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  Subjects -> SCIENCES: COMPREHENSIVE WORKS (Total: 426 journals)
Showing 1 - 200 of 265 Journals sorted alphabetically
AAS Open Research     Open Access   (Followers: 1)
ABC Journal of Advanced Research     Open Access  
Accountability in Research: Policies and Quality Assurance     Hybrid Journal   (Followers: 22)
Acta Materialia Transilvanica     Open Access  
Acta Nova     Open Access   (Followers: 1)
Acta Scientifica Malaysia     Open Access  
Acta Scientifica Naturalis     Open Access   (Followers: 3)
Adıyaman University Journal of Science     Open Access  
Advanced Science     Open Access   (Followers: 13)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 11)
Advanced Theory and Simulations     Hybrid Journal   (Followers: 5)
Advances in Research     Open Access  
Advances in Science and Technology     Full-text available via subscription   (Followers: 17)
African Journal of Science, Technology, Innovation and Development     Hybrid Journal   (Followers: 8)
Afrique Science : Revue Internationale des Sciences et Technologie     Open Access   (Followers: 2)
AFRREV STECH : An International Journal of Science and Technology     Open Access   (Followers: 4)
American Academic & Scholarly Research Journal     Open Access   (Followers: 6)
American Journal of Applied Sciences     Open Access   (Followers: 27)
American Journal of Humanities and Social Sciences     Open Access   (Followers: 16)
ANALES de la Universidad Central del Ecuador     Open Access   (Followers: 4)
Anales del Instituto de la Patagonia     Open Access  
Applied Mathematics and Nonlinear Sciences     Open Access   (Followers: 1)
Apuntes de Ciencia & Sociedad     Open Access  
Arab Journal of Basic and Applied Sciences     Open Access  
Arabian Journal for Science and Engineering     Hybrid Journal   (Followers: 5)
Archives Internationales d'Histoire des Sciences     Partially Free   (Followers: 7)
Archives of Current Research International     Open Access  
ARO. The Scientific Journal of Koya University     Open Access  
ARPHA Conference Abstracts     Open Access   (Followers: 6)
ARPHA Proceedings     Open Access   (Followers: 5)
ArtefaCToS : Revista de estudios sobre la ciencia y la tecnología     Open Access   (Followers: 1)
Asia-Pacific Journal of Science and Technology     Open Access  
Asian Journal of Advanced Research and Reports     Open Access   (Followers: 2)
Asian Journal of Applied Science and Engineering     Open Access   (Followers: 2)
Asian Journal of Scientific Research     Open Access   (Followers: 3)
Asian Journal of Technology Innovation     Hybrid Journal   (Followers: 7)
Australian Field Ornithology     Full-text available via subscription   (Followers: 4)
Australian Journal of Social Issues     Hybrid Journal   (Followers: 7)
AZimuth     Full-text available via subscription   (Followers: 2)
Bangladesh Journal of Scientific Research     Open Access   (Followers: 1)
Beni-Suef University Journal of Basic and Applied Sciences     Open Access   (Followers: 3)
Berichte Zur Wissenschaftsgeschichte     Hybrid Journal   (Followers: 10)
Berkeley Scientific Journal     Full-text available via subscription  
BIBECHANA     Open Access   (Followers: 2)
BibNum     Open Access  
Bilge International Journal of Science and Technology Research     Open Access   (Followers: 1)
Bioethics Research Notes     Full-text available via subscription   (Followers: 16)
Bistua : Revista de la Facultad de Ciencias Básicas     Open Access  
BJHS Themes     Open Access   (Followers: 1)
Black Sea Journal of Engineering and Science     Open Access  
Borneo Journal of Resource Science and Technology     Open Access  
Brazilian Journal of Science and Technology     Open Access   (Followers: 2)
Bulletin de la Société Royale des Sciences de Liège     Open Access  
Bulletin of the National Research Centre     Open Access  
Butlletí de la Institució Catalana d'Història Natural     Open Access  
Central European Journal of Clinical Research     Open Access  
Chain Reaction     Full-text available via subscription  
Ciencia & Natura     Open Access   (Followers: 1)
Ciencia Amazónica (Iquitos)     Open Access   (Followers: 1)
Ciencia en Desarrollo     Open Access   (Followers: 3)
Ciencia en su PC     Open Access   (Followers: 1)
Ciencia Ergo Sum     Open Access  
Ciência ET Praxis     Open Access  
