Wadi Alshatti University Journal of Pure and Applied Sciences

Optimum number of glass covers of thermal flat plate solar collectors

2024-04-28T16:24:16+00:00

Within the framework of Libya's pursuit to harness solar energy and integrate it into the national energy mix, surpassing a 50% contribution from renewable energies by 2050, this study focuses on the optimal utilization of solar energy, both photovoltaic and thermal, along with wind energy. The research presents an exemplary design for flat solar collectors, emphasizing the requisite number of transparent covers to achieve optimal thermal performance. Simulations were conducted under specified weather conditions, including solar irradiance of 100W/m2, ambient air temperature of 30°C, and wind speed of 3m/s. Operating conditions were set at a flow rate of 100m3/h, with the inlet air temperature equal to the ambient air temperature. The efficiency equation provided by the manufacturer, a linear function considering the fluid inlet temperature, ambient air temperature, and solar irradiance on the inclined collector surface at a 30° angle south, was adopted. Consequently, a novel design for flat solar collectors, incorporating both air and water channels, was proposed. The design was delineated based on temperature differentials between the absorber plate and ambient air in distinct intervals: the range (5-0°C) without any cover, the range (40-5°C) with one cover, the range (85-40°C) with two covers, the range (140-85°C) with three covers, the range (180-140°C) with four covers, and the range (>180°C) with five covers. This distribution was applied to an air-based flat solar collector of 5m length, resulting in the following configuration: no cover for distances (0-0.1m), one cover for distances (0.1-2.3m), two covers for distances (2.3-3.9m), and three covers for the remaining distance (3.9-5.0m).

Optimal visualization pipeline partitioning technique on the grid environment

2024-04-28T16:36:17+00:00

Remote visualization of large datasets requires the development of distributed visualization pipeline. Additionally, the computational environment should provide easy configuration and automatic selection technique for the pipeline according to the resources available. Grid computing provides the required infrastructure with limited services particularly for remote visualization. The current approaches for grid enabled visualization follow static and manual selection and mapping of the resources. This paper investigates the mechanism for predicting and partitioning the visualization pipeline on the grid environment. We propose a grid computing technique for dynamic partitioning for visualization pipeline with consideration of network bandwidth and total time delay between the visualization pipeline components.

A comparative study of gamma radiation shielding parameters for sodium silicate glass containing bismuth, barium and lead oxide in the energy range (0.6 – 1.5 MeV)

2024-04-28T16:41:42+00:00

This research focused on studying various parameters of radiation shielding, including Linear Attenuation Coefficient (LAC), Mass Attenuation Coefficient (MAC), Mean Free Path (MFP), Half-Value Layer (HVL), Tenth Value Layer (TVL), Effective Atomic Number (Zeff), and Effective Electron Density (Neff). The simulations were conducted using the PHY-X/PSD simulation program at energies of 0.662, 1.17, and 1.33 MeV for two compounds of bismuth and barium silicates (S1 and S2) with different weight percentages, as well as a bismuth and lead silicate compound (S3) with the following compositions:
S1: 12Bi2O3 12BaO 40SiO2 20ZnO 16Na2SO4, S2: 12Bi2O3 12PbO2 40 SiO2 20ZnO 16 Na2SO4, S3: 30Bi2O3 30BaO 30 SiO2 5ZnO 5 Na2SO4. Radiation interactions with the material were calculated using the X-COM program in a specified energy range ranging from 0.6 to 1.5 MeV. This range includes selected energy values commonly used in radiation therapy and scientific research, typically emitted by cobalt-60 and cesium-137. The results indicated that all attenuation parameters for sample S1 were close to those of sample S2 at the specified energies. With an increase in the concentration of bismuth and barium in sample S3, relative to other oxides, the results were better compared to samples S1 and S2. This suggests that environmentally friendly lead-free glass shielding systems can be manufactured using high-concentration bismuth and barium oxide glass to avoid toxic effects associated with lead.

