Abstract: Renewable energy sources, such as solar energy, could potentially provide an affordable alternative to conventionally generated electricity, especially in locations like the Caribbean which tend to have an abundant solar resource, but also high cost for electricity. Thin film and hybrid solar devices, including Dye-Sensitized Solar Cells (DSSCs), are especially promising energy solutions, due to the low cost of materials and equipment required for their fabrication. In this paper, we investigate the effect of doping titanium dioxide based DSSC photoanodes with lanthanum, cerium, and praseodymium species on the overall performance of the cell, along with results from optimization of the best performing cell formulation according to sintering time and sintering temperature, giving a maximum 39% increase in device efficiency.
Abstract: The main aim of this paper was to describe the viscosity and injection mold filling behavior of PA6 with 15% of glass fibers. Injection molding is one of the most widely used processes for polymer products. The quality of these products is directly linked to correct choice of process parameters. It is necessary to understand the filling behavior of the polymer material during the injection molding process. The spiral flow test was carried out in this study to explore the effects of several injection process parameters. The resulting lengths of spiral flow were compared. The polymer material under test was Polyamide 6 with 15% of short glass fibers (trade name: Durethan BKV 15). Virtual testing as well as real testing was performed. A predominantly linear relationship between the flow length and the mold temperature, melt temperature and injection pressure is described here. A special mold was designed for this test.
Abstract: In this paper, Single point diamond turning tests were carried out on rigid gas permeable contact lens (ONSI-56), using monocrystalline diamond cutting tools. During the tests, the depth of cut, feed rate, and cutting speed were varied. Turning experiments were designed based on Box-Behnken statistical experimental design technique. An artificial neural network (ANN) and response surface (RS) model were developed to predict surface roughness on the contact lens turned part surface. In the development of predictive models, cutting parameters of cutting speed, depth of cut and feed rate were considered as model variables. The required data for predictive models are obtained by conducting a series of turning test and measuring the surface roughness data. Good agreement is observed between the predictive models results and the experimental measurements. The ANN and RSM models for ONSI-56 contact lens turned part surfaces are compared with each other for accuracy and computational cost.
Abstract: The acceptability of polymer matrix composites for various industrial applications has been increased over the years due to their better mechanical properties. However, nonconductive nature and fibrous residuals produced during micro drilling of these materials has become major challenge for the research fraternity. The conventional machining of these materials causes high tool wear due to presence of abrasive particles. Recently, the electrochemical discharge machining (ECDM) process has emerged as potential contender for the machining of nonconductive hard and brittle materials. Keeping in mind all these challenges, the present research work focuses on micro drilling of PMCs using ECDM process. The experimentation was planned as per Taguchi’s methodology using L9 orthogonal array. Voltage, electrolyte concentration and duty factor were considered as process parameters whereas material removal rate and taper were observed as output quality characteristics. The regression equation and coefficients were obtained using regression analysis. Using this regression equations, further solutions were obtained by genetic algorithm.
Abstract: Aluminum metal matrix composites (Al-MMCs) is a one of the most demanding engineering material due to the combination of their light weight, excellent mechanical and tribological properties. To enhance the promising advantages of Al-MMCs, microwave sintering (MWS) is an ideal and emerging technique. The unique advantages of MWS of MMCs are ascribed to the size and distribution of the reinforcement, as well as to the grain size of the matrix along with uniform and efficient heating. The objective of this comprehensive review was to highlight the viability of sintering Al-MMC in a microwave oven, and compare the material characteristics of those with similar materials sintered in a conventional furnace.
Abstract: Aluminum ball joint is an advanced structure using to connect steering parts with the merits of simple and lighting. Usually extrusion strength and torque are the most important parameters to evaluate the ball joint properties. Generally, the ball sealed in the Aluminum housing by forming method which has an impact on the extrusion strength and torques. So how to control the forming and achieve the best properties is very important. In the paper, the relations between housing dimension and strength, torque are studied; the influence of forming on torque is researched. The rules in them are achieved.
Abstract: Composite materials with aluminium alloy 8011 matrix and 0, 4 and 8 weight percentages of ZrB2 reinforcements were synthesized by in-situ stir casting process. The presence and homogeneous distribution of the reinforcements were examined with X-ray diffraction analysis and scanning electron microscopic analysis. To investigate the effect of dry sliding wear parameters such as sliding distance, percentage reinforcement, load, sliding velocity and temperature on wear rate and co-efficient of friction, experiments were conducted using a pin on disc wear tester as per Taguchi’s orthogonal array design and the tribological behaviour of synthesized composites was investigated by statistical techniques. Significance and the influence of the parameters over the response were determined by analysis of variances and grey relational analysis was used to find the optimal combination of parameters to obtain minimum wear rate and co-efficient of friction.
Abstract: The purpose of this paper is to explore the potential of tablet manufacturing technology combined with 3D printing technology. The acetaminophen raw materials used for 3D printing are formulated in a clean environment according to the actual amount. And homemade material mixed-type three-dimensional printer is used to print double-layer acetaminophen tablets. In this paper, the factors influencing the quality of the tablet were explored by orthogonal experiments, and the optimal parameters were obtained. In order to determine whether the tablet meets the quality requirements, the hardness, friability and dissolution profiles of the 3D printing tablets were determined by the test instrument.
Abstract: A ternary micro Mg-0.5Zr-0.4Ce alloy is developed using disintegrated melt deposition method (DMD) followed by hot extrusion. The developed alloy exhibited superior mechanical properties i.e. microhardness, strength and ductility under tensile and compressive loading. In particular, the alloy exhibits excellent ductility (>25%) under both tensile and compressive loading. The mechanisms leading to strengthening and ductilization were examined through microstructural studies involving optical microscope, SEM and XRD texture analysis. Microstructure-property correlation studies are performed to understand these mechanisms.
Abstract: In this research study, two light weight multi-component high entropy alloys (HEAs) consisting of six constituent elements were synthesized. The high entropy alloy having a chemical composition of Mg35Al33Li15Zn7Ca5Y5 (atomic pct.) had a density of 2.25 g/cm3, while the high entropy alloy having a composition of Mg35Al33Li15Zn7Ca5Cu5 (atomic pct.) had a density of 2.27 g/cm3. The strategy of non-equiatomic composition, high entropy of mixing coupled with low density was applied in designing the alloy systems. Disintegrated melt deposition (DMD) technique was used to synthesize the materials and characterization studies were performed on as-cast materials. The present study emphasizes on examining and understanding the microstructural development in the two light weight high entropy alloys. The formation and presence of phases and microstructural evolution were studied by interchanging yttrium and copper. Microstructural observations revealed presence of multiple phases in the developed alloys and the simplification of the microstructure when copper is used instead of yttrium. Microhardness results revealed a significant increase in hardness of of both the HEAs (3.8 – 4.2 times) when compared to AZ31 commercial magnesium alloy.Keywords: High Entropy Alloy, Magnesium, Aluminum, Casting, Microstructure