Tribological Characterization of Electrical Discharge Machined Surfaces for AISI 304L

Surface treatments are normally carried out after machining. Surface treatment is a costly and time-consuming process. Hence, it makes sense to reduce the requirement of surface treatment as much as possible. Electrical Discharge Machining (EDM) is a frequently used machining process. EDM produces a recast layer on the surface of machined components. The tribological performance of this recast layer is not very well understood. The properties of the recast layer formed as a result of EDM depend upon the discharge current, electrodes and dielectrics. This work aims to study the effects of each on the tribological performance – in terms of the wear depth, friction coefficient, friction force and contact surface temperature of recast layers. Subsequent improvement in the quality of surfaces will significantly reduce the cost and time required to treat surfaces after machining. Hence, various combinations of discharge current, dielectrics and electrodes have been used to characterize and deduce their effects. The tribo-tests are performed in the boundary lubrication regime under pin-on-disc configuration to analyze sliding friction, contact surface temperature and the wear of the recast layers formed on AISI 304L. The surface morphology of the test pins has been performed by Scanning Electron Microscopy (SEM) before and after the tests. The results show that indeed it is possible to control the tribological performance of the recast layers by varying EDM parameters. This approach promises to be a useful methodology to improve the tribological performance of the layers formed after EDM and reduce the time and costs required for surface treatments post machining

Analysis of GPS and UWB positioning system for athlete tracking

In recent years, wearable performance monitoring systems have become increasingly popular in competitive sports. Wearable devices can provide vital information including distance covered, velocity, change of direction, and acceleration, which can be used to improve athlete performance and prevent injuries. Tracking technology that monitors the movement of an athlete is an important element of sport wearable devices. For tracking, the cheapest option is to use global positioning system (GPS) data however, their large margins of error are a major concern in many sports. Consequently, indoor positioning systems (IPS) have become popular in sports in recent years where the ultra-wideband (UWB) positioning sensor is now being used for tracking. IPS promises much higher accuracy, but unlike GPS, it requires a longer set-up time and its costs are significantly more. In this research, we investigate the suitability of the UWB-based localisation technique for wearable sports performance monitoring systems. We implemented a hardware set-up for both positioning sensors, UWB and the GPS-based (both 10 Hz and 1 Hz) localisation systems, and then monitored their accuracy in 2D and 3D side-by-side for the sport of tennis. Our gathered data shows a major drawback in the UWB-based localisation system. To address this major drawback we introduce an artificial intelligent model, which shows some promising results

Impact of Liquidity Ratio on Profitability of Firm: An Empirical Evidence from Automobile Industry of Pakistan

Pakistan automobile industry was experiencing a boom from the last two decades, but currently it is facing footraces due to financial suffering in the Pakistan market. This study is an attempt to investigate the impact of liquidity on profitability either positively or negatively. Liquidity of a firm can be measured through different ratios e.g. current ratio, cash ratio, and quick ratio, whereas profitability or financial performance of firm can be scaled with the proxies like return on equity and return on assets. Panel data of 5 years of 12 automobile firms listed in PSX is used for the analysis. Fixed effect model and random effect model were used for empirical investigation and Hausman test was employed to choose appropriate model between fixed and random effect. Results of the analysis revealed that the liquidity (quick ratio) positively effect on profitability; return on assets (ROA). However, there is a negative relationship between liquidity (current ratio and cash ratio) with return on asset. Keywords: Profitability, Liquidity, Return on assets, quick ratio, current ratio, cash ratio financial performance. DOI: 10.7176/RJFA/10-22-16 Publication date: November 30th 201

Ethyl 3-(3-oxo-3,4-dihydro­quinoxalin-2-yl)propano­ate

In the title compound, C13H14N2O3, the fused ring system is almost planar (r.m.s. deviation = 0.015 Å). The r.m.s. deviation for all the non-H atoms of the mol­ecule is 0.065Å. In the crystal, N—H⋯O and C—H⋯O hydrogen bonds generate polymeric chains along the b axis containing alternating centrsymmetric R 2 2(8) and R 2 2(20) loops

Seismic Interpretation and Reservoir Evaluation Utilizing 2-D Seismic Data and Wireline Logs of Bijnot-01 Well, Fort Abbas Field, Central Indus Basin, Pakistan

Present study attempts to decipher the subsurface structure and reservoir characterization of Fort-Abbas field, located in Punjab platform, Central Indus Basin utilizing 2-D seismic and wireline logs data. Four seismic lines, 944-FABS-42, 944-FABS-43, 944-FABS-48, 944-FABS-49 and wireline logs of Bijnot-01 well have been used for this research work to delineate subsurface structures and demarcation of zone having fair potential of hydrocarbon accumulation. Formation evaluation for hydrocarbon potential using the reservoir properties is also the foremost objective of this research work. Based on the results of seismic data interpretation of Fort-Abbas field and integrating it with formation tops and wireline logs data, three prominent reflectors have been marked i.e. Eocene Sui Main Limestone, Cretaceous Lower Goru and Jurassic Chiltan Limestone. The structure of the area is interpreted as gently dipping monocline. Based on the breakup of reflectors on seismic section, one normal fault is marked. Time and depth contour maps are generated to demarcate lateral extension and closure of the reservoir. Based on interpretation of wireline logs, a zone has been marked from depth of 504 m to 594 m (Datta Formation) as a favorable zone having good potential for hydrocarbon accumulation. Saturation of hydrocarbon (Sh) in this zone is calculated as 57%

