Effects of granulation process variables on the physical properties of dosage forms by combination of experimental design and principal component analysis

The current study was to understand how process variables of high shear wet granulations affect physical properties of granules and tablets. The knowledge gained was intended to be used for Quality-by-Design based process design and optimization. The variables were selected based on the risk assessment as impeller speed, liquid addition rate, and wet massing time. Formulation compositions were kept constant to minimize their influence on granules properties. Multiple linear regression models were built providing understanding of the impact of each variable on granule hardness, Carr’s index, tablet tensile strength, surface mean diameter of granules, and compression behavior. The experimental results showed that the impact of impeller speed was more dominant compared to wet massing time and water addition rate. The results also revealed that quality of granules and tablets could be optimized by adjusting specific process variables(impeller speed 1193 rpm, water spray rate 3.7 ml/min, and wet massing time 2.84 min). Overall desirability was 0.84 suggesting that the response values were closer to the target one. The SEM image of granules showed that spherical and smooth granules produced at higher impeller speed, whereas rough and irregular shape granules at lower speed. Moreover, multivariate data analysis demonstrated that impeller speed and massing time had strong correlation with the granule and tablet properties. In overall, the combined experimental design and principal component analysis approach allowed to better understand the correlation between process variables and granules and tablet attributes.

The Statistical Experimental Design for Chemical Reactors Modeling

The Statistical Experimental Design techniques are the most powerful tools for the chemical reactors experimental modeling. Empirical models can be formulated for representing the chemical behavior of reactors with the minimal effort in the necessary number of experimental runs, hence, minimizing the consumption of chemicals and the consumption of time due to the reduction in the number of experimental runs and increasing the certainty of the results. Four types of nonthermal plasma reactors were assayed seeking for the highest efficiency in obtaining hydrogen and ethylene. Three different geometries for AC high voltage driven reactors, and only a single geometry for a DC high voltage pulse driven reactor were studied. According to the fundamental principles of chemical kinetics and considering an analogy among the reaction rate and the applied power to the plasma reactor, the four reactors are modeled following the classical chemical reactors design to understand if the behavior of the nonthermal plasma reactors can be regarded as the chemical reactors following the flow patterns of PFR (Plug Flow Reactor) or CSTR (Continuous Stirred Tank Reactor). Dehydrogenation is a common elimination reaction that takes place in nonthermal plasmas. Owing to this characteristic, a paraffinic heavy oil with an average molecular weight corresponding to C15 was used to study the production of light olefins and hydrogen.

An Assessment Scale for Evaluating the Experimental Design Ability of Elementary Science Teachers Based on Primary Trait Analysis

In this study,an assessment scale for evaluating the experimental design ability of elementary science teachers was constructed based on primary trait analysis.This assessment scale contains three first-level indexes and eleven second-level indexes.The corresponding weights of indexes were determined by the objective weighting method.The scores of all the descriptions of the indexes were also assigned.After a trial test,this assessment scale was verified to be reliable and valid for evaluating the experimental design ability of elementary science teachers.

Key design parameters and optimum method of medium- and high-velocity synchronous induction coilgun based on orthogonal experimental design

The energy conversion efficiency of a multistage synchronous induction coilgun(MSSICG) has become one of the key factors that restricts its industrialization. To improve the launch efficiency of medium-and high-velocity MSSICG,we propose an optimization design scheme combining orthogonal experimental design(OED) and self-consistent design method in this paper. The OED is introduced to reduce the number of iterations and improve the identification accuracy and efficiency. A self-consistent design model is established to overcome a defect that the parameters that need to be optimized will multiply as the number of coil stages increases. The influence of six factors(radial thickness of armature, axial length of armature, axial length of coil, capacitance, wire diameter, and slip speed) on the launch efficiency are then evaluated by range analysis. This work presents a valuable reference for optimizing medium-and high-velocity MSSICG.

Application of experimental modal analysis technique to structural design of linear vibrating screen

A large model of the screen was mounted in the laboratory for studying its modal performance. The model is suspended with steel ropes. Modal test was carried out with artificially exciting by 500 g impacting hammer and 100 kg exciting force shaker respectively. Synthesis and correction of the modal parameters are obtained from both testing methods. Design faults of vibrating screen were determined based on the analy-sis and dynamic correction of structure approaches about the screen was put forward finally.

