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..

CAD tools for bridging microsystems and foundries

To move microsystems from research prototypes to an industrial market, CMP, the French multiproject wafer service, has adapted an existing commercial tool to the automated design of micromachined devices

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..

Iron salts catalyzed synthesis of Β-N-substituted aminoacrylates

International audienc

Towards space microsystems : design and manufacturing methodologies for CMOS compatible MEMS

International audienceThe use of standard technologies for ASICs and/or Micro Electro Mechanical Systems (MEMS) intended for space has the potential of a significative cost reduction, which, together with increased performance requirements and obsolescence problems, is at the source of the current interest on the use COTS products. The straightforward extension of the COTS concept to the latest developments of the mainstream semiconductor industry is the use of already available intellectual property (IP) in the development of ASICs optimally matched to the end product specifications. A short time-to-market is the driving force, and it can only be achieved through the use of fine tuned and tightly integrated CAD tools. A major hurdle to this development for space electronic systems resides on the lack of data on the radiation tolerance of standard commercial ASIC technologies. This void is felt even more acutely in the development of integrated MEMS, and emerging technology that holds the promise of a new generation of compact spacecrafts and instruments. Moreover, CAD tools are generally not yet MEMS-aware, and MEMS libraries are virtually inexistent. The work at TIMA has sought to address each one of these shortcomings, and the efforts pertinent to the development of space microsystems are described in this paper. The design and manufacturing methodologies of CMOS compatible MEMS, developed at TIMA, are presented with a demonstration on a micromachined infra-red imaging sensor scheduled to fly (as a passenger) on the STENTOR satellite

Advanced integrated solution for MEMS design

This paper presents a fully integrated solution for the development of Micro Electro Mechanical Systems which covers component libraries, design tools and designs methodologies which are used in conjunction with conventional design automation tools. This solution enables system houses in wireless and optical communications and consumers electronics markets to reduce their internal development costs and significantly accelerate their product development cycle

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