Hussein M Elmehdi

Hussein M Elmehdi
University of Sharjah | US · Department of Applied Physics

PhD BioMedical Physics

About

41
Publications
5,558
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285
Citations

Publications

Publications (41)
Conference Paper
The aim of the work is to evaluate and compare image quality obtained using different digital radiography systems with reference to size distortion, contrast and noise. An anthropomorphic pediatric head phantom was utilized and scanned using a general radiography machine that uses a digital direct detector, a portable radiography also uses a digita...
Conference Paper
The aim of the present work is to assess the effect of window width and window level selection on feature size in a 2D displayed multimodality images. DICOM images of CT, MR and PET were retrieved and retrospectively analyzed using a local PACS system running an image manipulation software AGFA NX v2.0 that supports several windows for each image m...
Conference Paper
Full-text available
In a previous study, the noise levels in classrooms and lecture halls at the University of Sharjah (UOS), United Arab Emirates (UAE) were identified as high and in many cases above the standard limits. To assess the effect of such high noise levels on students, we have conducted a campus-wide subjective survey to investigate the effects of such noi...
Chapter
Exposure to noise has received considerable attention in the past few years in the United Arab Emirates (UAE). It is now widely recognized among researchers in the field and local authority that noise is one the main environmental pollutions in the UAE. In addition, the number of complaints from people exposed to noise continues to increase. This i...
Research
The objective of this paper is to investigate the effectiveness of the Web-Based Homework (WBH) systems on the performance of University of Sharjah (UAE) students. We have investigated: 1) student perceptions and acceptability of WBH systems; 2) compare the students? performance in homework assignments conducted using WBH systems and conventional...
Research
The objective of this paper is to investigate the effectiveness of the Web-Based Homework (WBH) systems on the performance of University of Sharjah (UAE) students. We have investigated: 1) student perceptions and acceptability of WBH systems; 2) compare the students? performance in homework assignments conducted using WBH systems and conventional...
Conference Paper
Full-text available
Residents of major cities of the United Arab Emirates are exposed to multiple noise sources originating from road traffic, aircraft flyovers and various industrial activities. Predicting the contribution of each of these sources to public annoyance, and hence relating it to health effects on residents of these cities, is not an easy task because of...
Chapter
Previous research on noise levels arising form residential road traffic in the City of Sharjah, United Arab Emirates (UAE) has shown that noise levels in the city is high, exceeding national as well as international noise limits and standards. These studies have linked noise exposure in residential-industrial mixed area with annoyance, which is an...
Article
Full-text available
In a previous publication, noise effects on patients visiting these clinics were reported. In this paper, we report the effect of noise levels in dental clinics on professionals working in these clinics. Our approach included conducting surveys and interviews in a number of UAE dental clinics. Out of the 200 surveys distributed, 177 surveys were co...
Article
The objective of this paper is to investigate the effectiveness of the Web-Based Homework (WBH) systems on the performance of University of Sharjah (UAE) students. We have investigated: 1) student perceptions and acceptability of WBH systems; 2) compare the students? performance in homework assignments conducted using WBH systems and conventional p...
Article
Purpose: To probe the thermal and structural properties of gluten proteins using ultrasound. Methods: A new ultrasonic approach for characterizing the quality of wheat gluten proteins is described. Low frequency (50 kHz) longitudinal ultrasonic velocity, v L, measurements were performed on gluten samples extracted from three wheat flours differi...
Article
According to Airport Council International (ACI) traffic statistics for 2002, Dubai International Airport is the second fastest growing airport in the world. In 2007, it catered to more than 36 million passengers, with approximately 1,000 daily flight events, including takeoffs and landings. In this paper, we report the first assessment of communit...
Article
Previous research has identified noise as a source of concern in schools, where noise has been found to impact not only learning, but also have adverse health affects such loss of concentration, irritation and tiredness. No studies have been conducted in the UAE to assess noise levels in and outside the classroom. In this paper, we report prelimina...
