Search results for: Hatem Abdel Moniem Ahmed
1497 RANS Simulation of the LNG Ship Squat in Shallow Water
Authors: Mehdi Nakisa, Adi Maimun, Yasser M. Ahmed, Fatemeh Behrouzi
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Squat is the reduction in under-keel clearance between a vessel at-rest and underway due to the increased flow of water past the moving body. The forward motion of the ship induces a relative velocity between the ship and the surrounding water that causes a water level depression in which the ship sinks. The problem of ship squat is one among the crucial factors affecting the navigation of ships in restricted waters. This article investigates the LNG ship squat, its effects on flow streamlines around the ship hull and ship behavior and motion using computational fluid dynamics which is applied by Ansys-Fluent.Keywords: ship squat, CFD, confined, mechanic
Procedia PDF Downloads 6201496 Leaching Losses of Fertilizer Nitrogen as Affected by Sulfur and Nitrification Inhibitor Applications
Authors: Abdel Khalek Selim, Safaa Mahmoud
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Experiments were designed to study nitrogen loss through leaching in soil columns treated with different nitrogen sources and elemental sulfur. The soil material (3 kg alluvial or calcareous soil) were packed in Plexiglas columns (10 cm diameter). The soil columns were treated with 2 g N in the form of Ca(NO3)2, urea, urea + inhibitor (Nitrapyrin), another set of these treatments was prepared to add elemental sulfur. During incubation period, leaching was performed by applying a volume of water that allows the percolation of 250-ml water throughout the soil column. The leachates were analyzed for NH4-N and N03-N. After 10 weeks, soil columns were cut into four equal segments and analyzed for ammonium, nitrate, and total nitrogen. Results indicated the following: Ca(NO3)2 treatment showed a rapid NO3 leaching, especially in the first 3 weeks, in both clay and calcareous soils. This means that soil texture did not play any role in this respect. Sulfur addition also did not affect the rate of NO3 leaching. In urea treatment, there was a steady increase of NH4- and NO3–N from one leachate to another. Addition of sulfur with urea slowed down the nitrification process and decreased N losses. Clay soil contained residual N much more than calcareous soil. Almost one-third of added nitrogen might have been immobilized by soil microorganisms or lost through other loss paths. Nitrification inhibitor can play a role in preserving added nitrogen from being lost through leaching. Combining the inhibitor with elemental sulfur may help to stabilize certain preferred ratio of NH4 to NO3 in the soil for the benefit of the growing plants.Keywords: alluvial soil, calcareous soil, elemental sulfur, nitrate leaching
Procedia PDF Downloads 3181495 Effect of Nicorandil, Bone Marrow-Derived Mesenchymal Stem Cells and Their Combination in Isoproterenol-Induced Heart Failure in Rats
Authors: Sarah Elsayed Mohammed, Lamiaa Ahmed Ahmed, Mahmoud Mohammed Khattab
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Aim: The aim of the present study was to investigate whether combined nicorandil and bone marrow-derived mesenchymal stem cells (BMDMSC) treatment could offer an additional benefit in ameliorating isoproterenol (ISO)-induced heart failure in rats. Methods: ISO (85 and 170 mg/kg/day) was injected subcutaneously for 2 successive days, respectively. By day 3, electrocardiographic changes were recorded and serum was separated for determination of CK-MB level for confirmation of myocardial damage. Nicorandil (3 mg/kg/day) was then given orally with or without a single i.v. BMDMSC administration. Electrocardiography and echocardiography were recorded 2 weeks after beginning of treatment. Rats were then sacrificed and ventricles were isolated for estimation of vascular endothelial growth factor (VEGF), tumor necrosis factor-alpha (TNF-α) and transforming growth factor-beta (TGF-β) contents, caspase-3 activity as well as inducible nitric oxide synthase (iNOS) and connexin-43 protein expressions. Moreover, histological analysis of myocardial fibrosis was performed and cryosections were done for estimation of homing of BMDMSC. Results: ISO induced a significant increase in ventricles/body weight ratio, left ventricular end diastolic (LVEDD) and systolic dimensions (LVESD), ST segment and QRS duration. Moreover, myocardial fibrosis as well as VEGF, TNF-α and TGF-β contents were significantly increased. On the other hand, connexin-43 protein expression was significantly decreased, while caspase-3 and iNOS protein expressions were significantly increased. Combined therapy provided additional improvement compared to cell treatment alone towards reducing cardiac hypertrophy, fibrosis and inflammation. Furthermore, combined therapy induced significant increase in angiogenesis and BMDMSC homing and prevented ISO induced changes in iNOS, connexin-43 and caspase-3 protein expressions. Conclusion: Combined nicorandil/BMDMSC treatment was superior to BMDMSC alone towards preventing ISO-induced heart failure in rats.Keywords: fibrosis, isoproterenol, mesenchymal stem cells, nicorandil
Procedia PDF Downloads 5321494 Surgical Treatment of Glaucoma – Literature and Video Review of Blebs, Tubes, and Micro-Invasive Glaucoma Surgeries (MIGS)
Authors: Ana Miguel
