Optimal orientation angles for maximizing energy yield for solar PV in Saudi Arabia

This paper uses research-quality, ground measurements of irradiance and temperature that are accurate to ±2% to estimate the electric energy yield of fixed solar modules for utility-scale solar power plants at 18 sites in Saudi Arabia. The calculation is performed for a range of tilt and azimuth angles and the orientation that gives the optimum annual energy yield is determined. A detailed analysis is presented for Riyadh including the impact of non-optimal tilt and azimuth angles on annual energy yield. It is also found that energy yield in March and October are higher than in April and September, due to milder operating temperatures of the modules. A similar optimization of tilt and azimuth is performed each month separately. Adjusting the orientation each month increases energy yield by 4.01% compared to the annual optimum, but requires considerable labour cost. Further analysis shows that an increase in energy yield of 3.63% can be obtained by adjusting the orientation at five selected times during the year, thus significantly reducing the labour requirement. The optimal orientation and corresponding energy yield for all 18 sites is combined with a site suitability analysis taking into account climate, topography and proximity to roads, transmission lines and protected areas. Six sites are selected as having high suitability and high energy yield: Albaha, Arar, Hail, Riyadh, Tabuk and Taif. For these cities the optimal tilt is only slightly higher than the latitude, however the optimum azimuth is from 20° to 53° west of south due to an asymmetrical daily irradiance profile

Structural and Stratigraphic 3D Seismic Study of NahrUmr and Zubair Formations in Kifl oil field _ center of Iraq

This research is a reflection seismic study (structural and stratigraphic) of a 268.7 km2 area located in the central Iraq within the Karbala province (Kifl area). The study area was interpreted by using 3-D seismic data from Oil Exploration Company. Synthetic traces are prepared by using available data of the four wells (Kf-1), (Kf-2), (Kf-3) and (Kf-4), in order to define and piking the reflector on seismic section, These reflector are: (NahrUmr, Shuaiba, Zubair and Ratawi Formations) which are deposited during the lower cretaceous age. Faults were picked using instantaneous phase attribute of seismic section across 3D seismic volume of the studied reflectors. The study area affected by a major fault and minor normal faults, Two faults system has been observed in the study area; the major normal fault of (NW-SE) trending and minor normal faults of (NE-SW) trending, with a small displacement are influenced the studied reflectors. The time slices were studied across 3D seismic volume of the studied reflector, they proved the presence the structural anticline at lower cretaceous reflection level. Time, velocity and depth maps are prepared depending on the structural interpretation of the picked reflectors, the structural interpretation of these reflectors shows a structural anticline extending in NW-SE trend and plunges to the south east, and the general dip towards the east. Using seismic attribute techniques including (instantaneous frequency, RMS amplitude maps and reflection strength section), these attributes showed decreasing in frequency, amplitude and strength values. These reflect rocks of low velocity and indicate the presence of hydrocarbon accumulation area. The study of seismic facies of the picked reflectors distinction parallel seismic configuration. The results shows the Zubair and NahrUmrfacies are clastic depositional system deposited on delta platform, Zubair represents delta platform facies consisting of shallow- water, high-energy marine (delta sandstone, channel-fill sandstones).Pinch out are picked and interpreted by using cosine instantaneous phase attributes, these phenomena can be regarded as Pinch out stratigraphical traps. It's the main factor to explain the difference in thickness of the oil column between well Kf-4 and well Kf-1. Mound and Flat spot phenomenon has been observed within Zubair reflector by using the seismic composite attributes (Band bass filter on an instantaneousphase attributes, as mound stratigraphic traps and flat spot which is represent of Direct Hydrocarbon Indicators (DHI) that refers to the presence of hydrocarbons. Where the use of this techniques has helped to identify the (DHI) for hydrocarbon accumulation and have not been previously identified.Finally 3D seismic model for Kifl field show the extension of structural anticline and its plunge and the distribution of hydrocarbons accumulations in the Kifl field

Assessment of off-shore wind turbines for application in Saudi Arabia

This paper presents models and economic analysis of ten different wind turbines for the region of Yanbu, Saudi Arabia using the hybrid optimization models for energy resources (HOMER) software. This study serves as a guide for decision makers to choose the most suitable wind turbine for Yanbu to meet the target of 58.7GW of renewable energy as part of Saudi Vision 2030. The analysis was carried out based on the turbines initial capital cost, operating cost, net present cost (NPC) and the levelized cost of energy (LCOE). Additionally, the wind turbines were compared based on their electricity production, excess energy and the size of the storage devices required. The results show that Enercon E-126 EP4 wind turbine has the least LCOE (0.0885 $/kWh) and NPC ($23.8), while WES 30 has the highest LCOE (0.142 $/kWh) and NPC ($38.3) for a typical load profile of a village in Yanbu

