On the quantitative determination of coal seam thickness by means of in-seam seismic surveys

Czech Academy of Sciences Publication Activity Database

Schott, W.; Waclawik, Petr

2015-01-01

Roč. 52, č. 10 (2015), s. 1496-1504 ISSN 0008-3674. [International Colloquium on Geomechanics and Geophysics /5./. Karolinka, 25.06.2014-27.06.2014] R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk(CZ) LO1406 Institutional support: RVO:68145535 Keywords : in-seam seismic (ISS) * ISS wave * Love wave * coal seam thickness * dispersion Subject RIV: DH - Mining, incl. Coal Mining Impact factor: 1.877, year: 2015 http://www.nrcresearchpress.com/doi/full/10.1139/cgj-2014-0466#.VgqE1Zc70mt

Utilisation of thin-seam drum shearer loaders at Bergbau AG Niederrhein

Energy Technology Data Exchange (ETDEWEB)

Wenzel, W.; Klimek, K.H.

1983-03-10

Conventional shearer loaders which travel on the AFC can only be used in seams more than 1.6 m thick in the conditions of the Ruhr coalfield. Low design shearers have been developed for seams below 1.6 m, and can work in conditions down to 1.0 m seam thickness. At Bergbau AG Niederrhein these machines have been adapted to prevailing conditions and requirements. The demand for a high drive rating led to a thin-seam shearer thickness from 1.3 m upwards. The need for minimum feasible machine height with adequate drive rating has been obtained with another machine. Currently under development is a machine which should lower the utilisation limit of thin-seam shearers. With planning and the use of suitable types of supports, it is possible to work faces by shearer in seams of 1.0 m upwards, even under difficult extraction conditions.

Classification of coal seam outburst hazards and evaluation of the importance of influencing factors

OpenAIRE

Shi Xianzhi; Song Dazhao; Qian Ziwei

2017-01-01

Coal and gas outbursts are the result of several geological factors related to coal seam gas (coal seam gas pressure P, coal seam sturdiness coefficient f and coal seam gas content W), and these parameters can be used to classify the outburst hazard level of a coal seam.

18 CFR 270.302 - Occluded natural gas produced from coal seams.

Science.gov (United States)

2010-04-01

... produced from coal seams. 270.302 Section 270.302 Conservation of Power and Water Resources FEDERAL ENERGY... produced from coal seams. A person seeking a determination that natural gas is occluded natural gas produced from coal seams must file an application with the jurisdictional agency which contains the...

Palaeoenvironmental reconstruction of Hüsamlar coal seam, SW

Indian Academy of Sciences (India)

The Ören and Yatağan Basins in SW Turkey host several Miocene coal deposits currently under exploitation for power generation. The present study aims to provide insight into the palaeoenvironmental conditions, which controlled the formation of the Hüsamlar coal seam located in Ören Basin. The coal seam displays ...

Evaluation of bending rigidity behaviour of ultrasonic seaming on woven fabrics

Science.gov (United States)

Şevkan Macit, Ayşe; Tiber, Bahar

2017-10-01

In recent years ultrasonic seaming that is shown as an alternative method to conventional seaming has been investigated by many researchers. In our study, bending behaviour of this alternative method is examined by changing various parameters such as fabric type, seam type, roller type and seaming velocity. For this purpose fifteen types of sewn fabrics were tested according to bending rigidity test standard before and after washing processes and results were evaluated through SPSS statistical analyze programme. Consequently, bending length values of the ultrasonically sewn fabrics are found to be higher than the bending length values of conventionally sewn fabrics and the effects of seam type on bending length are seen statistically significant. Also it is observed that bending length values are in relationship with the rest of the parameters excluding roller type.

A Comprehensive Overview of CO2 Flow Behaviour in Deep Coal Seams

Directory of Open Access Journals (Sweden)

Mandadige Samintha Anne Perera

2018-04-01

Full Text Available Although enhanced coal bed methane recovery (ECBM and CO2 sequestration are effective approaches for achieving lower and safer CO2 levels in the atmosphere, the effectiveness of CO2 storage is greatly influenced by the flow ability of the injected CO2 through the coal seam. A precious understanding of CO2 flow behaviour is necessary due to various complexities generated in coal seams upon CO2 injection. This paper aims to provide a comprehensive overview on the CO2 flow behaviour in deep coal seams, specifically addressing the permeability alterations associated with different in situ conditions. The low permeability nature of natural coal seams has a significant impact on the CO2 sequestration process. One of the major causative factors for this low permeability nature is the high effective stresses applying on them, which reduces the pore space available for fluid movement with giving negative impact on the flow capability. Further, deep coal seams are often water saturated where, the moisture behave as barriers for fluid movement and thus reduce the seam permeability. Although the high temperatures existing at deep seams cause thermal expansion in the coal matrix, reducing their permeability, extremely high temperatures may create thermal cracks, resulting permeability enhancements. Deep coal seams preferable for CO2 sequestration generally are high-rank coal, as they have been subjected to greater pressure and temperature variations over a long period of time, which confirm the low permeability nature of such seams. The resulting extremely low CO2 permeability nature creates serious issues in large-scale CO2 sequestration/ECBM projects, as critically high injection pressures are required to achieve sufficient CO2 injection into the coal seam. The situation becomes worse when CO2 is injected into such coal seams, because CO2 movement in the coal seam creates a significant influence on the natural permeability of the seams through CO2

Geomechanics of subsidence above single and multi-seam coal mining

Directory of Open Access Journals (Sweden)

A.M. Suchowerska Iwanec

2016-06-01

Full Text Available Accurate prediction of surface subsidence due to the extraction of underground coal seams is a significant challenge in geotechnical engineering. This task is further compounded by the growing trend for coal to be extracted from seams either above or below previously extracted coal seams, a practice known as multi-seam mining. In order to accurately predict the subsidence above single and multi-seam longwall panels using numerical methods, constitutive laws need to appropriately represent the mechanical behaviour of coal measure strata. The choice of the most appropriate model is not always straightforward. This paper compares predictions of surface subsidence obtained using the finite element method, considering a range of well-known constitutive models. The results show that more sophisticated and numerically taxing constitutive laws do not necessarily lead to more accurate predictions of subsidence when compared to field measurements. The advantages and limitations of using each particular constitutive law are discussed. A comparison of the numerical predictions and field measurements of surface subsidence is also provided.

Gas Permeability Evolution Mechanism and Comprehensive Gas Drainage Technology for Thin Coal Seam Mining

Directory of Open Access Journals (Sweden)

Fangtian Wang

2017-09-01

Full Text Available A thin coal seam mined as a protective coal seam above a gas outburst coal seam plays a central role in decreasing the degree of stress placed on a protected seam, thus increasing gas permeability levels and desorption capacities to dramatically eliminate gas outburst risk for the protected seam. However, when multiple layers of coal seams are present, stress-relieved gas from adjacent coal seams can cause a gas explosion. Thus, the post-drainage of gas from fractured and de-stressed strata should be applied. Comprehensive studies of gas permeability evolution mechanisms and gas seepage rules of protected seams close to protective seams that occur during protective seam mining must be carried out. Based on the case of the LongWall (LW 23209 working face in the Hancheng coal mine, Shaanxi Province, this paper presents a seepage model developed through the FLAC3D software program (version 5.0, Itasca Consulting Group, Inc., Minneapolis, MI, USA from which gas flow characteristics can be reflected by changes in rock mass permeability. A method involving theoretical analysis and numerical simulation was used to analyze stress relief and gas permeability evolution mechanisms present during broken rock mass compaction in a goaf. This process occurs over a reasonable amount of extraction time and in appropriate locations for comprehensive gas extraction technologies. In using this comprehensive gas drainage technological tool, the safe and efficient co-extraction of thin coal seams and gas resources can be realized, thus creating a favorable environment for the safe mining of coal and gas outburst seams.

Temperature field distribution of coal seam in heat injection

OpenAIRE

Zhang Zhizhen; Peng Weihong; Shang Xiaoji; Wang Kun; Li Heng; Ma Wenming

2017-01-01

In this article, we present a natural boundary element method (NBEM) to solve the steady heat flow problem with heat sources in a coal seam. The boundary integral equation is derived to obtain the temperature filed distribution of the coal seam under the different injecting conditions.

Airbag Seams Leave Trails

Science.gov (United States)

2004-01-01

This image taken by the Mars Exploration Rover Opportunity's panoramic camera shows where the rover's airbag seams left impressions in the martian soil. The drag marks were made after the rover successfully landed at Meridiani Planum and its airbags were retracted. The rover can be seen in the foreground.

In-seam seismic surveys at Polio and Santiago collieries during the month of January

Energy Technology Data Exchange (ETDEWEB)

1987-01-01

In-seam seismic surveys were carried out over the last two weekends in January in order to assess two coal panels, one in seam Cuatro at Polio colliery between levels 4 and 5 of the Centella field and the other in the Mariana seam at Santiago colliery between levels 3,5, and 7 in the Desquite zone. Geological research called in-seam seismics, which is just being developed in Spain, is a geophysical method developed specially for detailed investigation of coal seams.

Methods for working thick seams and research on increasing their effectiveness

Energy Technology Data Exchange (ETDEWEB)

Sikora, W

1976-01-01

In Poland nearly 40 per cent of all coal is extracted from seams more than 3 m. thick. In absolute figures this represents about 70 million tons of coal per year. Working seams with thicknesses up to 3.5 m. does not present, at present, major difficulties. Working thicker seams calls for a steady improvement in order to increase the degree of utilizaion of the deposit and to enlarge the concentration of output. The seams are worked under protected surface structures which compels the mines to use hydraulic stowing with all its advantages and disadvantages. Rock burst hazard, the control of which is the basic problem hindering the mining, is a further problem. 3 refs.

On the problem of technological innovations in driving preparatory workings in thin coal seams

Energy Technology Data Exchange (ETDEWEB)

Peknik, J

1980-03-01

Possibilities of mechanizing preparation of thin coal seams for longwall mining are discussed. Until now preparatory workings in the Ostrava Karvina coal region have been driven mainly by manual work or blasting. Tables show the total length of preparatory workings driven in the period 1973-1978 and the average advance of preparatory working per day and per shift. Factors influencing mechanization of preparatory working drivage are: geological disturbances, angle of seam inclination and its changes, thickness of the seam and strength of coal. Some types of mining machines which can be used for driving preparatory workings in thin, horizontal and inclined coal seams and produced in the USSR and United Kingdom are reviewed. Two sets of machines used in coal seams inclined up to 18 or 20 degrees are presented: KN produced in the USSR and 'In seam Miner' produced by the Dosco firm in the UK. Parameters of both machines are compared. The following Soviet machines for driving preparatory workings in inclined seams are also reviewed: 2 KNP (slope 45-80 degrees), KMD-72 (slope 45-80 degrees, height of the seam 0.6 m to 1.2 m), MRS-2 (slope 45-90 degrees, height of the seam 0.55 m to 1.0 m). (7 refs.) (In Czech)

Utilization of thin-seam drum shearer loaders at Bergbau AG Niederrhein

Energy Technology Data Exchange (ETDEWEB)

Wenzel, W.; Klimek, K.H.

1983-03-10

Low design shearers have been developed for seams under 1.6 m, which can be introduced in thicknesses to 1.0 m in the Ruhr conditions. The opposed demands for high drive rating and low machine height produced a two-pronged development. The priority need for high drive rating led to the EDW 230-2 LN thin-seam shearer for seam thicknesses from 1.3 m upwards. The second demand for minimum feasible machine height with adequate drive rating is most closely matched so far by the EDW 200/230 LN. It is anticipated that the EDW 300 LN at present being developed is another stage in lowering the lower utilization limit of thin-seam shearers. For the best possible use of LN shearers the LN mode of shearing should also be adhered to in the majority of likely applications. With thorough planning and the use of suitable types of supports it is possible to work faces with shearing in seam thicknesses from 1.0 m even under difficult extraction conditions.

Towards predictive control of extrusion weld seams: an integrated approach

NARCIS (Netherlands)

Bakker, A.J. den; Werkhoven, R.J.; Sillekens, W.H.; Katgerman, L.

2010-01-01

Longitudinal weld seams are an intrinsic feature in hollow extrusions produced with porthole dies. The formation of longitudinal weld seams is a solid bonding process, controlled by the local conditions in the extrusion die. Being the weakest areas within the extrusion cross section, it is desirable

The relation between district raise in the multiple coal seams and its pillars

Energy Technology Data Exchange (ETDEWEB)

Zhai, X. [Jiaozuo Institute of Technology, Jiaozuo (China). Dept. of Mining Engineering

2002-02-01

Based on the geological condition of multiple coal seams mining in No.8 Colliery of Pingdingshan Coal Group, the behaviours of the front abutment pressure in each of the coal seams and the fixed abutment pressure are observed. The main cause of deformation and damage to the galleries is the increasing value of the valid load coefficient of the surrounding rock. The rational pillar width of the district raise is studied when its two side seams have been mined, and the layout question of district raise in the different set of seams is also studied. The conclusions derived from the study are useful guiding reference for the design of district raise layout in deep multiple coal seams mining. 6 refs., 3 figs., 1 tab.

Variability of Mercury Content in Coal Matter From Coal Seams of The Upper Silesia Coal Basin

Science.gov (United States)

Wierzchowski, Krzysztof; Chećko, Jarosław; Pyka, Ireneusz

2017-12-01

The process of identifying and documenting the quality parameters of coal, as well as the conditions of coal deposition in the seam, is multi-stage and extremely expensive. The taking and analyzing of seam samples is the method of assessment of the quality and quantity parameters of coals in deep mines. Depending on the method of sampling, it offers quite precise assessment of the quality parameters of potential commercial coals. The main kind of seam samples under consideration are so-called "documentary seam samples", which exclude dirt bands and other seam contaminants. Mercury content in coal matter from the currently accessible and exploited coal seams of the Upper Silesian Coal Basin (USCB) was assessed. It was noted that the mercury content in coal seams decreases with the age of the seam and, to a lesser extent, seam deposition depth. Maps of the variation of mercury content in selected lithostratigraphic units (layers) of the Upper Silesian Coal Basin have been created.

