Modern methods of surveyor observations in opencast mining under complex hydrogeological conditions.

NASA Astrophysics Data System (ADS)

Usoltseva, L. A.; Lushpei, V. P.; Mursin, VA

2017-10-01

The article considers the possibility of linking the modern methods of surveying security of open mining works to improve industrial safety in the Primorsky Territory, as well as their use in the educational process. Industrial Safety in the management of Surface Mining depends largely on the applied assessment methods and methods of stability of pit walls and slopes of dumps in the complex mining and hydro-geological conditions.

Sediment Transport and Slope Stability of Ship Shoal Borrow Areas for Coastal Restoration of Louisiana

NASA Astrophysics Data System (ADS)

Liu, H.; Xu, K.; Bentley, S. J.; Li, C.; Miner, M. D.; Wilson, C.; Xue, Z.

2017-12-01

Sandy barrier islands along Louisiana coast are degrading rapidly due to both natural and anthropogenic factors. Ship Shoal is one of the largest offshore sand resources, and has been used as a borrow area for Caminada Headland Restoration Project. Our knowledge of sediment transport and infilling processes in this new sandy and dynamic borrow area is rather limited. High resolution sub-bottom seismic data, side scan sonar images, multi-beam bathymetry and laser sediment grain size data were used to study seafloor morphological evolution and pit wall stability in response to both physical and geological processes. The multi-beam bathymetry and seismic profiling inside the pit showed that disequilibrium conditions led to rapid infilling in the pits at the beginning, but this process slowed down after the pit slope became stable and topography became smooth. We hypothesize that the erosion of the adjacent seabed sediment by energetic waves and longshore currents, the supply of suspended sediment from the rivers, and the erodible materials produced by local mass wasting on pit walls are three main types of infilling sediments. Compared with mud-capped dredge pits, this sandy dredge pit seems to have more gentle slopes on pit walls, which might be controlled by the angle of repose. Infilling sediment seems to be dominantly sandy, with some mud patches on bathymetric depressions. This study helps us better understand the impacts of mining sediment for coastal restoration and improves sand resource management efforts.

The effect of pits of different sizes on ultrasonic shear wave signals

NASA Astrophysics Data System (ADS)

Howard, Richard; Cegla, Frederic

2018-04-01

The use of 0-degree shear waves in NDE and SHM has become more commonplace as the disadvantage of coupling has been eliminated by permanent sensor installations or the use of non-contact transducers, such as EMATs. While the effect of rough surfaces and flat bottom holes on shear waves has been studied in depth, the effect of more complex geometries, such as pitting, has not. In this work, 3D finite element simulations are used to explore the reflection and scattering characteristics of shear bulk waves from pits. Specifically, three scenarios have been investigated, the effect on shear waves of: a sloped backwall; pitting directly under the transducer; and the effect of pits with variable pit position. High speed GPU finite element models enabled a wide range of pit radii and positions to be modeled. Hemispherical pits were used throughout. Key findings of the study are that the anisotropic effects that are clearly visible on sloped reflecting surfaces can also be measured on pits that are located not directly below the center of a shear wave transducer. These anisotropic effects are due to the nature of shear wave polarization. This can potentially be used for better defect characterization purposes.

Methodology of selecting dozers for lignite open pit mines in Serbia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stojanovic, D.; Ignjatovic, D.; Kovacevic, S.

1996-12-31

Apart from the main production processes (coal and overburden mining, rail conveyors transportation and storage of excavated masses) performed by great-capacity mechanization at open pit mines, numerous and different auxiliary works, that often have crucial influence on both the work efficiency of main equipment and the maintenance of optimum technical conditions of machines and plants covering technological system of open pit, are present. Successful realization of work indispensably requires a proper and adequate selection of auxiliary machines according to their type quantity, capacity, power etc. thus highly respecting specific conditions existing at each and every open pit mine. A dozermore » is certainly the most important and representative auxiliary machine at single open pit mine. It is widely used in numerous works that, in fact, are preconditions for successful work of the main mechanization and consequently the very selection of a dozer ranges among the most important operations when selecting mechanization. This paper presents the methodology of dozers selection when lignite open pit mines are concerned. A mathematical model defining the volume of work required for dozers to perform at open pit mines and consequently the number of necessary dozers was designed. The model underwent testing in practice at big open pit mines and can be used in design of future open pits mines.« less

Questa Baseline and Pre-mining Ground-Water Quality Investigation, 7. A Pictorial Record of Chemical Weathering, Erosional Processes, and Potential Debris-flow Hazards in Scar Areas Developed on Hydrothermally Altered Rocks

USGS Publications Warehouse

Plumlee, Geoffrey S.; Ludington, Steve; Vincent, Kirk R.; Verplanck, Philip L.; Caine, Jonathan S.; Livo, K. Eric

2009-01-01

Erosional scar areas developed along the lower Red River basin, New Mexico, reveal a complex natural history of mineralizing processes, rapid chemical weathering, and intense physical erosion during periodic outbursts of destructive, storm-induced runoff events. The scar areas are prominent erosional features with craggy headwalls and steep, denuded slopes. The largest scar areas, including, from east to west, Hottentot Creek, Straight Creek, Hansen Creek, Lower Hansen Creek, Sulfur Gulch, and Goat Hill Gulch, head along high east-west trending ridges that form the northern and southern boundaries of the lower Red River basin. Smaller, topographically lower scar areas are developed on ridge noses in the inner Red River valley. Several of the natural scar areas have been modified substantially as a result of large-scale open-pit and underground mining at the Questa Mine; for example, much of the Sulfur Gulch scar was removed by open pit mining, and several scars are now partially or completely covered by mine waste dumps.

Quantifying the Impact of Additional Laboratory Tests on the Quality of a Geomechanical Model

NASA Astrophysics Data System (ADS)

Fillion, Marie-Hélène; Hadjigeorgiou, John

2017-05-01

In an open-pit mine operation, the design of safe and economically viable slopes can be significantly influenced by the quality and quantity of collected geomechanical data. In several mining jurisdictions, codes and standards are available for reporting exploration data, but similar codes or guidelines are not formally available or enforced for geotechnical design. Current recommendations suggest a target level of confidence in the rock mass properties used for slope design. As these guidelines are qualitative and somewhat subjective, questions arise regarding the minimum number of tests to perform in order to reach the proposed level of confidence. This paper investigates the impact of defining a priori the required number of laboratory tests to conduct on rock core samples based on the geomechanical database of an operating open-pit mine in South Africa. In this review, to illustrate the process, the focus is on uniaxial compressive strength properties. Available strength data for 2 project stages were analysed using the small-sampling theory and the confidence interval approach. The results showed that the number of specimens was too low to obtain a reliable strength value for some geotechnical domains even if more specimens than the minimum proposed by the ISRM suggested methods were tested. Furthermore, the testing sequence used has an impact on the minimum number of specimens required. Current best practice cannot capture all possibilities regarding the geomechanical property distributions, and there is a demonstrated need for a method to determine the minimum number of specimens required while minimising the influence of the testing sequence.

Rock mass characterisation and stability analyses of excavated slopes

NASA Astrophysics Data System (ADS)

Zangerl, Christian; Lechner, Heidrun

2016-04-01

Excavated slopes in fractured rock masses are frequently designed for open pit mining, quarries, buildings, highways, railway lines, and canals. These slopes can reach heights of several hundreds of metres and in cases concerning open pit mines slopes larger than 1000 m are not uncommon. Given that deep-seated slope failures can cause large damage or even loss of life, the slope design needs to incorporate sufficient stability. Thus, slope design methods based on comprehensive approaches need to be applied. Excavation changes slope angle, groundwater flow, and blasting increases the degree of rock mass fracturing as well as rock mass disturbance. As such, excavation leads to considerable stress changes in the slopes. Generally, slope design rely on the concept of factor of safety (FOS), often a requirement by international or national standards. A limitation of the factor of safety is that time dependent failure processes, stress-strain relationships, and the impact of rock mass strain and displacement are not considered. Usually, there is a difficulty to estimate the strength of the rock mass, which in turn is controlled by an interaction of intact rock and discontinuity strength. In addition, knowledge about in-situ stresses for the failure criterion is essential. Thus, the estimation of the state of stress of the slope and the strength parameters of the rock mass is still challenging. Given that, large-scale in-situ testing is difficult and costly, back-calculations of case studies in similar rock types or rock mass classification systems are usually the methods of choice. Concerning back-calculations, often a detailed and standardised documentation is missing, and a direct applicability to new projects is not always given. Concerning rock mass classification systems, it is difficult to consider rock mass anisotropy and thus the empirical estimation of the strength properties possesses high uncertainty. In the framework of this study an approach based on numerical discrete element modelling (DEM) in combination with limit-equilibrium (LE) methods are presented. The advantage of DEM methods is that failure and displacement of discontinuities and the intact rock for the investigation of failure mechanisms and slope deformations are considered. Furthermore, DEM methods have its strength when rock masses are highly anisotropic and slope failure is structurally controlled. Herein DEM methods are applied to model potential failure geometries, which in turn serve as basis for further investigations by limit-equilibrium methods. LE-methods are used to determine the factor of safety for the pre-defined failure geometries where a sliding mechanism with a discrete and pre-defined basal shear zone is the most likely kinematical failure mode. In this study a parameter variation was performed to find the most reliable FOS based on field estimated strength parameters and the critical strength parameter where a FOS is equal to one (i.e. the lower limit for the parameters). Furthermore, the sensitivity of the shear strength parameters is studied, which enables plausibility checks with field measurements and back-calculated values. The combined approach can help to gain a better insight into failure processes and deformation mechanisms and facilitate to perform a parameter-variation study at a reasonable time frame.

LONGITUDINAL VIEW OF THE SOAKING PIT BUILDING INTERIOR WITH OPEN ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

LONGITUDINAL VIEW OF THE SOAKING PIT BUILDING INTERIOR WITH OPEN HEARTH IN BACKGROUND AND FURNACE PIT/ STACK AREA TO THE LEFT. - Pittsburgh Steel Company, Monessen Works, Open Hearth Plant, Donner Avenue, Monessen, Westmoreland County, PA

78 FR 44625 - Proposed Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-24

... DEPARTMENT OF VETERANS AFFAIRS Proposed Information Collection (Open Burn Pit Registry Airborne... to ``OMB Control No. 2900--NEW, Open Burn Pit Registry Airborne Hazard Self-Assessment Questionnaire... health effects of service members' exposure to toxic airborne chemicals and fumes caused by open burn...

Monitoring of surface deformation in open pit mine using DInSAR time-series: a case study in the N5W iron mine (Carajás, Brazil) using TerraSAR-X data

NASA Astrophysics Data System (ADS)

Mura, José C.; Paradella, Waldir R.; Gama, Fabio F.; Santos, Athos R.; Galo, Mauricio; Camargo, Paulo O.; Silva, Arnaldo Q.; Silva, Guilherme G.

2014-10-01

We present an investigation of surface deformation using Differential SAR Interferometry (DInSAR) time-series carried out in an active open pit iron mine, the N5W, located in the Carajás Mineral Province (Brazilian Amazon region), using 33 TerraSAR-X (TSX-1) scenes. This mine has presented a historical of instability and surface monitoring measurements over sectors of the mine (pit walls) have been done based on ground based radar. Two complementary approaches were used: the standard DInSAR configuration, as an early warning of the slope instability conditions, and the DInSAR timeseries analysis. In order to decrease the topographic phase error a high resolution DEM was generated based on a stereo GeoEye-1 pair. Despite the fact that a DinSAR contains atmospheric and topographic phase artifacts and noise, it was possible to detect deformation in some interferometric pairs, covering pit benches, road ramps and waste piles. The timeseries analysis was performed using the 31 interferometric pairs, which were selected based on the highest mean coherence of a stack of 107 interferograms, presenting less phase unwrapping errors. The time-series deformation was retrieved by the Least-Squares (LS) solution using an extension of the Singular Value Decomposition (SVD), with a set of additional weighted constrain on the acceleration deformation. The atmospheric phase artifacts were filtered in the space-time domain and the DEM height errors were estimated based on the normal baseline diversity. The DInSAR time-series investigation showed good results for monitoring surface displacement in the N5W mine located in a tropical rainforest environment, providing very useful information about the ground movement for alarm, planning and risk assessment.

PREVENTION OF ACID MINE DRAINAGE GENERATION FROM OPEN-PIT MINE HIGHWALLS

EPA Science Inventory

Exposed, open pit mine highwalls contribute significantly to the production of acid mine

drainage (AMD) thus causing environmental concerns upon closure of an operating mine. Available information on the generation of AMD from open-pit mine highwalls is very limit...

Dry Ice Moves on Mars

NASA Image and Video Library

2013-06-11

Serina Diniega, JPL Systems Engineer, describes the discovery that Martian gullies that end in pits rather than fan deltas are likely caused by block of frozen carbon dioxide (dry ice) sliding down slopes on a cushion of carbon dioxide gas. The pits are formed as the "dry ice" sublimates away.

Influence of the Haizhou Open Pit Coal Mine on the atmospheric flow over Fuxin, China.

PubMed

Chen, He; Yang, Zhi-Feng; Wang, Xuan

2004-01-01

The influence of the Haizhou Open Pit Mine on the atmospheric flow in nearby Fuxin City in China was analyzed with the aid of the steady-state Navier-Stokes equations. The finite element method was used to obtain numerical solutions to these equations. The results showed that the Haizhou Open Pit Coal Mine contributes to the turbulent flow in the Fuxin City and its surroundings. However, when compared with the climatic effects, the open pit mine has a relatively small impact on the atmospheric flow over Fuxin.

Comprehensive evaluation of high-steep slope stability and optimal high-steep slope design by 3D physical modeling

NASA Astrophysics Data System (ADS)

Lai, Xing-ping; Shan, Peng-fei; Cai, Mei-feng; Ren, Fen-hua; Tan, Wen-hui

2015-01-01

High-steep slope stability and its optimal excavation design in Shuichang open pit iron mine were analyzed based on a large 3D physical simulation technique. An optimal excavation scheme with a relatively steeper slope angle was successfully implemented at the northwest wall between Nos. 4 and 5 exploration lines of Shuichang Iron Mine, taking into account the 3D scale effect. The physico-mechanical properties of rock materials were obtained by laboratory tests conducted on sample cores from exploration drilling directly from the iron mine. A porous rock-like composite material was formed for the model, and the mechanical parameters of the material were assessed experimentally; specifically, the effect of water on the sample was quantitatively determined. We adopted an experimental setup using stiff modular applied static loading to carry out a visual excavation of the slope at a random depth. The setup was equipped with acoustic emission (AE) sensors, and the experiments were monitored by crack optical acquirement, ground penetrating radar, and close-field photogrammetry to investigate the mechanisms of rock-mass destabilization in the high-steep slope. For the complex study area, the model results indicated a clear correlation between the model's destabilization resulting from slope excavation and the collected monitoring information. During the model simulation, the overall angle of the slope increased by 1-6 degrees in different sections. Dramatically, the modeled excavation scheme saved over 80 million tons of rock from extraction, generating enormous economic and ecological benefits.

Gullies in a Central Pit Crater

NASA Image and Video Library

2015-10-14

Sometimes a central pit forms inside some Martian craters, especially when there substantial ground ice. Such is the case in this observation from NASA Mars Reconnaissance Orbiter spacecraft. Sometimes what we call "mass wasting" processes (think small avalanches or landslides) occur on the slopes of the central pit. We took this image to search for any recent activity that would add to or modify previously identified gullies. http://photojournal.jpl.nasa.gov/catalog/PIA20005

Control of groundwater in surface mining

NASA Astrophysics Data System (ADS)

Brawner, C. O.

1982-03-01

The presence of groundwater in surface mining operations often creates serious problems. The most important is generally a reduction in stability of the pit slopes. This is caused by pore water pressures and hydrodynamic shock due to blasting which reduce the shear strength and seepage pressures, water in tension cracks and increased unit weight which increase the shear stress. Groundwater and seepage also increase the cost of pit drainage, shipping, drilling and blasting, tyre wear and equipment maintenance. Surface erosion may also be increased and, in northern climates, ice flows on the slopes may occur. Procedures have been developed in the field of soil mechanics and engineering of dams to obtain quantitative data on pore water pressures and rock permeability, to evaluate the influence of pore water and seepage pressures on stability and to estimate the magnitude of ground-water flow. Based on field investigations, a design can be prepared for the control of groundwater in the slope and in the pit. Methods of control include the use of horizontal drains, blasted toe drains, construction of adits or drainage tunnels and pumping from wells in or outside of the pit. Recent research indicates that subsurface drainage can be augmented by applying a vacuum or by selective blasting. Instrumentation should be installed to monitor the groundwater changes created by drainage. Typical case histories are described that indicate the approach used to evaluate groundwater conditions.

Rational Use of Land Resource During the Implementation of Transportless System of Coal Strata Surface Mining

NASA Astrophysics Data System (ADS)

Gvozdkova, T.; Tyulenev, M.; Zhironkin, S.; Trifonov, V. A.; Osipov, Yu M.

2017-01-01

Surface mining and open pits engineering affect the environment in a very negative way. Among other pollutions that open pits make during mineral deposits exploiting, particular problem is the landscape changing. Along with converting the land into pits, surface mining is connected with pilling dumps that occupy large ground. The article describes an analysis of transportless methods of several coal seams strata surface mining, applied for open pits of South Kuzbass coal enterprises (Western Siberia, Russia). To improve land-use management of open pit mining enterprises, the characteristics of transportless technological schemes for several coal seams strata surface mining are highlighted and observed. These characteristics help to systematize transportless open mining technologies using common criteria that characterize structure of the bottom part of a strata and internal dumping schemes. The schemes of transportless systems of coal strata surface mining implemented in South Kuzbass are given.

Experimental research on micro-pit defects of SUS 430 stainless steel strip in cold rolling process

NASA Astrophysics Data System (ADS)

Li, Changsheng; Li, Miao; Zhu, Tao; Huo, Gang

2013-05-01

In order to improve surface glossiness of stainless steel strip in tandem cold rolling, experimental research on micro-pit defects of SUS 430 ferrite stainless steel was investigated in laboratory. The surface morphology of micro-pit defects was observed by SEM. The effects of micro-pit defects on rolling reduction, roll surface roughness and emulsion parameters were analyzed. With the pass number increasing, the quantity and surface of micro-pit defects were reduced, uneven peak was decreased and gently along rolling direction, micro-pit defects had equally distributed tendency along tranverse direction. The micro-pit defects were increased with the roll surface roughness increase. The defects ratio was declined with larger gradient at pass number 1 to 3, but gentle slope at pass number 4 to 5. The effects of temperature 55° and 63°, concentration 3% and 6% of emulsion on micro-pit effects had not obvious difference. Maintain of micro-pit was effected by rolling oil or air in the micro-pit, the quality of oil was much more than the air in the micro-pit in lubrication rolling.

Earth Observations taken by the Expedition 15 Crew

NASA Image and Video Library

2007-09-20

ISS015-E-29867 (20 Sept. 2007) --- Bingham Canyon Mine, Utah is featured in this image photographed by an Expedition 15 crewmember on the International Space Station. The Bingham Canyon Mine (center) located approximately 32 kilometers to the southeast of Salt Lake City, UT is one of the largest open-pit mines in the world, measuring over 4 kilometers wide and 1,200 meters deep. The mine exploits a porphyry copper, a type of geological structure formed by crystal-rich magma moving upwards through pre-existing rock layers. As the magma cools and crystallizes (forming an igneous rock with large crystals in a fine-grained matrix, known as a porphyry), hot fluids circulate through the magma and surrounding rocks via fractures. This process of hydrothermal alteration typically forms copper-bearing and other minerals in spatial patterns that a geologist recognizes as a potential porphyry copper deposit. Parallel benches (stepped terraces), visible along the western pit face (center left), range from 16 to 25 meters high - these provide access for equipment to work the rock face, as well as maintaining stability of the sloping pit walls. A dark, larger roadway is also visible directly below the benches. Brown to gray, flat topped hills of gangue (waste rock) surround the pit, and are thrown into sharp relief by shadows and the oblique viewing angle of this image. Leachate reservoirs associated with ore processing are visible to the south of the city of Bingham Canyon, UT (right).

Evidence for Recent Liquid Water on Mars: Gullies at 70oS in Polar Pit Walls

NASA Technical Reports Server (NTRS)

2000-01-01

[figure removed for brevity, see original site]

Gully landforms proposed to have been caused by geologically-recent seepage and runoff of liquid water on Mars are found in the most unlikely places. They typically occur in areas that are quite cold--well below freezing--all year round. Like the old adage about moss on trees, nearly all of them form on slopes that face away from sunlight. Most of the gullies occur at latitudes between 30o and 70o.

The highest latitude at which martian gullies have been found is around 70o-75oS on the walls of pits developed in the south polar pitted plains. If you were at this same latitude on Earth, you would be in Antarctica. This region spends much of the winter--which lasts approximately 6 months on Mars--in darkness and at temperatures cold enough to freeze carbon dioxide (around -130oC or -200oF). Nevertheless, gullies with very sharp, deep, v-shaped channels are seen on the pit walls (above, left).

Based upon the locations of the tops of the channels on the slope shown here, the inferred site of liquid seepage is located at a layer in the pit wall about 1/3 of the way down from the top of the MOC image. The channels start wide and taper downslope. The area above the channels is layered and has been eroded by mass movement--dry avalanching of debris--to form a pattern of chutes and ridges on the upper slope of the pit wall. The top layer appears to have many boulders in it (each about the size of a small house), these boulders are left behind on the upper slopes of the pit wall as debris is removed.

Centered near 70.7oS, 355.7oW, the MOC image was acquired July 14, 1999, and covers an area approximately 2.8 km (1.7 mi) wide by 2.1 km (1.3 mi) high. Sunlight illuminates the MOC image from the upper left and north is toward the upper left. The context view (right) is from the Viking 2 orbiter and was acquired in 1977. The Viking picture is illuminated from the top/upper left; north is toward the upper right. The small white box in the context frame (upper right corner) shows the location of the high resolution MOC view.

Modelling Geomechanical Heterogeneity of Rock Masses Using Direct and Indirect Geostatistical Conditional Simulation Methods

NASA Astrophysics Data System (ADS)

Eivazy, Hesameddin; Esmaieli, Kamran; Jean, Raynald

2017-12-01

An accurate characterization and modelling of rock mass geomechanical heterogeneity can lead to more efficient mine planning and design. Using deterministic approaches and random field methods for modelling rock mass heterogeneity is known to be limited in simulating the spatial variation and spatial pattern of the geomechanical properties. Although the applications of geostatistical techniques have demonstrated improvements in modelling the heterogeneity of geomechanical properties, geostatistical estimation methods such as Kriging result in estimates of geomechanical variables that are not fully representative of field observations. This paper reports on the development of 3D models for spatial variability of rock mass geomechanical properties using geostatistical conditional simulation method based on sequential Gaussian simulation. A methodology to simulate the heterogeneity of rock mass quality based on the rock mass rating is proposed and applied to a large open-pit mine in Canada. Using geomechanical core logging data collected from the mine site, a direct and an indirect approach were used to model the spatial variability of rock mass quality. The results of the two modelling approaches were validated against collected field data. The study aims to quantify the risks of pit slope failure and provides a measure of uncertainties in spatial variability of rock mass properties in different areas of the pit.

A novel environmental restoration method for an abandoned limestone quarry with a deep open pit and steep palisades: a case study

PubMed Central

Wang, Hanxun; Bai, Xueliang; Shi, Lei

2018-01-01

In general, exploitation of rock materials, such as limestone or granite exploitation, can cause serious damage to the environment near a mine area. With economic development and the ever-increasing demand for ore resources, mining activities have induced very serious environmental issues in China. Therefore, environmental restoration work around mines in China is urgently required. This study explores the Chuankou open-pit limestone quarry in Tongchuan City, Shaanxi Province, Northwest China, as the engineering case. The environmental issues caused by over 40 years of limestone exploitation, including land degradation, land occupation, dust pollution and potential geological disasters, were investigated. Combining the characteristics of this quarry with a summary of previous studies on environmental restoration work, this paper proposes a novel and systematic method that was comprehensively carried out through engineering and revegetation measures. The engineering measure, that is, the construction of an artificial slope by using local abandoned construction materials, solved the environmental problems in this quarry and provided site conditions favourable for revegetation. The revegetation measure restored the local ecosystem. This method provides both a new idea for the sustainable development of a mining area and a useful reference for analogous engineering cases. PMID:29892461

The Pits

NASA Technical Reports Server (NTRS)

2006-01-01

8 March 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a portion of a pit chain on the lower, northern flank of the giant martian volcano, Arsia Mons. Pits such as these commonly form as a result of collapse of surface materials into a subsurface void, possibly along a fault or into an old lava tube. The layered material, exposed near the top of several of the pits, is shedding house-sized boulders which can be seen resting on the sloping sidewalls and floors of many of the pits.

Location near: 6.7oS, 120.1oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Southern Summer

78 FR 33894 - Proposed Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-05

... Burn Pit Registry Airborne Hazard Self-Assessment Questionnaire) Activity: Comment Request AGENCY... ascertain and monitor the health effects of the exposure of members of the Armed Forces to toxic airborne... to ``OMB Control No. 2900-NEW, Open Burn Pit Registry Airborne Hazard Self-Assessment Questionnaire...

Utilization of open pit burned household waste ash--a feasibility study in Dhaka.

PubMed

Haque, Md Obaidul; Sharif, Ahmed

2014-05-01

Informal incineration or open pit burning of waste materials is a common practice in the peripheral area of Dhaka, one of the fastest growing mega-cities in the world. This study deals with the effect of open pit burned (i.e. open burned) household waste bottom ash on fired clay bricks. Between 0 to 50% (by weight) of open pit burned household waste bottom ash was mixed with clay to make bricks. The molded specimens were air-dried at room temperature for 24 h and then oven dried at 100 °C for another 24 h to remove the water. The raw bricks were fired in a muffle furnace to a designated temperature (800, 900 and 1000 °C, respectively). The firing behaviour (mechanical strength, water absorption and shrinkage) was determined. The microstructures, phase compositions and leachates were evaluated for bricks manufactured at different firing temperatures. These results demonstrate that open pit burned ash can be recycled in clay bricks. This study also presents physical observations of the incinerated ash particles and determination of the chemical compositions of the raw materials by wet analysis. Open pit burned ash can be introduced easily into bricks up to 20% wt. The concentrations of hazardous components in the leachates were below the standard threshold for inert waste category landfill and their environmental risk during their use-life step can be considered negligible.

Stability of highwalls in surface coal mines, western Powder Ridge Basin, Wyoming and Montana

USGS Publications Warehouse

Lee, Fitzhugh T.; Smith, William K.; Savage, William Z.

1976-01-01

Preliminary results from the first part of a two-part investigation of the stability of highwalls in open-pit coal mines in the Fort Union Formation of the western Powder River Basin of Wyoming and Montana indicate that these highwalls are subject to time-dependent deformation. Field investigations and laboratory physical-properties tests of coal and overburden rocks suggest that several factors influence highwall stability. Some of these factors are rebound of overconsolidated rocks, desiccation, water, orientation and spacing of fractures, and strength and deformation properties. Factors of safety for a typical highwall in the study area (calculated by the finite-element method) may be less than 1.0 when open fractures are present and the highwall has degraded. Although it is concluded that most open-pit mines in the Fort Union Formation within the study area have generally stable highwalls, these highwalls do deteriorate and become progressively less stable. Because of this, postmining failures are common and could be critical if mining were delayed and then resumed after a period of several months. The second part of the investigation will utilize field measurements of rock-mass properties and instrumentation of actively mined highwalls to obtain data for comparison with the results of the initial investigation. Because the height of highwalls will increase as the more shallow coal is exhausted, these data will also be used to predict the behavior of slopes higher than those presently found in the western Powder River Basin.

Prediction of slope stability based on numerical modeling of stress–strain state of rocks

NASA Astrophysics Data System (ADS)

Kozhogulov Nifadyev, KCh, VI; Usmanov, SF

2018-03-01

The paper presents the developed technique for the estimation of rock mass stability based on the finite element modeling of stress–strain state of rocks. The modeling results on the pit wall landslide as a flow of particles along a sloped surface are described.

Burn Pit Emissions Exposure and Respiratory and Cardiovascular Conditions Among Airborne Hazards and Open Burn Pit Registry Participants.

PubMed

Liu, Jason; Lezama, Nicholas; Gasper, Joseph; Kawata, Jennifer; Morley, Sybil; Helmer, Drew; Ciminera, Paul

2016-07-01

The aim of this study was to determine how burn pit emissions exposure is associated with the incidence of respiratory and cardiovascular conditions. We examined the associations between assumed geographic and self-reported burn pit emissions exposure and respiratory and cardiovascular outcomes in participants of the Airborne Hazards and Open Burn Pit Registry. We found significant dose-response associations for higher risk of self-reported emphysema, chronic bronchitis, or chronic obstructive pulmonary disease with increased days of deployment within 2 miles of selected burn pits (P-trend = 0.01) and self-reported burn pit smoke exposure (P-trend = 0.0005). We found associations between burn pit emissions exposure and higher incidence of post-deployment self-reported respiratory and cardiovascular conditions, but these findings should be interpreted with caution because the surrogate measurements of burn pit emissions exposure in this analysis may not reflect individual exposure levels.

49 CFR 192.187 - Vaults: Sealing, venting, and ventilation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... vault or pit is sealed, each opening must have a tight fitting cover without open holes through which an... Components § 192.187 Vaults: Sealing, venting, and ventilation. Each underground vault or closed top pit....7 cubic meters): (1) The vault or pit must be ventilated with two ducts, each having at least the...

Ultimate open pit stochastic optimization

NASA Astrophysics Data System (ADS)

Marcotte, Denis; Caron, Josiane

2013-02-01

Classical open pit optimization (maximum closure problem) is made on block estimates, without directly considering the block grades uncertainty. We propose an alternative approach of stochastic optimization. The stochastic optimization is taken as the optimal pit computed on the block expected profits, rather than expected grades, computed from a series of conditional simulations. The stochastic optimization generates, by construction, larger ore and waste tonnages than the classical optimization. Contrary to the classical approach, the stochastic optimization is conditionally unbiased for the realized profit given the predicted profit. A series of simulated deposits with different variograms are used to compare the stochastic approach, the classical approach and the simulated approach that maximizes expected profit among simulated designs. Profits obtained with the stochastic optimization are generally larger than the classical or simulated pit. The main factor controlling the relative gain of stochastic optimization compared to classical approach and simulated pit is shown to be the information level as measured by the boreholes spacing/range ratio. The relative gains of the stochastic approach over the classical approach increase with the treatment costs but decrease with mining costs. The relative gains of the stochastic approach over the simulated pit approach increase both with the treatment and mining costs. At early stages of an open pit project, when uncertainty is large, the stochastic optimization approach appears preferable to the classical approach or the simulated pit approach for fair comparison of the values of alternative projects and for the initial design and planning of the open pit.

Structure of energy consumption and improving open-pit dump truck efficiency

NASA Astrophysics Data System (ADS)

Koptev, V. Yu; Kopteva, A. V.

2017-10-01

This paper studies the dynamics of the improvement of wheel type transport vehicles environmental and energy performance in open-pit mines. The paper discloses characteristics of the gas turbine engine with capacity of 1250 hp, mounted on tanks, and technical-economic calculations, confirming reasonability of their use in open-pit dump trucks with the 120 …130-ton loading capacity. The general layout scheme of mechanical transmission with the gas turbine engine is shown.

Gravity-induced stresses in finite slopes

USGS Publications Warehouse

Savage, W.Z.

1994-01-01

An exact solution for gravity-induced stresses in finite elastic slopes is presented. This solution, which is applied for gravity-induced stresses in 15, 30, 45 and 90?? finite slopes, has application in pit-slope design, compares favorably with published finite element results for this problem and satisfies the conditions that shear and normal stresses vanish on the ground surface. The solution predicts that horizontal stresses are compressive along the top of the slopes (zero in the case of the 90?? slope) and tensile away from the bottom of the slopes, effects which are caused by downward movement and near-surface horizontal extension in front of the slope in response to gravity loading caused by the additional material associated with the finite slope. ?? 1994.

Pitted Landforms in Southern Hellas Planitia

NASA Image and Video Library

2015-03-25

This image is of a portion of the Southern plains region within Hellas, the largest impact basin on Mars, with a diameter of about 2300 kilometers 1400 miles, as observed by NASA Mars Reconnaissance Orbiter. There are three main phenomena apparent in this image. First, the faint dark streaks that criss-cross the terrain are dust devil tracks that clear the bright dust along their way. Second, the subtle overall bumpy "basketball" texture of the surface is formed by repeated seasonal freezing and thawing of the ice-rich regolith and is common at higher latitudes. Third, the large, elliptical, scalloped depressions are common in permafrost terrains in both hemispheres, where thick, latitude-dependent sedimentary mantles comprise the surface units. These mantles are composed of ice-rich sediments that degrade as the ice sublimates away and is heated either by the Sun or by locally higher geothermal gradients. Sublimation, or the direct change in phase from ice to gas, occurs on Mars because of its low density atmosphere. These depressions have steeper pole-facing slopes, whereas the equator-facing slopes gently fade into the surrounding terrain. At full resolution (see close up view), numerous sublimation pits and networks of polygonal cracks are visible on the steeper, unstable pole-ward facing slopes. The overall morphology of this terrain is characteristic of what is called "thermokarstic degradation processes," which is a term used to describe the formation of pits in an ice-rich terrain due to loss of ice creating pits and collapse features. http://photojournal.jpl.nasa.gov/catalog/PIA19350

Structural Design and Monitoring Analysis of Foundation Pit Support in Yiwu Huishang Tiandi

NASA Astrophysics Data System (ADS)

Zhang, Chunsu

2017-08-01

Huishang Tiandi deep foundation pit in Yiwu is a two-story basement,which is located in the downtown area and adjacent to the city center main traffic trunk. The surrounding environment is too com-plex to slope. The excavation depth is large, the formation is weak and complex, and the groundwater level is high.In order to ensure the safety of the foundation wall and the surrounding environment, the deformation of the foundation pit support is strictly controlled, and the deformation and internal force of the foundation supporting structure and the surrounding building are monitored.The deformation law of the foundation pit is obtained through the analysis of the horizontal displacement, the deformation rate of the supporting struc-ture, the surrounding environment of the foundation pit and the internal force of the anchor cable. The relia-bility and rationality of the design of foundation pit support are verified. It is of reference value for the de-sign and construction of other deep foundation pit engineering in Yiwu area.

Near-Field Microwave Detection of Corrosion Precursor Pitting under Thin Dielectric Coatings in Metallic Substrate

NASA Astrophysics Data System (ADS)

Hughes, D.; Zoughi, R.; Austin, R.; Wood, N.; Engelbart, R.

2003-03-01

Detection of corrosion precursor pitting on metallic surfaces under various coatings and on bare metal is of keen interest in evaluation of aircraft fuselage. Near-field microwave nondestructive testing methods, utilizing open-ended rectangular waveguides and coaxial probes, have been used extensively for detection of surface flaws in metals, both on bare metal and under a dielectric coating. This paper presents the preliminary results of using microwave techniques to detect corrosion precursor pitting under paint and primer, applique and on bare metal. Machined pits of 500 μm diameter were detected using open-ended rectangular waveguides at V-Band under paint and primer and applique, and on bare metal. Using coaxial probes, machined pits with diameters down to 150 μm on bare metal were also detected. Relative pit size and density were shown on a corrosion-pitted sample using open-ended rectangular waveguides at frequencies of 35 GHz to 70 GHz. The use of Boeing's MAUS™ scanning systems provided improved results by alleviating standoff variation and scanning artifact. Typical results of this investigation are also presented.

The Experience of Implementation of Innovative Technology of Quarry Waste Water Purifying in Kuzbass Open Pit

NASA Astrophysics Data System (ADS)

Lesin, Yu V.; Hellmer, M. C.

2016-08-01

Among all industries in Kuzbass (Western Siberia, Russia) the coal industry provides the most environmental threat. However, the construction of new and maintenance of existing open pit mines do not often correspond to the tasks of improving the environmental safety of surface mining. So the article describes the use of innovative quarry waste water purifying technology implemented in Kuzbass open pit mine «Shestaki». This technology is based on using artificial filter arrays made of overburden rock.

Correlation of Risk Analysis Method Results with Numerical and Limit Equilibrium Methods in Overall Slope Stability Analysis of Southern Wall of Chadormalu Iron Open Pit Mine-Iran / Korelacja wyników analizy ryzyka z wynikami obliczeń numerycznych oraz wynikami uzyskanymi w oparciu o metodę równowagi granicznej zastosowanych do badania stabilności wyrobiska pochyłego na południowej ścianie odkrywkowej kopalni rud żelaza w chadormalu w Iranie

NASA Astrophysics Data System (ADS)

Ahangari, Kaveh; Paji, Arman Gholinezhad; Behdani, Alireza Siami

2013-06-01

Slope stability analysis is one of the most important factors in designing open pit mines. Therefore an optimal slope design that supports both aspects of economy and safety is very significant. There are many different methods in slope stability analysis including empirical, limit equilibrium, block theory, numerical, and probabilistic methods. In this study, to analyze the overall slope stability of southern wall of Chadormalu iron open pit mine three numerical, limit equilibrium and probabilistic methods have been used. Software and methods that is used for analytical investigation in this study are FLAC software for numerical analysis, SLIDE software and circuit failure chart for limit equilibrium analysis and qualitative fault tree and semi-quantitative risk matrix for probabilistic analysis. The results of all above mentioned methods, was a circular failure occurrence in Metasomatite rock zone between 1405 to 1525 m levels. The main factors of failure occurrence in this range were heavily jointing and existing of faults. Safety factors resulted from numerical method; Circular chart method and SLIDE software are 1.16, 1.25 and 1.27 respectively. Regarding instability and safety factors in Metasomatite rock zone, in order to stabilize the given zone, some considerations such as bench angle and height reduction should be planned. In results of risk matrix method this zone was mentioned too as a high risk zone that numerical and limit equilibrium methods confirmed this. Badanie stabilności wyrobiska pochyłego jest jednym z najważniejszych czynników uwzględnianych przy projektowaniu kopalni odkrywkowych. Optymalne zaprojektowanie wyrobiska pochyłego z uwzględnieniem czynników ekonomicznych oraz bezpieczeństwa jest niezmiernie ważne. Istnieje wiele metod badania stabilności wyrobiska pochyłego, między innymi metody empiryczne, metoda równowagi granicznej, teoria bloków oraz metody numeryczne i probabilistyczne. W pracy tej omówiono zastosowanie trzech spośród tych metod: metody numerycznej, równowagi granicznej oraz metody probabilistycznej, do analizy stabilności wyrobiska pochyłego na południowej ścianie kopalni rud żelaza w Chadormalu w Iranie. Oprogramowanie wykorzystane w badaniach analitycznych to pakiet FLAK przy metodzie numerycznej, oprogramowanie SLIDE oraz wykresy kołowe przy metodzie równowagi granicznej oraz jakościowe drzewa określające występowanie uskoków i pół-jakościowe macierze ryzyka przy metodzie probabilistycznej. Wyniki uzyskane w oparciu o trzy wyżej wymienione metody wykazały wystąpienie zawalenia się skał metasomatycznych na poziomie od 1405 do 1525 m. Głównymi czynnikami warunkującymi zawalenie się skał w tym regionie była obecność licznych pęknięć oraz uskoków. Wskaźniki bezpieczeństwa uzyskane przy pomocy metod numerycznych, wykresu kołowego oraz oprogramowanie SLIDE wyniosły kolejno: 1.16, 1.25, 1.27. W odniesieniu do niestabilności w rejonie skał metasomatycznych, aby uczynić tę strefę bardziej stabilną należy uwzględnić takie czynniki jak kąt nachylenia ławy oraz obniżenie wysokości. Analiza przeprowadzona w oparciu o macierze ryzyka wykazała, że strefa ta jest strefą wysokiego ryzyka, zaś wyniki analizy numerycznej oraz wyników uzyskanych przy pomocy metody równowagi granicznej w pełni ten wniosek potwierdziły.

Domination of hillslope denudation by tree uprooting in an old-growth forest

NASA Astrophysics Data System (ADS)

Phillips, Jonathan D.; Šamonil, Pavel; Pawlik, Łukasz; Trochta, Jan; Daněk, Pavel

2017-01-01

Razula forest preserve in the Carpathian Mountains of the Czech Republic is an unmanaged forest that has not been logged or otherwise anthropically disturbed for at least 83 years, preceded by only infrequent selective logging. We examined this 25 ha area to determine the dominant geomorphological processes on the hillslope. Tree uprooting displaces about 2.9 m3 of soil and regolith per year, representing about 1.5 uprooted trees ha- 1 yr- 1, based on forest inventory records dating back to 1972, and contemporary measurements of displaced soil and pit-mound topography resulting from uprooting. Pits and mounds occupy > 14% of the ground surface. Despite typical slope gradients of 0.05 mm- 1, and up to 0.41, little evidence of mass wasting (e.g., slump or flow scars or deposits, colluvial deposits) was noted in the field, except in association with pit-mound pairs. Small avalanche and ravel features are common on the upslope side of uproot pits. Surface runoff features were rare and poorly connected, but do include stemwash erosion associated with stemflow. No rills or channels were found above the valley bottom area, and only small, localized areas of erosion and forest litter debris indicating overland flow. Where these features occurred, they either disappeared a short distance downslope (indicating infiltration), or indicate flow into tree throw pits. Surface erosion is also inhibited by surface armoring of coarse rock fragments associated with uprooting, as well as by the nearly complete vegetation and litter cover. These results show that the combination of direct and indirect impacts of tree uprooting can dominate slope processes in old-growth, unmanaged forests. The greater observed expression of different hillslope processes in adjacent managed forests (where tree uprooting dynamics are blocked by management activities) suggests that human interventions can change the slope process regime in forest ecosystems.

Birth outcomes among military personnel after exposure to documented open-air burn pits before and during pregnancy.

PubMed

Conlin, Ava Marie S; DeScisciolo, Connie; Sevick, Carter J; Bukowinski, Anna T; Phillips, Christopher J; Smith, Tyler C

2012-06-01

To examine birth outcomes in military women and men with potential exposure to documented open-air burn pits before and during pregnancy. Electronic data from the Department of Defense Birth and Infant Health Registry and the Defense Manpower Data Center were used to examine the prevalence of birth defects and preterm birth among infants of active-duty women and men who were deployed within a 3-mile radius of a documented open-air burn pit before or during pregnancy. In general, burn pit exposure at various times in relation to pregnancy and for differing durations was not consistently associated with an increase in birth defects or preterm birth in infants of active-duty military personnel. These analyses offer reassurance to service members that burn pit exposure is not consistently associated with these select adverse infant health outcomes.

Tectonic fault monitoring at open pit mine at Zarnitsa Kimberlite Pipe

NASA Astrophysics Data System (ADS)

Vostrikov, VI; Polotnyanko, NS; Trofimov, AS; Potaka, AA

2018-03-01

The article describes application of Karier instrumentation designed at the Institute of Mining to study fracture formation in rocks. The instrumentation composed of three sensors was used to control widening of a tectonic fault intersecting an open pit mine at Zarnitsa Kimberlite Pipe in Yakutia. The monitoring between 28 November and 28 December in 2016 recorded convergence of the fault walls from one side of the open pit mine and widening from the other side. After production blasts, the fault first grows in width and then recovers.

Millennium Open Pit Mine, Alberta, Canada

NASA Image and Video Library

2007-11-26

Near Fort McMurray, Alberta, Canada, on the east bank of the Athabasca River, are found the Steepbank and Millennium open pit mines. These images were acquired by NASA Terra satellite on September 22, 2000 and July 31, 2007.

Evaluation of modified crystal violet chromoendoscopy procedure using new mucosal pit pattern classification for detection of Barrett's dysplastic lesions.

PubMed

Yuki, T; Amano, Y; Kushiyama, Y; Takahashi, Y; Ose, T; Moriyama, I; Fukuhara, H; Ishimura, N; Koshino, K; Furuta, K; Ishihara, S; Adachi, K; Kinoshita, Y

2006-05-01

Pit pattern diagnosis is important for endoscopic detection of dysplastic Barrett's lesions, though using magnification endoscopy can be difficult and laborious. We investigated the usefulness of a modified crystal violet chromoendoscopy procedure and utilised a new pit pattern classification for diagnosis of dysplastic Barrett's lesions. A total of 1,030 patients suspected of having a columnar lined oesophagus were examined, of whom 816 demonstrated a crystal violet-stained columnar lined oesophagus. The early group of patients underwent 0.05% crystal violet chromoendoscopy, while the later group was examined using 0.03% crystal violet with 3.0% acetate. A targeted biopsy of the columnar lined oesophagus was performed using crystal violet staining after making a diagnosis of closed or open type pit pattern with a newly proposed system of classification. The relationship between type of pit pattern and histologically identified dysplastic Barrett's lesions was evaluated. Dysplastic Barrett's lesions were identified in biopsy samples with an open type pit pattern with a sensitivity of 96.0%. Further, Barrett's mucosa with the intestinal predominant mucin phenotype was closely associated with the open type pit pattern (sensitivity 81.9%, specificity 95.6%). The new pit pattern classification for diagnosis of Barrett's mucosa was found to be useful for identification of cases with dysplastic lesions and possible malignant potential using a crystal violet chromoendoscopic procedure.

Acquired pit of the optic nerve: a risk factor for progression of glaucoma.

PubMed

Ugurlu, S; Weitzman, M; Nduaguba, C; Caprioli, J

1998-04-01

To examine acquired pit of the optic nerve as a risk factor for progression of glaucoma. In a retrospective longitudinal study, 25 open-angle glaucoma patients with acquired pit of the optic nerve were compared with a group of 24 open-angle glaucoma patients without acquired pit of the optic nerve. The patients were matched for age, mean intraocular pressure, baseline ratio of neuroretinal rim area to disk area, visual field damage, and duration of follow-up. Serial optic disk photographs and visual fields of both groups were evaluated by three independent observers for glaucomatous progression. Of 46 acquired pits of the optic nerve in 37 eyes of 25 patients, 36 pits were located inferiorly (76%) and 11 superiorly (24%; P < .001). Progression of optic disk damage occurred in 16 patients (64%) in the group with acquired pit and in three patients (12.5%) in the group without acquired pit (P < .001). Progression of visual field loss occurred in 14 patients (56%) in the group with acquired pit and in six (25%) in the group without pit (P=.04). Bilateral acquired pit of the optic nerve was present in 12 patients (48%). Disk hemorrhages were observed more frequently in the group with acquired pit (10 eyes, 40%) compared with the group without pit (two eyes, 8%; P=.02). Among patients with glaucoma, patients with acquired pit of the optic nerve represent a subgroup who are at increased risk for progressive optic disk damage and visual field loss.

Land movement monitoring at the Mavropigi lignite mine using spaceborne D-InSAR

NASA Astrophysics Data System (ADS)

Papadaki, Eirini; Tripolitsiotis, Achilleas; Steiakakis, Chrysanthos; Agioutantis, Zacharias; Mertikas, Stelios; Partsinevelos, Panagiotis; Schilizzi, Pavlos

2013-08-01

This paper examines the capability of remote sensing radar interferometry to monitor land movements, as it varies with time, in areas close to open pit lignite mines. The study area is the "Mavropigi" lignite mine in Ptolemais, Northern Greece; whose continuous operation is of vital importance to the electric power supply of Greece. The mine is presently 100-120m deep while horizontal and vertical movements have been measured in the vicinity of the pit. Within the mine, ground geodetic monitoring has revealed an average rate of movement amounting to 10-20mm/day at the southeast slopes. In this work, differential interferometry (DInSAR), using 19 Synthetic Aperture Radar (SAR) images of ALOS satellite, has been applied to monitor progression of land movement caused my mining within the greater area of "Mavropigi" region. The results of this work show that DInSAR can be used effectively to capture ground movement information, well before signs of movements can be observed visually in the form of imminent fissures and tension cracks. The advantage of remote sensing interferometry is that it can be applied even in inaccessible areas where monitoring with ground equipment is either impossible or of high-cost (large areas).

Standardized emissions inventory methodology for open-pit mining areas.

PubMed

Huertas, Jose I; Camacho, Dumar A; Huertas, Maria E

2011-08-01

There is still interest in a unified methodology to quantify the mass of particulate material emitted into the atmosphere by activities inherent to open-pit mining. For the case of total suspended particles (TSP), the current practice is to estimate such emissions by developing inventories based on the emission factors recommended by the USEPA for this purpose. However, there are disputes over the specific emission factors that must be used for each activity and the applicability of such factors to cases quite different to the ones under which they were obtained. There is also a need for particulate matter with an aerodynamic diameter less than 10 μm (PM(10)) emission inventories and for metrics to evaluate the emission control programs implemented by open-pit mines. To address these needs, work was carried out to establish a standardized TSP and PM(10) emission inventory methodology for open-pit mining areas. The proposed methodology was applied to seven of the eight mining companies operating in the northern part of Colombia, home to the one of the world's largest open-pit coal mining operations (∼70 Mt/year). The results obtained show that transport on unpaved roads is the mining activity that generates most of the emissions and that the total emissions may be reduced up to 72% by spraying water on the unpaved roads. Performance metrics were defined for the emission control programs implemented by mining companies. It was found that coal open-pit mines are emitting 0.726 and 0.180 kg of TSP and PM(10), respectively, per ton of coal produced. It was also found that these mines are using on average 1.148 m(2) of land per ton of coal produced per year.

Pits and Channels of Hebrus Valles

NASA Image and Video Library

2017-01-26

The drainages in this image are part of Hebrus Valles, an outflow channel system likely formed by catastrophic floods. Hebrus Valles is located in the plains of the Northern lowlands, just west of the Elysium volcanic region. Individual channels range from several hundred meters to several kilometers wide and form multi-threaded (anastamosing) patterns. Separating the channels are streamlined forms, whose tails point downstream and indicate that channel flow is to the north. The channels seemingly terminate in an elongated pit that is approximately 1875 meters long and 1125 meters wide. Using the shadow that the wall has cast on the floor of the pit, we can estimate that the pit is nearly 500 meters deep. The pit, which formed after the channels, exposes a bouldery layer below the dusty surface mantle and is underlain by sediments. Boulders several meters in diameter litter the slopes down into the pit. Pits such as these are of interest as possible candidate landing sites for human exploration because they might retain subsurface water ice (Schulze-Makuch et al. 2016, 6th Mars Polar Conf.) that could be utilized by future long-term human settlements. http://photojournal.jpl.nasa.gov/catalog/PIA11704

43. (Credit JTL) View down into # 3 low service ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

43. (Credit JTL) View down into # 3 low service pump pit from elevator car. Worthington low service pump frame on left with pumps at bottom. Tunnel opening leads to #1 low service pump pit. Electric pump housing closest to tunnel opening installed in 1943; pump could deliver 6 mgd. Certrifugal pump near steps was installed in 1947 and is driven by a shaft from a motor at the top of the pit. - McNeil Street Pumping Station, McNeil Street & Cross Bayou, Shreveport, Caddo Parish, LA

Simplified cost models for prefeasibility mineral evaluations

USGS Publications Warehouse

Camm, Thomas W.

1991-01-01

This report contains 2 open pit models, 6 underground mine models, 11 mill models, and cost equations for access roads, power lines, and tailings ponds. In addition, adjustment factors for variation in haulage distances are provided for open pit models and variation in mining depths for underground models.

Groundwater monitoring of an open-pit limestone quarry: groundwater characteristics, evolution and their connections to rock slopes.

PubMed

Eang, Khy Eam; Igarashi, Toshifumi; Fujinaga, Ryota; Kondo, Megumi; Tabelin, Carlito Baltazar

2018-03-06

Groundwater flow and its geochemical evolution in mines are important not only in the study of contaminant migration but also in the effective planning of excavation. The effects of groundwater on the stability of rock slopes and other mine constructions especially in limestone quarries are crucial because calcite, the major mineral component of limestone, is moderately soluble in water. In this study, evolution of groundwater in a limestone quarry located in Chichibu city was monitored to understand the geochemical processes occurring within the rock strata of the quarry and changes in the chemistry of groundwater, which suggests zones of deformations that may affect the stability of rock slopes. There are three distinct geological formations in the quarry: limestone layer, interbedded layer of limestone and slaty greenstone, and slaty greenstone layer as basement rock. Although the hydrochemical facies of all groundwater samples were Ca-HCO 3 type water, changes in the geochemical properties of groundwater from the three geological formations were observed. In particular, significant changes in the chemical properties of several groundwater samples along the interbedded layer were observed, which could be attributed to the mixing of groundwater from the limestone and slaty greenstone layers. On the rainy day, the concentrations of Ca 2+ and HCO 3 - in the groundwater fluctuated notably, and the groundwater flowing along the interbedded layer was dominated by groundwater from the limestone layer. These suggest that groundwater along the interbedded layer may affect the stability of rock slopes.

Thermal comfort sustained by cold protective clothing in Arctic open-pit mining—a thermal manikin and questionnaire study

PubMed Central

JUSSILA, Kirsi; RISSANEN, Sirkka; AMINOFF, Anna; WAHLSTRÖM, Jens; VAKTSKJOLD, Arild; TALYKOVA, Ljudmila; REMES, Jouko; MÄNTTÄRI, Satu; RINTAMÄKI, Hannu

2017-01-01

Workers in the Arctic open-pit mines are exposed to harsh weather conditions. Employers are required to provide protective clothing for workers. This can be the outer layer, but sometimes also inner or middle layers are provided. This study aimed to determine how Arctic open-pit miners protect themselves against cold and the sufficiency, and the selection criteria of the garments. Workers’ cold experiences and the clothing in four Arctic open-pit mines in Finland, Sweden, Norway and Russia were evaluated by a questionnaire (n=1,323). Basic thermal insulation (Icl) of the reported clothing was estimated (ISO 9920). The Icl of clothing from the mines were also measured by thermal manikin (standing/walking) in 0.3 and 4.0 m/s wind. The questionnaire showed that the Icl of the selected clothing was on average 1.2 and 1.5 clo in mild (−5 to +5°C) and dry cold (−20 to −10°C) conditions, respectively. The Icl of the clothing measured by thermal manikin was 1.9–2.3 clo. The results show that the Arctic open-pit miners’ selected their clothing based on occupational (time outdoors), environmental (temperature, wind, moisture) and individual factors (cold sensitivity, general health). However, the selected clothing was not sufficient to prevent cooling completely at ambient temperatures below −10°C. PMID:29021416

Thermal comfort sustained by cold protective clothing in Arctic open-pit mining-a thermal manikin and questionnaire study.

PubMed

Jussila, Kirsi; Rissanen, Sirkka; Aminoff, Anna; Wahlström, Jens; Vaktskjold, Arild; Talykova, Ljudmila; Remes, Jouko; Mänttäri, Satu; Rintamäki, Hannu

2017-12-07

Workers in the Arctic open-pit mines are exposed to harsh weather conditions. Employers are required to provide protective clothing for workers. This can be the outer layer, but sometimes also inner or middle layers are provided. This study aimed to determine how Arctic open-pit miners protect themselves against cold and the sufficiency, and the selection criteria of the garments. Workers' cold experiences and the clothing in four Arctic open-pit mines in Finland, Sweden, Norway and Russia were evaluated by a questionnaire (n=1,323). Basic thermal insulation (I cl ) of the reported clothing was estimated (ISO 9920). The I cl of clothing from the mines were also measured by thermal manikin (standing/walking) in 0.3 and 4.0 m/s wind. The questionnaire showed that the I cl of the selected clothing was on average 1.2 and 1.5 clo in mild (-5 to +5°C) and dry cold (-20 to -10°C) conditions, respectively. The I cl of the clothing measured by thermal manikin was 1.9-2.3 clo. The results show that the Arctic open-pit miners' selected their clothing based on occupational (time outdoors), environmental (temperature, wind, moisture) and individual factors (cold sensitivity, general health). However, the selected clothing was not sufficient to prevent cooling completely at ambient temperatures below -10°C.

MINE WASTE TECHNOLOGY PROGRAM PREVENTION OF ACID MINE DRAINAGE GENERATION FROM OPEN-PIT HIGHWALLS

EPA Science Inventory

This document summarizes the results of Mine Waste Technology Program Activity III, Project 26, Prevention of Acid Mine Drainage Generation from Open-Pit Highwalls. The intent of this project was to obtain performance data on the ability of four technologies to prevent the gener...

Assessing Health Outcomes After Environmental Exposures Associated With Open Pit Burning in Deployed US Service Members.

PubMed

Rohrbeck, Patricia; Hu, Zheng; Mallon, Col Timothy M

2016-08-01

This study assessed the long-term health impact of environmental exposures associated with open pit burning in deployed US service members. Two hundred individuals deployed to Balad, Iraq, and Bagram, Afghanistan, with known exposure to open pits, were matched to 200 non-deployed service members. Both cohorts were observed for adverse health outcomes after returning from deployment. Slight increased risks were observed for respiratory diseases in the Bagram cohort (adj RR: 1.259), and for cardiovascular disease in the Balad cohort (adj RR: 1.072), but the findings were not significant. The combined deployed cohort showed lower risks for adverse health outcomes, suggesting a healthy deployer effect. In conclusion, this study did not find significantly increased risks for selected health outcomes after burn pit exposure during deployment among two deployed cohorts compared with a non-deployed cohort.

13. DETAIL WEST OF TURBINE PIT SHOWING PIT DRAINED AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. DETAIL WEST OF TURBINE PIT SHOWING PIT DRAINED AND TURBINE EXPOSED. ORIGINAL WATER LEVEL SHOWN BY LINE JUST ABOVE ARCHED OPENING TO LEFT. WATER LINE AFTER 1982 INSTALLATION OF FLASH BOARDS REVEALED BY DARK STAIN. - Middle Creek Hydroelectric Dam, On Middle Creek, West of U.S. Route 15, 3 miles South of Selinsgrove, Selinsgrove, Snyder County, PA

30 CFR 56.3131 - Pit or quarry wall perimeter.

Code of Federal Regulations, 2011 CFR

2011-07-01

... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Ground Control... performing their assigned tasks, loose or unconsolidated material shall be sloped to the angle of repose or...

30 CFR 56.3131 - Pit or quarry wall perimeter.

Code of Federal Regulations, 2010 CFR

2010-07-01

... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Ground Control... performing their assigned tasks, loose or unconsolidated material shall be sloped to the angle of repose or...

Complex Burial and Exhumation of South Polar Cap Pitted Terrain

NASA Technical Reports Server (NTRS)

2000-01-01

This image is illuminated by sunlight from the upper left. The two prominent bright stripes at the left/center of the image are covered with bright frost and thus create the illusion that they are sunlit from the lower left.

The large pits, troughs, and 'swiss cheese' of the south polar residual cap appear to have been formed in the upper 4 or 5 layers of the polar material. Each layer is approximately 2 meters (6.6 feet) thick. Some Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images of this terrain show examples in which older pitted and eroded layers have been previously buried and are now being exhumed. The example shown here includes two narrow, diagonal slopes that trend from upper left toward lower right at the left/center portion of the frame. Along the bottoms of these slopes are revealed a layer that underlies them in which there are many more pits and troughs than in the upper layer. It is likely in this case that the lower layer formed its pits and troughs before it was covered by the upper layer. This observation suggests that the troughs, pits, and 'swiss cheese' features of the south polar cap are very old and form over long time scales.

The picture is located near 84.6oS, 45.1oW, and covers an area 3 km by 5 km (1.9 x 3.1 mi) at a resolution of about 3.8 meters (12 ft) per pixel. The image was taken during southern spring on August 29, 1999.

Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

Newly reported lupus and rheumatoid arthritis in relation to deployment within proximity to a documented open-air burn pit in Iraq.

PubMed

Jones, Kelly A; Smith, Besa; Granado, Nisara S; Boyko, Edward J; Gackstetter, Gary D; Ryan, Margaret A K; Phillips, Christopher J; Smith, Tyler C

2012-06-01

To assess the relationship between possible exposure to smoke from documented open-air burn pits and newly reported lupus and rheumatoid arthritis among Millennium Cohort participants who have deployed in support of operations in Iraq and Afghanistan. Prospectively assessed self-reported lupus and rheumatoid arthritis among deployers who completed both 2004-2006 and 2007-2008 questionnaires. After exclusions, more than 18,000 participants were deployed, including more than 3000 participants deployed within a 3-mile radius of a documented burn pit. After adjustment, proximity within 3 miles of a burn pit was not significantly associated with rheumatoid arthritis or lupus in general; however, one location was associated with lupus, although few cases were at this site (n = 2). Results indicate deployers potentially exposed to documented burn pits in the combined three-camp analysis were not at an elevated risk of lupus or rheumatoid arthritis.

The effects of exposure to documented open-air burn pits on respiratory health among deployers of the Millennium Cohort Study.

PubMed

Smith, Besa; Wong, Charlene A; Boyko, Edward J; Phillips, Christopher J; Gackstetter, Gary D; Ryan, Margaret A K; Smith, Tyler C

2012-06-01

To investigate respiratory illnesses and potential open-air burn pit exposure among Millennium Cohort participants who deployed to Iraq or Afghanistan. Using multivariable logistic regression, newly reported chronic bronchitis or emphysema, newly reported asthma, and self-reported respiratory symptoms and possible burn pit exposure within 2, 3, or 5 miles were examined among Army and Air Force deployers surveyed in 2004 to 2006 and 2007 to 2008 (n = 22,844). Burn pit exposure within 3 or 5 miles was not associated with respiratory outcomes after statistical adjustment. Increased symptom reporting was observed among Air Force deployers located within 2 miles of Joint Base Balad; however, this finding was marginally significant with no evidence of trend. In general, these findings do not support an elevated risk for respiratory outcomes among personnel deployed within proximity of documented burn pits in Iraq.

Prospective assessment of chronic multisymptom illness reporting possibly associated with open-air burn pit smoke exposure in Iraq.

PubMed

Powell, Teresa M; Smith, Tyler C; Jacobson, Isabel G; Boyko, Edward J; Hooper, Tomoko I; Gackstetter, Gary D; Phillips, Christopher J; Smith, Besa

2012-06-01

To investigate the relationship between chronic multisymptom illness (CMI) and possible exposure to an open-air burn pit at three selected bases among those deployed to operations in Iraq and Afghanistan. Chronic multisymptom illness (reporting at least one symptom in at least two of the following symptom constructs: general fatigue; mood and cognition problems; and musculoskeletal discomfort) was assessed, differentiating by potential burn pit exposure, among deployers who completed 2004 and 2007 Millennium Cohort questionnaires. More than 21,000 Cohort participants were deployed in support of the current operations, including more than 3000 participants with at least one deployment within a 3-mile radius of a documented burn pit. After adjusting for covariates, no elevated risk of CMI was observed among those exposed. There was no increase in CMI symptom reporting in those deployed to three selected bases with documented burn pits compared with other deployers.

A Method of Effective Quarry Water Purifying Using Artificial Filtering Arrays

NASA Astrophysics Data System (ADS)

Tyulenev, M.; Garina, E.; Khoreshok, A.; Litvin, O.; Litvin, Y.; Maliukhina, E.

2017-01-01

The development of open pit mining in the large coal basins of Russia and other countries increases their negative impact on the environment. Along with the damage of land and air pollution by dust and combustion gases of blasting, coal pits have a significant negative impact on water resources. Polluted quarry water worsens the ecological situation on a much larger area than covered by air pollution and land damage. This significantly worsens the conditions of people living in cities and towns located near the coal pits, and complicates the subsequent restoration of the environment, irreversibly destroying the nature. Therefore, the research of quarry wastewater purifying is becoming an important mater for scholars of technical colleges and universities in the regions with developing open-pit mining. This paper describes the method of determining the basic parameters of the artificial filtering arrays formed on coal pits of Kuzbass (Western Siberia, Russia), and gives recommendations on its application.

77 FR 22609 - Notice of Intent To Prepare an Environmental Impact Statement for the Proposed Pan Mine Project...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-16

... business hours. SUPPLEMENTARY INFORMATION: Midway Gold US Inc. (Midway) proposes to construct and operate an open-pit gold mining operation, which would include open pits, a heap leach pad, waste rock dumps, and ancillary facilities. The mine would be located in the northern part of the Pancake Mountain Range...

Haulage Truck Operator. Open Pit Mining Job Training Series.

ERIC Educational Resources Information Center

British Columbia Dept. of Education, Victoria.

This training outline for haulage truck operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for…

Rotary Drill Operator. Open Pit Mining Job Training Series.

ERIC Educational Resources Information Center

Savilow, Bill

This training outline for rotary drill operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for…

Track Dozer Operator. Open Pit Mining Job Training Series.

ERIC Educational Resources Information Center

British Columbia Dept. of Education, Victoria.

This training outline for track dozer operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for…

Grader Operator. Open Pit Mining Job Training Series.

ERIC Educational Resources Information Center

Savilow, Bill

This training outline for grader operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for classroom…

Heavy Duty Tireman. Open Pit Mining Job Training Series.

ERIC Educational Resources Information Center

McColman, Don

This training outline for heavy duty tiremen, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for classroom…

Rubber Tire Dozer Operator. Open Pit Mining Job Training Series.

ERIC Educational Resources Information Center

British Columbia Dept. of Education, Victoria.

This training outline for rubber tire dozer operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for…

Front End Loader Operator. Open Pit Mining Job Training Series.

ERIC Educational Resources Information Center

Savilow, Bill

This training outline for front end loader operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for…

Shovel Operator. Open Pit Mining Job Training Series.

ERIC Educational Resources Information Center

Hartley, Larry

This training outline for shovel operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for classroom…

Developing an Ecological Passport for an Open-Pit Dump Truck to Reduce Negative Effect on Environment

NASA Astrophysics Data System (ADS)

Koptev, V. Yu; Kopteva, A. V.

2017-05-01

Expanding the open-pit dump truck usage areas and the need to transport more and more minerals results in producing more and more powerful open-pit dump trucks, and this all is about environmental problems and potential health risks for the personnel. Harmful gas concentrations in working areas became threatening enough to have the work in some areas completely halted, until the contents of harmful substances in the air, as well as visibility on the roads, get back to norm. The article represents the new methodology for assessing comparatively the efficiency of modern transportation systems with performance and ecology characteristics taken into account, by developing an ecological passport for machines, facilitating design improvements and reducing pollution during operation.

Selenium bioaccumulation in stocked fish as an indicator of fishery potential in pit lakes on reclaimed coal mines in Alberta, Canada.

PubMed

Miller, L L; Rasmussen, J B; Palace, V P; Sterling, G; Hontela, A

2013-07-01

Pit lakes are a common reclamation strategy for open pit mines; however, there is a concern about their water quality and suitability as fish habitat because they are often contaminated by metals or metalloids. This study assessed the exposure of fish and invertebrates to selenium (Se) and other metals and metalloids in pit lakes formed by open pit coal mining in Tertiary (thermal coal) and in Cretaceous (metallurgical coal) bedrock. Juvenile hatchery rainbow trout, Oncorhynchus mykiss, and brook trout, Salvelinus fontinalis, were stocked into two thermal coal pit lakes (water Se < 2 μg/L, low water Se) and two metallurgical coal pit lakes (water Se > 15 μg/L, high water Se). Se accumulation in stocked fish and concentrations in invertebrates were characterized over a period of 2 years. In the metallurgical pits, invertebrates had higher Se concentrations and fish accumulated Se to higher levels (exceeding USEPA tissue Se guidelines) than biota in the thermal pits. Rainbow and brook trout accumulated similar concentrations of Se in their muscle and exhibited a similar relationship between whole-body and muscle Se concentrations. These results may be used by resource managers to assess compliance with whole-body tissue Se guidelines and to determine if pit lakes in coal mining areas pose a significant Se risk to wildlife or human health. The high Se exposure in metallurgical coal pits indicates that under the current mining and reclamation strategy, these lakes are not suitable for management as recreational "put and take" fisheries.

What Is a Hill? An Analysis of the Meanings of Generic Topographic Terms

DTIC Science & Technology

1985-08-01

to describe the di,.ferent characters of forms. FLAT: An area or surface with gantle, non-varying slope, that is highly platykurtic but not...Slo;e Change Index value of zero. ROLLING: A surface without elevated or Inverted forms, with platykurtic slo a Slope Ctange Index value of zero and...and contour planes of similar extent. POCKMARKEC (pitted): A surface that has within its contour repeated, small, circular or elliptical platykurtic

An open source GIS-based tool to integrate the fragmentation mechanism in rockfall propagation

NASA Astrophysics Data System (ADS)

Matas, Gerard; Lantada, Nieves; Gili, Josep A.; Corominas, Jordi

2015-04-01

Rockfalls are frequent instability processes in road cuts, open pit mines and quarries, steep slopes and cliffs. Even though the stability of rock slopes can be determined using analytical approaches, the assessment of large rock cliffs require simplifying assumptions due to the difficulty of working with a large amount of joints, the scattering of both the orientations and strength parameters. The attitude and persistency of joints within the rock mass define the size of kinematically unstable rock volumes. Furthermore the rock block will eventually split in several fragments during its propagation downhill due its impact with the ground surface. Knowledge of the size, energy, trajectory… of each block resulting from fragmentation is critical in determining the vulnerability of buildings and protection structures. The objective of this contribution is to present a simple and open source tool to simulate the fragmentation mechanism in rockfall propagation models and in the calculation of impact energies. This tool includes common modes of motion for falling boulders based on the previous literature. The final tool is being implemented in a GIS (Geographic Information Systems) using open source Python programming. The tool under development will be simple, modular, compatible with any GIS environment, open source, able to model rockfalls phenomena correctly. It could be used in any area susceptible to rockfalls with a previous adjustment of the parameters. After the adjustment of the model parameters to a given area, a simulation could be performed to obtain maps of kinetic energy, frequency, stopping density and passing heights. This GIS-based tool and the analysis of the fragmentation laws using data collected from recent rockfall have being developed within the RockRisk Project (2014-2016). This project is funded by the Spanish Ministerio de Economía y Competitividad and entitled "Rockfalls in cliffs: risk quantification and its prevention"(BIA2013-42582-P).

Pit membranes of Ephedra resemble gymnosperms more than angiosperms

Treesearch

Roland Dute; Lauren Bowen; Sarah Schier; Alexa Vevon; Troy Best; Maria Auad; Thomas Elder; Pauline Bouche; Steven Jansen

2014-01-01

Bordered pit pairs of Ephedra species were characterized using different types of microscopy. Pit membranes contained tori that did not stain for lignin. SEM and AFM views of the torus surface showed no plasmodesmatal openings, but branched, secondary plasmodesmata were occasionally noted using TEM in conjunction with ultrathin sections. The margo consisted of radial...

Distribution, morphology, and origins of Martian pit crater chains

NASA Astrophysics Data System (ADS)

Wyrick, Danielle; Ferrill, David A.; Morris, Alan P.; Colton, Shannon L.; Sims, Darrell W.

2004-06-01

Pit craters are circular to elliptical depressions found in alignments (chains), which in many cases coalesce into linear troughs. They are common on the surface of Mars and similar to features observed on Earth and other terrestrial bodies. Pit craters lack an elevated rim, ejecta deposits, or lava flows that are associated with impact craters or calderas. It is generally agreed that the pits are formed by collapse into a subsurface cavity or explosive eruption. Hypotheses regarding the formation of pit crater chains require development of a substantial subsurface void to accommodate collapse of the overlying material. Suggested mechanisms of formation include: collapsed lava tubes, dike swarms, collapsed magma chamber, substrate dissolution (analogous to terrestrial karst), fissuring beneath loose material, and dilational faulting. The research described here is intended to constrain current interpretations of pit crater chain formation by analyzing their distribution and morphology. The western hemisphere of Mars was systematically mapped using Mars Orbiter Camera (MOC) images to generate ArcView™ Geographic Information System (GIS) coverages. All visible pit crater chains were mapped, including their orientations and associations with other structures. We found that pit chains commonly occur in areas that show regional extension or local fissuring. There is a strong correlation between pit chains and fault-bounded grabens. Frequently, there are transitions along strike from (1) visible faulting to (2) faults and pits to (3) pits alone. We performed a detailed quantitative analysis of pit crater morphology using MOC narrow angle images, Thermal Emission Imaging System (THEMIS) visual images, and Mars Orbiter Laser Altimeter (MOLA) data. This allowed us to determine a pattern of pit chain evolution and calculate pit depth, slope, and volume. Volumes of approximately 150 pits from five areas were calculated to determine volume size distribution and regional trends. The information collected in the study was then compared with non-Martian examples of pit chains and physical analog models. We evaluated the various mechanisms for pit chain development based on the data collected and conclude that dilational normal faulting and sub-vertical fissuring provide the simplest and most comprehensive mechanisms to explain the regional associations, detailed geometry, and progression of pit chain development.

A decision support system using analytical hierarchy process (AHP) for the optimal environmental reclamation of an open-pit mine

NASA Astrophysics Data System (ADS)

Bascetin, A.

