Variant-based cost estimation based on Information Management

Based on the product information structure related to the Manufacturing Engineering Reference Model, a method for variant-based cost estimation is proposed. The structure defines a product in terms of elements and their relations. The elements and their properties constitute product characteristics that can be used to compare products. For proper use in different engineering processes, the product characteristics are related to the four cost drivers - geometry, material, processes and production planning. The main advantage of the proposed method is a more flexible way of defining and valuing product characteristics without the use of rigid product classes and codes.     

苯酚丙酮装置脱烃塔产品质量不合格原因分析及对策

中沙（天津）石化有限公司苯酚丙酮装置精制工段在开车初期，脱烃塔塔顶及塔底产品指标均不合格。采取调整回流比、再沸量、塔顶采出量等手段未达到明显效果后，分析造成脱烃塔塔顶塔底产品质标不合格的主要原因是塔内件及支撑造成气液分布不均。在无法改变塔内件结构的情况下，通过在粗苯酚与脱烃塔之间增加液封管，并采用连续串级控制回流量，使该装置正常稳定运转，保证了脱烃塔的产品质量合格。     

Modeling water sorption dynamics of cellular solid food systems using free volume theory

Water sorption and dynamical properties of bread crust were studied using gravimetric sorption experiments. Water uptake and loss were measured while relative humidity (RH) was step-wise in- or decreased. Experimental results were compared with Fickian diffusion models and empirical models like the exponential and power-law model. From comparison of experimental sorption curves and the power-law model for short times it followed for all bread crust that the diffusional coefficient n is close to one. It turned out that this is not due to so-called case II diffusion and water transport that is limited by relaxation of the solid material but due to the fact that RH did not instantaneously but gradually increased to the set value.Sorption curves of isotherm experiments could be best described by the Fickian diffusion model for low RH and by the exponential model for large RH. Transport rates depend on moisture content and show a maximum around RH = 0.7, corresponding to a water mass fraction ω₁ = 0.12. Diffusion rates could be well described by free volume theory up to the maximum, but this theory could not explain the strong decrease at higher ω₁. Indications for a local glass-rubber transition at room temperature were found near a water mass fraction ω₁ ≈ 0.09. This corresponds very well to the start of the crisp–non-crisp transition as measured by a sensory panel, but not to the glass-rubber transition at ω₁ ≈ 0.12 as measured by other techniques like Differential Scanning Calorimetry. So it seems that more than one glass-rubber like transitions may be important to describe the properties of heterogeneous cellular food systems.     

拍式浮体闸门充压水封仿真计算研究

为了得到充压伸缩框型水封在不同线荷载下运行时水封背腔所需的充压值及相应的水封变形断面和封头接触属性,首先通过一种非线性近似方法得到各工况下框形水封各段的线压力,将三维问题转化为平面问题;然后通过仿真计算求得各充压值下的水封线压力和变形属性,反过来便是所求结果。计算结果表明,拍门充压水封较传统挤压水封在中低水头(一般水头)下具有更好的封水性能,又因其利于拍门缓冲和人为控制,因此具备较好的应用前景。     

Effects of high hydrostatic pressure processing and subsequent storage on phenolic contents and antioxidant activity in fruit and vegetable products

Fresh fruits and vegetables have been reported to possess a variety of bioactivities partly due to their high abundance of phenolics. However, traditional thermal pasteurisation during fruit and vegetable processing typically induces a pronounced loss of phenolic compounds. In contrast, nonthermal pasteurisation techniques, especially high hydrostatic pressure (HHP) processing, are beneficial to the retention of phenolics. In addition to more effectively keeping original freshness, flavour and colour of fruit and vegetable products to the greatest extent, in most cases, HHP processing and subsequent storage more effectively sustain the levels of phenolic compounds and antioxidant activity in fruit and vegetable products compared with thermal pasteurisation. Therefore, HHP processing has a huge potential to preserve fruit and vegetable products rich in phenolic compounds.     

Variables influencing food perception reviewed for consumer-oriented product development

Consumer wishes have to be translated into product characteristics to implement consumer-oriented product development. Before this step can be made, insight in food-related behavior and perception of consumers is necessary to make the right, useful, and successful translation. Food choice behavior and consumers' perception are studied in many disciplines. Models of food behavior and preferences therefore were studied from a multidisciplinary perspective. Nearly all models structure the determinants related to the person, the food, and the environment. Consequently, the overview of models was used as a basis to structure the variables influencing food perception into a model for consumer-oriented product development. To this new model, referred to as food perception model, other variables like time and place as part of consumption moment were added. These are important variables influencing consumers' perception, and therefore of increasing importance to consumer-oriented product development nowadays. In further research, the presented food perception model is used as a tool to implement successful consumer-oriented product development.     

仲丁醇—水体系的汽液相平衡

用静态法测定了仲丁醇—水体系在0.5MPa压力下的恒压气液平衡数据。用Heringon方法检验数据的热力学一致性,表明实测数据可靠。作者探讨了NRTL、UNIQUAC、ASOG和UNIFAC模型对该体系的关联和予测,并对各方程的拟合结果进行了分析。     

一种基于声誉的不良网页协作检测机制

大量不良网页的出现威胁了互联网安全。为了检测不良网页，提出了一种基于声誉的协作检测机制，WebShield。用户对网页评分，服务器汇聚用户评分得到网页的综合评分，并依此检测不良网页。设计了一种基于贡献的声誉模型，通过用户声誉加强评分汇聚的准确性和鲁棒性。模拟表明，WebShield对不良网页的检测效率较高、对恶意用户的抵抗性较好。     

DSC法测量低温相变蓄冷纳米流体的比热容

介绍差示扫描量热仪（DSC）测量液体比热容的原理和方法，并测量4种不同体积分数的TiO2-Ba-Cl2-H2O纳米流体比热容。结果表明，加入纳米粒子后其比热容都有所降低，并随TiO2体积分数的增大而逐渐减小。     

Massively parallel Modelling & Simulation of large crowd with GPGPU

In peacekeeping, domestic, or combat operations, unanticipated crowd confrontations can occur. As a highly dynamic social group, human crowd in confrontation is a fascinating phenomenon. This paper presents a novel method based on the concept of vector field to formulate the way in which external stimuli may affect the behaviours of individuals in a crowd. Furthermore, Modelling & Simulation (M&S) of large crowds at individual level has long been placed in the highly computation intensive world. This study adopts GPGPU to sustain massively parallel M&S of a confrontation operation involving a large crowd. This approach enables investigation of a crowd consisting of tens of thousands individuals whose size was prohibitively large for conventional M&S technique to support. Experimental results indicate that the approach is efficient in terms of both performance and energy consumption.