Stochastic reservoir simulation for the modeling of uncertainty in coal seam degasification

Science.gov (United States)

Karacan, C. Özgen; Olea, Ricardo A.

2015-01-01

Coal seam degasification improves coal mine safety by reducing the gas content of coal seams and also by generating added value as an energy source. Coal seam reservoir simulation is one of the most effective ways to help with these two main objectives. As in all modeling and simulation studies, how the reservoir is defined and whether observed productions can be predicted are important considerations.

Exploitation of the in-seam miner and operational experience

Energy Technology Data Exchange (ETDEWEB)

Wilson, W I.S.; Morris, A H

1977-12-01

The In-seam Miner started as an investigatory project at MRDE in 1969. Since that time it has passed through the classic development stages of design of prototype, surface trials, underground trials, modification, production of more machines, assessment of experience and then wider exploitation. At the present time well over 100 machines have been supplied to the National Coal Board. The original machine was hydraulically driven and all but five of the machines supplied to date are of this type. The variety of applications that the machine has found in the mining industry has caused derivative development to embrace machines of length varying from 12-ft centers to 44-ft centers, to work in seams ranging from 40 in. up to 68 in. The range of applications has included face drivages, stablehole operations, in-seam retreat roadways and dirt-absorbing headings. Five electrically driven machines are now coming onto the market and experience with them, though limited, is very encouraging. The paper concentrates on two major aspects of the overall development process: first, the management of exploitation; and second, some operational experience of the In-seam Miner in South Midlands area.

Solid Coal Stability with Regards to Seam Thickness or Bench mined

Directory of Open Access Journals (Sweden)

Bukovanský Stanislav

1998-03-01

Full Text Available In the paper the problem of working unit stability, showing a limit state of a rock tension with the Mohr envelope known from a theory of failure, is described. It is obvious that a load of building units in mountain massives can be expressed easily either by simple or multiaxial compressions, and then, on the basis of individual states characteristics, individual conditions of stability can be observed. So we may understand that such building units can be broken even in case of a certain discharge, i.e. lowering of one of main tensions of both of them as well. Combined methods of discharge and surchage can be used too. Another reactive power of an enormous value is caused by pre-fault then. In the OKR district it means even 10% of the seam thickness with common conditions (e.g. saddle seams. An area of a contact between a seam, original rocks and seam thickness should be taken into consideration as serious conditions of rock bumps origin. If this contact area is wavy of the seam thickness is small (possibly both conditions are valid, there will be no risk of any rock bump.

Workability of coal seams in the Upper Silesian Coal Basin

Energy Technology Data Exchange (ETDEWEB)

Sikora, W; Fels, M; Soltysik, K

1978-04-01

This paper presents results of an investigation on workability of coal seams of stratigraphic groups from 100 to 700 in the: Upper Silesian Coal Basin. Analyzed are 2900 petrographic logs taken in the longwall workings and in narrow openings as well as about 9000 individual samples. Workability of coal seams, floors and partings is determined. Workability is described by the indicator f, (according to the Protodyakonov shatter method) and the indicator U, (compression strength of the unshaped test samples). The mean percentage content of indivi dual petrographic groups of coal as well as the mean workability indicator, f, of coals in the stratigraphic groups of coal seams in Upper Silesia are also determined.

Improved Seam-Line Searching Algorithm for UAV Image Mosaic with Optical Flow.

Science.gov (United States)

Zhang, Weilong; Guo, Bingxuan; Li, Ming; Liao, Xuan; Li, Wenzhuo

2018-04-16

Ghosting and seams are two major challenges in creating unmanned aerial vehicle (UAV) image mosaic. In response to these problems, this paper proposes an improved method for UAV image seam-line searching. First, an image matching algorithm is used to extract and match the features of adjacent images, so that they can be transformed into the same coordinate system. Then, the gray scale difference, the gradient minimum, and the optical flow value of pixels in adjacent image overlapped area in a neighborhood are calculated, which can be applied to creating an energy function for seam-line searching. Based on that, an improved dynamic programming algorithm is proposed to search the optimal seam-lines to complete the UAV image mosaic. This algorithm adopts a more adaptive energy aggregation and traversal strategy, which can find a more ideal splicing path for adjacent UAV images and avoid the ground objects better. The experimental results show that the proposed method can effectively solve the problems of ghosting and seams in the panoramic UAV images.

Process for opening up carboniferous seams for underground gasification by drilling production holes downwards

Energy Technology Data Exchange (ETDEWEB)

Lokschin, J L; Volk, A F; Starinskii, A A

1977-12-01

This process will reduce drilling costs and times by 20 to 25% and will improve gasification under the influence of a thin liquid medium connecting adjacent holes. After determining the approximate depth and thickness of the seam to be opened up, e.g. by geological means, production holes of 100 to 400 mm (diameter) are made down to a depth of 400 m or more, by well-known boring bars and chisels. After passing the top of the seam (the roof of the seam), which can be recognised by discoloration of the drilling liquid, one goes 1/2 to 1 metre deeper and one determines the depth of the roof the seam exactly by the reduced natural radioactivity at the boundary layer, by introducing a gamma sensor on to the boring bar. The production holes are taken down in a second borehold to a free space 0.6 to 2 metres above the floor of the seam (bottom of the seam), according to the thickness of the seam. After replacing the boring bar by a feedpipe one continues to drill using a boring bar of smaller cutting diameter inside this tube. This hole reaches from the foot of the pipe of the feedpipe to the floor of the seam. It is preferably flushed with gas but may be flushed with liquid. A thin liquid introduced into this hole penetrates the surrounding mass of the seam horizontally (unhindered by any armouring) and represents the required connection to neighbouring bores for gasification. The process is suitable for mining coal, combustible shale oil, bituminous rock, heavy natural oil where this process is based on gasification, melting or dissolving of those deposits.

Exploiting Seams and Closing Gaps: Lessons from Mumbai and Beyond

Directory of Open Access Journals (Sweden)

Dr. Andrea J. Dew

2012-01-01

Full Text Available This article analyzes a single event—the 2008 Mumbai attacks—in order to consider the strategic and operational lessons for dealing with other armed groups. How and why was Lashkar-e-Tayyiba (LeT able to carry out such a sophisticated attack in the heart of Mumbai? And what lessons does Mumbai hold for strategists seeking to counter other armed groups around the world? While tactical level lessons from Mumbai have been well documented, it is important to also consider what the Mumbai attacks tell us at the strategic and operational levels. Specifically, the Mumbai attacks provide valuable insight into how armed groups use the maritime environment, and how they use surprise, denial, and deception to mask intention and invite over-reaction by states. In addition, studying the Mumbai attacks provides insight into some of the strategic and operational seams and gaps that armed groups seek to exploit. These include environmental and geographical factors; institutional, bureaucratic, and jurisdictional seams and gaps between agencies; cognitive seams and gaps that made the use of the sea by LeT so difficult to conceptualize; and the diplomatic seams and gaps that led to heightened tensions among states— in this case, India, Pakistan, and the United States. This article discusses how to categorize these seams and gaps in order to better address the problems they create, and how states might best direct and focus their limited resources when faced with similar challenges.

Polymer Drilling Fluid with Micron-Grade Cenosphere for Deep Coal Seam

Directory of Open Access Journals (Sweden)

Peng Xu

2015-01-01

Full Text Available Traditional shallow coal seam uses clean water, solid-free system, and foam system as drilling fluid, while they are not suitable for deep coal seam drilling due to mismatching density, insufficient bearing capacity, and poor reservoir protection effect. According to the existing problems of drilling fluid, micron-grade cenosphere with high bearing capacity and ultralow true density is selected as density regulator; it, together with polymer “XC + CMC” and some other auxiliary agents, is jointly used to build micron-grade polymer drilling fluid with cenosphere which is suitable for deep coal seam. Basic performance test shows that the drilling fluid has good rheological property, low filtration loss, good density adjustability, shear thinning, and thixotropy; besides, drilling fluid flow is in line with the power law rheological model. Compared with traditional drilling fluid, dispersion stability basically does not change within 26 h; settlement stability evaluated with two methods only shows a small amount of change; permeability recovery rate evaluated with Qinshui Basin deep coal seam core exceeds 80%. Polymer drilling fluid with cenosphere provides a new thought to solve the problem of drilling fluid density and pressure for deep coal seam drilling and also effectively improves the performance of reservoir protection ability.

Influence of Mining Thickness on the Rationality of Upward Mining in Coal Seam Group

Directory of Open Access Journals (Sweden)

Y. Li

2016-04-01

Full Text Available This study aimed to determine the influence of mining thickness on the rationality of upward mining in coal seam group. Numerical simulation and theoretical analysis were performed to investigate the influence of the mining thicknesses of initial mining seam on the destruction and pressure relief effect of the upper coal seam in a high-gas coal seam group. The mechanical model of the roof failure based on the mining thickness was established by assuming that the gob formed after adjacent panels have fully been caved is the infinite plane. On the basis of this model, an equation was derived to calculate the roof failure height of the panel. Considering the geological conditions of No. 9 and No. 12 coal seams of Zhaogezhuang Coal Mine, economic effectiveness, and proposed techniques, we concluded that the top layer (4 m of the No. 12 coal seam should be mined first. The top layer of the No. 9 coal seam should be subsequently mined. The topcaving technique was applied to the exploitation of the lower layer of the No. 12 coal seam. Practically monitored data revealed that the deformation and failure of the No. 2699 panel roadway was small and controllable, the amount of gas emission was reduced significantly, and the effect of upward mining was active. The results of this study provide theory basics for mine designing, and it is the provision of a reference for safe and efficient coal exploitation under similar conditions.

Microscopic analysis of the morphology of seams in friction stir welded polypropylene

Directory of Open Access Journals (Sweden)

Z. Kiss

2012-01-01

Full Text Available Supermolecular structure of welded seams prepared by friction stir welding (FSW of polypropylene sheets has been studied by optical and electron microscopy. It has been shown that in the central parts of the seam spherulitic structures similar to that of the base material are formed, while at the borderline of the seam, a complex supermolecular structure could be identified. Lower welding rotation speed resulted in a border transition zone of more complex feature than the higher rotation speed during FSW. This was accompanied by reduced joint efficiency.

Modeling of Three Flat Coal Seams Strata Developing at Open Pit Miming

Science.gov (United States)

Gvozdkova, Tatiana; Markov, Sergey; Demirel, Nuray; Anyona, Serony

2017-11-01

The use of low-cost direct dumpling technology, as is well known, has a relatively limited field of application: flat coal seams, and the higher the dip angle of the seam, the more difficult it is to place the necessary volume of overburden rock in the dumping layers. For this, we have to pour four-tier dumps. In this article, four possible options for piling the dump have been studied and prerequisites have been made for further research aimed at improving the efficiency of the use of direct dumpling technology in the development of flat coal seams.

Simulation of double-seaming in a two-piece aluminum can

International Nuclear Information System (INIS)

Romanko, Anne; Berry, Dale; Fox, David

2004-01-01

The aluminum can industry in the United States and Canada manufactures over 100 billion cans per year. Two-piece aluminum cans are commonly used to seal and deliver foodstuffs such as soft drinks, beer, pet food, and other perishable items. In order to ensure product safety and performance, the double seam between the can body and lid is a critical component of the package. Double-seaming is a method by which the flange of the can body and the curl of the end are folded over together such that the final joint is composed of five metal thicknesses. There are a number of design challenges involved with the art of double seaming, especially with the push to lightweight. Although the requirements vary by product, the typical beer package must be able to hold pressures in excess of 90psi. In addition, in production, double seaming is a high-speed operation with speeds as high as 3000 cans/minute on an 18-spindle seamer. For this high volume, low cost industry, understanding and optimizing the seaming process can advance the industry as well as help prevent various manufacturing problems that produce a poor seal between the two pieces of the can.To aid in understanding the mechanics of the can parts during double-seaming, a simulation procedure was developed and carried out on a 202 diameter beverage can and lid. Simulations were run with the explicit dynamics solver ABAQUS/Explicit using the continuum shell element technology available in the ABAQUS general purpose FEA program. The continuum shell is a shear-deformable shell element with the topology of an eight node brick. The element's formulation allows continuously varying, solution-dependent shell thickness and through-thickness pinching stress. One important advantage of using the continuum shell as opposed to a traditional shell element is that true contact interactions at the top and bottom surfaces of the can body and lid can be accurately modeled. With a conventional shell element, contact is performed at the

Simulation of Double-Seaming in a Two-piece Aluminum Can

Science.gov (United States)

Romanko, Anne; Berry, Dale; Fox, David

2004-06-01

The aluminum can industry in the United States and Canada manufactures over 100 billion cans per year. Two-piece aluminum cans are commonly used to seal and deliver foodstuffs such as soft drinks, beer, pet food, and other perishable items. In order to ensure product safety and performance, the double seam between the can body and lid is a critical component of the package. Double-seaming is a method by which the flange of the can body and the curl of the end are folded over together such that the final joint is composed of five metal thicknesses. There are a number of design challenges involved with the art of double seaming, especially with the push to lightweight. Although the requirements vary by product, the typical beer package must be able to hold pressures in excess of 90psi. In addition, in production, double seaming is a high-speed operation with speeds as high as 3000 cans/minute on an 18-spindle seamer. For this high volume, low cost industry, understanding and optimizing the seaming process can advance the industry as well as help prevent various manufacturing problems that produce a poor seal between the two pieces of the can. To aid in understanding the mechanics of the can parts during double-seaming, a simulation procedure was developed and carried out on a 202 diameter beverage can and lid. Simulations were run with the explicit dynamics solver ABAQUS/Explicit using the continuum shell element technology available in the ABAQUS general purpose FEA program. The continuum shell is a shear-deformable shell element with the topology of an eight node brick. The element's formulation allows continuously varying, solution-dependent shell thickness and through-thickness pinching stress. One important advantage of using the continuum shell as opposed to a traditional shell element is that true contact interactions at the top and bottom surfaces of the can body and lid can be accurately modeled. With a conventional shell element, contact is performed at the

Study of physiocochemical processes liable to affect methane drainage from an anthracite seam

Energy Technology Data Exchange (ETDEWEB)

Artemov, A V

1976-01-01

The molecular structure of anthracites is discussed, and liquids suitable for improving gas emission from anthracite seams are suggested. Infusion of the seam with ethylene glycol solution makes it possible to increase methane emission in drainage boreholes by eight or nine times.

