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Search Results: 1 - 10 of 401281 matches for " Abdulrhman M. Dhabbah "
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Ways of Analysis of Fire Effluents and Assessment of Toxic Hazards  [PDF]
Abdulrhman M. Dhabbah
Journal of Analytical Sciences, Methods and Instrumentation (JASMI) , 2015, DOI: 10.4236/jasmi.2015.51001
Abstract: Fire effluents, in most cases, have an adverse effect on human health and the environment. Exposure to some compounds may show both acute and chronic toxicity. There is a lack of knowledge on the effect of organic products on the human body in terms of the rate of organic material production in fires and their degree of toxicity. Thus, there is a need to expand the scope of studies about the organic products generated from fires and improve the methods of assessment to be included as part of fire hazard assessment. Different factors can be contributed to this lack of knowledge. For example, the composition of organic products generated from fires changes progressively and rapidly with progression of combustion and in a manner that is dependent on the fire condition. It is difficult to identify individual organic compounds produced during combustion. Another key factor is the lack of suitable instruments for measuring organic products generated from a fire. Also, the lack of procedures that are used to evaluate the lethal concentration limits and the lethal dose for a broad range of organic compounds generated from a fire may be another important factor which can be contributed to this lack of knowledge.
Comparison of Different Sampling Techniques for the Identification of Aromatic Hydrocarbons from Fire Effluents  [PDF]
Abdulrhman M. Dhabbah, A. Yacine Badjah-Hadj-Ahmed, Anna A. Stec, T. Richard Hull
American Journal of Analytical Chemistry (AJAC) , 2019, DOI: 10.4236/ajac.2019.101003
Abstract: Huge amounts of various polymers are being used in many fields with numerous benefits. However, their great ability to ignition and rapid flame spreading make these materials dangerous for human life and properties due to the release of highly toxic combustion products. The present work aims to investigate several methods of sampling and identification of aromatic hydrocarbons produced by controlled burning of low-density polyethylene (LDPE) using a toxicity tube furnace. Five different sampling methods were used: solid phase micro extraction (SPME), syringe, tedlar bags, sorption tubes, and gas-solution absorbers (midget impingers). The produced hydrocarbons were analysed by gas chromatography coupled to mass spectrometry with and without pyrolysis. Among the tested techniques, the most convenient sampling method was using syringe with a glass vessel which allowed detection of the highest amount of aromatic hydrocarbons at both 800°C and 600°C, and then followed by SPME. On the other hand, the use of gas-solution absorber (midget impinger) showed poorer results. Regarding the use of tedlar bags and sorption tubes, they did not give satisfactory results. Several carcinogenic or possibly carcinogenic compounds were identified in the combustion products, such as benzene, naphthalene, anthracene and pyrene.
Surface Roughness Quality and Dimensional Accuracy—A Comprehensive Analysis of 100% Infill Printed Parts Fabricated by a Personal/Desktop Cost-Effective FDM 3D Printer  [PDF]
Mohammad S. Alsoufi, Abdulrhman E. Elsayed
Materials Sciences and Applications (MSA) , 2018, DOI: 10.4236/msa.2018.91002
Abstract: Fused deposition modeling (FDM) has become widely used for personal/ desktop cost-effective printers. This work presents an investigational platform, which is used to study the surface roughness quality, and dimensional accuracy of 100% infill density printed parts fabricated by a personal/desktop cost-effective FDM 3D printer using different types of thermoplastic filament materials namely, PLA, PLA+, ABS and ABS+. Varieties of experiments were conducted after the fabricated parts were naturally cooled down for at least three hours to room temperature. During printing work, the nozzle diameter, layer height, nozzle temperature and printing speed were set at 0.3 mm, 0.1 mm, 220°C and 30 mm/s, respectively. According to the experimentally obtained data results over 10 mm scanned profile and 90° measuring direction (perpendicular to building direction), PLA+ thermoplastic filament material shows an excellent surface behaviour and is found to be more accurate while ABS does exhibit high surface roughness, waviness and primary behaviour. Both PLA and ABS+ show good surface performance.
