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Over the years, machinists have been exploring the hard part turning of AISI D2 steels. Initially, cylindrical grinding was used for this purpose, but it was later replaced by single-point turning due to its advantages such as high material removal, low cost, and greater flexibility. Conventional inserts are used in single-point turning, but they have been reported to have large radial forces, high notch wear, and poor surface finish. Therefore, multi-radii wiper inserts were designed to overcome these machining issues, but their use was restricted to shallower depths of cut and moderate feed rates because of the thick chips produced by the high entry angle. Prime inserts, on the other hand, were designed with a modest entry angle, making them ideal for evaluating tool wear/life, material removal and surface roughness at greater cutting speeds, depths of cut, and feed rates. It was observed that cutting speed has a significant effect on tool wear/life with a contribution of 55.38% followed by feed rate (13.72%) and depth of cut (11.43%). Cutting speed (84.87%) and feed rate (13.01%) are observed to be the most significant parameters controlling material removed. It was also observed that feed rate has a significant effect on workpiece surface roughness with a contribution of 67.30% followed by depth of cut (20.60%), whereas cutting speed had no significant effect on surface roughness. Moreover, it is found that prime insert outperformed wiper and conventional inserts in terms of tool life/wear and surface roughness.

In the light-activated work-holding devices, hardened adhesive residues on the fixture plate need to be removed to make it available for the subsequent work holding. There are several ways to remove the cured adhesive from the gripper, such as laser-based degradation, and softening and removing with high temperature pressured water wash. These processes are associated with the generation of carbon black, affecting transparency which compromises the efficiency of the light-activated device. A novel peripheral grinding-based cleaning process has been developed to strip the adhesive from the fixture plate. The present research is aimed to analyze the effect of variation in grinding parameters, viz., spindle speed, feed, depth of cut, and the grain size of the grinding wheel on the temperature of the adhesive being ground and cleaning of the adhesive-filled channel. Aggressive values of grinding parameters are selected to achieve the desired removal of adhesive, putting a step towards sustainability. Moreover, a comprehensive investigation of the temperature of the grinding zone and the grinding wheel is made by inspecting the effective cleaning of the cured adhesive-filled channel. Higher values of spindle speed (11.57 m/s) and feed (0.406 mm/rev) resulted in an improved, cleaned surface of the ground adhesive-filled channel. Moreover, the grinding wheel with a more prominent grain size (46/Ø 0.35 mm) and porosity was proved to be more effective in the cleaning process by reducing and maintaining the grinding temperature (~52 °C) of the adhesive-filled channel.

The superior engineering properties and excellent biocompatibility of titanium alloy (Ti6Al4V) stimulate applications in biomedical industries. Electric discharge machining, a widely used process in advanced applications, is an attractive option that simultaneously offers machining and surface modification. In this study, a comprehensive list of roughening levels of process variables such as pulse current, pulse ON time, pulse OFF time, and polarity, along with four tool electrodes of graphite, copper, brass, and aluminum are evaluated (against two experimentation phases) using a SiC powder-mixed dielectric. The process is modeled using the adaptive neural fuzzy inference system (ANFIS) to produce surfaces with relatively low roughness. A thorough parametric, microscopical, and tribological analysis campaign is established to explore the physical science of the process. For the case of the surface generated through aluminum, a minimum friction force of ~25 N is observed compared with the other surfaces. The analysis of variance shows that the electrode material (32.65%) is found to be significant for the material removal rate, and the pulse ON time (32.15%) is found to be significant for arithmetic roughness. The increase in pulse current to 14 A shows that the roughness increased to ~4.6 µm with a 33% rise using the aluminum electrode. The increase in pulse ON time from 50 µs to 125 µs using the graphite tool resulted in a rise in roughness from ~4.5 µm to ~5.3 µm, showing a 17% rise.

