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111.
112.
阀式浇注系统优化控制技术在注塑模中的应用 总被引:3,自引:1,他引:3
在分析注塑模普通浇注系统的基础上,为解决注塑成型存在的问题,介绍了一种新型阀式浇注控制系统,阐述了闯式浇注系统优化控制的关键技术,通过对浇注系统的浇口控制充填模式研究,以注塑流动分析为理论基础,依靠CAE分析技术对浇注充填过程进行流动模拟,科学准确地对阀式浇注系统的浇口位置确认,并根据分析结果应用热流道和自动控制技术对注塑工艺进行优化控制(如浇口阀门的开关时机、打开方式),为阀式浇注系统优化控制的实现提供基础。 相似文献
113.
为了解国际上绿色印刷包装研究的现状与发展态势,选取科学引文索引(SCI)2008~2012年所收录的绿色印刷包装中有关印刷电子、环保油墨、按需喷墨、印后加工等4个研究方向的文献进行汇总、利用文献研究法进行综合分析,可以看出近5年来印刷电子文献高速增长,环保油墨文献量维持在相对较高的水平,而按需喷墨、印后加工的文献量明显下滑,印刷电子和环保油墨成为行业研究的热点。 相似文献
114.
Oluwafemi J. Caleb Pramod V. Mahajan Marena Manley Umezuruike Linus Opara 《International Journal of Food Science & Technology》2013,48(11):2315-2323
This study evaluated the effects of passive modified atmosphere packaging design parameters as a function of the amount of product (g), temperature (°C) and time (days) on two pomegranate cultivars. Arils (75, 100 and 125 g) were packed in trays, heat sealed with polylid film and stored at 5, 10 and 15 °C for 14 days, and analysed for physicochemical parameters viz headspace gas composition, weight loss, total soluble solids, titratable acidity, pH, anthocyanin, aerobic‐mesophilic bacterial and fungal load (log CFU g?1). At the highest temperature and weight, O2 concentration continuously decreased below the critical limit (2%) after 4 days, while at 5 °C, this lower limit was not reached. Shelf life of arils was limited to 10, 7 and 3 days by fungal growth ≥2 log CFU g?1 at 5, 10 and 15 °C, respectively. Using unsteady‐state equation, a good agreement was found between simulated and experimental gas composition data. 相似文献
115.
Shelf life extension of whole Norway lobster Nephrops norvegicus using modified atmosphere packaging
Sebastian G. Gornik Amaya Albalat Chonchanok Theethakaew Douglas M. Neil 《International journal of food microbiology》2013
Once a nuisance by-catch, today the Norway lobster (Nephrops norvegicus) is a valuable UK fisheries commodity. Unfortunately, the species is very susceptible to quality deterioration post harvest as it quickly develops black spots and also spoils rapidly due to bacterial growth. Treatment with chemicals can stop the blackening and carefully monitored cold storage can result in a sensory shelf life of up to 6.5 days. The high susceptibility to spoilage greatly restricts the extent to which N. norvegicus can be distributed to retailers and displayed for sale. The application of modified atmosphere (MA) could be extremely beneficial, allowing the chilled product to stay fresh for a long period of time, thus ensuring higher sales. In the present study, we identified a gas mix for the MA packaging (MAP) of whole N. norvegicus lobster into 200 g retail packs. Our results show that a shelf life extension to 13 days can be achieved when retail packs are stored in MAP at 1 °C. Effectiveness of the MAP was evaluated by using a newly developed QIM for MA-packaged whole N. norvegicus and also by analyzing bacterial plate counts. Changes in the microflora and effects of different storage temperatures on the quality of the MA packs are also presented. The main specific spoilage organism (SSO) of modified atmosphere packaged Norway lobster is Photobacterium phosphoreum. 相似文献
116.
The suitability of a polyamide 6 monolayer film containing lactic acid for use as an antimicrobial package for fresh beef cuts was studied. The release of lactic acid in an aqueous environment was immediate (within 1 h) and was from approx. 55 μg lactic acid/cm2 film at 0–8 °C to approx. 67 μg lactic acid/cm2 film at 12–20 °C. Beef was contaminated with an Escherichia coli O157:H7 isolate with known minimum inhibitory concentration against lactic acid (0.09% v/v), then wrapped with the lactic-acid polyamide film and vacuum packaged. During storage at 12 °C, the numbers of E. coli were 1 log unit lower than that of a control (untreated polyamide film) and decreased by an additional 1 log during storage for 14 days. 相似文献
117.
《Food Reviews International》2013,29(3):244-263
Globalization of food trade, increasing demand for ready to eat fresh food products, and awareness among consumers towards side effects of chemical preservatives have led to research and development in the area of biopreservation. Biopreservation basically involves inhibition or killing of food spoilage microorganisms by the application of other microbes or their antimicrobial products. Bacteriocins are ribosomally synthesized peptides having potential as biopreservatives. The enhanced, stable, continuous, and economically viable production of these preservatives can be carried out by employing immobilization technology. Various matrices, operational conditions, and fermentation systems have been explored for achieving maximum bacteriocin production through immobilization; besides these, immobilization can be used for the application of bacteriocins in various packaging materials or films for their functional effects at the surface of different food products. Efficiency of an antimicrobial packaging system can be increased by its application in combination with other methods, including high-pressure processing (HPP), which in turn can improve the shelf life of food products. These antimicrobial packaging systems can play a significant role in extending shelf life of food products by reducing the risk of foodborne pathogens, thereby enhancing their quality and safety. 相似文献
118.
《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2013,30(4):557-566
Published diffusion prediction models for the diffusion of additives in food packaging simplify reality by having a small number of parameters only. Therefore, extrapolation of such models to barrier polymers, larger ranges of temperature and/or additive molecular weight (MW ) is questionable. Extra data is still required to generalize these existing prediction models. In this paper, diffusion of a specifically designed homologous set of model additives (from 236 to 1120 g mol?1) was monitored in two polystyrenes in the rubbery state (from 100 to 180°C): syndiotactic semi-crystalline polystyrene and its amorphous equivalent. Variations in associated diffusion coefficient D and activation energy Ea with migrant MW and temperature were surprisingly low. Comparison of experimental behaviour with model predictions was performed. In their actual form, none of the models is capable of describing all experimental data, but there is evidence of convergence of the different approaches. 相似文献
119.
基于加密QR二维码的商品包装防伪技术 总被引:1,自引:0,他引:1
为了改善大众商品包装的防伪效果,采用了基于唯一商品编码生成加密QR二维码的商品包装防伪技术。基于非对称加密密钥生成算法产生公私钥密钥对,利用私钥对唯一商品编码及商品名称等信息进行加密处理,针对加密后的密文信息形成QR二维码。公钥被植入到QR二维码识读软件中,作为解密密钥用来还原二维码信息。在应用中,QR二维码以"一品一码"的方式粘贴或采用数字印刷方式喷印到对应商品的包装盒上,智能手机终端通过运行加密QR二维码识读软件,实现对加密QR二维码识读的功能。 相似文献
120.