scholarly journals Flow Visualization of Footballs to Analyze the Factors Affecting their Aerodynamic Performance Using CFD

2020 ◽  
Vol 5 (9) ◽  
pp. 460-475
Author(s):  
Chandan Varma Tamada ◽  
Sai Ganesh Sabbavarapu
Keyword(s):  
Surface Roughness ◽  
Boundary Layer Separation ◽  
Aerodynamic Performance ◽  
Turbulent Regime ◽  
Cfd Analysis ◽  
Factors Affecting ◽  
Velocity Surface ◽  
Hydrodynamic Boundary Layer ◽  
The Individual ◽  
Smooth Sphere

The motion of a football in air is influenced by the combination of various aerodynamic effects caused by the parameters such as velocity, surface roughness, panel orientation and shape. This paper analyzes the individual and combined effects of these parameters on the flight characteristics of various footballs using CFD Analysis. Four balls, a smooth sphere, a 32-panel conventional football, 14-panel Teamgeist and 6-panel Brazuca ball are subjected to different velocities of air flow over them, both in the laminar and turbulent regime, different surface roughness values and the influence of these parameters on the aerodynamics of the balls is evaluated by the drag force, drag coefficient and hydrodynamic boundary layer separation angle. The effect of the seam length, number of panels and panel orientation are also compared. The results of these effects are discussed later in the paper and are used to explain the knuckling effects and unpredictable trajectory of the Jabulani ball.

scholarly journals Interactive effects between travel behaviour and COVID-19: a questionnaire study

2021 ◽  
Author(s):  
Jinbao Zhang ◽  
Jaeyoung Lee
Keyword(s):  
Early Stage ◽  
Travel Behaviour ◽  
Interactive Effects ◽  
Factors Affecting ◽  
Individual Level ◽  
Passenger Volume ◽  
Spatial Autoregressive ◽  
Railway Passenger ◽  
The Individual ◽  
And Control

Abstract This study has two main objectives: (i) to analyse the effect of travel characteristics on the spreading of disease, and (ii) to determine the effect of COVID-19 on travel behaviour at the individual level. First, the study analyses the effect of passenger volume and the proportions of different modes of travel on the spread of COVID-19 in the early stage. The developed spatial autoregressive model shows that total passenger volume and proportions of air and railway passenger volumes are positively associated with the cumulative confirmed cases. Second, a questionnaire is analysed to determine changes in travel behaviour after COVID-19. The results indicate that the number of total trips considerably decreased. Public transport usage decreased by 20.5%, while private car usage increased by 6.4%. Then the factors affecting the changes in travel behaviour are analysed by logit models. The findings reveal significant factors, including gender, occupation and travel restriction. It is expected that the findings from this study would be helpful for management and control of traffic during a pandemic.

scholarly journals High-quality net shape geometries from additively manufactured parts using closed-loop controlled ablation with ultrashort laser pulses

2020 ◽  
Vol 9 (1-2) ◽  
pp. 101-110 ◽  
Author(s):  
Daniel Holder ◽  
Artur Leis ◽  
Matthias Buser ◽  
Rudolf Weber ◽  
Thomas Graf
Keyword(s):  
Surface Roughness ◽  
Closed Loop ◽  
High Surface ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Minimum Thickness ◽  
High Quality ◽  
Surface Optical ◽  
The Individual ◽  
Ultrashort Laser

AbstractAdditively manufactured parts typically deviate to some extent from the targeted net shape and exhibit high surface roughness due to the size of the powder grains that determines the minimum thickness of the individual slices and due to partially molten powder grains adhering on the surface. Optical coherence tomography (OCT)-based measurements and closed-loop controlled ablation with ultrashort laser pulses were utilized for the precise positioning of the LPBF-generated aluminum parts and for post-processing by selective laser ablation of the excessive material. As a result, high-quality net shape geometries were achieved with surface roughness, and deviation from the targeted net shape geometry reduced by 67% and 63%, respectively.

scholarly journals Factors affecting the organizational performance of manufacturing firms

2017 ◽  
Vol 9 ◽  
pp. 184797901771262 ◽  
Author(s):  
Ahmad Adnan Al-Tit
Keyword(s):  
Organizational Performance ◽  
Measurement Instrument ◽  
Manufacturing Firms ◽  
Factors Affecting ◽  
Mediating Role ◽  
Values And Beliefs ◽  
The Individual ◽  
The Impact ◽  
The Relationship

Numerous studies have been conducted to explore the individual effects of organizational culture (OC) and supply chain management (SCM) practices on organizational performance (OP) in different settings. The aim of this study is to investigate the impact of OC and SCM on OP. The sample of the study consisted of 93 manufacturing firms in Jordan. Data were collected from employees and managers from different divisions using a reliable and valid measurement instrument. The findings confirm that both OC and SCM practices significantly predict OP. The current study is significant in reliably testing the relationship between SCM practices and OP; however, it is necessary to consider cultural assumptions, values and beliefs as the impact of OC on OP is greater than the impact of SCM practices. Based on the results, future studies should consider the moderating and mediating role of OC on the relationship between SCM practices and OP.

