Decision support for green supply chain operations by integrating dynamic simulation and LCA indicators: diaper case study

As the issue of environmental sustainability is becoming an important business factor, companies are now looking for decision support tools to assess the fuller picture of the environmental impacts associated with their manufacturing operations and supply chain (SC) activities. Lifecycle assessment (LCA) is widely used to measure the environmental consequences assignable to a product. However, it is usually limited to a high-level snapshot of the environmental implications over the product value chain without consideration of the dynamics arising from the multitiered structure and the interactions along the SC. This paper proposes a framework for green supply chain management by integrating a SC dynamic simulation and LCA indicators to evaluate both the economic and environmental impacts of various SC decisions such as inventories, distribution network configuration, and ordering policy. The advantages of this framework are demonstrated through an industrially motivated case study involving diaper production. Three distinct scenarios are evaluated to highlight how the proposed approach enables integrated decision support for green SC design and operation.     

Antidiabetic effect of Ficus racemosa Linn. stem bark in high-fat diet and low-dose streptozotocin-induced type 2 diabetic rats: A mechanistic study

The present study was designed to investigate the effects of the ethanol extract of Ficus racemosa (FRE) on biochemical parameters in type 2-like diabetes, induced by a combination of standardised high-fat diet and low-dose streptozotocin (25 mg kg⁻¹, i.p.) in rats. To elucidate the mode of action of FRE, its effects on a battery of targets involved in glucose homeostasis was evaluated. FRE (200 and 400 mg kg⁻¹, p.o.), in a dose-dependent manner, altered the biochemical parameters and significantly improved glucose tolerance and HDL-c levels. In different bioassays, FRE showed inhibition of PTP-1B (IC₅₀ 12.1 μg/mL) and DPP-IV (42.5%). FRE exhibited 82.6% binding to PPAR-γ. Furthermore FRE exhibited stimulation of glucose uptake by skeletal muscles (hemi-diaphragm). Bergenin was quantified in bioactive-FRE by high-performance liquid chromatography (0.15% w/w). This is the first report demonstrating the effectiveness of F. racemosa stem bark in type 2 diabetes and targets involved in it.     

Solar-assisted vapor compression/absorption cascaded air-conditioning systems

This article describes a hybrid air-conditioning system consisting of a conventional R-22 vapor compression refrigeration system cascaded with a solar-operated, ammonia-water, vapour absorption system. The condenser of the R-22 system is cooled by the evaporator of the the ammonia system. This facilitates operation of the R-22 system at a low condensing temperature and pressure. This is found to yield considerable savings in electrical energy consumption by the compression system.     

Nickel-decorated single vacancy phosphorene – A favourable candidate for hydrogen storage

This work studies the effect of nickel decoration on the hydrogen adsorption properties of single vacancy (SV) defective phosphorene. First principles simulations of Ni decoration show that the SV defective surfaces relax to a doped-like structure with the Ni atom in the place of the vacant phosphorus atom. The functionalised surface shows excess negative charge on neighbouring P atoms, making it suitable for sensing purposes. Additionally, the chemical activity of Ni is reduced due to strong bond formation with phosphorus. Both Ni-decorated SV phosphorene systems have H₂ adsorption energies more than 3 times than that of defective phosphorene, with values between ?0.594 eV and ?0.6 eV. The adsorption mechanism of H₂ is a two-fold process involving a small charge transfer from the surface P atoms and weak dipole-dipole interactions between the H₂ molecule and the Ni atom, as the reduced chemical activity of Ni prevents bond formation with H₂. The results demonstrate Ni-decorated SV Phosphorene as a promising candidate for Hydrogen storage and gas sensing applications. Further, decoration on defective phosphorene surfaces can be regarded as a method to control the chemical activity of transition metals for use in applications such as catalysis.     

Comparison of HgTe materials grown in (100), (110), (111), and (211) Orientations

We calculated energies required to remove atoms from various configurations on (111), (110), (100), and (211) HgTe surfaces. The excess pair energies for various species are then calculated and are used in a thermodynamic model to study the growth. All energies are obtained using a Green’s function method. The pair distributions are calculated from these energies in a generalized quasi-chemical approximation. The calculated critical temperatures for surface roughness transition are found to be considerably higher than the usual growth temperature of 185°C, so the growth on these surfaces is expected to be layer-by-layer with formation of two-dimensional islands. However, among the surfaces studied, only the (211) surfaces have an attractive binding energy for Hg, making those surfaces suited for better growth. The critical temperature for growth on (21 l)Hg is slightly higher than that for (211)Te, but we also find that Hg sticking coefficient on (21 l)Hg surface is considerably lower than that on (21 l)Te surface. These calculations are consistent with the observed higher growth rate of the (211)Te surface. Our calculations suggest that there will be fewer grown-in vacancies and Te antisites, at the expense of growth rate and sticking coefficient, for crystals grown on (211)Hg surface. We further calculated the Hg and Te vacancy formation energies as functions of surface orientations and layer depth. The cation vacancy formation energies from completed surface regions (islands) are higher than bulk values near anion terminated surfaces and smaller than bulk values near cation terminated surfaces.     

