Scientific Journal of Applied Sciences of Sabratha University

DETERMINATION OF HEAT CAPACITY OF SOME SEMICONDUCTOR COMPOUNDS USING A DELAUNAY'S INTEGRAL

Basmah A. Aldeeb — Tue, 27 Sep 2022 00:00:00 +0200

Using a numerical Delaunay's method, theoretical values of molar heat capacity C_p were calculated for some semiconductors (GeS, GeSe, GeTe). The obtained results have been compared with the n-dimensional Debye functions and with the corresponding experimental results in the 220-250 K temperature range. The estimated results are in good agreement with both the n-dimensional Debye functions and the experimental results over the entire temperature range. This confirms that the numerical Delaunay's method is able to represent the molar heat capacity C_p of semiconductor compounds.

CONTINUED FRACTION AND BINARY TREE GRAPHS

Fatma Ali Saad Alwafi, Asmaa Omar Mubayrash — Tue, 27 Sep 2022 00:00:00 +0200

A continued fraction is a way of representing a real number by a sequence of integers. In this paper, we display an explanation from the continued fraction expansion in a more general state, and we present a new method to think about these continued fractions using tree graphs. Continued fractions, binary tree graphs, the topological index Z, and the Euclidean division algorithm are combined. In fact, we found a new combinatorial realization of the continued fractions with the binary trees and number of connected components of binary trees. Our aim is to show how this realization reflects the convergence of the continued fractions, the topological index Z, and as well as the Euclidean division algorithm. We think that this different perspective can be useful because the continued fraction depends on the order of vertices, which are the set of all positive rational numbers. Thus, the choice of the right sequence for vertices of binary tree has a significant impact on the build of continued fraction. The connection between binary tree, sub binary trees, and continued fractions will be explored. Findings are to establish results on sums of vertices, palindromic continued fractions.

THE INFLUENCE OF IRON OXIDE ON THE STRUCTURAL AND OPTICAL PROPERTIES OF BOROSILICATE GLASSESTHE INFLUENCE OF IRON OXIDE ON THE STRUCTURAL AND OPTICAL PROPERTIES OF BOROSILICATE GLASSES

Fawzeya Gharghar, Sammer El-Jadal — Tue, 27 Sep 2022 00:00:00 +0200

Borosilicate glasses containing Fe₂O₃ with the chemical composition 30Na₂O - 2Al₂O₃- 25SiO₂- xFe₂O₃- (43-x) B₂O₃have been prepared and studied over a wide range of concentrations. The impact of such oxide on optical and physical properties of the present system has been examined. The further replacement of Fe₂O₃instead of B₂O₃ generally increases the density and molar volume due to the change in the internal structure of the glass network. The optical variation was interpreted according to the observed incorporation of iron oxide and the possible mechanism of non-bridging oxygen in silicate and bridging bonds in borate network. The investigated samples in this study were confirmed to be amorphous by means of XRD, which proved that there are no natural crystal contents.

THE EFFECT OF USING SILICA FUME IN HIGH STRENGTH CONCRETE ON WORKABILITY AND COMPRESSIVE STRENGTH: REVIEW

Serag Aonyas, Hajer Nasear — Tue, 27 Sep 2022 00:00:00 +0200

Supplementary Cementitious Materials (SCMs) are widely used to replace Ordinary Portland Cement (OPC) in High Strength Concrete (HSC). The addition of SCMs to HSC mixes generally results in altering the properties of the resulted HSC. This study focuses on reviewing the effect of a common SCM – Silica fume (SF)– as a partial cement replacement at different replacement levels by weight on workability and compressive strength of HSC. First, the researchers reviewed the chemical reactivity and particle characterization of SF. They also reviewed several research papers on the fresh and hardened properties of HSC mixes containing SF.

The review showed a significant enhancement in the compressive strength of HSC when OPC was partially replaced with SF. It also demonstrated the disagreement among researchers about the effect of SF on the workability of HSC.

While reviewing the research papers, the authors identified the optimum weight replacement of SF indicated in the reviewed papers. The researchers concluded that there are differences in the chemical composition, particle shape and size, and surface area of SF as compared to OPC. These differences in the characteristics of SF influence water demand, packing ability, and reactivity of the HSC mix, which could explain the change in the workability and compressive strength of the resulted HSC.

