Um estudo baseado em simulação sobre o efeito de nanopartículas metálicas e não metálicas no desempenho do concentrador de calha parabólica

This research investigates the simulation-based performance of metallic and non-metallic nanoparticles, along with water-based heat transfer fluids, used in parabolic trough concentrator. Its main goal is to analyze the performance enhancement of the concentrator, divided into two phases. The first phase focuses on validating the experimental setup using computational fluid dynamics through ANSYS software. The same validated simulation model is then utilized to assess the performance of solar parabolic trough concentrator with different metallic and non-metallic, plus water-based nanofluids. The study utilizes water alone, along with copper, gold, and silver, and two non-metallic nanoparticles, alumina oxide, and copper oxide, in varying volumetric concentrations from 1% to 3%. The simulation analysis, conducted at a speed of 0.12 m/s, reveals that the highest average temperature increase is observed in the case of alumina + water-based nanofluid at 3% volumetric concentration, with a maximum average heat transfer of 351.89 watts. Additionally, the silver + water-based nanofluid demonstrates the highest average value of the coefficient of convective heat transfer at 88055.5 W/(m2 K). The gold + water-based nanofluid shows a higher average value of the Reynolds Number at 4352.268, while the maximum Nusselt number is observed with alumina oxide + water-based nanofluid, measuring 1.7698.Esta investigación investiga el rendimiento basado en simulación de nanopartículas metálicas y no metálicas, junto con fluidos de transferencia de calor a base de agua, utilizados en concentradores cilindroparabólicos. Su principal objetivo es analizar la mejora del rendimiento del concentrador, dividido en dos fases. La primera fase se centra en validar la configuración experimental utilizando dinámica de fluidos computacional a través del software ANSYS. Luego se utiliza el mismo modelo de simulación validado para evaluar el rendimiento del concentrador cilindroparabólico solar con diferentes nanofluidos metálicos y no metálicos, además de a base de agua. El estudio utiliza agua sola, junto con cobre, oro y plata, y dos nanopartículas no metálicas, óxido de alúmina y óxido de cobre, en concentraciones volumétricas variables del 1% al 3%. El análisis de simulación, realizado a una velocidad de 0,12 m/s, revela que el mayor aumento de temperatura promedio se observa en el caso de alúmina + nanofluido a base de agua al 3% de concentración volumétrica, con una transferencia de calor promedio máxima de 351,89 vatios. Además, el nanofluido a base de plata + agua demuestra el valor promedio más alto del coeficiente de transferencia de calor por convección con 88055,5 W/(m2 K). El nanofluido de oro + agua muestra un valor promedio más alto del número de Reynolds con 4352,268, mientras que el número de Nusselt máximo se observa con óxido de alúmina + nanofluido de agua, que mide 1,7698.Esta pesquisa investiga o desempenho baseado em simulação de nanopartículas metálicas e não metálicas, juntamente com fluidos de transferência de calor à base de água, utilizados em concentradores de calha parabólica. Seu principal objetivo é analisar a melhoria de desempenho do concentrador, dividido em duas fases. A primeira fase concentra-se na validação da configuração experimental utilizando dinâmica de fluidos computacional através do software ANSYS. O mesmo modelo de simulação validado é então utilizado para avaliar o desempenho do concentrador solar parabólico com diferentes nanofluidos metálicos e não metálicos, além de nanofluidos à base de água. O estudo utiliza apenas água, juntamente com cobre, ouro e prata, e duas nanopartículas não metálicas, óxido de alumina e óxido de cobre, em concentrações volumétricas variadas de 1% a 3%. A análise de simulação, realizada a uma velocidade de 0,12 m/s, revela que o maior aumento médio de temperatura é observado no caso do nanofluido à base de alumina + água na concentração volumétrica de 3%, com transferência de calor média máxima de 351,89 watts. Além disso, o nanofluido à base de prata + água demonstra o maior valor médio do coeficiente de transferência de calor convectivo em 88.055,5 W/(m2 K). O nanofluido à base de ouro + água apresenta um valor médio mais elevado do Número de Reynolds em 4352,268, enquanto o número máximo de Nusselt é observado com óxido de alumina + nanofluido à base de água, medindo 1,7698

