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Search Results: 1 - 10 of 415979 matches for " Yousef M. Al-Yousef "
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Synthesis of Ba0.5Sr0.5Co0.2Fe0.8O3 (BSCF) Nanoceramic Cathode Powders by Sol-Gel Process for Solid Oxide Fuel Cell (SOFC) Application  [PDF]
Mohammad Ghouse, Yousef M. Al-Yousef
World Journal of Nano Science and Engineering (WJNSE) , 2011, DOI: 10.4236/wjnse.2011.14016
Abstract: The nano ceramic Ba0.5Sr0.5Co0.2Fe0.8O3 (BSCF) powders have been synthesized by Sol-Gel process using nitrate based chemicals for SOFC applications since these powders are considered to be more promising cathode materials for SOFC. Glycine was used as a chelant agent and ethylene glycol as a dispersant. The powders were calcined at 850℃/3 hr in the air using Thermolyne 47,900 furnace. These powders were characterized by employing SEM/EDS, XRD and TGA/DTA techniques. The SEM images BSCF powder indicate the presence of highly porous spherical particles with nano sizes. The XRD results shows the formation of BSCF perovskite phase at the calcination temperature of 850℃. From XRD line broadening technique, the average crystllite size of the BSCF powders were found to be around 9.15 - 11.83 nm and 13.63 - 17.47 nm for as prepared and after calcination at 850℃ respectively. The TGA plot shows that there is no weight loss after the temperature around 450℃ indicating completion of combustion.
Preparation of La0.6Ba0.4Co0.2Fe0.8O3 (LBCF) Nanoceramic Cathode Powders by Sol-Gel Process for Solid Oxide Fuel Cell (SOFC) Application  [PDF]
Y. M. Al-Yousef, M. Ghouse
Energy and Power Engineering (EPE) , 2011, DOI: 10.4236/epe.2011.33049
Abstract: The La0.6Ba0.4Co0.2Fe0.8O3 (LBCF) nano ceramic powders were prepared by Sol-Gel process using nitrate based chemicals for SOFC applications since these powders are considered to be more promising cathode materials for SOFC. Citric acid was used as a chelant agent and ethylene glycol as a dispersant. The powders were calcined at 650oC/6 h, 900oC/3 h in air using Thermolyne 47,900 furnace. These powders were charac terized by SEM/EDS, XRD and Porosimetry techniques. The SEM images indicate that the particle sizes of the LBCF powders are in the range of 50 - 200 nm. The LBCF perovskite phases are seen from the XRD patterns. From XRD Line broadening technique, the average particle size for the powders (as prepared and calcined at 650oC/6 h and 900oC/3 h) were found to be around 12.97 nm, 22.24 nm and 26 nm respectively. The surface area of the LBCF powders for the as prepared and calcined at 650oC were found to be 28.92 and 19.54 m2/g respectively.
A Survey Study on the Distribution of Saudi Baladi Chickens and Their Characteristics
Yousef M. Al-Yousef
International Journal of Poultry Science , 2007,
Abstract: Two surveys were conducted to determine the distribution and Characteristics of the local (baladi) chickens of Saudi Arabia. The results of the two surveys provided evidence that: 1. Local chickens exhibit large variations in body shape, feather color, comb type and shank color. They are small in size. 2. Most of the large baladi project (>1000 layers) were found in Makkah, Jedda and Madina. Medium size farms (250 - 600 hens) were found in Qasim, Madina, Makkah, Durma and Qatif. Smaller size farms (< 250 hens) were found in Makkah, Qasim and Hofuf. 3. Twenty three % of the large baladi projects were Poultry producers raising chicks as the main source of their income. 4. Eighty % of the small projects raise the baladi chickens along with other animals. 5. Average flock size of the large farms was 3479 birds. 6. Average marketing age of the birds were 14.6 weeks. 7. Baladi hens lay their 1st egg at 22.76 week of age and continue laying for 78.9 weeks producing 170 eggs. 8. Nine % of the large projects` owners found that New Castle disease (ND) was the most frequent occurring disease. All chickens owners vaccinate their birds against ND while 33 % vaccinate against Fowl pox. 9. About 80 % of small farms owners are making use of the broodiness phenomena to hatch eggs while only 8 % use small incubators for that purpose.
Breast and Ovarian Cancer in Young Women of the Arabian Gulf Region: Relationship to Age  [PDF]
Sarah Al-Gahtani, Suhair Abozaid, Elham Al-Nami, Leen Merie, Ayana Al-Yousef, Mohamed M. Shoukri
Open Journal of Epidemiology (OJEpi) , 2016, DOI: 10.4236/ojepi.2016.63019
Abstract: It is widely known that cancer is a disease of “old-age”. However available data show that this is not the case for many types of cancers. Incidences of breast and ovarian cancers have varying rates of change with age. Breast cancer data of Arabian-gulf women, show that the incidence rates increase with age and reach a maximum at 39 year. It then declines linearly with age to about 55 years. The rate of increase and its changes with age are similar to those of many other countries. In the premenopausal phase the relationship between incidence and age could be adequately modeled using a linear model for the logarithmic transformations of age and incidence. Similar observations are made for the ovarian cancer incidences. Results: It is shown that the rate of increase in breast and ovarian cancer incidence with respect to age is increasing in the premenopausal ages. Moreover, the burden of the disease with respect to mortality and “Disability Adjusted Life Years” or DALY, varied considerably among the six gulf countries. Conclusions: We conclude, based on the age incidence relationship that the number of cancer cases may double in the next period that follows our study period (1998-2009). Moreover, if the six countries have identical relationship between age and the two types of cancer, there should be an integrated and unified effort to have a common strategy for prevention and control.