Electric discharge machining is relatively a slow process in terms of machining time and material removal rate. The presence of overcut and the hole taper angle caused by the excessive tool wear are other challenges in the electric discharge machining die-sinking process. The areas of focus to solve these challenges in the performance of electric discharge machines include increasing the rate of material removal, decreasing the rate of tool wear, and reducing the rate of hole taper angle and overcut. Triangular cross-sectional through-holes have been produced in D2 steel through die-sinking electric discharge machining (EDM). Conventionally, the electrode with uniform triangular cross-section throughout the electrode length is used to machine triangular holes. In this study, new designs of electrodes (non-conventional designs) are employed by introducing circular relief angles. For material removal rate (MRR), tool wear rate (TWR), overcut, taper angle, and surface roughness of the machined holes, the machining performance of conventional and unconventional electrode designs is compared. A significant improvement in MRR (32.6% increase) has been achieved by using non-conventional electrode designs. Similarly, the hole quality resulted by non-conventional electrodes is way better than hole quality corresponding to conventional electrode designs, especially in terms of overcut and hole taper angle. A reduction of 20.6% in overcut and a reduction of 72.5% in taper angle can be achieved through newly designed electrodes. Finally, one electrode design has been selected (electrode with 20 degree relief angle) as the most appropriate electrode resulting in better EDM performance in terms of MRR, TWR, overcut, taper angle, and surface roughness of triangular holes.

Ablation sand casting is a new technology for casting aluminum alloys which helps to achieve superior cooling trends during the solidification and results in eutectic microstructure, reduced degree of defects, and improved mechanical attributes. To further enhance the functionality, water-soluble binder-based sand molds are used in conjunction with appropriate control over process parameters for specialized applications such as complex and thin-walled impeller manufacturing. In this regard, the influence of key process parameters including binder ratio (BR), sand grain fineness number (AFS number), and pouring temperature (PT) is investigated thoroughly on the mechanical characteristics (ultimate tensile strength and hardness) and dimensional accuracy of the thin-walled impeller. Ablation sand casting revealed exceptionally enhanced mechanical properties and dimensional accuracy as compared to conventional sand casting. The AFS number and binder ratio were most significant for controlling the dimensional accuracy. Multi-response optimization through Grey Relational Analysis reveals the optimal setting PT = 800 ℃, ASF number = 45, BR = 5% for lower dimensional deviation, higher hardness, and ultimate tensile strength through conventional sand casting. While for ablation case, the optimal conditions PT = 850 ℃, ASF number = 40, BR = 9% are attained against desired attributes. The attributes are significantly improved through ablated sand casting, dimensional accuracy 31.6%, hardness 58.9% and ultimate tensile strength 41.82%, and fractography analysis depicted the ductile fracture surface. The current technology is drawing attention of industry because of its potential in producing castings with superior mechanical properties and improved internal integrity.

This study investigates the nexus between real effective exchange rate (REER) misalignment and the economic growth of Pakistan. It relies on a single equation model for estimating equilibrium exchange rate using the autoregressive distributive lags (ARDL) approach. The study further uses the growth equation to explore the effects of misalignment of RER on growth proxies. The data were obtained from the official websites of the World development indicator, IMF, Penn World Table, Pakistan Bureau of Statistics, and Ministry of Finance Pakistan. In terms of trade, the data was available on three different bases in different editions of the economic survey of Pakistan. All unit values of imports and exports were changed as per new base 1991 so that the data from editions of survey becomes uniform. The study takes data from 1970 to 2020. The study findings show that gross capital formation, trade openness, and government spending have a substantial role in defining the equilibrium REER. The findings also identify a positive and significant effect of REER misalignment on the economic growth of Pakistan. This paper contributes by measuring the degree of misalignment of real exchange rates using the single equation approach which is rare in the case of Pakistani literature. The single equation approach not only measures the misalignment by PPP factor but also considers basic economic fundamentals such as trade openness, terms of trade, productivity differentials etc. The study further provides evidence of misalignment with economic growth over a longer period (1970-2020). The findings suggest the effective use of exchange rate policy to control exchange rate misalignment to get higher and more sustainable economic growth. The study is useful for policymakers in the long-term economic planning of Pakistan. The results can be generalized for other economies with similar features.

