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Search Results: 1 - 10 of 9386 matches for " Ahmed Ihlal "
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Experimental Investigation of Effects of Electric Operating Parameters on Pulsed Corona Discharges in Humid Air at Atmospheric Pressure  [PDF]
Hasna Guedah, Alyen Abahazem, Nofel Merbahi, Mohamed Yousfi, Karim Saber, Ahmed Ihlal
Journal of Analytical Sciences, Methods and Instrumentation (JASMI) , 2018, DOI: 10.4236/jasmi.2018.84005
Abstract:
The present work is devoted to electrical and optical study of a point-plane atmospheric pressure corona discharge reactor in humid air powered by pulsed high voltage supply. The corona current and the injected energy are analyzed as a function of several parameters such as applied voltage and humidity rate. Then, investigations based on emission spectroscopy analysis were used in UV range (from 200 nm to about 400 nm). The main observed excited species were the second positive (SPS), the first negative (FNS) systems and OH(A-X) rotational bands. The latter band was used to simulate the rotational temperature (Tr), whereas the N2+ (FNS) band was used to determine the vibrational temperature (Tv). The electron temperature (Te ) is determined from the ratio of line intensities of the spectral bands of both N2+ FNS at 391.4 nm and N2SPS at 394.4 nm. The rotational, vibrational and electronic temperatures are analyzed as a function of above parameters (applied voltage, frequency and hygrometry rate) near the anodic tip. As well we study the axial variation of electronic temperature for a fixed applied voltage at 6.4 kV, frequency at 10 kHz and 100% of humidity. It is found that the rotational, vibrational and electronic temperatures increased with increasing applied voltage, frequency and humidity rate. The increase of rate hygrometry for an inter-electrode distance fixed at 10 mm causes an increase in both the amplitude of the corona current discharge and the energy injected in corona discharge. This is indicative of more intense reactive plasma while increasing hygrometry rate.
Structural and Optical Properties of Thin Films Prepared by Flash Evaporation
K. Bouabid,A. Ihlal,A. Outzourhit,E. L. Ameziane
Active and Passive Electronic Components , 2004, DOI: 10.1080/08827510310001648899
Abstract: In2S3thin films were deposited by flash evaporation of In2S3 powder. The effect of annealing in vacuum and under sulphur atmosphere on the structural and optical properties of these films was investigated. X-ray diffraction studies reveal that the as-deposited films are amorphous. The formation of β-In2S3 phase is obtained after annealing under vacuum at 693 K. Heat treatments under sulphur pressure lead to the formation of the above phase at a less annealing temperature (573 K). The energy dispersive X-ray (EDX) analysis reveals that the sulphurized films are nearly stoichiometric and those annealed in vacuum are sulphur deficient. Optical transmission spectra showed a slight shift of the absorption edge towards lower wavelengths. The optical gap value varied between 2.4 and 3 eV as a function of the film thickness and the annealing temperature.
Treatment of Chronic Lateral Epicondylitis: Platelet Rich Plasma versus Extra-Corporeal Shock Wave Therapy  [PDF]
Ahmed Mohamed Ahmed Othman
Open Journal of Orthopedics (OJO) , 2014, DOI: 10.4236/ojo.2014.43013
