A binary particle swarm optimization algorithm for ship routing and scheduling of liquefied natural gas transportation

With the increasing global demands for energy, fuel supply management is a challenging task of today’s industries in order to decrease the cost of energy and diminish its adverse environmental impacts. To have a more environmentally friendly fuel supply network, Liquefied Natural Gas (LNG) is suggested as one of the best choices for manufacturers. As the consumption rate of LNG is increasing dramatically in the world, many companies try to carry this product all around the world by themselves or outsource it to third-party companies. However, the challenge is that the transportation of LNG requires specific vessels and there are many clauses in related LNG transportation contracts which may reduce the revenue of these companies, it seems essential to find the best option for them. The aim of this paper is to propose a meta-heuristic Binary Particle Swarm Optimization (BPSO) algorithm to come with an optimized solution for ship routing and scheduling of LNG transportation. The application demonstrates what sellers need to do to reduce their costs and increase their profits by considering or removing some obligations

Development of a wireless system to measure the strain/deformation of rock bolts

In this study a smart set-up integrated with rock bolts was proposed to automatically monitor, record and analyse rock mass deformation. The proposed system which includes sensors and a wireless data acquisition system, rapidly and readily generates data sets along with customisable graphs, calculations and analysis in a cloud system and can be used in modern mining. To evaluate the developed technique, rock bolts were instrumented lengthwise using resistive strain gauges and then connected to the wireless data logger system. Elastic tensile tests as well as pull-out tests were conducted and the strain values along the rock bolts were successfully and accurately measured, recorded and uploaded to the cloud system

Finite element numerical modelling of rock bolt axial behaviour subject to different geotechnical conditions

In rock bolting systems, grout acts as a medium to transfer initiated stress from the bolt to stable rock mass, and also to transfer the in-situ stress from surrounding rock to the bolt-grout interface. In this study interaction between the mechanical characteristics of the grout and rock bolt behaviour was investigated in different confining pressure conditions. First, the uniaxial compression strength of the grouts was experimentally determined, and then pull-out tests were carried out on rock bolts encapsulated using the same grouts to quantify the bonding behaviour. Numerical models using ABAQUS explicit finite element code were then applied to further analyse the effects of mechanical properties of the grouts and the confining stress on the behaviour of the rock bolting systems. The compression of the simulated results with the experimental tests showed that the proposed FE models simulate the axial behaviour of rock bolts efficiently. The results of the parametric study indicated that grout mechanical properties and the level of confining stress affect the ultimate bearing capacity of the encapsulated rock bolts and the force-displacement behaviour. The level of damage that occurred at the specimens due to pull-out load is also significantly influenced by these factors

Study of Toxic Effects of Oxothiazole Derivative as a New Antibacterial Agent

The spread of antibiotic-resistant bacteria in many humans and animals has driven researches to identify and design novel antibacterial agents. In vitro inhibitory activity of (2E)-2-(4,5-dihydro-4-oxothiazol-2-yl)-2-(thiazolidin-2-ylidene) acetonitrile against many bacterial pathogens has been proven in both veterinary and human medicine. In this study, its in vivo toxic effects was studied in mice. The median lethal dose (LD50) value of 239.88 mg/kg was estimated using intraperitoneal injection in 8 groups of mice after 48 h treatment. Then, intraperitoneal injections of LD50 of oxothiazole solution into 4 other mice were done to evaluate histopathological changes in their liver and kidney tissues. The histopathological studies were identified as fatty change, hepatitis, necrosis and regeneration in liver, and fibrosis, necrosis, nephritis, hyaline cast and hyperaemia in kidney. In conclusion, the synthesized oxothiazole derivative causes renal and hepatic toxicity in mice at medium concentrations. The change of thiazole substituents and complexation may reduce its toxicity

A reverse logistics supply chain network design for municipal solid waste Case Study: Shiraz City

In recent years, because of the increased social concerns about the environment, the reverse logistics concept has been linked to waste management. In fact, municipal solid waste management can be considered as one of the reverse logistics issues in managing the supply chain. In this research, a model for the design of a supply chain network of reverse logistic for municipal soild waste is presented. Using the two objective of profit and biological functions, we have tried to consider two dimensions of sustainable development.The economic objective function examines the maximization of profit and the environmental objective function examines the minimization of co2 due to waste transportation and landfill storage. The proposed model is able to determine the optimal number and the location of facilities and materials flow between nodes at different levels of the network in order to achieve simultaneous economic and environmental goals. The ɛ-constraint Methods has been used to solve a multi-objective model. Also, in order to reduce the problem space and monitor the potential locations of the supply chain network facility, an effective ranking method such as data envelopment analysis is presented. The present study has been used as an applied research data from the waste management organization of Shiraz Municipality and the proposed model has been solved in GAMS software

