Chemical formation,characterization and properties of polycarbazole

Polycarbazole (PCz) was synthesized by chemical polymerization of carbazole in acetonitrile medium using ammonium persulfate as oxidant. The selection of solvent, concentration of the monomer, composition of the solvent, polymerization time, temperature, and pH were optimized to obtain better quality and yield of the polycarbazole. The synthesized polycarbazole was characterized by various techniques such as UV–Visible, FTIR, ¹H‐NMR, ¹³C‐NMR, COSY, NOESY, and XRD spectroscopy. The solubility of the polycarbazole was tested in various solvents. The thermodynamic stability of the polycarbazole was examined by DSC and TGA‐DTA analysis. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Thermal,mechanical and rheological properties of poly (lactic acid)/epoxidized soybean oil blends

Summary  Poly(lactic acid) (PLA) was melt blended with epoxidized soybean oil (ESO) in an internal mixer and thermal, mechanical and rheological properties of the blends were investigated by means of differential scanning calorimetry, dynamic mechanical analysis, tensile test and small amplitude oscillatory shear rheometry. ESO lowered glass transition temperature and increased the ability of PLA to cold crystallization. The blend exhibited improved elongation-at-break along with a plastic deformation. The plasticization effect by ESO was also manifested by the lowering of dynamic storage modulus and viscosity in the melt state of the blends compared with neat PLA.     

Water hydraulic manipulator for fail safe and fault tolerant remote handling operations at ITER

Department of Intelligent Hydraulics and Automation (IHA) of Tampere University of Technology has been involved in the European Fusion program since 1994 within the ITER reactor maintenance activities. In this paper we discuss the design and development of a six degrees of freedom water hydraulic manipulator with a force feedback for teleoperation tasks. The manipulator is planned to be delivered to Divertor Test Platform 2 (DTP2) during year 2008. The paper also discusses the possibility to improve the fail safe and redundant operation of the manipulator. During the design of the water hydraulic manipulator, special provisions have been made in order to meet the safety requirements such as servo valve block for redundant operation and safety vane brakes for fail safe operation.     

Comparative study of predictive FE methods for mechanical properties of nuclear composites

Carbon fiber reinforced carbon (C/C) composites are candidate materials for plasma facing components in experimental fusion reactors such as: the ITER; the JT-60 - a Tokamak fusion test facility (JAEA); and for control rods in the next generation fission reactors. Therefore, determining their thermo-mechanical properties under irradiation is essential for safe design-cum-operation of future reactors. Development of reliable models which can predict such materials’ behavior is of massive advantage against the conventional experimental verification which is hugely expensive and time-consuming. Three-dimensional finite element (FE) methods are used here for predicting Young’s modulus of two woven C/C composites where tensile tests are performed for validation. Stress distribution results indicate that a novel image-based route for FE meshes compared to a unit cell approach gives stronger agreement with experimental data. The image-based approach captures true porosity as fine microstructural details are converted from X-ray tomographic data. In comparison, the unit cell model represents idealizations of composite architecture that ignores porosities.     

Boundary Stabilization of a Cosserat Elastic Body

Boundary stabilization of vibrating three‐dimensional Cosserat elastic solids are studied using mathematical tools, such as operator theory and semigroup techniques. The advantages of the boundary control laws for both boundary stabilization problems are investigated. The boundary stabilization problems are studied using a Lyapunov stability method and LaSalle's invariant set theorem. Numerical simulations are provided to illustrate the effectiveness and performance of the designed control scheme.     

Theoretical analysis of geometrical and mechanical parameters in plain woven structures

An analytic solution for the estimation of structural parameters and initial tensile modulus of plain woven fabrics under uniaxial tensile loading in their linear elastic domain of deformation is presented. For this purpose, a new approach in straight line geometry with a parallel segment to the fabric plane and an inclined segment at the weave intersection in 3D form is proposed which leads to the theoretical estimation of all the structural parameters of plain woven fabrics with saw-tooth geometry. Defining and applying of JJ₂ Ratio in the model enable us to modify the geometrical model and estimate the value of structural parameters considering the history of samples influenced mainly by its manufacturing process. The strain energy method and Castigliano’s theorem are used for the mechanical analysis of the structure. The elasticity, bending, shearing, and compression rigidity of yarns are incorporated into the model. It has been shown that predicting the geometrical and mechanical parameters of woven fabrics before production are possible if and only if the crimp value of the fabrics can be estimated before their production. The proposed theory is validated and compared by applying into some experimental data and a previous model.     

Recent Advances in Reactions of Alkylbenzenes Over Novel Zeolites: The Effects of Zeolite Structure and Morphology

Alkylbenzenes form an important segment of petrochemical industry for the manufacture of widely used commodities and specialty products. Since the last review on this topic (8), numerous new zeolite-based catalysts have been synthesized, characterized and evaluated in various transformations of aromatic hydrocarbons. This comprehensive review covers major reactions of mono-, di-, and tri-alkylbenzenes such as disproportionation, alkylation, transalkylation, isomerization, etc., over different zeolite-based acid catalysts. During the last decade, significant progress was made in the synthesis and structure determination of novel zeolites, mesoporous single crystals, hierarchic zeolites and two-dimensional zeolites. These developments have enhanced the understanding of the role of zeolites (effects of structural type, morphology, acid sites, accessibility of acid sites, shape selectivity factors) in transformations of aromatics. In this review, the emphasis is on the influence of the type of acid sites, zeolite topology, and reaction conditions on the activity, selectivity and pathways of these reactions. Thermodynamics and reaction kinetics of transformations of aromatic hydrocarbons are also discussed. This article covers mostly literature published during the period of 2002–2013.     

Determination of Elements Profile of Some Wild Edible Plants

Fruits and leafy vegetables are believed to occupy a modest place as a source of trace elements due to their high water content. Most of nutrient requirements can be met by increasing the consumption of fruits and vegetables to 5–13 servings/day. In addition to meeting nutrient intake levels, greater consumption of fruits and vegetables is associated with reduced risk of cardiovascular disease, stroke, and cancers of the mouth, pharynx, esophagus, lungs, stomach, and colon. Therefore, vegetable and fruit consumption prevents sickness in population. Results in this research showed that Portulaca oleracia Linn. contains high value of macro-elements such as sodium (7.17 mg/g), potassium (14.71 mg/g), and calcium (18.71 mg/g), and high ash value in comparison with other plants. Also, Eulophia ochreata Lindl. has maximum micro-elements such as iron (5.04 mg/g) and zinc (3.83 mg/g) in comparison with other plants in this study. Therefore, we can conclude that P. oleracia Linn. has high nutritional values from the viewpoint of macro-elements such as sodium, potassium, and calcium; and because E. ochreata Lindl. has micro-elements in maximum amounts such as iron and zinc in comparison with other edible plants, it has high nutritional value from the viewpoint of the above trace (micro) elements. Momordica dioicia Roxb. or Cordia myxa Roxb have the lowest nutritional values because they have ash minimum values. M. dioicia Roxb. contains minimum values of sodium and calcium, but C. myxa Roxb. has zinc minimum value. Alocacia indica Sch., Asparagus officinalis DC., Chlorophytum comosum Linn., C. myxa Roxb., E. ochreata Lindl. have medium nutritional values.