Tillage Mechanical Energy Input and Soil-Crop Response

1981 ◽  
Vol 24 (6) ◽  
pp. 1412-1419 ◽  
Author(s):  
Dan Wolf ◽  
Thomas H. Garner ◽  
Jack W. Davis
Keyword(s):  
Energy Input ◽  
Mechanical Energy ◽  
Crop Response

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 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

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.

Modeling the Efficiency of Movement: From Individual Muscles to Whole Organism

2009 ◽  
Author(s):  
Brian R. Umberger ◽  
Alexis D. Gidley
Keyword(s):  
Energy Consumption ◽  
Energy Input ◽  
Mechanical Energy ◽  
Human Movement ◽  
Metabolic Energy ◽  
Energy Output ◽  
Whole Body ◽  
Similar Data ◽  
Invasive Approach

In the context of human movement, efficiency is defined as the ratio of mechanical energy output (work) to metabolic energy input [1,2]. It is straightforward to determine whole-body efficiency in a task such as pedaling a bicycle ergometer. In this case, work is computed from the ergometer load and pedaling cadence, and metabolic energy is determined from pulmonary gas exchange. It is also relatively straightforward to determine the efficiency of contraction in isolated muscle preparations, where the work done is easily measured, and energy input can be inferred from heat production or oxygen consumption. However, our understanding of the efficiency of muscle function during locomotion, and how this contributes to organismal efficiency, is incomplete [1]. The ability to determine efficiency of individual muscles as they perform work in vivo would greatly enhance our understating in this area. Experimental measurement of both work and metabolic energy consumption in muscles during dynamic activities is currently limited to isolated applications in non-human animals [3]. Similar data could be obtained using computational modeling and simulation techniques, provided that estimates could be obtained for both muscle work and muscle metabolic energy consumption. This non-invasive approach would open the door to investigations in humans as well as other species. Therefore, the primary purpose of this study was to determine efficiency at both the organismal and muscular levels for bicycle pedaling, using a musculoskeletal modeling approach. A secondary purpose was to identify factors that account for between-muscle differences in efficiency.

scholarly journals Compounding of Short Fiber Reinforced Phenolic Resin by Using Specific Mechanical Energy Input as a Process Control Parameter

2021 ◽  
Vol 5 (5) ◽  
pp. 127
Author(s):  
Robert Maertens ◽  
Wilfried V. Liebig ◽  
Peter Elsner ◽  
Kay A. Weidenmann
Keyword(s):  
Glass Fiber ◽  
Energy Input ◽  
Control Parameter ◽  
Mechanical Energy ◽  
Major Influence ◽  
Injection Molding Process ◽  
Fiber Reinforced ◽  
Screw Speed ◽  
Molding Compounds ◽  
Specific Mechanical Energy

For a newly developed thermoset injection molding process, glass fiber-reinforced phenolic molding compounds with fiber contents between 0 wt% and 60 wt% were compounded. To achieve a comparable remaining heat of the reaction in all compound formulations, the specific mechanical energy input (SME) during the twin-screw extruder compounding process was used as a control parameter. By adjusting the extruder screw speed and the material throughput, a constant SME into the resin was targeted. Validation measurements using differential scanning calorimetry showed that the remaining heat of the reaction was higher for the molding compounds with low glass fiber contents. It was concluded that the SME was not the only influencing factor on the resin crosslinking progress during the compounding. The material temperature and the residence time changed with the screw speed and throughput, and most likely influenced the curing. However, the SME was one of the major influence factors, and can serve as an at-line control parameter for reactive compounding processes. The mechanical characterization of the test specimens revealed a linear improvement in tensile strength up to a fiber content of 40–50 wt%. The unnotched Charpy impact strength at a 0° orientation reached a plateau at fiber fractions of approximately 45 wt%.

Improving the productivity of the cutter-loader

2021 ◽  
pp. 10-16
Author(s):  
I.A. Gorobets
Keyword(s):  
Electric Motor ◽  
Energy Input ◽  
Mechanical Energy ◽  
Tooth Profile ◽  
Mathematical Apparatus ◽  
Translational Movement ◽  
The Face ◽  
Theoretical Performance ◽  
Haulage System ◽  
Mineral Mass

The task of the conducted research is to determine the dependence of the productivity of the cutter-loader on the parameters of the engagement of the teeth of the wheel-rack mover of chainless haulage systems. To solve this problem, the dependence of the influence of the parameters of the toothed gearing of the wheel-rack mover of the chainless haulage system on the performance of the cutter-loader is found using the mathematical apparatus. The equation of the balance of the power of the cutter-loader is made, taking into account the mechanical energy input for the destruction of the formation, loading the destroyed mineral mass onto the face conveyor (relevant for cutter-loaders for excavating thin flat-lying seams) and moving the cutter-loader. The theoretical performance of the cutter-loader depends on the redistribution of the mechanical energy of the drive electric motor, aimed at the destruction of the mineral and the translational movement of the cutter-loader. The correlation of the productivity of the cutter-loader with the parameters of the engagement of the teeth of the wheel-rack mover of chainless haulage system systems is revealed. The obtained dependences of the performance of the cutter-loader allow assessing the degree of influence of the parameters of the toothed gearing of the mover of the chainless haulage system on the performance of the cutter-loader. The possibility of increasing the minute productivity of the cutter-loader by up to 20% when using a wheel-rack mover of a chainless haulage system with an optimal tooth profile is established.

scholarly journals Wpływ emisji energii z terenów zurbanizowanych i szlaków komunikacyjnych na zmiany w rozwoju ekosystemów w ich otoczeniu

2012 ◽  
Vol 10 (2) ◽  
pp. 73-85
Author(s):  
Urszula Kaźmierczak ◽  
Andrzej Kulczycki
Keyword(s):  
Energy Consumption ◽  
Statistical Analysis ◽  
Human Health ◽  
Chemical Reactions ◽  
Environmental Effects ◽  
Acoustic Waves ◽  
Urban Areas ◽  
Small Area ◽  
Energy Input ◽  
Mechanical Energy

This article aims to draw attention to the hitherto unexplored and scarcely noticed the problem of the effects of the consumption of increasing amounts of energy to human health and ecosystems exposed to emissions processed in the phase of energy consumption. Ever-increasing amounts of energy are consumed in relatively small urban areas, in communication routes, and in airport areas. As far as Poland is concerned, these areas represent less than 10% of the country. For such a small area the energy consumed is converted to other forms of energy, much of which is emitted into the environment. These emissions primarily include heat and various forms of mechanical energy, mainly that of acoustic waves. It studies the effect of noise on the health of people living in the vicinity of highways, as well as studies of ecosystems in the surrounding routes. There is still no explanation for the reasons for this phenomenon, as research in this area has been mainly carried out at the level of statistical analysis. The article has pointed out the possible causes of this phenomenon. The new theory of catalysis demonstrates the effect of mechanical energy input on the direction and rate of chemical reactions. This effect can also be significant in the case of biochemical reactions. Finally, the paper points out the need and direction of research, conducted at various levels, to determine and explain the environmental effects of increasing energy consumption, other than the greenhouse one.

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