123 research outputs found

    Algeria and the African Union - between security and economic integration: a neofunctionalist and regionalist reading

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    This thesis investigates the process of integration in the African Union (AU), and the reasons behind the slow progress of the AU to achieve the goal of deeper economic integration. In the research I explore the role of an AU member state in the process of African integration: Algeria. The research scrutinises the development of Algerian foreign policy towards the AU and highlights any changes in the Algerian FP attitudes and the reasons behind these changes. Similarly, the research unveils the reality of the decision-making process in this country, and the different agents that influence it. To achieve the main goals of the research, different theoretical choices were elaborated. This resulted in researching European integration theories; Neofunctionalism was, then, selected to study the Algerian development in the making of its foreign policy in general and towards the African Union specifically. Some concepts within the Neofunctionalist thinking were used including the principle of the shift of loyalties, the socialisation process, the spillover system, and the role of interest groups in the process of integration. Moreover, the theory of Regionalism was used to examine the process of integration in the AU discovering new reasons that led to the slow development of economic integration in Africa. Consequently, the research highlights the current obstacles and challenges that have hindered the process of economic integration in the AU, including the poverty of most of the AU member states, the limited financial budget of the Union and the instability of the majority of African countries. Furthermore, the research unveiled the lack of political will towards AU economic integration plans. Hence, this contribution extends beyond the traditional models of explanation, and discusses the situation in AU member states (in this case Algeria) and points to other factors as well such as the weakness of the lobbyist activities and business groups in Algeria specifically and Africa more generally. The thesis, then, focusses on Algeria’s supportive and active status in the AU security sector, highlighting how Algeria has been successful in pushing its own security and antiterrorism agenda to the AU level, thereby demonstrating that integration into the AU is possible, if it is backed by influential member states, and wider coalitions can be built to promote integration and cooperation

    Numerical analysis of lateral torsional buckling of steel i-beams with and without web-openings under fire

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    Steel structures are being widely used in construction industry owing to their excellent structural flexibility and to their high ductility to withstand lateral forces. However, for the case of solid and cellular steel beams, high temperature effect may result in different fire response for each case due to a great reduction of yield stress and Young’s modulus. Moreover, when the beams are not restrained, lateral torsional bending phenomenon which are bound to take place is made worse in the case of fire. The aim of this study is to analyse the behaviour of steel beams with and without web openings when taking into account the effect of geometry and material imperfections. The results from the finite element models produced lateral and vertical displacements as well as the buckling moments.info:eu-repo/semantics/publishedVersio

    Atmospheric Pollutant Flow and Precipitation: Modeling Effects on the Vegetation Ecosystem

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    Because of their fixed life and wide distribution, plants are the first victims of air pollution. The atmosphere is considered polluted when the increase of the rate of certain components causes harmful effects on the different constituents of the ecosystems. The study of the flow of air near a polluting source (cement plant in our case), allows to predict its impact on the surrounding plant ecosystem. Different factors are to be considered. The chemical composition of the air, the climatic conditions, and the impacted plant species are complex parameters to be analyzed using conventional mathematical methods. In this study, we propose a system based on artificial neural networks. Since artificial neural networks have the capacity to treat different complex parameters, their application in this domain is adequate. The proposed system makes it possible to match the input and output spaces. The variables that constitute the input space are the chemical composition, the concentration of the latter in the rainwater, their duration of deposition on the leaves and stems, the climatic conditions characterizing the environment, as well as the species of plant studied. The output variable expresses the rate of degradation of this species under the effect of pollution. Learning the system makes it possible to establish the transfer function and thus predict the impact of pollutants on the vegetation

    Croissance et capacité réproductive de Gymnogongrus patens (J. Agardh) (Rhodophyceae, Gigartinale) de la cÎte atlantique marocaine

