Kinetische Feuchteverformungsmessungen an chemisch modifiziertem Holz

A special apparatus which permits continuous, three-dimensional measurements was constructed for the measurement of the kinetic swelling and shrinkage of chemically modified wood. The construction, function and use of this apparatus is the subject of the first report. The apparatus is designed for test pieces with side lengths from 2 mm to 60 mm. The climatic conditions under which the experiments are conducted can be regulated and controlled very accurately. The testing facilities were designed in a way permitting continuous measurements along the complete sorption isotherm from drying to storage in water. Inductive displacement transducers were installed for displacement measurements. The maximum sensitivity for the swelling and shrinkage measurements is 2·10^?4 cm/mV. The range of linearity is guaranteed within ±0.8 cm. The average accuracy of measurement is ±2.3%. The measurement technique is considered and discussed.     

Fibre Motion on the Slide Wall in Rotor Spinning

By using principles, established earlier, for particle motion in rotor spinning, it is possible to develop a mathematical model to describe the movement of actual fibres on the slide wall of the rotor. Three stages — attachment, sliding and collection — may be identified. By analysing the forces under which the fibre microcomponents move at each stage, it can be shown that their motion, like that of particles, occurs by centrifugal action in the direction of the internal generatrix of the rotor-cone, from its smaller to its larger diameter, to the collecting groove. Further details of the mechanism by which fibres move are also presented.     

Kontinuierliche Mengen- und Dichtemessung von Stärkesuspensionen

Continuous Volume and Density Measurement of Starch Suspensions. This contribution deals with continuous volume and density measurements of starch suspensions. After a foreword as introduction and presentation of the problem range the inductive volume, radiometric density and gravimetric density measurements are discussed in three different chapters. In each of these chapters first the principal of the measuring system as well as the construction and operation of the measurement unit tested are described. A detailed report on the performance of the tests finally is followed by the discussion of the results which can be summarized as follows: Apart from restrictions and difficulties demonstrated in detail no apparatus trouble did occur. Refered to the obtained test data all measurement units are to be evaluated as absolutely suitable for continuous volume and density measurements as absolute measurements. With regard to the inductive volume measurements the sediments amounted on the average less than 1,0% thus remaining within the measuring tolerance of ±1,25% as indicated by the manufacturing company. Also the radiometric density measurements on the average resulted in maximum divergences of only ±0,10% with the radiometric density measurement unit I and of likewise only ±0,15% with the radiometric density measurement unit II, thus again remaining within the measuring tolerance of ±1,0% of the measuring result as given by the two manufacturers. The observed divergences of the gravimetric density measurements as result of sediments in the measuring section stayed after one-week test period within the error limit of ±1,0% as limited by the manufacturing company. The determined measuring accuracy, therefore also was fully sufficient provided that the measuring divice was carefully rinsed once a week.     

Memory effects on adsorption tubes for mercury vapor measurement in ambient air: elucidation, quantification, and strategies for mitigation of analytical bias

The short- and long-term memory effects associated with measurements of mercury vapor in air using gold-coated silica adsorption tubes have been described. Data are presented to quantify these effects and to determine their dependence on certain relevant measurement parameters, such as number of heating cycles used for each analysis, age of adsorption tube, mass of mercury on adsorption tube, and the length of time between analyses. The results suggest that the long-term memory effect is due to absorption of mercury within the bulk gold in the adsorption tube, which may only be fully liberated by allowing enough time for this mercury to diffuse to the gold surface. The implications of these effects for air quality networks making these measurements routinely has been discussed, and recommendations have been made to ensure any measurement bias is minimized.     

Estimation of concentrations in ternary solutions

A simple method to predict the concentrations of homogeneous ternary mixtures by measuring two of their physical properties is presented. The method, which may be constructed by using a suitable graphical tool or software, can be used in chemical analysis of ternary aqueous solutions, for example. In order to validate the suggested method, four application examples are presented for different solution systems using available literature data of different physical properties. The method, which is found to be precise, may reduce the need for analytical measurements by replacing them with graphical methods.     

