Optimisation of rancidity stability in long‐chain PUFA concentrates obtained from a rainbow trout (Oncorhynchus mykiss) by‐product

This research was focused on the production of polyunsaturated fatty acid concentrates from a farmed rainbow trout (Oncorhynchus mykiss) by‐product (i.e. belly muscle). The effect of different process variables (urea/fatty acids (FA) contents ratio, crystallisation time and temperature and stirring speed of the urea/FA mixture) on the lipid oxidation development during the urea complexation process was investigated. For this purpose, an experimental design (26 runs) following the response‐surface methodology was developed. As a result, peroxide value and TOTOX index showed to be dependent on the crystallisation time and temperature and the urea/FA ratio, while no influence of the crystallisation stirring speed was detected on both indices; additionally, polyene index was affected by the urea/FA ratio and its interaction with the crystallisation time. An optimised desirability score near 1.0 was attained provided values of 2.8 °C, 3.05 h and 3.57 were applied for crystallisation temperature, crystallisation time and urea/FA ratio, respectively.     

从硫酸锌溶液中富集铟两种工艺的比较

介绍了锌粉置换法和氧化锌水解沉淀法从硫酸锌溶液中富集铟的原理和生产实践,比较了两种工艺的特点。     

从硫酸锌溶液中富集铟两种工艺的比较

介绍了锌粉置换法和氧化锌水解沉淀法从硫酸锌溶液中富集铟的原理和生产实践，比较了两种工艺的特点。     

Hydrolytic degradation of poly(L-lactic acid): Combined effects of UV treatment and crystallization

Amorphous and crystallized poly(L -lactic acid) (PLLA) films were prepared and the hydrolytic degradation of the ultraviolet (UV)-treated and UV-nontreated films was investigated. This study reveals that the combination of UV and thermal treatments can produce the PLLA materials having different hydrolytic degradation profiles and that the UV-irradiation in the environment will affect the design of recycling process for PLLA articles. In an early stage, the degrees of hydrolytic degradation monitored by weight loss (W_loss), number-average molecular weight (M _n), and melting temperature (T _m) were higher for the UV-treated films than for the UV-nontreated films. In a late stage, the trend traced by W_loss was reversed, and the difference in the degrees of hydrolytic degradation between the UV-treated and UV-nontreated films monitored by M _n and T _m became smaller, with the exception of the degrees of hydrolytic degradation of the amorphous films traced by T _m. Also, in the early stage, the degrees of hydrolytic degradation monitored by W_loss and M _n were higher for the crystallized films than for the amorphous films. In the late stage, this trend was reversed, with the exception of the degrees of hydrolytic degradation of the UV-treated films monitored by M _n. The main factors that determined the W_loss and T _m were the molecular weight and initial crystallinty but not the molecular structures such as terminal CC double bonds and crosslinks. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

A Modified Silane Treatment for Superior Hydrolytic Stability of Glass Reinforced Composites

A silicon tetrachloride-modified silane treatment of E-glass particles and fibers improved the hydrolytic stability of the glass reinforced composites by creating a water-resistant silane copolymer interphase of approximately 30 Angstroms thickness. SEM observation of E-glass particulate reinforced dimethacrylate-based resin composites showed that strong interfacial adhesion was maintained even under 72 hours of exposure to boiling water, while interfacial adhesion in the conventionally-treated materials was destroyed under the same conditions. Interfacial fracture energy was measured using an embedded single fiber fragmentation test. In the initial dry state, no interfacial debonding was observed in either the modified or conventionally-treated microcomposites, indicating strong interfacial adhesion in both cases. However, after exposure to boiling water for 24 hours, debonding occurred in both cases, with interfacial fracture energies of 281 J/m² and 54 J/m² for the modified and conventionally-treated interfaces, respectively. The improvement in hydrolytic stability of the interface is believed to be caused by a higher degree of crosslinking in the silane layer and the replacement of at least some of the hydroxyl groups on the glass surface by covalent O—Si—O bonds.     

