A Multi-Objective Production Inventory Model with Backorder for Fuzzy Random Demand Under Flexibility and Reliability

In this paper, an Economic Production Quantity (EPQ) model is developed with flexibility and reliability consideration of production process in an imprecise and uncertain mixed environment. The model has incorporated fuzzy random demand, an imprecise production preparation time and shortage. Here, the setup cost and the reliability of the production process along with the backorder replenishment time and production run period are the decision variables. Due to fuzzy-randomness of the demand, expected average demand is a fuzzy quantity and also imprecise preparation time is represented by fuzzy number. Therefore, both are first transformed to a corresponding interval number and then using the interval arithmetic, the single objective function for expected profit over the time cycle is changed to respective multi-objective functions. Due to highly nonlinearity of the expected profit functions it is optimized using a multi-objective genetic algorithm (MOGA). The associated profit maximization problem is illustrated by numerical examples and also its sensitivity analysis is carried out.     

Drug Surfactant and Polymer Mediated Acid Catalyzed Hydrolysis of Acetohydroxamic Acid

The effects of drug-surfactant and polymer on the acid hydrolysis of acetohydroxamic acid (AHA) have been studied at room temperature in 2% (v/v) dioxane medium. Kinetic data corresponding to the reaction with drug micelles are analyzed by using the pseudo-phase ion exchange model. The binding constant and first-order rate constant in micellar media in presence of AMYTP⁺-Drug, AMYTP⁺-β-Cyclodextrine, AMYTP⁺-SDS, AMYTP⁺-PEG, AMYTP⁺-TX-100, AMYTP⁺-CTAB, have been studied in 0.5 M HCl media.     

Kinetics and mechanism of oxidation of L-ascorbic acid by platinum(IV) in aqueous acid medium

The oxidation of l-ascorbic acid (H₂A) by platinum(IV) in aqueous acid medium exhibits overall second-order kinetics, being first order with respect to each reactant. Increasing both hydrogen and chloride ion concentrations inhibits the rate. The stoichiometry involves reaction of one platinum(IV) ion with H₂A to give dehydroascorbic acid. A reaction mechanism consistent with all the experimental observations is proposed.     

Self-assembled histidine acid phosphatase nanocapsules in ionic liquid [BMIM][BF4] as functional templates for hollow metal nanoparticles

We report the biomacromolecular self-assembly of histidine acid phosphatase (HAP), an enzyme of significant biomedical and industrial importance, in the ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF(4)]). The spontaneous self-assembly of HAP enzyme in [BMIM][BF(4)] results in the formation of HAP nanocapsules. The HAP enzyme molecules were found to retain their enzymatic activity after the self-assembly process, which enabled us to utilize self-assembled HAP capsules as self-catalyzing templates for the synthesis of a range of hollow metal nanoparticles (Au, Ag, Pd, and Ni) without employing any additional reducing agent. The hollow metal nanospheres with HAP encapsulated within their cavity were found to retain enzymatic activity for at least up to four cycles, as demonstrated in the case of Au-coated HAP capsules as the model system.     

Quantitative SAXS analysis of the P123/water/ethanol ternary phase diagram

The ternary phase diagram of the amphiphilic triblock copolymer PEO-PPO-PEO ((EO)(20)(PO)(70)(EO)(20) commercialized under the generic name P123), water, and ethanol has been investigated at constant temperature (T = 23 degrees C) by small-angle X-ray scattering (SAXS). The microstructure resulting from the self-assembly of the PEO-PPO-PEO block copolymer varies from micelles in solution to various types of liquid crystalline phases such as cubic, 3D hexagonal close packed spheres (HCPS), 2D hexagonal, and lamellar when the concentration of the polymer is increased. In the isotropic liquid phase, the micellar structural parameters are obtained as a function of the water-ethanol ratio and block copolymer concentration by fitting the scattering data to a model involving core-shell form factor and a hard sphere structure factor of interaction. The micellar core, the aggregation number, and the hard sphere interaction radius decrease when increasing the ethanol/water ratio in the mixed solvent. We show that the fraction of ethanol present in the core is responsible for the swelling of the PPO blocks. In the different liquid crystalline phases, structural parameters such as lattice spacing, interfacial area of PEO block, and aggregation number are also evaluated. In addition to classical phases such as lamellar, 2D hexagonal, and liquid isotropic phases, we have observed a two-phase region in which cubic Fm3m and P6(3)mmc (hexagonally close packing of spheres (HCPS)) phases coexist. This appears at 30% (w/w) of P123 in pure water and with 5% (w/w) of ethanol. At 10% (w/w) ethanol, only the HCPS phase remains present.     

