863 research outputs found
Design studies of infrastructural development for applications of hydrogen energy technologies
Countries around the world are trying to reduce their energy consumption, fossil fuel usage, and greenhouse gas (GHG) emissions. According to the International Energy Outlook 2012 released by the U.S. Energy Information Administration (EIA), the estimated fuel economy and greenhouse gas emissions standards proposed for light-duty vehicles for model years 2017-2025 has an increase of 44% in fuel economy and a reduction of 34% in GHG emissions. The use of alternative fuel vehicles and renewable energy sources are, therefore, inevitable toward achieving this goal. Biogas has untapped potential as an alternative energy source. This immediately available resource would allow countries to reduce their greenhouse gas emissions, energy consumption, and reliance on fossil fuels. This energy source is created by the anaerobic digestion of a feedstock. Sources for feedstock include organic and inorganic wastes, agricultural wastes, animal by-products, and industrial wastes, each a renewable energy source. A fuel cell can utilize the methane present in biogas using integrated heat, power, and hydrogen systems. A study was performed on both energy flow and resource availability to ascertain not only the type but also the source of feedstock needed to run a fuel cell system continuously while maintaining maximum capacity. A hydrogen fueling infrastructure was also created for the northeastern United States. The infrastructure is to be implemented between 2013 and 2025. The design itself gives priority to customer convenience with minimal additional investments. Extensive research has been done on a generating hydrogen supply from factories and other potential sources that can satisfy the demand in that region. Several markers (e.g., population density, traffic density, legislations, and growth patterns) have driven the process of estimation of the demand. --Abstract, page iv
Status of Using Quantitative Methods in Project Risk Management
This study aims to evaluate the current project risk management within UNRWA in Gaza in all areas related to the Agency’s mandate. Projects implemented by UNRWA in Gaza are subject to risks due to the volatile situation and the adverse situation representing risks and uncertainties that are difficult to predict and that impede the effective and timely implementation of projects according to their plans. This negatively impacts the outputs of these projects and creates grave repercussions and disruption consuming the project resources and budgets. This will also have a negative impact on the Agency’s image and funding as the relationship with the donor community will be also distorted
Evaluating of Short-Term Electrical Load Forecasting System Using Fuzzy Logic Control: A Study Case in Sudan
Generation, Transmission and Distribution sections of the electric power grid system are a function of electric load forecasting. This is because, many benefits can be obtained by using load forecasting, such as reduction in the generating cost and increasing the reliability of the power system due to improving energy management. The objective of this study is therefore to design a fuzzy logic system for short-term electric load forecasting to reduce power losses particularly in times where the electric power generation is higher than the electric load demand. In this study, the independent variables that were applied to the developed short-term load forecasting Simulink model were time, temperature, and similar previous electric day load demand, and they were collected from the specific area load control center in Sudan. Fuzzy rules were prepared using Mamdani implication. The obtained fuzzy logic results were compared with the actual load demand, and it was found that there was an error that ranged between 12% and 0.09%
Isotropic photonic band gap and anisotropic structures in transmission spectra of two-dimensional 5-fold and 8-fold symmetric quasiperiodic photonic crystals
We measured and calculated transmission spectra of two-dimensional
quasiperiodic photonic crystals (PCs) based on a 5-fold (Penrose) or 8-fold
(octagonal) symmetric quasiperiodic pattern. The photonic crystal consisted of
dielectric cylindrical rods in air placed normal to the basal plane on vertices
of tiles composing the quasiperiodic pattern. An isotropic photonic band gap
(PBG) appeared in the TM mode, where electric fields were parallel to the rods,
even when the real part of a dielectric constant of the rod was as small as
2.4. An isotropic PBG-like dip was seen in tiny Penrose and octagonal PCs with
only 6 and 9 rods, respectively. These results indicate that local multiple
light scattering within the tiny PC plays an important role in the PBG
formation. Besides the isotropic PBG, we found dips depending on the incident
angle of the light. This is the first report of anisotropic structures clearly
observed in transmission spectra of quasiperiodic PCs. Based on rod-number and
rod-arrangement dependence, it is thought that the shapes and positions of the
anisotropic dips are determined by global multiple light scattering covering
the whole system. In contrast to the isotropic PBG due to local light
scattering, we could not find any PBGs due to global light scattering even
though we studied transmission spectra of a huge Penrose PC with 466 rods.Comment: One tex file for manuscript and 12 PNG files for figures consisting
of Fig.1a-d, 2,3, ...
