Conductance of S-Alkylisothiouronium Iodides in Methanol at 25° C

Equivalent conductivities are reported for S-Methyl-, S-n- . -Butyl, S-n-Amyl- and S-n-Heptylisothiouronium iodides in methanol (D = 32.63) at 25 °c. The data were analyzed by the Fuoss-Onsager equation for 1 : 1 associated electrolytes. The characteristic constants: the equivalent conductance at infinite dilution A0 , the closest approach distance a0 and the association constant KA are · derived

MANAGEMENT’S PERCEPTION OF STOCK DIVIDEND DISTRIBUTION IN AN EMERGING CAPITAL MARKET: THE CASE OF KUWAIT

The purpose of this study is to investigate perceptions of top managers of Kuwaiti companies regarding factors the affect their companies’ decision to distribute stock dividend ( SD ). A questionnaire listing 32 reasons that could explain companies’ decisions to declare SDs was distributed to a sample of 120 randomly selected top managers from 100 Kuwaiti companies and 73 responses were received (representing a 61% response rate ). Participants were classified according to: ( 1 )business sector ( investment, real estate, banking, service, and industrial ) and ( 2 ) size of SDs ( small ( less than 25% ) and large ( 25% or more )). Nonparametric statistical tests were employed to analyze the data.Stock Dividends, Importance Ratings, Trading Liquidity, Institutional Investors

Microwave-assisted Synthesis Of Palladium Nanoparticles Supported On Copper Oxide In Aqueous Medium As An Efficient Catalyst For Suzuki Cross-coupling Reaction

We report here a reliable green method for the synthesis of palladium nanoparticles supported on copper oxide as a highly active and efficient catalyst for Suzuki cross-coupling reaction. The experimental synthetic approach is based on microwave-assisted chemical reduction of an aqueous mixture of palladium and copper salt simultaneously using hydrazine hydrate as reducing agent. The catalyst was fully characterized using various techniques showing well-dispersed palladium nanoparticles. The catalytic activity and recyclability of the prepared catalyst were experimentally explored in the ligand-free Suzuki cross-coupling reaction with a diverse series of functionalized substrates. The synthesized Pd/CuO catalyst shows many advantages beside its high catalytic efficiency such as the recyclability of up to five times with negligible loss of catalytic activity, short reaction times, use of environmentally benign solvent systems, and mild reaction conditions

Facile Synthesis Of Reduced Graphene Oxide-supported Pd/Cuo Nanoparticles As An Efficient Catalyst For Cross-coupling Reactions

The present communication reports a scientific investigation of a simple and versatile synthetic route for the synthesis of palladium nanoparticles decorated with copper oxide and supported on reduced graphene oxide (rGO). They are used as a highly active catalyst of Suzuki, Heck, and Sonogashira cross coupling reactions with a remarkable turnover number of 7000 and a turnover frequency of 85000 h-1. The Pd-CuO nanoparticles supported on reduced graphene oxide nanosheets (Pd-CuO/rGO) exhibit an outstanding performance through a high catalytic activity towards cross coupling reactions. A simple, reproducible, and reliable method is used to prepare this efficient catalyst using microwave irradiation synthetic conditions. The synthesis approach requires a simultaneous reduction of palladium and copper nitrates in presence of graphene oxide (GO) nanosheets using hydrazine hydrate as a strong reducing agent. The highly active and recyclable catalyst has many advantages including mild reaction conditions and short reaction durations in an environmentally benign solvent system. Moreover, the catalyst prepared can be recycled for up to five times with nearly identical high catalytic activity. Furthermore, the high catalytic activity and the recyclability of the catalyst prepared are due to the strong catalyst-support interaction. The defect sites of the reduced graphene oxide (rGO) act as nucleation centers that enable anchoring of both Pd and CuO nanoparticles and hence, minimize the possibility of agglomeration which leads to a severe decrease of the catalytic activity

Mathematica as an Efficient Tool to Optimize the Kinetic Study of Ethyl Acetate Hydrolysis

Mathematica is a powerful program for computing both numeric and algebraic calculations as well as graphing two- and three-dimensional curves and surfaces. It is used increasingly in many fields of science now such as physics, engineering, chemistry and even biology because of the fast interaction of mathematics with almost the fields of science nowadays. We report here, optimizing the kinetic data for the hydrolysis of ethyl acetate through caustic soda via using Mathematica

Impact of a Disaster Educational Program on Knowledge and Practices of Teachers among Primary Governmental Schools, Cairo Governorate

Disaster is an extreme event that causes loss of life, property, essential services and means of livelihood. Aim of this study; was to assess the impact of a disaster educational program on knowledge and practices of teachers. Research design; A (pre-post) quasi-experimental design was adopted in this research. Setting; the study was conducted at three primary governmental schools in Cairo governorate. Three educational departments were assigned randomly from total thirty two departments. One school from each educational department was selected randomly (3 schools). These schools were El-Sayida Sakina, Ahmed Lotfy El-Said and El-Kasr Elaini primary governmental schools. The study sample; consisted of 50 teachers were included from three selected school in the research. Teachers number was; 17 teachers in El-Sayida Sakina School, 18 teachers in Ahmed Lotfy El-Said school and 15 in El-Kasr Elaini. Tools for data collection; three tools were used in this study; 1) Demographic characteristics for teachers; 2) Pre/ post knowledge questionnaire sheet. 3) Pre/post observational checklist. Study results; results revealed that, 70 % of teachers were females, 54% aged from 35-55 years.  Nearly all teachers (94%) didn't have any experience in disaster management before the educational program compared to less than half (42%) of the teachers who had unsatisfactory knowledge about disaster management. While 96%, 100% respectively had good knowledge scores about disaster management immediately and 2 months after the educational program. Regarding to teacher's practices, 100% and 84% had good practice scores immediately and 2 months after the educational program respectively while 90% had unsatisfactory practice scores about disaster management before the educational program. A highly statistically significance differences were found between all practice subscales about dealing with injured personnel in disaster among teachers before, immediately and 2 months after the educational program.  The study concluded that, educational program implicated changes in teaches' knowledge, and practices regarding disaster management in primary governmental schools. The study recommended periodic training programs for teachers in primary governmental schools Key words: Teachers, disaster management, primary governmental school