In this work we present a high performance micro gas chromatograph column with a novel two dimensional axial heating technique for faster and more precise temperature programming, resulting in an improved separation performance. Three different axial resistive heater designs were simulated theoretically on a 3.0 m × 300 μm × 50 μm column for the highest temperature gradient on a 22 by 22 μm col...

Column generation is an indispensable tool in computational optimization to solve a mathematical program by iteratively adding the variables of the model. Even though the method is simple in theory there are many algorithmic choices and we discuss the most common ones. Particular emphasis in put on the dual interpretation, relating column generation to Langrangian relaxation and cutting plane a...

This paper presents a Constraint Programming-based Column Generation approach to the Minimum Graph Coloring problem. The proposed approach has two versions of the pricing subproblems: the first version formulates the pricing subproblem as the optimization problem of finding the most negative reduced cost column, the second version as the decision problem of finding a maximal stable set with neg...

In this work we present an overview of the main advances in column sequence optimization in zeotropic systems, ranging from systems using only conventional columns, each with a condenser and a reboiler, to fully thermally coupled systems with a single reboiler and a single condenser in the entire sequence. We also review the rigorous design of distillation columns, or column sequences. In all t...

seven caspian miniature horses, aged above two years, were used for this study. the skeleton of these horses were cleaned and prepared using appropriate techniques. the vertebral column was studied and photographed. the vertebral column in one of these horses showed variations in thoracic, lumbar and sacral region. the vertebral formola was c7, t19,l5,s6 and a pair of 19th rib was fused with th...

In this paper, a round-table group optimization (RTGO) algorithm is presented. RTGO is a simple metaheuristic framework using the insights of research on group creativity. In a cooperative group, the agents work in iterative sessions to search innovative ideas in a common problem landscape. Each agent has one base idea stored in its individual memory, and one social idea fed by a round-table gr...

hearing loss (hl) is the most common communication disorder affecting about 1/1000 births worldwide caused by environmental or genetic factors. about 30-50% is attributed to genetic factors and till now more than 85 genes have been implicated in non-syndromic hl. in iran, hl is second to intellectual disability as the most common disability, affecting 1 of every 166 persons. about 15 years ago ...