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. This study was funded by the Faculty of Computing, Engineering and Media at De Montfort University Since the development of additive manufacturing (3D printing), there has been a growing interest in the use of 3D printed lattice structures for a range of mechanical and biomedical applications. This study investigates the elastic properties of different types of strut-based lattice structures obtained through a series of compression tests and compares them against numerically calculated properties of intended designs. Two different 3D printing processes are employed for the fabrication of lattice structures, including selective laser sintering (SLS) and digital light processing (DLP). Gibson-Ashby power-law for cellular structures has been initially utilised as a framework for the comparison of numerical and experimental results. The results are normalised, allowing the comparison of elastic properties of lattices made in different polymer materials independent of the bulk material properties. This study suggests that although the mechanical properties of the fabricated parts are heavily dependent on the design of lattice unit-cell, the mechanical properties can be significantly different to those of intended designs depending on the 3D printing process used for the fabrication of lattice structures.

The requirement of cost-effective and ecological production systems is crucial in the competitive market. In this regard, the focus is shifted towards sustainable and cleaner machining processes. Besides the clean technologies, effective parametric control is required for machining materials (such as High Strength Low Alloy Steels) specifically designed for high strength applications having superior physio-chemical properties. Therefore, the machinability complexities require optimized solutions to reduce temperature elevation and tooling costs and improve machining of these materials. Complying to the market needs, this research examines the effectiveness of nanofluid on tool life, wear mechanisms, surface roughness (Ra), surface morphology, and material removal rate (MRR) in turning of 30CrMnSiA (HSLA) using minimum quantity lubrication (MQL) and SiO2-H2O nanofluids (NF-MQL). A systematic investigation based on physical phenomena involved is carried out considering four process parameters (cutting speed (VC), feed rate (Fr), depth of cut (DOC), and mode of lubrication for machining. Fr is found as the vital parameter for surface roughness while MRR is highly influenced by DOC regardless of lubrication approach. One-step sustainability technique is applied, in which process variables used for roughing conditions are analogous to attain surface comparable to finished machining without compromising process efficiency and demonstrate its feasibility through optimal settings under NF-MQL. Multi-response optimization proved the NF-MQL machining condition as the best alternative which result in 28.34% and 5.09% improvements for surface roughness and MRR, respectively. Moreover, the use of SiO2 is recommended over MQL due to lower energy consumption, low tool wear, and better surface integrity, sustainable liquid, and related costs.

One of the sustainability goals in the aeronautical industry includes developing cost-effective, high-performance engine components possessing complex curved geometries with excellent dimensional precision and surface quality. In this regard, several developments in wire electric discharge machining have been reported, but the influence of flushing attributes is not thoroughly investigated and is thus studied herein. The influence of four process variables, namely servo voltage, flushing pressure, nozzle diameter, and nozzle–workpiece distance, were analyzed on Inconel 718 in relation to geometrical errors (angular and radial deviations), spark gap formation, and arithmetic roughness. In this regard, thorough statistical and microscopical analyses are employed with mono- and multi-objective process optimization. The grey relational analysis affirms the reduction in the process’s limitations, validated through confirmatory experimentation results as 0.109 mm spark gap, 0.956% angular deviation, 3.49% radial deviation, and 2.2 µm surface roughness. The novel flushing mechanism improved the spark gap by 1.92%, reducing angular and radial deviations by 8.24% and 29.11%, respectively.

Activity of plant essential oils and their fractions was evaluated against characterized isolates of antibiotic resistant Enterococcus faecalis recovered from diarrheic children. The isolates were confirmed by polymerase chain reaction (PCR) targeting 16S rRNA gene amplification followed by nucleotide sequencing and accession numbers retrieved were MW349990.1, MW349859.1, MW332122.1, MW356805.1, MW349975.1, MW349988.1, MW356790.1, MW356244.1, MW341593.1 and MW332549.1. These isolates were screened for antibiotic susceptibility to a wide range of antibiotic groups and mean zone of inhibition (ZOI) of all antibiotics were recorded. Antibacterial activity of plant essential oils (n=05) was checked against three antibiotic resistant isolates of E. faecalis. Three plant essential oils having higher ZOI including Cinnamomum verum, Syzygium aromaticum and Nigella sativa were used against resistant E. faecalis isolates to determine minimum inhibitory concentration (MIC). The lowest MIC observed was of S. aromaticum (11.39±3.94 mg mL