2007-04-01

The selection of an optimal reclamation method is one of the most important factors in open-pit design and production planning. It also affects economic considerations in open-pit design as a function of plan location and depth. Furthermore, the selection is a complex multi-person, multi-criteria decision problem. The group decision-making process can be improved by applying a systematic and logical approach to assess the priorities based on the inputs of several specialists from different functional areas within the mine company. The analytical hierarchy process (AHP) can be very useful in involving several decision makers with different conflicting objectives to arrive at a consensus decision. In this paper, the selection of an optimal reclamation method using an AHP-based model was evaluated for coal production in an open-pit coal mine located at Seyitomer region in Turkey. The use of the proposed model indicates that it can be applied to improve the group decision making in selecting a reclamation method that satisfies optimal specifications. Also, it is found that the decision process is systematic and using the proposed model can reduce the time taken to select a optimal method.

Ensuring the Environmental and Industrial Safety in Solid Mineral Deposit Surface Mining

NASA Astrophysics Data System (ADS)

Trubetskoy, Kliment; Rylnikova, Marina; Esina, Ekaterina

2017-11-01

The growing environmental pressure of mineral deposit surface mining and severization of industrial safety requirements dictate the necessity of refining the regulatory framework governing safe and efficient development of underground resources. The applicable regulatory documentation governing the procedure of ore open-pit wall and bench stability design for the stage of pit reaching its final boundary was issued several decades ago. Over recent decades, mining and geomechanical conditions have changed significantly in surface mining operations, numerous new software packages and computer developments have appeared, opportunities of experimental methods of source data collection and processing, grounding of the permissible parameters of open pit walls have changed dramatically, and, thus, methods of risk assessment have been perfected [10-13]. IPKON RAS, with the support of the Federal Service for Environmental Supervision, assumed the role of the initiator of the project for the development of Federal norms and regulations of industrial safety "Rules for ensuring the stability of walls and benches of open pits, open-cast mines and spoil banks", which contribute to the improvement of economic efficiency and safety of mineral deposit surface mining and enhancement of the competitiveness of Russian mines at the international level that is very important in the current situation.

Functional Quality Criterion of Rock Handling Mechanization at Open-pit Mines

NASA Astrophysics Data System (ADS)

Voronov, Yuri; Voronov, Artyoni

2017-11-01

Overburden and mining operations at open-pit mines are performed mainly by powerful shovel-truck systems (STSs). One of the main problems of the STSs is a rather low level of their operating quality, mainly due to unjustified over-trucking. In this article, a functional criterion for assessing the qualify of the STS operation at open-pit mines is formulated, derived and analyzed. We introduce the rationale and general principles for the functional criterion formation, its general form, as well as variations for various STS structures: a mixed truck fleet and a homogeneous shovel fleet, a mixed shove! fleet and a homogeneous truck fleet, mixed truck and shovel fleets. The possibility of assessing the quality of the STS operation is of great importance for identifying the main directions for improving their operational performance and operating quality, optimizing the main performance indicators by the qualify criterion, and. as a result, for possible saving of material and technical resources for open-pit mining. Improvement of the quality of the STS operation also allows increasing the mining safety and decreasing the atmosphere pollution - by means of possible reducing of the number of the operating trucks.

Credit PSR. This view looks northeast (54°) at the open ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Credit PSR. This view looks northeast (54°) at the open burn unit as it is seen on approach from Circle Drive. The metal shed in front of the earth mound personnel shield contained controls for a stove that was formerly used to burn scrap propellants in the adjacent pit (see HAER photo CA163-V-1). Regulations changed to permit open pit burning of such materials - Jet Propulsion Laboratory Edwards Facility, Incinerator, Edwards Air Force Base, Boron, Kern County, CA

Relationship between the Foveal Avascular Zone and Foveal Pit Morphology

PubMed Central

Dubis, Adam M.; Hansen, Benjamin R.; Cooper, Robert F.; Beringer, Joseph; Dubra, Alfredo; Carroll, Joseph

2012-01-01

Purpose. To assess the relationship between foveal pit morphology and size of the foveal avascular zone (FAZ). Methods. Forty-two subjects were recruited. Volumetric images of the macula were obtained using spectral domain optical coherence tomography. Images of the FAZ were obtained using either a modified fundus camera or an adaptive optics scanning light ophthalmoscope. Foveal pit metrics (depth, diameter, slope, volume, and area) were automatically extracted from retinal thickness data, whereas the FAZ was manually segmented by two observers to extract estimates of FAZ diameter and area. Results. Consistent with previous reports, the authors observed significant variation in foveal pit morphology. The average foveal pit volume was 0.081 mm3 (range, 0.022 to 0.190 mm3). The size of the FAZ was also highly variable between persons, with FAZ area ranging from 0.05 to 1.05 mm2 and FAZ diameter ranging from 0.20 to 1.08 mm. FAZ area was significantly correlated with foveal pit area, depth, and volume; deeper and broader foveal pits were associated with larger FAZs. Conclusions. Although these results are consistent with predictions from existing models of foveal development, more work is needed to confirm the developmental link between the size of the FAZ and the degree of foveal pit excavation. In addition, more work is needed to understand the relationship between these and other anatomic features of the human foveal region, including peak cone density, rod-free zone diameter, and Henle fiber layer. PMID:22323466

Primitive environment control for preservation of pit relics in archeology museums of China.

PubMed

Gu, Zhaolin; Luo, Xilian; Meng, Xiangzhao; Wang, Zanshe; Ma, Tao; Yu, Chuck; Rong, Bo; Li, Ku; Li, Wenwu; Tan, Ying

2013-02-05

Immovable historical relics in some archeology museums of China suffer deterioration due to their improper preservation environment. The existing environmental control systems used in archeology museums are often designed for the amenities of visitors, and these manipulated environments are often inappropriate for the conservation of abiotic relics. This paper points out that the large open space of the existing archeology museum could be a cause of deterioration of the relics from the point of view of indoor air convective flow. The paper illustrates the need to introduce a local pit environmental control, which could reintegrate a pit primitive environment for the preservation of the historical relics by using an air curtain system, orientated to isolate the unearthed relics, semiexposed in pits to the large gallery open space of the exhibition hall.

A Comprehensive Pitting Study of High Velocity Oxygen Fuel Inconel 625 Coating by Using Electrochemical Testing Techniques

NASA Astrophysics Data System (ADS)

Niaz, Akbar; Khan, Sajid Ullah

2016-01-01

In the present work, Inconel 625 was coated on a mild steel substrate using a high velocity oxygen fuel coating process. The pitting propensity of the coating was tested by using open circuit potential versus time, potentiodynamic polarization, electrochemical potentiokinetic reactivation, and scanning electrochemical microscopy. The pitting propensity of the coating was compared with bulk Inconel 625 alloy. The results confirmed that there were regions of different electrochemical activities on the coating which have caused pitting corrosion.

Quantification of proportions of different water sources in a mining operation.

PubMed

Scheiber, Laura; Ayora, Carlos; Vázquez-Suñé, Enric

2018-04-01

The water drained in mining operations (galleries, shafts, open pits) usually comes from different sources. Evaluating the contribution of these sources is very often necessary for water management. To determine mixing ratios, a conventional mass balance is often used. However, the presence of more than two sources creates uncertainties in mass balance applications. Moreover, the composition of the end-members is not commonly known with certainty and/or can vary in space and time. In this paper, we propose a powerful tool for solving such problems and managing groundwater in mining sites based on multivariate statistical analysis. This approach was applied to the Cobre Las Cruces mining complex, the largest copper mine in Europe. There, the open pit water is a mixture of three end-members: runoff (RO), basal Miocene (Mb) and Paleozoic (PZ) groundwater. The volume of water drained from the Miocene base aquifer must be determined and compensated via artificial recharging to comply with current regulations. Through multivariate statistical analysis of samples from a regional field campaign, the compositions of PZ and Mb end-members were firstly estimated, and then used for mixing calculations at the open pit scale. The runoff end-member was directly determined from samples collected in interception trenches inside the open pit. The application of multivariate statistical methods allowed the estimation of mixing ratios for the hydrological years 2014-2015 and 2015-2016. Open pit water proportions have changed from 15% to 7%, 41% to 36%, and 44% to 57% for runoff, Mb and PZ end-members, respectively. An independent estimation of runoff based on the curve method yielded comparable results. Copyright © 2017 Elsevier B.V. All rights reserved.

Record of Technical Change 2 for Closure Report for Corrective Action Unit 204: Storage Bunkers, Nevada Test Site, Nevada, Revision 0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krauss, Mark J.; Birney, Cathleen

2006-04-01

CAS 05-33-01, Kay Blockhouse, consists of an area of approximately 11 acres and includes the Kay Blockhouse, two bum pits with steel frames, one bum pit with a soil berm, two open pits, two steel-lined subsurface pits, one berm with embedded piping, one berm with piping debris, a burn area with a large concrete block with an embedded steel prong, and one open pit with a concrete foundation at the north end. The Kay Blockhouse was constructed in 1951 and was used as an instrumentation bunker for Operation Ranger, a series of five atmospheric nuclear tests. The burn pits andmore » other surface features within the CAS boundary were not part of the nuclear testing. The Kay Blockhouse is constructed of concrete with a wooden entryway door. The details of the construction of the floor are unknown (NNSA/NSO, 2004b). During closure activities, lead- and radiologically impacted soil was removed, and verification samples were collected. Friable asbestos material was removed from the burn pits; the asbestos and steel frames from the bum pits were disposed of at the Area 23 Sanitary Landfill. In addition, the two steel-lined pits were filled with native soil and capped with 1.5 ft of concrete. The bunker was secured by installing security fencing and a gate around the entrance to the bunker. The RMA was reestablished and fenced with T-post and wire-rope fencing (NNSA/NSO, 2006a).« less

Proceedings of GeoTech 85: Personal computers in geology conference

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1985-01-01

This book presents the papers given at a conference which considered the use of microprocessors in the exploration of petroleum and natural gas deposits. Topics covered at the conference included seismic surveys, geochemistry, expert systems, artificial intelligence, data base management systems, a portable exploration work station, open pit planning on a microcomputer, well logging, fracture analysis, production scheduling of open pit mines, resistivity logging, and coal washability.

Evaluation of groundwater pollution in a mining area using analytical solution: a case study of the Yimin open-pit mine in China.

PubMed

Li, Tianxin; Li, Li; Song, Hongqing; Meng, Linglong; Zhang, Shuli; Huang, Gang

2016-01-01

This study focused on using analytical and numerical models to develop and manage groundwater resources, and predict the effects of management measurements in the groundwater system. Movement of contaminants can be studied based on groundwater flow characteristics. This study can be used for prediction of ion concentration and evaluation of groundwater pollution as the theoretical basis. The Yimin open-pit mine is located in the northern part of the Inner Mongolia Autonomous Region of China. High concentrations of iron and manganese are observed in Yimin open-pit mine because of exploitation and pumping that have increased the concentration of the ions in groundwater. In this study, iron was considered as an index of contamination, and the solute model was calibrated using concentration observations from 14 wells in 2014. The groundwater flow model and analytical solutions were used in this study to forecast pollution concentration and variation trend after calibration. With continuous pumping, contaminants will migrate, and become enriched, towards the wellhead in the flow direction. The concentration of the contaminants and the range of pollution increase with the flow rate increased. The suitable flow rate of single well should be <380 m/day at Yimin open-pit for the standard value of pollution concentration.

Copper Tube Pitting in Santa Fe Municipal Water Caused by Microbial Induced Corrosion.

PubMed

Burleigh, Thomas D; Gierke, Casey G; Fredj, Narjes; Boston, Penelope J

2014-06-05

Many copper water lines for municipal drinking water in Santa Fe, New Mexico USA, have developed pinhole leaks. The pitting matches the description of Type I pitting of copper, which has historically been attributed to water chemistry and to contaminants on the copper tubing surface. However, more recent studies attribute copper pitting to microbial induced corrosion (MIC). In order to test for microbes, the copper tubing was fixed in hexamethyldisilazane (HMDS), then the tops of the corrosion mounds were broken open, and the interior of the corrosion pits were examined with scanning electron microscopy (SEM). The analysis found that microbes resembling actinobacteria were deep inside the pits and wedged between the crystallographic planes of the corroded copper grains. The presence of actinobacteria confirms the possibility that the cause of this pitting corrosion was MIC. This observation provides better understanding and new methods for preventing the pitting of copper tubing in municipal water.

Copper Tube Pitting in Santa Fe Municipal Water Caused by Microbial Induced Corrosion

PubMed Central

Burleigh, Thomas D.; Gierke, Casey G.; Fredj, Narjes; Boston, Penelope J.

2014-01-01

Many copper water lines for municipal drinking water in Santa Fe, New Mexico USA, have developed pinhole leaks. The pitting matches the description of Type I pitting of copper, which has historically been attributed to water chemistry and to contaminants on the copper tubing surface. However, more recent studies attribute copper pitting to microbial induced corrosion (MIC). In order to test for microbes, the copper tubing was fixed in hexamethyldisilazane (HMDS), then the tops of the corrosion mounds were broken open, and the interior of the corrosion pits were examined with scanning electron microscopy (SEM). The analysis found that microbes resembling actinobacteria were deep inside the pits and wedged between the crystallographic planes of the corroded copper grains. The presence of actinobacteria confirms the possibility that the cause of this pitting corrosion was MIC. This observation provides better understanding and new methods for preventing the pitting of copper tubing in municipal water. PMID:28788679

Faunalpedturbation effects on soil microarthropods in the Negev Desert

USDA-ARS?s Scientific Manuscript database

Soil microarthropod communities in seed-harvester ant-nest (Messor spp.) soils and pits excavated by porcupines (Hystrix indica) were examined on a hill-slope catena in the Negev Desert to test the hypothesis that animal-produced soil disturbances increase abundance and diversity of soil biota. Ther...

Group traction drive as means to increase energy efficiency of lokomotives of open-pit transport

NASA Astrophysics Data System (ADS)

Antipin, D. Ya; Izmerov, O. V.; Bishutin, S. G.; Kobishchanov, V. V.

2017-10-01

Questions of possible use of a group drive for locomotives of an open-pit transport are considered. The possibility of a significant reduction of traction costs in the case of a combination of a group traction drive with devices for the non-inertial regulation of the coefficient of friction between the wheel and the rail has been shown, and new patentable solutions have been proposed.

Earth Observations taken by the Expedition 13 crew

NASA Image and Video Library

2006-08-02

ISS013-E-63766 (2 Aug. 2006) --- Berkeley Pit and Butte, Montana are featured in this image photographed by an Expedition 13 crewmember on the International Space Station. The city of Butte, Montana has long been a center of mining activity. Underground mining of copper began in Butte in the 1870s, and by 1901 underground workings had extended to the groundwater table. Thus began the creation of an intricate complex of underground drains and pumps to lower the groundwater level and continue the extraction of copper. Water extracted from the mines was so rich in dissolved copper sulfate that it was also "mined" (by chemical precipitation) for the copper it contained. In 1955, the Anaconda Copper Mining Company began open-pit mining for copper in what is now know as the Berkeley Pit (dark oblong area in center). The mine took advantage of the existing subterranean drainage and pump network to lower groundwater until 1982, when the new owner ARCO suspended operations at the mine. The groundwater level swiftly rose, and today water in the Pit is more than 900 feet deep. Many features of the mine workings are visible in this image such as the many terraced levels and access roadways of the open mine pits (gray and tan sculptured surfaces). A large gray tailings pile of waste rock and an adjacent tailings pond are visible to the north of the Berkeley Pit. Color changes in the tailings pond are due primarily to changing water depth. The Berkeley Pit is listed as a federal Superfund site due to its highly acidic water, which contains high concentrations of metals such as copper and zinc. The Berkeley Pit receives groundwater flowing through the surrounding bedrock and acts as a "terminal pit" or sink for these heavy metal-laden waters. Ongoing efforts include regulation of water flow into the pit to reduce filling of the Pit and potential release of contaminated water into local aquifers or surface streams.

Contaminant dispersion at the rehabilitated Mary Kathleen uranium mine, Australia

NASA Astrophysics Data System (ADS)

Lottermoser, B. G.; Ashley, P. M.; Costelloe, M. T.

2005-09-01

This study reports on the transfer of contaminants from waste rock dumps and mineralised ground into soils, sediments, waters and plants at the rehabilitated Mary Kathleen uranium mine in semi-arid northwest Queensland. Numerous waste rock dumps were partly covered with benign soil and the open pit mine was allowed to flood. The mineralised and waste calc-silicate rock in the open pit and dumps has major (>1 wt%) Ca, Fe and Mg, minor (>1,000 ppm) Ce, La, Mn, P and S, subminor (>100 ppm) Ba, Cu, Th and U, and trace (<100 ppm) As, Ni, Pb, Y and Zn values. Consequently, chemical and physical weathering processes have acted on waste rock and on rock faces within the open pit, mobilising many elements and leading to their dispersion into soils, stream sediments, pit water and several plant species. Chemical dispersion is initiated by sulfide mineral breakdown, generation of sulfuric acid and formation of several soluble, transient sulfate minerals as evaporative efflorescent precipitates. Radiation doses associated with the open pit average 5.65 mSv year-1; waste dumps commonly have lower values, especially where soil-covered. Surface pit water is slightly acid, with high sulfate values accompanied by levels of U, Cu and Ni close to or above Australian water guideline values for livestock. Dispersion of U and related elements into soils and stream sediments occurs by physical (erosional) processes and from chemical precipitation. Plants growing in the mine void, on waste dumps and contaminated soil display evidence of biological uptake of U, LREE, Cu and Th and to a lesser degree of As, Ni, Pb, Y and Zn, with values being up to 1-2 orders of magnitude above background sites for the same species. Although rehabilitation procedures have been partly successful in reducing dispersion of U and related elements into the surrounding environment, it is apparent that 20 years after rehabilitation, there is significant physical and chemical mobility, including transfer into plants.

Landscape monitoring of post-industrial areas using LiDAR and GIS technology

NASA Astrophysics Data System (ADS)

Wężyk, Piotr; Szostak, Marta; Krzaklewski, Wojciech; Pająk, Marek; Pierzchalski, Marcin; Szwed, Piotr; Hawryło, Paweł; Ratajczak, Michał

2015-06-01

The quarrying industry is changing the local landscape, forming deep open pits and spoil heaps in close proximity to them, especially lignite mines. The impact can include toxic soil material (low pH, heavy metals, oxidations etc.) which is the basis for further reclamation and afforestation. Forests that stand on spoil heaps have very different growth conditions because of the relief (slope, aspect, wind and rainfall shadows, supply of solar energy, etc.) and type of soil that is deposited. Airborne laser scanning (ALS) technology deliver point clouds (XYZ) and derivatives as raster height models (DTM, DSM, nDSM=CHM) which allow the reception of selected 2D and 3D forest parameters (e.g. height, base of the crown, cover, density, volume, biomass, etc). The automation of ALS point cloud processing and integrating the results into GIS helps forest managers to take appropriate decisions on silvicultural treatments in areas with failed plantations (toxic soil, droughts on south-facing slopes; landslides, etc.) or as regular maintenance. The ISOK country-wide project ongoing in Poland will soon deliver ALS point cloud data which can be successfully used for the monitoring and management of many thousands of hectares of destroyed post-industrial areas which according to the law, have to be afforested and transferred back to the State Forest.

Trace metal depositional patterns from an open pit mining activity as revealed by archived avian gizzard contents.

PubMed

Bendell, L I

2011-02-15

Archived samples of blue grouse (Dendragapus obscurus) gizzard contents, inclusive of grit, collected yearly between 1959 and 1970 were analyzed for cadmium, lead, zinc, and copper content. Approximately halfway through the 12-year sampling period, an open-pit copper mine began activities, then ceased operations 2 years later. Thus the archived samples provided a unique opportunity to determine if avian gizzard contents, inclusive of grit, could reveal patterns in the anthropogenic deposition of trace metals associated with mining activities. Gizzard concentrations of cadmium and copper strongly coincided with the onset of opening and the closing of the pit mining activity. Gizzard zinc and lead demonstrated significant among year variation; however, maximum concentrations did not correlate to mining activity. The archived gizzard contents did provide a useful tool for documenting trends in metal depositional patterns related to an anthropogenic activity. Further, blue grouse ingesting grit particles during the time of active mining activity would have been exposed to toxicologically significant levels of cadmium. Gizzard lead concentrations were also of toxicological significance but not related to mining activity. This type of "pulse" toxic metal exposure as a consequence of open-pit mining activity would not necessarily have been revealed through a "snap-shot" of soil, plant or avian tissue trace metal analysis post-mining activity. Copyright © 2010 Elsevier B.V. All rights reserved.

Earth Observation taken during the Expedition 37 mission

NASA Image and Video Library

2013-10-30

ISS037-E-022990 (30 Oct. 2013) --- This detailed image, photographed by an Expedition 37 crew member on the International Space Station, features the former US Borax mine located to the northwest of Boron, California. The mine, currently owned by the Rio Tinto Group, is the largest open-pit mine in California (covering approximately 54 square kilometers) and is among the largest borate mines in the world. Borates, chemical compounds that include the element boron (B), are important both as providers of an essential plant micronutrient, for metallurgical applications, and as components of specialized types of glass, anticorrosive coatings, fire retardants, and detergents (among other uses). Borate minerals such as borax, kernite, and ulexite are found in deposits at the Rio Tinto borax mine. The geologic setting is a structural, nonmarine basin ? a permanent shallow lake ? fed by thermal springs rich in sodium and boron that existed approximately 16 million years ago, according to scientists. The first mining claim in the area was filed in 1913, following discovery of boron-bearing nodules during well drilling. Much of the mine workings were underground until 1957, when US Borax changed to open-pit mining. The open pit is clearly visible at center; concentric benches along the pit wall are accentuated by shadows and mark successive levels of material extraction. Mine tailings are visible as stacked terraces along the northern boundary of the mine. Ore processing facilities occupy a relatively small percentage of the mine area, and are located directly to the west of the open pit. The Rio Tinto mine is one of the Earth?s richest borate deposits; together with mines in Argentina, they produce almost 40 percent of the world?s supply of industrial borate minerals.

Well-Preserved Impact Ejecta and Impact Melt-Rich Deposits in Terra Sabaea

NASA Image and Video Library

2017-01-12

This image of a well-preserved unnamed elliptical crater in Terra Sabaea, is illustrative of the complexity of ejecta deposits forming as a by-product of the impact process that shapes much of the surface of Mars. Here we see a portion of the western ejecta deposits emanating from a 10-kilometer impact crater that occurs within the wall of a larger, 60-kilometer-wide crater. In the central part is a lobe-shaped portion of the ejecta blanket from the smaller crater. The crater is elliptical not because of an angled (oblique) impact, but because it occurred on the steep slopes of the wall of a larger crater. This caused it to be truncated along the slope and elongated perpendicular to the slope. As a result, any impact melt from the smaller crater would have preferentially deposited down slope and towards the floor of the larger crater (towards the west). Within this deposit, we can see fine-scale morphological features in the form of a dense network of small ridges and pits. These crater-related pitted materials are consistent with volatile-rich impact melt-bearing deposits seen in some of the best-preserved craters on Mars (e.g., Zumba, Zunil, etc.). These deposits formed immediately after the impact event, and their discernible presence relate to the preservation state of the crater. This image is an attempt to visualize the complex formation and emplacement history of these enigmatic deposits formed by this elliptical crater and to understand its degradation history. http://photojournal.jpl.nasa.gov/catalog/PIA13078

On the influence of etch pits in the overall dissolution rate of apatite basal sections

NASA Astrophysics Data System (ADS)

Alencar, Igor; Guedes, Sandro; Palissari, Rosane; Hadler, Julio C.

2015-09-01

Determination of efficiencies for particle detection plays a central role for proper estimation of reaction rates. If chemical etching is employed in the revelation of latent particle tracks in solid-state detectors, dissolution rates and etchable lengths are important factors governing the revelation and observation. In this work, the mask method, where a reference part of the sample is protected during dissolution, was employed to measure step heights in basal sections of apatite etched with a nitric acid, HNO, solution at a concentration of 1.1 M and a temperature of 20 °C. We show a drastic increase in the etching velocity as the number of etch pits in the surface augments, in accordance with the dissolution stepwave model, where the outcrop of each etch pit generates a continuous sequence of stepwaves. The number of etch pits was varied by irradiation with neutrons and perpendicularly incident heavy ions. The size dependence of the etch-pit opening with etching duration for ion (200-300 MeV 152Sm and 238U) tracks was also investigated. There is no distinction for the etch pits between the different ions, and the dissolution seems to be governed by the opening velocity when a high number of etch pits are present in the surface. Measurements of the etchable lengths of these ion tracks show an increase in these lengths when samples are not pre-annealed before irradiation. We discuss the implications of these findings for fission-track modelling.

Uranium mining wastes, garden exhibition and health risks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmidt, Gerhard; Schmidt, Peter; Hinz, Wilko

2007-07-01

Available in abstract form only. Full text of publication follows: For more than 40 years the Soviet-German stockholding company SDAG WISMUT mined and milled Uranium in the East of Germany and became up to 1990 the world's third largest Uranium producer. After reunification of Germany, the new found state own company Wismut GmbH was faced with the task of decommissioning and rehabilitation of the mining and milling sites. One of the largest mining areas in the world, that had to be cleaned up, was located close to the municipality of Ronneburg near the City of Gera in Thuringia. After closingmore » the operations of the Ronneburg underground mine and at the 160 m deep open pit mine with a free volume of 84 Mio.m{sup 3}, the open pit and 7 large piles of mine waste, together 112 Mio.m{sup 3} of material, had to be cleaned up. As a result of an optimisation procedure it was chosen to relocate the waste rock piles back into the open pit. After taking this decision and approval of the plan the disposal operation was started. Even though the transport task was done by large trucks, this took 16 years. The work will be finished in 2007, a cover consisting of 40 cm of uncontaminated material will be placed on top of the material, and the re-vegetation of the former open pit area will be established. When in 2002 the City of Gera applied to host the largest garden exhibition in Germany, Bundesgartenschau (BUGA), in 2007, Wismut GmbH supported this plan by offering parts of the territory of the former mining site as an exhibition ground. Finally, it was decided by the BUGA organizers to arrange its 2007 exhibition on grounds in Gera and in the valley adjacent to the former open pit mine, with parts of the remediated area within the fence of the exhibition. (authors)« less

Construction integrity assessment report (ETN-98-0005) S-Farm overground transfer (OGT) system valve pit 241-S-B to valve pit 241-S-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

HICKS, D.F.

1999-08-12

The S-Farm overground transfer (OGT) line will bypass the existing line(s), between valve pits 241-S-B and 241-S-D that no longer meet system requirements. The new OGT line will provide a waste transfer pipeline between these valve pits in support of saltwell pumping activities. The length of the OGT line is approximately 180 ft from pit to pit. The primary pipe is nominal 1-in. diameter stainless steel (SST) braided Ethylene-propylene Diene Monomer (EPDM) hose. The encasement pipe is a nominal 3-in., flanged, SST pipe made up of several different length pipe spool pieces (drawing H-2-829564, sh. 1 and sh. 2). Themore » OGT line slopes from valve pit 241-S-B toward valve pit 241-S-D. At each end, the primary and encasement pipe connect to a pit entry spool piece. The pit entry spool pieces are constructed of prefabricated SST materials. These spool pieces allow for the separation of the primary and encasement pipelines after the pipes have entered the valve pits (drawing H-2-818280, sh. 2). The pit entry spool pieces also allow for leak detection of the encasement pipe at each end (drawing H-2-829564, sh. 2). The OGT encasement pipeline is supported above ground by adjustable height unistrut brackets and precast concrete bases (drawing H-2-829654, sh. 1). The pipeline is heat-traced and insulated. The heat tracing and insulation supply and retain latent heat that prevents waste solidification during transfers and provides freeze protection. The total length of the pipeline is above ground, thereby negating the need for cathodic corrosion protection. This Construction Integrity Assessment Report (CIAR) is prepared by Fluor Daniel Northwest for Numatec Hanford Corporation/Lockheed Martin Hanford Corporation, the operations contractor, and the U. S. Department of Energy, the system owner. The CIAR is intended to verify that construction was performed in accordance with the provisions of Washington Administrative Code, WAC-173-303-640 (3) (c), (e), (f) and (h).« less

The effect of plate position and size on tibial slope in high tibial osteotomy: a cadaveric study.

PubMed

Rubino, L Joseph; Schoderbek, Robert J; Golish, S Raymond; Baumfeld, Joshua; Miller, Mark D

2008-01-01

Opening wedge high tibial osteotomies are performed for degenerative changes and varus. Opening wedge osteotomies can change proximal tibial slope in the sagittal plane, possibly imparting stability in the ACL-deficient knee. The aim of this study was to assess the effect of plate position and size on change in tibial slope. Eight cadaveric knees underwent opening wedge high tibial osteotomy with Puddu plates of each different size. Plates were placed anterior, central, and posterior for each size used. Lateral radiographs were obtained. Tibial slope was measured and compared with baseline slope. Tibial slope was affected by plate position (P < 0.05) and size (P < 0.001). Smaller, posterior plates had less effect on tibial slope. However, anterior and central plates increased tibial slope over all plate sizes (P < 0.05). This study found that tibial slope increases with opening wedge high tibial osteotomy. Larger corrections and anterior placement of the plate are associated with larger increases in slope.

Stochastic production phase design for an open pit mining complex with multiple processing streams

NASA Astrophysics Data System (ADS)

Asad, Mohammad Waqar Ali; Dimitrakopoulos, Roussos; van Eldert, Jeroen

2014-08-01

In a mining complex, the mine is a source of supply of valuable material (ore) to a number of processes that convert the raw ore to a saleable product or a metal concentrate for production of the refined metal. In this context, expected variation in metal content throughout the extent of the orebody defines the inherent uncertainty in the supply of ore, which impacts the subsequent ore and metal production targets. Traditional optimization methods for designing production phases and ultimate pit limit of an open pit mine not only ignore the uncertainty in metal content, but, in addition, commonly assume that the mine delivers ore to a single processing facility. A stochastic network flow approach is proposed that jointly integrates uncertainty in supply of ore and multiple ore destinations into the development of production phase design and ultimate pit limit. An application at a copper mine demonstrates the intricacies of the new approach. The case study shows a 14% higher discounted cash flow when compared to the traditional approach.

Chiquicamata Mine, Chile

NASA Image and Video Library

2016-08-24

Chuquicamata, in Chile's Atacama Desert, is the largest open pit copper mine in the world, by excavated volume. The copper deposits were first exploited in pre-Hispanic times. Open pit mining began in the early 20th century when a method was developed to work low grade oxidized copper ores. The image was acquired September 2, 2007, covers an area of 19.5 by 29.3 km, and is located at 22.1 degrees south, 68.9 degrees west. http://photojournal.jpl.nasa.gov/catalog/PIA20973

The comparative morphology of pit organs in elasmobranchs.

PubMed

Peach, M B; Marshall, N J

2009-06-01

The pit organs of elasmobranchs (sharks, skates and rays) are free neuromasts of the mechanosensory lateral line system. Pit organs, however, appear to have some structural differences from the free neuromasts of bony fishes and amphibians. In this study, the morphology of pit organs was investigated by scanning electron microscopy in six shark and three ray species. In each species, pit organs contained typical lateral line hair cells with apical stereovilli of different lengths arranged in an "organ-pipe" configuration. Supporting cells also bore numerous apical microvilli taller than those observed in other vertebrate lateral line organs. Pit organs were either covered by overlapping denticles, located in open grooves bordered by denticles, or in grooves without associated denticles. The possible functional implications of these morphological features, including modification of water flow and sensory filtering properties, are discussed.

Influence of uneven distribution of coupling mass on locomotive wheel pairs, its tractive power, straight and curved sections of industrial rail tracks.

NASA Astrophysics Data System (ADS)

Keropyan, A. M.; Kantovich, L. I.; Voronin, B. V.; Kuziev, D. A.; Zotov, V. V.

2017-10-01

This article deals with the problems of unloading the axes of wheel sets of locomotives of industrial railway transport by the example of exploitation in conditions of open chasing works. Studies have established that the displacement of the center of mass of an open-pit locomotive depends primarily on the height of the center of gravity, the height of the location of the hook of the locomotive coupling over the rails and the slope of the track. Therefore, to increase the coefficient of utilization of the adhesive weight and to ensure rational operating conditions, it is necessary to provide an adjustable displacement of the locomotive’s center of mass taking into account the actual operating conditions, including when driving on rectilinear and curvilinear sections of the track. Analysis of calculation results showed that for the traction unit OPE1 when driving in traction mode in close to the extreme operating conditions, it is necessary to provide a constructive solution for displacement of the center of mass of the locomotive up to 0.5 m in the course of movement of the locomotive’s center of mass.

Identifying and Reducing Health Risks Associated with Open-Air Burn Pits

DTIC Science & Technology

2013-04-01

product to the base or local nationals to add nutrients to improve the soil .”19 While recycling and composting does require additional manpower, the...burn pits and to contaminated water at military bases at literally hundreds of locations throughout Iraq and Afghanistan.”21 All of the separate...proximity to smoke emanating from such burn pits. As to military personnel, there are a number of statutory remedies available to them, and with 6

Shindand Airbase: Use of Open-Air Burn Pit Violated Department of Defense Requirements

DTIC Science & Technology

2014-07-01

discontinue the use of the burn pit as soon 7 A refractory liner is made from a cement -like...initial combustion), asbestos, mercury, foam tent material, or any item containing any of the above items. The instruction allows for a small

Deformation processes within wheel-rail adhesion in contact area

NASA Astrophysics Data System (ADS)

Albagachiev, A. Yu; Keropyan, A. M.

2018-03-01

The study of working surface deformation during interaction of open-pit locomotive tires allowed defining outstanding features of phenomena occurring in the contact area of interacting surfaces. It was found that processes typical for plastic saturated contact occur in the area of wheel-rail interaction of industrial railway transport. In case of plastic deformation exposed to heavy loads typical for open-pit locomotives, upon all rough surfaces of the contour contact area being fully deformed, the frame on which they are found is exposed to plastic deformation. Plastic deformation of roughness within the contact area of interacting surfaces leads to the increase in the actual area of their contact and, therefore, increases the towing capacity of mining machines. Finally, the available data on deformation characteristics with regard to processes occurring in the contact area of wheel-rail interaction will allow making theoretical forecasts on the expected design value of friction coefficient and, therefore, the towing capacity of open-pit locomotives.

Numerical simulation of the free surface and water inflow of a slope, considering the nonlinear flow properties of gravel layers: a case study

NASA Astrophysics Data System (ADS)

Yang, Bin; Yang, Tianhong; Xu, Zenghe; Liu, Honglei; Shi, Wenhao; Yang, Xin

2018-02-01

Groundwater is an important factor of slope stability, and 90% of slope failures are related to the influence of groundwater. In the past, free surface calculations and the prediction of water inflow were based on Darcy's law. However, Darcy's law for steady fluid flow is a special case of non-Darcy flow, and many types of non-Darcy flows occur in practical engineering applications. In this paper, based on the experimental results of laboratory water seepage tests, the seepage state of each soil layer in the open-pit slope of the Yanshan Iron Mine, China, were determined, and the seepage parameters were obtained. The seepage behaviour in the silt layer, fine sand layer, silty clay layer and gravelly clay layer followed the traditional Darcy law, while the gravel layers showed clear nonlinear characteristics. The permeability increases exponentially and the non-Darcy coefficient decreases exponentially with an increase in porosity, and the relation among the permeability, the porosity and the non-Darcy coefficient is investigated. A coupled mathematical model is established for two flow fields, on the basis of Darcy flow in the low-permeability layers and Forchheimer flow in the high-permeability layers. In addition, the effect of the seepage in the slope on the transition from Darcy flow to Forchheimer flow was considered. Then, a numerical simulation was conducted by using finite-element software (FELAC 2.2). The results indicate that the free surface calculated by the Darcy-Forchheimer model is in good agreement with the in situ measurements; however, there is an evident deviation of the simulation results from the measured data when the Darcy model is used. Through a parameter sensitivity analysis of the gravel layers, it can be found that the height of the overflow point and the water inflow calculated by the Darcy-Forchheimer model are consistently less than those of the Darcy model, and the discrepancy between these two models increases as the permeability increases. The necessity of adopting the Darcy-Forchheimer model was explained. The Darcy-Forchheimer model would be applicable in slope engineering applications with highly permeable rock.

Numerical simulation of the free surface and water inflow of a slope, considering the nonlinear flow properties of gravel layers: a case study.

PubMed

Yang, Bin; Yang, Tianhong; Xu, Zenghe; Liu, Honglei; Shi, Wenhao; Yang, Xin

2018-02-01

Groundwater is an important factor of slope stability, and 90% of slope failures are related to the influence of groundwater. In the past, free surface calculations and the prediction of water inflow were based on Darcy's law. However, Darcy's law for steady fluid flow is a special case of non-Darcy flow, and many types of non-Darcy flows occur in practical engineering applications. In this paper, based on the experimental results of laboratory water seepage tests, the seepage state of each soil layer in the open-pit slope of the Yanshan Iron Mine, China, were determined, and the seepage parameters were obtained. The seepage behaviour in the silt layer, fine sand layer, silty clay layer and gravelly clay layer followed the traditional Darcy law, while the gravel layers showed clear nonlinear characteristics. The permeability increases exponentially and the non-Darcy coefficient decreases exponentially with an increase in porosity, and the relation among the permeability, the porosity and the non-Darcy coefficient is investigated. A coupled mathematical model is established for two flow fields, on the basis of Darcy flow in the low-permeability layers and Forchheimer flow in the high-permeability layers. In addition, the effect of the seepage in the slope on the transition from Darcy flow to Forchheimer flow was considered. Then, a numerical simulation was conducted by using finite-element software (FELAC 2.2). The results indicate that the free surface calculated by the Darcy-Forchheimer model is in good agreement with the in situ measurements; however, there is an evident deviation of the simulation results from the measured data when the Darcy model is used. Through a parameter sensitivity analysis of the gravel layers, it can be found that the height of the overflow point and the water inflow calculated by the Darcy-Forchheimer model are consistently less than those of the Darcy model, and the discrepancy between these two models increases as the permeability increases. The necessity of adopting the Darcy-Forchheimer model was explained. The Darcy-Forchheimer model would be applicable in slope engineering applications with highly permeable rock.

Numerical simulation of the free surface and water inflow of a slope, considering the nonlinear flow properties of gravel layers: a case study

PubMed Central

Yang, Bin; Xu, Zenghe; Liu, Honglei; Shi, Wenhao; Yang, Xin

2018-01-01

Groundwater is an important factor of slope stability, and 90% of slope failures are related to the influence of groundwater. In the past, free surface calculations and the prediction of water inflow were based on Darcy's law. However, Darcy's law for steady fluid flow is a special case of non-Darcy flow, and many types of non-Darcy flows occur in practical engineering applications. In this paper, based on the experimental results of laboratory water seepage tests, the seepage state of each soil layer in the open-pit slope of the Yanshan Iron Mine, China, were determined, and the seepage parameters were obtained. The seepage behaviour in the silt layer, fine sand layer, silty clay layer and gravelly clay layer followed the traditional Darcy law, while the gravel layers showed clear nonlinear characteristics. The permeability increases exponentially and the non-Darcy coefficient decreases exponentially with an increase in porosity, and the relation among the permeability, the porosity and the non-Darcy coefficient is investigated. A coupled mathematical model is established for two flow fields, on the basis of Darcy flow in the low-permeability layers and Forchheimer flow in the high-permeability layers. In addition, the effect of the seepage in the slope on the transition from Darcy flow to Forchheimer flow was considered. Then, a numerical simulation was conducted by using finite-element software (FELAC 2.2). The results indicate that the free surface calculated by the Darcy–Forchheimer model is in good agreement with the in situ measurements; however, there is an evident deviation of the simulation results from the measured data when the Darcy model is used. Through a parameter sensitivity analysis of the gravel layers, it can be found that the height of the overflow point and the water inflow calculated by the Darcy–Forchheimer model are consistently less than those of the Darcy model, and the discrepancy between these two models increases as the permeability increases. The necessity of adopting the Darcy–Forchheimer model was explained. The Darcy–Forchheimer model would be applicable in slope engineering applications with highly permeable rock. PMID:29515904

Real -time dispatching modelling for trucks with different capacities in open pit mines / Modelowanie w czasie rzeczywistym przewozów ciężarówek o różnej ładowności w kopalni odkrywkowej

NASA Astrophysics Data System (ADS)

Ahangaran, Daryoush Kaveh; Yasrebi, Amir Bijan; Wetherelt, Andy; Foster, Patrick

2012-10-01

Application of fully automated systems for truck dispatching plays a major role in decreasing the transportation costs which often represent the majority of costs spent on open pit mining. Consequently, the application of a truck dispatching system has become fundamentally important in most of the world's open pit mines. Recent experiences indicate that by decreasing a truck's travelling time and the associated waiting time of its associated shovel then due to the application of a truck dispatching system the rate of production will be considerably improved. Computer-based truck dispatching systems using algorithms, advanced and accurate software are examples of these innovations. Developing an algorithm of a computer- based program appropriated to a specific mine's conditions is considered as one of the most important activities in connection with computer-based dispatching in open pit mines. In this paper the changing trend of programming and dispatching control algorithms and automation conditions will be discussed. Furthermore, since the transportation fleet of most mines use trucks with different capacities, innovative methods, operational optimisation techniques and the best possible methods for developing the required algorithm for real-time dispatching are selected by conducting research on mathematical-based planning methods. Finally, a real-time dispatching model compatible with the requirement of trucks with different capacities is developed by using two techniques of flow networks and integer programming.

Airborne Hazards and Open Burn Pit Registry

MedlinePlus

... Burn Pit Registry requires a common web browser technology to guide you through the registry questionnaire. You may try a different browser, or you may try from a different computer. You may also see this problem if you are in a high security environment where this is disabled by a network policy. ...

Progressive Retinal Nerve Fiber Layer Atrophy Associated With Enlarging Peripapillary Pit.

PubMed

Lee, Eun Ji; Kim, Tae-Woo

2017-02-01

To report a case in which progressive retinal nerve fiber layer (RNFL) atrophy was observed along with enlargement of the peripapillary pit. A 34-year-old male was diagnosed with primary open-angle glaucoma and followed up for 4 years with regular ophthalmic examinations. Both eyes were myopic (-10 D, OD and -10.5 D, OS), and untreated intraocular pressures were 18 mm Hg (OD) and 16 mm Hg (OS). A subtle depression of the superotemporal peripapillary area was deepened and emerged as a peripapillary pit during the follow-up period. With the enlargement of the peripapillary pit, a RNFL defect at the location of pit widened and thinned continuously. The enlargement of the pit was documented by the spectral-domain optical coherence tomography posterior pole scanning. Progressive RNFL atrophy was observed with enlargement of the peripapillary pit. The finding suggests that tensile stress derived from the scleral stretching may have significant influence on the integrity of the RNFL.

Trabeculotomy combined with phacoemulsification and implantation of an intraocular lens for the treatment of primary open-angle glaucoma and coexisting cataract.

PubMed

Tanihara, H; Honjo, M; Inatani, M; Honda, Y; Ogino, N; Ueno, S; Negi, A; Ichioka, H; Mizoguchi, T; Matsumura, M; Nagata, M

1997-10-01

The authors previously reported the usefulness of trabeculotomy ab externo for the treatment of primary open-angle glaucoma in adult patients. In an attempt to elucidate the long-term risk-to-benefit ratio of this surgical modality in combination with cataract surgery, the authors conducted a retrospective study of the surgical effects and complications of a triple procedure: phacoemulsification, implantation (of an intraocular lens), and trabeculotomy (PIT). The authors conducted a retrospective study of patients treated with PIT at multiple hospitals. Intraocular pressure (IOP) and visual function data were obtained from patients after PIT as an initial surgical treatment in cases where antiglaucoma medications failed to resolve uncontrolled IOP (higher than 21 mm Hg). Included in this study were 96 eyes of 64 patients with primary open-angle glaucoma and coexisting cataract. The mean follow-up period was 22.6 +/- 14.7 months (range 3-56 months). In 94 (98%) of the 96 eyes, the IOP was well controlled, having achieved a level of 21 mm Hg or lower at the final examinations. The mean preoperative IOP of the 33 eyes that underwent the triple procedure using a single flap method (PIT-I) was 24.3 +/- 3.9 mm Hg, with an average of 2.1 +/- 1.1 medications. At the final examinations, the mean IOP had dropped to 16.0 +/- 1.2 mm Hg, with an average of 1.2 +/- 1.2 medications. The mean preoperative IOP of the 63 eyes that underwent the triple procedure using a double flap method (PIT-II) was 26.2 +/- 6.2 mm Hg, with an average of 1.9 +/- 1.2 medications. At the final examination, the mean IOP for this group was 15.6 +/- 2.9 mm Hg, with an average of 1.0 +/- 0.9 medications. The long-term results from this multicenter study showed that the triple procedure, PIT, can be useful and effective as an initial surgical treatment for open-angle glaucoma in glaucoma patients with coexisting cataract.

Additional disturbances as a beneficial tool for restoration of post-mining sites: a multi-taxa approach.

PubMed

Řehounková, Klára; Čížek, Lukáš; Řehounek, Jiří; Šebelíková, Lenka; Tropek, Robert; Lencová, Kamila; Bogusch, Petr; Marhoul, Pavel; Máca, Jan

2016-07-01

Open interior sands represent a highly threatened habitat in Europe. In recent times, their associated organisms have often found secondary refuges outside their natural habitats, mainly in sand pits. We investigated the effects of different restoration approaches, i.e. spontaneous succession without additional disturbances, spontaneous succession with additional disturbances caused by recreational activities, and forestry reclamation, on the diversity and conservation values of spiders, beetles, flies, bees and wasps, orthopterans and vascular plants in a large sand pit in the Czech Republic, Central Europe. Out of 406 species recorded in total, 112 were classified as open sand specialists and 71 as threatened. The sites restored through spontaneous succession with additional disturbances hosted the largest proportion of open sand specialists and threatened species. The forestry reclamations, in contrast, hosted few such species. The sites with spontaneous succession without disturbances represent a transition between these two approaches. While restoration through spontaneous succession favours biodiversity in contrast to forestry reclamation, additional disturbances are necessary to maintain early successional habitats essential for threatened species and open sand specialists. Therefore, recreational activities seem to be an economically efficient restoration tool that will also benefit biodiversity in sand pits.

Temporal variation in bed configuration and one-dimensional bottom roughness at the mid-shelf STRESS site

NASA Astrophysics Data System (ADS)

Wheatcroft, Robert A.

1994-08-01

Time-lapse stereophotographs were taken over a 90-day period from mid-November 1990 to late-February 1991 at a 90-m silt-bottom site on the central California shelf as part of the STRESS (Sediment Transport Events on Shelves and Slopes) project. Five distinct bed configurations were observed, in order of decreasing abundance, these are: (1) bioturbated bed; (2) smoothed bed; (3) current-rippled bed; (4) scour-pitted bed; and (5) wave-rippled bed. Concurrent measurements of the flow field implicate along-shelf currents, rather than waves, as the primary agent forming the physical bed configurations. The presence of a wave-induced cross-shelf gradient in near-bottom suspended sediment during storm events and the redistribution of this sediment by upwelling or downwelling currents is postulated to control the appearance of depositional current-ripples (northwest poleward flow, downwelling) and erosional scour-pits (southeast equatorward flow, upwelling). All physical bed forms are destroyed by bioturbation processes in periods of hours to days. Analytical photogrammetric techniques were used to extract high-resolution sea floor height data from the stereophotographs. Results indicate maximal relief over a 0.25-m 2 area at this site never exceeded 5 cm. Root-mean-square (rms) height varied by a factor of 3 (3.2-9.2 mm) and is a weak function of bed configuration. Current ripples have the largest rms-height, smoothed and scour-pitted beds the smallest. Rms-heights of bioturbated beds are variable and appear to depend on the previously produced physical bed configuration. Changes in rms-height can be abrupt with factor of 2 changes observed over a 12-h period. Horizontal descriptors of roughness such as peak spacing or peak width cannot separate bed configurations. Results from surface slope distributions are broadly coherent with the rms-height data, in that surfaces with large rms-heights have broad slope distributions and vice versa. Slope distribution data also indicate that all bed configurations except the current-rippled bed are isotropic. These preliminary data suggest that time series information is needed to adequately resolve both the micro-scale roughness of the sea floor on continental shelves and the presence of short lived, but potentially flow-diagnostic bed configurations.

Application of 3D Laser Scanning Technology in Inspection and Dynamic Reserves Detection of Open-Pit Mine

NASA Astrophysics Data System (ADS)

Hu, Zhumin; Wei, Shiyu; Jiang, Jun

2017-10-01

The traditional open-pit mine mining rights verification and dynamic reserve detection means rely on the total station and RTK to collect the results of the turning point coordinates of mining surface contours. It resulted in obtaining the results of low precision and large error in the means that is limited by the traditional measurement equipment accuracy and measurement methods. The three-dimensional scanning technology can obtain the three-dimensional coordinate data of the surface of the measured object in a large area at high resolution. This paper expounds the commonly used application of 3D scanning technology in the inspection and dynamic reserve detection of open mine mining rights.

Modelling effects of tree population dynamics, tree throw and pit-mound formation/diffusion on microtopography over time in different forest settings

NASA Astrophysics Data System (ADS)

Martin, Y. E.; Johnson, E. A.; Gallaway, J.; Chaikina, O.

2011-12-01

Herein we conduct a followup investigation to an earlier research project in which we developed a numerical model of tree population dynamics, tree throw, and sediment transport associated with the formation of pit-mound features for Hawk Creek watershed, Canadian Rockies (Gallaway et al., 2009). We extend this earlier work by exploring the most appropriate transport relations to simulate the diffusion over time of newly-formed pit-pound features due to tree throw. We combine our earlier model with a landscape development model that can incorporate these diffusive transport relations. Using these combined models, changes in hillslope microtopography over time associated with the formation of pit-mound features and their decay will be investigated. The following ideas have motivated this particular study: (i) Rates of pit-mound degradation remain a source of almost complete speculation, as there is almost no long-term information on process rates. Therefore, we will attempt to tackle the issue of pit-mound degradation in a methodical way that can guide future field studies; (ii) The degree of visible pit-mound topography at any point in time on the landscape is a joint function of the rate of formation of new pit-mound features due to tree death/topple and their magnitude vs. the rate of decay of pit-mound features. An example of one interesting observation that arises is the following: it appears that pit-mound topography is often more pronounced in some eastern North American forests vs. field sites along the eastern slopes of the Canadian Rockies. Why is this the case? Our investigation begins by considering whether pit-mound decay might occur by linear or nonlinear diffusion. What differences might arise depending on which diffusive approach is adopted? What is the magnitude of transport rates associated with these possible forms of transport relations? We explore linear and nonlinear diffusion at varying rates and for different sizes of pit-mound pairs using a numerical modelling approach. Model results suggest that longevity of pit-mound features is dependent on: (i) magnitude/dimensions of initial pit-mound features for forests in different regions; (ii) defining appropriate pit-mound diffusion rates for these different forests (unfortunately, almost no appropriate field observations exist for calibration of these transport relations). In the next stage of this research, we will combine our earlier model of forest disturbance/tree population dynamics, tree throw and pit-mound formation with the numerical model LandMod (Martin, 1998, 2000, 2007); the latter will be used to simulate pit-mound diffusion over time. In this way, we can observe changes in hillslope microtopographic signatures over time that are found in different forest settings.

Electrochemical analysis of the corrosion inhibition effect of trypsin complex on the pitting corrosion of 420 martensitic stainless steel in 2M H2SO4 solution.

PubMed

Loto, Roland Tolulope

2018-01-01

Inhibition effect of trypsin complex (TC) on the pitting corrosion of martensitic stainless steel (type 420) in 1M H2SO4 solution was studied with potentiodynamic polarization, open circuit potential measurement and optical microscopy. TC reduced the corrosion rate of the steel with maximum inhibition efficiency of 80.75%. Corrosion potential shifted anodically due to the electrochemical action of TC. The pitting potential increased from 1.088VAg/AgCl (3M) at 0% TC to 1.365VAg/AgCl(3M) at 4% TC. TC shifts the open circuit corrosion potential from -0.270s at 0% TC concentration to -0.255V at 5% TC. The compound completely adsorbed onto the steel according to Langmuir, Frumkin and Temkin isotherms. ATF-FTIR spectroscopy confirmed the inhibition mode to be through surface coverage. Thermodynamic calculations showed physisorption molecular interaction. Corrosion pits are present on the uninhibited 420 morphology in comparison to TC inhibited surface which slightly deteriorated.

Electrochemical analysis of the corrosion inhibition effect of trypsin complex on the pitting corrosion of 420 martensitic stainless steel in 2M H2SO4 solution

PubMed Central

Loto, Roland Tolulope

2018-01-01

Inhibition effect of trypsin complex (TC) on the pitting corrosion of martensitic stainless steel (type 420) in 1M H2SO4 solution was studied with potentiodynamic polarization, open circuit potential measurement and optical microscopy. TC reduced the corrosion rate of the steel with maximum inhibition efficiency of 80.75%. Corrosion potential shifted anodically due to the electrochemical action of TC. The pitting potential increased from 1.088VAg/AgCl (3M) at 0% TC to 1.365VAg/AgCl(3M) at 4% TC. TC shifts the open circuit corrosion potential from -0.270s at 0% TC concentration to -0.255V at 5% TC. The compound completely adsorbed onto the steel according to Langmuir, Frumkin and Temkin isotherms. ATF-FTIR spectroscopy confirmed the inhibition mode to be through surface coverage. Thermodynamic calculations showed physisorption molecular interaction. Corrosion pits are present on the uninhibited 420 morphology in comparison to TC inhibited surface which slightly deteriorated. PMID:29672541

Collapse Pits

NASA Technical Reports Server (NTRS)

2005-01-01

24 April 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a large and several small pits formed by collapse along the trend of a fault system in the Uranius Fossae region of Mars. Running diagonal from middle-right toward lower left is a trough that intersects the pit. The trough is a typical graben formed by faulting as the upper crust of Mars split and pulled apart at this location. The opening of the graben also led to formation of the collapse pits.

Location near: 26.2oN, 88.7oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Summer

Investigating pitting in X65 carbon steel using potentiostatic polarisation

NASA Astrophysics Data System (ADS)

Mohammed, Sikiru; Hua, Yong; Barker, R.; Neville, A.

2017-11-01

Although pitting corrosion in passive materials is generally well understood, the growth of surface pits in actively-corroding materials has received much less attention to date and remains poorly understood. One of the key challenges which exists is repeatedly and reliably generating surface pits in a practical time-frame in the absence of deformation and/or residual stress so that studies on pit propagation and healing can be performed. Another pertinent issue is how to evaluate pitting while addressing general corrosion in low carbon steel. In this work, potentiostatic polarisation was employed to induce corrosion pits (free from deformation or residual stress) on actively corroding X65 carbon steel. The influence of applied potential (50 mV, 100 mV and 150 mV vs open circuit potential) was investigated over 24 h in a CO2-saturated, 3.5 wt.% NaCl solution at 30 °C and pH 3.8. Scanning electron microscopy (SEM) was utilised to examine pits, while surface profilometry was conducted to measure pit depth as a function of applied potential over the range considered. Analyses of light pitting (up to 120 μm) revealed that pit depth increased linearly with increase in applied potential. This paper relates total pit volume (measured using white light interferometry) to dissipated charge or total mass loss (using the current response for potentiostatic polarisation in conjunction with Faraday's law). By controlling the potential of the surface (anodic) the extent of pitting and general corrosion could be controlled. This allowed pits to be evaluated for their ability to continue to propagate after the potentiostatic technique was employed. Linear growth from a depth of 70 μm at pH 3.8, 80 °C was demonstrated. The technique offers promise for the study of inhibition of pitting.

A GIS System for Inferring Subsurface Geology and Material Properties: Proof of Concept

DTIC Science & Technology

2006-09-01

geologic structure. For example, interbedded sedimentary rocks comprise significant proportions of the Appalachian Mountains as well as various mountain ...Pitted surfaces a. Shallow, rounded, non-uniform b. More or less circular Hills and Mountains … Drainage...pear-shaped ap - pendages; talus common at bases of slopes along boundaries; strongly verti- cally jointed; vertical escarpments; co- lumnar jointing

Open pit mining profit maximization considering selling stage and waste rehabilitation cost

NASA Astrophysics Data System (ADS)

Muttaqin, B. I. A.; Rosyidi, C. N.

2017-11-01

In open pit mining activities, determination of the cut-off grade becomes crucial for the company since the cut-off grade affects how much profit will be earned for the mining company. In this study, we developed a cut-off grade determination mode for the open pit mining industry considering the cost of mining, waste removal (rehabilitation) cost, processing cost, fixed cost, and selling stage cost. The main goal of this study is to develop a model of cut-off grade determination to get the maximum total profit. Secondly, this study is also developed to observe the model of sensitivity based on changes in the cost components. The optimization results show that the models can help mining company managers to determine the optimal cut-off grade and also estimate how much profit that can be earned by the mining company. To illustrate the application of the models, a numerical example and a set of sensitivity analysis are presented. From the results of sensitivity analysis, we conclude that the changes in the sales price greatly affects the optimal cut-off value and the total profit.

Earth Observations taken by the Expedition 22 Crew

NASA Image and Video Library

2010-01-14

ISS022-E-026137 (14 Jan. 2010) --- Open Pit Mines in southern Arizona are featured in this image photographed by an Expedition 22 crew member on the International Space Station. The State of Arizona is the United States? largest producer of the metal copper, primarily mined from ore bodies known as porphyry copper deposits. Copper is a good conductor of electricity and heat, and is a vital element of virtually all of our electronic devices and components. A porphyry copper deposit is a geological structure formed by crystal-rich magma moving upwards through pre-existing rock layers. As the magma cools and crystallizes, it forms an igneous rock with large crystals embedded in a fine-grained matrix, known as porphyry. Hot fluids circulate through the magma and surrounding rocks via fractures, depositing copper-bearing and other minerals in characteristic spatial patterns that signal the nature of the ore body to a geologist. The most common approach to extracting metal-bearing ore from a porphyry copper deposit is by open-pit mining. For more details, please refer to http://earth.jsc.nasa.gov/EarthObservatory/OpenPitMinesSouthernArizona.htm.

Stress state of rock mass under open pit mining in the influence zone of tectonic disturbances (in terms of the Oktorkoi Fault, North Tien Shan)

NASA Astrophysics Data System (ADS)

Kozhogulov, KCh; Nikolskaya, OV; Rybin, AK; Kuzikov, SI

2018-03-01

The qualitative connection between the crack growth direction and the orientation of the main axes of horizontal deformations in rocks mass in the area of the Boordin gold ore province is revealed. The effect of the rock mass quality (RQD) and contact conditions of crack surfaces on the stability index of pit wall rock mass is evaluated, and the influence of the rock mass quality index on the pit wall stability is determined.

Volcano Park Mosenberg near Bettenfeld / Eifel: A new concept of geological renaturation

NASA Astrophysics Data System (ADS)

Koziol, Martin; Kuhn, Nikolaus J.

2013-04-01

Mining of the lava deposited in the area of the Mosenberg volcano near the village of Bettenfeld in the Eifel ended in 1993. The German mining law calls for an operating plan for a closed mine. In many cases, the mines are simply backfilled and planted. Such filling hides many interesting geological outcrops forever. Geological outcrops are windows into the earth, they tell us fascinating stories about the origin and evolution of the rocks and landscape. Mining the Mosenberg exposed volcanic chimneys filled with solid basalt, lapilli beds of different grain sizes and scoria welded into cinder layers, offering a perfect and large cross-section through a cinder cone. The unique sight at the closed mine at the Mosenberg volcano group was, together with the Meerfeld maar, included in the 2006 list of the 80 best "Geotopes of Germany". In 2000, the community of Bettenfeld, the municipality of Manderscheid and the Maarmuseum Manderscheid started discussions on how to enable access to these pits and open them to geotourism. The "GeoRoute Vulkaneifel around Manderscheid"as well as the "Eifel" and "Lieser" hiking trails pass nearby the former lava mine which facilitated the connection of the outcrops to existing tourism routes. Eventually, the relocation of the "GeoRoute" into the pit and the development of safe pathways there to make the lava pit safe and accessible for visitors, combined with geological information boards was developed. The term of "renaturation" was redefined in the project for the first time and implemented as "Geological renaturation". Subsequently, funds from the European Union and the State of Rhineland-Palatine to support the development of the pit were sought. In 2009, the European Union and the State of Rhineland-Palatinate granted supported for the project as part of their structural development programs (LEADER / PAUL). Their contribution consisted of half of the construction cost. The other half was covered by the municipality of Manderscheid because of the regional importance of this site for tourism. Construction in the former mine began in late 2010. The bottom of the pit was leveled, the slopes secured with big magmatic rocks and some of the pathways were laid as barrier-free routes with grass pavers. In addition, a little trail with the volcanic rocks of the Eifel and an outdoor classroom were set up. Together they create the unique volcano theme park Mosenberg (www.vulkanerlebnis-mosenberg.de), a unique window into the Eifel volcanism!

Time scale for degradation and erosion of archaeological terraces in the Judea Mountains, Israel

NASA Astrophysics Data System (ADS)

Porat, Naomi; Elinson, Rotem; Ben Dor, Eyal; Avni, Yoav; Gadot, Yuval

2017-04-01

The fate of mountain bench terraces which have been abandoned in ancient times is puzzling. On the one hand recently abandoned terraces undergo rapid degradation by walls crumbling, leading to soil being washed by rain water out of breaches in the walls, suggesting that within a short time all soil would be washed down-slope. On the other hand slopes with degraded terraces appear to still retain much soil even though only faint remains of the terraces exist. Moreover, if soil is rapidly eroded down-slope when terraces are no longer maintained, where do subsequent terrace builders find the soil to fill behind the stone walls? These questions were addressed as part of a larger study on the chronology of terraces in the Judea Mountains, Israel. Previous OSL dating of terrace soils in the region showed that the majority of the maintained terraces were constructed during the past 700 years, and only occasionally older ages were obtained for the soil at the very base of these terraces. Concerns were raised that soil erosion caused earlier events of terrace construction to disappear. To check if terraces and soils indeed erode entirely and how long this might take, we selected a relatively smooth hill slope showing small patches of limestone bedrock as well as remains of highly degraded sets of terraces. Three pits were excavated in soils within three different terrace remains down to bedrock, some to a depth of 2 m, and samples for OSL dating were collected from the exposed soil sections. In all three pits the lowermost samples gave ages of 3000-4500 years before the present, possibly the natural soils before any human intervention. However samples from a depth of 35-45 cm gave ages of 350-200 years, providing the last time the soil at that depth was exposed to sunlight. This suggests that the terraces were abandoned in the past 200 years or so and since then degraded. However the thick soil present on most of the slope suggests that after the first stage of rapid degradation the slope reaches equilibrium, probably due to coverage by native shrubs that reduce direct soil erosion, and most of the soil is retained on the slope.

40 CFR 60.1435 - What is an air curtain incinerator?

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Small Municipal... forcefully projecting a curtain of air across an open chamber or open pit in which combustion occurs...

Extensive rill erosion and gullying on abandoned pit mining sites in Lusatia, Germany

NASA Astrophysics Data System (ADS)

Kunth, Franziska; Kaiser, Andreas; Vláčilová, Markéta; Schindewolf, Marcus; Schmidt, Jürgen

2015-04-01

As the major economic driver in the province of Lusatia, Eastern Germany, the large open-cast lignite mining sites characterize the landscape and leave vast areas of irreversible changed post-mining landscapes behind. Cost-intensive renaturation projects have been implemented in order to restructure former mine sites into stabile self-sustaining ecosystems and local recreation areas. With considerable expenditure the pits are stabilized, flooded and surrounding areas are restructured. Nevertheless, heavy soil erosion, extensive gullying and slope instability are challenges for the restructuring and renaturation of the abandoned open-cast mining sites. The majority of the sites remain inaccessible to the public due to instable conditions resulting in uncontrolled slides and large gullies. In this study a combined approach of UAV-based aerial imagery, 3D multi-vision surface reconstruction and physically-based soil erosion modelling is carried out in order to document, quantify and better understand the causes of erosion processes on mining sites. Rainfall simulations have been carried out in lausatian post mining areas to reproduce soil detachment processes and observe the responsible mechanisms for the considerable erosion rates. Water repellency and soil sealing by biological crusts were hindering infiltration and consequently increasing runoff rates despite the mainly sandy soil texture. On non-vegetated experimental plots runoff coefficients up to 87 % were measured. In a modelling routine for a major gully catchment regarding a 50 years rainfall event, simulation results reveal runoff coefficients of up to 84% and erosion rates of 118 Mg*ha^-1. At the sediment pass over point 450Mg of sediments enter the surface water bodies. A system response of this order of magnitude were unexpected by the authorities. By applying 3D multi-vision surface reconstruction a model validation is now possible and further may illustrate the great importance of soil conservation measures under the described conditions.

Natural radioactivity in lignite samples from open pit mines "Kolubara", Serbia--risk assessment.

PubMed

Ðurašević, M; Kandić, A; Stefanović, P; Vukanac, I; Sešlak, B; Milošević, Z; Marković, T

2014-05-01

Coal as fossil fuel mainly contains naturally occurring radionuclides from the uranium and thorium series and (40)K. Use of coal, primarily in industry, as a result has dispersion of radioactive material from coal in and through air and water. The aim of this study was to determine the activity concentrations of natural radionuclides in coal samples from open pit mines "Kolubara" and to evaluate its effect on population health. The results showed that all measured and calculated values were below the limits recommended in international legislation. © 2013 Published by Elsevier Ltd.

Equipment Selection by using Fuzzy TOPSIS Method

NASA Astrophysics Data System (ADS)

Yavuz, Mahmut

2016-10-01

In this study, Fuzzy TOPSIS method was performed for the selection of open pit truck and the optimal solution of the problem was investigated. Data from Turkish Coal Enterprises was used in the application of the method. This paper explains the Fuzzy TOPSIS approaches with group decision-making application in an open pit coal mine in Turkey. An algorithm of the multi-person multi-criteria decision making with fuzzy set approach was applied an equipment selection problem. It was found that Fuzzy TOPSIS with a group decision making is a method that may help decision-makers in solving different decision-making problems in mining.

Factors influencing habitat selection by arboreal pit vipers.

PubMed

Sawant, Nitin S; Jadhav, Trupti D

2013-01-01

We studied factors influencing habitat selection by two arboreal species of pit viper, namely Trimeresurus malabaricus (Malabar pit viper) and T. gramineus (Bamboo pit viper). The macrohabitat of these species was classified as forest, forest edge, or open habitat. To determine microhabitat selection, a variety of features at every other snake location were measured. Whether or not the animal was found in a tree, the tree species, its height of perch, position on the branch (distal/ apical/middle), diameter of the branch, the tree canopy (thick/sparse) and vegetation of the area (thick/sparse) were recorded. Assessment of habitat was done to determine how patterns of habitat use vary seasonally. Shaded ambient (air) temperatures and humidity were recorded. Data pertaining to 90 individuals of T. malabaricus and 100 individuals of T. gramineus were recorded. Trimeresurus malabaricus selected home ranges that included areas with thick vegetation and were encountered at regions of higher altitude. Neither of the species was found in open habitats. Both of the species preferred diverse habitats and were spread over the entire available space during the monsoon; they did not show any preference for the perch height during different seasons. Males had a positive correlation between body mass and preferred perch diameter. The present study suggests that several factors play an important role in habitat selection by these arboreal pit vipers, thus making them highly habitat-specific.

Seasonal Response and Characterization of a Scree Slope and Active Debris Flow Catchment Using Multiple Geophysical Techniques: The case of the Meretschibach Catchment, Switzerland

NASA Astrophysics Data System (ADS)

Fankhauser, Kerstin; Guzman, Daisy R. Lucas; Oggier, Nicole; Maurer, Hansruedi; Springman, Sarah M.

2015-04-01

Various types of mass movements cause extensive natural hazards in populated mountain regions. They need to be quantified, and possibly predicted, for implementing effective mitigation and protection measures. The Meretschibach catchment in the Valais area, Switzerland, is a source region for such events. Various forms of instabilities occur on the steep slopes. They manifest themselves in form of smaller rock falls and rock slides on the open scree slopes. Moreover, large sediment volumes of channelized stream deposits can evolve into debris flows, with a substantial run-out along the Meretschibach. Geophysical methods, such as electrical resistivity tomography (ERT) and ground-penetrating-radar (GPR) have been proven to be powerful tools for characterizing mass movements and slope instabilities. They complement other remote sensing techniques and in-situ geotechnical experiments. Ground-based and helicopter-borne GPR measurements were carried out at the Meretschibach test site, to determine the depth to the bedrock. The results indicate that the bedrock is generally shallow, ranging from a few centimetres to about 5 metres vertically below the surface. A particularly interesting aspect of the GPR investigations was the observation that bedrock depth could be resolved by both, ground-based and helicopter-borne GPR data. Ground-based GPR surveying proved to be extremely challenging on the steep slopes, and some areas were even inaccessible due to safety concerns. It is therefore encouraging for future projects that helicopter-borne GPR acquisition offers a promising alternative. The spatial distribution of the soil moisture content and the temporal variations were determined with repeated ERT measurements. The resulting tomograms allowed a conductive soil layer and more resistive bedrock to be distinguished clearly. The ERT results were in good agreement with in-situ geotechnical measurements in a nearby test pit, and the depth of the soil-bedrock interface was broadly consistent with the GPR results. A comparison of tomograms obtained during the relatively dry month of June 2014, with those acquired after heavy rainfall in July 2014, showed significant changes of the shallow subsurface resistivities. These changes could be attributed in a quantitative fashion to variations of the soil water Saturation.

A Critical Review of Landslide Failure Mechanisms

NASA Astrophysics Data System (ADS)

Stead, D.; Wolter, A.; Clague, J. J.

2011-12-01

During the last ten years several comprehensive geotechnical studies have been completed on major historic landslides including Randa in Switzerland, Frank in Canada, Aknes in Norway, La Clapiere in France and Vaiont in Italy. In addition, numerous researchers have documented deep-seated gravitational deformations and a wide variety of large prehistoric rock slope failures. The information provided by these studies is evidence of the significant advances made in our ability to map, monitor and model landslides. Over the same period, the mining industry has developed large open pits with slope heights exceeding 1000 m that provide important analogues to high mountain slopes. In this paper we analyse data from the literature to illustrate the importance of brittle fracture, 3D controls, anisotropy, overburden stress, geomorphic processes, groundwater and temperature in major landslides and provide some indicators as to the research required to further understand the complexity of rock slope failure mechanisms. The nature of the landslide failure surface has received inadequate attention in the past, with failure surfaces typically considered in 2D and simulated as discrete, smooth and often planar features. Current work shows that failure surfaces are inherently three-dimensional and have much structural variability across the area of the landslide scarp, reflecting complex structural histories. Such anisotropy and variations may result in multiple events or distinct blocks that move at different rates. Just as most failure surfaces vary spatially, they may also change with depth and thus should more realistically be considered failure zones rather than discrete surfaces. The increasing recognition of the importance of step-path failures, internal dilation and brittle fracture are indicative of the complexity in slope failure surfaces. Related to the variation in failure surface characteristics is the importance of 3D rotational displacements and both the availability and orientation of lateral and rear release surfaces. Accompanying the large increase in the application of numerical models, more consideration needs to be given to both the 3D shape and thickness of major landslides in order to address such questions as: are major landslides symmetric or asymmetric, of limited thickness or deep seated, brittle or ductile?

40 CFR 62.15365 - What is an air curtain incinerator?

Code of Federal Regulations, 2010 CFR

2010-07-01

... incinerator? An air curtain incinerator operates by forcefully projecting a curtain of air across an open chamber or open pit in which combustion occurs. Incinerators of this type can be constructed above or...

40 CFR 60.1910 - What is an air curtain incinerator?

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Emission Guidelines and Compliance Times for... incinerator operates by forcefully projecting a curtain of air across an open chamber or open pit in which...

Op-Ug TD Optimizer Tool Based on Matlab Code to Find Transition Depth From Open Pit to Block Caving / Narzędzie Optymalizacyjne Oparte O Kod Matlab Wykorzystane Do Określania Głębokości Przejściowej Od Wydobycia Odkrywkowego Do Wybierania Komorami

NASA Astrophysics Data System (ADS)

Bakhtavar, E.

2015-09-01

In this study, transition from open pit to block caving has been considered as a challenging problem. For this purpose, the linear integer programing code of Matlab was initially developed on the basis of the binary integer model proposed by Bakhtavar et al (2012). Then a program based on graphical user interface (GUI) was set up and named "Op-Ug TD Optimizer". It is a beneficial tool for simple application of the model in all situations where open pit is considered together with block caving method for mining an ore deposit. Finally, Op-Ug TD Optimizer has been explained step by step through solving the transition from open pit to block caving problem of a case ore deposit. W pracy tej rozważano skomplikowane zagadnienie przejścia od wybierania odkrywkowego do komorowego. W tym celu opracowano kod programowania liniowego w środowisku MATLAB w oparciu o model liczb binarnych zaproponowany przez Bakhtavara (2012). Następnie opracowano program z wykorzystujący graficzny interfejs użytkownika o nazwie Optymalizator Op-Ug TD. Jest to niezwykle cenne narzędzie umożliwiające stosowanie modelu dla wszystkich warunków w sytuacjach gdy rozważamy prowadzenie wydobycia metodą odkrywkową oraz wydobycie komorowe przy eksploatacji złóż rud żelaza. W końcowej części pracy podano szczegółową instrukcję stosowanie programu Optymalizator na przedstawionym przykładzie przejścia od wydobycia rud żelaza metodami odkrywkowymi poprzez wydobycie komorami.

