bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antibacterial and Antifungal Activities of Cyanobacterial Strains Isolated from Hot Springs in Oman
Authors: Sherwani1 Neelam , Abed Raeid M.M. , Dobretsov Sergey , Mary Sheji 
Published: May 2017

In this study, cyanobacterial microbial mats from five hot springs in Oman, namely Al Kasfah Rustaq, Al Thwara Nakhl, Al–Ali Hammam, Gala and Bowsher, were characterized using direct microscopy. Nine monoclonal cyanobacterial cultures were obtained and their extracts in butanol, dichloromethane (DCM) and hexane were screened for antibacterial and antifungal activities. Direct microscopy revealed the presence of 12 different unicellular and filamentous morphotypes, with different distribution in the various mats. Temperature seems to be one of the most important parameters that accounts for the differences in cyanobacterial composition of the mats. Cells of the nine isolates and their aqueous supernatants were subsequently extracted with butanol, DCM and hexane. Dried extracts were tested against nine bacterial (i.e. gram +ve Staphylococcus aureus, Bacillus subtilis and gram –ve, Escherichia coli, Klebsiella pneumoniae, Salmonella choleraesuis, S. enterica, Psuedomonas aeruginosa, Providencia stuartii, and Acinetobacter calcoaceticus) and two fungal pathogens (Rhizoctonia solani and Pythium sp.). All isolates exhibited antibacterial and antifungal activities, which depended mainly on the type of cyanobacterial culture, type of solvent used and the pathogen tested. The highest antibacterial activity was observed in Phormidium species, and butanol was found to be the most appropriate solvent to extract bioactivity from these cyanobacterial species. The results of this study suggest that thermal springs in Oman harbor diverse types of cyanobacteria, which may constitute an important source of antibacterial and antifungal compounds. Further investigation is needed to purify these compounds and find their chemical compositions and modes of action.
Crystal Field Parameters and Optical Parameters of Nd3+ in Sodium Bismuth Silicate Glass
Authors: Thomas Vinoy , Sofin Ramakrishna P.G.P.S. , Allen Mathew , Thomas Hysen 
Published: May 2017

Neodymium doped sodium bismuth silicate glasses were prepared by the melt quench technique. Optical absorption spectra of the Nd3+ion in the present glassy systems were recorded in the UV-Vis-NIR region. Taylor series expansion method was adopted for theoretical evaluation of various crystal field parameters such as the Slater-Condon (F2,F4,F6), spin orbit and Racah parameters (E1,E2,E3). Oscillator strength and electric dipole line strength of the observed transitions were evaluated with the help of Judd-Ofelt (JO) theory. Radiative transition probability (A), total radiative transition probability (At), radiative life time (trad), branching ratios (b) and integrated absorption (sa) cross section for stimulated emission between the meta stable state 4F3/2 and 4IJ ( J= 15/2,13/2,11/2 and 9/2) levels were calculated using JO parameters. Optical basicity of the glass was found to increase with the addition of bismuth.
Nodulation of Medicago Sativa L. by Different Rhizobium Strains in the Sultanate of Oman
Authors: Elshafie A.E. , Victor R. , Al-Mugbali N. 
Published: May 2017

Three native Rhizobium strains were isolated from Musandam. Buraimi and the Agricultural Experiment Station at Sultan Qaboos University in the Sultanate of Oman. An internationally known Rhizobium strain (TAI. 1373} was obtained from the Nitrogen Fixation for Tropical Agriculture I.egume Collection at the University of Hawaii. U.S.A-. for comparison. The different abilities of the strains to nodulate Medicago sativa I. were investigated. Different plant parameters namely, the fresh and dry weights of the shoot (g/plant ). the number of nodules per plant and the nitrogenase activity (u mole C2H2/sample/3hours) were measured. The results showed that the native Rhizobia were capable of nodulating M saliva. But inoculation with effective known strains such as TAL1373 enhanced nodulation.
IGBT Based DC/DC Converter
Authors: Akherraz M. 
Published: May 2017

