22 research outputs found

    Agitation of Complex Fluids in Cylindrical Vessels by Newly Designed Anchor Impellers: Bingham-Papanastasiou Fluids as a Case Study

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    The fluid flows and power consumption in a vessel stirred by anchor impellers are investigated in this paper. The case of rheologically complex fluids modeled by the Bingham-Papanastasiou model is considered. New modifications in the design of the classical anchor impeller are introduced. A horizontal blade is added to the standard geometry of the anchor, and the effect of its inclination angle (α) is explored. Four geometrical configurations are realized, namely: α = 0°, 20°, 40°, and 60°. The effects of the number of added horizontal blades, Reynolds number, and Bingham number are also examined. The obtained findings reveal that the most efficient impeller design is that with (case 4) arm blades inclined by 60°.This case allowed the most expansive cavern size with enhanced shearing in the whole vessel volume. The effect of adding second horizontal arm blades (with 60°) gave better hydrodynamic performance only with a slight increase in power consumption. A significant impact of Bingham number (Bn) was observed, where Bn = 5 allowed obtaining the lowest power input and most expansive well-stirred region

    Un syndrome malin des neuroleptiques compliquĂ© d’hĂ©morragie mĂ©ningĂ©e et rĂ©vĂ©lant une vascularite cĂ©rĂ©brale

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    Le syndrome malin des neuroleptiques est une complication du traitement par les neuroleptiques. Son incidence est estimĂ©e Ă  0,02% dans la population gĂ©nĂ©rale. Le traitement reste symptomatique et repose essentiellement sur l'arrĂȘt immĂ©diat du traitement antĂ©rieur. Nous rapportons l'observation clinique d'une patiente de 26 ans, schizophrĂ©nique sous Chlorpromazine, se prĂ©sentant aux urgences pour la prise en charge d'un syndrome malin des neuroleptiques compliquĂ© d'une hĂ©morragie mĂ©ningĂ©e et rĂ©vĂ©lant une vascularite cĂ©rĂ©brale

    Pancréatite surinfectée révélé par un abcÚs du psoas

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    Les pancrĂ©atites aigues grave peuvent se compliquer de pseudo kystes qui peuvent conduire Ă  la formation de fistules, ces fistules peuvent ĂȘtre dirigĂ©es vers diffĂ©rentes rĂ©gions avec diffĂ©rentes manifestations cliniques. Ces manifestations extra pancrĂ©atiques de la pancrĂ©atite aigue constituent, par leurs particularitĂ©s cliniques, biologiques et radiologiques, un rĂ©el apport au diagnostic positif. Le pronostic est celui de la pancrĂ©atite et dĂ©pend du site de la fistulisation. Le traitement par laparotomie a longtemps Ă©tĂ© le «Gold Standard», ces derniĂšres annĂ©es ont vu le dĂ©veloppement de moyens moins invasifs et donc offrants un minimum de morbi-mortalitĂ© (Chirurgie mini invasive, drainage percutanĂ©). Nous rapportons l'observation d'un patient ayant sĂ©journĂ© dans notre structure

    Choc hĂ©morragique suite Ă  une ponction biopsie rĂ©nale (PBR): Ă  propos d’un cas

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    La ponction biopsie rĂ©nale (PBR) est un examen indispensable en nĂ©phrologie mais Ă  risque de complications graves surtout hĂ©morragique. Nous rapportons l'observation d'un patient ĂągĂ© de 27 ans ayant bĂ©nĂ©ficiĂ© d'une PBR pour un diagnostic Ă©tiologique d'une insuffisance rĂ©nale aigue, l'Ă©volution aprĂšs la biopsie a Ă©tĂ© marquĂ©e par l'installation d'un choc hĂ©morragique d'oĂč la prise en charge en rĂ©animation avec une nĂ©phrectomie d'hĂ©mostase.Key words: Insuffisance rĂ©nale, ponction transcutanĂ©e, complication, choc hĂ©morragiqu

