Growth of homopolymer chain

Thermodynamic and kinetic properties of an homopolymer chain, in two dimensional square lattice, are studied by the use of chain growth algorithm based on the self avoiding walks process. Which is in accord with what happen in nature. All monomers are considered to be hydrophobic. In the thermodynamical study we examine the critical behaviour of the chain by following the evolution of the chain geometry with temperature. This is done by studying the behaviour of the mean distance R chosen to describe the homopolymer structure. Moreover, we give the behaviour of thermodynamic quantities such as conformational energy and specific heat. The effect of a force applied, in a fixed direction, on the chain when it is growing is also investigated. Finally, in a kinetic study, we analyse the evolution with temperature of the mean time necessarily for a given conformation to reach its native state.Thermodynamic and kinetic properties of an homopolymer chain, in two dimensional square lattice, are studied by the use of chain growth algorithm based on the self avoiding walks process. Which is in accord with what happen in nature. All monomers are considered to be hydrophobic. In the thermodynamical study we examine the critical behaviour of the chain by following the evolution of the chain geometry with temperature. This is done by studying the behaviour of the mean distance R chosen to describe the homopolymer structure. Moreover, we give the behaviour of thermodynamic quantities such as conformational energy and specific heat. The effect of a force applied, in a fixed direction, on the chain when it is growing is also investigated. Finally, in a kinetic study, we analyse the evolution with temperature of the mean time necessarily for a given conformation to reach its native state

“Authentic Islam” : the religious profile of Taqī al-Dīn al-Hilālī (1893-1987) as reflected in his fatwas

This study is an examination of the religious profile of Taqī al-Dīn Al-Hilālī (1894-1987) as it evolved throughout the various periods of his life. The study commences with an introduction, beginning with a discussion of the Origins of the Salafiyya in Morocco. The first chapter offers a brief sketch of the formative period of Al-Hilālī’s life. In the second chapter, Al-Hilālī’s attitudes are examined in the light of his early missionary work in Egypt and elsewhere. Chapter Three deals with the first steps in Al-Hilālī’s international preaching. Chapter Four discusses Al-Hilālī's activities during the time he spent in Germany. Chapter Five begins with a discussion of the reason for Al-Hilālī’s departure from Germany in 1942 and his vicissitudes thereafter in Spanish Morocco. Chapter Six discusses Al-Hilālī time in Iraq, where he had settled from 1947 to 1959. Chapter Seven shows how Al-Hilālī was able to lead an active intellectual and religious life in Morocco after Independence. In Chapter Eight, the extent to which Al-Hilālī’s religious profile was affected by his time in Saudi Arabia is examined and assessed. Chapter Nine offers a brief sketch of the final phase in Al-Hilālī’s life and his religious profile based on the unpublished fatwasReligious Studie

Significance of low energy impact damage on modal parameters of composite beams by design of experiments

This paper presents an experimental study on the effects of multi-site damage on the vibration response of composite beams damaged by low energy impacts around the barely visible impact damage limit (BVID). The variation of the modal parameters with different levels of impact energy and density of damage is studied. Vibration tests have been carried out with both burst random and classical sine dwell excitations in order to compare that which of the methods among Polymax and Half Bandwidth Method is more suitable for damping estimation in the presence of damage. Design of experiments (DOE) performed on the experimental data show that natural frequency is a more sensitive parameter for damage detection than the damping ratio. It also highlighted energy of impact as the factor having a more significant effect on the modal parameters. Half Bandwidth Method is found to be unsuitable for damping estimation in the presence of damage

A Novel Approach on Speaker Gender Identification and Verification Using DWT First Level Energy and Zero Crossing

The aim of this work is to find a new criterion for determining a range of values in order to determine the gender of a speaker. The use of the Discrete Wavelet Transform (DWT) of the Daubechies db7 parent wavelet and the computation of the zero crossing energy from the first level of the DWT was followed by computation of the values of the criterion for both genders and comparison with the value of the speech basic frequency for both genders for the same sign or sentence. The standard has a limited range of values close to the basic frequency range of the same speaker through which we can determine gender. This criterion has been tested on several men and women databases with different repeated sentences for the same person or for both genders and it gives acceptable results that can be worked on

