scholarly journals The management utility of large-scale environmental drivers of bat mortality at wind energy facilities: The effects of facility size, elevation and geographic location

2020 ◽  
Vol 21 ◽  
pp. e00871 ◽  
Author(s):  
Kathleen A. MacGregor ◽  
Jérôme Lemaître
Keyword(s):  
Wind Energy ◽  
Large Scale ◽  
Geographic Location ◽  
Environmental Drivers ◽  
Facility Size

scholarly journals Optimal Design of Novel Blade Profile for Savonius Wind Turbines

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3484
Author(s):  
Tai-Lin Chang ◽  
Shun-Feng Tsai ◽  
Chun-Lung Chen
Keyword(s):  
Wind Energy ◽  
Drag Force ◽  
Wind Turbines ◽  
Rural Areas ◽  
Large Scale ◽  
Design Method ◽  
Angular Position ◽  
Vertical Axis ◽  
Blade Profile ◽  
Main Concept

Since the affirming of global warming, most wind energy projects have focused on the large-scale Horizontal Axis Wind Turbines (HAWTs). In recent years, the fast-growing wind energy sector and the demand for smarter grids have led to the use of Vertical Axis Wind Turbines (VAWTs) for decentralized energy generation systems, both in urban and remote rural areas. The goals of this study are to improve the Savonius-type VAWT’s efficiency and oscillation. The main concept is to redesign a Novel Blade profile using the Taguchi Robust Design Method and the ANSYS-Fluent simulation package. The convex contour of the blade faces against the wind, creating sufficient lift force and minimizing drag force; the concave contour faces up to the wind, improving or maintaining the drag force. The result is that the Novel Blade improves blade performance by 65% over the Savonius type at the best angular position. In addition, it decreases the oscillation and noise accordingly. This study achieved its two goals.

Risk Factors for a Positive Hepatitis C Status in Fishermen in Kuantan Malaysia

2019 ◽  
Vol 31 (3) ◽  
pp. 227-237
Author(s):  
Priya Lall ◽  
Rumana Saifi ◽  
Diva Baggio ◽  
Samantha Fitzsimmons Schoenberger ◽  
Martin Choo ◽  
...  
Keyword(s):  
Hepatitis C ◽  
Confidence Interval ◽  
Risk Taking ◽  
Odds Ratio ◽  
Large Scale ◽  
Adjusted Odds Ratio ◽  
Environmental Drivers ◽  
Negative Effects ◽  
Risk Taking Behaviors ◽  
Risk Communities

Malaysia currently has an estimated hepatitis C virus (HCV) prevalence of 1.3% with an infected population of 384,000. Fishermen in Malaysia are at risk of HCV infection due to injection drug use and disproportionately high rates of incarceration. This study used quantitative data from Project WAVES, a large-scale mixed methods project charting environmental drivers of risk-taking behaviors among a respondent-driven sample of 406 fishermen in Malaysia. Over a quarter of participants (27.9%) reported injecting drugs in the past month; 49.8% of the sample tested positive for HCV. Respondents who had previously been arrested displayed increased odds of being HCV-positive (adjusted odds ratio = 4.79, confidence Interval = 2.46-9.35). Participants who reported being in lock-up displayed close to 6-fold odds of being HCV-infected (adjusted odds ratio = 5.49, confidence interval = 2.77-10.90, P < .001). These findings underscore the need for policies and structural interventions targeting the negative effects of aggressive incarceration contributing to the burden of HCV among high-risk communities.