The Method of Validity Evaluation of Hard Coal Excavation in Residual Seam Parts

Science.gov (United States)

Wodarski, Krzysztof; Bijańska, Jolanta; Gumiński, Adam

2017-12-01

The excavation of residual seam parts should be justified by positive assessment of the purposefulness, technical feasibility and economic effectiveness. The results of the profitability evaluation are crucial in a decision making process. The excavation of residual seam parts, even if it is possible from a technical point of view, should not be implemented if it is economically inefficient or when accompanied by a very high risk of non-recovery of invested capital resources. The article presents the evaluation method of possibilities of excavating hard coal from residual seam parts, and the example of its use in one of collieries in the Upper Silesian Coal Basin. Working in line with the developed method, allows to indicate the variant of residual seam part exploitation, which is feasible to implement from a technical point of view, and which is characterized by the highest economic effectiveness and lowest risk.

Lining seam elimination algorithm and surface crack detection in concrete tunnel lining

Science.gov (United States)

Qu, Zhong; Bai, Ling; An, Shi-Quan; Ju, Fang-Rong; Liu, Ling

2016-11-01

Due to the particularity of the surface of concrete tunnel lining and the diversity of detection environments such as uneven illumination, smudges, localized rock falls, water leakage, and the inherent seams of the lining structure, existing crack detection algorithms cannot detect real cracks accurately. This paper proposed an algorithm that combines lining seam elimination with the improved percolation detection algorithm based on grid cell analysis for surface crack detection in concrete tunnel lining. First, check the characteristics of pixels within the overlapping grid to remove the background noise and generate the percolation seed map (PSM). Second, cracks are detected based on the PSM by the accelerated percolation algorithm so that the fracture unit areas can be scanned and connected. Finally, the real surface cracks in concrete tunnel lining can be obtained by removing the lining seam and performing percolation denoising. Experimental results show that the proposed algorithm can accurately, quickly, and effectively detect the real surface cracks. Furthermore, it can fill the gap in the existing concrete tunnel lining surface crack detection by removing the lining seam.

Interanal seam loss in Asian turtles of the Cuora flavomarginata complex (Testudines, Geoemydidae)

Science.gov (United States)

Ernst, Carl H.; Lovich, Jeffrey E.

2015-01-01

The taxonomy of Asian box turtles of the genus Cuora is complicated by the description of numerous valid and invalid taxa over the last several decades. However, some characteristics used to differentiate species are questionable. Members of the C. flavomarginata complex are defined by some, but not all, taxonomists as having reduced interanal seam lengths relative to other species. We examined the ratio of interanal scute seam length divided by midline anal scute length in C. flavomarginata and C. evelynae. Hatchlings show a seam that divides 100% of the anal scute along the midline. As individuals increase in carapace length, there is a tendency for the percentage to decrease, especially in females, although there is considerable overlap. We suggest that the decrease in interanal seam length is due to abrasion of the plastron on the substrate as turtles grow larger and older. Differences in habitat substrates across the range of the species may contribute to the wide variation we observed.

Experience with dust suppression in mining a thick, dirty seam

Energy Technology Data Exchange (ETDEWEB)

Siepmann, D; Kohlhauer, H

1975-11-20

Dust suppression measures used when mining a thick, dirty seam are described. Dust sprays inside and outside the shearer drum helped to reduce coarse dust, but the resulting increase in moisture content of the coal limits the extent to which this method can be used. The shields were also fitted with sprays. Because of the dirt in the seam, continuous, remotely controlled deep infusion was used. This reduced the dust concentration from more than 10 mg/m/sup 3/ to between 3.9 and 6.6 mg/m/sup 3/.

Improving extraction technology of level seams. Sovershenstvovanie tekhnologii razrabotki pologikh plastov

Energy Technology Data Exchange (ETDEWEB)

Shetser, M G; Spitsyn, Yu G

1985-01-01

This report deals with conditions and prospects for intensifying extraction of level and inclined seams and improving extraction technology. Reviews mechanization of excavation of stables with automatic cutter-loaders (KA80 in conjunction with KD80); coal extraction using two cutter-loaders in seams 0.9 - 1.9 m thick and up to 20 degrees inclination (pillar mining); reciprocating method of coal cutting; one-sided method of coal extraction (KMK97 cutter loaders). Discusses strengthening of junctions of faces with gate roads (KSU and KSU3M props); improved types of props (hydraulic props SUG-30, SUG-V and GVD); roof control methods (induced caving, advance torpedoing or using KM87UMP and KMT power supports). Deals in detail with introduction of new extraction technology and strengthening of unstable rock by injecting polyurethene compounds, extraction of seams with wide-web cutter-loaders (Kirovets, IK101) and plowing. (3 refs.)

Characterization of Coal Quality Based On Ash Content From M2 Coal-Seam Group, Muara Enim Formation, South Sumatra Basin

Directory of Open Access Journals (Sweden)

Frillia Putri Nasution

2017-09-01

Full Text Available Muara Enim Formation is well known as coal-bearing formation in South Sumatra Basin. As coal-bearing formation, this formation was subjects of many integrated study. Muara Enim Formation can be divided into four coal-seam group, M1, M2, M3, and M4. The M2 group comprising of Petai (C, Suban (B, Lower Mangus (A2, and Upper Mangus (A1. Depositional environments of Group M2 is transitional lower delta plain with sub-depositional are crevasse splay and distributary channel. The differentiation of both sub-depositional environments can be caused the quality of coal deposit. One of quality aspects is ash content. This research conducted hopefully can give better understanding of relationship between depositional environments to ash content. Group M2 on research area were found only Seam C, Seam B, and Seam A2, that has distribution from north to central so long as 1400 m. Coal-seam thickness C ranged between 3.25-9.25 m, Seam B range 7.54-13.43 m, and Seam C range 1.53-8.37 m, where all of coal-seams thickening on the central part and thinning-splitting to northern part and southern part. The ash content is formed from burning coal residue material. Ash contents on coal seam caused by organic and inorganic compound which resulted from mixing modified material on surrounded when transportation, sedimentation, and coalification process. There are 27 sample, consists of 9 sample from Seam C, 8 sample from Seam B, and 10 sample from Seam A2. Space grid of sampling is 100-150 m. Ash content influenced by many factors, but in research area, main factor is existence of inorganic parting. Average ash content of Seam C is 6,04%, Seam B is 5,05%, and Seam A2 is 3,8%. Low ash content influenced by settle environment with minor detrital material. High ash content caused by oxidation and erosional process when coalification process. Ash content on coal in research area originated from detritus material carried by channel system into brackish area or originated

Computer-aided planning of brown coal seam mining in regard to coal quality

Energy Technology Data Exchange (ETDEWEB)

Ciesielski, R.; Lehmann, A.; Rabe, H.; Richter, S.

1988-09-01

Discusses features of the geologic SORVER software developed at the Freiberg Fuel Institute, GDR. The program processes geologic data from exploratory wells, petrographic characteristics of a coal seam model, technological mining parameters and coal quality requirements of consumers. Brown coal reserves of coking coal, gasification coal, briquetting coal and steam coal are calculated. Vertical seam profiles and maps of seam horizon isolines can be plotted using the program. Coal quality reserves along the surface of mine benches, mining block widths and lengths for excavators, maximum possible production of individual coal qualities by selective mining, and coal quality losses due to mining procedures are determined. The program is regarded as a means of utilizing deposit reserves more efficiently. 5 refs.

The Investigation of Knitted Materials Bonded Seams Behaviour upon Cyclical Fatigue Loading

Directory of Open Access Journals (Sweden)

Gita BUSILIENĖ

2017-08-01

Full Text Available In this research uniaxial tension behaviour of PES knitted materials with bonded seams is analysed. The objects of the investigation were two types of knitted materials, having the same fibre composition (93 % PES, 7 % EL, but different in knitting pattern, i. e. plain single jersey and rib 1 × 1. Bonded overlap seams were formed by changing the orientation of knitted materials strips, i. e. parallel/parallel, parallel/bias, parallel/perpendicular, bias/bias and bias/perpendicular. The strips of each knitted material were joined by two types of thermoplastic polyurethane (PU films different in thickness (75 mm and 150 mm. Mechanical characteristics of bonded seams were defined in longitudinal direction. During uniaxial tension such parameters as maximal force Fmax (N and maximal elongation ɛmax (% were recorded from typical tension diagrams. The changes of tested specimens strength and deformation were compared before and after cyclical fatigue tension the conditions of which were 50 cycles up to tension force F equal 24.5 N. The results have shown that changes before and after cyclical fatigue tension are mostly determined by the structure of knitted materials, the orientation of knitted materials strips in bonded seam, but not effected by thermoplastic polyurethane film. These results are opposite compared to the results of biaxial tension of the same type of specimens, which have shown that changes before and after cyclical fatigue punching are mostly determined by the type of thermoplastic film, but not effected by the orientation of knitted materials strips in bonded seams. DOI: http://dx.doi.org/10.5755/j01.ms.23.2.16065

The C. elegans engrailed homolog ceh-16 regulates the self-renewal expansion division of stem cell-like seam cells.

Science.gov (United States)

Huang, Xinxin; Tian, E; Xu, Yanhua; Zhang, Hong

2009-09-15

Stem cells undergo symmetric and asymmetric division to maintain the dynamic equilibrium of the stem cell pool and also to generate a variety of differentiated cells. The homeostatic mechanism controlling the choice between self-renewal and differentiation of stem cells is poorly understood. We show here that ceh-16, encoding the C. elegans ortholog of the transcription factor Engrailed, controls symmetric and asymmetric division of stem cell-like seam cells. Loss of function of ceh-16 causes certain seam cells, which normally undergo symmetric self-renewal expansion division with both daughters adopting the seam cell fate, to divide asymmetrically with only one daughter retaining the seam cell fate. The human engrailed homolog En2 functionally substitutes the role of ceh-16 in promoting self-renewal expansion division of seam cells. Loss of function of apr-1, encoding the C. elegans homolog of the Wnt signaling component APC, results in transformation of self-renewal maintenance seam cell division to self-renewal expansion division, leading to seam cell hyperplasia. The apr-1 mutation suppresses the seam cell division defect in ceh-16 mutants. Our study reveals that ceh-16 interacts with the Wnt signaling pathway to control the choice between self-renewal expansion and maintenance division and also demonstrates an evolutionarily conserved function of engrailed in promoting cell proliferation.

Resistance of Type 5 chemical protective clothing against nanometric airborne particles: Behavior of seams and zipper.

Science.gov (United States)

Vinches, Ludwig; Hallé, Stéphane

2017-12-01

In the field of dermal protection, the use of chemical protective clothing (CPC) (including coveralls) are considered as the last barrier against airborne engineered nanomaterials (ENM). In the majority of cases, Type 5 CPC, used against solid particles (ISO 13982-1), perform well against ENM. But in a recent study, a penetration level (PL) of up to 8.5% of polydisperse sodium chloride airborne nanoparticles has been measured. Moreover, in all the previous studies, tests were performed on a sample of protective clothing material without seams or zippers. Thus, the potential for permeation through a zipper or seams has not yet been determined, even though these areas would be privileged entry points for airborne ENM. This work was designed to evaluate the PL of airborne ENM through coveralls and specifically the PL through the seams on different parts of the CPC and the zipper. Eight current models of CPC (Type 5) were selected. The samples were taken from places with and without seams and with a zipper. In some cases, a cover strip can be added to the zipper to enhance its sealing. Polydisperse nanoparticles were generated by nebulization of a sodium chloride solution. A penetration cell was developed to expose the sample to airborne nanometric particles. The NaCl particle concentration in number was measured with an ultrafine particle counter and the PL was defined as the downstream concentration divided by the upstream concentration. The results obtained show that the PL increased significantly in the presence of seams and could reach up to 90% depending on the seam's design. Moreover, this study classifies the different types of seams by their resistance against airborne ENM. As for the penetration of airborne NaCl particles through the zipper, the PL was greatly attenuated by the presence of a cover strip, but only for certain models of coveralls. Finally, the values of the pressure drop were directly linked to the type of seam. All of these conclusions provide

Detecting voids in coal seams in surface mining by means of a biophysical method

Energy Technology Data Exchange (ETDEWEB)

Bek, E.

1985-07-01

Soviet research institutes, in cooperation with research intitutes from other countries, developed the Radar 1 system for detecting abandoned workings in coal seams in surface mines. The system will be used for detecting voids in seams at depths to 50 m. The Academy of Sciences of Czechoslovakia tested use of dowsing for detecting abandoned workings in the Pohranicni straz, the Brezova and the Medard coal surface mines. The workings were situated at depths from 2 to 12 m from the ground surface (dowser position). The dowser was not informed of position or dimensions of the workings. Accuracy of determining position of abandoned workings in coal seams was high. Results of dowsing were checked by drilling. 4 references.

