Instrumented and Computer Interfaced Single Punch Tablet Press for the Rapid Evaluation of Compression and Lubrication Behaviour

A low cost instrumented and computer interfaced single punch tablet press was developed for the rapid data aquisition of compression and lubrication properties of powders arid processed materials.

A Manesty type F3 tablet machine has been modified to enable the fitting of piezo electric load cells to both upper and lower punch assemblies. The paper describes how the modifications permit interchangability of a range of punch sizes and shapes and yet ensure good accuracy and reproducibility of compression end lubrication data.

The instrumentation is interfaced with a dedicated A. I. M. 65 microcomputer for the rapid conversion of the instrumentation outputs into compression force units and for statistical evaluation. The computer software also incorporates a novel method for the evaluation of lubrication properties from a single or a series of pre-determined compression events, using the some sensitivity for force measurement from the lower punch lord cell.

The compression data and the physical properties of the compacts can be stored and retreived as fingerprints using a P. E. T. microcomputer and a digital plotter. A date bank may then be developed for the evaluation of raw materials, product development, monitoring of production performance and trouble shooting.

The paper further describes the evaluation of new lubricants in comparison with magnesium stearate using the instrumentation described.     

3种亚像素位移测量算法的比较研究

梯度法、曲面拟合法和N-R法是数字散斑相关方法中提高位移测量精度的3种主要亚像素位移算法。研究了3种算法的原理并进行了数值模拟仿真。首先使用计算机模拟生成一系列位移为0.01 pixel的散斑图,并在生成的图像中添加方差不同的高斯噪声,对3种算法在噪声条件下的精度进行比较,结果显示在精度要求为0.01 pixel时,梯度法的噪声方差上限为0.006,N-R法的噪声方差上限为0.000 5,而曲面拟合法的计算精度具有较大不确定性,无法保证精度,梯度法更适用于工程应用。     

Instrumented and Computer Interfaced Single Punch Tablet Press for the Rapid Evaluation of Compression and Lubrication Behaviour

A low cost instrumented and computer interfaced single punch tablet press was developed for the rapid data aquisition of compression and lubrication properties of powders arid processed materials.

A Manesty type F3 tablet machine has been modified to enable the fitting of piezo electric load cells to both upper and lower punch assemblies. The paper describes how the modifications permit interchangability of a range of punch sizes and shapes and yet ensure good accuracy and reproducibility of compression end lubrication data.

The instrumentation is interfaced with a dedicated A. I. M. 65 microcomputer for the rapid conversion of the instrumentation outputs into compression force units and for statistical evaluation. The computer software also incorporates a novel method for the evaluation of lubrication properties from a single or a series of pre-determined compression events, using the some sensitivity for force measurement from the lower punch lord cell.

The compression data and the physical properties of the compacts can be stored and retreived as fingerprints using a P. E. T. microcomputer and a digital plotter. A date bank may then be developed for the evaluation of raw materials, product development, monitoring of production performance and trouble shooting.

The paper further describes the evaluation of new lubricants in comparison with magnesium stearate using the instrumentation described.     

Planning Experiments Using an Instrumented Tablet Machine in Formulation

Abstract

For a few years, we have been in possession of a methodology for the formulation of tablets. It is based on an experimental planning design of rational development work using an instrumented tablet machine. On the other hand, it is possible to organize mathematically the scientific studies in various fields so that we can reach the best result as fast as possible, i.e. to carry out an optimal number of experiments giving the maximum amount of information: this is the application of the statistical experimental designs. The aim of this study is to associate these two concepts.

The major principle is to study the variations of well-chosen answers (tablet crushing strength…) according to the percentages of vehicles chosen as variables (diluent, disintegration agent…) while the methodology of mixing remains fixed. An experimental design is built, a well-defined number of experiments are carried out, and then we try to put into equation the responses as a polynomial function of the percentages of vehicles. The best mathematical models are statistically determined by multilinear regression and used to plot the response surfaces. This mathematical treatment associated with the objectives of the pharmacist allows us to determine the optimal formula. And so, carrying out the theoretical optimal experiment we can verify the accordance of the experiment with the model.

A first approach with wet granulation showed all the difficulties in fixing all the parameters. But it has already shown all the advantages of the experimental designs and that this technique can be very helpful in building the experimental planning design.

