Robust Part Quality by Controlling the Injection Moulding Process with 24 Fraction Factorial Design: A Case Study

The author wants to use a case study to investigate the injection moulding machine parameters which will affect the horizontal length dimension of a plastic component used in digital camera. Currently the injection moulding machine process setting caused variations in the diameter exceeding the specification limit. Therefore the experiment is needed to identify the process factors that could be set to maintain the horizontal length dimension closest to the target value and smallest possible variation. The experimental model is used to investigate four factors to identify the factors having large effect by using the Full Factorial Design of Experiment (DOE). The experiment has emphasized the use of these designs in identifying the subset of factors that are active and provide some information about the interaction

A Study on Injection Moulding and Injection Blow Molding Technology

Injection moulding and blow moulding are probably the most widely used process for manufacturing parts by using plastic materials. A wide variety of products are manufactured by using these two technologies, which vary greatly in their size, complexity, and application. The injection moulding process requires the use of an injection moulding machine, raw plastic material and a mould. The process cycle for injection moulding consists of the following four stages: clamping, injection, cooling and ejection. Blow moulding is a manufacturing process that is used to create hollow plastic parts by inflating a heated plastic tube until it fills a mould and forms the desired shape. The manufacturing process is divided into three stages: injection, blowing and ejection. There are many types of materials that may be used in the injection moulding and blow moulding process. Most polymers may be used, including all thermoplastics, some thermosets, and some elastomers.Injection moulding industry is used to create many things such as milk cartons, packaging, bottle caps, automotive dashboards, pocket combs, and most other plastic products available today. Parts made from blow moulding are plastic, hollow, and thin-walled, such as bottles and containers that are available in a variety of shapes and sizes. These study is about the process, equipments, materials and applications involve injection moulding and blow moulding technology. At the same time it’s also discuss about the advantage and disadvantage of both manufacturing technology

Molecular Modeling Of Energetic Materials And Chemical Warfare Agents

Contamination of military sites by energetic materials and chemical warfare agents is a growing problem. To avoid health hazards associated with these compounds, it is necessary to decontaminate or remediate the contaminated sites. Effective decontamination requires knowledge of environmental fate of contaminants and the appropriate remediation methodologies. While the fate of chemical warfare agents are well studied, the impact of certain energetic materials in the environment is relatively unknown. So the current focus is determining environmental fate of Insensitive Munitions (IM) which are energetic materials that have low shock sensitivity and high thermal stability and developing detection schemes for identifying chemical warfare agents. For energetic materials, the environmental fate can be assessed by determining the partition coefficients, especially the octanol-water partition coefficient and Henry\u27s law constant. For chemical warfare agents, the most important criteria for developing sensors is the detection selectivity. Carbon adsorbents are a simple and effective way of increasing the sensor selectivity for the contaminants by concentration or prefiltration through physical adsorption. So it is necessary to study the adsorption behavior of the contaminants in carbon slit pores as a preliminary step to the sensing process. In this work, molecular modeling or simulation is proposed as a theoretical tool to determine thermophysical properties that aid in understanding how certain energetic materials behave in the environment and developing techniques for detecting chemical warfare agents. Molecular modeling is a promising alternative to experiments due to the hazardous nature of these compounds and the long experimental time scales involved in their testing. Molecular models or force fields are developed to predict various thermophysical properties. For energetic materials, atomistic molecular dynamics simulations are used to predict properties such as octanol-water partition coefficiens, Henry\u27s law constant and also critical parameters, vapor pressure, boiling point, lattice parameters, crystal density and melting point. For chemical warfare agents, the developed force fields are used to determine their phase coexistence properties, vapor pressures, critical parameters, pure and mixture isotherms with water over carbon slit pore using atomistic Monte Carlo simulations

Finding the Correlation between Formative and Summative Assessments by Spearman’s Correlation Coefficient: A Case Study

Academic progresses of students are measured by using variety of statistical analysis techniques like central tendency, variability, percentiles and others. These measures help the teaching professionals to understand their student progress in their class. A relatively simple technique that can be used for exploratory data analysis is the Spearman rank correlation coefficient. In this paper the authors describe how the Spearman rank correlation coefficient can be used as a statistical tool to find out the correlation between two different types of assessments for a mathematics unit as a case study. This method is perhaps the simplest method for calculation of coefficient correlation. Is a non parametric technique for evaluating the degree of linear association or correlation between two independent variables. It is operates on the ranks of the data rather than the raw data. The case study result show that existence of a positive correlation of medium order between the formative and summative assessments. That is, increase in formative assessment the summative assessment also increase. In other words, some students who scored high in the formative assessment only managed to get medium scores in the summative assessment and vice versa

The Teaching and Learning of Trigonometry in Tertiary Educations

Trigonometry is an important part of mathematics at high school, college and university. Trigonometry is a subject that many university students find it difficult because it is not offered in depth in the high school to the extent that algebra and geometry were taught. The teaching professionals often said that the tertiary students’ knowledge about trigonometry was quite poor based on the assessments given to them. It has been observed that some of the elementary concepts of trigonometry are more easily comprehended than much of the usual work in algebra. The authors also believe that the teaching of trigonometry has to be developed from the meaning of the trigonometry functions as ratios (measurement of angles and sides of right angle triangles) and as number (compute the numerical value of the ratios representing different functions). Students should be acquainted with meanings of the tangents ration, the sine ratio, cosine ration and also terms as “angle of elevation” and “angle of depression”. Trigonometric functions appear to be difficult for the students due to the fact that their meanings have not been adequately explained. Therefore in this paper the authors want discuss further on how and what to be taught from trigonometric for the beginners in tertiary level.This paper suggests some of the avenues for exploration

