立式圆筒形钢制焊接植物油罐质量计量的研究

对立式圆筒形钢制焊接植物油罐进行体积标定和液位测定,得出罐内植物油体积;找出合理准确实用的测温方法,准确地反应罐内油品的实际平均温度,查表,由公式计算得出植物油在该温度下的密度;然后计算出立式圆筒形储罐罐内植物油准确的质量。该法对植物油的储运计量有很强的指导意义。     

FSS1500NST触力传感器标定实验研究

针对FSS1500NST触力传感器在应用中存在偏差问题,文章在自制的传感器标定实验装置上,利用压力计,采用重物施压的方式进行了传感器标定实验。获得了传感器输出电压值与负载质量的关系,并进行了线性拟合,建立了传感器输出压力的经验公式,为该传感器在气动柔性机械手中的应用奠定了基础。     

真空制盐蒸发罐液位控制

中盐镇江盐化有限公司60万t/a真空制盐装置蒸发罐液位控制方案是先测量出相关高度的物料压力值,进入到DCS控制系统中,在程序中代入相关公式,计算出液位高度.由DCS控制系统中的PID控制器对现场自动阀门进行调节,从而达到了蒸发罐液位自动控制的目的.     

双法兰差压变送器在液位测量中的应用及校验

1概述在制糖生产过程中，常常需要对某些设备（如箱、槽、罐）的液位进行测量和调节，通过对这些设备的液位测量和调节，可以正确地求得容器中贮藏物料的容量和重量；随时知道容器内液位的高低，对液位上、下限进行报警；连续地对生产过程进行监控，使液位保持在所要求的高度。目前洲是液位的方法及仪表很多，如直读法、浮力法、静压法、电容法、放射性同位素法。超声波法、微波法以及激光洁等。但是在制糖生产当中．存在着许多特殊的液体介质，这些液体具有腐蚀性或含有结晶颗粒，粘度大，易凝固等。为了解决导压管线被腐蚀或被堵塞的问题…     

中子多重性探测器搭建及参数标定

该文介绍了自主设计的中子多重性探测器构成模块和搭建方法,以及相应的参数标定算法。在参数标定过程中,首先使用Am-Li中子源的相关计数率与本底计算率差值趋零化方法,提出了预延迟的标定公式;在均方差最小化基础上建立了三均分算法,进行了中子多重性死时间系数的拟合标定。根据6组252 Cf中子源获取的9个标定参数,利用中子多重性探测器对2个钚金属样品进行了测试,测试结果验证了探测器搭建方法的合理性及参数标定算法的正确性。     

毛织物的缩率及其估算公式

毛织物的结率是毛织物设计中最重要,也是变化最多的工艺参数之一。由于从原料到纺纱、织造及至染整,各工序变化频繁,影响很大,所以不易掌握。除此之外,由于各人的设计方法不同,也会带来某些差别,甚至其风格大相径庭。然而,从设计角度看,组织乃是重要的先决条件。组织不同,对织物的缩率(主要是幅缩)影响尤大。 因此,如能用某些简单可行的经验公式来对织物缩率进行估算,那将是有一定参考意义的。对于棉织物,国内外均有一些经验公式。这些公式有些较正确可行,但大多数繁复异常,且不够正确。 要制定毛织物缩率的估算公式,首先必须弄清影响毛织物…     

红外水分仪的标定

分析了在线红外水分仪和实验室红外水分仪在标定取样过程中可能存在的影响水分仪精度的问题 ,介绍了在线红外水分仪和实验室红外水分仪的标定方法及公式 ,并提出了标定和使用时的注意事项。     

近红外旋光测定法的新法定公式

NIR旋光测定法在制糖业变得越来越重要,由于对环境和健康话题愈来愈担忧,使得该法可理想地避免在澄清样品时使用碱性醋酸铅。直到1998年ICUMSA才建议用早已建立的Buruagel公式去标定NIR旋光测定仪,尽管这些仪器仅仅是根据在可见波长下测定的。在PTB、不伦瑞克的糖业研究所和SCh。idt＋Haensch的合作下,评价了为该旋光仪标定的新公式,该公式已于1998年在柏林召开的ICUMSA会议上被正式采用。评价的主要结果是用旧公式标定旋光仪的数值太低,低0．06Wi,同时,温度较正没有显著变化。该旋光仪作为糖分析替代方法的主要优点之一…     

