Graphite oxide constitutes carbon network with oxygen atoms both on hexagonal arrangement and the edge sites. Structural and electronic properties for graphite-oxygen complexes have been explored using first-principles total-energy calculations within the local density approximation (LDA). Band structures and density of states for the propose carbon 3D models are reported. A finite energy gap and...

This paper deals with resource unconstrained project scheduling problems with the objective of maximizing the net present value (NPV) of project cash flows. Here we present a heuristic algorithm named as differential procedure (Dif_AOA). In order to evaluate the efficiency of this algorithm, networks with node numbers between 10-1000 and network complexity coefficients between 1.3-6.6 have be...

This paper designs a mathematical model for supply chain network design problem including plants, distributors and customers in fuzzy environment. Each plant and distributor has several levels capacities. A multi-mode demand strategy is considered for the customers where only one of the modes is to be selected for each customer. Considering the acceptance degree of fuzzy constraints violated, a...

One of reasons that researchers in recent years have tried to produce ultrafine grained materials is producing lightweight components with high strength and reliability. There are disparate methods for production of ultra-fine grain materials,one of which is severe plastic deformation method. Severe plastic deformation method comprises different processes, one of which is Parallel tubular chann...

economic valuation of water is useful in the administration and management of water. population growth and urbanization caused municipal water demand increase in iran. limited water resource supply and urban water network capacity raised complexity in water resources management. present condition suggests using economic value of water as a criterion for allocating policies and feasibility study...

This paper presents a novel approach to automatically generate evalue instance models, based on skeletal design techniques. The approach has three phases. While the first two phases are related to the generation of a value activity network based on a given value skeleton, the third phase matches the elements of the value network with the capabilities of service providers. The main objective of ...

This study develops a typology of coopetition in value networks, wherein a distinction is made based on two factors. Firstly, whether coopetition takes place inside a particular value network (i.e., intra-value network coopetition) or between value networks (i.e., inter-value network coopetition); and secondly, whether the nature of collaboration is focused on value leveraging or value co-creat...