Ciencia y Tecnología     Open Access  
Ciencia, Docencia y Tecnología     Open Access  
Ciencias Holguin     Open Access   (Followers: 2)
CienciaUAT     Open Access   (Followers: 1)
Citizen Science : Theory and Practice     Open Access   (Followers: 2)
Communications Faculty of Sciences University of Ankara Series A2-A3 Physical Sciences and Engineering     Open Access  
Communications in Applied Sciences     Open Access  
Comprehensive Therapy     Hybrid Journal   (Followers: 3)
Comunicata Scientiae     Open Access   (Followers: 1)
ConCiencia     Open Access  
Conference Papers in Science     Open Access   (Followers: 2)
Configurations     Full-text available via subscription   (Followers: 10)
COSMOS     Hybrid Journal   (Followers: 1)
Crea Ciencia Revista Científica     Open Access   (Followers: 2)
Cuadernos de Investigación UNED     Open Access  
Current Issues in Criminal Justice     Hybrid Journal   (Followers: 15)
Current Research in Geoscience     Open Access   (Followers: 8)
Dalat University Journal of Science     Open Access  
Data     Open Access   (Followers: 5)
Data Curation Profiles Directory     Open Access   (Followers: 5)
Dhaka University Journal of Science     Open Access  
Dharmakarya     Open Access  
Diálogos Interdisciplinares     Open Access  
Digithum     Open Access   (Followers: 2)
Discover Sustainability     Open Access   (Followers: 3)
Einstein (São Paulo)     Open Access  
Ekaia : EHUko Zientzia eta Teknologia aldizkaria     Open Access  
Elkawnie : Journal of Islamic Science and Technology     Open Access  
Emergent Scientist     Open Access  
Enhancing Learning in the Social Sciences     Open Access   (Followers: 9)
Enseñanza de las Ciencias : Revista de Investigación y Experiencias Didácticas     Open Access  
Entramado     Open Access  
Entre Ciencia e Ingeniería     Open Access   (Followers: 1)
Epiphany     Open Access   (Followers: 4)
Ergo     Open Access  
Estação Científica (UNIFAP)     Open Access   (Followers: 1)
Ethiopian Journal of Education and Sciences     Open Access   (Followers: 6)
Ethiopian Journal of Science and Technology     Open Access  
Ethiopian Journal of Sciences and Sustainable Development     Open Access   (Followers: 5)
European Online Journal of Natural and Social Sciences     Open Access   (Followers: 12)
European Scientific Journal     Open Access   (Followers: 10)
Evidência - Ciência e Biotecnologia - Interdisciplinar     Open Access  
Exchanges : the Warwick Research Journal     Open Access   (Followers: 2)
Experimental Results     Open Access   (Followers: 2)
Extensionismo, Innovación y Transferencia Tecnológica     Open Access   (Followers: 3)
Facets     Open Access  
Fides et Ratio : Revista de Difusión Cultural y Científica     Open Access   (Followers: 1)
Fırat University Turkish Journal of Science & Technology     Open Access  
Fontanus     Open Access  
Forensic Science Policy & Management: An International Journal     Hybrid Journal   (Followers: 376)
Frontiers for Young Minds     Open Access  
Frontiers in Climate     Open Access   (Followers: 3)
Frontiers in Science     Open Access   (Followers: 1)
Fundamental Research     Open Access  
Futures & Foresight Science     Hybrid Journal   (Followers: 4)
Gaudium Sciendi     Open Access   (Followers: 1)
Gazi University Journal of Science     Open Access  
Ghana Studies     Full-text available via subscription   (Followers: 15)
Global Journal of Pure and Applied Sciences     Full-text available via subscription  
Global Journal of Science Frontier Research     Open Access   (Followers: 2)
Globe, The     Full-text available via subscription   (Followers: 4)
HardwareX     Open Access  
Heidelberger Jahrbücher Online     Open Access  
Heliyon     Open Access  
Himalayan Journal of Science and Technology     Open Access   (Followers: 1)
History of Science and Technology     Open Access   (Followers: 1)
Hoosier Science Teacher     Open Access  
Iberoamerican Journal of Science Measurement and Communication     Open Access   (Followers: 1)
Impact     Open Access   (Followers: 2)
Indian Journal of History of Science     Hybrid Journal   (Followers: 2)
Indonesian Journal of Fundamental Sciences     Open Access  
Indonesian Journal of Science and Mathematics Education     Open Access   (Followers: 4)
Indonesian Journal of Science and Technology     Open Access  
Ingenieria y Ciencia     Open Access   (Followers: 1)