2015国际纺机展:纺纱工程的革新

在意大利举办的2015国际纺织机械展(ITMA)上,纺织机械制造商们展示了机器及最新研发,由此可以得出纺织工程最新的发展趋势。迫于中国纺机制造业的竞争威胁,ITMA 2007展出了一些功能缩减的较低价的机器。但ITMA 2011则展出了多种具有革命性改进的机型,如苏拉欧瑞康(Saurer Oerlikon)公司开发的Autocoro 8转杯纺纱机,其每个纺纱锭位完全自动化,并运用了磁力轴承转子;立达(Rieter)公司的喷气纺纱机J 10及迈耶西(MayerCie)公司的全新纺纱-编织一体机理念。ITMA 2015则展有许多虽小但高效的革命性创新,可显著降低客户的生产要素成本。     

Non-invasive assessment of stratum corneum structure and function

Methods for the study of the stratum corneum in situ are described and their application to clinical problems and cosmetic science are discussed. In vivo measurements of the thickness of skin and the components of skin can be made using high frequency pulsed ultrasound. Improved resolution of the device should allow measurement of epidermal thickness, and even that of the stratum corneum, which may vary with hydration. The protective ability of the stratum corneum can be estimated in a number of ways, the most familiar technique being transepidermal water loss measurements. Mechanical properties of the stratum corneum have been widely investigated in vivo by numerous researchers. A recent technique devised by us to deform the stratum corneum using an extendable metal frame has been used on patients with ichthyotic disorders. The deformation or compliance of the skin surface has been measured using profilometric methods, and compared to normal individuals. The results appear to be in agreement with the loss of flexural ability experienced by ichthyotic patients. Other mechanical methods more usually involve the measurement of the forces generated by skin while undergoing extension. Three techniques are described which have been used to investigate hydrational change with emollient application. Finally, the phenomenon of desquamation is discussed and methods presented for its evaluation. Passive collection of corneocytes using chambers is useful for estimation of the rates of desquamation, but are laborious and inconvenient. Forced desquamation using the desquamator enables rapid controlled harvesting of corneocytes. In addition to this, the dansyl chloride fluorescence technique has been adopted for estimation of stratum corneum kinetics using visual comparison and fluorimetric techniques. These techniques require further refinement and validation, but the tests available now are nonetheless important in understanding the biology and pharmacology of the stratum corneum.     

基于人体的女装原型板的短寸式制板方法

随着经济的发展,人们对服装的审美要求越来越高,服装结构也因此变得越来越重要。对服装结构的深入研究使研究者更加深刻地认识到,研究服装结构的造型变化最终要回归到研究人体本身的结构变化中。在测量获得女性身体部位较多数据的基础上,通过短寸式作图法得到了针对个体的箱型原型。这是对短寸式作图法的一种实践验证,是获得适合更多个体原型的数据基础。这种根据人体体型变化特点的制板原理,以及在制板的过程中选用的一些新的人体测量部位,对研究服装结构设计以及服装与人体的关系,具有一定的启发作用。     

56—THE CONTACTLESS MEASUREMENT OF YARN SPEED WITH A LASER–DOPPLER VELOCITY METER

A laser–Doppler velocity-meter system can be used for contactless measurement of the velocity of any optically accessible object scattering light. A relatively simple set-up appears to be suitable for yarn-speed measurements. This system may be useful if contact methods are not possible or if contact methods influence the measurement, e.g., in measurements on yarns directly behind the spinneret, on hot plates and draw pins, and at very high speeds. The accuracy of the measurements depends on several circumstances, such as the optical properties of the yarn, the thickness of the yarn, and the measuring distance. In most cases, an accuracy of about ±2% is attainable. With the system described in this paper, yarn speeds of up to 3000 m/min have been measured with the accuracy mentioned above; the measurement of higher yarn speeds is possible.     