A comparison of conventional capture versus PIT reader techniques for estimating survival and capture probabilities of big brown bats (Eptesicus fuscus)

USGS Publications Warehouse

Ellison, L.E.; O'Shea, T.J.; Neubaum, D.J.; Neubaum, M.A.; Pearce, R.D.; Bowen, R.A.

2007-01-01

We compared conventional capture (primarily mist nets and harp traps) and passive integrated transponder (PIT) tagging techniques for estimating capture and survival probabilities of big brown bats (Eptesicus fuscus) roosting in buildings in Fort Collins, Colorado. A total of 987 female adult and juvenile bats were captured and marked by subdermal injection of PIT tags during the summers of 2001-2005 at five maternity colonies in buildings. Openings to roosts were equipped with PIT hoop-style readers, and exit and entry of bats were passively monitored on a daily basis throughout the summers of 2002-2005. PIT readers 'recaptured' adult and juvenile females more often than conventional capture events at each roost. Estimates of annual capture probabilities for all five colonies were on average twice as high when estimated from PIT reader data (P?? = 0.93-1.00) than when derived from conventional techniques (P?? = 0.26-0.66), and as a consequence annual survival estimates were more precisely estimated when using PIT reader encounters. Short-term, daily capture estimates were also higher using PIT readers than conventional captures. We discuss the advantages and limitations of using PIT tags and passive encounters with hoop readers vs. conventional capture techniques for estimating these vital parameters in big brown bats. ?? Museum and Institute of Zoology PAS.

Advantages and limitations for users of double pit pour-flush latrines: a qualitative study in rural Bangladesh.

PubMed

Hussain, Faruqe; Clasen, Thomas; Akter, Shahinoor; Bawel, Victoria; Luby, Stephen P; Leontsini, Elli; Unicomb, Leanne; Barua, Milan Kanti; Thomas, Brittany; Winch, Peter J

2017-05-25

In rural Bangladesh, India and elsewhere, pour-flush pit latrines are the most common sanitation system. When a single pit latrine becomes full, users must empty it themselves and risk exposure to fresh feces, pay an emptying service to remove pit contents or build a new latrine. Double pit pour-flush latrines may serve as a long-term sanitation option including high water table areas because the pits do not need to be emptied immediately and the excreta decomposes into reusable soil. Double pit pour-flush latrines were implemented in rural Bangladesh for 'hardcore poor' households by a national NGO, BRAC. We conducted interviews, focus groups, and spot checks in two low-income, rural areas of Bangladesh to explore the advantages and limitations of using double pit latrines compared to single pit latrines. The rural households accepted the double pit pour-flush latrine model and considered it feasible to use and maintain. This latrine design increased accessibility of a sanitation facility for these low-income residents and provided privacy, convenience and comfort, compared to open defecation. Although a double pit latrine is more costly and requires more space than a single pit latrine the households perceived this sanitation system to save resources, because households did not need to hire service workers to empty pits or remove decomposed contents themselves. In addition, the excreta decomposition process produced a reusable soil product that some households used in homestead gardening. The durability of the latrine superstructures was a problem, as most of the bamboo-pole superstructure broke after 6-18 months of use. Double pit pour-flush latrines are a long-term improved sanitation option that offers users several important advantages over single pit pour-flush latrines like in rural Bangladesh which can also be used in areas with high water table. Further research can provide an understanding of the comparative health impacts and effectiveness of the model in preventing human excreta from entering the environment.

Investigation and simulation on fate and transport of leachate from a livestock mortality burial site

NASA Astrophysics Data System (ADS)

Lim, J.-W.; Lee, S.; Kaown, D.; Lee, K.-K.

2012-04-01

Leachate released from livestock mortality burial during decomposition of carcasses can be a threat to groundwater quality. Monitoring study of groundwater quality in the vicinity of livestock burial reported that a caution is needed to prevent contamination of both groundwater and soil, especially in case of mortality burial (Glanville, 2000; Ritter and Chirnside, 1995). The average concentration of ammonium-N and chloride is reported to be 12,600 mg/l and 2,600 mg/l respectively, which is 2-4 times higher than leachate from earthen manure storages and landfills (Pratt, 2009). To assess the potential threat of burial leachate to groundwater quality, simulation of leachate transport is performed based on a hydrogeologic model of an actual mortality burial site. At the burial site of this study located at a hill slope, two mortality pits have been constructed along the slope to bury swine during the outbreak of nationwide foot and mouth disease(FMD) in 2011. Though the pits were partially lined with impermeable material, potential threat of leachate leakage is still in concern. Electrical resistivity survey has been performed several times at the burial site and abnormal resistivity zones have been detected which are supposed as leachate leakage from the burial. Subsurface model including unsaturated zone is built since the leakage is supposed to occur mainly in lateral of the burial pits which is in unsaturated zone. When examining leachate transport, main focus is given to a nitrogenous compound and colloidal character of FMD virus. Nitrifying of denitrifying characters of nitrogenous compound and transport of colloidal particles are affected mainly by soil water content in unsaturated zone. Thus, the fate and transport of burial leachate affected by seasonal variation in recharge pattern is investigated.

Evolution of mud-capped dredge pits following excavation: sediment trapping and slope instability

NASA Astrophysics Data System (ADS)

Obelcz, J.; Xu, K.; Bentley, S. J.; Li, C.; Miner, M. D.; O'Connor, M. C.; Wang, J.

2016-02-01

Many fluvial channels incised the Northern Gulf of Mexico inner continental shelf during the late Quaternary. Mud-capped dredge pits (MCDPs), which are generally elongate and deep (8-10 m) excavations, target sandy fluvial channel deposits for coastal restoration projects. The morphological evolution of dredge excavations in noncohesive sandy substrate is well studied, but MCDPs have up to a several-meter-thick veneer of Holocene shelf mud overlying sandy channel deposits. This stratigraphy is hypothesized to result in more complex post-dredge morphology than pit walls simply slumping to the angle of repose shortly after excavation. Numerical modeling of MCDP post-dredge response conducted prior to excavation indicates pit walls may retrogressively fail, which is accounted for in pit design by assigning no-dredge setback buffers from pipelines or cultural and environmental resources. To validate model results and test effectiveness of setback buffers, a geophysical survey of the Sandy Point MCDP (20 km west of the Mississippi River Delta in 10m deep water), where 1.7 million m3 of sandy sediment was excavated in 2012, was conducted May 2015. A total of 84 line-km of high-resolution chirp subbottom and a 27 km2 grid of swath bathymetry and sidescan sonar were collected. The data indicate the dredge pit walls are differentially slumping, with the western pit wall in a more active state of failure than the eastern wall. The western failures morphologically resemble features observed along the muddy Mississippi River Delta Front at water depths of 20-100 m, including bowl-shaped collapse failures and retrogressive stair-stepped slumps; these failures may play a key role in evaluating the distance of setback buffer zone to pipelines. These features indicate the cohesive mud overlying the sandy infill has a prominent role in pit wall stability. A 0.5-1 m thick acoustically transparent package overlies the entire pit floor (interpreted as a possible fluid mud layer), overlying 1-3 m of post-dredge deposition that is concentrated along the western wall and center of the pit. The Sandy Point MCDP lies within a clockwise gyre, and its relief may serve as a significant trap of suspended sediment. These findings emphasize the role MCDPs play in sediment dynamics as well as their potential for submarine geohazards.

Millennium Open Pit Mine, Alberta, Canada

NASA Technical Reports Server (NTRS)

2007-01-01

Near Fort McMurray, Alberta, Canada, on the east bank of the Athabasca River, are found the Steepbank and Millennium mines. These open pit mines produce oil sands that are processed to recover bitumen, and then upgrade it to refinery-ready raw crude oil, and diesel fuel.

The ASTER images were acquired September 22, 2000 and July 31, 2007, cover an area of 22.5 x 25.5 km, and are located near 57 degrees north latitude, 111.5 degrees west longitude.

The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

Open-pit coal mine production sequencing incorporating grade blending and stockpiling options: An application from an Indian mine

NASA Astrophysics Data System (ADS)

Kumar, Ashish; Chatterjee, Snehamoy

2017-05-01

Production scheduling is a crucial aspect of the mining industry. An optimal and efficient production schedule can increase the profits manifold and reduce the amount of waste to be handled. Production scheduling for coal mines is necessary to maintain consistency in the quality and quantity parameters of coal supplied to power plants. Irregularity in the quality parameters of the coal can lead to heavy losses in coal-fired power plants. Moreover, the stockpiling of coal poses environmental and fire problems owing to low incubation periods. This article proposes a production scheduling formulation for open-pit coal mines including stockpiling and blending opportunities, which play a major role in maintaining the quality and quantity of supplied coal. The proposed formulation was applied to a large open-pit coal mine in India. This contribution provides an efficient production scheduling formulation for coal mines after utilizing the stockpile coal within the incubation periods with the maximization of discounted cash flows. At the same time, consistency is maintained in the quality and quantity of coal to power plants through blending and stockpiling options to ensure smooth functioning.

GEOCHEMICAL EVOLUTION OF GROUND WATER AND TRANSPORT OF MERCURY AT THE SULPHUR BANK MERCURY MINE SUPERFUND SITE IN NORTHERN CALIFORNIA, USA

EPA Science Inventory

The Sulphur Bank Mercury Mine, located on the shore of Clear Lake, Lake County, California, is a potential source for a modern-day mercury flux into the local aquatic ecosystem. Surface mining created the Herman Pit, a 9.3 ha open pit with a depth > 30 m, while overburden and pr...

76 FR 60474 - Intent To Prepare a Draft Environmental Impact Statement (DEIS) for the Haile Gold Mine in...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-29

...--County on January 28, 2011. The public notice is available on Charleston District's public Web site at... eight open mining pits over a twelve-year period, with pit depths ranging from 110 to 840 feet deep. The... of January 28, 2011, and are available on Charleston District's public Web site at http://www.sac...

Cloning of the canine gene encoding transcription factor Pit-1 and its exclusion as candidate gene in a canine model of pituitary dwarfism.

PubMed

Lantinga-van Leeuwen, I S; Mol, J A; Kooistra, H S; Rijnberk, A; Breen, M; Renier, C; van Oost, B A

2000-01-01

Combined pituitary hormone deficiency (CPHD) is an autosomal recessive inherited disease of German shepherd dogs characterized primarily by dwarfism. In mice and humans a similar genetic disorder has been described that results from an alteration in the gene encoding the transcription factor Pit-1. In this study we characterized the canine Pit-1 gene, determined the chromosomal localization of the Pit-1 gene, and screened dwarf German shepherd dogs for the presence of mutations in this gene. The full-length canine Pit-1 cDNA contained an open reading frame encoding 291 amino acids, 92 bp of 5'-untranslated region, and 1959 bp of 3'-untranslated region. The deduced amino acid sequence was highly homologous with Pit-1 of other mammalian species. Using a Pit-1 BAC clone as probe, the Pit-1 gene was mapped by FISH to canine Chromosome (Chr) 31. In dwarf German shepherd dogs a C to A transversion was detected, causing a Phe (TTC) to Leu (TTA) substitution at codon 81. This alteration was present neither in other canine breeds analyzed nor in other mammalian species. However, healthy German shepherd dogs were also homozygous for the mutant allele, indicating that it is not the primary disease-causing mutation. In addition, linkage analysis of polymorphic DNA markers flanking the Pit-1 gene, 41K19 and 52L05, revealed no co-segregation between the Pit-1 locus and the CPHD phenotype. These findings suggest that a gene other than Pit-1 is responsible for the pituitary anomaly in dwarf German shepherd dogs.

Expression of ayu (Plecoglossus altivelis) Pit-1 in Escherichia coli: its purification and immunohistochemical detection using monoclonal antibody.

PubMed

Chiu, Chi-Chien; John, Joseph Abraham Christopher; Hseu, Tzong-Hsiung; Chang, Chi-Yao

2002-03-01

The pituitary-specific transcription factor Pit-1 belongs to the family of POU-domain proteins and is known to play an important role in the differentiation of pituitary cells. Here we report the complete nucleotide sequence of cDNA encoding Pit-1 from the brackish water fish, ayu (Plecoglossus altivelis). Nucleotide sequence analysis of 1910 bp of ayu Pit-1 cDNA revealed an open reading frame of 1074 bp that encodes a protein of 358 amino acids containing a POU-specific domain, POU homeodomain, and an STA (Ser/Thr-rich activation) transactivation domain. We inserted the coding region of Pit-1 cDNA, obtained by PCR, into a pET-20b(+) plasmid to produce recombinant Pit-1 in Escherichia coli BL21 (DE3) pLysS cells. Upon induction with isopropyl beta-D-thiogalactopyranoside, Pit-1 was expressed and accumulated as inclusion bodies in E. coli. The protein was then purified in one step by affinity chromatography on a nickel-nitrilotriacetic acid agarose column under denaturing conditions. This method yielded 0.7 mg of highly pure and stable protein per 200 ml of bacterial culture. A band of 40 kDa, resolved as recombinant ayu Pit-1 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, agrees well with the molecular mass calculated from the translated cDNA sequence. The purified recombinant Pit-1 was confirmed in vitro through Western blot analysis, using its monoclonal antibody. This monoclonal antibody detected Pit-1 in the nuclei of ayu developing pituitary by immunohistochemical reaction. It serves as a good reagent for the detection of ayu Pit-1 in situ. Copyright 2002 Elsevier Science (USA).

ETR, TRA642. ON GROUND FLOOR, CAMERA LOOKS SOUTHWEST INTO PIT. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ETR, TRA-642. ON GROUND FLOOR, CAMERA LOOKS SOUTHWEST INTO PIT. CANAL STRUCTURE IS AT RIGHT OF CENTER WITH RECTANGULAR OPENING TO BE MATED WITH THE DE-FUELING MECHANISM THAT WILL DEPOSIT FUEL RODS INTO THE WORKING CANAL. INL NEGATIVE NO. 56-3710. R.G. Larsen, Photographer, 11/13/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Focused feasibility study for surface soil at the main pits and pushout area, J-field toxic burning pits area, Aberdeen Proving Ground, Maryland

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patton, T.; Benioff, P.; Biang, C.

1996-06-01

The Environmental Management Division of Aberdeen Proving Ground (APG), Maryland, is conducting a remedial investigation and feasibility study of the J-Field area at APG pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act, as amended (CERCLA). J-Field is located within the Edgewood Area of APG in Harford County, Maryland. Since World War II, activities in the Edgewood Area have included the development, manufacture, testing, and destruction of chemical agents and munitions. These materials were destroyed at J-Field by open burning/open detonation. Portions of J-Field continue to be used for the detonation and disposal of unexploded ordnance (UXO) by openmore » burning/open detonation under authority of the Resource Conservation and Recovery Act.« less

Survey of nine surface mines in North America. [Nine different mines in USA and Canada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayes, L.G.; Brackett, R.D.; Floyd, F.D.

This report presents the information gathered by three mining engineers in a 1980 survey of nine surface mines in the United States and Canada. The mines visited included seven coal mines, one copper mine, and one tar sands mine selected as representative of present state of the art in open pit, strip, and terrace pit mining. The purpose of the survey was to investigate mining methods, equipment requirements, operating costs, reclamation procedures and costs, and other aspects of current surface mining practices in order to acquire basic data for a study comparing conventional and terrace pit mining methods, particularly inmore » deeper overburdens. The survey was conducted as part of a project under DOE Contract No. DE-AC01-79ET10023 titled The Development of Optimal Terrace Pit Coal Mining Systems.« less

Posterior tibial slope in medial opening-wedge high tibial osteotomy: 2-D versus 3-D navigation.

PubMed

Yim, Ji Hyeon; Seon, Jong Keun; Song, Eun Kyoo

2012-10-01

Although opening-wedge high tibial osteotomy (HTO) is used to correct deformities, it can simultaneously alter tibial slope in the sagittal plane because of the triangular configuration of the proximal tibia, and this undesired change in tibial slope can influence knee kinematics, stability, and joint contact pressure. Therefore, medial opening-wedge HTO is a technically demanding procedure despite the use of 2-dimensional (2-D) navigation. The authors evaluated the posterior tibial slope pre- and postoperatively in patients who underwent navigation-assisted opening-wedge HTO and compared posterior slope changes for 2-D and 3-dimensional (3-D) navigation versions. Patients were randomly divided into 2 groups based on the navigation system used: group A (2-D guidance for coronal alignment; 17 patients) and group B (3-D guidance for coronal and sagittal alignments; 17 patients). Postoperatively, the mechanical axis was corrected to a mean valgus of 2.81° (range, 1°-5.4°) in group A and 3.15° (range, 1.5°-5.6°) in group B. A significant intergroup difference existed for the amount of posterior tibial slope change (Δ slope) pre- and postoperatively (P=.04).Opening-wedge HTO using navigation offers accurate alignment of the lower limb. In particular, the use of 3-D navigation results in significantly less change in the posterior tibial slope postoperatively than does the use of 2-D navigation. Accordingly, the authors recommend the use of 3-D navigation systems because they provide real-time intraoperative information about coronal, sagittal, and transverse axes and guide the maintenance of the native posterior tibial slope. Copyright 2012, SLACK Incorporated.

Exhuming South Polar Crater

NASA Technical Reports Server (NTRS)

2004-01-01

7 February 2004 The large, circular feature in this image is an old meteor impact crater. The crater is larger than the 3 kilometers-wide (1.9 miles-wide) Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image, thus only part of the crater is seen. The bright mesas full of pits and holes--in some areas resembling swiss cheese--are composed of frozen carbon dioxide. In this summertime view, the mesa slopes and pit walls are darkened as sunlight causes some of the ice to sublime away. At one time in the past, the crater shown here may have been completely covered with carbon dioxide ice, but, over time, it has been exhumed as the ice sublimes a little bit more each summer. The crater is located near 86.8oS, 111.6oW. Sunlight illuminates this scene from the upper left.

Are Icelandic rock-slope failures paraglacial? Age evaluation of seventeen rock-slope failures in the Skagafjörður area, based on geomorphological stacking, radiocarbon dating and tephrochronology

NASA Astrophysics Data System (ADS)

Mercier, Denis; Coquin, Julien; Feuillet, Thierry; Decaulne, Armelle; Cossart, Etienne; Jónsson, Helgi Pall; Sæmundsson, Þorstein

2017-11-01

In Iceland there are numerous rock-slope failures, especially in the Tertiary basaltic formations of the northern, eastern and northwestern regions. The temporal pattern of rock-slope failures is fundamental for understanding post-glacial events. In the Skagafjörður district, central northern Iceland, 17 rock-slope failures were investigated to determine the age of their occurrence. A geomorphic survey was carried out to identify and characterize landform units, both on the rock-slope failures and in their immediate vicinity. In this coastal area, we used geomorphological stacking which included the relationship between rock-slope failures and raised beaches caused by glacial isostatic rebounds, the chronology of which was established in previous studies. We searched for depressions on the rock-slope failures to then excavate a series of pits and map the stratigraphy. The resulting stratigraphic framework was then validated using (i) radiocarbon dating of wood remains, and (ii) tephrochronology, both of which were complemented by age-depth model calibration. The results confirm that all the rock-slope failures potentially occurred before the Boreal (8 ka), while 94% occurred before the Preboreal (10 ka). They all potentially occurred after the glacial retreat following the maximal ice extent and the Preboreal. More precisely, 11 of them potentially occurred between the Preboreal and the first half of the Holocene. This study demonstrates the relationship between the deglaciation and destabilization of slopes during the paraglacial phase (debuttressing, decompression, glacial isostatic rebound, seismic activity, etc.), which are also controlling factors favouring landsliding, but are difficult to identify for each individual rock-slope failure.

Novel approach for extinguishing large-scale coal fires using gas-liquid foams in open pit mines.

PubMed

Lu, Xinxiao; Wang, Deming; Qin, Botao; Tian, Fuchao; Shi, Guangyi; Dong, Shuaijun

2015-12-01

Coal fires are a serious threat to the workers' security and safe production in open pit mines. The coal fire source is hidden and innumerable, and the large-area cavity is prevalent in the coal seam after the coal burned, causing the conventional extinguishment technology difficult to work. Foams are considered as an efficient means of fire extinguishment in these large-scale workplaces. A noble foam preparation method is introduced, and an original design of cavitation jet device is proposed to add foaming agent stably. The jet cavitation occurs when the water flow rate and pressure ratio reach specified values. Through self-building foaming system, the high performance foams are produced and then infused into the blast drilling holes at a large flow. Without complicated operation, this system is found to be very suitable for extinguishing large-scale coal fires. Field application shows that foam generation adopting the proposed key technology makes a good fire extinguishment effect. The temperature reduction using foams is 6-7 times higher than water, and CO concentration is reduced from 9.43 to 0.092‰ in the drilling hole. The coal fires are controlled successfully in open pit mines, ensuring the normal production as well as the security of personnel and equipment.

Open Pit Mine 3d Mapping by Tls and Digital Photogrammetry: 3d Model Update Thanks to a Slam Based Approach

NASA Astrophysics Data System (ADS)

Vassena, G.; Clerici, A.

2018-05-01

The state of the art of 3D surveying technologies, if correctly applied, allows to obtain 3D coloured models of large open pit mines using different technologies as terrestrial laser scanner (TLS), with images, combined with UAV based digital photogrammetry. GNSS and/or total station are also currently used to geo reference the model. The University of Brescia has been realised a project to map in 3D an open pit mine located in Botticino, a famous location of marble extraction close to Brescia in North Italy. Terrestrial Laser Scanner 3D point clouds combined with RGB images and digital photogrammetry from UAV have been used to map a large part of the cave. By rigorous and well know procedures a 3D point cloud and mesh model have been obtained using an easy and rigorous approach. After the description of the combined mapping process, the paper describes the innovative process proposed for the daily/weekly update of the model itself. To realize this task a SLAM technology approach is described, using an innovative approach based on an innovative instrument capable to run an automatic localization process and real time on the field change detection analysis.

Retaining latch for a water pit gate

DOEpatents

Beale, A.R.

1997-11-18

A retaining latch is described for use in a hazardous materials storage or handling facility to adjustably retain a water pit gate in a gate frame. A retaining latch is provided comprising a latch plate which is rotatably mounted to each end of the top of the gate and a recessed opening, formed in the gate frame, for engaging an edge of the latch plate. The latch plate is circular in profile with one side cut away or flat, such that the latch plate is D-shaped. The remaining circular edge of the latch plate comprises steps of successively reduced thickness. The stepped edge of the latch plate fits inside a recessed opening formed in the gate frame. As the latch plate is rotated, alternate steps of the latch plate are engaged by the recessed opening. When the latch plate is rotated such that the flat portion of the latch plate faces the recessed opening in the gate frame, there is no connection between the opening and the latch plate and the gate is unlatched from the gate frame. 4 figs.

Geochemical Trends and Natural Attenuation of RDX, Nitrate, and Perchlorate in the Hazardous Test Area Fractured-Granite Aquifer, White Sands Missile Range, New Mexico, 1996-2006

USGS Publications Warehouse

Langman, Jeff B.; Robertson, Andrew J.; Bynum, Jamar; Gebhardt, Fredrick E.

2008-01-01

A fractured-granite aquifer at White Sands Missile Range is contaminated with the explosive compound RDX, nitrate, and perchlorate (oxidizer associated with rocket propellant) from the previous use of the Open Burn/Open Detonation site at the Hazardous Test Area. RDX, nitrate, and perchlorate ground-water concentrations were analyzed to examine source characteristics, spatial and temporal variability, and the influence of the natural attenuation processes of dilution and degradation in the Hazardous Test Area fractured-granite aquifer. Two transects of ground-water wells from the existing monitoring-site network - one perpendicular to ground-water flow (transect A-A') and another parallel to ground-water flow (transect B-B') - were selected to examine source characteristics and the spatial and temporal variability of the contaminant concentrations. Ground-water samples collected in 2005 from a larger sampling of monitoring sites than the two transects were analyzed for various tracers including major ions, trace elements, RDX degradates, dissolved gases, water isotopes, nitrate isotopes, and sulfate isotopes to examine the natural attenuation processes of dilution and degradation. Recharge entrains contaminants at the site and transports them downgradient towards the Tularosa Basin floor through a poorly connected fracture system(s). From 1996 to 2006, RDX, nitrate, and perchlorate concentrations in ground water downgradient from the Open Burn/Open Detonation site have been relatively stable. RDX, nitrate, and perchlorate in ground water from wells near the site indicate dispersed contaminant sources in and near the Open Burn/Open Detonation pits. The sources of RDX and nitrate in the pit area have shifted with time, and the shift correlates with the regrading of the south and east berms of each pit in 2002 and 2003 following closure of the site. The largest RDX concentrations were in ground water about 0.1 mile downgradient from the pits, the largest perchlorate concentrations were in ground water about 0.15 mile downgradient from the pits, and the largest nitrate concentrations were in ground water about 0.25 mile down-gradient from the pits. Strong and moderate correlation of water level and the contaminant concentrations near the source areas and low correlation outside and downgradient from the source areas indicates a diminishing of the water level/contaminant relation with downgradient flow. Ground water was not progressively older at all locations downgradient from the Open Burn/Open Detonation site indicating multiple recharge areas. Major ion and strontium concentrations and d2H and d18O values identified similar sources of recharge waters comprising the aquifer except along the basin periphery where recharge water may be influenced by dissolution of mineral assemblages associated with ore deposits that are present along the basin margins. Ground-water ages, dissolved-solids concentrations, and calcium-strontium concentrations indicate limited or partial connectivity between fractures and contributions of uncontaminated recharge water downgradient from the site that dilutes contaminant concentrations. Changes in RDX and nitrate concentration patterns, the presence of methane, changes in carbon dioxide concentrations and d15N and d34S values, and variable reduction-oxidation conditions suggest degradation of contaminants in the downgradient direction. Estimated values of electron potential were assigned to ground water collected in October 2005 from all monitoring sites at the Hazardous Test Area. Moderate to strong reducing conditions were present upgradient from the Open Burn/Open Detonation site, at the site, and at various locations downgradient from the site, but the aquifer contained well-oxygenated water between many of the reducing areas. The spatial variability of reduction-oxidation conditions in the aquifer exemplifies the partial connectivity of the fracture system(s). Dilution of the contaminants i

Cavitation Resistance in Seedless Vascular Plants: The Structure and Function of Interconduit Pit Membranes1[W][OPEN

PubMed Central

Brodersen, Craig; Jansen, Steven; Choat, Brendan; Rico, Christopher; Pittermann, Jarmila

2014-01-01

Plant water transport occurs through interconnected xylem conduits that are separated by partially digested regions in the cell wall known as pit membranes. These structures have a dual function. Their porous construction facilitates water movement between conduits while limiting the spread of air that may enter the conduits and render them dysfunctional during a drought. Pit membranes have been well studied in woody plants, but very little is known about their function in more ancient lineages such as seedless vascular plants. Here, we examine the relationships between conduit air seeding, pit hydraulic resistance, and pit anatomy in 10 species of ferns (pteridophytes) and two lycophytes. Air seeding pressures ranged from 0.8 ± 0.15 MPa (mean ± sd) in the hydric fern Athyrium filix-femina to 4.9 ± 0.94 MPa in Psilotum nudum, an epiphytic species. Notably, a positive correlation was found between conduit pit area and vulnerability to air seeding, suggesting that the rare-pit hypothesis explains air seeding in early-diverging lineages much as it does in many angiosperms. Pit area resistance was variable but averaged 54.6 MPa s m−1 across all surveyed pteridophytes. End walls contributed 52% to the overall transport resistance, similar to the 56% in angiosperm vessels and 64% in conifer tracheids. Taken together, our data imply that, irrespective of phylogenetic placement, selection acted on transport efficiency in seedless vascular plants and woody plants in equal measure by compensating for shorter conduits in tracheid-bearing plants with more permeable pit membranes. PMID:24777347

Gas flow in plant microfluidic networks controlled by capillary valves

NASA Astrophysics Data System (ADS)

Capron, M.; Tordjeman, Ph.; Charru, F.; Badel, E.; Cochard, H.

2014-03-01

The xylem vessels of trees constitute a model natural microfluidic system. In this work, we have studied the mechanism of air flow in the Populus xylem. The vessel microstructure was characterized by optical microscopy, transmission electronic microscopy (TEM), and atomic force microscopy (AFM) at different length scales. The xylem vessels have length ≈15 cm and diameter ≈20μm. Flow from one vessel to the next occurs through ˜102 pits, which are grouped together at the ends of the vessels. The pits contain a thin, porous pit membrane with a thickness of 310 nm. We have measured the Young's moduli of the vessel wall and of the pits (both water-saturated and after drying) by specific nanoindentation and nanoflexion experiments with AFM. We found that both the dried and water-saturated pit membranes have Young's modulus around 0.4 MPa, in agreement with values obtained by micromolding of pits deformed by an applied pressure difference. Air injection experiments reveal that air flows through the xylem vessels when the differential pressure across a sample is larger than a critical value ΔPc=1.8 MPa. In order to model the air flow rate for ΔP ⩾ΔPc, we assumed the pit membrane to be a porous medium that is strained by the applied pressure difference. Water menisci in the pit pores play the role of capillary valves, which open at ΔP =ΔPc. From the point of view of the plant physiology, this work presents a basic understanding of the physics of bordered pits.

An InGaN/GaN Superlattice to Enhance the Performance of Green LEDs: Exploring the Role of V-Pits.

PubMed

Liu, Mengling; Zhao, Jie; Zhou, Shengjun; Gao, Yilin; Hu, Jinfeng; Liu, Xingtong; Ding, Xinghuo

2018-06-21

Despite the fact that an InGaN/GaN superlattice (SL) is useful for enhancing the performance of a GaN-based light-emitting diode (LED), its role in improving the efficiency of green LEDs remains an open question. Here, we investigate the influence of a V-pits-embedded InGaN/GaN SL on optical and electrical properties of GaN-based green LEDs. We recorded a sequence of light emission properties of InGaN/GaN multiple quantum wells (MQWs) grown on a 0- and 24-pair InGaN/GaN SL by using scanning electron microscopy (SEM) in combination with a room temperature cathodoluminescence (CL) measurement, which demonstrated the presence of a potential barrier formed by the V-pits around threading dislocations (TDs). We find that an increase in V-pit diameter would lead to the increase of V-pit potential barrier height. Our experimental data suggest that a V-pits-embedded, 24-pair InGaN/GaN SL can effectively suppress the lateral diffusion of carriers into non-recombination centers. As a result, the external quantum efficiency (EQE) of green LEDs is improved by 29.6% at an injection current of 20 mA after implementing the V-pits-embedded InGaN/GaN SL layer. In addition, a lower reverse leakage current was achieved with larger V-pits.

Development of partial rock veneers by root throw in a subalpine setting

USGS Publications Warehouse

Osterkamp, W.R.; Toy, T.J.; Lenart, M.T.

2006-01-01

Rock veneers stabilize hillslope surfaces, occur especially in areas of immature soil, and form through a variety of process sets that includes root throw. Near Westcliffe, Colorado, USA, data were collected from a 20 ?? 500 m transect on the east slope of the Sangre de Cristo Mountains. Ages of pit/mound complexes with rock fragments exposed at the surface by root throw ranged from recent (freshly toppled tree) to unknown (complete tree decay). Calculations based on dimensions of the pit/mound complexes, estimated time of free topppling, sizes of exposed rock fragments, and percentage rock covers at pit/mound complexes, as well as within the transect area, indicate that recent rates of root throw have resulted in only partial rock veneering since late Pleistocene deglaciation. Weathering of rock fragments prevent development of an extensive rock veneer and causes a balance, achieved within an estimated 700 years, between the rates of rock-fragment exposure by root throw and clast disintegration by chemical reduction. The estimated rate of rock-fragment reduction accounts for part of the fluvial sediment yields observed for forested subalpine areas of western North America. Copyright ?? 2005 John Wiley & Sons, Ltd.

Assessment of Rock Slope Stability in Limestone Quarries in the Tournai's Region (Belgium) Using Structural Data

NASA Astrophysics Data System (ADS)

Tshibangu, Jean-Pierre; Deloge, K. Pierre-Alexandre; Deschamps, Benoît; Coudyzer, Christophe

The Tournais region is characterised by famous outcrops of carboniferous limestone which is mined out for cement and raw material production. The four main quarries found in the Region, i.e. Gaurain-Ramecroix, Milieu, Antoing and Lemay; are owned by the three main cement producers in Belgium: Italcimenti, Holcim and CBR. The global production of limestone is about 20 millions tons per year, giving big pits with depths up to 150 m. With the growth of the pits, the quarries are approaching each other leading to the problem of managing the reserves contained in the separating walls and their mechanical stability. The limestone deposit is composed of different seams having varying thickness, chemical com- position and even mechanical properties. The deposit has an overall horizontal dip and is intersected by two main sets of discontinuities with a spacing of about 10 m or less. It is also crossed by a set of east to west faults but the quarries are implanted in the in between areas, so to not be crossed by these faults. The layers and specially the shallow ones are characterised by a typical karstic weathering giving open or filled cavities. This paper presents the global work quarried out in order to study the stability of the Lemays quarry. First a description of the orientation and spacing of discontinuities is presented, and an attempt made to correlate to the development of weathering. Mechanical laboratory tests have been performed and a qualification of the rock mass assessed. A coupled approach is then presented using a mining planning analysis and mechanical simulation (i.e. Finite Element method).

Geotechical Investigation of Landslides in Gurpinar Region

NASA Astrophysics Data System (ADS)

Karabulut, S.; Imre, N.; Dalgic, S.; Ozcep, F.

2012-04-01

Gürpinar in Beylikdüzü district in Istanbul, Rapid and uncontrolled construction have been exposed due to the current visual. Although to the previous zoning plan to covered a large part of the study area was recommended to use as green space, today's regulations have begun to define these areas as the areas mostly precautionary. With the development of engineering technology and knowledge, these areas were allowed to open of new structures to take necessary precautions. With increase in the effective construction in these regions, the existing slopes has led to start due to imbalance of mass movements. By using topographic map (1 / 5000 scale) and satellite images were examined in the region, the boundaries of existing landslides have been identified within the scope of this study. These areas are Çukurlar, Pınarkent, Pekmez and Onbeşevler. In addition to geophysical studies previously performed in the region; Seismic Reflection, Surface Wave Analysis (Active and Passive Source) and ground penetrating radar measurements were done. The geometry of surface planes and its depth, sand-gravel lenses, border of saturated clay units and the dynamic elastic parameters have been determined by using geophysical studies. The target depth of each method related to the properties of used sources or antenna and features of equipment. In Onbeşevler selected as pilot regions for georadar measurements, different water saturation at different depths s have been identified by using information taken from a depth of 30 meters. As a result of the geophysical studies, each in a landslide area, many slip plane have been identified and are given in sections. Geological cross-sections created for the workspace by using the drilling data and the pits belong to private companies and government agencies in the region. Inside the border of each landslides, the slope stability analysis done by using geological cross-sections and its physical parameters. Slope stability analysis made by using Slide program, safety coefficient were calculated using different slip planes obtained from geophysical parameters. Analysis were repeated for each slip plane for static and dynamic conditions. Examined to results of these slope stability analysis, safety coefficient have been identified below the limit values or very close to the border of even static conditions in Çukurlar, Pınarkent, Pekmez ve Onbeşevler's slope.

Study of the Rock Mass Failure Process and Mechanisms During the Transformation from Open-Pit to Underground Mining Based on Microseismic Monitoring

NASA Astrophysics Data System (ADS)

Zhao, Yong; Yang, Tianhong; Bohnhoff, Marco; Zhang, Penghai; Yu, Qinglei; Zhou, Jingren; Liu, Feiyue

2018-05-01

To quantitatively understand the failure process and failure mechanism of a rock mass during the transformation from open-pit mining to underground mining, the Shirengou Iron Mine was selected as an engineering project case study. The study area was determined using the rock mass basic quality classification method and the kinematic analysis method. Based on the analysis of the variations in apparent stress and apparent volume over time, the rock mass failure process was analyzed. According to the recent research on the temporal and spatial change of microseismic events in location, energy, apparent stress, and displacement, the migration characteristics of rock mass damage were studied. A hybrid moment tensor inversion method was used to determine the rock mass fracture source mechanisms, the fracture orientations, and fracture scales. The fracture area can be divided into three zones: Zone A, Zone B, and Zone C. A statistical analysis of the orientation information of the fracture planes orientations was carried out, and four dominant fracture planes were obtained. Finally, the slip tendency analysis method was employed, and the unstable fracture planes were obtained. The results show: (1) The microseismic monitoring and hybrid moment tensor analysis can effectively analyze the failure process and failure mechanism of rock mass, (2) during the transformation from open-pit to underground mining, the failure type of rock mass is mainly shear failure and the tensile failure is mostly concentrated in the roof of goafs, and (3) the rock mass of the pit bottom and the upper of goaf No. 18 have the possibility of further damage.

Use of overburden rocks from open-pit coal mines and waste coals of Western Siberia for ceramic brick production with a defect-free structure

NASA Astrophysics Data System (ADS)

Stolboushkin, A. Yu; Ivanov, A. I.; Storozhenko, G. I.; Syromyasov, V. A.; Akst, D. V.

2017-09-01

The rational technology for the production of ceramic bricks with a defect-free structure from coal mining and processing wastes was developed. The results of comparison of physical and mechanical properties and the structure of ceramic bricks manufactured from overburden rocks and waste coal with traditional for semi-dry pressing mass preparation and according to the developed method are given. It was established that a homogeneous, defect-free brick texture obtained from overburden rocks of open-pit mines and waste coal improves the quality of ceramic wall materials produced by the method of compression molding by more than 1.5 times compared to the brick with a traditional mass preparation.

Quasi-two-layer morphodynamic model for bedload-dominated problems: bed slope-induced morphological diffusion

NASA Astrophysics Data System (ADS)

Maldonado, Sergio; Borthwick, Alistair G. L.

2018-02-01

We derive a two-layer depth-averaged model of sediment transport and morphological evolution for application to bedload-dominated problems. The near-bed transport region is represented by the lower (bedload) layer which has an arbitrarily constant, vanishing thickness (of approx. 10 times the sediment particle diameter), and whose average sediment concentration is free to vary. Sediment is allowed to enter the upper layer, and hence the total load may also be simulated, provided that concentrations of suspended sediment remain low. The model conforms with established theories of bedload, and is validated satisfactorily against empirical expressions for sediment transport rates and the morphodynamic experiment of a migrating mining pit by Lee et al. (1993 J. Hydraul. Eng. 119, 64-80 (doi:10.1061/(ASCE)0733-9429(1993)119:1(64))). Investigation into the effect of a local bed gradient on bedload leads to derivation of an analytical, physically meaningful expression for morphological diffusion induced by a non-zero local bed slope. Incorporation of the proposed morphological diffusion into a conventional morphodynamic model (defined as a coupling between the shallow water equations, Exner equation and an empirical formula for bedload) improves model predictions when applied to the evolution of a mining pit, without the need either to resort to special numerical treatment of the equations or to use additional tuning parameters.

Structure-interfacial properties relationship and quantification of the amphiphilicity of well-defined ionic and non-ionic surfactants using the PIT-slope method.

PubMed

Ontiveros, Jesús F; Pierlot, Christel; Catté, Marianne; Molinier, Valérie; Salager, Jean-Louis; Aubry, Jean-Marie

2015-06-15

The Phase Inversion Temperature of a reference C10E4/n-Octane/Water system exhibits a quasi-linear variation versus the mole fraction of a second surfactant S2 added in the mixture. This variation was recently proposed as a classification tool to quantify the Hydrophilic-Lipophilic Balance (HLB) of commercial surfactants. The feasibility of the so-called PIT-slope method for a wide range of well-defined non-ionic and ionic surfactants is investigated. The comparison of various surfactants having the same dodecyl chain tail allows to rank the polar head hydrophilicity as: SO3Na⩾SO4Na⩾NMe3Br>E2SO3Na≈CO2Na⩾E1SO3Na⩾PhSO3Na>Isosorbide(exo)SO4Na≫IsosorbideendoSO4Na≫E8⩾NMe2O>E7>E6⩾Glucosyl>E5⩾Diglyceryl⩾E4>E3>E2≈Isosorbide(exo)>Glyceryl>Isosorbide(endo). The influence on the surfactant HLB of other structural parameters, i.e. hydrophobic chain length, unsaturation, replacement of Na(+) by K(+) counterion, and isomerism is also investigated. Finally, the method is successfully used to predict the optimal formulation of a new bio-based surfactant, 1-O-dodecyldiglycerol, when performing an oil scan at 25 °C. Copyright © 2015 Elsevier Inc. All rights reserved.

Quasi-two-layer morphodynamic model for bedload-dominated problems: bed slope-induced morphological diffusion.

PubMed

Maldonado, Sergio; Borthwick, Alistair G L

2018-02-01

We derive a two-layer depth-averaged model of sediment transport and morphological evolution for application to bedload-dominated problems. The near-bed transport region is represented by the lower (bedload) layer which has an arbitrarily constant, vanishing thickness (of approx. 10 times the sediment particle diameter), and whose average sediment concentration is free to vary. Sediment is allowed to enter the upper layer, and hence the total load may also be simulated, provided that concentrations of suspended sediment remain low. The model conforms with established theories of bedload, and is validated satisfactorily against empirical expressions for sediment transport rates and the morphodynamic experiment of a migrating mining pit by Lee et al. (1993 J. Hydraul. Eng. 119 , 64-80 (doi:10.1061/(ASCE)0733-9429(1993)119:1(64))). Investigation into the effect of a local bed gradient on bedload leads to derivation of an analytical, physically meaningful expression for morphological diffusion induced by a non-zero local bed slope. Incorporation of the proposed morphological diffusion into a conventional morphodynamic model (defined as a coupling between the shallow water equations, Exner equation and an empirical formula for bedload) improves model predictions when applied to the evolution of a mining pit, without the need either to resort to special numerical treatment of the equations or to use additional tuning parameters.

Appearance of the pituitary factor Pit-1 increases chromatin remodeling at hypersensitive site III in the human GH locus.

PubMed

Yang, Xiaoyang; Jin, Yan; Cattini, Peter A

2010-07-01

Expression of pituitary and placental members of the human GH and chorionic somatomammotropin (CS) gene family is directed by an upstream remote locus control region (LCR). Pituitary-specific expression of GH requires direct binding of Pit-1 (listed as POU1F1 in the HUGO database) to sequences marked by a hypersensitive site (HS) region (HS I/II) 14.6 kb upstream of the GH-N gene (listed as GH1 in the HUGO database). We used human embryonic kidney 293 (HEK293) cells overexpressing wild-type and mutant Pit-1 proteins as a model system to gain insight into the mechanism by which Pit-1 gains access to the GH LCR. Addition of Pit-1 to these cells increased DNA accessibility at HS III, located 28 kb upstream of the human GH-N gene, in a POU homeodomain-dependent manner, as reflected by effects on histone hyperacetylation and RNA polymerase II activity. Direct binding of Pit-1 to HS III sequences is not supported. However, the potential for binding of ETS family members to this region has been demonstrated, and Pit-1 association with this ETS element in HS III sequences requires the POU homeodomain. Also, both ETS1 and ELK1 co-precipitate from human pituitary extracts using two independent sources of Pit-1 antibodies. Finally, overexpression of ELK1 or Pit-1 expression in HEK293 cells increased GH-N RNA levels. However, while ELK1 overexpression also stimulated placental CS RNA levels, the effect of Pit-1 appeared to correlate with ETS factor levels and target GH-N preferentially. These data are consistent with recruitment and an early role for Pit-1 in remodeling of the GH LCR at the constitutively open HS III through protein-protein interaction.

Modeling pitting corrosion of iron exposed to alkaline solutions containing nitrate and nitrite

NASA Astrophysics Data System (ADS)

Chen, Lifeng

2001-07-01

Pitting corrosion could be extremely serious for dilute high-level radioactive waste stored or processed in carbon steel tanks at the Savannah River Site. In these solutions, nitrate is an aggressive ion with respect to pitting of carbon steel while nitrite can be used as an inhibitor. Excessive additions of nitrite increase the risk of generating unstable nitrogen compounds during waste processing, and insufficient additions of nitrite could increase the risk of corrosion-induced failure. Thus there are strong incentives to obtain a fundamental understanding of the role of nitrite in pitting corrosion prevention with these solution chemistries. In this dissertation, both a 1-D and a 2-D model are used to study the pitting mechanism as a function of nitrite/nitrate ratios. The 1-D model used BAND(J) to test a reaction mechanism for the passivation behavior by comparing the predicted Open Circuit Potential (OCP) with OCP data from experiments at different NO2-/NO3- ratio. The model predictions are compared with Cyclic Potentiodynamic Polarization (CPP) experiments. A 2-D model was developed for the propagation of a pit in iron by writing subroutines for finite element software of GAMBIT and FIDAP. Geometrically distributed anodic and cathodic reactions are assumed. The results show three partial explanations describing the inhibition influence of nitrite to iron corrosion: the competing reduction reaction of nitrate to nitrite, the formation of Fe(OH)+, and the function of the porous film. The current distributions and the effect of porosity of the film on pH are also explained. The calculation results also show that rate of pit growth decreases as the pit diameter increases until it reaches a constant value. The profile of the local current density on the pit wall is parabolic for small pits and it changes to a linear distribution for large pits. The model predicts that addition of nitrite will decrease the production of ferrous ions and those can prevent iron from dissolving. Also nitrate ion will accumulate in the pit if not enough inhibitor is added to the solution, and this will accelerate pit growth.

The character of long-term eruptions: Inferences from episodes 50-53 of the Pu'u 'Ō'ō-Kūpaianaha eruption of Kīlauea volcano

USGS Publications Warehouse

Heliker, C.C.; Mangan, M.T.; Mattox, T.N.; Kauahikaua, J.P.; Helz, R.T.

1998-01-01

The Pu'u 'Ō'ō-Kūpaianaha eruption on the east rift zone of Kīlauea began in January 1983. The first 9 years of the eruption were divided between the Pu'u 'Ō'ō (1983–1986) and Kūpaianaha (1986–1992) vents, each characterized by regular, predictable patterns of activity that endured for years. In 1990 a series of pauses in the activity disturbed the equilibrium of the eruption, and in 1991, the output from Kūpaianaha steadily declined and a short-lived fissure eruption broke out between Kūpaianaha and Pu'u 'Ō'ō. In February 1992 the Kūpaianaha vent died, and, 10 days later, eruptive episode 50 began as a fissure opened on the uprift flank of the Pu'u 'Ō'ō cone. For the next year, the eruption was marked by instability as more vents opened on the flank of the cone and the activity was repeatedly interrupted by brief pauses in magma supply to the vents. Episodes 50–53 constructed a lava shield 60 m high and 1.3 km in diameter against the steep slope of the Pu'u 'Ō'ō cone. By 1993 the shield was pockmarked by collapse pits as vents and lava tubes downcut as much as 29 m through the thick deposit of scoria and spatter that veneered the cone. As the vents progressively lowered, the level of the Pu'u 'Ō'ō pond also dropped, demonstrating the hydraulic connection between the two. The downcutting helped to undermine the prominent Pu'u 'Ō'ō cone, which has diminished in size both by collapse, as a large pit crater formed over the conduit, and by burial of its flanks. Intervals of eruptive instability, such as that of 1991–1993, accelerate lateral expansion of the subaerial flow field both by producing widely spaced vents and by promoting surface flow activity as lava tubes collapse and become blocked during pauses.

One year water chemistry monitoring of the flooding of the Meirama open pit (NW Spain)

NASA Astrophysics Data System (ADS)

Delgado, J.; Juncosa, R.; Vázquez, A.; Fernández-Bogo, S.

2009-04-01

In December, 2007, after 30 years of operations, the mine of Meirama finished the extraction of brown lignite. Starting in April 2008, the flooding of the open pit has started and this is leading to the formation of a large mining lake (~2 km2 surface and up to 180 m depth) in which surface (river and rain water) and ground waters are involved. Since the beginning of the flooding, lake waters are weekly sampled and analyzed for temperature, pH, redox, EC, TDS, TSS, DO,DIC, DOC, turbidity, alkalinity/acidity as well as nearly 40 inorganic chemical components. Stable water isotopes (deuterium and oxygen) are also being recorded. In order to better understand the dynamic chemical evolution of lake waters, the chemical characteristics of rain water as well as a series of lake tributaries and ground waters are also being measured. Since the beginning of the flooding process, the chemical quality of lake water has experienced an interesting evolution that obeys to a variety of circumstances. The silicic geologic substratum of the catchment determines that both ground and surface waters have a rather low alkalinity. Moreover, the presence of disseminated sulfides (mainly pyrite) within the schistous materials of the mine slopes and internal rock dumps provokes a significant acidic load. From April to October 2008, the lake waters had only the contribution of rain and ground waters. Since the beginning of October, a significant volume of surface waters has been derived to the mine hole. Taking pH as indicator, the first water body had a rather acidic pH (~3) which was progressively amended with the addition of a certain amount of lime to reach an upper value of ~8 by late August. The diminution in the addition of lime up to its elimination, in December, has conducted to the progressive acidification of the lake. At present, an instrumented floating deck is being deployed in the lake. This device will serve as a base point where it is planned to locate a series of instrumentation (complete weather monitoring station, multiparametric probe, sediment trap line) that will complement with depth profiles the surficial sampling performed so far.

Evidence of climatic effects on soil, vegetation and landform in temperate forests of south-eastern Australia

NASA Astrophysics Data System (ADS)

Inbar, Assaf; Nyman, Petter; Lane, Patrick; Sheridan, Gary

2016-04-01

Water and radiation are unevenly distributed across the landscape due to variations in topography, which in turn causes water availability differences on the terrain according to elevation and aspect orientation. These differences in water availability can cause differential distribution of vegetation types and indirectly influence the development of soil and even landform, as expressed in hillslope asymmetry. While most of the research on the effects of climate on the vegetation and soil development and landscape evolution has been concentrated in drier semi-arid areas, temperate forested areas has been poorly studied, particularly in South Eastern Australia. This study uses soil profile descriptions and data on soil depth and landform across climatic gradients to explore the degrees to which coevolution of vegetation, soils and landform are controlled by radiative forcing and rainfall. Soil depth measurements were made on polar and equatorial facing hillslopes located at 3 sites along a climatic gradient (mean annual rainfall between 700 - 1800 mm yr-1) in the Victorian Highlands, where forest types range from dry open woodland to closed temperate rainforest. Profile descriptions were taken from soil pits dag on planar hillslopes (50 m from ridge), and samples were taken from each horizon for physical and chemical properties analysis. Hillslope asymmetry in different precipitation regimes of the study region was quantified from Digital Elevation Models (DEMs). Significant vegetation differences between aspects were noted in lower and intermediate rainfall sites, where polar facing aspects expressed higher overall biomass than the drier equatorial slope. Within the study domain, soil depth was strongly correlated with forest type and above ground biomass. Soil depths and chemical properties varied between topographic aspects and along the precipitation gradient, where wetter conditions facilitate deeper and more weathered soils. Furthermore, soil depths showed different patterns as a function of contributing area. While soils on the polar facing slope became deeper, soils on the equatorial facing slope kept a uniform depth with increasing contributing area, pointing to different governing geomorphic processes at work. Using slope-area relationships analysis, polar facing slopes were found to be generally steeper and with longer distance to channel initiation point (if existent) than that of the equatorial facing slopes, strengthening the evidence of climate-affected differential geomorphic processes shaping the hillslope form. The results point out to the effect of climate on the development and coevolution of soil, vegetation and landform in the temperate part of Australia.

Analytical data for waters of the Harvard Open Pit, Jamestown Mine, Tuolumne County, California, March 1998-September 1999

USGS Publications Warehouse

Ashley, R.P.; Savage, K.S.

2001-01-01

The Jamestown mine is located in the Jamestown mining district in western Tuolumne County, California (see Fig. 1). This district is one of many located on or near the Melones fault zone, a major regional suture in the Sierra Nevada foothills. The districts along the Melones fault comprise the Mother Lode gold belt (Clark, 1970). The Harvard pit is the largest of several open pits mined at the Jamestown site by Sonora Mining Corporation between 1986 and 1994 (Fig. 2; Algood, 1990). It is at the site of an historical mine named the Harvard that produced about 100,000 troy ounces of gold, mainly between 1906 and 1916 (Julihn and Horton, 1940). Sonora Mining mined and processed about 17,000,000 short tons of ore, with an overall stripping ratio of about 4.5:1, yielding about 660,000 troy ounces of gold (Nelson and Leicht, 1994). Most of this material came from the Harvard pit, which attained dimensions of about 2700 ft (830 m) in length, 1500 ft (460 m) in width, and 600 ft (185 m) in depth. The bottom of the pit is at an elevation of 870 ft (265 m). Since mining operations ceased in mid-1994, the open pit has been filling with water. As of November, 2000, lake level had reached an elevation of about 1170 ft (357 m). Water quality monitoring data gathered after mine closure showed rising levels of arsenic, sulfate, and other components in the lake, with particularly notable increases accompanying a period of rapid filling in 1995 (County of Tuolumne, 1998). The largest potential source for arsenic in the vicinity of the Harvard pit is arsenian pyrite, the most abundant sulfide mineral related to gold mineralization. A previous study of weathering of arsenian pyrite in similarly mineralized rocks at the Clio mine, in the nearby Jacksonville mining district, showed that arsenic released by weathering of arsenian pyrite is effectively attenuated by adsorption on goethite or coprecipitation with jarosite, depending upon the buffering capacity of the pyrite-bearing rock (Savage and others, 2000). Although jarosite would be expected to dissolve in water having the composition of the developing pit lake, iron oxyhydroxide species (ferrihydrite and goethite) would be stable, and strong partitioning of arsenic onto suspended particles or bottom sediments containing these iron phases would be expected. Arsenic release to the lake would not be expected until stratification develops, producing a reducing, non-circulating hypolimnion in which the iron phases would be destroyed by dissolution. The fact that arsenic concentrations increased rapidly before the pit lake was deep enough to stratify shows that arsenic may not be attenuated in the ways that the earlier Clio mine area study indicated, and suggested that our understanding of release and transport of arsenic in this environment is incomplete. Therefore, in 1997 we decided to study the chemical evolution of the Harvard pit lake as part of a project on environmental impacts of gold mining in the Sierra Nevada, and in early 1998 we developed a cooperative study with several of the investigators in the Stanford University Department of Geological and Environmental Sciences who had done the Clio study. The U.S. Geological Survey portion of the project has been funded by the Mineral Resources Program. It is anticipated that a better understanding of the release and transport of arsenic into the Harvard pit lake and its accumulation there will contribute to more accurate predictions of arsenic release from weathering of sulfide-bearing rocks exposed by mining or other activities or events, and to better forecasts of pit lake evolution in this and similar environments, leading to more effective monitoring and mitigation strategies. An accurate predictive model is needed for the Harvard pit lake to forecast trends in metal concentrations, particularly arsenic, and also concentrations of major cations and anions. As the lake approaches pre-mining groundwater levels the lake water could move down the hydrologic gradient to the southeast into domestic wells, and could also affect the surface water of Woods Creek (see Figures 1-3). This report presents data for water samples collected from March, 1998 through September, 1999. Selected preliminary data for the pit lake for the 1998 calendar year have been reported (Savage and others, 2000).

An integrated geophysical and geochemical exploration of critical zone weathering on opposing montane hillslope

NASA Astrophysics Data System (ADS)

Singha, K.; Navarre-Sitchler, A.; Bandler, A.; Pommer, R. E.; Novitsky, C. G.; Holbrook, S.; Moore, J.

2017-12-01

Quantifying coupled geochemical and hydrological properties and processes that operate in the critical zone is key to predicting rock weathering and subsequent transmission and storage of water in the shallow subsurface. Geophysical data have the potential to elucidate geochemical and hydrologic processes across landscapes over large spatial scales that are difficult to achieve with point measurements alone. Here, we explore the connections between weathering and fracturing, as measured from integrated geochemical and geophysical borehole data and seismic velocities on north- and south-facing aspects within one watershed in the Boulder Creek Critical Zone Observatory. We drilled eight boreholes up to 13 m deep on north- and south-facing aspects within Upper Gordon Gulch, and surface seismic refraction data were collected near these wells to explore depths of regolith and bedrock, as well as anisotropic characteristics of the subsurface material due to fracturing. Optical televiewer data were collected in these wells to infer the dominant direction of fracturing and fracture density in the near surface to corroborate with the seismic data. Geochemical samples were collected from four of these wells and a series of shallow soil pits for bulk chemistry, clay fraction, and exchangeable cation concentrations to identify depths of chemically altered saprolite. Seismic data show that depth to unweathered bedrock, as defined by p-wave seismic velocity, is slightly thicker on the north-facing slopes. Geochemical data suggest that the depth to the base of saprolite ranges from 3-5 m, consistent with a p-wave velocity value of 1200 m/s. Based on magnitude and anisotropy of p-wave velocities together with optical televiewer data, regolith on north-facing slopes is thought to be more fractured than south-facing slopes, while geochemical data indicate that position on the landscape is another important characteristic in determining depths of weathering. We explore the importance of fracture opening in controlling both saprolite and regolith thickness within this watershed.

[Pit-picking surgery for pilonidal disease].

PubMed

Iesalnieks, I; Deimel, S; Kienle, K; Schlitt, H J; Zülke, C

2011-10-01

The pit-picking method was first described by J. Bascom in 1980, however, this minimally invasive technique is used only by a minority of surgeons yet. Surgery was performed under local anesthesia. All primary pits in the midline were removed by excising a border of skin of <1 mm and a 1 cm long incision was made parallel to one side of the cleft to open the chronic abscess cavity. No specific postoperative wound care was given. Pit-picking surgery was carried out 157 times in a total of 153 patients (126 males) between June 2007 and November 2010. Follow-up information was available in 123 cases and 21 patients (17%) developed disease recurrence after a mean follow-up time of 7.1 months. By multivariate analysis, a body mass index (BMI) >25 kg/m(2) (p=0.019) and duration of the disease of ≥6 months (p=0.017) were statistically significantly associated with disease recurrence after pit-picking surgery. The recurrence occurred more often in male than in female patients (20% versus 4.5%, p=0.12) Patients with pilonidal disease can be successfully treated by the pit-picking procedure in more than 80% of selected cases. Female patients and non-overweight male patients with short-term disease benefit most from this treatment method.

Building pit dewatering: application of transient analytic elements.

PubMed

Zaadnoordijk, Willem J

2006-01-01

Analytic elements are well suited for the design of building pit dewatering. Wells and drains can be modeled accurately by analytic elements, both nearby to determine the pumping level and at some distance to verify the targeted drawdown at the building site and to estimate the consequences in the vicinity. The ability to shift locations of wells or drains easily makes the design process very flexible. The temporary pumping has transient effects, for which transient analytic elements may be used. This is illustrated using the free, open-source, object-oriented analytic element simulator Tim(SL) for the design of a building pit dewatering near a canal. Steady calculations are complemented with transient calculations. Finally, the bandwidths of the results are estimated using linear variance analysis.

STS-48 crew participates in JSC fire fighting and fire training exercises

NASA Technical Reports Server (NTRS)

1991-01-01

STS-48 Mission Specialist (MS) Charles D. Gemar opens water hose nozzle as he approaches a fire blazing in JSC's Fire Training Pit during fire fighting and fire training exercises. Pilot Kenneth S. Reightler, Jr steadies the hose behind Gemar. At Gemars right is an unidentified fire department Official, MS Mark N. Brown, and Commander John O. Creighton. Brown and Crieghton are obscured by the water spray. The Fire Training Pit is located across from the Gilruth Center Bldg 207.

Uranium in mining water of kaolin open pit in Zarów (Lower Silesia); methodology of determination and genetic remarks.

PubMed

Chau, N D; Wyszomirski, P; Chruściel, E; Ochoński, A

1999-11-01

In this paper, a method of determination of uranium 238 and 234 in mining waters of Andrzej kaolin open pit in Zarów (Lower Silesia) is presented. The method is based on independent measurements of alpha and beta radiation intensities by means of a liquid scintillation spectrometer alpha/beta. The initial volume of water sample was 3 dm3, then it was diminished by chemical preparation to 6 cm3, and then 12 cm3 of scintillator was added. The lower limit of detection (for the measurement time of 8 h) for both 234U and 238U amounted to 0.02 Bq/dm3. For determination of the uranium content in ferruginous sediments precipitating from mining waters of the above-mentioned open pit, gamma ray spectrometry was used. The obtained results may be viewed as a contribution to studies on anomalous uranium concentration within this kaolin deposit. The elevated uranium content, in comparison with its average concentration in the Earth crust, is characteristic for parent rocks of Andrzej kaolin deposit, which are granitoids of Strzegom-Sobótka massif. In connection with it, the high uranium content can be observed not only in kaolin and weakly kaolinised granitoids from the deposit in question, but also in mining waters genetically related with them.

The use of vibration monitoring to record the blasting works impact on buildings surrounding open-pit mines

NASA Astrophysics Data System (ADS)

Sołtys, Anna; Pyra, Józef; Winzer, Jan

2018-04-01

Environmental protection law and geological and mining law require the mineral mining plant to protect its surroundings from the effects of mining operations. This also applies to the negative impact of vibrations induced by blasting works on people and construction facilities. Effective protection is only possible if the level of this impact is known, therefore it is necessary to record it. The thesis formulated in this way has been and continues to be the guiding principle of the research works carried out in the AGH Laboratory of Blasting Work and Environmental Protection. As a result of these works are procedures for conducting preventive activities by open-pit mines in order to minimize the impact of blasting on facilities in the surrounding area. An important element of this activity is the monitoring of vibrations in constructions, which is a source of knowledge for excavation supervisors and engineers performing blasting works, thus contributing to raising the awareness of the responsible operation of the mining plant. Developed in the Laboratory of the Mine's Vibration Monitoring Station (KSMD), after several modernizations, it became a fully automated system for monitoring and recording the impact of blasting works on the surrounding environment. Currently, there are 30 measuring devices in 10 open-pit mines, and additional 8 devices are used to provide periodic measurement and recording services for the mines concerned.

Discrete modelling of drapery systems

NASA Astrophysics Data System (ADS)

Thoeni, Klaus; Giacomini, Anna

2016-04-01

Drapery systems are an efficient and cost-effective measure in preventing and controlling rockfall hazards on rock slopes. The simplest form consists of a row of ground anchors along the top of the slope connected to a horizontal support cable from which a wire mesh is suspended down the face of the slope. Such systems are generally referred to as simple or unsecured draperies (Badger and Duffy 2012). Variations such as secured draperies, where a pattern of ground anchors is incorporated within the field of the mesh, and hybrid systems, where the upper part of an unsecured drapery is elevated to intercept rockfalls originating upslope of the installation, are becoming more and more popular. This work presents a discrete element framework for simulation of unsecured drapery systems and its variations. The numerical model is based on the classical discrete element method (DEM) and implemented into the open-source framework YADE (Šmilauer et al., 2010). The model takes all relevant interactions between block, drapery and slope into account (Thoeni et al., 2014) and was calibrated and validated based on full-scale experiments (Giacomini et al., 2012).The block is modelled as a rigid clump made of spherical particles which allows any shape to be approximated. The drapery is represented by a set of spherical particle with remote interactions. The behaviour of the remote interactions is governed by the constitutive behaviour of the wire and generally corresponds to a piecewise linear stress-strain relation (Thoeni et al., 2013). The same concept is used to model wire ropes. The rock slope is represented by rigid triangular elements where material properties (e.g., normal coefficient of restitution, friction angle) are assigned to each triangle. The capabilities of the developed model to simulate drapery systems and estimate the residual hazard involved with such systems is shown. References Badger, T.C., Duffy, J.D. (2012) Drapery systems. In: Turner, A.K., Schuster R.L., editors. Rockfall: Characterization and Control. Washington, DC: Transportation Research Board, 554-576. Giacomini, A., Thoeni, K., Lambert, C., Booth, S., Sloan, S.W. (2012) Experimental study on rockfall drapery systems for open pit highwalls. International Journal of Rock Mechanics and Mining Sciences 56, 171-181. Šmilauer, V., Catalano, E., Chareyre, B., Dorofenko, S., Duriez, J., Gladky, A., Kozicki, J., Modenese, C., Scholtès, L., Sibille, L., Stránskỳ, J., Thoeni, K. (2010) Yade Documentation. The Yade Project, 1st ed., http://yade-dem.org/doc/. Thoeni, K., Giacomini, A., Lambert, C., Sloan, S.W., Carter, J.P. (2014) A 3D discrete element modelling approach for rockfall analysis with drapery systems. International Journal of Rock Mechanics and Mining Sciences 68, 107-119. Thoeni, K., Lambert, C., Giacomini, A., Sloan, S.W. (2013) Discrete modelling of hexagonal wire meshes with a stochastically distorted contact model. Computers and Geotechnics, 49, 158-69.

78 FR 54956 - Agency Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-06

... Control No. 2900- 0766'' in any correspondence. FOR FURTHER INFORMATION CONTACT: Crystal Rennie... 20420, (202) 632-7492 or email crystal[email protected] . Please refer to ``OMB Control No. 2900-NEW, Open... over time through routine and adhoc analysis to improve health care programs and develop hypotheses for...

A crossover study of rosuvastatin and pitavastatin in patients with type 2 diabetes.

PubMed

Yanagi, Kazunori; Monden, Tsuyoshi; Ikeda, Shiori; Matsumura, Mihoko; Kasai, Kikuo

2011-02-01

The effects of a low dose of rosuvastatin (ROS) and pitavastatin (PIT) on lipid profiles and inflammation markers were assessed in subjects with type 2 diabetes mellitus. A total of 90 Japanese type 2 diabetes patients with hyperlipidemia (low-density lipoprotein cholesterol [LDL-C] ≥140 mg/dL) were enrolled in this study. They were randomly assigned to four groups with open-label treatment with ROS (2.5 mg daily) or PIT (2 mg daily); two groups were sequentially treated with both drugs, with crossover of medication after 12 weeks, and the other two groups underwent treatment with either ROS or PIT for 24 weeks. The primary endpoints were the percentage changes in LDL-C, high-density lipoprotein cholesterol (HDL-C) and triglyceride, and the LDL-C/HDL-C ratio. Both ROS and PIT lowered LDL-C and triglyceride, and increased HDL-C. In particular, significantly greater reduction in LDL-C was seen with ROS (-44.1%) than with PIT (-36.9%, P<0.01) in the crossover group from ROS to PIT, and the same result was detected in the crossover group from PIT (-34.8%) to ROS (-44.7%). The ratio of LDL-C/HDL-C was significantly reduced with ROS treatment (from 3.45 to 1.85) compared with that with PIT (from 3.45 to 2.22, P<0.01). Both ROS and PIT lowered plasma levels of high-sensitivity C-reactive protein (hsCRP), tumor necrosis factor (TNF)-alpha, and plasminogen activator inhibitor-1 (PAI-1). In addition, the hsCRP level with the administration of ROS was significantly improved compared with the administration of PIT. There was no significant correlation between changes in LDL-C and hsCRP, TNF-alpha, and PAI-1 levels. ROS and PIT did not have an adverse effect on glycemic control in type 2 diabetes patients. Therapy with both statins improved lipid profiles and reduced proinflammatory responses; however, 2.5 mg of ROS have a potent LDL-C-lowering and hsCRP-lowering effect compared with 2 mg of PIT in patients with diabetes.

Glacier Elevation Change in Western Nyainqentanglha Range, Tibetan Plateau

NASA Astrophysics Data System (ADS)

Zhang, Q.; Kang, S.; Zhang, G.

2016-12-01

Glacier retreat is a focus in the world with the global warming, local water resources and sea level rise was influenced greatly. Glacier area in western Nyainqentanglha range have a change of -6.8 to -18.2 percent from 1970 to 2010, the area in the northern slope decreased by larger rate. Changes in glacier area can not be used to estimate glacier mass variation. In this study, we use Landsat OLI images to extract glacier outlines, then glacier elevation change was calculated by Differential interferometry of TerraSAR-X/TanDEM-X and SRTM-C DEM. The decreasing rate of glacier elevation in the western Nyainqentanglha range was -0.28 ±0.11 m yr-1 during 2000 to 2014, the northern slope of -0.44 ±0.11 m yr-1 show a faster annual thinning rate than the southern slope of -0.22 ±0.11 m yr-1, which is conform to the area change trend. Detailed study of the typical glaciers elevation change suggests that , zhadang glacier represent the annual thinning rate of -0.61±0.11 m yr-1, 41 points elevation was measured by RTK-GPS in the field expedition in 2013, this values was used to validate the DInSAR results. The correlation coefficient between them was 0.77. Gurenhekou glacier in the south slope shows glacier elevation change of -0.25 m w.e. yr-1, the value is similar to -0.31 m w.e. yr-1 investigated by stakes and snow pits. Glacier have an elevation change of -0.70 m yr-1 head-ward 500 m from the terminus position along centre line, it approximate to -0.85 m yr-1 measured by RTK-GPS. Otherwise the height difference of zero lies at 5764 m which is close to the average ELA of 5777 m measured by stakes and snow pits. Glacier and climate change interacted with each other. Temperature in western Nyainqentanglha range showed prominent increasing trend from 1964 to 2014, precipitation have increased slowly meanwhile and can not make up the mass loss affected by warming temperature, Glaciers elevation have lowered in recent decades.

Estimating disperser abundance using open population models that incorporate data from continuous detection PIT arrays

USGS Publications Warehouse

Dzul, Maria C.; Yackulic, Charles B.; Korman, Josh

2017-01-01

Autonomous passive integrated transponder (PIT) tag antenna systems continuously detect individually marked organisms at one or more fixed points over long time periods. Estimating abundance using data from autonomous antennae can be challenging, because these systems do not detect unmarked individuals. Here we pair PIT antennae data from a tributary with mark-recapture sampling data in a mainstem river to estimate the number of fish moving from the mainstem to the tributary. We then use our model to estimate abundance of non-native rainbow trout Oncorhynchus mykiss that move from the Colorado River to the Little Colorado River (LCR), the latter of which is important spawning and rearing habitat for federally-endangered humpback chub Gila cypha. We estimate 226 rainbow trout (95% CI: 127-370) entered the LCR from October 2013-April 2014. We discuss the challenges of incorporating detections from autonomous PIT antenna systems into mark-recapture population models, particularly in regards to using information about spatial location to estimate movement and detection probabilities.

Application of wire beam electrode technique to investigate initiation and propagation of rebar corrosion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, Wei; Dong, Ze Hua, E-mail: zehua.dong@gmail.com; Kong, De Jie

Multi-electrode technique named as wire beam electrode (WBE) was used to study pitting corrosion of rebar under concrete cover. When WBE embedded mortar sample was immersed in NaCl solution, uneven distributions of galvanic current and open circuit potential (OCP) on the WBE were observed due to the initiation of pitting corrosion. The following oxygen depletion in mortar facilitated the negative shift of the OCP and the smoothing of the current and potential distributions. Wetting–drying cycle experiments showed that corrosion products instead of oxygen in wet mortar specimen sustained the propagation of pitting corrosion due to Fe (III) taking part inmore » cathodic depolarization during oxygen-deficient wet period, which was confirmed by micro-Raman spectroscopy. In addition, new pitting corrosion occurred mainly near the corrosion products, leading to preferentially horizontal propagation of rust layer on the WBE. A localized corrosion factor was further presented to quantify the localised corrosion based on galvanic current maps.« less

Spatial distribution level of land erosion disposition based on the analysis of slope on Central Lematang sub basin

NASA Astrophysics Data System (ADS)

Putranto, Dinar Dwi Anugerah; Sarino, Yuono, Agus Lestari

2017-11-01

Soil erosion is a natural process that is influenced by the magnitude of rainfall intensity, land cover, slope, soil type and soil processing system. However, it is often accelerated by human activities, such as improper cultivation of agricultural land, clearing of forest land for mining activities, and changes in topographic area due to use for other purposes such as pile materials, mined pits and so on. The Central Lematang sub-basin is part of the Lematang sub basin, at the Musi River Region Unit, South Sumatra Province, in Indonesia, which has a topographic shape with varying types of slope and altitude. The critical condition of Central Lematang sub basin has been at an alarming rate, as more than 47.5% of topographic and land use changes are dominated by coal mining activities and forest encroachment by communities. The method used in predicting erosion is by USPED (Unit Stream Power Erosion and Disposition). This is because the USPED [1] method can predict not only sediment transport but also the value of peeling (detachment) and sediment deposition. From slope analysis result, it is found that the highest erosion potential value is found on slope (8-15%) and the sediment is carried on a steep slope (15-25%). Meanwhile, the high sediment deposition area is found in the waters of 5.226 tons / ha / year, the steeper area of 2.12 tons / ha / year.