Innovare : Revista de ciencia y tecnología     Open Access  
Instruments     Open Access  
Integrated Research Advances     Open Access  
Interciencia     Open Access   (Followers: 1)
Interface Focus     Full-text available via subscription  
International Annals of Science     Open Access  
International Archives of Science and Technology     Open Access  
International Journal of Academic Research in Business, Arts & Science     Open Access   (Followers: 2)
International Journal of Advanced Multidisciplinary Research and Review     Open Access  
International Journal of Applied Science     Open Access  
International Journal of Basic and Applied Sciences     Open Access   (Followers: 4)
International Journal of Computational and Experimental Science and Engineering (IJCESEN)     Open Access  
International Journal of Culture and Modernity     Open Access   (Followers: 3)
International Journal of Engineering, Science and Technology     Open Access  
International Journal of Innovation and Applied Studies     Open Access   (Followers: 12)
International Journal of Innovative Research and Scientific Studies     Open Access   (Followers: 6)
International Journal of Network Science     Hybrid Journal   (Followers: 3)
International Journal of Recent Contributions from Engineering, Science & IT     Open Access   (Followers: 1)
International Journal of Research in Science     Open Access   (Followers: 2)
International Journal of Science & Emerging Technologies     Open Access   (Followers: 1)
International Journal of Social Sciences and Management     Open Access   (Followers: 3)
International Journal of Technology Policy and Law     Hybrid Journal   (Followers: 7)
International Letters of Social and Humanistic Sciences     Open Access   (Followers: 1)
International Review of Applied Sciences     Open Access  
InterSciencePlace     Open Access   (Followers: 1)
Investiga : TEC     Open Access  
Investigación Joven     Open Access  
Investigación Valdizana     Open Access  
Investigacion y Ciencia     Open Access   (Followers: 1)
Iranian Journal of Science and Technology, Transactions A : Science     Hybrid Journal  
iScience     Open Access   (Followers: 2)
Issues in Science & Technology     Free   (Followers: 7)
Ithaca : Viaggio nella Scienza     Open Access  
J : Multidisciplinary Scientific Journal     Open Access  
Jaunujų mokslininkų darbai     Open Access   (Followers: 1)
Journal de la Recherche Scientifique de l'Universite de Lome     Full-text available via subscription   (Followers: 2)
Journal of Chromatography & Separation Techniques     Open Access   (Followers: 12)
Journal of Advanced Research     Open Access   (Followers: 3)
Journal of Al-Qadisiyah for Pure Science     Open Access   (Followers: 1)
Journal of Alasmarya University     Open Access   (Followers: 2)
Journal of Analytical Science & Technology     Open Access   (Followers: 6)
Journal of Applied Science and Technology     Full-text available via subscription   (Followers: 1)
Journal of Applied Sciences and Environmental Management     Open Access   (Followers: 3)
Journal of Big History     Open Access   (Followers: 3)
Journal of Composites Science     Open Access   (Followers: 3)
Journal of Critical Thought and Praxis     Open Access   (Followers: 2)
Journal of Deliberative Mechanisms in Science     Open Access  
Journal of Diversity Management     Open Access   (Followers: 6)
Journal of Indian Council of Philosophical Research     Hybrid Journal  
Journal of Institute of Science and Technology     Open Access  
Journal of Integrated Science and Technology     Open Access  
Journal of Interaction Science     Open Access   (Followers: 1)
Journal of Kerbala University     Open Access   (Followers: 1)
Journal of King Saud University - Science     Open Access   (Followers: 1)
Journal of Mathematical and Fundamental Sciences     Open Access  
Journal of Natural Sciences and Mathematics Research     Open Access  
Journal of Natural Sciences Research     Open Access   (Followers: 4)
Journal of Negative and No Positive Results     Open Access  
Journal of Responsible Technology     Open Access   (Followers: 1)
Journal of Science (JSc)     Open Access  
Journal of Science and Engineering     Open Access  
Journal of Science and Technology     Open Access   (Followers: 2)
Journal of Science and Technology     Open Access   (Followers: 1)

