Synthesis of amino-modified ordered mesoporous silica as a new nano sorbent for the removal of chlorophenols from aqueous media

Contamination of natural water with organic pollutants is a problem of major concern and the demand for effective adsorbents for the removal of toxic compounds is increasing. Present work deals with the adsorption of 2-chlorpphenol (2-CP) and 2,4,6-trichlorophenol (2,4,6-TCP) from aqueous solutions on a new nano sorbent; amino-modified ordered mesoporous silica (APS-MCM-41) material. It was found that APS-MCM-41 shows significant adsorption for 2-CP and 2,4,6-TCP. This might be due to the acid and alkaline interactions among the amino functional groups and chlorophenols. Batch adsorption studies were carried out to study the effect of various parameters like adsorbent dose, pH, initial concentration and contact time. It was found that adsorption of 2-CP and 2,4,6-TCP depends upon the solution pH. From the sorption studies it was observed that the uptake of 2,4,6-TCP was higher than that of 2-CP. Freundlich and Langmuir adsorption isotherms were used to model the equilibrium adsorption data for 2-CP and 2,4,6-TCP.     

Springback in acetylated wood based composites

Reasons of the strength loss of the acetylated wood based composites were still under question. This research was considered to study springback in the acetylated particleboard and the medium density fibreboard. Chips and fibres were acetylated by using the acetic anhydride to gain different percentages of the weights (WPG). The boards were made based on the target thicknesses. Thickness of the boards as well as the modulus of elasticity (MOE) and the modulus of rupture (MOR) were determined after conditioning based on three point static bending test.Results showed that the moisture content and the thickness swelling of the boards were reduced as the WPG was increased. However, increase of the springback and reduction of the MOE and the MOR were revealed as the WPG increased in the test boards after condition. It was also revealed that the springback was correlated with the weight gain and increased as the WPG was raised in the test boards. Reduction of the MOE and the MOR was also correlated with the springback in the test boards.     

Self-efficacy and learning experience of information education: in case of junior high school

The purpose of this study is to make clear the relationships between student’s self-efficacy and learning experience of information education in case of junior high school. Two investigations were implemented in this study. The aim of first investigation was to grasp the present status of students’ feeling of effectiveness of their learning experience in information education. Also, the aim of second investigation was to verify the relationships between students’ self-efficacy and the abilities for information utilizing that promoted in information education. The first investigation with a question: “What kind of a learning experience do you feel is useful in your life?” was conducted on 426 junior high school students. As a result, almost half of the students feel effectiveness of gaining computer-operating skills in “Information and Computer” class. Also, it is suggested that utilization of Internet could promote the feeling of effectiveness in current daily lives. In second investigation, the relationship between self-efficacy and abilities for information utilizing was examined by using multi-regression analysis on 544 junior high school students. As a result, abilities for information utilizing were affected from self-evaluation of “social position of abilities” and “positive attitude to activities” in self-efficacy. Also, self-efficacy was affected from “processing ability of information” and “creation ability of information” in abilities for information utilizing. By the results of these investigations, it is suggested that these two factors are formed as a gradual cycle which promote each other. From these results, some suggestions for improvement of classroom activities in information education were proposed.     

Oppositional target domain estimation using grid-based simulation

In this paper we address the problem of estimating the target domain for search and navigation problems. We propose oppositional target domain estimation by modeling the search and navigation environment as a grid. Typically real-world applications exhibit an environment that is extremely large, dramatically diminishing the usability of intelligent agents for search and navigation. The reduction of the size of environment, hence, can help to increase the efficiency and applicability of the agents. We address this issue by modeling the environment as a grid and estimating the target domain inside the environment. The target domain is a reduced space which includes the target. The proposed technique is specifically concerned with reducing the environment using the concept of opposition. Experimental results show significant reduction of the environment size resulting in a shorter search time.     

A Hybrid Fuzzy-Based Multi-Objective PSO Algorithm for Conjunctive Water Use and Optimal Multi-Crop Pattern Planning

This paper focuses on extracting an optimal multi-crop pattern plan through multi-objective conjunctive surface-ground water use management. Minimizing shortages in meeting irrigation demands, maximizing groundwater resources sustainability and maximizing agricultural net benefits are the three main goals of the multi-objective optimization problem solved in this paper. A new robust fuzzy-based multi-objective PSO algorithm called f-MOPSO is adopted and modified to solve a three-objective real-world conjunctive use management problem presented in this paper after testing on standard test problems revealed f-MOPSO superiority as compared to the well-known multi-swarm vector evaluated PSO (VEPSO) algorithm. The f-MOPSO benefits from a well-organized Sugeno fuzzy inference system (SFIS) designed for handling multi-objective nature of the optimization problems. The unique performance of f-MOPSO is not only presenting the better final solutions, but also aggregating the capabilities for measurement of dominance and diversity of the solutions in one stage by one index named comprehensive dominance index, in contrast to a wide range of multi-objective algorithms that evaluate dominance and diversity in two separate stages resulting in excessive computational burden. The optimization model is carried out on a 10-year long-term simulation period, resulting in increasing irrigation efficiency i.e. decreasing water losses, decreasing water consumption per unit cultivated area and increasing water productivity compared to those similar criteria observed in actual operation in the study area. The wheat and rice crops were identified as the dominant crops, while the optimization model was the least interested to onion cultivation, assigning the least average cultivation area to this crop over the whole planning period.     

