Search results

The purpose of this paper is to develop a mathematical model for delamination during drilling by using a response surface methodology (RSM) and also to determine how the input parameters (tool diameter, spindle speed and feed rate) influence the output response (delamination) in machining of fiber metal laminates.

Three factors and a three-level central composite design in RSM are used to carry out the experimental investigation. A video measuring system is used to measure the width of maximum damage of the machined FML composite. The “Design Expert 7.0” is used to analyze the data collected graphically. Analysis of variance is carried out to validate the model and for determining the most significant parameter.

The response surface model is used to predict the input factors influencing the delamination on the machined surfaces of the ARALL composite at different cutting conditions with the chosen range of 95 percent confidence intervals. Analysis of the influences of entire individual input machining parameters on the delamination has been carried out using RSM.

The effect of delamination on drilling of ARALL composites with solid carbide tools of various diameters has not been analyzed yet using RSM.

The purpose of this paper is to identify the ideal process parameters to be set for the drilling of hybrid fibre-reinforced polymer (FRP) (kenaf and banana) composite using High-Speed Steel drill bits (5, 10, 15 mm) coated with tungsten carbide by means of statistical reproduction of the delamination factor and machining force using Taguchi–Grey Relational Analysis.

The contemplated process parameters are Feed, Speed and Drill Diameter. The trials were carried out by taking advantage of the L-27 factorial design by Taguchi. Three factors, the three level Taguchi Orthogonal Array design in Grey Relational Analysis was used to carry out the trial study. Video Measuring System was used to identify the damage around the drill region. “Minitab 18” was used to examine the data collected by taking advantage of the various statistical and graphical tools available. Examination of variance is used to legitimize the model in identifying the most notable parameter.

The optimised set of input parameters were found out successfully which are as follows: Feed Rate: 450 mm/min, Cutting Speed: 3,000 rpm and Drill Diameter of 5 mm. When these values are fed in as input the optimised output is being obtained. From ANOVA analysis, it is apparent that the Speed (contribution of 92.6%) is the most influencing parameter on the delamination factor and machining force of the FRP material.

Optimization of process parameters on drilling of natural fibres reinforced in epoxy resin matrices using Taguchi–Grey Relational Analysis has not been previously explored.

Effective performance of a direct ethanol fuel cell (FC) stack depends on the satisfactory operation of its individual cells where it is always challenging to manage the temperature gradient, water flow and distribution of reactants. In that, the design of the bipolar fuel flow path plate plays a vital role in achieving the aforementioned parameters. Further, the bipolar plates contribute 80% of the weight and 30%–40% of its total cost. Aim of this study is to enhance the efficiency of fuel to energy conversion and to minimize the overall cost of production.

The authors have specifically designed, simulated and fabricated a standard 2.5 × 2.5 cm² active area proton exchange membrane (PEM) FC flow path plate to study the performance by varying the flow fields in a single ladder, double ladder and interdigitated and varying channel geometries, namely, half curve, triangle and rectangle.

Using the 3D PEMFC model and visualizing the physical and electrochemical processes occurring during the operation of the FCs resulted in a better-performing flow path plate design. It is fabricated by using additive manufacturing technology. In addition, the assembly of the full cell with the designed flow path plate shows about an 11.44% reduction in total weight, which has a significant bearing on its total cost as well as specific energy density in the stack cell.

Simultaneous optimization of multiple flow path parameters being carried out for better performance is the hallmark of this study which resulted in enhanced energy density and reduced cost of device production.

The purpose of this study is to fabricate and compare the mechanical and thermal properties of Sansevieria and Kaans fiber reinforced polyester matrices composites.

Treated Sansevieria and Kaans fiber was used as reinforcement for the fabrication of polymer matrix composites. Kaans fiber, which was available plenty in the delta region, but physical and mechanical properties of Kaans fiber were low when it compared with Sansevieria fiber. To make use of Kaans fiber for the fabrication of composite, the physical and mechanical properties have to be enhanced. So Egg shell powder was selected as a filler material to enhance the Kaans fiber reinforced composite. The selected fibers were properly weaved after alkali treatment. A three-layered (0°/45°/0°) Sansevieria fiber reinforced polymer (S-FRP) and Kaans fiber reinforced polymer (K-FRP) composite plates were fabricated using the compression molding method. As per American Society for Testing and Materials standards, the specimens were cut and mechanical, thermal and absorption properties of Sansevieria and Kaans fiber composites were investigated experimentally.

Tensile and flexural test reveals that K-FRP composite has good ductility and bending property than S-FRP composite plate. But from the other test results, S-FRP possesses high elongation capability than K-FRP. Thermo gravimetric analysis, moisture absorption and swelling test too done which clearly appeared S-FRP composite plate has prevalent execution than K-FRP composite plate.

This original research study enlists the mechanical, thermal properties and absorption properties of fabricated S-FRP and K-FRP composite plates.

The purpose of the study is to highlight the potential of the sensor based smartphone in assessing the covid-19 cases. Coronavirus disease 2019 (COVID-19) is a noxious pandemic affecting the respiratory system of the human and leading to the severe acute respiratory syndrome, sometimes causing death. COVID-19 is a highly transmittable disease that spreads from an infected person to others. In this regard, a smart device is required to monitor the COVID-19 infected patients by which widespread pandemic can be reduced.