Abstract: Background: Several treatment options have been proposed to treat lateral epicondylitis. Both Platelet rich plasma (PRP) and Extra-corporeal Shock Wave Therapy (ESWT) are new treatment modalities for tendinopathy. Patients and Methods: Thirty seven patients suffering from chronic lateral epicondylitis (tennis elbow) for at least six months were treated in this study. The patients were divided into two treatment groups, the first group including 20 patients treated by ESWT and the second group including 17 patients treated by local injection of platelet-rich plasma. The results were evaluated using the visual analogue scale and the DASH score. Results: In the first group (treated by ESWT), the average follow-up period was 21.55 months. The average VAS improved from 8.2 to 1.95 and the average DASH score improved from 72.25 to 51.7. Moreover, 11 cases were satisfied (55%), 3 cases (15%) were satisfied with reservation and 6 cases (30%) were not satisfied. In the second group (treated by PRP), the average follow-up period was 18.47 months. The average VAS improved from 8.52 to 1.47, the DASH score improved from 72 to 48.23. Concerning patient satisfaction, 13 cases were satisfied (83.33%), 3 cases (10.52%) were satisfied with reservation and 1 case (5.55%) was not satisfied. Conclusion: Platelet rich plasma was proved to achieve superior results when compared to ESWT as regards pain relief, improvement of elbow function and patient satisfaction at follow-up.
Open versus Arthroscopic Treatment of Post-Traumatic Stiff Elbow  [PDF]
Ahmed Mohamed Ahmed Othman
Open Journal of Orthopedics (OJO) , 2014, DOI: 10.4236/ojo.2014.411047
Abstract: Thirty three patients with post-traumatic stiff elbow were divided into two groups. The first group included 18 patients with an average age of 31.05 years treated by open arthrolysis. The second included 15 patients with an average age of 31.66 years treated by arthroscopic method. The results were evaluated using the Mayo clinic score and DASH score for elbow function. In the open group, after an average period of follow-up 19.33 months, the average range of flexion-extension movement improved from 51.11° to 103.94°. The average Mayo clinic score improved from 63.38 to 92.83 and the average DASH score improved from 68.1 to 40.23. There were 13 cases (72.22%) excellent, 4 cases (22.22%) good and 1 case (5.55%) with the poor result. In the arthroscopic group, after an average period of follow-up 17.73 months, the average range of flexion-extension movement improved from 59.46° to 101.53°. The average Mayo clinic score improved from 62.93 to 92.73 and the average DASH score improved from 69.25 to 46.4. There were 10 cases (66.66%) excellent, 3 cases (20%) good and 2 cases (13.33%) with the poor result. Both open and arthro-scopic treatment can be effective in treatment of post-traumatic stiff elbow. Arthroscopic treatment is associated with less post-operative pain and morbidity. However, open treatment provides better range of motion and marked improvement of elbow function.
Energy-Efficient and Reliable Transport Protocols for Wireless Sensor Networks: State-of-Art  [PDF]
Ahmed Ayadi
Wireless Sensor Network (WSN) , 2011, DOI: 10.4236/wsn.2011.33011
Abstract: New wireless sensor network applications (e.g., military surveillance) require higher reliability than a simple best effort service could provide. Classical reliable transport protocols like Transmission Control Protocol (TCP) are not well suited for wireless sensor networks due to both the characteristics of the network nodes (low computing power, strong energy constraints) and those of the main applications running on those nodes (low data rates). Recent researches present new transport protocols for wireless sensor networks providing various type of reliability and using new mechanisms for loss detection and recovery, and congestion control. This paper presents a survey on reliable transport protocol for WSNs.
Modular Spaces Topology  [PDF]
Ahmed Hajji
Applied Mathematics (AM) , 2013, DOI: 10.4236/am.2013.49175
Abstract:

