The Development of a Blend-Sampling Technique to Assess the Uniformity of a Powder Mixture

This article discusses the challenges overcome during the development of a blendsampling technique and the successful validation of the blending operation for a tablet dosage form containing 2% active ingredient. Content uniformity results are discussed for three pilot-scale (15-kg) and seven commercial-scale (150-kg) batches of tablets. Blend and core content uniformity data from the pilot-scale batches were acceptable. For the initial commercial-scale batches, although the tablet core content uniformity data were acceptable, the blend uniformity results were poor. The blend data for these batches had very high mean values, but acceptable relative standard deviations (RSDs). This suggested that the drug was being preferentially sampled by the thief, but in a consistent, reproducible manner. Extensive testing was performed on a commercial-scale development batch to identify potential causes of sampling error. The results of this testing helped define the blend-sampling technique and strategy used to validate the mixing operation.     

一种非均匀采样系统采样均匀性的评价新方法

提出了在多A/D合成采样系统中采样均匀性的评价方法;通过使用正弦波激励系统,将各个子A/D的数据分别抽取形成子抽样序列,使用最小二乘正弦波曲线拟合法,获得各个子抽样序列初始相位间的差异,该差异对应的时间差即为各个子A/D间的采样延迟时间,它们的一致性就是系统的采样均匀性。在一组仿真数据上验证了方法的正确性。在数字存储示波器的实测数据上进行了实验验证,获得了有效的测量结果,验证了方法的可行性。该方法可以用来评价非均匀采样系统的采样均匀性。     

ICP－AES剖析陶瓷粉体化学组份均匀性

本文主要用ＩＣＰ－ＡＥＳ联用小体积循环回流进样装置．提出一种剖析精细陶瓷粉体化学组份均匀度的方法，可为配合陶瓷粉体材料的研制提供信息．     

一种基于主成分分析的TDLAS高频噪声滤波

针对TDLAS高温测量时,吸收光谱容易受到探测器和硬件电路高频噪声干扰,进而影响温度测量准确度和探测灵敏度等问题,提出了一种基于主成分分析的去噪方法。首先将原始吸光度列向量进行矩阵化排列;然后通过主成分分析将其分解为主成分矩阵和得分矩阵;取合适的主成分数,利用截取部分主成分矩阵和得分矩阵重构原始数据,其中截留的主成分代表原始数据主要信息,而剔除的部分仅包含噪声信息。实验结果表明该方法用于TDLAS测量水蒸气温度,噪声去除率达81%,温度解算标准差从8.9降至5.3。     

标准黑体源用铜-R134a热管研制及均温性实验研究

针对热管倾斜放置时均温性恶化的情况,改进了黑体源热管结构,设计了一个标准黑体源用铜-R134a热管并进行了实验研究,测试了倾角、运行温度及充液量对其均温性的影响。以区域温度的标准差作为热管均匀性的衡量标准,实验发现倾角小于45°情况下,该热管倾斜的角度对热管温度的均匀性影响不大;热管温度均匀性随着热管运行温度的升高而逐渐变差;当热管运行温度在40～50 ℃时,热管温度均匀性随充液量变化不大。     

聚能装药粉末药型罩材料技术的发展和现状

文章介绍了近年来国内外粉末药型罩材料技术的研究现状,综述了一些国内外优秀研究成果.重点分析了合金粉末药型罩中各成分的优化配比及制造工艺对粉末罩成型和射流质量的影响.最后以含能药型罩为主线,提出了其新的发展方向和应用前景.     

A／D量化,非线性,微分非线性误差对非同步,准同步采样算法误差影响 …

本文提出了具有量化误差、非线性误差和微分非线性误差的Ａ／Ｄ转换器的数据学模型,在该数学模型的基础上,仿真分析了非同步采样法、准同步采样递推算法各种情况下的误差,包括功率测量中电压线性、电流线性、相位变化误差及电压测量的误差。由于分析中的条件更近接应用中的实际情况,因此,仿真分析的结论为测量仪器设计中的误差估计提供了重要依据。     

Comparison of three pharmaceutical products obtained from Mexico and the United States: a case study

