Search results for: A. Mohamed Mustaq Ahmed Hameed
900 Study on the Impact of Windows Location on Occupancy Thermal Comfort by Computational Fluid Dynamics (CFD) Simulation
Authors: Farhan E Shafrin, Khandaker Shabbir Ahmed
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Natural ventilation strategies continue to be a key alternative to costly mechanical ventilation systems, especially in healthcare facilities, due to increasing energy issues in developing countries, including Bangladesh. Besides, overcrowding and insufficient ventilation strategies remain significant causes of thermal discomfort and hospital infection in Bangladesh. With the proper location of inlet and outlet windows, uniform flow is possible in the occupancy area to achieve thermal comfort. It also determines the airflow pattern of the ward that decreases the movement of the contaminated air. This paper aims to establish a relationship between the location of the windows and the thermal comfort of the occupants in a naturally ventilated hospital ward. It defines the openings and ventilation variables that are interrelated in a way that enhances or limits the health and thermal comfort of occupants. The study conducts a full-scale experiment in one of the naturally ventilated wards in a primary health care hospital in Manikganj, Dhaka. CFD simulation is used to explore the performance of various opening positions in ventilation efficiency and thermal comfort in the study area. The results indicate that the opening located in the hospital ward has a significant impact on the thermal comfort of the occupants and the airflow pattern inside the ward. The findings can contribute to design the naturally ventilated hospital wards by identifying and predicting future solutions when it comes to relationships with the occupants' thermal comforts.Keywords: CFD simulation, hospital ward, natural ventilation, thermal comfort, window location
Procedia PDF Downloads 196899 Moho Undulations beneath South of Egypt, Using the Seismic Waves Generated by Tele Earthquakes
Authors: Ahmed Hosny, Haroon Elshaikh, Gaber Hassib, Yassin Ali
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The Moho discontinuity undulations beneath the southern part of Egypt have been defined using the seismic waves generated by tele earthquakes. These earthquakes have been recorded by the Aswan seismic network, which consists of 10 seismic stations established around the lake of Nasser. An additional seismic station was located towards the east of the Lake of Nasser by about ~ 150 km. Receiver functions and H-k stacking methods were used for obtaining the depths of Moho discontinuity and the Vp/Vs ratios beneath each seismic station. Our results revealed that, the depths of Moho discontinuity beneath the stations located around the Lake of Nasser range from 36 to 39 km, with an average value of 37.5 km. These results are consistent with the previous works done on the same area. The obtained Vp/Vs ratios for the crust of this area were ranged from 1.73 to 1.86, with an average value of 1.79. While beneath the station located towards the east, the Moho discontinuity was detected at a shallowest depth of 27 km and the Vp/Vs ratio was 1.82. The difference in the Moho depths beneath the stations located around the Lake of Nasser and the station located to the east revealed the boundary position between the Saharan Metacraton to the west and the Nubian-Arabian Shield to the east. This structural boundary delineates the position of the old collision of the Oceanic crust of the Nubian-Arabian Shield to the east with the Continental crust of the Saharan Metacraton to the west.Keywords: Moho undulations, south of Egypt, seismic waves, earthquakes
Procedia PDF Downloads 512898 Evaluation of Antioxidants in Medicinal plant Limoniastrum guyonianum
Authors: Assia Belfar, Mohamed Hadjadj, Messaouda Dakmouche, Zineb Ghiaba
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Introduction: This study aims to phytochemical screening; Extracting the active compounds and estimate the effectiveness of antioxidant in Medicinal plants desert Limoniastrum guyonianum (Zeïta) from South Algeria. Methods: Total phenolic content and total flavonoid content using Folin-Ciocalteu and aluminum chloride colorimetric methods, respectively. The total antioxidant capacity was estimated by the following methods: DPPH (1.1-diphenyl-2-picrylhydrazyl radical) and reducing power assay. Results: Phytochemical screening of the plant part reveals the presence of phenols, saponins, flavonoids and tannins. While alkaloids and Terpenoids were absent. The acetonic extract of L. guyonianum was extracted successively with ethyl acetate and butanol. Extraction of yield varied widely in the L. guyonianum ranging from (0.9425 %to 11.131%). The total phenolic content ranged from 53.33 mg GAE/g DW to 672.79 mg GAE/g DW. The total flavonoid concentrations varied from 5.45 to 21.71 mg/100g. IC50 values ranged from 0.02 ± 0.0004 to 0.13 ± 0.002 mg/ml. All extracts showed very good activity of ferric reducing power, the higher power was in butanol fraction (23.91 mM) more effective than BHA, BHT and VC. Conclusions: Demonstrated this study that the acetonic extract of L. guyonianum contain a considerable quantity of phenolic compounds and possess a good antioxidant activity. Can be used as an easily accessible source of Natural Antioxidants and as a possible food supplement and in the pharmaceutical industry.Keywords: limoniastrum guyonianum, phenolics compounds, flavonoid compound, antioxidant activity
Procedia PDF Downloads 346897 Nonlinear Analysis of Torsionally Loaded Steel Fibred Self-Compacted Concrete Beams Reinforced by GFRP Bars
Authors: Khaled Saad Eldin Mohamed Ragab
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This paper investigates analytically the torsion behavior of steel fibered high strength self compacting concrete beams reinforced by GFRP bars. Nonlinear finite element analysis on 12 beams specimens was achieved by using ANSYS software. The nonlinear finite element analysis program ANSYS is utilized owing to its capabilities to predict either the response of reinforced concrete beams in the post elastic range or the ultimate strength of a reinforced concrete beams produced from steel fiber reinforced self compacting concrete (SFRSCC) and reinforced by GFRP bars. A general description of the finite element method, theoretical modeling of concrete and reinforcement are presented. In order to verify the analytical model used in this research using test results of the experimental data, the finite element analysis were performed. Then, a parametric study of the effect ratio of volume fraction of steel fibers in ordinary strength concrete, the effect ratio of volume fraction of steel fibers in high strength concrete, and the type of reinforcement of stirrups were investigated. A comparison between the experimental results and those predicted by the existing models are presented. Results and conclusions thyat may be useful for designers have been raised and represented.Keywords: nonlinear analysis, torsionally loaded, self compacting concrete, steel fiber reinforced self compacting concrete (SFRSCC), GFRP bars and sheets