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    L’algue carraghĂ©nophyte Gymnogongrus patens prĂ©sente une large distribution sur le littoral marocain, sa valorisation et son exploitation ont Ă©tĂ© prĂ©cĂ©dĂ©es par l’étude de sa biologie en milieu naturel. Le site Ă©tudié est la plage de MĂ©hdia situĂ© au nord de la cĂŽte atlantique marocaine. L’influence des facteurs environnementaux (tempĂ©rature, salinitĂ©, nitrates et phosphates) sur l’évolution de la croissance a Ă©té étudiĂ©e par d’analyse en composantes principales (ACP). La croissance de l’espĂšce prĂ©sente une variation saisonniĂšre, ainsi deux pĂ©riodes de croissance ont Ă©tĂ© dĂ©terminĂ©es : une pĂ©riode de forte croissance fin printemps et Ă©tĂ© et une pĂ©riode de faible croissance en automne et en hiver. L’ACP a confirmĂ© cette saisonnalitĂ© de la croissance, en prĂ©cisant que le gain en poids de thalles est principalement liĂ© à l’augmentation de nombre de ramification total. La pĂ©riode active de croissance est caractĂ©risĂ©e par l’élĂ©vation de la tempĂ©rature, de la salinitĂ© et de l’intensitĂ© lumineuse principalement. L’étude de la capacitĂ© reproductive de G. patens a permis de montrer que l’espĂšce est fertile toute l’annĂ©e avec une dominance de la gĂ©nĂ©ration tĂ©trasporophytiques. Le maximum de fertilitĂ© a Ă©tĂ© obtenu en Ă©tĂ©.Mots-clĂ©s : Gymnogongrus patens, croissance, reproduction, ACP, Maroc.Growth and reproductuive capacity of Gymnogongrus patens (Rhodophyceae, Gigartinale) on the Morccan Atlantic coastGymnogongrus patens represent an important biomass along the Atlantic coast of Morocco, the first step befor exploitation is gather information about the biology and growth of this species in naturel environment. The studied site is the beach of Mehdia located at the north of the Moroccan Atlantic Coast. The influence of environmental parametres (temperature, salinty, nitrates and phosphates) on growth has been studied using Principal Components Analysis (ACP). The monthly survey of its growth did sow seasonal variations. G. Patens has 2 periods of growth: period’s active growth at the ending of spring and summer and period’s weak growth in automn and winter. ACP showed a seaonal variation of the species growth. The active growth periods of G. Patens are characterized by important temperature and salinty and light intensities. The species was fertil almost all along the year and tetrasporophyte pahse predominated. The maximum of fertility was obtained in summer.Keywords : gymnogongrus patens, growth, reproduction, ACP, Morocco

    Reliability-based criterion for evaluating explicit approximations of Colebrook equation

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    Numerous explicit approximations of the Colebrook equation have been developed and evaluated based on two criteria: prediction accuracy and computational efficiency. This paper introduces a new evaluation criterion based on the reliability of each equation. The reliability is defined by the coefficient of variation (CV) of the explicit friction factor that is a function of the variabilities of component random variables (roughness height of the internal pipe surface and kinematic viscosity of the fluid). The coefficient of variation of the friction factor depends on its first derivative for roughness height of the inner pipe surface and kinematic viscosity of the fluid and their correlation. Seven explicit approximations were evaluated using the new reliability-based criterion. The results show that all explicit approximations are very reliable, but variations exist regarding the reliability level. The reliabilities of the seven approximations is very close for the rough-flow regime and when the CV of the viscosity is minimal. However, for the smooth-flow regime, and when the CV of the roughness is minimal, various approximations showed substantially different reliabilities. The novelty of the proposed criterion is that it addresses an evaluation dimension that complements the accuracy and efficiency criteria.Web of Science106art. no. 80

    Iterative Reconstructions in Reduced-Dose CT: Which Type Ensures Diagnostic Image Quality in Young Oncology Patients?