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Purpose: Glaucoma is the second cause of worldwide blindness and the first cause of irreversible blindness. Trabeculectomy, the standard glaucoma surgery, has a success rate between 36.0% and 98.0% at three years and a high complication rate, leading to the development of different surgeries, micro-invasive glaucoma surgeries (MIGS). MIGS devices are diverse and have various indications, risks, and effectiveness. We intended to review MIGS’ surgical techniques, indications, contra-indications, and IOP effect. Methods: We performed a literature review of MIGS to differentiate the devices and their reported effectiveness compared to traditional surgery (tubes and blebs). We also conducted a video review of the last 1000 glaucoma surgeries of the author (including MIGS, but also trabeculectomy, deep sclerectomy, and tubes of Ahmed and Baerveldt) performed at glaucoma and advanced anterior segment fellowship in Canada and France, to describe preferred surgical techniques for each. Results: We present the videos with surgical techniques and pearls for each surgery. Glaucoma surgeries included: 1- bleb surgery (namely trabeculectomy, with releasable sutures or with slip knots, deep sclerectomy, Ahmed valve, Baerveldt tube), 2- MIGS with bleb, also known as MIBS (including XEN 45, XEN 63, and Preserflo), 3- MIGS increasing supra-choroidal flow (iStar), 4-MIGS increasing trabecular flow (iStent, gonioscopy-assisted transluminal trabeculotomy - GATT, goniotomy, excimer laser trabeculostomy -ELT), and 5-MIGS decreasing aqueous humor production (endocyclophotocoagulation, ECP). There was also needling (ab interno and ab externo) performed at the operating room and irido-zonulo-hyaloïdectomy (IZHV). Each technique had different indications and contra-indications. Conclusion: MIGS are valuable in glaucoma surgery, such as traditional surgery with trabeculectomy and tubes. All glaucoma surgery can be combined with phacoemulsification (there may be a synergistic effect on MIGS + cataract surgery). In addition, some MIGS may be combined for further intraocular pressure lowering effect (for example, iStents with goniotomy and ECP). A good surgical technique and postoperative management are fundamental to increasing success and good practice in all glaucoma surgery.Keywords: glaucoma, migs, surgery, video, review
Procedia PDF Downloads 831493 Uderstanding Females' Perspective of Healthy Parental Involvement in Their University's Lives
Authors: Mona Bakry Abdel Meguid Abdelaal
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Despite growing evidence that parental involvement in their adolescents’ lives affects the way they perceive the community around them, little effort has been made to address the importance of this relationship and how it affect the adolescents' interaction with their environment. Adolescents are influenced by their parents while they are growing up and this socialization process services to shape the adolescents sense of self, influencing not only how adolescents feel about themselves, but affecting how they interact with their surroundings. In order to effectively understand this issue, it is important to understand the adolescents’ understanding of healthy parental involvement in their lives, in addition to the obstacles that hinder their communication styles with their parents. Understanding parental involvement in their adolescents’ lives will provide further understanding of the role that social work can perform in this field. The rationale for undertaking this study grew out of the literature on adolescents’ studies in addition to the researchers’ interaction with freshmen female students, who are still in the adolescent stage, in the university. The primary purpose of this study was to understand female adolescents’ awareness of healthy parental involvement in their freshmen year in the university life, as well as obstacles that might hinder that healthy involvement. Using semi-structured interview with a purposive sample of the first year female students in the university, the study managed to determine if the type of parental involvement and parental emotional responsiveness between the adolescents and their parents affects the way they interact with their environment, in addition, to determine the obstacles that hamper the communication between adolescents and their parents.Keywords: adolescents, parental involvement, interaction, university life
Procedia PDF Downloads 2561492 An Approach towards Intelligent Urbanism in New Communities
Authors: Sherine Shafik Aly, Farida Ahmed El Mallah
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Technology is a quoted keyword nowadays in all fields; it has been recently thought of and integrated into urban development. This research explains the role of technology in establishing intelligent urbanism to create a convivial and sustainable environment for people to live in. Cities are downgrading socially, economically and environmentally. A framework is to be developed where these three pillars are involved in the planning, design, and spreading of technology to create convivial environments. The aim of this research is achieved by highlighting the importance and approaches of intelligent urbanism, it’s characteristics and principles, then analyzing some relevant examples to achieve a set of guidelines.Keywords: convivial, intelligent, technology, urban development
Procedia PDF Downloads 2601491 Adverse Effects of Natural Pesticides on Human and Animals: An Experimental Analysis
Authors: Abdel-Tawab H. Mossa