Simulation and Experimental Analysis of Vortex Tube Using Steel Material

Experimental and computational fluid dynamics (CFD) are investigated through the vortex tube system. The benefit of vortex tube is a counter flow type tube, which has further designed and fabricated for investigation. The whole set up is consisting of a simple device that can separate a single stream of compressed air into two streams;one is at high temperature and the other is lower temperature following an inlet gas stream. The advantages of this tube are their compactness, safety, and low equipment cost mainly used in cooling and heating applications. This study addressed three-dimensional flows;the domain is using computational fluid dynamics (CFD) method and experimental approach to optimize the direction of RHVT. Through the CFD analysis, the best cold end diameter (dc), number of nozzles, and the best parameters for obtaining the highest hot gas temperature and lowest cold gas temperature were obtained and verified by experimental procedures.

Design and Analysis of Computer Experiments Based on a Simulation Model of Air Traffic Flow Optimization in Panama

There is a growing in number of operations in aviation all over the world.This growing is increasing the necessity of innovation and new technology to respond the increment of the demand.As a respond of this demand,FAA(Federal Aviation Administration)is working with NextGen in the United States and the EUROCONTROL is implementing the Point Merge as solution in the air traffic flow management in Europe.However,the FAA alternative and EUROCONTROL alternative are not mutually exclusive since Panama,a small country in Latin America,is trying to use a combination between the vectoring approach and the Point Merge in the air traffic flow management.In addition,the AAC(Autoridad de Aereonautica Civil)and the Tocumen(Tocumen International Airport)are working in a continuous collaboration between FAA and Panama with the mutual challenge to improve the actual system.As a result,the main airline of Panama,the Compania Panamena de Aviacion(COPA Airlines),and the Autoridad de Aeronautica Civil(AAC)constructed a simulation model to select an air traffic flow alternative that can be able to change the actual situation.In other words,COPA Airlines and AAC are pursuing the minimization of the numbers of conflicts,the number of sequence actions,the flight time,the track flight distance and the fuel burn.Furthermore,this study aims to use the final draft of this previous analysis based on a simulation methodology to conduct a Design and Analysis of Computer Experiments with the final objective to increment the statistical significance of the actual model.

基于MATLAB App Designer的加工误差统计分析实验系统设计

机械加工误差的统计分析是机械制造基础课程中典型的实验内容,同时也是机械专业生产实习期间评定工艺过程加工精度的重要巩固环节。为了使学生从理论更直接地过渡到实际应用中,改善传统实验教学手段的单一化,设计了一种基于MATLAB App Designer的加工误差统计分析实验系统。该系统针对多个常见工序随机产生能够模拟真实工序尺寸的样本,并引导学生按照实验步骤完成工艺过程的分布图法分析与点图法分析。实验过程中可随时查看分数,学生可反思纠错、反复练习。同时提供了可用于参考的测量尺寸频数分布图、x−R图,能帮助学生灵活直观地掌握加工误差的统计分析原理与应用过程,提高实验教学的水平。

Design and Robust Performance Evaluation of a Fractional Order PID Controller Applied to a DC Motor

This paper proposes a methodology for the quantitative robustness evaluation of PID controllers employed in a DC motor. The robustness analysis is performed employing a 2~3 factorial experimental design for a fractional order proportional integral and derivative controller(FOPID), integer order proportional integral and derivative controller(IOPID)and the Skogestad internal model control controller(SIMC). The factors assumed in experiment are the presence of random noise,external disturbances in the system input and variable load. As output variables, the experimental design employs the system step response and the controller action. Practical implementation of FOPID and IOPID controllers uses the MATLAB stateflow toolbox and a NI data acquisition system. Results of the robustness analysis show that the FOPID controller has a better performance and robust stability against the experiment factors.

Application of Uniform Experimental Design in Optimizing Excitation Parameters for Magnetic Frequency Mixing Measurements

Excitation parameter preferences are key factors a ecting the performance of magnetic frequency mixing detection.A uniform experimental design method was used to analyze this influence.Using fuzzy theory,a comprehensive model is established for evaluating the e ect of magnetic frequency mixing.A polynomial is selected as the regression function to express explicitly the correlation between the excitation parameters and the frequency-mixing e ect.The excitation parameters were then optimized using genetic algorithm.Magnetic frequency mixing experiments were conducted to measure the surface hardness of some ferromagnetic materials.Frequency mixing is further enhanced under the optimal settings,resulting in an improvement in the measurement sensitivity.The results of this study support the application of the magnetic frequency mixing technique in non-destructive testing.

