Objective Measurements of the Process of Curd Formation during Rennet Treatment of Milks by the Hot Wire Method

A new thermal method for nondestructive, continuous and objective measurements of the progress of curd development was proposed to obtain much more uniform industrial cheese production. The temperature measurements of the electrically heated (direct electric current, 0.7A) platinum wire (0.1 mm^ø× 106 mm) immersed axially in the renneted whole milk (volume, 660L) adequately monitored the whole process of milk curd coagulation in the actual cheesemaking. In addition, the temperature of the hot wire referred to the initial temperature resulted in the kinematic viscosity of the coagulating milks.     

可提高安全性及乘坐舒适性并考虑到驾驶员命令值变更的速度模式实时生成法的研究

由电机驱动的电动汽车适合于速度控制,这说明通过应用速度模式可提高通常及紧急情况下的乘坐舒适性及安全性.本文提出了一种考虑到驾驶员命令值变更的SMART速度模式实时生成器(RSSPG).在加速度及加速度的时间导数约束条件下,RSSPG可实现迅速的加减速.另外,可通过调整RSSPG的参数C来对应驾驶员个人喜好的驾驶风格.使用MATLAB进行模拟的结果,证明了RSSPG的有效性.     

电动汽车稳定性控制中的车体侧偏角观测器研究

采用轮毂电机独立驱动的电动汽车可采用直接横摆力矩控制(Direct Yaw-moment Control,DYC)等稳定性控制,而车体侧偏角(简称β角)是稳定性控制中的重要参数.直接测定车体侧偏角的传感器相当昂贵,所以需要从能够容易测得的参数来进行车体侧偏角的推测.Hori研究室设计了一种用于β角推测的观测器,并充分考虑了车辆运行工况变化所引起的系统模型参数变化,进行了观测器鲁棒性设计以及轮胎侧偏刚度在线辨识,使观测器具备了足够的鲁棒性来克服大的模型误差影响,试验结果证明了该观测器的有效性.     

超临界流体技术在苎麻织物中的应用研究

对影响超临界CO2流体处理苎麻纤维的因素，如温度、压力、时间以及助溶剂进行正交试验，对处理后的苎麻纤维的含杂情况、微结构、机械物理性能和热稳定性等性质作了测试分析。结果表明，超临界CO2流体处理苎麻织物的最佳工艺条件为：工作温度120℃、压力25MPa、时间40min、助溶剂0．1％。该处理可改善苎麻纤维的性能，提高其膨胀性，有利于后续加工，并为其进一步改性打下基础。     

Relationship Between Static Electrical Conductivity and Unfrozen Water Content in Food Products

The static electrical conductivity measurements on frozen foods such as citrus juice and varieties of cheese showed that both conductivity and unfrozen water content in food products varied directly with temperature. In describing the log σ vs 1/T curve, where σ is the conductivity and T is the absolute temperature, it was found that the linear portion of the curves at low temperature was related to bound water content which was independent of temperature, whereas the non-linear portion in the temperature range between the freezing point and 10 or 35 degrees below the freezing point was related to the unfrozen free water content which was dependent on temperature.     

Effects of Freezing and Thawing Green Curds Before Processing on the Rheological Properties of Cream Cheese

The rheological and proton pulsed NMR properties of cream cheese made from the green curds frozen and thawed were measured to determine the quantitative relationship between the freezing and thawing rates of the curds and the textural changes of the cream cheese. The hardness of the cream cheese decreased significantly as the thawing rate of the curds decreased, whereas the freezing injury was the minor source of the damage on the hardness. The bound but not free water in the cheese characterized these textural changes.     

Effects of Rennet Treatment and Water Content on Thermal Conductivity of Skim Milk

Effective thermal conductivities of skim milk and skim milk curd over a moisture range of 60–95% were measured by the hot wire method. The measured thermal conductivity of skim milk decreased significantly with change in structure through rennet treatment at 30.0°C; the intrinsic thermal conductivity of solids content was determined on the basis of the series model to be 0.346 W/mK for skim milk and 0.338 W/mK for skim milk curd. The relationship between the water content and effective thermal conductivity of the specimens was described by using a single parabolic formula. The deviations of empirical values based on this formula related to the experimental ones were 0.31 ± 0.30%.     

Strength-Toughness Relations in Sintered and Isostatically Hot-Pressed ZrO2-Toughened Al2O3

The fracture toughness of fine-grained undoped ZrO₂-toughened Al₂O₃ (ZTA) was essentially unchanged by postsintering hot isostatic pressing and increased monotonically with ZrO₂ additions up to 25 wt%. The strength of ZTA with 5 to 15 wt% tetragonal ZrO₂, which depended monotonically on the amount of ZrO₂ present before hot isostatic pressing, was increased by pressing but became almost constant between 5 and 15 wt% ZrO₂ addition. The strength appeared to be controlled by pores before pressing and by surface flaws after pressing; the size of flaws after pressing increased with ZrO₂ content. The strength of ZTA containing mostly monoclinic ZrO₂ (20 to 25 wt%) remained almost constant despite the noticeable density increase upon hot isostatic pressing because the strength was controlled by preexisting microcracks whose extent did not change on postsintering pressing. These strength-toughness relations in sintered and isostatically hot-pressed ZTA are explained on the basis of R -curve behavior. The importance of the contribution of microcracks to the toughness of ZTA is emphasized.     

Unified Theory of Electromagnetic Induction and Magnetic Resonant Coupling

The difference between electromagnetic induction and magnetic resonant coupling was pointed out in the first proposal of electromagnetic resonant coupling. However, there was no clear technical comparison between the two methods. Therefore, in this study, five circuits are compared by using a phasor diagram, which is a basic and well‐known method in electric circuit theory. The transition from typical electromagnetic induction to magnetic resonant coupling is shown. The mechanism of the high efficiency and high‐power transfer across a large air gap and displacement is discussed, where the primary‐ and secondary‐side resonant frequencies are the same. From the above discussion, we conclude that when the specific conditions of electromagnetic induction are satisfied, the wireless power transfer can be categorized as electromagnetic resonant coupling. The unified theory of electromagnetic induction and magnetic resonant coupling is verified through experiment.     

采用Ni—Cr合金热喷涂延长连铸结晶器寿命

三岛光产所开发的Ni-Cr合金热喷涂结晶器,是通过对连铸结晶器表面喷涂Ni-Cr合金涂层,使其寿命达到原来镀Ni结晶器的3-6倍,本文介绍Ni-Cr合金热喷涂结晶器的特性、使用效果和使用上的注意点。