Utility of Magnetic Resonance Imaging T2* in Diagnosing and Monitoring Severe Cardiac and Hepatic Siderosis

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A Novel Water Quality Index for Iraqi Surface Water

هدفت هذه الدراسة الى بناء موديل لنوعية المياه يكون مناسب للنظم المائية العراقي ويعكس الواقع البيئي للمياه العراقية. دليل نوعية المياه العراقية المطور يتضمن عوامل فيزيائية وكيميائية. من اجل بناء دليل نوعية المياه العراقي IQWQI  تم استخدام طريقة دلفي للتواصل مع الخبراء المحلين والعالميين المختصين بنوعية المياه لغرض الحصول على اراءهم بخصوص اهم العوامل المهمة التي يمكن استخدامها لبناء الدليل وحسب طبيعية النظام البيئي العراقي وتحديد وزن لكل عامل. 70% من البيانات التي تم الحصول عليها من هذه الدراسة قد استخدمت لبناء الدليل و 30% استخدمت لاختبار الدليل. تم تطبيق عدة سيناريوهات لمدخلات الموديل لغرض دراسة تأثير زيادة العوامل. تم بناء الموديل من 4 عوامل لأربع مرات جمع عينات حتى وصل الى 17 عامل لعشرة مرات جمع عينات. ومن الواضح انه عند زيادة عدد العوامل فان قيمة الدليل سوف تتغير. لغرض تقليل التأثير المخفي للعوامل التي تتجاوز المحددات المسموحة والذي يظهر عند استخدام WQI  ولحل هذا التداخل بين النوعية والتلوث فقد اوجدت هذه الدراسة دليل اخر يكون مرتبط بـ IQWQI والذي يضم كلا من درجة النوعية والتلوث. سمي الدليل الثاني دليل المخاطر البيئية ERI ويضم فقط العوامل التي تجاوزت الحدود البيئية المسموح بها. أجري تحليل الحساسية لغرض التنبؤ بقيم IQWQI وتحديد اهم العوامل المؤثرة في قيم IQWQI، تم اختيار موديلين  لأجراء تحليل الحساسية وهما انحدار الشبكة العصبية الاصطناعية والمعتمد على التعلم الالي ((ANNRThe study aims to build a water quality index that fits the Iraqi aquatic systems and reflects the environmental reality of Iraqi water. The developed Iraqi Water Quality Index (IQWQI) includes physical and chemical components. To build the IQWQI, Delphi method was used to communicate with local and global experts in water quality indices for their opinion regarding the best and most important parameter we can use in building the index and the established weight of each parameter. From the data obtained in this study, 70% were used for building the model and 30% for evaluating the model. Multiple scenarios were applied to the model inputs to study the effects of increasing parameters. The model was built 4 by 4 until it reached 17 parameters for 10 sampling times. Obviously, with the increasing number of parameters, the value of the index will change. To minimize the effect of eclipse that arises in WQI and to solve the problem of overlapping quality and pollution, this study has created another index linked with IQWQI, which included both the quality and the degree of pollution. The second index is called the Environmental Risk Index (ERI), where only the variables that exceed the permissible environmental limits were included. Sensitivity Analysis was done to predicate IQWQI and to determine the most influential parameters in the IQWQI score; two types of models were chosen for the run of the sensitivity test, which are the Artificial Neural Network Regression (ANNR) and Backward Linear Regression (BLR). The results of IWOI and ERI for freshwater use during the dry season were very poor water quality with a high degree of risk. While in the wet season, both indices' values ranged from poor water quality to very poor water quality with a high degree of risk

In-vitro application of a qatari burkholderia cepacia strain (QBC03) in the biocontrol of mycotoxigenic fungi and in the reduction of ochratoxin a biosynthesis by aspergillus carbonarius

Mycotoxins are secondary metabolites produced by certain filamentous fungi, causing human and animal health issues upon the ingestion of contaminated food and feed. Among the safest approaches to the control of mycotoxigenic fungi and mycotoxin detoxification is the application of microbial biocontrol agents. Burkholderia cepacia is known for producing metabolites active against a broad number of pathogenic fungi. In this study, the antifungal potential of a Qatari strain of Burkholderia cepacia (QBC03) was explored. QBC03 exhibited antifungal activity against a wide range of mycotoxigenic, as well as phytopathogenic, fungal genera and species. The QBC03 culture supernatant significantly inhibited the growth of Aspergillus carbonarius, Fusarium culmorum and Penicillium verrucosum in PDA medium, as well as A. carbonarius and P. verrucosum biomass in PDB medium. The QBC03 culture supernatant was found to dramatically reduce the synthesis of ochratoxin A (OTA) by A. carbonarius, in addition to inducing mycelia malformation. The antifungal activity of QBC03’s culture extract was retained following thermal treatment at 100 °C for 30 min. The findings of the present study advocate that QBC03 is a suitable biocontrol agent against toxigenic fungi, due to the inhibitory activity of its thermostable metabolites. View Full-TextFunding: Qatar National Research Fund (a member of Qatar Foundation) under National Priorities Research Program (NPRP) grant #NPRP8-392-4-003.Scopu