Impact of Annealing Prior to Solution Treatment on Aging Precipitates and Intergranular Corrosion Behavior of Al-Cu-Li Alloy 2050

NASA Astrophysics Data System (ADS)

Ye, Zhi-hao; Cai, Wen-xin; Li, Jin-feng; Chen, Xiang-rong; Zhang, Rui-feng; Birbilis, Nick; Chen, Yong-lai; Zhang, Xu-hu; Ma, Peng-cheng; Zheng, Zi-qiao

2018-06-01

The influences of annealing prior to solution treatment on the grain structure, subsequent aging precipitates, and intergranular corrosion (IGC) of Al-Cu-Li alloy (AA2050) sheet with T6 aging at 448 K (175 °C) were investigated. Annealing impedes the full recrystallization during solution treatment, increasing the population density of T1 (Al2CuLi) precipitates, but decreasing that of θ' (Al2Cu) precipitates, of the aged alloy. Meanwhile, annealing leads to the heterogeneous distribution of T1 precipitates, increasing the alloy hardness, and decreasing the open-circuit potential of the aged alloy. With prolonged aging time, the corrosion mode of the aged AA2050 samples with and without annealing evolved in a similar manner. The corrosion mode as a function of aging may be summarized as local IGC with pitting and general IGC with pitting (following initial aging and under the underaged condition), pitting corrosion (later in the under-aging stage), pitting with slight IGC (near the peak-aged condition), and pitting with local IGC (under the overaging condition). The annealing treatment hinders IGC propagation on the rolling surface while accelerating the IGC on transverse surfaces.

Impact of Annealing Prior to Solution Treatment on Aging Precipitates and Intergranular Corrosion Behavior of Al-Cu-Li Alloy 2050

NASA Astrophysics Data System (ADS)

Ye, Zhi-hao; Cai, Wen-xin; Li, Jin-feng; Chen, Xiang-rong; Zhang, Rui-feng; Birbilis, Nick; Chen, Yong-lai; Zhang, Xu-hu; Ma, Peng-cheng; Zheng, Zi-qiao

2018-04-01

The influences of annealing prior to solution treatment on the grain structure, subsequent aging precipitates, and intergranular corrosion (IGC) of Al-Cu-Li alloy (AA2050) sheet with T6 aging at 448 K (175 °C) were investigated. Annealing impedes the full recrystallization during solution treatment, increasing the population density of T1 (Al2CuLi) precipitates, but decreasing that of θ' (Al2Cu) precipitates, of the aged alloy. Meanwhile, annealing leads to the heterogeneous distribution of T1 precipitates, increasing the alloy hardness, and decreasing the open-circuit potential of the aged alloy. With prolonged aging time, the corrosion mode of the aged AA2050 samples with and without annealing evolved in a similar manner. The corrosion mode as a function of aging may be summarized as local IGC with pitting and general IGC with pitting (following initial aging and under the underaged condition), pitting corrosion (later in the under-aging stage), pitting with slight IGC (near the peak-aged condition), and pitting with local IGC (under the overaging condition). The annealing treatment hinders IGC propagation on the rolling surface while accelerating the IGC on transverse surfaces.

Inexpensive Device for Demonstrating Rock Slope Failure and Other Collapse Phenomena.

ERIC Educational Resources Information Center

Stimpson, B.

1980-01-01

Describes an inexpensive modeling technique for demonstrating large-scale displacement phenomena in rock masses, such as slope collapse and failure of underground openings. Excavation of the model material occurs through openings made in the polyurethane foam in the correct excavation sequence. (Author/SA)

Project W-314 acceptance test report HNF-4647 for HNF-4646 241-B pit leak detection ANB-WT-LDSTA-231 for project W-314

DOE Office of Scientific and Technical Information (OSTI.GOV)

HAMMERS, J.S.

The purpose of the test was to verify that the AN Tank Farm B Pit Leak Detector components are functionally integrated and operate in accordance with engineering design specifications. The Acceptance Test Procedure HNF-4646,241-AN-B-Pit Leak Detection ANB-WT-LDSTA-231 was conducted between 26 June and 02 July 1999 at the 200E AN Tank Farm. The test has been completed with no open test exceptions. The test was conducted prior to final engineering ''as built'' activities being completed this had no impact on the procedure or test results. All components, identified in the procedure were found to be labeled and identified as writtenmore » in the procedure.« less

Spontaneous revegetation vs. forestry reclamation in post-mining sand pits.

PubMed

Šebelíková, Lenka; Řehounková, Klára; Prach, Karel

2016-07-01

Vegetation development of sites restored by two different methods, spontaneous revegetation and forestry reclamation, was compared in four sand pit mining complexes located in the southern part of the Czech Republic, central Europe. The space-for-time substitution method was applied to collect vegetation records in 13 differently aged and sufficiently large sites with known history. The restoration method, age (time since site abandonment/reclamation), groundwater table, slope, and aspect in all sampled plots were recorded in addition to the visual estimation of percentage cover of all present vascular plant species. Multivariate methods and GLM were used for the data elaboration. Restoration method was the major factor influencing species pattern. Both spontaneously revegetated and forestry reclaimed sites developed towards forest on a comparable timescale. Although the sites did not significantly differ in species richness (160 species in spontaneously revegetated vs. 111 in forestry reclaimed sites), spontaneously revegetated sites tended to be more diverse with more species of conservation potential (10 Red List species in spontaneous sites vs. 4 Red List species in forestry reclaimed sites). These results support the use of spontaneous revegetation as an effective and low-cost method of sand pit restoration and may contribute to implementation of this method in practice.

Numerical modelling of the groundwater inflow to an advancing open pit mine: Kolahdarvazeh pit, Central Iran.

PubMed

Bahrami, Saeed; Doulati Ardejani, Faramarz; Aslani, Soheyla; Baafi, Ernest

2014-12-01

The groundwater inflow into a mine during its life and after ceasing operations is one of the most important concerns of the mining industry. This paper presents a hydrogeological assessment of the Irankuh Zn-Pb mine at 20 km south of Esfahan and 1 km northeast of Abnil in west-Central Iran. During mine excavation, the upper impervious bed of a confined aquifer was broken and water at high-pressure flowed into an open pit mine associated with the Kolahdarvazeh deposit. The inflow rates were 6.7 and 1.4 m(3)/s at the maximum and minimum quantities, respectively. Permeability, storage coefficient, thickness and initial head of the fully saturated confined aquifer were 3.5 × 10(-4) m/s, 0.2, 30 m and 60 m, respectively. The hydraulic heads as a function of time were monitored at four observation wells in the vicinity of the pit over 19 weeks and at an observation well near a test well over 21 h. In addition, by measuring the rate of pumping out from the pit sump, at a constant head (usually equal to height of the pit floor), the real inflow rates to the pit were monitored. The main innovations of this work were to make comparison between numerical modelling using a finite element software called SEEP/W and actual data related to inflow and extend the applicability of the numerical model. This model was further used to estimate the hydraulic heads at the observation wells around the pit over 19 weeks during mining operations. Data from a pump-out test and observation wells were used for model calibration and verification. In order to evaluate the model efficiency, the modelling results of inflow quantity and hydraulic heads were compared to those from analytical solutions, as well as the field data. The mean percent error in relation to field data for the inflow quantity was 0.108. It varied between 1.16 and 1.46 for hydraulic head predictions, which are much lower values than the mean percent errors resulted from the analytical solutions (from 1.8 to 5.3 for inflow and from 2.16 to 3.5 for hydraulic head predictions). The analytical solutions underestimated the inflow compared to the numerical model for the time period of 2-19 weeks. The results presented in this paper can be used for developing an effective dewatering program.

40 CFR 60.3062 - What is an air curtain incinerator?

Code of Federal Regulations, 2011 CFR

2011-07-01

... curtain of air across an open, integrated combustion chamber (fire box) or open pit or trench (trench... 40 Protection of Environment 6 2011-07-01 2011-07-01 false What is an air curtain incinerator? 60... Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.3062 What is...

Influence of copper recovery on the water quality of the acidic Berkeley Pit lake, Montana, U.S.A.

PubMed

Tucci, Nicholas J; Gammons, Christopher H

2015-04-07

The Berkeley Pit lake in Butte, Montana, formed by flooding of an open-pit copper mine, is one of the world's largest accumulations of acidic, metal-rich water. Between 2003 and 2012, approximately 2 × 10(11) L of pit water, representing 1.3 lake volumes, were pumped from the bottom of the lake to a copper recovery plant, where dissolved Cu(2+) was precipitated on scrap iron, releasing Fe(2+) back to solution and thence back to the pit. Artificial mixing caused by this continuous pumping changed the lake from a meromictic to holomictic state, induced oxidation of dissolved Fe(2+), and caused subsequent precipitation of more than 2 × 10(8) kg of secondary ferric compounds, mainly schwertmannite and jarosite, which settled to the bottom of the lake. A large mass of As, P, and sulfate was also lost from solution. These unforeseen changes in chemistry resulted in a roughly 25-30% reduction in the lake's calculated and measured total acidity, which represents a significant potential savings in the cost of lime treatment, which is not expected to commence until 2023. Future monitoring is needed to verify that schwertmannite and jarosite in the pit sediment do not convert to goethite, a process which would release stored acidity back to the water column.

40 CFR 440.44 - New source performance standards (NSPS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... reduction attainable by the application of the best available demonstrated technology (BADT): (a) The concentration of pollutants discharged in mine drainage from mines, either open pit or underground, that produce...

40 CFR 440.44 - New source performance standards (NSPS).

Code of Federal Regulations, 2012 CFR

2012-07-01

... reduction attainable by the application of the best available demonstrated technology (BADT): (a) The concentration of pollutants discharged in mine drainage from mines, either open pit or underground, that produce...

40 CFR 440.44 - New source performance standards (NSPS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... reduction attainable by the application of the best available demonstrated technology (BADT): (a) The concentration of pollutants discharged in mine drainage from mines, either open pit or underground, that produce...

Birth Outcomes Among Military Personnel Following Exposure to Documented Open-Air Burn Pits Before and During Pregnancy

DTIC Science & Technology

2012-06-01

of the parents’ exposure to the onset of pregnancy ( maternal model) or EDC ( paternal model), cumulative days of exposure to a burn pit region before...the infant’s date of birth ( maternal model) or EDC ( paternal model), and last exposed deployment, defined as the parent’s duty location (ie, Joint Base...in Table 1. Maternal age (ie, age of the deployer in the maternal model and the deployer’s spouse in the paternal model) was lower (ន years) among

A flexible open-source toolkit for lava flow simulations

NASA Astrophysics Data System (ADS)

Mossoux, Sophie; Feltz, Adelin; Poppe, Sam; Canters, Frank; Kervyn, Matthieu

2014-05-01

Lava flow hazard modeling is a useful tool for scientists and stakeholders confronted with imminent or long term hazard from basaltic volcanoes. It can improve their understanding of the spatial distribution of volcanic hazard, influence their land use decisions and improve the city evacuation during a volcanic crisis. Although a range of empirical, stochastic and physically-based lava flow models exists, these models are rarely available or require a large amount of physical constraints. We present a GIS toolkit which models lava flow propagation from one or multiple eruptive vents, defined interactively on a Digital Elevation Model (DEM). It combines existing probabilistic (VORIS) and deterministic (FLOWGO) models in order to improve the simulation of lava flow spatial spread and terminal length. Not only is this toolkit open-source, running in Python, which allows users to adapt the code to their needs, but it also allows users to combine the models included in different ways. The lava flow paths are determined based on the probabilistic steepest slope (VORIS model - Felpeto et al., 2001) which can be constrained in order to favour concentrated or dispersed flow fields. Moreover, the toolkit allows including a corrective factor in order for the lava to overcome small topographical obstacles or pits. The lava flow terminal length can be constrained using a fixed length value, a Gaussian probability density function or can be calculated based on the thermo-rheological properties of the open-channel lava flow (FLOWGO model - Harris and Rowland, 2001). These slope-constrained properties allow estimating the velocity of the flow and its heat losses. The lava flow stops when its velocity is zero or the lava temperature reaches the solidus. Recent lava flows of Karthala volcano (Comoros islands) are here used to demonstrate the quality of lava flow simulations with the toolkit, using a quantitative assessment of the match of the simulation with the real lava flows. The influence of the different input parameters on the quality of the simulations is discussed. REFERENCES: Felpeto et al. (2001), Assessment and modelling of lava flow hazard on Lanzarote (Canary islands), Nat. Hazards, 23, 247-257. Harris and Rowland (2001), FLOWGO: a kinematic thermo-rheological model for lava flowing in a channel, Bull. Volcanol., 63, 20-44.

40 CFR 440.44 - New source performance standards (NSPS).

Code of Federal Regulations, 2011 CFR

2011-07-01

... attainable by the application of the best available demonstrated technology (BADT): (a) The concentration of pollutants discharged in mine drainage from mines, either open pit or underground, that produce mercury ores...

40 CFR 440.40 - Applicability; description of the mercury ore subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Mercury Ore... are applicable to discharges from (a) mines, either open-pit or underground, that produce mercury ores...

Open Burn Pit Registry Act of 2011

THOMAS, 112th Congress

Sen. Udall, Tom [D-NM

2011-11-03

Senate - 06/13/2012 Committee on Veterans' Affairs. Hearings held. Hearings printed: S.Hrg. 112-567. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

The Study Of Soil And Agrochemical Features Of Zonal Soils Of Coal Mining Enterprises In Kemerovo Region

NASA Astrophysics Data System (ADS)

Yakovchenko, M. A.; Kosolapova, A. A.; Ermolaev, V. A.

2017-01-01

The paper represents the results of the study of soil and agrochemical features of zonal soils: the grain-size composition, the content of humus, phosphorus and potassium, and heavy metals, the reaction of soil solution of the territory of the open-pit coal mine No12 of Kemerovo region in the areas of the working enterprise. The species composition of the lignose and herbaceous vegetation of the undisturbed territories has been studied. It has been revealed that the fertile soil layer of the studied areas of the open-pit coal mine is characterized as fertile but can’t be removed and stored because the surface of the whole area under study is forest-covered very much, rumpled, there are gullies and a lot of wind-fallen trees.

Volume Computation of a Stockpile - a Study Case Comparing GPS and Uav Measurements in AN Open Pit Quarry

NASA Astrophysics Data System (ADS)

Raeva, P. L.; Filipova, S. L.; Filipov, D. G.

2016-06-01

The following paper aims to test and evaluate the accuracy of UAV data for volumetric measurements to the conventional GNSS techniques. For this purpose, an appropriate open pit quarry has been chosen. Two sets of measurements were performed. Firstly, a stockpile was measured by GNSS technologies and later other terrestrial GNSS measurements for modelling the berms of the quarry were taken. Secondly, the area of the whole quarry including the stockpile site was mapped by a UAV flight. Having considered how dynamic our world is, new techniques and methods should be presented in numerous fields. For instance, the management of an open pit quarry requires gaining, processing and storing a large amount of information which is constantly changing with time. Fast and precise acquisition of measurements regarding the process taking place in a quarry is the key to an effective and stable maintenance. In other words, this means getting an objective evaluations of the processes, using up-to-date technologies and reliable accuracy of the results. Often legislations concerning mine engineering state that the volumetric calculations are to present ±3% accuracy of the whole amount. On one hand, extremely precise measurements could be performed by GNSS technologies, however, it could be really time consuming. On the other hand, UAV photogrammetry presents a fast, accurate method for mapping large areas and calculating stockpiles volumes. The study case was performed as a part of a master thesis.

Spoil pile instabilities with reference to a strip coal mine in Turkey: mechanisms and assessment of deformations

NASA Astrophysics Data System (ADS)

Kasmer, Ozgu; Ulusay, Resat; Gokceoglu, Candan

2006-02-01

With the increasing adoption of the surface mining of coal, problems associated with spoil pile instability, which affects resource recovery, mining cost, and safety and presents environmental hazards, have become a matter of prime concern to mine planners and operators. The study of geotechnical aspects is thus very important in the rational planning for the disposal, reclamation, treatment and utilization of spoil material. A strip coal mine, one of the largest open pit mines in Turkey, is located in Central Anatolia and provides coal to a thermal power station. Coal production is carried out in two adjacent open pits, the Central Pit and South Pit. A large-scale spoil pile instability over an area of 0.3 km2 occurred within the dumping area of the Central pit. In addition, small-scale movement occurred in the outside dumping area. This paper outlines the results of field and laboratory investigations to describe the mechanisms of the spoil pile instabilities and to assess deformations monitored over a long period following the failure. Shear test results indicate that the interface between the floor and spoil material dumped by dragline has a negligible cohesion and is the most critical plane of weakness for spoil pile instability. Back analyses based on the method of limit equilibrium and the numerical modelling technique, and observations in the pit revealed that failure occurred along a combined sliding surface consisting of a circular surface through the spoil material itself and a planar surface passing along the interface between the spoil piles and floor. The analyses also indicated that pore water pressure ratios of about 0.25 satisfy limiting equilibrium condition and that rainfall about one month before the failure may be a contributing factor to the instability. Movement monitoring data obtained following the failure over a 1.5-year period suggested that the ongoing deformations were mainly due to compaction of the spoil material. Based on the monitoring data and the results of the analyses, the failure mode of the local instability occurring at the outside dumping area was considerably similar to that of the large instability.

Long term monitoring of water basin of an abandoned copper open pit mine

NASA Astrophysics Data System (ADS)

Nikolov, H.; Borisova, D.

2012-04-01

Nonoperating open pit mines, very often as a matter of fact abandoned, create serious ecological risk for the region of their location especially for the quality of the water since the rainfall fills the bottom of the pit forming water body having different depth. This water as a rule has very high concentration of the metals in it and is highly toxic. One example for such opencast, idle copper mine is Medet located in the central part of Bulgaria who was started for exploitation in 1964 and at that moment being the largest in Europe for production of copper concentrate. In the vicinity of it after autumn and spring rains there are many cases reported for water contamination by heavy metals such as arsenic, copper, cadmium in the rivers running close to this open pit mine. This justifies the need for long term and sustainable monitoring of the area of the water basin of this idle mine in order to estimate its acid drainage and imaging spectroscopy combined with is-situ investigations is proved to provide reliable results about the area of the water table. In the course of this study we have investigated historical data gathered by remote sensing which allowed us to make conclusions about the year behavior of this area. Our expectations are that the results of this research will help in the rehabilitation process of this idle mine and will provide the local authorities engaged in water quality monitoring with a tool to estimate the possible damage caused to the local rivers and springs. With this research we also would like to contribute to the fulfillment of the following EU Directives: Directive 2006/21/°C on the Management of Waste from the Extractive Industries and Directive 2004/35/ °C on Environmental Liability with regard to the Prevention and Remedying of Environmental Damage.

Measurements of evaporation from a mine void lake and testing of modelling approaches

NASA Astrophysics Data System (ADS)

McJannet, David; Hawdon, Aaron; Van Niel, Tom; Boadle, Dave; Baker, Brett; Trefry, Mike; Rea, Iain

2017-12-01

Pit lakes often form in the void that remains after open cut mining operations cease. As pit lakes fill, hydrological and geochemical processes interact and these need to be understood for appropriate management actions to be implemented. Evaporation is important in the evolution of pit lakes as it acts to concentrate various constituents, controls water level and changes the thermal characteristics of the water body. Despite its importance, evaporation from pit lakes is poorly understood. To address this, we used an automated floating evaporation pan and undertook measurements at a pit lake over a 12 month period. We also developed a new procedure for correcting floating pan evaporation estimates to lake evaporation estimates based on surface temperature differences. Total annual evaporation was 2690 mm and reflected the strong radiation inputs, high temperatures and low humidity experienced in this region. Measurements were used to test the performance of evaporation estimates derived using both pan coefficient and aerodynamic modelling techniques. Daily and monthly evaporation estimates were poorly reproduced using pan coefficient techniques and their use is not recommended for such environments. Aerodynamic modelling was undertaken using a range of input datasets that may be available to those who manage pit lake systems. Excellent model performance was achieved using over-water or local over-land meteorological observations, particularly when the sheltering effects of the pit were considered. Model performance was reduced when off-site data were utilised and differences between local and off-site vapor pressure and wind speed were found to be the major cause.

Geochemical evolution of a high arsenic, alkaline pit-lake in the Mother Lode Gold District, California

USGS Publications Warehouse

Savage, Kaye S.; Ashley, Roger P.; Bird, Dennis K.

2009-01-01

The Harvard orebody at the Jamestown gold mine, located along the Melones fault zone in the southern Mother Lode gold district, California, was mined in an open-pit operation from 1987 to 1994. Dewatering during mining produced a hydrologic cone of depression; recovery toward the premining ground-water configuration produced a monomictic pit lake with alkaline Ca-Mg-HCO3-SO4–type pit water, concentrations of As up to 1,200 μg/L, and total dissolved solids (TDS) up to 2,000 mg/L. In this study, pit-wall rocks were mapped and chemically analyzed to provide a context for evaluating observed variability in the composition of the pit-lake waters in relationship to seasonal weather patterns. An integrated hydrogeochemical model of pit-lake evolution based on observations of pit-lake volume, water composition (samples collected between 1998–2000, 2004), and processes occurring on pit walls was developed in three stages using the computer code PHREEQC. Stage 1 takes account of seasonally variable water fluxes from precipitation, evaporation, springs, and ground water, as well as lake stratification and mixing processes. Stage 2 adds CO2fluxes and wall-rock interactions, and stage 3 assesses the predictive capability of the model.Two major geologic units in fault contact comprise the pit walls. The hanging wall is composed of interlayered slate, metavolcanic and metavolcaniclastic rocks, and schists; the footwall rocks are chlorite-actinolite and talc-tremolite schists generated by metasomatism of greenschist-facies mafic and ultramafic igneous rocks. Alteration in the ore zone provides evidence for mineralizing fluids that introduced CO2, S, and K2O, and redistributed SiO2. Arsenian pyrite associated with the alteration weathers to produce goethite and jarosite on pit walls and in joints, as well as copiapite and hexahydrite efflorescences that accumulate on wall-rock faces during dry California summers. All of these pyrite weathering products incorporate arsenic at concentrations from <100 up to 1,200 ppm. In the pit lake, pH and TDS reach seasonal highs in the summer epilimnion; pH is lowest in the summer hypolimnion. Arsenic and bicarbonate covary in the hypolimnion, rising as stratification proceeds and declining during winter rains. The computational model suggests that water fluxes alone do not account for this seasonal variability. Loss of CO2 to the atmosphere, interaction with pit walls including washoff of efflorescent salts during the first flush and seasonal rainfall, and arsenic sorption appear to contribute to the observed pit-lake characteristics.

Transient bright "halos" on the South Polar Residual Cap of Mars: Implications for mass-balance

NASA Astrophysics Data System (ADS)

Becerra, Patricio; Byrne, Shane; Brown, Adrian J.

2015-05-01

Spacecraft imaging of Mars' south polar region during mid-southern summer of Mars year 28 (2007) observed bright halo-like features surrounding many of the pits, scarps and slopes of the heavily eroded carbon dioxide ice of the South Polar Residual Cap (SPRC). These features had not been observed before, and have not been observed since. We report on the results of an observational study of these halos, and spectral modeling of the SPRC surface at the time of their appearance. Image analysis was performed using data from MRO's Context Camera (CTX), and High Resolution Imaging Science Experiment (HiRISE), as well as images from Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC). Data from MRO's Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) were used for the spectral analysis of the SPRC ice at the time of the halos. These data were compared with a Hapke reflectance model of the surface to constrain their formation mechanism. We find that the unique appearance of the halos is intimately linked to a near-perihelion global dust storm that occurred shortly before they were observed. The combination of vigorous summertime sublimation of carbon dioxide ice from sloped surfaces on the SPRC and simultaneous settling of dust from the global storm, resulted in a sublimation wind that deflected settling dust particles away from the edges of these slopes, keeping these areas relatively free of dust compared to the rest of the cap. The fact that the halos were not exhumed in subsequent years indicates a positive mass-balance for flat portions of the SPRC in those years. A net accumulation mass-balance on flat surfaces of the SPRC is required to preserve the cap, as it is constantly being eroded by the expansion of the pits and scarps that populate its surface.

Characterization and comparison of emissions from rudimentary waste disposal technologies

EPA Science Inventory

Results from 2011 simulation of burn pit emissions and air curtain incinerator emissions, recent developments in methods for open air sampling, comparison of waste energy technologies, current SERDP programs in this area.

A Cultural Resources Survey of the Paul Pickle Permit Request Area, Bayou Deview - 7, Poinsett County, Arkansas.

DTIC Science & Technology

1989-12-01

Resources Survey of the Paul Pickle I r., Pit j FUNONG NiMBERS Request Area, Bayou Deview -7 I-)oinsvtt Io., AR 9t*" 1I 2 6. AUTHOR(S)Jimmy D. McNeil. 1...undulating, with low ridges or natural levees rising a few feet above the alluvial terrace. These lowlands are characterized primarily by poorly...ridges. Slopes are generally less than 1%. Drainage is generally to the southwest with the major natural drainage way being the L’Anguille River

Interference effects in laser-induced plasma emission from surface-bound metal micro-particles

DOE PAGES

Feigenbaum, Eyal; Malik, Omer; Rubenchik, Alexander M.; ...

2017-04-19

Here, the light-matter interaction of an optical beam and metal micro-particulates at the vicinity of an optical substrate surface is critical to the many fields of applied optics. Examples of impacted fields are laser-induced damage in high power laser systems, sub-wavelength laser machining of transmissive materials, and laser-target interaction in directed energy applications. We present a full-wave-based model that predicts the laser-induced plasma pressure exerted on a substrate surface as a result of light absorption in surface-bound micron-scale metal particles. The model predictions agree with experimental observation of laser-induced shallow pits, formed by plasma emission and etching from surface-bound metalmore » micro-particulates. It provides an explanation for the prototypical side lobes observed along the pit profile, as well as for the dependence of the pit shape on the incident laser and particle parameters. Furthermore, the model highlights the significance of the interference of the incident light in the open cavity geometry formed between the micro-particle and the substrate in the resulting pit shape.« less

Interference effects in laser-induced plasma emission from surface-bound metal micro-particles.

PubMed

Feigenbaum, Eyal; Malik, Omer; Rubenchik, Alexander M; Matthews, Manyalibo J

2017-05-01

The light-matter interaction of an optical beam and metal micro-particulates at the vicinity of an optical substrate surface is critical to the many fields of applied optics. Examples of impacted fields are laser-induced damage in high power laser systems, sub-wavelength laser machining of transmissive materials, and laser-target interaction in directed energy applications. We present a full-wave-based model that predicts the laser-induced plasma pressure exerted on a substrate surface as a result of light absorption in surface-bound micron-scale metal particles. The model predictions agree with experimental observation of laser-induced shallow pits, formed by plasma emission and etching from surface-bound metal micro-particulates. It provides an explanation for the prototypical side lobes observed along the pit profile, as well as for the dependence of the pit shape on the incident laser and particle parameters. Furthermore, the model highlights the significance of the interference of the incident light in the open cavity geometry formed between the micro-particle and the substrate in the resulting pit shape.

Nuts, nut cracking, and pitted stones at Gesher Benot Ya‘aqov, Israel

PubMed Central

Goren-Inbar, Naama; Sharon, Gonen; Melamed, Yoel; Kislev, Mordechai

2002-01-01

The Acheulian site of Gesher Benot Ya‘aqov (Israel) has revealed a unique association of edible nuts with pitted hammers and anvils. Located in the Dead Sea rift, on the boundary between the Arabian and African plates, the site dates to the Early-Middle Pleistocene, oxygen isotope stage 19. In a series of strata, seven species of nuts, most of which can be cracked open only by a hard hammer, were uncovered. Five of the species are extant terrestrial nuts, and two are aquatic nuts now extinct in the Levant. In addition, the site yielded an assemblage of pitted hammers and anvils similar in pit morphology to those used by chimpanzees and contemporary hunter–gatherers. This is the first time, to our knowledge, that a site has offered both paleobotanical and lithic evidence of plant foods eaten by early hominins and technologies used for processing these foods. The evidence also sheds light on the structure of the community: ethnographic analogies suggest that mixedgender groups may have been active on the shores of paleoLake Hula. PMID:11854536

The Western Environmental Technology Office (WETO), Butte, Montana. Technology summary

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-03-01

The Western Environmental Technology Office (WETO) is a multi-purpose engineering test facility located in Butte, Montana, and is managed by MSE, Inc. WETO seeks to contribute to environmental research by emphasizing projects to develop heavy metals removal and recovery processes, thermal vitrification systems, and waste minimization/pollution prevention technologies. WETO`s environmental technology research and testing activities focus on the recovery of usable resources from waste. In one of WETO`s areas of focus, groundwater contamination, water from the Berkeley Pit, located near the WETO site, is being used in demonstrations directed toward the recovery of potable water and metal from the heavymore » metal-bearing water. The Berkeley Pit is part of an inactive copper mine near Butte that was once part of the nation`s largest open-pit mining operation. The Pit contains approximately 25 billion gallons of Berkeley Pit groundwater and surface water containing many dissolved minerals. As part of DOE/OST`s Resource Recovery Project (RRP), technologies are being demonstrated to not only clean the contaminated water but to recover metal values such as copper, zinc, and iron with an estimated gross value of more than $100 million. When recovered, the Berkeley Pit waters could benefit the entire Butte valley with new water resources for fisheries, irrigation, municipal, and industrial use. At WETO, the emphasis is on environmental technology development and commercialization activities, which will focus on mine cleanup, waste treatment, resource recovery, and water resource management.« less

Arne - Exploring the Mare Tranquillitatis Pit

NASA Astrophysics Data System (ADS)

Robinson, M. S.; Thangavelautham, J.; Wagner, R.; Hernandez, V. A.; Finch, J.

2014-12-01

Lunar mare "pits" are key science and exploration targets. The first three pits were discovered within Selene observations [1,2] and were proposed to represent collapses into lava tubes. Subsequent LROC images revealed 5 new mare pits and showed that the Mare Tranquillitatis pit (MTP; 8.335°N, 33.222°E) opens into a sublunarean void at least 20-meters in extent [3,4]. A key remaining task is determining pit subsurface extents, and thus fully understanding their exploration and scientific value. We propose a simple and cost effective reconnaissance of the MTP using a small lander (<130 kg) named Arne, that carries three flying microbots (or pit-bots) [5,6,7]. Key measurement objectives include decimeter scale characterization of the pit walls, 5-cm scale imaging of the eastern floor, determination of the extent of sublunarean void(s), and measurement of the magnetic and thermal environment. After landing and initial surface systems check Arne will transmit full resolution descent and surface images. Within two hours the first pit-bot will launch and fly into the eastern void. Depending on results from the first pit-bot the second and third will launch and perform follow-up observations. The primary mission is expected to last 48-hours; before the Sun sets on the lander there should be enough time to execute ten flights with each pit-bot. The pit-bots are 30-cm diameter spherical flying robots [5,6,7] equipped with stereo cameras, temperature sensors, sensors for obstacle avoidance and a laser rangefinder. Lithium hydride [5,6] and water/hydrogen peroxide power three micro-thrusters and achieve a specific impulse of 350-400 s. Each pit-bot can fly for 2 min at 2 m/s for more than 100 cycles; recharge time is 20 min. Arne will carry a magnetometer, thermometer, 2 high resolution cameras, and 6 wide angle cameras and obstacle avoidance infrared sensors enabling detailed characterization of extant sublunarean voids. [1] Haruyama et al. (2010) 41st LPSC, #1285. [2] Haruyama et al. (2010) GRL, 36, dx.doi.org/ 10.1029/2009GL0406355. [3] Robinson et al (2012) PSS, 69, dx.doi.org/ 10.1016/j.pss.2012.05.008 [4] Wagner and Robinson (2014) Icarus, dx.doi.org/10.1016/j.icarus.2014.04.002. [5] Thangavelautham et al. (2012) IEEE ICRA [6] Strawser et al. (2014) J. Hydrogen Energy. [7] Dubowsky et al. (2007) Proc. CLAWAR.

Efficiency of Low-Profile External Dumping at Open Pit Coal Mining in Kemerovo Region

NASA Astrophysics Data System (ADS)

Selyukov, Alexey; Ermolaev, Vyacheslav; Kostinez, Irina

2017-11-01

Kemerovo region is one of the largest industrial regions of Russia, with a raw material specialization. The rapid growth of the coal industry in recent years has been greatly facilitated by the expansion and development of open pit mining for coal seams extraction, accompanied by an increase in the volumes of overburden and the height of the dumps. There are about 400 objects in the Russian Federation Government Register of Waste Disposal Facilities 80% of which are dumps. Approaches both to external dumping and to the technical stage of reclamation currently contribute to the growth of geomorphic system's instability. Thus, it is proposed to slightly change the approaches to external dumping: the essence consists in the formation of an external dump of overburden, which in future would represent a favorable landscape unit of a flat surface relief used for subsequent differently directed purposes.

Elimination of trench defects and V-pits from InGaN/GaN structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smalc-Koziorowska, Julita; Grzanka, Ewa; Czernecki, Robert

2015-03-09

The microstructural evolution of InGaN/GaN multiple quantum wells grown by metalorganic chemical vapor phase epitaxy was studied as a function of the growth temperature of the GaN quantum barriers (QBs). We observed the formation of basal stacking faults (BSFs) in GaN QBs grown at low temperature. The presence of BSFs terminated by stacking mismatch boundaries (SMBs) leads to the opening of the structure at the surface into a V-shaped trench loop. This trench may form above an SMB, thereby terminating the BSF, or above a junction between the SMB and a subsequent BSF. Fewer BSFs and thus fewer trench defectsmore » were observed in GaN QBs grown at temperatures higher than 830 °C. Further increase in the growth temperature of the GaN QBs led to the suppression of the threading dislocation opening into V-pits.« less

Long-Term Planning for Open Pits for Mining Sulphide-Oxide Ores in Order to Achieve Maximum Profit

NASA Astrophysics Data System (ADS)

Kržanović, Daniel; Conić, Vesna; Stevanović, Dejan; Kolonja, Božo; Vaduvesković, Jovan

2017-12-01

Profitable exploitation of mineralised material from the earth's crust is a complex and difficult task that depends on a comprehensive planning process. Answering the question of how to plan production depends on the geometry of the deposit, as well as the concentration, distribution, and type of minerals in it. The complex nature of mineral deposits largely determines the method of exploitation and profitability of mining operations. In addition to unit operating costs and metal prices, the optimal recovery of and achievement of maximum profit from deposits of sulphide-oxide ores also depend, to a significant extent, on the level of technological recovery achieved in the ore processing procedure. Therefore, in defining a long-term development strategy for open pits, special attention must be paid to the selection of an optimal procedure for ore processing in order to achieve the main objective: maximising the Net Present Value (NPV). The effect of using two different processes, flotation processing and hydrometallurgical methods (bioleaching acid leaching), on determining the ultimate pit is shown in the case of the Kraku Bugaresku-Cementacija sulphide-oxide ore deposit in eastern Serbia. Analysis shows that the application of hydrometallurgical methods of processing sulphide-oxide ore achieved an increase in NPV of 20.42%.

An Open Pit Nanofluidic Tool: Localized Chemistry Assisted by Mesoporous Thin Film Infiltration.

PubMed

Mercuri, Magalí; Pierpauli, Karina A; Berli, Claudio L A; Bellino, Martín G

2017-05-17

Nanofluidics based on nanoscopic porous structures has emerged as the next evolutionary milestone in the construction of versatile nanodevices with unprecedented applications. However, the straightforward development of nanofluidically interconnected systems is crucial for the production of practical devices. Here, we demonstrate that spontaneous infiltration into supramolecularly templated mesoporous oxide films at the edge of a sessile drop in open air can be used to connect pairs of landmarks. The liquids from the drops can then join through the nanoporous network to guide a localized chemical reaction at the nanofluid-front interface. This method, here named "open-pit" nanofluidics, allows mixing reagents from nanofluidically connected droplet reservoirs that can be used as reactors to conduct reactions and precipitation processes. From the fundamental point of view, the work contributes to unveiling subtle phenomena during spontaneous infiltration of fluids in bodies with nanoscale dimensions such as the front broadening effect and the oscillatory behavior of the infiltration-evaporation front. The approach has distinctive advantages such as easy fabrication, low cost, and facility of scaling up for future development of ultrasensitive detection, controlled nanomaterial synthesis, and novel patterning methods.

Psychoanalytic-Interactional Therapy versus Psychodynamic Therapy by Experts for Personality Disorders: A Randomized Controlled Efficacy-Effectiveness Study in Cluster B Personality Disorders.

PubMed

Leichsenring, Falk; Masuhr, Oliver; Jaeger, Ulrich; Rabung, Sven; Dally, Andreas; Dümpelmann, Michael; Fricke-Neef, Christian; Steinert, Christiane; Streeck, Ulrich

2016-01-01

With regard to cluster B personality disorders, most psychotherapeutic treatments focus on borderline personality disorder. Evidence-based treatments for patients with other cluster B personality disorders are not yet available. Psychoanalytic-interactional therapy (PIT) represents a transdiagnostic treatment for severe personality disorders. PIT has been applied in clinical practice for many years and has proven effective in open studies. In a randomized controlled trial, we compared manual-guided PIT to nonmanualized pychodynamic therapy by experts in personality disorders (E-PDT) in patients with cluster B personality disorders. In an inpatient setting, patients with cluster B personality disorders were randomly assigned to manual-guided PIT (n = 64) or nonmanualized E-PDT (n = 58). In addition, a quasi-experimental control condition was used (n = 46) including both patients receiving treatment as usual and patients waiting for treatment. Primary outcomes were level of personality organization and overall psychological distress. As secondary outcomes, depression, anxiety and interpersonal problems were examined. No significant improvements were found in the control patients. Both PIT and E-PDT achieved significant improvements in all outcome measures and were superior to the control condition. No differences were found between PIT and E-PDT in any outcome measure at the end of treatment. The type of cluster B personality disorder had no impact on the results. In an inpatient setting, both PIT and E-PDT proved to be superior to a control condition in cluster B personality disorders. In a head-to-head comparison, both treatments appeared to be equally effective. Further research on the treatment of cluster B personality disorders is required. © 2016 S. Karger AG, Basel.

Uranium activity ratio in water and fish from pit lakes in Kurday, Kazakhstan and Taboshar, Tajikistan.

PubMed

Strømman, G; Rosseland, B O; Skipperud, L; Burkitbaev, L M; Uralbekov, B; Heier, L S; Salbu, B

2013-09-01

Kurday in Kazhakstan and Taboshar in Tajikistan were U mining sites operated during the 1950s and 1960s as part of the USSR nuclear weapon program. Today, they represent sources of potential U contamination of the environment. Within both mining sites, open pits from which U ore was extracted have been filled with water due to ground water inflow and precipitation. These artificial pit lakes contain fish consumed occasionally by the local people, and wild and domestic animals are using the water for drinking purposes. To assess the potential impact from U in these pit lakes, field work was performed in 2006 in Kurday and 2006 and 2008 in Taboshar. Results show that the U concentration in the lake waters were relatively high, about 1 mg/L in Kurday Pit Lake and about 3 mg/L in Taboshar Pit Lake. The influence of U-bearing materials on the lakes and downstream waters were investigated by measuring the U concentration and the (234)U/(238)U activity ratios. In both Kurday and Taboshar, the ratios increased distinctively from about 1 at the pit lakes to >1.5 far downstream the lakes. The concentrations of (238)U in gill, liver, muscle and bones in fish from the pit lakes were much higher than in the reference fish. Peak concentration of U was seen in bones (13 mg/kg w.w.), kidney (9.1 mg/kg w.w.) and gills (8.9 mg/kg w.w.) from Cyprinus auratus caught in the Taboshar Pit Lake. Bioconcentration factors (BCF) calculated for organs from fish caught in the Taboshar Pit Lake, with the same tendency seen in the Kurday Pit Lake, showed that U accumulates most in bone (BCF = 4.8 L/kg w.w.), gills (BCF = 3.6 L/kg w.w.), kidney (BCF = 3.6 L/kg w.w.), and liver (BCF = 2.5 L/kg w.w.), while least was accumulated in the muscle (BCF = 0.12 L/kg w.w.). Copyright © 2012 Elsevier Ltd. All rights reserved.

Governing in the Sunshine: Open Meetings, Open Records, and Effective Governance in Public Higher Education. Public Policy Paper Series No. 04-01

ERIC Educational Resources Information Center

Hearn, James C.; McLendon, Michael K.; Gilchrist, Leigh Z.

2004-01-01

Sunshine laws are designed to make meetings and records of public entities visible so that a state can help ensure accountability of decision making affecting public resources. The laws often pit the news media's desire for greater public disclosure of information on public college and university governance against institutional leaders' desire to…

Pit Where a Scarp Exposes an Underground Deposit of Martian Ice

NASA Image and Video Library

2018-01-11

At this wedge-shaped pit on Mars, the steep slope (or scarp) at the northern edge (toward the top of the image) exposes a cross-section of a thick sheet of underground water ice. The image is from the High Resolution Imaging Stereo Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. The gray-scale portions on left and right are from a single waveband in the red-light portion of the visible spectrum. The middle section, in enhanced color, combines data from red, near-infrared and blue-green wavebands. The scene covers an area about three miles (five kilometers) wide. Figure 1 includes a one-kilometer scale bar. One kilometer is about six-tenths of a mile. The ice-exposing scarp at the northern edge of the pit has a steepness of about 45 to 55 degrees, plunging from the relatively level ground outside the pit. The HiRISE observation ESP_022389_1230 was made on May 7, 2011, at 56.6 degrees south latitude, 114.1 degrees east longitude. In January 2018, in the journal Science, researchers reported finding and studying eight such ice-exposing scarps in the middle latitudes of Mars. The presence of vast underground ice deposits in Mars' middle latitudes was known previously. The report of unusual sites where they are exposed provides new information about their depth and layering. It also identifies potential water resources for future Mars missions and possibilities for studying Martian climate history by examining the ice layers holding a record of past climate cycles. The ice may have been deposited as snow when the tilt of Mars' rotation axis was greater than it is now. https://photojournal.jpl.nasa.gov/catalog/PIA22078

Remedial Action Plan and site design for stabilization of the inactive uranium mill tailings site at Durango, Colorado: Attachment 5, Dewatering report. Revised final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-12-01

This report provides an update on dewatering activities at the Durango disposal embankment and presents recommendations for the work required to complete the closure of the cell in 1990 (Section 2). In October 1989, test pit investigations were performed and a toe trench was excavated at the eastern slope of the disposal embankment. A description and results of the test pit investigations along with the implications . of the results relative to the over . all dewatering effort are discussed in Sections 3 through 5. Installation and performance of the 17-well dewatering system were previously described in` the ``StatusReport onmore » Dewatering of Disposal Embankment`` issued in September, 1989. Additional studies are still on-going and are described in Section 6. Laboratory analysis continues on samples taken from the test pits. TAC`s characterization of the hydrogeological conditions at the Durango site is also proceeding. Results of these studies will be presented in subsequent reports. Appendices A and B present construction details of the well point system, toe trench and holding pond. Appendix C summarizes the performance-of the 17 pumping wells prior to winter shutdown and provides information on pumping rates, drawdowns, and disposition of the wells. Appendix D outlines the chronology of the dewatering effort to date.« less

Irregular Mare Patches (IMPs): 100 Ma or 3 Ga?

NASA Technical Reports Server (NTRS)

Stopar, Julie; Robinson, Mark Southwick; van der Bogert, Carolyn H.; Giguere, Thomas; Lawrence, Samuel J.; Ostrach, Lillian Rose; Clegg-Watkins, Ryan N.

2016-01-01

IMPs exhibit a perplexing combination of characteristics that are consistent with either an approximately 100 Ma or 3 Ga formation. Dozens of small-area IMPs have crisp morphologies and crater size-frequency distributions (SFDs) that denote relatively recent geologic activity (less than 100 Ma); however, the apparently well-developed regolith on portions of the IMPs are in conflict with such a young age [1]. To test possible formation hypotheses (e.g., [1-5]), which range from ancient volcanism to contemporary outgassing, we examined IMP morphology at the meter-scale with LROC NAC images and derived elevation models. We focused on the largest IMPs (Ina, Sosigenes, Cauchy, Maskelyne, and Nubium), where contacts between deposits are best developed. Most of our observations are consistent with multiple generations of inflation and breakouts (or squeeze-ups) of basaltic lavas that were affected by local slopes. Some of the extrusions coalesced into larger mounds or filled pre-existing craters. We did not observe evidence of large-scale void space (e.g., fissures, fractures, linear depressions, or pits) within or beneath the mounds or rougher deposits (e.g., [5]). But, small-scale voids may be signified by isolated pitted textures. We also did not detect evidence of the cooling fractures or lava plates expected in young lava flows and observed in lunar impact melt deposits. The smooth texture of the mounds is enigmatic. Block-less craters suggest at least 5 m of friable or poorly-cohesive material (such as regolith), yet mound margins exhibit slopes greater than 30 deg requiring significant material strength. Blocks are not common on the mounds, but are sometimes excavated by impacts (usually excavated from beneath the mounds). The uneven deposits are equally enigmatic and texturally varied (blocky, pitted, and crenulated). They are deficient in superposed craters compared to the mounds. If the mounds are indeed of similar age to the rougher units, then their different superposed crater morphologies and SFDs need to be explained by factors other than their ages. Any mounds originally composed of friable surface materials would evolve differently from more coherent deposits (e.g., [6-7]).

Ground-water conditions and effects of mine dewatering in Desert Valley, Humboldt and Pershing Counties, northwestern Nevada, 1962-91

USGS Publications Warehouse

Berger, D.L.

1995-01-01

Desert Valley is a 1,200-square-mile, north- trending, structural basin, about 30 miles northwest of Winnemucca, Nevada. Unconsolidated basin-fill deposits exceeding 7,000 feet in thickness constitute the primary ground-water reservoir. Dewatering operations at an open-pit mine began in the Spring of 1985 in the northeast part of Desert Valley. Ground-water withdrawal for mine dewatering in 1991 was greater than three times the estimated average annual recharge from precipitation. The mine discharge water has been allowed to flow to areas west of the mine where it has created an artificial wetlands. This report documents the 1991 hydrologic conditions in Desert Valley and the change in conditions since predevelopment (pre-1962). It also summarizes the results of analyzing the simulated effects of open-pit mine dewatering on a basin-wide scale over time. Water-level declines associated with the dewatering have propagated north and south of the mine, but have been attenuated to the west due to the infiltration beneath the artificial wetlands. Maximum water-level declines beneath the open pits at the mine, as of Spring 1991, are about 300 feet. Changes in the hydrologic conditions since predevelopment are observed predominantly near the dewatering operations and the associated discharge lakes. General ground-water chemistry is essentially unchanged since pre- development. On the basis of a ground-water flow model used to simulate mine dewatering, a new equilibrium may slowly be approached only after 100 years of recovery from the time mine dewatering ceases.

Trees for strip-mined lands

Treesearch

George Hart; William R. Byrnes

1960-01-01

Open-pit or strip mining has become an important method of mining bituminous coal in Pennsylvania. In 1958 some 19.5 million tons of soft coal - 29 percent of the total bituminous production in the State - were produced by this method.

46 CFR 108.173 - Class I, Division 2 locations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... locations. The following are Class I, Division 2 locations: (a) An enclosed space that has any open portion... mud pit. (b) A location in the weather that is— (1) Within the boundaries of the drilling derrick up...

75 FR 52780 - Notice of Availability of Final Supplemental Environmental Impact Statement for the Moore Ranch...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-27

... considered, but were eliminated from detailed analysis include: conventional mining (whether by open pit or... Agencywide Documents and Management System (ADAMS), which provides text and image files of the NRC's public...

Mars Methane Analogue Mission (M3): Analytical Techniques and Operations

NASA Astrophysics Data System (ADS)

Cloutis, E.; Vrionis, H.; Qadi, A.; Bell, J. F.; Berard, G.; Boivin, A.; Ellery, A.; Jamroz, W.; Kruzelecky, R.; Mann, P.; Samson, C.; Stromberg, J.; Strong, K.; Tremblay, A.; Whyte, L.; Wing, B.

2011-03-01

The Mars Methane Analogue Mission (M3) project is designed to simulate a rover-based search for, and analysis of, methane sources on Mars at a serpentinite open pit mine in Quebec, using a variety of instruments.

Coarse woody debris in managed central hardwood forests of Indiana, USA

Treesearch

Michael A. Jenkins; Christopher R. Webster; George R. Parker; Martin A. Spetich

2004-01-01

We evaluated the volume of down deadwood (DDW) and the basal area of standing deadwood (SDW) from a chronosequence of 110 silvicultural openings and 34 mature stands (72-105 years old) across three Ecological Landtype Phases (ELTP; wet-mesic bottomlands, mesic slopes, and dry-mesic slopes) in southern Indiana, USA. The volume of DDW decreased with increasing opening...

Mineral resource of the month: barite

USGS Publications Warehouse

Miller, M. Michael

2006-01-01

Also called barytes, barite forms in various geologic environments and is frequently found with both metallic and nonmetallic minerals. Most barite is produced by open-pit mining techniques, and most crude barite requires some upgrading to meet minimum purity or specific gravity levels.

Integrating weather and geotechnical monitoring data for assessing the stability of large scale surface mining operations

NASA Astrophysics Data System (ADS)

Steiakakis, Chrysanthos; Agioutantis, Zacharias; Apostolou, Evangelia; Papavgeri, Georgia; Tripolitsiotis, Achilles

2016-01-01

The geotechnical challenges for safe slope design in large scale surface mining operations are enormous. Sometimes one degree of slope inclination can significantly reduce the overburden to ore ratio and therefore dramatically improve the economics of the operation, while large scale slope failures may have a significant impact on human lives. Furthermore, adverse weather conditions, such as high precipitation rates, may unfavorably affect the already delicate balance between operations and safety. Geotechnical, weather and production parameters should be systematically monitored and evaluated in order to safely operate such pits. Appropriate data management, processing and storage are critical to ensure timely and informed decisions. This paper presents an integrated data management system which was developed over a number of years as well as the advantages through a specific application. The presented case study illustrates how the high production slopes of a mine that exceed depths of 100-120 m were successfully mined with an average displacement rate of 10- 20 mm/day, approaching an almost slow to moderate landslide velocity. Monitoring data of the past four years are included in the database and can be analyzed to produce valuable results. Time-series data correlations of movements, precipitation records, etc. are evaluated and presented in this case study. The results can be used to successfully manage mine operations and ensure the safety of the mine and the workforce.

Heavy metal contamination in the river toad, Bufo juxtasper (Inger), near a copper mine in East Malaysia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Yook Heng; Stuebing, R.B.

1990-08-01

Mining of metals creates a potential source of heavy metal contamination in the environment. An open pit copper mine situated in the Northwest of Sabah, East Malaysia has been known to pollute its surroundings especially with discharges involving heavy metals. Although extensive investigations of heavy metal pollution has been carried out, none of the studies performed so far has included amphibians as indicator of heavy metal contamination in the area. As amphibians live both on land and in water, a study on the heavy metal content of these animals will thus enable a more extensive evaluation of the degree ofmore » contamination by heavy metals. Bufo juxtasper was chosen since it inhabits the rocky streams and rivers which exist in both a polluted and non-polluted condition in Sabah. Its' tadpoles are herbivorous feeding mainly on plant detritus, while adults feed principally on ants (which are polyphagous). Furthermore the large adult size of Bufo juxtasper, in which the size of the liver has an allometric relationship with body size, may allow for differentiation between larval and adult uptake through regression analysis. Thus concentration of pollutants acquired only during the larval phase should show a declining or negative slope as a function of body size in adults.« less

Comet 67P's Pitted Surface

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2015-11-01

High-resolution imagery of comet 67P ChuryumovGerasimenko has revealed that its surface is covered in active pits some measuring hundreds of meters both wide and deep! But what processes caused these pits to form?Pitted LandscapeESAs Rosetta mission arrived at comet 67P in August 2014. As the comet continued its journey around the Sun, Rosetta extensively documented 67Ps surface through high-resolution images taken with the on-board instrument NavCam. These images have revealed that active, circular depressions are a common feature on the comets surface.In an attempt to determine how these pits formed, an international team of scientists led by Olivier Mousis (Laboratory of Astrophysics of Marseille) has run a series of simulations of a region of the comet the Seth region that contains a 200-meter-deep pit. These simulations include the effects of various phase transitions, heat transfer through the matrix of ices and dust, and gas diffusion throughout the porous material.Escaping VolatilesAdditional examples of pitted areas on 67Ps northern-hemisphere surface include the Ash region and the Maat region (both imaged September 2014 by NavCam) [Mousis et al. 2015]Previous studies have already eliminated two potential formation mechanisms for the pits: impacts (the sizes of the pits werent right) and erosion due to sunlight (the pits dont have the right shape). Mousis and collaborators assume that the pits are instead caused by the depletion of volatile materials chemical compounds with low boiling points either via explosive outbursts at the comets surface, or via sinkholes opening from below the surface. But what process causes the volatiles to deplete when the comet heats?The authors simulations demonstrate that volatiles trapped beneath the comets surface either in icy structures called clathrates or within amorphous ice can be suddenly released as the comet warms up. The team shows that the release of volatiles from these two structures can create 200-meter-deep pits within ~800 years and ~2,000 years, respectively. Since comet 67P has been around the inner solar system for about 7,000 years, both of these processes are viable explanations for the pits.The simulations also show that direct sublimation of crystalline ices of water, carbon monoxide, and carbon dioxide can cause deep pits but only in the absence of a surface layer of dust, known as a dust mantle, in that region of the comet. Direct sublimation could be a viable explanation for the pits, then, if dust grains in the area are so small that they are carried away with the released gas, rather than falling back to form a layer on the comets surface.Regardless of the formation mechanism for these pits, the authors conclude that their very existence implies that the physical and chemical properties across the surface and subsurface of the comet cannot be uniform. Further observations from Rosetta will continue to help us understand comet 67P.CitationO. Mousis et al 2015 ApJ 814 L5. doi:10.1088/2041-8205/814/1/L5

Proposed Iraq/Afghanistan War-Lung Injury (IAW-LI) Clinical Practice Recommendations: National Academy of Sciences' Institute of Medicine Burn Pits Workshop.

PubMed

Szema, Anthony; Mirsaidi, Niely; Patel, Bhumika; Viens, Laura; Forsyth, Edward; Li, Jonathan; Dang, Sophia; Dukes, Brittany; Giraldo, Jheison; Kim, Preston; Burns, Matthew

2017-11-01

High rates of respiratory symptoms (14%) and new-onset asthma in previously healthy soldiers (6.6%) have been reported among military personnel post-deployment to Iraq and Afghanistan. The term Iraq/Afghanistan War-Lung Injury (IAW-LI) is used to describe the constellation of respiratory diseases related to hazards of war, such as exposure to burning trash in burn pits, improvised explosive devices, and sandstorms. Burnpits360.org is a nonprofit civilian website which voluntarily tracks medical symptoms among soldiers post-deployment to the Middle East. Subsequent to initiation of the Burnpits360.org website, the Department of Veterans Affairs started the Airborne Hazards and Open Burn Pit registry. This paper: (a) analyzes the latest 38 patients in the Burnpits360.org registry, validated by DD214 Forms; (b) compares strengths and weaknesses of both registries as outlined at the National Academy of Sciences Institute of Medicine Burn Pits Workshop; (c) further characterizes the spectrum of disease in IAW-LI; (d) describes the risk factors of affected populations; (e) summarizes current practices regarding management of the condition; and (f) defines future research objectives.

Proposed Iraq/Afghanistan War-Lung Injury (IAW-LI) Clinical Practice Recommendations: National Academy of Sciences’ Institute of Medicine Burn Pits Workshop

PubMed Central

Szema, Anthony; Mirsaidi, Niely; Patel, Bhumika; Viens, Laura; Forsyth, Edward; Li, Jonathan; Dang, Sophia; Dukes, Brittany; Giraldo, Jheison; Kim, Preston; Burns, Matthew

2015-01-01

High rates of respiratory symptoms (14%) and new-onset asthma in previously healthy soldiers (6.6%) have been reported among military personnel post-deployment to Iraq and Afghanistan. The term Iraq/Afghanistan War-Lung Injury (IAW-LI) is used to describe the constellation of respiratory diseases related to hazards of war, such as exposure to burning trash in burn pits, improvised explosive devices, and sandstorms. Burnpits360.org is a nonprofit civilian website which voluntarily tracks medical symptoms among soldiers post-deployment to the Middle East. Subsequent to initiation of the Burnpits360.org website, the Department of Veterans Affairs started the Airborne Hazards and Open Burn Pit registry. This paper: (a) analyzes the latest 38 patients in the Burnpits360.org registry, validated by DD214 Forms; (b) compares strengths and weaknesses of both registries as outlined at the National Academy of Sciences Institute of Medicine Burn Pits Workshop; (c) further characterizes the spectrum of disease in IAW-LI; (d) describes the risk factors of affected populations; (e) summarizes current practices regarding management of the condition; and (f) defines future research objectives. PMID:26669772

Real-time monitoring of hemodynamic changes in tumor vessels during photoimmunotherapy using optical coherence tomography

NASA Astrophysics Data System (ADS)

Liang, Chia-Pin; Nakajima, Takahito; Watanabe, Rira; Sato, Kazuhide; Choyke, Peter L.; Chen, Yu; Kobayashi, Hisataka

2014-09-01

Photoimmunotherapy (PIT) is a cell-specific cancer therapy based on an armed antibody conjugate that induces rapid and highly selective cancer cell necrosis after exposure to near-infrared (NIR) light. The PIT treatment also induces the superenhanced permeability and retention effect, which allows high concentrations of nanoparticles to accumulate in the tumor bed. In our pilot studies, optical coherence tomography (OCT) reveals dramatic hemodynamic changes during PIT. We developed and applied speckle variance analysis, Doppler flow measurement, bulk motion removal, and automatic region of interest selection to quantify vessel diameter and blood velocity within tumors in vivo. OCT imaging reveals that blood velocity in peripheral tumor vessels quickly drops below the detection limit while the vessel lumen remains open (4 vessels from 3 animals). On the other hand, control tumor vessels (receive NIR illumination but no PIT drug) do not show the sustained blood velocity drop (5 vessels from 3 animals). Ultraslow blood velocity could result in a long drug circulation time in tumor. Increase of the blood pool volume within the central tumor (shown in histology) may be the leading cause of the periphery blood velocity drop and could also increase the drug pool volume in tumor vessels.

Coal and Open-pit surface mining impacts on American Lands (COAL)

NASA Astrophysics Data System (ADS)

Brown, T. A.; McGibbney, L. J.

2017-12-01

Mining is known to cause environmental degradation, but software tools to identify its impacts are lacking. However, remote sensing, spectral reflectance, and geographic data are readily available, and high-performance cloud computing resources exist for scientific research. Coal and Open-pit surface mining impacts on American Lands (COAL) provides a suite of algorithms and documentation to leverage these data and resources to identify evidence of mining and correlate it with environmental impacts over time.COAL was originally developed as a 2016 - 2017 senior capstone collaboration between scientists at the NASA Jet Propulsion Laboratory (JPL) and computer science students at Oregon State University (OSU). The COAL team implemented a free and open-source software library called "pycoal" in the Python programming language which facilitated a case study of the effects of coal mining on water resources. Evidence of acid mine drainage associated with an open-pit coal mine in New Mexico was derived by correlating imaging spectrometer data from the JPL Airborne Visible/InfraRed Imaging Spectrometer - Next Generation (AVIRIS-NG), spectral reflectance data published by the USGS Spectroscopy Laboratory in the USGS Digital Spectral Library 06, and GIS hydrography data published by the USGS National Geospatial Program in The National Map. This case study indicated that the spectral and geospatial algorithms developed by COAL can be used successfully to analyze the environmental impacts of mining activities.Continued development of COAL has been promoted by a Startup allocation award of high-performance computing resources from the Extreme Science and Engineering Discovery Environment (XSEDE). These resources allow the team to undertake further benchmarking, evaluation, and experimentation using multiple XSEDE resources. The opportunity to use computational infrastructure of this caliber will further enable the development of a science gateway to continue foundational COAL research.This work documents the original design and development of COAL and provides insight into continuing research efforts which have potential applications beyond the project to environmental data science and other fields.

30 CFR 77.1911 - Ventilation of slopes and shafts.

Code of Federal Regulations, 2010 CFR

2010-07-01

... or air contamination from any other source; (4) Equipped with an automatic signal device designed to... be examined before each shift and the quantity of air in the slope or shaft measured daily by a... connected to the slope or shaft opening with fireproof air ducts; (3) Designed to permit the reversal of the...

76 FR 63954 - Notice of Lodging of Consent Decree Under the Comprehensive Environmental Response, Compensation...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-14

... associated with waste rock piles and open mine pits present at the Site. Additionally, the Consent Decree... United States of America v. Newmont USA Limited, DJ. Ref. 90-11-3-1749. Commenters may request an...

Ride-on lawnmowers warnings: slope measurements and safety-by-separation.

PubMed

Karnes, Edward W; Leonard, S David; Lenorovitz, David R

2012-01-01

Various single-rider open vehicles, such as lawnmowers, are susceptible to overturning on slopes that are too steep for them. Warnings have included separation from the vehicles and avoiding slopes that are too steep. A recommended maximum slope is commonly 15 degrees. However, many individuals cannot evaluate slopes just by sight. Some mower manufacturers have warned about too steep slopes and have provided slope gauges for users to determine the slopes in natural settings. This article evaluated the usefulness of such gauges for users who might be expected to need to evaluate slopes and the efficacy of a separation procedure for avoiding injuries. It was concluded that neither of these were likely to be successful and suggestions are made for alternative approaches.

Evidence of stratabound liquefaction in the formation of fractured topographic margins, cone chains and pit catenas along the Martian Dichotomy Boundary and in Isidis Planitia, Mars.

NASA Astrophysics Data System (ADS)

Gallagher, C.; Balme, M. R.

2012-04-01

On the low-lying plains along much of the Martian Dichotomy Boundary (MDB) and in the Isidis impact basin, cones and curving chains of cones, referred to as thumbprint terrain (TPT), are common. In the same settings, pit chains (catenas) occur in orthogonal to curving and conchoidal fracture sets between mesa-like crustal blocks, generally at or near topographic margins. Many of the fractures consist of linked pits rather than simple propagated cracks. These assemblages are often associated with the more disaggregated populations of blocks comprising chaos terrain. We show that the local planimetric arrangement of the cone chains, fractures and pit catenas is strikingly similar in both shape and scale, including lateral separation, length, longitudinal slope and radius of curvature. The summits of cones tend to be closely accordant along individual cone chains. Neighbouring cone chains tend to be mutually accordant on low gradient basin surfaces but generally stepped en echelon closer to the fractured basin margins. Similarly, the crustal blocks (including very isolated block sets) are often mutually stepped, and fractures between these en echelon blocks tend to be very close to horizontal. Hence, many cone chains, fractures and pit catenas in fractures share the property of being arranged along strike. They diverge morphologically by the cone chains being positive forms separated by narrow gulfs but the pit catenas being negative forms separated by planar blocks. All of these characteristics point to the possibility that the arcuate cone chains and the arcuate pit catenas have a common origin. In particular, we hypothesise that the cone chains characteristic of TPT along the MDB and in Isidis are filled, indurated and then exhumed pit catenas revealed by the stripping-away of intervening blocks [cf. 1]. Many other surfaces on Mars are pervaded by pits and pit catenas, with evidence of former water flow through the catenas suggesting that ground-ice thaw played a role in at least one mode of catena formation [2]. As well as presenting the morphological evidence for a genetic association between TPT and pit catenas, we present corroborative evidence that fluvial channel networks on Mars have in places increased in complexity through the linking of pits arranged in linear to arcuate arrays, culminating in a pseudo-branching channel network. Such systems do not occur at topographic margins and did not disintegrate into stepped crustal blocks. However, the scale of these channels and the volumes of liquid intermittently impounded in craters along these channel systems indicate that pit chains are associated with significant excess groundwater production leading to channelized flow, including catastrophic discharges when crater-impounded lakes along-flow were breached. Are the MDB and Isidis cone chains exhumed pit catenas and are the pits the surface expression of more deep-seated conduits? Do pit catenas indicate excess pore-water production, sufficient to link individual pits and dissect crustal blocks? Together, do these assemblages reflect the degradation of the MDB and Isidis margins and the subsequent stripping of adjacent low-lying plains? The crucial observations presented in this research (cone chains lying between crustal blocks, together with the morphometric similarities) are consistent with the interpretation of the cones and catenas having a common origin. Consequently, we hypothesise that the translated, back-rotated, tilted and capsized disposition of en echelon blocks is very reminiscent of the morphology produced during lateral spreading [3] associated with stratabound liquefaction below a low-gradient, rigid, insensitive surface. Significantly, such liquefaction events cause extensive, arcuate ground fractures along with the discharge of sediment-laden groundwater from the liquefiable substratum to the surface through pipes and conical boils confined within inter-block fractures. These conduits and their injectite are frequently indurated by secondary mineralisation, often making them more competent and less erodible than the confining material. Most often, lateral spreads occur at coastlines, with basin-ward normal faulting and extension of the original surface. Generally, seismic shaking of susceptible materials is responsible for lateral spreading but pore-water pressure changes, e.g. due to rapid marine recession and drawdown, may also play a role. Given the basin-and-margin setting of the martian cone, pit and block assemblages described in this research, we speculate that all three broad morphological types reflect the degradation of extensive marine margins and the deflation of the interiors of marine basins during long-term marine recession. [1] Williams et al. (2007) in Willis et al. (eds), Utah Geological Association Publication 36. [2] Weitz et al. (2006) Icarus 184, 436-451. [3] Wang et al. (2005) Icarus 175, 551-555.

Accelerated slab replacement using temporary precast panels and self-consolidating concrete : [summary].

DOT National Transportation Integrated Search

2016-06-01

Researchers at Florida State University demonstrated the feasibility of using precast reinforced concrete panels to temporarily fill slab removal pits. The precast slabs can be driven on so traffic lanes can be open during the day, and new slab casti...

Tanacetum vulgare as a bioindicator of trace-metal contamination: a study of a naturally colonized open-pit lignite mine.

PubMed

Jasion, Mateusz; Samecka-Cymerman, Aleksandra; Kolon, Krzysztof; Kempers, Alexander J

2013-10-01

We investigated the possibility of use of Tanacetum vulgare (tansy) as an ecological indicator of metal concentration in a naturally colonized open-pit lignite mine in Bełchatów (Poland). Tanacetum vulgare is the only species growing abundantly and spontaneously in the lignite mine waste dumps. Metal concentrations in roots, stems, leaves, flowers, and soil were measured in dump sites differing in type and time of reclamation and therefore differing in pollution levels. Tanacetum vulgare appeared to be an accumulator of chromium and iron in roots, whereas highest concentrations of manganese and zinc were found in leaves. A high bioaccumulation factor for cadmium (Cd) was observed in dumps and control sites, indicating that even small amounts of Cd in the environment may result in significant uptake by the plant. The lowest concentrations of metals were found in plants from sites situated on dumps reclaimed with argillaceous limestone.

Air quality status of an open pit mining area in India.

PubMed

Chaulya, S K

2005-06-01

This investigation presents the assessment of ambient air quality carried out at an open pit coal mining area in Orissa state of India. The 24-h average concentrations of suspended particulate matter (SPM), respirable particulate matter (RPM, particles of less than 10 microm aerodynamic diameter), sulphur dioxide (SO2) and oxides of nitrogen (NO(x)) were determined at regular interval throughout one year at 13 monitoring stations in residential area and four stations in mining/industrial area. During the study period, the 24-h and annual average SPM and RPM concentrations exceeded the respective standards set in the Indian ambient air quality standard (NAAQS) protocol in most of the residential and industrial areas. However, the 24-h and annual average concentrations of SO2 and NO(x) were well within the prescribed limit of the NAAQS in both residential and industrial areas. A management strategy is formulated for effective control of particulate matter at source and other mitigative measures are recommended including implementation of green belts around the sensitive areas.

Electrical Current Leakage and Open-Core Threading Dislocations in AlGaN-Based Deep Ultraviolet Light-Emitting Diodes.

DOE PAGES

Moseley, Michael William; Allerman, Andrew A.; Crawford, Mary H.; ...

2014-08-04

Electrical current transport through leakage paths in AlGaN-based deep ultraviolet (DUV) lightemitting diodes (LEDs) and their effect on LED performance are investigated. Open-core threading dislocations, or nanopipes, are found to conduct current through nominally insulating Al0.7Ga0.3N layers and limit the performance of DUV-LEDs. A defect-sensitive phosphoric acid etch reveals these opencore threading dislocations in the form of large, micron-scale hexagonal etch pits visible with optical microscopy, while closed-core screw-, edge-, and mixed-type threading dislocations are represented by smaller and more numerous nanometer-scale pits visible by atomic-force microscopy. The electrical and optical performances of DUV-LEDs fabricated on similar Si-doped Al0.7Ga0.3N templatesmore » are found to have a strong correlation to the density of these nanopipes, despite their small fraction (<0.1% in this study) of the total density of threading dislocations.« less

Design and construction of a dual recharge system at Minot, North Dakota

USGS Publications Warehouse

Pettyjohn, Wayne A.

1968-01-01

In 1965, a ground-water recharge facility was constructed and placed in operation to forestall an impending water shortage at Minot, North Dakota. The facility is unique in that the rate of recharge to a buried sand and gravel aquifer is augmented by perforating an overlying bed of clay using hydraulic connectors (gravel-filled bored holes) in conjunction with an open-pit excavation. The connectors were drilled by typical well-boring techniques and the open pit was excavated by common construction methods. The recharge technique made it possible to add about million gallons per day of water to underground storage with a total capital investment of about $200,000. The alternative originally proposed was a 50-mile long pipeline to Garrison Reservoir, at a 1959 estimated cost of $12,000,000. The recharge technique employed at Minot should have wide application in the ground-water industry in areas where natural recharge to permeable deposits is impeded by overlying beds of low permeability.

Oil sands mining and reclamation cause massive loss of peatland and stored carbon

PubMed Central

Rooney, Rebecca C.; Bayley, Suzanne E.; Schindler, David W.

2012-01-01

We quantified the wholesale transformation of the boreal landscape by open-pit oil sands mining in Alberta, Canada to evaluate its effect on carbon storage and sequestration. Contrary to claims made in the media, peatland destroyed by open-pit mining will not be restored. Current plans dictate its replacement with upland forest and tailings storage lakes, amounting to the destruction of over 29,500 ha of peatland habitat. Landscape changes caused by currently approved mines will release between 11.4 and 47.3 million metric tons of stored carbon and will reduce carbon sequestration potential by 5,734–7,241 metric tons C/y. These losses have not previously been quantified, and should be included with the already high estimates of carbon emissions from oil sands mining and bitumen upgrading. A fair evaluation of the costs and benefits of oil sands mining requires a rigorous assessment of impacts on natural capital and ecosystem services. PMID:22411786

Testing and modeling the influence of reclamation and control methods for reducing nonpoint mercury emissions associated with industrial open pit gold mines.

PubMed

Miller, Matthieu B; Gustin, Mae S

2013-06-01

Industrial gold mining is a significant source of mercury (Hg) emission to the atmosphere. To investigate ways to reduce these emissions, reclamation and dust and mercury control methods used at open pit gold mining operations in Nevada were studied in a laboratory setting. Using this information along with field data, and building off previous work, total annual Hg emissions were estimated for two active gold mines in northern Nevada. Results showed that capping mining waste materials with a low-Hg substrate can reduce Hg emissions from 50 to nearly 100%. The spraying of typical dust control solutions often results in higher Hg emissions, especially as materials dry after application. The concentrated application of a dithiocarbamate Hg control reagent appears to reduce Hg emissions, but further testing mimicking the actual distribution of this chemical within an active leach solution is needed to make a more definitive assessment.

A simplified economic filter for open-pit gold-silver mining in the United States

USGS Publications Warehouse

Singer, Donald A.; Menzie, W. David; Long, Keith R.

1998-01-01

In resource assessments of undiscovered mineral deposits and in the early stages of exploration, including planning, a need for prefeasibility cost models exists. In exploration, these models to filter economic from uneconomic deposits help to focus on targets that can really benefit the exploration enterprise. In resource assessment, these models can be used to eliminate deposits that would probably be uneconomic even if discovered. The U. S. Bureau of Mines (USBM) previously developed simplified cost models for such problems (Camm, 1991). These cost models estimate operating and capital expenditures for a mineral deposit given its tonnage, grade, and depth. These cost models were also incorporated in USBM prefeasibility software (Smith, 1991). Because the cost data used to estimate operating and capital costs in these models are now over ten years old, we decided that it was necessary to test these equations with more current data. We limited this study to open-pit gold-silver mines located in the United States.