In this paper, an electrochemical sensor-enabled smartphone has been developed to assess the COVID-19 infected patients. The data-enabled smartphone uses the Internet of Things (IoT) to share the details with the other devices. The electrochemical sensor enables the smartphone to evaluate the ribonucleic acid (RNA) of COVID-19 without the nucleic acid and feeds the data into the data server by using a smartphone.

The obtained result identifies the infected person by using the portable electrochemical sensor-enabled smartphone, and the data is feed into the data server using the IoT. Whenever an infected person moves outside the restricted zone, the data server gives information to the concerned department.

The developed electrochemical sensor-enabled smartphone gives an accuracy of 81% in assessing the COVID-19 cases. Thus, through the developed approach, a COVID-19 infected person can be identified and the spread can be minimized.

The purpose of this paper is to generalize the traditional risk evaluation methods and to specify a multi-level risk evaluation framework, in order to prepare customized risk evaluation and to enable effectively integrating the elements of risk evaluation.

A real case study of an electric motor manufacturing company is presented to illustrate the advantages of this new framework compared to the traditional and fuzzy failure mode and effect analysis (FMEA) approaches.

The essence of the proposed total risk evaluation framework (TREF) is its flexible approach that enables the effective integration of firms’ individual requirements by developing tailor-made organizational risk evaluation.

Increasing product/service complexity has led to increasingly complex yet unique organizational operations; as a result, their risk evaluation is a very challenging task. Distinct structures, characteristics and processes within and between organizations require a flexible yet robust approach of evaluating risks efficiently. Most recent risk evaluation approaches are considered to be inadequate due to the lack of flexibility and an inappropriate structure for addressing the unique organizational demands and contextual factors. To address this challenge effectively, taking a crucial step toward customization of risk evaluation.

Organic cotton, which is produced without any chemical fertilizers and pesticides, is playing a vital role in creating a less harmful environment. An investigation of the properties of weft knitted fabrics produced from organically made cotton vis-à-vis regular cotton knitted fabric is reported. The yarn is made with both organically produced and regular cotton, and the fabric is knitted by using single jersey machines. The fabrics are subsequently dyed by using natural dyes. The naturally dyed knitted fabrics are examined for shrinkage, bursting strength, abrasion resistance, and colour fastness properties. The result shows that the knitted fabrics produced from organically grown cotton is superior in performance in comparison with fabrics produced from regular cotton.

Hot and humid climates (HHCs) are potential environmental hazards that directly affect construction workers' health and safety (HS) and negatively impact workers' productivity. Extensive research efforts have addressed the effects of HHCs. However, these efforts have been inconsistent in their approach for selecting factors influencing workers in such conditions. There are also increasing concerns about the drop-off in research interest to follow through intrusive and non-real-time measurements. This review aims to identify the major research gaps in measurements applied in previous research with careful attention paid to the factors that influence the intrusiveness and selection of the applied data collection methods.

This research integrates a manual subjective discussion with a thematic analysis of Leximancer software and an elaborating chronological, geographical and methodological review that yielded 701 articles and 76 peer-reviewed most related articles.

The literature included the physiological parameters as influencing factors and useful indicators for HHC effects and identified site activity intensity as the most influencing work-related factor. In total, three main gaps were identified: (1) the role of substantial individual and work-related factors; (2) managerial interventions and the application of the right time against the right symptoms, sample size and measurement intervals and (3) applied methods of data collection; particularly, the intrusiveness of the utilised sensors.

The focus of researchers and practitioners should be in applying nonintrusive, innovative and real-time methods that can provide crew-level measurements. In particular, methods that can represent the actual effects of allocated tasks are aligned with real-time weather measurements, so proactive HHC-related preventions can be enforced on time.

This review contributes to the field of construction workers' safety in HHCs and enables researchers and practitioners to identify the most influential individual and work-related factors in HHCs. This review also proposes a framework for future research with suggestions to cover the highlighted research gaps and contributes to a critical research area in the construction industry.

The effects of Opuntia ficus indica (OFI) cladodes on uricemia level, endothelial dysfunction and oxidative damage were studied in young rats fed a cafeteria diet (CD).

A total of 16 young male Wistar rats (weighing 110 ± 20 g and four weeks old) were divided into two homogenous groups. The first group received a CD containing 50% of hyperlipidic diet and 50% of junk food mix (processed mix: hyper-fat, hyper-salted and sweetened) (CD group), and the second group (CD + OFI nopalitos) received the same diet supplemented with 50 g of fresh OFI nopalitos (young cladodes) for 30 days.

OFI nopalitos regulate the hyperuricemia, improve the endothelial dysfunction by raising the bioavailability of nitric oxide(NO) and reduce prooxidant markers by reducing lipid peroxidation and protein oxidation (p < 0.05) and boosting antioxidant capacity and enhancing the antioxidant enzymes activities (p < 0.05) in blood and aorta tissues of rats early fed with a high-fat diet /junk food.

By-products of OFI have specific functional properties that may be beneficial in metabolic disorders and offer a better alternative with an economic and sustainable development perspective.

By-products of OFI highlight potential functional properties mainly based on its potent antioxidant capacity. By-products of OFI can be used as a promising nutraceutical resource to prevent various metabolic disorders in relation with cardiovascular diseases or hyperuricemia in subjects consuming junk food and or living in the Western society to reach the objectives of health policy and maintain a sustainable health system development.