this study mainly focuses on enhancing the overall efficiency of gas transmission networks. the authors developed a model with detailed characteristics of compressor and pressure reduction stations. following this, they suggested three different systems with gas turbine including: organic rankine cycle (orc), air bottoming cycle (abc), and abc along with steam injection (si-abc). in addition, u...

We consider the problem of computing a minimum cycle basis of an undirected non-negative edge-weighted graph G with m edges and n vertices. In this problem, a {0, 1} incidence vector is associated with each cycle and the vector space over F2 generated by these vectors is the cycle space of G. A set of cycles is called a cycle basis of G if it forms a basis for its cycle space. A cycle basis whe...

The packaging of DNA into nucleosomes influences the accessibility of underlying regulatory information. Nucleosome occupancy and positioning are best characterized in the budding yeast Saccharomyces cerevisiae, albeit in asynchronous cell populations or on individual promoters such as PHO5 and GAL1-10. Using FAIRE (formaldehyde-assisted isolation of regulatory elements) and whole-genome microa...

Comparative energy and exergy investigations are reported for a transcritical N2O refrigeration cycle with a throttling valve or with an expander when the gas cooler exit temperature varies from 30 to 55 ◦C and the evaporating temperature varies from −40 to 10 ◦C. The system performance is also compared with that of similar cycles using CO2. Results show that the N2O expander cycle exhibits a l...

BACKGROUND The amount of carbon dioxide in the atmosphere steadily increases as a consequence of anthropogenic emissions but with large interannual variability caused by the terrestrial biosphere. These variations in the CO2 growth rate are caused by large-scale climate anomalies but the relative contributions of vegetation growth and soil decomposition is uncertain. We use a biogeochemical mod...

We show that the largest subsurface projection distance between a marking and its image under the nth step of a random walk grows logarithmically in n, with probability approaching 1 as n → ∞. Our setup is general and also applies to (relatively) hyperbolic groups and to Out(Fn).

Given a set of n points S in the Euclidean plane, we address the problem of computing an annulus A, (open region between two concentric circles) of largest width, that partitions S into a subset of points inside and a subset of points outside the circles, such that no point p ∈ S lies in the interior of A. This problem can be considered as a maximin facility location problem for n points such t...

the determination of the ultimate pit limit (upl) is the first step in the open pit mine planning process. in this stage that parts of the mineral deposit that are economic to mine are determined. there are several mathematical, heuristic and meta-heuristic algorithms to determine upl. the optimization criterion in these algorithms is maximization of the total profit whilst satisfying the...

In this paper we consider the problem of computing a minimum cycle basis in a graph G with m edges and n vertices. The edges of G have non-negative weights on them. The previous best result for this problem was an O(mn) algorithm, where ω is the best exponent of matrix multiplication. It is presently known that ω < 2.376. We obtain an O(mn +mn logn) algorithm for this problem. Our algorithm als...