Procedia PDF Downloads 453896 Molecular Dynamics Simulation of the Effect of the Solid Gas Interface Nanolayer on Enhanced Thermal Conductivity of Copper-CO2 Nanofluid
Authors: Zeeshan Ahmed, Ajinkya Sarode, Pratik Basarkar, Atul Bhargav, Debjyoti Banerjee
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The use of CO2 in oil recovery and in CO2 capture and storage is gaining traction in recent years. These applications involve heat transfer between CO2 and the base fluid, and hence, there arises a need to improve the thermal conductivity of CO2 to increase the process efficiency and reduce cost. One way to improve the thermal conductivity is through nanoparticle addition in the base fluid. The nanofluid model in this study consisted of copper (Cu) nanoparticles in varying concentrations with CO2 as a base fluid. No experimental data are available on thermal conductivity of CO2 based nanofluid. Molecular dynamics (MD) simulations are an increasingly adopted tool to perform preliminary assessments of nanoparticle (NP) fluid interactions. In this study, the effect of the formation of a nanolayer (or molecular layering) at the gas-solid interface on thermal conductivity is investigated using equilibrium MD simulations by varying NP diameter and keeping the volume fraction (1.413%) of nanofluid constant to check the diameter effect of NP on the nanolayer and thermal conductivity. A dense semi-solid fluid layer was seen to be formed at the NP-gas interface, and the thickness increases with increase in particle diameter, which also moves with the NP Brownian motion. Density distribution has been done to see the effect of nanolayer, and its thickness around the NP. These findings are extremely beneficial, especially to industries employed in oil recovery as increased thermal conductivity of CO2 will lead to enhanced oil recovery and thermal energy storage.Keywords: copper-CO2 nanofluid, molecular dynamics simulation, molecular interfacial layer, thermal conductivity
Procedia PDF Downloads 337895 Layer-by-Layer Coated Dexamethasone Microcrystals for Experimental Inflammatory Bowel Disease Therapy
Authors: Murtada Ahmed Oshi, Jin-Wook Yoo
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Layer-by-layer (LBL) coating has gained popularity for drug delivery of therapeutic drugs. Herein we described a novel approach for enhancing the therapeutic efficiency of the locally administered dexamethasone (Dex) for inflammatory bowel disease (IBD). We utilized a LBL-coating technique on Dex microcrystals (DexMCs) with multiple layers of polyelectrolytes composed of poly (allylamine hydrochloride) (PAH), poly (sodium 4-styrene sulfonate) (PSS) and Eudragit® S100 (ES). The successful deposition of the layers onto DexMCs surfaces were confirmed through zeta potential measurement and confocal laser scanning microscopy. The surface morphology was investigated through scanning electron microscopy. The drug encapsulation efficiency was 95% with a mean particle size of 2 µm and negative surface charge (-40 mV). Moreover, in vitro drug release study showed a minimum release of the drug ( 15%) at an acidic condition during initial first 5 h, followed by sustained-release at an alkaline condition. For in vivo study, LBL-DxMCs were administered orally to ICR mice suffering from dextran sulfate sodium-induced colitis. LBL-DxMCs substantially enhanced anti-IBD activities as compared to DxMCs. Macroscopic, histological and biochemical (tumor necrosis factor-α, interleukin-6 and myeloperoxidase) examinations revealed marked improvements of colitis signs in the mice treated with LBL-DxMCs compared with those treated with DxMCs. Overall, LBL-DxMCs could be a suitable candidate for the treatment of IBD.Keywords: dexamethasone, inflammatory bowel disease, LBL-coating, polyelectrolytes
Procedia PDF Downloads 196894 Developing Mathematical Relationships to Evaluate the Amount of Added Ease to the Basic Pattern of Weft Knitting Fabrics and Its Fitting to the Upper Part of Egyptian Women's Bodies
Authors: Hebatullah Ali Abdel-Aleem Abdel-Hamid, Camellia Mousa Mohamed Elzean
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Knitted garments recently became a key component in wardrobes of the Egyptian woman. Many Egyptian women depend on garments made of knitted fabrics in their outer appearance because of its specific properties including flexibility. Through observation and application, it was noticed that knitwear blocks that used for knitted fabrics somehow does not fit the figures of the Egyptian women. Moreover, the pattern makers are usually confused and unable to choose the suitable blocks for different knitting fabrics taking into consideration its physical and mechanical properties. This study seeks to develop mathematical relationships for evaluation of the amount of added- or subtracted ease to Aldrich’s basic fitting blocks for some weft knitting fabrics and its fitting to the upper part of Egyptian women's bodies. To achieve this goal, 12 samples were used to evaluate fitting of Aldrich’s Basic Fitting Block to the upper part of Egyptian women's bodies. The samples were evaluated before and after alterations, through wear trials on the standard mannequins of size 48 and 56, and judged by experienced assessors using fit evaluation scale. The data obtained were statistically analyzed to identify the efficiency of the adjustments. The Aldrich’s Basic Fitting Block was selected because his method is known internationally and easy to use.Keywords: Aldrich basic fitting block, clothing industry, knitted fabrics, pattern construction
Procedia PDF Downloads 266893 Laparoscopic Proximal Gastrectomy in Gastroesophageal Junction Tumours
Authors: Ihab Saad Ahmed