    Paracetamol self-poisoning: when oral N-acetylcysteine saves life? a case report

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    Paracetamol is the most widely drug involved in accidental paediatric exposures and deliberate self-poisoning cases because of its availability. Nacetyl cystein is the main treatment for this poisoning. We report a case of a 24-year-old Arab female who has deliberately ingested 100 tablets of 500 mg paracetamol each (50g). Her first examination was normal. She has received oral N-acetyl cystein (NAC) 6 hours after the ingestion. Serum paracetamol level done 18 hours post ingestion was 900 mg/l. On review the next days, she did not develop any symptoms of liver failure. However, due to the massive paracetamol ingestion associated with high serum paracetamol levels, oral NAC was continued for 3 days. The patient was discharged well on the fifth day of hospitalization. Our patient has ingested one of the highest paracetamol overdose (50g) with the highest paracetamol blood levels ever reported in medical literature. She was treated, six hours after ingestion, with oral NAC for 3 days without any side effects

    Asthenic peritonitis by stercoral perforation

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    La perforation stercorale est une entitĂ© assez rare et trĂšs peu dĂ©crite dans la littĂ©rature surtout francophone. C’est une complication Ă  la constipation chronique et survient prĂ©fĂ©rentiellement chez les personnes ĂągĂ©es et alitĂ©es. Le tableau clinique est non spĂ©cifique et l’évolution est dĂ©favorable dans 30 Ă  45 % des cas vue l’association des comorbiditĂ©s au sepsis intra-abdominal ou systĂ©mique. Nous rapportons le cas d’une perforation stercorale asthĂ©nique chez un sujet de 80 ans avec une Ă©volution favorable.Stercoral perforation is an uncommon entity and has been very rarely described in the literature (especially French literature). It is a complication of chronic constipation and usually occurs in the elderly and bedridden patients. The clinical examination is nonspecific and outcome is unfavorable in 30-45% of cases due to the association of comorbidities with intra-abdominal or systemic sepsis. We report a case of asthenic stercoral perforation in an 80-year patient with a favorable outcome