This paper presents an in-depth analytical and experimental investigation of an indirect DC-DC converter. The DC-AC conversion is a full bridge based on IGBT power modules, and the AC-DC conversion is done via a high frequency AC link and a first diode bridge. The AC link, which consists of snubbing capacitors and a variable air-gap transformer, is analytically designed to fulfill Zero Voltage commutation requirement. The proposed converter is simulated using PSPICE and a prototype is designed built and tested in the laboratory. PSPICE simulation and experimental results are presented and compared.
Using Switching Linear Systems to Reach a Prespecified Traget
Authors: Benmerzouga A. 
Published: May 2017

A conventional enumeration approach, and a new approach for the solution of the control of switched linear systems with input constraints are presented. The main objective in this work is to determine control sequences {U‘(K), i -l , M and k –O, l, ….., N - l} which transfer the system from a given initial state X(0) to a specific target state Xt, (or to be as close as possible). Considering both the conventional enumeration and the new approach, extensive computer simulations are performed using the discrete time system obtained by sampling (or discretizing) a continuous system. The new approach is found to be more efficient than the enumeration one in terms of computations and computer storage and performs adequately under a variety of input data The procedure developed can be generalized and used to solve several versions of the switching control problem. In particular, a procedure using a quadratic cost function (distance) is given for problems with time-invariant coefficients.
A Comparative Analysis and Prediction of Traffic Accident Causalities in the Sultanate of Oman using Artificial Neural Networks and Statistical methods
Authors: Ali Galal A. , Al-Alawi Saleh M. , S.Bakheit Charles 
Published: May 2017

Traffic accidents are among the major causes of death in the Sultanate of Oman This is particularly the case in the age group of I6 to 25. Studies indicate that, in spite of Oman's high population-per-vehicle ratio, its fatality rate per l0,000 vehicles is one of the highest in the world. This alarming Situation underlines the importance of analyzing traffic accident data and predicting accident casualties. Such steps will lead to understanding the underlying causes of traffic accidents, and thereby to devise appropriate measures to reduce the number of car accidents and enhance safety standards. In this paper, a comparative study of car accident casualties in Oman was undertaken. Artificial Neural Networks (ANNs) were used to analyze the data and make predictions of the number of accident casualties. The results were compared with those obtained from the analysis and predictions by regression techniques. Both approaches attempted to model accident casualties using historical data on related factors, such as population, number of cars on the road and so on, covering the period from I976 to 1994. Forecasts for the years 1995 to 2000 were made using ANNs and regression equations. The results from ANNs provided the best fit for the data. However, it was found that ANNs gave lower forecasts relative to those obtained by the regression methods used, indicating that ANNs are suitable for interpolation but their use for extrapolation may be limited. Nevertheless, the study showed that ANNs provide a potentially powerful tool in analyzing and forecasting traffic accidents and casualties.
Weak Complexes of Sulfur Compounds with Halide Ligands
Authors: Salama Salama B. , Wasif Saad 
Published: May 2017

This review summarizes the study of the formation of SO2 -X- , SOCl2 -X- , SOBr2 -X- , SO2 Cl2 -X- complexes (X- = Cl- , Br- , I- , and SCN- ) in pure and mixed solvents of acetonitrile and dimethylsulfoxide over the past 30 years. Spectrometry (290nm-380nm) was the principal technique used for the investigation, since the enthalpies of formation Δ Hfo of the above complexes are low ( -6.03  -22.51 kJ/mol ). The stability of the complexes depend on the nature of the solvent, acceptor properties of the sulfur compounds, the donor properties of the halide ions and the temperature of the reaction. Also, it was found that the extent of the iodide ion replacement reactions by the other halide depends on the nature of the solvent and the halide ions. SO2 -I- + X- → SO2 -X- + I- The structures of SO2 -X- compounds are pyramidal, with X- at the top of the pyramid, the S atom at the center, and the angle depends on the nature of the halide ion.
Voltage Stability Analysis of Muscat Power System During Summer Weather Conditions
Authors: Ellithy K. , Gastli A. , Al-Alawi S. , Al-Hinai A. , Al-Abri Z. 
Published: May 2017

