Determination of the optimal escape routes of underground mine networks in emergency cases

Escaping is natural in the case of accidents in underground mines. Determining the optimal escape route is one of the most important factors for relief of miners in the emergency cases. This paper aims at developing a mathematical method to determine the shortest escape time from a given point to alternative points of an underground mine network. It also aims to find the shortest routes between each pair of the given points. The first point refers to the place of the accident where some miners may exist, and the alternative points show the safe places that the miners can escape to. After determining the shortest escape time and its corresponding route between each pair of mine work junctions, it is possible to set an electronic board that shows the access route to the nearest safe location by an arrow sign in each mine work. In this paper, Floyd–Warshall and π algorithms are used to determine the shortest escape time between the place of accident and safe places as well as their corresponding routes. Those algorithms are rigorous since they are supported by mathematical proof. Finally, the algorithms are implemented on the network of a certain underground coal mine and the results are presented.     

Modeling and Mapping of Soil Salinity and Alkalinity Using Remote Sensing Data and Topographic Factors: a Case Study in Iran

Environmental Modeling & Assessment - Soil salinity and alkalinity seriously threaten crop production, soil productivity, and sustainable agriculture, especially in arid and semi-arid areas,...     

GIS aided prediction of CO2 emission dispersion from geothermal electricity production

CO₂ is the dominant constituent of non-condensable gases in the steam phase of most geothermal fluids. This paper attempts to present the results of a study conducted to develop prediction modeling of CO₂ dispersion in the surrounding atmosphere from a planned 50 MWe geothermal power plant prior to its production. Dispersion models are widely used for predicting future concentrations of environmental emissions on a range of geographic scales. The dispersion type for gases and their average removal rate depends on the meteorological conditions such as wind direction, wind speed, precipitation, atmospheric stability, and surface roughness and topography. Geographic Information System (GIS) capabilities were used for quality visualization of the model outputs and presenting an accurate numerical copy of the study area. The results by the prediction model show that the natural transfer of CO₂ will be from the power plant toward east and northeast and CO₂ concentration trends after the power plant utilization will be similar to the background conditions with minor changes. This dispersion test was carried out to validate and field test the GIS aided dispersion modeling approach described in the paper and the procedure may be applicable for other studies assessing the emission dispersion of pollutants from a point source.     

Psychosocial and Individual Characteristics and Musculoskeletal Complaints Among Clinical Laboratory Workers

Musculoskeletal disorders (MSDs) are an important health problem among healthcare workers, including clinical laboratory ones. The aim of the present study was to investigate the prevalence of MSDs and individual and psychosocial risk factors among clinical laboratory workers. A cross-sectional study was carried out among 156 workers of 30 clinical laboratories in 3 towns of Iran. The Nordic questionnaire with individual and psychosocial risk factors was used to collect data. Multiple logistic regression analysis was performed. The prevalence of reported MSDs among the study population was 72.4% in the past 12 months. The most prevalent MSDs were pain in the lower back and neck; 42.7% and 33.3%, respectively. Significant relations were found between MSDs and age, gender, heavy work at home and job control (p < .05). MSDs among laboratory workers were high and associated with age, gender, heavy work at home and job control. More research into measuring these factors and workplace physical demands is suggested.     

Nitrate adsorption onto surface-modified red mud in batch and fixed-bed column systems: equilibrium,kinetic, and thermodynamic studies

Environmental Science and Pollution Research - This research aimed to develop a novel composite as a low-cost adsorbent for the removal of nitrate ion from aqueous solutions. The characterization...