scholarly journals Comparison of unidirectional and bidirectional airfoils in a tidal stream turbine

2021 ◽  
Vol 1201 (1) ◽  
pp. 012004
Author(s):  
K E T Giljarhus ◽  
J O Owolabi ◽  
O A Frøynes
Keyword(s):  
Power Output ◽  
Power Loss ◽  
Low Cost ◽  
Theory Approach ◽  
Yaw Control ◽  
Starting Point ◽  
Tidal Stream ◽  
Dynamics Simulations ◽  
Renewable Energy Generation ◽  
Tidal Stream Turbine

Abstract Tidal stream turbines offer an attractive method for stable renewable energy generation. Due to the periodicity of the tidal stream, a tidal stream turbine can be designed to operate in a bidirectional manner, thereby avoiding a yaw control system. This article compares a unidirectional design with a bidirectional design to estimate the expected power loss for the bidirectional design. First, a blade-element momentum theory approach is used to find optimum pitch angles for the blades and give a low-cost estimate of the power production. Next, fully-resolved computational fluid dynamics simulations are performed to validate the BEMT approach and gain insight into the flow patterns. The two approaches estimate that the power output of the bidirectional design is approximately 15-20 % lower than for the unidirectional design. This suggests that although a bidirectional design will have some power loss compared to a unidirectional design it is an interesting alternative as it can yield the same power output for both the ebb and the tide. The study also serves as a starting point for further optimization of the bidirectional design.

Design of Inhibitors for Glyceraldehyde-3-phosphate Dehydrogenase (GAPDH) Enzyme of Leishmania mexicana

2020 ◽  
Vol 16 (6) ◽  
pp. 784-795
Author(s):  
Krisnna M.A. Alves ◽  
Fábio José Bonfim Cardoso ◽  
Kathia M. Honorio ◽  
Fábio A. de Molfetta
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Binding Site ◽  
Point Of View ◽  
New Drugs ◽  
Leishmania Mexicana ◽  
Receptor Complexes ◽  
Starting Point ◽  
Dynamics Simulations ◽  
Selection Of

Background:: Leishmaniosis is a neglected tropical disease and glyceraldehyde 3- phosphate dehydrogenase (GAPDH) is a key enzyme in the design of new drugs to fight this disease. Objective:: The present study aimed to evaluate potential inhibitors of GAPDH enzyme found in Leishmania mexicana (L. mexicana). Methods: A search for novel antileishmanial molecules was carried out based on similarities from the pharmacophoric point of view related to the binding site of the crystallographic enzyme using the ZINCPharmer server. The molecules selected in this screening were subjected to molecular docking and molecular dynamics simulations. Results:: Consensual analysis of the docking energy values was performed, resulting in the selection of ten compounds. These ligand-receptor complexes were visually inspected in order to analyze the main interactions and subjected to toxicophoric evaluation, culminating in the selection of three compounds, which were subsequently submitted to molecular dynamics simulations. The docking results showed that the selected compounds interacted with GAPDH from L. mexicana, especially by hydrogen bonds with Cys166, Arg249, His194, Thr167, and Thr226. From the results obtained from molecular dynamics, it was observed that one of the loop regions, corresponding to the residues 195-222, can be related to the fitting of the substrate at the binding site, assisting in the positioning and the molecular recognition via residues responsible for the catalytic activity. Conclusion:: he use of molecular modeling techniques enabled the identification of promising compounds as inhibitors of the GAPDH enzyme from L. mexicana, and the results obtained here can serve as a starting point to design new and more effective compounds than those currently available.

Review on Switches for Power Applications: Macro to Micro

2019 ◽  
Vol 12 (3) ◽  
pp. 200-209
Author(s):  
Femi Robert
Keyword(s):  
Leakage Current ◽  
Power Loss ◽  
Low Cost ◽  
Electrical System ◽  
High Isolation ◽  
Fast Switching ◽  
Environmental Friendly ◽  
State Resistance ◽  
Very High ◽  
Bulk Production

Background: Switches are important component in electrical system. The switches needs to have the advantages of low ON-state resistance, very high OFF-state resistance, high isolation, no leakage current, less power loss, fast switching, high linearity, small size, arcless and low cost in bulk production. Also these switches have to be reliable and environmental friendly. Methods: In this paper, macro and microswitches for power applications are extensively reviewed and summarized. Various types of switches such as mechanical, solid-state, hybrid and micromechanical switches have been used for power applications are reviewed. The importance and challenge in achieving arcless switching is presented. Results: The use of micromechanical switches for power applications, actuation techniques, switching modes, reliability and lifetime are also reviewed. The modeling and design challenges are also reviewed. Conclusion: The applications of micromechanical switches shows that the switches can reduce the leakage current in battery operated systems and reduce the size of the system considerably.