Orapa Diamond Mine, Botswana

NASA Image and Video Library

2015-11-16

This image from NASA Terra spacecraft shows the Orapa diamond mine, the world largest diamond mine by area. The mine is located in Botswana. It is the oldest of four mines operated by the same company, having begun operations in 1971. Orapa is an open pit style of mine, located on two kimberlite pipes. Currently, the Orapa mine annually produces approximately 11 million carats (2200 kg) of diamonds. The Letlhakane diamond mine is also an open pit construction. In 2003, the Letlhakane mine produced 1.06 million carats of diamonds. The Damtshaa diamond mine is the newest of four mines, located on top of four distinct kimberlite pipes of varying ore grade. The mine is forecast to produce about 5 million carats of diamond over the projected 31 year life of the mine. The image was acquired October 5, 2014, covers an area of 28 by 45 km, and is located at 21.3 degrees south, 25.4 degrees east. http://photojournal.jpl.nasa.gov/catalog/PIA20104

New Onset Migraine Associated With a Civilian Burn Pit.

PubMed

Chalela, Julio A

2017-05-01

Deployed service members exposed to burn pit smoke can experience a multitude of symptoms. Respiratory symptoms after burn pit smoke exposure are well recognized, but neurologic symptoms are less well recognized. There are reports of migraines triggered by odors but no specific reports of new onset migraines triggered by exposure to burn pit smoke. Clinicians encountering patients with new onset migraines in the deployed setting face the dilemma of evacuating the patients to perform neuroimaging or keeping them in theatre. Retrospective case series study and review of the literature. Three patients with new onset headache after exposure to open burn pit smoke are described. The headaches met established criteria to be classified as migraine with aura in two patients and migraine without aura in one patient. The migraines were triggered by exposure to the burn pit smoke and relieved by avoidance of the smoke. The patients did not have history of migraine and had normal neurological examinations. Computed tomography performed in one patient and optic nerve insonation performed in all three patients were normal. The patients responded well to triptans and antiemetic medicines. Nociceptive odors can trigger classic migraines in adults without prior history of migraine. The temporal association between exposure to the odor and the development of the headache, the absence of abnormalities on neurologic examination, and the response to triptans help establish the diagnosis. Activation of the trigeminal system leading to release of pain-related neuropeptides may mediate the migrainous symptoms. Evacuation for advanced neuroimaging or specialized consultation can be avoided if the above-mentioned criteria are met. Reprint & Copyright © 2017 Association of Military Surgeons of the U.S.

Snow distribution throughout small subalpine catchment post-insect infestation of spruce and pine beetle.

NASA Astrophysics Data System (ADS)

Beverly, D.; Ewers, B. E.; Hyde, K.; Ohara, N.; Speckman, H. N.

2015-12-01

High elevation watersheds of the Rocky Mountains region contribute over 70% of the streamflow needed for infrastructure, agriculture, and ecological processes. Snow-water yields are heterogeneous in space and time and are driven by a multitude of snow distribution processes, including snowpack evolution driven by physical and biological factors. Quantifying heterogeneity of snowpack is further complicated by vegetation perturbations; much of the Rocky Mountains have experienced significant tree mortality due to bark beetle outbreaks. Reduction of living crown area decreases canopy interception while increasing radiation to snow surfaces, which alters snowpack distribution throughout the catchment. We hypothesize that, in a complex watershed, topographic variation (i.e., slope and aspect) will have a greater effect on snowpack evolution and distribution than densities of canopy mortality due to beetle infestation. The 120 ha No Name watershed, located in southern Wyoming at 3000 m elevation was divided into twenty-one 175 m2 parcels, in which plots were randomly assigned within each parcel. Peak snow was measured in April; in the 50 m2 plots, depths were measured every 2 m along north-south and east-west transects. Twenty-one snow pits were excavated to quantify snow densities in 10 cm increments throughout the pit profile. Forest inventories occurred the following summer. Peak snowpack levels occurred in April with mean depth of 92.3 ­­± 2.4 cm and peak SWE of 34.0 ± 0.84 cm. Binary decision trees accounted for 63% of the variability after including topographic indices, beetle condition of the trees, LAI, and basal area. Snow depth showed a slight positive relationship with increased in beetle mortality on slopes less than 11 degrees. Overall, topographic indices are greater drivers for snow distributions compared to effects of tree mortality.

Spatial-temporal dynamics of chemical composition of surface snow in East Antarctica along the Progress station-Vostok station transect

NASA Astrophysics Data System (ADS)

Khodzher, T. V.; Golobokova, L. P.; Osipov, E. Yu.; Shibaev, Yu. A.; Lipenkov, V. Ya.; Osipova, O. P.; Petit, J. R.

2014-05-01

In January of 2008, during the 53rd Russian Antarctic Expedition, surface snow samples were taken from 13 shallow (0.7 to 1.5 m depth) snow pits along the first tractor traverse from Progress to Vostok stations, East Antarctica. Sub-surface snow/firn layers are dated from 2.1 to 18 yr. The total length of the coast to inland traverse is more than 1280 km. Here we analysed spatial variability of concentrations of sulphate ions and elements and their fluxes in the snow deposited within the 2006-2008 time interval. Anions were analysed by high-performance liquid chromatography (HPLC), and the determination of selected metals, including Na, K, Mg, Ca and Al, was carried out by mass spectroscopy with atomization by induced coupled plasma (ICP-MS). Surface snow concentration records were examined for trends versus distance inland, elevation, accumulation rate and slope gradient. Na shows a significant positive correlation with accumulation rate, which decreases as distance from the sea and altitude increase. K, Ca and Mg concentrations do not show any significant relationship either with distance inland or with elevation. Maximal concentrations of these elements with a prominent Al peak are revealed in the middle part of the traverse (500-600 km from the coast). Analysis of element correlations and atmospheric circulation patterns allow us to suggest their terrestrial origin (e.g. aluminosilicates carried as a continental dust) from the Antarctic nunatak areas. Sulphate concentrations show no significant relationship with distance inland, elevation, slope gradient and accumulation rate. Non-sea salt secondary sulphate is the most important contribution to the total sulphate budget along the traverse. Sulphate of volcanic origin attributed to the Pinatubo eruption (1991) was revealed in the snow pit at 1276 km (depth 120-130 cm).

Tectonic history of the Syria Planum province of Mars

USGS Publications Warehouse

Tanaka, K.L.; Davis, P.A.

1988-01-01

We attribute most of the development of extensive fractures in the Tharsis region to discrete tectonic provinces within the region, rather than to Tharsis as a single entity. One of these provinces is in Syria Planum. Faults and collapse structures in the Syria Planum tectonic province on Mars are grouped into 13 sets based on relative age, areal distribution, and morphology. According to superposition and fault crosscutting relations and crater counts we designate six distinct episodes of tectonic activity. Photoclinometric topographic profiles across 132 grabens and fault scarps show that Syria Planum grabens have widths (average of 2.5 km, and most range from 1 to 6 km) similar to lunar grabens, but the Martian grabens have slightly higher side walls (average abour 132 m) and gentler wall slopes (average of 9?? and range of 2??-25??) than lunar grabens (93 m high and 18?? slopes). Estimates of the amount of extension for individual grabens range from 20 to 350 m; most estimates of the thickness of the faulted layer range from 0.5 to 4.5 km (average is 1.5 km). This thickness range corresponds closely to the 0.8- to 3.6-km range in depth for pits, troughs, and canyons in Noctis Labyrinthus and along the walls of Valles Marineris. We propose that the predominant 1- to 1.5-km values obtained for both the thickness of the faulted layer and the depths of the pits, troughs, and theater heads of the canyons reflect the initial depth to the water table in this region, as governed by the depth to the base of ground ice. Maximum depths for these features may indicate lowered groundwater table depths and the base of ejecta material. -from Authors

Metazoan meiofauna in deep-sea canyons and adjacent open slopes: A large-scale comparison with focus on the rare taxa

NASA Astrophysics Data System (ADS)

Bianchelli, S.; Gambi, C.; Zeppilli, D.; Danovaro, R.

2010-03-01

Metazoan meiofaunal abundance, total biomass, nematode size and the richness of taxa were investigated along bathymetric gradients (from the shelf break down to ca. 5000-m depth) in six submarine canyons and on five adjacent open slopes of three deep-sea regions. The investigated areas were distributed along >2500 km, on the Portuguese to the Catalan and South Adriatic margins. The Portuguese and Catalan margins displayed the highest abundances, biomass and richness of taxa, while the lowest values were observed in the Central Mediterranean Sea. The comparison between canyons and the nearby open slopes showed the lack of significant differences in terms of meiofaunal abundance and biomass at any sampling depth. In most canyons and on most slopes, meiofaunal variables did not display consistent bathymetric patterns. Conversely, we found that the different topographic features were apparently responsible for significant differences in the abundance and distribution of the rare meiofaunal taxa (i.e. taxa accounting for <1% of total meiofaunal abundance). Several taxa belonging to the temporary meiofauna, such as larvae/juveniles of Priapulida, Holothuroidea, Ascidiacea and Cnidaria, were encountered exclusively on open slopes, while others (including the Tanaidacea and Echinodea larvae) were found exclusively in canyons sediments. Results reported here indicate that, at large spatial scales, differences in deep-sea meiofaunal abundance and biomass are not only controlled by the available food sources, but also by the region or habitat specific topographic features, which apparently play a key role in the distribution of rare benthic taxa.

Soft valves in plants

NASA Astrophysics Data System (ADS)

Park, Keunhwan; Tixier, Aude; Christensen, Anneline; Arnbjerg-Nielsen, Sif; Zwieniecki, Maciej; Jensen, Kaare

2017-11-01

Water and minerals flow from plant roots to leaves in the xylem, an interconnected network of vascular conduits that spans the full length of the organism. When a plant is subjected to drought stress, air pockets can spread inside the xylem, threatening the survival of the plant. Many plants prevent propagation of air by using hydrophobic nano-membranes in the ``pit'' pores that link adjacent xylem cells. This adds considerable resistance to flow. Interestingly, torus-margo pit pores in conifers are open and offer less resistance. To prevent propagation of air, conifers use a soft gating mechanism, which relies on hydrodynamic interactions between the xylem liquid and the elastic pit. However, it is unknown exactly how it is able to combine the seemingly antagonist functions of high permeability and resistance to propagation of air. We conduct experiments on biomimetic pores to elucidate the flow regulation mechanism. The design of plant valves is compared to other natural systems and optimal strategies are discussed. This work was supported by a research Grant (13166) from VILLUM FONDEN.

HIP1 exhibits an early recruitment and a late stage function in the maturation of coated pits.

PubMed

Gottfried, Irit; Ehrlich, Marcelo; Ashery, Uri

2009-09-01

Huntingtin interacting protein 1 (HIP1) is an accessory protein of the clathrin-mediated endocytosis (CME) pathway, yet its precise role and the step at which it becomes involved are unclear. We employed live-cell imaging techniques to focus on the early steps of CME and characterize HIP1 dynamics. We show that HIP1 is highly colocalized with clathrin at the plasma membrane and shares similar dynamics with a subpopulation of clathrin assemblies. Employing transferrin receptor fused to pHluorin, we distinguished between open pits to which HIP1 localizes and newly internalized vesicles that are devoid of HIP1. Moreover, shRNA knockdown of clathrin compromised HIP1 membranal localization, unlike the reported behavior of Sla2p. HIP1 fragment, lacking its ANTH and Talin-like domains, inhibits internalization of transferrin, but retains colocalization with membranal clathrin assemblies. These data demonstrate HIP1's role in pits maturation and formation of the coated vesicle, and its strong dependence on clathrin for membranal localization.

Surface mining

Treesearch

Robert Leopold; Bruce Rowland; Reed Stalder

1979-01-01

The surface mining process consists of four phases: (1) exploration; (2) development; (3) production; and (4) reclamation. A variety of surface mining methods has been developed, including strip mining, auger, area strip, open pit, dredging, and hydraulic. Sound planning and design techniques are essential to implement alternatives to meet the myriad of laws,...

The Phoneme Identification Test for Assessment of Spectral and Temporal Discrimination Skills in Children: Development, Normative Data, and Test-Retest Reliability Studies.

PubMed

Cameron, Sharon; Chong-White, Nicky; Mealings, Kiri; Beechey, Tim; Dillon, Harvey; Young, Taegan

2018-02-01

Previous research suggests that a proportion of children experiencing reading and listening difficulties may have an underlying primary deficit in the way that the central auditory nervous system analyses the perceptually important, rapidly varying, formant frequency components of speech. The Phoneme Identification Test (PIT) was developed to investigate the ability of children to use spectro-temporal cues to perceptually categorize speech sounds based on their rapidly changing formant frequencies. The PIT uses an adaptive two-alternative forced-choice procedure whereby the participant identifies a synthesized consonant-vowel (CV) (/ba/ or /da/) syllable. CV syllables differed only in the second formant (F2) frequency along an 11-step continuum (between 0% and 100%-representing an ideal /ba/ and /da/, respectively). The CV syllables were presented in either quiet (PIT Q) or noise at a 0 dB signal-to-noise ratio (PIT N). Development of the PIT stimuli and test protocols, and collection of normative and test-retest reliability data. Twelve adults (aged 23 yr 10 mo to 50 yr 9 mo, mean 32 yr 5 mo) and 137 typically developing, primary-school children (aged 6 yr 0 mo to 12 yr 4 mo, mean 9 yr 3 mo). There were 73 males and 76 females. Data were collected using a touchscreen computer. Psychometric functions were automatically fit to individual data by the PIT software. Performance was determined by the width of the continuum for which responses were neither clearly /ba/ nor /da/ (referred to as the uncertainty region [UR]). A shallower psychometric function slope reflected greater uncertainty. Age effects were determined based on raw scores. Z scores were calculated to account for the effect of age on performance. Outliers, and individual data for which the confidence interval of the UR exceeded a maximum allowable value, were removed. Nonparametric tests were used as the data were skewed toward negative performance. Across participants, the median value of the F2 range that resulted in uncertain responses was 33% in quiet and 40% in noise. There was a significant effect of age on the width of this UR (p < 0.00001) in both quiet and noise, with performance becoming adult like by age 9 on the PIT Q and age 10 on the PIT N. A skewed distribution toward negative performance occurred in both quiet (p = 0.01) and noise (p = 0.006). Median UR scores were significantly wider in noise than in quiet (T = 2041, p < 0.0000001). Performance (z scores) across the two tests was significantly correlated (r = 0.36, p = 0.000009). Test-retest z scores were significantly correlated in both quiet and noise (r = 0.4 and 0.37, respectively, p < 0.0001). The PIT normative data show that the ability to identify phonemes based on changes in formant transitions improves with age, and that some children in the general population have performance much worse than their age peers. In children, uncertainty increases when the stimuli are presented in noise. The test is suitable for use in planned studies in a clinical population. American Academy of Audiology

Tunable plasmon-induced transparency in plasmonic metamaterial composed of three identical rings

NASA Astrophysics Data System (ADS)

Tian, Yuchen; Ding, Pei; Fan, Chunzhen

2017-10-01

We numerically investigated the plasmon-induced transparency (PIT) effect in a three-dimensional plasmonic metamaterial composed of three identical rings. It is illustrated that the PIT effect appears as a result of the destructive interference between the electric dipole and the quadrupole resonance mode. By tuning gap distance, radius or rotation angle of the metamaterial, the required transmission spectra with a narrow sharp transparency peak can be realized. In particular, it is found that an on-to-off amplitude modulation of the PIT transparency window can be achieved by moving or rotating the horizontal ring. Two dips move to high frequency and low frequency regions, respectively, in the transmission spectra by moving the horizontal ring, namely, the width of transmission peak becomes larger. With the rotation of horizontal ring, both width and position of transmission peak are kept invariant. Our designed structure achieved a maximum group index of 352 in the visible frequency range, which has a significant slow light effect. Moreover, the PIT effect is explained based on the classical two-oscillator theory, which is in well agreement with the numerical results. It indicates our proposed structure and theoretical analysis may open up avenues for the tunable control of light in highly integrated optical circuits.

Use of Electrochemical Noise (EN) Technique to Study the Effect of sulfate and Chloride Ions on Passivation and Pitting Corrosion Behavior of 316 Stainless Steel

NASA Astrophysics Data System (ADS)

Pujar, M. G.; Anita, T.; Shaikh, H.; Dayal, R. K.; Khatak, H. S.

2007-08-01

In the present paper, studies were conducted on AISI Type 316 stainless steel (SS) in deaerated solutions of sodium sulfate as well as sodium chloride to establish the effect of sulfate and chloride ions on the electrochemical corrosion behavior of the material. The experiments were conducted in deaerated solutions of 0.5 M sodium sulfate as well as 0.5 M sodium chloride using electrochemical noise (EN) technique at open circuit potential (OCP) to collect the correlated current and potential signals. Visual records of the current and potential, analysis of data to arrive at the statistical parameters, spectral density estimation using the maximum entropy method (MEM) showed that sulfate ions were incorporated in the passive film to strengthen the same. However, the adsorption of chloride ions resulted in pitting corrosion thereby adversely affecting noise resistance ( R N). Distinct current and potential signals were observed for metastable pitting, stable pitting and passive film build-up. Distinct changes in the values of the statistical parameters like R N and the spectral noise resistance at zero frequency ( R°SN) revealed adsorption and incorporation of sulfate and chloride ions on the passive film/solution interface.

Influences of Cr/Ni equivalent ratios of filler wires on pitting corrosion and ductility-dip cracking of AISI 316L weld metals

NASA Astrophysics Data System (ADS)

Kim, Y. H.; Kim, D. G.; Sung, J. H.; Kim, I. S.; Ko, D. E.; Kang, N. H.; Hong, H. U.; Park, J. H.; Lee, H. W.

2011-02-01

To study the pitting corrosion of AISI 316L weld metals according to the chromium/nickel equivalent ratio (Creq/Nieq ratio), three filler wires were newly designed for the flux-cored arc welding process. The weld metal with delta-ferrite at less than 3 vol.%, was observed for ductility-dip cracking (DDC) in the reheated region after multi-pass welding. The tensile strength and yield strength increased with increasing Creq/Nieq ratio. The result of anodic polarization tests in a 0.1 M NaCl solution at the room temperature (25) for 45 min, revealed that the base metal and weld metals have a similar corrosion potential of -0.34 VSCE. The weld metal with the highest content of Cr had the highest pitting potential (0.39 VSCE) and the passivation range (0.64 VSCE) was higher than the base metal (0.21 VSCE and 0.46 VSCE, respectively). Adding 0.001 M Na2S to the 0.1M NaCl solution, the corrosion occurred more severely by H2S. The corrosion potentials of the base metal and three weld metals decreased to -1.0 VSCE. DDC caused the decrease of the pitting potential by inducing a locally intense corrosion attack around the crack openings.

Analysis of rainfall characteristics and its related disasters of slag disposal pit of a certain Gold-Copper Deposit in Fujian province

NASA Astrophysics Data System (ADS)

Pan, Huali; Hu, Mingjian; Ou, Guoqiang

2017-04-01

According to the geological investigation in Fujian province, the total number of geological disasters was 9513, in which the number of landslide, collapse, unstable slope and surface collapse was 5816, 1888, 1591, 103 and 115 respectively. The main geological disaster was the landslide with 61.1% of total geological disasters. Among all these geological disasters, only 6.0% was relative stable, 17.0% was basic stable, nearly 76.0% was unstable. The slope disaster was the main geological disaster, if the unstable slope was the potential landslide or collapse; the slope collapse was 98.0% of all geological disasters. The rainfall, in particular the heavy rain, was direct dynamic factor for geological disasters, but the occurrence probability of geological disasters was different because of the sensitivity of the geological environment though of the same intensity rainfall. To obtain the characteristics of soil erosion under the rainfall condition, the rainfall characteristics and its related disasters of slag disposal pit of a certain Gold-Copper Deposit in Fujian province was analyzed by the meteorological and rainfall data. According to the distribution of monitoring stations of hydrological and rainfall in Longyan city of Fujian province and the location of gold-copper deposit, the Shanghang monitoring station of hydrological and rainfall was chosen, which is the nearest one to the gold-copper deposit. Then main parameters of the prediction model, the antecedent precipitation, the rainfall on the day and the rainfall threshold, were calculated by using the rainfall data from 2002 to 2010. And the relationship between geological disasters and the rainfall characteristics were analyzed. The results indicated that there was high risk for the debris flow with landslide collapse when either the daily rainfall was more than 100.0 mm, or the total rainfall was more than 136.0mm in the gold-copper deposit and the Shanghang region. At the same time, although there was few risk for the debris flow when the daily rainfall was between 50.0-100.0mm, once the soil was saturated or nearly saturated because of the continuous antecedent precipitation, debris flow disaster would occur even the daily rainfall was only 50.0mm. In addition, it was prone to trigger debris flow disaster when the daily heavy rainfall was more than 100.0mm or the torrential rainfall in 3 days was between 250.0 -300.0mm.

Why Save a Can?

ERIC Educational Resources Information Center

Gutierrez, Melida; Johnson, Cheryl

2009-01-01

This activity ties together the recycling of aluminum and the protection of rain forests. Students use critical thinking to study the effects of open pit mining of bauxite in rain forests and then draw their own conclusions about how to minimize the impact of bauxite mining and boost recycling efforts within their communities. Drawing conclusions…

Can we quantify the variability of soil moisture across scales using Electromagnetic Induction ?

NASA Astrophysics Data System (ADS)

Robinet, Jérémy; von Hebel, Christian; van der Kruk, Jan; Govers, Gerard; Vanderborght, Jan

2017-04-01

Soil moisture is a key variable in many natural processes. Therefore, technological and methodological advancements are of primary importance to provide accurate measurements of spatial and temporal variability of soil moisture. In that context, ElectroMagnetic Induction (EMI) instruments are often cited as a hydrogeophysical method with a large potential, through the measurement of the soil apparent electrical conductivity (ECa). To our knowledge, no studies have evaluated the potential of EMI to characterize variability of soil moisture on both agricultural and forested land covers in a (sub-) tropical environment. These differences in land use could be critical as differences in temperature, transpiration and root water uptake can have significant effect, notably on the electrical conductivity of the pore water. In this study, we used an EMI instrument to carry out a first assessment of the impact of deforestation and agriculture on soil moisture in a subtropical region in the south of Brazil. We selected slopes of different topographies (gentle vs. steep) and contrasting land uses (natural forest vs. agriculture) within two nearby catchments. At selected locations on the slopes, we measured simultaneously ECa using EMI and a depth-weighted average of the soil moisture using TDR probes installed within soil pits. We found that the temporal variability of the soil moisture could not be measured accurately with EMI, probably because of important temporal variations of the pore water electrical conductivity and the relatively small temporal variations in soil moisture content. However, we found that its spatial variability could be effectively quantified using a non-linear relationship, for both intra- and inter-slopes variations. Within slopes, the ECa could explained between 67 and 90% of the variability of the soil moisture, while a single non-linear model for all the slopes could explain 55% of the soil moisture variability. We eventually showed that combining a specific relationship for the most degraded slope (steep slope under agriculture) and a single relationship for all the other slopes, both non-linear relations, yielded the best results with an overall explained variance of 90%. We applied the latter model to measurements of the ECa along transects at the different slopes, which allowed us to highlight the strong control of topography on the soil moisture content. We also observed a significant impact of the land use with higher moisture content on the agricultural slopes, probably due to a reduced evapotranspiration.

Mars Global Surveyor observations of Martian fretted terrain

USGS Publications Warehouse

Carr, M.H.

2001-01-01

The Martian fretted terrain between latitudes 30?? and 50?? N and between 315?? and 360?? W has been reexamined in light of new Mars Orbiter Camera (MOC) and Mars Orbiter Laser Altimeter (MOLA) data from Mars Global Surveyor. Much of the terrain in the 30??-50?? latitude belt in both hemispheres has a characteristic stippled or pitted texture at MOC (1.5 m) scale. The texture appears to result from partial removal of a formerly smooth, thin deposit as a result of sublimation and deflation. A complex history of deposition and exhumation is indicated by remnants of a former, thicker cover of layered deposits. In some hollows and on some slopes, particularly those facing the pole, are smooth textured deposits outlined by an outward facing escarpment. Throughout the study area are numerous escarpments with debris flows at their base. The escarpments typically have slopes in the 20??-30?? range. At the base of the escarpment is commonly a deposit with striae oriented at right angles to the escarpment. Outside this deposit is the main debris apron with a surface that typically slopes 2??-3?? and complex surface textures suggestive of compression, sublimation, and deflation. The presence of undeformed impact craters indicates that the debris flows are no longer forming. Fretted valleys contain lineated fill and are poorly graded. They likely form from fluvial valleys that were initially like those elsewhere on the planet but were subsequently widened and filled by the same mass-wasting processes that formed the debris aprons. Slope reversals indicate that downvalley flow of the lineated fill is minor. The ubiquitous presence of breaks in slope formed by mass wasting and the complex surface textures that result from mass wasting, deflation, and sublimation decreases the recognizability of the shorelines formerly proposed for this area.

Dissected Mantle Terrain on Mars: Formation Mechanisms and the Implications for Mid- latitude Near-surface Ground Ice

NASA Astrophysics Data System (ADS)

Searls, M. L.; Mellon, M. T.

2008-12-01

Determining the present and past distribution of surface and subsurface ice on Mars is critical for understanding the volatile inventory and climatic history of the planet. An analysis of a latitude-dependent layer of surface material known as the dissected mantle terrain can provide valuable insight into the distribution of ice in the recent past. The dissected mantle terrain is a surface unit that occurs globally in the mid-latitude of Mars. This unit is characterized by a smooth mantle of uniform thickness and albedo that is draped over the existing topography. This smooth mantle is disaggregated and dissected in places resulting in a hummocky pitted appearance. We propose that the mid-latitude dissected terrain results from collapse of a dusty mantle into the void left from desiccation of an underlying ice-rich (pure or dirty ice) layer. During period(s) of high obliquity, it is possible for ice to become stable at lower latitudes. Due to lack of direct solar insolation, surface ice deposits will preferentially accumulate on pole-ward facing slopes first. A mantle of dust and dirt is then deposited on top of these ice-rich deposits. As the climate changes, desiccation of the now buried ice leads to collapse of the overlying dusty layer resulting in a hummocky pitted appearance. This theory is supported by the pole-ward preference for the dissection pits as well an increase in dissection with increasing latitude. A study of the global distribution of the mid-latitude dissected terrain can provide invaluable clues towards unlocking the distribution of ice in the recent past. An analysis of HiRISE images and MOLA data indicate that the distribution of dissection pits varies from one region to the next. Knowing the distribution of ice in conjunction with ice stability modeling can provide a global view of the climate and orbital history of Mars at the time these features formed.

Control of water erosion and sediment in open cut coal mines in tropical areas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ueda, T.; Nugraha, C.; Matsui, K.

2005-07-01

The purpose is to reduce the environmental impacts from open cut mining in tropical areas, such as Indonesia and Vietnam. Research conducted on methods for the control of water erosion and sediment from open cut coal mines is described. Data were collected on climate and weathering in tropical areas, mechanism of water erosion and sedimentation, characteristics of rocks in coal measures under wet conditions, water management at pits and haul roads and ramps, and construction of waste dumps and water management. The results will be applied to the optimum control and management of erosion and sediments in open cut mining.more » 6 refs., 8 figs.« less

Map showing areas with potential for talc deposits in the Gravelly, Greenhorn, and Ruby ranges and the Henrys Lake Mountains of southwestern Montana

USGS Publications Warehouse

Van Gosen, Bradley S.; Berg, Richard B.; Hammarstrom, Jane M.

1998-01-01

For the last several years, Montana has been the leading talc producing state in the United States (U.S. Geological Survey, 1996). For example, in 1992 Montana supplied about 40 percent of the U.S. mine production of talc (Virta, 1992). All of this production has come from the large deposits of high purity talc in the southwestern part of the state. All Montana talc is currently (1997) extracted from four mines, each within the study area of this map—the open pit operations of the Treasure State, Regal, and Yellowstone mines and the underground operation of the Beaverhead mine (see map numbers 1-4 on list and map to the left). The related mineral chlorite is mined at the Antler mine, located nearby, but outside of the study area in the Highland Mountains. Montana talc has at least two market advantages: (1) some deposits are very large and near surface, allowing economic mining by open pit methods; and (2) the deposits are of high purity and lack tremolite or other amphibole mineral contaminants (such as absestos) that occur in some other talc-rich deposits. Talc from southwest Montana is used in ceramics, paint, paper, plastics, cosmetics, rubber, roofing, flooring, caulking, and agricultural applications. The talc is also used in the processes of recycling paper and plastics. Talc was first discovered in the early 1900's at the present site of the Yellowstone mine (Perry, 1948, p. 9). Modest production began in 1942 from shallow pits and adits, supplying steatite (massive, compact, high-purity) talc that was used to make ceramic insulators. The southwest Montana talc industry grew to become a significant part of the region's economy; this history is described by Perry (1948), Olson (1976), and Berg (1997). Exploration and development are likely to continue for the foreseeable future for several reasons: (1) mines are active in the area at present and an infrastructure for talc processing exists; (2) large changes in domestic and export talc markets are not expected in the next few years based on recent market trends (Virta, 1997); (3) the talc of this region is especially pure and asbestos-free; and (4) except for potential ground stabilization problems and land disturbance associated with largescale open pit mining, no significant environmental impacts are associated with talc mining

Gross and microscopic observations on the lingual structure of the Florida Manatee Trichechus manatus latirostris.

PubMed

Levin, M J; Pfeiffer, C J

2002-10-01

The tongue of the Florida manatee (Trichechus manatus latirostris) was studied macroscopically, light and electron microscopically. The tongue was slender, muscular and firmly fixed in the oral cavity; only the cranial tip was free and mobile. Numerous filiform papillae were distributed over the dorsal surface of the rostral tongue. Multiple raised, round fungiform-like papillae were distributed over most of the dorsum. Typical fungiform papillae were restricted to the lateral margins of the tongue. Foliate papillae, presenting as multi-fossulate openings, were noted on the caudolateral margins. Open pits were located on the dorsocaudal surface and lateral walls. Microscopic examination showed that most of the lingual dorsum was covered with a thick stratified squamous epithelium. Open pits led to well-developed mucous salivary glands. Glands within the foliate papillae were mostly mucous, although some seromucous glands were present. Taste buds were restricted to the epithelium of the foliate papillae. Throughout the tongue, striated muscle was abundant below the epithelium. Blood vessels, lymph channels and nerve fibres were freely distributed throughout the intermuscular stroma. Nerve fibres reacted positively with neurone specific enolase (NSE) antibody throughout the tongue, including nerve bundles, glands and taste buds. Clear to translucent vacuoles were found juxtaposed to nuclei in the stratum spinosum in the foliate papillae epithelium.

Structural graph-based morphometry: A multiscale searchlight framework based on sulcal pits.

PubMed

Takerkart, Sylvain; Auzias, Guillaume; Brun, Lucile; Coulon, Olivier

2017-01-01

Studying the topography of the cortex has proved valuable in order to characterize populations of subjects. In particular, the recent interest towards the deepest parts of the cortical sulci - the so-called sulcal pits - has opened new avenues in that regard. In this paper, we introduce the first fully automatic brain morphometry method based on the study of the spatial organization of sulcal pits - Structural Graph-Based Morphometry (SGBM). Our framework uses attributed graphs to model local patterns of sulcal pits, and further relies on three original contributions. First, a graph kernel is defined to provide a new similarity measure between pit-graphs, with few parameters that can be efficiently estimated from the data. Secondly, we present the first searchlight scheme dedicated to brain morphometry, yielding dense information maps covering the full cortical surface. Finally, a multi-scale inference strategy is designed to jointly analyze the searchlight information maps obtained at different spatial scales. We demonstrate the effectiveness of our framework by studying gender differences and cortical asymmetries: we show that SGBM can both localize informative regions and estimate their spatial scales, while providing results which are consistent with the literature. Thanks to the modular design of our kernel and the vast array of available kernel methods, SGBM can easily be extended to include a more detailed description of the sulcal patterns and solve different statistical problems. Therefore, we suggest that our SGBM framework should be useful for both reaching a better understanding of the normal brain and defining imaging biomarkers in clinical settings. Copyright © 2016 Elsevier B.V. All rights reserved.

Effectiveness Using Circular Fibre Steel Flap Gate As a Control Structure Towards the Hydraulic Characteristics in Open Channel

NASA Astrophysics Data System (ADS)

Adib, M. R. M.; Amirza, A. R. M.; Wardah, T.; Junaidah, A.

2016-07-01

Hydraulic control gate structure plays an important role in regulating the flow of water in river, canal or water reservoir. One of the most appropriate structures in term of resolving the problem of flood occured is the construction of circular fibre steel flap gate. Therefore, an experiment has been conducted by using an open channel model at laboratory. In this case, hydraulic jump and backwater were the method to determined the hydraulic characteristics of circular fibre steel flap gate in an open channel model. From the experiment, the opening angle of flap gate can receive discharges with the highest flow rate of 0.035 m3/s with opening angle was 47°. The type of jump that occurs at the slope of 1/200 for a distance of 5.0 m is a standing jump or undulating wave. The height of the backwater can be identified based on the differences of specific force which is specific force before jump, F1 and specific force after jump, F2 from the formation of backwater. Based on the research conducted, the tendency of incident backwater wave occurred was high in every distance of water control location from water inlet is flap slope and the slope of 1/300 which is 0.84 m/s and 0.75 m/s of celerity in open channel model.

Geologic features of dam sites in the Nehalem, Rogue, and Willamette River basins, Oregon, 1935-37

USGS Publications Warehouse

Piper, A.M.

1947-01-01

The present report comprises brief descriptions of geologic features at 19 potential dam sites in the Nehalem, Rogue, and Willamette River basins in western Oregon. The topography of these site and of the corresponding reservoir site was mapped in 1934-36 under an allocation of funds, by the Public Works Administration for river-utilization surveys by the Conservation Branch of the United States Geological Survey. The field program in Oregon has been under the immediate charge of R. O. Helland. The 19 dam sites are distributed as follows: three on the Nehalem River, on the west or Pacific slope of the Oregon Coast range; four on Little Butte Creek and two on Evans Creek, tributaries of the Rogue River in the eastern part of the Klamath Mountains; four on the South and Middle Santiam Rivers, tributaries of the Willamette River from the west slope of the Cascade mountains; and six on tributaries of the Willamette River from the east slope of the Coast Range. Except in the Evans Creek basin, all the rocks in the districts that were studied are of comparatively late geological age. They include volcanic rocks, crystalline rocks of several types, marine and nonmarine sedimentary rocks, and recent stream deposits. The study of geologic features has sought to estimate the bearing power and water-tightness of the rocks at each dam site, also to place rather broad limits on the type of dam for which the respective sites seem best suited. It was not considered necessary to study the corresponding reservoir sites in detail for excessive leakage appears to be unlikely. Except at three of the four site in the Santiam River basin, no test pits have been dug nor exploratory holes drilled, so that geologic features have been interpreted wholly from natural outcrops and from highway and railroad cuts. Because these outcrops and cuts are few, many problems related to the construction and maintenance of dams can not be answered at the this time and all critical features of the sites should be thoroughly explored by test pits and drilled holes before any dam is designed. This applied especially to sites in the Nehalem and Willamette River basins where commonly the cover of timber and brush is dense and the rocks are rather deeply weathered. On the Middle Santiam and South Santiam Rivers, the Cascadia, Greenpeter, and Sweet Home sits have been studies intensively by the United States Engineer Department, whose work included exploration by diamond-drill holes and test pits. Their conclusions as to geologic features are given in a report by McKitrick and have been reviewed by the writer. Data from this source have been used freely in the discussion of the respective sites in this report. The probability of destructive earthquakes in the region appears to be small but is not negligible. Prudence suggests that any high dam should embody features to assure stability against moderately strong earth motions.

A statistical overview of mass movement characteristics on the North American Atlantic outer continental margin

USGS Publications Warehouse

Booth, James S.; O'Leary, Dennis W.

1992-01-01

An analysis of 179 mass movements on the North American Atlantic continental slope and upper rise shows that slope failures have occurred throughout the geographic extent of the outer margin. Although the slope failures show no striking affinity for a particular depth as an origination level, there is a broad, primary mode centered at about 900 m. The resulting slides terminate at almost all depths and have a primary mode at 1100 m, but the slope/rise boundary (at 2200 m) also is an important mode. Slope failures have occurred at declivities ranging from 1° to 30° (typically, 4°); the resultant mass movement deposits vary in width from 0.2 to 50 km (typically, 1-2 km) and in length from 0.3 to 380 km (typically, 2–4 km), and they have been reported to be as thick as 650 m. On a numeric basis, mass movements are slightly more prevalent on open slopes than in other physiographic settings, and both translational and rotational failure surfaces are common. The typical mass movement is disintegrative in nature. Open slope slides tend to occur at lower slope angles and are larger than canyon slides. Further, large‐scale slides rather than small‐scale slides tend to originate on gentle slopes (≍ 3-4°). Rotational slope failures appear to have a slightly greater chance of occurring in canyons, but there is no analogous bias associated with translational failures. Similarly, disintegrative slides seem more likely to be associated with rotational slope failures than translational ones and are longer than their nondisintegrative counterparts. The occurrence of such a variety of mass movements at low declivities implies that a regional failure mechanism has prevailed. We suggest that earthquakes or, perhaps in some areas, gas hydrates are the most likely cause of the slope failures.

The impact of soil erosion on soil fertility and vine vigor. A multidisciplinary approach based on field, laboratory and remote sensing approaches.

PubMed

Novara, Agata; Pisciotta, Antonino; Minacapilli, Mario; Maltese, Antonino; Capodici, Fulvio; Cerdà, Artemi; Gristina, Luciano

2018-05-01

Soil erosion processes in vineyards, beyond surface runoff and sediment transport, have a strong effect on soil organic carbon (SOC) loss and redistribution along the slope. Variation in SOC across the landscape can determine differences in soil fertility and vine vigor. The goal of this research was to analyze the interactions among vines vigor, sediment delivery and SOC in a sloping vineyard located in Sicily. Six pedons were studied along the slope by digging 6 pits up to 60cm depth. Soil was sampled every 10cm and SOC, water extractable organic carbon (WEOC) and specific ultraviolet absorbance (SUVA) were analyzed. Erosion rates, detachment and deposition areas were measured by the pole height method which allowed mapping of the soil redistribution. The vigor of vegetation, expressed as Normalized Difference Vegetation Index (NDVI), derived from high-resolution satellite multispectral data, was compared with measured pruning weight. Results confirmed that soil erosion, sediment redistribution and SOC across the slope was strongly affected by topographic features, slope and curvature. The erosion rate was 16Mgha -1 y -1 since the time of planting (6years). SOC redistribution was strongly correlated with the detachment or deposition areas as highlighted by pole height measurements. The off-farm SOC loss over six years amounted to 1.2MgCha -1 . SUVA 254 values, which indicate hydrophobic material rich in aromatic constituents of WEOC, decreased significantly along the slope, demonstrating that WEOC in the detachment site is more stable in comparison to deposition sites. The plant vigor was strongly correlated with WEOC constituents. Results demonstrated that high resolution passive remote sensing data combined with soil and plant analyses can survey areas with contrasting SOC, soil fertility, soil erosion and plant vigor. This will allow monitoring of soil erosion and degradation risk areas and support decision-makers in developing measures for friendly environmental management. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of wind velocity and slope on fire behavior

Treesearch

D.R. Weise; G.S. Biging

1994-01-01

Effects of wind velocity and slope on fire spread rate and flame length were examined. Fuel beds of vertical sticks (13.97 cm x 0.455 cm x 0.1 10 cm) and coarse excelsior were burned in an open-topped tilting wind tunnel. Mean fuel moisture content of sticks and excelsior was 11% and 12%, respectively. Mean surface area to volume ratio was 23 cm-! Five slopes (negative...

Vascular plant species richness along environmental gradients in a cool temperate to sub-alpine mountainous zone in central Japan.

PubMed

Tsujino, Riyou; Yumoto, Takakazu

2013-03-01

In order to clarify how vegetation types change along the environmental gradients in a cool temperate to sub-alpine mountainous zone and the determinant factors that define plant species richness, we established 360 plots (each 4 × 10 m) within which the vegetation type, species richness, elevation, topographic position index (TPI), slope inclination, and ground light index (GLI) of the natural vegetation were surveyed. Mean elevation, TPI, slope inclination, and GLI differed across vegetation types. Tree species richness was negatively correlated with elevation, whereas fern and herb species richness were positively correlated. Tree species richness was greater in the upper slope area than the lower slope area, whereas fern and herb species richness were greater in the lower slope area. Ferns and trees species richness were smaller in the open canopy, whereas herb species richness was greater in the open canopy. Vegetation types were determined firstly by elevation and secondary by topographic configurations, such as topographic position, and slope inclination. Elevation and topography were the most important factors affecting plant richness, but the most influential variables differed among plant life-form groups. Moreover, the species richness responses to these environmental gradients greatly differed among ferns, herbs, and trees.

New insights into trace element wet deposition in the Himalayas: amounts, seasonal patterns, and implications.

PubMed

Cong, Zhiyuan; Kang, Shichang; Zhang, Yulan; Gao, Shaopeng; Wang, Zhongyan; Liu, Bin; Wan, Xin

2015-02-01

Our research provides the first complete year-long dataset of wet deposition of trace elements in the high Himalayas based on a total of 42 wet deposition events on the northern slope of Mt. Qomolangma (Everest). Except for typical crustal elements (Al, Fe, and Mn), the concentration level of most trace elements (Sc, V, Cr, Co, Ni, Cu, Zn, As, Mo, Cd, Sn, Cs, Pb, Bi, and U) are generally comparable to those preserved in snow pits and ice cores from the nearby East Rongbuk Glacier. Cadmium was the element most affected by anthropogenic emissions. No pronounced seasonal variations are observed for most trace elements despite different transport pathways. In our study, the composition of wet precipitation reflects a regional background condition and is not clearly related to specific source regions. For the trace element record from ice cores and snow pits in the Himalayas, it could be deduced that the pronounced seasonal patterns were caused by the dry deposition of trace elements (aerosols) during their long exposure to the atmosphere after precipitation events. Our findings are of value for the understanding of the trace element deposition mechanisms in the Himalayas.

Study of application of ERTS-1 imagery to fracture-related mine safety hazards in the coal mining industry

NASA Technical Reports Server (NTRS)

Wier, C. E. (Principal Investigator); Wobber, F. J. (Principal Investigator); Russell, O. R.; Amato, R. V.

1972-01-01

The author has identified the following significant results. Numerous fractures are identifiable on the 1:120,000 color infrared photography. Some of these fractures are in the proximity of operating open pit mines and should provide opportunities for field checking and confirmation.

76 FR 52688 - Notice of Intent To Prepare an Environmental Impact Statement for the Sheep Mountain Uranium...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-23

... project employing open pit and underground mining methods and using heap leach methods for uranium...] Notice of Intent To Prepare an Environmental Impact Statement for the Sheep Mountain Uranium Project... comments regarding issues and resource information for the proposed Sheep Mountain Uranium Project (the...

The study of aluminium anodes for high power density Al/air batteries with brine electrolytes

NASA Astrophysics Data System (ADS)

Nestoridi, Maria; Pletcher, Derek; Wood, Robert J. K.; Wang, Shuncai; Jones, Richard L.; Stokes, Keith R.; Wilcock, Ian

Aluminium alloys containing small additions of both tin (∼0.1 wt%) and gallium (∼0.05 wt%) are shown to dissolve anodically at high rates in sodium chloride media at room temperatures; current densities >0.2 A cm -2 can be obtained at potentials close to the open circuit potential, ∼-1500 mV versus SCE. The tin exists in the alloys as a second phase, typically as ∼1 μm inclusions (precipitates) distributed throughout the aluminium structure, and anodic dissolution occurs to form pits around the tin inclusions. Although the distribution of the gallium in the alloy could not be established, it is also shown to be critical in the formation of these pits as well as maintaining their activity. The stability of the alloys to open circuit corrosion and the overpotential for high rate dissolution, both critical to battery performance, are shown to depend on factors in addition to elemental composition; both heat treatment and mechanical working influence the performance of the alloy. The correlation between alloy performance and their microstructure has been investigated.

Typical whole body vibration exposure magnitudes encountered in the open pit mining industry.

PubMed

Howard, Bryan; Sesek, Richard; Bloswick, Don

2009-01-01

According to recent research, a causal link has been established between occupational exposure to whole body vibration and an increased occurrence of low back pain. To aid in the further development of an in-house health and safety program for a large open pit mining facility interested in reducing back pain among its operators, whole body vibration magnitudes were characterized for a range of jobs. Specifically, thirty-five individual jobs from five different areas across the facility were evaluated for tri-axial acceleration levels during normal operating conditions. Tri-axial acceleration magnitudes were categorized into thirteen job groups. Job groups were ranked according to exposure and compared to the ISO 2631-1 standard for health risk assessment. Three of the thirteen job groups produced tri-axial acceleration magnitudes below the ISO 2631-1 low/moderate health caution limit for a twelve hour exposure. Six of the thirteen job groups produced exposures within the moderate health risk range. Four job groups were found to subject operators to WBV acceleration magnitudes above the moderate/high health caution limit.

Short-term scheduling of an open-pit mine with multiple objectives

NASA Astrophysics Data System (ADS)

Blom, Michelle; Pearce, Adrian R.; Stuckey, Peter J.

2017-05-01

This article presents a novel algorithm for the generation of multiple short-term production schedules for an open-pit mine, in which several objectives, of varying priority, characterize the quality of each solution. A short-term schedule selects regions of a mine site, known as 'blocks', to be extracted in each week of a planning horizon (typically spanning 13 weeks). Existing tools for constructing these schedules use greedy heuristics, with little optimization. To construct a single schedule in which infrastructure is sufficiently utilized, with production grades consistently close to a desired target, a planner must often run these heuristics many times, adjusting parameters after each iteration. A planner's intuition and experience can evaluate the relative quality and mineability of different schedules in a way that is difficult to automate. Of interest to a short-term planner is the generation of multiple schedules, extracting available ore and waste in varying sequences, which can then be manually compared. This article presents a tool in which multiple, diverse, short-term schedules are constructed, meeting a range of common objectives without the need for iterative parameter adjustment.

Geology of the fushun coalfield, Liaoning Province, People's Republic of China

USGS Publications Warehouse

Johnson, E.A.

1990-01-01

The Fushun coalfield is located in Liaoning Province 45 km east of Shenyang in a relatively small east-west-trending exposure of Mesozoic and Cenozoic rocks surrounded by Precambrian terrane. The coal is included in a sequence of early Tertiary rocks consisting of Paleocene basalt and tuff, and Eocene coal, oil shale and mudstone. These units have been folded into a syncline that plunges gently to the east. The overturned north limb of this fold has been partly removed by a thrust fault. The principal coal beds are low-sulfur subbituminous and bituminous in rank, are of limnic origin, and are contained in the 55-m-thick Eocene Guchengzi Formation. The field, which has been active since the turn of the century, has both open pit and underground mines. The largest operation is the West Open Pit mine, which measures 2.0 km wide, 6.6 km long, and 300 m deep. Coal is mined by means of power shovels, trucks, and an electric rail system. Oil shale from the Eocene Jijuntun Formation is also mined. ?? 1990.

Modeling the Use of Mine Waste Rock as a Porous Medium Reservoir for Compressed Air Energy Storage

NASA Astrophysics Data System (ADS)

Donelick, R. A.; Donelick, M. B.

2016-12-01

We are studying the engineering and economic feasibilities of constructing Big Mass Battery (BiMBy) compressed air energy storage devices using some of the giga-tonnes of annually generated and historically produced mine waste rock/overburden/tailings (waste rock). This beneficial use of waste rock is based on the large mass (Big Mass), large pore volume, and wide range of waste rock permeabilities available at some large open pit metal mines and coal strip mines. Porous Big Mass is encapsulated and overlain by additional Big Mass; compressed air is pumped into the encapsulated pore space when renewable energy is abundant; compressed air is released from the encapsulated pore space to run turbines to generate electricity at the grid scale when consumers demand electricity. Energy storage capacity modeling: 1) Yerington Pit, Anaconda Copper Mine, Yerington, NV (inactive metal mine): 340 Mt Big Mass, energy storage capacity equivalent to 390k-710k home batteries of size 10 kW•h/charge, assumed 20% porosity, 50% overall efficiency. 2) Berkeley Pit, Butte Copper Mine, Butte, MT (inactive metal mine): 870 Mt Big Mass, energy storage capacity equivalent to 1.4M-2.9M home batteries of size 10 kW•h/charge, assumed 20% porosity, 50% overall efficiency. 3) Rosebud Mine, Colstrip, MT (active coal strip mine): 87 Mt over 2 years, energy storage capacity equivalent to 45k-67k home batteries of size 10 kW•h/charge, assumed 30% porosity, 50% overall efficiency. Encapsulating impermeable layer modeling: Inactive mine pits like Yerington Pit and Berkeley Pit, and similar active pits, have associated with them low permeability earthen material (silt and clay in Big Mass) at sufficient quantities to manufacture an encapsulating structure with minimal loss of efficiency due to leakage, a lifetime of decades or even centuries, and minimal need for the use of geomembranes. Active coal strip mines like Rosebud mine have associated with them low permeability earthen material such as coal combustion products (fly ash, bottom ash, boiler slag, other) that may be put to beneficial use as part of the encapsulating structure; however, coal strip mines have lower volume to surface ratios than mine pits increasing the potential need to use geomembranes.

Procedure for assessing the performance of a rockfall fragmentation model

NASA Astrophysics Data System (ADS)

Matas, Gerard; Lantada, Nieves; Corominas, Jordi; Gili, Josep Antoni; Ruiz-Carulla, Roger; Prades, Albert

2017-04-01

A Rockfall is a mass instability process frequently observed in road cuts, open pit mines and quarries, steep slopes and cliffs. It is frequently observed that the detached rock mass becomes fragmented when it impacts with the slope surface. The consideration of the fragmentation of the rockfall mass is critical for the calculation of block's trajectories and their impact energies, to further assess their potential to cause damage and design adequate preventive structures. We present here the performance of the RockGIS model. It is a GIS-Based tool that simulates stochastically the fragmentation of the rockfalls, based on a lumped mass approach. In RockGIS, the fragmentation initiates by the disaggregation of the detached rock mass through the pre-existing discontinuities just before the impact with the ground. An energy threshold is defined in order to determine whether the impacting blocks break or not. The distribution of the initial mass between a set of newly generated rock fragments is carried out stochastically following a power law. The trajectories of the new rock fragments are distributed within a cone. The model requires the calibration of both the runout of the resultant blocks and the spatial distribution of the volumes of fragments generated by breakage during their propagation. As this is a coupled process which is controlled by several parameters, a set of performance criteria to be met by the simulation have been defined. The criteria includes: position of the centre of gravity of the whole block distribution, histogram of the runout of the blocks, extent and boundaries of the young debris cover over the slope surface, lateral dispersion of trajectories, total number of blocks generated after fragmentation, volume distribution of the generated fragments, the number of blocks and volume passages past a reference line and the maximum runout distance Since the number of parameters to fit increases significantly when considering fragmentation, the final parameters selected after the calibration process are a compromise which meet all considered criteria. This methodology has been tested in some recent rockfall where high fragmentation was observed. The RockGIS tool and the fragmentation laws using data collected from recent rockfall have been developed within the RockRisk project (2014-2016, BIA2013-42582-P). This project was funded by the Spanish Ministerio de Economía y Competitividad.

Neutralisation of an acidic pit lake by alkaline waste products.

PubMed

Allard, Bert; Bäckström, Mattias; Karlsson, Stefan; Grawunder, Anja

2014-01-01

A former open pit where black shale (alum shale) was excavated during 1942-1965 has been water filled since 1966. The water chemistry was dominated by calcium and sulphate and had a pH of 3.2-3.4 until 1997-1998, when pH was gradually increasing. This was due to the intrusion of leachates from alkaline cement waste deposited close to the lake. A stable pH of around 7.5 was obtained after 6-7 years. The chemistry of the pit lake has changed due to the neutralisation. Concentrations of some dissolved metals, notably zinc and nickel, have gone down, as a result of adsorption/co-precipitation on solid phases (most likely iron and aluminium hydroxides), while other metals, notably uranium and molybdenum, are present at elevated levels. Uranium concentration is reaching a minimum of around pH 6.5 and is increasing at higher pH, which may indicate a formation of neutral and anionic uranyl carbonate species at high pH (and total carbonate levels around 1 mM). Weathering of the water-exposed shale is still in progress.

Influence of aggressive ions on the degradation behavior of biomedical magnesium alloy in physiological environment.

PubMed

Xin, Yunchang; Huo, Kaifu; Tao, Hu; Tang, Guoyi; Chu, Paul K

2008-11-01

Various electrochemical approaches, including potentiodynamic polarization, open circuit potential evolution and electrochemical impedance spectroscopy (EIS), are employed to investigate the degradation behavior of biomedical magnesium alloy under the influence of aggressive ions, such as chloride, phosphate, carbonate and sulfate, in a physiological environment. The synergetic effects and mutual influence of these ions on the degradation behavior of Mg are revealed. Our results demonstrate that chloride ions can induce porous pitting corrosion. In the presence of phosphates, the corrosion rate decreases and the formation of pitting corrosion is significantly delayed due to precipitation of magnesium phosphate. Hydrogen carbonate ions are observed to stimulate the corrosion of magnesium alloy during the early immersion stage but they can also induce rapid passivation on the surface. This surface passivation behavior mainly results from the fast precipitation of magnesium carbonate in the corrosion product layer that can subsequently inhibit pitting corrosion completely. Sulfate ions are also found to stimulate magnesium dissolution. These results improve our understanding on the degradation mechanism of surgical magnesium in the physiological environment.

A New Platform for Investigating In-Situ NIR Reflectance in Snow

NASA Astrophysics Data System (ADS)

Johnson, M.; Taubenheim, J. R. L.; Stevenson, R.; Eldred, D.

2017-12-01

In-situ near infrared (NIR) reflectance measurements of the snowpack have been shown to have correlations to valuable snowpack properties. To-date many studies take these measurements by digging a pit and setting up a NIR camera to take images of the wall. This setup is cumbersome, making it challenging to investigate things like spatial variability. Over the course of 3 winters, a new device has been developed capable of mitigating some of the downfalls of NIR open pit photography. This new instrument is a NIR profiler capable of taking NIR reflectance measurements without digging a pit, with most measurements taking less than 30 seconds to retrieve data. The latest prototype is built into a ski pole and automatically transfers data wirelessly to the users smartphone. During 2016-2017 winter, the device was used by 37 different users resulting in over 4000 measurements in the Western United States, demonstrating a dramatic reduction in time to data when compared to other methods. Presented here are some initial findings from a full winter of using the ski pole version of this device.

Hyperspectral analysis for qualitative and quantitative features related to acid mine drainage at a remediated open-pit mine

NASA Astrophysics Data System (ADS)

Davies, G.; Calvin, W. M.

2015-12-01

The exposure of pyrite to oxygen and water in mine waste environments is known to generate acidity and the accumulation of secondary iron minerals. Sulfates and secondary iron minerals associated with acid mine drainage (AMD) exhibit diverse spectral properties in the ultraviolet, visible and near-infrared regions of the electromagnetic spectrum. The use of hyperspectral imagery for identification of AMD mineralogy and contamination has been well studied. Fewer studies have examined the impacts of hydrologic variations on mapping AMD or the unique spectral signatures of mine waters. Open-pit mine lakes are an additional environmental hazard which have not been widely studied using imaging spectroscopy. A better understanding of AMD variation related to climate fluctuations and the spectral signatures of contaminated surface waters will aid future assessments of environmental contamination. This study examined the ability of multi-season airborne hyperspectral data to identify the geochemical evolution of substances and contaminant patterns at the Leviathan Mine Superfund site. The mine is located 24 miles southeast of Lake Tahoe and contains remnant tailings piles and several AMD collection ponds. The objectives were to 1) distinguish temporal changes in mineralogy at a the remediated open-pit sulfur mine, 2) identify the absorption features of mine affected waters, and 3) quantitatively link water spectra to known dissolved iron concentrations. Images from NASA's AVIRIS instrument were collected in the spring, summer, and fall seasons for two consecutive years at Leviathan (HyspIRI campaign). Images had a spatial resolution of 15 meters at nadir. Ground-based surveys using the ASD FieldSpecPro spectrometer and laboratory spectral and chemical analysis complemented the remote sensing data. Temporal changes in surface mineralogy were difficult to distinguish. However, seasonal changes in pond water quality were identified. Dissolved ferric iron and chlorophyll-a concentrations were determined to be the major influences on pond water spectral variation.

Assessment of the natural sources of particulate matter on the opencast mines air quality.

PubMed

Huertas, J I; Huertas, M E; Cervantes, G; Díaz, J

2014-09-15

Particulate matter is the main air pollutant in open pit mining areas. Preferred models that simulate the dispersion of the particles have been used to assess the environmental impact of the mining activities. Results obtained through simulation have been compared with the particle concentration measured in several sites and a coefficient of determination R(2)<0.78 has been reported. This result indicates that in the open pit mining areas there may be additional sources of particulate matter that have not been considered in the modeling process. This work proposes that the unconsidered sources of emissions are of regional scope such as the re-suspension particulate matter due to the wind action over uncovered surfaces. Furthermore, this work proposes to estimate the impact of such emissions on air quality as a function of the present and past meteorological conditions. A statistical multiple regression model was implemented in one of the world's largest open pit coal mining regions which is located in northern Colombia. Data from 9 particle-concentration monitoring stations and 3 meteorological stations obtained from 2009 to 2012 were statistically compared. Results confirmed the existence of a high linear relation (R(2)>0.95) between meteorological variables and particulate matter concentration being humidity, humidity of the previous day and temperature, the meteorological variables that contributed most significantly in the variance of the particulate matter concentration measured in the mining area while the contribution of the AERMOD estimations to the short term TSP (Total Suspended Particles) measured concentrations was negligible (<5%). The multiple regression model was used to identify the meteorological condition that leads to pollution episodes. It was found that conditions drier than 54% lead to pollution episodes while humidities greater than 70% maintain safe air quality conditions in the mining region in northern Colombia. Copyright © 2014 Elsevier B.V. All rights reserved.

A Vectorial Model to Compute Terrain Parameters, Local and Remote Sheltering, Scattering and Albedo using TIN Domains for Hydrologic Modeling.

NASA Astrophysics Data System (ADS)

Moreno, H. A.; Ogden, F. L.; Steinke, R. C.; Alvarez, L. V.

2015-12-01

Triangulated Irregular Networks (TINs) are increasingly popular for terrain representation in high performance surface and hydrologic modeling by their skill to capture significant changes in surface forms such as topographical summits, slope breaks, ridges, valley floors, pits and cols. This work presents a methodology for estimating slope, aspect and the components of the incoming solar radiation by using a vectorial approach within a topocentric coordinate system by establishing geometric relations between groups of TIN elements and the sun position. A normal vector to the surface of each TIN element describes slope and aspect while spherical trigonometry allows computing a unit vector defining the position of the sun at each hour and DOY. Thus, a dot product determines the radiation flux at each TIN element. Remote shading is computed by scanning the projection of groups of TIN elements in the direction of the closest perpendicular plane to the sun vector. Sky view fractions are computed by a simplified scanning algorithm in prescribed directions and are useful to determine diffuse radiation. Finally, remote radiation scattering is computed from the sky view factor complementary functions for prescribed albedo values of the surrounding terrain only for significant angles above the horizon. This methodology represents an improvement on the current algorithms to compute terrain and radiation parameters on TINs in an efficient manner. All terrain features (e.g. slope, aspect, sky view factors and remote sheltering) can be pre-computed and stored for easy access for a subsequent ground surface or hydrologic simulation.

The boundary conditions for simulations of a shake-table experiment on the seismic response of 3D slope

NASA Astrophysics Data System (ADS)

Tang, Liang; Cong, Shengyi; Ling, Xianzhang; Ju, Nengpan

2017-01-01

Boundary conditions can significantly affect a slope's behavior under strong earthquakes. To evaluate the importance of boundary conditions for finite element (FE) simulations of a shake-table experiment on the slope response, a validated three-dimensional (3D) nonlinear FE model is presented, and the numerical and experimental results are compared. For that purpose, the robust graphical user-interface "SlopeSAR", based on the open-source computational platform OpenSees, is employed, which simplifies the effort-intensive pre- and post-processing phases. The mesh resolution effect is also addressed. A parametric study is performed to evaluate the influence of boundary conditions on the FE model involving the boundary extent and three types of boundary conditions at the end faces. Generally, variations in the boundary extent produce inconsistent slope deformations. For the two end faces, fixing the y-direction displacement is not appropriate to simulate the shake-table experiment, in which the end walls are rigid and rough. In addition, the influence of the length of the 3D slope's top face and the width of the slope play an important role in the difference between two types of boundary conditions at the end faces (fixing the y-direction displacement and fixing the ( y, z) direction displacement). Overall, this study highlights that the assessment of a comparison between a simulation and an experimental result should be performed with due consideration to the effect of the boundary conditions.

Patella height is not altered by descending medial open-wedge high tibial osteotomy (HTO) compared to ascending HTO.

PubMed

Krause, Matthias; Drenck, Tobias Claus; Korthaus, Alexander; Preiss, Achim; Frosch, Karl-Heinz; Akoto, Ralph

2018-06-01

The primary purpose of the study was to gain insight into geometric changes of the patellar height (PH) and posterior tibial slope (PTS) after a biplanar ascending medial open-wedge high tibial osteotomy (HTO) compared to biplanar descending medial open-wedge HTO in patients with genu varum. Sixty-four patients (mean age 45.2 ± 8.7 years, females n = 24, males n = 40) with varus malalignment and medial gonarthrosis were retrospectively studied. Patients received either a biplanar ascending or descending medial open-wedge HTO. Radiographic analysis included the assessment of standing total leg axis, PH, and PTS prior to and after surgery. In the ascending HTO group, PH decreased significantly by 4.0% (p = 0.037, Caton-Deschamps index) after an average leg axis valgus-producing correction of 7.1° ± 2.8°. In the descending HTO group, with an average leg axis correction of 7.0° ± 3.7°, there were no significant PH changes. There were no significant differences between the ascending and descending HTO groups regarding PTS or leg axis. The mean post-operative leg axis between ascending (1.6° ± 1.9°) and descending HTO (1.9° ± 2.4°) was not significantly different. Compared to the biplanar ascending medial open-wedge HTO, the descending HTO did not influence patella height or increase the posterior tibial slope. In order to respect patellofemoral and slope-related knee kinematics, a biplanar descending medial open-wedge HTO has proven useful to control patella height and posterior tibial slope. These findings underscore the importance of the preoperative patella height assessment in the osteotomy planning and subsequent choice of the biplanar osteotomy direction. IV.

Icy Erosion

NASA Image and Video Library

2015-12-23

This image from NASA Mars Reconnaissance Orbiter spacecraft shows an interesting collection of kilometer-scale craters with flat and smooth floors. The craters themselves may be the result of secondary impacts, craters caused by debris from a distant larger impact. Since then, the surface has been significantly modified and reworked, muting the craters and flattening their floors. Presently, there are a few sand dunes and a broad overlay of a dusty soil mantle. This soil mantle occurs over much of the middle latitudes of Mars. Here, as elsewhere, the mantle covers these craters, but a closer inspection reveals that its smooth texture becomes significantly pitted and bumpy on the pole facing slopes of each crater interior wall. http://photojournal.jpl.nasa.gov/catalog/PIA20288

10. EXTERIOR VIEW OF STONE RETAINING WALL, AIRWAY, BALTIMORE FAN ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. EXTERIOR VIEW OF STONE RETAINING WALL, AIRWAY, BALTIMORE FAN HOUSE AND HILLMAN FAN HOUSE LOOKING EAST The stone retaining wall encloses a pit which may have been the original site of the Hillman Fan House steam engine. The concrete foundations in the left foreground are more recent (c. 1930) additions which may be supports for a porch or stairway. The sloping airshaft, in the middle ground, connected the Baltimore shaft to the New Fan House (not shown) and Hillman Fan House in the background. The Hillman engine house is on the left. - Dorrance Colliery Fan Complex, South side of Susquehanna River at Route 115 & Riechard Street, Wilkes-Barre, Luzerne County, PA

Monoplanar versus biplanar medial open-wedge proximal tibial osteotomy for varus gonarthrosis: a comparison of clinical and radiological outcomes.

PubMed

Elmalı, Nurzat; Esenkaya, Irfan; Can, Murat; Karakaplan, Mustafa

2013-12-01

We compared clinical and radiological results of two proximal tibial osteotomy (PTO) techniques: monoplanar medial open-wedge osteotomy and biplanar retrotubercle medial open-wedge osteotomy, stabilised by a wedged plate. We evaluated 88 knees in 78 patients. Monoplanar medial open-wedge PTO was performed on 56 knees in 50 patients with a mean age of 55 ± 9 years. Biplanar retrotubercle medial open-wedge PTO was performed on 32 knees in 28 patients with a mean age of 57 ± 7 years. Mean follow-up periods were 40.6 ± 7 months for the monoplanar PTO group and 38 ± 5 months for the biplanar retrotubercle PTO group. Clinical outcome was evaluated using the hospital for special surgery scoring system, and radiological outcome was evaluated by the measurements of femorotibial angle (FTA), patellar height and tibial slope changes. In both groups, post-operative HSS scores increased significantly. No significant difference was found between groups in FTA alteration, but the FTA decreased significantly in both groups. Patellar index ratios decreased significantly in the monoplanar PTO group (Insall-Salvati Index by 0.07, Blackburne-Peel Index by 0.07), but not in the biplanar retrotubercle PTO group. Tibial slopes were increased significantly in the monoplanar PTO group, but not in the retrotubercle PTO group. Biplanar retrotubercle medial open-wedge osteotomy and monoplanar medial open-wedge osteotomy are both clinically effective for the treatment for varus gonarthrosis. Retrotubercle osteotomy also prevents patella infera and tibial slope changes radiologically.

The sanitation situation: a case study.

PubMed

Ali, S

1993-10-15

In India, interviews with and observations of members of 100 households with a latrine were done in the towns of Satna and Khandwa, in Madhya Pradesh State, to examine the sanitation situation, to evaluate the maintenance and performance of the 2 pit pour-flush water seal (PF) latrines of poor households, and to recommend actions to improve the sanitation situation. The upper caste Hindus and Muslims tended to use the PF latrines, while the low caste Hindus tended not to use them. Few dry latrines existed in Satna. More than 75% of the households used the PF latrines, especially in Khandwa. The latrines generally were in disrepair, because more families did not receive either instruction or back-up latrine maintenance. Other apparent reasons for poor maintenance were limited water, illiteracy, limited knowledge of how the PF latrine works, poor construction, excreta adhering to the squatting pan, rain entering the leach pits through the squatting pan causing overflow of the pits contents, clogged outlets and Y-junctions, difficulty in emptying the pits, and collapsed brick drains. Children did not use the latrines in more than 50% of households were the latrines were used. Uncomfortable seats were the reason the children chose to defecate in the open. These findings led the author to recommend that the government adopt laws addressing sanitation in low-cost housing settlements, slums, and other areas. A PF latrine must be constructed for each new building. Dry or bucket latrines must be connected to sewers, if available. Leach pits must be constructed for converting latrines into PF latrines. There should be a ban on new dry or bucket latrines. The government should provide the local authorities the power to enforce these regulations. PF latrines should be free for the poor.

Quantification of skeletal fraction volume of a soil pit by means of photogrammetry

NASA Astrophysics Data System (ADS)

Baruck, Jasmin; Zieher, Thomas; Bremer, Magnus; Rutzinger, Martin; Geitner, Clemens

2015-04-01

The grain size distribution of a soil is a key parameter determining soil water behaviour, soil fertility and land use potential. It plays an important role in soil classification and allows drawing conclusions on landscape development as well as soil formation processes. However, fine soil material (i.e. particle diameter ≤2 mm) is usually documented more thoroughly than the skeletal fraction (i.e. particle diameter >2 mm). While fine soil material is commonly analysed in the laboratory in order to determine the soil type, the skeletal fraction is typically estimated in the field at the profile. For a more precise determination of the skeletal fraction other methods can be applied and combined. These methods can be volume-related (sampling rings, percussion coring tubes) or non-volume-related (sieve of spade excavation). In this study we present a framework for the quantification of skeletal fraction volumes of a soil pit by means of photogrammetry. As a first step 3D point clouds of both soil pit and skeletal grains were generated. Therefore all skeletal grains of the pit were spread out onto a plane, clean plastic sheet in the field and numerous digital photos were taken using a reflex camera. With the help of the open source tool VisualSFM (structure from motion) two scaled 3D point clouds were derived. As a second step the skeletal fraction point cloud was segmented by radiometric attributes in order to determine volumes of single skeletal grains. The comparison of the total skeletal fraction volume with the volume of the pit (closed by spline interpolation) yields an estimate of the volumetric proportion of skeletal grains. The presented framework therefore provides an objective reference value of skeletal fraction for the support of qualitative field records.

STS-32 crewmembers use water hoses during fire fighting training at JSC

NASA Image and Video Library

1989-09-22

STS-32 crewmembers use water hoses during fire fighting exercises at JSC's Fire Training Pit across from the Gilruth Center Bldg 207. Mission Specialist (MS) G. David Low with nozzle open directs water into the fire as fire/ security personnel coaches and instructs him on his attempt to extinguish the blaze. MS Bonnie J. Dunbar maneuvers the hose behind Low. A second group of crewmembers alongside Low and Dunbar, MS Marsha S. Ivins, holding hose nozzle, Commander Daniel C. Brandenstein, and Pilot James D. Wetherbee position themselves before opening hose nozzle.

STS-32 crewmembers use water hoses during fire fighting training at JSC

NASA Technical Reports Server (NTRS)

1989-01-01

STS-32 crewmembers use water hoses during fire fighting exercises at JSC's Fire Training Pit across from the Gilruth Center Bldg 207. Mission Specialist (MS) G. David Low with nozzle open directs water into the fire as fire/ security personnel coaches and instructs him on his attempt to extinguish the blaze. MS Bonnie J. Dunbar maneuvers the hose behind Low. A second group of crewmembers alongside Low and Dunbar, MS Marsha S. Ivins, holding hose nozzle, Commander Daniel C. Brandenstein, and Pilot James D. Wetherbee position themselves before opening hose nozzle.

Slope/Shelf Circulation and Cross-Slope/Shelf Transport Out of a Bay Driven by Eddies from the Open Ocean

DTIC Science & Technology

2009-09-01

channel. More recently, they examined the role of eddies in the overturning circulation of the Southern Ocean using the hemispheric HIM with realistic... meridional velocity with intervals of 0.1 · 10−3ms−1 159 PV equation to study the bay-scale circulations : d dt ( f + ζ H0 − f0h0 H 20 ) = F, (4.30) where...2009-18 DOCTORAL DISSERTATION by Yu Zhang September 2009 Slope/shelf Circulation and Cross-slope/shelf Transport Out of a Bay Driven by Eddies from

75 FR 21343 - Notice of Availability of the Final Environmental Impact Statement for the Round Mountain...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-23

... INFORMATION: The Round Mountain Gold Corporation, which is a joint venture of Kinross Gold Corporation and Barrick Gold Corporation, proposes to expand its Round Mountain Mine, an existing open-pit gold mining and... about 66.2 acres between the Round Mountain area and the Gold Hill area. The primary method of...

78 FR 7808 - Notice of Intent To Prepare an Environmental Impact Statement for the Proposed Buffalo Valley...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-04

... amended, the Bureau of Land Management (BLM) Mount Lewis Field Office, Battle Mountain, Nevada, intends to... Buffalo Valley Mine Project, a proposed open pit gold mine, mill, and associated facilities, located on..._mountain_field.html . In order to be considered during the preparation of the Draft EIS, all comments must...

Farewell to Alexandria: Solutions to Space, Growth, and Performance Problems of Libraries.

ERIC Educational Resources Information Center

Gore, Daniel, Ed.

All of the contributions in this volume, except the last, were presented at a conference sponsored by the Associated Colleges of the Midwest, held in Chicago, April 17-18, 1975. Entitled "Touching Bottom in the Bottomless Pit," the conference was intended to open a national debate on space, growth, and performance problems of…

78 FR 70067 - Notice of Availability of the Final Environmental Impact Statement for the Proposed Pan Mine...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-22

..._programs/minerals/mining_projects/pan_mine_project.html . FOR FURTHER INFORMATION CONTACT: Miles Kreidler...: Midway Gold US, Inc. (Midway) proposes to construct and operate an open-pit gold mining operation in the... years, which includes 13 years of mining and additional time for associated construction, closure, and...

Validation of Airborne Visible-Infrared Imaging Spectrometer Data at Ray Mine, AZ

NASA Technical Reports Server (NTRS)

Lang, H.; Baloga, S.

1999-01-01

We validate 1997 Airborne Visible-Infrared Imaging Spectrometer (AVIRIS) reflectance spectra covering 0.4 meu - 2.4 meu from a stable, flat mineralogically characterized man-made target at Ray Mine, AZ, the site for an EPA/NASA assessment of the utility of remote sensing for monitoring acid drainage from an active open pit mine.

COMPARISON OF DATA FROM SYNTHETIC LEACHATE AND DIRECT SAMPLING OF ACID DRAINAGE FROM MINE WASTES: IMPLICATIONS FOR MERCURY TRANSPORT AND WASTE MANAGEMENT

EPA Science Inventory

The Sulphur Bank Mercury Mine (SBMM) in Lake County, California operated from the 1860s through the 1950's. Mining for sulfur started with surface operations and progressed to shaft, then open pit techniques to obtain mercury. Mining has resulted in deposition of approximately ...

