Open data from the third observing run of LIGO, Virgo, KAGRA, and GEO

The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages

Deep generative models for fast photon shower simulation in ATLAS

The need for large-scale production of highly accurate simulated event samples for the extensive physics programme of the ATLAS experiment at the Large Hadron Collider motivates the development of new simulation techniques. Building on the recent success of deep learning algorithms, variational autoencoders and generative adversarial networks are investigated for modelling the response of the central region of the ATLAS electromagnetic calorimeter to photons of various energies. The properties of synthesised showers are compared with showers from a full detector simulation using geant4. Both variational autoencoders and generative adversarial networks are capable of quickly simulating electromagnetic showers with correct total energies and stochasticity, though the modelling of some shower shape distributions requires more refinement. This feasibility study demonstrates the potential of using such algorithms for ATLAS fast calorimeter simulation in the future and shows a possible way to complement current simulation techniques

Hydrogeochemical investigation and quality assessment of mine water resources in the Korba coalfield, India

Hydrogeochemical investigation of water discharged from the mines of Korba coalfield was carried out to assess mine water geochemistry, solute acquisition processes, and its suitability for domestic, irrigation, and industrial uses. A total of 44 mine water samples were collected from coal mines of Korba coalfield and analyzed for pH, electrical conductivity (EC), total dissolved solids (TDS), major cations (Ca2+, Mg2+, Na+, K+), major anions (HCO3−, Cl−, SO42−, NO3−), dissolved silica (H4SiO4), and trace metals. pH of the analyzed mine water samples varied from 6.7 to 8.5, indicating mildly acidic to alkaline nature of water. Concentration of total dissolved solids ranged from 97 to 785 mg L−1, and spatial differences in TDS values reflect variation in lithology, surface activities, and hydrological regime prevailing in the mining region. HCO3− and SO42− were the dominant anions in mine water of the area, while Ca2+ and Mg2+ dominated in cation chemistry. Higher contribution of SO42− to the total anions (TZ−) may be attributed to weathering of pyrites associated with the coal strata. High concentrations of Ca2+, Mg2+, HCO3−, and SO42− and the average HCO3−/(HCO3− + SO42−) ratio of 0.58 suggest coupled reactions involving both sulfuric acid– and carbonic acid–aided weathering which largely controls the solute acquisition processes. The factor and cluster analyses of hydrochemical data also suggest the reaction paths expected from solution interacting with carbonate and silicate rocks attacked by H2CO3 and/or H2SO4. Ca-Mg-SO4-Cl and Ca-Mg-HCO3 were the dominant water types in mine water of the Korba coalfield. The computed saturation indices demonstrate oversaturation condition with respect to calcite, dolomite, and aragonite and undersaturation with respect to gypsum, anhydrite, and halite. The quality assessment for drinking uses indicates that TDS, total hardness, and concentration of some trace metals (Fe, Mn, Ni, Al) exceeded the acceptable levels in a number of mine water samples and need treatment before its utilization. In general, the mine waters of the Korba coalfield are of good to permissible quality and can be used for livestock and irrigation in most cases. Higher salinity and magnesium hazard values at some sites limit its suitability for irrigation uses

Precipitation chemistry and occurrence of acid rain over Dhanbad, coal city of India

The present study investigated the chemical composition of wet atmospheric precipitation over Dhanbad, coal city of India. The precipitation samples were collected on event basis for three years (July 2003 to October 2005) at Central Mining Research Institute. The precipitation samples were analyzed for pH, conductivity, major anions (F, Cl, NO3, SO4) and cations (Ca, Mg, Na, K, NH4). The pH value varied from 4.01 to 6.92 (avg. 5.37) indicating acidic to alkaline nature of rainwater. The pH of the rainwater was found well above the reference pH (5.6), showing alkalinity during the non-monsoon and early phase of monsoon, but during the late phase of monsoon, pH tendency was towards acidity (1.0) indicating that Ca and NH4 play an important role in neutralization of acidic ions in rainwater. Ca and SO4 dominate the bulk ionic deposition and these two ions along with NH4 accounts 63% of the annual ionic deposition

Hydrogeochemistry, Elemental Flux, and quality assessment of mine water in the pootkee-balihari mining area, jharia coalfield, India