    Spectroscopie électronique et couplage spin-orbite de composés organométalliques

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    The theoretical work of the thesis have allowed us to study in detail, on the basis of DFT methods, TD-DFT and ab initio structural, electronic and spectroscopic properties of two classes of molecules, carbonyl compounds, hydrides transition metals of the 1st and 3rd row (Mn, Re) and complex cyclomĂ©talants phenyl pyridine iridium. The focus was specifically on the effects of spin-orbit coupling on the electronic absorption spectra of these molecules. The quantification of these effects showed that only electronic spectra of the complexes with a metal center of the 3rd row transition metals (Re, Ir) were modified by correcting spin-orbit perturbation. The character states, MC or MLCT, the proximity of singlet and triplet states are the factors that strongly influence the spin-orbit interaction between excited states. A remarkable effect observed for the rhenium complex is the large shift of the absorption spectrum to the red of the bursting of the lowest triplet state. In this case the effect of spin-orbit coupling must be taken into account to get closer to the experience spectrum. A spin-orbit effects already observed on other systems is to increase the density of states per burst and triplet states as decreasing the oscillator strength which fall on these statements lead to absorption spectra electronic broader and less intense. The study of the iridium complexes for which experimental spectra are particularly poorly resolved, shows a remarkable agreement between them is the theoretical absorption spectra of TDDFT. However, the functional effects can play an important role in the quality of the spectra. For these molecules ab initio calculations do not reach beyond the CASSCF level. The excited states are delocalized in these molecules and it is difficult to describe the same level of approximation the different types of states MLCT, LLCT, MC, LMCT ... In mostcases the functional B3LYP and PW91 give satisfactory results for the iridium complexes. The spin-orbit explosions electronic triplet states may be higher than 1500 cm-1 in complex with metal center 3rd row transition metals.Les travaux thĂ©oriques rĂ©alisĂ©s dans le cadre de la thĂšse nous ont permis d’étudier en dĂ©tail, sur la base de mĂ©thodes DFT, TD-DFT et ab initio les propriĂ©tĂ©s structurales, Ă©lectroniques et spectroscopiques de deux classes de molĂ©cules, les composĂ©s carbonyles hydrures des mĂ©taux de transition de la 1re et 3me rangĂ©e (Mn, Re) et les complexes cyclomĂ©talants phenyl pyridine de l’iridium. L’accent a Ă©tĂ© mis plus particuliĂšrement sur les effets de couplage spin-orbite sur les spectres d’absorption Ă©lectronique de ces molĂ©cules. La quantification de ces effets a permis de montrer que seuls les spectres Ă©lectroniques des complexes possĂ©dant un centre mĂ©tallique de la 3me rangĂ©e des mĂ©taux de transition (Re, Ir) Ă©taient modifiĂ©s par la correction spin-orbite en perturbation. Le caractĂšre des Ă©tats, MC ou MLCT, la proximitĂ© des Ă©tats singulets et triplets sont les facteurs qui influencent fortement l’interaction spinorbite entre Ă©tats excitĂ©s. Un effet remarquable observĂ© pour le complexe du rhenium est le dĂ©calage important du spectre d’absorption vers le rouge du Ă  l’éclatement de l’état triplet le plus bas. Dans ce cas l’effet de couplage spinorbite doit ĂȘtre pris en compte pour obtenir un spectre plus proche de l’expĂ©rience. Un effet spin-orbite dĂ©jĂ  observĂ© sur d’autres systĂšmes est l’augmentation de de la densitĂ© d’états par Ă©clatement des Ă©tats triplets et la diminuation des force d’oscillateur qui se rĂ©partissent sur ces Ă©tats pour aboutir Ă  des spectres d’absorption Ă©lectronique plus Ă©tendus et moins intenses. L’étude menĂ©e sur les complexes d’iridium pour lesquels les spectres expĂ©rimentaux sont particuliĂšrement mal rĂ©solus, montre un accord remarquable entre ceux-ci est les spectres d’absorption thĂ©oriques TD-DFT. Cependant les effets de fonctionnelle peuvent jouer un rĂŽle important sur la qualitĂ© des spectres. Pour ces molĂ©cules les calculs ab initio n’ont pu aboutir au-delĂ  du niveau CASSCF. Les Ă©tats excitĂ©s sont trĂšs dĂ©localisĂ©s dans ces molĂ©cules et il est difficile de dĂ©crire au mĂȘme niveau d’approximation les diffĂ©rents types d’états MLCT, LLCT, MC, LMCT... Dans la plupart des cas les fonctionnelles B3LYP et PW91 donnent des rĂ©sultats satisfaisants pour les complexes d’iridium. Les Ă©clatements spin-orbite des Ă©tats Ă©lectroniques triplets peuvent ĂȘtre supĂ©rieurs Ă  1500 cm-1 dans les complexes possĂ©dant un centre mĂ©tallique de la 3me rangĂ©e des mĂ©taux de transition

