Preliminary Structural Design of OCAES Vessel

2014 ◽  
Author(s):  
Jinfu Xiao ◽  
M. Gabr ◽  
M. S. Rahman
Keyword(s):  
Cyclic Load ◽  
Material Selection ◽  
Water Pressure ◽  
Air Pressure ◽  
Compressed Air ◽  
Deformation Pattern ◽  
Additional Advantage ◽  
Large Water ◽  
Rectangular Configuration

A vessel for Offshore Compressed Air Energy Storage (OCAES) is being considered as a part of the emerging technology to store intermittently generated energy from offshore renewable sources. The basic idea is to submerge the storage vessel into the ocean at a large water depth, convert the energy into compressed air, store it with using the hydrostatic water pressure to balance the compressed air pressure without requiring the storage vessels to resist high internal air pressure. An additional advantage is that the interface of air and water acts as a piston to maintain the air pressure level. In this study, a rectangular configuration and a cylindrical configuration are proposed for the OCEAS vessel. Stress controlled analyses are performed for the preliminary design of the OCAES vessel with emphasis on characterization of applied cyclic load induced by the air/water exchange in the inflation/deflation process. The stress distribution and deformation pattern in the OCAES vessel at different loading stages are studied by using the multi-physics FEM program COMSOL. Key parameters including storage volume, geometry of OCAES vessel, and material selection are discussed.

Hydrogeotechnical characterization of a metallurgical waste

2006 ◽  
Vol 43 (10) ◽  
pp. 1042-1060 ◽  
Author(s):  
R Rodríguez
Keyword(s):  
Tensile Strength ◽  
Hydraulic Conductivity ◽  
Cyclic Load ◽  
Water Pressure ◽  
Degree Of Saturation ◽  
Water Retention Curve ◽  
Triaxial Tests ◽  
Drying Process ◽  
Metallurgical Waste

This paper presents the results of hydrogeotechnical characterization tests carried out on the metallurgical waste (MW) from a tailings impoundment located on the terraces of the Moa River, Cuba. Characterization of the MW includes chemical and mineralogical analysis, oedometer tests, triaxial tests, tensile strength tests, determination of the water retention curve, and shrinkage and permeability tests. The MW, which has a grain-size distribution similar to that of a silt, mainly contains iron and heavy metals minerals and has low plasticity. Consolidated undrained triaxial tests on remoulded samples indicate a dilative behaviour, with a decrease in pore-water pressure near failure. The material is susceptible to liquefaction when subjected to a cyclic load in the triaxial test. Hydraulic conductivity, soil stiffness, and compressive and tensile strength of the MW have an important dependence on the degree of saturation and vary significantly during the drying process. The results indicate that, during the drying process, cracks in the MW initiate in quasi-saturated conditions. The cracks increase the hydraulic conductivity by more than one order of magnitude compared with that of intact samples of MW. The main environmental risk with this MW is the possibility of liquefaction under a cyclic load due to an earthquake and the increase in saturated hydraulic conductivity due to desiccation cracks.Key words: desiccation cracks, hydrogeotechnical properties, liquefaction, metallurgical waste, characterization.

Viscoelastic Characterization of Human Descending Thoracic Aortas Under Cyclic Load

2021 ◽  
Author(s):  
Giulio Franchini ◽  
Ivan D. Breslavsky ◽  
Gerhard A. Holzapfel ◽  
Marco Amabili
Keyword(s):  
Cyclic Load

scholarly journals Environmental impact of intensive farming in sloping areas

2018 ◽  
Vol 174 ◽  
pp. 01001
Author(s):  
Giovanni Bosco ◽  
Lucia Simeoni
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Sprinkler Irrigation ◽  
High Yield ◽  
Qualitative And Quantitative ◽  
Intensive Farming ◽  
Yield Production ◽  
Large Water ◽  
The Stability ◽  
Irrigation Runoff

The increased demand for food causes intensive farming with high yield production and large water consumption to extend significantly. Depending on soil properties, seasonal rainfall, surface drainage and water resources, hence the consumption-infiltration balance, the ground water table might be raised or depleted; soils could be saturated or remain partly saturated with negative pore pressures. As a result sloping grounds may become prone to shallow slides, as mudflows, or deep seated movements, involving large volumes of soil, especially after rupture of major watering lines or after long uncontrolled irrigations. Within this framework the paper investigates the possible effects of replacing grassland with intensive apple farming on the stability conditions of slopes. Apples require frequent watering, especially during spring and summer to meet qualitative and quantitative productive standards. Also, sprinkler irrigation is often used to protect against hail. From the precipitation, irrigation, runoff, evaporation and plant transpiration balance, the evolution of the pore water pressure distribution within an average year is calculated. Then the modified shear strength of the unsaturated-saturated soils is determined and the factor of safety against sliding is calculated.

Material Characterization for Sheet-Bulk Metal Forming

2012 ◽  
Vol 504-506 ◽  
pp. 1029-1034 ◽  
Author(s):  
Bernd Arno Behrens ◽  
Kathrin Voges-Schwieger ◽  
Anas Bouguecha ◽  
Jens Mielke ◽  
Milan Vucetic
Keyword(s):  
Metal Forming ◽  
Material Characterization ◽  
Cyclic Load ◽  
Material Behavior ◽  
Forming Force ◽  
Forming Process ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Metal Forming Process

Sheet-bulk metal forming is a novel manufacturing technology, which unites the advantages and design solutions of sheet metal and bulk metal forming. To challenge the high forming force the process is superimposed with an oscillation in the main flow of the process. The paper focuses on the characterization of the material behavior under cyclic load and the effects for the sheet bulk metal forming process.