Surface Roughness of Two CAD/CAM Restorative Materials as Affected by Chewing Simulation v1

2022 ◽  
Author(s):  
eaeldwakhly not provided
Keyword(s):  
Surface Roughness ◽  
Computer Aided Design ◽  
Surface Characteristics ◽  
Ceramic Materials ◽  
Study Groups ◽  
Significance Level ◽  
Chewing Simulation ◽  
Computer Aided ◽  
Cad Cam ◽  
The Individual

This study was conducted to assess the surface characteristics in terms of roughness of two CAD/CAM (Computer-Aided-Design/Computer-Aided Manufacturing)restorative material spre and post chewing simulation exposure. Methods: Specimens were prepared from two CAD/CAM ceramic materials: Cerec Blocs C and IPS e-max ZirCAD. A total of 10 disks were prepared for each study group. 3D optical noncontact surface profiler was used to test the surface roughness (ContourGT, Bruker, Campbell, CA, USA). A silicone mold was used to fix the individual samples using a self-curing resin. Surface roughness (SR) was examined pre and post exposure to chewing simulation. 480,000 simulated chewing cycles were conducted to mimic roughly two years of intraoral clinical service. The results data was first tested for normality and equal variance (Levene’s test >0.05) then examined with paired and independent sample t-test at a significance level of (p < 0.05). Results:The two CAD-CAM materials tested exhibited increased surface roughness from baseline. The highest mean surface roughness was observed in Cerec blocs C group after chewing simulation (2.34 µm± 0.62 µm). Whereas the lowest surface roughness was observed in IPS e.max ZirCAD group before chewing simulation (0.42 µm± 0.16 µm). Both study groups exhibited significantly different surface roughness values (p< 0.05). There was a statistically higher surface roughness values after the chewing simulation in Cerec blocs C when compared to IPS e.max ZirCAD groups (p = 0.000).Conclusion:Even though both tested CAD/CAM materials differ in recorded surface roughness values, results were within clinically accepted values.

Investigation of Loss Impact From Production-Like Features in a Compressor Duct Under Engine Realistic Conditions

2017 ◽  
Author(s):  
Fredrik Wallin ◽  
Mark H. Ross ◽  
Max Rusche ◽  
Scott Morris ◽  
Steven Ray
Keyword(s):  
Surface Roughness ◽  
Total Pressure ◽  
Experimental Testing ◽  
Computational Grid ◽  
Test Facility ◽  
Pressure Probe ◽  
Cfd Analysis ◽  
Roughness Model ◽  
Geometrical Features ◽  
Real Geometry

An experimental and numerical investigation of the flow in a compressor duct with engine-realistic in-production features is presented in this paper. The experimental testing was conducted in the ND-FSCC test facility at University of Notre Dame, Indiana, USA. A baseline duct was also tested for back-to-back comparison. The ducts were heavily instrumented; duct inlet and exit flowfields were scanned using a five-hole pressure probe that provided total pressure, velocities and flow angles. Based on the five-hole probe total pressures, duct losses could be assessed. Furthermore the duct inlet boundary layers were traversed and turbulence intensity levels were assessed. For the CFD analysis of the production-like duct, a highly complex computational grid, resolving all the geometrical features present, was used. A previously validated surface roughness model was used to account for the cast aero-surfaces. Both experimental and numerical results show that there is a significant increase in loss for the production-like duct when compared to the baseline duct loss. The CFD results agree very well with experimental results for the baseline duct, which makes it possible to use the experimental data recorded for the production-like duct to validate CFD tools for real geometry effects, such as interface steps and surface roughness for example.

scholarly journals Factors affecting retention in the Philippine National Rural Physician Deployment Program from 2012 to 2019: a mixed methods study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Erika Louise L. Flores ◽  
Edric Matthew R. Manahan ◽  
Miguel Paulo B. Lacanilao ◽  
Isabella Ma. Beatriz T. Ladaw ◽  
Mico Martin B. Mallillin ◽  
...  
Keyword(s):  
Mixed Methods ◽  
Healthcare Providers ◽  
Well Being ◽  
The Philippines ◽  
Social Needs ◽  
Factors Affecting ◽  
Work Related ◽  
Universal Healthcare ◽  
The Individual ◽  
Rural Physician