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Synthetic pesticides are widely used in large-scale worldwide for control pests in agriculture and public health sectors in both developed and developing countries. Although the positive role of pesticides, they have many adverse toxic effects on humans, animals, and the ecosystem. Therefore, in the last few years, scientists have been searching for new active compounds from natural resources as an alternative to synthetic pesticides. Currently, many commercial natural pesticides are available commercially worldwide. These products are recommended for uses in organic farmers and considered as safe pesticides. This paper focuses on the adverse effects of natural pesticides on mammals. Available commercial pesticides in the market contain essential oils (e.g. pepper, cinnamon, and garlic), plant extracts, microorganism (e.g. bacteria, fungi or their toxin), mineral oils and some active compounds from natural recourses e.g. spinosad, neem, pyrethrum, rotenone, abamectin and other active compounds from essential oils (EOs). Some EOs components, e.g., thujone, pulegone, and thymol have high acute toxicity (LD50) is 87.5, 150 and 980 mg/kg. B.wt on mice, respectively. Natural pesticides such as spinosad, pyrethrum, neem, abamectin, and others have toxicological effects to mammals and ecosystem. These compounds were found to cause hematotoxicity, hepato-renal toxicity, biochemical alteration, reproductive toxicity, genotoxicity, and mutagenicity. It caused adverse effects on the ecosystem. Therefore, natural pesticides in general not safe and have high acute toxicity and can induce adverse effects at long-term exposure.Keywords: natural pesticides, toxicity, safety, genotoxicity, ecosystem, biochemical
Procedia PDF Downloads 1721490 The K-Distance Neighborhood Polynomial of a Graph
Authors: Soner Nandappa D., Ahmed Mohammed Naji
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In a graph G = (V, E), the distance from a vertex v to a vertex u is the length of shortest v to u path. The eccentricity e(v) of v is the distance to a farthest vertex from v. The diameter diam(G) is the maximum eccentricity. The k-distance neighborhood of v, for 0 ≤ k ≤ e(v), is Nk(v) = {u ϵ V (G) : d(v, u) = k}. In this paper, we introduce a new distance degree based topological polynomial of a graph G is called a k- distance neighborhood polynomial, denoted Nk(G, x). It is a polynomial with the coefficient of the term k, for 0 ≤ k ≤ e(v), is the sum of the cardinalities of Nk(v) for every v ϵ V (G). Some properties of k- distance neighborhood polynomials are obtained. Exact formulas of the k- distance neighborhood polynomial for some well-known graphs, Cartesian product and join of graphs are presented.Keywords: vertex degrees, distance in graphs, graph operation, Nk-polynomials
Procedia PDF Downloads 5491489 A Variant of a Double Structure-Preserving QR Algorithm for Symmetric and Hamiltonian Matrices
Authors: Ahmed Salam, Haithem Benkahla
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Recently, an efficient backward-stable algorithm for computing eigenvalues and vectors of a symmetric and Hamiltonian matrix has been proposed. The method preserves the symmetric and Hamiltonian structures of the original matrix, during the whole process. In this paper, we revisit the method. We derive a way for implementing the reduction of the matrix to the appropriate condensed form. Then, we construct a novel version of the implicit QR-algorithm for computing the eigenvalues and vectors.Keywords: block implicit QR algorithm, preservation of a double structure, QR algorithm, symmetric and Hamiltonian structures
Procedia PDF Downloads 4091488 Antihyperglycaemic and Antihyperlipidemic Activities of Pleiogynium timorense Seeds and Identification of Bioactive Compounds
Authors: Ataa A. Said, Elsayed A. Abuotabl, Gehan F. Abdel Raoof, Khaled Y. Mohamed
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The aim of this study is to evaluate antihyperglycaemic and antihyperlipidemic activities of Pleiogynium timorense (DC.) Leenh (Anacardiaceae) seeds as well as to isolate and identify the bioactive compounds. Antihyperglycaemic effect was evaluated by measuring the effect of two dose levels (150 and 300 mg/kg) of 70% methanol extract of Pleiogynium timorense seeds on blood glucose level when administered 45 minutes before glucose loading. In addition, the effect of the plant extract on the lipid profile was determined by measuring serum total lipids (TL), total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C). Furthermore, the bioactive compounds were isolated and identified by chromatographic and spectrometric methods.The results showed that the methanolic extract of the seeds significantly reduced the levels of blood glucose,(TL), (TC), (TG) and (LDL-C) but no significant effect on (HDL-C) comparing with control group. Furthermore, four phenolic compound were isolated which were identified as; catechin, gallic acid, para methoxy benzaldehyde and pyrogallol which were isolated for the first time from the plant. In addition sulphur -containing compound (sulpholane) was isolated for the first time from the plant and from the family. To our knowledge, this is the first study about antihyperglycaemicand antihyperlipidemic activities of the seeds of Pleiogyniumtimorense and its bioactive compounds. So, the methanolic extract of the seeds of Pleiogynium timorense could be a step towards the development of new antihyperglycaemic and antihyperlipidemic drugs.Keywords: antihyperglycaemic, bioactive compounds, phenolic, Pleiogynium timorense, seeds
Procedia PDF Downloads 2191487 Magnesium Ameliorates Lipopolysaccharide-Induced Liver Injury in Mice
Authors: D. M. El-Tanbouly, R. M. Abdelsalam, A. S. Attia, M. T. Abdel-Aziz