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    To compare adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR) algorithms for reduced-dose computed tomography (CT). Forty-four young oncology patients (mean age 30 ± 9 years) were included. After routine thoraco-abdominal CT (dose 100%, average CTDI javax.xml.bind.JAXBElement@e7f585f 9.1 ± 2.4 mGy, range 4.4-16.9 mGy), follow-up CT was acquired at 50% (average CTDI javax.xml.bind.JAXBElement@2e35610f 4.5 ± 1.2 mGy, range 2.2-8.4 mGy) in 29 patients additionally at 20% dose (average CTDI javax.xml.bind.JAXBElement@37ad3473 1.9 ± 0.5 mGy, range 0.9-3.4 mGy). Each reduced-dose CT was reconstructed using both ASIR and MBIR. Four radiologists (two juniors and two seniors) blinded to dose and technique read each set of CT images regarding objective and subjective image qualities (high- or low-contrast structures), subjective noise or pixilated appearance, diagnostic confidence, and lesion detection. At all dose levels, objective image noise was significantly lower with MBIR than with ASIR (P < 0.001). The subjective image quality for low-contrast structures was significantly higher with MBIR than with ASIR (P < 0.001). Reduced-dose abdominal CT images of patients with higher body mass index (BMI) were read with significantly higher diagnostic confidence than images of slimmer patients (P < 0.001) and had higher subjective image quality, regardless of technique. Although MBIR images appeared significantly more pixilated than ASIR images, they were read with higher diagnostic confidence, especially by juniors (P < 0.001). Reduced-dose CT during the follow-up of young oncology patients should be reconstructed with MBIR to ensure diagnostic quality. Elevated body mass index does not hamper the quality of reduced-dose CT

    Failure of hydrogenation in protecting polycyclic aromatic hydrocarbons from fragmentation

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    A recent study of soft X-ray absorption in native and hydrogenated coronene cations, C24_{24}H12+m+_{12+m}^+ m=0−7m=0-7, led to the conclusion that additional hydrogen atoms protect (interstellar) Polycyclic Aromatic Hydrocarbon (PAH) molecules from fragmentation [Reitsma et al., Phys. Rev. Lett. 113, 053002 (2014)]. The present experiment with collisions between fast (30-200 eV) He atoms and pyrene (C16_{16}H10+m+_{10+m}^+, m=0m=0, 6, and 16) and simulations without reference to the excitation method suggests the opposite. We find that the absolute carbon-backbone fragmentation cross section does not decrease but increases with the degree of hydrogenation for pyrene molecules.Comment: 10 pages, 5 figure

    Unusual hydrogen and hydroxyl migration in the fragmentation of excited doubly-positively-charged amino acids in the gas phase

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    We present a combined experimental and theoretical study of the fragmentation of doubly-positively- charged amino acids in the gas phase. The combination of ab initio molecular dynamics simulations with ion- molecule collisions followed by multiple-coincidence mass spectrometric techniques, allows us to obtain a complete picture of the fragmentation dynamics. In addition to the expected Coulomb explosion, we have found evidence of hydrogen and hydroxyl-group migration processes, which leads to unusual fragmentation product

    The puzzle of self-reported weight gain in a month of fasting (Ramadan) among a cohort of Saudi families in Jeddah, Western Saudi Arabia

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    <p>Abstract</p> <p>Background</p> <p>During Ramadan fast, approximately one billion Muslims abstain from food and fluid between the hours of sunrise to sunset, and usually eat a large meal after sunset and another meal before sunrise. Many studies reported good health-related outcomes of fasting including weight loss. The objective of this study is to identify the local pattern of expenditure on food consumption, dietary habits during Ramadan and correlate that to self-reported weight gain after Ramadan in a group of families in Jeddah, Western Saudi Arabia.</p> <p>Methods</p> <p>A Cross-section study using a pre-designed questionnaire to identify the local pattern of expenditure on food consumption, dietary habits during Ramadan and correlate that to self-reported weight gain after Ramadan in a representative cohort of Saudis living in Jeddah. It was piloted on 173 nutrition students and administered by them to their families.</p> <p>Results</p> <p>A total of 173 Saudi families were interviewed. One out of 5 indicated that their expenditure increases during Ramadan. Approximately two thirds of the respondents (59.5%) reported weight gain after Ramadan. When asked about their perspective explanations for that: 40% attributed that to types of foods being rich in fat and carbohydrates particularly date in (Sunset meal) 97.7% and rice in (Dawn meal) 80.9%. One third (31.2%) indicated that it was due to relative lack of physical exercise in Ramadan and 14.5% referred that to increase in food consumption. Two thirds (65.2%) of those with increased expenditure reported weight gain.</p> <p>Conclusion</p> <p>Surprisingly weight gain and not weight loss was reported after Ramadan by Saudis which indicates timely needed life-style and dietary modification programs for a population which reports one of the highest prevalence rates of diabetes.</p
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