scholarly journals Mechanical energy input to the world oceans due to atmospheric loading

2006 ◽  
Vol 51 (3) ◽  
pp. 327-330 ◽  
Author(s):  
Wei Wang ◽  
Qian Chengchun ◽  
Huang Ruixin
Keyword(s):  
Energy Input ◽  
Mechanical Energy ◽  
Atmospheric Loading ◽  
The World

Shock Waves and the Interpretation of the Chromospheric Calcium K-line

1972 ◽  
Vol 2 (3) ◽  
pp. 146-147 ◽  
Author(s):  
L. E. Cram
Keyword(s):  
Energy Source ◽  
Shock Waves ◽  
Energy Loss ◽  
Temperature Rise ◽  
Energy Input ◽  
Mechanical Energy ◽  
Theoretical Models ◽  
Radiative Energy ◽  
Heating Process ◽  
Radiative Energy Loss

Dissipation of shock waves has often been proposed as the energy source required to sustain the outward temperature rise in the solar atmosphere. Theoretical models for the heating process have been developed by equating the mechanical energy input to the radiative energy loss at each height, but neither of these processes is well understood, and the lack of data means that the models are necessarily crude.

scholarly journals Stellar population of the superbubble N 206 in the LMC

2017 ◽  
Vol 609 ◽  
pp. A7 ◽  
Author(s):  
Varsha Ramachandran ◽  
R. Hainich ◽  
W.-R. Hamann ◽  
L. M. Oskinova ◽  
T. Shenar ◽  
...  
Keyword(s):  
Energy Input ◽  
Large Scale ◽  
Massive Stars ◽  
Mechanical Energy ◽  
Mass Loss Rate ◽  
Large Magellanic Cloud ◽  
High Mass ◽  
Clear Correlation ◽  
Physical Parameters ◽  
X Ray

Context. Massive stars severely influence their environment by their strong ionizing radiation and by the momentum and kinetic energy input provided by their stellar winds and supernovae. Quantitative analyses of massive stars are required to understand how their feedback creates and shapes large scale structures of the interstellar medium. The giant H ii region N 206 in the Large Magellanic Cloud contains an OB association that powers a superbubble filled with hot X-ray emitting gas, serving as an ideal laboratory in this context. Aims. We aim to estimate stellar and wind parameters of all OB stars in N 206 by means of quantitative spectroscopic analyses. In this first paper, we focus on the nine Of-type stars located in this region. We determine their ionizing flux and wind mechanical energy. The analysis of nitrogen abundances in our sample probes rotational mixing. Methods. We obtained optical spectra with the multi-object spectrograph FLAMES at the ESO-VLT. When possible, the optical spectroscopy was complemented by UV spectra from the HST, IUE, and FUSE archives. Detailed spectral classifications are presented for our sample Of-type stars. For the quantitative spectroscopic analysis we used the Potsdam Wolf-Rayet model atmosphere code. We determined the physical parameters and nitrogen abundances of our sample stars by fitting synthetic spectra to the observations. Results. The stellar and wind parameters of nine Of-type stars, which are largely derived from spectral analysis are used to construct wind momentum − luminosity relationship. We find that our sample follows a relation close to the theoretical prediction, assuming clumped winds. The most massive star in the N 206 association is an Of supergiant that has a very high mass-loss rate. Two objects in our sample reveal composite spectra, showing that the Of primaries have companions of late O subtype. All stars in our sample have an evolutionary age of less than 4 million yr, with the O2-type star being the youngest. All these stars show a systematic discrepancy between evolutionary and spectroscopic masses. All stars in our sample are nitrogen enriched. Nitrogen enrichment shows a clear correlation with increasing projected rotational velocities. Conclusions. The mechanical energy input from the Of stars alone is comparable to the energy stored in the N 206 superbubble as measured from the observed X-ray and Hα emission.

Wind Stress Dependence on Ocean Surface Velocity: Implications for Mechanical Energy Input to Ocean Circulation

2006 ◽  
Vol 36 (2) ◽  
pp. 202-211 ◽  
Author(s):  
Thomas H. A. Duhaut ◽  
David N. Straub
Keyword(s):  
Wind Stress ◽  
Ocean Circulation ◽  
Energy Input ◽  
Mechanical Energy ◽  
Quadratic Function ◽  
Ocean Surface ◽  
Power Source ◽  
Surface Velocity ◽  
Stress Dependence ◽  
Scaling Arguments

Abstract It is pointed out that accounting for an ocean surface velocity dependence in the wind stress τ can lead to a significant reduction in the rate at which winds input mechanical energy to the geostrophic circulation. Specifically, the wind stress is taken to be a quadratic function of Ua − uo, where Ua and uo are the 10-m wind and ocean surface velocity, respectively. Because |Ua| is typically large relative to |uo|, accounting for a uo dependence leads only to relatively small changes in τ. The change to the basin-averaged wind power source, however, is considerably larger. Scaling arguments and quasigeostrophic simulations in a basin setting are presented. They suggest that the power source (or rate of energy input) is reduced by roughly 20%–35%.