Ninety nine mine water discharge samples were collected and analyzed for pH, electrical conductivity (EC), major cations, anions, and trace metals in the Pootkee- Balihari coal mining area of the Jharia coalfield. The mines of the area annually discharge 34.80 x 106 m3 of mine water and 39,099 t of solute loads. The pH of the analyzed mine waters ranged from 6.97 to 8.62. EC values ranged from 711 μS cm-1 to 1862 μS cm-1, and reflect variations in lithology, geochemical processes, and hydrological regimes in the mines. The cation and anion chemistry indicate the general ionic abundance as: Mg2+ > Ca2+ > Na+ > K+ and HCO3- > SO42- > Cl- > NO3- > F-, respectively. Elevated SO42- concentrations in the Gopalichuck, Kendwadih, and Kachhi-Balihari mine waters are attributed to pyrite weathering. The water quality assessment indicated that TDS, hardness, Mg2+, and SO42- are the major parameters of concern in the study area. Except for Fe, all of the measured metals in the mine water were well within the levels recommended for drinking water. With only a few exceptions, the mine water is of good to permissible quality and suitable for irrigation

Assessment of Air Pollution in and Around of Dhanbad

In the atlas of India, Jharia coalfields play an important role in the production of coking coal known as black diamond. During the production of coal, it produces huge quantity of particulate matter as well as gaseous pollutants, like SO2 and NOx, which polluted the area badly. Another major source of air pollution in the area is presence of various coking and briquetting units. Transportation of coal and heavy traffic play an important role in the degradation of ambient air quality. Due to tremendous population growth in last two decades and develop as an important business center also, the area paying its toll as a polluted city. The ambient air quality is measured in the vicinity of coalmines to assess the impact of mining and related activity on ground level concentration. The study indicates that suspended particulate matters are the major concern, exceeding the prescribed limit quite often in ambient air. The paper deals, in brief, field study and laboratory analysis with respect to ambient air study of Dhanbad and discusses the result of the study

Hydrogeochemistry and Quality Assessment of Mine Water of West Bokaro Coalfields, Hazaribag, Jharkhand, India

A total of 33 samples of mine water discharges from the different mines of West Bokaro Coalfields of Hazaribag district of Jharkhand, India, were analyzed to carry out qualitative assessment and suitability for domestic, irrigation and industrial purposes. The electrical conductivity (EC) for measured samples and spatial differences reflects the wide variation in lithology, surface activities and hydrological regime prevailing in the region. The anion chemistry shows the dominance of SO4 2- and HCO3 - with minor contribution from Cl, NO3 and F. The cation chemistry indicate that 79% of the samples are Ca > Mg > Na > K, while the 6% belong to Ca > Na > Mg > K and 1% of Ca > Mg > K > Na. Concentrations of some heavy metals (Fe, Mn, Ni, Cr) are found to be well above the prescribed permissible levels recommended for the drinking water. The water quality assessment for drinking purposes indicate that most of the mine water having high TDS, total hardness (TH) and sulphate concentrations, suggests that mine water of the study area is not suitable for direct use in drinking and domestic purposes. The mine water can be used for irrigation purposes; however, high values of salinity, %Na, SAR, RSC and Mg-hazard at certain sites restrict its suitability for agriculture uses

VALIDATION OF TWO AIR QUALITY MODELS FOR INDIAN MINING CONDITIONS

All major mining activity particularly opencast mining contributes to the problem of suspended particulate matter (SPM) directly or indirectly. Therefore, assessment and prediction are required to prevent and minimize the deterioration of SPM due to various opencast mining operations. Determination of emission rate of SPM for these activities and validation of air quality models are the first and foremost concern. In view of the above, the study was taken up for determination of emission rate for SPM to calculate emission rate of various opencast mining activities and validation of commonly used two air quality models for Indian mining conditions. To achieve the objectives, eight coal and three iron ore mining sites were selected to generate site specific emission data by considering type of mining, method of working, geographical location, accessibility and above all resource availability. The study covers various mining activities and locations including drilling, overburden loading and unloading, coal/mineral loading and unloading, coal handling or screening plant, exposed overburden dump, stock yard, workshop, exposed pit surface, transport road and haul road. Validation of the study was carried out through Fugitive Dust Model (FDM) and Point, Area and Line sources model (PAL2) by assigning the measured emission rate for each mining activity, meteorological data and other details of the respective mine as an input to the models. Both the models were run separately for the same set of input data for each mine to get the predicted SPM concentration at three receptor locations for each mine. The receptor locations were selected such a way that at the same places the actual filed measurement were carried out for SPM concentration. Statistical analysis was carried out to assess the performance of the models based on a set measured and predicted SPM concentration data. The value of coefficient of correlation for PAL2 and FDM was calculated to be 0.990–0.994 and 0.966–0.997, respectively, which shows a fairly good agreement between measured and predicted values of SPM concentration. The average index of agreement values for PAL2 and FDM was found to be 0.665 and 0.752, respectively, which represents that the prediction by PAL2 and FDM models are accurate by 66.5 and 75.2%, respectively. These indicate that FDM model is more suited for Indian mining conditions