基于四圆X射线衍射仪的纤维衍射图样测量

为克服四圆X射线衍射仪只能应用于晶体颗粒的局限性,设计出了新的样品夹持器和实验测量方法。测量参数和参照系的合理设置有利于得到纤维状样品较清晰的衍射图样,而去除因空气产生的X射线衍射密度则可以大大提高测量结果的准确性。最后,一个针对PHB纤维的测量实例证明了该方法的可行性。     

THE DETERMINATION OF BEER COLOUR—COLLABORATIVE TRIAL

The data and analyses on which the Institute of Brewing based its decision to modify its method for the determination of beer colour are presented. Spectrophotometric measurements at 430 nm are shown to be more precise than measurements made at 530 nm or by using comparators. The Institute of Brewing Analysis Committee recommends that measurement at 430 nm is adopted. Equations relating precision to beer colour determinations at 430 nm are advanced.     

转杯纺纱机生产竹节纱的原理分析

在转杯纺纱机纺杯上加装阻尼块可以生产短竹节纱，改变喂棉速度和引纱速度可以纺制长竹节纱。介绍了利用可编程序控制器和变频器对BD200RCE型、BD200SN型转杯纺纱机进行传动改造生产长竹节纱的方法；分析了高速喂棉时间、正常速度喂棉时间、变速倍数、纺杯直径及机械惯性对转杯纺竹节纱规格的影响；介绍了选定转杯纺竹节纱捻系数应考虑的因素及开发生产的转杯纺竹节纱产品。     

33—FACTORIAL STUDIES IN ROTOR-SPINNING PART I: COTTON YARNS

An investigation is described in which the effects of several factors, such as rotor diameter and rotor speed, twist multiplier and yarn twist, and type of draw-off nozzle, were studied in factorial experiments in which measurements were made of the main yarn parameters, such as tenacity, elongation at break, and regularity, and of the trash accumulated in the rotor. The experiments were made for cotton on two types of machine. Süssen and SKF.

For twist values remote from the optimum twist, the linear and quadratic components of the twist multiplier affect the yarn tenacity, and its linear component affects the elongation at break; but, for values close to the optimum twist, the only significant effect is the linear influence on elongation at break. Yarn irregularity is significantly affected only by the twist multiplier. The rotor speed affects the tenacity, elongation at break, and yarn irregularity in a linear manner, but the rotor diameter affects these parameters both linearly and quadratically. The type of draw-off nozzle has only a slight effect on tenacity, whereas trash accumulation in the rotor is influenced by the linear components of both the twist and the rotor diameter.

Some significant interactions were detected, which principally affect elongation at break generally, and trash accumulation in the rotor and tenacity when one of the interacting factors is the type of draw-off nozzle. The two machine types produced concurrent results.     

薄膜蒸发器转子模态分析及系统稳态不平衡响应研究

应用ANSYS Workbench对薄膜蒸发器转子进行模态分析,求得转子结构的模态参数,对转子某些位置上的不平衡量进行不平衡响应分析.结果表明:转子结构安全,不会发生共振,且工作转速还有很大的上升空间;固有频率与偏心载荷及偏心质量大小和位置无关;中间位置刮板装置上的偏心质量引起的振幅最大,应严格控制中间刮板装置的不平衡量.     

Delayed light emission as a means of quality evaluation of fruits and vegetables

DLE is probably produced by all fruits, vegetables, and plant materials undergoing photosynthesis. However, the intensity and duration of the emitted light vary widely depending upon many factors. Because of the strong dependence of DLE on the chlorophyll content, variation in the DLE can be expected among different varieties of the same product. Therefore, quality evaluation based on DLE measurements require careful selection of measuring criteria such as duration and intensity of illumination, dark period, and temperature. It is necessary to obtain precise values of DLE for a particular product under a set condition; and the measurement conditions should be carefully validated to establish a standard measuring criteria. In general, the quality evaluation of fruits and vegetables is based on three major aspects: maturity and/or ripeness evaluation, composition analysis, and internal and external defect detection. DLE measurements so far have focused mainly on maturity evaluation because of the definite relationship between the emitted light and chlorophyll concentration, which changes with maturity. It should be noted that chlorophyll alone is not sufficient; it is the complex of in situ chlorophyll and related compounds in plant materials that jointly contribute to the DLE. Composition of fruits such as sugar content has been related to DLE. Recently, DLE measurements have been applied to detect certain physiological stress responses and defects such as chilling injuries. However, these areas of research have not yet been fully explored. Further investigation relating to compositional quality and internal and external defects of fruits and vegetables with DLE measurement may offer solutions to certain complex quality evaluation problems. The duration of DLE after excitation involves a matter of at least several seconds. From a mechanical standpoint, this extended period of light emission offers a convenient time in which to separate excitation and measurement. However, the exponential decay necessitates very precise control of time between illumination and measurement. The broad activation spectrum permits wide choice and simple design of excitation sources. However, size, shape, and varietal variations of plant materials make uniform DLE measurements difficult. It is suggested that DLE measuring instruments be designed to make several measurements over the entire surface of the specimen. An average of such measurements would reduce the effect of surface nature and shape of the product. Reporting the DLE intensity per unit surface area of the product will eliminate the dependence of area of excitation on DLE.(ABSTRACT TRUNCATED AT 400 WORDS)     

