Assessment of Heavy Metal Contamination in Soils and Vegetables in Cameron Highlands Vegetable Farms

Vegetable cultivation is the most important agricultural activity in Cameron Highlands; about 64% of the population are involved in vegetable cultivation, with a total area of 2 599 hectares. Due to the extensive land levelling and construction of terraces, the vegetables are essentially grown on the subsoil. The subsoil are mainly sandy clay or clay, with large amounts of organic matter being added usually in the form of chicken manure. In a study of assessment of heavy metals in soils and vegetables of Cameron Highlands, Peninsular Malaysia, 200 soil and 40 vegetable samples from various locations were analyzed for cation exchange capacity (CEC), texture, cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb), chromium (Cr) and zinc (Zn), organic carbon COe), pH and available phosphorus (P). The results showed that there was no relationship between total Cd, Cr, Cu, Ni, Pb and Zn concentrations in the soils and in the vegetables. Correlation studies of soil fertility parameters and total heavy metal concentration showed positive correlation between total P and Pb (r =0.492*) and Ni (r = 0.514*). This is indicative of addition of these metals as impurities in organic and inorganic fertilizers Organic Cd showed a positive correlation (r = 0.538*) with soil carbon (OC), while Pb showed a negative correlation (r = - 0.507*). This is indicative of addition of Cd as impurities in organic manures. Copper was positively correlated with clay content (r = 0.678**), while Pb (r = - 0.484*) and Ni (r = -0.554*) were negatively correlated with AI. Pb was negatively correlated with CEC (r = -0.502*). Anova analysis of total Zn, Cd, Cu, Cr, Ni and Pb with soil depth showed a very strong positive relationship. The concentration of Zn, Cd, Cr and Cu are high only in the topsoil (0-20 em), but the concentration of these elements remain the same in the depths of 20-40 em and 40-60 em. This is indicative of the contamination from agriculture activities. The difference in heavy metals from the cultivated soils and the control (primary forest) provides further evidence of the contamination by agriculture activities. The concentrations of heavy metal in Cameron Highlands soils from different vegetable farms were studied. Brinchang and Tanah Rata vegetable farms had very high concentration of Zn (219.80 mglkg); in Brinchang it is above the background values (Dutch Standard Guidelines). Also Brinchang and Tanah Rata farms had very high concentration of eu (61.80 and 71.20 mglkg, respectively), which is above the background level. Cd tends to be high in all Cameron Highlands farm soils

Thermodynamics of Mixing Water with Dimethyl Sulfoxide, as Seen from Computer Simulations

The Helmholtz free energy, energy, and entropy of mixing of eight different models of dimethyl sulfoxide (DMSO) with four widely used water models are calculated at 298 K over the entire composition range by means of thermodynamic integration along a suitably chosen thermodynamic path, and compared with experimental data. All 32 model combinations considered are able to reproduce the experimental values rather well, within RT (free energy and energy) and R (entropy) at any composition, and quite often the deviation from the experimental data is even smaller, being in the order of the uncertainty of the calculated free energy or energy, and entropy values of 0.1 kJ/mol and 0.1 J/(mol K), respectively. On the other hand, none of the model combinations considered can accurately reproduce all three experimental functions simultaneously. Furthermore, the fact that the entropy of mixing changes sign with increasing DMSO mole fraction is only reproduced by a handful of model pairs. Model combinations that (i) give the best reproduction of the experimental free energy, while still reasonably well reproducing the experimental energy and entropy of mixing, and (ii) that give the best reproduction of the experimental energy and entropy, while still reasonably well reproducing the experimental free energy of mixing, are identified

Design of supramolecular nanomaterials : from molecular recognition to hierarchical self-assembly