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Background For Siewert type I and II gastroesophageal junction tumor (GEJ) laparoscopic proximal gastrectomy can be performed. It is associated with several perioperative benefits compared with open proximal gastrectomy. The use of laparoscopic proximal gastrectomy (LPG) has become an increasingly popular approach for select tumors Methods We describe our technique for LPG, including the preoperative work-up, illustrated images of the main principle steps of the surgery, and our postoperative course. Results Thirteen pts (nine males, four female) with type I, II (GEJ) adenocarcinoma had laparoscopic radical proximal gastrectomy and D2 lymphadenectomy. All of our patient received neoadjuvant chemotherapy, eleven patients had intrathoracic anastomosis through mini thoracotomy (two hand sewn end to end anastomoses and the other 9 patient end to side using circular stapler), two patients with intrathoracic anastomosis had flap and wrap technique, two patients had thoracoscopic esophageal and mediastinal lymph node dissection with cervical anastomosis The mean blood loss 80ml, no cases were converted to open. The mean operative time 250 minute Average LN retrieved 19-25, No sever complication such as leakage, stenosis, pancreatic fistula ,or intra-abdominal abscess were reported. Only One patient presented with empyema 1.5 month after discharge that was managed conservatively. Conclusion For carefully selected patients, LPG in GEJ tumour type I and II is a safe and reasonable alternative for open technique , which is associated with similar oncologic outcomes and low morbidity. It showed less blood loss, respiratory infections, with similar 1- and 3-year survival rates.Keywords: LPG(laparoscopic proximal gastrectomy, GEJ( gastroesophageal junction tumour), d2 lymphadenectomy, neoadjuvant cth
Procedia PDF Downloads 125892 Role of Pakistani Physicians in the Pharmacotherapy of Obesity
Authors: Sadia Suri Kashif, Raheeda Fatima, Maqsood Ahmed Khan
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Purpose of the study: The objective of this research was to determine the perception of Pakistani physicians (whether primary care, specialists or residents) in Karachi, being one of the largest and highly populated cities of Pakistan, regarding clinical approaches towards diet, exercise, and therapy in obese patients. This research determines their understanding of obesity and employability of obesity management in their daily practices. Research methodology: This is a questionnaire-based survey. A minimum of 300 questionnaires (N=300) were distributed and filled by practicing physicians in a random selection of medical setups in Karachi. Randomly 246 physicians responded to the survey. The survey tested their views regarding weight management, importance of general awareness and their strategies to control weight. Results: In the first part of survey the physicians responded to almost 66% regarding the seriousness of obesity management with advising diet modification, physical exercise and decreasing calorie intake; 57% failed to employ Body Mass Index and Waist Hip Ratio as weight measurement tools in their daily practice; 50% disagreed on using pharmacotherapy as an option; 67% were not sure about the proper dosage and indication of anti-obesity medication while almost same disagreed on using surgical options for management of obesity; 83.3% physicians agreed on the increased obesity pandemic in Pakistan. Conclusion: The findings indicate that there is a gap between awareness and knowledge among Pakistani practicing physicians regarding pharmacotherapy for obesity. There is a need to frequently update latest guidelines to help manage this condition, which is becoming more prevalent in our country day by day. Physicians should be obligated to use updated knowledge for managing obesity.Keywords: obesity, physicians, BMI, weight management, obesity awareness
Procedia PDF Downloads 170891 Effects of Plant Growth Promoting Microbes and Mycorrhizal Fungi on Wheat Growth in the Saline Soil
Authors: Ahmed Elgharably, Nivien Nafady
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Arbuscular mycorrhizal fungi (AMF) and plant growth promoting microbes (PGPM) can promote plant growth under saline conditions. This study investigated how AMF and PGPM affected the growth and grain yield of wheat at different soil salinity levels (0, 75 and 150 mM NaCl). AMF colonization percentage, grain yield and dry weights and lengths of shoot and root, N, P K, Na, malondialdehyde, chlorophyll and proline contents and shoot relative permeability were determined. Salinity reduced NPK uptake and malondialdehyde and chlorophyll contents, and increased shoot Na concentration, relative permeability, and proline content, and thus declined plant growth. PGPM inoculation enhanced AMF colonization, P uptake, and K/Na ratio, but alone had no significant effect on plant growth and grain yield. AMF inoculation significantly enhanced NPK uptake, increased chlorophyll content and decreased shoot relative permeability, proline and Na contents, and thus promoted the plant growth. The inoculation of PGPM significantly enhanced the positive effects of AMF in controlling Na uptake and in increasing chlorophyll and NPK contents. Compared to AMF inoculation alone, dual inoculation with AMF and PGPM resulted in approximately 10, 25 and 25% higher grain yield at 0, 75 and 150 mM NaCl, respectively. The results provide that PGPM inoculation can maximize the effects of AMF inoculation in alleviating the deleterious effects of NaCl salts on wheat growth.Keywords: mycorrhizal fungi, salinity, sodium, wheat
Procedia PDF Downloads 180890 mm-Wave Wearable Edge Computing Module Hosted by Printed Ridge Gap Waveguide Structures: A Physical Layer Study
Authors: Matthew Kostawich, Mohammed Elmorsy, Mohamed Sayed Sifat, Shoukry Shams, Mahmoud Elsaadany
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6G communication systems represent the nominal future extension of current wireless technology, where its impact is extended to touch upon all human activities, including medical, security, and entertainment applications. As a result, human needs are allocated among the highest priority aspects of the system design and requirements. 6G communications is expected to replace all the current video conferencing with interactive virtual reality meetings involving high data-rate transmission merged with massive distributed computing resources. In addition, the current expansion of IoT applications must be mitigated with significant network changes to provide a reasonable Quality of Service (QoS). This directly implies a high demand for Human-Computer Interaction (HCI) through mobile computing modules in future wireless communication systems. This article proposes the utilization of a Printed Ridge Gap Waveguide (PRGW) to host the wearable nodes. To the best of our knowledge, we propose for the first time a physical layer analysis within the context of a complete architecture. A thorough study is provided on the impact of the distortion of the guiding structure on the overall system performance. The proposed structure shows small latency and small losses, highlighting its compatibility with future applications.Keywords: ridge gap waveguide, edge computing module, 6G, multimedia IoT applications
Procedia PDF Downloads 71889 Infertility Awareness: Knowledge and Attitude of Medical & Non-Medical Moroccan Young People