Biocontrôle de la fusariose vasculaire du melon par des microorganismes marins

The aim of this work was the biocontrol of Fusarium wilt of melon by marine microorganisms. In vitro screening of fifty marine microorganisms has allowed us to select 27 active strains which eleven were identified and tested in vivo in melon seedlings infected by Fusarium oxysporum f.sp. melonis. The in vivo test was used to select a strain of Chryseomonas luteola, a strain of Pantoea spp. and two Aeromonas hydrophilastrains for biocontrol of Fusarium wilt of melon. Marine microorganisms can be an alternative to fight against phytopathogenic fungi.L’objectif de ce travail a été le biocontrôle de la fusariose vasculaire du melon par des microorganismes marins. Le criblage in vitro de cinquante microorganismes marins nous a permis de sélectionner 27 souches actives dont onze ont été identifiées et testées in vivo chez des plantules de melon infectées par Fusarium oxysporum f.sp. melonis, agent dela fusariose vasculaire. Le test in vivo a permis de sélectionner une souche de Chryseomonas luteola, une souche de Pantoea spp. et deux souches de l’espèce Aeromonas hydrophilapour le biocontrôle de la fusariose vasculaire du melon. Les microorganismes marins peuvent constituer une alternative pour lutter contre les champignons phytopathogènes

dc and ac conductivities of the yLi2O–(1-y)[0.35(MoO3)2–0.65(P2O5) glasses

Glass formation and properties of glasses containing Li2O and MoO3 oxides have been investigated to determine the influence of lithium oxide Li2O in phosphomolybdate glasses. Conductivity spectra have been taken on yLi2O–(1-y)[0.35(MoO3)2–0.65(P2O5)] glasses at various temperatures in the frequency range 10-2Hz – 1MHz. The frequency dependent conductivity is found to display the universal dynamic response behaviour widely observed in disordered solid electrolytes. Contrary to some ion conducting glasses, no typical conductivity scaling was observed for these glasses.Glass formation and properties of glasses containing Li2O and MoO3 oxides have been investigated to determine the influence of lithium oxide Li2O in phosphomolybdate glasses. Conductivity spectra have been taken on yLi2O–(1-y)[0.35(MoO3)2–0.65(P2O5)] glasses at various temperatures in the frequency range 10-2Hz – 1MHz. The frequency dependent conductivity is found to display the universal dynamic response behaviour widely observed in disordered solid electrolytes. Contrary to some ion conducting glasses, no typical conductivity scaling was observed for these glasse

Elaboration and characterization by XRD and SEM of the glass-ceramics in BaTiO3 – NaPO3 system

There is a strong need for low cost glass-ceramic materials whose high chemical stability and dielectric properties can be engineered flexibly in bulk and fiber forms. Therefore we have manufactured transparent ferroelectric glass-ceramics consisting of barium titanate (BT) crystallites in a chain metaphosphate glass matrix. Several glass compositions, in the series (1-x) NaPO3 – x BaTiO3 have been prepared by a conventional melt quenching method. The compositions have been selected on the basis of chemical stability. X-ray diffraction (XRD) and scanning electron microscopy (SEM) indicate the formation of small particle size of BaTiO3 in the glass network when its amount is above 4 mol%.There is a strong need for low cost glass-ceramic materials whose high chemical stability and dielectric properties can be engineered flexibly in bulk and fiber forms. Therefore we have manufactured transparent ferroelectric glass-ceramics consisting of barium titanate (BT) crystallites in a chain metaphosphate glass matrix. Several glass compositions, in the series (1-x) NaPO3 – x BaTiO3 have been prepared by a conventional melt quenching method. The compositions have been selected on the basis of chemical stability. X-ray diffraction (XRD) and scanning electron microscopy (SEM) indicate the formation of small particle size of BaTiO3 in the glass network when its amount is above 4 mol%

A linear CO chemistry parameterization in a chemistry-transport model: evaluation and application to data assimilation