Influence of Energy Input on Suspension Properties

2010 ◽  
Vol 62 ◽  
pp. 141-146 ◽  
Author(s):  
Anja Meyer ◽  
Kerstin Lenzner ◽  
Annegret Potthoff
Keyword(s):  
Energy Input ◽  
Molar Mass ◽  
Mechanical Energy ◽  
Particle Surface ◽  
Significant Loss ◽  
Polymer Chains ◽  
Background Solution ◽  
Electrosteric Stabilization ◽  
Before And After ◽  
Nanoscale Range

Electrosteric stabilization of a commercially available boehmite powder in water was investigated to perform milling experiments and reduce the particle size to the nanoscale range. The effect of three sodium polyacrylate dispersants (Na-PA) with different molar masses (2,100, 8,000, 15,000 g/mol) on the suspension properties before and after milling experiments was assessed by electroacoustic measurements in comparison with rheological tests. A significant loss of the stabilizing effect of the sodium polyacrylates due to the application of mechanical energy was detectable. Measurements of the adsorbed amount of the dispersants after milling via detection of the COD in the background solution show a considerable desorption from the particle surface. Accessorily performed analyses of the molar mass of the polymers yielded a destruction of the polymer chains due to the mechanical energy.

scholarly journals Electrical Power Generation Using Footsteps

2018 ◽  
Vol 14 (21) ◽  
pp. 318 ◽  
Author(s):  
Iqbal Mahmud
Keyword(s):  
Mechanical Energy ◽  
Electrical Power ◽  
Water Reservoir ◽  
Cost Effective ◽  
Human Movement ◽  
Electrical Energy ◽  
Load Shedding ◽  
Reservoir Water ◽  
The World ◽  
Unidirectional Valve

Electricity is the most general forms of energy used across the world. This paper focuses on designing a setup that leads to the generation of electrical energy which is going to waste when humans are walking. Footsteps are an untapped natural resources. This generated energy is, however, costeffective and nonhazardous for human. Electrical energy can be produced by converting mechanical energy using footsteps. Generating the electric power through the fabrication of footstep arrangement by a prototype comprises of a pipe, nozzle, unidirectional valve, water reservoir, turbine, and DC motor. Whenever pressure is exerted on the reservoir, water flows through the nozzle into the turbine and generates electrical energy. This energy is stored in the battery. This project will reduce the global warming and load shedding in a much cleaner cost-effective way. Since this project is related directly to the human movement, the weight of the setup is a crucial factor.

scholarly journals Deflection Behaviour of RC Beams using Reshaped Waste Tyre Rubber as Partial Replacement of Coarse Aggregate

2019 ◽  
Vol 8 (2) ◽  
pp. 4392-4395
Keyword(s):  
Natural Resources ◽  
Coarse Aggregate ◽  
Mechanical Energy ◽  
Research Work ◽  
Partial Replacement ◽  
Portland Cement Concrete ◽  
Conventional Concrete ◽  
Concrete Production ◽  
The World ◽  
Waste Tyre

The increasing demand of natural resources for the concrete production has impacted the surroundings and the concern to protect these natural resources is increasing. Lately, handling and management of scrap is the primary issue faced by the countries worldwide. The waste problem is the most important problems facing the world as a source of the environmental pollution. One of the censorious wastes to be control in today is ‘waste tyre’ because; recent development in transportation has create big number of vehicles, which produce huge quantities of used tyres. Disposing such waste tyres is a critical waste management concern around the world at the moment. Various research work had been conducted in the past which had results that showed reduction in the mechanical energy of the concrete. The motive of this study is to use the reshaped waste tyre rubber as partial alteration of coarse aggregate in the concrete and to examine the outcome of providing an mooring hole of10mm in dia on the surface of the rubber gravel which makes the cement plaster to form a cylindrical mooring between the gravel and the concrete as well work as are bar to the rubber gravel thereby, increase withstanding power to failure under load which simultaneously increase the strength. The partial replacements of coarse aggregates are done at 0%, 5%, 10%, 15% and 20% by quantity of coarse gravel. The resulting concrete beams are tested for the physical characteristics of concrete. The Comparison of flexural response of beams are made with ordinary Portland cement concrete (OPCC)and Reshaped Waste Tyre Rubber Aggregate Concrete (RWTRAC)for various compositions of Reshaped Waste Tyre Rubber Aggregate replacement to coarse aggregate. Consequently the tests on RWTRAC beams of 10 % rubber aggregate replacement are conducted and results indicated that all the beams are failed in pure bending region and gives deflection nearly same as the conventional beam with the influence of the ultimate moment. Based on the observations during testing, the beams failed in pure flexural compression failure mode. Ductility factor of RWTRAC beam also showed enhanced performance when compared with the performance of conventional concrete. After testing it is inferred that till 10% of RWTRA replacement, the compressive and flexural strength of concrete is nearly same as the conventional concrete, but from 10 to 20% the strengths are abruptly fallen.

