Simulation of Adsorption kinetics of malachite green onto coffee residues

Abstract – In this work, coffee residues were used as a zero-cost adsorbent for the application of adsorption removal of malachite green dye from simulated aqueous solution. Coffee residues were characterized by the point of zero charge (Mass titration). The point of zero charge of coffee residues was 4.37. Adsorption kinetics of malachite green onto coffee residues were studied in a batch system. The effects of pH and contact time were examined. The malachite green maximum adsorption occurred at pH 6 and the lowest adsorption occurred at pH 2. The apparent equilibrium was reached after 240 min. Optimal experimental conditions were determined. In order to determine the best-fit-kinetic adsorption, the experimental data were analyzed using pseudo-first-order, pseudo-second-order, pseudo-third-order, Esquivel, and Elovich models. Linear regressive method and non-linear regressive method were used to obtain the relative parameters. The statistical functions were estimated to find the suitable method which fit better the experimental data. Both methods were suitable to obtain the parameters. The linear elovich(type 1 and 2)model was best to fit the equilibrium data. The present work showed that coffee residues can be used as a low cost adsorbent for the malachite green removal from water.  Keywords: coffee residues (CR), linear, non-linear regression, Adsorption kinetics, error estimation, regression coefficient (R

Kick-start workshop on improved food crops marketing through appropriate transport for poor farmers in Uganda

The United Kingdom Department for International Development (DFID) Crop Post-Harvest Programme started to fund the first phase of the project on "Improved Food Crops Marketing through Appropriate Transport for Poor Farmers in Uganda" in April 2002. Subject to the results of a review by March 2003, the project may be extended on terms to be agreed on. The project purpose is to develop and promote strategies that will improve food security of poor households through increased availability and improved quality of food and better access to markets. The main outputs of the project are: a) Baseline study, b) Validated technology for IMTs, c) Promotional material. The outputs of this project will enhance the understanding of issues related to rural transport in Uganda, such as needs for intermediate means of transportation, constraints to up-take, and potential implications of improved transport for the farming system. Means of transportation will be tested and validated and the recommendations consequently developed will be presented to private sector associations, Government bodies (relevant Ministries), and National Agricultural Research Organisation (NARO), the donor community, non-government Organisations (NGOs), and relevant Networks. Their uptake will lead to an improvement of poor fanners' livelihoods

Effect of Al substitution on structural and electrical properties of Bi1.6Pb0.4Sr2CaCu2-x Mx O8+δ superconducting ceramics

In this work we study the effect on structural and electrical properties of superconducting compound Bi1.6Pb0.4Sr 2CaCu2-y My O8+δ were M=Al (with y=0-0.6). The samples were prepared by the solid-state reaction method. The samples have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), direct current (DC) resistivity versus temperature ρ(T) and alternative current (AC) susceptibility measurements. Structural analysis shows that the crystalline lattice structure of the prepared sample belongs, mainly, to the superconductive tetragonal phase Bi(Pb)2212. The SEM micrographs show that in the undoped sample the grain size has a random distribution with few grains greater than 5 μm. The grains are very dense and well connected. A quite different microstructure is obtained for the doped samples of which grains are more connected with a flat characteristic shape of Bi(Pb)2212 superconductors. All samples exhibit a superconducting character and Tc and the superconducting volume fraction decrease with increasing rate of aluminum

The ubiquitin-conjugating enzyme CDC34 is essential for cytokinesis in contrast to putative subunits of a SCF complex in Trypanosoma brucei

