Studies on Hg(II) ion retention properties of cross-linked graft copolymer of acrylic acid and its analytical application

The effects of different parameters such as time, concentration, pH and temperature, on metal ion retention properties of the polymer have been investigated. Metal ion adsorption kinetics, isotherms and thermodynamics have been studied. A plausible mechanism for mercury ion retention has been suggested. Mercuric ion has been isolated quantitatively from various synthetic mixture containing metal ions (Ni²⁺, Cd²⁺, Pb²⁺ and Zn²⁺).     

The design,analysis, and cost estimation of a generic adder and subtractor using the layered T (LT) logic reduction methodology with a quantum-dot cellular-automata-based approach

The quantum-dot cellular automata (QCA) is considered to be one of the ground-breaking nanotechnologies developed over the last two decades. A layered T (LT) logic cell library is constructed herein, and the methodology is extended to generic adder and subtractor module designs. The two proposed algorithms lead to more efficient QCA layout designs for an n-bit ripple carry adder (RCA) and subtractor based on an effective clock zone assignment approach. The suggested one-, four-, and eight-bit RCAs and subtractors surpass most of their existing counterparts by offering lower effective area and cell complexity. A comparative analysis is presented regarding the complexity, irreversible power dissipation, and Cost_α of the proposed n-bit layouts from a cost estimation purview.

     

Reactivity of medium-chain substrates in the interesterification of tripalmitin catalyzed by papaya lipase

Reactivity of different medium-chain substrates, i.e., n-octanol, caprylic acid, and its alkyl (methyl, ethyl, n-propyl, and n-butyl) esters, was assessed in the interesterification of tripalmitin catalyzed by papaya (Carica papaya) lipase. Alcoholysis with n-octanol was the fastest reaction leading to the highest conversion of tripalmitin to n-octyl palmitate and concomitant formation of di- as well as monopalmitoylglycerols. This was followed by transesterification of tripalmitin with n-butyl and n-propyl caprylates, which in turn were faster than transesterification with ethyl and methyl caprylates, yielding in each case the corresponding alkyl palmitates and triacylglycerols containing palmitoyl and capryloyl moieties as the major reaction products. Acidolysis of tripalmitin with caprylic acid yielded palmitic acid and triacylglycerols containing palmitoyl and capryloyl moieties as the major reaction products, however, with the lowest conversion among the three interesterification reactions studied. In each case, interesterification was accompanied by some hydrolysis of tripalmitin.