The experimental and theoretical study of life raft safety under strong wind

The paper presents the study on the reliability of life rafts in different environmental and operational conditions. The information of the reliability of life saving appliances is essential during a search and rescue action; however, there are no available methods allowing the determinination of life saving appliances failure in heavy weather. The first attempt was made to determine the life raft safety using the random variable of “limit wind velocity”. The reliability function for the life raft was developed on the basis of the results of experimental research on hydrodynamic and aerodynamic reaction forces for 6-, 10- and 20-person life rafts with and without a drogue. The main conclusions with respect to the safety of life rafts in dependence on their operational conditions are presented and discussed.     

Difference between the 1/f noise spectral density before and after stress as a measure of the submicron MOS transistors degradation

The paper deals with the 1/f noise as a measure of the submicron MOS transistor degradation. As the reference point of the investigations has been assumed the plot of the 1/f noise drain voltage spectral density S_VD versus the channel length L of the long-channel device which in log-log scale is linear (1/L) at slope equals −1. A theoretical analysis and experimental investigations indicate that before stress decrease of the carrier effective mobility, when the MOS transistors channel becomes shorter, causes deviate down of the plot S_VD vs. L in comparison with the extrapolated linear plot of the long channel device. During stress the hot-electron effect leads to the out of controll generation of additional interface states near drain edge which influence on deviate up of the plot S_VD vs. L in comparison with the value before stress. The measure of the degradation due to the hot-electron effect is difference between S_VD after and before stress. It is showed that S_VD of the extrinsic transistors do not dependent on the parasitic resistances therefore the considerations concern both of the conventional and LDD-MOS devices. Moreover the fundamental conditions of the measurement have been determined     

Stability,sensory quality,texture properties and nutritional value of fish oil‐enriched spreadable fat

A Correction has been published for this article in Journal of the Science of Food and Agriculture 84(15):2142 (2004). The intake of omega‐3 long‐chain polyunsaturated fatty acids (PUFAs) in the typical Western diet is usually below the recommended level. Without radical changes of eating patterns the diet may be enhanced by enrichment of foods with unhydrogenated fish oil, which is the richest source of the long‐chain omega‐3s, eicosapentaenoicacid (EPA) and docosahexaenoicacid (DHA). The aims of the study were to establish the sensorily acceptable fish oil enrichment level of a reduced‐fat spread, to enhance the omega‐3 long‐chain PUFA content and to evaluate the enriched spread's stability during 3 months of storage (6°C, limited exposure to light and air). Samples were prepared in an industrial pilot plant. Overall sensory quality, intensity of fishy flavour, texture properties (sensory and instrumental), peroxide value, acid number and fatty acids composition were measured. A spread enriched by addition of 30.0 g kg^?1 of unhydrogenated fish oil could be stored for up to 3 months without significant decrease of the measured stability indicators. A daily portion of this enriched spread (30 g) would provide 0.25 g of EPA and DHA, significantly increasing long‐chain omega‐3 levels in the average diet. Copyright © 2004 Society of Chemical Industry     

Sensory properties of some synthetic high‐intensity sweeteners in water solutions

BACKGROUND: When sucrose is eliminated from products to meet consumers' demand for calorie‐free products and substitutes are used, sweetness becomes an important characteristic. The objective of this study was to compare sensory properties of four sucrose substitutes: aspartame, acesulfame K, sodium saccharin and sodium cyclamate in water solutions. RESULTS: The lowest concentrations of sweeteners such as 0.35 g kg^?1 for aspartame and acesulfame K showed an equi‐sweet level relative to approx. 55 g kg^?1 aqueous sucrose solution, whereas 2.3 g kg^?1 sodium cyclamate and 0.4 g kg^?1 sodium saccharin relative to approx. 65 g kg^?1. Aspartame had almost the same sweetness potency as acesulfame K, whereas the remaining sweeteners differed completely. The four sweeteners showed their specific sensory profiles. Besides the characteristics of sweetness and bitterness, metallic and astringent attributes plus warming and cooling effects were found. CONCLUSIONS: Of the four sweeteners, aspartame and sodium cyclamate can be considered as the best sucrose substitutes due to their similar sensory profiles to the sucrose. The data showing the interdependence between sweetness intensity of the sweeteners and sucrose are useful as a quick and easy indicator of the sweetener amount having equi‐sweet levels relative to sucrose. Copyright © 2009 Society of Chemical Industry     

The Synthesis and Absolute Configuration of Enantiomeric Pure (R)- and (S)-3-(piperidin-3-yl)-1H-Indole Derivatives

This article describes the synthesis of new chiral 3-(piperidin-3-yl)-1H-indole derivatives (R)-10a-c and (S)-11a-c from the corresponding diastereomers: (3R, 2R) and (3S, 2R)-2-[3-(1H-indol-3-yl)-1-piperidyl]-2-phenyl-acetamides (3R, 2R)-4a, (3R, 2R)-6b, (3R, 2R)-8c and (3S, 2R)-5a, (3S, 2R)-7b, (3S, 2R)-9c. Diastereomers were obtained by N-alkylation of derivatives of racemic 3-(piperidin-3-yl)-1H-indoles 1a-c using (S)-2-(4-toluenesulfonyloxy)-phenylacetic amide (S)–II. The same method was applied to obtain (3R, 2S)-methyl-2-[3-(1H-indole-3-yl)-1-piperidyl]-2-phenylacetate (3R, 2S)-2a and (3S, 2S)-methyl-2-[3-(1H-indole-3-yl)-1-piperidyl]-2-phenylacetate (3S, 2S)-3a diastereomers by treating amine 1a with (R)-2-(4-toluenesulfonyloxy)-phenylacetic acid methylester (R)-I. Systematic studies via single crystal X-ray crystallography were used to determine the molecular structure of the racemates 1a-c and the absolute configuration of the enantiomers. The solid racemates 1b and 1c were “true racemates” crystallizing in a centrosymmetric space group, while 1a formed a racemic conglomerate of homoenantiomeric crystals. The absolute configuration was determined for the enantiomeric pairs (R)-10a/(S)-11a, (R)-10b/(S)-11b, and (R)-12c/(S)-13c, as well as for (3S,2S)-3a. Spectra of ¹H, ¹³CNMR, HPLC, and HRMS for diastereomers and enantiomers were consistent with the determined structures.     

