106 research outputs found

    Surface Optical Waves at Air/Metal Interfaces: Surface Plasmon Polaritons

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    The surface plasmon resonance (SPR) phenomenon has been known for nearly five decades now; since then this method has made great advances in terms of instrumentation development and applications, and it still attracts researchers because of certain subtle issues that could benefit from it mainly detection and analysis of chemical and biochemical substances in different areas including medicine, environmental monitoring, biotechnology and drug and food monitoring. Our interest is focused on the use of this technique for studying thin coating and some application in nanophotonics. In this paper, we discuss the configuration of surface plasmons at air/metal interface by Atenuated total reflection (ATR) technique in the Kretchman configuration, and we present preliminary experimental results on surface plasmons at a Ag/air interface that we obtained in our laboratory.The surface plasmon resonance (SPR) phenomenon has been known for nearly five decades now; since then this method has made great advances in terms of instrumentation development and applications, and it still attracts researchers because of certain subtle issues that could benefit from it mainly detection and analysis of chemical and biochemical substances in different areas including medicine, environmental monitoring, biotechnology and drug and food monitoring. Our interest is focused on the use of this technique for studying thin coating and some application in nanophotonics. In this paper, we discuss the configuration of surface plasmons at air/metal interface by Atenuated total reflection (ATR) technique in the Kretchman configuration, and we present preliminary experimental results on surface plasmons at a Ag/air interface that we obtained in our laboratory

    Éléments d’aide au contrôle de gestion et au management de l’agrumiculture au Maroc

