Past efforts to estimate methane emissions from underground mines, surface mines, and other coal mine operations have been hampered, to different degrees, by a lack of direct emissions data. Direct measurements have been completely unavailable for several important coal mining operations. A primary goal of this study was to collect new methane emissions measurements and other data for the most ...

Injection of carbon dioxide into geological formations for long-term storage is widely regarded as a promising tool for reducing global atmospheric CO2 emissions. Given the environmental and health risks associated with leakage of CO2 from such a storage site, it is critical to ensure that injected CO2 remain trapped underground for the foreseeable future. Careful site selection and effective i...

Underground mines are a special type of environment which requires significant attention since they directly relate to miners‟ productivity, health and safety. With coal or ore exploitation into deep underground mine environments, high temperature and humidity creates risks because of large amounts of heat generated from geothermal heat, mining machines, groundwater and mine water. There have b...

today, saving and storing water are among the most critical and important issues which have attracted the world's attention. history of storing water in the form of ghanat and water reservoir by iranians goes back to ancient times. studies on this field show that benefiting from underground dams was one of the methods employed for exploiting water in past times. in countries like iran, due...

unaccounted-for-water is a misleading term long used by water industry. unaccounted-for-water includes unmeasured volume of water that run out of access from supply to end consumer and consequently leads no revenue for supplier. examples of water losses are: meter inaccuracies, illegal connection and unauthorized usage of water, abnormal meter reading, reservoir seepage and leakage, reservoir o...

Abstract Large-scale underground storage of hydrogen gas is expected to play a key role in the energy transition and near future renewable systems. Despite this potential, experience remains limited. This work critically reviews most important elements crucial technology, including properties their significance for subsurface operations, sources historical set state art. The cyclical nature ope...

A central unresolved issue in evolutionary biology is how metabolic innovations emerge. Low-level enzymatic side activities are frequent and can potentially be recruited for new biochemical functions. However, the role of such underground reactions in adaptation toward novel environments has remained largely unknown and out of reach of computational predictions, not least because these issues d...

A Bluetooth beacon-based underground navigation system (BBUNS) was developed to identify the optimal haul road in an underground mine, track the locations of dump trucks, and display this information on mobile devices. A three-dimensional (3-D) geographic information system (GIS) database of the haul roads in an underground mine was constructed, and the travel time for each section was calculat...

Researchers have long noted that child support policy for low-income parents may discourage formal child support payments and increase fathers’ participation in the underground economy. Among other factors, low-income fathers may have an incentive to avoid the formal child support system through underground work, since child support order amounts for low-income fathers can be quite high relativ...

Wireless Underground Communication Networks (WUCNs) consist of wireless devices that operate below the ground surface. These devices are either (i) buried completely under dense soil, or (ii) placed within a bounded open underground space, such as underground mines and road/subway tunnels. The main difference between WUCNs and the terrestrial wireless communication networks is the communication...