539 research outputs found

    Amine-functionalized MCM-48 as Adsorbent of Zn2+ and Ni2+ Ions

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    A compound, 3-aminopropyltrimetoxy silane, has been used to modify mesoporous silica, MCM-48. The modified silica (NH2-MCM-48) was utilized to remove Zn2+ and Ni2+ ions from solutions. The mesoporous material was synthesized in the alkaline solution. Characterization of the unmodified materials was conducted by X-ray diffraction and FT-IR spectroscopy. The ions adsorbed on NH2-MCM-48 were studied at various pHs, contact times and initial ions concentrations. An Atomic Absorption Spectrophotometer (AAS) measured the ions content in the solution.. Pseudo-first-order and pseudo-second-order models performed the kinetic adsorption. The adsorption isotherm was examined by Langmuir and Freundlich isotherms. The result found that optimum contact time for the adsorption of Zn2+ ion was lower than that for Ni2+ ion. The adsorption followed the pseudo-second-order model with the adsorption rate of 4.56x10-2 g mg-1 min-1 for Zn2+ ion and 7x10-4 g mg-1 min-1 for Ni2+ ion. The optimum pH was 6 and 4 for Zn2+ and Ni2+ adsorption, respectively. The uptake of both ions from solutions by NH2-MCM-48 fixed better the Langmuir than the Freundlich model with the adsorption capacity of 0.55 and 0.43 mmol g-1, correspondingly. This research work provides valuable information on the interaction between the ions and the functional group of adsorbent

    Correlates of measured prehypertension and hypertension in Latina women living along the US-Mexico border, 2007-2009.

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    IntroductionAlthough Latinos have lower hypertension rates than non-Latino whites and African Americans, they have a higher prevalence of undiagnosed and uncontrolled hypertension. Research on predictors of hypertension has mostly focused on intrapersonal factors with no studies assessing the combined influence of intrapersonal, interpersonal, and environmental factors. The purpose of this study was to assess a broad range of correlates including intrapersonal, interpersonal, and environmental factors on measured blood pressure category (nonhypertensive, prehypertensive, and hypertensive) in a sample of Latina women residing in San Diego, California.MethodsThis cross-sectional study used baseline data from the San Diego Prevention Research Center's Familias Sanas y Activas program, a promotora-led physical activity intervention. The sample was 331 Latinas who self-selected into this program. Backward conditional logistic regression analysis was conducted to determine the strongest correlates of measured blood pressure category.ResultsLogistic regression analysis suggested that the strongest correlates of prehypertension were soda consumption (odds ratio [OR] = 1.34, [1.00-1.80], P ≤ .05) and age (OR = 1.03, [1.00-1.05], P ≤ .05). The strongest correlates of hypertension were soda consumption (OR = 1.92, [1.20-3.07], P ≤ .01), age (OR = 1.09, [1.05-1.13], P ≤ .001), and measured body mass index (OR = 1.13, [1.05-1.22], P ≤ .001). All analyses controlled for age and education. No interpersonal or environmental correlates were significantly associated with blood pressure category.ConclusionFuture research should aim to further understand the role of soda consumption on risk for hypertension in this population. Furthermore, interventions aimed at preventing hypertension may want to focus on intrapersonal level factors

    Essai de lutte contre oryctes monoceros olivier (coleoptera : dynastidae) par l’utilisation de l’acide 4-méthyloctanoïque en côte -d’ivoire

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    (Arecaceae), en Côte d’Ivoire. Pour lutter contre ce ravageur, l’acide 4-methyloctanoïque a été initié. Au cours de ces travaux, 3 types de diffuseurs (Da, Db, Dc) contenant les différentes doses ont été expérimentés. L’étude a été menée sur 9 mois repartie sur 4 phases dont 1 mois sans diffuseurs, 4 mois avec diffuseurs, 2 mois retrait desdiffuseurs et 2 mois post diffuseurs. Les visites des cocotiers ont été effectuées 3 fois par semaine avec extraction des insectes des galeries en notant les caractéristiques climatiques et le sexe des insectes. Les diffuseurs ont été pesés au début et chaque mois pendant la phase avec diffuseurs. On note que les trois types de diffuseurs ont la même efficacité contre les attaques de O. monoceros mais le diffuseur Dc, caractérisé par la dose faible, est économiquement plus avantageux et pourrait être vulgarisé auprès des paysans, pour la protection de leurs plantations.Mots clés : Cocos nucifera, Oryctes monoceros, Diffuseurs, Acide 4-méthyloctanoïqueOryctes monoceros Olivier is one of the most dangerous pests of young coconuts Cocos nucifera Linne (Arecaceae) in Côte-d’Ivoire. In order to reduce their populations, 4-methyloctanoïc acid was initiated. In this work, 3 different types of diffusers (Da, Db, Dc) was tested. The study over nine months covered four phases with one month (without diffusers), four month (with diffusers), two month (diffuser withdrawal) and two month (post diffuser). Coconuts were visited 3 twice in a week by collecting insects of galleries and wrote down climatic characteristics, sex of insects. Diffusers were weighted at the beginning and every month during phase with diffusers. We notice that three types of diffusers have the same effectiveness against O. monoceros attacks, diffuser Dc, characterized by a low concentration, is economically more reasonable and could be recommended to the farmer for the protection of their plantations