保护层开采被保护层卸压增透效果的应用研究%Effect of protective seam mining on pressure relief and permeability enhancement of protected coal seam

Institute of Scientific and Technical Information of China (English)

冯拥军; 周玉军; 张喜传

2014-01-01

In view of the coal seam occurrence condition and geological condition of the west-ern region of Henan Province,the gas pressure releasing and drainage in protective coal seam was designed and the drilling design was investigated. In addition,the gas parameters and the dis-placement of roof and floor of B1 coal seam were determined. The research results showed that after the protective seam mining,coal seam gas pressure was decreased from the original 0.9 MPa to 0.12 MPa,the original gas content was reduced from the previous 6.52 m3/t to 3.1 m3/t,the expansion deformation of roof and floor reached 20.6 ‰,and the coal seam permeability coefficient was increased 810 times,so that the outburst danger at No. 12112 working face of B1 coal seam was eliminated in the pressure released area.%针对豫西煤田煤层赋存情况及地质状况,设计了被保护层的卸压抽采方案及考察钻孔,对瓦斯基础参数和二1煤层的煤层顶底板移近量进行了测定.研究结果表明,二1煤层在受到保护层开采后,煤层瓦斯压力由原始的0.9 MP a降为0.12 MP a ,原始瓦斯含量由以前的6.52 m3/t降为3.1 m3/t,顶底板膨胀变形量达到20.6‰,煤层透气性系数增大了810倍,在卸压区内完全消除了二1煤层12112工作面的突出危险性.

Method of gas emission control for safe working of flat gassy coal seams

Science.gov (United States)

Vinogradov, E. A.; Yaroshenko, V. V.; Kislicyn, M. S.

2017-10-01

The main problems at intensive flat gassy coal seam longwall mining are considered. For example, mine Kotinskaja JSC “SUEK-Kuzbass” shows that when conducting the work on the gassy coal seams, methane emission control by means of ventilation, degassing and insulated drain of methane-air mixture is not effective and stable enough. It is not always possible to remove the coal production restrictions by the gas factor, which leads to financial losses because of incomplete using of longwall equipment and the reduction of the technical and economic indicators of mining. To solve the problems, the authors used a complex method that includes the compilation and analysis of the theory and practice of intensive flat gassy coal seam longwall mining. Based on the results of field and numerical researches, the effect of parameters of technological schemes on efficiency of methane emission control on longwall panels, the non-linear dependence of the permissible according to gas factor longwall productivity on parameters of technological schemes, ventilation and degassing during intensive mining flat gassy coal seams was established. The number of recommendations on the choice of the location and the size of the intermediate section of coal heading to control gassing in the mining extracted area, and guidelines for choosing the parameters of ventilation of extracted area with the help of two air supply entries and removal of isolated methane-air mixture are presented in the paper. The technological scheme, using intermediate entry for fresh air intake, ensuring effective management gassing and allowing one to refuse from drilling wells from the surface to the mined-out space for mining gas-bearing coal seams, was developed.

Innovative technology summary report: Sealed-seam sack suits

International Nuclear Information System (INIS)

1998-09-01

Sealed-seam sack suits are an improved/innovative safety and industrial hygiene technology designed to protect workers from dermal exposure to contamination. Most of these disposable, synthetic-fabric suits are more protective than cotton suits, and are also water-resistant and gas permeable. Some fabrics provide a filter to aerosols, which is important to protection against contamination, while allowing air to pass, increasing comfort level of workers. It is easier to detect body-moisture breakthrough with the disposable suits than with cotton, which is also important to protecting workers from contamination. These suits present a safe and cost-effective (6% to 17% less expensive than the baseline) alternative to traditional protective clothing. This report covers the period from October 1996 to August 1997. During that time, sealed-seam sack suits were demonstrated during daily activities under normal working conditions at the C Reactor and under environmentally controlled conditions at the Los Alamos National Laboratory (LANL)

Image resizing using saliency strength map and seam carving for white blood cell analysis

Directory of Open Access Journals (Sweden)

Nam JaeYeal

2010-09-01

Full Text Available Abstract Background A new image-resizing method using seam carving and a Saliency Strength Map (SSM is proposed to preserve important contents, such as white blood cells included in blood cell images. Methods To apply seam carving to cell images, a SSM is initially generated using a visual attention model and the structural properties of white blood cells are then used to create an energy map for seam carving. As a result, the energy map maximizes the energies of the white blood cells, while minimizing the energies of the red blood cells and background. Thus, the use of a SSM allows the proposed method to reduce the image size efficiently, while preserving the important white blood cells. Results Experimental results using the PSNR (Peak Signal-to-Noise Ratio and ROD (Ratio of Distortion of blood cell images confirm that the proposed method is able to produce better resizing results than conventional methods, as the seam carving is performed based on an SSM and energy map. Conclusions For further improvement, a faster medical image resizing method is currently being investigated to reduce the computation time, while maintaining the same image quality.

Image resizing using saliency strength map and seam carving for white blood cell analysis.

Science.gov (United States)

Ko, ByoungChul; Kim, SeongHoon; Nam, JaeYeal

2010-09-20

A new image-resizing method using seam carving and a Saliency Strength Map (SSM) is proposed to preserve important contents, such as white blood cells included in blood cell images. To apply seam carving to cell images, a SSM is initially generated using a visual attention model and the structural properties of white blood cells are then used to create an energy map for seam carving. As a result, the energy map maximizes the energies of the white blood cells, while minimizing the energies of the red blood cells and background. Thus, the use of a SSM allows the proposed method to reduce the image size efficiently, while preserving the important white blood cells. Experimental results using the PSNR (Peak Signal-to-Noise Ratio) and ROD (Ratio of Distortion) of blood cell images confirm that the proposed method is able to produce better resizing results than conventional methods, as the seam carving is performed based on an SSM and energy map. For further improvement, a faster medical image resizing method is currently being investigated to reduce the computation time, while maintaining the same image quality.

Coal seam has boom - powering North Queensland industrial growth

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-06-01

Reduced operating costs, lower greenhouse gas emissions and security of supply are being cited by North Queensland industry leaders as the reasons for investing more than A$550 million to expand operations and convert to coal seam gas as their preferred fuel source. The article, by Enertrade, reports that just a few months after commissioning its North Queensland Gas Pipeline to transport coal seam gas from Moranbah to Townsville, Enertrade has signed contracts that will see combined cycle gas-fired baseload electricity generated in Townsville and the Queensland Nickel Refinery, and Xstrata Copper Refinery switch from liquid fuels to gas. The development has been driven by state government policy that 13% of Queensland's electricity be sourced from gas-fired power generation from 1 January 2005. Further information is available from Enertrade on Tel +617 3331 9929. 2 photos.

Influence of Industrial Washing and Cyclic Fatigue on Slippage of Linen Fabric Threads along the Seam

Directory of Open Access Journals (Sweden)

Irina KORUNČAK

2014-04-01

Full Text Available All seams of garments shall withstand the established force effect in the longitudinal and transverse directions. Resistance to thread slippage along the seam is a major property of fabrics that is regulated by strict guidelines. In many research works, lining fabrics are chosen as the object of research as thread slippage is the most typical of them. What concerns the reports exploring slippage of linen fabric threads along the seam, just very few papers are available. Studies dealing with the influence made by industrial washing and cyclic load on the defect under investigation, thereby taking into account operational properties of garments are not readily available at all. The objective of the paper is to define the influence of industrial washing and cyclic tensile on slippage of linen fabric threads along the seam. For the research, five 100 % linen fabrics of plain weave have been selected. Control test specimens, unwashed and processed with different washing methods, have been analysed. Cyclic tensile of the test specimens has been carried out by a tensile machine “Tinius Olsen” at tensile force P = 20 N, tensile speed of 12.55 mm/s, number of cycles of 100. The carried-out testing has demonstrated that industrial washing decreased resistance of linen fabrics to thread slippage along the seam in the most cases. Analysis of the results obtained has shown that cyclic tensile led to particularly significant increase in the seam gap. DOI: http://dx.doi.org/10.5755/j01.ms.20.1.2486

Impacts of Coal Seam Gas (Coal Bed Methane) Extraction on Water Resources in Australia

Science.gov (United States)

Post, David

2017-04-01

While extraction of methane from shale gas deposits has been the principal source of the recent expansion of the industry in the United States, in Australia extraction of methane from coal bed methane deposits (termed 'coal seam gas' in Australia) has been the focus to date. The two sources of methane share many of the same characteristics including the potential requirement for hydraulic fracturing. However, as coal seam gas deposits generally occur at shallower depths than shale gas, the potential impacts of extraction on surface and groundwater resources may be of even greater concern. In Australia, an Independent Expert Scientific Committee (IESC) has been established to provide scientific advice to federal and state government regulators on the impact that coal seam gas and large coal mining developments may have on water resources. This advice is provided to enable decisions to be informed by the best available science about the potential water-related impacts associated with these developments. To support this advice, the Australian Government Department of the Environment has implemented a programme of research termed 'bioregional assessments' to investigate these potential impacts. A bioregional assessment is defined as a scientific analysis of the ecology, hydrology, geology and hydrogeology of a bioregion with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and large coal mining development on water resources. These bioregional assessments are currently being carried out across large portions of eastern Australia underlain by coal reserves. Further details of the programme and results to date can be found at http://www.bioregionalassessments.gov.au. The bioregional assessment programme has modelled the impacts of coal seam gas development on surface and groundwater resources in three regions of eastern Australia, namely the Clarence-Moreton, Gloucester, and Namoi regions. This presentation will discuss the

Sequence stratigraphy, organic petrology and chemistry applied to the upper and lower coal seams in the Candiota Coalfield, Parana Basin, RS, Brazil

Energy Technology Data Exchange (ETDEWEB)

Oliveira, J.S. de; Kalkreuth, W. [Instituto de Geociencias, UFRGS, Porto Alegre (Brazil)

2010-12-01

The Permian age coal seams in the Candiota Coalfield represent the largest coal deposit of the country. Currently two seams are mined, called ''Camada Candiota Superior'' and ''Camada Candiota Inferior''. The other coal seams of the coalfield, seams S1-S9 (upper seams) and I1-I5 (lower seams) have as yet not been exploited. The objective of this paper is to perform a detailed sequence stratigraphic, petrologic and chemical study of the upper and lower coal seams, thereby generating data for assisting in the development and better use of the coal-bearing interval. The methodology includes application of the concepts of sequence stratigraphy, which includes the lithological interpretation of the core to establish the depositional environments and genetic correlation between facies associations to define parasequences and bounding surfaces; coal petrology (analysis of the reflectance of vitrinite, determination of the petrographic composition of the coals by maceral analyses), and chemical analyses such as sulphur determination, proximate analyses (ash, moisture, volatile matter, and fixed carbon), and elemental analyses. Three main depositional systems were so far identified: alluvial fan, fluvial system, lagoonal estuary system. This study shows that coal development was controlled by accommodation/accumulation rates, with coal seams with greater thickness and lateral continuity being formed within the transgressive systems tract (lagoonal depositional system) of parasequence 2 (PS2), indicating that the accumulation rates of the peat and distribution of the coal seams were controlled by stratigraphic setting. Vitrinite reflectances for the upper and lower coal seams are indicative of subbituminous rank (Rrandom = 0.36-0.47%), with evidence that anomalously low reflectance values are related to high mineral-matter contents. Maceral composition is highly variable, with some coal seams being extremely rich in inertinite (up to

Law of Strata Pressure Behavior in Shallow Coal Seam

Science.gov (United States)

Zhao, Jian; Liu, Leibin; Zheng, Zhiyang

2018-02-01

The law of strata pressure behavior in shallow coal seam is analyzed, according to the load data of Jinjie Coal Mine 31109 working face hydraulic supports. The first weighting distance of main roof is 80 m, and the periodic weighting distance of main roof is about 20 m. And according to the load data in the middle and both ends of the working face, the working resistance of hydraulic supports and the setting load are a bit small, so they couldn’t meet the needs of supporting roof. Then, the front abutment pressure of working face is analyzed by numerical simulation. It does not only explain the reason that the load is too big, but also explains the reason that the strata pressure behavior in shallow coal seam is serious. The length of undamaged main roof rock beam verifies the correctness of the periodic weighting distance.

Principles of integrated modeling of coal seam mining

Energy Technology Data Exchange (ETDEWEB)

Magda, R

1983-01-01

Mathematical modeling of underground coal mining is discussed. Construction of a mathematical model of an underground mine is analyzed. The model is based on integrating the elementary units (modules). A so-called elementary mining field is defined with the example of a longwall face. A model of an elementary coal seam zone is constructed by integrating the elementary mining fields (in time and space) and supplementing them with a suitable model of mine roadway structure. By integrating the elementary coal seam zones a model of mining level is constructed. Such a mathematical model is used for optimizing the selected mining parameters e.g. structure of mine roadways, size of a coal mine, and organizational scheme of underground mining in a mine or in a mine section using the standardized optimization criterion e.g. investment. Use of the integration model of underground mining for optimizing coal mine construction is evaluated. The following elements of investment and operating cost are considered: shaft excavation, shaft equipment, investment in mining sections, ventilation, mine draining etc. 1 reference.