A systematic and general formulation of a Propagation Simulation Program (PSP) is developed for the coherent field of microwave and millimeter wave carrier signals traversing intermediate layered precipitation media taking into account the random behavior of particle size, orientation, shape and concentration distributions. Based on a rigorous solution of the volumetric multiple-scattering integral equations, the formalism offers the capability of treating the potential transmission impairments on satellite-earth links and radar remote sensing generated by composite atmospheric layers of precipitation in conjunction with the finite polarization isolation of dual-polarized transmitting and receiving antennas. A multi-layered formulation is employed which encompasses an ensemble of discrete particles comprising an arbitrary mixture of ice crystals, melting snow and raindrops that may exist simultaneously along satellite-earth communication paths.
Effect of pH on the Removal of Chromium (Cr) (VI) by Sugar Cane Bagasse
Authors: Ahmed Khan Nasim , Ali Syed Iqbal , Ayub Sohail 
Published: May 2017

The industrial estates in India are dominated by small and medium scale industries, which are posing a serious threat to the environment by virtue of discharging effluents of a polluting nature. The problems become severe due to the presence of heavy metals in the effluents. Chromium is widely used in a number of industries such as electroplating, metal finishing, cooling towers, dyes, paints, anodising and leather tanning industries. The toxicity of chromium (VI) is well known and is considered a hazard to the health of humans and animals. The presence of chromium (VI) in aquatic environments at high concentrations is also lethal to marine species. The treatment of chromium bearing effluents have been reported through several methods, such as chemical reduction, precipitation, ion exchange, electrochemical reduction, evaporation, reverse osmosis and adsorption. However among these, adsorption is found to be highly effective, inexpensive and an easy method to operate. India is an agricultural country and generates a considerable amount of agricultural wastes such as sugar cane bagassess, coconut jute, nut shell, rice straw, rice husk, waste tea leaves, ground nut husk, crop wastes, peanut hulls and fertilizer wastes. Successful studies on these materials could be beneficial to developing countries and could be easily applied as adsorbents for the removal of chromium from wastewater. Most of the previous work highlights the use of commercial activated carbon but these adsorbents are relatively expensive and less feasible to be used in developing countries. Keeping these in view batch experiments have been designed to study the feasibility of sugar cane bagasse to remove chromium (VI) from the aqueous solutions. While evaluationg the impact of various parameters, such as adsorbent does, contact time, initial concentration and pH on chromium removal efficiency, the results indicate a prominent effect of pH on the chromium reduction by the adsorbent used in the present study.
Biological Effects of EM Radiations from Mobile Phones
Authors: Ali Adel A. , Al-Naamany Ahmed M. 
Published: May 2017

Direct health effects could result following exposure to RF by thermal (heating effects). Recent Studies have shown that there are public fears on effects that can be caused mainly by holding mobile phones close to the body, or as a result of possible non-thermal effects from both phones and base stations. This paper offers an overview on the biological effects of electromagnetic radiation caused by mobile phones. Exposures of individuals to RF radiation from these sources will depend upon their proximity and may be above those from mobile phone base stations, although still well below guidelines. From a review of the scientific literature, it is concluded that there were no established health effects from exposure to the RF fields from mobile phones. However, there are gaps in knowledge requiring further research, but current knowledge suggests that RF exposure to levels below the guidelines were not a risk to health.
Development and Application of Back-Propagation-Based Artificial Neural Network Models in Solving Engineering
Authors: Al-Alawi Saleh Mohammed 
Published: May 2017

Artificial Neural Networks (ANNs) are computer software programs that mimic the human brain's ability to classify patterns or to make forecasts or decisions based on past experience. The development of this research area can be attributed to two factors, sufficient computer power to begin practical ANN-based research in the late 1970s and the development of back-propagation in 1986 that enabled ANN models to solve everyday business, scientific, and industrial problems. Since then, significant applications have been implemented in several fields of study, and many useful intelligent applications and systems have been developed. The objective of this paper is to generate awareness and to encourage applications development using artificial intelligence-based systems. Therefore, this paper provides basic ANN concepts, outlines steps used for ANN model development, and lists examples of engineering applications based on the use of the back-propagation paradigm conducted in Oman. The paper is intended to provide guidelines and necessary references and resources for novice individuals interested in conducting research in engineering or other fields of study using back-propagation artificial neural networks.
Xanthotoxin and Other Furanocoumarins as Phytoalexins in Pastinaca sativa L. roots
Authors: Al-Barwani Fatma M. , Eltayeb Elsadig A. 
Published: May 2017

