Electrochemical treatment of the pollutants generated in an ink-manufacturing process

The effluents of ink-manufacturing processes contain a large variety of pollutants such as dyes, surfactants, biocides, water soluble solvents, etc. In this work, the electrochemical oxidation of several dyes (methylene blue and rhodamine B), solvents (monoethylene glycol, diethylene glycol and glycerol) and surfactants (sodium dodecylbenzenesulfonate) has been studied. To carry out the electrolyses, a bench-scale plant with a single-compartment electrochemical flow-cell was used. Boron doped diamond (BDD) was used as anode and stainless steel (AISI 304) as cathode. For all the compounds tested, the conductive diamond electrooxidation allows achieving the almost complete removal of COD of the waste with a very high current efficiency. The efficiencies of the electrochemical processes seem to depend on the current density and on the nature of the anions contained in the waste (chlorine, sulphate, phosphate). Thus, it has been observed that the use of chloride media favours the treatment of dyes. On the contrary, the use of sulphate- or phosphate-containing solutions improves the removal of the aliphatic compounds studied (solvents). These results suggest an important role of the mediated electrochemical processes on the overall performance of the reaction system.     

Reflexive transitive invariant relations: A basis for computing loop functions

Invariant assertions play an important role in the analysis and verification of iterative programs. In this paper, we introduce a related but distinct concept, namely that of invariant relation. While invariant assertions are useful to prove the correctness of a loop with respect to a specification (represented by a precondition/ postcondition pair) in Hoare’s logic, invariant relations are useful to derive the function of the loop in Mills’ logic.     

Electrochemical degradation of an anionic surfactant on boron-doped diamond anodes

In this work, the electrochemical oxidation on boron-doped diamond of synthetic wastes polluted with surfactant sodium dodecylbenzenesulfonate (SDBS) has been studied. Results show that SDBS can be successfully removed with this technology inside different current densities and concentration ranges. The oxidation of the SDBS seems to occur in two main sequential steps: the first is the rapid degradation of SDBS, and the final is the less efficient oxidation of aliphatic intermediates to carbon dioxide. The nature of supporting electrolyte (NaCl, Na(2)SO(4) and K(3)PO(4)) influences on the efficiency of the electrochemical oxidation process. The treatment of the NaCl solution seems to be more efficient in the chemical oxygen demand (COD) removal, while the sulphate and specially the phosphate media improve the TOC removal. However, in spite of this observation, chemical oxidation of SDBS by different types of oxidants cannot explain alone the results of the electrochemical oxidation with diamond anodes. This suggests that the synergistic effect of the different oxidation mechanisms that occurs into the electrochemical cell (direct oxidation and mediated oxidation by hydroxyl radicals and by oxidants formed from the electrolyte) is the responsible of the great efficiencies obtained with this technology in the treatment of organics.     

Extending the analog input capabilities of the DS1102 DSP controller board

The paper deals with an extention of the number of analog inputs of the DS1102 controller board which is commonly used in the area of electric machines. Manufactured with just four analog inputs, the DS1102 has been found inadequate for the implementation of a vector control strategy in the rotor converter of a doubly-fed wind generator. In order to extend the number of analog inputs without reducing the real time control capability of the DS1102, an appropriate analog multiplexing board has been developed. It is directly addressed by the TMS320C31: the DSP around which the DS1102 is built. Experimental tests show that the performances of the proposed board are satisfactory.     

Electrochemical Oxidation of Benzoic Acid Derivatives on Boron Doped Diamond: Voltammetric Study and Galvanostatic Electrolyses

The electrochemical oxidation of aqueous wastes polluted with benzoic and salicylic acids and phthalic anhydride on boron‐doped diamond electrodes has been studied. The complete mineralization of the organic waste has been obtained in each case regardless of the nature of the compound, composition of the solution, and current density. Different voltammetric behaviors between benzoic acid, salicylic acid, and phthalic anhydride were obtained in the voltammetric study, but no differences in the electrochemical oxidation of the three compounds seems to exist in the bulk electrolyses study. The total mineralization of the three compounds at different current densities confirms that the oxidation must occur directly on the electrode surface and/or by hydroxyl radicals generated by decomposition of water and/or by other oxidants electro‐generated from the sulfate oxidation.     