scholarly journals Single-phase friction riveting: metallic rivet deformation, temperature evolution, and joint mechanical performance

2019 ◽  
Vol 64 (1) ◽  
pp. 47-58 ◽  
Author(s):  
Gonçalo Pina Cipriano ◽  
Aakash Ahiya ◽  
Jorge F. dos Santos ◽  
Pedro Vilaça ◽  
Sergio T. Amancio-Filho
Keyword(s):  
Energy Input ◽  
Single Phase ◽  
Mechanical Performance ◽  
Mechanical Energy ◽  
Tensile Force ◽  
Energy Conditions ◽  
Two Phase ◽  
Axial Forces ◽  
Joint Properties ◽  
Riveting Process

Abstract The present work explores the feasibility of single-phase friction riveting on unreinforced thermoplastics. In single phase, the load is kept constant throughout the process, avoiding the forging phase with higher axial force, used in the conventional process. This process variant can constitute an answer when payload restrictions exist. The results demonstrate the feasibility of single-phase friction riveting on unreinforced polyetherimide plates joined by AA2024 rivets with 5 mm of diameter. A Box-Behnken design of experiments and analysis of variance were used to set parameter matrix and understand the correlations between parameters and joint properties. A large variation of the mechanical energy input was observed (151–529 J). Over-deformation and material rupture were observed in higher energy conditions. Lower energy input yielded a bell-shaped rivet plastic deformation, corresponding to the best performance. The maximum process temperatures varied between 461 and 509 °C. This friction riveting process variant allowed a considerable high mechanical strength to be achieved, with ultimate tensile force of 7486 N, comparable with the two-phase friction riveting process, albeit applying lower axial forces, such as 2400 N. Within the investigated conditions, this study proves the feasibility of the single-phase process, achieving good global mechanical performance and energetically efficient conditions, without forging phase.

A Renewable Source of Hydroelectricity

2013 ◽  
Vol 310 ◽  
pp. 399-402
Author(s):  
Saleh A. Aboukhres ◽  
Ali S. Zayed ◽  
Hisham A. Ayad ◽  
S. Ganesan
Keyword(s):  
Kinetic Energy ◽  
Mechanical Energy ◽  
Pressure Fluctuations ◽  
Ocean Waves ◽  
Wave Power ◽  
Sea Waves ◽  
Power Devices ◽  
Regular Form ◽  
The World ◽  
Different Parts

The Sea-waves, as a kinetic energy, is one of the renewable sources of energy which can be harnessed to generate electricity. Wave power devices extract energy directly from the surface motion of sea (ocean) waves or from pressure fluctuations below the surface. A variety of technologies have been proposed to capture the energy from waves and some of the more promising designs are undergoing demonstration testing at economical scales. In this research, the irregular kinetic energy in sea waves is to be converted to a stored potential energy and used in a regular form, with conversion once again to mechanical energy, for driving a turbine which to be connected to an electricity generator through a gear box. Wave power varies considerably in different parts of the world and wave energy cannot be harnessed effectively everywhere. Because sea waves may become ineffective for a period of time, this research is concerned with the storage of energy in one of its forms.

scholarly journals PENINGKATAN PERAN IBU RUMAH TANGGA TERHADAP PENCEGAHAN SINDROMA METABOLIK

2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Nazwirman Nazwirman ◽  
Juniarti Juniarti ◽  
Yurika Sandra
Keyword(s):  
Metabolic Syndrome ◽  
Laboratory Tests ◽  
Energy Input ◽  
Know How ◽  
The Metabolic Syndrome ◽  
The Family ◽  
The World ◽  
Prevalence Of Obesity ◽  
The City ◽  
Symptoms And Signs

Obesity is a health problem throughout the world. Obesity as a component of the metabolic syndrome, is very complex and multifactorial. Obesity is generally caused by energy input exceeding the body's use of energy for the sake of basal metabolism, physical activity, food waste disposal and for growth. The city of Tangerang ranks first for the prevalence of obesity from Banten Province. The results of the activity stated that the prevalence of obesity in Taklim women was 44 percent. This program is an empowerment of Majelis Taklim women to overcome and prevent health problems, especially metabolic syndrome by conducting screening and counseling. The result is that participants can know the symptoms and signs of metabolic syndrome through anthropometric measurements and laboratory tests, participants can know how to prevent metabolic syndrome and can provide explanations to the family and the surrounding community about prevention of metabolic syndrome

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