Toward Recovering Complete SRS for Softbody Simulation System and a Sample Application - a Team 4 SOEN6481-W13 Project Report
Oualid El Halimi,Peyman Derafshkavian,Abdulrhman Albeladi,Faisal Alrashdi
Computer Science , 2013,
Abstract: This document gathers high-level users requirements and describes the system features. It provides a detailed explanation of the main functionalities of the system with a more emphasis on the stakeholders needs and wants. Indeed, the document goes through design constraints that may restrict various aspects of the design and implementation.
Sedative Drug Use among King Saud University Medical Students: A Cross-Sectional Sampling Study
Ahmed A. Al-Sayed,Abdualltef H. Al-Rashoudi,Abdulrhman A. Al-Eisa,Abdullah M. Addar,Abdullah H. Al-Hargan,Albaraa A. Al-Jerian,Abdullah A. Al-Omair,Ahmed I. Al-Sheddi,Hussam I. Al-Nowaiser,Omar A. Al-Kathiri,Abdullah H. Al-Hassan
Depression Research and Treatment , 2014, DOI: 10.1155/2014/378738
Abstract: Introduction. Medical students experience significant psychological stress and are therefore at higher risk of using sedatives. There are currently no studies describing the prevalence of sedative drug use among medical students in Saudi Arabia. The aim of this study was to evaluate the prevalence and factors associated with sedative drug use among medical students in Saudi Arabia. Materials and Methods. A cross-sectional convenience sampling study gathered data by anonymous questionnaire from students enrolled at the King Saud University College of Medicine in 2011. The questionnaires collected data regarding social and demographic variables, sleep patterns, and the use of stimulant and sedative drugs since enrollment. Sedatives were defined as any pharmaceutical preparations that induce sleep. Results and Discussion. Of the 729 students who returned questionnaires, 17.0% reported sedative drug use at some time since enrollment. Higher academic year, lower grade point average, regular exercise, fewer hours of sleep per day, poorer quality of sleep, and the presence of sleeping disorders were found to be significantly associated with sedative drug use. Conclusions. Further study is required to increase our understanding of sedative drug use patterns in this relatively high-risk group, as such understanding will help in the development of early intervention programs. 1. Introduction The evidence base linking high rates of stress in students in general [1] and medical students in particular [2] is virtually unassailable. This is from both objective [3] and subjective [4] viewpoints. However, it is unclear if there is a significant level of geographical variation in these rates and a lack of data from Saudi Arabia in particular is notable [5]. As a result it is less clear if stress is a significant issue in Saudi medical students, as with other nations, and therefore coping mechanisms in this population are underexplored [5]. Indeed, a literature search reveals no previous studies linking Saudi medical students, stress levels, and coping mechanisms, although one can note the Pani paper [5], which attempted to quantify stress levels in Saudi dental students and concluded that perceived levels of stress did not always correspond with measured biological levels of stress in this group. However, only forty students participated in this study and the authors explored neither psychological aspects nor coping mechanisms associated with stress. Psychological manifestations of stress include conditions such as anxiety, [6] depression, [7, 8] or burnout [9].
Poland-Mobius syndrome in an infant girl
Al-Mazrou Khalid,Al-Ghonaim Yazeed,Al-Fayez Abdulrhman
Annals of Saudi Medicine , 2009,
Abstract: Mobius syndrome is a rare condition of unclear origin, characterized by a unilateral or bilateral congenital facial weakness with impairment of ocular abduction, which is frequently associated with limb anomalies . Poland described a condition in which there was unilateral absence of pectoralis major muscle and ipsilateral syndactyly. The combination of Poland-Mobius syndrome is rare, with an estimated prevalence 1:500 000. We describe a case of Poland-Mobius syndrome in association with congenital bilateral vocal fold immobility. To our knowldge, this is the first report of such an association between Poland-Mobius syndrome and congenital bilateral vocal fold immobility.