p16INK4A Positively Regulates Cyclin D1 and E2F1 through Negative Control of AUF1
Huda H. Al-Khalaf, Dilek Colak, Maher Al-Saif, Albandary Al-Bakheet, Siti-Faujiah Hendrayani, Nujoud Al-Yousef, Namik Kaya, Khalid S. Khabar, Abdelilah Aboussekhra
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0021111
Abstract: Background The cyclin-D/CDK4,6/p16INK4a/pRB/E2F pathway, a key regulator of the critical G1 to S phase transition of the cell cycle, is universally disrupted in human cancer. However, the precise function of the different members of this pathway and their functional interplay are still not well defined. Methodology/Principal Findings We have shown here that the tumor suppressor p16INK4a protein positively controls the expression of cyclin D1 and E2F1 in both human and mouse cells. p16INK4a stabilizes the mRNAs of the corresponding genes through negative regulation of the mRNA decay-promoting AUF1 protein. Immunoprecipitation of AUF1-associated RNAs followed by RT-PCR indicated that endogenous AUF1 binds to the cyclin D1 and E2F1 mRNAs. Furthermore, AUF1 down-regulation increased the expression levels of these genes, while concurrent silencing of AUF1 and p16INK4a, using specific siRNAs, restored normal expression of both cyclinD1 and E2F1. Besides, we have shown the presence of functional AU-rich elements in the E2F1 3′UTR, which contributed to p16/AUF1-mediated regulation of E2F1 post-transcriptional events in vivo. Importantly, genome-wide gene expression microarray analysis revealed the presence of a large number of genes differentially expressed in a p16INK4a -dependent manner, and several of these genes are also members of the AUF1 and E2F1 regulons. We also present evidence that E2F1 mediates p16-dependent regulation of several pro- and anti-apoptotic proteins, and the consequent induction of spontaneous as well as doxorubicin-induced apoptosis. Conclusion/Significance These findings show that the cyclin-dependent kinase inhibitor p16 INK4a is also a modulator of transcription and apoptosis through controlling the expression of two major transcription regulators, AUF1 and E2F1.
Modeling the Effect of Variable Timing of the Exhaust Valves on SI Engine Emissions for Greener Vehicles  [PDF]
Osama H. M. Ghazal, Yousef S. H. Najjar, Kutaeba J. M. Al-Khishali
Energy and Power Engineering (EPE) , 2013, DOI: 10.4236/epe.2013.53018

The problem with fixed valve timing that the valve train is set by the automaker for peak efficiency running at a specific point in the engines operating range. When the vehicle is moving slower or faster than this ideal operating point the engines combustion cycle fails to properly burn the air/fuel mixture leading to considerably compromised engine performance and wastes fuel. Variable Valve Timing (VVT) is a solution developed to overcome this engine deficiency, dynamically altering the valve's opening and closing for optimal performance at any speed. The intension in this work is to contribute towards pursuing the development of variable valve timing (VVT) for improving the engine performance. This investigation covers the effect of exhaust valve opening (EVO), and closing (EVC) angle on engine performance and emissions. The aim is to optimize engine power and brake specific fuel consumption (BSFC) where the effect of engine speed has also been considered. Power, BMEP, BSFC, NO, and CO were calculated and presented to show the effect of varying valve timing on them for all the valve timing cases. The calculations of engine performance were carried out using the simulation and analysis engineering software: LOTUS”, and engine emissions were calculated using “ZINOX” program. Sensitivity analysis shows that the reduction of 10% of (EVO) angle gave a reduction of around 2.5% in power and volumetric efficiency, also a slight increase in nitrogen oxide (NO) and carbon monoxide (CO), while a 10% decrease in (EVC) causes around 1% improvement in Power. The effects of different (VVT) from the simulations are analyzed and compared with those in the reviewed literature.