Analysis of the electrical power distribution system in Tarhuna City (Libya) to avoid future loads using NEPLAN software

2024-04-28T16:56:13+00:00

The electrical distribution systems in Tarhuna city suffer from several problems, including the drop in voltage and overloading as a result of the increasing demand for electrical energy at the present time, due to the urban boom and the expansion of the residential area in the city, and because of the presence of one 30/11 kV station on which the city depends entirely to provide electrical energy. This study aimed at analyzing and planning for the short term (four years) from 2017 to 2021 for the electrical power distribution network for the central area of Tarhuna city in order to face the challenges of demand for electrical capacity and future loads and its proposed expansion using the NEPLAN program, and the results of this study showed the following: For the year of 2017, the total load amounted to (4.913 MVA), the presence of an overload on some network elements more than the permissible limit, which is a transformer (Alkudrawat, Alaswaq), whereas the year 2021, the amount of the total load reached to (6.684 MVA), the presence of many network problems from overloading some elements and loading more than the permissible limit, which is the adapter (Alohum, Alaswaq, Alkudrawat, Albaldia), this study is proposed to solve these problems by replacing the old transformers that appeared with problems with other transformers with greater capacities .However the results showed that there is no overloading on the network elements .It also showed the absence of transformers loading more than the permissible limit, as there is no an unacceptable drop in voltage at the nodes, and a clear improvement was observed in the performance of the network in terms of load and lost capacities in some transformers as well as in the voltage values and angles at the nodes compared to the previous case. This study recommends periodical studies in order to develop electrical load plans and their development with the determination of the requirements and needs of the current electrical network, and to conduct research for long-term planning (from 10 years and above).

The role of knowledge management in supporting job performance of employees at Wadi AlShatti University

2024-04-28T17:04:51+00:00

The study aimed to identify the role of knowledge management (KM) in developing administrative skills among employees at Wadi AlShati University. The sample of the current study consisted of (340) employees of Wadi Alshatti University. The study tools included a questionnaire prepared by the researcher, and the study relied on the descriptive, comparative approach. The study reached a set of results through which the researcher confirmed that knowledge management has an important role in developing administrative skills in the functional departments at Wadi AlShatti University. At the end of the study, the researcher also recommended a set of recommendations.

Internal factors facing the conversion of conventional banks to Islamic banks in Libya: A field study on Jumhouria Bank, Sabha Branch

2024-04-28T17:12:15+00:00

The study attempted to find out the impact of internal factors constraining traditional banks converting into Islamic banks in Libya, by making use of previous theoretical studies as well as applied research. Where the problem of the study was the non-compliance of (traditional) commercial banks and those in charge of them to apply the rules and provisions of Islamic Sharia in financial, banking and economic transactions, and the lack of understanding of the two parties (Shariah and economists) and harmony among them on the analysis of the issue of bank interest. While the aim of the study was to find out the impact of internal factors on converting traditional banks into Islamic banks in Libya. To achieve this goal, the study used a closed-ended questionnaire to survey the data, and it was analyzed using the SPSS analysis program. The results of the study show that the rate of answering yes was (33.11%), while the rate of answering no was equal to (66.89%), and this indicates that the degree of handicap It was high, so the study hypothesis is accepted, "There are internal obstacles affecting the process of converting conventional banks to Islamic banks in Libya

Organization and management of household solid waste in Brack Alshatti City and its environs

2024-04-28T17:18:53+00:00

Dealing with solid waste is considered one of the important matters in civilized societies, and the main factor in environmental development, and we must use and consume these materials optimally. The research aims to analyze the reality of the situation of household solid waste in the southern Libyan city of Brack Alshatti as a research example, where we calculated the quantities of waste produced daily, the place of its collection, and how to deal with it currently. And to study how to solve this problem according to the engineering and environmental parties that work to improve the current reality, health and correct treatment. Therefore, a questionnaire was implemented that included 168 families randomly from the study areas (Al-Zawiya - Zalwaz - Al-Afiya - Al-Zawiya). It included many questions, as shown later in the research, with the aim of Determine the method of solving this problem, both physically and engineeringly, through the work of an integrated administrative organization to find the solution to the problem of waste accumulation and how to sort it from the source and transport it to the final collection place. The research included calculating the quantities of waste collected daily according to the number of residents, determining the daily production of waste for the individual and family, and calculating thenumber of machines and labor needed to implement it. The program and all the necessary accompanying matters to reach an acceptable solution, and taking into account the population increase, I took the city of Brack Alshatti and its environs as an example that fulfills the requirements of the imposed research and is generalizable to other regions. Taking into account the experiences carried out in this field from the reality of the Libyan situation and outside of Libya. Interest in recycling, making energy from waste, and the importance of waste in the field of energy