40 CFR 440.33 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2012 CFR

2012-07-01

...) The concentration of pollutants discharged in mine drainage from mines, either open-pit or underground, that produce uranium ore, including mines using in-situ leach methods, shall not exceed: Effluent...). Except as provided in subpart L of this part and 40 CFR 125.30 through 125.32, any existing point source...

40 CFR 440.33 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2011 CFR

2011-07-01

... concentration of pollutants discharged in mine drainage from mines, either open-pit or underground, that produce uranium ore, including mines using in-situ leach methods, shall not exceed: Effluent characteristic... provided in subpart L of this part and 40 CFR 125.30 through 125.32, any existing point source subject to...

40 CFR 440.33 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2014 CFR

2014-07-01

...) The concentration of pollutants discharged in mine drainage from mines, either open-pit or underground, that produce uranium ore, including mines using in-situ leach methods, shall not exceed: Effluent...). Except as provided in subpart L of this part and 40 CFR 125.30 through 125.32, any existing point source...

40 CFR 440.33 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... concentration of pollutants discharged in mine drainage from mines, either open-pit or underground, that produce uranium ore, including mines using in-situ leach methods, shall not exceed: Effluent characteristic... provided in subpart L of this part and 40 CFR 125.30 through 125.32, any existing point source subject to...

30 CFR 75.372 - Mine ventilation map.

Code of Federal Regulations, 2010 CFR

2010-07-01

... at each opening. (8) The elevation at the top and bottom of each shaft and slope, and shaft and slope... of all ventilation controls, including permanent stoppings, overcasts, undercasts, regulators, seals... seals for each worked-out area. (19) The entry height, velocity and direction of the air current at or...

Interior of east side bathroom showing the sloped ceiling and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Interior of east side bathroom showing the sloped ceiling and window grill openings, light coming from right to left, view facing north-northeast - U.S. Naval Base, Pearl Harbor, Dry Dock No. 1, Latrine, Sixth Street, adjacent to Dry Dock No. 1, Pearl City, Honolulu County, HI

Particle and gas emissions from a simulated coal-burning household fire pit.

PubMed

Tian, Linwei; Lucas, Donald; Fischer, Susan L; Lee, S C; Hammond, S Katharine; Koshland, Catherine P

2008-04-01

An open fire was assembled with firebricks to simulate the household fire pit used in rural China, and 15 different coals from this area were burned to measure the gaseous and particulate emissions. Particle size distribution was studied with a microorifice uniform-deposit impactor (MOUDI). Over 90% of the particulate mass was attributed to sub-micrometer particles. The carbon balance method was used to calculate the emission factors. Emission factors for four pollutants (particulate matter, CO2, total hydrocarbons, and NOx) were 2-4 times higherfor bituminous coals than for anthracites. In past inventories of carbonaceous emissions used for climate modeling, these two types of coal were not treated separately. The dramatic emission factor difference between the two types of coal warrants attention in the future development of emission inventories.

Minimizing Alteration of Posterior Tibial Slope During Opening Wedge High Tibial Osteotomy: a Protocol with Experimental Validation in Paired Cadaveric Knees

PubMed Central

Westermann, Robert W; DeBerardino, Thomas; Amendola, Annunziato

2014-01-01

Introduction The High Tibial Osteotomy (HTO) is a reliable procedure in addressing uni- compartmental arthritis with associated coronal deformities. With osteotomy of the proximal tibia, there is a risk of altering the tibial slope in the sagittal plane. Surgical techniques continue to evolve with trends towards procedure reproducibility and simplification. We evaluated a modification of the Arthrex iBalance technique in 18 paired cadaveric knees with the goals of maintaining sagittal slope, increasing procedure efficiency, and decreasing use of intraoperative fluoroscopy. Methods Nine paired cadaveric knees (18 legs) underwent iBalance medial opening wedge high tibial osteotomies. In each pair, the right knee underwent an HTO using the modified technique, while all left knees underwent the traditional technique. Independent observers evaluated postoperative factors including tibial slope, placement of hinge pin, and implant placement. Specimens were then dissected to evaluate for any gross muscle, nerve or vessel injury. Results Changes to posterior tibial slope were similar using each technique. The change in slope in traditional iBalance technique was -0.3° ±2.3° and change in tibial slope using the modified iBalance technique was -0.4° ±2.3° (p=0.29). Furthermore, we detected no differences in posterior tibial slope between preoperative and postoperative specimens (p=0.74 traditional, p=0.75 modified). No differences in implant placement were detected between traditional and modified techniques. (p=0.85). No intraoperative iatrogenic complications (i.e. lateral cortex fracture, blood vessel or nerve injury) were observed in either group after gross dissection. Discussion & Conclusions Alterations in posterior tibial slope are associated with HTOs. Both traditional and modified iBalance techniques appear reliable in coronal plane corrections without changing posterior tibial slope. The present modification of the Arthrex iBalance technique may increase the efficiency of the operation and decrease radiation exposure to patients without compromising implant placement or global knee alignment. PMID:25328454

Sesquinary reimpacts dominate surface characteristics on Phobos

NASA Astrophysics Data System (ADS)

Nayak, Michael

2018-01-01

We use topographic data to show that impact craters with pitted floor deposits are among the deepest on Mars. This is consistent with the interpretation of pitted materials as primary crater-fill impactite deposits emplaced during crater formation. Our database consists of 224 pitted material craters ranging in size from ˜1 to 150 km in diameter. Our measurements are based on topographic data from the Mars Orbiter Laser Altimeter (MOLA) and the High-Resolution Stereo Camera (HRSC). We have used these craters to measure the relationship between crater diameter and the initial post-formation depth. Depth was measured as maximum rim-to-floor depth, (dr), but we also report the depth measured using other definitions. The database was down-selected by refining or removing elevation measurements from "problematic" craters affected by processes and conditions that influenced their dr/D, such as pre-impact slopes/topography and later overprinting craters. We report a maximum (deepest) and mean scaling relationship of dr = (0.347±0.021)D0.537±0.017 and dr = (0.323±0.017)D0.538±0.016, respectively. Our results suggest that significant variations between previously-reported MOLA-based dr vs. D relationships may result from the inclusion of craters that: 1) are influenced by atypical processes (e.g., highly oblique impact), 2) are significantly degraded, 3) reside within high-strength regions, and 4) are transitional (partially collapsed). By taking such issues into consideration and only measuring craters with primary floor materials, we present the best estimate to date of a MOLA-based relationship of dr vs. D for the least-degraded complex craters on Mars. This can be applied to crater degradation studies and provides a useful constraint for models of complex crater formation.

A depth versus diameter scaling relationship for the best-preserved melt-bearing complex craters on Mars

NASA Astrophysics Data System (ADS)

Tornabene, Livio L.; Watters, Wesley A.; Osinski, Gordon R.; Boyce, Joseph M.; Harrison, Tanya N.; Ling, Victor; McEwen, Alfred S.

2018-01-01

We use topographic data to show that impact craters with pitted floor deposits are among the deepest on Mars. This is consistent with the interpretation of pitted materials as primary crater-fill impactite deposits emplaced during crater formation. Our database consists of 224 pitted material craters ranging in size from ∼1 to 150 km in diameter. Our measurements are based on topographic data from the Mars Orbiter Laser Altimeter (MOLA) and the High-Resolution Stereo Camera (HRSC). We have used these craters to measure the relationship between crater diameter and the initial post-formation depth. Depth was measured as maximum rim-to-floor depth, (dr), but we also report the depth measured using other definitions. The database was down-selected by refining or removing elevation measurements from ;problematic; craters affected by processes and conditions that influenced their dr/D, such as pre-impact slopes/topography and later overprinting craters. We report a maximum (deepest) and mean scaling relationship of dr = (0.347 ± 0.021)D0.537 ± 0.017 and dr = (0.323 ± 0.017)D0.538 ± 0.016, respectively. Our results suggest that significant variations between previously-reported MOLA-based dr vs. D relationships may result from the inclusion of craters that: 1) are influenced by atypical processes (e.g., highly oblique impact), 2) are significantly degraded, 3) reside within high-strength regions, and 4) are transitional (partially collapsed). By taking such issues into consideration and only measuring craters with primary floor materials, we present the best estimate to date of a MOLA-based relationship of dr vs. D for the least-degraded complex craters on Mars. This can be applied to crater degradation studies and provides a useful constraint for models of complex crater formation.

Size of the foveal blue scotoma related to the shape of the foveal pit but not to macular pigment.

PubMed

Chen, Yun; Lan, Weizhong; Schaeffel, Frank

2015-01-01

When the eye is covered with a filter that transmits light below 480 nm and a blue field is observed on a computer screen that is modulated in brightness at about 1 Hz, the fovea is perceived as small irregular dark spot. It was proposed that the "foveal blue scotoma" results from the lack of S-cones in the foveal center. The foveal blue scotoma is highly variable among subjects. Possible factors responsible for the variability include differences in S-cone distribution, in foveal shape, and in macular pigment distribution. Nine young adult subjects were instructed to draw their foveal blue scotomas on a clear foil that was attached in front of the computer screen. The geometry of their foveal pit was measured in OCT images in two dimensions. Macular pigment distribution was measured in fundus camera images. Finally, blue scotomas were compared with Maxwell's spot which was visualized with a dichroic filter and is commonly assumed to reflect the macular pigment distribution. The diameters of the foveal blue scotomas varied from 15.8 to 76.4 arcmin in the right eyes and 15.5 to 84.7 arcmin in the left and were highly correlated in both eyes. It was found that the steeper the foveal slopes and the narrower the foveal pit, the larger the foveal blue scotoma. There was no correlation between foveal blue scotoma and macular pigment distribution or Maxwell's spot. The results are therefore in line with the assumption that the foveal blue scotoma is a consequence of the lack of S-cones in the foveal center. Unlike the foveal blue scotoma, Maxwell's spot is based on macular pigment as previously proposed. Copyright © 2014 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

K.E. Rasmuson

The U.S. Department of Energy has implemented a program to reclaim lands disturbed by site characterization at Yucca Mountain. Long term goals of the program are to re-establish processes on disturbed sites that will lead to self-sustaining plant communities. The Biological Opinion for Yucca Mountain Site Characterization Studies required that the U.S. Department of Energy develop a Reclamation Standards and Monitoring Plan to evaluate the success of reclamation efforts. According to the Reclamation Standards and Monitoring Plan, reclaimed sites will be monitored periodically, remediated if necessary, and eventually compared to an appropriate reference area to determine whether reclamation goals havemore » been achieved and the site can be released from further monitoring. Plant cover, density, and species richness (success parameters) on reclaimed sites are compared to 60 percent of the values (success criteria) for the same parameters on the reference area. Small sites (less than 0.1 ha) are evaluated for release using qualitative methods while large sites (greater than 0.1 ha) are evaluated using quantitative methods. In the summer of 2000, 31 small sites reclaimed in 1993 and 1994 were evaluated for reclamation success and potential release from further monitoring. Plant density, cover, and species richness were estimated on the C-Well Pipeline, UE-25 Large Rocks test site, and 29 ground surface facility test pits. Evidence of erosion, reproduction and natural recruitment, exotic species abundance, and animal use (key attributes) also were recorded for each site and used in success evaluations. The C-Well Pipeline and ground surface facility test pits were located in a ''Larrea tridentata - Ephedra nevadensis'' vegetation association while the UE-25 Large Rocks test site was located in an area dominated by ''Coleogyne ramosissima and Ephedra nevadensis''. Reference areas in the same vegetation associations with similar slope and aspect were chosen for comparison to the reclaimed sites. Sixty percent of the reference area means for density, cover, and species richness were compared to the estimated means for the reclaimed sites. Plant density, cover, and species richness at the C-Well Pipeline and UE-25 Large Rocks test site were greater than the success criteria and all key attributes indicated the sites were in acceptable condition. Therefore, these two sites were recommended for release from further monitoring. Of the 29 ground surface facility test pits, 26 met the criterion for density, 21 for cover, and 23 for species richness. When key attributes and conditions of the plant community near each pit were taken into account, 27 of these pits were recommended for release. Success parameters and key attributes at ground surface facility test pits 19 and 20 were inadequate for site release. Transplants of native species were added to these two sites in 2001 to improve density, cover, and species richness.« less

Mixed sand and gravel beaches: accurate measurement of active layer depth and sediment transport volumes using PIT tagged tracer pebbles

NASA Astrophysics Data System (ADS)

Holland, A.; Moses, C.; Sear, D. A.; Cope, S.

2016-12-01

As sediments containing significant gravel portions are increasingly used for beach replenishment projects globally, the total number of beaches classified as `mixed sand and gravel' (MSG) increases. Calculations for required replenishment sediment volumes usually assume a uniform layer of sediment transport across and along the beach, but research into active layer (AL) depth has shown variations both across shore and according to sediment size distribution. This study addresses the need for more accurate calculations of sediment transport volumes on MSG beaches by using more precise measurements of AL depth and width, and virtual velocity of tracer pebbles. Variations in AL depth were measured along three main profile lines (from MHWS to MLWN) at Eastoke, Hayling Island (Hampshire, UK). Passive Integrated Transponder (PIT) tagged pebbles were deployed in columns, and their new locations repeatedly surveyed with RFID technology. These data were combined with daily dGPS beach profiles and sediment sampling for detailed analysis of the influence of beach morphodynamics on sediment transport volumes. Data were collected over two consecutive winter seasons: 2014-15 (relatively calm, average wave height <1 m) and 2015-16 (prolonged periods of moderate storminess, wave heights of 1-2 m). The active layer was, on average, 22% of wave height where beach slope (tanβ) is 0.1, with variations noted according to slope angle, sediment distribution, and beach groundwater level. High groundwater levels and a change in sediment proportions in the sandy lower foreshore reduced the AL to 10% of wave height in this area. The disparity in AL depth across the beach profile indicates that traditional models are not accurately representing bulk sediment transport on MSG beaches. It is anticipated that by improving model inputs, beach managers will be better able to predict necessary volumes and sediment grain size proportions of replenishment material for effective management of MSG beaches.

Development of a GIS-based failure investigation system for highway soil slopes

NASA Astrophysics Data System (ADS)

Ramanathan, Raghav; Aydilek, Ahmet H.; Tanyu, Burak F.

2015-06-01

A framework for preparation of an early warning system was developed for Maryland, using a GIS database and a collective overlay of maps that highlight highway slopes susceptible to soil slides or slope failures in advance through spatial and statistical analysis. Data for existing soil slope failures was collected from geotechnical reports and field visits. A total of 48 slope failures were recorded and analyzed. Six factors, including event precipitation, geological formation, land cover, slope history, slope angle, and elevation were considered to affect highway soil slope stability. The observed trends indicate that precipitation and poor surface or subsurface drainage conditions are principal factors causing slope failures. 96% of the failed slopes have an open drainage section. A majority of the failed slopes lie in regions with relatively high event precipitation ( P>200 mm). 90% of the existing failures are surficial erosion type failures, and only 1 out of the 42 slope failures is deep rotational type failure. More than half of the analyzed slope failures have occurred in regions having low density land cover. 46% of failures are on slopes with slope angles between 20° and 30°. Influx of more data relating to failed slopes should give rise to more trends, and thus the developed slope management system will aid the state highway engineers in prudential budget allocation and prioritizing different remediation projects based on the literature reviewed on the principles, concepts, techniques, and methodology for slope instability evaluation (Leshchinsky et al., 2015).

Land disturbances from strip-mining in eastern Kentucky: 2. Princess Coal Reserve District

Treesearch

William T. Plass

1967-01-01

Open-pit or strip-mining - primarily for coal - has expanded rapidly in eastern Kentucky during the past 15 years. Information about the amount, location, and general characteristics of the disturbed areas is necessary for appraising the economic impacts and overall effects of strip-mining in that section of the state, for planning reclamation programs, and for...

Land disturbances from strip-mining in eastern Kentucky: 1. Upper Cumberland coal reserve district

Treesearch

William T. Plass

1966-01-01

Open-pit or strip-mining - primarily for coal - has expanded rapidly in eastern Kentucky during the past 15 years. Information about the amount, location, and general characteristics of the disturbed areas is necessary for appraising the economic impacts and overall effects of strip-mining in that section of the state, for planning reclamation programs, and for...

78 FR 77706 - Notice of Intent To Prepare an Environmental Impact Statement for the Proposed Gemfield Mine...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-24

... gold mine and associated processing and ancillary facilities. The project would be located on public... media, newspapers and the BLM Web site at: http://www.blm.gov/nv/st/en/fo/battle_mountain_field.html... to construct, operate, reclaim, and close an open pit, heap leach, gold mining operation known as the...

Multiculturalism as State Policy. Conference Report. Second Canadian Conference on Multiculturalism, Government Conference Centre (Ottawa, Ontario, February 13-15, 1976).

ERIC Educational Resources Information Center

Canadian Consultative Council on Multiculturalism, Ottawa (Ontario).

The Second Canadian Conference on Multiculturalism was held to clarify some of the issues upon which multiculturalism as a concept and as a policy depend. Cultural pluralism was investigated within the social, political, and historical framework of Canadian society. The opening session, called "The Bear Pit," invited questions and…

A deposit model for magmatic iron-titanium-oxide deposits related to Proterozoic massif anorthosite plutonic suites: Chapter K in Mineral Deposit Models for Resource Assessment

USGS Publications Warehouse

Woodruff, Laurel G.; Nicholson, Suzanne W.; Fey, David L.

2013-01-01

Active mines have developed large open pits with extensive waste-rock piles, but because of the nature of the ore and waste rock, the major environmental impacts documented at the mine sites are reported to be waste disposal issues and somewhat degraded water quality.

SEASONAL VARIATIONS OF DISSOLVED MERCURY CONCENTRATIONS AT THE SULPHUR BANK MERCURY MINE, CLEAR LAKE, CALIFORNIA: IMPLICATIONS FOR MINE DRAINAGE MONITORING

EPA Science Inventory

The Sulphur Bank Mercury Mine in Lake County, California (SBMM) was operated from the 1860s through the 1950s. Mining for sulfur started with surface operations and then progressed to shaft and later open pit techniques to obtain mercury. SBMM is located adjacent to the shore o...

40 CFR 440.32 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

..., radium and vanadium including mill-mine facilities and mines using in-situ leach methods shall not exceed...). Except as provided in subpart L of this part and 40 CFR 125.30 through 125.32, any existing point source... available (BPT): (a) The concentration of pollutants discharged in mine drainage from mines, either open-pit...

40 CFR 440.32 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2011 CFR

2011-07-01

..., radium and vanadium including mill-mine facilities and mines using in-situ leach methods shall not exceed...). Except as provided in subpart L of this part and 40 CFR 125.30 through 125.32, any existing point source... available (BPT): (a) The concentration of pollutants discharged in mine drainage from mines, either open-pit...

Intelligent Mining Engineering Systems in the Structure of Industry 4.0

NASA Astrophysics Data System (ADS)

Rylnikova, Marina; Radchenko, Dmitriy; Klebanov, Dmitriy

2017-11-01

The solution of the problem of improving the human environment and working conditions at mines is based on the provision of the rationale of parameters and conditions for the implementation of an environmentally balanced cycle of comprehensive development of mineral deposits on the basis of the design of mining engineering systems characterized by the minimization of the human factor effect in danger zones of mining operations. In this area, robotized technologies are being developed, machinery and mechanisms with the elements of artificial intelligence, and mining and transport system automatic controls are being put into service throughout the world. In the upcoming decades, mining machines and mechanisms will be virtually industrial robots. The article presents the results of zoning of open-pit and underground mine production areas, as well as mining engineering system of combined development depending on the fact and periodicity of human presence in zones of mining processes. As a surface geotechnology case study, the software structure based on a modular concept is described. The performance philosophy of mining and transport equipment with the elements of artificial intelligence is shown when it is put into service in an open pit.

Using radon-222 for tracing groundwater discharge into an open-pit lignite mining lake--a case study.

PubMed

Schmidt, Axel; Schubert, Michael

2007-12-01

Groundwater discharge into an open pit lignite mining lake was investigated using radon-222 as a naturally occurring environmental tracer. The chosen study site was a meromictic lake, i.e., a water body that is divided horizontally into two separate layers--the upper mixolimnion (with seasonal mixing) and the lower monimolimnion (without seasonal mixing). For the estimation of groundwater discharge rates into the lake, a simple box model including all radon sinks and sources related to each layer was applied. Two field investigations were performed. During the October campaign, the total groundwater discharge into the lake was found to be 18.9 and 0.7 m(3) d(-1) for the mixolimnion and monimolimnion, respectively. During the December campaign, the groundwater discharge into the mixolimnion was 15.0 m(3) d(-1), whereas no discharge at all was observed into the monimolimnion. Based on the given water volumes, the residence time of lake water was 5.3 years for the monimolimnion and varies between 0.9 and 1.1 years for the mixolimnion. The investigation confirmed radon to be a useful environmental tracer for groundwater and surface water interactions in meromictic lake environments.

Public exposure to hazards associated with natural radioactivity in open-pit mining in Ghana.

PubMed

Darko, E O; Faanu, A; Awudu, A R; Emi-Reynolds, G; Yeboah, J; Oppon, O C; Akaho, E H K

2010-01-01

The results of studies carried out on public exposure contribution from naturally occurring radioactive materials (NORMS) in two open-pit mines in the Western and Ashanti regions of Ghana are reported. The studies were carried out under International Atomic Energy Agency-supported Technical Co-operation Project GHA/9/005. Measurements were made on samples of water, soil, ore, mine tailings and air using gamma spectrometry. Solid-state nuclear track detectors were used for radon concentration measurements. Survey was also carried out to determine the ambient gamma dose rate in the vicinity of the mines and surrounding areas. The effective doses due to external gamma irradiation, ingestion of water and inhalation of radon and ore dusts were calculated for the two mines. The average annual effective dose was found to be 0.30 +/- 0.06 mSv. The result was found to be within the levels published by other countries. The study provides a useful information and data for establishing a comprehensive framework to investigate other mines and develop guidelines for monitoring and control of NORMS in the mining industry and the environment as a whole in Ghana.

Cover design for radioactive and AMD-producing mine waste in the Ronneburg area, eastern Thuringia.

PubMed

Gatzweiler, R; Jahn, S; Neubert, G; Paul, M

2001-01-01

At the former uranium mining site of Ronneburg, large scale underground and open pit mining for nearly 40 years resulted in a production of about 113,000 tonnes of uranium and about 200 million cubic metres of mine waste. In their present state, these materials cause risks to human health and strong environmental impacts and therefore demand remedial action. The remediation options available are relocation of mine spoil into the open pit and on site remediation by landscaping/contouring, placement of a cover and revegetation. A suitable vegetated cover system combined with a surface water drainage system provides long-term stability against erosion and reduces acid generation thereby meeting the main remediation objectives which are long-term reduction of radiological exposure and contaminant emissions and recultivation. The design of the cover system includes the evaluation of geotechnical, radiological, hydrological, geochemical and ecological criteria and models. The optimized overall model for the cover system has to comply with general conditions as, e.g. economic efficiency, public acceptance and sustainability. Most critical elements for the long-term performance of the cover system designed for the Beerwalde dump are the barrier system and its long-term integrity and a largely self-sustainable vegetation.

A simplified economic filter for open-pit mining and heap-leach recovery of copper in the United States

USGS Publications Warehouse

Long, Keith R.; Singer, Donald A.

2001-01-01

Determining the economic viability of mineral deposits of various sizes and grades is a critical task in all phases of mineral supply, from land-use management to mine development. This study evaluates two simple tools for estimating the economic viability of porphyry copper deposits mined by open-pit, heap-leach methods when only limited information on these deposits is available. These two methods are useful for evaluating deposits that either (1) are undiscovered deposits predicted by a mineral resource assessment, or (2) have been discovered but for which little data has been collected or released. The first tool uses ordinary least-squared regression analysis of cost and operating data from selected deposits to estimate a predictive relationship between mining rate, itself estimated from deposit size, and capital and operating costs. The second method uses cost models developed by the U.S. Bureau of Mines (Camm, 1991) updated using appropriate cost indices. We find that the cost model method works best for estimating capital costs and the empirical model works best for estimating operating costs for mines to be developed in the United States.

Proteomics technique opens new frontiers in mobilome research.

PubMed

Davidson, Andrew D; Matthews, David A; Maringer, Kevin

2017-01-01

A large proportion of the genome of most eukaryotic organisms consists of highly repetitive mobile genetic elements. The sum of these elements is called the "mobilome," which in eukaryotes is made up mostly of transposons. Transposable elements contribute to disease, evolution, and normal physiology by mediating genetic rearrangement, and through the "domestication" of transposon proteins for cellular functions. Although 'omics studies of mobilome genomes and transcriptomes are common, technical challenges have hampered high-throughput global proteomics analyses of transposons. In a recent paper, we overcame these technical hurdles using a technique called "proteomics informed by transcriptomics" (PIT), and thus published the first unbiased global mobilome-derived proteome for any organism (using cell lines derived from the mosquito Aedes aegypti ). In this commentary, we describe our methods in more detail, and summarise our major findings. We also use new genome sequencing data to show that, in many cases, the specific genomic element expressing a given protein can be identified using PIT. This proteomic technique therefore represents an important technological advance that will open new avenues of research into the role that proteins derived from transposons and other repetitive and sequence diverse genetic elements, such as endogenous retroviruses, play in health and disease.

Structure and Evolution of Hawaii's Loihi Seamount from High-resolution Mapping

NASA Astrophysics Data System (ADS)

Clague, D. A.; Paduan, J. B.; Moyer, C. L.; Glazer, B. T.; Caress, D. W.; Yoerger, D.; Kaiser, C. L.

2016-12-01

Loihi Seamount has been mapped repeatedly using shipboard multibeam sonars with improving resolution over time. Simrad EM302 data with 25m resolution at the 950m summit and 90m at the 5000m base of the volcano were collected from Schmidt Ocean Institute's R/V Falkor in 2014. A contracted multibeam survey in 1997 employing a deep-towed vehicle has 7m resolution for the summit and upper north and south rift zones, but suffered from poor navigation. Woods Hole Oceanographic Institution's AUV Sentry surveyed most of the summit and low-T hydrothermal vents on the base of the south rift in 2013 and 2014. The 2m resolution of most data is more precise than the navigation. The 6 summit surveys were reprocessed using MB-System to remove abundant bad bottom picks and adjust the navigation to produce a spatially accurate map. The 3 summit pits, including Pele's Pit that formed in 1996, are complex collapse structures and nested inside a larger caldera that was modified by large landslides on the east and west summit flanks. The pits cut low shields that once formed a complex of overlapping summit shields, similar to Kilauea before the current caldera formed 1500 to 1790 CE. An 11m section of ash deposits crops out on the east rim of the summit along a caldera-bounding fault and is analogous to Kilauea where the caldera-bounding faults expose ash erupted as the present caldera formed. Most of the Loihi ash section is 3300 to 5880 yr BP, indicating that the larger caldera structure at Loihi is younger than 3300 yr BP. The landslides on the east and west edges of the summit are therefore younger 3300 yr BP. The uppermost south rift has several small pit craters between cones and pillow ridges, also analogous to Kilauea. Two cones near the deep low-T vents are steep pillow mounds with slopes of talus. High-resolution mapping reveals, for the first time, the many similarities between the structure and evolution of submarine Loihi Seamount and subaerial Kilauea Volcano.

Can vector control play a useful supplementary role against bancroftian filariasis?

PubMed Central

Maxwell, C. A.; Mohammed, K.; Kisumku, U.; Curtis, C. F.

1999-01-01

A single campaign of mass treatment for bancroftian filariasis with diethylcarbamazine (DEC) in Makunduchi, a town in Zanzibar, United Republic of Tanzania, combined with elimination of mosquito breeding in pit latrines with polystyrene beads was followed by a progressive decline over a 5-year period in the microfilarial rate from 49% to 3%. Evidence that vector control had contributed to this long-term decline was obtained by comparison with another town, Moga, where a DEC campaign was used without vector control and where resurgence of microfilariae could be observed 3-6 years after the campaign. In Zanzibar town, treatment of 3844 wet pit latrines and cesspits with polystyrene beads reduced the adult mosquito population in houses by about 65%. Supplementary treatment of open drains and marshes with Bacillus sphaericus produced little or no additional reduction compared to a sector of the town where only pit treatment with polystyrene was carried out. The cost and effort of achieving the 65% reduction in mosquito population could hardly be justified for its impact on filariasis alone, but its noticeable impact on biting nuisance might help to gain community support for an integrated programme. PMID:10083712

Geospatial analysis of residential proximity to open-pit coal mining areas in relation to micronuclei frequency, particulate matter concentration, and elemental enrichment factors.

PubMed

Espitia-Pérez, Lyda; Arteaga-Pertuz, Marcia; Soto, José Salvador; Espitia-Pérez, Pedro; Salcedo-Arteaga, Shirley; Pastor-Sierra, Karina; Galeano-Páez, Claudia; Brango, Hugo; da Silva, Juliana; Henriques, João A P

2018-09-01

During coal surface mining, several activities such as drilling, blasting, loading, and transport produce large quantities of particulate matter (PM) that is directly emitted into the atmosphere. Occupational exposure to this PM has been associated with an increase of DNA damage, but there is a scarcity of data examining the impact of these industrial operations in cytogenetic endpoints frequency and cancer risk of potentially exposed surrounding populations. In this study, we used a Geographic Information Systems (GIS) approach and Inverse Distance Weighting (IDW) methods to perform a spatial and statistical analysis to explore whether exposure to PM 2.5 and PM 10 pollution, and additional factors, including the enrichment of the PM with inorganic elements, contribute to cytogenetic damage in residents living in proximity to an open-pit coal mining area. Results showed a spatial relationship between exposure to elevated concentrations of PM 2.5, PM 10 and micronuclei frequency in binucleated (MNBN) and mononucleated (MNMONO) cells. Active pits, disposal, and storage areas could be identified as the possible emission sources of combustion elements. Mining activities were also correlated with increased concentrations of highly enriched elements like S, Cu and Cr in the atmosphere, corroborating its role in the inorganic elements pollution around coal mines. Elements enriched in the PM 2.5 fraction contributed to increasing of MNBN but seems to be more related to increased MNMONO frequencies and DNA damage accumulated in vivo. The combined use of GIS and IDW methods could represent an important tool for monitoring potential cancer risk associated to dynamically distributed variables like the PM. Copyright © 2018 Elsevier Ltd. All rights reserved.

Monitoring of ground movement in open pit iron mines of Carajás Province (Amazon region) based on A-DInSAR techniques using TerraSAR-X data

NASA Astrophysics Data System (ADS)

Silva, Guilherme Gregório; Mura, José Claudio; Paradella, Waldir Renato; Gama, Fabio Furlan; Temporim, Filipe Altoé

2017-04-01

Persistent scatterer interferometry (PSI) analysis of a large area is always a challenging task regarding the removal of the atmospheric phase component. This work presents an investigation of ground movement measurements based on a combination of differential SAR interferometry time-series (DTS) and PSI techniques, applied on a large area of extent with open pit iron mines located in Carajás (Brazilian Amazon Region), aiming at detecting linear and nonlinear ground movement. These mines have presented a history of instability, and surface monitoring measurements over sectors of the mines (pit walls) have been carried out based on ground-based radar and total station (prisms). Using a priori information regarding the topographic phase error and a phase displacement model derived from DTS, temporal phase unwrapping in the PSI processing and the removal of the atmospheric phases can be performed more efficiently. A set of 33 TerraSAR-X (TSX-1) images, acquired during the period from March 2012 to April 2013, was used to perform this investigation. The DTS analysis was carried out on a stack of multilook unwrapped interferograms using an extension of SVD to obtain the least-square solution. The height errors and deformation rates provided by the DTS approach were subtracted from the stack of interferograms to perform the PSI analysis. This procedure improved the capability of the PSI analysis for detecting high rates of deformation, as well as increased the numbers of point density of the final results. The proposed methodology showed good results for monitoring surface displacement in a large mining area, which is located in a rain forest environment, providing very useful information about the ground movement for planning and risk control.

Monitoring of surface movement in a large area of the open pit iron mines (Carajás, Brazil) based on A-DInSAR techniques using TerraSAR-X data

NASA Astrophysics Data System (ADS)

Mura, José C.; Paradella, Waldir R.; Gama, Fabio F.; Silva, Guilherme G.

2016-10-01

PSI (Persistent Scatterer Interferometry) analysis of large area is always a challenging task regarding the removal of the atmospheric phase component. This work presents an investigation of ground deformation measurements based on a combination of DInSAR Time-Series (DTS) and PSI techniques, applied in a large area of open pit iron mines located in Carajás (Brazilian Amazon Region), aiming at detect high rates of linear and nonlinear ground deformation. These mines have presented a historical of instability and surface monitoring measurements over sectors of the mines (pit walls) have been carried out based on ground based radar and total station (prisms). By using a priori information regarding the topographic phase error and phase displacement model derived from DTS, temporal phase unwrapping in the PSI processing and the removal of the atmospheric phases can be performed more efficiently. A set of 33 TerraSAR-X-1 images, acquired during the period from March 2012 to April 2013, was used to perform this investigation. The DTS analysis was carried out on a stack of multi-look unwrapped interferogram using an extension of SVD to obtain the Least-Square solution. The height errors and deformation rates provided by the DTS approach were subtracted from the stack of interferogram to perform the PSI analysis. This procedure improved the capability of the PSI analysis to detect high rates of deformation as well as increased the numbers of point density of the final results. The proposed methodology showed good results for monitoring surface displacement in a large mining area, which is located in a rain forest environment, providing very useful information about the ground movement for planning and risks control.

Spatial variability of active layer thickness detected by ground-penetrating radar in the Qilian Mountains, Western China

NASA Astrophysics Data System (ADS)

Cao, Bin; Gruber, Stephan; Zhang, Tingjun; Li, Lili; Peng, Xiaoqing; Wang, Kang; Zheng, Lei; Shao, Wanwan; Guo, Hong

2017-03-01

The active layer plays a key role in geomorphic, hydrologic, and biogeochemical processes in permafrost regions. We conducted a systematic investigation of active layer thickness (ALT) in northeastern Qinghai-Tibetan Plateau by using ground-penetrating radar (GPR) with 100 and 200 MHz antennas. We used mechanical probing, pit, and soil temperature profiles for evaluating ALT derived from GPR. The results showed that GPR is competent for detecting ALT, and the error was ±0.08 m at common midpoint co-located sites. Considerable spatial variability of ALT owing to variation in elevation, peat thickness, and slope aspect was found. The mean ALT was 1.32 ± 0.29 m with a range from 0.81 to 2.1 m in Eboling Mountain. In Yeniu Gou, mean ALT was 2.72 ± 0.88 m and varied from 1.07 m on the north-facing slope to 4.86 m around the area near the lower boundary of permafrost. ALT in peat decreased with increasing elevation at rates of -1.31 m/km (Eboling Mountain) and -2.1 m/km (Yeniu Gou), and in mineral soil in Yeniu Gou, the rate changed to -4.18 m/km. At the same elevation, ALT on the south-facing slope was about 0.8 m thicker than that on the north-facing slopes, while the difference was only 0.18 m in peat-covered area. Within a 100 m2 area with a local elevation difference of 0.8 m, ALT varied from 0.68 m to 1.25 m. Both field monitoring and modeling studies on spatial ALT variations require rethinking of the current strategy and comprehensive design.

Performance evaluation of setback buildings with open ground storey on plain and sloping ground under earthquake loadings and mitigation of failure

NASA Astrophysics Data System (ADS)

Ghosh, Rahul; Debbarma, Rama

2017-06-01

Setback structures are highly vulnerable during earthquakes due to its vertical geometrical and mass irregularity, but the vulnerability becomes higher if the structures also have stiffness irregularity in elevation. The risk factor of such structure may increase, if the structure rests on sloping ground. In this paper, an attempt has been made to evaluate the seismic performance of setback structures resting on plain ground as well as in the slope of a hill, with soft storey configuration. The analysis has been performed in three individual methods, equivalent static force method, response spectrum method and time history method and extreme responses have been recorded for open ground storeyed setback building. To mitigate this soft storey effect and the extreme responses, three individual mitigation techniques have been adopted and the best solution among these three techniques is presented.

Soils, surficial geology, and geomorphology of the Bear Creek Valley Low-Level Waste Disposal Development and Demonstration Program site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lietzke, D.A.; Lee, S.Y.; Lambert, R.E.

1988-04-01

An intensive soil survey was conducted on the proposed Low-Level Waste Disposal Development and Demonstration Program site (LLWDDD) in Bear Creek Valley. Soils on the site were related to the underlying residuum and to the surficial colluvium and alluvium. Within any particular geologic formation, soils were subdivided based mostly on the degree of weathering, as reflected by saprolite weathering and morphologic features of the soils. Degree of weathering was related both to slope shape and gradient and to the joint-fracture system. Erosion classes were also used to make further subdivisions of any particular soil. Deep pits were dug in eachmore » of the major Conasauga Group formations (Pumpkin Valley, Rogersville, Maryville, and Nolichucky) for soil and saprolite characterization. Because of the widespread presence of alluvium and colluvium, which are potential sources of fill and final cover material, pits and trenches were dug to characterize the properties of these soils and to try to understand the past geomorphic history of the site. The results of the soil survey investigation indicated that the deeply weathered Pumpkin Valley residuum has good potential for the construction of tumuli or other types of belowground or aboveground burial of prepackaged compacted waste. 11 refs., 30 figs., 3 tabs.« less

Thermally driven up-slope flows: state of the art and open questions

NASA Astrophysics Data System (ADS)

Zardi, D.

2015-12-01

Thermally driven flows over simple slopes are a relevant research topic, not only per se, but also as a source of key concepts for understanding and modelling many other flows over more complex topographies. However, compared to down-slope, up-slope flows have received much less attention in the literature. Indeed, to investigate katabatic winds many extensive and well equipped field measurements were performed in recent years under various research projects, and a series of high-resolution numerical simulations were run. On the contrary, few field experiments have provided detailed datasets documenting the development of anabatic flows, and the analysis of numerical investigations still relies on Schumann's (1990) pioneering LES simulations. Also, analytic solutions - such as Prandtl's (1942) constant-K profiles - reproduce fairly well katabatic flows, but are definitely inadequate to accurately reproduce field data for up-slope flows (Defant 1949). In particular, some open questions still claim for further investigations, such as the conditions of instability of slope-parallel flow vs. vertical motions, and the related possible occurrence of flow separation, and the similarity analysis of slope-normal velocity profiles of temperature anomaly, wind intensity and turbulence related quantities. Here a review of the state of the art on the subject is proposed, along with some insights into possible future developments. ReferencesDefant, F., 1949: Zur Theorie der Hangwinde, nebst Bemerkungen zur Theorie der Berg- und Talwinde. [A theory of slope winds, along with remarks on the theory of mountain winds and valley winds]. Arch. Meteor. Geophys. Bioclimatol., Ser. A, 1, 421-450 (Theoretical and Applied Climatology). [English translation: Whiteman, C.D., and E. Dreiseitl, 1984: Alpine meteorology: Translations of classic contributions by A. Wagner, E. Ekhart and F. Defant. PNL-5141 / ASCOT-84-3. Pacific Northwest Laboratory, Richland, Washington, 121 pp]. Prandtl, L., 1942: Strömungslehre [Flow Studies]. Vieweg und Sohn, Braunschweig, 382 pp. Schumann, U., 1990: Large-eddy simulation of the up-slope boundary layer. Quart. J. Roy. Meteor. Soc., 116, 637-670.

A field study of the geomorphic effects of sublimating CO2 blocks on dune slopes at Coral Pink Dunes, Utah.

NASA Astrophysics Data System (ADS)

Bourke, Mary; Nield, Jo; Diniega, Serina; Hansen, Candy; McElwaine, Jim

2016-04-01

The seasonal sublimation of CO2 ice is an active driver of present-day surface change on Mars. Diniega et al (2013) proposed that a discrete type of Martian gully, found on southern hemisphere dunes, were formed by the movement of CO2 seasonal ice blocks. These 'Linear Gullies' consist primarily of long (100 m - 2.5 km) grooves with near-uniform width (few-10 m wide), and typical depth of <2 m. They are near-linear throughout most of their length but sometimes contains zones of low-to-high sinuosity. They are commonly bounded by levées. The groove is generally prefaced by a small alcove that originates at the dune brink. We present the results of a set of field experiments that were undertaken at the Coral Pink sand dunes, Utah. These are sister experiments to those undertaken in Arizona (Bourke et al, 2016). The experiments were undertaken on an active barchan dune with a 16 m long lee slope (30.3°). Ambient air temperature was 30°C and relative humidity was 25%; sand surface temperatures were 26.5°C. A CO2 ice block (60x205x210 mm) was placed at the dune brink and with a gentle nudge it moved downslope. The dynamics of the block movement were recorded using a pair of high resolution video cameras. Geomorphological observations were noted and topographic change was quantified using a Leica P20 terrestrial laser scanner with a resolution of 0.8 mm at 10 m, and change detection limits less than 3 mm. The block run was repeated a total of 10 times and launched from the same location at the dune brink. The experiment ran for 45 minutes. The block size was reduced to (45 x 190 x 195 mm) by the end of the run series. The resultant geomorphology shows that the separate block runs occupied different tracks leading to a triangular plan form shape with a maximum width of 3.5 m. This is different from the findings in Arizona where a narrower track span was recorded (1.7m) (Bourke et al, 2016). Similar block dynamics were observed at both sites (as blocks moved straight, swiveled and bounced downslope). Distinctive pits with arcuate rims on their downslope edge were formed where blocks bounced on the surface. These pits are at an almost equidistant spacing. Despite a longer slope (16 m as opposed to 8m at Grand Falls), no depositional apron was formed. Levee development was less consistent compared to the Arizona site, but a pronounced unpaired-levee formed towards the base of the lee slope. These data show that sublimating blocks of CO2 ice leave signatures of transport paths and are capable of eroding and transporting sediment. Diniega,S. et al (2013) A new dry hypothesis for the formation of Martian linear gullies. Icarus. Vol. 225, 1, p. 526-537. Bourke, M.C. et al (2016) The geomorphic effect of sublimating CO2 blocks on dune lee slopes at Grand Falls, Arizona. LPSC

Introduction to Department of Defense Research on Burn Pits, Biomarkers, and Health Outcomes Related to Deployment in Iraq and Afghanistan.

PubMed

Mallon, Col Timothy M; Rohrbeck, Maj Patricia; Haines, Maj Kevin M; Jones, Dean P; Utell, Mark; Hopke, Philip K; Phipps, Richard P; Walker, Douglas I; Thatcher, Thomas; Woeller, Collynn F; Baird, Coleen P; Pollard, Harvey B; Dalgard, Clifton L; Gaydos, Joel C

2016-08-01

This paper provides an overview of our study that was designed to assess the health impact of environmental exposures to open pit burning in deployed troops. The rationale for the study and the structure of the research plan was laid out. An overview of each article in the supplement was provided. The cohort of deployed Service members was assessed for airborne exposure, relevant biomarkers, and health outcomes following deployment to Balad, Iraq, and/or Bagram, Afghanistan. Polycyclic aromatic hydrocarbon (PAH) exposures were elevated, and serum biomarkers were statistically different postdeployment. Associations were noted between PAHs and dioxins and microRNAs. Some health outcomes were evident in deployers compared with nondeployers. Future research will examine the associations between demographic variables, smoking status, biomarker levels, and related health outcomes.

Molecular cloning, expression and purification of L-amino acid oxidase from the Malayan pit viper Calloselasma rhodostoma.

PubMed

Kommoju, Phaneeswara Rao; Macheroux, Peter; Ghisla, Sandro

2007-03-01

A cDNA encoding LAAO from the Malayan pit viper (Calloselasma rhodostoma) was cloned into an expression vector of the methylotropic yeast Pichia pastoris. The LAAO open reading frame was inserted after the alpha-MF-signal sequence. Upon induction soluble and active LAAO is produced and exported into the culture supernatant at a concentration of up to 0.4 mg/L. Recombinant LAAO was purified from this by ion exchange and molecular sieve chromatography to yield apparently homogeneous protein in quantities of approximately 0.25 mg/L growth medium. Expressed LAAO exhibits the same electrophoretic mobility as native LAAO (62 kDa) and exhibits approximately the same extent of glycosylation as authentic LAAO from snake venom. Catalytic properties and substrate specificity of recombinant LAAO are similar to those of native enzyme.

Geomorphic characteristics and classification of Duluth-area streams, Minnesota

USGS Publications Warehouse

Fitzpatrick, Faith A.; Peppler, Marie C.; DePhilip, Michele M.; Lee, Kathy E.

2006-01-01

In 2003 and 2004, a geomorphic assessment of streams in 20 watersheds in the Duluth, Minn., area was conducted to identify and summarize geomorphic characteristics, processes, disturbance mechanisms, and potential responses to disturbance. Methods used to assess the streams included watershed characterization, descriptions of segment slopes and valley types, historical aerial photograph interpretation, and rapid field assessments and intensive field surveys of stream reaches. Geomorphic conditions were summarized into a segment-scale classification with 15 categories mainly based on drainage-network position and slope, and, secondarily, based on geologic setting, valley type, and dominant geomorphic processes. Main causes of geomorphic disturbance included historical logging and agriculture, and ongoing urban development, human-caused channel alterations, road and storm sewer drainage, ditching, hiking trails, and gravel pits or quarries. Geomorphic responses to these disturbances are dependent on a combination of drainage-network position, slope, and geologic setting. Geologic setting is related to drainage-network position because the geologic deposits parallel the Lake Superior shoreline. Headwater streams in large watersheds flow over glacial deposits above altitudes of about 1,200 feet (ft). Headwater tributaries and upper main stems have ditch-like channels with gentle slopes and no valleys. Urban development and road drainage cause increased runoff and flood peaks in these segments resulting in channel widening. Below about 1,200 ft, main-stem segments generally are affected by bedrock type and structure and have steep slopes and confined or entrenched valleys. Increases in flood peaks do not cause incision or widening in the bedrock-controlled valleys; instead, the flow and scour areas are expanded. Feeder tributaries to these main stems have steep, confined valleys and may be sources for sediment from urban areas, road runoff, or storm sewer outfalls. Main-stem segments near the glacial deposits/surficial bedrock contact (1,000–1,200 ft) have the most potential for response to disturbance because they tend to have narrow valleys with sandy glacial lakeshore deposits and moderate slopes. Increases in flood peaks (from upstream increases in runoff) increase the potential for landslides and mass wasting from valley sides as well as channel widening.

Rate of progression of total, upper, and lower visual field defects in patients with open-angle glaucoma and high myopia.

PubMed

Yoshino, Takaiko; Fukuchi, Takeo; Togano, Tetsuya; Sakaue, Yuta; Seki, Masaaki; Tanaka, Takayuki; Ueda, Jun

2016-03-01

We evaluated the rate of progression of total, upper, and lower visual field defects in patients with treated primary open-angle glaucoma (POAG) with high myopia (HM). Seventy eyes of 70 POAG patients with HM [≤-8 diopters (D)] were examined. The mean deviation (MD) slope and the upper and lower total deviation (upper TD, lower TD) slopes of the Humphrey Field Analyzer were calculated in patients with high-tension glaucoma (HTG) (>21 mmHg) versus normal-tension glaucoma (NTG) (≤21 mmHg). The mean age of all the patients (29 eyes with HTG and 41 eyes with NTG) was 48.5 ± 9.6 years. The MD slope, and upper and lower TD slopes of the HM group were compared to those of the non-HM group (NHM) (>-8 D) selected from 544 eyes in 325 age-matched POAG patients. In all, 70 eyes with HM and NHM were examined. The mean MD slope was -0.33 ± 0.33 dB/year in the HM, and -0.38 ± 0.49 dB/year in the NHM. There were no statistical differences between the HM and NHM (p = 0.9565). In the comparison of HTG versus NTG patients in both groups, the MD slope, and upper and lower TD slopes were similar. The rate of progression of total, upper, and lower visual field defects was similar among patients with HM and NHM. Although HM is a risk factor for the onset of glaucoma, HM may not be a risk factor for progression of visual field defects as assessed by the progression rate under treatment.

Shallow landsliding, root reinforcement, and the spatial distribution of trees in the Oregon Coast Range

USGS Publications Warehouse

Roering, J.J.; Schmidt, K.M.; Stock, J.D.; Dietrich, W.E.; Montgomery, D.R.

2003-01-01

The influence of root reinforcement on shallow landsliding has been well established through mechanistic and empirical studies, yet few studies have examined how local vegetative patterns influence slope stability. Because root networks spread outward from trees, the species, size, and spacing of trees should influence the spatial distribution of root strength. We documented the distribution and characteristics of trees adjacent to 32 shallow landslides that occurred during 1996 in the Oregon Coast Range. Although broadly classified as a conifer-dominated forest, we observed sparse coniferous and abundant hardwood trees near landslide scars in an industrial forest (Mapleton) that experienced widespread burning in the 19th century. In industrial forests that were burned, selectively harvested, and not replanted (Elliott State Forest), swordfern was ubiquitous near landslides, and we observed similar numbers of live conifer and hardwood trees proximal to landslide scarps. We demonstrate that root strength quantified in landslide scarps and soil pits correlates with a geometry-based index of root network contribution derived from mapping the size, species, condition, and spacing of local trees, indicating that root strength can be predicted by mapping the distribution and characteristics of trees on potentially unstable slopes. In our study sites, landslides tend to occur in areas of reduced root strength, suggesting that to make site-specific predictions of landslide occurrence slope stability analyses must account for the diversity and distribution of vegetation in potentially unstable terrain.

Correction: Alvarado, M., et al. Towards the Development of a Low Cost Airborne Sensing System to Monitor Dust Particles after Blasting at Open-Pit Mine Sites. Sensors 2015, 15, 19667-19687.

PubMed

Alvarado, Miguel; Gonzalez, Felipe; Fletcher, Andrew; Doshi, Ashray

2016-07-05

The author wishes to change Figure 1 and Figure 3 from his paper published in Sensors [1], doi:10.3390/s150819667, website: http://www.mdpi.com/1424-8220/15/8/19667 for Figures 1 and 2 presented in this 'Correction'.[...].

The Study of Soil Protection in the System of the Cultivated Lands of Kemerovo Region

NASA Astrophysics Data System (ADS)

Yakovchenko, M. A.; Konstantinova, O. B.; Kosolapova, A. A.

2015-09-01

The heavy metal content in the surface soils is characterized with their ingress for the given period of time. The sources of heavy metals in the soil are precipitation, seeds, dust, organic and mineral fertilizers, and others. The paper studies the heavy metal content in the soils of the waste dumps of the open-pit coal mines.

USE OF ENVIRONMENTAL ISOTOPES TO DIFFERENTIATE WATER SOURCES AND CONSTRAIN THE WATER BUDGET AT THE SULPHUR BANK MERCURY MINE, CLEAR LAKE, CALIFORNIA

EPA Science Inventory

The Sulphur Bank Mercury Mine (SBMM) is a 65 ha site located on the eastern shore of the Oaks Arm of Clear Lake, Lake County, California. Between 1864 and 1957, SBMM was the site of underground and open pit mining operations for S and Hg, coinciding with past and present hot spr...

Getty: producing oil from diatomite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zublin, L.

1981-10-01

Getty Oil Company has developed unconventional oil production techniques which will yield oil from diatomaceous earth. They propose to mine oil-saturated diatomite using open-pit mining methods. Getty's diatomite deposit in the McKittrick field of California is unique because it is cocoa brown and saturated with crude oil. It is classified also as a tightly packed deposit, and oil cannot be extracted by conventional oil field methods.

Cytogenetic instability in populations with residential proximity to open-pit coal mine in Northern Colombia in relation to PM10 and PM2.5 levels.

PubMed

Espitia-Pérez, Lyda; da Silva, Juliana; Espitia-Pérez, Pedro; Brango, Hugo; Salcedo-Arteaga, Shirley; Hoyos-Giraldo, Luz Stella; de Souza, Claudia T; Dias, Johnny F; Agudelo-Castañeda, Dayana; Valdés Toscano, Ana; Gómez-Pérez, Miguel; Henriques, João A P

2018-02-01

Epidemiological studies indicate that living in proximity to coal mines is correlated with numerous diseases including cancer, and that exposure to PM 10 and PM 2.5 components could be associated with this phenomenon. However, the understanding of the mechanisms by which PM exerts its adverse effects is still incomplete and comes mainly from studies in occupationally exposed populations. The aims of this study were to: (1) evaluate DNA damage in lymphocytes assessing the cytokinesis-block micronucleus cytome assay (CBMN-cyt) parameters; (2) identify aneugenic or clastogenic effects in lymphocytes of exposed populations using CREST immunostaining for micronuclei; (3) evaluate multi-elemental composition of atmospheric particulate matter; and (4) verify relation between the DNA damage and PM 2.5 and PM 10 levels around the mining area. Analysis revealed a significant increase in micronuclei frequency in binucleated (MNBN) and mononucleated (MNMONO) cells of individuals with residential proximity to open-pit coal mines compared to residents from non-mining areas. Correlation analysis demonstrated a highly significant association between PM 2.5 levels, MNBN frequencies and CREST+ micronuclei induction in exposed residents. These results suggest that PM 2.5 fraction generated in coal mining activities may induce whole chromosome loss (aneuploidy) preferentially, although there are also chromosome breaks. Analysis of the chemical composition of PM 2.5 by PIXE demonstrated that Si, S, K and Cr concentrations varied significantly between coal mining and reference areas. Enrichment factor values (EF) showed that S, Cr and Cu were highly enriched in the coal mining areas. Compared to reference area, mining regions had also higher concentrations of extractable organic matter (EOM) related to nonpolar and polar compounds. Our results demonstrate that PM 2.5 fraction represents the most important health risk for residents living near open-pit mines, underscoring the need for incorporation of ambient air standards based on PM 2.5 measures in coal mining areas. Copyright © 2017. Published by Elsevier Inc.

February 2011 sensitive clay landslides at the Çöllolar coalfield, eastern Turkey

NASA Astrophysics Data System (ADS)

Akçar, Naki; Yavuz, Vural; Ivy-Ochs, Susan; Nyffenegger, Franziska; Fredin, Ola; Stolz, Martin; Schlunegger, Fritz

2016-04-01

The Elbistan basin is an intramontane basin, which is located in the eastern Turkey and bound by the Taurus and Antitaurus Mountains. The basin covers an area of 900 km² at a mean elevation of about 1200 m. The basement rock in this field is karstic limestone, which is overlain by a thick layer of clay (>100 m), followed by 20-50 m thick Lignite series that is overlain by the 20-50 m thick Gyttja sequence. These deposits are overlain by Quaternary deposits, comprising the top surfaces of the terraces of the Hurman River, which drains the surface and ground water from the surrounding hills to the northeast towards the center of the Elbistan basin. The Çöllolar open pit mine, situated in the northwestern sector of the Elbistan basin, contains 90 km2 of mineable coal which has been excavated since 2008. In February 2011, two landslides in which 10 workers were killed, occurred in this field. Of the two landslides, the 2nd and largest which covers an area of ca. 2.3 km2,was caused by the collapse of the northeastern wall of the open-pit mine. The failure was made of successive rearward collapses with the debris flowing into the open-pit. In this study, we focus on the geologic factors that led to instability and the trigger of the landslides. To reveal these factors, we employ sedimentological and geotechnical analysis of deposits, with a special emphasis on the Pliocene lacustrine carbonaceous sediments and the sensitivity of the overlying Quaternary clays. First results from the fieldwork and the mineralogical composition and physical properties of the collected samples indicate that the landslide was caused by the liquefaction of one of the layers within the thick sequence of this part of the Elbistan basin based on the flow style of the movement and nature of the failure. In brief, we conclude that massive failures at the Çöllolar coalfield are unique examples of sensitive clay landslides occurred in a subtropical arid region beyond the extent of Quaternary glaciations.

Renewed mining and reclamation: Imapacts on bats and potential mitigation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, P.E.; Berry, R.D.

Historic mining created new roosting habitat for many bat species. Now the same industry has the potential to adversely impact bats. Contemporary mining operations usually occur in historic districts; consequently the old workings are destroyed by open pit operations. Occasionally, underground techniques are employed, resulting in the enlargement or destruction of the original workings. Even during exploratory operations, historic mine openings can be covered as drill roads are bulldozed, or drills can penetrate and collapse underground workings. Nearby blasting associated with mine construction and operation can disrupt roosting bats. Bats can also be disturbed by the entry of mine personnelmore » to collect ore samples or by recreational mine explorers, since the creation of roads often results in easier access. In addition to roost disturbance, other aspects of renewed mining can have adverse impacts on bat populations, and affect even those bats that do not live in mines. Open cyanide ponds, or other water in which toxic chemicals accumulate, can poison bats and other wildlife. The creation of the pits, roads and processing areas often destroys critical foraging habitat, or change drainage patterns. Finally, at the completion of mining, any historic mines still open may be sealed as part of closure and reclamation activities. The net result can be a loss of bats and bat habitat. Conversely, in some contemporary underground operations, future roosting habitat for bats can be fabricated. An experimental approach to the creation of new roosting habitat is to bury culverts or old tires beneath waste rock. Mining companies can mitigate for impacts to bats by surveying to identify bat-roosting habitat, removing bats prior to renewed mining or closure, protecting non-impacted roost sites with gates and fences, researching to identify habitat requirements and creating new artificial roosts.« less

Sodium-dependent phosphate cotransporters and phosphate-induced calcification of vascular smooth muscle cells: Redundant roles for PiT-1 and PiT-2

PubMed Central

Crouthamel, Matthew H.; Lau, Wei Ling; Leaf, Elizabeth M.; Chavkin, Nick; Wallingford, Mary C.; Peterson, Danielle F.; Li, Xianwu; Liu, Yonggang; Chin, Michael T.; Levi, Moshe; Giachelli, Cecilia M.

2014-01-01

Objective Elevated serum phosphate has emerged as a major risk factor for vascular calcification. The sodium-dependent phosphate cotransporter, PiT-1, was previously shown to be required for phosphate-induced osteogenic differentiation and calcification of cultured human VSMCs, but its importance in vascular calcification in vivo, as well as the potential role of its homologue, PiT-2, have not been determined. We investigated the in vivo requirement for PiT-1 in vascular calcification using a mouse model of chronic kidney disease, and the potential compensatory role of PiT-2 using in vitro knockdown and over-expression strategies. Approach and Results Mice with targeted deletion of PiT-1 in VSMCs were generated (PiT-1Δsm). PiT-1 mRNA levels were undetectable whereas PiT-2 mRNA levels were increased 2 fold in the vascular aortic media of PiT-1Δsm compared to PiT-1flox/flox control. When arterial medial calcification was induced in PiT-1Δsm and PiT-1flox/flox by chronic kidney disease followed by dietary phosphate loading, the degree of aortic calcification was not different between genotypes, suggesting compensation by PiT-2. Consistent with this possibility, VSMCs isolated from PiT-1Δsm mice had no PiT-1 mRNA expression, increased PiT-2 mRNA levels, and no difference in sodium-dependent phosphate uptake or phosphate-induced matrix calcification compared to PiT-1flox/flox VSMCs. Knockdown of PiT-2 decreased phosphate uptake and phosphate-induced calcification of PiT-1Δsm VSMCs. Furthermore, over-expression of PiT-2 restored these parameters in human PiT-1-deficient VSMCs. Conclusions PiT-2 can mediate phosphate uptake and calcification of VSMCs in the absence of PiT-1. Mechanistically, PiT-1 and PiT-2 appear to serve redundant roles in phosphate-induced calcification of vascular smooth muscle cells. PMID:23968976

29 CFR Appendix B to Subpart P of... - Sloping and Benching

Code of Federal Regulations, 2013 CFR

2013-07-01

... excavations 20 feet or less in depth made in layered soils shall have a maximum allowable slope for each layer.... Distress means that the soil is in a condition where a cave-in is imminent or is likely to occur. Distress... 24 hours that an excavation is open. (c) Requirements—(1) Soil classification. Soil and rock deposits...

29 CFR Appendix B to Subpart P of... - Sloping and Benching

Code of Federal Regulations, 2012 CFR

2012-07-01

... excavations 20 feet or less in depth made in layered soils shall have a maximum allowable slope for each layer.... Distress means that the soil is in a condition where a cave-in is imminent or is likely to occur. Distress... 24 hours that an excavation is open. (c) Requirements—(1) Soil classification. Soil and rock deposits...

29 CFR Appendix B to Subpart P of... - Sloping and Benching

Code of Federal Regulations, 2014 CFR

2014-07-01

... excavations 20 feet or less in depth made in layered soils shall have a maximum allowable slope for each layer.... Distress means that the soil is in a condition where a cave-in is imminent or is likely to occur. Distress... 24 hours that an excavation is open. (c) Requirements—(1) Soil classification. Soil and rock deposits...

29 CFR Appendix B to Subpart P of... - Sloping and Benching

Code of Federal Regulations, 2011 CFR

2011-07-01

... excavations 20 feet or less in depth made in layered soils shall have a maximum allowable slope for each layer.... Distress means that the soil is in a condition where a cave-in is imminent or is likely to occur. Distress... 24 hours that an excavation is open. (c) Requirements—(1) Soil classification. Soil and rock deposits...

29 CFR Appendix B to Subpart P of... - Sloping and Benching

Code of Federal Regulations, 2010 CFR

2010-07-01

... excavations 20 feet or less in depth made in layered soils shall have a maximum allowable slope for each layer.... Distress means that the soil is in a condition where a cave-in is imminent or is likely to occur. Distress... 24 hours that an excavation is open. (c) Requirements—(1) Soil classification. Soil and rock deposits...

Recurring slope lineae in equatorial regions of Mars

USGS Publications Warehouse

McEwen, Alfred S.; Dundas, Colin M.; Mattson, Sarah S.; Toigo, Anthony D.; Ojha, Lujendra; Wray, James J.; Chojnacki, Matthew; Byrne, Shane; Murchie, Scott L.; Thomas, Nicolas

2014-01-01

The presence of liquid water is a requirement of habitability on a planet. Possible indicators of liquid surface water on Mars include intermittent flow-like features observed on sloping terrains. These recurring slope lineae are narrow, dark markings on steep slopes that appear and incrementally lengthen during warm seasons on low-albedo surfaces. The lineae fade in cooler seasons and recur over multiple Mars years. Recurring slope lineae were initially reported to appear and lengthen at mid-latitudes in the late southern spring and summer and are more common on equator-facing slopes where and when the peak surface temperatures are higher. Here we report extensive activity of recurring slope lineae in equatorial regions of Mars, particularly in the deep canyons of Valles Marineris, from analysis of data acquired by the Mars Reconnaissance Orbiter. We observe the lineae to be most active in seasons when the slopes often face the sun. Expected peak temperatures suggest that activity may not depend solely on temperature. Although the origin of the recurring slope lineae remains an open question, our observations are consistent with intermittent flow of briny water. Such an origin suggests surprisingly abundant liquid water in some near-surface equatorial regions of Mars.

A novel pit pattern identifies the precursor of colorectal cancer derived from sessile serrated adenoma.

PubMed

Kimura, Tomoaki; Yamamoto, Eiichiro; Yamano, Hiro-O; Suzuki, Hiromu; Kamimae, Seiko; Nojima, Masanori; Sawada, Takeshi; Ashida, Masami; Yoshikawa, Kenjiro; Takagi, Ryo; Kato, Ryusuke; Harada, Taku; Suzuki, Ryo; Maruyama, Reo; Kai, Masahiro; Imai, Kohzoh; Shinomura, Yasuhisa; Sugai, Tamotsu; Toyota, Minoru

2012-03-01

Sessile serrated adenomas (SSAs) are known to be precursors of sporadic colorectal cancers (CRCs) with microsatellite instability (MSI), and to be tightly associated with BRAF mutation and the CpG island methylator phenotype (CIMP). Consequently, colonoscopic identification of SSAs has important implications for preventing CRCs, but accurate endoscopic diagnosis is often difficult. Our aim was to clarify which endoscopic findings are specific to SSAs. The morphological, histological and molecular features of 261 specimens from 226 colorectal tumors were analyzed. Surface microstructures were analyzed using magnifying endoscopy. Mutation in BRAF and KRAS was examined by pyrosequencing. Methylation of p16, IGFBP7, MLH1 and MINT1, -2, -12 and -31 was analyzed using bisulfite pyrosequencing. Through retrospective analysis of a training set (n=145), we identified a novel surface microstructure, the Type II open-shape pit pattern (Type II-O), which was specific to SSAs with BRAF mutation and CIMP. Subsequent prospective analysis of an independent validation set (n=116) confirmed that the Type II-O pattern is highly predictive of SSAs (sensitivity, 65.5%; specificity, 97.3%). BRAF mutation and CIMP occurred with significant frequency in Type II-O-positive serrated lesions. Progression of SSAs to more advanced lesions was associated with further accumulation of aberrant DNA methylation and additional morphological changes, including the Type III, IV and V pit patterns. Our results suggest the Type II-O pit pattern is a useful hallmark of the premalignant stage of CRCs with MSI and CIMP, which could serve to improve the efficacy of colonoscopic surveillance.

Assessment of factors limiting algal growth in acidic pit lakes--a case study from Western Australia, Australia.

PubMed

Kumar, R Naresh; McCullough, Clint D; Lund, Mark A; Larranaga, Santiago A

2016-03-01

Open-cut mining operations can form pit lakes on mine closure. These new water bodies typically have low nutrient concentrations and may have acidic and metal-contaminated waters from acid mine drainage (AMD) causing low algal biomass and algal biodiversity. A preliminary study was carried out on an acidic coal pit lake, Lake Kepwari, in Western Australia to determine which factors limited algal biomass. Water quality was monitored to obtain baseline data. pH ranged between 3.7 and 4.1, and solute concentrations were slightly elevated to levels of brackish water. Concentrations of N were highly relative to natural lakes, although concentrations of FRP (<0.01 mg/L) and C (total C 0.7-3.7 and DOC 0.7-3.5 mg/L) were very low, and as a result, algal growth was also extremely low. Microcosm experiment was conducted to test the hypothesis that nutrient enrichment will be able to stimulate algal growth regardless of water quality. Microcosms of Lake Kepwari water were amended with N, P and C nutrients with and without sediment. Nutrient amendments under microcosm conditions could not show any significant phytoplankton growth but was able to promote benthic algal growth. P amendments without sediment showed a statistically higher mean algal biomass concentration than controls or microcosms amended with phosphorus but with sediment did. Results indicated that algal biomass in acidic pit lake (Lake Kepwari) may be limited primarily by low nutrient concentrations (especially phosphorus) and not by low pH or elevated metal concentrations. Furthermore, sediment processes may also reduce the nutrient availability.

Metagenomic investigation of the microbial diversity in a chrysotile asbestos mine pit pond, Lowell, Vermont, USA.

PubMed

Driscoll, Heather E; Vincent, James J; English, Erika L; Dolci, Elizabeth D

2016-12-01

Here we report on a metagenomics investigation of the microbial diversity in a serpentine-hosted aquatic habitat created by chrysotile asbestos mining activity at the Vermont Asbestos Group (VAG) Mine in northern Vermont, USA. The now-abandoned VAG Mine on Belvidere Mountain in the towns of Eden and Lowell includes three open-pit quarries, a flooded pit, mill buildings, roads, and > 26 million metric tons of eroding mine waste that contribute alkaline mine drainage to the surrounding watershed. Metagenomes and water chemistry originated from aquatic samples taken at three depths (0.5 m, 3.5 m, and 25 m) along the water column at three distinct, offshore sites within the mine's flooded pit (near 44°46'00.7673″, - 72°31'36.2699″; UTM NAD 83 Zone 18 T 0695720 E, 4960030 N). Whole metagenome shotgun Illumina paired-end sequences were quality trimmed and analyzed based on a translated nucleotide search of NCBI-NR protein database and lowest common ancestor taxonomic assignments. Our results show strata within the pit pond water column can be distinguished by taxonomic composition and distribution, pH, temperature, conductivity, light intensity, and concentrations of dissolved oxygen. At the phylum level, metagenomes from 0.5 m and 3.5 m contained a similar distribution of taxa and were dominated by Actinobacteria (46% and 53% of reads, respectively), Proteobacteria (45% and 38%, respectively), and Bacteroidetes (7% in both). The metagenomes from 25 m showed a greater diversity of phyla and a different distribution of reads than the two upper strata: Proteobacteria (60%), Actinobacteria (18%), Planctomycetes, (10%), Bacteroidetes (5%) and Cyanobacteria (2.5%), Armatimonadetes (< 1%), Verrucomicrobia (< 1%), Firmicutes (< 1%), and Nitrospirae (< 1%). Raw metagenome sequence data from each sample reside in NCBI's Short Read Archive (SRA ID: SRP056095) and are accessible through NCBI BioProject PRJNA277916.

Nobody’s perfect: can irregularities in pit structure influence vulnerability to cavitation?

PubMed Central

Plavcová, Lenka; Jansen, Steven; Klepsch, Matthias; Hacke, Uwe G.

2013-01-01

Recent studies have suggested that species-specific pit properties such as pit membrane thickness, pit membrane porosity, torus-to-aperture diameter ratio and pit chamber depth influence xylem vulnerability to cavitation. Despite the indisputable importance of using mean pit characteristics, considerable variability in pit structure within a single species or even within a single pit field should be acknowledged. According to the rare pit hypothesis, a single pit that is more air-permeable than many neighboring pits is sufficient to allow air-seeding. Therefore, any irregularities or morphological abnormalities in pit structure allowing air-seeding should be associated with increased vulnerability to cavitation. Considering the currently proposed models of air-seeding, pit features such as rare, large pores in the pit membrane, torus extensions, and plasmodesmatal pores in a torus can represent potential glitches. These aberrations in pit structure could either result from inherent developmental flaws, or from damage caused to the pit membrane by chemical and physical agents. This suggests the existence of interesting feedbacks between abiotic and biotic stresses in xylem physiology. PMID:24273549

Quantifying the variability of snowpack properties and processes in a small-forested catchment representative of the boreal zone

NASA Astrophysics Data System (ADS)

Parajuli, A.; Nadeau, D.; Anctil, F.; Parent, A. C.; Bouchard, B.; Jutras, S.

2017-12-01

In snow-fed catchments, it is crucial to monitor and to model snow water equivalent (SWE), particularly to simulate the melt water runoff. However, the distribution of SWE can be highly heterogeneous, particularly within forested environments, mainly because of the large variability in snow depths. Although the boreal forest is the dominant land cover in Canada and in a few other northern countries, very few studies have quantified the spatiotemporal variability of snow depths and snowpack dynamics within this biome. The objective of this paper is to fill this research gap, through a detailed monitoring of snowpack dynamics at nine locations within a 3.57 km2 experimental forested catchment in southern Quebec, Canada (47°N, 71°W). The catchment receives 6 m of snow annually on average and is predominantly covered with balsam fir stand with some traces of spruce and white birch. In this study, we used a network of nine so-called `snow profiling stations', providing automated snow depth and snowpack temperature profile measurements, as well as three contrasting sites (juvenile, sapling and open areas) where sublimation rates were directly measured with flux towers. In addition, a total of 1401 manual snow samples supported by 20 snow pits measurements were collected throughout the winter of 2017. This paper presents some preliminary analyses of this unique dataset. Simple empirical relations relying SWE with easy-to-determine proxies, such as snow depths and snow temperature, are tested. Then, binary regression trees and multiple regression analysis are used to model SWE using topographic characteristics (slope, aspect, elevation), forest features (tree height, tree diameter, forest density and gap fraction) and meteorological forcing (solar radiation, wind speed, snow-pack temperature profile, air temperature, humidity). An analysis of sublimation rates comparing open area, saplings and juvenile forest is also presented in this paper.

The microbial quality of drinking water in Manonyane community: Maseru District (Lesotho).

PubMed

Gwimbi, P

2011-09-01

Provision of good quality household drinking water is an important means of improving public health in rural communities especially in Africa; and is the rationale behind protecting drinking water sources and promoting healthy practices at and around such sources. To examine the microbial content of drinking water from different types of drinking water sources in Manonyane community of Lesotho. The community's hygienic practices around the water sources are also assessed to establish their contribution to water quality. Water samples from thirty five water sources comprising 22 springs, 6 open wells, 6 boreholes and 1 open reservoir were assessed. Total coliform and Escherichia coli bacteria were analyzed in water sampled. Results of the tests were compared with the prescribed World Health Organization desirable limits. A household survey and field observations were conducted to assess the hygienic conditions and practices at and around the water sources. Total coliform were detected in 97% and Escherichia coli in 71% of the water samples. The concentration levels of Total coliform and Escherichia coli were above the permissible limits of the World Health Organization drinking water quality guidelines in each case. Protected sources had significantly less number of colony forming units (cfu) per 100 ml of water sample compared to unprotected sources (56% versus 95%, p < 0.05). Similarly in terms of Escherichia coli, protected sources had less counts (7% versus 40%, p < 0.05) compared with those from unprotected sources. Hygiene conditions and practices that seemed to potentially contribute increased total coliform and Escherichia coli counts included non protection of water sources from livestock faeces, laundry practices, and water sources being down slope of pit latrines in some cases. These findings suggest source water protection and good hygiene practices can improve the quality of household drinking water where disinfection is not available. The results also suggest important lines of inquiry and provide support and input for environmental and public health programmes, particularly those related to water and sanitation.