In the present thesis, are reported new strategies for the design of nanostructures to partly address environmental issues. The work carried out has been divided into three parts: the design of cyclodextrin (CD)-based polymeric materials, the molecular engineering of a pyrene derivative for the formation of self-assembled nanostructures and the design of smart nanocarriers. Considerable efforts have been devoted to the design of molecular receptors capable of specific recognition of a wide variety of targets ranging from small inorganic ions to large biomolecules. These molecular receptors have been widely used to produce (nano)materials with superior molecular recognition properties. While these materials have been extensively studied for biomedical applications, their use in environmental sciences or biotechnology has been, to some extent, neglected. Supramolecular materials, because of their superior molecular recognition properties may find a wealth of new applications for the selective removal of harmful or valuable targets from industrial waste streams. While the specific recovery of valuable chemicals from waste streams represents an environmentally-friendly and potentially economically-relevant alternative to synthetic chemical productions, it remains a largely unmet challenge. This is partially explained by the complexity of designing sorption materials able to target one specific compound and able to function in complex matrices. In this manuscript, is reported the synthesis of a series of CD-based polymers (CDPs) designed to selectively extract phenolic compounds from a complex organic matrix that is OMW. In order to endow these polymers with selective adsorption properties, several monomers and cross-linkers were screened and selected. The adsorption properties of the CDPs produced were first tested with selected phenolic compounds commonly found in OMW, namely syringic acid, p-coumaric acid, tyrosol (TY) and caffeic acid. The selected CDPs were subsequently tested for their ability to adsorb phenolic compounds directly from OMW, which is known to possess a high and complex organic content. Adsorption models and adsorption kinetics were studied and allowed to set a new method on a pilot plant. It was demonstrated through liquid chromatography-mass spectroscopy (LC-MS) analyses that efficient removal of phenolic compounds from OMW could be achieved but also that two compounds, namely TY and hydroxytyrosol (HT), could be selectively extracted from OMW. The chemical oxygen demand (COD) level which is correlated to the amount of organic compounds was also reduced in the recovered fractions after extraction of the phenolic compounds, which makes the recovered waters relevant for irrigation purposes. The use of CD-based polymeric materials for the removal of valued added molecules could represent a new approach that will benefit from the ease of production of CDP and cost. Nature represents an inexhaustible source of inspiration for elegant hierarchically assembled structures and biology is replete with numerous examples of highly complex self-assembled structures. From cell membranes to proteins and viruses, the precise internal organisation of these biological structures is based on non-covalent interactions of subunits. Self-assembly strategies have been extensively exploited for the creation of supramolecular entities due to the complex synthesis of large structures through covalent synthetic strategies. Bottom-up approaches permit to build large and complex supramolecular assemblies through the interactions of building blocks. The accurate molecular design of organic building blocks is of great importance for the creation of large supramolecular entities with precise dimensional organisation. In this PhD thesis, we report the synthesis and template-free hierarchical self-assembly of a novel pyrene derivative into well-defined nanorods. The formation and the three dimensional packing of this pyrene derivative into nanorods were studied by means of fluorescence and UV-Vis spectroscopy, scanning electron microscopy, single crystal and powder X-ray diffraction studies. Nowadays oil and hydrocarbons cover most of our energy needs. In 2008, the world demand reached 85.62 million barrels/day.[1] Consequently spill accidents cause also considerable damages and water contamination by oil spills represents a major global problem. Several approaches for the degradation of oil spills are available including mechanical removal, wiping with absorbent materials or booming and skimming, but these techniques stay fairly limited in efficiency. Besides these methods, bioremediation has emerged as one of the most promising treatment for oil spill. Bioremediation is divided into two branches, biostimulation and bioaugmentation. We propose in this thesis an alternative way to overcome dilution related issues in biostimulation to degrade hydrocarbons through the stimulation of the microbial growth to increase the rate and efficiency of hydrocarbons degradation. The system would be able then to target specifically the oil phase and avoid any dilution of the needed nutrients into the sea, which should lead to a higher performance of the bacteria. We reported in this manuscript the synthetic strategy to produce what we named "Smart Gates Particles" (SGPs) that can act as nanocarriers and deliver specifically the nutrients to bacteria. The loading and kinetic releases of the nutrients contained in the SGPs have been studied in different environments, water and mixture oil/water. The design of such particles represents an alternative and ecological way to overcome the dilution or the non-targeted release of nutrients for oil-degrading bacteria

La négation en rifain (parler de Ait Qamra)