    Piégeage des Mouches des Fruits (Diptera : Tephritidae) À Base D’extraits de Ocimum Basilicum L. (Lamiaceae) : Cas de Bactrocera Dorsalis, Principal Ravageur de Mangues en Côte d’Ivoire

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    Les cultures fruitières, en particulier la mangue en Côte d’Ivoire, sont sous la menace des mouches des fruits. Les dégâts se sont accrus avec l’invasion de Bactrocera dorsalis. En outre, la baisse des pertes en vergers de manguiers exige l’utilisation du méthyl eugénol pour sa détection et le suivi du monitoring de sa population. Malheureusement, les attractifs sexuels spécifiques de mouchessont inaccessibles aux producteurs de la Côte d’Ivoire. L’objectif de cette étude est d’évaluer l’efficacité de Ocimum basilicum dans de la capture de B. dorsalis. Ces trois formulations du basilic (feuilles fraîches malaxées, poudre de basilic et macérât du basilic) et le méthyl eugénol sont utilisées en piégeage dans les vergers de manguiers à Korhogo. Les pièges ont été relevés chaque semaine et chaque jour respectivement pour le Méthyl eugénol et les formulations du basilic. Les formulations ont permis de capturer une importante population de B. dorsalis (99,41 %) avec une prévalence (FTD) moyenne journalière de 10,141 individus/jour/piège et d’autres espèces de mouches de fruits. La poudre de basilic montre une rémanence plus longue (28,67 ± 18,17 jours) tandis que le macérât de basilic montre une capture hebdomadaire plus élevée (513,4 ± 72,34 individus). Les captures moyennes les plus élevées ont été observées avec le Macérât de basilic (4419 ± 1090 individus) et le Méthyl eugénol (4899,67 ± 1511,74 individus). Le macérât de feuilles fraîches de basilic et la poudre de feuilles sèches de basilic peuvent être recommandées auprès des producteurs de mangues dans la lutte contre B. dorsalis. Fruit crops, especially mangoes in Côte d'Ivoire are threatened by the fruit flies. The damage has increased with the invasion of Bactrocera dorsalis. In addition, the decline in mango orchard losses requires the use of methyl eugenol for the detection and monitoring of Bactrocera population. Unfortunately, the sex-specific attractants of flies are inaccessible to producers in Côte d'Ivoire. The aims of this study is to evaluate the efficacy of Ocimum basilicum in the capture of B. dorsalis. Three basil formulations (fresh mixed leaves, basil powder and basil macerate) and methyl eugenol are used for trapping in mango orchards in Korhogo. The captured insects were collected weekly and daily for methyl eugenol and basil formulations respectively. The formulations captured a large population of B. dorsalis (99.41%) with an average daily prevalence (FTD) of 10,141 individuals / day / trap and other fruit fly species. Basil powder has the longest persistence (28.67 ± 18.17 days) and basil macerate has the highest weekly catch (513.4 ± 72.34 individuals). The highest average catches were observed with basil macerate (4419 ± 1090 individuals) and methyl eugenol (4899.67 ± 1511.74 individuals). Fresh basil leaf macerate and dry basil leaf powder may be recommended to mango growers in the control of B. dorsalis

    SINTESIS KARBON MESOPORI, CMK-1 DAN POTENSI ADSORPSINYA ATAS SURFAKTAN DI PERAIRAN

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    Marina Chimica Acta 5(1) 2004Adsorption of sodium dodecyl benzene sulfonate (SDBS) on mesoporous carbon, CMK-1 with a variation\ud of the contact time, the concentration of SDBS and a variation of pH has been conducted. The\ud concentration of SDBS before and after adsorption was determined by a UV spectrophotometer. Freundlich\ud and Langmuir models were used to study the adsorption capacity of SDBS by CMK-1. The Results\ud showed that the optimum contact time was 4 hours. To know the adsorption capacity of SDBS on CMK-1,\ud adsorption of SDBS at various consentrations and various pH were conducted at optimum contact time.\ud From the results, it was clear that the adsorption capacity at pH of 7 > pH of 4 > at pH of 10 and\ud adsorption followed isoterm Freundlich

    Parametric tolerance study of Trojan Horse plasma wakefield acceleration scheme

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    A promising scheme for plasma wakefield acceleration is the hybrid plasma acceleration mechanism, which is experimentally connected to world-wide programs at various accelerator facilities. This scheme may lead to extremely high quality electron bunches, which can be used to drive ultrabright light sources such as free electron lasers. The big challenge for plasma acceleration is to produce electron bunches with high quality in terms of low emittance, energy spread and high brightness. To overcome this challenge, the Trojan Horse scheme [1,2,3,4,5] is used for production of designer electron beams. This work explores the Trojan Horse mechanism in a parametric study by variation of the injector laser pulse by intensity a0, spot size w0 and relative spatiotemporal synchronization and alignment. These parameters define output electron witness beam parameters and its quality. This sensitivity study shows a high robustness of the scheme, which is promising for a wider key prospect of the approach, namely the development of compact plasma accelerators to produce electron beams with unprecedented emittance and brightness in order to power free-electron lasers
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