تأثير الألياف الفولاذية على مقاومة الضغط والشد للخرسانة عالية المقاومة
مقال في مجلة علميةThe marked brittleness with low tensile strength and strain capacities of high-strength concrete (HSC) can be overcome by the addition of steel fibers. This research investigated the effects of hooked-end steel fiber content with different silica fume (S.F.) content on the mechanical properties of HSC.
This study depends on 3 main reference concrete mix contains silica fume (5%, 10%, 15%) as a percentage of the weight of cement. and Also, 3.5% of the super plasticizers type (Plastocrete ®-N) has been added to all concrete mixes.
The steel fibers were added at the volume fractions of (0.2 %, 0.4 %, 0.6 %, 0.8 %,1 %). Compressive and splitting tensile strengths were conducted.
The main conclusions were that the compressive strength and splitting tensile strengths of the fiber-reinforced concrete enhanced by 10% and 50% respectively at 1.0% volume fraction, and 10% of S.F .
Strength models were established to predict the splitting tensile strengths by knowing the compressive strength and a model to predict a compressive Strength by using enhancement factor.
Key Words: High resistance concrete, steel fibers, silica dust, pressure resistance and direct tensile strength.
خالد محمد عمرو أمحمد، (06-2020)، المعهد العالي للعلوم والتقنية غريان: مجلة غريان للتقنية، 6 (6)، 35-51
Applications of EOQ Technique to Reduce Inventory Costs in Industrial Sectors: A Case Study on a Water Desalination and Bottling Plant in Libya
Journal ArticleThe purpose of this paper is to minimize the total cost of raw material inventory for
water desalination and bottling plant resulting in a more profitable approach in
accordance with the production needs. The classical application of Economic Order
Quantity is used to support this paper and in order to reduce the costs related to
inventory. For this purpose, this method generates a minimum total inventory cost by
finding when ordering cost and carrying cost are equal. From this result, the inventory
level and the number of raw material demand become more economically suitable with
the production needs. It is because this method applies two types of cost, carrying cost
and ordering cost that make the total inventory cost more productive. So, this method
can be used to get the most economical total inventory cost and reduce storage cost
swelling. And hence, decreasing costs means that more profit is achieved.
Elbahlul M Abogrean, (06-2020), مجلة البحوث العلمية: جامعة أفريقيا, 10 (5), 125-130
The optimization of glycidyl methacrylate based terpolymer monlith synthesis an effective candida rugosa lipase immobilization support
Journal Article.
khaled ahmed ali taleb, (05-2020), taipel: Journal of polymer research, 127 (127), 4-16
RADIATION HEAT TRANSFER ANALYSIS IN TWO-PHASE MIXTURE ASSOCIATED WITH LIQUID METAL REACTOR ACCIDENTS
PhD ThesisAnalytical study associated with liquid-metal fast breeder reactor (LMFBR) has been investigated by using scattering and non-scattering mathematical radiation models. In the nonscattering model, the radiative transfer equation (RTE) was solved together with the continuity equations of mixture components under local thermodynamic equilibrium. A MATLAB code was used to solve these equations. This application employed a numerical integration to compute the temperature distribution within the bubble and the transient wall heat flux. First, in Rayleigh nonscattering model the particle size was 0.01 µm [6], and according to Mie theory principle, the absorption coefficient for small particle –size distribution was estimated (k = 10 m-1 was used) from reference [7] at complex refractive index of UO2 at λ = 600 µm and x = 0.0785. A MATLAB code was used to solve the radiative heat equation (RTE) in spherical coordinates. The mixture is in local thermodynamic equilibrium inside the bubble which has a black body surface boundary. The mixture in the bubble contains three components: the non-condensable gas Xenon, Uranium dioxide vapor, and fog. To simulate fuel bubble’s geometry as realistically as possible, according to experimental observation, the energy equation in a spherical coordinate system has been solved with the radiative flux heat transfer equation (RTE) to obtain the effect of fuel bubble’s geometry on the transient radiative heat flux and to predict the transient temperature iv distribution in the participating medium during a hypothetical core disruptive accident (HCDA) for liquid metal fast breeding reactor (LMFBR) for FAST. The transient temperature distribution in fog region was used to predict the amount of condensable UO2 vapor. The conclusion that can be drawn from the present study, is that the Fuel Aerosol Simulant Test (FAST) facility at Oak Ridge National Laboratory has a larger margin of safety since the bubble rising time is greater than the bubble collapse time. Second in the scattering model, the spherical harmonics method was used to solve the radiative heat transfer equation (RTE) in spherical coordinates, and the particle size was 0.07 µm [6]. The scattering coefficient of UO2 particles (σ = 1.24 m-1 ), was calculated using Mie theory at the same number of stable nuclei N (2.9 E15 nuclei/m3 ) that resulted from the absorption coefficient k = 0.082 m-1 [7]. The P1 approximation method was used to solve the radiative transfer equation (RTE) in spherical coordinates of participating medium confined between two concentric spheres. The surfaces of the spheres are assumed to be gray, diffusely emitting and diffusely reflecting boundaries, and isothermal boundary conditions were assumed at these surfaces. Marsak’s boundary condition was used to compute the net radiative heat flux, q(τ), and the incident radiation, G(τ), to analyze and interpret CVD experiments data that were conducted in the FAST facility at ORNL [8] and Fast Flux Test Facility reactor (FFTF) at ANL. From this study, it can be concluded that there is greater margin of safety when the bubble rise time is a greater than the bubble collapse time since the bubble collapses (UO2 condenses) before it can reach the top of the vessel. In addition, the work transfer by itself can’t completely eliminate the super-heated vapor, as the bubble contains noncondensable species which hinder condensation. However, it is reasonable to assume that work transfer could decrease the amount of UO2 vapor contained in the bubble as it reached the covergas [63].