The ubiquitin-proteasome system is a post-translational regulatory pathway for controlling protein stability and activity that underlies many fundamental cellular processes, including cell cycle progression. Target proteins are tagged with ubiquitin molecules through the action of an enzymatic cascade composed of E1 ubiquitin activating enzymes, E2 ubiquitin conjugating enzymes, and E3 ubiquitin ligases. One of the E3 ligases known to be responsible for the ubiquitination of cell cycle regulators in eukaryotes is the SKP1-CUL1-F-box complex (SCFC). In this work, we identified and studied the function of homologue proteins of the SCFC in the life cycle of Trypanosoma brucei, the causal agent of the African sleeping sickness. Depletion of trypanosomal SCFC components TbRBX1, TbSKP1, and TbCDC34 by RNAi resulted in decreased growth rate and contrasting cell cycle abnormalities for both procyclic (PCF) and bloodstream (BSF) forms. Depletion of TbRBX1 in PCF cells interfered with kinetoplast replication, whilst depletion of TbSKP1 arrested PCF and BSF cells in the G1/S transition. Silencing of TbCDC34 in BSF cells resulted in a block in cytokinesis and caused rapid clearance of parasites from infected mice. We also show that TbCDC34 is able to conjugate ubiquitin in vitro and in vivo, and that its activity is necessary for T. brucei infection progression in mice. This study reveals that different components of a putative SCFC have contrasting phenotypes once depleted from the cells, and that TbCDC34 is essential for trypanosome replication, making it a potential target for therapeutic intervention

ELIMINATION DU VERT DE MALACHITE PAR ADSORPTION SUR CHARBON ACTIF: MODELISATION DE LA CINETIQUE D’ADSORPTION

In this work, actived carbon was produced from residue of fruit of Sapindus and used for the application of adsorption removal of malachite green dye from simulated aqueous solution. Adsorption kinetics of malachite green onto actived carbon was studied in a batch system. The effects of pH and contact time were examined. The malachite green maximum adsorption occurred at pH 6 (4.5 mg/g) and the lowest adsorption occurred at pH 2 (4.1 mg/g). The apparent equilibrium was reached after 120 min. Optimal experimental conditions were determined. In order to determine the best-fit-adsorption kinetics, the experimental data were analyzed using pseudo-first-order, pseudo-second-order, pseudo-third-order, esquivel, and elovich models. Linear regressive and non-linear regressive methods were used to obtain the relative parameters. The statistical functions were estimated to find the suitable method which fit better the experimental data. Both methods were suitable to obtain the parameters. The non linear pseudo-first-order model was the best to fit the equilibrium data. The present work showed that actived carbon can be used as a low cost adsorbent for the malachite green removal from water.Dans ce travail, le charbon actif a été préparé à partir des résidus du fruit de Sapindus et utiliser comme adsorbant pour éliminer le vert de malachite contenu dans une solution aqueuse simulée. La cinétique d’adsorption du vert de malachite sur charbon actif a été étudiée en batch. Les effets du pH et du temps de contact ont été examiné. La quantité maximale adsorbée du vert de malachite a été obtenu à pH 6 (4.5 mg/g) et la quantité minimale a été obtenue à pH 2 (4.1 mg/g). Le temps d’équilibre apparent été atteint après 120 min. Les conditions expérimentales optimales ont été déterminées. Dans le but de déterminer le modèle de cinétique d’adsorption le plus adéquat, les résultats expérimentaux ont été analysés en utilisant les modèles cinétiques pseudo-premier-ordre, pseudo-deuxième-ordre, pseudo-troisième-ordre, pseudo-premier-ordre, esquivel, et elovich. Le modèle non linaire pseudo-premier-ordre est le plus adapté pour représenter les résultats expérimentaux. Cette présente étude montre que le charbon actif est un adsorbant moins onéreux, qui peut être utilisé, pour éliminer le vert de malachite de l’eau

Role of neuropeptide Y and its receptors in the development of epileptogenesis in mice and rats

STRASBOURG-Sc. et Techniques (674822102) / SudocSudocFranceF

Développement et optimisation des systèmes alphaviraux pour l'expression fonctionnelles des protéines membranaires

STRASBOURG-Sc. et Techniques (674822102) / SudocSudocFranceF

Berkshire RG45 6AU

TITLE: by: Urban transport services i