Microstructure of NiCrBSi Laser Cladding Coatings Textured by Nd-YAG Laser

2011 ◽  
Author(s):  
A. Higuera-Garrido ◽  
R. Gonza´lez ◽  
M. Cadenas ◽  
J. L. Viesca ◽  
A. Herna´ndez-Battez
Keyword(s):  
Surface Treatment ◽  
Internal Combustion Engines ◽  
Tribological Behavior ◽  
Energy Levels ◽  
Full Range ◽  
High Energy ◽  
Low Energy ◽  
Manufacturing Processes ◽  
Combustion Engines ◽  
Scientific Fields

The use of texturing as a surface treatment that improves the tribological behavior is widespread in industrial and scientific fields, it is used in internal combustion engines [1], in biomechanical applications [2], in manufacturing processes [3] and in a full range of different applications. When texturing is carried out at low energy levels, the material melts superficially in a process governed by convection and thermocapillarity phenomena [4], whereas at high energy levels the reaction of the material could lead to its sudden vaporization [5] and local melting.

Improving the tribological behavior of internal combustion engines via the addition of nanoparticles to engine oils

2015 ◽  
Vol 4 (4) ◽  
Author(s):  
Mohamed Kamal Ahmed Ali ◽  
Hou Xianjun
Keyword(s):  
Internal Combustion Engines ◽  
Tribological Behavior ◽  
Internal Combustion ◽  
Valve Train ◽  
Combustion Engines ◽  
Power Losses ◽  
Oil Consumption ◽  
Engine Oils ◽  
Engine Efficiency ◽  
Sliding Surfaces

AbstractThe friction between two sliding surfaces is probably one of the oldest problems in mechanics. Frictional losses in any I.C. engine vary between 17% and 19% of the total indicated horse power. The performance of internal combustion engines in terms of frictional power loss, fuel consumption, oil consumption, and harmful exhaust emissions is closely related to the friction force and wear between moving parts of the engine such as piston assembly, valve train, and bearings. To solve this problem, most modern research in the area of Nanotribology (Nanolubricants) aims to improve surface properties, reduce frictional power losses, increase engine efficiency, and reduce consumed fuel and cost of maintenance. Nanolubricants contain different nanoparticles such as Cu, CuO, TiO

Theoretical photoionization study of Ti9+ ion

2020 ◽  
Author(s):  
Hongbin Wang ◽  
Gang Jiang
Keyword(s):  
Cross Sections ◽  
Energy Levels ◽  
Radiative Transition ◽  
High Energy ◽  
Low Energy ◽  
Transition Rates ◽  
Channel Coupling ◽  
R Matrix ◽  
Good Consistency ◽  
Good Agreement

Photoionization (PI) of Ti<sup>9+</sup> ion is investigated by the Dirac R-matrix method. Multi-Configuration Dirac-Fock (MCDF) calculations are performed to construct accurate target functions. Good agreement of energy levels and radiative transition rates indicate the accuracy of target functions. PI cross sections show good consistency between length and velocity forms. The results are consistent with the previous theoretical values in high-energy regions. Partial waves contribution to the total PI cross sections are discussed for the ground and metastable states. Moreover, the PI cross sections are dominated by many resonance structures and affected by the channel coupling effects in low-energy region. In addition to providing data for the Opacity Project TOPbase, the present work promotes plasma simulation and diagnosis.

scholarly journals Ruminal Microbiota and Fermentation in Response to Dietary Protein and Energy Levels in Weaned Lambs

Animals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 109 ◽  
Author(s):  
Xiaokang Lv ◽  
Kai Cui ◽  
Minli Qi ◽  
Shiqin Wang ◽  
Qiyu Diao ◽  
...  
Keyword(s):  
Growth Performance ◽  
Energy Levels ◽  
High Energy ◽  
Metabolizable Energy ◽  
Low Energy ◽  
Dietary Energy ◽  
Ruminal Fermentation ◽  
Protein Levels ◽  
Energy Group ◽  
Low Energy Diet

Supplying sufficient nutrients, such as dietary energy and protein, has a great effect on the growth and rumen development of ruminants. This study was conducted to evaluate the effects of dietary energy and protein levels on growth performance, microbial diversity, and structural and physiological properties of the rumen in weaned lambs. A total of 64 two-month-old Hu lambs were randomly allotted to 2 × 2 factorial arrangements with four replicates and with four lambs (half male and half female) in each replicate. The first factor was two levels of dietary metabolizable energy (ME) density (ME = 10.9 MJ/Kg or 8.6 MJ/Kg), and the second factor was two levels of dietary crude protein (CP) content (CP = 15.7% or 11.8%). The trial lasted for 60 days. A low dietary energy level restrained the growth performance of lambs (p < 0.05). The ruminal concentration of acetate and the ratio of acetate to propionate increased but the propionate concentration decreased significantly with the low energy diet. However, the rumen morphology was not affected by the diet energy and protein levels. Moreover, a low energy diet increased ruminal bacterial diversity but reduced the abundance of the phylum Proteobacteria (p < 0.05) and genus Succinivibrionaceae_uncultured (p < 0.05), which was associated with the change in ruminal fermentation phenotypes. By indicator species analysis, we found three indicator OTUs in the high energy group (Succinivibrionaceae_uncultured, Veillonellaceae_unclassified and Veillonellaceae_uncultured (p < 0.01)) and two indicator OTUs in the low energy group (Bacteroidales_norank and Lachnospiraceae_uncultured (p < 0.01)). In conclusion, these findings added new dimensions to our understanding of the diet effect on rumen microbial community and fermentation response, and are of great significance for establishing the optimal nutrient supply strategy for lambs.