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    L’étude est dĂ©diĂ©e aux grandes entreprises agrumicoles structurĂ©es et dĂ©centralisĂ©es. Elle fournit les Ă©lĂ©ments agronomiques et financiers pour un modèle de contrĂ´le de gestion de type bottom-up concevable Ă  partir de l’expĂ©rience sur la nouvelle agrumiculture nĂ©e du plan Maroc Vert. Le modèle suppose la transparence, un travail en partenariat fermes-contrĂ´le de gestion, un système d’information fiable et une fluiditĂ© de circulation de l’information. En agriculture, il n’y a pas d’analogie parfaite avec l’industrie concernant l’évaluation des Ă©carts de performance par rapport aux objectifs de gestion affichĂ©s par le budget. Dans l’industrie, les mĂŞmes inputs et le mĂŞme process produisent en gĂ©nĂ©ral le mĂŞme rĂ©sultat, ce qui facilite amplement l’analyse des Ă©carts constatĂ©s et aide beaucoup Ă  proposer des mesures correctives. En agriculture, avec une mĂŞme quantitĂ© d’inputs (eau, engrais, pesticides), et un mĂŞme process de production (porte greffe, variĂ©tĂ©, densitĂ©, taille), le rĂ©sultat peut ĂŞtre très diffĂ©rent selon l’annĂ©e climatique, la rĂ©gion ou le type de sol. Par consĂ©quent, le plus important dans cette activitĂ©, n’est pas l’écart de performance lui-mĂŞme, mais de pouvoir expliquer la part de cet Ă©cart qui revient Ă  la gestion et celle due aux facteurs externes non maitrisables du milieu. Une contre-performance sur la productivitĂ© ou la qualitĂ© peut ĂŞtre la consĂ©quence d’effets pervers d’un Chergui (chute des fruits, marbrures, coup de soleil) alors qu’aucune modification n’a Ă©tĂ© apportĂ©e au process usuel de production. De mĂŞme qu’une excellente performance est parfois en partie le fait d’une annĂ©e climatique favorable et d’un bon prix sur le marchĂ© et non d’un effort particulier de gestion. Cette Ă©norme difficultĂ© Ă  prĂ©voir avec une certaine confiance, ce que sera le comportement du verger d’une annĂ©e Ă  l’autre, rend donc malaisĂ© l’usage de « normes Â» figĂ©es pour le contrĂ´le de gestion. C’est pourquoi dans la prĂ©sente Ă©tude, l’effort a plus portĂ© sur l’exploration des causes des Ă©carts autour des chiffres moyens que sur les chiffres eux-mĂŞmes. Au Maroc, on est en prĂ©sence d’un système Ă©conomique libĂ©ral certes, mais la surproduction avec l’idĂ©e d’ensuite vendre les agrumes « a dime a dozen Â» ou de laisser la main invisible d’Adam Smith rĂ©guler le marchĂ© n’a jamais Ă©tĂ© un objectif du plan Maroc Vert. Le but recherchĂ©, est plutĂ´t de produire pour ensuite exporter davantage afin d’amĂ©liorer la balance commerciale du pays. Aujourd’hui, on est en situation d’offre excessive en petits fruits aggravĂ©e par un Export qui peine Ă  monter en charge, il est donc lĂ©gitime que chacun cherche Ă  tirer son Ă©pingle du jeu. Faute de pouvoir agir sur les prix, la mission basique du contrĂ´le de gestion est donc de maĂ®triser au moins les charges. MĂŞme si la vraie solution pour le Maroc, aurait Ă©tĂ© plutĂ´t d’instaurer un super-contrĂ´le de gestion innovant de type filière avec notamment des prĂ©rogatives de gel provisoire des plantations, le temps de conquĂ©rir de nouveaux marchĂ©s. Ce que nous craignions est maintenant arrivĂ© en 2018, c'est-Ă -dire finir après autant d’investissements par vendre la clĂ©mentine de qualitĂ© sur le marchĂ© local Ă  10cts/kg. L’étude suggère entre autres, comment sortir de cette pĂ©riode trouble et surmonter la crise avec un minimum de dĂ©gâts pour le producteur. Mots clĂ©s : ContrĂ´le de gestion, agrumes, MarocThe study concerns the large structured and decentralized citrus fruit companies. It provides the agronomic and financial tools for management control. The present management model is based on a bottom-up design. It is inspired from the new citrus cropping experience born from the Green Morocco plan. The model assumes transparency, farm and management control partnership, reliable information system and fluidity of information. In agriculture, there is no perfect analogy with the industry sector concerning the assessment of performance gaps compared to the management objectives reported by the budget. In industry, the same inputs combined to the same process generally produce the same result. Thus, the analysis of the observed performance gaps become easier and corrective measures can be suggested. In agriculture, the result can’t be similar even the same amount of inputs (water, fertilizer, pesticides), and the same production process (rootstock, cultivar, density, pruning) have been used. This situation is related to climatic year, location and soil type. Therefore, the most important in agricultural activity, is to explain the causes of the performance gap. Then, to classify these causes into manageable factors and not manageable factors of the environment. A low performance on productivity or quality can be related to the negative effect of “Chergui” wind (fall, physical damage, sunburn, ...) even we keep the same usual production process. Also, an excellent performance is sometimes related to a very good climate year and not to a specific management effort. The enormous difficulty of predicting confidently the orchard behavior, for each year, constrains the establishment of fixed "standards" useful for management control. Thus, in the present study, we try to explore causes of deviations around average numbers. In Morocco, a liberal economy is established. However, the overproduction with the idea of selling the citrus fruit as dime a dozen or leaving the Adam Smith invisible hand regulates the market has never been the goal of the Green Morocco Plan. Such plan aims to produce and to export more in order to improve the country's trade balance. Today, we are in a situation of excessive clementine supply aggravated by the difficulty to increase export quantity. This situation pushes each producer to perform well. Regarding the difficulty to regulate prices, the basic mission of the management control is to master at least the production costs. The true solution would to introduce an innovative super-control management of citrus sector. This management would include a provisional plantation freezing waiting for finding new markets. In fact, the feared problem is occurred in 2018. Indeed, high quality clementine has been sold at 10 cts kg-1. on the local market after many investments of the producer. The study aims to give suggestions to producers on how to manage this troubled period and overcome the crisis with minimal damage. Key words: Management control, citrus fruits, Morocc

    Éléments d’aide au contrôle de gestion et au management de l’agrumiculture au Maroc