Our results confirm the presence of the furanocoumarins psoralen, xanthotoxin, isopimpinellin, angelicin and bergapten as normal constituents of Pastinaca sativa roots. However, the amounts of these compounds were increased in induced roots. The amount of increase in the induced roots varied depending on the inducing agent and time of incubation. In addition the results show for the first time the presence of pimpinellin and isobergapten as constitutive antifungal compounds in P. sativa roots.
Performance Modification of Asphalt Binders using Thermoplastic Polymers
Authors: Al-Abdul Wahhab H. I. , Abaker I. 
Published: May 2017

There is a need to improve the performance of asphalt binders to minimize stress cracking that occurs at low temperatures and plastic deformation at high temperatures. Importation of used asphalt-polymers from abroad, leads to an increase in the total construction cost as compared to the cost if the used polymers were of local origin. The main objective of this research was to modify locally produced asphalt. Ten polymers were identified as potential asphalt modifiers based on their physical properties and chemical composition. After preliminary laboratory evaluation for the melting point of these polymers, five polymers were selected for local asphalt modification. In the initial stage, required mixing time was decided based on the relation between shear loss modulus and mixing time .The optimum polymer content was selected based on Superpave binder performance grade specifications.The suitability of improvement was verified through the evaluation of permanent deformation and fatigue behavior of laboratory prepared asphalt concrete mixes. The results indicated that the rheological properties of the modified binders improved significantly with sufficient polymer content (3%). The aging properties of the modified binders were found to be dependent on the type of polymer.The fatigue life and resistance to permanent deformation were significantly improved due to enhanced binder rheological properties. Thus, local asphalts can be modified using thermoplastic polymers.
Kinetics of Hydrodesulfurization of Dibenzothiophene on Sulfided Commercial Co-Mo/γ-Al2O3 Catalyst
Authors: Al-Zeghayer Y.S. , Jibril B.Y. 
Published: May 2017

Kinetics of hydrodesulfurization of dibenzothiophene (DBT) has been studied on a commercial CoMo/γ-Al2O3 catalyst at 633 - 683 K and 10 atm. A low DBT concentration typically obtained in hydrodesulfurization operations was used. Pseudo-first-order model was found to fit the experimental data for the consumption of DBT. The activation energy for the conversion of DBT was found to be 51.7 kcal/mol. Biphenyl (BP) and cyclohexylbenzene (CHB) were obtained as dominant products. For the reaction network, both parallel and parallel-sequential routes were explored. The latter was found to give a better description of the BP and CHB distributions. The ratio of BP to CHB depended on the reaction temperature. The values of activation energies of DBT hydrogenolysis to BP (EBP), DBT hydrogenation to CHB (ECHB1) and hydrogenation of BP to CHB (ECHB2) were found to be in a decreasing order of ECHB2 > EBP > ECHB1. The result suggests the presence of different catalytic sites leading to the two products on the catalysts.
Study of Date Palm Stem as Raw Material in Preparation of Activated Carbon
Authors: Houache O. , Al-Maamari R. , Al-Rashidi B. , Jibril B. 
Published: May 2017

Activated carbon adsorbent was prepared using Omani date palm tree stem as a precursor. Precursor samples were subjected to thermal treatment (at 400, 500 and 600 oC) before or after impregnation with either H3PO4 (85 wt %) or KOH (3 wt %). The activated carbon obtained was characterized by BET (surface area and porosity), Gas Pycnometry (true density) and SEM (texture). Sample subjected to carbonization, without chemical activation, exhibited low surface areas ~ 1.0 m2/g at 400 and 500 oC and 124 m2/g at 600 oC. Further treatment of such samples with either the acid or the base did not show improvement in surface area or other properties. Impregnations of the precursor with acid before carbonization significantly improved the surface area to as high as 1,100 m2/g at a carbonization temperature of 500 oC. Thus, activated carbon with a moderate surface area could be produced from date palm stem using low carbonization temperature.
Exploring Possible Seasonal Trends in Mortality Rate in Relation to Age, Gender and Environmental Conditions in Kuwait: A Preliminary Analysis
Authors: Al-Rifaia N. , Elmi A. , Khan A.R. 
Published: May 2017