International audienceEn rifain, il existe différents morphèmes qui servent à obtenir des énoncés négatifs, ainsi ce travail sepropose de dresser un tableau de leurs différents emplois et d’en faire une analyse morphosyntaxiqueet sémantique. Cette étude sera basée sur le parler de la commune de Ait Qamra qui se situe à unevingtaine de kilomètres au sud-ouest de la ville de Al Hoceima dans le canton de Ait Waryaghel(Maroc).Avant de rentrer dans le détail de nos recherches, il convient de donner une définition de ce qu’est lanégation. Je reprends à mon compte la définition que donne Robert Forest à ce sujet et qui me sembleêtre très complète : La négation est un « ensemble de procédures morphosyntaxiques de marquage,ayant pour fonctions principales de faire en sorte que les énoncés qu’elles contribuent à formerexhibent avec d’autres énoncés un rapport systématique d’opposition sémantique, et d’introduire dansla situation de l’énonciation la communication du rejet par l’énonceur d’un contenu propositionnel (ouéventuellement situationnel non verbal) à l’expression duquel le marquage négatif se trouveformellement lié » (Forest 1993).En fonction de ce qu’il vient d’être dit précédemment ce type d’énoncé négatif en berbère secaractérise par la combinaison d’un ou plusieurs morphèmes négatifs à un prédicat verbal ou nonverbal(énoncé minimal), c’est ce que nous allons rendre compte précisément en les passanten revue le plus exhaustivement possible et en articulant notre étude autour de ces marqueurs denégations

Comment se dénomme-t-on en rifain / tmaziɣt ? Etude onomastique : Essai théorique, approche psycholinguistique (partie I)

International audienc

HOPX Crossover Operator for the Fixed Charge Logistic Model with Priority Based Encoding

In this paper, we are interested to an important Logistic problem modelised us optimization problem. It is the fixed charge transportation problem (FCTP) where the aim is to find the optimal solution which minimizes the objective function containig two costs, variable costs proportional to the amount shipped and fixed cost regardless of the quantity transported. To solve this kind of problem, metaheuristics and evolutionary methods should be applied. Genetic algorithms (GAs) seem to be one of such hopeful approaches which is based both on probability operators (Crossover and mutation) responsible for widen the solution space. The different characteristics of those operators influence on the performance and the quality of the genetic algorithm. In order to improve the performance of the GA to solve the FCTP, we propose a new adapted crossover operator called HOPX with the priority-based encoding by hybridizing the characteristics of the two most performent operators, the Order Crossover (OX) and Position-based crossover (PX). Numerical results are presented and discussed for several instances showing the performance of the developed approach to obtain optimal solution in reduced time in comparison to GAs with other crossover operators

Modelisation of the maintenanceproduction

couple by a graph of schedulin

Anesthésie pour prothése totale de la hanche: à propos de 50 cas

La chirurgie de la prothèse totale de la hanche (PTH) est une chirurgie fonctionnelle qui consiste en un remplacement d'une articulation endommagée afin d'améliorer la qualité de vie du patient. L'anesthésie pour PTH exige une préparation rigoureuse à l'intervention, la consultation d'anesthésie sera donc la clef de cette réussite. Nous avons réalisé une étude rétrospective concernant 60 arthroplasties totales de la hanche implantées chez 50 patients adultes, colligée au sevice de Traumatologie et de chirurgie orthopédique à l'Hôpital Militaire Avicenne de Marrakech sur une période étalée de Janvier 2010 au Décembre 2012. Nous avons évalué la prise en charge anesthésique : pré, per et postopératoire des patients opérés pour une PTH. La moyenne d'âge était de 56,5 ans, le sex-ratio était de 1,63 en faveur des hommes. L'indication prédominante était la coxarthrose primitive. L'anesthésie générale était la technique anesthésique la plus utilisée (66% des cas), l'intubation difficile était rencontrée chez 6 % de nos patients. La durée moyenne de l'acte chirurgical était de 114 +/- 25,33 mn. 12 % de nos patients ont présenté une hypotension artérielle peropératoire. L'incidence de la transfusion homologue perop était de 14%. Nous avons noté 08 cas de complications postop : 03 cas d'infection de la PTH 15 jours après l'intervention, 03 cas de descellement aseptique, 01 cas de luxation de PTH et 01 cas de descellement septique avec un recul moyen de 54 mois.Pan African Medical Journal 2015; 2

Multilayer Perceptron: Architecture Optimization and Training

The multilayer perceptron has a large wide of classification and regression applications in many fields: pattern recognition, voice and classification problems. But the architecture choice has a great impact on the convergence of these networks. In the present paper we introduce a new approach to optimize the network architecture, for solving the obtained model we use the genetic algorithm and we train the network with a back-propagation algorithm. The numerical results assess the effectiveness of the theoretical results shown in this paper, and the advantages of the new modeling compared to the previous model in the literature