Peculiar characteristics of squeeze casted hybrid aluminum matrix composites (AMCs) enable it as an appropriate candidate for various manufacturing applications but also make their machining challenging. For that reason, wire electric discharge machining (WEDM) has been preferred over conventional machining processes for the cutting squeeze casted Al2024/Al2O3/W hybrid composite in this study. The presence of nanoparticles in the material affects the machining performance of wire electrodes. Therefore, molybdenum and zinc-coated wires have been chosen, and cryogenic treatment has been applied to improve their machining performance. To analyze the effects of cryogenic treatment, the machining efficiency of cryogenic treated (CT) wire has been compared with non-treated (NT) wire. Besides wire type, four key input variables including pulse duration (TON), wire feed rate (FR), wire runoff speed (SW), and wire tension (TW) have also been optimized to improve the imperative response measures including cutting speed (CS), surface roughness (SR), and kerf width (KW). Microstructural analysis of NT wire depicts a high concentration of micro-voids, micro-cracks, and deep craters, while the surface of CT wire has been observed relatively fine after the machining. Comparative analysis of both wire electrodes has declared that CT wire yields 26.96% and 15.10% superior results for CS and SR respectively, and 6.92% deprived results for KW than NT wire. Grey relational analysis (GRA) has been practiced for multi-objective optimization and presented TON = 3 μs, FR = 13 m/min, SW = 11 m/min, and TW = 10 g as an optimal set of input variables to achieve 75.1% and 72.5% overall results with NT and CT wire, respectively.

The present study aims to examine the short-run and long-run impact of China’s trade liberalization policies on its energy demand over the period from 1980 to 2018. The results of Autoregressive Distributed Lag approach of co-integration show that energy consumption significantly increases as a result of trade openness and increase in real Gross Domestic Product (GDP). The results of the granger causality test also confirm the unidirectional causality running from trade openness and real GDP to energy demand. The results of the study have an important implication because if China wants to continue its trade liberalization policies then it must increase its energy production.Keywords: Energy Consumption, Gross Domestic Product, Trade Openness, China, Time SeriesJEL Classifications: C22, F15, L98, Q43DOI: https://doi.org/10.32479/ijeep.11160

Since the emergence of COVID-19 pandemic in China in late 2019, scientists are striving hard to explore non-toxic, viable anti-SARS-CoV-2 compounds or medicines. We determined In vitro anti-SARS-CoV-2 activity of oral formulations (syrup and capsule)of an Iodine-complex (Renessans). First, cell cytotoxicity of Renessans on the Vero cells was determined using MTT assay. Afterwards, the antiviral activity of Renessans was determined using viral inhibition assays and TCID50. For this, nontoxic concentrations of the Renessans were used. The results showed that Renessans is nontoxic to the cells up to 50 µg/mL. At 1.5 µg/mL concentration, SARS-CoV-2 production was significantly reduced to 101.43 TCID50 and 101.58 TCID50 for the syrup and capsule, respectively, as compare to virus infected control cells 106.08 TCID50 and we found the dose dependent inhibition of virus replication in the presence of Renessans. Renessans inhibited SARS-CoV-2 with an EC50 value of 0.425 µg/mL and 0.505 µg/mL for syrup and capsule, respectively. Furthermore, there was no virus detected at concentration of 50 µg/mL of Renessans. This study indicates that Renessans, containing iodine, have potential activity against SARS-CoV-2 which needs to be further investigated in human clinical trials.

Bubble electrospinning is an effective method to produce nanofibers with different morphologies. Numerous polymer film fragments are formed from bursting bubbles, which elongate to nanofibers under high electrostatic voltage. In two polymers, bubble electrospinning film fragments of both polymers could interact due to the dominant surface-induced force named geometrical potential. Mathematical models are established to elaborate on the non-linear oscillators with singular terms. Parameter expansion technology used in the homotopy perturbation method can be useful for such kind of non-linear oscillators. In this paper, this technique is implemented to find the amplitude-frequency relationship of the attachment oscillator used in the molecular electrospinning process to produce nanofibers. The results depict the effectiveness of the method and show that the frequency obtained for duffing oscillator is highly accurate in exceptional cases.