Authors: Sana El Adlani, Yassir Ait Ben Kaddour, Abdelhafid Benksim, Abderraouf Soummani, Mohamed Cherkaoui
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Background: Infertility in all countries of the word is on an increase, it’s why the World Health Organization included an investigation into young people's fertility. In this sense, it’s important to increase efforts to improve the knowledge about fertility for the young population. The aim of this study is to describe the difference between knowledge and attitude of medical and non-medical Moroccan young people. Materials and Methods: 100 medical Moroccan students (group 1) participated in the study, between 18 and 30 years, by a simple random sampling method, during 2020 and using a previously validated questionnaire. The answers were confronted to the result of our same study among 355 non-medical Moroccan young people (group 2) in 2019. Statistical analyses were performed using Statistical Package for the Social Sciences (version 10). Result: Medical students had a significantly higher level of knowledge about infertility than non-medical young people. However, both groups were aware of the impact of lifestyle on infertility. The knowledge state of the first group about infertility management was higher than the second group. Moreover, all non-medical Moroccan young people believed that it is easier to conceive if the couples had already their first baby, whereas, among medical students, only 53% had confirmed this belief. The results showed that 65% of medical students had proposed to try fertility treatments more than one time if treatment fails. Besides, the first advice of the second group was polygamy and adoption. Conclusion: Following the result of our study, the investigation of young people is the measure to optimize reproductive health. So, it’s crucial that the government increase efforts to improve the knowledge about infertility not only for medical universities but for all scholar programs.Keywords: attitude, infertility, knowledge, medical, non-medical, young people
Procedia PDF Downloads 228888 A Study on the Effect of Mg and Ag Additions and Age Hardening Treatment on the Properties of As-Cast Al-Cu-Mg-Ag Alloys
Authors: Ahmed. S. Alasmari, M. S. Soliman, Magdy M. El-Rayes
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This study focuses on the effect of the addition of magnesium (Mg) and silver (Ag) on the mechanical properties of aluminum based alloys. The alloying elements will be added at different levels using the factorial design of experiments of 22; the two factors are Mg and Ag at two levels of concentration. The superior mechanical properties of the produced Al-Cu-Mg-Ag alloys after aging will be resulted from a unique type of precipitation named as Ω-phase. The formed precipitate enhanced the tensile strength and thermal stability. This paper further investigated the microstructure and mechanical properties of as cast Al–Cu–Mg–Ag alloys after being complete homogenized treatment at 520 °C for 8 hours followed by isothermally age hardening process at 190 °C for different periods of time. The homogenization at 520 °C for 8 hours was selected based on homogenization study at various temperatures and times. The alloys’ microstructures were studied by using optical microscopy (OM). In addition to that, the fracture surface investigation was performed using a scanning electronic microscope (SEM). Studying the microstructure of aged Al-Cu-Mg-Ag alloys reveal that the grains are equiaxed with an average grain size of about 50 µm. A detailed fractography study for fractured surface of the aged alloys exhibited a mixed fracture whereby the random fracture suggested crack propagation along the grain boundaries while the dimples indicated that the fracture was ductile. The present result has shown that alloy 5 has the highest hardness values and the best mechanical behaviors.Keywords: precipitation hardening, aluminum alloys, aging, design of experiments, analysis of variance, heat treatments
Procedia PDF Downloads 157887 Parametric Study on Dynamic Analysis of Composite Laminated Plate
Authors: Junaid Kameran Ahmed
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A laminated plate composite of graphite/epoxy has been analyzed dynamically in the present work by using a quadratic element (8-node diso-parametric), and by depending on 1st order shear deformation theory, every node in this element has 6-degrees of freedom (displacement in x, y, and z axis and twist about x, y, and z axis). The dynamic analysis in the present work covered parametric studies on a composite laminated plate (square plate) to determine its effect on the natural frequency of the plate. The parametric study is represented by set of changes (plate thickness, number of layers, support conditions, layer orientation), and the plates have been simulated by using ANSYS package 12. The boundary conditions considered in this study, at all four edges of the plate, are simply supported and fixed boundary condition. The results obtained from ANSYS program show that the natural frequency for both fixed and simply supported increases with increasing the number of layers, but this increase in the natural frequency for the first five modes will be neglected after 10 layers. And it is observed that the natural frequency of a composite laminated plate will change with the change of ply orientation, the natural frequency increases and it will be at maximum with angle 45 of ply for simply supported laminated plate, and maximum natural frequency will be with cross-ply (0/90) for fixed laminated composite plate. It is also observed that the natural frequency increase is approximately doubled when the thickness is doubled.Keywords: laminated plate, orthotropic plate, square plate, natural frequency (free vibration), composite (graphite / epoxy)
Procedia PDF Downloads 348886 Stipagrostis ciliata (Desf.) De Winter: A Promising Pastoral Species for Ecological Restoration in North African Arid Bioclimate
Authors: Lobna Mnif Fakhfakh, Mohamed Chaieb