THE EFFECT OF SALINITY ON NUTRIENT AVAILABILITY AND UPTAKE IN CROP PLANTS

Amal F Ehtaiwesh — Tue, 27 Sep 2022 00:00:00 +0200

Crops are influenced by many climatic and environmental factors that can be of abiotic and biotic factors and they respond directly to changes in temperature, CO₂ concentration, moisture, light intensity, condition of the soil, and so on. Salinity is a major factor that reduces plant growth and productivity throughout the world. Salinity usually occurs when high concentration of soluble salts is present in soil and water; it mainly occur in arid or semi-arid regions as well as in coastal regions. Excessive salts damage plants by disrupting the uptake of water by plant roots and by interfere with the uptake of competitive nutrients. It is well known that nutrient availability and uptake by plants are influenced by salinity. Some soil and plant factor influence nutrient uptake and availability. This review provides an update about soil factors and plant factors that affect nutrients availability and uptake. Soil factors such as soil pH and water availability have a significant role in controlling nutrients availability and uptake. Regarding plant factors, plant species vary in how well they tolerate saline soils; some plants will stand high levels of salinity while others cannot stand salinity. In addition, plants differ in their salinity tolerances depending on the plant growth stages. Physiologically, salinity may have negative impact on many processes, but the most important impacts are in the form of reduced cell growth and decreased leaf area, biomass and yield.

ASSESSMENT OF PHYSICOCHEMICAL PROPERTIES AND MICROBIAL CONTAMINATIONS OF LOCAL AND IMPORTED COUSCOUS

Hawa Mokhtar JabAllah, Ashref M Eshtewi, Muna Ilowefah, Mohammed Hadi Nahaisi — Tue, 27 Sep 2022 00:00:00 +0200

Limited studies have been carried out to investigate the physicochemical properties and microbial contaminations of couscous in Libya. The purposes of the investigation were to determine the physicochemical properties and microbial contaminations of locally manufactured couscous, traditional couscous and imported couscous. Five samples of local couscous were monthly collected from different factories. Additionally, twenty fresh samples and twenty sunlight-dried samples were collected from different regions in Tripoli, and twelve samples of imported couscous were collected too. The results of protein content in traditional dried, local and imported couscous were 11.99, 10.81, and 12.04%, respectively. Traditional wet and dried couscous recorded the highest ash content. Fiber content and acidity for all samples were in the recommended limits. The amount of lead and cadmium were in the recommended limit (0.0003 and 0.012 mg/kg, respectively). The results showed that local couscous had the highest heterotrophic bacteria, 3.03 CFU/g, then comes the traditional dried couscous 2.92 CFU/g, and finally comes the traditional wet couscous 2.88 CFU/g. Yeasts and molds found in local and traditional dried couscous exceeded the maximum limit indicated by WHO (2.99-3.18 CFU/g). The outcomes presented a greater content of molds in fine semolina compared to coarse semolina. Most of the measured properties of the studied samples are in the recommended limits, however, more heather condition are needed during couscous production.

PRODUCTION ENHANCEMENT BY REDUCING FORMATION DAMAGE OF AMAL FIELD

Salem Khalefah Fattouh, Najw Abdulmajid Salim Bahroun — Tue, 27 Sep 2022 00:00:00 +0200

Experience in the oil industry has indicated that many oil wells have suffered flow restriction because of scale deposition within the oil producing formation through matrix and the down hole equipment.

Scale in oil field, just like the scale found in home plumbing or tea kettles, can be deposited all along water paths from injectors through the reservoir to surface equipment. Most scale found in oil fields forms either by direct precipitation from the water that occurs naturally in reservoir rocks, or because of produced water becomes over saturated with scale components when two incompatible waters meet down hole.

To tackle the effect of inorganic scale (Calcium Carbonate) on well productivity, three wells from Amal field namely B96, B20 and B72 have been included in this study. Most of the wells in Amal field, area B, were subjected to the same kind of in organic scale, and to the test of scale solubility, and all samples were successfully dissolved in HCL.

Prosper software as well performance tool was used to generate models of inflow and out flow curves before and after stimulation job was done to those wells. The results showed a significant increase in production

THEORETICAL DESIGN AND STRESS ANALYSIS FOR FLANGE COUPLING

Asya A. Gabbasa, Othman M. Daas, Tarak Assaleh, Siddig Dabbashi — Tue, 27 Sep 2022 00:00:00 +0200

Flange couplings are used into pressurizing piping systems that require the connection of tubing ends or two pipes. Flange couplings are characterized by strong connecting methods. This paper aims to design and analyze the stresses of a gray cast iron protected flange coupling, that connects a motor to a pump. The flange will transfer 15KW at 900rpm to momentum (215KN.m) on the right side with a service factor of 1.35. The flange design was based on the theoretical structure analysis and was modeled into a three-dimensional model. Results have shown that the shaft and key were the most components affected by the applied torque. The applied torque had a relatively insignificant effect on the resulting parameters of the flange, and the only significant effect on the bolt was at the contact points with the flange. The theoretical results were compared to the allowable stresses of the chosen material. The results of this comparison have shown that the flange coupling’s material can endure the applied torque without failure or deformation and within an acceptable safety margin.