Innovative Extraction Method for a Coal Seam with a Thick Rock-Parting for Supporting Coal Mine Sustainability

Directory of Open Access Journals (Sweden)

Meng Li

2017-10-01

Full Text Available As thick rock partings delay the efficient mining of coal seams and constrain the sustainable development of coal mines, an innovative extraction method for a coal seam with thick rock parting was proposed. The coal seams were divided into different sub-zones according to the thickness of rock parting and then the sub-zones were mined by separately using three mining schemes involving full-seam mining, combined mining using backfill and caving (CMBC, and reducing height mining. Afterwards, the study introduced the basic mechanism and key devices for the CMBC and analysed the working state of the backfill support in detail. Moreover, the method for calculating the length of the backfill zone was proposed to design the length of backfill zone and the influences of four factors (including bulking coefficient of rock parting on the length of the backfill zone were also explored. By taking the No. 22203 panel, Buertai mine, Inner Mongolia, China as an example, the mined coal resource by using the CMBC extraction method will increase by 1.83 × 106 tons and the recovery ratio will rise from 56.2% to 92.4% compared with mining of the 2-2 upper coal seam alone. Moreover, by applying CMBC, a series of environmental and ecological problems caused by rock parting is reduced, which can improve the environment in mined areas. The research can provide technological guidance for mining panels of a coal seam with a thick rock parting and the disposal thereof under similar conditions.

Petrographic properties of major coal seams in Turkey and their formation

Energy Technology Data Exchange (ETDEWEB)

Toprak, Selami [Mineral Research and Exploration Directorate (MTA), 06520 Ankara (Turkey)

2009-06-01

Most types of coal in Turkey are generally low in rank: lignite, and subbituminous. Most of the coal was formed during the Miocene, Eocene, and Pliocene ages. There are only a few thin Jurassic-age coal occurrences in Turkey. Pennsylvanian age bituminous coal is found on the Black Sea coast. General implications of the petrographic properties of Turkey's coal seams and coal deposits have not yet been taken into consideration comparatively or as a whole. For this study, about 190 channel samples were collected from different locales. The composite profile samples of the seams were taken into considerations. The content and depositional properties as well as some chemical and physical properties of the main coal seams are compared. All coal samples tend to have similar coal petrographic properties and were deposited in intermontane lacustrine basins. Later, they were affected by faulting and post-depositional volcanic activity. As a result, there are variations in the properties and rank of the coal samples. The most abundant coal maceral group is huminite and the most abundant maceral is gelinite. The liptinite and inertinite contents of the coal are low and the maceral contents of the coals show great similarity. The depositional environments of the all coals are lacustrine dominated. (author)

Palynological dating of a coal seam in Ayyanapalem area, Khamman District, Andhra Pradesh, India

Energy Technology Data Exchange (ETDEWEB)

Rao, M.R.; Lakshminarayana, G.; Ramanujam, C.G.K. (Geological Survey of India, Hyderabad (India). Southern Region)

1990-05-25

A palynological study of five subsurface samples of a coal seam near Ayyanapalem, Chintalapudi sub-basin of Godavari valley, Andhra Pradesh, was carried out. Twenty-five genera, including monosaccate, striate and nonstriate bisaccate, and trilete sporomorphs were identified; striate bisaccates predominate. Based on occurrence of {ital Rhizomaspora, Microbaculispora, Indotriradites, Crucisaccites ital} and {ital Corisaccites}, the coal seam is inferred to be similar in age to the Permian age Barakar Formation of the Lower Gondwana. 3 refs., 2 figs.

3D Discrete element approach to the problem on abutment pressure in a gently dipping coal seam

Science.gov (United States)

Klishin, S. V.; Revuzhenko, A. F.

2017-09-01

Using the discrete element method, the authors have carried out 3D implementation of the problem on strength loss in surrounding rock mass in the vicinity of a production heading and on abutment pressure in a gently dripping coal seam. The calculation of forces at the contacts between particles accounts for friction, rolling resistance and viscosity. Between discrete particles modeling coal seam, surrounding rock mass and broken rocks, an elastic connecting element is introduced to allow simulating coherent materials. The paper presents the kinematic patterns of rock mass deformation, stresses in particles and the graph of the abutment pressure behavior in the coal seam.

The Single Needle Lockstitch Machine. [Sewing Seams.] Module 4.

Science.gov (United States)

South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

This module on sewing seams, one in a series on the single needle lockstitch sewing machine for student self-study, contains three sections. Each section includes the following parts: an introduction, directions, an objective, learning activities, student information, student self-check, check-out activities, and an instructor's final checklist.…

Mechanism of Rock Burst Occurrence in Specially Thick Coal Seam with Rock Parting

Science.gov (United States)

Wang, Jian-chao; Jiang, Fu-xing; Meng, Xiang-jun; Wang, Xu-you; Zhu, Si-tao; Feng, Yu

2016-05-01

Specially thick coal seam with complex construction, such as rock parting and alternative soft and hard coal, is called specially thick coal seam with rock parting (STCSRP), which easily leads to rock burst during mining. Based on the stress distribution of rock parting zone, this study investigated the mechanism, engineering discriminant conditions, prevention methods, and risk evaluation method of rock burst occurrence in STCSRP through setting up a mechanical model. The main conclusions of this study are as follows. (1) When the mining face moves closer to the rock parting zone, the original non-uniform stress of the rock parting zone and the advancing stress of the mining face are combined to intensify gradually the shearing action of coal near the mining face. When the shearing action reaches a certain degree, rock burst easily occurs near the mining face. (2) Rock burst occurrence in STCSRP is positively associated with mining depth, advancing stress concentration factor of the mining face, thickness of rock parting, bursting liability of coal, thickness ratio of rock parting to coal seam, and difference of elastic modulus between rock parting and coal, whereas negatively associated with shear strength. (3) Technologies of large-diameter drilling, coal seam water injection, and deep hole blasting can reduce advancing stress concentration factor, thickness of rock parting, and difference of elastic modulus between rock parting and coal to lower the risk of rock burst in STCSRP. (4) The research result was applied to evaluate and control the risk of rock burst occurrence in STCSRP.

Spatio-temporal evolution of apparent resistivity during coal-seam hydraulic flushing

Science.gov (United States)

Li, Dexing; Wang, Enyuan; Song, Dazhao; Qiu, Liming; Kong, Xiangguo

2018-06-01

Hydraulic flushing in gas predrainage is widely used, but the hydraulic-flushing effect is evaluated in a traditional way, by determining the desorption volume, moisture content, gas drainage rate and other conventional indices. To verify the rationality and feasibility of the multielectrode resistivity method in the evaluation of coal-seam hydraulic flushing and to research the spatio-temporal evolution of apparent resistivity during hydraulic flushing, a field test was conducted in 17# coal seam at Nuodong Mine, Guizhou. During hydraulic flushing, four stages were defined according to the variation in coal rock resistivity with time, namely, the preparation stage, the sharply decreasing stage, the rapidly increasing stage and the steady stage. The apparent resistivity of the coal rock mass is affected mainly by its own degree of fragmentation and flushing volume. A more serious rupture and a greater flushing volume yield a smaller apparent resistivity during the sharply decreasing stage and a higher resistivity during the stable stage. After three months of gas predrainage, the residual gas content and the gas pressure at different points in the expected affected area decrease below the critical value. Changes in the residual gas content and gas pressure at these points are consistent with the apparent resistivity, which validates the rationality and feasibility of the multielectrode resistivity method in evaluating coal-seam hydraulic flushing.

Effect of Seams on Drape of Fabrics (Pp. 62-72)

African Journals Online (AJOL)

Nekky Umera

Jinlian ... Drape profile of fabrics with seams provide guidance for garment designs ... holder consists of flat plates, circular in shape, mounted on a shaft coming through ... The image of this draped pattern is cast onto a sheet by means of a lens.

Stress distribution characteristics in the vicinity of coal seam floor

Science.gov (United States)

Cui, Zimo; Chanda, Emmanuel; Zhao, Jingli; Wang, Zhihe

2018-01-01

Although longwall top-coal caving (LTCC) has been a popular, more productive and cost-effective method in recent years, roadway floor heave and rock bursts frequently appear when exploiting such coal seams with large dip angle. This paper proposes addressing this problem by adopting three-dimensional roadway layout of stagger arrangement (3-D RLSA). In this study, the first step was to analyse the stress distribution characteristics in the vicinity of coal seam floor based on the stress slip line field theory. In the second step, numerical calculation using FLAC3D was conducted. Finally, an evaluation of the 3-D RLSA for solving this particular issue was given. Results indicate that for this particular mine the proposed 3-D RLSA results in 24% increase in the coal recovery ratio and a modest reduction in excavation and maintenance costs compared to the conventional LTCC method.

SEAM PUCKERING EVALUATION METHOD FOR SEWING PROCESS

Directory of Open Access Journals (Sweden)

BRAD Raluca

2014-07-01

Full Text Available The paper presents an automated method for the assessment and classification of puckering defects detected during the preproduction control stage of the sewing machine or product inspection. In this respect, we have presented the possible causes and remedies of the wrinkle nonconformities. Subjective factors related to the control environment and operators during the seams evaluation can be reduced using an automated system whose operation is based on image processing. Our implementation involves spectral image analysis using Fourier transform and an unsupervised neural network, the Kohonen Map, employed to classify material specimens, the input images, into five discrete degrees of quality, from grade 5 (best to grade 1 (the worst. The puckering features presented in the learning and test images have been pre-classified using the seam puckering quality standard. The network training stage will consist in presenting five input vectors (derived from the down-sampled arrays, representing the puckering grades. The puckering classification consists in providing an input vector derived from the image supposed to be classified. A scalar product between the input values vectors and the weighted training images is computed. The result will be assigned to one of the five classes of which the input image belongs. Using the Kohonen network the puckering defects were correctly classified in proportion of 71.42%.

Determination of mineral matter distribution in a coal seam using O sub 2 chemisorption technique

Energy Technology Data Exchange (ETDEWEB)

Palmer, A.D.; Goulet, J.-C.; Grandsen, J.; Price, J.T.; Furimsky, E. (CANMET, Ottawa, ON (Canada). Energy Research Laboratories)

1990-08-01

A series of samples taken from different depths of the seam of a bituminous coal in Western Canada was used to determine the mineral matter distribution. The measurements were carried out using the O{sub 2} chemisorption based on a thermogravimetric technique. The O{sub 2} chemisorption increased with decreasing mineral matter content. The employed technique was found to be suitable for identifying the portion of coal seam least contaminated with mineral matter. 5 refs., 3 figs., 1 tab.

Influence of Loading Direction and Weld Reinforcement on Fatigue Performance of TIG Weld Seam

Directory of Open Access Journals (Sweden)

HUI Li

2018-02-01

Full Text Available The influence of loading direction and weld reinforcement on fatigue performance of TC2 titanium alloy TIG weld seam was investigated via fatigue experiments and SEM fracture observation. The results show that the fatigue life of retaining weld reinforcement specimens is lower than that of removing one in the same weld direction. The fatigue life of oblique weld specimens is higher than that of straight one with the same weld reinforcement treatment. The initiation of removing weld reinforcement specimens' fatigue crack sources is in the hole defect, but the weld reinforcement specimen initiate at the weld toes. During the early stage of fatigue crack propagation, the cracks all grow inside the weld seam metal with obvious fatigue striation. And the fatigue cracks of oblique weld specimens pass through the weld seam into the base with a typical toughness fatigue striation during the last stage of fatigue crack propagation. The dimple of straight weld specimens is little and shallow in the final fracture zone. The oblique weld specimens broke in the base metal area, and the dimple is dense.

A comparison of geochemical features of extracts from coal-seams source rocks with different polarity solvents

Energy Technology Data Exchange (ETDEWEB)

Chen, Jianping; Deng, Chunping; Wang, Huitong

2009-02-15

There exists a great difference in group-type fractions and biomarker distributions of chloroform extracts from coals and coal-seams oils, which makes the source identification of coal-seams oils in sedimentary basins rather difficult. The experiment, in which four different polarity solvents, n-hexane, benzene, dichloromethane and chloroform, were used to extract 9 coal-seams source rocks and 3 typical lacustrine source rocks, showed that the yield of extracts increased gradually with increasing solvent polarity. The distribution features of their n-alkanes, isoprenoids and sterane and terpane biomarkers remained, in general, similar, showing no distinct enrichment or depletion for a certain fraction by any solvent. The compositional analysis on n-hexane and chloroform extracts showed that the absolute amount (concentration) of biomarkers was relatively low for the n-hexane extract but comparatively high for the chloroform extract, this difference became great among coal-seams source rocks but small among lacustrine mudstones. The statistical analysis on the relative amount of the 18 major biomarkers in n-hexane and chloroform extracts from 10 source rock samples showed that extracts with a proportional error for the same biomarker of less than 5% (including the analytical error) accounted for 84% while those with a proportional error over 10% amounted to below 5%. This suggested that the outcome of oil-source correlation made by these biomarkers will be independent of variations in amounts of saturates and biomarkers arising from solvent polarity. Therefore, biomarkers obtained from organic-rich source rocks including coals by the extraction with the commonly used chloroform solvent can be applied for the oilsource correlation of coal-seams petroliferous basins.

Adult Education and Radical Habitus in an Environmental Campaign: Learning in the Coal Seam Gas Protests in Australia

Science.gov (United States)

Ollis, Tracey; Hamel-Green, Michael

2015-01-01

This paper examines the adult learning dimensions of protestors as they participate in a campaign to stop coal seam gas exploration in Gippsland in Central Victoria, Australia. On a global level, the imposition of coal seam gas exploration by governments and mining companies has been the trigger for movements of resistance from environmental…

Analysis of support installation and strata control in ventilation tunnels and coal chutes in steep seams

Energy Technology Data Exchange (ETDEWEB)

Moroz, V D; Belyaev, A N; Kostyuk, I S

1984-01-01

The VNIMI and the Donugi branch in Gorlovka developed and tested a system for strata control in gate roads for ventilation and in coal chutes in inclined and steep medium and thick coal seams. The roof is supported by cribbings made of slabs of reinforced concrete with yielding elements. Timber is used as yielding material. Tests showed that thickness of yielding layers between concrete slabs should range from 15 to 20% of coal seam thickness. Yielding elements increase yield strength of the system to about 2 MN (load distribution is more regular). The tests show that the cribbings are an efficient system for strata control in workings driven in coal seams with dip angle from 35 to 60 degrees. Performance of concrete cribbings in ventilation gate roads and coal chutes in selected mines of the Ukrainian SSR is analyzed.