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Most ecological studies in North Africa reveal a process of continuous degradation of pastoral ecosystems as a result of overgrazing. This degradation appears across the depletion of perennial grass species. Indeed, the majority of steppic ecosystems are characterized by a low density of perennial grasses. This phenomenon reveals a drop in food value of rangelands, which is now estimated at less than 100 UF.ha -1. -1 Year in all North African steppes. However, for ecological restoration initiatives, some species such the genus of Stipagrostis and Stipa can be considered a good candidates species for effective pastoral improvement under arid bioclimate. The present work concerns Stipagrostis ciliata (Desf.) De Winter, perennial grasses, abundant in ecosystems characterized by the high content of gypsum (CaSO4)2H2O in the southern Tunisia. This tufted species with C4 biochemical photosynthesis type is able to grow and develop under high temperature and low annual rainfall, where the minimum water potential (ψmd), can reach -4 MPa during the summer season with a phenological growth maintained throughout the season unfavorable. At this point in the early autumn rains, S. ciliata begins its growth, especially with a heading which occurs 2-3 weeks after the first autumn rains. From the foregoing, it can be concluded that Stipagrostis ciliata is an excellent promising pastoral species for the ecological restoration, and enhancement of ecosystems biological productivity in arid bioclimate of North Africa.Keywords: Stipagrostis ciliata, pastoral species, ecological restoration, arid bioclimate
Procedia PDF Downloads 416885 The Relationship between Life Event Stress, Depressive Thoughts, and Working Memory Capacity
Authors: Eid Abo Hamza, Ahmed Helal
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Purpose: The objective is to measure the capacity of the working memory, ie. the maximum number of elements that can be retrieved and processed, by measuring the basic functions of working memory (inhibition/transfer/update), and also to investigate its relationship to life stress and depressive thoughts. Methods: The study sample consisted of 50 students from Egypt. A cognitive task was designed to measure the working memory capacity based on the determinants found in previous research, which showed that cognitive tasks are the best measurements of the functions and capacity of working memory. Results: The results indicated that there were statistically significant differences in the level of life stress events (high/low) on the task of measuring the working memory capacity. The results also showed that there were no statistically significant differences between males and females or between academic major on the task of measuring the working memory capacity. Furthermore, the results reported that there was no statistically significant effect of the interaction of the level of life stress (high/low) and gender (male/female) on the task of measuring working memory capacity. Finally, the results showed that there were significant differences in the level of depressive thoughts (high/low) on the task of measuring working memory. Conclusions: The current research concludes that neither the interaction of stressful life events, gender, and academic major, nor the interaction of depressive thoughts, gender, and academic major, influence on working memory capacity.Keywords: working memory, depression, stress, life event
Procedia PDF Downloads 161884 Vehicle Gearbox Fault Diagnosis Based on Cepstrum Analysis
Authors: Mohamed El Morsy, Gabriela Achtenová
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Research on damage of gears and gear pairs using vibration signals remains very attractive, because vibration signals from a gear pair are complex in nature and not easy to interpret. Predicting gear pair defects by analyzing changes in vibration signal of gears pairs in operation is a very reliable method. Therefore, a suitable vibration signal processing technique is necessary to extract defect information generally obscured by the noise from dynamic factors of other gear pairs. This article presents the value of cepstrum analysis in vehicle gearbox fault diagnosis. Cepstrum represents the overall power content of a whole family of harmonics and sidebands when more than one family of sidebands is present at the same time. The concept for the measurement and analysis involved in using the technique are briefly outlined. Cepstrum analysis is used for detection of an artificial pitting defect in a vehicle gearbox loaded with different speeds and torques. The test stand is equipped with three dynamometers; the input dynamometer serves as the internal combustion engine, the output dynamometers introduce the load on the flanges of the output joint shafts. The pitting defect is manufactured on the tooth side of a gear of the fifth speed on the secondary shaft. Also, a method for fault diagnosis of gear faults is presented based on order cepstrum. The procedure is illustrated with the experimental vibration data of the vehicle gearbox. The results show the effectiveness of cepstrum analysis in detection and diagnosis of the gear condition.Keywords: cepstrum analysis, fault diagnosis, gearbox, vibration signals
Procedia PDF Downloads 379883 Writing Hybridized Narratives to Enact Scientific Literacy and the Myth of the Scientific Method
Authors: Ajaz Shaheen, Jawaid Ahmed Siddqui
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This world has purely become scientific and technological, and therefore it demands more from our young learners to be more intellectual in learning sciences. A point of concern that is dragging the attention of educationists is that young learners are gradually detaching from science and scientific theory. To deal with this matter, we must arrange such engaging activities that may improve the imaginative skills of our young learners. Our ongoing research program highlights the effects of such activities that demand the learners to interpret scientific information in the form of text they possess. These mixed stories are also known as what we call BioStories. Learners upload their narratives on different websites to let their peers go through their manuscripts. That, as a result, brings more refinement to their works. Moreover, stories allow the learners to read, understand and learn on a broader spectrum. We have conducted separate studies with learners from Grades 6, 9, and 12 that involve case studies and quasi-experimental designs. The conclusion we drew from the analysis of Grade 6 learners was that the alignment of stories helped them become more familiar with the scientific issue. Not only this but also the learners of the respective grade built up their interest in the subject and also developed a clear understanding of related subject topics. On the other hand, results from the 8th and 9th grades study support the argument that learners reflected a positive attitude toward writing scientific information. Lastly, we concluded from the 12th-grade learners that they took pride in their writing skills and built up their strength, determination, and interest. The students became self-conscious as they wrote hybridized scientific narratives in science.Keywords: BioStories, hybridized writing, scientific literacy, scientific method
Procedia PDF Downloads 79882 Thermo-Mechanical Behavior of Steel-Wood Connections of Wooden Structures Under the Effect of a Fire
Authors: Ahmed Alagha, Belkacem Lamri, Abdelhak Kada.
