Scientific Journal of Applied Sciences of Sabratha University

EXTRINSIC TOOTH BLEACHING AND ITS EFFECT ON AESTHETIC DENTAL RESTORATIVE MATERIALS: A REVIEW

2023-09-29T03:57:57+02:00

Recently, aesthetic dentistry has been greatly focused on, and tooth bleaching has gradually been a considerable portion of this field. Concerns about the increasing use of peroxide products have driven the research to investigate their impact on oral and tooth tissue, and dental restorative materials.

In this research, the Focus has been on the effect of the extrinsic tooth bleaching on commonly used dental restorative materials including restorative glass-ionomer cements and resin composites.

From reviewing previous studies, it has been found that bleaching materials, even in low concentrations, can cause changes in the properties of these aesthetic restorative materials such as colour, hardness, surface texture, and fluoride release.

APPLICATION OF LINEAR PROGRAMMING FOR OPTIMAL USE OF AL-AMEER FACTORY IN AL-AJAYLAT FOR THE PRODUCTION OF FOODSTUFFS

2023-09-29T03:57:59+02:00

Linear programming is a mathematical method aims to optimize the available resources through several possible ways. This study is to highlight the role of linear programming in decision-making in Al-Ajaylat Foodstuff Factory. It focuses on solving linear programming problems in a simplified way "simplex" with the help of TORA Software

COMPARATIVE STUDY OF THEORETICAL AND EXPERIMENTAL HEAT CAPACITY CV FOR CADMIUM TELLURIDE

2023-09-29T03:58:00+02:00

The aim of this study was to compare theoretical values with experimental measurements of molar heat capacity at a constant volume (C_v) in order to determine the best value for a Debye's temperature (θ_D) for cadmium telluride (CdTe). Debye's model was used to calculate the molar heat capacity C_v as a function of the absolute temperature for CdTe in the temperature ranges 7 K to 700 K. The experimental measurements were compared with the calculated values using several Debye's temperatures to determine the best congruence between the calculated and the experimental results of heat capacity C_v.

The results showed great agreement between the calculated theoretical values of C_vand the experimental data at medium and high temperatures. In general, the Debye's temperature of 144.67 K gave a best fit between the experimental and the theoretical results almost in the entire temperature range, where the sum of squares of deviations was .

ASSESSMENT OF IRRIGATION GROUNDWATER IN ALGHURAYFAH MUNICIPALITY, LIBYA

2023-09-29T03:58:02+02:00

To understanding the hydrochemical characteristics and the suitability for irrigation purposes of the groundwater, fifteen samples from different sites in the municipality of Alghurayfah, Libya were collected and analyzed.

Irrigation water quality indices were used to evaluate water quality based on the total dissolved solids (TDS), electrical conductivity (EC), sodium absorption ratio (SAR), Kelly’s index (KI), sodium percentage (Na%), residual sodium carbonate (RSC) and permeability index (PI). Furthermore, graphical representation diagrams were prepared such as USSL, Gibbs, Doneen and Wilcox.

The results indicated that the majority of the groundwater samples in the study area were suitable for irrigation. According to Gibbs classification, the majority of groundwater samples fall under rock weathering dominance. The USSLS chart indicates that the water is of low salinity and sodium, and it is of an excellent grade. Besides, Wilcox and Doneen diagrams show that the samples are safe for irrigation usage.

GEOLOGICAL AND GEOMORPHOLOGICAL STUDY OF WADI ABOU AL GOMEL, WEST, TOBRUK CITY, NORTHEAST LIBYA

2023-09-29T03:58:05+02:00

This study has been carried out in Wadi Abou Al Gomel area in the eastern region of the Libyan seacoast, which lies between latitudes N32°03’00 N32°08'30 and Longitudes E23°45' 00 E23°52'00. This area has specific geological features, where the different rock formations exhibit good exposures that give a clear view of the stratigraphic column.

The exposed formations belong to Al Faidiyah and Al Khowymat Formations. The main objective of the study is to evaluate some features namely lithology, stratigraphic analysis, fossil distribution, and structural features.

The results of field surveys, supported by photo interpretation, have led to the classification of coastal geomorphological features, which outlines the processes and related deposits and landforms.

Field observations and the obtained data revealed that the area has been affected by variable geological factors and changes in depositional environments, in addition to tectonic movements that led to the formation of various structures such as normal faults, fissures, joints, and unconformities.

PREVALENCE OF CUTANEOUS LEISHMANIASIS IN WESTERN REGION OF LIBYA

2023-09-29T03:58:07+02:00

Cutaneous leishmaniasis is an endemic parasitic infection in the Mediterranean region, including Libya. This study was to determine the epidemiological changes of cutaneous leishmaniasis about incidence, age of patients, sex, season and residency from May 2020 to February 2022 at Zwaga Health centre in Sabratha city. The samples studied were from different cities in the Western part of Libya. 294 samples of which 180 were males and 114 were females, and whose age was 20-80 years.