Numerical Recipes in Python

Numerical Recipes in Python is to serve as Laboratory Manual of Simplified Numerical Analysis (Python Version): A companion book of the principal book: Simplified Numerical Analysis (Fourth Edition) by Dr. Amjad Ali

The Impact of Corporate Strategy on the Capital Structure of Pakistani Companies (Diversification and Capital Structure)

Research into the capital structure of firms has been the subject of extensive empirical investigation. This study seeks to extend the debate by examining the endogenous influence of corporate strategy on financing decisions made by firms. Diversification is one of the corporate strategies that allow a company to enter business lines that are same or different from current operations as well as operate in several economic markets. Financial choices need to be evaluated because of their close interaction with management choices. Optimal capital structure plays a key role in achieving the overriding goal of financial management. The study sought to discover the impact of corporate diversification strategies on financial choices because study main focus is diversification strategy (A type of corporate strategy). For purposes of comparison, the current study used four of the nine Rumelt categories which correspond to Wrigley's original four, which were single product strategy, dominant strategy, related firm strategy and unrelated firm strategy. Panel data model was constructed and using a sample of 120 companies listed on the Pakistan Stock Exchange and data was obtained for companies with seven years’ quarterly data annually from 2010 to 2017. Using empirical tests, we found no relationship between diversification and leverage. Our analysis suggests that Diversifications strategy impact on capital structure indicate that this focus of enquiry has considerable potential for further resolution of the capital structure puzzle

A Survey of “Knowledge, Attitudes & Practices” of Islamic Banking Clients: An Evidence from FATA and PATA, Pakistan

Islamic banking & Finance and conventional banking are described as having the "same purpose but the essence and operations of Islamic banking are in accordance with Shariah law and have same "basic objectives" as other business and financial entities, i.e. "maximization of shareholder wealth". The speedy development of an Islamic banking system may improve financial insertion by providing an alternative to faith sensitive Muslims who are willingly excluded themselves from the system of conventional finance due to the nature of interest based. In Pakistan, the Islamic banking system eroding the growth of conventional banking so it’s worthy to explore the effect of religious belief the occurrence of a financial exclusion. The target population is from FATA and PATA maintain accounts at Islamic banks and conventional banks and a sample size of one hundred and fifty customers were picked up. The methodology focuses on the KAP Model (knowledge, attitude, practices), which indicates if attitude influences the association among “knowledge and practice” of an “Islamic banking”. Looking into KAP Analysis survey, through study result we find out that knowledge about Islamic banking and practices of Islamic banking are closely related. People having information about Islamic Banking and Products are more inclined towards Islamic Banking and people who don’t have much information are less interested in Islamic banking and Islamic products. KAP survey suggested that customers of conventional and Islamic banks are driven by the same motivating factors that have impact on their attitude. However, there have some likable factors that could be valued by “Islamic bank account holders only such as “variety of products & services, reliability, confidence in bank’s management, reputation and most important compliance with the Shariah rules in finance & investment.”. Low-cost services are some factors result in non-Muslims prefer Islamic Banking over the conventional banking

How growing tumour impacts intracranial pressure and deformation mechanics of brain

