Vinyl polymerization by Ziegler catalysts

Summary Methylmethacrylate and styrene were polymerized with Co(acac)₃-AlEt₂ Br catalyst system in benzene at 40°C. Rate of polymerization is linear to monomer concentrations. Maximum percent conversion of polymer was obtained when Al/Co2 with styrene and Al/Co3 with methylmethacrylate. With increase in aging time catalytic activity decreases. Activation energy was found to be 60 KJ mol^–1. with styrene and 40 KJ mol^–1. with methylmethacrylate.The authors arc thankful to the UGC, INDIA for the financial support.     

Anti-corrosion coatings on SS 304 by incorporation of Pr6O11–TiO2 in siloxane network

This paper describes an attempt to develop anticorrosive siloxane coatings based on Pr₆O₁₁–TiO₂ composite films for SS 304 substrate by sol-gel technique. We demonstrate for the use of praseodymium oxide doped Titanium oxide (Pr₆O₁₁–TiO₂) nanocomposites loaded in a hybrid sol-gel layer, to effectively protect the underlying steel substrate from corrosion attack. The influence of Pr₆O₁₁–TiO₂ gives the surprising aspects based on active anti-corrosion coatings. The silica sol was treated with Pr₆O₁₁–TiO₂ to achieve different level of add-on i.e.) 0–1 wt % of nanocomposites. The influence of different weight percent of nanocomposites on silica matrix for anticorrosion performance was investigated by Electrochemical Impedance Spectroscopy (EIS). Pr₆O₁₁–TiO₂ nanocomposites loaded in a hybrid sol-gel layer effectively protect the underlying substrate from corrosion attack. The results showed significant improvement in anticorrosion property for higher add-ons up to the optimized percent of nanocomposites. Furthermore, Transmission Electron Microscopy (TEM) and Scanning Electron Microscope Microscopy (SEM) were used to characterize the surface morphology of doped and undoped coatings. The studied showed a synergistic effect between Pr₆O₁₁–TiO₂ and siloxane matrix has leads to a self-healing coatings.     

Crab shell-based biosorption technology for the treatment of nickel-bearing electroplating industrial effluents

This paper discusses the possible application of a biosorption system with acid-washed crab shells in a packed bed up-flow column for the removal of nickel from electroplating industrial effluents. Between two nickel-bearing effluents, effluent-1 is characterized by considerable amount of light metals along with trace amounts of lead and copper. Effluent-2 is characterized by relatively low conductivity, total dissolved solids and total hardness compared to effluent-1. Crab shells exhibited uptakes of 15.08 and 20.04 mg Ni/g from effluent-1 and effluent-2, respectively. The crab shell bed was regenerated using 0.01 M EDTA (pH 9.8, aq. NH3) and reused for seven sorption-desorption cycles. The EDTA elution provided elution efficiencies up to 99% in all the seven cycles. This, together with the data from regeneration efficiencies for seven cycles, provided evidence that the reusability of crab shell in the treatment of nickel-bearing electroplating industrial effluents is viable.     

求解非光滑燃料费用函数的基于进化规划的机组最优潮流

提出求解具有非光滑燃料费用函数的存在爬坡率限制的最优潮流方法。针对两次、阶梯形、联合循环机组的非光滑燃料费用函数,介绍一个基于进化规划的算法。在该算法中,为避免早熟,交叉操作随后代的数目非线性变化。介绍了所提出的进化算法应用于有线路约束的IEEE30节点系统和印度62节点系统的情况。以MVA为单位的线路潮流直接采用牛顿-拉夫逊法计算。算例证明所提出的进化算法简单,对求解具有非光滑燃料费用函数的存在很多约束的最优潮流问题有效。     

Geographic Information System for Coordination of Fast-Track Projects

To meet the increasing demands to deliver projects within a short period of time, many projects are being executed on a fast-track basis. On fast-track projects, the construction begins when the design is between 35% and 65% complete. This poses numerous challenges. One of the key challenges is to ensure that the flow of information and deliverables between the engineering, procurement, and construction is synchronized. This work initially studied the information flow on process plant projects, the disruptions to information flow, and the problems faced due to the disruptions. It was identified that an information system that has the capability to (1) capture the relationships between different deliverables, (2) record the status of deliverables, and (3) process queries from any of the teams regarding status and impact of disruptions will support the decision-making required for rapid development of pragmatic plans. Further, as the information requirements require the representation and querying of both spatial and nonspatial data, the design and implementation of the system using the concepts and features of a geographic information system was explored. The paper discusses the design of the geographic information system and its implementation within the AutoCAD Map environment. The use of the system to retrieve information required for project coordination is illustrated through sample queries.     