Mathematical model for abrasive suspension jet cutting based on orthogonal test design

This paper describes the application of orthogonal test design coupled with non-linear regression analysis to optimize abrasive suspension jet （AS J） cutting process and construct its cutting model. Orthogonal test design is applied to cutting stainless steel. Through range analysis on experiment results, the optimal process conditions for the cutting depth and the kerr ratio of the bottom width to the top width can be determined. In addition, the analysis of ranges and variances are all employed to identify various factors： traverse rate, working pressure, nozzle diameter, standoff distance which denote the importance order of the cutting parameters affecting cutting depth and the kerf ratio of the bottom width to the top width. ~rthermore, non-linear regression analysis is used to establish the mathematical models of the cutting parameters based on the cutting depth and the kerr ratio. Finally, the verification experiments of cutting parameters＇ effect on cutting performance, which show that optimized cutting parameters and cutting model can significantly improve the prediction of the cutting ability and quality of ASJ.

Influence of structure and material on the vibration modal characteristics of novel combined flexible road wheel

Aiming at the independent development of tracked vehicles,it is urgent to improve its mobility,passability and ride comfort,a new type of flexible road wheel with a“wheel-hinge-hub”combined structure is proposed in this study.The vibration model characteristics of the flexible road wheel were studied by the combination of numerical simulation and experiments.The superelasticity of rubber is obtained through uniaxial tensile experiment of the material and a detail three-dimensional nolinear finite element model of the flexible road wheel is established through finite element software ABAQUS.The free vibration equation of the flexible road wheel is solved by Lanczos vector direct superposition method,and its predicted modes and natural frequencies are compared with experimental results,which verifies the accuracy and reliability of the established finite element model.On this basis,the effects of various key structural or material factors on the natural frequencies of the flexible road wheel are studied using orthogonal experimental design method.Besides,the vibration modal characteristics of the flexible road wheel are also compared with those of the rigid road wheel.The research results provide a theoretical basis for the vibration and noise reduction of flexible road wheel.

Analysis of Heat Transfer Performance of Oscillating Heat Pipes Based on a Central Composite Design

Oscillating heat pipes (OHPs) are very promising cooling devices. Their heat transfer performance is af- fected by many factors, and the form of the relationship between the performance and the factors is complex and non-linear. In this paper, the effects of charging ratio, inclination angle, and heat input and their interaction effects on heat transfer performance of a looped copper-water OHP are analyzed. First, suppose that the relationship between the response and the variables approximates a second-order model. And use the central composite design to arrange the ex- periment. Then, the method of least squares is used to estimate the parameters in the second-order model. Finally, multi- variate variance analysis is used to analyze the model. The results show that the assumption is right, that is to say, the re- lationship is well modeled by a second-order function. Among the three main effect variables, the effect of inclination angle is the most significant, but their interaction effects are not significant. In the range of the considered factors, both the optimum charging ratio and the optimum inclination angle increase as the heating water flow rate increases.

A Novel Statistical Analysis for Residual Stress in Injection Molding

Residual stresses can reduce the reliability of plastic injection molding parts. This work is an attempt to model the residual stresses as a function of injection molding parameters. More stress is placed on reducing the number of input factors and to include all possible interactions. For this purpose, two-stage experimentation is suggested: a factor screening stage and Response Surface optimization stage. In screening stage Taguchi 3 level experimental design is used to classify the input parameters as significant and non-significant factors. Eight input variables were classified into 3 non-significant and 5 significant factors using this screening stage. Thus for the Response Surface optimization stage: instead of doing 160 experiments in Central Composite, 56 are only needed after the screening stage in half Central Composite Design. The best subset and regression model fitting tools in addition to model verification using randomly selected input setting were used to select a model for predicting residual stresses with a verified Root Mean Square Error (RSME) of nearly 0.93 MPa.

Automotive Interior Noise Reduction in High Frequency Using Statistical Energy Analysis

Statistical energy analysis (SEA) is an effective method for predicting high frequency vibro-acoustic performance of automobiles. A full vehicle SEA model is presented for interior noise reduction. It is composed of a number of subsystems based on a 3D model with all parameters for each subsystem. The excitation inputs are measured through road tests in different conditions,including inputs from the engine vibration and the sound pressure of the engine bay. The accuracy in high frequency of SEA model is validated,by comparing the analysis results with the testing pressure level data at driver's right ear. Noise contribution and sensitivity of key subsystems are analyzed. Finally,the effectiveness of noise reduction is verified. Based on the SEA model,an approach combining test and simulation is proposed for the noise vibration and harshness (NVH) design in vehicle development. It contains building the SEA model,testing for subsystem parameter identification,validating the simulation model,identifying subsystem power inputs,analyzing the design sensitivity. An example is given to demonstrate the interior noise reduction in high frequency.