    Electronic spectroscopy and spin-orbit coupling of organometallic compounds

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    Les travaux thĂ©oriques rĂ©alisĂ©s dans le cadre de la thĂšse nous ont permis d’étudier en dĂ©tail, sur la base de mĂ©thodes DFT, TD-DFT et ab initio les propriĂ©tĂ©s structurales, Ă©lectroniques et spectroscopiques de deux classes de molĂ©cules, les composĂ©s carbonyles hydrures des mĂ©taux de transition de la 1re et 3me rangĂ©e (Mn, Re) et les complexes cyclomĂ©talants phenyl pyridine de l’iridium. L’accent a Ă©tĂ© mis plus particuliĂšrement sur les effets de couplage spin-orbite sur les spectres d’absorption Ă©lectronique de ces molĂ©cules. La quantification de ces effets a permis de montrer que seuls les spectres Ă©lectroniques des complexes possĂ©dant un centre mĂ©tallique de la 3me rangĂ©e des mĂ©taux de transition (Re, Ir) Ă©taient modifiĂ©s par la correction spin-orbite en perturbation. Le caractĂšre des Ă©tats, MC ou MLCT, la proximitĂ© des Ă©tats singulets et triplets sont les facteurs qui influencent fortement l’interaction spinorbite entre Ă©tats excitĂ©s. Un effet remarquable observĂ© pour le complexe du rhenium est le dĂ©calage important du spectre d’absorption vers le rouge du Ă  l’éclatement de l’état triplet le plus bas. Dans ce cas l’effet de couplage spinorbite doit ĂȘtre pris en compte pour obtenir un spectre plus proche de l’expĂ©rience. Un effet spin-orbite dĂ©jĂ  observĂ© sur d’autres systĂšmes est l’augmentation de de la densitĂ© d’états par Ă©clatement des Ă©tats triplets et la diminuation des force d’oscillateur qui se rĂ©partissent sur ces Ă©tats pour aboutir Ă  des spectres d’absorption Ă©lectronique plus Ă©tendus et moins intenses. L’étude menĂ©e sur les complexes d’iridium pour lesquels les spectres expĂ©rimentaux sont particuliĂšrement mal rĂ©solus, montre un accord remarquable entre ceux-ci est les spectres d’absorption thĂ©oriques TD-DFT. Cependant les effets de fonctionnelle peuvent jouer un rĂŽle important sur la qualitĂ© des spectres. Pour ces molĂ©cules les calculs ab initio n’ont pu aboutir au-delĂ  du niveau CASSCF. Les Ă©tats excitĂ©s sont trĂšs dĂ©localisĂ©s dans ces molĂ©cules et il est difficile de dĂ©crire au mĂȘme niveau d’approximation les diffĂ©rents types d’états MLCT, LLCT, MC, LMCT... Dans la plupart des cas les fonctionnelles B3LYP et PW91 donnent des rĂ©sultats satisfaisants pour les complexes d’iridium. Les Ă©clatements spin-orbite des Ă©tats Ă©lectroniques triplets peuvent ĂȘtre supĂ©rieurs Ă  1500 cm-1 dans les complexes possĂ©dant un centre mĂ©tallique de la 3me rangĂ©e des mĂ©taux de transition.The theoretical work of the thesis have allowed us to study in detail, on the basis of DFT methods, TD-DFT and ab initio structural, electronic and spectroscopic properties of two classes of molecules, carbonyl compounds, hydrides transition metals of the 1st and 3rd row (Mn, Re) and complex cyclomĂ©talants phenyl pyridine iridium. The focus was specifically on the effects of spin-orbit coupling on the electronic absorption spectra of these molecules. The quantification of these effects showed that only electronic spectra of the complexes with a metal center of the 3rd row transition metals (Re, Ir) were modified by correcting spin-orbit perturbation. The character states, MC or MLCT, the proximity of singlet and triplet states are the factors that strongly influence the spin-orbit interaction between excited states. A remarkable effect observed for the rhenium complex is the large shift of the absorption spectrum to the red of the bursting of the lowest triplet state. In this case the effect of spin-orbit coupling must be taken into account to get closer to the experience spectrum. A spin-orbit effects already observed on other systems is to increase the density of states per burst and triplet states as decreasing the oscillator strength which fall on these statements lead to absorption spectra electronic broader and less intense. The study of the iridium complexes for which experimental spectra are particularly poorly resolved, shows a remarkable agreement between them is the theoretical absorption spectra of TDDFT. However, the functional effects can play an important role in the quality of the spectra. For these molecules ab initio calculations do not reach beyond the CASSCF level. The excited states are delocalized in these molecules and it is difficult to describe the same level of approximation the different types of states MLCT, LLCT, MC, LMCT ... In mostcases the functional B3LYP and PW91 give satisfactory results for the iridium complexes. The spin-orbit explosions electronic triplet states may be higher than 1500 cm-1 in complex with metal center 3rd row transition metals
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