Evaluation of basidiomycetous fungi for pretreatment of contaminated soil

BACKGROUND: For most dioxin‐contaminated sawmill soils, combustion is recommended. However, the process may be inefficient if the soil has a high organic matter content. The use of saprotrophic basidiomycetous fungi is an alternative for pretreatment of this kind of soil. A total of 147 fungi were evaluated for their ability to grow in sawmill soil. From this screening, the best soil colonizing fungi were selected to study their enzyme activities and degradation of soil organic matter. Pine (Pinus sylvestris) bark was used as a co‐substrate to propagate the fungi into the soil. The activities of manganese peroxidase (MnP), laccase, endo‐1,4‐β‐glucanase, endo‐1,4‐β‐xylanase, and endo‐1,4‐β‐mannanase were analysed from the inocula and fungal treated soil. RESULTS: The screening revealed that 56 out of 147 fungi were able to grow in non‐sterile soil, and most of them were litter‐decomposing fungi (LDF). In pine bark cultures, the highest enzyme activities were observed with Phanerochaete velutina, which produced 5 U g^?1 of MnP. The activity of endo‐1,4‐β‐glucanase was generally higher than that of other hydrolytic enzymes. The highest carbon loss from soil with a high organic matter content was achieved by P. velutina (3.4%) and Stropharia rugosoannulata (2.4%). CONCLUSIONS: Many LDF, and in addition the white‐rot fungus P. velutina, are potential degraders of soil organic matter since they showed good growth and respiratory activity. Pine bark was a suitable lignocellulosic co‐substrate and a good promoter of MnP activity. Copyright © 2009 Society of Chemical Industry     

Recent observations on the occurrence of fishy flavour in bacon

An examination of reject bacon samples supplied directly from a factory showed that some samples described by a sensory panel as oily and fishy contained significantly higher levels of long chain polyunsaturated fatty acids (PUFA) in their fat than normal samples. When bacon samples obtained from retail outlets were similarly analysed and then subjected to sensory assessment, those found to contain long chain PUFA were given significantly higher scores for oily and fishy flavour. Observations on the fatty acid composition of fishy bacon samples as compared to non-fishy ones and further investigation into the diets of pigs producing suspect carcasses led to the conclusion that too high a content of fish products in the diet was the main cause of the problem. Contrary to what had been believed, fresh non-fishy bacon samples did not develop fishy flavour after storage at ?20°C for 15 weeks. Perceived fishiness was not related to total copper content as determined by atomic absorption spectroscopy.     

混凝-缺氧-好氧工艺处理纺织印染废水

采用混凝－－水争酸化－－生物接触氧化工艺流程处理纺织印染废水，处理量４０００ｍ＾３／ｄ，进水ＣＯｃｒ１０００～３０００ｍｇ／Ｌ、色度４５１２～１０２４倍、ＰＨ１１～１３。从１９９８年７月开始运行至今，ＣＯＤｃｒ平均去除经为９２．３２％，色度平均去除率为９２．１９％，出水Ｐ来７，出水各项指标均符合《纺织染整工业水污染物排放标准》ＧＢ４２８７～１９９２一组标准的要求，运行结果表明，该工艺处理效果稳定、     

染织废水处理改造工程设计及调试运行

介绍了某染织厂废水处理设施的改造工程.采用水解酸化、接触氧化、混凝气浮工艺处理染织废水,取得了良好的处理效果.运行结果表明,在进水CODCr、BOD5、SS分别为900～1 100、250～350、350～450 mg/L的条件下,出水达到GB 8978-1996一级排放标准.     

1,5-萘二异氰酸酯型聚氨酯弹性体的制备及性能

通过预聚法合成了以己二酸乙二醇丙二醇二酯、聚四氢呋喃二醚、1,5-萘二异氰酸酯(NDI)、甲苯二异氰酸酯(TDI)、1,4-丁二醇及4,4'-二氨基-3,3'-二氯二苯甲烷为主要原料的聚氨酯弹性体。通过水解后弹性体的拉伸、撕裂等力学性能保持率的比较,发现NDI型聚氨酯弹性体比TDI型具有更好的水解稳定性;通过不同温度下和热空气老化后弹性体力学性能保持率的对比,证明NDI型聚氨酯弹性体的耐热稳定性要优于TDI型。