The results showed that, most of the infected cases (48.6%) were less than 20 years old. It was also noticed that males are more likely to be infected (61.2%) than females (38.8%). Moreover, Sabratha was the most affected city (62.6%).

The results also showed that most of the infected cases were in the leg, hand and foot (42.5%). The highest incidence was in the winter (81.0%).

Knowing the prevalence and epidemiology of the disease can help reduce and prevent cutaneous leishmaniasis. Hence, further studies are needed to identify vector, reservoir and species of leishmania can help control this endemic infectious disease.

THE EFFECT OF WEIGHT COMPOSITION OF SARDINA PILCHARDUS FISHED FROM BENGHAZI COAST ON ITS CONTENT OF MERCURY AND LEAD

2023-09-29T03:58:11+02:00

This study was conducted in order to evaluate the contents of mercury, and cadmium common fish in Benghazi coast nominated Sardina Pilchardus. The effects of the fishing area and weight composition on the accumulation of these minerals were also studied.

Data showed the concentration of mercury and lead in the tissues (muscles, gills, gut, and spinal column) of Sardina Pilchardus from Benghazi coast was 0.2331 ppm and 8.403 ppm, respectively. The weight composition of Sardina Pilchardus no significant differences were found for concentration of lead; the less concentration was observed in mussels and less concentration of mercury was found in the gut.

There was a fishing area effect on the content of these minerals; whereas the effect was clear for the concentration of lead in muscles, gills and spinal columns. The same effect was found for cadmium in the gill, gut and spinal column, while was an effect on mercury concentration was only in the spinal column.

ANALYTICAL SOLUTION FOR DYNAMIC ANALYSIS OF ASYMMETRIC LAMINATED COMPOSITE SHEAR-DEFORMABLE BEAMS

2023-09-29T03:58:13+02:00

The exact analytical solutions towards investigating the dynamic analysis of extensional-flexural coupled vibration responses for asymmetric composite laminated rectangular beams under various harmonic axial and bending forces are presented.

Three governing coupled differential equations and related boundary conditions were derived from the variational form of Hamilton’s principle. The formulations are based on the first order shear-deformable beam theory, account for the effects of rotary inertia, Poisson’s ratio, and structural bending-extensional coupling coming from material anisotropy. The resulting coupled equations for asymmetric composite beams were exactly solved and closed-form solutions for extensional-flexural coupled response were obtained for different boundary conditions. Numerical examples were performed for antisymmetric cross-ply and angle-ply laminated composite beams in order to investigate the effects of transverse shear deformation, fibre orientation angle on coupled natural frequencies, quasi-static, and steady state dynamic responses.

Results for dynamic bending and axial displacements are discussed in detail and the validity and accuracy of the present solutions were verified against published exact and finite element solutions.

ESTIMATION OF LIQUID FUEL AND ENERGY PRODUCTION FROM PYROLYSIS OF WASTE TIRES

2023-09-29T03:58:17+02:00

The pyrolysis process is a new technology for dealing with daily generated scrap tires. The process involves heating the tires in absence of oxygen to high temperatures between 300°C and 900°C. The final products are gas, liquid and solid char. The pyrolytic liquid has a high calorific value (40 – 41 MJ/kg) and its properties are similar to those of diesel fuel and it can be used as diesel alternative. This process is optimized for maximum liquid product yield.

This research reviews experimental works run on the pyrolysis process investigating its optimal conditions. In addition, a case study in Jumayel city, Libya, is studied to calculate the amount of energy that can be recovered as liquid fuel from pyrolysis of scrap tires.

The results showed that 250 ton of pyrolytic oil with energy of 315 kW is recoverable from 480 ton of disposed tire for the year of 2019.These results were extended for the next decay.

COMPARISON BETWEEN NUMERICAL AND THEORETICAL STUDIES FOR: FLANGE COUPLING DESIGN

2023-09-29T03:58:20+02:00

The purpose of this paper is to compare the numerical and theoretical studies for designing and analyzing the stresses of a gray cast iron-protected flange coupling that connects a motor to a pump.

The flange was designed according to the analysis of the theoretical structure, and was modeled into a three-dimensional model by using the Solid Works program. The simulation was performed by using ANSYS Static Structural where an appropriate mesh, boundary conditions, and solution parameters were selected. Boundary conditions were the torque on the surface of the driving shaft and the fixed driven shaft.

The results have shown that the shaft and key are mostly affected by the applied torque. The applied torque had relatively little effect on the resulting parameters of the flange and the only significant effect on the bolt was at the points of contact with the flange.

The simulation results were compared with the theoretical and permissible pressures of the selected material; this comparison showed that the flange coupling material can withstand the applied torque without failure or deformation and within the acceptable margin of protection.

THE GEOLOGIC CONTRIBUTION TO MOUNTAIN SLOPE INSTABILITY AND ITS EFFECT ON LANDSLIDES. A CASE STUDY TO THE GHARIAN AREA, NW LIBYA

2023-09-29T03:58:22+02:00

This research investigates the causes of Landsides at Gharian Tripoli highway. Geomorphology, geology, and climate play the most important role in preparatory process of landslide initiation in any region.