With direct compression, two experimental designs were built to determine the optimal formula as fast as possible: these were a Scheffe design and a Mac Lean and Anderson design.

When the constraints on vehicle percentages lead to a triangular experimental field, Scheffe designs are recommanded. For any other configuration Mac Lean and Anderson designs will be useful.

The responses were:

1. Y1/D, where Yl is the maximal pressure measured at the upper punch and D the crushing strength of the tablet.

2. (V10-V500), where V10 and V500 are the volumes of 100 grammes of the final mix of powder after 10 and 500 tamping taps given by a standardized apparatus. Their difference (V10 - V500) should not exceed 20 ml.

3. td, the disintegration time of tablets measured by way of the European Pharmacopea test.

In both cases, the results were excellent considering the differences between the response values given by the mathematical models and the corresponding experimental values.     

A Comparison of Three Different Procedures for Estimating Variance Components

An analytic procedure for obtaining variances of estimates of variance components in a general multi-way classification is described. As an application, three methods for estimating variance components are compared for a two-way classification. Since the variances of the estimates are affected by the magnitude of the true variance components (parameters) as well as the arrangement of the subclass numbers (n _ij 's), a numerical tabulation is necessary in order to make a comparison. Using a UNIVAC 1105, the variances of the estimates of variance components are evaluated over a substantial range of parameters and n _ij 's. These results are presented in tabular form for selected sets of parameter values.     

一类具有三重指标的分批排序问题

本文研究现代排序问题一具有三重指标的批容量无限制平行分批排序问题。第一指标为最大延迟,第二指标为最大完工时间,第三指标为关于工件完工时间的任意正规函数。本文通过分析前两个指标最优解的性质给出了此问题的多项式时间算法。     

三种方法制备HDPE/LDHs复合材料的性能比较

分别采用硬脂酸表面改性、高密度聚乙烯接枝马来酸酐(HDPE-g-MA)熔融接枝水滑石(LDHs)、乙烯丙烯酸无规共聚物(EAA)熔融接枝水滑石与高密度聚乙烯共混挤出制备纳米复合材料。结果表明,采用EAA接枝水滑石较其他两种方法制备的HDPE/LDHs冲击性能可提高25%以上,拉伸强度可提高35%以上;差示扫描量热(DSC)和X射线衍射(WAXD)等方法证实,EAA熔融接枝LDHs提高了LDHs在HDPE中的分散,有利于HDPE结晶,晶粒细化。采用EAA熔融接枝LDHs填充HDPE可制备性能优异的聚烯烃纳米复合材料。     

3种测量石蜡比定压热容实验方法的比较

用差示扫描法、气相色谱法和水浴法对石蜡的比定压热容进行了测量.差示扫描法可以给出石蜡比定压热容的精确值.气相色谱法通过测量各烷烃的质量分数,可较准确地对液态石蜡的比热容进行测量.相对于差示扫描实验的结果,误差小于3.9%,用这种方法测量固态石蜡的比热容存在较大误差.水浴法可对固态石蜡的比热容进行较准确的测量,误差小于3.5%.用该法测量液态石蜡的比热容时,必须对水浴上方存在液态石蜡时的散热进行准确测量.     

单冲式压片机发展现状及趋势

以小型单冲式压片机为例,介绍了单冲式压片机的基本结构组成、工作原理及工作过程,阐述了国内外单冲式压片机的发展现状,同时根据其发展现状分析了目前单冲式压片机所存在的主要缺陷,并指明了其发展趋势.     

Estimating Displacement of Periodic Motion With Inertial Sensors

Inertial sensors, like accelerometers and gyroscopes, are rarely used by themselves to measure displacement. Accuracy of inertial sensors is greatly handicapped by the notorious integration drift, which arises due to numerical integration of the sensors zero bias error. A solution is proposed in this paper to provide drift free estimation of displacement from inertial sensors.     

A Remark on Multiple Comparison Methods

Quantitative measurement is an accepted ideal, but pass–fail inspection remains a fact of life, even in high-technology industries. For pass–fail data, variance components do not separate gauge and material variation. This article focuses on maximum likelihood estimation of conditional misclassification rates, with and without reference evaluations to anchor the analysis. Likelihood-based confidence intervals and testing for reproducibility effects are also discussed.     