Objective: The objective of the study was to assess the knowledge, attitude, and practices (KAP) about Hepatitis B virus (HBV) among the students of medical and dental colleges of Karachi. Methodology: The cross-sectional study was conducted in five medical and dental colleges of Karachi. Students of the 3rd, 4th, and final year were invited to join the study. The questionnaire included sociodemographic information followed by three sections evaluating the knowledge, attitudes, and practices regarding HBV. Twenty-nine questions were related to knowledge, 11 for attitude, and 4 for practices. Pearson's Chi-square test/Fisher's Exact test and Spearman correlation were utilized to find the association and correlation of knowledge, attitudes, and practices with independent variables. Results: Three hundred and seventy-nine students participated in the study. Two hundred and nine of them (78.9%) were females and 253 (66.8%) students were medical students. Ninety-five percent of the students correctly responded of the causative organism of HBV. Knowledge of MBBS and BDS students for transmission of HBV were significantly different for the questions: “mother to child,” coughing and sneezing' and “kissing.” Almost all the responses regarding complications due to HBV (respiratory failure, stroke, congestive heart failure liver, cirrhosis, colorectal cancer, and spine and bone fracture) received more than 90% of correct answers. In response to contraindication factors for HBV, only “extreme of ages” showed a significant difference between the genders. The percentage of poor, moderate, and good knowledge were 17.4%, 53%, and 29.6% respectively. About 60% of students indicated that they have gone through screening for HBV. About 20% of students indicated that they had experience of needle injury and only 43% of them taken postexposure prophylactic measures. Conclusion: Study revealed that the KAP of medical and dental students of Karachi are satisfactory and have been improved. However, few elements need to be focused in curricula and workshops for further improvement.

With advancement of nanoscience, "nanofluids" are becoming quite popular among thermal engineers. High thermal conductivity, relatively less settling speed, and higher surface area of nanoparticles are a few key promoting properties. The last two decades have seen dramatic progress towards using nanoparticles in industrial applications. However, the stability and rheological characteristics of prepared nanofluids have serious effects on their transport characteristics, but unfortunately, this has not found proper attention from researchers. In this study, stability and rheological characteristics of ZnO nanoparticles within deionized water, ethylene glycol, and their blends have been extensively tested. Stability was observed using UV-vis spectroscopy, while the viscosity was measured with the help of a rheometer. The data was collected with 0.011-0.044 wt.% loading of nanoparticles, while experiments were conducted within 15-55?C temperature range. Better stability was recorded when nanofluids were prepared with pure ethylene glycol. Experiments showed that the viscosity increased with particle loading, whereas the effect of surfactants appeared to be insignificant. Research results were used to assess predictions of different viscosity models. Experimental data was overpredicted by Einstein, Brinkman, and Batchelor?s models.

The emerging demands of industry for developing the novel materials with superior mechanical properties have successfully resulted in the development of distinct materials such as Al-matrix composites. Among these composites, newly developed Al6061-7.5% SiC holds promising mechanical characteristics. But, the SiC reinforcement in the Al-matrix makes the machining of this composite challenging, thus posing a serious concern regarding its effective utilization. In this research, high-speed wire electric discharge machining (WEDM) was employed for the precise machining of a squeeze casted Al6061-7.5% SiC composite. The cutting performance of the WEDM was assessed in terms of roughness (SR), cutting rate (Cs) and kerf width (KW). Experimentation was performed according to the response surface methodology. The experimental findings were thoroughly investigated using statistical, optical and scanning electron microscopic (SEM) analyses. It has been revealed that the voltage is most influential/contributing parameter (having a percentage contribution of 25%) for controlling theSRduring WEDM of Al6061-7.5% SiC composite, whereas for theCSandKW, pulse and current are the major contributing control variables with percentage contributions of 90% and 84%, respectively. At low magnitude of both current and voltages, the surface quality is improved up to 33.3%. The SEM and optical microscopic evidences reveal shallow craters, small size melt re-deposits and micro globules on the machined surface at lower settings of both the said variables. Contrarily, for achieving higher cutting speed, high values of current and voltage along with low pulse are deemed essential. In case ofKW, low magnitude of current and voltage along with smaller pulse yields 20% reduction in the kerf width. The analyses revealed the conflicting nature of the studied output responses (SR,CsandKW). Therefore, multi-objective genetic algorithm (MOGA) was used to find a parametric combination. The best combination of WEDM input parameters found is current = 3 A, voltage = 84.999 V and pulse = 10 mu. This combination gives a minimumSRof 5.775 μm with aKWof 0.3111 mm at aCSof 5.885 mm/min. The suitability of the MOGA-proposed parametric combination was witnessed through confirmation trials. Furthermore, the parametric effects have also been mathematically quantified with respect to the defined machinability parameters.