scholarly journals Energy Efficiency of Pneumatic Cylinder Control with Different Levels of Compressed Air Pressure and Clamping Cartridge

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3711
Author(s):  
Vladislav Blagojevic ◽  
Dragan Seslija ◽  
Slobodan Dudic ◽  
Sasa Randjelovic
Keyword(s):  
Energy Consumption ◽  
Air Pressure ◽  
Compressed Air ◽  
Pneumatic Cylinder ◽  
Final Position ◽  
Return Stroke ◽  
Cylinder Piston ◽  
Reduce Energy Consumption ◽  
The Cost ◽  
Different Levels

Since pneumatic systems are widely used in various branches of industry, the need to find ways to reduce energy consumption in these systems has become very pressing. The reduction in energy consumption in these systems is reflected in the reduction of compressed air consumption. The paper presents a cylinder control system with a piston rod on one side, in which the reduction in energy consumption is ensured by using different levels of supply pressure in the working and the return stroke, and by holding the cylinder piston rod in its final positions with a clamping cartridge. Clamping and holding the piston rod in its final position further affects the reduction in energy consumption. Experimental data show that the application of the proposed control leads to a decrease in compressed air consumption of 25.54% to 32.97%, depending on the compressed air pressure used in the return stroke. The cost-effectiveness of the proposed cylinder control with different levels of compressed air pressure and holding the final position by clamping cartridge is presented.

scholarly journals Gallium phosphide optical metasurfaces for visible light applications

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mauro Melli ◽  
Melanie West ◽  
Steven Hickman ◽  
Scott Dhuey ◽  
Dianmin Lin ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Visible Light ◽  
Material Properties ◽  
Gallium Phosphide ◽  
Material Selection ◽  
Viable Alternative ◽  
Fabrication And Characterization ◽  
Selection For

AbstractThere are few materials that are broadly used for fabricating optical metasurfaces for visible light applications. Gallium phosphide (GaP) is a material that, due to its optical properties, has the potential to become a primary choice but due to the difficulties in fabrication, GaP thin films deposited on transparent substrates have never been exploited. In this article we report the design, fabrication, and characterization of three different amorphous GaP metasurfaces obtained through sputtering. Although the material properties can be further optimized, our results show the potential of this material for visible applications making it a viable alternative in the material selection for optical metasurfaces.

scholarly journals Elevation changes and dynamic provinces of Jakobshavn Isbræ, Greenland, derived using generalized spatial surface roughness from ICESat GLAS and ATM data

2014 ◽  
Vol 60 (223) ◽  
pp. 834-848 ◽  
Author(s):  
Ute C. Herzfeld ◽  
Brian McDonald ◽  
Bruce F. Wallin ◽  
William Krabill ◽  
Serdar Manizade ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Water Pressure ◽  
Remote Sensing Data ◽  
Internal Dynamic ◽  
Laser Altimeter ◽  
Ice Dynamics ◽  
Bed Topography ◽  
Elevation Changes ◽  
System Data

AbstractOur objective is to map dynamic provinces and investigate dynamic changes in Jakobshavn Isbræ, Greenland. We use an approach that combines structural glaciology and remote-sensing data analysis, facilitated by mathematical characterization of generalized spatial surface roughness that provides parameters related to ice dynamics, deformation and interaction of the ice with bed topography. The approach is applied to derive time series of elevation and roughness changes and to attribute changes during rapid retreat. Different dynamic types of fast- and slow-moving ice can be mapped from ICESat Geoscience Laser Altimeter System data (2003–09) and Airborne Topographic Mapper data, using spatial roughness characterization, validated with ASTER and bed-topographic data. Results of comparative analysis of elevation changes and roughness changes of Jakobshavn south ice stream indicate (1) surface lowering of 10–15 m a-1 between 2004 and 2009 and (2) no change in surface roughness and dynamic types. These findings are consistent with a front retreat as part of a fjord-glacier cycle or following warming of fjord water and with climatic warming, but not with an internal dynamic acceleration as a cause of the observed changes during rapid retreat. Relationships to changes in basal water pressure are discussed. All glaciodynamic changes appear to have initiated near the front and propagated up-glacier.

scholarly journals Test Study on Airtight Capability of Filter Cakes for Slurry Shield and Its Application in a Case

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Fanlu Min ◽  
Wei Zhu ◽  
Shengquan Xia ◽  
Rui Wang ◽  
Daiwei Wei ◽  
...  
Keyword(s):  
Yangtze River ◽  
Filter Cake ◽  
Water Pressure ◽  
Air Pressure ◽  
Test Results ◽  
Test Study ◽  
Capillary Bundle ◽  
Slurry Shield ◽  
Filter Cakes ◽  
The Relationship

To learn the airproof capacity of filter cakes as opening chambers under air pressure, a series of tests were carried out. The variations of discharged water with air pressure and time were observed, and the relationship between airproof capacity of filter cakes and surrounding air pressure was analysed. The test results indicated that there were three stages as compressed air acting on filter cakes: completely not infiltration, a very small amount of infiltration, and penetration leakage. The certain air pressure between the first and second stages was called the airproofing value of filter cake. And a capillary bundle model was used to explain the mechanism of air tightness of filter cakes. In Nanjing Yangtze River Tunnel, a 5 cm thickness filter cake was formed in gravel sand, and its airproofing value was a little lower than 0.12 MPa. The air pressure used as opening chamber should be equal to the summation of water pressure in sand and airproofing value of filter cake. While the air pressure is larger than the summation, the filter cake would be gas permeable. The slurry formulation and airproofing value of filter cakes obtained in the tests were applied successfully in Nanjing Yangtze River Tunnel.

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