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ARO. The Scientific Journal of Koya University
Number of Followers: 0  

  This is an Open Access Journal Open Access journal
ISSN (Print) 2410-9355 - ISSN (Online) 2307-549X
Published by Koya University Homepage  [1 journal]
  • Design and Fabrication of a Novel Ultra Compact Microstrip Diplexer Using
           Interdigital and Spiral Cells

    • Authors: Salah I. Yahya; Abbas Rezaei
      Abstract: A dual-band bandpass-bandpass microstrip diplexer with very small size and good performance is designed in this work. The proposed diplexer has a novel structure which is introduced for the first time in this paper. In comparison with the previously reported diplexers, it occupies the most compact size of 0.002 λg2 (226.7 mm2), fabricated on 0.787 mm dielectric substrate height. The resonance frequencies of the presented diplexer are located at 0.76 GHz and 1.79 GHz making it suitable for the global system for mobile communications (GSM) applications. It has a wide flat channels with two fractional bandwidths (FBWs) of 41.1% and 50%. Another feature of the proposed diplexer is its ability to suppress the harmonics. It can attenuate the 1st to 7th harmonics. Moreover, it has low insertion losses and low group delays at both channels while the isolation and return losses are acceptable. Finally, the proposed diplexer is fabricated and measured to verify the simulation results, where a good agreement between the simulation and measurement results is obtained.
      PubDate: Wed, 30 Jun 2021 00:00:00 +000
       
  • Chemical Characterization and Antidiabetic Activity of Essential Oils from
           Pelargonium graveolens Leaves

    • Authors: Javed Ahamad; Subasini Uthirapathy
      Abstract: Pelargonium graveolens (Geranium) is a source of the finest quality of fragrance and its essential oils are used as antibacterial, and antifungal agents. The aim of the current research is to determine chemical constituents in the essential oil of P. graveolens by GC-MS and evaluate its antidiabetic activity via α-glucosidase inhibition assay. The chemical composition of P. graveolens essential oil was determined by GC/MS and its antidiabetic activity was assessed through inhibition of α-glucosidase enzyme in in-vitro models. GC-MS analysis determines 36 chemical components in the essential oil of P. graveolens leaves, and citronellyl isovalerate (10.41 %), menthol (9.61 %), linalool (8.63 %), p-menthone (6.31 %), and geranyl tiglate (4.99 %) were recorded as major constituents. The essential oil of P. graveolens leaves showed concentration dependant inhibition of α-glucosidase enzyme ranging from 28.13±1.41 to 74.24±2.53 µg/mL for concentration ranging from 31.25 to 1000 µg/mL. The IC50 values for of P. graveolens and acarbose were found as 93.72±4.76 and 80.4±2.17 µg/mL, respectively against the α-glucosidase enzyme. The study finding explores the chemical components of P. graveolens growing in the Iraqi Kurdistan region and scientifically supported its possible use in diabetic patients for controlling postprandial hyperglycemia.
      PubDate: Wed, 30 Jun 2021 00:00:00 +000
       
  • A Study on the Prevalence and Source of Staphylococci and
           Methicillin-resistant Staphylococcus aureus Causing Superficial Incisional
           Surgical Site Infection