Brain is an actuator for control and coordination. When a pathology arises in cranium, it may leave a degenerative, disfiguring and destabilizing impact on brain physiology. However, the leading consequences of the same may vary from case to case. Tumour, in this context, is a special type of pathology which deforms brain parenchyma permanently. From translational perspective, deformation mechanics and pressures, specifically the intracranial cerebral pressure (ICP) in a tumour-housed brain, have not been addressed holistically in literature. This is an important area to investigate in neuropathy prognosis. To address this, we aim to solve the pressure mystery in a tumour-based brain in this study and present a fairly workable methodology. Using image-based finite-element modelling, we reconstruct a tumour-based brain and probe resulting deformations and pressures (ICP). Tumour is grown by dilating the voxel region by 16 and 30 mm uniformly. Cumulatively three cases are studied including an existing stage of the tumour. Pressures of cerebrospinal fluid due to its flow inside the ventricle region are also provided to make the model anatomically realistic. Comparison of obtained results unequivocally shows that as the tumour region increases its area and size, deformation pattern changes extensively and spreads throughout the brain volume with a greater concentration in tumour vicinity. Second, we conclude that ICP pressures inside the cranium do increase substantially; however, they still remain under the normal values (15 mmHg). In the end, a correlation relationship of ICP mechanics and tumour is addressed. From a diagnostic purpose, this result also explains why generally a tumour in its initial stage does not show symptoms because the required ICP threshold has not been crossed. We finally conclude that even at low ICP values, substantial deformation progression inside the cranium is possible. This may result in plastic deformation, midline shift etc. in the brain

Effect of adjusting orientation for solar energy applications in multiple climatic zones

South-facing collectors are the optimum choice for solar applications in the northern hemisphere. However, obstacles may limit the feasibility of this orientation. Therefore, altering the orientation of the collector impacts solar insolation. In this study, the Perez model is utilized to evaluate incoming solar radiation on tilted surfaces for solar collectors in four climatic zones across Pakistan. The results are presented in contour plots to analyze the optimal tilt and orientation for solar applications. The findings of the study indicate substantial energy gains when collectors are placed at optimum angles. More specifically, Quetta leads with a 14.54% increase, followed by Karachi and Multan at 9.81% and 9.3%, respectively, compared to horizontally placed collectors. Analysis of vertical surfaces reveals a notable decrease in monthly solar radiation, especially in Peshawar (37.22%). Monthly adjustments in tilt angles outperform fixed positions, enhancing solar energy intensity. When comparing yearly adjustments with monthly adjustments, Quetta shows the maximum increase of 5.92%, followed by Karachi (4.86%), Multan (4.01%), and Peshawar (3.65%). It is also observed that ±15° azimuth angle change from the south ensures receiving up to 98% of insolation, regardless of the climatic region. Lastly, the validation against the NASA SSE database further highlights the reliability of our simulation model. Overall, the outcomes of the study will contribute to informed solar energy planning in the studied regions

MANAGING AND IMPLEMENTING CHANGE SUCCESSFULLY WITH RESPECT TO COVID-19: A WAY FORWARD FOR SMES

The pandemic has changed the way of doing things in the entire world. To survive in situations, we need change. All the organizations are trying their level best to implement change successfully, however, all of them are facing severe issues. The purpose of this study is to identify the major hurdles in implementing change and identifying a way out to cope with the situation based on available literature on SMEs and change management. This study follows a synthesized literature review methodology and is a kind of review paper. In this research, literature that has been written on crisis management and especially over the COVID 19 has been reviewed. In this review analysis, previous studies regarding change management and the importance of SMEs in economic sustainability have been discussed. The paper is a review of existing literature and will identify how the organizations can survive through implementing change successfully. The study is significant for SMEs in the entire world. The study is useful for understanding the issues that are related to managing and implementing change in small and medium enterprises especially while facing contingencies. Finally, in this research, future researchers are guided to empirically test the factors identified in the findings of the study

Dryopteris juxtapostia Root and Shoot: Determination of Phytochemicals; Antioxidant, Anti-Inflammatory, and Hepatoprotective Effects; and Toxicity Assessment