Hmza Ashur Milad Mohamed, (05-2020), USA: University of Dayton,
Treatment Of Water Hardness Using Activated Carbon Prepared From Libyan Olive Oil Mill Residue
Conference paperABSTRACT
Massive amounts of solid olive mill residues (olive-waste cake) generated
every year and disposed of in the environment. Thus, the present work aims
to study the preparation of activated carbon (AC) from Libyan Olive-Waste
Cakes as a natural source. The solid olive mill residue was carbonized at
200 C0 and chemically activated with 25% Zncl2 and 25% Zncl2 + 25%
H2SO4 . The prepared AC was used to reduce total hardness in groundwater.
The results showed that the addition of H2SO4 increased the treatment
efficiency of AC leading to decrease the total hardness concentration.
Several parameters affecting the efficiency of AC were investigated
including pH, initial concentration of AC, and contact time. The achieved
results showed that the optimum values were at pH: 3, AC initial
concentration: 2.5 g/L, and contact time 120 min. At these conditions the
maximum reduction of hardness was 75%. According to these results the
olive- waste cake can be considered as an effective natural source of
activated Carbon.
Abdulbasit Mohamad Saleh Abeish, (03-2020), libya: المؤتمر الهندسي الثالث لنقابة المهن الهندسية بالزاوية, 1-9
SOLUBILITY AND PRECIPITATION OF Nb IN AN ANNEALED Fe-30Mn STEEL
Journal ArticleThe metallurgical influence of niobium (Nb) on an annealed high manganese (Mn) steel is still an active issue of discussion between automobile companies and steel manufacturers. Some controversy exists in the literature concerning the influence of Nb solubility on microstructure and thereby on mechanical properties. The influence of Nb-solubility on microstructure of Fe30Mn alloy steel was investigated experimentally and by computational materials modeling. Nb was added in 0.05, 0.1, 0.2, 0.4, 0.6 and 1% additions and the alloy samples were annealed at 1200oC for 2, 5, 10, 30 and 60 minutes. The microstructure was investigated using an optical microscope, TEM and SEM-EDX and precipitates were chemically tested. Niobium solubility in Fe30Mn austenite was theoretically studied based on Gladman assumptions and was also examined by Thermo-Calc analysis. The result of this work is a comparison between the microstructure analysis and theoretical studies, and it has been found that Nb was soluble in Fe30Mn austenite phase and has had a solute drag effect where Nb(C,N) and NbN precipitates were seen and the effect was pinning effect
حسن رمضان فرج زائد, (03-2020), Journal of Engineering Research: University of Tripoli, 29 (29), 11-20
Evaluation of Sustainable Micro-Alloyed HSLA Steel for Pipeline Application
Conference paperMusa Mohamed Hossin Abdullrhman, (02-2020), IGRC 2020 MUSCAT: International Gas Union Research Conference in MASCAT, 1-5
Design and Implementation Smart Transformer based on IoT
Conference paperPower transformers, which perform the function of transforming the voltage levels, are one of the most important electrical equipments that are used in power transmission systems. Hence, it is mandatory to perform power transformermaintenance; as they are normally scattered geographically, it is impractical to do periodical monitoring due to insufficient manpower. As the reason above, transformer failure may occur which causes the transformer from network unexpectedly power shutdown. To overcome this shutdown from transformer failure of the adapter, a system for transformer monitoring and self- protection was proposed in case the maintenance is delayed. In this paper, the temperature and humidity within the transformer were monitored, in addition to monitoring the rate of loading on the transformer. By using the internet of things (IoT), a self-protection system is designed and implemented for thetransformer. Where, if the transformer is not serviced quickly, the transformer will separate loads of low-importance (workshops, Homes,….) and it will keep the loads of high importance (hospitals,…) .and if the transformer is unable to feed the loads of high importance, in this case the transformer will separates all loads and stay in no-load status where the transformer monitor its parameters by itself, if all parameters of the transformer return to the normal level, the transformer automatically returns the loads in order of priority. All these components have been grouped and combined into one device. In addition the device is powered using an AC-DC adapter by an external power source.
