Horizontal drilling and hydraulic fracturing are transforming energy production, but their potential environmental effects remain controversial. We analyzed 141 drinking water wells across the Appalachian Plateaus physiographic province of northeastern Pennsylvania, examining natural gas concentrations and isotopic signatures with proximity to shale gas wells. Methane was detected in 82% of dri...

Recent studies in northeastern Pennsylvania report higher concentrations of dissolved methane in domestic water wells associated with proximity to nearby gas-producing wells [ Osborn et al. Proc. Natl. Acad. Sci. U. S. A. 2011 , 108 , 8172 ] and [ Jackson et al. Proc. Natl. Acad. Sci. U. S. A. , 2013 , 110 , 11250 ]. We test this possible association by using Chesapeake Energy's baseline data s...

this study at first level focused on definitions and descriptions of  some landfills and landfills sites all around the world and  survey on how important they are for regional governments and responsible in duty  as a very important responsibility for locals and their health. at the second level we had a look on heavy metals concentration which are by many definitions as follows: lead, nickel,...

Atrazine and simazine are pre-emergence herbicides that are known to contaminate ground water from normal agricultural use. According to a recent U.S. Environmental Protection Agency (EPA) re-registration eligibility decision for atrazine, the breakdown products of atrazine and simazine were determined to be as toxic as the parent chemical. Consequently, EPA concluded that the concentrations of...

IMPORTANCE The Wells score to determine the pretest probability of deep vein thrombosis (DVT) was validated in outpatient settings, but it is unclear whether it applies to inpatients. OBJECTIVE To evaluate the utility of the Wells score for risk stratification of inpatients with suspected DVT. DESIGN, SETTING, AND PARTICIPANTS A prospective study was conducted in a 793-bed quaternary care, ...

We conducted a push-pull test to study in-situ biosurfactant production byexogenous biosurfactant producers to aid in oil recovery from depleted reservoirs. Fivewells from the same formation were used. Two wells received cells and nutrients, twowells were treated with nutrients only, and one well was used as the negative controlwhere only brine was injected. We hypothesized that...

In this work, the Parameters Estimation in petroleum wells is presented; it is based on Intelligent Systems (neural networks and fuzzy logic). For validating the results, the estimation is applied in wells that need artificial lift using well heading data (gas and production pressure). Key-Words: neo-fuzzy models, oil system production, artificial gas lift wells, parameters estimation.

The fundamental intrinsic radiative process associated with excitons in semiconductor multiple quantum wells is discussed within the context of exciton polaritons. Multiple quantum wells in which each well is randomly displaced from its ideal periodic position are discussed in order to investigate the effect of disorder on excitonic radiative widths. The coherent transpori of excitons in multip...

BACKGROUND A groundwater-associated outbreak affected approximately 1,450 residents and visitors of South Bass Island, Ohio, between July and September 2004. OBJECTIVES To examine the microbiological quality of groundwater wells located on South Bass Island, we sampled 16 wells that provide potable water to public water systems 15-21 September 2004. METHODS We tested groundwater wells for f...