吹气式液位测量法

1.安装困难。近几年来,随着造纸自动化的不断发展,需要对生产过程的某些容器液位进行检测。若象上述安装方法,必须等容器空时方可安装。这对制浆造纸生产过程中的某些容器例如贮浆池,难以有这样的机会。另外,对于某些特殊容器,例如测量网前箱液位及工厂自备大水池等等,将很难安装变送器。 2.取样管道易堵。因为贮浆池底部浆浓度较大,且流动少,易使取样管路堵塞,造成仪表测量不准。冲刷取样管路也必须等池空时方可冲刷。 3.校表困难。大多数检测仪表运行半年左右需校验一次。上述安装方法,校验变送器时,需将变送器从取样管路上卸下来,因此给校表带来不便。 4.仪表易损坏,有些设备自身震动幅度较大,超过了仪表本身所允许的震动幅度即0.05mm,因此对差压变送器的破坏性很大。 根据上述存在的这些问题,我们设计了一种新颖、独特,对测量开口容器液位几乎都适用的测量方法即吹气式液位测量方法。其     

计算机技术基础讲座(连载十五) 第七讲 Excel 2003

(接上期)4)输入公式Excel的一个主要功能是进行数值的计算和统计,而计算数值通常使用两种方法:公式计算和函数计算。"公式"是在单元格中执行某些计算的方程式。①公式组成Excel中的公式必须以英文等号"="开始,后面是参与运算的操作数和运算符。     

Irritancy ranking of 31 cleansers in the Indian market in a 24-h patch test

Cleansing trends promise freshness, sensory and health benefits but may also be accompanied by an increase in soap-induced skin irritation. The aim of this study was to evaluate the irritant effect of 31 cleansers (28 bar soaps and 3 liquid cleansers) available in the Indian market. Eight percent w/v solutions of the soaps/cleansers were made and 30 microL of each of the solutions were applied to Finn chambers and occluded for 24 h along with distilled water (negative control) and 20% sodium dodecyl sulphate (SDS) as positive control. The sites were graded for erythema and scaling 30 min after removing the patches. The pH of each of the soap solutions was determined. Mean with SD and ANOVA (F-value) was computed separately for each soap/cleanser with respect to the two parameters, erythema and scaling. The total of the means for both the parameters, erythema and scaling was also computed. The cleansers were listed based on this total from the least irritant to the most irritant. The differences between soaps (F-value) was significant for erythema and scaling [erythema = 4.106 (P = 0.000); scaling = 6.006 (P = 0.000)]. Cetaphil cleansing lotion had the lowest erythema score of 0.25. Lowest scaling score of zero was recorded for Cetaphil cleansing lotion and Elovera moisturizing body wash. Aquasoft and Lifebuoy soaps had the highest erythema score of 2.13. Acnex had the highest scaling score of 1.75; Aquasoft, Hamam scrub bath soap and Naturepower sandal soaps were the next with a scaling score of 1.63. Cetaphil cleansing lotion, Aquaderm liquid soap, Dove bar soap and Elovera moisturizing body wash proved to be the least irritant cleansers with a total score of less than 1. The four most irritant soaps/cleansers had an average score of 3.65. The irritant potential of the majority of the cleansers fell between these extremes. The pH of all the soap/cleanser solutions was neutral to alkaline (pH 7-9) except that of Dove bar, Cetaphil cleansing lotion, Aquaderm liquid soap and Elovera moisturizing body wash which tested acidic (pH 5-6). The pH of the positive control--20% SDS, was acidic (pH 6). The difference in the irritancy potential between soaps/cleansers as determined by the 24-h patch test was significant. There were individual variations in the irritant potential of the soaps/cleansers in the volunteers, thus when the patient queries on what soap to use, it may be advisable to test each patient separately and educate him/her regarding the soaps/cleansers less likely to cause irritation. The limitations of the study was that it was single blind and non-randomized as all the 14 soap solutions were applied on 15 volunteers in the first panel and subsequently all the 17 soap solutions were applied on eight volunteers in the second panel. However, we could compare the irritant potential of 31 cleansers. The results of 24-h patch testing of 31 soaps/cleansers in the Indian market in two panels of 14 and 17 soaps/cleansers on 15 and eight volunteers, respectively, are presented.     