    Get PDF
    L’étude est dĂ©diĂ©e aux grandes entreprises agrumicoles structurĂ©es et dĂ©centralisĂ©es. Elle fournit les Ă©lĂ©ments agronomiques et financiers pour un modèle de contrĂ´le de gestion de type bottom-up concevable Ă  partir de l’expĂ©rience sur la nouvelle agrumiculture nĂ©e du plan Maroc Vert. Le modèle suppose la transparence, un travail en partenariat fermes-contrĂ´le de gestion, un système d’information fiable et une fluiditĂ© de circulation de l’information. En agriculture, il n’y a pas d’analogie parfaite avec l’industrie concernant l’évaluation des Ă©carts de performance par rapport aux objectifs de gestion affichĂ©s par le budget. Dans l’industrie, les mĂŞmes inputs et le mĂŞme process produisent en gĂ©nĂ©ral le mĂŞme rĂ©sultat, ce qui facilite amplement l’analyse des Ă©carts constatĂ©s et aide beaucoup Ă  proposer des mesures correctives. En agriculture, avec une mĂŞme quantitĂ© d’inputs (eau, engrais, pesticides), et un mĂŞme process de production (porte greffe, variĂ©tĂ©, densitĂ©, taille), le rĂ©sultat peut ĂŞtre très diffĂ©rent selon l’annĂ©e climatique, la rĂ©gion ou le type de sol. Par consĂ©quent, le plus important dans cette activitĂ©, n’est pas l’écart de performance lui-mĂŞme, mais de pouvoir expliquer la part de cet Ă©cart qui revient Ă  la gestion et celle due aux facteurs externes non maitrisables du milieu. Une contre-performance sur la productivitĂ© ou la qualitĂ© peut ĂŞtre la consĂ©quence d’effets pervers d’un Chergui (chute des fruits, marbrures, coup de soleil) alors qu’aucune modification n’a Ă©tĂ© apportĂ©e au process usuel de production. De mĂŞme qu’une excellente performance est parfois en partie le fait d’une annĂ©e climatique favorable et d’un bon prix sur le marchĂ© et non d’un effort particulier de gestion. Cette Ă©norme difficultĂ© Ă  prĂ©voir avec une certaine confiance, ce que sera le comportement du verger d’une annĂ©e Ă  l’autre, rend donc malaisĂ© l’usage de « normes Â» figĂ©es pour le contrĂ´le de gestion. C’est pourquoi dans la prĂ©sente Ă©tude, l’effort a plus portĂ© sur l’exploration des causes des Ă©carts autour des chiffres moyens que sur les chiffres eux-mĂŞmes. Au Maroc, on est en prĂ©sence d’un système Ă©conomique libĂ©ral certes, mais la surproduction avec l’idĂ©e d’ensuite vendre les agrumes « a dime a dozen Â» ou de laisser la main invisible d’Adam Smith rĂ©guler le marchĂ© n’a jamais Ă©tĂ© un objectif du plan Maroc Vert. Le but recherchĂ©, est plutĂ´t de produire pour ensuite exporter davantage afin d’amĂ©liorer la balance commerciale du pays. Aujourd’hui, on est en situation d’offre excessive en petits fruits aggravĂ©e par un Export qui peine Ă  monter en charge, il est donc lĂ©gitime que chacun cherche Ă  tirer son Ă©pingle du jeu. Faute de pouvoir agir sur les prix, la mission basique du contrĂ´le de gestion est donc de maĂ®triser au moins les charges. MĂŞme si la vraie solution pour le Maroc, aurait Ă©tĂ© plutĂ´t d’instaurer un super-contrĂ´le de gestion innovant de type filière avec notamment des prĂ©rogatives de gel provisoire des plantations, le temps de conquĂ©rir de nouveaux marchĂ©s. Ce que nous craignions est maintenant arrivĂ© en 2018, c'est-Ă -dire finir après autant d’investissements par vendre la clĂ©mentine de qualitĂ© sur le marchĂ© local Ă  10cts/kg. L’étude suggère entre autres, comment sortir de cette pĂ©riode trouble et surmonter la crise avec un minimum de dĂ©gâts pour le producteur. Mots clĂ©s : ContrĂ´le de gestion, agrumes, MarocThe study concerns the large structured and decentralized citrus fruit companies. It provides the agronomic and financial tools for management control. The present management model is based on a bottom-up design. It is inspired from the new citrus cropping experience born from the Green Morocco plan. The model assumes transparency, farm and management control partnership, reliable information system and fluidity of information. In agriculture, there is no perfect analogy with the industry sector concerning the assessment of performance gaps compared to the management objectives reported by the budget. In industry, the same inputs combined to the same process generally produce the same result. Thus, the analysis of the observed performance gaps become easier and corrective measures can be suggested. In agriculture, the result can’t be similar even the same amount of inputs (water, fertilizer, pesticides), and the same production process (rootstock, cultivar, density, pruning) have been used. This situation is related to climatic year, location and soil type. Therefore, the most important in agricultural activity, is to explain the causes of the performance gap. Then, to classify these causes into manageable factors and not manageable factors of the environment. A low performance on productivity or quality can be related to the negative effect of “Chergui” wind (fall, physical damage, sunburn, ...) even we keep the same usual production process. Also, an excellent performance is sometimes related to a very good climate year and not to a specific management effort. The enormous difficulty of predicting confidently the orchard behavior, for each year, constrains the establishment of fixed "standards" useful for management control. Thus, in the present study, we try to explore causes of deviations around average numbers. In Morocco, a liberal economy is established. However, the overproduction with the idea of selling the citrus fruit as dime a dozen or leaving the Adam Smith invisible hand regulates the market has never been the goal of the Green Morocco Plan. Such plan aims to produce and to export more in order to improve the country's trade balance. Today, we are in a situation of excessive clementine supply aggravated by the difficulty to increase export quantity. This situation pushes each producer to perform well. Regarding the difficulty to regulate prices, the basic mission of the management control is to master at least the production costs. The true solution would to introduce an innovative super-control management of citrus sector. This management would include a provisional plantation freezing waiting for finding new markets. In fact, the feared problem is occurred in 2018. Indeed, high quality clementine has been sold at 10 cts kg-1. on the local market after many investments of the producer. The study aims to give suggestions to producers on how to manage this troubled period and overcome the crisis with minimal damage. Key words: Management control, citrus fruits, Morocc

