http://dspace.zu.edu.ly/xmlui/handle/1/437 حولية علمية محكمة تصدر عن مركز البحوث والاستشارات العلمية والتدريب بجامعة الزاوية Wed, 08 Apr 2026 21:44:31 GMT 2026-04-08T21:44:31Z http://dspace.zu.edu.ly/xmlui/handle/1/943 A Scanning Electron Microscopic Evaluation of SurfaceDefects of New and Used Retreatment Files Abo Algaith, Ebtisam Almahdi This study evaluated the surface defects of new and used Retreatment files using scanning electron microscope. Methods: Thirty extracted human mandibular molars with curvature 10o to 25o were used in the study. The selected teeth decapitated and distal roots were separated then cut coronally to establish 16 mm length. Root canal preparation was performed using ProTaper Rotary system, Obturation was performed with lateral compaction technique using master cone size F2 with Resin sealer. The obturated teeth were randomly divided into two main groups of fifteen teeth. In-group I: ten sets of ProTaper retreatment files will be used to remove gutta-percha from thirty obturated canals and in group II: ten sets of D-race retreatment files were used to remove gutta-percha from thirty obturated canals. ProTaper and D-race retreatment files were examined before and after being used. Results: scanning electron microscopic analysis of both the retreatment file systems revealed that, the ProTaper retreatment files were less surface defects than the D-Race retreatment files but, the difference was not statistically significant. Conclusion: ProTaper retreatment files showed less distortion and fracture when compared to D-Race retreatment files Wed, 01 May 2019 00:00:00 GMT http://dspace.zu.edu.ly/xmlui/handle/1/943 2019-05-01T00:00:00Z http://dspace.zu.edu.ly/xmlui/handle/1/942 The Influence of Service Quality on Passengers' Satisfaction and Loyalty. A Study on Air Malta Esarwi, Abougagela; Treki, Mustafa This research examines and investigates the impact of service quality on airline customer satisfaction and loyalty. The researchers analyzed the secondary data and exercised personal observation to identify the nature of the relationship between service quality and customer satisfaction, loyalty, and to study further the impact of service quality on both market share and profitability of Air Malta. In addition, the result showed an effective marketing strategy that can be offered and implemented based on further investigation and analysis of the relationship between service quality, customer satisfaction, and loyalty. Some recommendations for the management at Air Malta were suggested to help them to make better choices with special emphasis on the reliability of their services. The limitations of the research were also discussed. Wed, 01 May 2019 00:00:00 GMT http://dspace.zu.edu.ly/xmlui/handle/1/942 2019-05-01T00:00:00Z http://dspace.zu.edu.ly/xmlui/handle/1/941 Hydrochemical Investigation and Quality Assessment of Groundwater in WadiJarif, Sirte City, Libya Aboshaala, Nouria; Grabel, LutfiaM; Bahroun, Najway Hydrochemistry of groundwater in WadiJarif, Sirte City, Libya was used to assess the quality of groundwater for determining its suitability for drinking, domestic and agricultural purposes. A total of 30 groundwater samples were collected randomly from WadiJarif, boring and analyzed for major ion chemistry to understand the operating mechanism of geochemical processes for ground water quality. The quality analysis is performed through the estimation of pH, EC, TDS, TH, Ca2+, Mg2+, Na+, K+, Cl-, NO3 -, SO4 2-, HCO3 -. The results of chemical analyses indicate that the groundwater chemistry of the Wadi Jarifaquifers is highly influenced by their bearing facies and sea water intrusion. The water salinity is moderately saline classes, where the (TDS) ranges from 3311 to 8187ppm. The dominant water types are Na2SO4 of meteoric genesis and NaCl of marine genesis. Assessment of groundwater of WadiJarif for different uses indicates that the groundwater are classed as unsuitable for drinking (all studied samples TDS more than 1500), also, this groundwater can't be used for domestic purposes for its high TDS and TH. Moreover most of the groundwater of the study area is not recommended for irrigation under normal conditions. However, it is suitable for the salt tolerant crops and high permeable soils under good irrigation management Wed, 01 May 2019 00:00:00 GMT http://dspace.zu.edu.ly/xmlui/handle/1/941 2019-05-01T00:00:00Z http://dspace.zu.edu.ly/xmlui/handle/1/940 Measurement of Mechanical Properties of Re-Cycled Waste Refractory Brick Hassine, Nabile; Zindah, E. M.; Jamhour, Hana Misrata Iron and Steel Complex waste brick used in this study was subjected to cleaning and crushing to granules of 30 mm size. The resultant granules were hammer milled to powder particles of an average size of 1 mm and then sieved to give coarse + 0.355 mm waste powder. A high energy ball mill was used to convert this waste powder to nano-crystalline powder with a crystallite size in the range from 45 to 51 mm. The present work involved the preparation of three powder batches with each batch composed of nano–crystalline powder, +0.355 mm waste brick powder, and Sebha Kaolin clay powder of 75 microns particle size. These batches were pressed, dried at a temperature of 110°C, and finally sintered at 1000, 1300, and 1500°C. The obtained results revealed the presence of a molten glassy phase at the sintering temperature of 1500 °C. This had a weakening effect on the mechanical properties and hence limited the maximum working temperature of the produced bricks to 1300°C. Wed, 01 May 2019 00:00:00 GMT http://dspace.zu.edu.ly/xmlui/handle/1/940 2019-05-01T00:00:00Z