The migration law of overlay rock and coal in deeply inclined coal seam with fully mechanized top coal caving.

Science.gov (United States)

Liu, Jian; Chen, Shan-Le; Wang, Hua-Jun; Li, Yu-Cheng; Geng, Xiaowei

2015-07-01

In a mine area, some environment geotechnics problems always occure, induced by mined-out region such as the subsidence and cracks at ground level, deformation and destruction of buildings, landslides destruction of water resources and the ecological environment. In order to research the migration of surrounding rock and coal in steeply inclined super high seams which used fully mechanized top coal caving, a working face of a certain mine was made as an example, analyzed the migration law of the overlay rock and coal under different caving ratio of fully mechanized top coal caving with numerical simulation analysis. The results suggest that the laws of overlay rock deformation caused by deeply inclined coal seam were different from horizontal coal seam. On the inclined direction, with an increase of dip angle and caving ratio, the vertical displacement of overlay rock and coal became greater, the asymmetric phenomenon of vertical displacement became obvious. On the trend direction, active region and transition region in goaf became smaller along with the increase of mining and caving ratio. On the contrary, the stable region area became greater. Therefore, there was an essential difference between the mechanism of surface movement deformation with deeply inclined coal seam and that with horizontal coal seam.

Drag resistance measurements for newly applied antifouling coatings and welding seams on ship hull surface

DEFF Research Database (Denmark)

Wang, Xueting; Olsen, S. M.; Andres, E.

Drag resistances of newly applied antifouling coatings and welding seams on ship hull surface have been investigated using a pilot-scale rotary setup. Both conventional biocide-based antifouling (AF) coatings and silicone-based fouling release (FR) coatings have been studied and compared in their......Drag resistances of newly applied antifouling coatings and welding seams on ship hull surface have been investigated using a pilot-scale rotary setup. Both conventional biocide-based antifouling (AF) coatings and silicone-based fouling release (FR) coatings have been studied and compared...

C. elegans GATA factors EGL-18 and ELT-6 function downstream of Wnt signaling to maintain the progenitor fate during larval asymmetric divisions of the seam cells.

Science.gov (United States)

Gorrepati, Lakshmi; Thompson, Kenneth W; Eisenmann, David M

2013-05-01

The C. elegans seam cells are lateral epithelial cells arrayed in a single line from anterior to posterior that divide in an asymmetric, stem cell-like manner during larval development. These asymmetric divisions are regulated by Wnt signaling; in most divisions, the posterior daughter in which the Wnt pathway is activated maintains the progenitor seam fate, while the anterior daughter in which the Wnt pathway is not activated adopts a differentiated hypodermal fate. Using mRNA tagging and microarray analysis, we identified the functionally redundant GATA factor genes egl-18 and elt-6 as Wnt pathway targets in the larval seam cells. EGL-18 and ELT-6 have previously been shown to be required for initial seam cell specification in the embryo. We show that in larval seam cell asymmetric divisions, EGL-18 is expressed strongly in the posterior seam-fated daughter. egl-18 and elt-6 are necessary for larval seam cell specification, and for hypodermal to seam cell fate transformations induced by ectopic Wnt pathway overactivation. The TCF homolog POP-1 binds a site in the egl-18 promoter in vitro, and this site is necessary for robust seam cell expression in vivo. Finally, larval overexpression of EGL-18 is sufficient to drive expression of a seam marker in other hypodermal cells in wild-type animals, and in anterior hypodermal-fated daughters in a Wnt pathway-sensitized background. These data suggest that two GATA factors that are required for seam cell specification in the embryo independently of Wnt signaling are reused downstream of Wnt signaling to maintain the progenitor fate during stem cell-like divisions in larval development.

Selection of an Appropriate Mechanized Mining Technical Process for Thin Coal Seam Mining

Directory of Open Access Journals (Sweden)

Chen Wang

2015-01-01

Full Text Available Mechanized mining technical process (MMTP related to the control method of the shearer is a vital process in thin coal seam mining operations. An appropriate MMTP is closely related to safety, productivity, labour intensity, and efficiency. Hence, the evaluation of alternative MMTP is an important part of the mining design. Several parameters should be considered in MMTP evaluation, so the evaluation is complex and must be compliant with a set of criteria. In this paper, two multiple criteria decision-making (MCDM methods, Analytic Hierarchy Process (AHP and Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE, were adopted for this evaluation. Then, the most appropriate MMTP for a thin coal seam working face was selected in China.

Permeability Prediction in Deep Coal Seam: A Case Study on the No. 3 Coal Seam of the Southern Qinshui Basin in China

Science.gov (United States)

2013-01-01

The coal permeability is an important parameter in mine methane control and coal bed methane (CBM) exploitation, which determines the practicability of methane extraction. Permeability prediction in deep coal seam plays a significant role in evaluating the practicability of CBM exploitation. The coal permeability depends on the coal fractures controlled by strata stress, gas pressure, and strata temperature which change with depth. The effect of the strata stress, gas pressure, and strata temperature on the coal (the coal matrix and fracture) under triaxial stress and strain conditions was studied. Then we got the change of coal porosity with strata stress, gas pressure, and strata temperature and established a coal permeability model under tri-axial stress and strain conditions. The permeability of the No. 3 coal seam of the Southern Qinshui Basin in China was predicted, which is consistent with that tested in the field. The effect of the sorption swelling on porosity (permeability) firstly increases rapidly and then slowly with the increase of depth. However, the effect of thermal expansion and effective stress compression on porosity (permeability) increases linearly with the increase of depth. The most effective way to improve the permeability in exploiting CBM or extracting methane is to reduce the effective stress. PMID:24396293

An influence function method based subsidence prediction program for longwall mining operations in inclined coal seams

Energy Technology Data Exchange (ETDEWEB)

Yi Luo; Jian-wei Cheng [West Virginia University, Morgantown, WV (United States). Department of Mining Engineering

2009-09-15

The distribution of the final surface subsidence basin induced by longwall operations in inclined coal seam could be significantly different from that in flat coal seam and demands special prediction methods. Though many empirical prediction methods have been developed, these methods are inflexible for varying geological and mining conditions. An influence function method has been developed to take the advantage of its fundamentally sound nature and flexibility. In developing this method, significant modifications have been made to the original Knothe function to produce an asymmetrical influence function. The empirical equations for final subsidence parameters derived from US subsidence data and Chinese empirical values have been incorporated into the mathematical models to improve the prediction accuracy. A corresponding computer program is developed. A number of subsidence cases for longwall mining operations in coal seams with varying inclination angles have been used to demonstrate the applicability of the developed subsidence prediction model. 9 refs., 8 figs.

Improved coal winning in Zollverein 7/8 seam by toe-in plough 9. 30 v supplied by GEW Luenen

Energy Technology Data Exchange (ETDEWEB)

Schwolow, G; Dornack, M; Plich, H

1982-04-01

The project aimed at mining Zollverein 7/8 seam more efficiently than with drag-hook ploughs. Zollverein 7/8 seam is characterized by mechanically tough coal changing, seam thickness, a somewhat 'corrugated' shape, and a soft floor. Comparative investigations on one toe-in plough face and one drag-hook plough face in two neighbouring panels of said seam were made for individual plough travels as well as over several months of operation. These investigations were backed up by measuring. The measuring conditions were identical in both panels. The face equipments were identical except for the plough systems. The energy pick-up relative to the web is by 43% lower with the toe-in plough compared to the drag-hook plough. As to wear, for the toe-in plough in comparison to the drag-hook plough twice the longevity of the latter was recorded. For the noise level on the plough guides only marginal difference in favor to the toe-in plough could be recorded. Analyses of dust and particle-size distribution showed no obvious advantages for either of both plough systems.

Dynamic mapping of conical intersection seams: A general method for incorporating the geometric phase in adiabatic dynamics in polyatomic systems.

Science.gov (United States)

Xie, Changjian; Malbon, Christopher L; Yarkony, David R; Guo, Hua

2017-07-28

The incorporation of the geometric phase in single-state adiabatic dynamics near a conical intersection (CI) seam has so far been restricted to molecular systems with high symmetry or simple model Hamiltonians. This is due to the fact that the ab initio determined derivative coupling (DC) in a multi-dimensional space is not curl-free, thus making its line integral path dependent. In a recent work [C. L. Malbon et al., J. Chem. Phys. 145, 234111 (2016)], we proposed a new and general approach based on an ab initio determined diabatic representation consisting of only two electronic states, in which the DC is completely removable, so that its line integral is path independent in the simply connected domains that exclude the CI seam. Then with the CIs included, the line integral of the single-valued DC can be used to construct the complex geometry-dependent phase needed to exactly eliminate the double-valued character of the real-valued adiabatic electronic wavefunction. This geometry-dependent phase gives rise to a vector potential which, when included in the adiabatic representation, rigorously accounts for the geometric phase in a system with an arbitrary locus of the CI seam and an arbitrary number of internal coordinates. In this work, we demonstrate this approach in a three-dimensional treatment of the tunneling facilitated dissociation of the S 1 state of phenol, which is affected by a C s symmetry allowed but otherwise accidental seam of CI. Here, since the space is three-dimensional rather than two-dimensional, the seam is a curve rather than a point. The nodal structure of the ground state vibronic wavefunction is shown to map out the seam of CI.

"Knitting Nannas" and "Frackman": A Gender Analysis of Australian Anti-Coal Seam Gas Documentaries (CSG) and Implications for Environmental Adult Education

Science.gov (United States)

Larri, Larraine J.; Newlands, Maxine

2017-01-01

"Frackman" ("FM") and "Knitting Nannas" ("KN") are two documentaries about the anti-coal seam gas movement in Australia. "Frackman" features a former construction worker turned eco-activist, Dayne Pratzky (DP), fighting coal seam gas extraction. "Knitting Nannas" follows a group of women…

Automated concept and relationship extraction for the semi-automated ontology management (SEAM) system.

Science.gov (United States)

Doing-Harris, Kristina; Livnat, Yarden; Meystre, Stephane

2015-01-01

We develop medical-specialty specific ontologies that contain the settled science and common term usage. We leverage current practices in information and relationship extraction to streamline the ontology development process. Our system combines different text types with information and relationship extraction techniques in a low overhead modifiable system. Our SEmi-Automated ontology Maintenance (SEAM) system features a natural language processing pipeline for information extraction. Synonym and hierarchical groups are identified using corpus-based semantics and lexico-syntactic patterns. The semantic vectors we use are term frequency by inverse document frequency and context vectors. Clinical documents contain the terms we want in an ontology. They also contain idiosyncratic usage and are unlikely to contain the linguistic constructs associated with synonym and hierarchy identification. By including both clinical and biomedical texts, SEAM can recommend terms from those appearing in both document types. The set of recommended terms is then used to filter the synonyms and hierarchical relationships extracted from the biomedical corpus. We demonstrate the generality of the system across three use cases: ontologies for acute changes in mental status, Medically Unexplained Syndromes, and echocardiogram summary statements. Across the three uses cases, we held the number of recommended terms relatively constant by changing SEAM's parameters. Experts seem to find more than 300 recommended terms to be overwhelming. The approval rate of recommended terms increased as the number and specificity of clinical documents in the corpus increased. It was 60% when there were 199 clinical documents that were not specific to the ontology domain and 90% when there were 2879 documents very specific to the target domain. We found that fewer than 100 recommended synonym groups were also preferred. Approval rates for synonym recommendations remained low varying from 43% to 25% as the

Element geochemistry and cleaning potential of the No. 11 coal seam from Antaibao mining district

Energy Technology Data Exchange (ETDEWEB)

Wang, W.F.; Qin, Y.; Song, D.Y.; Sang, S.X.; Jiang, B.; Zhu, Y.M.; Fu, X.H. [China University of Mining & Technology, Xuzhou (China). College for Resources & Geoscience

2005-12-15

Based on the analyses of sulfur and 41 other elements in 8 channel samples of the No. 11 coal seam from Antaibao surface mine, Shanxi, China and 4 samples from the coal preparation plant of this mine, the distribution of the elements in the seam profile, their geochemical partitioning behavior during the coal cleaning and the genetic relationships between the both are studied. The coal-forming environment was probably invaded by sea water during the post-stage of peatification, which results in the fact that the contents of As, Fe, S, etc. associated closely with sea water tend to increase toward the top of the seam. These elements studied are dominantly associated with kaolinite, pyrite, illite, montmorillonite, etc., of which the As, Pb, Mn, Cs, Co, Ni, etc. are mainly associated with sulfides, the Mo, V, Nb, Hf, REEs, Ta etc. mainly with kaolinite, the Mg, Al etc. mainly with epigenetic montmorillonite, and the Rb, Cr, Ba, Cu, K, Hg, etc. mainly with epigenetic illite. The physical coal cleaning is not only effective in the removal of ash and sulfur, but also in reducing the concentration of most major and trace elements. The elements Be, U, Sb, W, Br, Se, P, etc. are largely or partly organically bound showing a relatively low removability, while the removability of the other elements studied is more than 20%, of which the Mg, Mn, Hg, Fe, As, K, AI, Cs, and Cr associated mostly with the coarser or epigenetic minerals show a higher removability than that of ash. The distribution of the elements in the seam profile controls their partitioning behavior to a great degree during the coal cleaning processes.

Fault capability problem about seams in Shika NPP

International Nuclear Information System (INIS)

Katagawa, H.