Optical interconnection reverse data vortex network: performance analysis

Multistage interconnection networks are employed in data centres to interchange information between the processors and memory elements. Data Vortex (DV) is a multistage minimum logic network which can be used in data centres. DV satisfies the requirements of the interconnection networks such as scalability and throughput. However, the latency is on higher side, and reduction in latency can lead to higher throughput. In the present paper, we describe the feasibility and performance analysis of DV architecture in reverse direction. The routing and the possible hardware model of the node switch have been discussed. We present the performance analysis of Reverse Data Vortex (RDV) architecture in terms of throughput, latency and latency distribution. A comparative study with DV on throughput, latency and latency distribution is also presented. The simulation result shows that the decrease in latency of RDV is about 50 % that of DV and this leads to an increase in injection rate of RDV to values more than two times that of DV.     

Preferential oxidation of CO in H2 stream on Au/CeO2–TiO2 catalysts

A series of Au catalysts supported on CeO₂–TiO₂ with various CeO₂ contents were prepared. CeO₂–TiO₂ was prepared by incipient-wetness impregnation with aqueous solution of Ce(NO₃)₃ on TiO₂. Gold catalysts were prepared by deposition–precipitation method at pH 7 and 65 °C. The catalysts were characterized by XRD, TEM and XPS. The preferential oxidation of CO in hydrogen stream was carried out in a fixed bed reactor. The catalyst mainly had metallic gold species and small amount of oxidic Au species. The average gold particle size was 2.5 nm. Adding suitable amount of CeO₂ on Au/TiO₂ catalyst could enhance CO oxidation and suppress H₂ oxidation at high reaction temperature (>50 °C). Additives such as La₂O₃, Co₃O₄ and CuO were added to Au/CeO₂–TiO₂ catalyst and tested for the preferential oxidation of CO in hydrogen stream. The addition of CuO on Au/CeO₂–TiO₂ catalyst increased the CO conversion and CO selectivity effectively. Au/CuO–CeO₂–TiO₂ with molar ratio of Cu:Ce:Ti = 0.5:1:9 demonstrated very high CO conversion when the temperature was higher than 65 °C and the CO selectivity also improved substantially. Thus the additive CuO along with the promoter and amorphous oxide ceria and titania not only enhances the electronic interaction, but also stabilizes the nanosize gold particles and thereby enhancing the catalytic activity for PROX reaction to a greater extent.     

Physical properties of infrared (IR) assisted hot air dried nutmeg (Myristica fragrans) seeds

A combined infrared (IR) and hot air assisted drying is an efficient synergistic process compared with usage of IR and hot air drying distinctly. In this work, physical properties of IR assisted hot air dried nutmeg (Myristica fragrans) seeds were determined. These properties are necessary for the design and manufacturing of equipment on handling, processing, and storing of nutmeg seeds. The mean length, width and thickness of the seeds were 3.08, 2.42, and 2.39 cm, respectively. The average value for geometric mean diameter, Sphericity, mass, surface area, area of projection, minimum and maximum radius, volume, true density, bulk density, and porosity were 2.607 cm, 0.85, 5.3 g, 21.39 cm², 1.88 cm², 1.21 cm, 1.71 cm, 9.3 cm³, 1,027.4 g/cm³, 21.5 g/cm³, and 97.82%, respectively, also the coefficient of static friction on five types of structural surface was found to be ranging from 0.276 (glass) to 0.476 (cardboard).

Practical applications

For the design and manufacturing of equipment on handling, processing, and storing of nutmeg seeds, infra‐red assisted hot air drying is an alternative method for industrial nutmeg post‐harvest processing applications. The study of physical properties of treated seeds is essential for uniformity and packing in standard cartons.