Article
We report the first indoor radon concentration measurements in the coastal city of Sharjah, United Arab Emirates (UAE). The measurements were carried out using an active radon detector in the living rooms in 61 houses in various parts of the city following the EPA protocol. Radon concentrations were found to range between 7 and 71 Bq/m3 in the wint...
Article
High noise levels were previously reported in residential-industrial mixed districts in the city of Shrajah, United Arab Emirates (UAE), which exceeded national as well as international permissible noise limits. Reasons for such high noise levels are mainly due to the exponential increase in the number of vehicles on the roads, frequent traffic jam...
Chapter
Since breadmaking can be viewed as a set of process operations where bubble numbers and sizes in dough are controlled, it is highly desirable to have tools that can non-invasively monitor the presence of bubbles in dough, their subsequent growth and effect on dough's mechanical properties, and the cellular structure that they create in the resultin...
Article
Producing an aerated bread dough starts at the mixing stage where air bubble nuclei are incorporated into the dough. During fermentation, the production of CO2, due to yeast's metabolic activities, causes the bubbles to increase in size thereby increasing the volume and reducing the density. Therefore, the way in which the density of the dough is r...
Chapter
We report the results of ultrasonic frequency profile measurements performed on unyeasted dough samples of different bubble concentrations. The bubble concentration was controlled by mixing the dough under two different headspace pressures. The longitudinal ultrasonic velocity, VL, and attenuation coefficient, α, were measured in the frequency rang...
Article
In the paper written by Joiner (IJROBP 2004; 58(3): 871–875), entitled A simple α/β‐independent method to derive fully isoeffective effective schedules following a change in dose per fraction, the author derived two mathematical expressions by which dosimetric errors in delivering the prescribed dose per fraction in a treatment can be corrected for...
Article
Full-text available
Cereal Chem. 81(4):504–510 Mixing is critical to attainment of a desirable gas cell distribution in dough. By varying mixer headspace pressure, changes in the mechanical properties of dough were investigated as a function of the dough's void concentration using low frequency (50 kHz) ultrasonic techniques. For the mixer used, this allowed the volum...
Article
We use low frequency ultrasonic waves (50 kHz) to investigate the mechanical properties of anisotropic freeze-dried bread foams that were prepared by applying uniaxial stress to fresh breadcrumb. Longitudinal ultrasonic velocity and amplitude measurements were taken in directions parallel and perpendicular to the compression direction. The velocity...
Article
Fermentation of the sugars in bread dough produces carbon dioxide which diffuses through the dough matrix into the gas cell nuclei formed during dough mixing. As a result, the void fraction of the dough increases and dough density decreases. It is shown in this paper that low intensity ultrasound can be used to monitor changes in the void fraction...
Article
In this paper, ultrasonic techniques were used to study how the mechanical properties of bread crumb are affected by changing the size, concentration and shape of the crumb cells. Since the gas cells determine the structural integrity of the bread crumb, these effects can form the basis of methods for predicting loaf quality, and hence are of consi...
Article
Full-text available
Low frequency (54 kHz) longitudinal ultrasonic velocity, v l , measurements were performed on the gluten of three wheat varieties (extracted from strong spring, soft spring and winter wheat flours). For the three samples, the magnitude of v l was found to change considerably when the temperature of the gluten was raised from 20 o C to 90 o C. Conti...
Article
Dynamic rounding of the susceptibility in strong Random-Field (RF) samples of Dy(AsxV1−x)O4 has been observed in the critical region using ultrasonic velocity measurements. In weaker random fields, however, the dynamics do not mask the static critical behaviour, enabling an accurate measurement, γ=1.80±0.07, to be made of the RF susceptibility crit...
Article
Full-text available
Two ultrasonic parameters that give information about the structural properties of materials are the longitudinal ultrasonic velocity, vL, and the attenuation coefficient, α. The sensitivity of these parameters to gas bubbles means that ultrasound is ideal for investigating the properties of baked foods where cell structure is a vital component of...

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Projects (2)
Project
Evaluating patient dose undergoing CT examinations