2016-01-01

Against the opinion of the Nuclear Regulation Authority that insists that the on-site seams of Shika Nuclear Power Plant is fault, Hokuriku Electric Power Company shows the view that they are not the fault. Additional survey result was submitted by Hokuriku Electric Power Company, and the evaluation draft for it by the expert meeting of Nuclear Regulation Authority, as well as the peer review were published. The evaluation draft mentioned that the seams cannot be denied for the possibility to become active, and the peer review issued many evaluations different from the evaluation draft. This paper describes the contents of the evaluation draft and peer review summarized by Hokuriku Electric Power Company. Against the three major points of the evaluation draft, the peer review pointed out the defect of fact recognition in every issue of discussion that lacks in examination on the points that should have been checked, and questioned the eligibility of the contents of evaluation. Many of the suggestions and comments of the peer review were the contents that approved the on-site survey and the report at the expert meeting made by Hokuriku Electric Power Company. In addition, this paper summarizes the focal points of the evaluation draft, and points out the question for fault assumption and discrepancies in the case of existence of fault. Hokuriku Electric Power Company has published a rebuttal to the evaluation draft as the written opinion. (A.O.)

THE EFFECTS OF DIFFERENT WORK-LOADING APPLIED TO THE WORKERS THAT WORK PRODUCING OF SHIRT TO THE SEAM FAULT RATES

Directory of Open Access Journals (Sweden)

Önder YÜCEL

2001-03-01

Full Text Available Human efficiency is of big importance in the clothing industry. So as to provide high quality and productivity stabilized work –loading must be given to the workers that work in the cloth production lines. In addition to it, the kind of work must be paid attention in the studies to be done on stabilized work-loading. The aim of this study is to determine the effects of different work-loading to the seam fault rates. For this purpose, four different work-loading had been applied to the workers and determined seam faults on the clothes had been recorded. As a result of this study, seam fault rates in the different work-loading had been evaluated.

Time-lapse analysis of methane quantity in Mary Lee group of coal seams using filter-based multiple-point geostatistical simulation

Science.gov (United States)

Karacan, C. Özgen; Olea, Ricardo A.

2013-01-01

Coal seam degasification and its success are important for controlling methane, and thus for the health and safety of coal miners. During the course of degasification, properties of coal seams change. Thus, the changes in coal reservoir conditions and in-place gas content as well as methane emission potential into mines should be evaluated by examining time-dependent changes and the presence of major heterogeneities and geological discontinuities in the field. In this work, time-lapsed reservoir and fluid storage properties of the New Castle coal seam, Mary Lee/Blue Creek seam, and Jagger seam of Black Warrior Basin, Alabama, were determined from gas and water production history matching and production forecasting of vertical degasification wellbores. These properties were combined with isotherm and other important data to compute gas-in-place (GIP) and its change with time at borehole locations. Time-lapsed training images (TIs) of GIP and GIP difference corresponding to each coal and date were generated by using these point-wise data and Voronoi decomposition on the TI grid, which included faults as discontinuities for expansion of Voronoi regions. Filter-based multiple-point geostatistical simulations, which were preferred in this study due to anisotropies and discontinuities in the area, were used to predict time-lapsed GIP distributions within the study area. Performed simulations were used for mapping spatial time-lapsed methane quantities as well as their uncertainties within the study area.

Study of geological and technologic evaluation for steeply inclined coal seams

Energy Technology Data Exchange (ETDEWEB)

Zhang Xiao-bing; Wang Zhong-qiang; Zhang Wei (and others) [China University of Mining & Technology, Beijing (China). School of Resources and Safety Engineering

2007-07-01

In order to predict the mining effect and choice of the technical decision comprehensive evaluation on steep coal seams was taken. Based on technical test, mining practice and analysis of statistic data, the hierarchical structure of evaluation about steeply inclined coal seam was obtained. In the structure, there are 8 multiple factors, which can divide 13 fundamental factors. Using the method of comprehensive evaluation with multi-index and fuzzy mathematics, the evaluation functions of the influencing factors are structured, and the model of fuzzy evaluation is proposed. 289 mining faces in Datai mine were evaluated using this model and the single outputs of these faces were predicted. The result shows that the number of mining faces in the first class is 27, covering 9.43% of the total, the number of the second class is 87, covering 30.1% of the total, the number of the third class is 112, covering 38.75%, and the number of the fourth class is 63, covering 21.8%.The evaluation and the reality are largely uniform. 8 refs., 3 tabs.

Coiled-tubing fracturing of coal seams on the Vermejo Park Ranch

Energy Technology Data Exchange (ETDEWEB)

Bybee, K.

2003-06-01

Coiled-tubing (CT) fracturing currently is used to stimulate the Vermejo and Raton coal seams on the Vermejo Park Ranch in northern New Mexico. The CT fracturing process increased the number of stimulation stages from 4 to 18 per well. CT fracturing results in more accurate proppant placement and more effective stimulation of the producing zones.

近距离煤层群上行开采研究%Study on ascending mining of close distance coal seams group

Institute of Scientific and Technical Information of China (English)

庞冬冬

2017-01-01

为研究8煤开采对上部11煤的影响,综合运用理论分析和数值计算的方法,对上行开采过程中,上部11煤底板位移场.应力场变化规律进行研究.结果表明:11煤位于8煤开采的弯曲下沉带内,煤体有一定的破坏,但保持了很好的连续性,而且14128工作面的开采降低了上煤层的应力,形成应力降低区;同时,增大了11煤的透气性,减小瓦斯压力,卸压效果显著,对高瓦斯的11煤安全开采提供了保障.最后,计算得出了卸压影响范围.%In order to study the influence of No.8 seam mining on the upper No.11 seam,theoretical analysis and numerical calculation were used to study the change law of the displacement field and stress field of the upper No.11 seam floor during ascending mining.The results show that No.11 seam is located in the curve subsidence zone of No.8 seam mining,the coal body has certain damage,but it has a good continuity,and the stress of the upper coal seam is reduced because of the mining of 14128 working face and the stress decreasing zone has formed;at the same time,the permeability of No.11 coal increases,the gas pressure reduces,and pressure-relaxing effect is obvious,and it provides protection for the safe mining of No.11 seam which is of high gas.At last,the influence range of pressure relief is calculated.

Fracture mechanics characterisation of the WWER-440 reactor pressure vessel beltline welding seam of Greifswald unit 8

International Nuclear Information System (INIS)

Viehrig, Hans-Werner; Schuhknecht, Jan

2008-01-01

WWER-440 second generation (V-213) reactor pressure vessels (RPV) were produced by IZHORA in Russia and by SKODA in the former Czechoslovakia. The surveillance Charpy-V and fracture mechanics SE(B) specimens of both producers have different orientations. The main difference is the crack extension direction which is through the RPV thickness and circumferential for ISHORA and SKODA RPV, respectively. In particular for the investigation of weld metal from multilayer submerged welding seams the crack extension direction is of importance. Depending on the crack extension direction in the specimen there are different welding beads or a uniform structure along the crack front. The specimen orientation becomes more important when the fracture toughness of the weld metal is directly determined on surveillance specimens according to the Master Curve (MC) approach as standardised in the ASTM Standard Test Method E1921. This approach was applied on weld metal of the RPV beltline welding seam of Greifswald Unit 8 RPV. Charpy size SE(B) specimens from 13 locations equally spaced over the thickness of the welding seam were tested. The specimens are in TL and TS orientation. The fracture toughness values measured on the SE(B) specimens with both orientations follow the course of the MC. Nearly all values lie within the fracture toughness curves for 5% and 95% fracture probability. There is a strong variation of the reference temperature T 0 though the thickness of the welding seam, which can be explained with structural differences. The scatter is more pronounced for the TS SE(B) specimens. It can be shown that specimens with TS and TL orientation in the welding seam have a differentiating and integrating behaviour, respectively. The statistical assumptions behind the MC approach are valid for both specimen orientations even if the structure is not uniform along the crack front. By comparison crack extension, JR, curves measured on SE(B) specimens with TL and TS orientation show

Evaluation of coal bed methane potential of coal seams of Sawang ...

Indian Academy of Sciences (India)

This analysis shows that the maximum methane gas adsorbed in the coal sample CG-81 is 17 m3/t (Std. daf), at maximum pressure of 5.92 MPa ... vast coal reserves are ideal reservoirs for the gen- eration and accumulation of CBM. ... of gases in coal seams, such as, compression as free gas in the pore spaces, condensed ...

Relaxation and gas drainage boreholes for high performance longwall operations in low permeability coal seams

Energy Technology Data Exchange (ETDEWEB)

Imgrund, Thomas [DMT GmbH und Co. KG, Essen (Germany); Bauer, Frank [Hazemag und EPR GmbH, Duelmen (Germany). Mining

2013-06-15

With an increasing depth of cover, gas emission control and gas outbursts prevention has become an increasingly important issue in coal mining. Deep multi-seam mining often requires operation in an environment characterised by a high gas content and gas pressure. Control of gas related risks has to be realised during heading and close to the longwall by proper risk assessment and flexible drilling schemes. These cover exploration and relaxation drilling, in-seam drilling for pre-drainage and cross measure drilling for drainage of roof and the floor gas emissions. DMT provides comprehensive solutions based on a scientific background. These solutions are engineered considering their technical feasibility. Hazemag Mining offers a large number of complete machinery including tools systems for the implementation of those solutions. (orig.)

Prediction and control of rock burst of coal seam contacting gas in deep mining

Energy Technology Data Exchange (ETDEWEB)

En-yuan Wang; Xiao-fei Liu; En-lai Zhao; Zhen-tang Liu [China University of Mining and Technology, Xuzhou (China). School of Safety Engineering

2009-06-15

By analyzing the characteristics and the production mechanism of rock burst that goes with abnormal gas emission in deep coal seams, the essential method of eliminating abnormal gas emission by eliminating the occurrence of rock burst or depressing the magnitude of rock burst was considered. The No.237 working face in Nanshan coal mine was selected as the typical working face contacting gas in deep mining; aimed at this working face, a system of rock burst prediction and control for coal seam contacting gas in deep mining was established using the three-dimensional distinct element code software 3DEC. This system includes three parts: (1) regional prediction of rock burst hazard before mining; (2) local prediction of rock burst hazard during mining; and (3) rock burts control by an electromagnetic radiation method and specific drilling method. 8 refs., 4 figs., 1 tab.

The effect of the gas factor on selecting the thickness of a layer during two-layer getting of thick seams. [USSR

Energy Technology Data Exchange (ETDEWEB)

Varekha, Zh P; Kurkin, A S; Vechera, V N

1979-01-01

For technico-economic verification of the selection of the efficient removed thickness of upper and lower layers under conditions of high gas abundance of seams, the KNIUI has developed an economic model of converted costs within a getting field, allowing for natural and technical factors. The calculation considers specific costs for stoping work when getting the upper and lower layers, digging and maintenance of development workings, coal transport, assembly-disassembly work, ventilation, labor costs, degassing, etc. The calculation dependences and nomogram obtained enable comparatively easy definition of efficient thicknesses of removed layers when designing stoping work at thick, gently sloping seams, as well as calculation converted costs using as the initial data the total thickness of the seam, its natural gas content, and the expected degree of preliminary degassing.

Time-Lapse Analysis of Methane Quantity in the Mary Lee Group of Coal Seams Using Filter-Based Multiple-Point Geostatistical Simulation.

Science.gov (United States)

Karacan, C Özgen; Olea, Ricardo A

2013-08-01

Coal seam degasification and its success are important for controlling methane, and thus for the health and safety of coal miners. During the course of degasification, properties of coal seams change. Thus, the changes in coal reservoir conditions and in-place gas content as well as methane emission potential into mines should be evaluated by examining time-dependent changes and the presence of major heterogeneities and geological discontinuities in the field. In this work, time-lapsed reservoir and fluid storage properties of the New Castle coal seam, Mary Lee/Blue Creek seam, and Jagger seam of Black Warrior Basin, Alabama, were determined from gas and water production history matching and production forecasting of vertical degasification wellbores. These properties were combined with isotherm and other important data to compute gas-in-place (GIP) and its change with time at borehole locations. Time-lapsed training images (TIs) of GIP and GIP difference corresponding to each coal and date were generated by using these point-wise data and Voronoi decomposition on the TI grid, which included faults as discontinuities for expansion of Voronoi regions. Filter-based multiple-point geostatistical simulations, which were preferred in this study due to anisotropies and discontinuities in the area, were used to predict time-lapsed GIP distributions within the study area. Performed simulations were used for mapping spatial time-lapsed methane quantities as well as their uncertainties within the study area. The systematic approach presented in this paper is the first time in literature that history matching, TIs of GIPs and filter simulations are used for degasification performance evaluation and for assessing GIP for mining safety. Results from this study showed that using production history matching of coalbed methane wells to determine time-lapsed reservoir data could be used to compute spatial GIP and representative GIP TIs generated through Voronoi decomposition

New method for protecting mine roadways in thin coal seams by means of prefabricated yielding blocks

Energy Technology Data Exchange (ETDEWEB)

Peknik, J

1983-05-01

The use of concrete blocks for strata control in mine roadways driven in thin coal seams is evaluated. Two types of prefabricated blocks are used: BZT blocks made of reinforced concrete and yielding elements or popilbet blocks made of a mixture of fly ash (from coal power plants) and concrete. When the popilbet blocks were used no yielding elements were necessary. Mechanical properties of blocks made of reinforced concrete were controlled by yielding elements. Mechanical properties (compression strength) of the popilbet blocks were controlled by proportion of water, cement and fly ash. The BZT and the popilbet blocks were used for strata control in mine roadways in coal seams from 60 to 80 cm thick and dip angle from 5 to 18 degrees. Use of the BZT and the popilbet blocks reduced roadway deformation by about 50% in comparison to traditional strata control methods (timber cribbings, use of waste rock, etc.). Use of the blocks is explained. The BZT and the popilbet blocks were placed in a roadway wall. Height of the block wall equaled coal seam thickness. Yielding arched steel supports and timber liners were used for strata control in the roadway. The popilbet blocks were 50% less expensive than the BZT blocks. 9 references

Influence of a Large Pillar on the Optimum Roadway Position in an Extremely Close Coal Seam

Directory of Open Access Journals (Sweden)

Li Yang

2016-01-01

Full Text Available Based on the mining practice in an extremely close coal seam, theoretical analysis was conducted on the vertical stress distribution of the floor strata under a large coal pillar. The vertical stress distribution regulation of a No. 5 coal seam was revealed. To obtain the optimum position of the roadway that bears the supporting pressure of a large coal pillar, numerical modeling was applied to analyze the relation among the stress distribution of the roadway surrounding the rock that bears the supporting pressure of a large coal pillar, the plastic zone distribution of the roadway surrounding the rock, the surrounding rock deformation, and the roadway layout position. The theoretical calculation results of the stress value, stress variation rate, and influencing range of the stress influencing angle showed that the reasonable malposition of the No. 5 coal seam roadway was an inner malposition of 4 m. The mining practice showed the following: the layout of No. 25301 panel belt roadway at the position of the inner malposition of 4 m was reasonable, the roadway support performance was favourable without deformation, and ground pressure was not obvious. The research achievement of this study is the provision of a reference for roadway layouts under similar conditions.