Effect of some plant extracts on larval mortality against the stem nematode (Ditylenchusdipsaci) and compared with synthetic pesticides

Abstract: Studies were carried out in 2014,in department of plant protection-Damascus University, to determine the nematicidal effect of leaves of Inulaviscosa, dry fruits of Meliaazedaracht, whole plant of Tagetespatula and leaves of Eucalyptus camaldulensis on the stem nematode (DitylenchusdipsaciKühn, 1857)and compared with synthetic pesticides (carbofuran, methomyl, carbaryl and dimethoate) in vitro.The ethanol extracts of the tested plants were the most toxic against D. dipsaci, followed by water extracts. Ethanol extracts of Inulaviscosahad the highest effect on fourth-stage juveniles (J4)the corrected mortality %, (78%&82%), followed by ethanol extract of Meliaazedarachtwhich gave the corrected mortality %, (73%& 77%) after 24 and 48 hrs. of exposer, respectively.The concentration of 100 mg/kg -1 of carbofuran, methomyl, carbaryl and dimethoate gave the corrected mortality %,:94%, 89%, 43% and 65 % of the treated juveniles (J4) nematodes after 48 hrs. Carbofuran and methomyl had better activity as compared to water and methanol extracts of tested plants. When the dead nematodes were studied under the microscope it became apparent that they had either one of four very distinct shapes, namely: straight (I-shape), bent (banana-shape), sigmoid (∑-shape), or curly (∞-shape). We can arranged the effect of plant extraction and pesticides at corrected mortality %: carbofuran>methomyl> Inulaviscosa> Meliaazedarach> dimethoate>Tagetespatula>carbaryl>Eucalyptus camaldulensis.In the consequence, Ethanol and water extracts of leaves of Inulaviscosa and dry fruits of Meliaazedarachtshowed nematicidal activity against Ditylenchusdipsaci under laboratory condition

A preliminary study on whether HbA1c levels can predict visual dependence for spatial orientation in asymptomatic Type 2 diabetic patients

Introduction: Diabetes-induced vestibular dysfunction has been commonly reported, and asymptomatic patients with type 2 diabetes display higher degrees of perceptual visual dependence for spatial orientation than healthy controls. This study aims to assess whether HbA1c can predict such visual dependence in the diabetic patients. Methods and Materials: Diabetic patients were divided into 2 groups: 22 subjects with “good” (HbA1c < 7%) and 25 with “poor” (HbA1c ≥ 7%) glycemic control. Otolithic vestibular function was tested using the computerized rod-and-frame test (CRFT) and results for the two diabetic groups were compared to 29 healthy controls. Results: When the frame was tilted, the diabetic group with “good” glycemic control had largest positioning errors, with a significant difference only in comparison to the control group. The “good” glycemic group exhibited larger degree of asymmetry under titled frame condition. Although HbA1c was not associated with vestibular asymmetry in any diabetic group, it was significantly associated with visual dependence in the “good” glycemic group. During frame tilts, 10 diabetic patients had positioning errors above the reference range of 3.3°, 8 of which belonged to the “good” glycemic diabetic group. Conclusions: Diabetes disease processes may affect vestibular symmetry during visuo-vestibular conflicts, even in asymptomatic diabetics within the recommended glycemic range. The weak correlations between HbA1c and CRFT parameters may indicate that HbA1c cannot fully predict visual dependence or asymmetry on the CRFT in patients with diabetes, and different glycemic disorders may affect vestibular dependent spatial orientation in diabetic patients

Relationship between Social Anxiety and Parental Authority among College of Education Students’ at SQU

The purpose of this study was to explore the relationship between parental authority and social anxiety. The study attempted to answer the following question: Are there significant differences in social anxiety due to parental authority factors: (support, control, psychological control, emotion and accomplishment of missions)? Data was collected from 172 students of College of Education at Sultan Qaboos University. The Parental Authority Questionnaire (FAQ), and Social Anxiety Scale (SAS) were used to assess variables. To answer the study question, re- gression analysis was used. Findings indicated that there was significant relationship between parental authority and social anxiety in several domains. The findings also revealed that there were significant differences in social anxiety due to mother authority and student's gender