    • Authors: Kameran M. Ali; Bahrouz M. A. Al-Jaff
      Abstract: Staphylococcus aureus and coagulase-negative staphylococci (CoNS) are common causatives of superficial incisional surgical site infection (SSI). The source of the pathogens is still not fully diagnosed whether it is endogenous or exogenous particularly with regard to the extent of its resistance to antibiotics. Therefore, this study is designed to determine the rate of infection, the source of pathogens, and the extent of their resistance to antibiotics. For this purpose, pre-, intra- and post-operative swabs from the nasal and skin of patients undergoing surgeries and samples from the hospital environment have been collected and processed for isolation and identification of staphylococci. Bacterial analysis and antibiotic susceptibility profiles of the isolates are assessed by unweighted pair group method with arithmetic mean (UPGMA) analysis based on random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) and disc diffusion test for antibiotics susceptibility profile. The microbiological and PCR results indicate that SSIs are found in 113/512 (22.07%), Staphylococcus spp. rated 67/512 (13.09%) of infections. Further analysis indicates that S. aureus, CoNS, and both of them were causes SSI with different rates 41/67 (61.2%), 23/67 (34.3%), and 3/67 (4.5%), respectively. Results of RAPD-PCR for 70 isolates reveal that 52/70 (74.28%) of SSIs are from endogenous source, followed by 10/70 (14.29%) and 8/70 (11.43%) from hospitals acquired and undetermined sources, respectively. Moreover, results of antibiotic susceptibility test reveal that 24/44 (54.5%) of isolates belong to methicillin-resistant Staphylococcus aureus; from both endogenous and exogenous sources with 13/24 (54.17%) and 11/24 (45.83%), respectively.
      PubDate: Wed, 30 Jun 2021 00:00:00 +000
       
  • Assessment the Natural Radioactivity of Radionuclides ( 226Ra, 232Th, 40K,
           and 137Cs) in Wheat Grain

    • Authors: Zakariya A. Hussein; Najeba F. Salih, Shalaw Z. Sedeeq
      Abstract: This paper investigates the activity concentration of radionuclides (226Ra, 232Th, 40K and 137Cs) in the wheat grain samples using a high-purity germanium detector. Thirty-six wheat grain samples were collected from different locations of Koya City, Iraqi Kurdistan region. Average activity concentrations of 226Ra, 232Th and 40K in wheat grain are found to be 0.407 ± 0.097 Bq.kg-1 for 226Ra, 0.36 ± 0.14 Bq.kg-1 for 232Th and 109.25± 2.214 Bq.kg-1 for 40K, respectively. The measured activity concentrations for the radionuclides are compared with the reported data from other countries. In addition, the fallout radionuclide of 137Cs has no detection of in the wheat grain samples. The radium equivalent activity Raeq, internal and external hazard indices Hin and Hex, and annual gonadal dose equivalent are calculated for the measured samples. The total ingestion dose is 113.19 µSv.y-1, which is below the world average value of 290 µSv.y-1.
      PubDate: Mon, 28 Jun 2021 00:00:00 +000
       
  • A Comparative Study of Electrical Characterization of P-Doped Distributed
           Bragg Reflectors Mirrors for 1300 nm Vertical Cavity Semiconductor Optical
           Amplifiers

    • Authors: Faten A. Chaqmaqchee
      Abstract: This paper presents an electrical analysis of various diameters of two p-types of GaAs/Al0.9Ga0.1As and two p-types of GaAs/Al0.3Ga0.7As/Al0.9Ga0.1As distributed Bragg reflectors (DBRs) mirrors structure grown on undoped and on p-doped GaAs, which affects the characteristics of 1300 nm vertical cavity surface emitting lasers (VCSELs) and vertical cavity semiconductor optical amplifiers (VCSOAs). Electrical characterizations and Hall measurements of current−voltage (IV) for GaAs/Al0.9Ga0.1As linear DBRs and GaAs/Al0.3Ga0.7As/Al0.9Ga0.1 As graded DBRs were also performed at temperatures between 13 and 300 K. Consequently, p-type DBRs are designed with graded composition interfaces technique. The smaller mesa diameters are used to reduce vertical and longitudinal resistances and to limit the heating effect and improve the characteristics of VCSEL/VCSOA devices.
      PubDate: Thu, 03 Jun 2021 00:00:00 +000
       