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Lipopolysaccharide (LPS) endotoxin, a component of the outer membrane of Gram-negative bacteria, is involved in the pathogenesis of sepsis. LPS administration induces systemic inflammation that mimics many of the initial clinical features of sepsis and has deleterious effects on several organs including the liver and eventually leading to septic shock and death. The present study aimed to investigate the protective effect of magnesium, a well-known cofactor in many enzymatic reactions and a critical component of the antioxidant system, on hepatic damage associated with LPS induced- endotoxima in mice. Mg (20 and 40 mg/kg, po) was administered for 7 consecutive days. Systemic inflammation was induced one hour after the last dose of Mg by a single dose of LPS (2 mg/kg, ip) and three hours thereafter plasma was separated, animals were sacrificed and their livers were isolated. LPS-treated mice suffered from hepatic dysfunction revealed by histological observation, elevation in plasma transaminases activities, C-reactive protein content and caspase-3, a critical marker of apoptosis. Liver inflammation was evident by elevation in liver cytokines contents (TNF-α and IL-10) and myeloperoxidase (MPO) activity. Additionally, oxidative stress was manifested by increased liver lipoperoxidation, glutathione depletion, elevated total nitrate/nitrite (NOx) content and glutathione peroxidase (GPx) activity. Pretreatment with Mg largely mitigated these alternations through its anti-inflammatory and antioxidant potentials. Mg, therefore, could be regarded as an effective strategy for prevention of liver damage associated with septicemia.Keywords: LPS, liver damage, magnesium, septicemia
Procedia PDF Downloads 3971486 Evaluation of Hydrocarbons in Tissues of Bivalve Mollusks from the Red Sea Coast
Authors: Asma Ahmed Aljohani, Mohammed Orif
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The concentration of polycyclic aromatic hydrocarbons (PAH) in clam (A. glabrata) was examined in samples collected from Alseef Beach, 30 km south of Jeddah city. Gas chromatography-mass spectrometry (GC-MS) was used to analyse the 14 PAHs. The concentration of total PAHs was found to range from 11.521 to 40.149 ng/gdw with a mean concentration of 21.857 ng/gdw, which is lower compared to similar studies. The lower molecular weight PAHs with three rings comprised 18.14% of the total PAH concentrations in the clams, while the high molecular weight PAHs with four rings, five rings, and six rings account for 81.86%. Diagnostic ratios for PAH source distinction suggested pyrogenic or anthropogenic sources.Keywords: bivalves, biomonitoring, hydrocarbons, PAHs
Procedia PDF Downloads 981485 Behavior of Square Reinforced-Concrete Columns Strengthened with Carbon Fiber Reinforced Polymers under Eccentric Loading
Authors: Dana J. Abed, Mu'tasim S. Abdel-Jaber, Nasim K. Shatarat
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In this paper, an experimental study on twelve square columns was conducted to investigate the influence of cross-sectional size on axial compressive capacity of carbon fiber reinforced polymers (CFRP) wrapped square reinforced concrete (RC) short columns subjected to eccentric loadings. The columns were divided into three groups with three cross sections (200×200×1200, 250×250×1500 and 300×300×1800 mm). Each group was tested under two different eccentricities: 10% and 20% of the width of samples measured from the center of the column cross section. Four columns were developed in each arrangement. Two columns in each category were left unwrapped as control samples, and two were wrapped with one layer CFRP perpendicular to the specimen surface. In general; CFRP sheets has enhanced the performance of the strengthened columns compared to the control columns. It was noticed that the percentage of compressive capacity enhancement was decreased by increasing the cross-sectional size, and increasing loading eccentricity generally leads to reduced load bearing capacity in columns. In the same group specimens, when the eccentricity increased the percentage of enhancement in load carrying capacity was increased. The study concludes that the optimum use of the CFRP sheets for axial strength enhancement is for smaller cross-section columns under higher eccentricities.Keywords: CFRP, columns, eccentric loading, cross-sectional
Procedia PDF Downloads 1751484 A Two-Step Framework for Unsupervised Speaker Segmentation Using BIC and Artificial Neural Network
Authors: Ahmad Alwosheel, Ahmed Alqaraawi
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This work proposes a new speaker segmentation approach for two speakers. It is an online approach that does not require a prior information about speaker models. It has two phases, a conventional approach such as unsupervised BIC-based is utilized in the first phase to detect speaker changes and train a Neural Network, while in the second phase, the output trained parameters from the Neural Network are used to predict next incoming audio stream. Using this approach, a comparable accuracy to similar BIC-based approaches is achieved with a significant improvement in terms of computation time.Keywords: artificial neural network, diarization, speaker indexing, speaker segmentation
Procedia PDF Downloads 5021483 The Potential of M-Government towards Successful Implementation of E-Government in Saudi Arabia
Authors: Majed Ahmed Alfayad
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Technology is now present in almost all areas and practices globally, and this has led governments around the world to adopt technology in the public sector. Therefore, electronic government has been introduced as a means of the automation of government services. New technologies and trends appear every single day, and governments need to meet the citizen’s requirements and expectations in order to succeed in the E-Government program. This research investigates the potential of mobile government as an enhancement force for the E-Government project in the Kingdom of Saudi Arabia, where the usage of mobile technology is coming to be favoured by citizens. Qualitative methodology has been adopted in this study for the data collection and analysis, and in particular the grounded theory approach.Keywords: e-government, e-participation, m-government, mobile technology