共混对淀粉玻璃化转变特性的影响

采用DSC曲线分析法对各种添加刑与淀粉的相容性进行了判断，首次给出了这些添加剂与淀粉的相客性结果。对黄原肢与淀粉的共混体系的玻璃化转变行为进行了实验研究，根据高分子聚合物的共混模型对糯米淀粉与黄原胶共混物的玻璃化转变实验数据进行了拟合，得到适用于此体系的经验关联式，并应用玉米等其他淀粉与黄原胶共混后的实验数据进行验证，表明该关联式可用于定量预计淀粉与黄原肢共混后的玻璃化温度。     

降膜式蒸发器的分程及其注意事项

降膜式蒸发器的特点是料液在蒸发器中受热的时间较短,减少受热时间无疑可以最大限度保持料液中有益元素不被破坏,从而保证产品的品质。分程是因为降膜管的周边润湿量不足,为防止结垢结焦加速或干壁现象产生,采取分程的方法进料以加大降膜管的周边润湿量。仅以YNNM03-3800型三效降膜式蒸发器在椰奶生产中的应用为例进行阐述。     

Quantitative event-specific multiplex PCR detection of Roundup Ready soya using LabChip technology

EU legislation demands the use of efficient methods for the detection of genetically modified ingredients in the labelling of foodstuffs. These strict performance characteristics are most readily met with the use of "real-time" polymerase chain reaction (PCR) technologies and their associated platforms. However, the costs of the associated equipment may be beyond the scope of some molecular laboratories. This report presents a scaling technique for the determination of genetically modified content using multiplex PCR and quantitative analysis from data obtained using LabChip technology. The scaling technique is a sensitive, accurate and precise quantitative method, and is less time-consuming and uses fewer reagents than similar techniques utilising LabChip technology, as well as giving comparable results to a real-time PCR technique. This scaling technique therefore represents an alternative for genetic modification detection and quantification to that of real time PCR, with associated cost saving implications.     

珠宝体验营销

从体验营销的角度,通过分析某些著名珠宝企业建立品牌形象的案例,阐述了珠宝体验营销的特点和原则,进一步说明了体验营销在建立珠宝企业形象中的重要作用.     

Image analysis of skin scaling using D-Squame samplers: comparison with clinical scoring and use for assessing moisturizer efficacy

The severity of scaling disorders can be evaluated objectively using the D-Squame technique coupled with image analysis. The parameters of scaling derived using this approach need to be clinically relevant and should have greater discrimination than visual grading. Improvements to an existing method that fulfil these requirements are presented. Three scaling parameters were calculated using image analysis of digitized video-captured images of obliquely lit D-Squame samples. These parameters were compared to clinical scores of scaling made by five observers from photographs of the same areas sampled with D-Squame. In addition, two clinical studies were carried out to assess moisturizer effects on different degrees of xerosis, and to compare two different moisturizer preparations. The three scaling parameters gave correlation coefficients, r, between 0.6 and 0.75 when compared with global clinical scores of scaling. Significant reductions in all parameters were observed with 2 weeks of moisturizer use on lower leg skin with marked xerosis compared to an untreated control. The same moisturizer had a similar effect on milder xerosis of the forearm, and showed a greater decrease than a moisturizer with lower glycerol content. Increases in skin hydration, as measured with a corneometer, were also seen in both clinical studies, and corresponded well with D-Squame results. Differences in the degrees of scaling between these two anatomical sites were also detected with this technique. In a previous publication, the same technique was shown to be repeatable and reproducible; in the current article its correlation with clinical observations of scaling or flaking skin has been demonstrated.     