An estimated 450 species of Dryopteris in the Dryoperidaceae family grow in Japan, North and South Korea, China, Pakistan, and Kashmir. This genus has been reported to have biological capabilities; however, research has been conducted on Dryopteris juxtapostia. Therefore, with the present study, we aimed to exploring the biological potential of D. juxtapostia root and shoot extracts. We extracted dichloromethane and methanol separately from the roots and shoots of D. juxtapostia. Antioxidant activity was determined using DPPH, FRAP, and H2O2 assays, and anti-inflammatory activities were evaluated using both in vitro (antiurease activity) and in vivo (carrageenan- and formaldehyde-induced paw edema) studies. Toxicity was evaluated by adopting a brine shrimp lethality assay followed by determination of cytotoxic activity using an MTT assay. Hepatoprotective effects of active crude extracts were examined in rats. Activity-bearing compounds were tentatively identified using LC-ESI-MS/MS analysis. Results suggested that D. juxtapostia root dichloromethane extract exhibited better antioxidant (DPPH, IC50 of 42.0 µg/mL; FRAP, 46.2 mmol/g; H2O2, 71% inhibition), anti-inflammatory (urease inhibition, 56.7% at 50 µg/mL; carrageenan-induced edema inhibition, 61.7% at 200 µg/mL; formaldehyde-induced edema inhibition, 67.3% at 200 µg/mL), brine shrimp % mortality (100% at 1000 µg/mL), and cytotoxic (HeLa cancer, IC50 of 17.1 µg/mL; prostate cancer (PC3), IC50 of 45.2 µg/mL) effects than D. juxtapostia root methanol extract. D. juxtapostia shoot dichloromethane and methanol extracts exhibited non-influential activity in all biological assays and were not selected for hepatoprotective study. D. juxtapostia root methanol extract showed improvement in hepatic cell structure and low cellular infiltration but, in contrast the dichloromethane extract, did not show any significant improvement in hepatocyte morphology, cellular infiltration, or necrosis of hepatocytes in comparison to the positive control, i.e., paracetamol. LC-ESI-MS/MS analysis showed the presence of albaspidin PP, 3-methylbutyryl-phloroglucinol, flavaspidic acid AB and BB, filixic acid ABA and ABB, tris-desaspidin BBB, tris-paraaspidin BBB, tetra-flavaspidic BBBB, tetra-albaspidin BBBB, and kaempferol-3-O-glucoside in the dichloromethane extract, whereas kaempferol, catechin, epicatechin, quinic acid, liquitrigenin, and quercetin 7-O-galactoside in were detected in the methanol extract, along with all the compounds detected in the dichloromethane extract. Hence, D. juxtapostia is safe, alongside other species of this genus, although detailed safety assessment of each isolated compound is obligatory during drug discovery

Cycling vs Running – An in-depth analysis

This short letter to the editor provides ideas about exercises that improves cardiovascular fitness

Personal and sociocultural factors as barriers to exercise among female university students. A cross-sectional study

It is a well-known fact that the illness rate is increasing day by day in the world and physical inactivity is a major factor of it. According to studies physical inactivity is the 4th most leading cause of mortality worldwide, accounting for 6% of all casualties. Objective: This cross-sectional study aims to explore the personal and sociocultural factors that act as barriers to exercise among female university students. By examining these factors, the study seeks to provide valuable insights for researchers, policymakers, and health professionals to develop targeted strategies that address the identified barriers and promote physical activity among this demographic. Material and Method: This was a cross-sectional study conducted in different universities of Faisalabad. The sample size of 800 female university students of age 17-27 was included in the study through a simple random sampling method. Females with recent injury, pregnant, mentally retarded female were excluded. Data was collected by self-generated questionnaire and the collected data was analyzed through SPSS version 16 Results: The finding of the study showed that females had many personal and sociocultural factors which acted as an obstacle in their exercise and made them inactive. Most prominent obstacle for females related to sociocultural factors was the lack of sidewalks in parks which provide enjoyable and safe strolling and a smaller number of gyms specifically for females. And another prominent personal barrier in exercise was time shortage and the parent’s preference of academic activities over exercise. Conclusion: This study sheds light on the personal and sociocultural factors that hinder exercise participation among female university students. The findings underscore the importance of developing targeted interventions to address these barriers. Strategies focused on enhancing self-efficacy, promoting positive body image, and time management skills can help alleviate personal barriers