Two-echelon closed-loop supply chain deterministic inventory models in a batch production environment

This paper considers a two-echelon closed-loop supply chain consisting of a manufacturer and a remanufacturer at the upper echelon and a retailer at the lower echelon. The retailer faces a constant demand from customers, which is satisfied through recovered and new products received from the remanufacturer and the manufacturer, respectively. The manufacturer produces the product with finite rate, whereas the recovery of returned product is instantaneous at the remanufacturer. We develop three models to determine the optimal production-inventory policy of the players for minimizing the joint total cost of the system. In the first model, the retailer receives the product in batches from the manufacturer and the remanufacture simultaneously, whereas in the second and third models, the batches are received alternatively. In the third model, however, the procurement of raw material at the manufacturer is also considered. Numerical illustration is presented to examine the impact of certain key parameters.     

Identifying and modeling key trade-offs between hydrogen fuel cell and electric vehicles

Through a sensitivity analysis, the trade-off between vehicle range and CO₂ emissions is investigated as a function of electric emissions coefficient. Various powertrains were analysed for use in a small crossover sport utility vehicle. Gasoline, gasoline electric hybrid, diesel, fuel cell and battery electric vehicles (BEVs) were considered. Using various upstream fuel pathways and a model for vehicle performance, emissions and energy use were estimated. The hydrogen fuel cell vehicle was found preferable to BEVs under conditions of high CO₂ emissions per kW-hr and a high vehicle range requirement. The BEV was preferable for all other conditions.     

Comparative Response of Indigenously Developed Bacterial Consortia on Progressive Degradation of Polyhydroxybutyrate Film Composites

The global demand of bioplastics has lead to an exponential increase in their production commercially. Hence, biodegradable nature needs to be evaluated in various ecosystems viz. air, water, soil and other environmental conditions to avoid the polymeric waste accumulation in the nature. In this paper, we investigated the progressive response of two indigenously developed bacterial consortia, i.e., consortium-I (C-I: Pseudomonas sp. strain Rb10, Pseudomonas sp. strain Rb11 and Bacillus sp. strain Rb18), and consortium-II (C-II: Lysinibacillus sp. strain Rb1, Pseudomonas sp. strain Rb13 and Pseudomonas sp. strain Rb19), against biodegradation behavior of polyhydroxybutyrate (PHB) film composites, under natural soil ecosystem (in net house). The biodegraded films recovered after 6 and 9 months of incubation were analyzed through Fourier transform infrared spectroscopy and scanning electron microscopy to determine the variations in chemical and morphological parameters (before and after incubation). Noticeable changes in the bond intensity, surface morphology and conductivity were found when PHB composites were treated with C-II. These changes were drastic in case of blends in comparison to copolymer. The potential isolates not only survived, but, also, there was a significant increase in bacterial diversity during whole period of incubation. To the best of our knowledge, it is the first report which described the biodegradation potential of Lysinibacillus sp. as a part of C-II with Pseudomonas sp. against PHB film composites.     

Static and Dynamic Behavior of Fibrous Polymeric Composite Materials at Different Environmental Conditions

The study of static and dynamic behavior of environmentally conditioned fibre reinforced polymeric (FRP) composites is necessary and crucial to examine the durability, reliability and sustainability of these noble materials. FRP composites are being used all around the globe and substituting the conventional materials, starting from mini toys to large aerospace components. Present review has introduced to accumulate and understand the disseminate literature in concentrating the significance of understanding the static and dynamic behavior of FRPs with changing environmental conditionings (hygrothermal, low and high temperature, salt solution, freeze thaw, UV light) and with the interaction of different nano-fillers. Their stability and integrity in diverse service environments may be reformed by their reactions against different nature of loadings i.e. static or dynamic and the components such as fibre, matrix and fibre/matrix interfaces in those environments. The static and dynamic states of loading may come with a possible weaker region to encounter the durability and integrity of the composites. To understand the exact failure modes that correlates the position of environmentally conditioned interfaces and dynamic state of loadings, thus confusing the estimation of its overall performance and mechanical behavior. Interface reliability and durability is vital since in-service environments the degradation in the interfacial region leads to complete composite failure. Therefore, the study of combined effects of various in-service environmental conditions and the role of static and dynamic behavior on the interface will be a crucial part related to the multiaxial dynamic states of failures occurring in FRP’s.     

The synergistic effect of air mass on outdoor performance for different PV module in India

The effect of air mass (AM) on the performance of multi-crystalline silicon (m-Si), amorphous silicon (a-Si), and hetero-junction with intrinsic thin layer (HIT)-technology-based photovoltaic (PV) modules are evaluated for representative day of four seasons during the year 2011 for composite climate of India. To find the best performing PV module technology with respect to AM at the site, annual energy yields and performance ratio against different AM bands (AM 1–4.5) are plotted. It is found that HIT modules perform better than m-Si and a-Si at each AM band. Annual energy yields for all three technologies decrease with increasing order of AM bands. The performance ratio for HIT and m-SI modules initially increases and then decreases with increasing order of AM bands. However, for a-Si modules, the performance ratio decreases with increasing order of the AM bands.     

