The Experts below are selected from a list of 7926 Experts worldwide ranked by ideXlab platform
V. F. Shatokhin - One of the best experts on this subject based on the ideXlab platform.
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Studying the development of asynchronous rolling of the rotor over the stator with the turbine Unit protection systems having different response times
Thermal Engineering, 2014Co-Authors: V. F. ShatokhinAbstract:The possibility to stabilize the developing asynchronous rolling of the rotor over the stator under the conditions of power Unit protections coming in action with different response times is considered. Asynchronous rolling of the rotor over the stator may develop when the rotating rotor comes in contact with the stator at high amplitudes of vibration caused by an abrupt loss of rotor balancing, by forced or self-excited vibration of the rotor, and by other factors. The danger of asynchronous rolling is connected with almost instantaneous development of self-excited vibration of the rotor when it comes in contact with the stator and with the rotor vibration amplitudes and forces of interaction between the rotor and stator dangerous for the turbine Unit integrity. It is assumed that the turbine Unit protection systems come in action after the arrival of signal of exceeding the permissible vibration level and produce commands to disconnect the generator from the grid, and to stop the supply of working fluid into the flow path, due to which an accelerating torque ceases to act on the turbine Unit shaft. The protection system response speed is determined by a certain time t = ABtime that is taken for its components to come in action from the commencement of the event (application of the signal) to closure of the stop valves. The time curves of the main rolling parameters as functions of the ABtime value are presented. It is shown that the response time of existing protection systems is not sufficient for efficiently damping the rolling phenomenon, although the use of an electrical protection system (with the response time equal to 0.40–0.45 s) may have a positive effect on stabilizing the vibration amplitudes to a certain extent during the rolling and on smoothing its dangerous consequences. The consequences of rotor rolling over the stator can be efficiently mitigated by increasing the energy losses in the rotor-stator system (especially in the stator) and by fulfilling the recommendations of the Machinery Unit catastrophe prevention system.
A. Walsh - One of the best experts on this subject based on the ideXlab platform.
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A parametric approach to Machinery Unitization in shipbuilding. Discussion. Authors' closure
Journal of ship production, 1998Co-Authors: P. E. Jaquith, Richard M. Burns, L. A. Duneclift, M. Gaskari, T. Green, John L. Silveira, A. Walsh, J. P. Carson, S. Sato, J. J. HopkinsonAbstract:During the past ten years, both U.S. and foreign shipyards have developed advanced Unitization concepts that include multi-level assemblies representing large vertical segments of ship Machinery spaces. This paper describes a parametrically derived family of large, fully integrated standard Machinery Units that are applicable over a range of ship types and installed horsepower. The results include a hierarchy of standard Units, the selection of standard Unit sizes and interfaces, the development of parametric standards for system design, engine room arrangement and structural design, and Machinery Unit structural and outfitting design. Benchmarking is reported with respect to Japanese and European shipbuilding practices, and with respect to U.S. land-based industrial plant design and construction practices. The proposed Unitization concept is demonstrated in a ship-specific engine room arrangement design effort. A business assessment for this Unitization concept is presented which addresses its potential shipbuilding cost and schedule impacts as evaluated by three U.S. shipyards.
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A Parametric Approach to Machinery Unitization in Shipbuilding
Journal of Ship Production, 1998Co-Authors: P. E. Jaquith, Richard M. Burns, L. A. Duneclift, M. Gaskari, T. Green, John L. Silveira, A. WalshAbstract:During the past ten years, both U.S. and foreign shipyards have developed advanced Unitization concepts that include multi-level assemblies representing large vertical segments of ship Machinery spaces. This paper describes a parametrically derived family of large, fully integrated standard Machinery Units that are applicable over a range of ship types and installed horsepower. The results include a hierarchy of standard Units, the selection of standard Unit sizes and interfaces, the development of parametric standards for system design, engine room arrangement and structural design, and Machinery Unit structural and outfitting design. Benchmarking is reported with respect to Japanese and European shipbuilding practices, and with respect to U.S. land based industrial plant design and construction practices. The proposed Unitization concept is demonstrated in a ship-specific engine room arrangement design effort. A business assessment for this Unitization concept is presented which addresses its potential shipbuilding cost and schedule impacts as evaluated by three U.S. shipyards.
