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Search Results: 1 - 10 of 408414 matches for " M. Ben Hassen "
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Comparative Study of the Properties of Plain Knitted Fabrics Made of the Ring and Hybrid Cotton Folded Yarns
F. Zaghouani,M. Ben Hassen,M. Cheikhrouhou
Journal of Applied Sciences , 2007,
Abstract: The objective of present study was to compare plain knitted fabrics comfort properties realized with hybrid and ring cotton folded yarns formed of two single yarns. The quality of the knitted fabric is determined by adiathermic power, air permeability and abrasion resistance. The results indicate that the plain knitted fabrics properties made of hybrid folded yarns are similar to those made of ring folded yarns. In addition to that, we notice that the yarn linear density and the folding twist factor have the most important effect on plain knitted fabrics properties realised with hybrid and ring folded yarns. This result is of a great industrial interest because the hybrid folded yarns costs less dearly than the ring folded yarns. In present study, Statistical models of the prediction are being presenting describing the variation of knitted fabric characteristics with the spinning and folding parameters and single yarns properties.
Generation of Length Distribution, Length Diagram, Fibrogram, and Statistical Characteristics by Weight of Cotton Blends
B. Azzouz,M. Ben Hassen,F. Sakli
Modelling and Simulation in Engineering , 2007, DOI: 10.1155/2007/27521
Abstract: The textile fibre mixture as a multicomponent blend of variable fibres imposes regarding the proper method to predict the characteristics of the final blend. The length diagram and the fibrogram of cotton are generated. Then the length distribution, the length diagram, and the fibrogram of a blend of different categories of cotton are determined. The length distributions by weight of five different categories of cotton (Egyptian, USA (Pima), Brazilian, USA (Upland), and Uzbekistani) are measured by AFIS. From these distributions, the length distribution, the length diagram, and the fibrogram by weight of four binary blends are expressed. The length parameters of these cotton blends are calculated and their variations are plotted against the mass fraction x of one component in the blend .These calculated parameters are compared to those of real blends. Finally, the selection of the optimal blends using the linear programming method, based on the hypothesis that the cotton blend parameters vary linearly in function of the components rations, is proved insufficient.
New Onset of Atrial Fibrillation in a Medical ICU: Prevalence and Risk Factors  [PDF]
S. Della Ayed, S. Ayed, R. Atig, N. Tilouche, H. Ben Sik Ali, R. Gharbi, M. Fekih Hassen, S. Elatrous
International Journal of Clinical Medicine (IJCM) , 2012, DOI: 10.4236/ijcm.2012.37105
Abstract: Objectives: To evaluate the prevalence and the risk factors of new onset atrial fibrillation (AF) in a single medical ICU. Methods: A prospective observational study was conducted in a 10 bed single medical ICU over a period of 18 months. All patients with sinus rhythm admitted in the medical ICU were included. Those presenting with any arrhythmia on admission, having a PACEMAKER or having undergone a recent cardiothoracic surgery were excluded. Results: Of the 377 patients included on the study, atrial fibrillation occurred in 26 patients (7%). Patients who developed AF were older, had higher severity scores on admission, and required significantly more fluids, catecholamine, and mechanical ventilation. They had a longer ICU and hospital LOS. ICU mortality was significantly higher in AF patients. Five inde- pendent risk factors of AF were identified by multivariate analysis: advanced age, the presence of COPD, sepsis, car- diogenic shock, and hypoxemia. Conclusion: AF occurs in approximately 7% of medical critically ill patients and is associated with age, a history of COPD, the presence of sepsis, cardiogenic shock and hypoxemia. AF occurs in more critically ill patients and is associated with increased morbidity and mortality.