An integrated gas-oil and bio-diesel supply network model with strategic and tactical applications considering the environmental aspects

In recent years, research has shown that biomass can be a source of energy to replace fossil fuels and effectively reduce current environmental crises. Researchers have studied how biofuels are supplied through the oil supply chain to achieve tangible results. This paper presents an optimization model for the gas-oil and biodiesel supply chains suggesting the optimization of both supply chains simultaneously for the first time. The proposed model deals with the connection points of two supply chains and determines the two chains’ connection points by considering two economic and environmental objective functions. The model can be used to make decisions on issues such as location, allocation, production planning, inventory management, capacity expansion, and so forth. The proposed programming model’s performance has been studied through a real case study in Iran and the sensitivity analyses have been performed. The ε-constraint method was used to solve the multi-objective model. The proposed model is expected to be effective in the future management of countries’ fuel sources, particularly to be used as an alternative to fossil fuels. Also, this research can provide a basis for more extensive research on fuel supply chain integration

Reducing passenger waiting time and energy consumption for metro timetabling: A robust optimization approach

Urban subway scheduling is a quite complicated task as any small fluctuation could disturb the entire system. Subway companies need an efficient scheduling system that best serves passengers and optimizes the utilization of resources. They need, therefore, to include real-world problems in their schedule through non-deterministic modeling. A robust optimization approach is applied in real-world data to propose an optimum train schedule that minimizes passenger waiting time and maximizes electrical energy converted from kinetic energy. Three high, normal, and low travel demand scenarios are considered to optimize train running-time duration in all three interstation movement categories, namely acceleration, coasting, and braking. To find the optimal solution, a genetic algorithm (GA) model has been applied to real data from a subway line in Tehran Metro

A sustainable cross-efficiency DEA model for international MSW-to-biofuel supply chain design

Fossil fuels, as the primary source of the energy supply in today’s global society, are being depleted much faster than expected and are raising serious environmental and social concerns for contemporary societies. To deal with issues, a global movement towards the generation of sustainable renewable energy is underway. One of the most promising sources of renewable energy alternatives is the use of municipal solid waste, as a biomass source since it does not endanger food security and considerably the biomass made by municipal solid waste will enable the appropriate management of the waste and help cities to be sustainable. The supply chain of converting the municipal solid waste to bioenergy is a challenging issue that have attracted the attention of academic and industrial research. In this direction, a three-echelon mathematical model is developed to design MSW-to-biofuel supply chain network. This supply network is a global network; hence, the international supply chain-related issues and the disruption in the raw material supply have also been studied. Identifying appropriate potential locations to site facilities is a challenge faced in the municipal solid waste-to-biofuel supply chain models. To achieve goal, in this research, the use has been made of a proposed sustainable cross-efficiency DEA model which is an effective ranking method, especially for finding potential points. To deal with sustainability, the social and environmental indicators have also been presented in the form of some criteria in this DEA method. In addition, effort has been made to improve the ecological indicators of the supply chain design in line with the sustainable development as an objective function. Finally, in order to validate the proposed model, a case study with real data is presented

A robust crude oil supply chain design under uncertain demand and market price: A case study

In today’s global economy, the oil industry plays a vital role and has an effect on most of countries within leading business environments, particularly in oil producing countries. To deal with the complexity of the crude oil supply network, a mathematical programming model is developed to formulate a crude oil supply chain. A robust optimization model is developed to maximize the profitability of the entire chain and take uncertainties of price and demand into account. The results show that according to the real case study data the robust optimization technique will increase the profitability of the crude oil supply chain

A robust crude oil supply chain design under uncertain demand and market price: A case study

In today’s global economy, the oil industry plays a vital role and has an effect on most of countries within leading business environments, particularly in oil producing countries. To deal with the complexity of the crude oil supply network, a mathematical programming model is developed to formulate a crude oil supply chain. A robust optimization model is developed to maximize the profitability of the entire chain and take uncertainties of price and demand into account. The results show that according to the real case study data the robust optimization technique will increase the profitability of the crude oil supply chain