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Steel-wood assemblies often have complex geometric configurations whose overall behavior under the effect of a fire is conditioned by the thermal response, by combining the two materials steel and wood, whose thermal characteristics are greatly influenced by high temperatures. The objective of this work is to study the thermal behavior of a steel-wood connection, with or without insulating material, subjected to an ISO834 standard fire model. The analysis is developed by the analytical approach using the Eurocode, and numerically, by the finite element method, through the ANSYS calculation code. The design of the connections is evaluated at room temperature taking the cases of single shear and double shear. The thermal behavior of the connections is simulated in transient state while taking into account the modes of heat transfer by convection and by radiation. The variation of temperature as a function of time is evaluated in different positions of the connections while talking about the heat produced and the formation of the carbon layer. The results relate to the temperature distributions in the connection elements as a function of the duration of the fire. The results of the thermal analysis show that the temperature increases rapidly and reaches more than 260 °C in the steel material for an hour of exposure to fire. The temperature development in wood material is different from that in steel because of its thermal properties. Wood heats up on the outside and burns, its surface can reach very high temperatures in points on the surface.Keywords: Eurocode 5, finite elements, ISO834, simple shear, thermal behaviour, wood-steel connection
Procedia PDF Downloads 86881 Optical Emission Studies of Laser Produced Lead Plasma: Measurements of Transition Probabilities of the 6P7S → 6P2 Transitions Array
Authors: Javed Iqbal, R. Ahmed, M. A. Baig
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We present new data on the optical emission spectra of the laser produced lead plasma using a pulsed Nd:YAG laser at 1064 nm (pulse energy 400 mJ, pulse width 5 ns, 10 Hz repetition rate) in conjunction with a set of miniature spectrometers covering the spectral range from 200 nm to 720 nm. Well resolved structure due to the 6p7s → 6p2 transition array of neutral lead and a few multiplets of singly ionized lead have been observed. The electron temperatures have been calculated in the range (9000 - 10800) ± 500 K using four methods; two line ratio, Boltzmann plot, Saha-Boltzmann plot and Morrata method whereas, the electron number densities have been determined in the range (2.0 – 8.0) ± 0.6 ×1016 cm-3 using the Stark broadened line profiles of neutral lead lines, singly ionized lead lines and hydrogen Hα-line. Full width at half maximum (FWHM) of a number of neutral and singly ionized lead lines have been extracted by the Lorentzian fit to the experimentally observed line profiles. Furthermore, branching fractions have been deduced for eleven lines of the 6p7s → 6p2 transition array in lead whereas the absolute values of the transition probabilities have been calculated by combining the experimental branching fractions with the life times of the excited levels The new results are compared with the existing data showing a good agreement.Keywords: LIBS, plasma parameters, transition probabilities, branching fractions, stark width
Procedia PDF Downloads 283880 Characterization of the Immune Response of Inactivated RVF Vaccine: A Comparative Study in Sheep and Goats as Experimental Model
Authors: Ahmed Zaghawa
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Rift Valley Fever is an economically specific disease of the health and arboviral disease that affects many types of animals, causing significant economic losses in livestock, and it is transmitted to humans and has public health issues. The vaccine program is the backbone for the control of this disease. The goal of this study was to apply a new approach to evaluate the inactivated RVF vaccine developed in Egypt. In this study, the RVF vaccine was evaluated in young puppies and compared with sheep; the findings showed that young puppies were susceptible to infection with the inhibitory RVF virus and had a strong response of antibodies with two doses of the RVF vaccine within the two-week interval. The neutralization indices began to appear to the protective level on the 7th day at 1.35 and steadily elevated at 14,21 and 28 days to 1.35, 1.43, and 1.20, respectively, in comparison to the control group. While in sheep, the neutralization indices began to appear to the protective level on the 7th day at 1.10 and remain strongly at high titer at 14, 21, and 28 days with NI values 1.20, 1.50, and 1.50, respectively. The new approach for comparing the immune response in puppies and sheep via SNT indicated the high response in both species was evident as well as the neutralization indices values in young puppies at different periods after RVF vaccination reported the value of 1.08±0.03, 1.23±0.04, 1.30±0.03, and 1.45±0.02 after 7, 14, 21, and 28 days post-vaccination respectively. On the other side, a nearly similar immune response was noticed in sheep with NI values of 1.15±0.02, 1.27±0.02, 1.42±0.05, and 1.55±0.03 at 7, 14, 21, and 28 days post-vaccination, respectively. In conclusion, young puppies are similar to sheep in developing antibodies after vaccination with the RVF vaccine and can replace sheep for evaluating the efficacy of the RVF vaccine. Further studies are mandatory to assess more recent methods for evaluating inhibition of the RVF vaccine.Keywords: immune response, puppies, RVF, sheep, vaccine
Procedia PDF Downloads 176879 An Institutional Leadership Framework on University Academics’ Decision to Become Institutional Leaders: A Malaysian Perspective
Authors: Norazharuddin Shah Abdullah, Harshita Aini Haroon, Norazian Mohmad Azman, Erlane K. Ghani, Ismie Roha Mohamed Jais, Kamaruzzaman Muhammad, Azleen Ilias
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This study examines the factors that influence academics' decisions to accept or decline leadership roles in Malaysian universities. A questionnaire survey was distributed to a total of 1771 academics from public and private institutions in Malaysia. This study shows that the majority of academics in universities, regardless of whether they are public or private, have a reluctance to take on administrative roles. In particular, this study shows that female academics in public universities have no ambition for administrative roles, while female academics in private universities show a strong enthusiasm for taking up administrative positions. In terms of age, academics of all age groups made comparable choices, but academics who are under 30 years old have a greater propensity to aspire to an administrative position. Associate professors at private universities also opt for an administrative position. The factors that influence academics' decisions to accept or decline an administrative position are categorised into five categories: career development, skills and experience, preferences, perceptions, and organization. The findings of this study suggest that the increasing number of academics not seeking institutional leadership positions is a concern, as universities need a sufficient pool of potential successors to effectively fulfil the purpose and vision of the university. This study suggests the implementation of awareness and training initiatives to inspire academics, especially young academics, to take up leadership roles within the institutions.Keywords: academics, institutional leadership, leadership, universities, Malaysia
