Model identification of the bundle thickness dynamics in drum friction spinning

The dynamics of the friction yarn formation process is described in terms of the dynamic behavior of the process state variables. Production efficiency and product quality of friction spinning are influenced by these process state variables. This study was performed with the intention of setting up a dynamic model based on mass balance in order to delineate the dynamic behavior of the cross-sectional area of the in-process bundle on the friction drum surface and to attain the distribution profiles of the cross-sectional area in transient state and in steady state as well. Then, simulation results were compared with those of the experiment, while the input variation was used as a test signal. Theoretical model shows that the bundle thickness on the friction drum has the dynamic characteristics of an integrating system with interval due to the finite length of the input fleece zone, and is in good correspondence with the results of the experiment. A periodic change in the fleece feeding rate led to the fact that there was a specific range of the fluctuation wavelength in the fleece feeding rate, whereas a change in the in-process bundle thickness completely disappeared or became locally maximized in certain wavelength areas. This could lead to a magnification or inaction of the perturbations with the corresponding wavelength in the bundle thickness; a bundle thickness irregularity. Experiments also identified that the theoretical model accurately described the fiber accumulation dynamics in a friction spinning process.     

多喷枪协同式喷涂五轴混联机器人设计

针对大型扁平型立方体工件的喷涂工艺特点,将并联机构应用于喷涂工艺,设计了一种控制解耦性很好的五轴混联喷涂机器人,阐述了这种喷涂机器人的机构设计、工作原理、运动学分析、驱动方式、控制系统硬件组成及其控制方式。该机器人具有结构紧凑、喷涂效率高、涂层厚度均匀和操作简便等特点,具有较好的应用前景。     

Optimization of Enzymatic Treatments for Deskinning of Catfish Nuggets

One collagenase (CLS1^®) and two proteases (Proleather FG-F^® and Protease N^®) were used to deskin the peritoneal membrane of catfish nuggets. The factors were used in a full factorial experiment design: enzyme solution concentration (0.2, 0.3, and 0.4% by weight), temperature of enzyme solution (30, 37, and 44°C), and immersion time (10, 15, and 20 min). Contour plots showed that the enzyme Proleather FG-F^® maximized whiteness of catfish nuggets at 40–44°C for 15–19 min. Treatment of the enzyme Proleather FG-F^® at 0.2% for 15 min had the highest yield (103.4%) at 44°C. Enzymatic skinning has potential in removing the peritoneal membrane from catfish nuggets, improving color (whiteness), and yield.     

Study of Photo and Thermoluminescence Properties to Identify Irradiated Dried-Fishery Products

ABSTRACT

Radiation-specific luminescence properties in irradiated dried-fishery products (pollack, little pollack, clams, and shrimp) were investigated at different dose levels (0–10 kGy). Photostimulated luminescence (PSL) analysis of whole samples was effective for dried clams and shrimp, while low PSL sensitivity was observed in dried pollack and little pollack. Thermoluminescence (TL) analysis was conducted after isolation of silicate minerals, in which the two methods of mineral isolation—density separation and acid hydrolysis—were compared. Irradiated samples were easily distinguishable through the strong TL glow curves, with maximum peaks in temperature range of 150–250°C. TL ratios (TL₁/TL₂) were < 0.1 for nonirradiated samples, while > 0.1 for irradiated. There was a clear effect of applied irradiation dose, with a negligible effect of the method used for mineral separation. The mineral composition showed that feldspar and quartz minerals were mainly responsible for the well-characterized luminescence behavior upon irradiation.     

Effects of Phosphate Type on the Quality of Vacuum-Tumbled Catfish Fillets

The objective of this study was to determine the effects of various agglomerated phosphate blends on the quality of vacuum-tumbled catfish fillets. Catfish fillets were tumbled with a brine solution at 15% over initial, raw weight prior to tray-packing and storage at 4°C for 10 days. Fillets were evaluated for protein exudate, tumbling yield, color, pH, cooking loss, tenderness, purge loss, and shelf life. A specific blend of agglomerated sodium phosphates (AGSP) that contains mono-, tri-, and polyphosphates had significantly less protein (p < 0.05) exudate and significantly higher pH (p < 0.05) than other treatments. All phosphate treatments significantly increased (p < 0.05) tenderness and significantly decreased (p < 0.05) purge loss, but agglomerated phosphate blends significantly decreased (p < 0.05) cooking loss and yellowness. Psychrotrophic plate counts for all phosphate treatments were similar to the control at each storage time. All phosphate treatments improved the yield and quality of catfish fillets, but the use of AGSP may optimize quality attributes.     

微小隐孢子虫重组蛋白CP21的免疫特性

采用微小隐孢子虫CP21基因的原核表达蛋白的抗血清对微小隐孢子虫感染HCT-8细胞进行了体外阻断试验,检测不同浓度抗血清对HCT-8细胞感染隐孢子虫感染率的影响.同时应用纯化的重组CP21蛋白对小鼠进行免疫,检测体液免疫水平和细胞免疫水平的变化.对免疫后的小鼠接种微小隐孢子虫,检测重组CP21蛋白对微小隐孢子虫感染的保...     

茶叶叶绿素混合液浸提法提取条件优化

本文采用混合液浸提法制得叶绿素提取液,分别从混合液配比、提取的温度、提取时间和浸提液用量等方面进行了系统试验,并从叶绿素的提取量和提取液的稳定性方面比较了混合液提取法与传统的丙酮研磨法.结果表明,混合液浸提法提取叶绿素,提取完全,提取量高于传统法;而且,混合液浸提法制得的叶绿素提取液稳定性更好.试验总结出,混合液浸提法的最佳条件是:室温下,以丙酮∶乙醇∶水=3∶6∶1的混合液30 mL,避光提取1 h.     

The state and consumer confidence in eco-labeling: organic labeling in Denmark,Sweden, The United Kingdom and The United States

Trustworthy eco-labels provide consumers with valuable information on environmentally friendly products and thus promote green consumerism. But what makes an eco-label trustworthy and what can government do to increase consumer confidence? The scant existing literature indicates that low governmental involvement increases confidence. This suggests that government should just provide the basic legal framework for eco-labeling and leave the rest to non-governmental organizations. However, the empirical underpinning of this conclusion is insufficient. This paper analyses consumer confidence in different organic food labeling regimes with varying degrees of governmental involvement. Using unique and detailed survey data from the US, United Kingdom, Denmark, and Sweden, the analysis shows that confidence is highest in countries with substantial state involvement. This suggests that governments can increase green consumerism through active and substantial involvement in eco-labeling.     

小麦新品种鄂麦27的特征特性及栽培技术

小麦(Triticum aestivum L.)鄂麦27是孝感市农业科学研究所针对湖北省农业生产中对小麦品种的需求,主要围绕改良小麦产量、面粉品质、小麦的抗逆性及熟期等性状选育而成的新品种。2010年10月由湖北省品种审定委员会审定命名。介绍了该品种的选育概况、主要特征特性和栽培技术要点,简述了该品种的推广应用前景。