Molasses-based growth and lipid production by Chlorella pyrenoidosa: A potential feedstock for biodiesel

Biodiesel provides a feasible solution to the twin crisis of energy security and environmental concerns prevalent today, and it can be extracted from conventional oil crops as well as microalgae. However, lipid productivity in case of microalgae is much higher and has several advantages as compared with crop plants, so it is a better feedstock for biodiesel. In case of Chlorella pyrenoidosa, the heterotrophic cultured cells were found to be better in terms of lipid production, and ultimately biodiesel production, but the bottleneck is that in this mode glucose is used to feed the cells, which amounts to almost 80% of the total cost of biodiesel production. The purpose of this study is to evaluate and highlight the feasibility of using the industrially cheap cane molasses as a carbon source in place of glucose for a large-scale, low-cost lipid production of Chlorella pyrenoidosa. When treated molasses was used as a carbon source instead of glucose, the biomass sharply increases from 0.89 to 1.22 g L^–1. On the other hand, the total lipid content increases from 0.27 to 0.66 g g^–1. The specific growth rate and yield was higher in treated molasses as compared with that in glucose-supplemented. A mathematical model was also developed based on logistic, Luedeking–Piret, and Luedeking-Piret-like equations. Model predictions were in satisfactory agreement with the measured data, and the mode of lipid production was growth-associated.     

Photodegradation of Oryzalin in aqueous isopropanol and acetonitrile

The phototransformation of Oryzalin was studied under UV light (λ_max ≥ 290 nm) and sunlight (λ_max ≥ 250 nm) in aqueous isopropanol and acetonitrile solution in absence and presence of TiO₂ as sensitizer. The rate of photodegradation of Oryzalin in different solvent system followed first-order kinetics, and calculated half-lives were found to be in the range of 23.52-53.75 h for UV light and 41.23-61.43 h for sunlight. From this study, total 12 photoproducts were identified and characterized on the basis of column chromatography and Q-Tof micromass spectral data. The plausible mechanism of phototransformation involved was hydrolysis, breaking of sulfonic bond, and loss of amino and sulfonic acid group.     

Emerging trends in photodegradation of petrochemical wastes: a review

Various human activities like mining and extraction of mineral oils have been used for the modernization of society and well-beings. However, the by-products such as petrochemical wastes generated from such industries are carcinogenic and toxic, which had increased environmental pollution and risks to human health several folds. Various methods such as physical, chemical and biological methods have been used to degrade these pollutants from wastewater. Advance oxidation processes (AOPs) are evolving techniques for efficient sequestration of chemically stable and less biodegradable organic pollutants. In the present review, photocatalytic degradation of petrochemical wastes containing monoaromatic and poly-aromatic hydrocarbons has been studied using various heterogeneous photocatalysts (such as TiO₂, ZnO and CdS. The present article seeks to offer a scientific and technical overview of the current trend in the use of the photocatalyst for remediation and degradation of petrochemical waste depending upon the recent advances in photodegradation of petrochemical research using bibliometric analysis. We further outlined the effect of various heterogeneous catalysts and their ecotoxicity, various degradation pathways of petrochemical wastes, the key regulatory parameters and the reactors used. A critical analysis of the available literature revealed that TiO₂ is widely reported in the degradation processes along with other semiconductors/nanomaterials in visible and UV light irradiation. Further, various degradation studies have been carried out at laboratory scale in the presence of UV light. However, further elaborative research is needed for successful application of the laboratory scale techniques to pilot-scale operation and to develop environmental friendly catalysts which support the sustainable treatment technology with the “zero concept” of industrial wastewater. Nevertheless, there is a need to develop more effective methods which consume less energy and are more efficient in pilot scale for the demineralization of pollutant.     

The cause and consequences of road mortality of herpetofauna in durgapur,West Bengal,India

The mortality rate of herpetofauna due to road accidents in one of the busiest tarmacked metalled roads of Durgapur, an industrial town of West Bengal, India was studied. Road survey for 27 days covering a total distance of 94.5 km was conducted. Within this span of time and the total stretch of road, 354 amphibians belonging to 6 species and 133 reptiles belonging to 11 species were observed to be killed in road-accidents. Among amphibians, Duttaphrynus melanostictus and amongst the reptiles Hemidactylus spp. were killed in highest numbers. The stretch of road under survey passed through different habitat patches like’s agricultural land, human habitation, dumping area, fragmented forest and wetland. On an average, 18 herpetofauna was noted to be killed daily. It was difficult to identify the species as the key characters were missing in the remains in a few cases of road casualties. High road mortality of herpetofauna would surely affect the balance of adjoining ecosystems as well as may be crucial for the local herpetofaunal population attributes.