Uncertain Saturated Discrete‐Time Sliding Mode Control for A Wind Turbine Using A Two‐Mass Model

The aim of this paper is to propose a new design variable speed wind turbine control by discrete‐time sliding mode approach. The control objective is to obtain a maximum extraction of wind energy, while reducing mechanical loads and rotor speed tracking combined with an electromagnetic torque. For this application, we designed a discrete time sliding mode control using the equivalent discrete time reaching law. Furthermore, a systematic and improved design procedure for uncertainties discrete‐time sliding mode control (SMC) with saturation problem is provided in this paper. The saturation constraint is reported on inputs vector. LMI technique and polytopic models are used in the design of the switching surface. To achieve some performance requirements and good robustness, in the sliding mode, the pole clustering method is investigated. Based on the unit vector control approach, a robust control is developed, then, to direct and maintain the system states onto the sliding manifold in finite time. Finally, a systematic design procedure for DSMC required to achieve a given performance level is provided and its effectiveness is varied by applying it to variable speed wind turbine systems.     

Evaluation of different supplementary nutrients for enhanced biohydrogen production by Enterobacter aerogenes NRRL B 407 using waste derived crude glycerol

Crude glycerol (CG) has several advantages over a range of conventional substrates used for biohydrogen production by Enterobacter aerogenes NRRL B 407. Meanwhile, high process cost due to requirement of expensive supplementary media component is a concern. Therefore, different less expensive (or wastes) materials have been evaluated as supplementary nutrient for H₂ production by CG (meat processing and restaurant waste based biodiesel derived) bioconversion. Among the materials selected, slaughterhouse liquid waste (SL), brewery waste biomass (BWB) and urea was found to improve the production by 18.81 ± 3.56, 27.30 ± 3.54 and 38.57 ± 3.66%, respectively. Further, in the case of urea (10 mg/L), cumulative production as high as 116.41 ± 3.72 mmol H₂/L media has been achieved; which is comparable to other reports available on CG bioconversion. Thus, present study demonstrates successful replacement of large amount (∼5–6 g/L) of expensive nutrients/buffering agents by negligible amount (∼10 mg/L) of different waste materials, without compromising the cumulative H₂ yield. Further, the strain used in the present study was found to grow at an acidic pH as low as 3.3, indicating its prospective application for dark fermentative H₂ production.     

Invariant relations, invariant functions, and loop functions

The increasing criticality of software applications, the increasing size and complexity of such applications, and the increasing reliance of software engineering paradigms on third party software assets combine to place a high premium on the ability to analyze software products to an arbitrary level of thoroughness and precision. Yet despite several decades of research, the goal of analyzing the functional properties of software products to an arbitrary level of thoroughness and precision remains unfulfilled. In this paper, we discuss the use of a relation-theoretic approach inspired from Mills?? logic to analyze while loops, and we support our approach by an operational prototype tool. The proposed method and tool have applications in program comprehension, reverse engineering, program verification, software maintenance, and programmer education.     

Maintaining consistency between CAD elements in collaborative design using association management and propagation

The complete definition of a product often requires the collaboration of various partners. Data sharing and exchange between partners has thus become an important task throughout a product's entire life cycle. Even while subsets of the product definition are exchanged (as work packages) and modified by various partners, the global product definition must remain consistent. This paper focuses on maintaining consistency between Computer-Aided Design (CAD) work packages and the global product Digital Mock-Up (DMU). The approach is designed to ensure better management of the associations between objects when a work package is extracted from the global DMU, modified by a partner, sent back to the originator and then re-inserted into the global DMU, which must be modified in turn so as to maintain consistency. To this end, we propose an association management model for the digital mock-up (Digital Mock-up Association Management Model, DMU-AMM) that transposes the associations that exist between a DMU and a work package, including package extraction and modifications, to ultimately guide the evolution of the DMU so as to reconcile the associations between a modified DMU and the modified work package and there by maintain consistency.