Parametric study of a horizontal axis wind turbine with similar characteristics to those of the Villonaco wind power plant

<p class="JAREAbstract">The present paper focuses on the selection of parameters that maximize electrical energy production of a horizontal axis wind turbine using Python programming language. The study takes as reference turbines of Villonaco wind field in Ecuador. For this aim, the Blade Element Momentum (BEM) theory was implemented, to define rotor geometry and power curve. Furthermore, wind speeds were analyzed using the Weibull probability distribution and the most probable speed was 10.50 m/s. The results were compared with mean annual energy production of a Villonaco’s wind turbine to validate the model. Turbine height, rated wind speed and rotor radius were the selected parameters to determine the influence in generated energy. Individual increment in rotor radius and rated wind speed cause a significant increase in energy produced. While the increment in turbine’s height reduces energy generated by 0.88%.</p>

Optimization of material delivery time analysis by using Visual Basic for applications in Excel

<p>In small and medium enterprises, huge numbers of reports are prepared regarding the procurement, planning, production etc on daily, weekly, monthly, quarterly and yearly basis. If the interval between preparation of same report is longer then there is the greater probability that employee can forget the procedure of preparing the report; thus it is beneficial to automate these types of reports especially when there is no cost required for automation. In the same way, material delivery analysis is a kind of report which is prepared on monthly basis and as per the employees` feedback they usually forget some of the steps of report formation; therefore, there was the chance of mistake at the end of employee. Therefore, this report was automated for to minimize the chance of error and report preparation time. All the manual tasks were enlisted and were programmed for automation by the help of VBA macros. For the execution of macros, userform was designed in visual basic editor (in MS excel) consisted on four command buttons and macros were called on command buttons` click. On pressing ‘ctrl + q’ userform used to appear on the screen. Furthermore, the comparison of old and automated methods was conducted to reflect the best suitable method. The report used to take 1.55 minutes to be made manually. Comparison of time of both methods of report formation indicated that suggested method took 70.86% less time as compared to the old method of preparing material delivery time analysis report.</p>

Analysis of various polymer parts in contact with biodiesel

<p>In this paper, several parts consisting of polymeric materials are studied, in order to determine if they are affected when they are kept in contact with biodiesel at constant temperature and pressure. The samples used are constituted by polymers of silicone (S), acrylonitrile (AN) and propylene hexafluor (Viton-V7). These materials have been selected for investigation because they form part of an industrial process in which they are used, and have been observed early wear characteristics thereof. They consist of seals and cords which are in contact with biodiesel. These materials were kept immersed in biodiesel at atmospheric pressure at a temperature of 40°C for time periods up to 120 days. Virgins tested ones are characterized by various techniques: OM, SEM, XRD, DTA-TGA, among others. Viton sample was the least affected by treatment, while the acrylonitrile sample is the one that has shown the greatest variations.</p>

Statistical analysis of waiting time of patients by queuing techniques: case study of large hospital in Pakistan

<p class="JARTEAbstractHeader">The purpose of this empirical research was to analyze the comfortable waiting time (CWT) of patients at the outpatient department (OPD) of Gastrology of ABC hospital of Karachi. It is based on the analysis of CWT of patients who were being served at the OPD of Gastrology of ABC hospital of Karachi. The data was collected by the help of questionnaire. Altogether 250 questionnaires were distributed among the patients, 210 of them were collected back and 10 of them were incompletely filled. Data was analysed in the statistical package for social sciences (SPSS) version 22. Data analysis included frequency distribution of various demographics;stratification tables were made for the comparison of CWT across various demographics. Results indicated that more females (old aged) had greater CWT in the comparison of males. It is found that the mean CWT of patients decreased with decreasing age, increasing OPD visiting time and increasing income. It is also found that he mean CWT for the patients from Afghanistan was greater than the patients from other regions i.e. Baluchistan, interior Sindh and Karachi. The authors highlighted that when patients arrive at the hospital and wait for their service, in this scenario, waiting cost is associated with their waiting time; since it is the matter of cost, thus it should be known to the hospital that if patients are made to wait longer, it can lead to the customer dissatisfaction. In this regard, analysis of comfortable waiting time of patients was extremely needed. Since, Karachi is the biggest city of Pakistan and targeted hospital is one the biggest private hospitals of Karachi and in the analysis of this paper. Only 200 patients were approached for data collection which is the main limitation of the paper. In future, the researchers should also focus on the same OPD for more responses and at the same time, other departments can also be targeted for conclude better and precise results. The authors have tried to focus on the CWT of patients so that the waiting capacity of patients could be highlighted. At the same time, detailed analysis was conducted across demographics so that their influence on CWT could be analysed.</p><p class="JARTEKeywords"> </p>

Manufacturing and compatibilization of binary blends of polyethylene and poly(bulylene succinate) by injection molding