A Dicationic Calix 4 Pyrrole Derivative and Its Use for the Selective Recognition and Displacement-Based Sensing of Pyrophosphate

A new bis-pyridinium calix[4] pyrrole derivative is reported. This system forms a non-fluorescent complex upon exposure to the chromenolate anion. The resulting supramolecular ensemble binds the pyrophosphate anion with high affinity (K-a (2.55 +/- 0.12) x 10(7) M-1) in acetonitrile. It exhibits sensitive "turn-on" fluorescence when exposed to tetrabutylammonium pyrophosphate, and does so in preference to other anions, including the fluoride and phosphate anions.NRF 2009-0087013BK21 programNational Science Foundation NSF CHE-1057904Chemistr

Determining optimal moulding process parameters by two level factorial design with center points

Determining optimal process parameter setting critically influences productivity, quality and cost of production in the injection moulding industry. Previously production engineers used trial and error method to determine optimal process parameter setting. Inappropriate machine parameter settings can cause production and quality problems. In this paper the authors used a case study to investigate the moulding machine parameters which will affect the dimensions (length and width) in a plastic component. The machine process setting in use currently caused variations in the dimensions exceeding the specification limit. Therefore the experiment is needed to identify the optimal machine parameter setting which could be set to maintain the dimensions closest to the target value with smallest possible variation. A design of experiments (two level factorial design with center points) was conducted to study the effect of three injection moulding process parameters (mould temperature, injection speed and injection pressure) versus dimensions (length and width). Finally, the optimal process parameters to maintain the dimensions closest to the target values were identified. Statistical results and analysis are used to provide better interpretation of the experiment. The models are form from ANOVA and the models passed the tests for normality and independence assumptions

In vivo evaluation of newly developed losartan potassium sustained release dosage form using healthy male Indian volunteers

Sustained release (SR) matrix tablets of losartan potassium were prepared by wet granulation using xanthene as the polymer. The studies indicated that the drug release can be modulated by varying the concentration of the polymer and the fillers. The estimation of losartan potassium from human plasma method involves simple protein precipitation techniques using nifedipine as internal standard. Chromatographic separation was carried out on a reversed phase C18 column using mixture of 0.5% triethyl amine (pH 3.5) and acetonitrile (60:40, v/v) at a flow rate of 1.0 mL/min with UV detection at 225 nm. The method was validated and found to be linear in the range of 20-300 ng/ml. An open, randomized, two-treatment, two period, single dose crossover, bioavailability study in 24 fasting, healthy, male, volunteers was conducted. Various pharmacokinetic parameters including AUC0–t, AUC0–∞, Cmax, Tmax, T1/2, and elimination rate constant (Kel) were determined from plasma concentration of both formulations. These results indicated that the analytical method was linear, precise and accurate. The sustained and efficient drug delivery system developed in the present study will maintain plasma losartan potassium levels better, which will overcome the drawbacks associated with the conventional therapy

Interval Based in Fuzzy Sliding Window for Forecasting Crude Palm Oil

Interval is the main component in time series forecasting, hence a Fuzzy Sliding Window Forecasting Method (SWM) suggested in obtaining intervals of forecasting in the Fuzzy Time Series (FTS). Formerly, almost all the intervals were calculated using class frequency. The intervals are then regrouping into the sub-intervals using the provided category. Whereas in this study, the prediction of interval obtained by embedding the idea of SWM into FTS forecasting. The intention of this suggested method is to further improve the success of a time series forecast and indirectly increase forecasting precision. The daily prices of Crude Palm Oil (CPO) data are taken for verification purposes. Hence, the precision of the suggested method is differentiating the existing forecasting method. The outcome of this method is compared to the other methods and it reveals that the suggested method produces precise intervals determination. The discovery of this study can be used as a replacement of existing forecasting method to get an improved prediction interval

Targeted drug delivery system:- formulation and evaluation of chitosan nanospheres containing doxorubicin hydrochloride

A chitosan molecule form self-assembled nanoparticles that can encapsulate a quantity of drugs and deliver them to a specific site. Chemical attachment of drug to chitosan throughout the functional linker has possibility to produce useful prodrugs, exhibiting biological activity at target site. In vivo residence time of the dosage form in the gastrointestinal tract and bioavailability of various drugs increases by mucoadhesive and absorption enhancement properties of chitosan. Antitumour activity of doxorubicin(DOX)-incorporated nanoparticles in vitro on DOX- resistant C6 glioma cells. Nanoparticles showed increased cytotoxicity compared to DOX alone. These results suggest that doxorubicin (DOX) was unable to penetrate into cells and did not effectively inhibit cell proliferation. In contrast, nanoparticles can penetrate into cells and effectively inhibit cell proliferation. There are 3 batches of drug loaded nanospheres in which 2.5mg,5mg and 10mg of DOX were loaded into nanospheres where the concentration of chitosan is 1%w/v. Anticancer drugs without targeting a specific site cause side effects. The objective of this research is to reduce side effects. HPLC device was used to quantitatively analyze amount of doxorubicin loaded in nanospheres. The result had showed concentration of anticancer drug loaded in nanospheres is directly proportional to the drug payload capacity until saturation point. The in vitro drug release studies was carried out for 48 hours to obtain a more precise result by carrying out this studies in a medium resembling our body environment such as pH7.4, 37ºC with analytical grade water for this studies. In vitro release of doxorubicin is of zero order kinetic. This shows that release is independent of the concentration of drug loaded in the nanospheres. Besides that, the graphs also show a sustained release manner, indicating these nanospheres formulation are suitable for targeting drug delivery system and for efficient treatment of cancerous cells