Procedia PDF Downloads 3331482 Pressure Gradient Prediction of Oil-Water Two Phase Flow through Horizontal Pipe
Authors: Ahmed I. Raheem
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In this thesis, stratified and stratified wavy flow regimes have been investigated numerically for the oil (1.57 mPa s viscosity and 780 kg/m3 density) and water twophase flow in small and large horizontal steel pipes with a diameter between 0.0254 to 0.508 m by ANSYS Fluent software. Volume of fluid (VOF) with two phases flows using two equations family models (Realizable k-Keywords: CFD, two-phase flow, pressure gradient, volume of fluid, large diameter, horizontal pipe, oil-water stratified and stratified wavy flow
Procedia PDF Downloads 4331481 Cheiloscopy and Dactylography in Relation to ABO Blood Groups: Egyptian vs. Malay Populations
Authors: Manal Hassan Abdel Aziz, Fatma Mohamed Magdy Badr El Dine, Nourhan Mohamed Mohamed Saeed
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Establishing association between lip print patterns and those of fingerprints as well as blood groups is of fundamental importance in the forensic identification domain. The first aim of the current study was to determine the prevalent types of ABO blood groups, lip prints and fingerprints patterns in both studied populations. Secondly, to analyze any relation found between the different print patterns and the blood groups, which would be valuable in identification purposes. The present study was conducted on 60 healthy volunteers, (30 males and 30 females) from each of the studied population. Lip prints and fingerprints were obtained and classified according to Tsuchihashi's classification and Michael Kuchen’s classification, respectively. The results show that the ulnar loop was the most frequent among both populations. Blood group A was the most frequent among Egyptians, while blood groups O and B were the predominant among Malaysians. Significant relations were observed between lip print patterns and fingerprint (in the second quadrant for Egyptian males and the first one for Malaysian). For Malaysian females, a statistically significant association was proved in the fourth quadrant. Regarding the blood groups, 89.5% of ulnar loops were significantly related to blood group A among Egyptian males. The results proved an association between the fingerprint pattern and the lip prints, as well as between the ABO blood group and the pattern of fingerprints. However, further researches with larger sample sizes need to be directed to approve the current results.Keywords: ABO, cheiloscopy, dactylography, Egyptians, Malaysians
Procedia PDF Downloads 2191480 Study the Multifaceted Therapeutic Properties of the IQGAP1shRNA Plasmid on Rat Liver Cancer Model
Authors: Khairy M. A. Zoheir, Nehma A. Ali, Ahmed M. Darwish, Mohamed S. Kishta, Ahmed A. Abd-Rabou, Mohamed A. Abdelhafez, Karima F. Mahrous
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The study comprehensively investigated the multifaceted therapeutic properties of the IQGAP1shRNA plasmid, encompassing its hepatoprotective, immunomodulatory, and anticancer activities. The study employed a Prednisolone-induced immunosuppressed rat model to assess the hepatoprotective and immunomodulatory effects of IQGAP1shRNA plasmid. Using this model, IQGAP1shRNA plasmid was found to modulate haematopoiesis, improving RBC, platelet, and WBC counts, underscoring its potential in hematopoietic homeostasis. Organ atrophy, a hallmark of immunosuppression in spleen, heart, liver, ovaries, and kidneys, was reversed with IQGAP1shRNA plasmid treatment, reinforcing its hepatotrophic and organotropic capabilities. Elevated hepatic biomarkers (ALT, AST, ALP, LPO) indicative of hepatocellular injury and oxidative stress were reduced with GST, highlighting its hepatoprotective and antioxidative effects. IQGAP1shRNA plasmid also restored depleted antioxidants (GSH and SOD), emphasizing its potent antioxidative and free radical scavenging capabilities. Molecular insights into immune dysregulation revealed downregulation of IQGAP1, IQGAP3 interleukin-2 (IL-2), and interleukin-4 (IL-4) mRNA expression in the liver of immunosuppressed rats. IL-2 and IL-4 play pivotal roles in immune regulation, T-cell activation, and B-cell differentiation. Notably, treatment with IQGAP1shRNA plasmid exhibited a significant upregulation of IL-2 and IL-4 mRNA expression, thereby accentuating its immunomodulatory potential in orchestrating immune homeostasis. Additionally, immune dysregulation was associated with increased levels of TNF-α. However, treatment with IQGAP1shRNA plasmid effectively decreased the levels of TNF-α, further underscoring its role in modulating inflammatory responses and restoring immune balance in immunosuppressed rats. Additionally, pharmacokinetics, bioavailability, drug-likeness, and toxicity risk assessment prediction suggest its potential as a pharmacologically favourable agent with no serious adverse effects. In conclusion, this study confirms the therapeutic potential of the IQGAP1shRNA plasmid, showcasing its effectiveness against hepatotoxicity, oxidative stress, immunosuppression, and its notable anticancer activity.Keywords: IQGAP1, shRNA, cancer, liver, rat
Procedia PDF Downloads 31479 Specification Requirements for a Combined Dehumidifier/Cooling Panel: A Global Scale Analysis
Authors: Damien Gondre, Hatem Ben Maad, Abdelkrim Trabelsi, Frédéric Kuznik, Joseph Virgone
