Fatal hydrogen sulphide poisoning usually occurs in confined spaces. We report two fatal accidents in unconfined spaces. The first accident caused the death of three workers who entered an unconfined room in a silo of sludge at the same time that a truck dumped several tons of sludge from water purification stations. The hydrogen sulphide that had accumulated inside the silo spilled out into th...

Abstract In this work, we propose a mathematical model to depict the conversion of groundwater flow from confined unconfined aquifers. The problem occurs due heavy pumping aquifers over time, which later leads depletion an aquifer system. phenomenon is interesting one, hence several models have been developed and used capture process. However, one can point out that has limitations its own, as ...

SPAtially Referenced Regressions On Watershed attributes (SPARROW) models were developed to estimate nutrient inputs [total nitrogen (TN) and total phosphorus (TP)] to the northwestern part of the Gulf of Mexico from streams in the South-Central United States (U.S.). This area included drainages of the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf hydrologic regions. The models were sta...

While openings are an essential requirement in buildings as a source of access, fresh air and sunlight, these cause reduction the lateral stiffness torsional resistance masonry wall units. A detailed numerical investigation was carried out to explore impact opening percentage on in-plane strength unconfined confined panels prepared using calcium silicate bricks, for sustainable structures. comm...

Based upon the statistical distribution of flexural fatigue life data and flexural fatigue strength of the steel fibre reinforced concrete (SFRC) containing blends of limestone powder (LP) and silica fume (SF), the influence of these inserts on the flexural fatigue performance of concretes is probed. Concrete mixes were proportioned to replace 30% cement with these mineral inserts in different ...

In early 1980s, researchers discovered self-setting calcium orthophosphate cements, which are a bioactive and biodegradable grafting material in the form of a powder and a liquid. Both phases form after mixing a viscous paste that after being implanted, sets and hardens within the body as either a non-stoichiometric calcium deficient hydroxyapatite (CDHA) or brushite, sometimes blended with unr...

The paper presents the results of tests on the effect of the low calcium fly ash (LCFA) addition, in the amounts of: 0% (LCFA-00), 20% (LCFA-20) and 30% (LCFA-30) by weight of cement, on fracture processes in structural concretes. In the course of the experiments, compressive strength of concrete and fracture toughness for: I (tensile), II (in-plane shear) and III (anti-plane shear) models of c...

Jet impingement heat transfer is an effective and practical approach that is employed in many industrial processes where heating, cooling, or drying is required. Details of the heat or mass transfer rate have been investigated both experimentally and numerically and can be found in the published literature. In most of the numerical studies, control-volume approach has been employed to solve the...

[1] When not laterally confined in valleys, pyroclastic flows create their own channel along the slope by selecting a given flowing width. Furthermore, the lobe-shaped deposits display a very specific morphology with high parallel lateral levees. A numerical model based on Saint Venant equations and the empirical variable friction coefficient proposed by Pouliquen and Forterre (2002) is used to...