Sorption Study of a Basic Dye “Gentian Violet” from Aqueous Solutions Using Activated Bentonite

AbstractVarious industries like textiles, papers, food, plastics, leather, etc are great water and organic colorant users. Hence, the resulting effluents could be an important source of environmental problems, since they may contain stable and non biodegradable contaminants, like organic dyes. The treatment of which is the main scope of the present study. Different ways of dye removal from these effluents do exist, such as flotation, reverse osmosis, chemical flocculation and adsorption etc. Adsorption is used in this work for the removal of a particular basic dye, known as Gentian violet (GV) from an aqueous solution, by means of a natural clay material. The influence of various key parameters like contact time, temperature, ionic strength, etc. on the adsorbed amount of the dye was investigated, for batch conditions. A kinetic study was also carried out, the obtained experimental results were tested against the pseudo first order and the pseudo second order equations. An analysis of the obtained equilibrium data showed that the dye adsorption is best described by the Langmuir model. The obtained results showed that temperature did enhance the Gentian violet dye retention process onto the considered bentonite whereas the obtained thermodynamic parameters indicated that the adsorption process is spontaneous and endothermic. The simultaneous presence of methylene blue, which is another colorant compound, with the Gentian violet was also considered. The clay materials showed a better affinity for the first one i e. methylene blue. In conclusion and according to the obtained results, the clay material may be recommended as an industrial adsorbent for the treatment of effluents containing Gentian violet (GV)

Asynchronous SRT Dividers: The Real Cost

Synchronous systems represent the majority of digital circuits built, essentially because they are easier to design and test. However asynchronous approaches are becoming more attractive to designers because of the potential advantages brought in terms of power consumption and delay, and also favoured by the increased sophistication of today's CAD tools. An important topic in asynchronous research is the SRT (Sweeny, Robertson, Tocher) selftimed divider. In this paper we compare two versions of a 32-bit SRT divider, synchronous and asynchronous. Our results show that the asynchronous circuit is faster, but consumes more power over an increased area. 1. Introduction The major parts of digital circuits now designed are synchronous and the main reason for their widespread use is the simplicity of the design and test. This has allowed CAD tool designers to develop powerful tools for this purpose. In a synchronous system, a designer can simply define the combinational logic necessary to co..

Asynchronous SRT Dividers: The Real Cost

Synchronous systems represent the majority of digital circuits built, essentially because they are easier to design and test. However asynchronous approaches are becoming more attractive to designers because of the potential advantages brought in terms of power consumption and delay, and also favoured by the increased sophistication of today's CAD tools. An important topic in asynchronous research is the SRT (Sweeny, Robertson, Tocher) selftimed divider. In this paper we compare two versions of a 32-bit SRT divider, synchronous and asynchronous. Our results show that the asynchronous circuit is faster, but consumes more power over an increased area. 1. Introduction The major parts of digital circuits now designed are synchronous and the main reason for their widespread use is the simplicity of the design and test. This has allowed CAD tool designers to develop powerful tools for this purpose. In a synchronous system, a designer can simply define the combinational logic necessary to co..

Determination of Volatile Organic Compounds using Quartz Crystal Microbalances Coated with Hexamethyldisiloxane

International audienc

Iron salts catalyzed synthesis of Β-N-substituted aminoacrylates

International audienc

An analysis of individual gas using non-selective sensor array

International audienc

A composite integrated mixed-technology design environment to support micro electro mechanical systems development

International audienceA major hurdle to the development of Micro Electro Mechanical Systems (MEMS) resides on the lack of communication link between the mechanical (or physical) world and the electronic world. Within a development phase, each team handles the tools traditionally used in its disciplines without any common interface. When using fieldd solvers, e.g. finite elements methods (FEM), MEMS engineers identify materials properties and boundary conditions, and build a mesh, so the tool can run a 3D finite elements solution. The tool can predict the amount of stress and strain in the structures, the movement or any other interesting characteristics, but none of this information can be automatically transferred to an IC design tool. In addition, the straightforward advances within the latest developments of the mainstream semiconductorr industry is the use of already available intelluctual property (IP) in the develpment of systems optinally matched to the end product specifications. These prospects calls for a new generation of design tools that combines aspects of EDA and mechanical / thermal / fluidic CAD. The new product suite presented in this paper offers an integrated solution allowing a continuous design flow from front-end to back-end. The end objective is to bring to the system level designer, a complete design flow, down to the chip level, anchored on design re-use and reliable system-level simulation, thus leveraging standard IP products for the realization of sophisticated miniature systems, at low cost. The environment contains elements for the device designer, enabling him to design modules, to simulate them, and finally to put the knowledge in the form of characterized standard cells in library. Commercially available optimization and yield management tools have been extended to MEMS technology to enhance the work of the MEMS device engineer. Furthermore, tools, such as FEM to HDL-A translator, has been developed in order to bridge the gap between the device engineer and the system engineer. The tool allows the generation of nonlinear dynamic behavioral and functional HDL-A models from models on a hierarchical lower level of abstraction (such as Finite-elements or transistor-level description) or measured data. The system level user takes profit of this standard cell library that contains multi-level information (e.g. layout information, behavioral models, FEM-models) in order to run the complete design flow

CAD and Foundries for Microsystems

Besides foundry facilities, Computer-Aided Design (CAD) tools are also required to move microsystems from research prototypes to an industrial market. Currently available CAD tools need extensions before they can be used for the automated design of micromachined devices. This paper presents a low cost access to microsystem technology (MST), applied by the CMP service, and based on the use of existing microelectronics production lines, with additional post-processing for microsystem specific 2D and 3D structures, and a global CAD approach for the design and simulation of microsystems applied to currently available commercial CAD tools, e.g. Mentor Framework, in order t o ensure a continuous flow from the design to the manufacturing