The area has specific geological features, where the clastic rocks formations and carbonates formations exhibit good exposures that give a clear knowledge for causes of the landside. Data presented here are based on a detailed fieldwork mapping and analysis of rainfall statistical data, which were monitored from 2011 until 2019.

The results of this study confirm that the weakness in the rock blocks will lead to the movements of the most important rock fall (Landsides) because the angle of stability of blocks ranging from (60 - 89) with NNW faults -dipping steeply NE and down throwing to the NE.

The excavation works used to make the Gharian Tripoli highway on the slopes had significant impact in determining the angle of stability of the blocks and making the rock (road cut) more susceptible to erosion factors.

ELECTRICAL SUBMERSIBLE PUMPS (ESP) DESGIN OF WELLS (FD32) (FB18) NC-174, ALFEEL FIELD IN MORZUQ BASINE

2023-09-29T03:58:25+02:00

The main objective of this study is to identify and select an electric submersible pump to produce high flow rates of oil. The electric submersible pump was chosen because it provides good flow rates in a given range. This electric submersible pump was used to raise production rates.

The study was conducted on two wells from Mellitah Oil Company in El Feel field and the results were as follows. Well (FD32) results were the required rate of 3283STB/d can be obtained using only 166 stages, while Well (FB18) results were 6180STB/d and 204 stages, and this required 2300V.

ELECTROCHEMICAL AND THEORETICAL EVALUATION OF 4-(4-BROMOPHENYL) THIOSEMICARBAZIDE AS THE CORROSION INHIBITION FOR MILD STEEL IN 1.0 M HCL

2023-10-02T23:56:33+02:00

This examination researched the impact of changing measures of 4-(4-bromophenyl) Thiosemicarbazide (4-BrPh TSC) by assessing air conditioning impedance and AC and flow potentiometry in a 1.0 M HCl arrangement at 20°C. When the E_corr value is -0.518 V, the concentration of the inhibitor solution changes and the grouping of the inhibitor changes. The present's thickness of the anodic and cathodic districts is bring down contrasted with that of the 1.0 M HCl arrangement, with an I_corr estimation of 158.78 μA•cm⁻² in the uninhibited arrangement and 8.10 μA•cm⁻² at the 1x10^-2 M concentration of 4-BrPh TSC. The percent restraint proficiency extended from 71% to 95%. For the uninhibited and most astounding grouping of 4-BrPh TSC arrangement, the estimations of R_pblank and R_pinh were 235 and 2006 Ω.cm^-2, separately, CPE_blank and CPE_inh were 348 and 36 μF.cm^-2, individually, n_blank and n_inh were 0.94 and 0.84. As the R_p esteem builds, the CPE esteem and n diminish as the inhibitor focus increments, potentially because of abatement in neighborhood dielectric steady or an expanded thickness at the metal/arrangement interface. For the subsidiaries of 4-BrPh TSC, the estimation of ΔG^o_ads and is -36.00 kJ mol^-1, demonstrating that the adsorption of these inhibitors includes two sorts of communications: physical adsorption and chemisorption. The thickness utilitarian hypothesis (DFT) of the B3LYP work with the 6-311G (d,p) premise set was performed .

دراسة نقص فيتامين د (D) على النساء الحوامل المترددين على بعض المختبرات الصحية بمدينة العجيلات

2023-10-02T23:59:44+02:00

This study was conducted to assess the percentage of vitamin D deficiency among pregnant women all over the year, and to find out the relationship between vitamin D deficiency and age among pregnant women during the different seasons.

The study was conducted on pregnant women visiting some health laboratories in Al-Ajailat from January 2021 to January 2022. Women ages ranged between 15-50 years.

The results showed that 58% of the study samples had severe vitamin D deficiency (less than 10 ng/ml), 29% with moderate vitamin D deficiency (less than 20 ng/ml). The significant difference in the mean concentration of vitamin D during winter and spring was P≤0.05. While during summer and autumn, the substantial differences in the average age and vitamin D concentration were at P ≤0.05. It was also shown that there is correlation between age and vitamin D deficiency during the cold and hot seasons.

These results may be due to factors such as lack of exposure to sun, environmental factors, geographical location, food, and some medications taken by pregnant women.

معايير الراحة الأساسية في التصميمات السكنية

2023-10-03T00:02:53+02:00

After Covid 19 pandemic experience, we may see that it is appropriate to review the planning and design laws in our country. Comfort Basic Standards are part of part of planning and design laws. These standards account for both privacy and the appropriate living conditions.

After many years of teaching Urban Design course and reviewing the Libyan urban planning regulations, in this paper, the researcher discusses the concept of residents' Comfort Basic Standards and the current Libyan regulations of such standards.

The researcher concluded that Libyan Comfort Standards need to be updated in order to account for the development and circumstances similar to Covid 19.