  • Evaluation of Flying Ad Hoc Network Topologies, Mobility Models, and IEEE
           Standards for Different Video Applications

    • Authors: Ghassan QasMarrogy
      Abstract: Nowadays, drones became very popular with the enhancement of the technological progress of moving devices with a connection to each other, known as Flying Ad Hoc Network (FANET). It is used in most worldwide necessary life scenarios such as video recording, search and rescue, military missions, moving items between different areas, and many more. This leads to the necessity to evaluate different network strategies between these flying drones, which are essential to improve their quality of performance in the field. Several challenges must be addressed to effectively use FANET, to provide stable and reliable transmission for different types of data during vast changing topologies, such as different video sizes, different types of mobility models, recent Wireless Fidelity standards, types of routing protocols used, security problems, and many more. In this paper, a fully comprehensive analysis of FANET will be done to evaluate and enhance these challenges that concern different video types, mobility models, and IEEE 802.11n standards for best performance, by measuring throughput, retransmission attempt, and delay metrics. The result shows that Gauss–Markov mobility model gives the highest result using Ad Hoc On-Demand Vector and lowest delay, whereas for retransmission attempts, 2.4 GHz frequency has the lowest as it can reach more coverage area than 5 GHz.
      PubDate: Sat, 08 May 2021 19:06:17 +000
       
  • Design and Construction of Zana Robot for Modeling Human Player in
           Rock-paper-scissors Game using Multilayer Perceptron, Radial basis
           Functions and Markov Algorithms

    • Authors: Maryam Ghasemi; Abdolreza Roshani, Peshawa J. Muhammad Ali, Farhad F. Nia, Ehsan Nazemi, Gholam H. Roshani
      Abstract: In this paper, the implementation of artificial neural networks (multilayer perceptron [MLP] and radial base functions [RBF]) and the upgraded Markov chain model have been studied and performed to identify the human behavior patterns during rock, paper, and scissors game. The main motivation of this research is the design and construction of an intelligent robot with the ability to defeat a human opponent. MATLAB software has been used to implement intelligent algorithms. After implementing the algorithms, their effectiveness in detecting human behavior pattern has been investigated. To ensure the ideal performance of the implemented model, each player played with the desired algorithms in three different stages. The results showed that the percentage of winning computer with MLP and RBF neural networks and upgraded Markov model, on average in men and women is 59%, 76.66%, and 75%, respectively. Obtained results clearly indicate a very good performance of the RBF neural network and the upgraded Markov model in the mental modeling of the human opponent in the game of rock, paper, and scissors. In the end, the designed game has been employed in both hardware and software which include the Zana intelligent robot and a digital version with a graphical user interface design on the stand. To the best knowledge of the authors, the precision of novel presented method for determining human behavior patterns was the highest precision among all of the previous studies.
      PubDate: Mon, 08 Mar 2021 20:46:02 +000
       
  • Determination of Multi-performance Characteristics in Electric Discharge
           Machining of DIN 1.2767 Steel Using Grey Relational Analysis

    • Authors: Abubaker Y. Fatatit; Ali Kalyon
      Abstract:    Electric discharge machining (EDM) is one of the most important unconventional machining processes, which can cut hard materials and complex shapes that are difficult to machine by conventional machining processes easily and with high accuracy. In this study, L18 orthogonal array combined with gray relational analysis (GRA) is implemented to investigate the multiple performances characteristics in EDM of DIN 1.2767 Tool Steel. Machining process parameters selected were discharge current (Ip), pulse-on time (Ton), pulse-off time (Toff), and electrode material (copper alloys [NSS and B2]). The investigated performances characteristics were tool wear rate (TWR) and material removal rate (MRR). Analysis of variance (ANOVA) and Taguchi’s signal-to-noise ratio with the help of Minitab-17 software were used to analysis the effect of the process parameters on TWR and MRR. The experimental results and data analysis reveal that TWR and MRR are more affected by Ip and Ton. The minimum TWR was obtained at parametric combination Ip (6A), Ton (800 μs), and Toff (800 μs) and the maximum MRR attained at Ip (25A), Ton (800 μs), Toff (200 μs), and NSS electrode. After applying GRA, the optimal parametric combination for MRR and TWR was determined as Ip (25A), Ton (800 μs), Toff (200 μs), and NSS electrode. The study also exhibited the occurrence of an interaction between the variables on the responses. In addition, scanning electron microscopy images showed that the metal surface was affected with the increase in Ton and Toff.
      PubDate: Mon, 01 Mar 2021 00:00:00 +000
       