STAND FOR RUNNING AND TESTING OF LOW POWER MOBILE FARM MACHINERY ENGINES

2016 ◽  
Vol 1 (2) ◽  
pp. 51-53 ◽  
Author(s):  
Иншаков ◽  
Aleksandr Inshakov ◽  
Байков ◽  
Dmitriy Baykov ◽  
Десяев ◽  
...  
Keyword(s):  
Low Power ◽  
Internal Combustion Engine ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
High Energy ◽  
Combustion Engines ◽  
Farm Machinery ◽  
Three Phase ◽  
Wide Range

The purpose of research is to improve the quality of production and repair internal low-power mobile farm combustion engines. To achieve this goal it was suggested to carry out running and testing the engines of small tools and equipment in specialized economical braking stands. The design of such stand, consisting of internal combustion engine, connected crank shaft with asynchronous electric machine with wound rotor, connected to the three-phase network, and matrix converter frequency included in the three-phase electrical network and consisting of nine bidirectional transistor switches, which receive signals space-vector control with automatic control system connected with the test equipment on the basis of a personal computer on which the signals from the sensors mounted on the internal combustion engine is also coming. This stand design for running and testing of internal combustion engines of mobile low power farm machinery is technically easy to manufacture and cost-effective to use. In addition, the design feature of the proposed technical solution is characterized by high energy efficiency and reliability, small dimensions and weight parameters, and wide range of speed control asynchronous machine with wound rotor.

Challenges Facing Hydrogen Fuel Cell Technology to Replace Combustion Engines

2013 ◽  
Vol 724-725 ◽  
pp. 715-722 ◽  
Author(s):  
R. K. Calay ◽  
Mohamad Y. Mustafa ◽  
Mahmoud F. Mustafa
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Internal Combustion Engines ◽  
High Energy ◽  
Current Status ◽  
Combustion Engines ◽  
Cell Technology ◽  
Fuel Cell Technology ◽  
Heat Engines ◽  
The Future

In this paper; technological challenges and commercialization barriers for Proton Exchange Membrane (PEM) fuel cell are presented. Initially, the criteria that must be met by the energy source of the future is presented from the point of view of the authors. Sustainability, high energy content and combustion independence are recognized as the main decisive factor of future fuels, which are all met by hydrogen, consequently the application of fuel cells as combustion free direct energy converters of the future. Fuel cell technology as an alternative to heat engines is discussed in the context of the current status of fuel cells in various applications. Finally, the challenges facing fuel cell technology to replace heat engines from the commercial and research points of view are presented and discussed supported by current trends in the industry. It is concluded that there have been several advancements and breakthrough in materials, manufacturing and fabricating techniques of fuel cells since the eighties, many of these challenges which are associated with cost and durability still exist when compared with the already matured technology of internal combustion engines. Any effort to achieve these goals would be a significant contribution to the technology of the fuel cell.

Crude protein requirements of large frame cattle fed two levels of energy as weaned calves or as backgrounded yearlings

1993 ◽  
Vol 73 (2) ◽  
pp. 315-325 ◽  
Author(s):  
J. J. McKinnon ◽  
R. D. H. Cohen ◽  
D. A. Christensen ◽  
S. D. M. Jones
Keyword(s):  
Energy Balance ◽  
Key Words ◽  
Crude Protein ◽  
Energy Levels ◽  
Average Daily Gain ◽  
High Energy ◽  
Carcass Composition ◽  
Low Energy ◽  
Protein Requirements ◽  
Daily Gain

Two trials were conducted to determine the crude protein (CP) requirements of large-frame (LF) cattle managed under two regimes and fed one of two energy levels. Trial 1 involved 216 recently weaned LF calves, while trial 2 involved 192 LF backgrounded yearling steers. In each trial, the cattle were fed diets formulated to one of two energy levels (11.17 and 11.88 MJ ME kg−1 DM) and one of six CP levels (11, 13, 15, 16, 17 and 19% DM basis). High-energy feeding increased (P < 0.05), average daily gain (ADG), average daily carcass gain (ADCG) and average daily fat gain (ADFG) of weaned calves but did not influence the performance of the backgrounded yearlings. Weaned calves fed 16, 17 or 19% CP had higher (P < 0.05) ADG than those fed 11%, while those fed 16% CP exhibited increased (P < 0.05) ADFG. ADG and ADCG of weaned calves and backgrounded yearlings and ADFG of weaned calves fed low-energy diets increased (P < 0.05) linearly with increasing dietary CP concentration. Daily carcass lean gain of weaned calves fed low-energy diets decreased in a quadratic manner (P < 0.05) as dietary CP level increased. No influence of dietary CP concentration was observed on carcass tissue gain of the backgrounded yearlings. It was concluded that energy balance of animals fed low-energy diets improved with CP supplementation and that current NAS-NRC (1984) CP requirements accurately predict performance of LF cattle. Key words: Steers, growth, carcass composition, energy, crude protein