<p class="JARTEAbstract">In this study was analyzed the effect of three different compatibilizers polyethylene-graft-maleic anhydride (PE-g-MA), unmodified halloysite nanotubes (HNTs), and HNTs treated by silanization with (3-glycidyloxypropyl) trimethoxysilane (GLYMO) (silanized HNTs) in blends of bio-based high-density polyethylene (bioPE) and poly(butylene succinate) (PBS) with a weight ratio of (70/30). Each compatibilizer was added in a proportion of (3 phr regarding PBS). Standard samples were obtained by extrusion and subsequent injection molding. The analyzes of the samples were performed by mechanical tests, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), field emission scanning electron microscopy (FESEM), and wettability (θ_w). Results suggest that the addition of modified HNTs (silanized HNTs) allowed to obtain better properties than samples compatibilized with unmodified HNTs and PE-g-MA, due to it contributes with the improvement in mechanical properties regarding bioPE/PBS blend, for instance, the tensile modulus and elongation at break increase about 8% and 13%, respectively. In addition, it was determined through FESEM images and that silanized HNTs particles were better dispersed over the matrix, which in fact contribute to the enhance in mechanical properties. TGA showed that silanized HNTs delay the degradation temperature regarding the uncompatibilized blend. While DMTA indicated the reduction in the mobility of the chains in samples with unmodified and modified HNTs. Therefore, it was successfully obtained compatibilized bioPE/PBS blends, which constitutes an interesting option to develop new sustainable polymers.</p>

Degradation of a mechanically recycled polylactide/halloysite nanocomposite in an ethanolic food simulant

<p class="JARTEAbstract">This work aims to study the effect of immersion in a ethanolic food simulant in mechanically recycled poly(lactic acid) (PLAR) and its nanocomposites reinforced with halloysite nanotubes (HNT). PLAR was obtained by subjecting PLA to an accelerated ageing process, which includes photochemical, thermal and hydrothermal ageing steps, followed by a final demanding washing step. PLAR was further reinforced with 4 %wt. HNT to improve the properties of the PLAR films. The materials were melt compounded by melt extrusion and processed into films by compression molding. The resulting films were exposed to food simulant D1 (50 %vol. ethanol solution) for 10 days at 40 °C. The intrinsic viscosity, crystallization behavior, thermal stability as well as the mechanical performance were analyzed before and after the contact with the food simulant. The swelling, plasticizing and hydrolyzing effect of the food simulant led to an important decrease of the intrinsic viscosity of all the samples, along with a significant increase of the crystallinity. Thermal stability was negatively affected by the decrease of the molecular weight, while the high crystallinity values resulted in materials with higher Vickers hardness values after the immersion in the food simulant.</p>

Integration of FMECA and statistical snalysis for predictive maintenance

<p>The estimation of time-to-failure of machines is of utmost importance in the Manufacturing Industry. As the world is moving towards Industry 4.0, it is high time that we progress from the traditional methods, where we wait for a breakdown to occur, to the prognostics based methods. It is the need of the era to be aware of any incident before it occurs. This study provides application of Statistical-based Predictive maintenance. A BOPP Production line has been considered as a case study for this research. Since the inception of the line in 2013, it is evident that 60% of breakdowns are due to lack of maintenance and timely replacement of bearings. Therefore, the research is based on the application of FMECA (Failure Modes, Effects and Criticality Analysis) to determine which bearing in the production line is most prone to failure and determination of which statistical model best fits the failure data of the most critical bearing. The result provides the best distribution fit for the failure data and the fit can be utilized for further study on RUL (Remaining Useful Life) of the bearing through Bayesian Inference.</p>

Preparation and mechanical properties of Nanoclay-MWCNT/Epoxy hybrid nanocomposites

<p>Among the various kinds of reinforcing element, Multi Wall Carbon Nano-tubes (MWCNT) and Nanoclay have found much more attention as a filler element to upgrade the mechanical properties of polymer composite material. In this paper, production of hybrid nanocomposites and the effect of MWCNT and nanoclay on mechanical properties of hybrid nanocomposites have been evaluated. In hybrid nanocomposites, MWCNT and nanoclay are embedded in epoxy resin. The processing of hybrid nanocomposite is always been a difficult task for researcher to prepare defects free samples. Here, the processing of Epoxy/Nanoclay-MWCNT hybrid composites has been done by using homogenizer and ultrasonic techniques for complete dispersion of nanoparticles into epoxy resin. The MWCNT and nanoclay were embedded into epoxy resin in different weight fractions and mixtures were used for tensile test and hardness specimen production. The tensile modulus and tensile strength values have been calculated via tensile tests. The test result shows that tensile modulus of samples increases as the filler content increase up to certain extent but then start decreasing. Also the elongation reduces as the filler content rises in the epoxy which shows the brittleness present in the samples. Rockwell hardness on B-scale was conducted on Nanocomposite samples and found that increasing the filler content excessively does not improve hardness as much.</p>

Design and simulation of a resorbable bone fixation plate made by additive manufacturing for femoral mid-SHAFT fractures

<p class="JARTEKeywords">Finite element method has been employed to establish the feasibility of a fixation plate made of PLA by additive manufacturing for femoral shaft fractures. For this purpose, Von Mises stress and the pressure contact between bones had been analysed. The proposed design has been compared with an actual titanium fixation plate as a point of reference.</p>

An approach to a maintenance plan for a turbine of hydroelectric power plant. Optimisation based in RCM and FMECA analysis

<p class="JARTEAbstract">The generation of electric energy is a continuous process of great strategic importance in the development of countries. The evolution in the last decades of different environmental control protocols at a global level has influenced the rise of renewable energies with low impact on the environment. These reasons make it important that this process has an effective maintenance management system that guarantees adequate reliability, availability and useful life of its assets. This article describes the implementation of the optimization of the traditional preventive maintenance that is carried out in regular temporary intervals with unavailability of the hydroelectric group, to be able to take advantage of the data base of operation of the group (failure modes, criticality, application of maintenance strategies to condition and maintenance 4.0, etc…).</p>