Evaluating the chemical composition of food mixtures prepared for pregnant women and calculating their cost and energy content

2024-04-28T17:35:56+00:00

Some physiological changes occur in a woman’s body during pregnancy, lead to decrease its ability to eat, nausea, and vomiting. Her needs for nutrients also increase due to the formation of new tissues in the body and the formation and growth of the fetus, which may expose her to malnutrition, affecting the health of her body and the health of her fetus. Therefore, the main goal of this study was to manufacture nutritional mixtures for pregnant women with high nutritional value and easy to prepare. The mixture ingredients included wheat, millet, corn, chickpeas, beans, fava beans, peas, lentils, cowpeas, flax seeds, sesame seeds, pumpkin seeds, sunflower seeds, peanuts, walnuts, cashews, almonds. In addition to dates, raisins and full-fat dried milk. Since the stages of pregnancy are divided into three stages according to the development of the fetus. Accordingly, three mixtures were manufactured based on the needs of the pregnant woman and the fetus needs for each stage. Each mixture contained some of the mentioned materials in different proportions and were called mixture (1), mixture (2) and mixture (3). The mixtures were analyzed and the results of the study were as follows. Mixture (1) contained 10.2% moisture, 14.6% protein, 2.01% lipids, 2.3% ash, 70.89% carbohydrates and 342.57 Kcal. Mixture (2) contained 7% moisture, 15.7% protein, 6.07% lipids, 2.6% ash, 68.63% carbohydrates and 374.99 Kcal, while the contents of mixture (3) were 13.33% moisture, 18.35% protein, 27.37% lipids, 2.31% ash, 38.64% carbohydrates and 462.65 Kcal. From the results, it is clear that mixture (3) contained the highest value of moisture, proteins, fats and energy and the lowest content of carbohydrates, and there were no significant differences in the ash content between it and mixture (1), which has lower ash content compared to mixture (2). Mixture (2) has the lowest moisture content. While, the lowest levels of proteins, fats, and energy were in mixture (1), in contrast to its content of carbohydrates, which was the highest among the three mixtures. The study concluded that these meals are considered complementary meals to the main meals of the pregnant woman and thus provide her with the deficiencies nutrients.

The effect of playing football on the concentration of lactic acid and lactate dehydrogenase activity for some players in the Brack Alshati area - Libya

2024-04-28T17:45:27+00:00

Background: The practice of non-strenuous sports such as football is one of the sports that stimulate blood circulation, however, when it is practiced randomly and irregularly, it can lead to the occurrence of some physical damage.
Objective: The study aimed to find out the negative impact of football on some biochemical variables (lactic acid) and the effect of this sport on the activity of the lactate dehydrogenase enzyme by measuring the concentration of these variables before and after playing football in some athletes.
Materials and methods: This study was conducted on a group of athletes (25 person) with an average age of (20-45 years) and individuals, who did not exercise used as a control group. Lactic acid measured and the activity of the lactate dehydrogenase enzyme. Minitab16 statistical analysis software was used to analyze the results.
Results: the results of the study illustrated that a slight increase in the concentration of lactic acid was observed in the samples of people who practice football (13.22. ± 4.12mg / 100 ml) compared with the samples of people who did not playing football (10.90 ± 02.9 mg / 100 ml), while the results showed that the concentration of lactic acid Immediately after practicing sports, where its average concentration was (17.14± 5.33 mg/100 ml), the results showed that there were statistically significant differences between the first group who practiced football (before entering the stadium) and the second group after leaving the stadium. The study also showed that there were statistically significant differences between the all groups. The second group and the control group (P value < 0.05), while no statistical differences were observed between the first group (before entering the stadium) and the control group. The results of analyzing the effectiveness of the lactate dehydrogenase enzyme showed that there were significant differences between the first group (before entering the stadium) and the second group (after exercising).
Conclusion: The study concluded that the concentration of lactic acid and the activity of the enzyme lactic dehydrogenase increase with exercise when compared with non-exercising subjects. The study also confirms that the practice of football works to stimulate the muscles to increase the effectiveness of the enzyme and also increase the concentration of lactic acid.