Procedia PDF Downloads 60878 Phenological Variability among Stipagrostis ciliata Accessions Growing under Arid Bioclimate of Southern of Tunisia
Authors: Lobna Mnif Fakhfakh, Mohamed Chaieb
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Most ecological studies in North Africa arid bioclimate reveal a process of continuous degradation of pastoral ecosystems as a result of overgrazing during a long time. This degradation appears across the depletion of perennial grass species. Indeed, the majority of steppe ecosystems are characterized by a low density of perennial grasses. The objective of the present work is to examine the phenology and the above ground growth of several Stipagrostis ciliata accessions, growing under different arid bioclimate of North Africa (case of Tunisia). The results of the ANOVA test, next to the mean values of all measurements show significant differences in all morphological parameters of S. ciliata accessions. Plant diameter, biovolume, root biomass with protective sleeve and spike number show very significant. Differences between S. ciliata accessions. Significance tests for the differences of means indicate high distinctiveness of accessions. Pearson’s correlation analysis of the morphological traits suggests that these traits are significantly and positively correlated. Cluster analysis indicates overall differences among accessions and exhibits the presence of three clusters. The Principal component analysis (PCA) is applied on a table with four observations and 12 variables. Dispersion of Stipagrostis ciliata accessions on the first two axes of principal component analysis confirms the presence of three groups of plants. The characterization of Stipagrostis ciliata plants has shown that significant differences exist in terms of morphological and phenological parameters.Keywords: accession, morphology, phenology, Stipagrostis ciliata
Procedia PDF Downloads 254877 Comparative Analysis of Hybrid Dynamic Stabilization and Fusion for Degenerative Disease of the Lumbosacral Spine: Finite Element Analysis
Authors: Mohamed Bendoukha, Mustapha Mosbah
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The Radiographic apparent assumed that the asymptomatic adjacent segment disease ASD is common after lumbar fusion, but this does not correlate with the functional outcomes while compensatory increased motion and stresses at the adjacent level of fusion is well-known to be associated to ASD. Newly developed, the hybrid stabilization are allocated to substituted for mostly the superior level of the fusion in an attempt to reduce the number of fusion levels and likelihood of degeneration process at the adjacent levels during the fusion with pedicle screws. Nevertheless, its biomechanical efficiencies still remain unknown and complications associated with failure of constructs such screw loosening and toggling should be elucidated In the current study, a finite element (FE) study was performed using a validated L2/S1 model subjected to a moment of 7.5 Nm and follower load of 400 N to assess the biomedical behavior of hybrid constructs based on dynamic topping off, semi rigid fusion. The residual range of motion (ROM), stress distribution at the fused and adjacent levels, stress distribution at the disc and the cage-endplate interface with respect to changes of bone quality were investigated. The hybrid instrumentation was associated with a reduction in compressive stresses compared to the fusion construct in the adjacent-level disc and showed high substantial axial force in the implant while fusion instrumentation increased the motion for both flexion and extension.Keywords: intervertebral disc, lumbar spine, degenerative nuclesion, L4-L5, range of motion finite element model, hyperelasticy
Procedia PDF Downloads 185876 Developing Performance Model for Road Side Elements Receiving Periodic Maintenance
Authors: Ayman M. Othman, Hassan Y. Ahmed, Tallat A. Ali
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Inadequate maintenance programs and funds allocated for highway networks in the developed countries have led to fast deterioration of road side elements. Therefore, this research focuses on developing a performance model for road side elements periodic maintenance activities. Road side elements that receive periodic maintenance include; earthen shoulder, road signs and traffic markings. Using the level of service concept, the developed model can determine the optimal periodic maintenance intervals for those elements based on a selected level of service suitable with the available periodic maintenance budget. Data related to time periods for progressive deterioration stages for the chosen elements were collected. Ten maintenance experts in Aswan, Sohag and Assiut cities were interviewed for that purpose. Time in months related to 10%, 25%, 40%, 50%, 75%, 90% and 100% deterioration of each road side element was estimated based on the experts opinion. Least square regression analysis has shown that a power function represents the best fit for earthen shoulders edge drop-off and damage of road signs with time. It was also evident that, the progressive dirtiness of road signs could be represented by a quadratic function an a linear function could represent the paint degradation nature of both traffic markings and road signs. Actual measurements of earthen shoulder edge drop-off agree considerably with the developed model.Keywords: deterioration, level of service, periodic maintenance, performance model, road side element
Procedia PDF Downloads 572875 Effect of Inspiratory Muscle Training on Diaphragmatic Strength Following Coronary Revascularization
Authors: Abeer Ahmed Abdelhamed
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Introduction: Postoperative pulmonary complications (PPCs) are the most common complications observed and managed after abdominal or cardiothoracic surgery. Hypoxemia, atelectasis, pleural effusion, or diaphragmatic dysfunction, are often a source of morbidity in cardiac surgery patients, and are more common in patients receiving unilateral or bilateral internal mammary artery (IMT) grafts than patients receiving saphenous vein (SV) grafts alone. Purpose: The aim of this work was to investigate the effect of Threshold load inspiratory muscle training on pulmonary gas exchange and maximum inspiratory pressure (MIP) in patient undergoing coronary revascularization. Subject: Thirty three male patients eligible for coronary revascularization were selected to participate in the study. Method: They were divided into two groups(17 patients in the intervention group and 16 patients in the control group), the interventional group received inspiratory muscle training at 30% of their maximum inspiratory pressure throughout the hospitalization period in addition to routine post operative care. Result: The results of this study showed a significant improvement on maximum inspiratory pressure(MIP), Arterial-alveolar pressure gradient (A-a gradient) and oxygen saturation in the intervention group. Conclusion: Inspiratory muscle training using threshold mode significantly improves maximum inspiratory pressure, pulmonary gas exchange tested by alveolar-arterial gradient and oxygen saturation in Patients undergoing coronary revascularization.Keywords: coronary revascularization, inspiratory muscle training, maximum inspiratory pressure, pulmonary gas exchange
Procedia PDF Downloads 300874 Challenges in Creating Social Capital: A Perspective of Muslim Female Managers in Malaysia
Authors: Zubeida Rossenkhan, Pervaiz K. Ahmed, Wee Chan Au
