RHEOLOGICAL BEHAVIOR OF COCOA DISPERSIONS WITH COCOA BUTTER REPLACERS

The steady shear viscosity and yield stress of cocoa powder dispersed in three cocoa butter replacers (CBRs) are measured over a wide range of powder concentration and temperature. The flow activation energies of the three CBRs are nearly the same, and close to that of cocoa butter. Values of intrinsic viscosity of cocoa powder dispersed in corn oil and Socolate 36–38 are in the range of 4.0–5.0, (similar to that in cocoa butter), suggesting that these two CBRs are good cocoa replacers. A lower value of intrinsic viscosity is found for the powder dispersed in Super YZ-2. Viscosity measurements indicate that all three CBR dispersions exhibit Newtonian behavior at low volume fraction, but non-Newtonian shear thinning characteristics when the volume fraction φ > 0.3 at 60C. The non-Newtonian behavior can be described by the Casson model when φ exceeds a critical value, φ mo , the maximum packing fraction at zero shear. The yield stress can be related to the powder volume fraction using a four-parameter equation originally proposed by Zhou et al. (1995).     

IMPLEMENTATION of an AUTOMATED REAL-TIME STATISTICAL PROCESS CONTROLLER

Through a simple application, this research demonstrates the potential and procedure of applying computer vision and control techniques in developing automated real-time statistical process controllers (SPC). A computer vision system was developed to sample and measure quality variables (area, length, and width) of an extruded food product. Shewhart control charts were used to monitor the state of statistical control. Corrective actions were determined by using a PI control algorithm to minimize the product size variation caused by material inconsistency in moisture content. the system was implemented and tested. Considerable improvement was achieved in product size uniformity.     

FLOW MODELING OF A POWER-LAW FLUID IN A FULLY-WIPED,CO-ROTATING TWIN-SCREW EXTRUDER1

The two-dimensional flow theory of a power law fluid in a fully-wiped co-rotating twin-screw extruder was investigated under steady-state, isothermal conditions. The important distinction between this approach and previously published theories (Denson and Hwang 1980; Booy 1980; Wang and White 1989; Lai-Fook et al. 1989, 1991) is that actual boundary conditions were used instead of boundary conditions based on the parallel plate model developed for single screw extruders. The generalized screw curves constructed for both double-lead and single-lead screw elements were similar in shape to those published for single screw extruders with rectangular channels. Noticeable increases in the closed discharge pressure and the open discharge flow rate were observed, which are the result of the screw geometry. Experimental results with corn meal were in agreement with theoretical predictions for single-lead screw elements. Theoretical predictions for double-lead screw elements using the new solution also showed reasonable agreement with experimental data from published literature after the incorporation of the intermeshing effect.     

基于Docker容器的快速开发网页服务器

C/S模式是早期的开发网页服务器架构,它使用复杂、成本高并且缺少通用性.B/S模式通过将系统功能集中到服务器中弥补了使用复杂成本高的缺点,但是没有对用户端的环境和数据传输率进行深入测试和研究,使得过多的外部用户访问网页,给服务器带来压力.针对传统C/S模式和B/S模式的局限性,引入Docker容器化开发思路,分别融合N...     

Identification of Geosmin as the Major Muddy Off-flavor of Louisiana Brackish Water Clam (Rangia cuneata)

The major compound responsible for the objectionable muddy or musty/earthy off-flavor in Louisiana brackish water clams (Rangia cuneata)was positively identified as geosmin (trans-1,10-dimethyl-trans-g-de-calol), based on gas chromatographic retention times, electron ionization mass spectra, and odor characteristics. Confirmation was based on analysis of authentic geosmin under experimental conditions comparable to those of the clam samples.     

Breaking Stress and Syneresis of Rennin Curds from Reconstituted Skim Milk Frozen Concentrate

Skim milk was concentrated to 17–18% solid non-fat (SNF) by reverse osmosis and then stored at ?20 ± 2°C. Samples were thawed, reconstituted, and manufactured into rennin curds. Breaking stress and syneresis of curds increased with calcium or magnesium, and decreased as pH values increased. Breaking stress and syneresis of curds prepared from skim milk reconstituted from a frozen concentrate (SMRFC) were lower than of curds from raw or heated skim milk. The formation of curds results from a three-dimensional network of protein chain and clusters, and the addition of calcium chloride resulted in partial disintegration of the micelle, producing larger particles. Curds from raw milk showed more protein aggregatiom curds from SMRFC, and also had a more open matrix.     

Gel Point of Whey and Egg Proteins Using Dynamic Rheological Data

The gel point temperatures of coagulation type proteins and gelation type proteins were determined by extrapolating the rapidly rising phase of the storage modulus G’back to the temperature axis. The gelation onset. temperatures of the concentration-independent proteins oval-bumin, ovotransferrin, and BSA were 81°C, 62°C, and 75°, respectively, Gelation of whey protein isolate and egg white gels, both concentration-dependent, was presumably due to disulfide bonds formed by the interactions of the concentration-independent proteins: α-lac-talbumin and β-lactoglobulin, and ovalbumin and ovotransferrin, respectively. Moreover, the incipient gel temperature of whey proteins decreased when the concentration of whey proteins increased.     

网球视频中球员的侦测与追踪

针对现有的球员侦测与追踪方法中颜色信息的提取容易受到目标与噪声之间的色差及光照变化的干扰,从而影响侦测准确度的问题,提出了一种球员侦测与追踪的新方法.首先运用较为可靠的边缘信息侦测网球球场的场线,重建场地信息.其次运用重建场地信息设计过滤器,过滤球场噪声; 运用场线信息,定义上下半场球员侦测的范围与两种不同尺寸的搜寻视窗.然后通过提取图像边缘密度信息,在搜寻窗内利用模板匹配方法估测球员位置.最后利用3种场地类型对本文方法进行了验证,结果表明本方法的平均正确率(92.3%)高于文献[3]的方法(91.12%),且比文献[3]更具有普适性.     

石材裂纹扩展分形特性

 利用楔形劈裂试验系统观测石材裂纹起裂与扩展，利用应变片系统量测出试件在不同加载速率下裂纹尖端附近裂纹扩展速度的分布及其分形特性。所得结果如下：在考虑不同加载速率下，得到在静态或准静态加载条件下试体的断裂韧性基本上变化不大；但加载速率愈快，裂纹扩展实测平均速度愈高。考虑分形特性，在相同加载速率条件下，所得分形维数越大，则分形裂纹速度也越大，这与理论推导是相符的；分形维数与相关参数(断裂韧性、加载速率)的关系，在静态或准静态加载下近似为一个常数关系。     

APPLICATION OF THE TAGUCHI METHOD TO OPTIMIZE MONASCUS SPP. CULTURE

The Taguchi method was applied to determine optimum conditions for submerged culture of Monascus spp. fermentation to produce a high yield of monacolin K (also known as lovastain, mevinolin or mevacor). The control factors included carbon, nitrogen, oil, and salt sources and pH values. In the growth phase the optimum culture conditions are 1% whole wheat flour, l% peptone, 0.01% olive oil and 0.01% potassium phosphate and a pH of 5.0 (P < 0.05). In the metabolic phase the optimal culture conditions are 1% whole wheat flour, 1% peptone, 0.01% soybean oil, 0.01% potassium phosphate and a pH of 3.0 (P < 0.001). Using optimal culture conditions in the growth and metabolic phases, the yield of monacolin K in the fermentation process was 151.06 ppm.