SUPERIOR OXIDATIVE STABILITY OF DOCOSAHEXAENOIC ACID-ENRICHED OILS IN THE FORM OF PHOSPHOLIPIDS

Oxidative stabilities of docosahexaenoic acid (DHA, 22:6 n-3)-enriched oils (7.0 – 7.1 mol% of total fatty acids), in the form of phospholipids (PL), triacylglycerols (TG) and ethyl esters (EE), were comparatively investigated with those of control oil (palm oil supplemented with 20% soybean oil; containing no DHA). Autoxidation of sample oil (50 mg) was performed in a 10 mL glass vial at 25C for 42 days in the dark. During the oxidation, headspace oxygen absorption was significantly lower in oil in the form of PL than TG and EE, and was almost equivalent to that of control oil. At day 42 of oxidation, peroxide value and carbonyl value of PL were lower than those of TG and EE. The change of constituent fatty acids during the oxidation was larger in TG and EE than PL. The results indicated that DHA-enriched oils in the form of PL are more stable to autoxidation than those in the form of TG and EE.     

ECM-abrasive polishing of metals

The combined action of abrasives and electrochemical machining (ECM) results in a better surface finish than that could be achieved by using abrasives alone. From an initial roughness of R_tm 30 to 50 nm, flat carbon steel and stainless steel specimens could be finished to a roughness of R_tm 0-4 μm. The procedures in conducting the experiments and analysing the data are discussed in this paper.     

Fluorometric Peroxygenase Assay for Lipid Hydroperoxides in Meats and Fish

A fluorometric assay for lipid hydroperoxide in meats and fish was developed using pea peroxygenase, a hydroperoxide-dependent hy-droxylase. The freeze-dried microsome fraction of germinating pea seed was used as a peroxygenase source. Linear relationships between the hydroperoxide added (25 to 150 nmol) and fluorescence were observed with methyl linoleate hydroperoxide, linoleic acid hydroperoxide, triglyceride hydroperoxide, and phosphatidylcholine hydroperoxide. α-Tocopherol at levels equivalent to those in meats and fish did not affect the peroxygenase reaction. The assay was specific for hydroperoxides. The method enables determination of total lipid hy droperoxides in sample homogenates without extracting total lipids from retail meats and fish.     

Phase Diagram for a Portion of the System Li2O-Nd2O3-P2O5

In the ternary system Li₂O-Nd₂O₃-P₂0₅, part of the phase diagram relevant to the growth of single LindP₄O₁₂ (LNP) crystals was examined. LNP melts incongruently and decomposes into NdP₃O₉ and liquid at the peritectic temperature of 970°C. For the crystal growth, an Li₂O-P₂O₅ mixture should be used as a flux. The melt compositions from which LNP nucleates were clarified.     

Quantized robust H-two filtering for Markovian jump linear systems over networks with nonaccessible mode information

This paper is concerned with the problems of H-two filtering for discrete-time Markovian jump linear systems subject to logarithmic quantization. We assume that only the output of the system is available, and therefore the mode information is nonaccessible. In this paper, a mode-independent quantized H-two filter is designed such that filter error system is stochastically stable. To this end, sufficient conditions for the existence of an upper bound of H-two norm are presented in terms of linear matrix inequalities. Considering uncertainty of system matrices, a robust H-two filter is designed. The proposed method is also applicable to cover the case where the transition probability matrix is not exactly known but belongs to a given polytope. Finally, numerical examples are provided to demonstrate the effectiveness of the proposed approach.     

电沉积Co-Ni-Al2O3复合镀层微观结构及高温性能

在氨基磺酸盐电解液中,利用复合电沉积技术制备得到了Co-Ni合金基中弥散分布Al₂O₃颗粒的金属基复合镀层。通过SEM,AFM以及XRD等分析测试方法,研究了Co-Ni-Al₂O₃复合镀层的表面形貌和微观晶体结构。结果发现:Co-Ni-Al₂O₃的表面形貌和微观晶体结构主要受镀层中钴含量的影响。高钴含量复合镀层具有Hcp结构,其表面形貌比具有Fcc结构的低钴含量镀层的表面更加均匀细致。Al₂O₃颗粒在Co-Ni合金中的共沉积,没有改变合金固溶体的相组成,但却改变了各晶面的优势生长。通过研究复合镀层的硬度、高温耐磨性、高温抗氧化性、热膨胀系数和热导率表明:Co-Ni-Al₂O₃具有较好的高温耐磨性和高温抗氧化能力,并且高钴含量的复合镀层相对于低钴镀层具有较低的热膨胀系数和较高的热导率。      

Generation of Mannitol from Copra Meal

Saccharification of copra meal with hydrochloric acid was found to be suitable method for forming reducing sugars. The presence of protein and lignin in the meal did not have a significant effect on the yield of reducing sugars. Borohydride reduction of the reducing sugars gave sugar alcohols in 44% yield based on the raw material or 81% based on carbohydrate content. The sugar alcohol mixture contained 66% mannitol, 24% sorbitol and 5% galactitol. The recovery of hydrochloric acid which renders the process more economically feasible was done by vacuum distillation.     

High Temperature Storage Effect on Longevity of Rice Seeds

Storage of Indica (Oryza sativa L. cv. Katakutara) and Japonica (Oryza sativa L. cv. Kusabue) rice seeds at 30° and 40°C for 2 months in the dark did not result in the loss of viability in both cultivars. Storage at 60°C, however, resulted in a complete loss of germination after 45 days in the case of Kusabue while the Katakutara rice seeds retained the germination potential well above 95%. Corresponding increases in the linoleic acid content of the free fatty acid fraction and TBA values of the extracted lipid fraction were also observed in Kusabue rice seeds. The investigation indicated that the Indica rice seeds were better protected than the Japonica rice seeds by the enclosing rice hull during the storage period.     

Volatile Flavor Components of Chive (Allium schoenoprasum L.)

Using well-established techniques, a sample was obtained of the steam volatile oil of chive (Allium schoenoprasum L.). A total of 30 components were identified and the neutral oil contained mainly sulfur compounds (16.8%). The most important constituents are dipropyl disulfide, methyl pentyl disulfide, pentyl hydrodisulfide and (cis and trans) 3,5-diethyl-1,2,4-trithiolane. Methyl pentyl disulfide and pentyl hydrodisulfide have not been described previously.