Focusing multiple high-order harmonics in the extreme-ultraviolet and soft-x-ray regions by a platinum-coated ellipsoidal mirror

The focusability of multiple high-order harmonics in the extreme-ultraviolet and soft-x-ray regions is described, together with the design and performance of the ellipsoidal mirror used for this purpose. The mirror focuses intense coherent light in the spectral-region from 25 to 40 nm into a 2.4 microm spot size with a focused peak intensity of 6 x 10(13) W/cm2. The focal images indicate that a good beam profile is obtained with a near-Gaussian distribution and a beam quality factor (M2 value) as low as 2.4.     

A review of meat protein hydrolysates and hypertension

We tested the hypothesis that meat is a source of peptides that are effective at preventing and reducing chronic lifestyle-related diseases (CLSRDs) such as hypertension. This analysis reflects the importance of empowering hypertensive people in quality versus quantity of life issues, and in offering nutritional treatment options rather than medical alternatives. For both hypertensive and normotensive individuals, chemically based medications may have harmful side effects. Functional food rich in antioxidant vitamins, and proteins or biologically active peptides, can lower blood pressure in persons with essential hypertension, possibly by preventing an underlying cause of the condition. Deficiency in consumption of crucial nutrients such as proteins from meat origins, along with abnormalities in carbohydrate and fat metabolism, may underlie the etiology of the clinical course of hypertension. Food derived from meat rich in nutrients may provide physiologically functional peptides, as well as improve digestion, and the metabolism of carbohydrate and fats, thus lowering blood pressure, and normalizing associated biochemical and histopathological changes.     

Double-pass fiber Raman laser-a powerful and widely tunable in theultraviolet, visible, and near-infrared fiber Raman laser for biomedicalinvestigations

We present the operating principle, general features, and advantages of a novel concept for the development of powerful and widely tunable fiber Raman lasers (FRL's), based on the high-power pumping of large-core low-loss multimode fibers using a simple double-pass laser arrangement with Littrow-prism-tuned emission. Basic experimental results obtained with various modification double-pass FRL schemes, which provide the generation of both discretely tunable emission in the UV/blue (360-493 nm) at λ_p=355 nm and continuously tunable emission in the visible/near-IR (0.54-1.01 μm) at λ _p=532 nm, are reported. The double-pass FRL schemes permit powerful and widely tunable spectral components to be generated, due to the double passing of nonlinear-converted laser emission through the optical fiber, maximum cavity feedback, the use of multimode fibers, and high-power pumping     

Oxidation Kinetics of Hafnium Carbide in the Temperature Range of 480° to 600°C

The isothermal oxidation of HfC powders was carried out at temperatures of 480° to 600°C at oxygen pressure of 4, 8, and 16 kPa, using an electromicrobalance. The oxidized product was identified by X-ray analysis, Raman spectroscopy, X-ray photoelectron spectroscopy, and electron diffraction, and the morphology of the oxidized grains was observed by scanning electron microscopy. Oxidation proceeds by two processes: a diffusion-controlled process operates up to about 50% oxidation and a phase-boundary-controlled process operates above about 50% oxidation. The activation energies for both processes are the same (197 ± 15 kJ.mol⁻¹). The change in the oxidation process is associated with the generation of cracks on the grains, resulting from the growth or expansion stress due to the formation of monoclinic HfO₂ microcrystallites less than 3 nm in size. In the latter process, the thickness of the diffusion layer is kept constant, being time-independent, which allows the process to apparently obey the phase-boundary-controlled reaction.     

Thermal stabilization of poly(vinyl chloride) treated with organoaluminium compounds: 2. Effect of solvents

Poly(vinyl chloride) was treated with organoaluminium compounds in various solvents. The strong Lewis acids, alkyl-aluminium chlorides, predominantly cause the decomposition of PVC rather than the alkylation of the polymer regardless of solvents. In non-polar hydrocarbons, the treatment of PVC with trialkylaluminiums leads to increased heat sensitivity. In 1,2-dichloroethane solution and in benzene slurry, the trialkylaluminium-treated PVC exhibits significant improvement in thermal stability over unmodified PVC due to the exchange of the labile chlorines inherent in the polymer for relatively more stable alkyl groups. The apparent activation energy of the reaction of PVC with triethylaluminium in benzene slurry is the same as that in 1,2-dichloroethane solution, but the initial rate of alkylation of the polymer in benzene is about 10 times faster than that of the polymer in 1,2-dichloroethane. The aluminium concentration in the PVC particles is about twice that calculated from the swelling ratio of the PVC particles in benzene, suggesting that triethylaluminium not only penetrates into the swollen particles but is also adsorbed on the surface of the PVC particles to cause the increase in the aluminium concentration around the labile chlorines in the polymer chain. The alkylated PVC, compounded with only small amounts of zinc soap including an epoxidized oil and a chelating compound, shows excellent initial stabilization and long-term stability superior to the starting polymer even when this is compounded with 3 parts organotin stabilizers.     

An Attempt to Evaluate the Subsite Structure of Cycloamylose glucanotransferase from Bacillus stearothermophilus: Based on its Transfer Reaction with Substrate Malto-oligosaccharides

Based on determination of the transferred products (maltooligosaccharides G_n), the plausible degradation modes of G₂, G₃, and G₄ were analyzed quantitatively, and it was made an attempt to evaluate the binding affinity A_i on some subsites of cycloamylose glucanotransferase (CGT) from Bacillus stearothermophilus. This method can be employed instead of the technique using a radioisotope. The quantities of the substrates (G₂–G₄) and products G_n were measured by using the HPLC techniques as a function fo time for the CGT-catalysed reaction.