Portfolio selection with a minimax measure in safety constraint

In this paper, we attempt to design a portfolio optimization model for investors who desire to minimize the variation around the mean return and at the same time wish to achieve better return than the worst possible return realization at every time point in a single period portfolio investment. The portfolio is to be selected from the risky assets in the equity market. Since the minimax portfolio optimization model provides us with the portfolio that maximizes (minimizes) the worst return (worst loss) realization in the investment horizon period, in order to safeguard the interest of investors, the optimal value of the minimax optimization model is used to design a constraint in the mean-absolute semideviation model. This constraint can be viewed as a safety strategy adopted by an investor. Thus, our proposed bi-objective linear programming model involves mean return as a reward and mean-absolute semideviation as a risk in the objective function and minimax as a safety constraint, which enables a trade off between return and risk with a fixed safety value. The efficient frontier of the model is generated using the augmented -constraint method on the GAMS software. We simultaneously solve the ratio optimization problem which maximizes the ratio of mean return over mean-absolute semideviation with same minimax value in the safety constraint. Subsequently, we choose two portfolios on the above generated efficient frontier such that the risk from one of them is less and the mean return from other portfolio is more than the respective quantities of the optimal portfolio from the ratio optimization model. Extensive computational results and in-sample and out-of-sample analysis are provided to compare the financial performance of the optimal portfolios selected by our proposed model with that of the optimal portfolios from the existing minimax and mean-absolute semideviation portfolio optimization models on real data from S&P CNX Nifty index.     

RuCl3 anchored onto post-synthetic modification MIL-101(Cr)-NH2 as heterogeneous catalyst for hydrogenation of CO2 to formic acid

A series of efficient ruthenium chloride (RuCl_3)-anchored MOF catalysts,such as RuCl_3@MIL-101 (Cr)-Sal,and RuCl_3@MIL-101 (Cr)-DPPB, have been successfully synthesized by post-synthetic modification (PSM)of the terminal amino of MIL-101(Cr)-NH_2 with salicylaldehyde, 2-diphenylphosphinobenzaldehyde (DPPBde) and anchoring of Ru (Ⅲ) ions. The stronger coordination electron donor interaction between Ru (Ⅲ) ions and chelating groups in the RuCl_3@MIL-101 (Cr)-DPPB enhances its catalytic performance for CO_2 hydrogenation to formic acid. The turnover number (TON) of formic acid was up to 831 in reaction time of 2 h with dimethyl sulfoxide (DMSO) and water (H_2O) as mixed solvent, trimethylamine (Et_3N) as organic base, and PPh_3 as electronic additive.     

A computer program system for kinetic analysis of non-isothermal thermogravimetric data: I. Data acquisition and preparation for kinetic analysis

FORTRAN software is described which enables the generation of rate of weight change data (DTG) from percentage weight change measurements (TG), obtained under non-isothermal conditions. The program also transposes this information into the dimensionless extent and rate of reaction at unit temperature intervals by means of a cubic spline interpolation. A simple search routine identifies all DTG spikes in the thermogravimetric record, and the temperature and extent of reaction at which the rate attains its maximum value. This total information serves as input data for the kinetic analysis software to be discussed in part II of this communication. An example of the application of this program to the pyrolysis of bituminous coal is presented.     

Gas chromatographic separation of anaesthetic gases on a single column

Summary Gas chromatography has been employed in the separation of mixtures of air, carbon dioxide, nitrous oxide and a volatile anaesthetic (halothane, isoflurane or enflurane) on a single Chromosorb 101 column by temperature programming from room temperature. Calibration over the required range for the analysis of exhaled air, demonstrated good linearity with a repeatability for test mixtures of about 1%.