Characteristic Period Value of the Seismic Design Response Spectrum of UHV Electrical Equipment

Characteristic period is an important parameter of the seismic design response spectrum.There is important theoretical significance and engineering application value to the study of the characteristic period of seismic design response spectrum of ultra high voltage(UHV)electrical equipment.In this paper,1448 horizontal earthquake records within the world scope including the United States and Japan for Site Class Ⅲ were analyzed.Results show that both magnitude and epicentral distance have great influence on the characteristic period.About80% of characteristic periods of strong earthquake records are about 0.9s.Statistical analysis was conducted on the seismic hazard assessment results of 312 projects of China in recent years,and it is found that about 70% of characteristic periods are about 0.9s.Combined with the related code comparison and analysis,it is suggested that the characteristic period of the seismic design response spectrum of UHV electrical equipment should select 0.9s in order to effectively guarantee the seismic safety of UHV electrical equipment.

基于正交试验的民用飞机抗爆结构参数敏感性分析

最小风险炸弹位置(LRBL)结构是放置飞机上可疑爆炸物的装置,探究结构尺寸和炸药位置对其抗爆性能的影响程度可为其改进设计提供参考。基于正交试验设计与数值模拟相结合的方法,以LRBL结构各危险部位的最大应变和变形为评价指标,分别运用极差分析法和方差分析法对LRBL结构的罐体壁厚、底盖厚度、连接凸台厚度、剪切销直径和炸药位置5个影响因素开展参数敏感性分析。结果表明:在200 g炸药当量的工况下,各因素对LRBL结构的抗爆性能的影响显著程度从大到小为炸药位置、罐体壁厚、底盖厚度、凸台厚度和剪切销直径;结合评价指标综合分析得到各个因素最优水平下的LRBL结构设计方案。

Data Processing System （DPS） software with experimental design, statistical analysis and data mining developed for use in entomological research

A comprehensive but simple-to-use software package called DPS （Data Pro- cessing System） has been developed to execute a range of standard numerical analyses and operations used in experimental design, statistics and data mining. This program runs on standard Windows computers. Many of the functions are specific to entomological and other biological research and are not found in standard statistical sottware. This paper presents applications of DPS to experimental design, statistical analysis and data mining in entomology.

土动力学与岩土地震工程

社会发展需求的增长、工程建造能力的提升以及气候变化等环境因素的改变带来的新震害现象、技术手段和工程需求,为土动力学及岩土地震工程研究提出了新挑战并创造了新机遇。文章重点针对近年来土动力学与岩土地震工程领域的一些新现象、新手段和新挑战进行综述,聚焦于土的动力特性、砂土地震液化、土的动力测试和岩土地震工程试验、岩土地震工程数值模拟以及岩土工程抗震等方面,分析当前理论研究和工程实践所面临的新问题和新挑战,梳理近年来所取得的一些最新进展,并对今后的研究方向进行探讨。

落石被动柔性防护网非线性静力设计方法及验证

被动柔性防护网是一种常见的落石灾害防治措施。针对当前落石被动柔性防护网尚无适用的工程化设计方法的现状,以非线性计算过程中结构内能与设计防护能级相等作为加载完成的判别准则,建立了落石被动柔性防护网的非线性静力设计方法。基于LS-DYNA对250~5000 kJ共8种常用能级的被动柔性防护网开展非线性动力分析,明确了冲击力的分布范围及相对大小,形成了适用于不同能级落石被动柔性防护网非线性静力设计的荷载模式。为了有效模拟被动柔性防护网特殊的受力特征,开发了由索单元与受拉弹簧单元组成的非线性耗能单元用于耗能器模拟,开发了内部由多段索单元组成的滑移索单元用于滑移边界以及网环单元模拟。基于对网片冲击试验的反演和3500 kJ被动柔性防护网的设计及足尺冲击试验检验,验证了所提出的落石被动柔性防护网非线性静力设计方法的有效性。