Al-matrix composites specifically Al6061-7.5%SiC which holds promising mechanical properties, is a potential candidate in aeronautical industry. Though the reinforcement of SiC in Al-substrate has ...

It is very difficult to electrospin pure chitosan (CS) due to the repulsive forces between its ionic groups produced in the electrospinning process, resulting in the formation of nanofibers by blending CS with other natural or synthetic polymers for electrospinning. In this research work, a high-throughput fabrication of CS/poly(ethylene oxide) (PEO) nanofibers were obtained using a modified free surface electrospinning (MFSE), which contained a titanium solution reservoir with thick smooth edges. Effects of the concentrations of acetic acid (AA), CS and PEO on the conductivity and viscosity of spinning solutions as well as the morphology, crystallinity and yield of CS/PEO nanofibers were investigated. And the fabrication mechanism of MFSE was studied by simulating the electric field distribution using Maxwell 3D due to the importance of electric field distribution in the spinning process. The simulation results of electric field were in keeping with the experimental data and indicated the MFSE could produce a lot of high-quality CS/PEO nanofibers.

World health organization (WHO) data shows that air pollution kills an estimated seven million people worldwide every year. A nanofiber based biodegradable facemask can keep breath from smoke and other particles suspended in the air. In this study, we propose branched polymeric nanofibers as a biodegradable material for air filters and facemasks. Fibers have been elecrospun using double bubble electrospinning technique. Biodegradable polymers, PVA and PVP were used in our experiment. Two tubes, each filled with one of the polymers, were supplied with air from the bottom to form bubbles of polymer solutions. DC 35-40 kV was used to deposit the fibers on an aluminum foil. Results show that the combination of polymers under specific conditions produced branched fibers with average nanofibers diameter of 495nm. FT-IR results indicate the new trends in the graph of composite nanofibers.

The COVID-19 pandemic is striking the world with serious public health and socioeconomic complications. The pandemic has influenced all forms of daily life, including educational institutions. Therefore, this cross-sectional survey was conducted to understand knowledge, attitudes, and practices related to COVID-19 among the students of the University of Veterinary and Animal Sciences, Lahore. The data was collected using an online self-directed questionnaire. The survey form includes six items about sociodemographic characteristics, 14 knowledge-based questions, seven questions on attitude, and eight questions on practices. The sample number was calculated using the Raosoft sample size calculator. A total number of 3,854 students, including 1,823 men and 2,031 women, were engaged in this survey, having student representation from all the provinces in the country. The data were analyzed using a chi-square test. A total of 97% of the students knew that the etiological agent of COVID-19 is a virus and that it is a disease of the respiratory system (94%). Many students kept visiting their relatives during the lockdown (45%), and their relatives kept visiting them at home (59%). The responses from the students varied a lot on specific questions about the transmission of the virus. Women tended to have less information regarding precautionary travel measures (p < 0.01), but supplemental knowledge of prevention of disease transmission from positive patients (p < 0.01). Conclusively, the majority of the university students surveyed had imperative knowledge, a good attitude, and active practice in response to the COVID-19 outbreak. Moreover, the KAP scores have varied by demography, gender, and the number of family members. Therefore, continuous awareness of preventative behaviors should be disseminated regularly in emergencies.