    L’INCONTINENCE URINAIRE DU POST PARTUM : INTERET DE LA REEDUCATION PERINEALE

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    The urinary incontinence is defined as the occurrence of involuntary urine leakage responsible for social or hygienic problem. The prevalence of symptoms of urinary incontinence increases during pregnancy and decreases spontaneously in the first three months in the postpartum. Several risk factors can be incriminated, some related to pregnancy and childbirth and others are constitutional. Prevention plays an important role and perineal rehabilitation gives good results.L’incontinence urinaire d’effort se définit comme la survenuede fuites involontaires d'urineresponsables d'un problème hygiénique ou social.La prévalence des symptômes d’incontinence urinaire augmente au cours de la grossesse puis diminue spontanément dans les trois premiers mois du post-partum. Plusieurs facteurs de risque peuvent être incriminés, certains sont liés à la grossesse et l’accouchement et d’autres sont constitutionnels. La prévention joue un rôle important et la rééducation périnéale donne de bons résultats

    ABSENCE DE LA GELEE DE WHARTON AUTOUR D’UNE ARTERE OMBILICALE

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    Introduction: Wharton's jelly is a mucoid connective tissue, avascular who plays the role of protection vis-à-vis the umbilical vessels avoiding compression. The umbilical arteries devoid of Wharton's jelly are more prone to compression. A complete absence is most often associated with fetal death. Clinical case: We report a case of a newborn in the maternity compiled des Orangers, having one of the umbilical arteries, devoid of Wharton's jelly over a distance of 10 cm from the umbilicus and whose clinical course was satisfactory. Discussion: In the literature, five cases have been reported, and several hypotheses have been discussed: Degeneration of Wharton tissue around the vessels, fusion incomplete coating amniotic mesenchymal umbilical cord during early embryonic development, hypoplastic amniotic coating with secondary loss of Wharton's jelly. In our context, since only one of the two umbilical arteries was not protected and covered by the thick meconium, two hypotheses arise: action "biochemical" thick meconium components of Wharton's jelly. A also discuss the underlying infection related with the absence of Wharton's jelly. Conclusion: The total absence of Wharton's jelly around the umbilical artery or two remains poorly understood, however, biochemical action of the components of meconium on Wharton's jelly or infectious origin can’t be excluded.Introduction : La gelée de Wharton est un tissu conjonctif mucoïde, avasculaire qui joue le rôle de protection vis-à-vis des vaisseaux ombilicaux en évitant leur compression. Les artères ombilicales dépourvues de la gelée de Wharton sont plus sujettes à la compression. Une absence complète est associée le plus souvent à la mort fœtale. Le cas clinique : Nous rapportons une observation d’un nouveau-né colligé à la maternité des Orangers, présentant une des artères ombilicales dépourvue de la gelée de Wharton sur une distance de 10 cm de l’ombilic et dont l’évolution clinique est satisfaisante. Discussion : Dans la littérature, cinq cas ont été rapportés, et plusieurs hypothèses ont été discutées : Dégénérescence du tissu de Wharton autour des vaisseaux, fusion incomplète du revêtement amniotique et du mésenchyme du cordon ombilical pendant le développement embryonnaire précoce, hypoplasie du revêtement amniotique avec perte secondaire de la gelée de Wharton. Dans notre contexte, vu que seule une des 2 artères ombilicales a été non protégée et recouverte par du liquide méconial épais, deux hypothèses se posent : l’action « biochimique » des composants du méconium épais sur la gelée de Wharton. A discuter aussi le contexte infectieux en rapport avec l’absence de la gelée de Wharton. Conclusion : L’absence totale de la gelée de Wharton autour d’une ou des 2 artères ombilicales reste encore mal comprise, toutefois une action biochimique des composants du méconium sur la gelée de Wharton ou une origine infectieuse ne peut être écartée