This paper presents an evaluation of a new linear parameterization valid for the troposphere and the stratosphere, based on a first order approximation of the carbon monoxide (CO) continuity equation. This linear scheme (hereinafter noted LINCO) has been implemented in the 3-D Chemical Transport Model (CTM) MOCAGE (MOdèle de Chimie Atmospherique Grande Echelle). First, a one and a half years of LINCO simulation has been compared to output obtained from a detailed chemical scheme output. The mean differences between both schemes are about ±25 ppbv (part per billion by volume) or 15% in the troposphere and ±10 ppbv or 100% in the stratosphere. Second, LINCO has been compared to diverse observations from satellite instruments covering the troposphere (Measurements Of Pollution In The Troposphere: MOPITT) and the stratosphere (Microwave Limb Sounder: MLS) and also from aircraft (Measurements of ozone and water vapour by Airbus in-service aircraft: MOZAIC programme) mostly flying in the upper troposphere and lower stratosphere (UTLS). In the troposphere, the LINCO seasonal variations as well as the vertical and horizontal distributions are quite close to MOPITT CO observations. However, a bias of ~−40 ppbv is observed at 700 Pa between LINCO and MOPITT. In the stratosphere, MLS and LINCO present similar large-scale patterns, except over the poles where the CO concentration is underestimated by the model. In the UTLS, LINCO presents small biases less than 2% compared to independent MOZAIC profiles. Third, we assimilated MOPITT CO using a variational 3D-FGAT (First Guess at Appropriate Time) method in conjunction with MOCAGE for a long run of one and a half years. The data assimilation greatly improves the vertical CO distribution in the troposphere from 700 to 350 hPa compared to independent MOZAIC profiles. At 146 hPa, the assimilated CO distribution is also improved compared to MLS observations by reducing the bias up to a factor of 2 in the tropics. This study confirms that the linear scheme is able to simulate reasonably well the CO distribution in the troposphere and in the lower stratosphere. Therefore, the low computing cost of the linear scheme opens new perspectives to make free runs and CO data assimilation runs at high resolution and over periods of several years

Computational Analysis of Subcooled Flow Boiling in a Vertical Minichannel with Two Different Shapes under Various Mass Fluxes

In the current research project, two-dimensional numerical simulations are conducted to analyze the effects of geometrical configuration on flow structures and the thermal performances of subcooled flow boiling. The CFD simulations are carried out in two different configurations (straight and periodic constriction expansion) in a minichannel mounted vertically at four mass fluxes (500 kg/m2s; 836.64 kg/m2s; 1170 kg/m2s; and 2535 kg/m2s). The present predicted results exhibit excellent accordance with the previous experiments, with mean errors of 6.39% and 9.78%, demonstrating the efficiency of the present numerical study. The simulation results show that the periodic constriction expansion design provides good mixing between the layers, leading to a 43.11% mean enhancement of the thermal transfer, which is more important than the slight pressure drop penalty of 4.32 for a mass flux of 500 kg/m2s due to the combined pressure drop along the minichannel that resulted from the periodic constriction and expansion regions. Furthermore, the visualization of flow patterns shows that the bubbly flow is the dominant flow regime in the periodic constriction-expansion configuration

CONDUITE A TENIR DEVANT UN CORPS ETRANGER DU GLOBE OCULAIRE

Les corps étrangers (C.E.) du globe oculaire sont fréquents en traumatologie oculaire (18%) et peuvent être responsables de complications graves qui aboutissent parfois à la perte anatomique et /ou fonctionnelle de l’œil. Ils doivent toujours être recherchés devant un œil rouge ou un œil traumatique (plaie, brûlure oculaire ...etc.). C’est une urgence diagnostique et thérapeutique et le praticien doit toujours mener son examen avec l’arrière pensée de l’existence d’un corps étranger intraoculaire devant un traumatisé oculaire. Avant d’adresser le patient vers un ophtalmologiste, l’omnipraticien peut déjà à ce stade évaluer la gravité de la lésion et son degré d’urgence et commencer même certaines attitudes thérapeutiques qui peuvent jouer un rôle primordial dans le pronostic fonctionnel du patient si elles sont prises précocement. Lors de l’examen un éclairage direct et un système grossissant (loupes, lunettes, ophtalmoscope direct…) sont indispensables pour le diagnostic. Ces corps étrangers peuvent être subdivisés en corps étrangers superficiels et corps étrangers intra-oculaires