Host (nanocavity of zeolite-Y)/guest (Mn(II), Co(II), Ni(II) and Cu(II) complexes of pentadendate Schiff-base ligand) nanocomposite materials (HGNM): application in the heterogeneous oxidation of cyclohexene

Transition metal (M = Mn(II), Co(II), Ni(II) and Cu(II)) complexes with pentadendate Schiff-base ligand; N,N′-bis(salicylidene)-2,6-pyridinediaminato, H₂[sal-2,6-py]; was entrapped in the nanocavity of zeolite-Y by a two-step process in the liquid phase: (i) adsorption of bis(salicylaldiminato)metal(II); [M(sal)₂]-NaY; in the supercages of the zeolite, and (ii) in situ Schiff condensation of the metal(II) precursor complex with the corresponding 2,6-pyridinediamine; [M(sal-2,6-py)]-NaY. The new materials were characterised by several techniques: chemical analysis, spectroscopic methods (DRS, BET, FTIR and UV/Vis), conductometric and magnetic measurements. Analysis of the data indicates that the M(II) complexes are encapsulated in the nanodimensional pores of zeolite-Y and exhibit different from those of the free complexes, which can arise from distortions caused by steric effects due to the presence of sodium cations, or from interactions with the zeolite matrix. The Host–Guest Nanocomposite Materials (HGNM); [M(sal-2,6-py)]-NaY; catalyzes the oxidation of cyclohexene with tert-butylhydroperoxide (TBHP). Oxidation of cyclohexene with HGNM gave 2-cyclohexene-1-one, 2-cyclohexene-1-ol and 1-(tert-butylperoxy)-2-cyclohexene. [Mn(sal-2,6-py)]-NaY shows significantly higher catalytic activity than other catalysts.     

A Nano-Hybrid of Molybdenum Oxide Intercalated by Dithiocarbamate as an Oxidation Catalyst

A novel nano-layered material based on molybdenum oxide has been synthesized by hydrothermal method using dithiocarbamate. On the basis of the X-ray diffraction, scanning electron microscopy, thermal analysis and infrared spectroscopy results, a possible arrangement of organic ligands in the interlayer space of molybdenum oxide has been proposed. Moreover, the catalytic activity of the synthesized nanohybrid of molybdenum oxide was investigated in oxygen transfer reactions. This reagent can oxidize alkenes, alcohols, sulfides, and amines in the presence of hydrogen peroxide with high yield and selectivity.     

Synthesis,characterization, and curing of a new acrylate‐based dental restorative resin

The synthesis of monomer 1,3‐bis [(2‐hydroxy‐3‐acrylate) propyloxy]2‐hydroxy propane (BHAPP) is reported for the possible use in dental restoratives. The monomer was prepared by the reaction of acrylic acid with diglycerol diglycidyl ether (DGE) in the presence of triethyl amine as a catalyst. The progress of the reaction at 60°C followed by measuring the intensity of the epoxide absorption peak at 915 cm^?1 which has reached to its minimum value after 5 h. The structure of the monomer was characterized by FTIR and ¹H‐NMR. The monomer was a moderately viscous light yellow color liquid having a refractive index of 1.544. Thermal curing of the monomer in DSC in the presence of benzoyl peroxide showed exothermic peak with maximum temperature (T_p) varied from 89 to 107°C depending on the heating rate and activation energy of 83 kJ/mol. Photopolymerization of the monomer by visible light in the presence of camphorquinone and N,N‐dimethylaminoethyl methacrylate as the photoinitiating system showed maximum 60% conversion after 40 s exposure. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Carbon Permeability of Nickel and Ni–Cu Alloys

A Ni–20Cr alloy and variants containing 5, 10 and 20Cu (all in wt.%) were carburised in H₂-5% CH₄ at 1,000 °C. All alloys formed internal carburisation zones containing Cr₃C₂ and Cr₇C₃. The Ni–20Cr alloy also developed a surface deposit of graphite, but the copper-bearing alloys did not. Measured parabolic rate constants for intragranular carburisation were used to calculate carbon permeabilities from Wagner’s diffusion analysis. The value obtained for Ni–20Cr was in good agreement with the product of independently measured carbon solubility and diffusion coefficient values for nickel. Permeabilities found for copper-bearing alloys were similar, showing that the presence of copper had little effect on carbon diffusion in nickel. This finding is used in analysing the mechanism by which nickel undergoes metal dusting.