Water reuse in a shrimp processing line: Safety considerations using a HACCP approach

The large consumption of water involved in food manufacturing is prompting food processors to optimise the use. Treating and reusing or recycling water within the food plant results in substantial reduction of water use and wastewater production and discharge. If implemented, water reuse should be integrated into existing HACCP programs, and HACCP plans specifically addressed to the actual reuse should be elaborated. This paper evaluates the microbiological safety issues associated with water recycling during the production of shrimps (Pandalus borealis) in brine, and it indicates how the hazards may be effectively controlled using a HACCP approach. Following these procedures, process water recovered from peeling during shrimp processing and treated by means of reverse osmosis could be recycled within the same food unit operation.     

Mechanical properties and thermal stability of double‐shell thermal‐energy‐storage microcapsules

Double‐shell‐structured microcapsules encapsulating phase‐change materials (micro‐PCMs) with an average diameter of 5–10 μm were successfully fabricated with a melamine–formaldehyde resin as the coating material. The mechanical properties of the obtained piled micro‐PCMs, tested under compression, were evaluated with a pressure sensor. Typical stress–strain curves showed that both the single‐shell‐ and double‐shell‐structured microcapsules had yield points and maximum point pressures. The morphological changes in the shell surface confirmed the existence of yield points by scanning electron microscopy. When the pressure was beyond the yield point, the microcapsules showed conventional plastic behavior, and the double‐shell structure was more mechanically stable than the single‐shell one. Differential scanning calorimetry analysis results revealed that the properties of the phase‐change materials experienced no variation after coating with a single‐shell‐ or double‐shell‐structured polymer. Thermogravimetric analysis showed that the double‐shell‐structured micro‐PCMs experienced a weight loss of only about 5% from 86.3 to 232°C but did so more rapidly from 232 to 416°C. Thermoregulation was determined with periodical heating and cooling tests. The data showed that the micro‐PCMs changed temperature in a narrow range of 20–25°C with a time lag of 20 min to reach the maximum or minimum temperature in comparison with a reference temperature of 18–28°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1295–1302, 2007     

Optimal Design of Two-Chamber Gas Distributor with CFD Approach

Computational fluid dynamics( CFD) is used to investigate a new type of two-chamber natural gas distributor,which has a natural gas inlet and nine nozzle outlets. The uniformity at the outlet of distributor is practice proven to have significant degree influence on its comprehensive performance. To improve the uniformity at the nozzles of the gas distributor,CFD modeling with the RNG k-ε turbulence model is undertaken to understand the mass flow rate of nozzles with reference to different length of chambers and the most optimal length is obtained. The internal flow pattern of the natural gas distributor is analyzed. It is found that the local maximum deviation of the nozzle outflow rate increases with the increase of chambers length when the length is more than 64 mm. The results provide useful suggestions for the optimal design of two-chamber natural gas distributor.     

求解最大团问题的混合修复遗传算法及其在社会网络中的应用

社会网络分析是数据挖掘中与社会生活联系最紧密的热点之一,凝聚子群分析是一种典型的社会网络子结构分析方法,其中最大团结构是关系最紧密的凝聚子群,最大团问题的研究在社会网络分析中有重要意义。针对遗传算法在求解最大团问题中运行时间长、部分基准图例求解精度不高等问题,提出了一种基于混合修复策略的遗传算法MGA。MGA算法融合度修复和随机染色体修复方法并结合随机配对的精英选择、均匀块交叉和倒位变异算子,可以有效避免算法陷入局部最优,在加快收敛速度和丰富种群多样性方面有明显效果。算法在DIMACS基准图例和典型的社会网络实例上进行了测试,实验结果表明MGA算法具有较好的求解精度和较快的收敛速度。     

集成一体化智能熔点仪的设计

介绍由微控制器（单片机）、温度传感器、加热系统、搅拌系统、键盘和LCD显示等组成的集成一体化智能熔．最仪的工作原理,阐述其硬件电路结构和软件程序设计,并进行反复实验。实验结果表明：该仪器控温精度达到4-0．2℃,线性升温误差不超过0．5％,各项指标符合国家药典标准,具有硬件结构简单、软件算法科学的特点,能够低成本、高精度地实现对温度的控制。     