  • Assessment of the Upstream Slope Stability of Darbandikhan Rockfill Dam
           during Drawdown

    • Authors: Sirwan Gh. Salim; Krikar M. G. Noori
      Abstract: Earth and rockfill dams face a variety of loading conditions during lifetime. One of the most critical loading conditions is the rapid drawdown of water level after steady state conditions. Rapid drawdown may cause instability of upstream slope of the dam. The present work examines the stability of a rockfill dam under different drawdown rates in terms of factor of safety for the upstream slope of the dam. For this purpose, a computer software named GeoStudio 2012 SEEP/W and SLOPE/W has been used for the numerical analysis. The results showed that the drawdown rate has a significant effect on stability of rockfill dam in which increasing the drawdown rate from 1 m/day to 10 m/day decreases the stability of the dam by 33%. Based on the outcomes, for the studied case the drawdown rate (1 m/day) can be recommended.
      PubDate: Mon, 01 Mar 2021 00:00:00 +000
       
  • Effect of Sand Percentage on the Compaction Properties and Undrained Shear
           Strength of Low Plasticity Clay

    • Authors: Iyad Alkroosh; Ali Al-Robay, Prabir Sarker, Saif Alzabeebee
      Abstract: This paper investigates the influence of sand content on the mechanical behavior of a low plasticity clay that collected from south of Iraq (Sumer town). Samples have been prepared with sand contents of 0%, 10%, 20%, 30%, and 40% of the clay weight. Standard Proctor and unconfined compression tests have been carried out and the optimum moisture content, maximum dry density, and undrained shear strength have been determined. The results show a gradual increasing trend of the maximum dry density with the increase of the sand content up to 30%. The highest dry density reaches 1.90 g/cm3 corresponding to an optimum moisture content of 12%. In addition, this paper shows that the undrained shear strength is inversely proportional to the increase of the percentage of sand. The results of this work provide a useful addition to the literature regarding the behaviour or low plasticity clay-sand mixture.
      PubDate: Mon, 01 Mar 2021 00:00:00 +000
       
  • Corrosion in Crude Oil Distillation Unit Overhead: A recent Case Study

    • Authors: Ari A. Ahmed
      Abstract: Despite all the technological advances and the control mechanisms that exist today to achieve the control of corrosion in overhead systems in atmospheric crude oil distillation units, there is still a high level of difficulty in predicting the phenomenon due to the complexity of the chemical compounds involved in the entire process. The study of this practical case aims to determine what control mechanisms should be optimized in a refinery located in the Autonomous Region of Iraqi Kurdistan to prevent corrosion phenomena’s in this specific system and how it should be done to achieve these improvements. It has been suggested that the corrosion mechanisms by hydrochloric acid and by ammonium chloride have been those that have acted in the operational context of the mentioned facility. To test this hypothesis, a study of the unit’s operational conditions and analytical tests were carried out on the construction material of various components and the products (sediments) found inside the tower. The results show that a lack of control in the salts and sediments content of the feed crude have caused an increase in the hydrolysis process of certain components upstream of the tower and thus the generation of acids and salts was promoted. On this basis, it is necessary to optimize the primary treatment of crude oil and update the chemical treatments and washing water systems to adapt to the new conditions of the feed of the refinery.
      PubDate: Mon, 01 Mar 2021 00:00:00 +000
       