Molecular organization of cholesterol in unsaturated phosphatidylethanolamines: X-ray diffraction and solid state 2H NMR reveal differences with phosphatidylcholines

The major mammalian plasma membrane lipids are phosphatidylcholines (PCs), phosphatidylethanolamines (PEs), and cholesterol. Whereas PC-cholesterol interactions are well studied, far less is known about those between PE and cholesterol. Here, we investigated the molecular organization of cholesterol in PEs that vary in their degree of acyl chain unsaturation. For heteroacid sn-1 saturated (palmitoyl), sn-2 unsaturated (various acyl chain) PEs, cholesterol solubility determined by X-ray diffraction was essentially identical with 1 (oleoyl, 51 +/- 3 mol %) and 2 (linoleoyl, 49 +/- 2 mol %) double bonds before decreasing progressively with 4 (arachidonyl, 41 +/- 3 mol %) and 6 (docosahexaenoyl, 31 +/- 3 mol %) double bonds. With 6 double bonds in each chain, cholesterol solubility was further reduced to 8.5 +/- 1 mol %. However, (2)H NMR experiments established that the orientation of cholesterol in the same heteroacid PE membranes was unaffected by the degree of acyl chain unsaturation. A tilt angle of 15 +/- 1 degrees was measured when equimolar [3alpha-(2)H(1)]cholesterol was added, regardless of the number of double bonds in the sn-2 chain. The finding that solubility of cholesterol in sn-1 saturated PEs depends on the amount of polyunsaturation in the sn-2 chain of PE differs from the equivalent PCs that universally incorporate approximately 50 mol % sterol. Unlike PCs, a differential in affinity for cholesterol and tendency to drive lateral segregation is inferred between polyunsaturated PEs. This distinction may have biological implications reflected by the health benefits of dietary polyunsaturated fatty acids that are often taken up into PE > PC.     

Coagulation Behavior of Antimony Oxyanions in Water: Influence of pH,Inorganic and Organic Matter on the Physicochemical Characteristics of Iron Precipitates

The presence of inorganic and organic substances may alter the physicochemical properties of iron (Fe) salt precipitates, thereby stabilizing the antimony (Sb) oxyanions in potable water during the chemical treatment process. Therefore, the present study aimed to examine the surface characteristics, size of Fe flocs and coagulation performance of Sb oxyanions under different aqueous matrices. The results showed that surface properties of Fe flocs significantly varies with pH in both Sb(III, V) suspensions, thereby increasing the mobility of Sb(V) ions in alkaline conditions. The negligible change in surface characteristics of Fe flocs was observed in pure water and Sb(III, V) suspension at pH 7. The key role of Van der Waals forces of attraction as well as hydration force in the aggregation of early formed flocs were found, with greater agglomeration capability at higher more ferric chloride dosage. The higher Sb(V) loading decreased the size of Fe flocs and reversed the surface charge of precipitates, resulting in a significant reduction in Sb(V) removal efficiency. The competitive inhibition effect on Sb(III, V) removal was noticed in the presence of phosphate anions, owing to lowering of ζ-potential values towards more negative trajectory. The presence of hydrophobic organic matter (humic acid) significantly altered the surface characteristics of Fe flocs, thereby affecting the coagulation behavior of Sb in water as compared to the hydrophilic (salicylic acid). Overall, the findings of this research may provide a new insight into the variation in physicochemical characteristics of Fe flocs and Sb removal behavior in the presence of inorganic and organic compounds during the drinking water treatment process.     

Catalytic reduction of 4-nitrophenol using synthesized and characterized CoS@MorphcdtH/CoS@4-MPipzcdtH nanoparticles

CoS@MorphcdtH NPs and CoS@4-MPipzcdtH NPs were synthesized by precipitation method involving three mechanisms: inclusion, occlusion, and adsorption. The synthesized NPs were characterized with the help of UV-Vis spectroscopy, FESEM-EDAX, powder x-ray diffraction, TEM, ESIMS, TG/DSC analysis. The morphology of the CoS@MorphcdtH NPs and CoS@4-MPipzcdtH NPs were hexagonal and rectangular, and the particles were in the range 7–12 nm. UV–visible spectral measurements showed surface plasmon resonance at 320 nm–340 nm with band gap of 3.65 eV–3.86 eV. The catalytically active CoSNPs called were investigated for the reduction of 4-nitrophenol (4-NP) via hydrogenation using sodium borohydride (NaBH₄) as a reducing agent. Both the CoS NPs successfully reduced 4-NP to 4- aminophenol (4-AP) in a short time, catalytic performances are almost unchanged for the first five cycles. Herein, we report the preparation and characterizations of efficient active CoS NPs consisting carbodithioic acid framework as a support/capping material, along with catalytic property.