基于B/S信息系统的分层树形任务评价模式

阐述基于B/S模式网络信息系统环境下企业各级任务逐层分解、以树形关系管理的流程模式以及以任务、创新业绩评价指标模型为基础的评价、监督和多级反馈模式。任务的分解、树形关联关系的确立以及多级反馈模式是以企业部门的层次结构为框架、部门所属岗位为基点、人员之间的领导关系为纽带,运用计算机编码技术实现的。该系统以务实的指标体系、实用的评价流程解决了企业对知识型员工工作能力、创新能力评价及趋势分析等问题,为知识型员工评价的客观性、公平性、及时性提供了技术保障。     

基于粒度仪的双枪喷涂雾化场的粒度的研究

目的 在保证喷涂雾化表征均匀性的前提下实现宽幅覆膜,提高覆膜的效率,以期得到均匀一致的大豆蛋白覆膜。方法 利用粒度仪测量不同干涉程度下的大豆蛋白液双枪喷涂雾化场的索特平均直径（Sauter Mean Diameter,SMD）,利用Spraylink软件处理粒度数据,得到粒度数据并对比。结果 双枪喷涂喷雾场的SMD随着液压的增大先增大后趋于平稳,随着气压的增大先减小后趋于平稳。当液压分别为0.08 MPa和0.16 MPa时,SMD基本不随偏转程度的变化而变化;当液压为0.24 MPa时,SMD随着偏转程度的增大而增大。双枪喷涂喷雾场的径向SMD从中心到边缘缓慢减小,在干涉区域内的轴向2点粒径基本相等。结论 当液压为0.08 MPa、气压为0.24 MPa、偏转角为0°时,SMD相对较小。文中的研究为实现宽幅覆膜奠定了理论基础。     

多孔PDMS基底复合柔性互连导线拉伸时3D变形行为研究

目的 探究多孔聚二甲基硅氧烷(PDMS)基底复合柔性互连导线的透气性能和延展性能,以使其更好地应用在医疗领域。方法 本文采用三维数字图像相关(3D-DIC)方法检测了25 ℃下不同孔隙率的多孔PDMS基底复合柔性互连导线单轴拉伸过程中导线与基底的面内应变失配和离面位移特征。在此基础上,本文引入平均位移(wm)和位移幅(wa)作为量化表征复合柔性电子离面变形的指标,并结合多孔PDMS基底的气密性实验结果评价了不同导线样品。结果 研究结果表明,多孔PDMS材料作为基底能显著降低复合柔性电子的离面变形程度,并使复合柔性电子具有良好的透气性。在相同拉伸载荷(20 N)和拉伸距离下,PDMS与去离子水质量比为6∶1时的多孔PDMS基底复合柔性互联导线具有稳定的离面变形变化量。结论 多孔PDMS基底复合柔性电子不仅具有良好的透气性,而且可以有效地增强金属互联层与柔性基底的粘连程度。本文所获得的PDMS与去离子水最佳掺杂质量比,可为制造高延展性多孔基底柔性电子器件提供参考。     

电子商务专业实践教学体系构建与实施的研究

实践教学是高等教育的重要组成部分,是培养学生动手能力和创新能力的重要的环节。本文确立了电子商务专业实践教学的总体目标是"知业—专业—创业",并对如何构建相对完整的新型电子商务专业实践教学体系进行研究和探讨。     

基于混合神经网络的车辆路径模型研究

为有效解决现代物流配送中的车辆路径问题,发挥BP神经网络在解决分类问题和Hopfield神经网络在解决组合优化问题中的优势,依据"分而治之"策略提出了基于混合神经网络的优化模型。通过BP神经网络对一个配送中心范围内的多个配送点进行区域划分,在各子区域内使用Hopfield神经网络求得最优配送路径,从而得到质量较高的解和较快的收敛速度。基于Matlab的仿真实验结果表明,与传统的爬山算法、遗传算法相比,该模型能够获得性能更好的全局最优解。