Estimation of microbial growth using population measurements subject to a detection limit

In this paper we develop a maximum likelihood estimation procedure for determining the mean and variance in microbial population size from microbial population measurements subject to a detection limit. Existing estimation methods generally set non-detectable measurements equal to the detection limit and are highly biased. Because changes in the mean and variance in the microbial population size are typical in industrial processes we also outline statistical tests for detecting such changes when measurements are subject to a detection limit, which is critical for process control. In an industrial process there may also potentially be variability in the microbial growth rate due to variation in the microbial strain, environment, and food characteristics. Accordingly, we also present a maximum likelihood procedure for estimating microbial growth model parameters and their variance components from microbial population measurements subject to a detection limit. Such information can be used to generate the mean and variance through time of the microbial population size, which is vital for the application of predictive microbiological models to risk assessment and food product shelf-life estimation.     

BT902型与BT903型转杯纺纱机的性能及使用

通过分析目前各挡次转杯纺纱机的性能特点，组合公司压锭改造后剩余前纺设备的生产能力，选择了BT902型及带有半自动接头装置的BT903型转杯纺纱机组成中档中速型转杯纺生产线，生产中高档产品。介绍了BT902型、BT903型转杯纺纱机的性能特点，BT903型转杯纺纱机纺制捻针织纱的生产情况以及BT902型转杯纺纱机与BD200SN型转杯纺纱机的成纱质量对比情况。指出了设备运转中存在的问题及采取的措施，设备维修与保养中应重点注意的问题。     

7—SOME EFFECTS OF HUMIDITY IN OPEN-END SPINNING PART III: TEMPERATURE AND RELATIVE HUMIDITY INSIDE THE ROTOR

The importance of the air conditions inside rotor-spinning equipment is discussed. A special hygrometer, which was designed and made to measure the temperature and relative humidity of the air inside the rotor, is described. In starting from rest, the temperature inside the rotor was found to increase for a time and then reach an equilibrium condition that depended on the rotor speed, whereas the relative humidity of the air inside the rotor decreased for a time and then reached a steady value, which also depended on the rotor speed. The equilibrium conditions varied according to the type of fibre processed. As rotor speeds are increased, this may become a very important problem.     

高浓碎浆机螺旋转子的有限元分析

螺旋转子是高浓碎浆机的关键部件。本文介绍了应用Pro/E软件进行螺旋转子的三维建模和有限元分析。重点是通过有限元分析直观地表示出转子运动过程中的应力和应变,同时通过结构分析对转子结构进行优化设计。     

PSYCHOLOGICAL CORRELATES OF SUGAR CONSUMPTION1

This paper reviews some of the research on the sweet taste which has been published during the past several decades. It stresses the division of our understanding of sweetness into three sections: quality (type of taste, and the role of sweetness), measurement of sweetness intensity or strength of the perception and the correlation with physical measurements, and finally the hedonics of sweetness which represents the affective portion. Data is presented from a real-world study on the sweetness and liking of a beverage which illustrates that although children and adults may perceive the sensory characteristics of sweetness in similar manners, nonetheless their hedonic reactions are quite different to the same sweetened beverage.