Study on the performance characterization and yarn mechanical properties of poly-m-phenylene isophthalamide nanofiber

In this paper, poly- m-phenylene isophthalamide (PMIA) staple fibers were dissolved in a LiCl/ N, N-dimethylacetamide solvent system in order to prepare PMIA nanofibers via the electrospinning method. The mean diameter of the nanofiber was between 72 and 247 nm and gradually increased with increasing LiCl concentration. PMIA nanofibers were characterized by scanning electron microscopy, Fourier transform infrared spectrometry, a thermogravimetric analyzer and Brunauer–Emmett–Teller analysis. Besides, the tensile strength of PMIA nanofiber yarns was tested and analyzed, combining the orthogonal array method. The results showed that the diameter and uniformity of nanofibers decreased gradually with increasing PMIA and LiCl solution concentration. The thermal properties, the specific surface area and chemical structures of PMIA nanofibers were improved comparing with PMIA stable fiber. It was found out that the LiCl concentration could influence the interactions among polymer molecules and caused the fibrils to wrap around each other, forming fiber clusters. The LiCl concentration was the most important factor affecting the tensile strength of PMIA nanofiber yarn.

Influence of the Kinematic System on the Geometrical and Dimensional Accuracy of Holes in Drilling

This article attempts to show how the kinematic system affects the geometrical and dimensional accuracy of through-holes in drilling. The hole cutting tests were performed using a universal turning center. The tool was a TiAlN-coated Ø 6 mm drill bit, while the workpiece was a C45 steel cylinder with a diameter of 30 mm and a length of 30 mm. Three kinematic systems were studied. The first consisted of a fixed workpiece and a rotating and linearly moving tool. In the second, the workpiece rotated, while the tool moved linearly. The third system comprised a rotating workpiece and a rotating and linearly moving tool, but they rotated in opposite directions. The geometrical and dimensional accuracy of the hole was assessed by analyzing the cylindricity, straightness, roundness, and diameter errors. The experiment was designed using the Taguchi orthogonal array method to determine the significance of the effects of the input parameters (cutting speed, feed per revolution, and type of kinematic system) on the accuracy errors. A multifactorial statistical analysis (ANOVA) was employed for this purpose. The study revealed that all the input parameters considered had a substantial influence on the hole quality in drilling.

Methodology for assessing the service level offered in the check-in area of brazilian regional airports

This paper proposes a methodology to evaluate the level of service offered in the check-in area of Brazilian regional airports, using as a case study a passenger terminal project proposed by the National Civil Aviation Secretariat. For this study operational aspects, terminal infrastructure and user profile were considered. The Taguchi Experiment Orthogonal Array Method was used to reduce the number of scenarios evaluated with Queueing Theory. An easy to apply analytical approach to passenger terminal check-in yield results that can assist decision makers in their efforts to reduce investments in the airport construction phase and optimize system operation.

Process optimization of the mechanical properties of AISI 1020 steel quenched using maize-stover ash potash solution

The process parameter optimization of maize-stover ash potash (MSAP) as a quenching medium for heat treatment of AISI-1020 steel was conducted in this study to improve the mechanical properties of steel after carburization and quenching. The optimization process utilized Taguchi L9(32) orthogonal array method to determine the individual Signal to Noise (S/N) ratio and Analysis of Variance (ANOVA). A multi-response weighted analysis technique was applied to derive combined quality responses of the heat treated test pieces. The result shows that the optimal factor level of MSAP solution strength was achieved at AM1BM1, which offered 57.6 HRC hardness, 39 J toughness and 1971 N/mm2 tensile strength as improved mechanical properties for the heat treated steel. Keywords: Optimization, MSAP, quenching, Taguchi, ANOVA

Parameter Sensitivity Analysis of a Beam Seal Based on a New Sealing Criterion and Orthogonal Array Method

A beam seal with an elliptical groove is proposed and parameterized. Based on the stochastic grid percolation model, macroscopic and microscopic finite element analysis, a sealing performance index is developed for the beam seal, which can consider the contact bandwidth and contact pressure synthetically. Taking the sealing performance index as the objective function, the sensitivity analysis of six main structural parameters of the beam seal is carried out by using the orthogonal array method. The orthogonal experiment with six factors and two levels is used to examine the interaction between parameter. It is found that there are parameter interactions between the length of the long axis and the short axis of elliptical groove, between taper angle and inclined angle U-shaped section, and between nominal contact width of the first seal and long axis of the elliptical groove. Furthermore, the sensitivity of each parameter on the sealing performance index of the beam seal is evaluated by the orthogonal design of L81(340) and F-test. The sensible parameters for sealing performance are obtained, and the optimal structural parameters of beam seal are suggested.

