This paper is designed to present an experimental study being recently conducted for investigating the effect of some fuel additives on the performance of spark ignition within a benzene engine. Three types of additives were added separately (Gasoline Additive, Gasoline Booster, and Octane Booster) to pure gasoline with a volumetric ratio 1:6, 1:7, and 1:8 respectively. Four separate laboratory experiments being conducted using an internal combustion engine at rotational speed ranges from 600 to 3000 rpm, where the three mixtures and the pure gasoline itself were used. The findings showed that there was a positive effect on the engine performance as the brake power increases by 8%, 13% and 23% at the use of Gasoline Additive, Gasoline Booster, and Octane Booster respectively as compared with using only the pure gasoline. The brake thermal efficiency (ɳth) was also affected positively showing its maximum value of about 8% for Octane Booster, and with a minimum value for using Gasoline Additive at about 4.7%. In addition, this study showed that the value changes in the brake specific fuel consumption for Gasoline Additive, Gasoline Booster, and Octane Booster was at the levels of 1%, 2%, and 5% respectively compared with using only the pure gasoline. Furthermore, the results also showed that the use of Octane Booster gave the highest level of air fuel ratio arabic 18 English 97
ٌRajab HOKOMA, Nabil M. Muhaisen(1-2017)

This paper investigated the implementation status of Just-In-Time practices within the Libyan cement industry. The required data/information were gathered from the target factories through interviewing the most involved people in the decision making process within this business area, and through a questionnaire, developed for this survey in order to identify the actual application levels for the key-factors being considered as the most crucial for any successful and effective application. The findings showed that the cement industry suffers from many problems in managerial, manufacturing, and industrial operations. Among of them are lack of clear policies and strategic plans. Based on the findings, the paper recommended that the management body should pay more attention for providing all the requirements to qualify and train the related employees and personnel, providing the spare parts required for maintenance programs, and do not neglect the security aspect, and should focus on the safety issues within the work-place. The paper also suggested that clear policies and strategies should be well-formulated, adapting modern technologies and techniques for maximizing the efficiency and effectiveness throughout the cement industrial operations arabic 13 English 66
ٌRajab HOKOMA, Hala Mansour Amaigl(7-2018)

This paper is concerned with calculating boiler efficiency as one of the most important types of performance measurements in any steam power plant. That has a key role in determining the overall effectiveness of the whole system within the power station. For this calculation, a Visual-Basic program was developed, and a steam power plant known as El-Khmus power plant, Libya was selected as a case study. The calculation of the boiler efficiency was applied by using heating balance method. The findings showed how the maximum heat energy which produced from the boiler increases the boiler efficiency through increasing the temperature of the feed water, and decreasing the exhaust temperature along with humidity levels of the of fuel used within the boiler. arabic 15 English 78
Rajab HOKOMA, Nabil M. Muhaisen(1-2012)