Omar Al-Mukhtar University Journals
Not a member yet
747 research outputs found
Sort by
Influence of Age, Sex, and Refractive Error on Intraocular Pressure Measurement Using Applanation Tonometer Among Healthy Individuals in Shahat
Get PDFThe present study aimed to estimate the distribution of IOP and the relation with gender, age, and refractive error in a healthy Libyan population. This observational cross-sectional study was conducted in Cyrenaic Teaching Hospital from December 2023 to February 2024. 200 patients who presented to the hospital took part in the questionnaire. A Goldman applanation tonometer was used to measure IOP following the instillation of a drop of Benzoyl Peroxide. There were no significant differences noted between IOP in the right and left eyes. There was a correlation between IOP and age, but there was no correlation between IOP and gender (p < 0.05). IOP is one of the most important indicators for monitoring the health of the eyes. Concerning age, the mean IOP increased with age and refractive errors. Conclusion: This study supported the hypothesis that age and high myopia are major risk factors for ocular hypertension development
Assessment of Content Cations Present in Groundwater Samples Collected from Wells of Ajdabya City and its Environs
Get PDFThe purpose of this study was aimed to evaluate the quality of the drinking water in fifteen wells for Ajdabya City and its surrounding areas in Libya by measuring the conductivity, total dissolved solids, major calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium(K+), lithium(Li+) and total hardness (TH) in the groundwater. According to this study, the conductivity, total dissolved solids, and cation concentrations were rose in the majority of the groundwater samples except in forth wall of Zuwaytinah area, which was in limiting value (EC = 770), (TDS =340), (TH =360), (Ca2+ =160). Meanwhile rest the chemical analysis were higher than limiting value (Na+= 390), (k+ 60) and (Li+ =60) when compared to the WHO and Libyan drinking water standards
Comparison between Green and Chemical Synthesis of Silver Nanoparticles: Characterization and Antibacterial Activit
Get PDFUsing chemical reduction and green technology, two different approaches are used in the current work to synthesize silver nanoparticles. Pomegranate peel extract has been utilized in green technology applications. Furthermore, In the chemical approach, polyvinylpyrrolidine and ascorbic acid were utilized as reducing agents, and the optical, structural, and antibacterial characteristics of the two versions were investigated. In comparison to the chemical reduction variant (30.38 nm), the particle sizes in the green technique (19.5 nm) were smaller. Comparing green silver nanoparticles to chemically synthesized silver nanoparticles, SEM pictures showed that the former had formed a distinct crystalline shape and were evenly distributed on the surface. Granules constituted the shape of the particles. Additionally, it spreads topically. Whereas the greenly synthesized variant\u27s absorption band was at 280 nm, the chemically synthesized variant\u27s absorption band was at 300 nm. It was demonstrated by spectroscopic data of green silver nanoparticles that they have the capacity to produce and stabilize silver nanoparticles. Chemically produced green silver nanoparticles were also exposed to FTIR analysis to identify active functional groups. Silver particles can also be stabilized by chemically produced silver nanoparticles. To assess the antibacterial activity, the nanoparticle agar diffusion method was employed. The bacteria detected in the medium were Staphylococcus aureus and Escherichia coli. In the green form, the bacterial growth inhibition zone was larger and was produced with varying concentrations of 25 ml, 50 ml, 75 ml, and 100 ml, or 13 ml, 10 ml, 9 ml, and 8 ml for Staphylococcus aureus and 15 ml, 12 ml, 10 ml, and 7 ml for E. coli, respectively. Green-produced transcripts exhibited higher antibacterial responses, which were likely caused by the faster rate of nanoparticle stabilization mechanism by organic compounds found in pomegranate fruit peel extract
Foraging Behaviour of Apis mellifera Responses to the Position of Apple Flowers (Malus domestica)
Get PDFThis study was conducted to investigate the effect of flower height on the number of worker bees, Apis mellifera, and its effect on the foraging behavior during its visit to the flowers of Malus domestica. The flowering region of the tree was divided into two equal heights, and the number of honey bee visitors and foraging behavior during the first hours of the day were monitored and calculated. The two regions showed apparent significant differences in the average number of nectar collections at 11:00 am, the highest number of visitors was recorded in the upper region 96.0 ± 6.0 workers/m2, and the lower region of nectar with an average of 84.0±3.3 workers/m2, and the lowest rates were recorded in the upper region of nectar, with an average of 73.3 ±63.3 workers/m2 at 12 noon. At 9:00 am, the lower region of nectar was recorded with an average of 36.6 ± 4.6 workers/m2. The two regions had the highest average number of pollen collectors. At 9 am, the upper region recorded 25.3 ± 0.4 workers /m2, and the lower region recorded 13.3±0.77 workers/m2. The lowest rates were recorded in the upper region7.00±0.9 workers/m2 at 11:00 am. At noon, the average area recorded 3.6±0.1 workers /m2.The result revealed no significant differences in the handling time in the two regions during the nectar collection. However, differences were recorded in the traveling time in the lower region only for nectar collectors; we conclude that the tree\u27s height affected the behavior of the honey bee workers during the search for food and pollen collection