In recent years, there has been much debate concerning the relative pros and cons of purchasing medications from foreign markets such as Mexico and Canada. The following study compares the content uniformity and weight variation for three medicinal products, acquired from pharmacies in both Mexico and the United States: amoxicillin capsules (500 mg), amoxicillin/clavulanic acid suspension (400 mg and 57 mg/5 mL, respectively), and furosemide tablets (40 mg). Twenty capsules/tablets were individually weighed and a designated aliquot was taken. Following dissolution in an appropriate solvent and sonication, a sample was taken and analyzed via high performance liquid chromatography (HPLC). The suspensions were prepared according to directions on the label. Five samples of the suspensions were then taken and analyzed via an appropriate HPLC method. The content uniformity for the amoxicillin capsules was found to be 15.4 ± 2.4% and 99.4 ± 9.3%, for Mexican and U.S. capsules, respectively. The percent relative standard deviation (% RSD) for weight variation was found to be 8.7% and 1.5% for capsules obtained from Mexico and the United States, respectively. Content uniformity analysis for the Mexican suspension product resulted in an average of 85.5 ± 1.2% for amoxicillin and 98.6 ± 1.9% for the clavulanic acid content, while the results for the U.S. suspension product were 104.4 ± 3.1% and 117.8 ± 3.6% for amoxicillin and clavulanic acid, respectively. Content uniformity for the furosemide tablets was found to be 90.3 ± 4.8% and 95.6 ± 2.1% for Mexican and U.S. tablets, respectively. The % RSD of weight variation for the Mexican tablets was 2.1%, while the % RSD for the U.S. tablets was found to be 1.0%. From the three products tested, content analysis revealed that the amount of active ingredients for two of the products acquired in Mexico were appreciably less than the concentrations for their U.S. counterparts.     

DNAN基熔铸炸药的预整形同步块铸技术研究

为了提高熔铸炸药块铸装药质量,以质量比DNAN/RDX/Al:55/20/25的基础配方为研究载体,采用两种不同装药工艺进行装药对比试验,并对样品的内外部质量、装药密度及其均匀性进行分析.结果表明,与常规块铸工艺相比,采用预整形同步块铸技术所装填的药柱,其装药密度达到了1.726g/cm3,相对密度为95.8％,与常规块铸工艺相比分别提高了0.041 g,/cm3和2.2％;同时减少了装药的缺陷,使装药内外部质量获得提高,并改善了装药的密度及其均匀性.     

用周期倍差法评价数据采集系统的动态特性

数据采集系统的采样周期是有下限的,即其采集速率不可能无限高,这在实际应用中常常限了其瞬态响应特性的获得。本介绍了一种方法,通过对其加载特定周期性输入信号,利用采要周期的整数倍和信号周期的整数倍间的微小偏差,获得比实际采样周期小得多的等效采样周期,从而解决了数据采集系统瞬态响应特性的获取问题。     

The Adsorption of Gelatin to a Silver Powder

A silver powder was prepared by borohydride reduction of freshly precipitated silver bromide. Its surface area was estimated by dye adsorption to be 1·6m²g.^–1. The adsorption of gelatin from solution at pH6 was studied and isotherms were derived at 25° and 35°C. The results showed features typical of polymer adsorption generally. For gelatin concentrations below about 0·25 per cent, adsorption was not detectably dependent on temperature. Above this level, adsorption is greater at 25°, which is attributed to the effect of gelling forces in the adsorbed layer. A Langmuir plot of the 35° isotherm was approximately linear. The adsorbed gelatin could not be desorbed. The last fact does not necessarily forbid the application of equilibrium thermodynamic theory, since the apparent irreversibility may reside solely in the need to desorb many polymer segments simultaneously. Heat of adsorption was investigated with the aid of a microcalorimeter. With a 0·2 per cent gelatin solution, a slow heat evolution was observed over 40 mins., amounting to 2·1 millicals., or 420cal./100g., based on the weight of gelatin adsorbed. Passage of solvent then caused the heat consumption of 0·5 millicals., which, since there is no associated gelatin desorption must be ascribed to a purely entropic effect. The picture given by these heat measurements is similar to that reported previously for adsorption to silver bromide (Chem. & Ind., 1964, p. 2057). The heat of adsorption in the latter case was 1,500cal./100g. This may represent a genuine difference, but caution is nesessary because of the following factors. Heat will probably have been consumed due to desorption of solvent molecules. The average number of segments of a gelatin molecule attached to the adsorbent and the relevant energies of the possibly various groups are unknown.     

Development of a Work Sampling Methodology for Behavioral Observations: Application to Teamwork

Engineering programs must assess students' abilities to master “criteria 3 a‐k.” Skills such as teamwork, problem solving, design, and ethical understanding entail learning various processes; hence, assessing these outcomes is better accomplished by focusing on the process rather than the result. Methods for observing students' performance, such as 100 percent behavioral observation, are ideal but expensive. We extend work sampling, an economic industry‐based alternative, to observe cognitive and behavioral processes. Specifically, we describe a work sampling methodology to assess students engaged in teamwork. We then determine attributes of teamwork, establish target time proportions using 100 percent observation, and statistically compare the targets to proportions obtained from work sampling intervals to determine the effective interval. The robustness of work sampling is tested in four learning environments. Results indicate that sampling provides a statistically valid alternative for assessing teamwork. However, when observing design and ethical understanding processes, additional research is needed to make work sampling viable.     