1,4-Bis(pyrimidin-2-yl­sulfanyl)­butane

The –SCH2CH2CH2CH2S– portion of the title compound, C12H14N2S2, adopts an extended zigzag conformation. The angles at the tetra­hedral carbon atoms are marginally increased [113.63 (12)° and 111.38 (17)° for S—C—C and C—C—C respectively] from the idealized tetra­hedral angle. The mol­ecule lies on an inversion center located at the mid-point of the butyl chain. In the crystal, there is a π–π stacking inter­action between inversion-related pyrimidine rings with mean inter­planar spacing of 3.494 (2) Å

Topology control for harvesting enabled wireless sensor networks: a design approach

While there has been a lot of research on energy efficient topology control protocols destined for different applications, topology control has never been explored in the presence of harvesting enabled sensors. Largely, researchers in this domain have considered a fixed battery design. We argue that arrival of harvesting enabled sensors necessitates rethink of topology control. The objective of topology control in this context should not be to minimize the spent energy and maintain a reduced topology, but to maximize fault tolerance in the network and increase the sensing coverage region. In this work, we first describe a taxonomy of existing topology control schemes and analyze the impact of reduced topology over fault tolerance and sensing coverage. We then describe the necessity of new design parameters in the presence of harvest-able ambient energy. We also outline guiding principles for designing a harvesting enabled topology control scheme. To cater for whether such a scheme is feasible or not, an insight is also provided onto the solar energy availability from solar radiations for near perpetual operation—as an example of available ambient energy. Based on the insight gained from the solar radiations availability, we explain why new design parameters are required for performance measurement of harvesting enabled sensors. The mathematical and empirical findings reveal that the topology control strategies, which do not take into account harvesting opportunity, are unable to provide better results in terms of fault tolerance and sensing coverage

Impact of CSR on Financial Performance of Banks: A Case Study

The aim of current study is to investigate the impact of CSRRI on bank’s financial performance. For this purpose, ROA, EPS and PAT are taken as proxies for measuring bank’s financial performance by using time series and panel data. The time span is from 2004 to 2017. The current study used HBL and MCB bank for analysis. The dependent variables are ROA, EPS and PAT while independent variables are CSRRI and bank size. To estimate the model, the current study used quantitative data to analyse the results by using descriptive analysis, correlation analysis, and multiple regression analysis. The findings of the current study revealed that the slope coefficient of intercept and CSRRI are positive except bank size which is negative in three models. In short, the CSRRI can Further, CSR reporting may provide welfare for both banks and econometric models suggests that socially responsible banks can not only attract large numbers of customers but also increases profitability

Clinical profile and predictors of mortality in neonates born with non-immune hydrops fetalis: Experience from a lower-middle-income country

Introduction: Hydrops fetalis (HF) is a life-threatening condition in which a fetus has an abnormal collection of fluid in the tissue around the lungs, heart, abdomen, or under the skin. Based on its pathophysiology, it is classified into immune and non-immune types. With the widespread use of anti-D immunoglobulin, non-immune HF has become more common, with an incidence of one in 1,700-3,000 live births. A multitude of fetal diseases with various causes can lead to non-immune HF. Due to the recent advances in prenatal diagnostic and therapeutic interventions together with improved neonatal intensive care, the diagnosis and subsequent management of HF have been refined. However, HF is still associated with a high mortality rate. A recent assessment of the literature found that there is a lack of data on prognostic variables in neonates with HF from low- and middle-income countries. In light of this, we sought to establish the etiologic causes, predictors of mortality, and eventual fate of newborns born non-immune HF at the Aga Khan University Hospital, Karachi during the 10-year period spanning January 2009-December 2019 in this retrospective analysis.Methodology: For this study, we collected data from the computerized database and patient record files at the hospital on all infants with non-immune HF. Demographic data, postnatal interventions, clinical and laboratory findings, outcomes, and the results of comparison between HF patients who died and those who survived were analyzed.Results: The incidence of non-immune HF at our hospital was 0.62/1,000 live births during the period under study, with 33 newborn babies diagnosed with non-immune HF from a total of 53,033 live-born deliveries. An etiologic factor was discovered in 17 (51.5%) neonates with non-immune HF while 16 (48.4%) were classified as those with unidentified etiology. The most common causes were cardiovascular and genetic syndromes, which resulted in 100% mortality. The overall mortality rate was 67%. The need for mechanical ventilation, surfactant therapy, and prolonged hospitalization were identified as independent risk factors of mortality.Conclusion: Our study proves that the need for mechanical ventilation [moderate to severe hypoxic respiratory failure (HRF)] and prolonged hospitalization are strong predictors of poor outcomes in neonates with non-immune HF. Therefore, severe hydrops causing significant mortality can be anticipated based on the patients\u27 respiratory status and the need for escalated oxygen support