Effect of Fiber Weight Ratio and Fiber Modification on Flexural Properties of Posidonia-Polyester Composites  [PDF]
S. Zannen, L. Ghali, M. T. Halimi, M. Ben Hassen
Open Journal of Composite Materials (OJCM) , 2016, DOI: 10.4236/ojcm.2016.63007
Abstract: The main objective of this research is to study the effect of fiber weight ratio and chemical fiber modification on flexural properties of composites reinforced with Posidonia fiber. An unsaturated polyester matrix reinforced with untreated and treated Posidonia fibers was fabricated under various fiber weight ratios. Results showed that the combined chemical treatment provided better mechanical properties of composites in comparison with untreated fiber. The fiber weight ratio influenced the flexural properties of composites. Indeed, a maximum value of flexural modulus was observed for 10% fiber weight ratio for composites reinforced with treated fibers. SEM photographs revealed a different fracture surface between Posidonia fibers reinforced polyester composites.
Modelling Absorbent Phenomena of Absorbent Structure
S. Sayeb,N. Ladhari,M. Ben Hassen,F. Sakli
Journal of Applied Sciences , 2007,
Abstract: Absorption, retention and strike through time, as evaluating criteria of absorbent structures quality were studied. Determination of influent parameters on these criteria were realized by using the design method of experimental sets. In this study, the studied parameters are: Super absorbent polymer (SAP)/fluff ratio, compression and the porosity of the non woven used as a cover stock. Absorption capacity and retention are mostly influenced by SAP/fluff ratio. However, strike through time is affected by compression. Thus, a modelling of these characteristics in function of the important parameter was established.
Effects of Drying on the Biochemical Composition of Atherina boyeri from the Tunisian Coast  [PDF]
Mohamed Ali Ben Smida, Alěs Bolje, Anissa Ouerhani, Manel Barhoumi, Hassen Mejri, M’hamed El Cafsi, Rafika Fehri-Bedoui
Food and Nutrition Sciences (FNS) , 2014, DOI: 10.4236/fns.2014.514152
Abstract:

The effects of solar and experimental drying on the protein concentration and total fatty acid (TFA) content of the muscles of Atherina boyeri (sand smelt) were studied. The percentage of protein was 18.3% for fresh fish and 14.2% for sun-dried fish, while TFA content was 4.9 g/100g and 0.5 g/100g. After the drying experiment, the percentage of protein was 23% and the fatty acid (FA) content was 2.8 g/100g. The results show that natural or experimental drying favors saturated fatty acids. The n-3 polyunsaturated fatty acids (PUFAs) are less sensitive to heat than the n-6 PUFAs. From a nutritional point of view, it seems that the drying conditions, where parameters are T = 50℃, moisture = 30% and air speed = 2 m/s, would be the most beneficial for the preservation of sand smelt.

Modelling Absorption Capacity Performance of Hygienic Product  [PDF]
Soumaya Sayeb, Mohamed Ben Hassen, Faouzi Sakli
Open Journal of Applied Sciences (OJAppS) , 2013, DOI: 10.4236/ojapps.2013.32023
Abstract:

The performance prediction of hygienic products can be a major advantage for manufacturers. Among the interesting performances to be expected, we find the absorption capacity. This is a parameter governed by the composition of the absorbent core, particularly the fibrous component and the characteristics of the superabsorbent polymer (SAP). Thus, various theoretical models have been established to predict the absorption capacity. All these models have taken into account the nature of the fibrous support and the ratio of superabsorbent polymer. Certainly, other factors, less obvious in their modelling, are involved in determining the performance such as the homogeneity of the mixture formed by the fluff and SAP, the distribution of polymer particles in the entire structure, the porous structure, the shape of the capillary, the nature of the nonwoven webs used, etc. Various theoretical models are proposed here to describe the absorption capacity and we will outline the model which best describes this performance. The experimental test results are discussed to verify if the theoretical model selected can be confirmed.