用周期倍差法评价数据采集系统的传递函数

数据采集系统传递函数的辨识和评价,是其总体性能评价中至关重要的一个目标,在此,首要的前提条件是其瞬态响应的获得。由于采样周期是有下限的,即采集速率不可能无限高,这在实际应用中常常限制了其瞬态响应特性的获得,因而也限制了其传递函数的辨识和评价。本介绍一种方法,通过对其加载特定的周期性输入信号,使用采样周期的整数倍和信号周期整数倍间的微小偏差,获得经实际采集得多的等效采样周期,从而解决了数据采集系统     

The use of a Micro Reflectance Photometer to Measure the Colour Uniformity and Gloss of Tablets

Abstract

The use of a microscope photometer to measure the colour uniformity and gloss of tablets is described. The influence of processing variables and type of dye on the colour uniformity is reported and the use of the instrument to optimize the polishing of coated tablets is also discussed.     

真空测量技术发展溯源

文中以确切的资料信息介绍了真空测量技术创始以来的发展过程，使人们永记住这些在此领域做出突出贡献的劳动者以及他们的科学成就。     

西德粉状炸药自动装药机的引进和应用

简述了我厂引进设备——西德CARTEX-12型粉状炸药自动装药机的技术特点及其在生产应用中的实效,并结合行业技术发展浅析了推广应用的前景。     

冰箱制冷性能测试技术的研究

本文对冰箱制冷性能测试标准、从开发到生产过程检测系统和方法等方面作较全面的探讨分析。列出了冰箱制冷性能试验存在的问题，提出了测试方法在研发和生产在线阶段的发展方向。     

A parallel adaptive sampling strategy to accelerate the sampling process during the modeling of a Kriging metamodel

ABSTRACT

Higher modeling efficiency is an important goal for the modeling of a Kriging (KG) metamodel, and the sampling approach affects the modeling efficiency directly. Considering the effect of the employed correlation model on prediction accuracy of a KG model, a multiple KG models based parallel adaptive sampling strategy (MKPAS) is proposed using the combination forecasting method, in which the added new points in the sampling process are determined using multiple KG models with different correlation models. The effectiveness of the proposed approach is verified by two low dimensional benchmark functions as well as a high dimensional one. And an engineering application is also used to demonstrate the effectiveness of the proposed MKPAS approach. The results show that the proposed approach can improve the modeling efficiency of a KG model significantly compared with other ordinary sampling approaches.     

Development and Demonstration of a Method to Evaluate Bio-Sampling Strategies Using Building Simulation and Sample Planning Software

In an effort to validate and demonstrate response and recovery sampling approaches and technologies, the U.S. Department of Homeland Security (DHS), along with several other agencies, have simulated a biothreat agent release within a facility at Idaho National Laboratory (INL) on two separate occasions in the fall of 2007 and the fall of 2008. Because these events constitute only two realizations of many possible scenarios, increased understanding of sampling strategies can be obtained by virtually examining a wide variety of release and dispersion scenarios using computer simulations. This research effort demonstrates the use of two software tools, CONTAM, developed by the National Institute of Standards and Technology (NIST), and Visual Sample Plan (VSP), developed by Pacific Northwest National Laboratory (PNNL). The CONTAM modeling software was used to virtually contaminate a model of the INL test building under various release and dissemination scenarios as well as a range of building design and operation parameters. The results of these CONTAM simulations were then used to investigate the relevance and performance of various sampling strategies using VSP. One of the fundamental outcomes of this project was the demonstration of how CONTAM and VSP can be used together to effectively develop sampling plans to support the various stages of response to an airborne chemical, biological, radiological, or nuclear event. Following such an event (or prior to an event), incident details and the conceptual site model could be used to create an ensemble of CONTAM simulations which model contaminant dispersion within a building. These predictions could then be used to identify priority area zones within the building and then sampling designs and strategies could be developed based on those zones.     

The Development of a Hybrid Technique Employing the Boundary Element Method for Thermoelastic Stress Separation

Abstract: This paper presents a development of a hybrid technique employing a boundary element method for determining individual stress components in two-dimensional arbitrarily shaped domains from experimental isopachics only. The procedure consists of a numerical solution of two Poisson equations representing equilibrium for two-dimensional plane-stressed solids with zero body forces. An existing technique is employed for smoothing interior thermoelastic data and enhancing boundary information. The algorithm of stress separation has been implemented with the help of commercial codes. The whole procedure has been tested through a complete post-processing example of thermoelastic stress analysis data.