Flavor Components and Factors Associated with the Development of Off-Flavors in Cooked Turkey Rolls

The influence of storage and roll position on the development of warmed-over flavors in cooked turkey rolls was investigated. Following cooking the rolls were refrigerated for 0, 2 and 4 days and analyzed by headspace gas chromatography/mass spectrometry, TBA numbers, flavor profile analysis, and sensory category scaling. TBA numbers increased significantly by 52 and 165% after 4 days in the interior and exterior portions of the rolls, respectively, and were correlated with flavor deteriorations. Thirty-two compounds were identified, 30 of which are potential products of fatty acid autoxidation. In general, their concentrations were influenced by storage and roll position and correlated to TBA numbers and off-odor and flavor notes.     

Estimation of the free volume of starch–water barriers

The permeation of volatiles through amorphous barrier materials is affected by their size and geometry as well as by their physical–chemical affinity for the barrier. The gas barrier property of an amorphous polymer is generally a function of density, cohesive energy density and stiffness as well as of the free volume available for the diffusion of volatiles in the microstructure of polymers. The barrier property of amorphous starch is investigated by measuring the density and the cohesive energy density as a function of water contents in an extended temperature range in which the material is either a brittle to rubbery solid or a viscoelastic liquid melt. Free volumes available for the diffusion of volatiles in starch barriers are deduced numerically from a mean field equation of state providing molecular scaling parameters for starch–water mixtures from a least squares fit of experimental data. The consistency of the mean field scaling parameters is reflected in their ability to predict accurate surface tension for these systems. The adsorption of small amounts of water is found to increase the density and to reduce the free volume of starch glasses by a phenomenon called antiplasticization as it results in an increase of Young's moduli of materials whereas the opposite is true for plasticization. At higher moisture contents, an overwhelming plasticization leads to a weakening of gas barrier properties as the free volume of starch is increased during swelling by water.     

Invisible criteria in a portfolio-based assessment of prior learning: a cat and mouse chase

Institutions of higher education in South Africa have been encouraged to find ways of recognising the informal learning of historically disadvantaged adult learners. In order to facilitate the process of recognition of prior learning (RPL), portfolio-based experiential learning courses are advocated. These courses are expected to give RPL candidates an opportunity to revisit what they know and articulate it into academic modes of knowing. The article critically evaluates the capacity of the assessment processes involved in such courses to transmit clear sets of criteria for what an RPL candidate is required to demonstrate. The article draws on Bernstein's (1996) distinction between two pedagogical types, 'competence' and 'performance', and analyses the instructional logic of the pedagogy used to recognise prior learning in a portfolio-based assessment. This analysis is used to reflect on our pedagogical experiences of running a portfolio development course, with a view to highlighting the ways in which some of the demands of prior learning assessment constrained our ability to specify the criteria for the learning we set to recognise.     

Analyzing assessors and products in sorting tasks: DISTATIS,theory and applications

In this paper we present a new method called distatis that can be applied to the analysis of sorting data. Distatis is a generalization of classical multidimensional scaling which allows one to analyze 3-ways distance tables. When used for analyzing sorting tasks, distatis takes into account individual sorting data. Specifically, when distatis is used to analyze the results of an experiment in which several assessors sort a set of products, we obtain two types of maps: One for the assessors and one for the products. In these maps, the proximity between two points reflects their similarity, and therefore these maps can be read using the same rules as standard metric multidimensional scaling methods or principal component analysis. Technically, distatis starts by transforming the individual sorting data into cross-product matrices as in classical mds and evaluating the similarity between these matrices (using Escoufier’s R_V coefficient). Then it computes a compromise matrix which is the best aggregate (in the least square sense, as statis does) of the individual cross-product matrices and analyzes it with pca. The individual matrices are then projected onto the compromise space. In this paper, we present a short tutorial, and we illustrate how to use distatis with a sorting task in which ten assessors evaluated eight beers. We also provide some insights into how distatis evaluates the similarity between assessors.