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In view of cross cultural career experiences, to the author’s best knowledge, the crucial role of culture and religious traditions in Asia remains understudied. Drawing on the notion of social capital as an invaluable resource needed for manager’s to progress, the purpose of this study is to probe the contextual experiences of Muslim women to elucidate unique challenges associated with social capital and career progress. Twenty-three in-depth interviews with top level Malay managers were conducted to probe experiences of upward career mobility and inequities in the workplace. Interpretive phenomenology was used to surface unique challenges and processes of creating and leveraging social capital. The study uncovers the unique challenges of Muslim women in Malaysia. Narratives of participants highlight not only generic forms of gender discrimination, but also culturally specific stereotypes and social expectations limiting their advancement. Interestingly, the findings identify a gender-religion handicap in the form of perceived inequality and restrictions rooted from the women manager’s gender and religion. The analysis also reveals how these Muslim women managers’ negotiate their challenges, especially how they access social capital and progress their careers. The research offers a unique perspective on the career experiences of Malay women managers’ in top management. The research provides insight into the unique processes of developing social capital utilized by this group of women for career success.Keywords: career success, gender discrimination, malaysia, Muslim women, social capital
Procedia PDF Downloads 130873 Behavior of Composite Reinforced Concrete Circular Columns with Glass Fiber Reinforced Polymer I-Section
Authors: Hiba S. Ahmed, Abbas A. Allawi, Riyadh A. Hindi
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Pultruded materials made of fiber-reinforced polymer (FRP) come in a broad range of shapes, such as bars, I-sections, C-sections, and other structural sections. These FRP materials are starting to compete with steel as structural materials because of their great resistance, low self-weight, and cheap maintenance costs-especially in corrosive conditions. This study aimed to evaluate the effectiveness of Glass Fiber Reinforced Polymer (GFRP) of the hybrid columns built by combining (GFRP) profiles with concrete columns because of their low cost and high structural efficiency. To achieve the aims of this study, nine circular columns with a diameter of (150 mm) and a height of (1000mm) were cast using normal concrete with compression strength equal to (35 MPa). The research involved three different types of reinforcement: hybrid circular columns type (IG) with GFRP I-section and 1% of the reinforcement ratio of steel bars, hybrid circular columns type (IS) with steel I-section and 1% of the reinforcement ratio of steel bars, (where the cross-section area of I-section for GFRP and steel was the same), compared with reference column (R) without I-section. To investigate the ultimate capacity, axial and lateral deformation, strain in longitudinal and transverse reinforcement, and failure mode of the circular column under different loading conditions (concentric and eccentric) with eccentricities of 25 mm and 50 mm, respectively. In the second part, an analytical finite element model will be performed using ABAQUS software to validate the experimental results.Keywords: composite, columns, reinforced concrete, GFRP, axial load
Procedia PDF Downloads 55872 Novel Poly Schiff Bases as Corrosion Inhibitors for Carbon Steel in Sour Petroleum Conditions
Authors: Shimaa A. Higazy, Olfat E. El-Azabawy, Ahmed M. Al-Sabagh, Notaila M. Nasser, Eman A. Khamis
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In this work, two novel Schiff base polymers (PSB1 and PSB₂) with extra-high protective barrier features were facilely prepared via Polycondensation reactions. They were applied for the first time as effective corrosion inhibitors in the sour corrosive media of petroleum environments containing hydrogen sulfide (H₂S) gas. For studying the polymers' inhibitive action on the carbon steel, numerous corrosion testing methods including potentiodynamic polarization (PDP), open circuit potential, and electrochemical impedance spectroscopy (EIS) have been employed at various temperatures (298-328 K) in the oil wells formation water with H₂S concentrations of 100, 400, and 700 ppm as aggressive media. The activation energy (Ea) and other thermodynamic parameters were computed to describe the mechanism of adsorption. The corrosion morphological traits and steel samples' surfaces composition were analyzed by field emission scanning electron microscope and energy dispersive X-ray analysis. The PSB2 inhibited sour corrosion more effectively than PSB1 when subjected to electrochemical testing. The 100 ppm concentration of PSB2 exhibited 82.18 % and 81.14 % inhibition efficiencies at 298 K in PDP and EIS measurements, respectively. While at 328 K, the inhibition efficiencies were 61.85 % and 67.4 % at the same dosage and measurements. These poly Schiff bases exhibited fascinating performance as corrosion inhibitors in sour environment. They provide a great corrosion inhibition platform for the sustainable future environment.Keywords: schiff base polymers, corrosion inhibitors, sour corrosive media, potentiodynamic polarization, H₂S concentrations
Procedia PDF Downloads 100871 Stabilization of Medical Waste Incineration Fly Ash in Cement Mortar Matrix
Authors: Tanvir Ahmed, Musfira Rahman, Rumpa Chowdhury
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We performed laboratory experiments to assess the suitability of using medical waste incineration fly ash in cement as a construction material based on the engineering properties of fly ash-cement matrix and the leaching potential of toxic heavy metals from the stabilized mix. Fly ash-cement samples were prepared with different proportions of fly ash (0%, 5%, 10%, 15% and 20% by weight) in the laboratory controlled conditions. The solidified matrix exhibited a compressive strength from 3950 to 4980 psi when fly ash is mixed in varying proportions. The 28-day compressive strength has been found to decrease with the increase in fly ash content, but it meets the minimum requirement of compressive strength for cement-mortar. Soundness test results for cement-mortar mixes having up to 15% fly ash. Final and initial setting times of cement have been found to generally increase with fly ash content. Water requirement (for normal consistency) also increased with the increase in fly ash content in cement. Based on physical properties of the cement-mortar matrix it is recommended that up to 10% (by weight) medical waste incineration fly ash can be incorporated for producing cement-mortar of optimum quality. Leaching behaviours of several targeted heavy metals (As, Cu, Ni, Cd, Pb, Hg and Zn) were analyzed using Toxicity Characteristics Leaching Procedure (TCLP) on fly ash and solidified fly ash-cement matrix. It was found that the leached concentrations of As, Cu, Cd, Pb and Zn were reduced by 80.13%, 89.47%, 33.33% and 23.9% respectively for 10% fly ash incorporated cement-mortar matrix compared to that of original fly ash. The leached concentrations of heavy metals were from the matrix were far below the EPA land disposal limits. These results suggest that the solidified fly ash incorporated cement-mortar matrix can effectively confine and immobilize the heavy metals contained in the fly ash.Keywords: cement-mortar, fly ash, leaching, waste management
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