A Proposed Large-Scale Wind Energy Program for California

1980 ◽  
Vol 5 (2) ◽  
pp. 141-169 ◽  
Author(s):  
MATANIA GINOSAR
Keyword(s):  
Wind Energy ◽  
Large Scale

Design of a Magnetic Wall-Climbing Car

2014 ◽  
Vol 526 ◽  
pp. 211-216
Author(s):  
Qiong Ying Lv ◽  
Yu Shi Mei ◽  
Xi Jia Tao
Keyword(s):  
Renewable Energy ◽  
Wind Energy ◽  
Wind Power ◽  
Large Scale ◽  
Magnetic Force ◽  
Mechanical Analysis ◽  
Heavy Duty ◽  
Magnetic Wall ◽  
Force Curves

As the trend of large-scale wind Power, People pay more attention to wind energy, which as a clean, renewable energy. Traditional unarmed climbing and crane lifting has been unable to meet the requirements of the equipment maintenance. Magnetic climb car can automatically crawl along the wall of the steel tower, the maintenance equipment and personnel can be sent to any height of the tower. The quality of the magnetic wall-climbing car is 550kg, which can carry 1.3 tons load. In this paper completed the magnetic wall-climbing car design and modeling, mechanical analysis in static and dynamic, obtained with the air gap and Magnetic Force curves. The application shows that the magnetic wall-climbing car meets the reliable adsorption, heavy-duty operation, simple operation etc..

scholarly journals Atmospheric tropical modes are important drivers of Sahelian springtime heatwaves

2020 ◽  
Author(s):  
Kiswendsida H. Guigma ◽  
Françoise Guichard ◽  
Martin Todd ◽  
Philippe Peyrille ◽  
Yi Wang
Keyword(s):  
Large Scale ◽  
Geographic Location ◽  
Longwave Radiation ◽  
Potential Predictability ◽  
Modes Of Variability ◽  
Physical Mechanisms ◽  
Hot Air ◽  
Western Sahel ◽  
Maximum Temperatures ◽  
Sahel Region

AbstractHeatwaves pose a serious threat to human health worldwide but remain poorly documented over Africa. This study uses mainly the ERA5 dataset to investigate their large-scale drivers over the Sahel region during boreal spring, with a focus on the role of tropical modes of variability including the Madden–Julian Oscillation (MJO) and the equatorial Rossby and Kelvin waves. Heatwaves were defined from daily minimum and maximum temperatures using a methodology that retains only intraseasonal scale events of large spatial extent. The results show that tropical modes have a large influence on the occurrence of Sahelian heatwaves, and, to a lesser extent, on their intensity. Depending on their convective phase, they can either increase or inhibit heatwave occurrence, with the MJO being the most important of the investigated drivers. A certain sensitivity to the geographic location and the diurnal cycle is observed, with nighttime heatwaves more impacted by the modes over the eastern Sahel and daytime heatwaves more affected over the western Sahel. The examination of the physical mechanisms shows that the modulation is made possible through the perturbation of regional circulation. Tropical modes thus exert a control on moisture and the subsequent longwave radiation, as well as on the advection of hot air. A detailed case study of a major event, which took place in April 2003, further supports these findings. Given the potential predictability offered by tropical modes at the intraseasonal scale, this study has key implications for heatwave risk management in the Sahel.

Simulation of Flow Field on a Large Scale Wind Turbine

2008 ◽  
Author(s):  
I. Janajreh ◽  
C. Ghenai
Keyword(s):  
Flow Field ◽  
Wind Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Cross Sections ◽  
Large Scale ◽  
Wind Farms ◽  
Operating Characteristics ◽  
Cross Sectional ◽  
Capital Costs