Abstract Background To address the maldistribution of healthcare providers and the shortage of physicians in geographically isolated and disadvantaged areas of the Philippines, the Philippine National Rural Physician Deployment Program, or more commonly known as the Doctors to the Barrios (DTTB) program was established in 1993. However, as of 2011, only 18% of the DTTBs chose to stay in their assigned municipalities after their two-year deployment, termed retention. This study aims to identify the individual, local, work, national, and international factors affecting the retention of DTTBs in their assigned communities after their two-year deployment. Methods A descriptive, mixed-methods, explanatory design was used. For the quantitative part, the modified and updated Stayers Questionnaire was given to all current DTTBs present in a Continuing Medical Education session in the Development Academy of the Philippines. Descriptive statistics were then presented. For the qualitative part, individual, semi-structured key informant interviews were conducted in-person or via phone with current and alumni DTTBs from 2012 to 2019. Proceedings of the interviews were transcribed, translated, and analyzed thematically. Results 102 current DTTBs participated in the quantitative part of our study, while 10 current and former DTTBs participated in the interviews. Demographic factors and location, personal beliefs, well-being, friends and family dynamics, and perceptions about work were the individual factors identified to affect retention. Social working conditions, career development, and infrastructure, medical equipment, and supplies were among the work factors identified to affect retention. Geography, living conditions, local social needs, and technology were among the local factors identified to affect retention. Compensation, the recently signed Universal Healthcare Law, and Safety and Security were identified as national factors that could affect retention. International factors did not seem to discourage DTTBs from staying in their communities. Conclusions A host of individual, work-related, local, national, and international factors influence the DTTB’s decision to be retained in different, complex, interconnected, and dynamic ways. We also identified implementation issues in the DTTB program and suggested interventions to encourage retention.

scholarly journals Motivating factors affecting the individual energy consumption behavior

2021 ◽  
Vol 124 ◽  
pp. 08003
Author(s):  
Jalal ud Din Akbar ◽  
Muhammad Ridhuan Tony Lim Abdullah
Keyword(s):  
Climate Change ◽  
Energy Consumption ◽  
Human Behavior ◽  
Clean Energy ◽  
Daily Routine ◽  
Factors Affecting ◽  
Number Of Factors ◽  
Development Goals ◽  
The Government ◽  
The Individual

Global challenges of climate change and environmental deterioration helped in formulating seventeen sustainable development goals through United Nation. Achieving these sustainable goals, Malaysia initiated and track progress towards affordable and clean energy. The natural environment and climate are mostly influenced by human behavior. Due to the role of human behavior in climate change, a strong tendency towards the pursuit of energy sustainability exists. Attention is paid to strengthen the human behavior from general acts of doing things to carrying specific actions by adopting a responsible behavior into daily routine. A number of factors were identified through literature such as social structure, institution, and education for understanding the individual behavior for sustainability with regard to energy consumption. Many experts related to the field of energy were engaged to sort and prioritize these factors with respect to their importance by using multi-criteria decision making tool of analytical hierarchy process (AHP). The experts were selected from different sectors such as academia, NGOs and industry. With the help of experts, a framework of individual energy consumption behaviour is developed to allow the government and other stakeholders to make policies accordingly to achieve energy sustainable.

scholarly journals Regional brands produced beyond the region: An analysis of beer brands from recently closed breweries in Europe

2021 ◽  
Vol 29 (3) ◽  
pp. 168-183
Author(s):  
Jiří Hasman ◽  
David Hána ◽  
Kryštof Materna
Keyword(s):  
Individual Characteristics ◽  
Economic Perspective ◽  
Complete Sample ◽  
Firm Level ◽  
Factors Affecting ◽  
Global Industry ◽  
Production Location ◽  
Country Level ◽  
Wide Range ◽  
The Individual

Abstract Global industry has been undergoing changes in the concentration of brand ownership and production, with acquisitions and closures being a major factor in this evolution. The impacts of such activities are commonly studied from an economic perspective and from the perspective of internal firm-level and deal-level factors, while the influence of external geographical factors is largely neglected. Our research focuses mainly on the importance of geographical cultural factors affecting beer brands whose production location was moved after the closure of the original breweries. The research includes a complete sample of 30 brands from recently closed breweries across Europe. Brands are divided into seven categories according to how their marketing strategy has (or has not) changed in terms of exploiting regional and national identity. The overall success of these brands is then measured in terms of the development of their share in the home countries’ markets. Differences in brands’ strategies and successes are explained through a wide range of country-level factors and the individual characteristics of the breweries. It is shown that the level of beer tradition or identity in the countries, as well as the country’s beer life-cycle position, plays a crucial role in the evolution of the studied brands.

scholarly journals Innovation in education: problems and ways of their solution

2020 ◽  
Vol 210 ◽  
pp. 18054
Author(s):  
Uliana Milhaleva
Keyword(s):  
Education System ◽  
New Technologies ◽  
Innovative Development ◽  
New Approach ◽  
Factors Affecting ◽  
Modern Education ◽  
Professional Activities ◽  
Innovation In Education ◽  
Starting Point ◽  
The Individual

This article analyzes the problems of modern education, and on the basis of this analysis, a search for a new approach to the formation of not only necessary knowledge, but also skills in the learning process is conducted. It will be about contextual, cross-contextual and existential skills, their improvement and transformation. Such skills should be developed in modern educational centers, which, in turn, should become the starting point of an individual educational route. It is the individual approach and new technologies that will help to form a personality adapted to professional activities in a rapidly changing world. The article also classifies the factors affecting the modern education system, they are divided into three main groups: social, technological and geopolitical. This classification, in turn, is used to study the strategies of innovative development of the educational system in Russia.

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