Effect of Blending Ratio of Fibers on the Properties of Nonwoven Fabrics Based of Alfa Fibers  [PDF]
Lassaad Ghali, Mohamed Taher Halimi, Mohamed Ben Hassen, Faouzi Sakli
Advances in Materials Physics and Chemistry (AMPC) , 2014, DOI: 10.4236/ampc.2014.46014
Abstract: Natural fibers are nowadays increasingly employed for making nonwoven, replacing the synthetic materials due to economic and environmental considerations. In this setting, we examine the use of Alfa fibers in nonwoven. Extracted Alfa fibers present satisfying mechanical properties that allow them to be used to produce nonwoven textiles materials. Therefore, Alfa fibers are, mainly, blended with cotton, polyester, Tencel and wool. Webs are prepared using cotton or wool cards in regular width. The nonwoven consolidation is made by needle-punching method. The weight, thickness, air permeability, adiathermic capacity and tensile properties are investigated. The results exhibit that the air permeability increases with the increase of Alfa fibers ratio for the nonwoven Alfa blended with short fibers. It decreases in case of Alfa/Wool blend. We can conclude also that the nonwoven Alfa blended with wool fibers have the highest properties values for all the Alfa fibers blends. Data also revealed that the tensile properties are reduced with the increment of Alfa fibers ratio.
A Gain-Computation Enhancements Resource Allocation for Heterogeneous Service Flows in IEEE 802.16?m Mobile Networks
Wafa Ben Hassen,Meriem Afif
International Journal of Digital Multimedia Broadcasting , 2012, DOI: 10.1155/2012/431958
Abstract: This paper deals with radio resource allocation in fourth generation (4G) wireless mobile networks based on Orthogonal Frequency Division Multiple Access (OFDMA) as an access method. In IEEE 802.16?m standard, a contiguous method for subchannel construction is adopted in order to reduce OFDMA system complexity. In this context, we propose a new subchannel gain computation method depending on frequency responses dispersion. This method has a crucial role in the resource management and optimization. In a single service access, we propose a dynamic resource allocation algorithm at the physical layer aiming to maximize the cell data rate while ensuring fairness among users. In heterogeneous data traffics, we study scheduling in order to provide delay guaranties to real-time services, maximize throughput of non-real-time services while ensuring fairness to users. We compare performances to recent existing algorithms in OFDMA systems showing that proposed schemes provide lower complexity, higher total system capacity, and fairness among users. 1. Introduction In fourth Generation (4G) wireless cellular networks, increasing demands for higher speed data rates transmission, mobility, and multiservice access, have imposed staggering challenges. Therefore, IEEE 802.16 standards propose the use of Orthogonal Frequency Division Multiple Access (OFDMA) among multiple alternatives. OFDMA has become one of the most interesting developments in the area of new broadband wireless networks due to its powerful capability to mitigate Inter-Symbol Interference (ISI), provide high spectral efficiency and immunity of multipath fading. Looking at wireless networks literature, several researches focus on adaptive resource allocation algorithms for single service required by users, in order to achieve some objectives aimed either to minimize total power under data rate constraint, called Margin Adaptive (MA) problem [1–3], or to maximize the total system throughput under power constraints referred as Rate Adaptive (RA) problem [4–6]. However, in practice how to efficiently allocate resources in multiservice wireless networks is not well-explored, nowadays. To resolve this challenge, recent multiservice transmission researches in wireless networks are paid more attention [7–9]. To handle a multiservice access network of heterogeneous traffic, the resource management scheme that can efficiently allocate subchannels to different users and services is essential. The major characteristics of resource allocation algorithms consist of their running time, computational complexity, and
4-Hydroxy-3-[(E)-3-phenylprop-2-enoyl]-2H-chromen-2-one
Afef Ghouili,Rached Ben Hassen
Acta Crystallographica Section E , 2011, DOI: 10.1107/s1600536811029801
Abstract: In the title molecule, C18H12O4, the phenyl ring is twisted by 23.2 (1)° from the mean plane of the chromene system. In the crystal, weak intermolecular C—H...O hydrogen bonds link molecules into zigzag chains extending in the [010] direction. An intramolecular O—H...O hydrogen bond is also present.
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