  • Feasibility Study of Concrete Louvers for High-rise Residential Buildings
           in Terms of Cooling Energy Requirements

    • Authors: Sara Dh. Bahaadin; Binaee Y. Raof, Hendren Abdulrahman
      Abstract: High-rise residential buildings are increasing worldwide, including cities in the Kurdistan Region of Iraq. Therefore, creating sustainable environments in and around these residential buildings are becoming an important problem. Improving energy efficiency in buildings has received critical attention worldwide. Countries have developed national sustainability strategies that lead to the lower energy consumption while maintaining comfort, reducing energy consumption, and minimizing harmful emissions. In this paper, an analysis of the impact of external shading devices in high-rise residential buildings on energy consumption of a 13-storey building in Sulaimani city is studied. The study is focused on fixed shading elements, explaining the influence of the design of vertical and horizontal shading devices on the total energy consumption of this type of building. The results show that both a single fixed horizontal blind with a depth of 20 cm and a triple vertical shading with the same depth are considered useless. The reduction in cooling loads by two fixed horizontal louvers almost doubled compared to a single fixed horizontal shading with 20 cm. Moreover, triple fixed horizontal louvers with 40 cm have almost the same effect on reducing cooling loads as triple fixed louvers with 60 cm. On the other hand, a triple fixed horizontal shading device with 60 cm has twice the effect on reducing annual cooling loads as a triple fixed vertical shading device with 60 cm.
      PubDate: Mon, 01 Mar 2021 00:00:00 +000
       
  • Structural Behavior of Reinforced Concrete Beams Incorporating Foamed
           Glass as Aggregates

    • Authors: Dawood S. Atrushi
      Abstract: Natural resources that are utilized in civil engineering applications can be saved by replacing them with some recycled materials to produce sustainable concrete with required mechanical and durability properties. In recent years, recycled glass is being used as aggregates in concrete production in many countries across the world. In the present study, the structural properties of reinforced concrete beams containing foamed glass (FG) as a partial natural coarse aggregate replacement are investigated. Five concrete mixes were employed to conduct the present study. The coarse aggregate was replaced with 0%, 25%, 50%, 75%, and 100% (by volume) of FG. Four point-loading flexural tests on beams were conducted up to failure. The results showed that the compressive strength was decreasing linearly with the increasing amount of FG. It was also observed that the ductility of the reinforced concrete beams significantly improved. However, the load-carrying capacity of the beam and load at which the first crack occurs was reduced. It was concluded that the inclusion of FG in structural concrete applications is possible and the structural behavior of concrete beams proved to be similar to that of other types of lightweight aggregate concrete such as wood and plastic aggregates used in similar structural elements.
      PubDate: Mon, 01 Mar 2021 00:00:00 +000
       
  • The Assessment of Acoustical Characteristics for Recent Mosque Buildings
           in Erbil City of Iraq

    • Authors: Dawa A. A. Masih; Nawzad K. Jalal, Manar N. A. Mohammed, Sulaiman A. Mustafa
      Abstract: The study of mosque acoustics, concerning acoustical features, sound quality for speech intelligibility, and additional practical acoustic criteria, is commonly overlooked. Acoustic quality is vital to the fundamental use of mosques, in terms of contributing toward prayers and worshippers’ appreciation. This paper undertakes a comparative analysis of the acoustic quality level and the acoustical characteristics for two modern mosque buildings constructed in Erbil city. This work investigates and examines the acoustical quality and performance of these two mosques and their prayer halls through room simulation using ODEON Room Acoustics Software, to assess the degree of speech intelligibility according to acoustic criteria relative to the spatial requirements and design guidelines. The sound pressure level and other room-acoustic indicators, such as reverberation time (T30), early decay time, and speech transmission index, are tested. The outcomes demonstrate the quality of acoustics in the investigated mosques during semi-occupied and fully-occupied circumstances. The results specify that the sound quality within the both mosques is displeasing as the loudspeakers were off.
      PubDate: Mon, 01 Mar 2021 00:00:00 +000
       
 
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