Modeling and performance analysis of cluster tools using Petri nets

The performance of cluster tools is gaining ever-increasing importance as the semiconductor industry migrates to larger wafer sizes, and smaller device geometries. Customers demand higher throughput-to-footprint ratios for semiconductor equipment. Cluster tool throughput is the outcome of complex interactions of various subsystems, and there is a critical need for appropriate tools that aid in understanding these interactions, and their effects on throughput. Current methods for throughput analysis are not very well oriented toward understanding the dynamics in cluster tool processing. In this paper we present a procedure to model cluster tools using Petri nets. These models help designers to comprehend the flow of wafers during processing. While Petri nets have been used extensively in the modeling and analysis of diverse manufacturing processes/systems, this to the best of our knowledge is the first attempt to specifically model cluster tools. A state cycle analysis is discussed next; this method enables equipment designers to extract steady state throughput information, as well as understand the interplay of subsystems during the wafer Row. Two example configurations are used to illustrate Petri net-based model building and analysts. These two examples encompass a variety of design features found in the industry today, e.g., sequential and parallel processing, single and dual end effector robots, anticipatory and simple scheduling     

Enhanced bioaccessibility of β‐carotene from yellow‐orange vegetables and green leafy vegetables by domestic heat processing

Effect of heat treatment involved in domestic cooking on the bioaccessibility of β‐carotene from yellow‐orange as well as green leafy vegetables was evaluated. Heat treatment of these vegetables by pressure‐cooking, stir‐frying and open‐pan boiling had a beneficial influence on the bioaccessibility of β‐carotene. The extent of increase in the per cent bioaccessibility of β‐carotene as a result of pressure‐cooking was 21–84%. Stir‐frying in presence of a small quantity of oil brought about an enormous increase in the bioaccessibility of β‐carotene from these vegetables, the extent of increase being 67–191%. Open‐pan boiling of vegetables increased the bioaccessibility of β‐carotene in the range 23–36%. Thus, among the three domestic heat processing methods, stir‐frying results in maximum bioaccessibility of this provitamin. The use of suitably heat‐processed vegetable sources of β‐carotene could form a dietary strategy to derive this micronutrient maximally by the population dependent on plant foods.     

Influence of β-carotene-rich vegetables on the bioaccessibility of zinc and iron from food grains

Widespread deficiencies of iron and zinc, commonly found in populations dependent on plant foods, necessitate food-based strategies to maximise their bioavailability from plant foods. In this study, β-carotene-rich vegetables were evaluated for their effects on the bioaccessibility of iron and zinc from cereals and pulses by employing a simulated gastrointestinal digestion procedure involving equilibrium dialysis. Addition of carrot or amaranth (2.5 g and 5 g per 10 g of grain) significantly enhanced the bioaccessibility of iron and zinc from the food grains, the percent increase being 13.8–86.2 in the case of carrot and 11–193% in the case of amaranth. Pure β-carotene added at an equivalent level also enhanced the bioaccessibility of iron (19.6–102% increase) and zinc (16.5–118.0% increase) from the cereals examined. This is the first report on the beneficial influence of β-carotene on iron and zinc bioaccessibilities.     

Electroless nickel deposition from methane sulfonate bath

Electroless plating is a controlled autocatalytic chemical reduction process for depositing metals. The process involves a continuous build up of a nickel coating on a substrate by immersion of the substrate in a suitable nickel plating under appropriate conditions. In this paper the authors have studied the effect of pH and temperature on the rate of deposition and phosphorous content from nickel methane sulfonate bath. Effect of phosphorous content on hardness, wear resistance and corrosion resistance were also studied. SEM and XRD measurements show nodular and amorphous character of the deposits. As the bath is free from sulfate ions the bath can be operated for more number of turn overs and orthophosphite formed during the process can be removed easily.     

AC impedance studies on nickel oxide electrodes to determine self-discharge characteristics of Ni-H2 batteries

AC impedance measurements were made on nickel oxide electrodes in an alkaline medium. The electrodes were prepared by electrodeposition of nickel oxide on nickel foils from a nickel nitrate solution. The main purpose of the investigation was to determine the dependence of impedance parameters on the state of charge of the electrode. The results demonstrated that the current phase shift and impedance modulus vary linearly with state of charge at low frequencies. Hence, the state of charge can be estimated from the values of phase shift and modulus. The state of charge of nickel electrodes exposed to argon and hydrogen was determined at various time intervals. It was found that the electrode exposed to hydrogen discharged faster than that exposed to argon, indicating that hydrogen enhances the self-discharge rate of nickel oxide electrodes.