MetaSensing's FastGBSAR: ground based radar for deformation monitoring

NASA Astrophysics Data System (ADS)

Rödelsperger, Sabine; Meta, Adriano

2014-10-01

The continuous monitoring of ground deformation and structural movement has become an important task in engineering. MetaSensing introduces a novel sensor system, the Fast Ground Based Synthetic Aperture Radar (FastGBSAR), based on innovative technologies that have already been successfully applied to airborne SAR applications. The FastGBSAR allows the remote sensing of deformations of a slope or infrastructure from up to a distance of 4 km. The FastGBSAR can be setup in two different configurations: in Real Aperture Radar (RAR) mode it is capable of accurately measuring displacements along a linear range profile, ideal for monitoring vibrations of structures like bridges and towers (displacement accuracy up to 0.01 mm). Modal parameters can be determined within half an hour. Alternatively, in Synthetic Aperture Radar (SAR) configuration it produces two-dimensional displacement images with an acquisition time of less than 5 seconds, ideal for monitoring areal structures like dams, landslides and open pit mines (displacement accuracy up to 0.1 mm). The MetaSensing FastGBSAR is the first ground based SAR instrument on the market able to produce two-dimensional deformation maps with this high acquisition rate. By that, deformation time series with a high temporal and spatial resolution can be generated, giving detailed information useful to determine the deformation mechanisms involved and eventually to predict an incoming failure. The system is fully portable and can be quickly installed on bedrock or a basement. The data acquisition and processing can be fully automated leading to a low effort in instrument operation and maintenance. Due to the short acquisition time of FastGBSAR, the coherence between two acquisitions is very high and the phase unwrapping is simplified enormously. This yields a high density of resolution cells with good quality and high reliability of the acquired deformations. The deformation maps can directly be used as input into an Early Warning system, to determine the state and danger of a slope or structure. In this paper, the technical principles of the instrument are described and case studies of different monitoring tasks are presented.

Ruminal pH predictions for beef cattle: Comparative evaluation of current models.

PubMed

Sarhan, M A; Beauchemin, K A

2015-04-01

This study evaluated 8 empirical models for their ability to accurately predict mean ruminal pH in beef cattle fed a wide range of diets. Models tested that use physically effective fiber (peNDF) as a dependent variable were Pitt et al. (1996, PIT), Mertens (1997, MER), Fox et al. (2004, FOX), Zebeli et al. (2006, ZB6), and Zebeli et al. (2008, ZB8), and those that use rumen VFA were Tamminga and Van Vuuren (1988, TAM), Lescoat and Sauvant (1995, LES), and Allen (1997, ALL). A data set of 65 published papers (231 treatment means) for beef cattle was assembled that included information on animal characteristics, diet composition, and ruminal fermentation and mean pH. Model evaluations were based on mean square prediction error (MSPE), concordance correlation coefficient (CCC), and regression analysis. The prediction potential of the models varied with low root MSPE (RMSPE) values of 4.94% and 5.37% for PIT and FOX, RMSPE values of 9.66% and 12.55% for ZB6 and MER, and intermediate RMSPE values of 5.66% to 6.26% for the other models. For PIT and FOX, with the lowest RMSPE, approximately 96% of MSPE was due to random error, whereas for ZB6 and MER, with the highest RMSPE, 15.85% and 23.42% of MSPE, respectively, was due to linear bias, and 37.19% and 60.12% of the error, respectively, was due to deviation of the regression slope from unity. The CCC was greatest for PIT (0.67) and FOX (0.62), followed by 0.60 for LES and TAM, 0.52 for ZB8, 0.39 for MER, 0.34 for ALL, and 0.22 for ZB6. Residuals plotted against model-predicted values showed linear bias (P < 0.001) for all models except PIT (P = 0.976) and FOX (P = 0.054) and mean bias (P < 0.001) except for FOX (P = 0.293), LES (P = 0.215), and TAM (P = 0.119). The study showed that the empirical models PIT and FOX, based on peNDF, and LES and TAM, based on VFA, are preferred over the others for prediction of mean ruminal pH in beef cattle fed a wide range of diets. Several animal (BW and intake), diet (forage and OM contents), and ruminal (ammonia and acetate concentrations) factors were (P < 0.001) related to the residuals for each model. We conclude that the accuracy of prediction of mean ruminal pH was relatively low for all extant models. Consideration of factors in addition to peNDF and total VFA, as well as the use of data from studies with continuous measurement of ruminal pH over 24 h or more, would be useful in the development of improved models for predicting ruminal pH in beef cattle.

Application of Three Existing Stope Boundary Optimisation Methods in an Operating Underground Mine

NASA Astrophysics Data System (ADS)

Erdogan, Gamze; Yavuz, Mahmut

2017-12-01

The underground mine planning and design optimisation process have received little attention because of complexity and variability of problems in underground mines. Although a number of optimisation studies and software tools are available and some of them, in special, have been implemented effectively to determine the ultimate-pit limits in an open pit mine, there is still a lack of studies for optimisation of ultimate stope boundaries in underground mines. The proposed approaches for this purpose aim at maximizing the economic profit by selecting the best possible layout under operational, technical and physical constraints. In this paper, the existing three heuristic techniques including Floating Stope Algorithm, Maximum Value Algorithm and Mineable Shape Optimiser (MSO) are examined for optimisation of stope layout in a case study. Each technique is assessed in terms of applicability, algorithm capabilities and limitations considering the underground mine planning challenges. Finally, the results are evaluated and compared.

Credit PSR. This view depicts the southwest and southeast facades ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Credit PSR. This view depicts the southwest and southeast facades as seen when looking west southwest (260°). The building consists of a small lean-to control room and a two-story space containing a large casting pit. The pit, which can be seen through the open doors, was never used due to changes in JPL's mission. This steel frame structure is clad in "Transite" board (a fire resistant pressed asbestos composite material) and interior lighting consists of individual explosion proof lamps mounted around the walls. The building was rated for 10,000 pounds (4,545 Kg) of class 2 materials and four personnel. It was licensed 5 June 1989 for ammonium perchlorate (NH4C10,), ammonium nitrate (NH4NO3), and sodium nitrate (NaNO3) - Jet Propulsion Laboratory Edwards Facility, Casting & Curing Building, Edwards Air Force Base, Boron, Kern County, CA

Application of Universal Thermal Climate Index (UTCI) for assessment of occupational heat stress in open-pit mines.

PubMed

Nassiri, Parvin; Monazzam, Mohammad Reza; Golbabaei, Farideh; Dehghan, Somayeh Farhang; Rafieepour, Athena; Mortezapour, Ali Reza; Asghari, Mehdi

2017-10-07

The purpose of this article is to examine the applicability of Universal Thermal Climate Index (UTCI) index as an innovative index for evaluating of occupational heat stress in outdoor environments. 175 workers of 12 open-pit mines in Tehran, Iran were selected for this research study. First, the environmental variables such as air temperature, wet-bulb temperature, globe temperature, relative humidity and air flow rate were measured; then UTCI, wet-bulb globe temperature (WBGT) and heat stress index (HSI) indices were calculated. Simultaneously, physiological parameters including heart rate, oral temperature, tympanic temperature and skin temperature of workers were measured. UTCI and WBGT are positively significantly correlated with all environmental parameters (p<0.03), except for air velocity (r<-0.39; p>0.05). Moreover, a strong significant relationship was found between UTCI and WBGT (r=0.95; p<0.001). The significant positive correlations exist between physiological parameters including oral temperature, tympanic and skin temperatures and heart rate and both the UTCI and WBGT indices (p<0.029). The highest correlation coefficient has been found between the UTCI and physiological parameters. Due to the low humidity and air velocity (~<1 m/s) in understudied mines, UTCI index appears to be appropriate to assess the occupational heat stress in these outdoor workplaces.

Proteomics technique opens new frontiers in mobilome research

PubMed Central

Davidson, Andrew D.; Matthews, David A.

2017-01-01

ABSTRACT A large proportion of the genome of most eukaryotic organisms consists of highly repetitive mobile genetic elements. The sum of these elements is called the “mobilome,” which in eukaryotes is made up mostly of transposons. Transposable elements contribute to disease, evolution, and normal physiology by mediating genetic rearrangement, and through the “domestication” of transposon proteins for cellular functions. Although ‘omics studies of mobilome genomes and transcriptomes are common, technical challenges have hampered high-throughput global proteomics analyses of transposons. In a recent paper, we overcame these technical hurdles using a technique called “proteomics informed by transcriptomics” (PIT), and thus published the first unbiased global mobilome-derived proteome for any organism (using cell lines derived from the mosquito Aedes aegypti). In this commentary, we describe our methods in more detail, and summarise our major findings. We also use new genome sequencing data to show that, in many cases, the specific genomic element expressing a given protein can be identified using PIT. This proteomic technique therefore represents an important technological advance that will open new avenues of research into the role that proteins derived from transposons and other repetitive and sequence diverse genetic elements, such as endogenous retroviruses, play in health and disease. PMID:28932623

Environmental Improvement Of Opencast Mining

NASA Astrophysics Data System (ADS)

Prokopenko, S.; Sushko, A.; Filatov, Yu; Kislyakov, M.; Kislyakov, I.

2017-01-01

Existing classifications of waste dumps in the quarries are given and their phenomenological nature is clarified. The need to identify the essence of the term "dump" is shown as well as the idea of "dump" as an artificial formation with everted and mixed rocks distanced from the quarry. Essential classification of man-made rock formations in quarries is developed. Characteristic of variations of man-made waste formations in quarries is developed. To reduce harmful effects of open-pit mining, dumps should be substituted with strat-lays - man-made structures relevant to natural stratification of litho-substances. Construction of strat-lays would improve ecological and technological culture of open cast mining.

Developing Mathematical Provisions for Assessment of Liquid Hydrocarbon Emissions in Emergency Situations

NASA Astrophysics Data System (ADS)

Zemenkova, M. Yu; Zemenkov, Yu D.; Shantarin, V. D.

2016-10-01

The paper reviews the development of methodology for calculation of hydrocarbon emissions during seepage and evaporation to monitor the reliability and safety of hydrocarbon storage and transportation. The authors have analyzed existing methods, models and techniques for assessing the amount of evaporated oil. Models used for predicting the material balance of multicomponent two-phase systems have been discussed. The results of modeling the open-air hydrocarbon evaporation from an oil spill are provided and exemplified by an emergency pit. Dependences and systems of differential equations have been obtained to assess parameters of mass transfer from the open surface of a liquid multicomponent mixture.

A comparative study on seismic response of two unstable rock slopes within same tectonic setting but different activity level

NASA Astrophysics Data System (ADS)

Kleinbrod, Ulrike; Burjánek, Jan; Hugentobler, Marc; Amann, Florian; Fäh, Donat

2017-12-01

In this study, the seismic response of two slope instabilities is investigated with seismic ambient vibration analysis. Two similar sites have been chosen: an active deep-seated slope instability at Cuolm da Vi and the geologically, structurally and morphologically similar, but presently not moving Alp Caschlè slope. Both slopes are located at the upper Vorderrheintal (Canton Graubünden, Switzerland). Ambient vibrations were recorded on both slopes and processed by time-frequency polarization and site-to-reference spectral ratio analysis. The data interpretation shows correlations between degree of disintegration of the rock mass and amplification. However, the ambient vibration analysis conducted, does not allow retrieving a resonance frequency that can be related to the total depth of the instability of Cuolm da Vi. Even though seismic waves can be hardly traced in rock instabilities containing open fractures, it was possible to retrieve a dispersion curve and a velocity profile from the array measurement at Cuolm da Vi due to the high level of disintegration of the rock material down to a depth of about 100 m. From the similar amplification pattern at the two sites, we expect a similar structure, indicating that also the slope at Alp Caschlè was active in the past in a similar manner as Cuolm da Vi. However, a smoother increase of amplification with frequency is observed at Alp Caschlè, which might indicate less disintegration of the rock mass in a particular depth range at this site, when comparing to Cuolm da Vi where a high level of disintegration is observed, resulting from the high activity at the slope. From the frequency-dependent amplification, we can distinguish between two parts within both instabilities, one part showing decreasing disintegration of the rock mass with increasing depth, for the other parts less-fractured blocks are observed. Since the block structures are found in the lower part of the instabilities, they might contribute to the stability of the slopes. Using the velocity profiles, it was possible to estimate the depth of the two largest open fractures (i.e. tension cracks) at Cuolm da Vi.

Slope stability radar for monitoring mine walls

NASA Astrophysics Data System (ADS)

Reeves, Bryan; Noon, David A.; Stickley, Glen F.; Longstaff, Dennis

2001-11-01

Determining slope stability in a mining operation is an important task. This is especially true when the mine workings are close to a potentially unstable slope. A common technique to determine slope stability is to monitor the small precursory movements, which occur prior to collapse. The slope stability radar has been developed to remotely scan a rock slope to continuously monitor the spatial deformation of the face. Using differential radar interferometry, the system can detect deformation movements of a rough wall with sub-millimeter accuracy, and with high spatial and temporal resolution. The effects of atmospheric variations and spurious signals can be reduced via signal processing means. The advantage of radar over other monitoring techniques is that it provides full area coverage without the need for mounted reflectors or equipment on the wall. In addition, the radar waves adequately penetrate through rain, dust and smoke to give reliable measurements, twenty-four hours a day. The system has been trialed at three open-cut coal mines in Australia, which demonstrated the potential for real-time monitoring of slope stability during active mining operations.

Experimental Study on Shear Strength of Unsaturated Loess Based on Different Water Content in Xining Area

NASA Astrophysics Data System (ADS)

guibo, Bao; hui, Li; yu, Zhang; wuyu, Zhang; ningshan, Jiang

2018-05-01

Today, the study of shear strength of unsaturated soils has become a hot topic in unsaturated soil mechanics research. There are any number of factors affecting the strength of unsaturated soils. Among these factors, the moisture content has the most significant effect on the shear strength. In this paper, unsaturated loess in Xining is taken as the research object, the triaxial test without consolidation and undrain is used to determine the shear strength and its parameters under the condition of different water content, then the relationship between unsaturated loess’ water content and shear strength parameters is explored, and curve fitting is performed. The relevantily approximate mathematics formulas are obtained. The study can provide strength parameter for slope stability and foundation pit support in Xining.

20. RW Meyer Sugar Mill: 18761889. Boiling House Interior, 1878. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

20. RW Meyer Sugar Mill: 1876-1889. Boiling House Interior, 1878. View: Remains of south wall. The molasses storage pits are below the floor in the foreground. The remaining piece of floor indicates the form of the entire floor. The sorghum pan and boiling range flue slope from left to right (east to west) and permitted batches of cane juice to flow through the boiling pan by gravity. The beams, joists, truss work are built of northwest pine. The sides and floor boards are built of redwood. The boiling range flue is built of fire-brick, masonry, and portland cement. The corrugated roof appears to be a later addition, not contemporary with mill operation. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

Nucleation sites of Ge nanoislands grown on pit-patterned Si substrate prepared by electron-beam lithography

NASA Astrophysics Data System (ADS)

Smagina, Zh. V.; Zinovyev, V. A.; Rudin, S. A.; Novikov, P. L.; Rodyakina, E. E.; Dvurechenskii, A. V.

2018-04-01

Regular pit-patterned Si(001) substrates were prepared by electron-beam lithography followed by plasma chemical etching. The geometry of the pits was controlled by varying the etching conditions and the electron-beam exposure duration. It was shown that the location of three-dimensional (3D) Ge nanoislands subsequently grown on the pit-patterned Si substrates depends on the shape of the pit bottom. In the case of pits having a sharp bottom, 3D Ge islands nucleate inside the pits. For pits with a wide flat bottom, the 3D Ge island nucleation takes place at the pit periphery. This effect is attributed to the strain relaxation depending not only on the initial pit shape, but also on its evolution during the Ge wetting layer deposition. It was shown by Monte Carlo simulations that in the case of a pit with a pointed bottom, the relaxation is most effective inside the pit, while for a pit with a wide bottom, the most relaxed area migrates during Ge deposition from the pit bottom to its edges, where 3D Ge islands nucleate.

Arizona Copper

NASA Image and Video Library

2014-03-19

Arizona produces 60% of the total copper mined in the US; in 2007, 750,000 tons of copper came out of the state. One of the major mining districts is located about 30 km south of Tucson. Starting around 1950, open-pit mining replaced underground operations, and the ASARCO-Mission complex, Twin Buttes, and Sierrita mines became large open pit operations. Accompanying copper mineralization, silver, molybdenum, zinc, lead and gold are extracted. In addition to the pits themselves, enormous leach ponds and tailings piles surround the pits. The image was acquired May 31, 2012, covers an area of 22 by 28 km, and is located at 31.9 degrees north, 111 degrees west. With its 14 spectral bands from the visible to the thermal infrared wavelength region and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched Dec. 18, 1999, on Terra. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate, Washington, D.C. More information about ASTER is available at asterweb.jpl.nasa.gov/ Credit: NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Martian Central Pit Craters

NASA Technical Reports Server (NTRS)

Hillman, E.; Barlow, N. G.

2005-01-01

Impact craters containing central pits are rare on the terrestrial planets but common on icy bodies. Mars is the exception among the terrestrial planets, where central pits are seen on crater floors ( floor pits ) as well as on top of central peaks ( summit pits ). Wood et al. [1] proposed that degassing of subsurface volatiles during crater formation produced central pits. Croft [2] argued instead that central pits might form during the impact of volatile-rich comets. Although central pits are seen in impact craters on icy moons such as Ganymede, they do show some significant differences from their martian counterparts: (a) only floor pits are seen on Ganymede, and (b) central pits begin to occur at crater diameters where the peak ring interior morphology begins to appear in terrestrial planet craters [3]. A study of craters containing central pits was conducted by Barlow and Bradley [4] using Viking imagery. They found that 28% of craters displaying an interior morphology on Mars contain central pits. Diameters of craters containing central pits ranged from 16 to 64 km. Barlow and Bradley noted that summit pit craters tended to be smaller than craters containing floor pits. They also noted a correlation of central pit craters with the proposed rings of large impact basins. They argued that basin ring formation fractured the martian crust and allowed subsurface volatiles to concentrate in these locations. They favored the model that degassing of the substrate during crater formation was responsible for central pit formation due to the preferential location of central pit craters along these basin rings.

Morphology and mechanism of the very large dunes in the tidal reach of the Yangtze River, China

NASA Astrophysics Data System (ADS)

Shuwei, Zheng; Heqin, Cheng; Shuaihu, Wu; Shengyu, Shi; Wei, Xu; Quanping, Zhou; Yuehua, Jiang

2017-05-01

High-resolution multibeam data was used to interpret the surface morphology of very large dunes (VLDs) in the tidal reach of the Yangtze River, China. These VLDs can be divided into three categories according to their surface morphological characteristics. (1) VLDs-I: those with a smooth surface and cross-section; (2) VLDs-II: those accompanied by secondary dunes; (3) VLDs-III: those accompanied by secondary dunes and numerous elliptical pits. Parameters and spatial distribution of VLDs, and bed surface sediment were analyzed in the laboratory. Overall, channel morphology is an important factor affecting the development of VLDs, and channels with narrow and straight and certain water surface slope are facilitating the development of VLDs by constraining stream power. Meanwhile, distribution density of VLDs depicts a decreasing trend from Chizhou towards the estuary, are probably influenced by channel morphology and width. Associated pits in VLDs-III change the 3D dune morphology by distributing in secondary dunes as beads. The Three Gorges Dam project (TGP) leads to the bed surface sediment activity frequently and leads to the riverbed surface sediment coarsens, which promotes the further development of dunes. Moreover, other human activities, such as river regulation project, sand mining and Deep Water Channel Regulation Project have changed the regional river boundary conditions and hydrodynamic conditions are influential on the development of VLDs.

The analysis of the Tectonics - SSS - Seismicity System in the 3D-model of the Rasvumchorr Mine - Central Open Pit Natural and Technical System (Khibiny)

NASA Astrophysics Data System (ADS)

Zhirov, Dmitry; Klimov, Sergey; Zhirova, Anzhela; Panteleev, Alexey; Rybin, Vadim

2017-04-01

Main hazardous factors during the operation of deposits represent tectonics (structural dislocation), strain and stress state (SSS), and seismicity. The cause and effect relationships in the Fault Tectonics - SSS - Seismicity system were analyzed using a 3D geological and structural Rasvumchorr Mine - Central Open Pit model. This natural and technical system (NTS) has resulted from the development of the world-class apatite-nepheline deposits the Apatite Circus and Rasvumchorr Plateau. The 3D model integrates various spatial data on the earth's surface topography before and after mining, geometry of mines and dumps, SSS measurements and rock pressure, seismicity, fault tectonics and etc. The analysis of the 3D model has clearly demonstrated the localization of three main seismic emanation zones in the areas of maximum anthropogenic variation of the initial rock state, and namely: ore pass zone under the Southern edge of the Central open pit, collapse and joining zone of the Rasvumchorr Mine and NW edge of the open pit, and zone under the Apatite Circus plate - collapse console. And, on the contrary, in the area of a large dump under the underground mine, a perennial seismic minimum zone was identified. The relation of the seismicity and fault tectonics was revealed only in three local sectors near come certain echelon fissures of the Main Fault(MF). No confinement of increased seismicity areas to the MF and other numerous echelon fissures is observed. The same picture occurs towards manifestations of rock pressure. Only an insignificant part of echelon fissures (including low rank of hierarchy) controls hazardous manifestations of rock pressure (dumps, strong deformations of the mine contour, etc.). It is shown that the anthropogenic factor (explosive, geometry and arrangement of mined spaces and collapse console), as well as the time factor significantly change orientation and structure (contrast and heterogeneity) of the stress fields. Time series of natural geophysical field fluctuations were additionally analyzed in order to find relationships with the seismicity. A sustainable regular relationship between the seismicity and solar and lunar tides has been observed; though, medium (classes 3 to 6) and high (class 7 and above) energy values of the events reveal various symmetry towards the Lunar cycle phases. The relationship of seismicity with other geophysical fields, e.g., geomagnetic disturbances, is defined as weak to very weak. The anthropogenic (man-induced) factor mostly influences the seismicity in the NTS rock masses. A law for shifting of maximum seismicity zones following the advance of the mining front has been found. The 3D model integrates various spatial data on the earth's surface topography before and after mining, geometry of mines and dumps, SSS measurements, and rock pressure, seismicity, fault tectonics, and other manifestations. The study is made within R&D topic No. 0231-2015-0013. The collection, processing, and analysis of data for natural stress fields became possible due to the support from RSF grant 14-17-00751.

Modified Stability Charts for Rock Slopes Based on the Hoek-Brown Failure Criterion / Zmodyfikowane Diagramy Stabilności Skalistych Zboczy Otrzymane W Oparciu O Warunek Wytrzymałości Hoeka-Browna

NASA Astrophysics Data System (ADS)

Nekouei, Mahdi; Ahangari, Kaveh

2013-09-01

Only an article rendered by Lia et al. in 2008 has represented charts based on Hoek-Brown criterion for rock slopes, however, these charts are not precise and efficient. Because of this problem, a modification is suggested for the mentioned charts in this study. The new charts are calculated according to four methods. Among the methods, one relates to finite element method using Phase2 software. The other three methods are Janbu, Bishop and Fellenius that belong to limit equilibrium method by using Slide software. For each slope angle, the method having high correlation coefficient is selected as the best one. Then, final charts are rendered according to the selected method and its specific equations. Among forty equations, twenty-five ones or 62.5% relate to numerical method and Phase2 software, six ones or 15% belong to Fellenius limit equilibrium, six ones or 15% relate to Bishop limit equilibrium, and three ones or 7.5% belong to Janbu limit equilibrium. In order to validate new charts, slope stability analysis is carried out for several sections of Chadormalu iron ore open pit mine, Iran. The error percentage of new charts in limit equilibrium method using Slide software and in Bishop method for slopes of Chadormalu iron ore mine are rendered and compared. The charts on a basis of Hoek-Brown failure criterion for rock slopes show less than ±4% error. This indicates that these charts are appropriate tools and their safety factor is optimal for rock slopes. Diagramy stabilności skalistych zboczy otrzymane w oparciu o warunek wytrzymałości Hoeka- Browna znaleźć można jedynie w pracy Lia et al. (2008), choć wykresy te nie są absolutnie dokładne i jasne. Dlatego też w niniejszym artykule zaproponowano pewną modyfikację diagramów. Nowe wykresu sporządzono w oparciu o cztery metody. Jedna z metod opiera się na metodzie elementów skończonych i wykorzystuje oprogramowanie Phase2. Pozostałe trzy podejścia to metody Janbu, Bishopa i Felleniusa bazujące na metodzie równowagi granicznej i wykorzystujące oprogramowanie Slide. Dla każdego kąta nachylenia zbocza, wybierana jest metoda najskuteczniejsza, czyli taka która zapewnia wysoki współczynnik korelacji. Następnie sporządzane są wykresy końcowe, zgodnie w wybraną metodą i z wykorzystaniem odpowiednich równań. Spośród 40 równań, 25 z nich (czyli 62.5%) odnosi się do metod numerycznych (oprogramowanie Phase2), sześć równań (15%) należy do metody równowagi granicznej Felleniusa, kolejne sześć równań (15%) ma odniesienie do metody równowagi granicznej Bishopa, zaś trzy równania (7.5%) należą do metody równowagi granicznej Janbu. W celu walidacji nowych diagramów, przeprowadzono analizę stabilności zboczy na kilku wybranych odcinkach kopalni odkrywkowej rud żelaza w Chadormalu, Iran. Następnie porównano otrzymane procentowe wskaźniki niedokładności nowych diagramów uzyskanych za pomocą metody równowagi granicznej i przy wykorzystaniu oprogramowania Slide oraz w metodzie Bishopa obliczone dla zboczy kopalni rud żelaza Chadormalu. Diagramy uzyskane na podstawie warunku stabilności Hoeka-Browna dla zboczy w kopalni dają wskaźnik błędu na poziomie ±4%. Oznacza to, że diagramy takie są odpowiednimi narzędziami a współczynniki bezpieczeństwa dla zboczy skalnych wyliczone na ich podstawie uznać można za optymalne.

Mapping of the minimal inorganic phosphate transporting unit of human PiT2 suggests a structure universal to PiT-related proteins from all kingdoms of life

PubMed Central

2011-01-01

Background The inorganic (Pi) phosphate transporter (PiT) family comprises known and putative Na+- or H+-dependent Pi-transporting proteins with representatives from all kingdoms. The mammalian members are placed in the outer cell membranes and suggested to supply cells with Pi to maintain house-keeping functions. Alignment of protein sequences representing PiT family members from all kingdoms reveals the presence of conserved amino acids and that bacterial phosphate permeases and putative phosphate permeases from archaea lack substantial parts of the protein sequence when compared to the mammalian PiT family members. Besides being Na+-dependent Pi (NaPi) transporters, the mammalian PiT paralogs, PiT1 and PiT2, also are receptors for gamma-retroviruses. We have here exploited the dual-function of PiT1 and PiT2 to study the structure-function relationship of PiT proteins. Results We show that the human PiT2 histidine, H502, and the human PiT1 glutamate, E70, - both conserved in eukaryotic PiT family members - are critical for Pi transport function. Noticeably, human PiT2 H502 is located in the C-terminal PiT family signature sequence, and human PiT1 E70 is located in ProDom domains characteristic for all PiT family members. A human PiT2 truncation mutant, which consists of the predicted 10 transmembrane (TM) domain backbone without a large intracellular domain (human PiT2ΔR254-V483), was found to be a fully functional Pi transporter. Further truncation of the human PiT2 protein by additional removal of two predicted TM domains together with the large intracellular domain created a mutant that resembles a bacterial phosphate permease and an archaeal putative phosphate permease. This human PiT2 truncation mutant (human PiT2ΔL183-V483) did also support Pi transport albeit at very low levels. Conclusions The results suggest that the overall structure of the Pi-transporting unit of the PiT family proteins has remained unchanged during evolution. Moreover, in combination, our studies of the gene structure of the human PiT1 and PiT2 genes (SLC20A1 and SLC20A2, respectively) and alignment of protein sequences of PiT family members from all kingdoms, along with the studies of the dual functions of the human PiT paralogs show that these proteins are excellent as models for studying the evolution of a protein's structure-function relationship. PMID:21586110

Mapping of the minimal inorganic phosphate transporting unit of human PiT2 suggests a structure universal to PiT-related proteins from all kingdoms of life.

PubMed

Bøttger, Pernille; Pedersen, Lene

2011-05-17

The inorganic (Pi) phosphate transporter (PiT) family comprises known and putative Na(+)- or H(+)-dependent Pi-transporting proteins with representatives from all kingdoms. The mammalian members are placed in the outer cell membranes and suggested to supply cells with Pi to maintain house-keeping functions. Alignment of protein sequences representing PiT family members from all kingdoms reveals the presence of conserved amino acids and that bacterial phosphate permeases and putative phosphate permeases from archaea lack substantial parts of the protein sequence when compared to the mammalian PiT family members. Besides being Na(+)-dependent P(i) (NaP(i)) transporters, the mammalian PiT paralogs, PiT1 and PiT2, also are receptors for gamma-retroviruses. We have here exploited the dual-function of PiT1 and PiT2 to study the structure-function relationship of PiT proteins. We show that the human PiT2 histidine, H(502), and the human PiT1 glutamate, E(70),--both conserved in eukaryotic PiT family members--are critical for P(i) transport function. Noticeably, human PiT2 H(502) is located in the C-terminal PiT family signature sequence, and human PiT1 E(70) is located in ProDom domains characteristic for all PiT family members.A human PiT2 truncation mutant, which consists of the predicted 10 transmembrane (TM) domain backbone without a large intracellular domain (human PiT2ΔR(254)-V(483)), was found to be a fully functional P(i) transporter. Further truncation of the human PiT2 protein by additional removal of two predicted TM domains together with the large intracellular domain created a mutant that resembles a bacterial phosphate permease and an archaeal putative phosphate permease. This human PiT2 truncation mutant (human PiT2ΔL(183)-V(483)) did also support P(i) transport albeit at very low levels. The results suggest that the overall structure of the P(i)-transporting unit of the PiT family proteins has remained unchanged during evolution. Moreover, in combination, our studies of the gene structure of the human PiT1 and PiT2 genes (SLC20A1 and SLC20A2, respectively) and alignment of protein sequences of PiT family members from all kingdoms, along with the studies of the dual functions of the human PiT paralogs show that these proteins are excellent as models for studying the evolution of a protein's structure-function relationship. © 2011 Bøttger and Pedersen; licensee BioMed Central Ltd.

Relationship between consecutive deterioration of mean deviation value and progression of visual field defect in open-angle glaucoma.

PubMed

Naito, Tomoko; Yoshikawa, Keiji; Mizoue, Shiro; Nanno, Mami; Kimura, Tairo; Suzumura, Hirotaka; Takeda, Ryuji; Shiraga, Fumio

2015-01-01

To analyze the relationship between consecutive deterioration of mean deviation (MD) value and glaucomatous visual field (VF) progression in open-angle glaucoma (OAG), including primary OAG and normal tension glaucoma. The subjects of the study were patients undergoing treatment for OAG who had performed VF tests at least 10 times with a Humphrey field analyzer (SITA standard, C30-2 program). The VF progression was defined by a significantly negative MD slope (MD slope worsening) at the final VF test during the follow-up period. The relationship between the MD slope worsening and the consecutive deterioration of MD value were retrospectively analyzed. A total of 165 eyes of 165 patients were included in the analysis. Significant progression of VF defects was observed in 72 eyes of 72 patients (43.6%), while no significant progression was evident in 93 eyes of 93 patients (56.4%). There was significant relationship between the frequency of consecutive deterioration of MD value and MD slope worsening (P<0.0001, Cochran-Armitage trend test). A significant association was observed for MD slope worsening in the eyes with three (odds ratio: 2.1, P=0.0224) and four (odds ratio: 3.6, P=0.0008) consecutive deterioration of MD value in multiple logistic regression analysis, but no significant association in the eyes with two consecutive deterioration (odds ratio: 1.1, P=0.8282). The eyes with VF progression had significantly lower intraocular pressure reduction rate (P<0.01). This retrospective study has shown that three or more consecutive deterioration of MD value might be a predictor to future significant MD slope worsening in OAG.

Bottom currents observed in and around a submarine valley on the continental slope of the northern South China Sea

NASA Astrophysics Data System (ADS)

Wu, Lunyu; Xiong, Xuejun; Li, Xiaolong; Shi, Maochong; Guo, Yongqing; Chen, Liang

2016-12-01

Bottom currents at about 1000 m depth in and around a submarine valley on the continental slope of the northern South China Sea were studied by a 14-month long experiment from July 2013 to September 2014. The observations reveal that bottom currents are strongly influenced by the topography, being along valley axis or isobaths. Power density spectrum analysis shows that all the currents have significant peaks at diurnal and semi-diurnal frequencies. Diurnal energy is dominant at the open slope site, which is consistent with many previous studies. However, at the site inside the valley the semi-diurnal energy dominates, although the distance between the two sites of observation is quite small (11 km) compared to a typical horizontal first-mode internal tide wavelength (200 km). We found this phenomenon is caused by the focusing of internal waves of certain frequencies in the valley. The inertial peak is found only at the open slope site in the first deployment but missing at the inside valley site and the rest of the deployments. Monthly averaged residual currents reveal that the near-bottom currents on the slope flow southwestward throughout the year except in August and September, 2013, from which we speculate that this is a result of the interaction between a mesoscale eddy and the canyon/sag topography. Currents inside the valley within about 10 mab basically flow along slope and in the layers above the 10 mab the currents are northwestward, that is, from the deep ocean to the shelf. The monthly mean current vectors manifest an Ekman layer-like vertical structure at both sites, which rotate counter-clockwise looking from above.

Time indices of multiphasic development in genotypes of sweet cherry are similar from dormancy to cessation of pit growth.

PubMed

Gibeaut, David M; Whiting, Matthew D; Einhorn, Todd

2017-02-01

The archetypical double sigmoid-shaped growth curve of the sweet cherry drupe (Prunus avium) does not address critical development from eco-dormancy to anthesis and has not been correlated to reproductive bud development. Accurate representation of the growth and development of post-anthesis ovaries is confounded by anthesis timing, fruiting-density and the presence of unfertilized and defective ovaries whose growth differs from those that persist to maturation. These factors were addressed to assess pre-anthesis and full-season growth and development of three sweet cherry cultivars, 'Chelan', 'Bing' and 'Sweetheart', differing primarily in seasonal duration and fruit size. Volume was calculated from photographic measurements of reproductive buds, ovaries and pits at all phases of development. A population of unfertilized ovaries was produced using bee-exclusion netting to enable a statistical comparison with an open pollinated population to detect differences in size and shape between successful and failing fruit growth. Anthesis timing and fruiting-density were manipulated by floral extinction at the spur and whole-tree scales. Developmental time indices were analysed using polynomial curve fitting of log-transformed data supported by Richards and logistic functions of asymptotic growth of the pit and maturing fruit, respectively. Pre-anthesis growth began at the completion of eco-dormancy. A slight decline in relative growth rate (RGR) was observed during bud scale separation approx. -16 d from anthesis (DFA) before resumption of exponential growth to a maximum about 14 DFA. After anthesis, reduced growth of unfertilized or defective ovaries was partly discriminated from successful fruit at 5 DFA and completely at 25 DFA. Time indices of RGR inflections were similar among cultivars when adjusted for anthesis date alone, until the end of pit growth. Asymptotic growth of the pit underpinned the declining growth rate of fruit at the end of the first exponential growth phase. Duration of the subsequent expansive growth phase accounted for genotypic differences in seasonal duration and final size. Pit size and final fruit size were inversely related to fruiting-density. Developmental differences among early, mid and late maturing cultivars were not detected until the final growth period. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Time indices of multiphasic development in genotypes of sweet cherry are similar from dormancy to cessation of pit growth

PubMed Central

Gibeaut, David M.; Whiting, Matthew D.; Einhorn, Todd

2017-01-01

Background and Aims The archetypical double sigmoid-shaped growth curve of the sweet cherry drupe (Prunus avium) does not address critical development from eco-dormancy to anthesis and has not been correlated to reproductive bud development. Accurate representation of the growth and development of post-anthesis ovaries is confounded by anthesis timing, fruiting-density and the presence of unfertilized and defective ovaries whose growth differs from those that persist to maturation. These factors were addressed to assess pre-anthesis and full-season growth and development of three sweet cherry cultivars, ‘Chelan’, ‘Bing’ and ‘Sweetheart’, differing primarily in seasonal duration and fruit size. Methods Volume was calculated from photographic measurements of reproductive buds, ovaries and pits at all phases of development. A population of unfertilized ovaries was produced using bee-exclusion netting to enable a statistical comparison with an open pollinated population to detect differences in size and shape between successful and failing fruit growth. Anthesis timing and fruiting-density were manipulated by floral extinction at the spur and whole-tree scales. Developmental time indices were analysed using polynomial curve fitting of log-transformed data supported by Richards and logistic functions of asymptotic growth of the pit and maturing fruit, respectively. Key Results Pre-anthesis growth began at the completion of eco-dormancy. A slight decline in relative growth rate (RGR) was observed during bud scale separation approx. −16 d from anthesis (DFA) before resumption of exponential growth to a maximum about 14 DFA. After anthesis, reduced growth of unfertilized or defective ovaries was partly discriminated from successful fruit at 5 DFA and completely at 25 DFA. Time indices of RGR inflections were similar among cultivars when adjusted for anthesis date alone, until the end of pit growth. Asymptotic growth of the pit underpinned the declining growth rate of fruit at the end of the first exponential growth phase. Duration of the subsequent expansive growth phase accounted for genotypic differences in seasonal duration and final size. Pit size and final fruit size were inversely related to fruiting-density. Conclusions Developmental differences among early, mid and late maturing cultivars were not detected until the final growth period. PMID:28064193

Musculoskeletal symptoms and exposure to whole-body vibration among open-pit mine workers in the Arctic.

PubMed

Burström, Lage; Aminoff, Anna; Björ, Bodil; Mänttäri, Satu; Nilsson, Tohr; Pettersson, Hans; Rintamäki, Hannu; Rödin, Ingemar; Shilov, Victor; Talykova, Ljudmila; Vaktskjold, Arild; Wahlström, Jens

2017-06-19

This cross-sectional questionnaire study was carried out at 4 open-pit mines in Finland, Norway, Russia and Sweden as part of the MineHealth project. The aim has been to compare the prevalence of musculoskeletal symptoms between drivers of mining vehicles and non-drivers. The mine workers were asked whether they had suffered from any musculoskeletal symptoms during the previous 12 months in specified body regions, and to grade the severity of these symptoms during the past month. They were also asked about their daily driving of mining vehicles. The questionnaire was completed by 1323 workers (757 vehicle drivers) and the reported prevalence and severity of symptoms were highest for the lower back, followed by pain in the neck, shoulder and upper back. Drivers in the Nordic mines reported fewer symptoms than non-drivers, while for Russian mine workers the results were the opposite of that. The daily driving of mining vehicles had no significant association with the risk of symptoms. Female drivers indicated a higher prevalence of symptoms as compared to male drivers. The study provided only weak support for the hypothesis that drivers of vehicles reported a higher prevalence of musculoskeletal symptoms than non-vehicle drivers. There were marked differences in the prevalence of symptoms among workers in various enterprises, even though the nature of the job tasks was similar. Int J Occup Med Environ Health 2017;30(4):553-564. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

The three principles of action: a Pavlovian-instrumental transfer hypothesis

PubMed Central

Cartoni, Emilio; Puglisi-Allegra, Stefano; Baldassarre, Gianluca

2013-01-01

Pavlovian conditioned stimuli can influence instrumental responding, an effect called Pavlovian-instrumental transfer (PIT). During the last decade, PIT has been subdivided into two types: specific PIT and general PIT, each having its own neural substrates. Specific PIT happens when a conditioned stimulus (CS) associated with a reward enhances an instrumental response directed to the same reward. Under general PIT, instead, the CS enhances a response directed to a different reward. While important progress has been made into identifying the neural substrates, the function of specific and general PIT and how they interact with instrumental responses are still not clear. In the experimental paradigm that distinguishes specific and general PIT an effect of PIT inhibition has also been observed and is waiting for an explanation. Here we propose an hypothesis that links these three PIT effects (specific PIT, general PIT and PIT inhibition) to three aspects of action evaluation. These three aspects, which we call “principles of action”, are: context, efficacy, and utility. In goal-directed behavior, an agent has to evaluate if the context is suitable to accomplish the goal, the efficacy of his action in getting the goal, and the utility of the goal itself: we suggest that each of the three PIT effects is related to one of these aspects of action evaluation. In particular, we link specific PIT with the estimation of efficacy, general PIT with the evaluation of utility, and PIT inhibition with the adequacy of context. We also provide a latent cause Bayesian computational model that exemplifies this hypothesis. This hypothesis and the model provide a new framework and new predictions to advance knowledge about PIT functioning and its role in animal adaptation. PMID:24312025

Effects of wind velocity and slope on flame properties

Treesearch

David R. Weise; Gregory S. Biging

1996-01-01

Abstract: The combined effects of wind velocity and percent slope on flame length and angle were measured in an open-topped, tilting wind tunnel by burning fuel beds composed of vertical birch sticks and aspen excelsior. Mean flame length ranged from 0.08 to 1.69 m; 0.25 m was the maximum observed flame length for most backing fires. Flame angle ranged from -46o to 50o...

Secrets of the Noachian Highlands: Pit Craters

NASA Technical Reports Server (NTRS)

2001-01-01

[figure removed for brevity, see original site] A) Context Image [figure removed for brevity, see original site] B) Gullies in M12-00595 [figure removed for brevity, see original site] C) Layers and gullies in M09-00539, M15-00964

Among the most exciting places that the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) has photographed during its three and a half years in orbit has been this crater in central Noachis Terra. Located at 47oS, 355oW, the crater appears to have been almost completely filled, and subsequently eroded in localized pits, by unknown processes. In this one place we see elements of the two most important results of the MOC investigation--the discovery of young gullies formed by fluid erosion and the occurrence of thick sequences of layered rock attesting to a martian past of substantial geologic activity.

Picture A shows the location of the other two figures, which are sections of three of about a dozen images acquired of this crater. Picture B (M12-00595) shows examples of gullies on the pit walls. Their contributary pattern (including the angles at which they join) argues for fluid behavior during their creation; the dark floors suggest that they have been active recently (or else they, like the slopes around them and most of Mars, would be lighter-toned owing to the accumulation of dust). These gullies are formed well down on the pit wall, where a distinctive, boulder-rich layer is found. Figure C, a mosaic of two high resolution images (M09-00539 and M15-00964), shows an area somewhat higher in the sequence of layered material that fills the crater. This sequence clearly alternates between layers that either contain or erode to form boulders and layers that do not have boulders. Note in particular the overhanging layers near the top center--such overhangs are evidence of the strength of the material. Here, too, gullies appear to start at specific layers; these, however, may not be as young as those seen in (B), as they appear to have at least a thin covering of dust. How it is that this crater came to be filled with layers of material containing (or eroding to create) boulders is a mystery.

A probability distribution model of tooth pits for evaluating time-varying mesh stiffness of pitting gears

NASA Astrophysics Data System (ADS)

Lei, Yaguo; Liu, Zongyao; Wang, Delong; Yang, Xiao; Liu, Huan; Lin, Jing

2018-06-01

Tooth damage often causes a reduction in gear mesh stiffness. Thus time-varying mesh stiffness (TVMS) can be treated as an indication of gear health conditions. This study is devoted to investigating the mesh stiffness variations of a pair of external spur gears with tooth pitting, and proposes a new model for describing tooth pitting based on probability distribution. In the model, considering the appearance and development process of tooth pitting, we model the pitting on the surface of spur gear teeth as a series of pits with a uniform distribution in the direction of tooth width and a normal distribution in the direction of tooth height, respectively. In addition, four pitting degrees, from no pitting to severe pitting, are modeled. Finally, influences of tooth pitting on TVMS are analyzed in details and the proposed model is validated by comparing with a finite element model. The comparison results show that the proposed model is effective for the TVMS evaluations of pitting gears.

Subtypes of the Type II Pit Pattern Reflect Distinct Molecular Subclasses in the Serrated Neoplastic Pathway.

PubMed

Aoki, Hironori; Yamamoto, Eiichiro; Yamano, Hiro-O; Sugai, Tamotsu; Kimura, Tomoaki; Tanaka, Yoshihito; Matsushita, Hiro-O; Yoshikawa, Kenjiro; Takagi, Ryo; Harada, Eiji; Nakaoka, Michiko; Yoshida, Yuko; Harada, Taku; Sudo, Gota; Eizuka, Makoto; Yorozu, Akira; Kitajima, Hiroshi; Niinuma, Takeshi; Kai, Masahiro; Nojima, Masanori; Suzuki, Hiromu; Nakase, Hiroshi

2018-03-15

Colorectal serrated lesions (SLs) are important premalignant lesions whose clinical and biological features are not fully understood. We aimed to establish accurate colonoscopic diagnosis and treatment of SLs through evaluation of associations among the morphological, pathological, and molecular characteristics of SLs. A total of 388 premalignant and 18 malignant colorectal lesions were studied. Using magnifying colonoscopy, microsurface structures were assessed based on Kudo's pit pattern classification system, and the Type II pit pattern was subcategorized into classical Type II, Type II-Open (Type II-O) and Type II-Long (Type II-L). BRAF/KRAS mutations and DNA methylation of CpG island methylator phenotype (CIMP) markers (MINT1, - 2, - 12, - 31, p16, and MLH1) were analyzed through pyrosequencing. Type II-O was tightly associated with sessile serrated adenoma/polyps (SSA/Ps) with BRAF mutation and CIMP-high. Most lesions with simple Type II or Type II-L were hyperplastic polyps, while mixtures of Type II or Type II-L plus more advanced pit patterns (III/IV) were characteristic of traditional serrated adenomas (TSAs). Type II-positive TSAs frequently exhibited BRAF mutation and CIMP-low, while Type II-L-positive TSAs were tightly associated with KRAS mutation and CIMP-low. Analysis of lesions containing both premalignant and cancerous components suggested Type II-L-positive TSAs may develop into KRAS-mutated/CIMP-low/microsatellite stable cancers, while Type II-O-positive SSA/Ps develop into BRAF-mutated/CIMP-high/microsatellite unstable cancers. These results suggest that Type II subtypes reflect distinct molecular subclasses in the serrated neoplasia pathway and that they could be useful hallmarks for identifying SLs at high risk of developing into CRC.

The Role of Economic Uncertainty on the Block Economic Value - a New Valuation Approach / Rola Czynnika Niepewności Przy Obliczaniu Wskaźnika Rentowności - Nowe Podejście

NASA Astrophysics Data System (ADS)

Dehghani, H.; Ataee-Pour, M.

2012-12-01

The block economic value (EV) is one of the most important parameters in mine evaluation. This parameter can affect significant factors such as mining sequence, final pit limit and net present value. Nowadays, the aim of open pit mine planning is to define optimum pit limits and an optimum life of mine production scheduling that maximizes the pit value under some technical and operational constraints. Therefore, it is necessary to calculate the block economic value at the first stage of the mine planning process, correctly. Unrealistic block economic value estimation may cause the mining project managers to make the wrong decision and thus may impose inexpiable losses to the project. The effective parameters such as metal price, operating cost, grade and so forth are always assumed certain in the conventional methods of EV calculation. While, obviously, these parameters have uncertain nature. Therefore, usually, the conventional methods results are far from reality. In order to solve this problem, a new technique is used base on an invented binomial tree which is developed in this research. This method can calculate the EV and project PV under economic uncertainty. In this paper, the EV and project PV were initially determined using Whittle formula based on certain economic parameters and a multivariate binomial tree based on the economic uncertainties such as the metal price and cost uncertainties. Finally the results were compared. It is concluded that applying the metal price and cost uncertainties causes the calculated block economic value and net present value to be more realistic than certain conditions.

Earth Observations taken by the Expedition 16 Crew

NASA Image and Video Library

2008-03-05

ISS016-E-031056 (3 March 2008) --- Cananea Copper Mine, Sonora, Mexico is featured in this image photographed by an Expedition 16 crewmember on the International Space Station. One of the largest open-pit copper mines in the world, the Cananea mine produced over 164,000 tons of copper in 2006. The mine is located approximately 40 kilometers south of the border between the USA (Arizona) and Mexico (Sonora). Copper and gold ores at Cananea are found in a porphyry copper deposit, a geological structure formed by crystal-rich magma moving upwards through pre-existing rock layers. A porphyry - an igneous rock with large crystals in a fine-grained matrix -- is formed as the magma cools and crystallizes. While crystallization is occurring, hot fluids can circulate through the magma and surrounding rocks via fractures. This hydrothermal alteration of the rocks typically forms copper-bearing and other minerals. Much of the Cananea mine's ore is concentrated in breccia pipes -- mineralized rod or chimney-shaped bodies that contain broken rock fragments. The active, two-kilometers-in-diameter Colorada Pit (top right) is recognizable in this image by the concentric steps or benches cut around its perimeter. These benches allow for access into the pit for extraction of ore and waste materials. Water (black) is visible filling the bottom of the pit, and several other basins in the surrounding area. The city of Cananea -- marked by its street grid -- is located to the northeast of the mine workings. A leachate reservoir is located to the east of the mine (lower left) for removal and evaporation of water pumped from the mine workings -- the bluish-white coloration of deposits near the reservoir suggests the high mineral content of the leachate. A worker strike halted mine operations in 2007.

General and crevice corrosion study of the in-wall shielding materials for ITER vacuum vessel

NASA Astrophysics Data System (ADS)

Joshi, K. S.; Pathak, H. A.; Dayal, R. K.; Bafna, V. K.; Kimihiro, Ioki; Barabash, V.

2012-11-01

Vacuum vessel In-Wall Shield (IWS) will be inserted between the inner and outer shells of the ITER vacuum vessel. The behaviour of IWS in the vacuum vessel especially concerning the susceptibility to crevice of shielding block assemblies could cause rapid and extensive corrosion attacks. Even galvanic corrosion may be due to different metals in same electrolyte. IWS blocks are not accessible until life of the machine after closing of vacuum vessel. Hence, it is necessary to study the susceptibility of IWS materials to general corrosion and crevice corrosion under operations of ITER vacuum vessel. Corrosion properties of IWS materials were studied by using (i) Immersion technique and (ii) Electro-chemical Polarization techniques. All the sample materials were subjected to a series of examinations before and after immersion test, like Loss/Gain weight measurement, SEM analysis, and Optical stereo microscopy, measurement of surface profile and hardness of materials. After immersion test, SS 304B4 and SS 304B7 showed slight weight gain which indicate oxide layer formation on the surface of coupons. The SS 430 material showed negligible weight loss which indicates mild general corrosion effect. On visual observation with SEM and Metallography, all material showed pitting corrosion attack. All sample materials were subjected to series of measurements like Open Circuit potential, Cyclic polarization, Pitting potential, protection potential, Critical anodic current and SEM examination. All materials show pitting loop in OC2 operating condition. However, its absence in OC1 operating condition clearly indicates the activity of chloride ion to penetrate oxide layer on the sample surface, at higher temperature. The critical pitting temperature of all samples remains between 100° and 200°C.

Lake Superior, Duluth, MN

NASA Technical Reports Server (NTRS)

1973-01-01

This view shows the west end of Lake Superior and Duluth, MN (47.0N, 91.0W). Portions of Minnesota, Michigan and Ontario, Canada are in the scene. The Duluth metropolitan area is at the west end of the lake. The discoloration plume in the water at Duluth is the result of tailings from the iron ore smelters that process the iron ore from the nearby open pit mines seen near the upper left corner of the photo.

Research into robotic automation of drilling equipment by the Institute of Mining, UB RAS

NASA Astrophysics Data System (ADS)

Regotunov, AS; Sukhov, RI

2018-03-01

The article discusses the issues connected with the development of instrumentation for the express-determination of strength characteristics of rocks during blasthole drilling in open pit mines. The trial results of the instrumentation are reported in terms of the drilling rate–energy content interrelation determined in the analyses of experimental drilling block data and by the digital model of rock distribution in depth versus drilling complexity index.

Surface Analytical Techniques for Microbiologically Influenced Corrosion. A Review

DTIC Science & Technology

1994-01-01

chemical process, oil and gas. and power generation industries and the U.S. pitting of stainle steels is 1h military have acknowledged the occurrence...ony on metal surface. photosynthetic biofilm may influence ennoblement of the open circuit potential of type 316L stainless steel so that it approaches...at depths within an estuarine biofilm on type 304 stainless steel . fur-oxidizing. iron-red ing. sulfate- -producing, and hydr en-producing b

Ambulatory Surgery Centers and Their Intended Effects on Outpatient Surgery.

PubMed

Hollenbeck, Brent K; Dunn, Rodney L; Suskind, Anne M; Strope, Seth A; Zhang, Yun; Hollingsworth, John M

2015-10-01

To assess the impact of ambulatory surgery centers (ASCs) on rates of hospital-based outpatient procedures and adverse events. Twenty percent national sample of Medicare beneficiaries. A retrospective study of beneficiaries undergoing outpatient surgery between 2001 and 2010. Health care markets were sorted into three groups-those with ASCs, those without ASCs, and those where one opened for the first time. Generalized linear mixed models were used to assess the impact of ASC opening on rates of hospital-based outpatient surgery, perioperative mortality, and hospital admission. Adjusted hospital-based outpatient surgery rates declined by 7 percent, or from 2,333 to 2,163 procedures per 10,000 beneficiaries, in markets where an ASC opened for the first time (p < .001 for test between slopes). Within these markets, procedure use at ASCs outpaced the decline observed in the hospital setting. Perioperative mortality and admission rates remained flat after ASC opening (both p > .4 for test between slopes). The opening of an ASC in a Hospital Service Area resulted in a decline in hospital-based outpatient surgery without increasing mortality or admission. In markets where facilities opened, procedure growth at ASCs was greater than the decline in outpatient surgery use at their respective hospitals. © Health Research and Educational Trust.

Short-range variation in a Wisconsin soilscape (USA)

NASA Astrophysics Data System (ADS)

Hartemink, A. E.; Gennadiyev, A. N.; Bockheim, J. G.; Bero, N.

2017-02-01

Here we report on the variation of a soilscape in south central Wisconsin, USA. The variation in soil properties and soil features results in four soil order (Entisols, Inceptisols, Alfisols and Mollisols). Observations were made along a 200 m transect in a field that was cultivated since 1870. Slopes ranged from 7.5% on the back slope to 0% in the lower part. The soilscape had a total relief difference of 7.0 m. The soils were studied by 41 soil pits (60 cm), 6 soil pits (125 cm), 15 soil augers (100 cm), and ground-penetrating radar imagery. The summit and shoulder consist of coarse glacial outwash (loamy sands) over limestone whereas the lower part is lacustrine sediments over coarse outwash (loams, silty loams). The A-horizon thickness ranged from 14 to 52 cm with thick A horizons at the toeslope that also had the lowest soil pH. The soil organic carbon (SOC) contents of the A horizons ranged from 11.6 to 46.9 g C kg-1, and the higher contents are in the lower part of the soilscape. SOC stocks (0-20 cm depth) ranged from 50 to 70 Mg C ha-1 on the summit and backslope, but were 80 to 95 Mg C ha-1 in the flat part of the soilscape. The lowest soybean yields (1.6 Mg ha-1) were found at the summit and the highest yield (6.3 Mg ha-1) at the lower end of the backslope. Soybean yields were correlated to the thickness of the A horizon, and every 10 cm increase in A horizon thickness yielded an extra 0.6 Mg soybeans ha-1. Analysis of spherical magnetic particles was used to estimate soil erosion rates that were highest on the backslope (16.2 Mg ha-1 yr-1) and rates of soil deposition in the lowest part of the soilscape was 18.8 Mg haP1 yr-1. It seems that there is no net soil and SOC loss within this soilscape. All in all, we found 4 soil taxonomic orders within 200 m. The variation in this soilscape was substantial and probably enhanced by 140 years of cultivation.

NIR detection of pits and pit fragments in fresh cherries (abstract)

USDA-ARS?s Scientific Manuscript database

The feasibility of using near infrared (NIR) diffuse reflectance spectroscopy for the detection of pits and pit fragments in cherries was demonstrated. For detection of whole pits, 300 cherries were obtained locally and pits were removed from half. NIR reflectance spectra were obtained in triplicate...

7 CFR 52.779 - Freedom from pits.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Freedom from pits. 52.779 Section 52.779 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Freedom from pits. (a) General. The factor of freedom from pits refers to the incidence of pits and pit...

The effects of pitting on fatigue crack nucleation in 7075-T6 aluminum alloy

NASA Technical Reports Server (NTRS)

Ma, LI; Hoeppner, David W.

1994-01-01

A high-strength aluminum alloy, 7075-T6, was studied to quantitatively evaluate chemical pitting effects of its corrosion fatigue life. The study focused on pit nucleation, pit growth, and fatigue crack nucleation. Pitting corrosion fatigue experiments were conducted in 3.5 percent NaCl aqueous solution under constant amplitude sinusoidal loading at two frequencies, 5 and 20 Hz. Smooth and unnotched specimens were used in this investigation. A video recording system was developed to allow in situ observation of the surface changes of the specimens during testing. The results indicated that pitting corrosion considerably reduces the fatigue strength by accelerating fatigue crack nucleation. A metallographic examination was conducted on the specimens to evaluate the nature of corrosion pits. First, the actual shapes of the corrosion pits were evaluated by cross-sectioning the pits. Secondly, the relation between corrosion pits and microstructure was also investigated. Finally, the possibility of another corrosion mechanism that might be involved in pitting was explored in this investigation. The fractography of the tested specimens showed that corner corrosion pits were responsible for fatigue crack nucleation in the material due to the associated stress concentration. The pits exhibited variance of morphology. Fatigue life for the experimental conditions appeared to be strongly dependent on pitting kinetics and the crack nucleation stage.

30 CFR 881.10 - Obligations of States or local authorities.

Code of Federal Regulations, 2010 CFR

2010-07-01

... coal measures as may be required to assure the stability and continued existence of the project and to... open shafts, slopes, air holes and other mine openings to underground workings where public safety... State shall have or acquire such right, title or interest in the lands as will assure the stability and...

Ecohydrology applications to ecosystem reconstruction after oil-sand mining

NASA Astrophysics Data System (ADS)

Mendoza, Carl; Devito, Kevin

2014-05-01

Oil-sand deposits in northeast Alberta, Canada comprise some of the world's largest oil reserves. Open-pit mining of these resources leads to waste-rock piles, tailings ponds and open pits that must be reclaimed to "equivalent landscape capability", with viable forests and wetlands, using only native vegetation. Understanding ecohydrological processes in natural systems is critical for designing the necessary landforms and landscapes. A challenge is the cold, sub-humid climate, with highly variable precipitation. Furthermore, there are competing demands, needs or uses for water, in both quantity and quality, for reclamation and sustainability of forestlands, wetlands and end-pit lakes. On average there is a potential water deficit in the region, yet wetlands cover half of the undisturbed environment. Water budget analyses demonstrate that, although somewhat unpredictable and uncontrollable, the magnitude and timing of water delivery largely control water storage and conservation within the landscape. The opportunity is to design and manipulate these reconstructed landscapes so that water is stored and conserved, and water quality is naturally managed. Heterogeneous geologic materials can be arranged and layered, and landforms sculpted, to minimize runoff, enhance infiltration, and promote surface and subsurface storage. Similarly, discharge of poor quality water can be minimized or focused. And, appropriate vegetation choices are necessary to conserve water on the landscape. To achieve these ends, careful attention must be paid to the entire water budget, the variability in its components, interconnections between hydrologic units, in both space and time, and coupled vegetation processes. To date our knowledge is guided primarily by natural analogues. To move forward, it is apparent that numerous priorities and constraints, which are potentially competing, must be addressed. These include geotechnical and operational requirements, material limitations or excesses, time, money and performance expectations. Careful landform design and integration of ecohydrological principles can be used to address some of these issues.

Hydrogeological features conditioning trophic levels of quarry lakes in western Po plain (north-western Italy)

NASA Astrophysics Data System (ADS)

De Luca, Domenico Antonio; Castagna, Sara; Lasagna, Manuela

2013-04-01

Quarry lakes occur in plains areas due to the extraction of alluvial sand and gravel used for grout and concrete in the construction industry. Excavation depths can reach and intersect the groundwater surface, thus creating a lake. Because of the need to optimize efficiency, the number of active open pit mines has increased in recent years; consequently, the global number of pit lakes will increase in coming decades (Castendyk and Eary 2009; Klapper and Geller 2001; Castro and Moore 2000). Similar to natural lakes, pit lakes are subject to eutrophication process, both during and after quarrying activity; during mining activity, the eutrophic level is strongly controlled by the excavation method. In the Piedmont territory (north-western Italy) there are 70 active quarry lakes, corresponding to approximately 0.1% of the entire plain area. Quarry lakes, located primarily along the main rivers occur in alluvial deposits of the plain area and have average depths between 20 and 30 m (maximum of 60 m deep) and surface areas between 3 and 30 hectares (Castagna 2008). The present study describes the trophic status of 23 active quarry lakes in the Piedmont plain that were evaluated by applying classifications from scientific literature. Currently, the majority of the studied quarry lakes may be defined as mesotrophic or eutrophic according to the trophic state classifications. Based on historic data, lake trophic levels have increased over time, during active mining. At the end of mining activity, further deterioration of water quality was expected, especially for smaller lakes with minimal oxygen stratification and higher levels of nutrients and algal growth. In addition, the paper focuses on the pit lake water quality and pit dimension; From an environmental perspective the excavation of quarry lakes with an appreciable size will likely result in a better safeguard of water quality and enhanced possibilities for lake end use after the cessation of mining. Piedmont quarry lakes, for the most part, have rather large depths (over 20 m), and moreover, unlike natural lakes, this type of lake is not influenced by sewage inputs that are often a primary cause of eutrophication in natural lakes. It was shown that, in Piedmont, lakes with a larger depth and volume generally had a lower tendency towards eutrophication. References Castendyk D, Eary T (2009). The nature and global distribution of pit lakes. In, Mine Pit Lakes: Characteristics, Predictive Modeling, and Sustainability Castendyk, D.; Eary, T. and Park, B. (eds.) Society for Mining Engineering (SME), Colorado, USA, 1-11pp. Klapper H, Geller W (2001) Water quality management of mining lakes - a new field of applied hydrobiology. Acta Hydrochim Hydrobiol, 29: 363-374 Castro JM, Moore JN (2000) Pit lakes: their characteristics and the potential for their remediation. Environ Geol, 39(11):1254-1260 Castagna S (2008) Studio delle problematiche idrogeologiche nelle attività estrattive sottofalda per materiali granulari. Ph.D. Thesis.

Dose-Dependent Dual Role of PIT-1 (POU1F1) in Somatolactotroph Cell Proliferation and Apoptosis

PubMed Central

Jullien, Nicolas; Roche, Catherine; Brue, Thierry; Figarella-Branger, Dominique; Graillon, Thomas; Barlier, Anne; Herman, Jean-Paul

2015-01-01

To test the role of wtPIT-1 (PITWT) or PIT-1 (R271W) (PIT271) in somatolactotroph cells, we established, using inducible lentiviral vectors, sublines of GH4C1 somatotroph cells that allow the blockade of the expression of endogenous PIT-1 and/or the expression of PITWT or PIT271, a dominant negative mutant of PIT-1 responsible for Combined Pituitary Hormone Deficiency in patients. Blocking expression of endogenous PIT-1 induced a marked decrease of cell proliferation. Overexpressing PITWT twofold led also to a dose-dependent decrease of cell proliferation that was accompanied by cell death. Expression of PIT271 induced a strong dose-dependent decrease of cell proliferation accompanied by a very pronounced cell death. These actions of PIT271 are independent of its interaction/competition with endogenous PIT-1, as they were unchanged when expression of endogenous PIT-1 was blocked. All these actions are specific for somatolactotroph cells, and could not be observed in heterologous cells. Cell death induced by PITWT or by PIT271 was accompanied by DNA fragmentation, but was not inhibited by inhibitors of caspases, autophagy or necrosis, suggesting that this cell death is a caspase-independent apoptosis. Altogether, our results indicate that under normal conditions PIT-1 is important for the maintenance of cell proliferation, while when expressed at supra-normal levels it induces cell death. Through this dual action, PIT-1 may play a role in the expansion/regression cycles of pituitary lactotroph population during and after lactation. Our results also demonstrate that the so-called “dominant-negative” action of PIT271 is independent of its competition with PIT-1 or a blockade of the actions of the latter, and are actions specific to this mutant variant of PIT-1. PMID:25822178

Evaluation of nature-like and technical fishways for the passage of alewives at two coastal streams in New England

USGS Publications Warehouse

Franklin, Abigail E.; Haro, Alex; Castro-Santos, Theodore; Noreika, John

2012-01-01

Nature-like fishways have been designed with the intent to reconnect river corridors and provide passage for all species occurring in a system. The approach is gaining popularity both in Europe and North America, but performance of these designs has not been quantitatively evaluated in a field setting for any North American species. Two nature-like fishways and three technical fishways in New England were evaluated for passage of anadromous adult alewives Alosa pseudoharengus by using passive integrated transponder (PIT) telemetry. A perturbation boulder rock ramp (32 m long; 4.2% slope) constructed in Town Brook (Plymouth, Massachusetts) passed 94% of the fish that made passage attempts, with most fish ascending the ramp in less than 22 min. In the East River (Guilford, Connecticut), a step-pool bypass design (48 m long; 7.1% slope) passed only 40% of attempting fish, with a median transit time of 75 min. In Town Brook, a technical pool-and-weir fishway (14 m long; 14.3% slope) exhibited poor entry and poor passage for the fish. In contrast, in the East River, two technical steeppass fishways (3 m long; 29.6% and 9.6% slopes) passed the majority of available fish, although one of these steeppass fishways may have lacked sufficient flow to attract fish to the entrance. In both Town Brook and the East River, tagged fish passed rapidly downstream through all fishways after spawning. In the East River, the amount of time fish spent in the spawning habitat before migrating downstream ranged from 1 to 41 d. These studies demonstrate that some nature-like and technical fishway designs can effectively facilitate passage of alewives, but a fishway's location in relation to a spillway is important, and further evaluations are required to more precisely identify the influence of the vertical drop per pool and the specific local hydraulics on alewife behaviors and passage performance.

Rain Erosion Studies of Sapphire, Aluminum Oxynitride, Spinel, Lanthana- Doped Yttria, and TAF Glass

DTIC Science & Technology

1990-07-01

small , there is little change in average scatter for any material in any test. CONCLUSIONS AND DISCUSSION The principal conclusions are 1. ALON...20 Sample broke erosion damage 10 Slight pitting, 20 No change erosion damage 15 Pitting, cratering, 20 Small surface pits erosion damage 15 Pitting...Sample broke 10 No damage 15 Sample pitted, small edge fracture 15 Slight pitting, 1 crater, 20 Sample pitted, erosion damage small edge fracture 15 SUght

Minimal feedback to a rhythm generator improves the robustness to slope variations of a compass biped.

PubMed

Spitz, Jonathan; Evstrachin, Alexandrina; Zacksenhouse, Miriam

2015-08-20

In recent years there has been a growing interest in the field of dynamic walking and bio-inspired robots. However, while walking and running on a flat surface have been studied extensively, walking dynamically over terrains with varying slope remains a challenge. Previously we developed an open loop controller based on a central pattern generator (CPG). The controller applied predefined torque patterns to a compass-gait biped, and achieved stable gaits over a limited range of slopes. In this work, this range is greatly extended by applying a once per cycle feedback to the CPG controller. The terrain's slope is measured and used to modify both the CPG frequency and the torque amplitude once per step. A multi-objective optimization algorithm was used to tune the controller parameters for a simulated CB model. The resulting controller successfully traverses terrains with slopes ranging from +7° to -8°, comparable to most slopes found in human constructed environments. Gait stability was verified by computing the linearized Poincaré Map both numerically and analytically.

Potential risk assessment in stream sediments, soils and waters after remediation in an abandoned W>Sn mine (NE Portugal).

PubMed

Antunes, I M H R; Gomes, M E P; Neiva, A M R; Carvalho, P C S; Santos, A C T

2016-11-01

The mining complex of Murçós belongs to the Terras de Cavaleiros Geopark, located in Trás-os-Montes region, northeast Portugal. A stockwork of NW-SE-trending W>Sn quartz veins intruded Silurian metamorphic rocks and a Variscan biotite granite. The mineralized veins contain mainly quartz, cassiterite, wolframite, scheelite, arsenopyrite, pyrite, sphalerite, chalcopyrite, galena, rare pyrrhotite, stannite, native bismuth and also later bismuthinite, matildite, joseite, roosveltite, anglesite, scorodite, zavaritskite and covellite. The exploitation produced 335t of a concentrate with 70% of W and 150t of another concentrate with 70% of Sn between 1948 and 1976. The exploitation took place mainly in four open pit mines as well as underground. Three lakes were left in the area. Remediation processes of confination and control of tailings and rejected materials and phytoremediation with macrophytes from three lakes were carried out between 2005 and 2007. Stream sediments, soils and water samples were collected in 2008 and 2009, after the remediation process. Most stream sediments showed deficiency or minimum enrichment for metals. The sequential enrichment factor in stream sediments W>Bi>As>U>Cd>Sn=Ag>Cu>Sb>Pb>Be>Zn is mainly associated with the W>Sn mineralizations. Stream sediments receiving drainage of a mine dump were found to be significantly to extremely enriched with W, while stream sediments and soils were found to be contaminated with As. Two soil samples collected around mine dumps and an open pit lake were also found to be contaminated with U. The waters from the Murçós W>Sn mine area were acidic to neutral. After the remediation, the surface waters were contaminated with F(-), Al, As, Mn and Ni and must not be used for human consumption, while open pit lake waters must also not be used for agriculture because of contamination with F(-), Al, Mn and Ni. In most waters, the As occurred as As (III), which is toxic and is easily mobilized in the drainage system. The remediation promoted a decrease in metals and As concentrations of soils and waters, however the applied processes were not enough to rehabilitate the area. Copyright © 2016 Elsevier Inc. All rights reserved.

Phosphate (Pi)-regulated heterodimerization of the high-affinity sodium-dependent Pi transporters PiT1/Slc20a1 and PiT2/Slc20a2 underlies extracellular Pi sensing independently of Pi uptake.

PubMed

Bon, Nina; Couasnay, Greig; Bourgine, Annabelle; Sourice, Sophie; Beck-Cormier, Sarah; Guicheux, Jérôme; Beck, Laurent

2018-02-09

Extracellular phosphate (P i ) can act as a signaling molecule that directly alters gene expression and cellular physiology. The ability of cells or organisms to detect changes in extracellular P i levels implies the existence of a P i -sensing mechanism that signals to the body or individual cell. However, unlike in prokaryotes, yeasts, and plants, the molecular players involved in P i sensing in mammals remain unknown. In this study, we investigated the involvement of the high-affinity, sodium-dependent P i transporters PiT1 and PiT2 in mediating P i signaling in skeletal cells. We found that deletion of PiT1 or PiT2 blunted the P i -dependent ERK1/2-mediated phosphorylation and subsequent gene up-regulation of the mineralization inhibitors matrix Gla protein and osteopontin. This result suggested that both PiTs are necessary for P i signaling. Moreover, the ERK1/2 phosphorylation could be rescued by overexpressing P i transport-deficient PiT mutants. Using cross-linking and bioluminescence resonance energy transfer approaches, we found that PiT1 and PiT2 form high-abundance homodimers and P i -regulated low-abundance heterodimers. Interestingly, in the absence of sodium-dependent P i transport activity, the PiT1-PiT2 heterodimerization was still regulated by extracellular P i levels. Of note, when two putative P i -binding residues, Ser-128 (in PiT1) and Ser-113 (in PiT2), were substituted with alanine, the PiT1-PiT2 heterodimerization was no longer regulated by extracellular P i These observations suggested that P i binding rather than P i uptake may be the key factor in mediating P i signaling through the PiT proteins. Taken together, these results demonstrate that P i -regulated PiT1-PiT2 heterodimerization mediates P i sensing independently of P i uptake. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Analysis of the bacterial community in aged and aging pit mud of Chinese Luzhou-flavour liquor by combined PCR-DGGE and quantitative PCR assay.