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The use of a radiant cooling solution would enable to lower cooling needs which is of great interest when the demand is initially high (hot climate). But, radiant systems are not naturally compatibles with humid climates since a low-temperature surface leads to condensation risks as soon as the surface temperature is close to or lower than the dew point temperature. A radiant cooling system combined to a dehumidification system would enable to remove humidity for the space, thereby lowering the dew point temperature. The humidity removal needs to be especially effective near the cooled surface. This requirement could be fulfilled by a system using a single desiccant fluid for the removal of both excessive heat and moisture. This task aims at providing an estimation of the specification requirements of such system in terms of cooling power and dehumidification rate required to fulfill comfort issues and to prevent any condensation risk on the cool panel surface. The present paper develops a preliminary study on the specification requirements, performances and behavior of a combined dehumidifier/cooling ceiling panel for different operating conditions. This study has been carried using the TRNSYS software which allows nodal calculations of thermal systems. It consists of the dynamic modeling of heat and vapor balances of a 5m x 3m x 2.7m office space. In a first design estimation, this room is equipped with an ideal heating, cooling, humidification and dehumidification system so that the room temperature is always maintained in between 21◦C and 25◦C with a relative humidity in between 40% and 60%. The room is also equipped with a ventilation system that includes a heat recovery heat exchanger and another heat exchanger connected to a heat sink. Main results show that the system should be designed to meet a cooling power of 42W.m−2 and a desiccant rate of 45 gH2O.h−1. In a second time, a parametric study of comfort issues and system performances has been achieved on a more realistic system (that includes a chilled ceiling) under different operating conditions. It enables an estimation of an acceptable range of operating conditions. This preliminary study is intended to provide useful information for the system design.Keywords: dehumidification, nodal calculation, radiant cooling panel, system sizing
Procedia PDF Downloads 1751478 From the Local to the Global: New Terrorism
Authors: Shamila Ahmed
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The paper examines how the fluidity between the local level and the global level is an intrinsic feature of new terrorism. Through using cosmopolitanism, the narratives of the two opposing sides of ISIS and the ‘war on terrorism’ response are explored. It is demonstrated how the fluidity between these levels facilitates the radicalisation process through exploring how groups such as ISIS highlight the perceived injustices against Muslims locally and globally and therefore exploit the globalisation process which has reduced the space between these levels. Similarly, it is argued that the ‘war on terror’ involves the intersection of fear, security, threat, risk and social control as features of both the international ‘war on terror’ and intra state policies.Keywords: terrorism, war on terror, cosmopolitanism, global level terrorism
Procedia PDF Downloads 5841477 The Conjugated Polymers in improving the Organic Solar Cells Efficiency
Authors: Samia Moulebhar, Chahrazed Bendenia, Souhila Bendenia, Hanaa Merad-dib, Sarra Merabet, Sid Ahmed Khantar, Baghdad Hadri
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The photovoltaic solar field is today experiencing exponential advancement with the exploitation of new technological sectors of nanoparticles, namely the field of solar cells based on organic polymer materials. These cells are flexible, easy to process and low cost. This work includes a presentation of the conjugated polymer materials used in the design of photovoltaic technology devices while determining their properties and then the models used for the modeling of thin film photovoltaic cells heterojunction.Keywords: photovoltaic, cells, nanoparticles, organic
Procedia PDF Downloads 851476 The Protection and Enhancement of the Roman Roads in Algeria
Authors: Tarek Ninouh, Ahmed Rouili
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The Roman paths or roads offer a very interesting archaeological material, because they allow us to understand the history of human settlement and are also factors that increase territorial identity. Roman roads are one of the hallmarks of the Roman empire, which extends to North Africa. The objective of this investigation is to attract the attention of researchers to the importance of Roman roads and paths, which are found in Algeria, according to the quality of the materials and techniques used in this period of our history, and to encourage other decision makers to protect and enhance these routes because the current urbanization, intensive agricultural practices, or simply forgotten, decreases the sustainability of this important historical heritage.Keywords: Roman paths, quality of materials, property, valuation
Procedia PDF Downloads 4301475 A Simulated Evaluation of Model Predictive Control
Authors: Ahmed AlNouss, Salim Ahmed