    THROMBASTHENIE DE GLANZMANN ET GROSSESSE : A PROPOS D’UN CAS COMPLIQUE D’HEMORRAGIE DE LA DELIVRANCE

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    Glanzmann's thrombasthenia is a rare hereditary, having autosomal recessive transmission, due to a deficiency of platelet membrane glycoprotein GPIIbIIIa, which is responsible for a decrease in platelet aggregation. It is the source of bleeding more or less important, appearing in childhood. Its association with pregnancy is rare, and may be complicated by bleeding. Mrs F.Z, a 23 years old primigravida, reaching Glanzmann’s thrombastenia since its infancy and has a postpartum hemorrhage that could be treated medically. We tried, through this case and a review of the literature, to review the management of this rare association, which may involve the prognosis of the mother.La thrombasthénie de Glanzmann est une maladie héréditaire rare, à transmission autosomale récessive, due à un déficit de la glycoprotéine membranaire plaquettaire GPIIbIIIa responsable d’une diminution de l’agrégation plaquettaire. Elle est à l'origine d'hémorragies plus ou moins importantes, apparaissant dès l'enfance. Son association avec la grossesse est rare, et peut se compliquer de plusieurs accidents hémorragiques. Nous rapportant le cas d’une primigeste de 23ans, connue porteuse d’une thrombasthénie de Glanzmann depuis son bas âge et qui présente une hémorragie de la délivrance qui a pu être jugulée médicalement. Nous avons essayé, à travers ce cas et une revue de la littérature, de mettre le point sur la prise en charge de cette association rare, qui peut mettre en jeu le pronostic vital maternel

    Modeling, Evaluation, and Scale on Artificial Pedestrians: A Literature Review

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    Modeling pedestrian dynamics and their implementation in a computer are challenging and important issues in the knowledge areas of transportation and computer simulation. The aim of this article is to provide a bibliographic outlook so that the reader may have quick access to the most relevant works related to this problem. We have used three main axes to organize the article's contents: pedestrian models, validation techniques, and multiscale approaches. The backbone of this work is the classification of existing pedestrian models; we have organized the works in the literature under five categories, according to the techniques used for implementing the operational level in each pedestrian model. Then the main existing validation methods, oriented to evaluate the behavioral quality of the simulation systems, are reviewed. Furthermore, we review the key issues that arise when facing multiscale pedestrian modeling, where we first focus on the behavioral scale (combinations of micro and macro pedestrian models) and second on the scale size (from individuals to crowds). The article begins by introducing the main characteristics of walking dynamics and its analysis tools and concludes with a discussion about the contributions that different knowledge fields can make in the near future to this exciting area

    Chemical Additives for Corrosion Control in Desalination Plants

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    The addition of chemical additives has been considered as a standard operation in water treatment systems. This chapter discusses the chemical additives used for the control of corrosion in desalination systems. Specifically, corrosion inhibitors for various metallurgies, biocides, and oxygen scavengers are covered. The pros and cons of the additive chemicals have been highlighted. The need to utilize green corrosion inhibitors based on plants and ionic liquids materials have been emphasized. This class of materials are environmentally friendly, cheap, and readily available
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