to 6%) did not greatly reduce protein solubility and ammonia production. Heat treatment reduced protein solubility to less than 10% of the untreated in pH 6.8 buffer and to 50% of the untreated in pH 2.5 buffer and reduced ammonia production to approximately 20% of the untreated. Growth and feed intake of mice were decreased with 1% formaldehyde treated diets (17% protein), indicating overprotection of protein. Growth decreased as tannic acid increased. Mouse growth also decreased as the length of heat treatment increased. Diets with .5% formaldehydecasein depressed gains. Based on these in vitro and mouse-evaluation studies, formaldehyde less than .5% of the dry weight is required to protect whey protein and casein from ruminal degradation and permit solubilization in the lower intestinal tract.     

Photovoltaic module calibration value versus optical air mass: the air mass function

So‐called “air mass functions” of photovoltaic modules are used to approximate the effects of spectral responsivity and to correct short‐circuit current to or from a reference condition. These empirical functions are determined from outdoor measurements with test modules mounted on two‐axis solar trackers and then calculated from plots of normalized calibration value (short‐circuit current divided by total irradiance) versus optical air mass. Because they are incorporated into a number of photovoltaic system modeling and sizing software programs, the accuracy of the functions has direct implications for system costs. We discuss the assumptions associated with these functions that are generally not considered or ignored, and study their variability with respect to atmospheric constituents. The variability study included a 6‐month outdoor measurement on a crystalline‐Si module and a software simulation of the same module using a solar spectral irradiance model. We conclude that air mass functions depend on the measurement location and time, and therefore are not unique to a particular device. Also, using these functions introduces two distinct errors, the magnitudes of which are unknown without knowledge of spectral irradiance conditions. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.     

Frequency-domain optical tomographic imaging of arthritic finger joints

We are presenting data from the largest clinical trial on optical tomographic imaging of finger joints to date. Overall we evaluated 99 fingers of patients affected by rheumatoid arthritis (RA) and 120 fingers from healthy volunteers. Using frequency-domain imaging techniques we show that sensitivities and specificities of 0.85 and higher can be achieved in detecting RA. This is accomplished by deriving multiple optical parameters from the optical tomographic images and combining them for the statistical analysis. Parameters derived from the scattering coefficient perform slightly better than absorption derived parameters. Furthermore we found that data obtained at 600 MHz leads to better classification results than data obtained at 0 or 300 MHz.     

A review of triticale uses and the effect of growth environment on grain quality

Triticale (× Triticosecale sp. Wittmack ex A. Camus 1927) is an anthropogenic cereal designed to incorporate the functionality and high yield of wheat (Triticum spp. Linnaeus 1753) and durability of rye (Secale cereale Linnaeus 1753). The potential of triticale has remained largely unrealised, and in the 135 years since A. Stephen Wilson first crossed wheat and rye, triticale has mostly been used as animal feed. Growing demand for food resources has led to an increased interest in triticale development. Efforts to breed cultivars appropriate for baking have met with difficulty, although relatively new approaches to triticale end-use propose greater applicability for human consumption. Further, environmental awareness has generated interest in the use of triticale within biofuel production. We review environmental and genetic effects on triticale yield with a view towards increased demand on a hardy and useful cereal crop. We find triticale could satisfy many of the hopes originally placed upon it, and may be useful in foodstuffs and fuel, but only when growth environment is carefully considered.     

Phosphorous emitter etch back and bulk hydrogenation by means of an ECR-hydrogen plasma applied to form a selective emitter structure on mc-Si

In this paper, we study the effect of hydrogen-electron cyclotron resonance plasma (ECR plasma) on the phosphorous-doped emitter of a solar cell based on multicrystalline silicon (POLIX^®). The purpose of this experiment is to realise a selective emitter structure, using the front metal contacts as a mask. We show that hydrogen plasma etches the surface of the emitter away, and simultaneously diffuses into the silicon and increase the bulk lifetime. Both minority carrier lifetime and etch rate depend on the grain orientation. Hydrogen diffusion is hindered by the high phosphorous concentration of the emitter, as shown on the SIMS profiles. Besides, SIMS profiles are revealing an anomalous behaviour of phosphorous, which diffuses into the silicon at temperatures as low as 350°C on (1 0 0) oriented grains.