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Process control refers to the techniques to control the variables in a process in order to maintain them at their desired values. Advanced process control (APC) is a broad term within the domain of control where it refers to different kinds of process control and control related tools, for example, model predictive control (MPC), statistical process control (SPC), fault detection and classification (FDC) and performance assessment. APC is often used for solving multivariable control problems and model predictive control (MPC) is one of only a few advanced control methods used successfully in industrial control applications. Advanced control is expected to bring many benefits to the plant operation; however, the extent of the benefits is plant specific and the application needs a large investment. This requires an analysis of the expected benefits before the implementation of the control. In a real plant simulation studies are carried out along with some experimentation to determine the improvement in the performance of the plant due to advanced control. In this research, such an exercise is undertaken to realize the needs of APC application. The main objectives of the paper are as follows: (1) To apply MPC to a number of simulations set up to realize the need of MPC by comparing its performance with that of proportional integral derivatives (PID) controllers. (2) To study the effect of controller parameters on control performance. (3) To develop appropriate performance index (PI) to compare the performance of different controller and develop novel idea to present tuning map of a controller. These objectives were achieved by applying PID controller and a special type of MPC which is dynamic matrix control (DMC) on the multi-tanks process simulated in loop-pro. Then the controller performance has been evaluated by changing the controller parameters. This performance was based on special indices related to the difference between set point and process variable in order to compare the both controllers. The same principle was applied for continuous stirred tank heater (CSTH) and continuous stirred tank reactor (CSTR) processes simulated in Matlab. However, in these processes some developed programs were written to evaluate the performance of the PID and MPC controllers. Finally these performance indices along with their controller parameters were plotted using special program called Sigmaplot. As a result, the improvement in the performance of the control loops was quantified using relevant indices to justify the need and importance of advanced process control. Also, it has been approved that, by using appropriate indices, predictive controller can improve the performance of the control loop significantly.Keywords: advanced process control (APC), control loop, model predictive control (MPC), proportional integral derivatives (PID), performance indices (PI)
Procedia PDF Downloads 4071474 Low Voltage Ride through Capability Techniques for DFIG-Based Wind Turbines
Authors: Sherif O. Zain Elabideen, Ahmed A. Helal, Ibrahim F. El-Arabawy
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Due to the drastic increase of the wind turbines installed capacity; the grid codes are increasing the restrictions aiming to treat the wind turbines like other conventional sources sooner. In this paper, an intensive review has been presented for different techniques used to add low voltage ride through capability to Doubly Fed Induction Generator (DFIG) wind turbine. A system model with 1.5 MW DFIG wind turbine is constructed and simulated using MATLAB/SIMULINK to explore the effectiveness of the reviewed techniques.Keywords: DFIG, grid side converters, low voltage ride through, wind turbine
Procedia PDF Downloads 4251473 Parallel Multisplitting Methods for DAE’s
Authors: Ahmed Machmoum, Malika El Kyal
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We consider iterative parallel multi-splitting method for differential algebraic equations. The main feature of the proposed idea is to use the asynchronous form. We prove that the multi-splitting technique can effectively accelerate the convergent performance of the iterative process. The main characteristic of an asynchronous mode is that the local algorithm not have to wait at predetermined messages to become available. We allow some processors to communicate more frequently than others, and we allow the communication delays tobe substantial and unpredictable. Note that synchronous algorithms in the computer science sense are particular cases of our formulation of asynchronous one.Keywords: computer, multi-splitting methods, asynchronous mode, differential algebraic systems
Procedia PDF Downloads 5491472 Exploring the Association between Risks Emerging from Climate Change Scenarios and the Built Environment
Authors: Abdullah M. Alzahrani, Abdel Halim Boussabaine
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There is an international consensus on the climate change in the entire world and this is as a result of the combination of the natural factors, such as volcanoes and hurricanes with increased of human activity on the earth, such as industrial renaissance. Where this solidarity increases emissions of greenhouse gases GHGs that considered as the main driver of climate change scenarios and related emerging risks and impacts on buildings. These climatic risks including damages, disruption and disquiet are set to increase and it is considered as the main challenges and difficulties facing built environment due to major implications on assets sector. Consequently, the threat from climate change patterns has a significant impact on a variety of complex human decisions, which affect all aspects of living. Understanding the relationship between buildings and such risks arising from climate change scenarios on buildings are the key in insuring the optimal timing and design of policies and systems, which affect all aspects of the built environment. This paper will uncovering this correlation between emerging climate change risks and the building assets. In addition, how these emerging risks can be classified in practical way in terms of their impact type on buildings. Hence, this mapping will assist professionals and interested parties in the building sector to cope with such risks in several systematic ways including development and designing of mitigation and adaptation strategies and processes of design, specification, construction, and operation; all these leads to successful management of assets.Keywords: climate change, climate change risks, built environment, building sector, impacts