A Context Transfer Approach to Enhance Mobile Multicast
International Journal of Computer Science and Security , 2008,
Abstract: With the advent of the handheld devices and multimedia applications, there has been an increasing interest for mobile multicast. IETF proposes two approaches. The first approach is Bi-directional Tunneling (BT), where the mobile node subscribes to a multicast group through its home network. The second approach is Remote Subscription (RS), where the mobile node joins the multicast group via a local multicast router on the foreign link being visited. However, in BT approach the home agent is typical far and this will lead to high signaling cost at the same time the home agent represents a single point of failure and introduces scalability issues. RS approach suffers mainly from frequent tree reconstruction. The main aim for this paper is to propose a new mobile multicast approach to reduce the signaling cost and reduce the packet loss especially in case of macromibiliy. The proposed solution integrates Hierarchical Mobile IPv6 with Mobile context transfer. This paper presents and evaluates the proposed solution. Our results shows that compared to BT approach, the proposed solution gives lower signaling cost.
Toward Refactoring of DMARF and GIPSY Case Studies a Team 7 SOEN6471-S14 Project Report
Abdulrhman Albeladi,Ahmed Almessabi,Aber Abozkhar,Huda Mohamed,Jilson Thomas,Zakaria Alomari
Computer Science , 2014,
Abstract: Software architecture is defined as the process of a well-structured solution that meets all of the technical and operational requirements, as well as improving the quality attributes of the system such as readability, Reliability, maintainability, and performance. It involves a series of design decisions that can have a considerable impact on the systems quality attributes, and on the overall success of the application. In this work, we start with analysis and investigation of two open source software (OSS) platforms DMARF and GIPSY, predominantly implemented in Java. Many research papers have been studied in order to gain more insights and clear background about their architectures, enhancement, evolution, challenges, and features. Subsequently, we extract and find their needs, high-level requirements, and architectural structures which lead to important design decisions and thus influence their quality attributes. Primarily, we reversed engineering each system0s source code to reconstruct its domain model and class diagram model. We tried to achieve the traceability between requirements and other design artifacts to be consistent. Additionally, we conducted both manual and automated refactoring techniques to get rid of some existing code smells to end up with more readable and understandable code without affecting its observable behavior.
Toward Software Measurement and Quality Analysis of MARF and GIPSY Case Studies a Team 13 SOEN6611-S14 Project Report
Abdulrhman Albeladi,Rabe Abdalkareem,Farhat Agwaeten,Khalid Altoum,Youssef Bennis,Zakaria Nasereldine
Computer Science , 2014,
Abstract: It is no longer a debate that quality is an essential requirement in any software product, especially in a highly competitive market and a context of mission critical product. To obtain better product quality, software metrics are the only reliable indicators provided to assess and measure this attribute of a software product. Several metrics have been elaborated but none of them were really convenient in an object oriented ecosystem. However, the MOOD metrics have proven their efficiency in gauging the software quality at system level, while CK Metrics measure the quality of software at class level . These metrics, well suited for Object-Oriented design, allow measuring object oriented design properties such as coupling, cohesion, encapsulation, Inheritance and polymorphism. The goal of the present study is using the mentioned metrics to assess the quality of two different case studies, MARF and GIPSY. For this purpose, different tools such as McCabe, Logiscope and, JDeodorant have been used to measure the quality of these projects by implementing in different manners the metrics composing the CK and MOOD suite metrics, whilst MARFCAT has been used to detect vulnerable code files in both case studies. The present study puts the light on the strengths of these tools to measure the quality of proven and largely researched software products.
Study of Duct Characteristics Deduced from Low Latitude Ground Observations of Day-Time Whistler at Jammu  [PDF]
M. Altaf, M. M. Ahmad
International Journal of Astronomy and Astrophysics (IJAA) , 2013, DOI: 10.4236/ijaa.2013.33032

Propagation characteristics of low latitude whistler duct characteristics have been investigated based on day-time measurements at Jammu. The morphogical characteristics of low latitude whistlers are discussed and compared with characteristics of middle and high latitude whistlers. The Max. electron density (Nm) at the height of the ionosphere obtained from whistler dispersion comes out to be higher than that of the background which is in accordance with the characteristics of whistler duct. The equivalent width is found to be close to the satellite observations and the characteristics of whistler duct in low latitude ionosphere are similar to those in middle and high latitude ionosphere. The width of ducts estimated from the diffuseness of the whistler track observed during magnetic storm is found to lie in the range of 50 - 200 Km.

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