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The National Shipbuilding Research Program, 1997 Ship Production Symposium, Paper No. 21: A Parametric Approach to Machinery Unitization in Shipbuilding
1997Co-Authors: P. E. Jaquith, Richard M. Burns, L. A. Duneclift, M. Gaskari, T. Green, John L. Silveira, A. WalshAbstract:Abstract : During the past ten years, both U.S. and foreign shipyards have developed advanced Unitization concepts that include multi-level assemblies representing large vertical segments of ship Machinery spaces. This paper describes a parametrically derived family of large, fully integrated standard Machinery Units that are applicable over a range of ship types and installed horsepower. The results include a hierarchy of standard Units, the selection of standard Unit sizes and interfaces, the development of parametric standards for system design, engine room arrangement and structural design, and Machinery Unit structural and outfitting design. Benchmarking is reported with respect to Japanese and European shipbuilding practices, and with respect to U.S. land-based industrial plant design and construction practices. The proposed Unitization concept is demonstrated in a ship-specific engine room arrangement design effort. A business assessment for this Unitization concept is presented which addresses its potential shipbuilding cost and schedule impacts as evaluated by three U.S. shipyards.
Hussain Jebur*, Yasir A. A. A. Alsayyah - One of the best experts on this subject based on the ideXlab platform.
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THE EFFECT OF SOIL MOISTURE CONTENT ON THE ENERGY REQUIREMENT AND FUEL CONSUMPTION OF THE Machinery Unit
2016Co-Authors: Hussain Jebur*, Yasir A. A. A. AlsayyahAbstract:The field experiment was conducted in one of college of agricultural fields – university of Baghdad – Abu ghraib for 2016 in a silty clay loam soil study power and fuel consumption requirement s , two types of tractors and three types of plows were used as a Machinery Unit , this study design by a spilt plot under randomize complete block design with three replicates and tasted by the average less significant different with level of probability ( 0.05 ) , the main factor was use two level of soil moisture content ( 18 – 20 % ) and ( 14 – 16 % ) , the secondary factor was use three type of plow ( moldboard , chisel and sweep ) , The research includes the study of fuel consumption ( L/hr ) , specific fuel consumption ( L/hr.hp ) , drawbar pull ( kn ) and specific energy ( hp/m3 ) . The results showed that the soil moisture content ( 14 – 16 % ) having less fuel consumption ( 8.36 L/hr ) and less specific fuel consumption ( 0.221 L/hr.hp ) and less drawbar pull ( 8.99 kn ) and less specific energy ( 1.027 hp/m3 ) , the sweep plow having a less fuel consumption ( 8.75 L/hr ) and less specific fuel consumption ( 0.233 L/hr.hp ) and less drawbar pull ( 9.07 kn ) and less specific energy ( 0.887 hp/m3 ) , the interaction between the soil moisture content ( 14 – 16 % ) and sweep plow having a less fuel consumption ( 7.11 L/hr ) and less specific fuel consumption ( 0.186 L/hr.hp ) and less drawbar pull ( 7.9 kn ) and less specific energy ( 0.844 hp/m3 )
Hussein A. Jebur - One of the best experts on this subject based on the ideXlab platform.
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The Effect of Some Primary Tillage Equipment on Performance Efficiency Under Two Level of Soil Moisture Content and Different Machinery Unit Speeds
Al-Qadisiyah Journal For Agriculture Sciences (QJAS) (P-ISSN: 2077-5822 E-ISSN: 2617-1479), 2018Co-Authors: Yasir A. Alsayyah, Hussein A. JeburAbstract:A field experiment was conducted in the experiment fields of the college of agriculture - University of Baghdad – Abu Ghraib , 2016 in a silt clay loam soil , to Evaluate the effect of some primary tillage equipment and two of levels of soil moisture content in some of performance efficiency indicator for different forward speed , ArmaTrac 845e and ITM 285 New tractor with moldboard and chisel and sweep plow as a Machinery Unit have been used in this study . Two levels of soil Moisture content include (18 – 20 % ) and (14 – 16%) represented main plot , three types of plow ( moldboard , chisel and sweep) represent sub plot , five Machinery speeds included ( 1.5 , 2.53 , 3.75 , 5.3 and 6.71 km.hr-1 ) represent sub plot , Slippage percentage (%) , fuel consumption (L.hr-1) , drawbar pull (KN) , Field capacity (he.hr-1) are have beenbeen measured in this study . And the results have been analyzed by using the order of the spilt - spilt - plot with randomize complete block design with three replicates and tested by the way averages less significant difference and the level of probability of 0.05 . The results show that : the soil moisture content ( 14 – 16 % ) has got a less value of slippage percentage % , fuel consumption L.hr-1 , drawbar pull Kn and higher field capacity ha.hr-1 , and sweep plow has got a less value of slippage percentage , fuel consumption and drawbar pull , and the chisel plow has got a higher field capacity , and when the tractor speed is increased it leads to aincrease in the slippage and fuel consumption and drawbar pull and field capacity will be anincrease .