Parametric Analysis of Electrochemical Discharge Drilling on Soda-Lime Glass Material Using Taguchi L27 Orthogonal Array Method

The Electrochemical discharge machining (ECDM) is a hybrid non-traditional process which is specifically used for machining of conducting as well as non-conducting materials. In this research work, the fabricated ECDM experimental setup was used to machine the Soda-lime glass material with Brass tool material. The experiments were done on Soda-lime glass material with the help of Taguchi L27 orthogonal array method and analysed by using MINITAB 17 software. The average hole diameter and average machined depth results were checked after ECDM drilling on Soda-lime glass material with considering the input process parameters such as an electrolyte concentration, voltage and rotation. The experimental results indicated that voltage was the most dominant factor for average machined depth followed by an electrolyte concentration and rotation speed. The rotation speed was the most dominant factor for average hole diameter followed by voltage and electrolyte concentration.

Taguchi Optimization of Carboxymethylation Process and Effect Reaction Efficiency on Swelling Capacity

The aim of this research paper was to ascertain the optimum conditions required to economical synthesis carboxymethylated starch using experimental design technique by Taguchi for Larger-is-better and smaller-is better of reaction efficiency (RE). Orthogonal Array method was utilized in the design of the experiment which consisted of eighteen (18) runs based on three (3) independent Factors which are; Sodium hydroxide (NaOH) with three concentration levels (1, 1.5, and 2.0M), Sodium monochloroacetate (SMCA) with three concentration levels (1, 1.5, and 2.0M) and Reaction Time (T) with two (2) levels (2 and 4 hours) respectively and the response is reaction efficiency (R.E). The result obtained from the experiment was interpreted using the Taguchi method of larger-is-better and smaller-is-better was apply to estimate the Response for Signal-to-Noise Ratios. The analysis showed that for larger-is-better, the optimal condition to obtain high reaction efficiency (R.E.) of 9.97%, will require NaOH at 2.0 M, SMCA at 1.0 M, at reaction period of, while for smaller-is-better, the optimal condition to obtain low reaction efficiency (RE) of 1.93 %, will required the concentration of NaOH (aq) and SMCA (aq) to be 1.5 M and 1.5 M with a reaction period (T) of 4 hours respectively. The result was also study the influence of variable SMCA (aq) and NaOH (aq) concentrations on swelling capacity (SC) at reaction time of 2 hours. The result shows that 2M NaOH is the optimum concentration for carboxymethyl starch (CMS) synthesis. .Significant difference was ascertained using Tukey method, and at 95% Confidence level.

Statistically Validated and Optimized Tabu Search Estimation of Cutting Tool Life in Turning

In machining, tool life is the measure that gives manufacturers fundamental indications on useful tool utilization. In this work, investigated is the influence of turning parameters such as spindle speed, depth of cut, and tool feed on tool life. Literature-reported studies typically utilize Taguchi orthogonal array method for experimental design while tool-wear estimates utilized mathematical expressions by means ofregression analysis. In this work, the authors combine a tabu search (TS) algorithm with the traditional regression analysis (REG) to introduce a combined (TS-REG) scheme that minimizes a weighted sum of the outputs that represent different measures of turning quality. The aim in this paper is to show that the proposed novel combination TS-REG reaches better fitted models in minimal time as compared with other statistical methods. Tool life estimates are plotted versus different turning process parameters. The results that represent optimized tool life of the process are compared to literature reported experimental values. Good correlations confirm desirable efficiency and the ability of the TS-REG method in estimating tool life in turning. In order to determine statistical significance decisions, both p-values and mean absolute percentage error (MAPE: mean of the relative absolute error) were employed. The TS-REG method aids in determining the optimal set of parameters for any combination of the weighting factors resulting in improved tool life.