Indoor Radon Concentration in Dwellings of Baghdad City and In Dora Refinery Using Rad-7 Detector
Indoor radon gas (222Rn) has been recognized as one of the health hazards for human. Rn-222 is the most important source of natural radiation and is responsible for approximately half of the received dose from all sources. Most of this dose is from inhalation of the Rn-222 progeny, especially in closed atmospheres. Air radon comes mainly from soil and construction materials. Radon concentration was measured in two room of 9 dwellings from various regions of Baghdad city and in Dora Refinery, electronic detector of radon Rad-7 was used which is an active measurement method. The results show that Radon concentrations of the dwellings were varied from (0) Bq m-3 to (82.6) Bq m-3 with an average activity value of (22.75) Bq m-3. The results show that radon concentration was high in sample B4 and low in samples B2,B5, B6 ,B8, .and for Dora Refinery the high concentration was (71.3 ) Bq m-3 in sample D11 and low was (0) Bq m-3 in samples D1,D2,D4,D5,D6,D7 and D8 an average activity value 19.2 Bq m-3 . the annual effective dose ranged between ( 0-3.3) mSv/y, with a mean value 0.4 mSv/y for Baghdad city and ranged between (0-2.8) mSv/y with a mean value 0.4 mSv/y for Dora Refinery . These results are lower than the value 1 mSv/y recommended by ICRP report. Keywords: Radon, RAD-7, Baghdad city, Dora Refinery, Annual effective dose
Biosynthesis and in vivo wound healing abilities of Dactyloctenium aegyptium-mediated silver nanoparticles used as hydrogel dressing
Wounds offer a medium for the growth of pathogens and their entry into the body, which necessitates effective wound healing treatments. Herein, we report the green synthesis of silver nanoparticles (AgNPs) using Dactyloctenium aegyptium extract as a capping and reducing agent for wound healing applications. The synthesized nanoparticles were characterized by UV-Vis, FT-IR, SEM, XRD, and in vitro antibacterial activity. Nanoparticles were then incorporated into PVA, Na-alginate, and gelatin-based hydrogel dressings to investigate their in vivo wound healing capability in rats. The color change of the reaction mixture and the surface plasmon resonance (400 nm) confirmed the formation of AgNPs. FT-IR analysis revealed the involvement of plant extract phytochemicals in the capping and stabilization of nanoparticles. The nanoparticles were crystalline in nature, with an average crystallite size of 28.03 nm and exhibited antibacterial activity against S. aureus, P. aeruginosa, K. pneumoniae and E. coli (ZOI 19 ± 0.0, 9 ± 0.0, 13 ± 0.0, and 13 ± 0.0 mm respectively). Furthermore, silver nanoparticle-loaded hydrogels showed accelerated wound healing in rats compared to untreated rats and rats treated with a commercial product. Thus, the developed hydrogel dressing has the potential for clinical application in wound healing and infection treatment
First serodetection and molecular phylogenetic documentation of; Coxiella burnetii; isolates from female camels in Wasit governorate, Iraq
This study aims to detect Coxiellaburnetiiin one-humped female camels (Camelus dromedarius) using ELISA andconfirmation of infection by PCR with the phylogenetic analysis of local isolates. The 91 adult female camels were selected for clinical examination and blood sampling fromdifferent areas in Badra and Al-Numaniyah districts in Wasitgovernorate, Iraq, from February to April 2019. The prevalence of Coxiella(C.) burnetiiwas 19.8% and 4.4% by ELISA and PCR, respectively. Targeting 16S rRNA genes from three positive samples were documented in the Genbank-NCBI under accession numbers of MN900579.1, MN900580.1, and MN900581.1. Clinical evaluation revealed insignificant variation in temperature, pulse, respiratory rates, and lymph node enlargement among the positive and negative animals. The findings also showed that camels of the Badra regions have positive signs. burnetiicompared to other regions, and the infection was increased significantly in April and March. In conclusion, our findings confirmed the prevalence ofC. burnethamong Iraqi female camels, suggesting that these animals might be a source of the pathogenfor humans and other animal species. Therefore, further studies are necessary to provide more detailed data about the prevalence of C. burnetiito to improve effective control measures
The effect of pedunculopontine nucleus deep brain stimulation on postural sway and vestibular perception
© 2016 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of Europe an Academy of Neurology. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and re production in any medium, provided the original work is properly cited, see https://creativecommons.org/licenses/by/3.0/BACKGROUND AND PURPOSE: Deep brain stimulation (DBS) of the pedunculopontine nucleus (PPN) reduces the number of falls in patients with Parkinson's disease (PD). It was hypothesized that enhanced sensory processing contributes to this PPN-mediated gait improvement. METHODS: Four PD patients (and eight matched controls) with implanted bilateral PPN and subthalamic nucleus DBS electrodes were assessed on postural (with/without vision) and vestibular perceptual threshold tasks. RESULTS: Pedunculopontine nucleus ON stimulation (compared to OFF) lowered vestibular perceptual thresholds but there was a disproportionate increase in the normal sway increase on going from light to dark. CONCLUSIONS: The disproportionate increased sway with PPN stimulation in the dark may paradoxically improve balance function since mechanoreceptor signals rapidly adapt to continuous pressure stimulation from postural akinesia. Additionally, the PPN-mediated vestibular signal enhancement also improves the monitoring of postural sway. Overall, PPN stimulation may improve sensory feedback and hence balance performance.Peer reviewedFinal Published versio
Effects of Occupational Noise Exposure on Arterial Blood Pressure of Workers in Selected Industrial Places in Duhok City.
Noise pollution is increasingly being recognized as a physical factor in the environment that is injurious to many aspects of health. Environmental noise induces alterations of various physiological responses in individuals exposed to it. The aim of the present study is to assess the effects of industrial noise on some aspects related to the cardiovascular system of workers exposed to industrial noise in the woodworking industry in Duhok city, Iraq. The sound levels of electrical saws can be as high as about 100 dB. The study group included 29 workers employed in the woodworking industry (Carpentry) exposed to industrial noise levels exceeding 95 dB. In order to observe the harmful effects of the noise caused by the Occupational Noise from the Carpentry machines, a questionnaire was made for all the workers (29 persons) included in this study. The results of this study showed significant changes in systolic blood pressure, diastolic blood pressure, mean arterial pressure, pulse pressure and pulse rate in the workers in the woodworking industry. Thus this study lead to conclude that industrial noise could be possible contributing factor in the development of arterial hypertension
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