Procedia PDF Downloads 3531471 SOTM: A New Cooperation Based Trust Management System for VANET
Authors: Amel Ltifi, Ahmed Zouinkhi, Mohamed Salim Bouhlel
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Security and trust management in Vehicular Ad-hoc NETworks (VANET) is a crucial research domain which is the scope of many researches and domains. Although, the majority of the proposed trust management systems for VANET are based on specific road infrastructure, which may not be present in all the roads. Therefore, road security should be managed by vehicles themselves. In this paper, we propose a new Self Organized Trust Management system (SOTM). This system has the responsibility to cut with the spread of false warnings in the network through four principal components: cooperation, trust management, communication and security.Keywords: ative vehicle, cooperation, trust management, VANET
Procedia PDF Downloads 4301470 Viability of EBT3 Film in Small Dimensions to Be Use for in-Vivo Dosimetry in Radiation Therapy
Authors: Abdul Qadir Jangda, Khadija Mariam, Usman Ahmed, Sharib Ahmed
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The Gafchromic EBT3 film has the characteristic of high spatial resolution, weak energy dependence and near tissue equivalence which makes them viable to be used for in-vivo dosimetry in External Beam and Brachytherapy applications. The aim of this study is to assess the smallest film dimension that may be feasible for the use in in-vivo dosimetry. To evaluate the viability, the film sizes from 3 x 3 mm to 20 x 20 mm were calibrated with 6 MV Photon and 6 MeV electron beams. The Gafchromic EBT3 (Lot no. A05151201, Make: ISP) film was cut into five different sizes in order to establish the relationship between absorbed dose vs. film dimensions. The film dimension were 3 x 3, 5 x 5, 10 x 10, 15 x 15, and 20 x 20 mm. The films were irradiated on Varian Clinac® 2100C linear accelerator for dose range from 0 to 1000 cGy using PTW solid water phantom. The irradiation was performed as per clinical absolute dose rate calibratin setup, i.e. 100 cm SAD, 5.0 cm depth and field size of 10x10 cm2 and 100 cm SSD, 1.4 cm depth and 15x15 cm2 applicator for photon and electron respectively. The irradiated films were scanned with the landscape orientation and a post development time of 48 hours (minimum). Film scanning accomplished using Epson Expression 10000 XL Flatbed Scanner and quantitative analysis carried out with ImageJ freeware software. Results show that the dose variation with different film dimension ranging from 3 x 3 mm to 20 x 20 mm is very minimal with a maximum standard deviation of 0.0058 in Optical Density for a dose level of 3000 cGy and the the standard deviation increases with the increase in dose level. So the precaution must be taken while using the small dimension films for higher doses. Analysis shows that there is insignificant variation in the absorbed dose with a change in film dimension of EBT3 film. Study concludes that the film dimension upto 3 x 3 mm can safely be used up to a dose level of 3000 cGy without the need of recalibration for particular dimension in use for dosimetric application. However, for higher dose levels, one may need to calibrate the films for a particular dimension in use for higher accuracy. It was also noticed that the crystalline structure of the film got damage at the edges while cutting the film, which can contribute to the wrong dose if the region of interest includes the damage area of the filmKeywords: external beam radiotherapy, film calibration, film dosimetery, in-vivo dosimetery
Procedia PDF Downloads 4941469 Impact of Implementation of Right to Education in Pakistan
Authors: Rukhsar Ahmed, Jawed Aziz Masudi
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In the present study, an attempt has been made about the right to an education in Pakistan. The research is the focus in respect of International Law Article 26 of the Universal Declaration of Human Rights. The main motivation behind getting great training is, as a rule, decent resident and afterward being effective in close to home and expert life. We are fragmented without decent instruction since training makes us the right mastermind and right chief. In such a focused world, instruction has turned into a need for people after sustenance, dress and haven. It can give answers for all issues; it advances great propensities and mindfulness about defilement, fear-mongering, and other social issues among us.Keywords: education, right to education, human right, universal declaration, law
Procedia PDF Downloads 1621468 Modeling of Crack Growth in Railway Axles under Static Loading
Authors: Zellagui Redouane, Bellaouar Ahmed, Lachi Mohammed
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The railway axles are the essential parts in the bogie of train, and its failure creates a big problem in the railway transport; during the work of this parts we noticed a premature deterioration. The aim has been presented a predictive model allowing the identification of the probable causes that are the cause of these premature deterioration. The results are employed for predicting fatigue crack growth in the railway axle, Also we want to present the variation value of stress intensity factor in different positions of elliptical crack tip. The modeling of axle in performed by the SOLID WORKS software and imported into ANSYS.Keywords: crack growth, static load, railway axle, lifetime
Procedia PDF Downloads 364