Impact of the institutional quality on economic growth in Libya

2024-04-28T17:54:42+00:00

In this study, the researchers focused on investigating the effect of institutional quality on the economic growth of Libya. This paper used the auto-regressive distributed lag (ARDL) method to determine time series data in the period from 1981 to 2019. The results showed that institutional quality positively affected economic growth in Libya. In addition, an adverse relationship an institutional quality has with economic growth above certain of level institutional quality exceeded.
Hence, the implication of this finding is that Libya requires high level of institutional quality for ensuring long-term economic growth.

Isolation and identification of bacteria causing dental caries among the children in Brack Alshatti City

2024-04-29T05:01:52+00:00

There are many genus and species of bacteria that are naturally present in the human oral cavity which are called oral bacteria living in the mouth without causing any harm to the hard or soft tissues. However, by carelessness of oral and dental hygiene, it becomes a suitable environment for the growth and reproduction of bacteria, and therefore these bacteria may invade the teeth causing caries and other diseases. Due to high prevalence of caries among children especially infants, and subsequent resulting health problems such as caries of permanent teeth, this study aims to isolate and identify bacteria that cause dental caries among children in Brack Alshatti City. A total of 25swabs were taken from dental plaque. The samples were collected from children aged from 2 to 6 years attending the dental clinic at Brack General Hospital and Al-Sarah Dental Clinic. The samples were cultured on culture media immediately or within two hours of collection. The groups were divided by sex, age, presence of tooth decay, genus and species of bacteria. The results showed that children of 5years old were the most effected with tooth decay especially at posterior teeth. The results obtained showed that 60% of the children were females, and 40% of them were males. Moreover, the genus Streptococcus appeared in 24 isolates and with prevalence rate of 44%, which was the most common isolated bacteria. Gram-positive streptococcus strains are therefore mainly responsible for causing tooth caries among these children compared to other bacteria species found in the oral cavity.

Impact of substrate thickness on the rectangular patch antenna for 5G communication system by CST Studio

2024-04-29T05:10:29+00:00

An antenna is of extensive significance for a conversation device because the layout of an air interface is specifically reliant at the antenna layout. With the significant wireless evolution from 1G to 5G, technologies and network capacities are also evolving to full-fill the promptly growing customer demands. These continually increasing demands have gone concurrently with extensive technological accomplishments of the antenna design community. This paper discusses fifth-generation (5G) smart antennas, presents design of an efficient micro-strip antenna for 5G communication systems and the antenna is designed on low-loss Teflon based RT/duroid 5880 substrate with (ε_r) of (2.2) and a (tanδ = 0.0009) to wrap things up, and presented a comparative study of effect of height in the performance parameters of rectangular shaped micro-strip patch antenna, the antennas were simulated for purpose of the application of wireless LAN for (f_r= 28 GHz ) using CST Microwave Studio software, the performance of the designed antenna was analysed in terms of bandwidth, gain, return loss, voltage standing wave ratio, and radiation pattern (3D), the conclusion showed that the submitted designs have a bandwidth of (10 dB) greater than (2 GHz ), with an achieved total gain of more than (10 dB), the performance of the proposed antenna satisfies the requirements of 5G communications systems in terms of high gain, high radiation efficiency and adequate bandwidth.