Modeling and Simulation Study of Space Data Link Protocol  [PDF]
Ismail Hababeh, Rizik M. H. Al-Sayyed, Ja’far Alqatawna, Yousef Majdalawi, Marwan Nabelsi
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2014, DOI: 10.4236/ijcns.2014.710045
Abstract: This research paper describes the design and implementation of the Consultative Committee for Space Data Systems (CCSDS) standards REF _Ref401069962 \r \h \* MERGEFORMAT [1] for Space Data Link Layer Protocol (SDLP). The primer focus is the telecommand (TC) part of the standard. The implementation of the standard was in the form of DLL functions using C++ programming language. The second objective of this paper was to use the DLL functions with OMNeT++ simulating environment to create a simulator in order to analyze the mean end-to-end Packet Delay, maximum achievable application layer throughput for a given fixed link capacity and normalized protocol overhead, defined as the total number of bytes transmitted on the link in a given period of time (e.g. per second) divided by the number of bytes of application data received at the application layer model data sink. In addition, the DLL was also integrated with Ground Support Equipment Operating System (GSEOS), a software system for space instruments and small spacecrafts especially suited for low budget missions. The SDLP is designed for rapid test system design and high flexibility for changing telemetry and command requirements. GSEOS can be seamlessly moved from EM/FM development (bench testing) to flight operations. It features the Python programming language as a configuration/scripting tool and can easily be extended to accommodate custom hardware interfaces. This paper also shows the results of the simulations and its analysis.
Fasting ramadan in kidney transplant patients is safe
Boobes Yousef,Bernieh Bassam,Al Hakim M
Saudi Journal of Kidney Diseases and Transplantation , 2009,
Abstract: Muslims with renal transplant often ask their doctors whether fasting Ramadan is safe. Scanty studies have addressed this question. This prospective study was undertaken to identify any clinical or biological changes with Muslim fasting. 22 kidney transplant patients with stable kidney functions, who were transplanted for more than one year, and voluntarily chose to fast during Ramadan in 1425 H (October-November 2004), were studied. Total of 22 subjects (10 men and 12 women) with a mean age of 47 ± 11.6 years were studied. Full clinical and biological assessment was done before during and after the month of Ramadan fasting. Medications were taken in two divided doses at sunset (time of breaking the fast) and pre dawn (before the fast). None of the patients experienced any undue fatigue, or symptoms. Body weight, blood pressure, kidney function tests, blood sugar, lipid profile, and cyclosporine levels remained stable. In conclusion it is safe for renal transplant recipients of more than one year and having stable graft function to fast during the month of Ramadan; however caution is advised for moderate to severe impaired renal function.
The Impact of a Structured Clinical Pathway on the Application of Management Standards in Patients with Diabetic Ketoacidosis and Its Acceptability by Medical Residents  [PDF]
Imad S. Hassan, Azzam D. Al-Otaibi, Meteb M. Al-Bugami, Salih Bin Salih, Yousef Al Saleh, Salman Abdulaziz
Journal of Diabetes Mellitus (JDM) , 2014, DOI: 10.4236/jdm.2014.44038
Abstract: Diabetic Ketoacidosis (DKA) is a serious and potentially a fatal complication of diabetes mellitus. Tools to guarantee proper, evidence-based, guideline implementation are of paramount importance and an essential element for quality patient care. Clinical pathways represent one such tool that clearly promotes the implementation of guidelines and research evidence into clinical practice. The aims of this study were to measure quantitatively and qualitatively the impact of a specially structured Resident-friendly, DKA clinical pathway on the application of evidence-based management standards and its acceptability by the treating resident physicians. A retrospective chart review of patients who were admitted prior to and after the launching of the clinical pathway and a questionnaire assessment of resident’s acceptance of the pathway format were undertaken. Eighty one episodes of DKA in a total of 58 patients fulfilled the criteria for inclusion in the study. Thirty seven admissions were on the pathway (45.7%) and 44 were not (54.3%). Documentation of severity indices of patients who were admitted under the pathway were significantly improved with a trend for a shorter hospital stay. The duration of intravenous insulin therapy, intensive care unit consultation and diabetes educator involvement in patient care were not different between the two groups. Residents found the pathway user-friendly, educationally very valuable, reduced their workload and had a positive effect on their DKA management skills. Conclusions: Use of specially structured, resident-friendly pathway led to significant improvement in documentation of DKA severity indices and empowered our residents with evidence-based knowledge and skills to deal with this serious diabetic complication.
An Architecture of the Lexicon: New Perspectives
Sabri Alshboul,Yousef Al shaboul,Suhail M.Asassfeh
Studies in Literature and Language , 2011, DOI: 10.3968/j.sll.1923156320110203.010
Abstract: Most approaches to inflectional morphology propose a synchronic account for the establishment of defaultness in the plural inflection. The current research aims at exploring the representation of the default system in JA at a diachronic level. The grammar of JA displays two default plural forms: the sound feminine plural marked with the suffix –aat (e.g.mataar/matar-aat 'an airport/airports') where a suffixation rule predicts the occurrence of the default plural. The second default plural is the iambic broken plural marked with an internal vowel change (short–long vowel) (kursi/karaasi 'a seat /seats'). Our diachronic analysis would take into account the default shift that occurred in the grammar of JA in two different periods: the Turkish period and the British period. The findings reveal the importance of the diachronic factors in determining the status of ‘defaultness’ in terms of the ability of the lexicon to accept two default inflections. So, JA consists a hierarchy that contains two defaults: the iambic broken plural and the sound feminine plural. This mechanism of accepting two defaults gives insights into applying this multiple default format crosslinguistically in which a grammar of a language can host a multiple default system. Key words: Defaultness; Jordanian Arabic; Diachronic Default; Sound Feminine; Plural; Iambic Broken Plural
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