Densitometric determination of carbohydrates: Application to purification and molecular weight determination of polysaccharide from Hericium erinaceum mushroom

A simple, precise, sensitive and quick densitometric method for quantitative total carbohydrate determination as well as for preparation of elution profiles of polysaccharides was developed and validated. The method is based on spotting 3 μL of sample solution by use of disposable micro capillary pipettes as a single drop on a TLC silica gel plate. The plate is then submitted to in situ derivatization with orcinol–sulfuric acid reagent and is scanned densitometrically at 560 nm (for hexoses, deoxy sugars, and uronic acids) or at 610 nm (for pentoses and ketoses). It was demonstrated that the densitometric method has a greater linearity range and similar precision in comparison to the widely used colorimetric phenol–sulfuric acid method. The proposed method was successfully applied to elution profile preparation during purification and molecular weight determination of a novel polysaccharide isolated from the mycelium of edible and medicinal mushroom Hericium erinaceum.     

Oxidized rapeseed oil methyl ester as a bitumen flux: Structural changes in the ester during catalytic oxidation

Structural changes occurring in the rapeseed oil methyl ester upon catalytic oxidation at 200 °C were examined. Oxidative decomposition of fatty acid chains to lower molecular weight compounds and the formation of oligomers were the major oxidation pathways at 200 °C. FT-IR and ¹H NMR examinations, as well as the fall in iodine number, revealed the disappearance of double bonds. Quantitative analysis of the rapeseed oil methyl ester and the liquid products of its oxidation showed that oxidation of fatty acid methyl esters possessing three and two double bonds was practically complete whereas for structures possessing one double bond the loss of unsaturation amounted to 25% only. The decrease in iodine number from about 110 to about 65 and the 1.5-fold increase in molecular weight of the liquid products in the course of 25-h oxidation suggest that only a part of the unsaturated bonds in the fatty acid methyl ester was engaged in the formation of liquid oligomers and volatile oxidation products. The addition of dicumyl peroxide promoted the formation of organic peroxides during the initial stage of oxidation, which resulted in a higher molecular weight of the liquid products. The volatile oxidation products were found to contain lower molecular weight aldehydes, ketones, free fatty acids and their methyl esters, alkylfurans, lactones, n- and isoalkanes. The reaction schemes for their formation were presented. The results of the study are of importance to the optimization of the conditions for oxidation of the ester in order to obtain a quality ecological bitumen flux.     

Chemical Form of Dietary Selenium Affects the Fatty Acids Profile and Oxidative Stability of Muscles of Broilers Supplemented with Lycopene and Oils

The aim of this study is to determine the effects of the addition of different chemical forms of selenium (Se)—selenate (SeVI) or selenized yeast (SeY) to chickens’ diet containing equal amounts of fish (FO) and sunflower oils and lycopene (Lyc) on fatty acids (FA) profile and peroxidation yield in thigh muscles of chickens. FA profile is analyzed by gas chromatography coupled with mass spectrometry while content of malondialdehyde is determined by ultra‐fast liquid chromatography (UPLC) with photodiode detection. The diets containing SeY or SeVI increase the feed conversion efficiency of chickens compared with the control diet. SeY or SeVI added to the diet containing Lyc and FO stimulates concentrations of monounsaturated and polyunsaturated (PUFA) FA in muscles. Muscles of chickens fed a diet only with Lyc and FO have the highest indices of atherogenic (A‐SFA) and thrombogenic (T‐SFA) saturated FA and the highest ratios of A‐SFA and T‐SFA to all assayed FA. Dietary Se‐compounds also decrease the PUFA peroxidation indices in muscles compared with the diet containing only FO and Lyc. Therefore Se‐compounds may be added to diets including FO and Lyc to improve the growth parameters, nutritive value, and oxidative stability of chicken meat. Practical Applications: Poultry meat, which is characterized by high protein content of high biological value, high minerals and vitamins, and low collagen and fat content, is recommended as particularly desirable in a balanced diet to replace red and highly processed meat. Also, relatively good price makes this type of meat one of the most popular among consumers. The present study aims to check if inclusion of different chemical forms of selenium into chickens’ diets improves nutritional value of broiler meat. Feeding chickens with seleno‐supplements significantly enhances poultry production efficiency and nutritional value of broilers’ meat, because it favorably modifies FA composition (enhanced monounsaturated and polyunsaturated FA and decrease atherogenic and thrombogenic saturated FA in muscles) and reduces lipid oxidation in chickens’ meat. These results are important from the both producers’ and consumers’ point of view and correspond to contemporary nutritional recommendations.