Abdulrazzak A. Jasim - One of the best experts on this subject based on the ideXlab platform.
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Evaluation the Performance Efficiency of Manufactured, Modified and Assembled Combine Implement and Studying It’s Impact on Some Soil Physical Properties and Total Costs
International Journal of Environment Agriculture and Biotechnology, 2018Co-Authors: Abdulrazzak A. Jasim, Osama H. JwerAbstract:The experiment was conducted to evaluate the efficiency performance of the combine implement which manufactured and assembled locally and studying it's effect on some soil physical properties and total costs in one of the Agricultural College University of Baghdad Experimental Fields in loamy soil, 2017. Brazilian Massy Ferguson Tractor (MF-650) was used with the combine implement as a Machinery Unit. Three Machinery Unit speeds included 3.15, 4.60 and 6.10 km/h and seedling treatments included manufactured combine implement, seedling and fertilizer implement and manual seedling were used in this experiment. Soil bulk density, soil moisture content, amount of added water and total costs were measured. Nested design under randomized complete block design with three replications was used in this experiment. Least significant differences (LSD = 0.05) level under 0.05 probability was used to compare treatment means. The results can be summarized as following: 1. Incrased Machinery Unit speeds from 3.15 to 4.60 km.h-1 led to significant increase in soil bulk density from 1.30 to 1.36 Mg.mˉ³and significant increase in soil moisture content from 0.18 to 0.20 %. 2. Manufactured combine implement treatment was superior in getting less soil bulk density stood 1.22 Mg.mˉ³ higher soil moisture content stood 0.22%.and less amount of added water during the season stood 1103.43 mm. and less costs stood 796370 Iraqi Dinars. 3. The interaction between 3.15 km.h-1Machinery speed and manufactured combine implement got less soil bulk density stood 1.19 Mg.mˉ³, while the interference between 6.1 km.h-1 Machinery Unit speed and manufactured equipment was superior in obtaining a higher moisture content stood 0.229%. 4. Using the locally manufacturing modified combine implement for primary and secondary tillage, shallow furrow opener, seedling and fertilization in one time was successfully done in this study with high performance efficiency.
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EFFECT OF TILLAGE SYSTEM, PULVERIZATION TOOLS AND TRACTOR SPEEDS ON PRODUCTIVITY, MEAN WEIGHT DIAMETER AND RATE WATER INFILTRATION
Misr Journal of Agricultural Engineering, 2009Co-Authors: Abdulrazzak A. Jasim, Shaima' S. D. S. Al-ajeliAbstract:A field experiment was conducted at Abu-Ghraib during 2007-2008 to study the effect of ploughing system, pulverization tools and tractor speeds on Machinery group, mean weight diameter and rate water infiltration. In this study, two tractor's speed; (2.414 and 3.973 km/h) represented the main plots, two types of plows: mold board plow and chisel plow and zero-Tillage, represented the sub plots. And three pulverization tools; the rotivator, disk harrows and spring cultivator, represented sub- sub plots, were used with tow tractor's speed, New Holland, as Machinery Unit for plowing silty clay loam soil at depth of 17 cm. The study included some technical performance indicators of Machinery Unit that included some characteristics of soil like: practical productivity, disturbed soil volume and mean weight diameter, and rate water infiltration. The experiment was conducted by using Split-Split Plot Design under RCBD with three replicates. The results were showed the following: Increasing speed at pulverizity tools resulted in a significant increase in disturbed soil volume (632.81- 1035.58 m3/h).Neither plow type nor pulverization tool affected, practical productivity, mean weight diameter or saturated hydraulic conductivity. Spring cultivator affected significantly in getting the highest practical productivity (0.684 ha/h), disturbed soil volume (1164.22 m2/h), mean weight diameter (0.905 mm) and rate water infiltration (5.878 cm /h). The interaction between the spring cultivator and the speed 3.973 km/h was superior in getting higher productivity (0.850 ha/h) and disturbed soil volume (1447.00 m3/h). The interaction between the spring cultivator and the speed 2.414 km/h was superior in getting higher mean weight diameter (0.918 mm) and rate water infiltration (6.002 cm/h). The interaction between the chisel plow and the pulverization by spring cultivator was superior in getting higher practical productivity (0.695ha/h) disturbed soil volume (1182.02 m3/h) and rate water infiltration (6.108 cm/h). The tri-interaction between the plowing treatment by the chisel plow, the pulverization by spring cultivator and the speed 3.973 km/h was superior in getting higher disturbed soil Volume (1484.4 m3/h) and practical productivity (0.872 ha/h).