Tribological Aspects in Manufacturing Processes of Microstructured Components and their Tribological Behavior in Operation

2014 ◽  
Vol 966-967 ◽  
pp. 323-335 ◽  
Author(s):  
Tobias Schrader ◽  
Martin Weschta ◽  
Marion Merklein ◽  
Stephan Tremmel ◽  
Ulf Engel ◽  
...  
Keyword(s):  
Tribological Behavior ◽  
High Accuracy ◽  
Friction Reduction ◽  
Manufacturing Processes ◽  
Combustion Engines ◽  
Technological Basis ◽  
Backward Extrusion ◽  
Microstructured Surfaces ◽  
Increasing Demand ◽  
Manufacturing Technologies

An ever increasing mobility and a shortage of resources lead to restrictive politically driven limits for fuel consumption as well as an increasing demand of customers for efficient vehicles. Though electrification of cars proceeds, combustion engines will play an important role for conventional and hybrid concepts within next decades. Thus, for a contribution to increasing energy efficiency of vehicles it is vital to trace sources of friction losses and to identify possibilities for friction reduction in combustion engines. Therefore, the follower as a main contributor to friction losses in valve trains was chosen as a demonstrator for friction reduction effects by microstructured components. However, the realization of theoretically advantageous microstructures with filigree geometries is challenging for manufacturing technologies. The present study focuses on the elaboration of a technological basis for a repeatable production of components with microstructured surfaces by a combined cup backward extrusion micro coining process, coping with the demands of large-lot production. For realization of a high accuracy the influence of friction on geometry of microstructured components was investigated. In addition, running-in of components is decisive for final geometry and tribological behavior of microstructured surfaces and hence considered as well.

Comparison of Blended Elemental (BE) and Mechanical Alloyed (MA) Powder Compact Forging into Ti-6Al-4V Rocker Arms

2012 ◽  
Vol 520 ◽  
pp. 82-88 ◽  
Author(s):  
Ming Tu Jia ◽  
De Liang Zhang ◽  
Brian Gabbitas
Keyword(s):  
Master Alloy ◽  
Internal Combustion Engines ◽  
Powder Compact ◽  
High Energy ◽  
Combustion Engines ◽  
Alloyed Powder ◽  
Blended Elemental ◽  
Blended Powder ◽  
Forged Parts ◽  
Powder Compacts

Ti-6Al-4V rocker arms for internal combustion engines were produced by forging of compacts of blended powder consisting of elemental hydride-dehydride (HDH) titanium powder and Al60V40 (wt%) master alloy powder or mechanical alloyed (MA) powder synthesized by high energy mechanical milling of a mixture of HDH titanium and Al60V40 master alloy powders. The powder compacts were made by warm compaction, and their relative density was 90%. The mechanical properties and microstructures of as-forged parts made using blended powder were improved significantly with increasing holding time at forging temperature, and close to those of as-forged parts produced by powder compact forging of HDH Ti-6Al-4V pre-alloyed powder. However, the as-forged part produced by powder compact forging of MA powder was brittle, and fractured prematurely during tensile testing.

CONCEPT OF THE AUTONOMOUS HYDROGEN FUELLING STATION BASED ON PHOTOVOLTAIC AND METAL-HYDRIDE TECHNOLOGIES FOR FUEL CELL ELECRIC VEHICLE. ANALYSIS OF EXISTING FUELLING STATIONS TYPES AND VEHICLES USING HYDROGEN, HYDROGEN PRODUCTION AND STORING METHODS

2019 ◽  
pp. 26-31
Author(s):  
Wu Po ◽  
Boris Tymoshevskyy ◽  
Yuriy Halynkin ◽  
Andriy Proskurin
Keyword(s):  
Power Generation ◽  
Energy Efficiency ◽  
Fuel Cell ◽  
Internal Combustion Engines ◽  
Negative Impact ◽  
Low Energy ◽  
Combustion Engines ◽  
Electric Motors ◽  
Harmful Substances ◽  
Emissions Of Harmful Substances

At present time internal combustion engines (ICE) are the most spread as main and auxiliary ICE for vehicles, vessels, power generation, etc. Their application is associated with low energy efficiency, negative impact on the environment due to high emissions of harmful substances and the use of oil fuels. The vehicles with electric motors are alternative upon to existing ones.

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