Surface Electron Channels on Suspended Helium Films

No Heading The profile of a suspended helium film over a narrow channel is calculated self-consistently for several values of the bulk liquid helium level. We also determine the electron distribution in the channel when surface electrons are deposited on the film. It is shown that a thin van der Waals film with spatially dependent thickness is formed in a wide region at the channel center where a large fraction of electrons are confined. We obtain that the effective lateral confining potential can be described by a parabolic one is experimental conditions reported in the literature.PACS numbers: 73.20.Dx, 67.70.+n     

A comparative study on the effect of some antioxidants on the lipid and pigment oxidation in dry-fermented sausages

A comparative study on the effect of antioxidants on the lipid and pigment oxidation in Bulgarian dry‐fermented sausage type lukanka is described. A commercial mix of antioxidants, called ‘grindox 1021’ (GR), restricted the development of the peroxidation processes in dry‐fermented sausages (type lukanka) to a greater extent than either rosemary (RS), rutine (RT), sodium erythrobate (SE) or l ‐ascorbic acid, when applied at the same concentration. The latter compounds did not effectively stabilize lipids in sausages against oxidation; they only slowed down the lypolysis and did not greatly change the colour of the cross‐sectional surface. However, the sausage lipids were best stabilized when 1 g kg^?1 GR, RS or RT was added. The addition of 1 g kg^?1 RS and GR most efficiently suppressed the hydroperoxides – primary derivatives of lipid peroxidation, while the secondary derivatives in the final product were most reduced when 1 g kg^?1 GR and SE were added.     

Characteristics of the formation of a resistive zone in spatially bounded multiple-wire superconducting current-carrying elements

An analysis is made of possible mechanisms for the propagation of a normally conducting zone in a superconducting multiple-wire current-carrying element spatially bounded in one direction. It is shown that irreversible growth of the resistive zone is characterized by the formation of a flattened front propagating in the spatially unbounded direction. Pis’ma Zh. Tekh. Fiz. Pis’ma Zh. Tekh. Fiz. 23, 30–36 (May 26, 1997)     

Effect of vacuum‐packaging on the changes of Russian sturgeon muscle lipids during frozen storage

The changes in fatty acid composition, non‐polar (triglycerols) and polar lipids (phospholipids), total free fatty acids and total cholesterol of Russian sturgeon (Acipenser gueldenstaedtii) were studied during 360 days of storage at ?18°C. It was established that total neutral lipids and phospholipids content decreased and total free fatty acids concentration increased significantly during the frozen storage. Lower non‐polar and polar lipids content and higher free fatty acids concentration of vacuum‐packaged samples in comparison with air‐packaged samples were found. The changes in total cholesterol concentration and phospholipid classes of frozen stored sturgeon were not influenced by the frozen storage period and the type of packaging. It was established that the sturgeon polar lipids consisted mainly of phosphatidylcholine – 54.98 ± 0.85%, phosphatidylethanolamine – 28.42 ± 0.61%, and phosphatidylserine – 8.64 ± 0.45%. The increase of the total free fatty acids concentration was associated with the free n ? 3 PUFA accumulation as a result of hydrolysis of non‐polar and polar lipids. During the frozen storage DHA percentage of non‐polar lipids and phospholipids decreased approximately 3 and 1.75%, respectively. After 360 days of storage at ?18°C the n ? 3/n ? 6 PUFA ratio of total lipids decreased 4.9%.     

Production of pipe blanks from corrosion-resistant duplex steel

The introduction of pipe-blank production (blank diameter 180 mm) from corrosion-resistant duplex steel (UNS S 31803, UNS S 32205, DIN 1.4462, and 03X22H5AM3) at PAO Dneprospetsstal’ plant is considered. The chemical composition of the melts at PAO Dneprospetsstal’ and pipe blank produced from duplex at traditional foreign suppliers is compared. The content of nonmetallic inclusions is studied, as well as the distribution and content of ferrite-austenite phases, the impact strength, the resistance to pitting corrosion, and the high-temperature deformability.     

Optimal semi-oblique tiling

For 2D iteration space tiling, we address the problem of determining the tile parameters that minimize the total execution time on a parallel machine. We consider uniform dependency computations tiled so that (at least) one of the tile boundaries is parallel to the domain boundaries. We determine the optimal tile size as a closed form solution. In addition, we determine the optimal number of processors and also the optimal slope of the oblique tile boundary. Our results are based on the BSP model, which assures the portability of the results. Our predictions are justified on a sequence global alignment problem specialized to similar sequences using Fickett's k-band algorithm, for which our optimal semi-oblique tiling yields an improvement of a factor of 2.5 over orthogonal tiling. Our optimal solution requires a block-cyclic distribution of tiles to processors. The best one can obtain with only block distribution (as many authors require) is three times slower. Furthermore, our best running time is within 10 percent of the "predicted theoretical peak" performance of the machine!.