Results from investigations with an Instrumented Impact Machine on a molybdenum base alloy,nickel base alloys,and incoloy 800

Experiments were performed on the molybdenum base alloy TZM, the nickel base alloys Nimocast 713 LC, Inconel 625, Nimonic 86, Hastelloy S, and the iron base alloy Incoloy 800 with an instrumented impact machine. The results are discussed in terms of absorbed impact energies and dynamic fracture toughness. In all cases the agreement between the energy determined by the dial reading and the energy determined by the integration of the load vs. load point displacement diagram was excellent. A procedure for the determination of the dynamic fracture toughness for load vs. load point displacement diagrams exhibiting high oscillations using an averaged curve is proposed. Using this procedure a pronounced influence of the experiments with tup and chisel (5.0 m/s and 0.1 m/s respectively) on the dynamic fracture toughness is not detectable. Using half the drop height, i.e. halving the total energy, lowers the dynamic fracture toughness values for these types of alloys. Low absorbed impact energies are often combined with high fracture toughness values. In these cases there is no or only a small reserve in deformation and/or stable crack growth.     

油水驱动问题的 Godunov-mixed 方法数值分析

不可压缩油水渗流驱动问题一般由两个方程给出:压力方程和饱和度方程,采用Godunov- mixed方法逼近,即用混合元方法近似压力方程:饱和度方程的对流项用Godunov-flux函数来处理,而扩散项则用混合元来逼进。当流动是光滑分布时可以得到最优阶的估计。     

Comparison of Interval Analysis and Standard Statistical Methods for Estimating Experimental Data with Uncertainty

Measurement Techniques - Interval analysis procedures are used to estimate the parameters of an experimental chemical process under conditions of noise and uncertainty in the probabilistic...     

基于局部法由示波冲击试验预测裂纹尖端张开位移

材料的COD(裂纹张开位移)、示波冲击试验是常用的断裂韧性测试,根据局部法若能从一种实验结果预测另一种实验结果具有重要意义。本研究以X65钢为试验材料,对其进行了示波冲击及COD试验,并对试验数据进行统计处理,证明断裂参量CTOD(裂纹尖端张开位移)符合三参数威布尔分布。编制了自动求解局部断裂参量及由示波冲击预测CTOD的程序。通过比较COD实验和预测结果,表明在脆性断裂条件下基于局部法能够实现由示波冲击试验预测CTOD断裂韧性。     

考虑急件到达的单机鲁棒调度方法

实际生产过程中经常会有急件到达。由于急件的优先级最高,其到达容易扰乱初始调度,使实际调度性能恶化,影响调度目标的实现。针对以总拖期为目标且带有释放时间的单机调度问题,研究了在有急件到达情况下的鲁棒调度方法,以降低急件对实际调度性能的影响。鉴于该调度问题是NP hard问题,根据工件释放时间和交货期的关系构造“金字塔”结构,获得该调度问题的占优性质。根据这些占优性质和急件到达特点,研究急件到达情景下的占优规则,据此求解急件到达情景下的占优调度集合,作为鲁棒调度的备选调度方案集合。提出了应对急件到达的鲁棒调度算法。给出仿真算例验证了算法的有效性,算例表明本文给出的鲁棒调度方法能有效避免急件到达造成实际调度性能的恶化。      

冷却塔三种运行控制方式的比较

分析了三种冷却塔运行方式的特点并进行比较.     

微弱电离电流测量方法的比较

为了在实验中可以对静电计直接测量法和高增益负反馈法及汤森零位补偿法更好地使用,用这3种方法分别对监督源中电离室的电离电流进行了多次重复性测量,测量结果显示,静电计直接测量法对微弱电流的测量不确定度较大,而后两种绝对测量方法的相对不确定度则较小,所以在测量微弱电离电流时,对于不同的不确定度要求可根据实际情况选择合适的方法进行测量.     

基于西门子S7-200系列PLC的小冲杆试验机自动化改造

介绍了西门子S7-200系列PLC在小冲杆试验机系统中的运用,实现了试验机的自动化改造,有效地简化了试验步骤。并且使用Visual Basic6．0软件实现了PLC与PC机之间的串行通讯,实现了对试验数据自动采集、显示以及相关计算等功能。