Modelling and simulation of flexural behavior for reinforced concrete beams using ANSYS
Get PDFOver the last twenty years, many investigators are used finite element software, to validate and compare the FE results with their experimental research. This work focused on the development of a numerical model implemented by the ANSYS 2022R2 software, to simulate the flexural behavior of the RC beam. Numerical models are tested under four-point bending. To investigate the influence of reinforcement steel ratio and compressive strength of concrete on the flexural capacity of the model. The results indicated that the Finite Element model was able to predict the flexural behavior of the experimental test beam. Furthermore, the influence of different tensile reinforcement ratios has the most effect on the flexural behaviour of the FE models at maximum loads. While the change in concrete compressive strength has affected the flexural performance of the models. This influence shows slight increases in the first crack load and maximum loads of the models. Furthermore, cracking pattern behaviour at the final stage for numerical models showed a good agreement with experimental cracks behaviour
Top Glass Cover Effect on the Performance of a Parabolic Trough Solar Receiver
Get PDFSolar energy is a promising solution to the rapidly increasing energy consumption. The parabolic trough collector (PTC) can be a practical solution, particularly in providing domestic water heating in developing countries. The impact of the glass envelope on PTC performance has been investigated extensively. However, only a few studies have investigated the effects of a flat-top glass cover. This study examines the impact of a top glass cover on the PTC performance by manufacturing two identical PTCs, one with a top glass cover and the other without a top cover. The top-covered collector showed a higher maximum absorber surface temperature (11%) and higher maximum water temperature (4%) than the temperatures of uncovered PTC. The results also showed that the theoretical efficiency was %56.9 and the experimental efficiency was %50.4. Installing the glass cover has led to a gain in theoretical thermal efficiency by 5% and in experimental thermal efficiency by 4%. The study recommends that future studies improve the reflecting mirrors and increase the size of the prototype
Modeling and Experimentation of Monocrystalline Photovoltaic Module Performance with Flat Mirror Reflectors in Elbida Climate Conditions
Get PDFThe purpose of this paper is togive an outline of a method for optimizing solarpanel performance in the presence of solartracking mirrors in order to maximize energyoutput. Under the climate circumstances ofElbieda, as well as to examine the primaryinfluence of cell temperature on the performanceof mono-crystalline modules with a mirrorreflector. For the photovoltaic system with flatmirror reflectors, a mathematical model has beendeveloped to predict solar radiation. Thecomponents of solar radiation [global, direct, anddiffuse], geometric factors, and geographicalfeatures of a PV installation are included in themodel. In addition, to calculate the temperature ofthe cells. Where meteorological parameters suchas ambient temperature, slope radiation, and windspeed are used to apply the energy balancingtechnique. On a specific day in July, the testswere carried out. The findings of the modelingsimulation were compared to measurements takenduring two periods, with and without the use of areflector. For a traditional PV system and a PVreflector system, the coefficient of determination(R2) was 98.7% and 97% , respectively. In bothsituations, the mean bias error (MBE) valueswere less than 1%. The root means square error(RMSE) was 26.774% , 36.914% respectively inboth cases. The estimated results were validatedby comparing the results obtained for themeasured slope surface irradiance and themeasured unit cell temperature. The addition offlat mirror reflectors to successfully listed PVpanels was extremely effective in detecting solarirradiance, resulting in positive findings of fittedparameters
Television and the Child: Impact of Viewing on the Educational Role of the Family
