We consider the problem of optimally determining an investment portfolio for an energy company owning a network of gas pipelines, and in charge of purchasing, selling and distributing gas. We propose a two stage stochastic investment model which hedges risk by means of Conditional Value at Risk constraints. The model, solved by a decomposition method, is assessed on a real-life case, of a Brazi...

Purpose. Ensuring the optimal mode of gas transportation from local sections main trunkline (GT), subject to repair (maintenance) and/or shutdown, existing based on calculation, determination, and establishment rational values operating modes mobile compressor stations during entire time pumping. Methodology. The studies are physical principles laws that describe effect properties natural geome...

Nowadays, the stress analysis mostly aimed at general buried pipelines. And few of the gas pipelines in tunnel (especially under the seismic action) were analyzed. Therefore, it is necessary to analyze the stress distribution of gas pipeline under seismic action in tunnel. In this paper, CEASAR II software was used to establish the stress model of China-Myanmar XX tunnel pipeline under seismic ...

Human saliva offers a unique noninvasive approach for populational study. Purposes of this study were to investigate the feasibility of using saliva manganese (Mn) concentration as a biomarker of Mn exposure among career welders and to study the variations of Mn, copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb) in saliva as affected by the welding profession. Forty-nine male welders, of whom...

The study related serum lead level to cardiopulmonary function, quality of life and musculoskeletal pain welders in Enugu, Nigeria. Snowball sampling technique was adopted reach over 100 Enugu resident welders. first who met the inclusion criteria gave their consent participate were sampled. welders’ 0.522µg/dl (0.06-1.26 µg/dl). had prevalent low back a very high for domain physical health wit...

OBJECTIVES The aim of this study was to evaluate the coexisting factors and usefulness of diagnostic methods in metal-induced asthma in Polish welders. MATERIALS AND METHODS Examination of 50 welders occupationally exposed to metals and with suspicion of metal-induced asthma (group A), 100 welders occupationally exposed to metals but without suspicion of metal-induced asthma (group B), and tw...

There must be few other situations where there are eager purchasers of natural gas (India and Pakistan), willing suppliers of natural gas (Turkmenistan, Iran, Qatar and Oman), and yet, no pipeline. The distances involved are modest, and techno-economic viability appears straightforward. This paper examines in detail the policy, technology, and economics of an overland pipeline supplying natural...

OBJECTIVES The objectives of this study were to evaluate manganese (Mn)-containing welding fumes' exposure, assess urinary Mn as a biomarker for Mn exposure and investigate the correlation of Mn in air, total fumes and urinary Mn with pulmonary function indices in 118 welders and 37 unexposed controls from two regions in Iran, Assaluyeh and Borujen. METHODS Air samples were collected on mixed...

A new method for detecting DNA-protein cross-links involving selective precipitation of DNA containing cross-linked proteins by K(+)-sodium dodecyl sulfate was utilized in the peripheral WBC of 21 male metal arc welders and in 26 male controls of similar age and racial characteristics who were not exposed to welding fumes. DNA was quantitated by Hoechst fluorescence. Although the concentration ...

OBJECTIVES The welding process produces metal fumes and gases which may affect respiratory health. Technetium-99m diethylenetriaminepentaacetic acid (Tc-99m DTPA) dynamic lung scanning is an easy, noninvasive method to assess disorders of alveolar-capillary barrier permeability secondary to epithelial damage. We aimed to investigate the alveolar clearance by Tc-99m DTPA radioaerosol inhalation ...