The purpose of the studies was to evaluate an in-vitro anti-mycobacterial activity of Aloe vera and Allium sativum against MDR-MTB, their cytotoxicity and mutagenicity. Four extracts of Aloe vera and Allium sativum were prepared by Soxhlet apparatus and their minimum inhibitory concentrations (MIC's) were determined by BACTEC MGIT960 system against multi drug resistant Mycobacterium tuberculosis (MDR-MTB) isolates, collected from pediatric patients. Fractions of Aloe vera and Allium sativum extracts were separated using glass column chromatography, followed by evaluation of cytotoxicity and mutagenicity by tetrazolium salt (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Ames test, respectively. Out of four extracts, ethanol extracts of Aloe vera and Allium sativum exhibited activity at MIC 5mg/mL to 7mg/mL and 3mg/mL to 5mg/mL, respectively and IC

Differential equations have a remarkable potential to exhibit real life phenomenon. Many methods have been developed to solve these differential equations, though only a few stands with time. This paper presents a comparison of Pseudo Spectral Galerkin Method for solving ordinary differential equations with many other global methods. Results shows the high accuracy and rapid convergence of said method. Graphical comparison and error tables have been provided for better understanding of results.

Aluminum–copper alloys are widely employed in automobile and aerospace industries owing to their marvelous mechanical and physical attributes. But the major hindrance in their application is that these materials are more susceptible to casting defects such as porosity, hot tears, and shrinkage occurring during solidification. The said issues have a negative impact on the mechanical properties of the casted materials and thus limit their use. Squeeze casting is a promising choice for these materials that has an ability to manufacture near-net shape parts with superior surface finish and better mechanical properties. Although, the potential of this method is tested for a variety of materials, but its capability for casting AA2026 alloy is yet to be comprehensively explored which is the primary focus of this research. Three key parameters of squeeze casting process, namely squeeze pressure, die temperature, and pouring temperature are selected for investigating their influence on surface roughness, ultimate tensile strength, and hardness using response surface methodology. Experimental results are analyzed using analysis of variance to find the control factor’s significance and adequacy of models. It has been found that squeeze pressure is the most influencing parameter for surface roughness whereas for ultimate tensile strength and hardness, pouring temperature is the major contributing factor. SEM analysis is carried out to reveal the micro-details of the fractured samples. In addition to finding optimal ranges of control variables (using contour plot analysis) for each response individually, a multi-response optimization has also been carried out using desirability approach. Furthermore, mathematical models are also developed and validated through confirmatory tests. The results of confirmatory runs depict that the proposed models have a high degree of prediction accuracy.

Increasing demand for aluminum matrix composites (AMCs) in the manufacturing sector leads to the development of squeeze casted hybrid AMCs bearing superior mechanical attributes. Excessive hardness due to squeeze pressure and the presence of reinforcement particles makes the machining of AMCs challenging and results in excessive tool wear and inadequate surface finish. Wire electric discharge machining (WEDM) process has been preferred over conventional manufacturing processes for the machining of squeeze casted Al2024/Al2O3/W hybrid composite. This study investigates the selection of the most pertinent wire electrode for the precise machining of Al2024/Al2O3/W. Simple zinc-coated (NT) and cryogenic treated (CT) brass wire electrodes have been selected for machining. Scanning electron microscope (SEM) analysis of CT wire shows that cryogenic treatment enhances the soundness and stability by reducing microcavities in its microstructure. To analyze the effects of cryogenic treatment, the machining performance of CT wire has been compared with NT wire. Besides wire type, the influence of key input variables has also been analyzed on the imperative response measures including cutting speed (CS), surface roughness (SR) and kerf width (KW) to make the machining process more effective. Microstructural analysis of NT wire depicts a high concentration of micro-voids, micro-cracks, and deep craters, while the surface of CT has been observed relatively fine after the machining. Comparative analysis of both wire electrodes has declared that CT wire yields 26.96% and 15.10% superior results for CS and SR respectively, and 6.92% deprived results for KW than NT wire.