PubMed

Liang, Huipeng; Li, Wenfang; Luo, Qingchun; Liu, Chaolan; Wu, Zhengyun; Zhang, Wenxue

2015-10-01

The community structure of bacteria in aged and aging pit mud, which was judged according to their sensory and physicochemical characteristics, was analysed using polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) and quantitative real-time PCR (qPCR). The phyla Firmicutes, Actinobacteria, Proteobacteria, Synergistetes and Unclassified Bacteria were detected and the fermentative Firmicutes was predominant in both types of pit mud in the PCR-DGGE analysis. Among Firmicutes, Clostridiales was dominant in aged pit mud while Bacillales and Lactobacillales were dominant in aging pit mud. The diversity of bacterial communities in aged pit mud was higher than that in aging pit mud. In the qPCR analysis the abundance of Clostridium IV in aged pit mud was higher than that in aging pit mud and there were significant differences in the quantity of Clostridium IV between aged and aging pit mud of the same cellar (P < 0.05). There were some significant differences in the microbial community structure between aged and aging pit mud. The differences in the quantity of Clostridium IV might be involved in the distinction that the aged pit mud has a strong aroma while the aging pit mud does not. © 2014 Society of Chemical Industry.

Structure and function of bordered pits: new discoveries and impacts on whole-plant hydraulic function.

PubMed

Choat, Brendan; Cobb, Alexander R; Jansen, Steven

2008-01-01

Bordered pits are cavities in the lignified cell walls of xylem conduits (vessels and tracheids) that are essential components in the water-transport system of higher plants. The pit membrane, which lies in the center of each pit, allows water to pass between xylem conduits but limits the spread of embolism and vascular pathogens in the xylem. Averaged across a wide range of species, pits account for > 50% of total xylem hydraulic resistance, indicating that they are an important factor in the overall hydraulic efficiency of plants. The structure of pits varies dramatically across species, with large differences evident in the porosity and thickness of pit membranes. Because greater porosity reduces hydraulic resistance but increases vulnerability to embolism, differences in pit structure are expected to correlate with trade-offs between efficiency and safety of water transport. However, trade-offs in hydraulic function are influenced both by pit-level differences in structure (e.g. average porosity of pit membranes) and by tissue-level changes in conduit allometry (average length, diameter) and the total surface area of pit membranes that connects vessels. In this review we address the impact of variation in pit structure on water transport in plants from the level of individual pits to the whole plant.

[The structure of the gastric mucosa of the llamas (Lama guanocoe and Lama lamae). I. Forestomach].

PubMed

Luciano, L; Voss-Wermbter, G; Behnke, M; von Engelhardt, W; Reale, E

1979-01-01

The mucous membrane of the first and second compartments (ventral regions) as well as of the third compartment of Lama guanacoe and Lama lamae stomach shows tubular glands opening into pits. Below the surface epithelium blood capillaries of the fenestrated type form a regular network, each mesh of which surrounds a gastric pit. From a morphological point of view (thin section and freeze-fracture replicas) the columnar cells of the surface epithelium and those of the pits closest to the capillaries are largely similar to the epithelial cells of the rabbit gallbladder. This similarity suggests that at the level of the columnar cells sodium-dependent water reabsorption occurs. This reabsorption has already been demonstrated in the abovementioned compartments by physiological methods. The surface and foveolae epithelial cells as well as some cells of the tubular glands have a secretory function. Their secretory granules contain mucosubstances, as indicated by light-(PAS- and Alcian blue reactions) and electron microscopic (PA-TCH-Ag-reaction) histochemistry. The secretory granules originate from the Golgi complex which shows a positive histochemical reaction in its innermost sacculi at the electron microscope level. Endocrine cells (s. second part of this investigation) are rare. The mucosal membrane of each muscular lip separating the glandular sacs in the first compartment shows a stratified, not keratinized, squamous epithelium.

Low-power, ultrafast, and dynamic all-optical tunable plasmon induced transparency in two stub resonators side-coupled with a plasmonic waveguide system

NASA Astrophysics Data System (ADS)

Wang, Boyun; Zeng, Qingdong; Xiao, Shuyuan; Xu, Chen; Xiong, Liangbin; Lv, Hao; Du, Jun; Yu, Huaqing

2017-11-01

We theoretically and numerically investigate a low-power, ultrafast, and dynamic all-optical tunable plasmon induced transparency (PIT) in two stub resonators side-coupled with a metal-dielectric-metal (MDM) plasmonic waveguide system. The optical Kerr effect is enhanced by the local electromagnetic field of surface plasmon polaritons (SPPs) and the plasmonic waveguide based on graphene-Ag composite material structures with large effective Kerr nonlinear coefficient. An ultrafast response time of the order of 1 ps is reached because of ultrafast carrier relaxation dynamics of graphene. With dynamically tuning the propagation phase of the plasmonic waveguide, π-phase shift of the transmission spectrum in the PIT system is achieved under excitation of a pump light with an intensity as low as 5.8 MW cm-2. The group delay is controlled between 0.14 and 0.67 ps. Moreover, the tunable bandwidth of about 42 nm is obtained. For the indirect coupling between two stub cavities or the phase coupling scheme, the phase shift multiplication effect of the PIT effect is found. All observed schemes are analyzed rigorously through finite-difference time-domain simulations and coupled-mode formalism. This work not only paves the way towards the realization of on-chip integrated nanophotonic devices but also opens the possibility of the construction of ultrahigh-speed information processing chips based on plasmonic circuits.

Metalorganic vapor phase epitaxy of AlN on sapphire with low etch pit density

NASA Astrophysics Data System (ADS)

Koleske, D. D.; Figiel, J. J.; Alliman, D. L.; Gunning, B. P.; Kempisty, J. M.; Creighton, J. R.; Mishima, A.; Ikenaga, K.

2017-06-01

Using metalorganic vapor phase epitaxy, methods were developed to achieve AlN films on sapphire with low etch pit density (EPD). Key to this achievement was using the same AlN growth recipe and only varying the pre-growth conditioning of the quartz-ware. After AlN growth, the quartz-ware was removed from the growth chamber and either exposed to room air or moved into the N2 purged glove box and exposed to H2O vapor. After the quartz-ware was exposed to room air or H2O, the AlN film growth was found to be more reproducible, resulting in films with (0002) and (10-12) x-ray diffraction (XRD) rocking curve linewidths of 200 and 500 arc sec, respectively, and EPDs < 100 cm-2. The EPD was found to correlate with (0002) linewidths, suggesting that the etch pits are associated with open core screw dislocations similar to GaN films. Once reproducible AlN conditions were established using the H2O pre-treatment, it was found that even small doses of trimethylaluminum (TMAl)/NH3 on the quartz-ware surfaces generated AlN films with higher EPDs. The presence of these residual TMAl/NH3-derived coatings in metalorganic vapor phase epitaxy (MOVPE) systems and their impact on the sapphire surface during heating might explain why reproducible growth of AlN on sapphire is difficult.

PitScan: Computer-Assisted Feature Detection

NASA Astrophysics Data System (ADS)

Wagner, R. V.; Robinson, M. S.

2018-04-01

We developed PitScan to assist in searching the very large LROC image dataset for pits — unusual <200m wide vertical-walled holes in the Moon's surface. PitScan reduces analysts' workload by pre-filtering images to identify possible pits.

Quantitative Correlation of 7B04 Aluminum Alloys Pitting Corrosion Morphology Characteristics with Stress Concentration Factor

NASA Astrophysics Data System (ADS)

Liu, Zhiguo; Yan, Guangyao; Mu, Zhitao; Li, Xudong

2018-01-01

The accelerated pitting corrosion test of 7B04 aluminum alloy specimen was carried out according to the spectrum which simulated airport environment, and the corresponding pitting corrosion damage was obtained and was defined through three parameters A and B and C which respectively denoted the corrosion pit surface length and width and corrosion pit depth. The ratio between three parameters could determine the morphology characteristics of corrosion pits. On this basis the stress concentration factor of typical corrosion pit morphology under certain load conditions was quantitatively analyzed. The research shows that the corrosion pits gradually incline to be ellipse in surface and moderate in depth, and most value of B/A and C/A lies in 1 between 4 and few maximum exceeds 4; The stress concentration factor Kf of corrosion pits is obviously affected by the its morphology, the value of Kf increases with corrosion pits depth increasement under certain corrosion pits surface geometry. Also, the value of Kf decreases with surface width increasement under certain corrosion pits depth. The research conclusion can set theory basis for corrosion fatigue life analysis of aircraft aluminum alloy structure.

Proteomics informed by transcriptomics for characterising active transposable elements and genome annotation in Aedes aegypti.

PubMed

Maringer, Kevin; Yousuf, Amjad; Heesom, Kate J; Fan, Jun; Lee, David; Fernandez-Sesma, Ana; Bessant, Conrad; Matthews, David A; Davidson, Andrew D

2017-01-19

Aedes aegypti is a vector for the (re-)emerging human pathogens dengue, chikungunya, yellow fever and Zika viruses. Almost half of the Ae. aegypti genome is comprised of transposable elements (TEs). Transposons have been linked to diverse cellular processes, including the establishment of viral persistence in insects, an essential step in the transmission of vector-borne viruses. However, up until now it has not been possible to study the overall proteome derived from an organism's mobile genetic elements, partly due to the highly divergent nature of TEs. Furthermore, as for many non-model organisms, incomplete genome annotation has hampered proteomic studies on Ae. aegypti. We analysed the Ae. aegypti proteome using our new proteomics informed by transcriptomics (PIT) technique, which bypasses the need for genome annotation by identifying proteins through matched transcriptomic (rather than genomic) data. Our data vastly increase the number of experimentally confirmed Ae. aegypti proteins. The PIT analysis also identified hotspots of incomplete genome annotation, and showed that poor sequence and assembly quality do not explain all annotation gaps. Finally, in a proof-of-principle study, we developed criteria for the characterisation of proteomically active TEs. Protein expression did not correlate with a TE's genomic abundance at different levels of classification. Most notably, long terminal repeat (LTR) retrotransposons were markedly enriched compared to other elements. PIT was superior to 'conventional' proteomic approaches in both our transposon and genome annotation analyses. We present the first proteomic characterisation of an organism's repertoire of mobile genetic elements, which will open new avenues of research into the function of transposon proteins in health and disease. Furthermore, our study provides a proof-of-concept that PIT can be used to evaluate a genome's annotation to guide annotation efforts which has the potential to improve the efficiency of annotation projects in non-model organisms. PIT therefore represents a valuable new tool to study the biology of the important vector species Ae. aegypti, including its role in transmitting emerging viruses of global public health concern.

Structures of Bordered Pits Potentially Contributing to Isolation of a Refilled Vessel from Negative Xylem Pressure in Stems of Morus australis Poir.: Testing of the Pit Membrane Osmosis and Pit Valve Hypotheses.

PubMed

Ooeda, Hiroki; Terashima, Ichiro; Taneda, Haruhiko

2017-02-01

Two hypotheses have been proposed to explain the mechanism preventing the refilling vessel water from being drained to the neighboring functional vessels under negative pressure. The pit membrane osmosis hypothesis proposes that the xylem parenchyma cells release polysaccharides that are impermeable to the intervessel pit membranes into the refilling vessel; this osmotically counteracts the negative pressure, thereby allowing the vessel to refill. The pit valve hypothesis proposes that gas trapped within intervessel bordered pits isolates the refilling vessel water from the surrounding functional vessels. Here, using the single-vessel method, we assessed these hypotheses in shoots of mulberry (Morus australis Poir.). First, we confirmed the occurrence of xylem refilling under negative pressure in the potted mulberry saplings. To examine the pit membrane osmosis hypothesis, we estimated the semi-permeability of pit membranes for molecules of various sizes and found that the pit membranes were not semi-permeable to polyethylene glycol of molecular mass <20,000. For the pit valve hypothesis, we formed pit valves in the intervessel pits in the short stem segments and measured the maximum liquid pressure up to which gases in bordered pits were retained. The threshold pressure ranged from 0.025 to 0.10 MPa. These values matched the theoretical value calculated from the geometry of the pit chamber (0.0692-0.101 MPa). Our results suggest that gas in the pits is retained by surface tension, even under substantial positive pressure to resolve gases in the refilling vessel, whereas the molecule size required for the pit membrane osmosis mechanism in mulberry would be unrealistically large. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Flambeau Mining Corporation, Ladysmith, Rusk County, Wisconsin. Proposed Open Pit Copper Mine and Waste Containment Area, Draft Environmental Impact Statement.

DTIC Science & Technology

1976-08-01

American elm Lonicera tatarica - tartarian honeysuckle Ulmus rubra - slippery elm Siiibucus canadenis - common elder Ulmus thoiii~sii - cork elm ...community borders the marshes and swamps. 2.060 The predominant species are the trembling aspen (Populus tremuloides), red maple (Acer rubrum), the elms ...succession. The most numerous trees (in descending order) are: white birch, red maple, aspen, sugar maple, black ash, basswood, elm (Ulmus sp.), hemlock

Geological and technological evaluation of gold-bearing mineral material after photo-electrochemical activation leaching

NASA Astrophysics Data System (ADS)

Manzyrev, DV

2017-02-01

The paper reports the lab test results on simulation of heap leaching of unoxidized rebellious ore extracted from deep levels of Pogromnoe open pit mine, with different flowsheets and photo-electrochemically activated solutions. It has been found that pre-treatment of rebellious ore particles -10 mm in size by photo-electrochemically activated solutions at the stage preceding agglomeration with the use of rich cyanide solutions enhances gold recovery by 6%.

Arc-related porphyry molybdenum deposit model: Chapter D in Mineral deposit models for resource assessment

USGS Publications Warehouse

Taylor, Ryan D.; Hammarstrom, Jane M.; Piatak, Nadine M.; Seal, Robert R.

2012-01-01

Geoenvironmental concerns are generally low because of low volumes of sulfide minerals. Most deposits are marginally acid-generating to non-acid-generating with drainage waters being near-neutral pH because of the acid generating potential of pyrite being partially buffered by late-stage calcite-bearing veins. The low ore content results in a waste:ore ratio of nearly 1:1 and large tailings piles from the open-pit method of mining.

Characterization of Black Carbon Mixing State

DOE Data Explorer

Sedlacek, Arthur; S, Satheesh; Springston, Stephen

2013-11-06

This measurement characterizes the types of BC emissions that result in near­surface BC­ containing particles in a region that is dominated by biomass and open pit/stove cooking. Specifically, examine three primary BC emission sources: (i) urban setting (e.g., fossil fuel emissions); and (ii) biomass burning. Source (i) are captured at the Indian Institute of Science (IISc) in Bangalore. Biomass emissions (ii) contains a series of 1­2 day measurement excursions to the rural area surrounding Bangalore.

Bacterial community composition in the water column of a lake formed by a former uranium open pit mine.

PubMed

Edberg, Frida; Andersson, Anders F; Holmström, Sara J M

2012-11-01

Mining of pyrite minerals is a major environmental issue involving both biological and geochemical processes. Here we present a study of an artificial lake of a former uranium open pit mine with the aim to connect the chemistry and bacterial community composition (454-pyrosequencing of 16S rRNA genes) in the stratified water column. A shift in the water chemistry from oxic conditions in the epilimnion to anoxic, alkaline, and metal and sulfide-rich conditions in the hypolimnion was corresponded by a strong shift in the bacterial community, with few shared operational taxonomic units (OTU) between the water layers. The epilimnetic bacterial community of the lake (~20 years old) showed similarities to other temperate freshwater lakes, while the hypolimnetic bacterial community showed similarity to extreme chemical environments. The epilimnetic bacterial community had dominance of Actinobacteria and Betaproteobacteria. The hypolimnion displayed a higher bacterial diversity and was dominated by the phototrophic green sulphur bacterium of the genus Chlorobium (ca. 40 % of the total community). Deltaproteobacteria were only represented in the hypolimnion and the most abundant OTUs were affiliated with ferric iron and sulfate reducers of the genus Geobacter and Desulfobulbus, respectively. The chemistry is clearly controlling, especially the hypolimnetic, bacterial community but the community composition also indicates that the bacteria are involved in metal cycling in the lake.

Dispersion and bioaccumulation of elements from an open-pit olivine mine in Southwest Greenland assessed using lichens, seaweeds, mussels and fish.

PubMed

Søndergaard, Jens

2013-08-01

This study investigated dispersion and bioaccumulation of mining-related elements from an open-pit olivine mine at Seqi in Southwest Greenland (64° N) using lichens (Flavocetraria nivalis), seaweeds (Fucus vesiculosus), mussels (Mytilus edulis) and fish (Myoxocephalus scorpius). The mine operated between 2005 and 2009, and samples were taken every year within a monitoring area 0-17 km from the mine during the period 2004-2011. A total of 46 elements were analysed in the samples. After mining began, highly elevated metal concentrations, especially nickel (Ni), chromium (Cr), iron (Fe) and cobalt (Co), were observed in lichens relative to pre-mining levels (up to a factor of 130) caused by dust dispersion from the mining activity. Elevated metal concentrations could be measured in lichens in distances up to ~5 km from the mine/ore treatment facility. Moderately elevated concentrations of Ni and Cr (up to a factor of 7) were also observed in seaweeds and mussels but only in close vicinity (<1 km) to the mine. Analyses of fish showed no significant changes in element composition. After mine closure, the elevated metal concentrations in lichens, seaweeds and mussels decreased markedly, and in 2011, significantly elevated metal concentrations could only be measured in lichens and only within a distance of 1 km from the mine.

Natural radionuclide content and radiological hazard associated with usage of quartzite sand samples from Ovacik-Silifke-Mersin open pit as building material in Turkey.

PubMed

Turhan, S; Aykamis, A S; Kiliç, A M

2009-09-01

Activity concentrations of (238)U, (232)Th, (226)Ra and (40)K in quartzite sand samples collected from the Ovacik-Silifke-Mersin open pit located in the East Mediterranean region of Turkey were determined by using a gamma-ray spectrometry technique. The mean activity concentrations of the (238)U, (232)Th, (226)Ra and (40)K in quartzite sand samples were found as 81.7 +/- 22.9 Bq kg(-1), 6.3 +/- 2.8 Bq kg(-1), 77.5 +/- 24.3 Bq kg(-1)and 140.0 +/- 124.1 Bq kg(-1), respectively. The gamma index (I(gamma)), the internal exposure index (I(alpha)), the indoor absorbed dose rate (D(in)) and the corresponding annual effective dose (H(in)) were evaluated for the public exposure to radiological hazard arising due to the use of quartzite sand samples as building material. The values of I(gamma), I(alpha), D(in) and H(in) ranged from 0.20 to 0.75, with a mean of 0.34 +/- 0.11, 0.23 to 0.77 with a mean of 0.39 +/- 0.12, 58.27 to 201.51 nGy h(-1) with a mean of 93.33 +/- 27.63 nGy h(-1) and 0.29 to 0.99 mSv with a mean of 0.46 +/- 0.14 mSv, respectively.

HYPGEO - A collaboration between geophysics and remote sensing for mineral exploration

NASA Astrophysics Data System (ADS)

Meyer, Uwe; Frei, Michaela; Petersen, Hauke; Papenfuß, Anne; Ibs-von Seht, Malte; Stolz, Ronny; Queitsch, Matthias; Buchholz, Peter; Siemon, Bernhard

2017-04-01

The German Federal Institute for Geosciences and Natural Resources (BGR) aims to promote and design application oriented, generic techniques for the detection and 3D-characterisation of mineral deposits. Most newly developed mineral mining structures are still exploiting near surface sources. Since exploration and exploitation of mineral resources are increasingly under public review concerning environmental issues and social acceptance, non-invasive methods using satellites, fixed-wing aircraft, helicopters or unmanned aerial vehicles are preferred techniques within this investigation. Therefore, a data combination of helicopter-borne gamma ray spectrometry, hyperspectral imagery and full tensor gradient magnetometry is being evaluated. Test areas are open pit mining structures in Aznalcollar and Tharsis within the Pyrite Belt of southern Spain. First test flights using gamma-ray spectrometry and gradient magnetometry using SQUID-based sensors have been performed. Hyperspectral imagery has been applied on ground. Rock and core samples from the mines have been taken or investigated for further analysis. The basic idea is to combine surface triggered signals from gamma-ray spectrometry and hyperspectral imagery to enhance the detection of shallow mineralisation structures. In order to investigate whether these structures are connected with near-surface ore veins, gradient magnetometry was applied to model subsurface formations. To verify that good correlations between the applied methods are given, open pit mining structures were chosen, where the mineral content and the local to regional geology is well known.

Sphagnum Moss as an Indicator of Contemporary Rates of Atmospheric Dust Deposition in the Athabasca Bituminous Sands Region.

PubMed

Mullan-Boudreau, Gillian; Belland, Rene; Devito, Kevin; Noernberg, Tommy; Pelletier, Rick; Shotyk, William

2017-07-05

Sphagnum moss was collected from ombrotrophic (rain-fed) peat bogs to quantify dust emissions from the open-pit mining and upgrading of Athabasca bituminous sands (ABS). A total of 30 bogs were sampled in the ABS region, and 5 were sampled in central Alberta. Ash was separated into the acid-insoluble ash (AIA) and acid-soluble ash (ASA) fractions using HCl. The AIA concentrations increase toward industry from 0.4 ± 0.5% to 4.7 ± 2.0% over a distance of 30 km; the control site at the Utikuma Region Study Area (URSA) yielded 0.29 ± 0.07% (n = 30). Mass accumulations rates showed similar spatial variation. The morphology and mineralogy of the AIA particles were studied using scanning electron microscopy and energy-dispersive X-ray analysis and the particle size distributions using optical methods. Particle size was more variable in moss closer to industry. Major ions in the ASA fraction showed elevated accumulation rates of Ca, K, Fe, Mg, P, and S, with P being up to 5 times greater in samples nearest industry compared to those in distal locations. Given that P has been regarded as the growth-limiting nutrient in bogs, fertilization of nutrient-poor ecosystems, such as these from fugitive emissions of dusts from open-pit mining, may have long-term ecological ramifications.

Underground Pumped Storage Hydropower using abandoned open pit mines: influence of groundwater seepage on the system efficiency

NASA Astrophysics Data System (ADS)

Pujades, Estanislao; Bodeux, Sarah; Orban, Philippe; Dassargues, Alain

2016-04-01

Pumped Storage Hydropower (PSH) plants can be used to manage the production of electrical energy according to the demand. These plants allow storing and generating electricity during low and high demand energy periods, respectively. Nevertheless, PSH plants require a determined topography because two reservoirs located at different heights are needed. At sites where PSH plants cannot be constructed due to topography requirements (flat regions), Underground Pumped Storage Hydropower (UPSH) plants can be used to adjust the electricity production. These plants consist in two reservoirs, the upper one is located at the surface (or at shallow depth) while the lower one is underground (or deeper). Abandoned open pit mines can be used as lower reservoirs but these are rarely isolated. As a consequence, UPSH plants will interact with surrounding aquifers exchanging groundwater. Groundwater seepage will modify hydraulic head inside the underground reservoir affecting global efficiency of the UPSH plant. The influence on the plant efficiency caused by the interaction between UPSH plants and aquifers will depend on the aquifer parameters, underground reservoir properties and pumping and injection characteristics. The alteration of the efficiency produced by the groundwater exchanges, which has not been previously considered, is now studied numerically. A set of numerical simulations are performed to establish in terms of efficiency the effects of groundwater exchanges and the optimum conditions to locate an UPSH plant.

Laser induced breakdown spectroscopy (LIBS) as a rapid tool for material analysis

NASA Astrophysics Data System (ADS)

Hussain, T.; Gondal, M. A.

2013-06-01

Laser induced breakdown spectroscopy (LIBS) is a novel technique for elemental analysis based on laser-generated plasma. In this technique, laser pulses are applied for ablation of the sample, resulting in the vaporization and ionization of sample in hot plasma which is finally analyzed by the spectrometer. The elements are identified by their unique spectral signatures. LIBS system was developed for elemental analysis of solid and liquid samples. The developed system was applied for qualitative as well as quantitative measurement of elemental concentration present in iron slag and open pit ore samples. The plasma was generated by focusing a pulsed Nd:YAG laser at 1064 nm on test samples to study the capabilities of LIBS as a rapid tool for material analysis. The concentrations of various elements of environmental significance such as cadmium, calcium, magnesium, chromium, manganese, titanium, barium, phosphorus, copper, iron, zinc etc., in these samples were determined. Optimal experimental conditions were evaluated for improving the sensitivity of developed LIBS system through parametric dependence study. The laser-induced breakdown spectroscopy (LIBS) results were compared with the results obtained using standard analytical technique such as inductively couple plasma emission spectroscopy (ICP). Limit of detection (LOD) of our LIBS system were also estimated for the above mentioned elements. This study demonstrates that LIBS could be highly appropriate for rapid online analysis of iron slag and open pit waste.

Parturition pit: the bony imprint of vaginal birth.

PubMed

McArthur, Tatum A; Meyer, Isuzu; Jackson, Bradford; Pitt, Michael J; Larrison, Matthew C

2016-09-01

To retrospectively evaluate for pits along the dorsum of the pubic body in females and compare the presence/absence of these pits to vaginal birth data. We retrospectively reviewed females with vaginal birth data who underwent pelvic CT. The presence of pits along the dorsum of the pubic body, pit grade (0 = not present; 1 = faintly imperceptible; 2 = present; 3 = prominent), and the presence of osteitis condensans ilii, preauricular sulcus, and sacroiliac joint vacuum phenomenon were assessed on imaging. Musculoskeletal radiologists who were blinded to the birth data evaluated the CTs. 48 males were also evaluated for the presence of pits. 482 female patients underwent CT pelvis and 171 were excluded due to lack of vaginal birth data. Of the 311 study patients, 262 had prior vaginal birth(s) and 194 had pits on CT. Only 7 of the 49 patients without prior vaginal birth had pits. There was a statistically significant association between vaginal birth and presence of pits (p < 0.0001). Patients with more prominent pits (grades 2/3) had a greater number of vaginal births. As vaginal deliveries increased, the odds of having parturition pits greatly increased, adjusting for age and race at CT (p < 0.0001). No males had pits. Our study indicates that parturition pits are associated with prior vaginal birth and should be considered a characteristic of the female pelvis. The lytic appearance of prominent pits on imaging can simulate disease and create a diagnostic dilemma for interpreting radiologists.

Parturition Pit: The Bony Imprint of Vaginal Birth

PubMed Central

Meyer, Isuzu; Jackson, Bradford; Pitt, Michael J.; Larrison, Matthew C.

2017-01-01

Purpose To retrospectively evaluate for pits along the dorsum of the pubic body in females and compare the presence/absence of these pits to vaginal birth data. Materials and Methods We retrospectively reviewed females with vaginal birth data who underwent pelvic CT. The presence of pits along the dorsum of the pubic body, pit grade (0 = not present; 1 = faintly imperceptible; 2 = present; 3 = prominent), and the presence of osteitis condensans ilii, preauricular sulcus, and sacroiliac joint vacuum phenomenon were assessed on imaging. Musculoskeletal radiologists who were blinded to the birth data evaluated the CTs. 48 males were also evaluated for the presence of pits. Results 482 female patients underwent CT pelvis and 171 were excluded due to lack of vaginal birth data. Of the 311 study patients, 262 had prior vaginal birth(s) and 194 had pits on CT. Only 7 of the 49 patients without prior vaginal birth had pits. There was a statistically significant association between vaginal birth and presence of pits (p<0.0001). Patients with more prominent pits (grades 2/3) had a greater number of vaginal births. As vaginal deliveries increased, the odds of having parturition pits greatly increased, adjusting for age and race at CT (p<0.0001). No males had pits. Conclusion Our study indicates that parturition pits are associated prior vaginal birth and should be considered a characteristic of the female pelvis. The lytic appearance of prominent pits on imaging can simulate disease and create a diagnostic dilemma for interpreting radiologists. PMID:27270921

The effect of normal pulsed Nd-YAG laser irradiation on pits and fissures in human teeth.

PubMed

Bahar, A; Tagomori, S

1994-01-01

The effects of normal pulsed Nd-YAG laser irradiation on the acid resistance of human dental enamel of pits and fissures, the cleaning of the pit and fissure contents and fluoride uptake into deep pits and fissures were examined. The acid resistance of the pit and fissure enamel was evaluated by the amount of dissolved calcium per square millimeter of the surface area. The pit and fissure enamel treated with laser irradiation obtained an acid resistance 30% higher than that of the unlased controls. The cleaning effect of laser irradiation on the pit and fissure contents was compared with chemicomechanical and mechanical methods. The laser irradiation was found to clean the pits and fissures to a greater depth without alterating the shape of pits and fissures, compared with the other two methods. The distribution of calcium, phosphorus and fluoride in the enamel of the pits and fissures was then measured by electron probe microanalyzer. At the entrance and in the deep part of the pits and fissures, the fluoride content of the enamel treated with acidulated phosphate fluoride after laser irradiation was higher than that of the enamel treated with acidulated phosphate fluoride alone. These results thus suggest that Nd-YAG laser irradiation might be effective in increasing the acid resistance of the pit and fissure enamel, while removing the pit and fissure debris contents and increasing the fluoride uptake into the pit and fissure enamel.

Pitting Corrosion Behaviour of New Corrosion-Resistant Reinforcement Bars in Chloride-Containing Concrete Pore Solution

PubMed Central

Liu, Yao; Chu, Hong-yan; Wang, Danqian; Ma, Han; Sun, Wei

2017-01-01

In this study, the pitting behaviour of a new corrosion-resistant alloy steel (CR) is compared to that of low-carbon steel (LC) in a simulated concrete pore solution with a chloride concentration of 5 mol/L. The electrochemical behaviour of the bars was characterised using linear polarisation resistance (LPR) and electrochemical impedance spectroscopy (EIS). The pitting profiles were detected by reflective digital holographic microscopy (DHM), scanning electron microscopy (SEM), and the chemical components produced in the pitting process were analysed by X-ray energy dispersive spectroscopy (EDS). The results show that the CR bars have a higher resistance to pitting corrosion than the LC bars. This is primarily because of the periodic occurrence of metastable pitting during pitting development. Compared to the pitting process in the LC bars, the pitting depth grows slowly in the CR bars, which greatly reduces the risk of pitting. The possible reason for this result is that the capability of the CR bars to heal the passivation film helps to restore the metastable pits to the passivation state. PMID:28777327

Pitting corrosion as a mixed system: coupled deterministic-probabilistic simulation of pit growth

NASA Astrophysics Data System (ADS)

Ibrahim, Israr B. M.; Fonna, S.; Pidaparti, R.

2018-05-01

Stochastic behavior of pitting corrosion poses a unique challenge in its computational analysis. However, it also stems from electrochemical activity causing general corrosion. In this paper, a framework for corrosion pit growth simulation based on the coupling of the Cellular Automaton (CA) and Boundary Element Methods (BEM) is presented. The framework assumes that pitting corrosion is controlled by electrochemical activity inside the pit cavity. The BEM provides the prediction of electrochemical activity given the geometrical data and polarization curves, while the CA is used to simulate the evolution of pit shapes based on electrochemical activity provided by BEM. To demonstrate the methodology, a sample case of local corrosion cells formed in pitting corrosion with varied dimensions and polarization functions is considered. Results show certain shapes tend to grow in certain types of environments. Some pit shapes appear to pose a higher risk by being potentially significant stress raisers or potentially increasing the rate of corrosion under the surface. Furthermore, these pits are comparable to commonly observed pit shapes in general corrosion environments.

Closure Report for Corrective Action Unit 544: Cellars, Mud Pits, and Oil Spills, Nevada National Security Site, Nevada, Revision 0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mark Krauss and Catherine Birney

2011-05-01

This Closure Report (CR) presents information supporting the closure of Corrective Action Unit (CAU) 544: Cellars, Mud Pits, and Oil Spills, Nevada National Security Site, Nevada. This CR complies with the requirements of the Federal Facility Agreement and Consent Order that was agreed to by the State of Nevada; U.S. Department of Energy (DOE), Environmental Management; U.S. Department of Defense; and DOE, Legacy Management. The corrective action sites (CASs) within CAU 544 are located within Areas 2, 7, 9, 10, 12, 19, and 20 of the Nevada National Security Site. Corrective Action Unit 544 comprises the following CASs: • 02-37-08,more » Cellar & Mud Pit • 02-37-09, Cellar & Mud Pit • 07-09-01, Mud Pit • 09-09-46, U-9itsx20 PS #1A Mud Pit • 10-09-01, Mud Pit • 12-09-03, Mud Pit • 19-09-01, Mud Pits (2) • 19-09-03, Mud Pit • 19-09-04, Mud Pit • 19-25-01, Oil Spill • 19-99-06, Waste Spill • 20-09-01, Mud Pits (2) • 20-09-02, Mud Pit • 20-09-03, Mud Pit • 20-09-04, Mud Pits (2) • 20-09-06, Mud Pit • 20-09-07, Mud Pit • 20-09-10, Mud Pit • 20-25-04, Oil Spills • 20-25-05, Oil Spills The purpose of this CR is to provide documentation supporting the completed corrective actions and data confirming that the closure objectives for CASs within CAU 544 were met. To achieve this, the following actions were performed: • Review the current site conditions, including the concentration and extent of contamination. • Implement any corrective actions necessary to protect human health and the environment. • Properly dispose of corrective action and investigation wastes. • Document Notice of Completion and closure of CAU 544 issued by the Nevada Division of Environmental Protection.« less

An open source high-performance solution to extract surface water drainage networks from diverse terrain conditions

USGS Publications Warehouse

Stanislawski, Larry V.; Survila, Kornelijus; Wendel, Jeffrey; Liu, Yan; Buttenfield, Barbara P.

2018-01-01

This paper describes a workflow for automating the extraction of elevation-derived stream lines using open source tools with parallel computing support and testing the effectiveness of procedures in various terrain conditions within the conterminous United States. Drainage networks are extracted from the US Geological Survey 1/3 arc-second 3D Elevation Program elevation data having a nominal cell size of 10 m. This research demonstrates the utility of open source tools with parallel computing support for extracting connected drainage network patterns and handling depressions in 30 subbasins distributed across humid, dry, and transitional climate regions and in terrain conditions exhibiting a range of slopes. Special attention is given to low-slope terrain, where network connectivity is preserved by generating synthetic stream channels through lake and waterbody polygons. Conflation analysis compares the extracted streams with a 1:24,000-scale National Hydrography Dataset flowline network and shows that similarities are greatest for second- and higher-order tributaries.

Giant-geode endowment of tumuli in the Veia Alta flow, Ametista do Sul

NASA Astrophysics Data System (ADS)

Hartmann, L. A.; Pertille, J.; Duarte, L. C.

2017-08-01

Tumuli are a common feature of pahoehoe basaltic flows, interspersed with pits, and furnished the necessary volume of rock in the Paraná volcanic province for hydrothermal alteration and ballooning to form large cavities (1-2 m common). Filling by amethyst and other minerals resulted in the largest world deposit of geodes, Ametista do Sul. The flat-lying fracture positioned 1 m below the 2-3 m thick geodic level crosses the plateau and is a major guide for exploration and gallery opening. The geodes are limited on the top by the platy joint layer, which is covered by an auto-breccia with undulating lower limit. This wave mimicks and is internal to the structure of tumuli and pits at the surface. This field-oriented survey of galleries selected out of 300 active mines resulted in the description of the internal structure of the remarkable Veia Alta pahoehoe flow, in addition to observations in Uruguay.

Oceanic corrosion test of bare and zinc-protected aluminum alloys for seawater heat exchangers

NASA Technical Reports Server (NTRS)

Sasscer, D. S.; Morgan, T. O.; Rivera, C.; Ernst, R.; Scott, A. C.; Summerson, T. J.

1982-01-01

Bare 3004 tubes, 7072 Alclad 3004 tubes, and bare and zinc diffusion treated 3003 extrusions from a brazed aluminum, plate-fin heat exchanger were exposed to 1.8 m/sec flowing seawater aboard an open ocean test facility moored 3.4 km off the southeast coast of Puerto Rico. After six months exposure, the average corrosion rates for most varieties of aluminum materials converged to a low value of 0.015 mm/yr (0.6 mils/yr). Pitting did not occur in bare 3003 and 3004 samples during the six month test. Pitting did occur to varying degrees in the Alclad and zinc diffusion treated material, but did not penetrate to the base metal. Biofouling countermeasures (intermittent chlorination and brushing) did not affect the corrosion rates to any significant extent. Intermittent chlorination at a level of 0.5 ppm for 28 minutes daily controlled microbiofouling of the samples but did not prevent the development of a macrobiofouling community in areas of the plumbing with low flow.

Corrosion behavior of binary titanium aluminide intermetallics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saffarian, H.M.; Gan, Q.; Hadkar, R.

1996-08-01

The corrosion behavior of arc-melted binary titanium aluminide intermetallics TiAl, Ti{sub 2}Al, and TiAl{sub 3} in aqueous sodium sulfate and sodium chloride solutions was measured and compared to that of pure Ti and Al. Effects of electrolyte composition (e.g., sulfate [0.25 M SO{sub 4}{sup 2}{sup {minus}}], chloride [0.1 to 1.0 M Cl{sup {minus}}], and pH [3 to 10]) were examined. Anodic polarization of titanium aluminides in aqueous SO{sub 4}{sup 2}{sup {minus}} solutions was similar (showing passive behavior), but no pitting or pitting potential (E{sub pit}) was observed. In aqueous NaCl, however, titanium aluminides were susceptible to pitting, and E{sub pit}more » decreased with increasing Al content (i.e., Ti{sub 3}Al had the highest E{sub pit} and, therefore, a greater resistance to pitting, followed by TiAl and TiAl{sub 3}). For TiAl, E{sub pit} was slightly dependent upon pH or Cl{sup {minus}} concentration. Pit morphology and E{sub pit} values were quite different for TiAl compared to Ti{sub 3}Al. TiAl showed numerous small pits, whereas Ti{sub 3}Al exhibited fewer but larger and deeper pits. The larger pit density for TiAl was associated with Al-rich interdendrite regions. One interesting feature of the anodic polarization curves for Ti{sub 3}Al was a small anodic peak frequently observed at {approximately}1.4 V{sub SCE} to 1.8 V{sub SCE}. Results suggested this peak was associated with pit initiation, since pitting initiated concurrently with the peak or immediately afterward.« less

Legacy of the California Gold Rush: Environmental geochemistry of arsenic in the southern Mother Lode Gold District

USGS Publications Warehouse

Savage, K.S.; Bird, D.K.; Ashley, R.P.

2000-01-01

Gold mining activity in the Sierra Nevada foothills, both recently and during the California Gold Rush, has exposed arsenic-rich pyritic rocks to weathering and erosion. This study describes arsenic concentration and speciation in three hydrogeologic settings in the southern Mother Lode Gold District: mineralized outcrops and mine waste rock (overburden); mill tailings submerged in a water reservoir; and lake waters in this monomictic reservoir and in a monomictic lake developing within a recent open-pit mine. These environments are characterized by distinct modes of rock-water interaction that influence the local transport and fate of arsenic. Arsenic in outcrops and waste rock occurs in arsenian pyrite containing an average of 2 wt% arsenic. Arsenic is concentrated up to 1300 ppm in fine-grained, friable iron-rich weathering products of the arsenian pyrite (goethite, jarosite, copiapite), which develop as efflorescences and crusts on weathering outcrops. Arsenic is sorbed as a bidentate complex on goethite, and substitutes for sulfate in jarosite. Submerged mill tailings obtained by gravity core at Don Pedro Reservoir contain arsenic up to 300 ppm in coarse sand layers. Overlying surface muds have less arsenic in the solid fraction but higher concentrations in porewaters (up to 500 ??g/L) than the sands. Fine quartz tailings also contain up to 3.5 ppm mercury related to the ore processing. The pH values in sediment porewaters range from 3.7 in buried gypsum-bearing sands and tailings to 7 in the overlying lake sediments. Reservoir waters immediately above the cores contain up to 3.5 ??g/L arsenic; lake waters away from the submerged tailings typically contain less than 1 ??g/L arsenic. Dewatering during excavation of the Harvard open-pit mine produced a hydrologic cone of depression that has been recovering toward the pre-mining groundwater configuration since mining ended in 1994. Aqueous arsenic concentrations in the 80 m deep pit lake are up to 1000 ??g/L. Redistribution of the arsenic occurs during summer stratification, with highest concentrations at middle depths. The total mass of arsenic in the pit lake increases coinciding with early winter rains that erode, partially dissolve, and transport arsenic-bearing salts into the pit lake. Arsenic concentration, speciation, and distribution in the Sierra Nevada foothills depend on many factors, including the lithologic sources of arsenic, climatic influences on weathering of host minerals, and geochemical characteristics of waters with which source and secondary minerals react. Oxidation of arsenian pyrite to goethite, jarosite, and copiapite causes temporary attenuation of arsenic during summer, when these secondary minerals accumulate; subsequent rapid dissemination of arsenic into the aqueous environment is caused by annual winter storms. As the population of the Mother Lode area grows, it is increasingly important to consider these effects during planning and development of land and groundwater resources.

Evaluation of magnifying colonoscopy in the diagnosis of serrated polyps.

PubMed

Ishigooka, Shinya; Nomoto, Masahito; Obinata, Nobuyuki; Oishi, Yoshichika; Sato, Yoshinori; Nakatsu, Satoko; Suzuki, Midori; Ikeda, Yoshiko; Maehata, Tadateru; Kimura, Tomoaki; Watanabe, Yoshiyuki; Nakajima, Takashi; Yamano, Hiro-o; Yasuda, Hiroshi; Itoh, Fumio

2012-08-28

To elucidate the colonoscopic features of serrated lesions of the colorectum using magnifying colonoscopy. Broad division of serrated lesions of the colorectum into hyperplastic polyps (HPs), traditional serrated adenomas (TSAs), and sessile serrated adenomas/polyps (SSA/Ps) has been proposed on the basis of recent molecular biological studies. However, few reports have examined the colonoscopic features of these divisions, including magnified colonoscopic findings. This study examined 118 lesions excised in our hospital as suspected serrated lesions after magnified observation between January 2008 and September 2011. Patient characteristics (sex, age), conventional colonoscopic findings (location, size, morphology, color, mucin) and magnified colonoscopic findings (pit pattern diagnosis) were interpreted by five colonoscopists with experience in over 1000 colonoscopies, and were compared with histopathological diagnoses. The pit patterns were categorized according to Kudo's classification, but a more detailed investigation was also performed using the subclassification [type II-Open (type II-O), type II-Long (type II-L), or type IV-Serrated (type IV-S)] proposed by Kimura T and Yamano H. Lesions comprised 23 HPs (23/118: 19.5%), 39 TSAs (39/118: 33.1%: with cancer in one case), 50 SSA/Ps (50/118: 42.4%: complicated with cancer in three cases), and six others (6/118: 5.1%). We excluded six others, including three regular adenomas, one hamartoma, one inflammatory polyp, and one juvenile polyp for further analysis. Conventional colonoscopy showed that SSA/Ps were characterized as larger in diameter than TSAs and HPs (SSA/P vs HP, 13.62 ± 8.62 mm vs 7.74 ± 3.24 mm, P < 0.001; SSA/Ps vs TSA, 13.62 ± 8.62 mm vs 9.89 ± 5.73 mm, P < 0.01); common in the right side of the colon [HPs, 30.4% (7/23): TSAs, 20.5% (8/39): SSA/P, 84.0% (42/50), P < 0.001]; flat-elevated lesion [HPs, 30.4% (7/23): TSAs, 5.1% (2/39): SSA/Ps, 90.0% (45/50), P < 0.001]; normal-colored or pale imucosa [HPs, 34.8% (8/23): TSAs, 10.3% (4/39): SSA/Ps, 80% (40/50), P < 0.001]; and with large amounts of mucin [HPs, 21.7% (5/23): TSAs, 17.9% (7/39): SSA/Ps, 72.0% (36/50), P < 0.001]. In magnified colonoscopic findings, 17 lesions showed either type II pit pattern alone or partial type II pit pattern as the basic architecture, with 14 HPs (14/17, 70.0%) and 3 SSA/Ps. Magnified colonoscopy showed the type II-O pit pattern as characteristic of SSA/Ps [sensitivity 83.7% (41/49), specificity 85.7% (54/63)]. Cancer was also present in three lesions, in all of which a type VI pit pattern was also present within the same lesion. There were four HPs and four TSAs each. The type IV-S pit pattern was characteristic of TSAs [sensitivity 96.7% (30/31), specificity 89.9% (72/81)]. Cancer was present in one lesion, in which a type VI pit pattern was also present within the same lesion. In our study, serrated lesions of the colorectum also possessed the features described in previous reports of conventional colonoscopic findings. The pit pattern diagnosis using magnifying colonoscopy, particularly magnified colonoscopic findings using subclassifications of surface architecture, reflected the pathological characteristics of SSA/Ps and TSAs, and will be useful for colonoscopic diagnosis. We suggest that this system could be a good diagnostic tool for SSA/Ps using magnifying colonoscopy.

Morphology and Evolution of Sublimation Pits on Pluto

NASA Astrophysics Data System (ADS)

Abu-Hashmeh, N.; Conrad, J. W.; Nimmo, F.; Moore, J. M.; Stern, A.; Olkin, C.; Weaver, H. A., Jr.; Ennico Smith, K.; Young, L. A.

2017-12-01

Pluto's Sputnik Planitia region hosts a geologically young surface of nitrogen ice that exhibits striking pitted terrain (Moore et al., Science 351, 2016). These pits are most likely formed by sublimation due to incident sunlight, similar to the southern polar cap of Mars (Byrne and Ingersoll, Science 299, 2003); however, their evolution over time has resulted in unique morphological characteristics. Motivated by this, we used the high-resolution mosaic strips captured by New Horizons' Long Range Reconnaissance Imager (LORRI) to map sublimation pits in the southernmost region of Sputnik Planitia. Statistical data shows pit orientations appearing North-South dominant; their morphology also indicates extensional evolution along the major axis caused by further sublimation and contact-coalescence processes. Qualitative analysis of the region yielded indications of an evolutionary path for individual pits that coalesce into each other and exhibit an elongated end-stage. Additionally, densely-pitted regions generally appear to correlate with regions containing longer pits, implying that coalescence may be an important process for elongation. We also model the evolution geometry through competing effects of diffusion (viscous relaxation) and retreat (sublimation) (Buhler and Ingersoll, LPSC Abstract #1746, 2017). The model demonstrates single-pit and coalescing-pit evolutions that influence overall length, as well as a potential ability for the pit center to move in space while the pit morphology evolves.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Magie, Robert J.; Morris, Matthew S.; Ledgerwood, Richard D.

In 2008, we sampled migrating juvenile Pacific salmonids Oncorhynchus spp. tagged with passive integrated transponder (PIT) tags using a surface pair trawl in the upper Columbia River estuary (rkm 61-83). The cod-end of the trawl was replaced with a cylindrical PIT-tag detection antenna with an 86-cm-diameter fish-passage opening and two detection coils connected in series. The pair trawl was 105 m long with a 91.5-m opening between the wings and a sample depth of 4.9 m. Also during 2008, we finalized the development of a prototype 'matrix' antenna, which was larger than previous antennas by a considerable magnitude. The matrixmore » antenna consisted of 6 coils: a 3-coil front component and a 3-coil rear component, which were separated by 1.5-m of net mesh. The fish-passage opening was 2.5 m wide by 3.0 m tall and was attached to a standard-size pair trawl net. Intermittent sampling with a single crew began on 7 March and targeted yearling Chinook salmon O. tshawytscha and steelhead O. mykiss. Daily sampling using two crews began on 30 April and continued through 14 June; during this period we detected 2.7% of all juvenile salmonids previously detected at Bonneville Dam--a measure of sample efficiency. Sampling with a single crew continued through 20 August and targeted subyearling Chinook salmon. We detected 7,397 yearling Chinook salmon, 2,735 subyearling Chinook salmon, 291 coho salmon O. kisutch, 5,950 steelhead, and 122 sockeye salmon O. nerka in the upper estuary. We deployed the matrix antenna system and the older, cylindrical antenna system (86-cm-diameter fish-passage opening) simultaneously in mid-May 2008 to test matrix detection efficiency. The cylindrical antenna system had been used successfully in 2007 and early 2008. Because distribution of migrating salmonids in the estuary changes rapidly, we felt that a tandem sampling effort between the two systems was the only way to truly evaluate comparative detection efficiency. We deployed both systems within 1 km of each other during a period of high fish densities on 13, 14, and 15 May. Detections of the matrix system surpassed those of the cylindrical system by 53% in 14 h of simultaneous sampling (total detections 716 and 339, respectively). We believe that the higher detection rate observed with the matrix system was due to fewer smolts escaping the trawl entrance and to more smolts readily passing through the larger fish-passage opening. After tandem sampling, we continued exclusive use of the matrix system for the remainder of the 2008 juvenile migration season. Mean survival rates from Lower Granite to Bonneville Dam for yearling Chinook salmon and steelhead were 42% (SE = 3.7%) and 46% (SE = 1.5%), respectively. Over 358,000 PIT-tagged salmonids were transported, and we detected 4,619 of these fish.« less

Initation of pitting corrosion in martensitic stainless steels. [17-4PH; 13-8Mo; Custom 450

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cieslak, W.R.; Semarge, R.E.; Bovard, F.S.

1986-01-01

The form of localized corrosion known as pitting often initiates preferentially at microstructural inhomogeneities. The pit initiation resistance, therefore, is controlled by the characteristics of the initiation sites, rather than by the bulk material composition. This investigation correlates the pit initiation resistance, as measured by critical pitting potentials, with preferred pit initiation sites for 3 martensitic stainless steels. Pit initiation sites are determined by secondary electron (SE) and backscattered electron (BSE) imaging and energy dispersive and wavelength dispersive spectrometries (EDS and WDS) with a scalling electron microscope (SEM) and an electron probe microanalyzer (EPMA).

Pitted terrains on (1) Ceres and implications for shallow subsurface volatile distribution

PubMed Central

Platz, T.; Schorghofer, N.; Prettyman, T. H.; De Sanctis, M. C.; Crown, D. A.; Schmedemann, N.; Neesemann, A.; Kneissl, T.; Marchi, S.; Schenk, P. M.; Bland, M. T.; Schmidt, B. E.; Hughson, K. H. G.; Tosi, F.; Zambon, F.; Mest, S. C.; Yingst, R. A.; Williams, D. A.; Russell, C. T.; Raymond, C. A.

2017-01-01

Abstract Prior to the arrival of the Dawn spacecraft at Ceres, the dwarf planet was anticipated to be ice‐rich. Searches for morphological features related to ice have been ongoing during Dawn's mission at Ceres. Here we report the identification of pitted terrains associated with fresh Cerean impact craters. The Cerean pitted terrains exhibit strong morphological similarities to pitted materials previously identified on Mars (where ice is implicated in pit development) and Vesta (where the presence of ice is debated). We employ numerical models to investigate the formation of pitted materials on Ceres and discuss the relative importance of water ice and other volatiles in pit development there. We conclude that water ice likely plays an important role in pit development on Ceres. Similar pitted terrains may be common in the asteroid belt and may be of interest to future missions motivated by both astrobiology and in situ resource utilization. PMID:28989206

Pitted terrains on (1) Ceres and implications for shallow subsurface volatile distribution.

PubMed

Sizemore, H G; Platz, T; Schorghofer, N; Prettyman, T H; De Sanctis, M C; Crown, D A; Schmedemann, N; Neesemann, A; Kneissl, T; Marchi, S; Schenk, P M; Bland, M T; Schmidt, B E; Hughson, K H G; Tosi, F; Zambon, F; Mest, S C; Yingst, R A; Williams, D A; Russell, C T; Raymond, C A

2017-07-16

Prior to the arrival of the Dawn spacecraft at Ceres, the dwarf planet was anticipated to be ice-rich. Searches for morphological features related to ice have been ongoing during Dawn's mission at Ceres. Here we report the identification of pitted terrains associated with fresh Cerean impact craters. The Cerean pitted terrains exhibit strong morphological similarities to pitted materials previously identified on Mars (where ice is implicated in pit development) and Vesta (where the presence of ice is debated). We employ numerical models to investigate the formation of pitted materials on Ceres and discuss the relative importance of water ice and other volatiles in pit development there. We conclude that water ice likely plays an important role in pit development on Ceres. Similar pitted terrains may be common in the asteroid belt and may be of interest to future missions motivated by both astrobiology and in situ resource utilization.

Pitted terrains on (1) Ceres and implications for shallow subsurface volatile distribution

USGS Publications Warehouse

Sizemore, H.G.; Platz, Thomas; Schorghofer, Norbert; Prettyman, Thomas; De Sanctis, Maria Christina; Crown, David A.; Schmedemann, Nico; Nessemann, Andeas; Kneissl, Thomas; Simone Marchi,; Schenk, Paul M.; Bland, Michael T.; Schmidt, B.E.; Hughson, Kynan H.G.; Tosi, F.; Zambon, F; Mest, S.C.; Yingst, R.A.; Williams, D.A.; Russell, C.T.; Raymond, C.A.

2017-01-01

Prior to the arrival of the Dawn spacecraft at Ceres, the dwarf planet was anticipated to be ice-rich. Searches for morphological features related to ice have been ongoing during Dawn's mission at Ceres. Here we report the identification of pitted terrains associated with fresh Cerean impact craters. The Cerean pitted terrains exhibit strong morphological similarities to pitted materials previously identified on Mars (where ice is implicated in pit development) and Vesta (where the presence of ice is debated). We employ numerical models to investigate the formation of pitted materials on Ceres and discuss the relative importance of water ice and other volatiles in pit development there. We conclude that water ice likely plays an important role in pit development on Ceres. Similar pitted terrains may be common in the asteroid belt and may be of interest to future missions motivated by both astrobiology and in situ resource utilization.

Force-displacement measurements of earlywood bordered pits using a mesomechanical tester.

PubMed

Zelinka, Samuel L; Bourne, Keith J; Hermanson, John C; Glass, Samuel V; Costa, Adriana; Wiedenhoeft, Alex C

2015-10-01

The elastic properties of pit membranes are reported to have important implications in understanding air-seeding phenomena in gymnosperms, and pit aspiration plays a large role in wood technological applications such as wood drying and preservative treatment. Here we present force-displacement measurements for pit membranes of circular bordered pits, collected on a mesomechanical testing system. The system consists of a quartz microprobe attached to a microforce sensor that is positioned and advanced with a micromanipulator mounted on an inverted microscope. Membrane displacement is measured from digital image analysis. Unaspirated pits from earlywood of never-dried wood of Larix and Pinus and aspirated pits from earlywood of dried wood of Larix were tested to generate force-displacement curves up to the point of membrane failure. Two failure modes were observed: rupture or tearing of the pit membrane by the microprobe tip, and the stretching of the pit membrane until the torus was forced out of the pit chamber through the pit aperture without rupture, a condition we refer to as torus prolapse. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Relative Error Evaluation to Typical Open Global dem Datasets in Shanxi Plateau of China

NASA Astrophysics Data System (ADS)

Zhao, S.; Zhang, S.; Cheng, W.

2018-04-01

Produced by radar data or stereo remote sensing image pairs, global DEM datasets are one of the most important types for DEM data. Relative error relates to surface quality created by DEM data, so it relates to geomorphology and hydrologic applications using DEM data. Taking Shanxi Plateau of China as the study area, this research evaluated the relative error to typical open global DEM datasets including Shuttle Radar Terrain Mission (SRTM) data with 1 arc second resolution (SRTM1), SRTM data with 3 arc second resolution (SRTM3), ASTER global DEM data in the second version (GDEM-v2) and ALOS world 3D-30m (AW3D) data. Through process and selection, more than 300,000 ICESat/GLA14 points were used as the GCP data, and the vertical error was computed and compared among four typical global DEM datasets. Then, more than 2,600,000 ICESat/GLA14 point pairs were acquired using the distance threshold between 100 m and 500 m. Meanwhile, the horizontal distance between every point pair was computed, so the relative error was achieved using slope values based on vertical error difference and the horizontal distance of the point pairs. Finally, false slope ratio (FSR) index was computed through analyzing the difference between DEM and ICESat/GLA14 values for every point pair. Both relative error and FSR index were categorically compared for the four DEM datasets under different slope classes. Research results show: Overall, AW3D has the lowest relative error values in mean error, mean absolute error, root mean square error and standard deviation error; then the SRTM1 data, its values are a little higher than AW3D data; the SRTM3 and GDEM-v2 data have the highest relative error values, and the values for the two datasets are similar. Considering different slope conditions, all the four DEM data have better performance in flat areas but worse performance in sloping regions; AW3D has the best performance in all the slope classes, a litter better than SRTM1; with slope increasing, the relative error for the SRTM3 data increases faster than other DEM datasets; so SRTM3 is better than GDEM-v2 in flat regions but worse in sloping regions. As to FSR value, AW3D has the lowest value, 4.37 %; then SRTM1 data, 5.80 %, similar to AW3D data; SRTM3 has higher value, about 8.27 %; GDEM-v2 data has the highest FSR value, about 12.15 %. FSR can represent the performance of correctly creating the earth surface based on DEM data. Hence, AW3D has the best performance, which is approximate to but a little better than SRTM1. The performance of SRTM3 and GDEM-v2 is similar, which is much worse than AW3D and SRTM1, and the performance of GDEM-v2 is the worst of all. Originated from the DEM dataset with 5m resolution, AW3D is regarded as the most precise global DEM datasets up to now, so it may exerts more effect in topographic analysis and geographic research. Through analysis and comparison of the relative error for the four open global DEM datasets, this research will provide reference in open global DEM datasets selection and applications in geosciences and other relevant fields.

The OMIV Observatory on landslides - Observing with Multi-parameters the Instability of Versants

NASA Astrophysics Data System (ADS)

Grasso, J.-R.; Garambois, S.; D; Jongmans; Helmstetter, A.; Lebourg, T.; Malet, J.-P.; Berolo, W.; Bethoux, R.; Daras, L.; Ulrich, P.

2010-05-01

The OMIV Observatory on landslides (Observatoire Multi-disciplinaire des Instabilités de Versants; e.g. Multi-disciplinary Observatory on Slope Instabilities) is a French-research initiative clustering five research institutes in earth sciences (e.g. GéoAzur in Nice; EOST-IPGS in Strasbourg, LETG in Caen, LGIT in Grenoble, LST in Lyon) under the auspices of INSU (Institut National des Sciences de l'Univers) since 2007. The primary objectives of OMIV are (1) to deploy and maintain permanent instrumental networks in order to be able to (2) to provide robust, long-lasting multi-parameter, open datasets to the international geoscience community. Such continuous monitoring of ongoing landslides are missing and they will provide constrains on the processes that lead to slope instabilities. Worldwide, the societal impact of landslides is one of the most important natural hazard in mountainous and rocky coastal areas. The variability in time and space of the slope structures and their susceptibility to external forcing (weathering, earthquake, climatic triggers) restrain our ability to simulate and forecast slope instabilities. Four active large landslides are monitored by the OMIV observatory group; these sites have been chosen according to their past history of monitoring, to the risk they may create and to the scientific challenges they raise up. The four studied landslides are: the Avignonet landslide (30 km South of Grenoble) and the Super-Sauze landslide (5 km South to Barcelonnette) which are soft-rock slides developed in clays for which the susceptibility to rainfalls and earthquake is the main open question; the La Clapière (100 km North of Nice) and the Séchilienne landslide (25km East of Grenoble) which are typical mature and immature large scale rock mass gravitational instabilities, respectively. On these four pilot sites, the OMIV research group is monitoring in continuous three types of observations: landslide kinematics (deformation and displacements), landslide seismic activity (through passive seismic auscultation), and landslide slope hydrology (hydrodynamics and hydro-geochemistry). These observables are open datasets which are available through the OMIV website (for the four sites, http://www-lgit.obs.ujf-grenoble.fr/observations/omiv/donnees.html and for the Super-Sauze landslide also at http://eost.u-strasbg.fr/omiv). When kinematics, hydrology and seismic activity are the main observables for many monitored landslides worldwide, only a few of them combines the three types of observables at relevant spatial and temporal scales. It is hypothesized by the OMIV observatory group that the combination of these three measurements will give access to a better knowledge on the physical processes controlling landslide behavior, such as the generation of brittle damage in the landslide material during sliding, the recognition and characterization of slip surface(s), the characterization of the hydrological behavior of the slope before and after failure. It opens possible routes toward characterizing the macro-scale rheology of the systems (e.g. brittle plastic transition for hard rock slopes, slide to flow transition for soft-rock landslides). The cross analysis of the monitoring data will bring new insights on the kinematics and dynamics of unstable slopes. In this study, we present (i) the technical organization of the multi-parameter monitoring datasets, and (ii) preliminary results from the ongoing monitoring.

Application of soil nails to the stability of mine waste slopes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tant, C.R.; Drumm, E.C.; Mauldon, M.

1996-12-31

The traditional soil nailed structure incorporates grouted or driven nails, and a wire mesh reinforced shotcrete facing to increase the stability of a slope or wall. This paper describes the construction and monitoring of a full-scale demonstration of nailing to stabilize coal mine spoil. The purpose of the investigation is to evaluate the performance of nailed slopes in mine spoil using methods proven for the stabilization of soil walls and slopes. The site in eastern Tennessee is a 12 meter high slope of dumped fill, composed of weathered shale chips, sandstone, and coal. The slope was formed by {open_quotes}pre-regulatory{close_quotes} contourmore » surface mining operations and served as a work bench during mining. The material varies in size from silt to boulders, and has a small amount of cohesion. Portions of the mine spoil slope have experienced slope instability and erosion which have hampered subsequent reclamation activities. Three different nail spacings and three different nail lengths were used in the design. The 12 meter high structure is instrumented to permit measurement of nail strain, and vertical inclinometer readings and survey measurements will be used for the detection of ground movement. The results of this study will aid in the development of design recommendations and construction guidelines for the application of soil nailing to stabilize mine spoil.« less

Least tern and piping plover nesting at sand pits in Nebraska

USGS Publications Warehouse

Sidle, John G.; Kirsch, E.M.

1993-01-01

Endangered Least Terns (Sterna antillarum) and threatened Piping Plovers (Charadrius melodus) nest at commercial sand and gravel mining operations (sand pits) along the Platte River system in Nebraska. Sandbar habitat has been disappearing since the early 1900's along the Platte River system, but numbers of sand pits have increased. We hypothesized that birds would more fully utilize sand pits where suitable sandbar habitat was limited. We inventoried sand pits and censused terns and plovers on both habitats along the Loup River, part of the North Loup River, and most of the Platte River during 1988-1991. Using aircraft, we also quantified features of suitable sand pits present on the central Platte in 1988 and lower Platte in 1990, and related features to abundance and presence of birds. We found 225 sand pits of which 78 were suitable and 187 were unsuitable for nesting. Along the central Platte, where sandbar habitat is severely degraded, birds nested at 81% of the suitable sand pits (N = 32) at least once during 1988-1991, and most birds (61-94%) nested on sand pits. Along the lower Platte, where both sandbar and sand pit habitat are plentiful, birds nested at 60% of the suitable sand pits (N = 35) at least once during 1988-1991, and most birds (60-86%) nested on sandbars. Numbers of terns and plovers were more weakly correlated with features of sand pits on the central Platte than on the lower Platte. Least Terns and Piping Plovers seem to use more of the suitable sand pit habitat on the central Platte than on the lower Platte. Sand pits probably have influenced the birds' distribution by providing alternative nesting habitat along rivers where suitable sandbars are rare or absent.

Efficacy of UV-Pit-light traps for discerning micro-habitat-specific beetle and ant species related with different oil palm age stands and tropical annual seasons for accurate ecology and diversity interpretations

NASA Astrophysics Data System (ADS)

Ahmad Bukhary, A. K.; Ruslan, M. Y.; Mohd. Fauzi, M. M.; Nicholas, S.; Muhamad Fahmi, M. H.; Izfa Riza, H.; Idris, A. B.

2015-09-01

A newly innovated and efficient UV-Pit-light Trap is described and the results of the experiments on its efficacy that were carried out within different oil palm age stands of the year 2013 were evaluated and compared with previous study year of 2010, with out the implementation of the UV-Pit-light Trap. In 2013 the UV-Pit-light Traps, the Malaise Traps, and the Pit-fall Traps were employed, while in 2010, the conventional canopy-height UV-Light Traps, Malaise Traps, and the Pit-fall Traps were employed. The UV-Pit-light traps caught more beetle and ant families, morpho-species, and individuals per species compared with the passive Pit-fall traps. The UV-Pit-light Trap targets different subsets of the oil palm beetles and ants' communities, specifying on epigaeic-related micro-habitats, with different oil palm age stands have different compositions of micro-habitats. The UV-Pit-light Traps have the dual quality for satisfying both the biological and statistical data requirements and evaluations. There were no significant difference between the UV-Pit-light Traps and the passive Pit-fall Traps, while the trapping difference with the Malaise traps for different seasons of the year 2013. The UV-Pit-light Traps and the Malaise Traps were complementary to each other, detecting the activities of beetles and ants around the epigaeic-related micro-habitats or having active flight activities respectively according to annual seasons. The UV-Pit-light Trap is an oil-palm specific type of passive trapping system, focusing on the insect species dwelling the upper-ground/epigaeic micro-habitats.

Near-bottom currents over the continental slope in the Mid-Atlantic Bight

USGS Publications Warehouse

Csanady, G.T.; Churchill, J.H.; Butman, B.

1988-01-01

From a set of 28 current meter records we have found that near-bottom currents faster than 0.2 m s-1 occur frequently over the outer continental shelf of the Mid-Atlantic Bight (bottom depth <210 m) but very rarely (<1% of the time) between bottom depths of 500 m and 2 km over the slope. The rarity of strong near-bottom flow over the middle and lower slope allows the accumulation of fine-grained sediment and organic carbon in this region. Fast near-bottom currents which do occur over the slope are invariably associated with topographic waves, although it is often superimposed inertial oscillations which increase current speed above the level of 0.2 m s-1. Episodes of intense inertial oscillations occur randomly and last typically for 10-20 days. Their energy source is unknown. Topographic wave energy exhibits a slight, but statistically significant, minimum over the mid-slope. These waves appear irregularly and vary both along isobaths and in time. The irregularity is presumably a consequence of random topographic wave generation by Gulf Stream instability. The current regime within sea-floor depressions in the slope (canyons and gullies) is distinctly different from that of the open slope; most notable is the near absence of topographic wave motion within depressions. ?? 1988.

Covariant open bosonic string field theory on multiple D-branes in the proper-time gauge

NASA Astrophysics Data System (ADS)

Lee, Taejin

2017-12-01

We construct a covariant open bosonic string field theory on multiple D-branes, which reduces to a non-Abelian group Yang-Mills gauge theory in the zero-slope limit. Making use of the first quantized open bosonic string in the proper time gauge, we convert the string amplitudes given by the Polyakov path integrals on string world sheets into those of the second quantized theory. The world sheet diagrams generated by the constructed open string field theory are planar in contrast to those of the Witten's cubic string field theory. However, the constructed string field theory is yet equivalent to the Witten's cubic string field theory. Having obtained planar diagrams, we may adopt the light-cone string field theory technique to calculate the multi-string scattering amplitudes with an arbitrary number of external strings. We examine in detail the three-string vertex diagram and the effective four-string vertex diagrams generated perturbatively by the three-string vertex at tree level. In the zero-slope limit, the string scattering amplitudes are identified precisely as those of non-Abelian Yang-Mills gauge theory if the external states are chosen to be massless vector particles.

First experience with Remote Sensing methods and selected sensors in the monitoring of mining areas - a case study of the Belchatow open cast mine

NASA Astrophysics Data System (ADS)

Wajs, Jaroslaw

2018-01-01

The paper presents satellite imagery from active SENTINEL-1A and passive SENTINEL-2A/2B sensors for their application in the monitoring of mining areas focused on detecting land changes. Multispectral scenes of SENTINEL-2A/2B have allowed for detecting changes in land-cover near the region of interest (ROI), i.e. the Szczercow dumping site in the Belchatow open cast lignite mine, central Poland, Europe. Scenes from SENTINEL-1A/1B satellite have also been used in the research. Processing of the SLC signal enabled creating a return intensity map in VV polarization. The obtained SAR scene was reclassified and shows a strong return signal from the dumping site and the open pit. This fact may be used in detection and monitoring of changes occurring within the analysed engineering objects.

One dimensional Linescan x-ray detection of pits in fresh cherries

USDA-ARS?s Scientific Manuscript database

The presence of pits in processed cherries is a concern for both processors and consumers, in many cases causing injury and potential lawsuits. While machines used for pitting cherries are extremely efficient, if one or more plungers in a pitting head become misaligned, a large number of pits may p...

Large heterogeneities in comet 67P as revealed by active pits from sinkhole collapse.

PubMed

Vincent, Jean-Baptiste; Bodewits, Dennis; Besse, Sébastien; Sierks, Holger; Barbieri, Cesare; Lamy, Philippe; Rodrigo, Rafael; Koschny, Detlef; Rickman, Hans; Keller, Horst Uwe; Agarwal, Jessica; A'Hearn, Michael F; Auger, Anne-Thérèse; Barucci, M Antonella; Bertaux, Jean-Loup; Bertini, Ivano; Capanna, Claire; Cremonese, Gabriele; Da Deppo, Vania; Davidsson, Björn; Debei, Stefano; De Cecco, Mariolino; El-Maarry, Mohamed Ramy; Ferri, Francesca; Fornasier, Sonia; Fulle, Marco; Gaskell, Robert; Giacomini, Lorenza; Groussin, Olivier; Guilbert-Lepoutre, Aurélie; Gutierrez-Marques, P; Gutiérrez, Pedro J; Güttler, Carsten; Hoekzema, Nick; Höfner, Sebastian; Hviid, Stubbe F; Ip, Wing-Huen; Jorda, Laurent; Knollenberg, Jörg; Kovacs, Gabor; Kramm, Rainer; Kührt, Ekkehard; Küppers, Michael; La Forgia, Fiorangela; Lara, Luisa M; Lazzarin, Monica; Lee, Vicky; Leyrat, Cédric; Lin, Zhong-Yi; Lopez Moreno, Josè J; Lowry, Stephen; Magrin, Sara; Maquet, Lucie; Marchi, Simone; Marzari, Francesco; Massironi, Matteo; Michalik, Harald; Moissl, Richard; Mottola, Stefano; Naletto, Giampiero; Oklay, Nilda; Pajola, Maurizio; Preusker, Frank; Scholten, Frank; Thomas, Nicolas; Toth, Imre; Tubiana, Cecilia

2015-07-02

Pits have been observed on many cometary nuclei mapped by spacecraft. It has been argued that cometary pits are a signature of endogenic activity, rather than impact craters such as those on planetary and asteroid surfaces. Impact experiments and models cannot reproduce the shapes of most of the observed cometary pits, and the predicted collision rates imply that few of the pits are related to impacts. Alternative mechanisms like explosive activity have been suggested, but the driving process remains unknown. Here we report that pits on comet 67P/Churyumov-Gerasimenko are active, and probably created by a sinkhole process, possibly accompanied by outbursts. We argue that after formation, pits expand slowly in diameter, owing to sublimation-driven retreat of the walls. Therefore, pits characterize how eroded the surface is: a fresh cometary surface will have a ragged structure with many pits, while an evolved surface will look smoother. The size and spatial distribution of pits imply that large heterogeneities exist in the physical, structural or compositional properties of the first few hundred metres below the current nucleus surface.

The Effects of Exposure to Documented Open-Air Burn Pits on Respiratory Health Among Deployers of the Millennium Cohort Study

DTIC Science & Technology

2012-06-01

reproduction of this article is prohibited. C© 2012 American College of Occupational and Environmental Medicine 709 Smith et al JOEM Volume 54, Number 6...C© 2012 American College of Occupational and Environmental Medicine 711 Smith et al JOEM Volume 54, Number 6, June 2012 TABLE 2. Adjusted Odds of...Environmental Medicine 713 Smith et al JOEM Volume 54, Number 6, June 2012 for disposal elsewhere. Findings revealed that those who deployed within 3 miles

Prospective Assessment of Chronic Multisymptom Illness Reporting Possibly Associated with Open-Air Burn Pit Smoke Exposure in Iraq

DTIC Science & Technology

2012-06-01

clearly implicating any specific war exposure as a cause of postwar symptoms, which is noteworthy, given the large and contin- ued military presence in...dioxide, sulfur dioxide, and polycyclic aromatic hydrocarbons are being released in the smoke from the fires, and many are known carcinogens and may cause ...exposure by providing benefits to veterans who self-report this type of exposure and have a variety of health conditions.26 The Millennium Cohort Study was

PBF Reactor Building (PER620). Camera on main floor faces south ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PBF Reactor Building (PER-620). Camera on main floor faces south (open) doorway. In foreground is canal gate, lined with stainless steel and painted with protective coatings. Reactor pit is round with protective coatings. Reactor put is round form discernible beyond. Lifting beams and rigging are in place for a load test before reactor vessel arrives. Photographer: John Capek. Date: January 26, 1970. INEEL negative no. 70-347 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

Correlating Meteorological, Satellite, and Ground Sampling Data to Determine Source of PM2.5 at Bagram Airfield (BAF), Afghanistan

DTIC Science & Technology

2015-07-08

Bethesda, MD 20814 D!SSERT A TION APPROVAL FOR THE MASTER IN SCIENCE IN PUBLIC HEAL TH DISSERTATION IN THE PREVENTIVE MEDICINE AND BIOMETRICS...such as asthma, bronchitis, cardiopulmonary disease, cancer , and premature death. One source of PM2.5 is open burning (i.e. burn pits), which is...combat zones encounter many different types of environmental hazards that are associated with adverse health outcomes (e.g. cancer and respiratory