Large scale wind turbines and wind farms continue to evolve mounting 94.1GW of the electrical grid capacity in 2007 and expected to reach 160.0GW in 2010 according to World Wind Energy Association. They commence to play a vital role in the quest for renewable and sustainable energy. They are impressive structures of human responsiveness to, and awareness of, the depleting fossil fuel resources. Early generation wind turbines (windmills) were used as kinetic energy transformers and today generate 1/5 of the Denmark’s electricity and planned to double the current German grid capacity by reaching 12.5% by year 2010. Wind energy is plentiful (72 TW is estimated to be commercially viable) and clean while their intensive capital costs and maintenance fees still bar their widespread deployment in the developing world. Additionally, there are technological challenges in the rotor operating characteristics, fatigue load, and noise in meeting reliability and safety standards. Newer inventions, e.g., downstream wind turbines and flapping rotor blades, are sought to absorb a larger portion of the cost attributable to unrestrained lower cost yaw mechanisms, reduction in the moving parts, and noise reduction thereby reducing maintenance. In this work, numerical analysis of the downstream wind turbine blade is conducted. In particular, the interaction between the tower and the rotor passage is investigated. Circular cross sectional tower and aerofoil shapes are considered in a staggered configuration and under cross-stream motion. The resulting blade static pressure and aerodynamic forces are investigated at different incident wind angles and wind speeds. Comparison of the flow field results against the conventional upstream wind turbine is also conducted. The wind flow is considered to be transient, incompressible, viscous Navier-Stokes and turbulent. The k-ε model is utilized as the turbulence closure. The passage of the rotor blade is governed by ALE and is represented numerically as a sliding mesh against the upstream fixed tower domain. Both the blade and tower cross sections are padded with a boundary layer mesh to accurately capture the viscous forces while several levels of refinement were implemented throughout the domain to assess and avoid the mesh dependence.

Techno-Economic Assessment of Utilizing Wind Energy for Hydrogen Production Through Electrolysis

2017 ◽  
Author(s):  
Reza Ziazi ◽  
Kasra Mohammadi ◽  
Navid Goudarzi
Keyword(s):  
Hydrogen Production ◽  
Wind Energy ◽  
Wind Turbines ◽  
Alternative Energy ◽  
Large Scale ◽  
Fossil Fuels ◽  
Combustion Engine ◽  
Economic Assessment ◽  
Large Cities ◽  
North East

Hydrogen as a clean alternative energy carrier for the future is required to be produced through environmentally friendly approaches. Use of renewables such as wind energy for hydrogen production is an appealing way to securely sustain the worldwide trade energy systems. In this approach, wind turbines provide the electricity required for the electrolysis process to split the water into hydrogen and oxygen. The generated hydrogen can then be stored and utilized later for electricity generation via either a fuel cell or an internal combustion engine that turn a generator. In this study, techno-economic evaluation of hydrogen production by electrolysis using wind power investigated in a windy location, named Binaloud, located in north-east of Iran. Development of different large scale wind turbines with different rated capacity is evaluated in all selected locations. Moreover, different capacities of electrolytic for large scale hydrogen production is evaluated. Hydrogen production through wind energy can reduce the usage of unsustainable, financially unstable, and polluting fossil fuels that are becoming a major issue in large cities of Iran.

A Large Scale Cross-Validation of Second-Order Personality Structure Defined by the 16PF

1986 ◽  
Vol 59 (2) ◽  
pp. 683-693 ◽  
Author(s):  
Samuel E. Krug ◽  
Edgar F. Johns
Keyword(s):  
Large Scale ◽  
Common Factor ◽  
Geographic Location ◽  
Second Order ◽  
Personality Factor ◽  
Personality Factor Questionnaire ◽  
Normal Males ◽  
Definition Of ◽  
High Degree ◽  
Factor Estimation

The second-order factors structure of the 16 Personality Factor Questionnaire (16PF) was cross-validated on a large sample ( N = 17,381) of normal males and females. Subjects were sampled across a broad range of ages, socioeconomic levels, education, geographic location, and ethnicity. The purposes of this investigation were (1) to provide a precise definition of 16PF second-order factor structure, (2) to shed additional light on the nature of two second-order factors that have been previously identified but described as “unstable” and “poorly reproduced,” and (3) to determine the extent to which common factor estimation formulas for men and women would prove satisfactory for applied work. The resulting solutions were congruent with previous studies and showed a high degree of simple structure. Support was provided for one, but not both, of the two additional second-order factors. Results also supported the use of simplified estimation formulas for applied use.

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