Mohamed Abdalla Mohamed Alkelsh, (08-2019), Conference: IEEE International Conference on Computing, Electronics and Communications Engineering: London: IEEE, 16-21
An example of industrialization of melt electrospinning: Polymer melt differential electrospinning
Journal ArticleIn recent years, researchers are paying more attention to high efficiency, high process stability and eco-friendly nanofiber fabrication techniques. Among all of the nanofiber fabrication methods, electrospinning including solution electrospinning and melt electrospinning is the most promising method for nanofiber mass production. Compared to solution electrospinning, melt electrospinning could be applied in many areas such as tissue engineering and wound dressings due to the absence of any toxic solvent involvement. Capillary melt electrospinning generates only one jet with low efficiency. Hence, we have proposed polymer melt differential electrospinning (PMDES) method, which could produce multiple jets with smallest interjet distance of 1.1 mm from an umbrella shape spinneret, thus improving the production efficiency significantly. Many techniques such as material modification, suction wind, and …
MAHMOUD M BUBAKIR, (07-2019), Advanced Industrial and Engineering Polymer Research: ELSEVIER, 3 (2), 110-115
أهمية برامج التدريب المطورة والفعالة للعاملين في قطاع التصنيع محليا وعربيا
مقال في مجلة علميةإن العولمة الدولية ألسواق العالم الخاصة بالمواد المصنعة وخاصة منها المواد االستهالكية أو ذات العالقة بالمستهلك وضعت ضغوطات و تأكيدات على الدول من اجل تحسين أو تطوير إنتاجياتها التصنيعية. وكلما تغيرت التقنيات أو طورت فأن المهارات التي يحتاجها العامل أيضا هي بحاجة للتطوير وذلك من أجل المنافسة بنجاح في السوق العالمية. أن الهيئات أو المنظمات الهندسية وغيرها العاملة في مجال التصنيع يجب أن تركز وتستهدف على تدريب العاملين لديها في مهارات أساسية ضرورية وذلك من أجل أن تكون مؤهلة وقادرة على تصنيع منتجات ذات جودة عالية وتنافسية . تلك الحاجة لتحسين وتطوير اإلنتاجية تم تحفيزها أو أستحثاثها أكثر بواسطة فاقد كامن في الحد التنافسي في السوق العالمية. أن المنافسة السوقية والفاعلية ألي دولة تعتمد أساسا على عوامل عدة كاألقتصاد، الموثوقية، الجودة، االستجابة السريعة لتغيرات السوق، سهولة العمليات التصنيعية المتبعة، وجودة المنتج، ولهذا وإلى حد كبير فأن مها ارت قوة العمل من مهندسين، فنيين، وعمالة هي التي تحدد فاعلية وقدرة عمليات التصنيع وجودة المنتجات المصنعة. ولكن وإلى اآلن مازال هناك قصور ونقص في ب ارمج التدريب المطورة والفعالة للمها ارت التي تحتاجها القوى العاملة في المؤسسات التصنيعية الهندسية وغيرها محليا بل وعربيا. في هذه الورقة البحثية سنحاول توضيح أهمية الحاجة الماسة والملحة لتدريب العاملين في المؤسسات التصنيعية الليبية والعربية وبالتالي تحسين الفاعلية والقدرة الكلية لتلك المؤسسات خاصة وللدول العربية بشكل عام لتكون منافس حقيقي وفعال في السوق العالمي.
محمود محمد عاشور ابوبكر، حمزةأبوبكر عمر علي، نورالدين علي فرج الدالي، (06-2019)، مجلة ليبيا للعلوم التطبيقية والتقنية: LJAST، 1 (6)، 15-26