No full textتهدف هذه الورقة إلى التعرف على الآثار السلبية والايجابية الناتجة عن مشاهده الأطفال للتلفزيون وخاصة في مجال النمو المعرفي و ألمعلوماتي ومدى مساهمة هذه المشاهدة في تشكيل اتجاهات الأطفال نحو المعرفة الاجتماعية والسلوك الاجتماعي في عمليه التنشئة المبكرة للطفل كما تهدف إلى معرفه دور الأسرة من خلال التنشئة الاجتماعية المبكرة للطفل في توجيه عمليه المشاهدة وما هي الأمور التي تجعل الإباء و الأمهات يقلقون من علاقة أطفالهم بالتلفزيون.This paper endeavors to examine the nuanced impacts, both positive and negative, arising from children\u27s exposure to television, with a specific focus on cognitive and informational dimensions. It further seeks to elucidate the contribution of such exposure to the formation of children\u27s social knowledge and behavioral inclinations within the context of early developmental stages. Moreover, the study aims to delineate the role of familial influence, specifically through early socialization, in steering the trajectory of children\u27s viewing habits. Additionally, it aspires to discern the specific concerns that parents harbor regarding their children\u27s engagement with television
The impact of World War II mines on land use in the Batnan region
Get PDFتؤدي التوزيعات المكانية لحقول الألغام في إلحاق العديد من الأضرار بعناصر قوة الدولة البشرية، وذلك بسبب توافق توزيعاتها المكانية مع التوزيعات المكانية لاستعمالات الأراضي سواءً أكانت الاستعمالات التي تهدف منها إلى الوصول إلى الاهداف الاقتصادية للدولة، وذلك لغرض إنتاج المواد الخام في شكلها الأولي، أو عن طريق إنتاج المواد المصنعة في الشكل المناسب للاستهلاك البشري، وكذلك في استعمالات الأراضي التي تهدف إلى تحقيق الأهداف الاجتماعية الاستيطانية للدولة من حيث إقامة المستوطنات الحضرية والريفية، كما تؤثر في استعمالات الأراضي الخاصة بتحقيق الأهداف الاجتماعية الحضارية، والتي تسعى الدولة من خلالها لإنشاء وتوزيع الخدمات في المستوطنات الحضرية والريفية. من خلال الدراسة الميدانية لمنطقة لإقليم البطنان ومطابقة التوزيعات المكانية لحقول الألغام على استعمالات الأراضي، ومدى تأثر تلك الاستعمالات بالألغام المزروعة، فقد تم العثور على العديد من الأضرار التي لحقت بالعديد من العناصر الاقتصادية، والسكانية بإقليم البطنان، بالإضافة إلى التأثير الذي ستؤديه تلك التوزيعات المكانية لحقول الألغام بشكل مباشر في العديد من استعمالات الأراضي المستقبلية في المنطقة ، وذلك من حيث استعمالات أراضي الموارد المعدنية أم أراضي الموارد الغذائية، أم الرعوية، أم شبكات النقل، أم موارد المياه، أم أراضي السياحة، بالإضافة إلى إلحاقها العديد من الأضرار بالأفراد القائمون بهذه الاستعمالات. The spatial distributions of minefields lead to various damages to elements of the human state\u27s power due to their spatial alignment with land use distributions. This includes uses aimed at achieving the state\u27s economic goals through raw material production or manufacturing for human consumption. It also affects land use for social settlement objectives, such as establishing urban and rural settlements, as well as achieving cultural and societal goals. A study in the Batnan region found numerous damages to economic and population elements, as well as the direct impact of minefield spatial distributions on future land uses in the area, including mineral resources, food resources, pastoral lands, transportation networks, water resources, and tourism lands, in addition to causing harm to individuals involved in these uses
Assessment of the Housing Situation in Al-Bayda City
Get PDFتهدف هذه الدراسة إلي تقييم الوضع السكني في مدينة البيضاء , بغية إظهار المشكلة السكنية بالمدينة في إطار علمي من خلال إخضاع الواقع السكني لمعايير الإسكان التقييمية , ومن ثم طرح بعض المقترحات التي قد تساعد على التخفيف من حدة تردئ الوضع السكني في المدينة. ومن اجل تحقيق هذا الهدف، اعتمدت الدراسة على التعدادات السكانية والإسكانية، كما اعتمدت الدراسة على الدراسة الميدانية، حيث تم استبيان 389 رب أسرة في مدينة البيضاء خلال الربع الأول من عام 2012. أما تحليل بيانات الدراسة فقد استند على أسلوب التحليل الكمي، وذلك باستخدام البرنامج الإحصائي (SPSS). وقد كشفت هذه الدراسة على العديد من النتائج أهمها، ان مدينة البيضاء تعاني من عجز سكني قوامه 1511 وحدة سكنية، كما ان المدينة تعاني من الاكتظاظ والازدحام السكني بشكل يفوق المعايير التخطيطية، هذا إلي جانب تزايد انتشار سكن الصفيح الهامشي، والسكن العشوائي بشكل كبير، فعلى سبيل المثال في محلة البيضاء الغربية تصل نسبة المساكن الهامشية إلي 40 % من جملة المساكن بهذه المحلة السكنية.This study aims to assess the housing situation in Al-Bayda City, highlighting the housing problem within a scientific framework by applying evaluative housing criteria to the current housing reality. It also proposes some suggestions that may help alleviate the poor housing conditions in the city. To achieve this goal, the study relied on population and housing census data, as well as field research. A survey was conducted on 389 households in Al-Bayda City during the first quarter of 2012. The data analysis utilized quantitative analysis methods using the statistical software (SPSS). The study revealed several important findings, including a housing shortfall of 1511 housing units in Al-Bayda City. The city also suffers from overcrowding and residential congestion that exceeds planning standards. Moreover, there is a significant prevalence of informal housing and unplanned settlements, such as tin-sheet housing. For example, in the western district of Al-Bayda, the percentage of informal dwellings reaches 40% of the total housing in this residential area.