الملخص: Tafila wind turbines farm is the largest project of wind energy to generate the electricity in Jordan until now. The major Tafilawind turbines farm (38 wind turbines) presents a 117-Mega Watt (3.075 MW/ Turbine) wind turbine power. Total design/build phase of the project is 21 months and the operations phase is 20 years, the total cost of the project is 290 million $ with100% funded through private investment which produce about4 % of the national electricity demand each year that is enough electricity to power 85,000 homes. The main objectives of this project is to reduce energy import dependency, reinforce reliability of supply and achieve energy security, contribute to Jordan’s national strategy for energy as well as to regional targets in the field of clean energy (better to the environment) and reduce greenhouse gas emissions. This paper is to evaluate the Tafila wind turbines farm in terms of financial analysis.

الملخص: The aim of this work was to investigate the stress analysis of crankpin fillets of a crankshaft. Fatigue failure in the crankpin fillet zone is one of the primary causes of the breakdown of crankshafts. In this paper, a polarization–optical method (photoelasticity) was used to study the distribution of stresses from bending in the crank-throw plane of a crankshaft on flat transparent photoelastic models. Results showed that the influence of the radius of crankpin fillet on the value of the stress concentration coefficient is estimated. Results achieved can be used in fatigue life calculation and optimization of this component.

الملخص: This study presents an approach to developing a method to generate an optimized keyway broach tool design based on constant cutting forces. The obtained experimental data, as a result of the studies carried out by the method of photomechanics on models of optically sensitive material, allow us to recommend it in the practice of calculating keyway broaches. The results obtained on keyway broach models can be transferred to the real structure, which is made of tool material, taking into account the geometric and force similarity.

الملخص: The performance of a genetic algorithm (GA) depend on many factors: the selection method is one of them. It is well known that the genetic algorithm efficiency depends to a high degree upon the selection of the good GA operators and parameters that suitable to the different scheduling problems. In this paper, we find the selection methods of genetic algorithm that are more suitable for scheduling problem. Also, a number of selection methods used in scheduling problem have been described in this paper like random selection, roulette wheel selection, rank selection and tournament selection. The make span is the measure of performance used to evaluate the genetic selection methods. This paper will help researchers in selecting appropriate selection methods for different scheduling problems for better results. Copyright © 2018, Hani A. AL-Rawashdeh et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

الملخص: The aim of this study was to investigate the range of opportunities and future prospects of presenting a blend of gasoline/ethanol fuel to run a gasoline engine. Biofuel’s advantages involve emission of low quantities of contaminants to the atmosphere and its renewable character in order to trim down dependency on gasoline as a fuel. Analyses have been carried out to show the influence of compression ratio on engine performance and tailpipe emissions by using unleaded gasoline and gasoline blends with (10 and 20%) pure ethanol SI (spark ignition) engine having a variable compression ratio with the air-cooled single-cylinder engine. Experiments were conducted on five different compression ratios (CRs) of 4:1, 5.5:1, 7:1 8.5:1, and 10:1 with a wide-open throttle. Two combinations of blended fuels were compared to the unleaded gasoline. The results showed that the BMEP (brake mean effective pressure), BTE (brake thermal efficiency), and BSFC (brake specific fuel consumption) obtained with the use of gasoline blends at all CRs were generally higher in comparison to those of pure gasoline. In general, gasoline blends provided a lower exhaust emission compared to gasoline’s emissions at all CRs. Furthermore, NOx emissions were affected much more than other exhaust emissions when changing the compression ratios compared to unleaded gasoline.