Experimental study of the wake homogeneity evolution behind a horizontal axis tidal stream turbine

2021 ◽  
Vol 111 ◽  
pp. 102644
Author(s):  
Zhi Zhang ◽  
Yuquan Zhang ◽  
Jisheng Zhang ◽  
Yuan Zheng ◽  
Wei Zang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Horizontal Axis ◽  
Tidal Stream ◽  
Tidal Stream Turbine

scholarly journals Multi-scale ocean response to a large tidal stream turbine array

2017 ◽  
Vol 114 ◽  
pp. 1160-1179 ◽  
Author(s):  
Michela De Dominicis ◽  
Rory O'Hara Murray ◽  
Judith Wolf
Keyword(s):  
Multi Scale ◽  
Ocean Response ◽  
Tidal Stream ◽  
Tidal Stream Turbine

Starting System for Darrieus Water Turbine of Tidal Stream Electricity Generation

2016 ◽  
Author(s):  
Seiji Shimizu ◽  
Masayuki Fujii ◽  
Tetsuya Sumida ◽  
Kenji Sasa ◽  
Yasuhiro Kimura ◽  
...  
Keyword(s):  
Experimental Data ◽  
Cross Section ◽  
Electricity Generation ◽  
Lift Coefficient ◽  
Vertical Axis ◽  
Cylindrical Shape ◽  
Water Turbine ◽  
Tidal Stream ◽  
Tidal Stream Turbine ◽  
Original Experimental Data

Darrieus type vertical axis water turbine in a cylindrical shape which consists of some straight blades is simple, efficient and easy to install a generator upward. However, it has difficulty in starting revolution. As a method to cope with such a problem, a starting revolution assist mechanism was fabricated and set on a prototype of the turbine. Assist experiment was carried out. It resulted helping well the starting revolution. The improved prototype of tidal stream turbine can generate 1.4 W under a water flow of 1 m/s where impossible to self-start. Besides that, Darrieus water turbine’s generating torque property was investigated by the famous original experimental data of lift coefficient Cl and drag coefficient Cd for straight blades of NACA63 3-018 cross section. It was found that setting two or four blades in a turbine would help to improve the difficulty of starting revolution.

A Low-Cost Biofuel Cell with pH-Dependent Power Output Based on Porous Carbon as Matrix

2005 ◽  
Vol 11 (17) ◽  
pp. 4970-4974 ◽  
Author(s):  
Ying Liu ◽  
Mingkui Wang ◽  
Feng Zhao ◽  
Baifeng Liu ◽  
Shaojun Dong
Keyword(s):  
Power Output ◽  
Porous Carbon ◽  
Low Cost ◽  
Biofuel Cell ◽  
Ph Dependent

scholarly journals ANALYSIS ON 3D RECONSTRUCTION OF THE MONUMENT TO HEROES AS A TOOL FOR A CONCEPTUAL AND METHODOLOGICAL APPROACH IN THE PATRIMONIZATION AND EVALUATION OF CULTURAL INTEREST GOODS

2019 ◽  
Vol XLII-2/W17 ◽  
pp. 279-286
Author(s):  
M. I. Rodriguez-Laiton ◽  
H. A. León-Vega ◽  
E. Upegui
Keyword(s):  
Public Space ◽  
Low Cost ◽  
Methodological Approach ◽  
The Public ◽  
Future Developments ◽  
The North ◽  
North Side ◽  
Starting Point ◽  
Simon Bolivar ◽  
The City

Abstract. The following article describes the implementation of a methodology for the structural reconstruction of the Heroes monument and the statue on the north side of Simon Bolivar Ecuestre located between the intersection of the north highway and 80th Street in Bogota (Colombia) from the acquisition of SFM photogrammetry methods and images, using low-cost sensors for this process and making use of drones from the obtaining of frames of a video to for areas with lower altimetric reach, and thereby creating an analysis in their accuracy, sizing and quality within the framework of appropriation and documentation of the cultural assets in the public space of the city Bogotá taking this data as a starting point for future developments in the process of 3D reconstructions Colombia.

scholarly journals A Control Theory Approach to Optimal Irrigation Scheduling in the Oklahoma Panhandle

1980 ◽  
Vol 12 (1) ◽  
pp. 165-171 ◽  
Author(s):  
Thomas R. Harris ◽  
Harry P. Mapp
Keyword(s):  
Great Plains ◽  
Crop Production ◽  
Crop Yields ◽  
Low Cost ◽  
Primary Source ◽  
Irrigation Scheduling ◽  
Climatic Conditions ◽  
Theory Approach ◽  
Agricultural Producers ◽  
The Past

Climatic conditions in semiarid regions like the Oklahoma Panhandle result in wide fluctuations in rainfall, dryland crop yields, and returns to agricultural producers in the area. Irrigated crop production increases peracre yields and significantly reduces fluctuations in yields and net returns.Irrigated production of food and fiber in the Oklahoma Panhandle has developed rapidly during the past three decades, increasing from 11,500 to 385,900 acres since 1950 (Schwab). The primary source of irrigation water in the area is the Ogallala Formation, an aquifer underlying much of the Great Plains region. Until the past couple of years, the presence of relatively low cost natural gas led producers to expand irrigated production and apply high levels of water to crops irrigated in the area.

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