In this paper, we present and discuss the topology of modular spaces using the filter base and we then characterize closed subsets as well as its regularity.

Acquisition of the Inter-Dental Fricatives /θ/ and /ð/ in ESL/EFL and Jamaican Creole: A Comparative Study  [PDF]
Ahmed Mousa
Open Journal of Modern Linguistics (OJML) , 2014, DOI: 10.4236/ojml.2014.41004
Abstract:

This study aims at investigating to what extent the linguistic processes exhibited in creolization parallel those manifested by Arab learners of English in particular and those of child language and second/foreign language in general. Another aim of the study is to highlight the link between second/foreign language learning and historical change. To this end, the speech of two speakers of the Broad Jamaican Creole was compared with the performance of Saudi school and university learners of English as a foreign language and data from child language, with respect to the pronunciation of English inter-dental fricatives /θ/ and /e/. The results show that learning in the above three situations takes place according to the same principles. Furthermore, the sound substitutions made in the three situations (i.e. [t], [d] respectively) are the same as those witnessed in historical sound change.

Does FDI Crowd in or out Domestic Investment? New Evidence from Emerging Economies  [PDF]
Ahmed Kamaly
Modern Economy (ME) , 2014, DOI: 10.4236/me.2014.54038
Abstract: Foreign direct investment (FDI) has been for a while now an acronym associated with improvement in competitiveness and economic growth. To assess the expediency of FDI, it is imperative to answer the following question: what is the dynamic effect of FDI on total investment? In other words, what is the effect of FDI on domestic investment (DI); does it crowd in or out domestic investment? Research addressing this question is relatively recent and its empirical findings are ambiguous. This paper attempts to dodge the pitfalls in the theoretical and especially the empirical literature in assessing the link between FDI and domestic investment. The paper develops a simple theoretical model which is commonly used in the literature to come up with a reduced-form equation. Using data on 16 emerging countries over a 30-year period, the empirical model is estimated as a system of equations where each equation represents a country. Grouping all individual country regression in one system of equations aims to take into account the common contemporaneous errors associated with global shocks affecting FDI flows. This system of equations is estimated using 3SLS to account for both the existence of contemporaneous errors among individual country equations as well as the endogeneity of FDI. Results show that in general the effect of FDI on DI is country specific; however, in most countries, on impact, FDI has a positive and significant effect on DI. In subsequent periods, FDI may crowd out DI. In most countries included in the sample, FDI has a neutral long-term effect on DI. Crowding in or crowding out effect of FDI on DI is only found in few countries. This indicates that the rule is the neutrality of FDI on DI and the exception is otherwise (whether crowding in or out).
Assessment and Evaluation of Band Ratios, Brovey and HSV Techniques for Lithologic Discrimination and Mapping Using Landsat ETM+ and SPOT-5 Data  [PDF]
Ahmed Madani
International Journal of Geosciences (IJG) , 2014, DOI: 10.4236/ijg.2014.51002
Abstract:

This study aims to assess and to evaluate band ratios, brovey and HSV (Hue-Saturation-Value) techniques for discrimination and mapping the basement rock units exposed at Wadi Bulghah area, Saudi Arabia using multispectral Landsat ETM+ and SPOT-5 panchromatic data. FieldSpec instrument is utilized to collect the spectral data of diorite, marble, gossan and volcanics, the main rock units exposed at the study area. Spectral profile of diorite exhibits very distinguished absorption features around 2.20 μm and 2.35 μm wavelength regions. These absorption features lead to lowering the band ratio values within the band-7 wavelength region. Diorite intrusions appear to have grey and dark grey image signatures on 7/3 and 7/2 band ratio images respectively. On the false color composite ratio image (7/3:R; 7/2:G and 5/2:B), diorite, marble, gossan and volcanics have very dark brown, dark blue, white and yellowish brown image signatures respectively. Image fusion between previously mentioned FCC ratio image and high spatial resolution (5 meters) SPOT-5 panchromatic image is carried out by using brovey and HSV transformation

Acute Toxicity (Lethal Dose 50 Calculation) of Herbal Drug Somina in Rats and Mice  [PDF]
Muhammad Ahmed
Pharmacology & Pharmacy (PP) , 2015, DOI: 10.4236/pp.2015.63019
Abstract: Somina (herbal preparation) prepared by Hamdard Laboratories (Waqf) Pakistan is a mixture of five different medicinal plants, widely prescribed for the treatment of mental illness. For acute toxicity, the Karber arithmetic method for the calculation of LD50 and Hodge and Sterner toxicity scale was used. In this study, different doses (10, 100, 285, 500, 1000, 5000 and 10,000 mg/kg) of the extract was administered orally to the different groups of rats and mice. Signs of toxicity and possible death of animals were monitored for 24 hrs to calculate the median lethal dose (LD50) of somina. At the end of the study, all the animals in all the dose groups were sacrificed and the internal organ-body was compared with values from the control group. The LD50 was found to be >10,000 mg/kg body weight upon oral administration in mice and rats as no mortality was observed after single dose administration. According to Hodge and Sterner toxicity scale, the obtained value of LD 50 > 10,000 mg/kg classified the Somina as Practically non-toxic herbal medicine.
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