Inherently, Kuwait a high frequency of dusty events through out the year due to its arid climate. Particulate air pollution has been linked to increased mortality due to various illnesses. For the purpose of improving health services, it is important to develop/establish an empirical basis for the possible link between mortality and air quality. In this paper, we examined mortality rates in Kuwait in relation to age, sex and dust episodes during a five-year period. Each year was divided into four seasons to detect any potential episodes in the death rate for a particular season. The results showed that the mortality rates did not correlate significantly (p = 0.67) with the occurrence of total dust events. Contrary to the popular perception in Kuwait that illnesses and, consequently, deaths increased in recent years as a result of deteriorating air quality due to particulate matter, the collected data did not show a consistent temporal trend. While this work represents an initial effort on an important issue upon which further investigations can be elaborated upon, a more detailed data have to be collected and analyzed.
Competitividade da Indústria de Couro e Calçados de Sri Lanka
Authors: Kusum P.P. Ajith , Yinghua Song 
Published: May 2017

This research paper explores the relationship among skills of entrepreneurs of leather products and footwear industry in Sri Lanka and entrepreneurs’ involvement of innovations in product, process, raw material and market in the industry. Further, the survey investigates firms’ competitiveness and innovativeness in the industry. Database of firms in the industry available in Sri Lanka Industrial Development Board was used to administer an expert reviewed and piloted questionnaire among the population of firms. Personal interviews and a mail survey were undertaken which jointly brought above-average response rate of completed questionnaires used for analysis. The research has found that there is a strong link between skills of entrepreneurs and their involvement in innovations. Research has found that entrepreneur focus on product innovations rather than process, raw material and market innovations due to their low level of general education and the main mode of acquiring skills remains on-the-job-training. Usage of technology has been found to be lower level which has a negative effect on innovations. However, the entrepreneurs have a positive attitude towards innovations the relevant agencies can capitalize-on for expansion of the industry and increase competitiveness. The research unearths an intelligent view that in an efficiency-driven economy, what matters is productivity where skilling of entrepreneurs will yield enormous results for harnessing the potential of this ever growing industry.
Splenomegaly in small‐breed dogs: 45 cases(2005–2011)
Authors: Corbin Erin E. , Cavanaugh Ryan P. , Schwartz Pamela , Zawadzki Katherine I. , Donovan Taryn 
Published: May 2017

Abstract
OBJECTIVE
To assess causes of splenomegaly and postsurgical outcomes in small-breed (ie, < 16-kg [< 35.2-lb]) dogs that underwent splenectomy and evaluate associations among malignant disease, hemoperitoneum, and survival time in these patients.
DESIGN
Retrospective case series.
ANIMALS
45 client-owned dogs.
PROCEDURES
Medical records of 2 veterinary facilities were reviewed to identify small-breed dogs that underwent splenectomy and had a histologic diagnosis recorded. Data analyzed included signalment, diagnosis, presence or absence of hemoperitoneum, and survival time.
RESULTS
21 dogs had malignant neoplasia and 24 had benign splenic diseases. Hemangiosarcoma was the most common malignancy (14/21 [67%] dogs) and lymphoid nodular hyperplasia, hematoma, or extramedullary hematopoiesis (alone or in combination) was most commonly diagnosed in dogs with benign disease (17/24 [71%]). Wheaton Terriers were significantly more likely to have malignant splenic disease than were dogs of other breeds. Malignant splenic disease and the presence of hemoperitoneum had significant negative associations with survival time. Malignant disease was not significantly associated with the presence of hemoperitoneum.
CONCLUSIONS AND CLINICAL RELEVANCE
Causes for splenomegaly and survival times were similar to those previously reported for populations that primarily included large-breed dogs. There were approximately equal numbers of benign and malignant causes for splenomegaly in this population. Results suggested that Wheaton Terriers with splenomegaly had a higher likelihood of malignant neoplasia than other breeds and that hemoperitoneum may not be a significant predictor of malignancy in small-breed dogs. However, further research including a larger number of dogs is needed to confirm these findings. (J Am Vet Med Assoc 2017;250:1148–1154)