Characteristics of the Roof Behaviors and Mine Pressure Manifestations During the Mining of Steep Coal Seam

Science.gov (United States)

Hong-Sheng, Tu; Shi-Hao, Tu; Cun, Zhang; Lei, Zhang; Xiao-Gang, Zhang

2017-12-01

A steep seam similar simulation system was developed based on the geological conditions of a steep coal seam in the Xintie Coal Mine. Basing on similar simulation, together with theoretical analysis and field measurement, an in-depth study was conducted to characterize the fracture and stability of the roof of steep working face and calculate the width of the region backfilled with gangue in the goaf. The results showed that, as mining progressed, the immediate roof of the steep face fell upon the goaf and backfilled its lower part due to gravity. As a result, the roof in the lower part had higher stability than the roof in the upper part of the working face. The deformation and fracture of main roof mainly occurred in the upper part of the working face; the fractured main roof then formed a "voussoir beam" structure in the strata's dip direction, which was subjected to the slip- and deformation-induced instability. The stability analysis indicated that, when the dip angle increased, the rock masses had greater capacity to withstand slip-induced instability but smaller capacity to withstand deformation-induced instability. Finally, the field measurement of the forces exerted on the hydraulic supports proved the characteristics of the roof's behaviors during the mining of a steep seam.

The origin of weld seam defects related to metal flow in the hot extrusion of aluminium alloys en AW-6060 and en AW-6082

NARCIS (Netherlands)

Bakker, A.J. den; Werkhoven, R.J.; Sillekens, W.H.; Katgerman, L.

2014-01-01

Longitudinal weld seams are an intrinsic feature in hollow extrusions produced with porthole dies. As these joins occur along the entire extruded length, it is desirable that these weld seams have a minimal impact on the structural integrity of the extrudate. In particular, defects associated with

Hybrid Technology of Hard Coal Mining from Seams Located at Great Depths

Science.gov (United States)

Czaja, Piotr; Kamiński, Paweł; Klich, Jerzy; Tajduś, Antoni

2014-10-01

Learning to control fire changed the life of man considerably. Learning to convert the energy derived from combustion of coal or hydrocarbons into another type of energy, such as steam pressure or electricity, has put him on the path of scientific and technological revolution, stimulating dynamic development. Since the dawn of time, fossil fuels have been serving as the mankind's natural reservoir of energy in an increasingly great capacity. A completely incomprehensible refusal to use fossil fuels causes some local populations, who do not possess a comprehensive knowledge of the subject, to protest and even generate social conflicts as an expression of their dislike for the extraction of minerals. Our times are marked by the search for more efficient ways of utilizing fossil fuels by introducing non-conventional technologies of exploiting conventional energy sources. During apartheid, South Africa demonstrated that cheap coal can easily satisfy total demand for liquid and gaseous fuels. In consideration of current high prices of hydrocarbon media (oil and gas), gasification or liquefaction of coal seems to be the innovative technology convergent with contemporary expectations of both energy producers as well as environmentalists. Known mainly from literature reports, underground coal gasification technologies can be brought down to two basic methods: - shaftless method - drilling, in which the gasified seam is uncovered using boreholes drilled from the surface, - shaft method, in which the existing infrastructure of underground mines is used to uncover the seams. This paper presents a hybrid shaft-drilling approach to the acquisition of primary energy carriers (methane and syngas) from coal seams located at great depths. A major advantage of this method is the fact that the use of conventional coal mining technology requires the seams located at great depths to be placed on the off-balance sheet, while the hybrid method of underground gasification enables them to

Study on Seam Deformation and Permeability Improved Effect of Pressure Released Mining in Protective Seam%保护层卸压开采煤层变形与增透效应研究

Institute of Scientific and Technical Information of China (English)

涂敏; 袁亮; 缪协兴; 刘泽功; 徐乃忠; 付宝杰

2013-01-01

为了研究高瓦斯赋存煤层卸压增透效应,以达到提高低渗透性松软煤层瓦斯抽采率,降低工作面瓦斯突出危险性,采用RFPA2D-Gasflow软件分析下保护层卸压开采后上覆煤岩采动裂隙发育、应力分布特征及由此产生的卸压煤层增透效应.结果表明:卸压开采煤层的透气性系数增大200倍左右,增透效果显著.利用该研究结果在顾桥矿沿空留巷内布置斜向上长短穿层钻孔,代替传统的底板巷内布置向上穿层钻孔抽采本层采空区内和上覆卸压煤层内瓦斯,可使沿空留巷中回风流和上隅角瓦斯体积分数均控制在0.5％以下,平均瓦斯抽采率达50％ ～ 70％,保证了工作面的安全回采.%In order to study the pressure released and permeability improved effect of the high gas content seam and to reach the targets to improve the gas drainage rate of the low permeability soft seam and to reduce the gas outburst danger of the coal mining face,the RFPA -Gasflow software was applied to analyze the mining crack development and the stress distribution features of the overburden coal and rock and thus created pressure released and permeability effect after the pressure released mining in the underneath protective seam.The results showed that the permeability coefficient of the pressure released mining seam could be increased about 200 times and the permeability improved effect was obvious.The study results were applied to the layout of the inclined upward long and short boreholes in the gateway retained along goaf in Guqiao Mine to replace the layout of the inclined upward borehole in the conventional floor gateway for the gas drainage in the mining goaf and the overburden pressure released seam.Thus the gas volume fractions of the air returning flow in the gateway retained and the gas in the upper corner both could be controlled below 0. 5%, the average gas drainage rate could be 50% ~ 70% and the safety mining of the coal mining face

Depositional environments of the Jurassic Maghara main coal seam in north central Sinai, Egypt

Science.gov (United States)

Edress, Nader Ahmed Ahmed; Opluštil, Stanislav; Sýkorová, Ivana

2018-04-01

Twenty-eight channel samples with a cumulative thickness of about 4 m collected from three sections of the Maghara main coal seam in the middle Jurassic Safa Formation have been studied for their lithotype and maceral compositions to reconstruct the character of peat swamp, its hydrological regime and the predominating type of vegetation. Lithotype composition is a combination of dully lithotypes with duroclarain (19% of total cumulative thickness), clarodurain (15%), black durain (15%), and shaly coal (15%) and bright lithotypes represented by clarain (23%), vitrain (12%) and a small proportion of wild fire-generated fusain (1%). Maceral analyses revealed the dominance of vitrinite (70.6% on average), followed by liptinite (25.2%) and inertinite (8.1%). Mineral matter content is ∼9% on average and consists of clay, quartz and pyrite concentrate mostly at the base and the roof of the seam. Dominantly vitrinite composition of coal and extremely low fire- and oxidation-borne inertinite content, together with high Gelification Indices imply predomination of waterlogged anoxic conditions in the precursing mire with water tables mostly above the peat surface throughout most of the time during peat swamp formation. Increases in collotelinite contents and Tissue Preservation Index up the section, followed by a reversal trend in upper third of the coal section, further accompanied by a reversal trend in collodetrinite, liptodetrinite, alginite, sporinite and clay contents records a transition from dominately limnotelmatic and limnic at the lower part to dominately limnotelmatic with increase telmatic condition achieved in the middle part of coal. At the upper part of coal seam an opposite trend marks the return to limnic and limnotelmatic conditions in the final phases of peat swamp history and its subsequent inundation. The proportion of arborescent (mostly coniferous) and herbaceous vegetation varied throughout the section of the coal with tendency of increasing

'Cut in two', Part 1: Exposing the Seam in Q 12:42−46

African Journals Online (AJOL)

2015-06-22

Jun 22, 2015 ... 'Cut in two', Part 1: Exposing the Seam in Q 12:42−46. This publication ..... on as normal for everyone except the appointed slave. This .... Greek and English with parallels from the Gospels of Mark and Thomas, Fortress,.

Testing the shearer-loader EDW 170/200 ln for thin seams in connection with chainless haulage. Final report

Energy Technology Data Exchange (ETDEWEB)

Tegenthoff, J.; Klimek, K.H.

1982-01-01

Coal extraction by cutting was investigated. A low clearance machine design was tested. To decrease average seam thickness, a system able to operate in a seam aperture of approximately 1.7 m was needed. Maximum possible clearance above the machine was sought, while maintaining sufficient clearance underneath the machine for haulage. A machine height of 855 mm with underbody clearance of 475 mm was achieved. The drive performance and traction force of the winch require improvement. For better utilization of machine potential, a rotational angle should be adapted to the positioning of the drum cutters. (ESA)

An Innovative Approach for Gob-Side Entry Retaining in Thick Coal Seam Longwall Mining

Directory of Open Access Journals (Sweden)

Manchao He

2017-11-01

Full Text Available Gob-side entry retaining (GER is a popular non-pillar mining technique regarding how to reserve a gateroad for the use of next panel mining. When used in thick coal seams, the conventional entry retaining method requires a huge amount of filling materials and may cause entry (gateroad accidents. Thus, an innovative non-pillar longwall mining approach is introduced. First, structural and mechanical models were built to explore the mechanism of the new approach. The modeling results indicate that effective bulking of the gob roof and reasonable support of the entry roof were key governing factors in improving entry stabilities and reducing roof deformations. Accordingly, a directional roof fracturing technique was proposed to contribute to gob roof caving, and a constant resistance and large deformation anchor (CRLDA cable was used to stabilize the entry roof. Subsequently, the evolutionary laws of the roof structure and stresses were explored using numerical simulation. It was found that the structure of the surrounding rocks around the retained entry changed significantly after roof fracturing. The stress-bearing center was transferred to the gob area, and the entry roof was in a low stress environment after adopting the approach. Finally, the approach was tested on a thick coal seam longwall mining panel. Field monitoring indicates that the retained entry was in a stable state and the index of the retained entry met the requirement of the next mining panel. This work provides an effective and economical approach to non-pillar longwall mining in thick coal seams.

Corrosion resistance of ERW (Electric Resistance Welded) seam welds as compared to metal base in API 5L steel pipes

Energy Technology Data Exchange (ETDEWEB)

Gonzalez Velasquez, Jorge L.; Godinez Salcedo, Jesus G.; Lopez Fajardo, Pedro [Instituto Politecnico Nacional (IPN), Mexico D.F. (Mexico). Escuela Superior de Ingenieria Quimica e Industrias Extractivas (ESIQIE). Dept. de Ingenieria Metalurgica

2009-07-01

The corrosion resistance of ERW seam welds and the base metal in API 5L X70 steel pipes was evaluated by Tafel tests. The procedure was according to ASTM G3 standard. The study was completed with metallographic and chemical characterization of the tested zones, that is, the welded zone and the base metal away of the weld. All tests were made on the internal surface of the pipe in order to assess the internal corrosion of an in-service pipeline made of the API 5L X70 steel. The test solution was acid brine prepared according to NACE Publications 1D182 and 1D196. The results showed that the ERW seam weld corrodes as much as three times faster than the base material. This behavior is attributed to a more heterogeneous microstructure with higher internal energy in the ERW seam weld zone, as compared to the base metal, which is basically a ferrite pearlite microstructure in a normalized condition. This result also indicates that pipeline segments made of ERW steel pipe where the seam weld is located near or at the bottom of the pipe are prone to a highly localized attack that may form channels of metal loss if there is water accumulation at the bottom of the pipeline. (author)

Pore pressure propagation in a permeable thin-layer coal seam based on a dual porosity model: A case of risk prediction of water inrush in coalmines

Science.gov (United States)

Zhu, B.; Gao, F.; Yang, J. W.; Zhou, G. Q.

2016-08-01

Thin-layer coal seams, a type of filling coal rock body, are considered aquifer systems made up of dual porosity medium with immediate floor. A numerical simulation for the pore pressure propagation along a thin-layer coal seam was carried out for the case of the Zhaogezhuang coalmine in China. By valuing the permeability (Kf ) of the thin-layer coal seam, pore pressure variation with time was simulated and compared to the analytical solutions of a dual porosity model (DPM). The main conclusions were drawn as follow: (1) Seepage in the thin-layer coal seam was predominant in the whole process, and the distance of seepage was lengthened and the pore pressure decreased with increased Kf , (2) A series of simulated hydraulic graphs demonstrated that the pore pressure characteristics of peak-occurring and time-lag effects agreed with the analytical solutions of DPM; (3) By adjusting the parameters of DPM, two results of analytical solutions and numerical solutions fit well, particularly in the thin-layer coal seam, (4) The power law relationship between the peak-values and lag time of pore pressure were derived statistically under consideration of the Kf parameter in the range of 10-8 to 10-10 m2/pa-s orders, and it was reasonable that the Kf of the thin-layer coal seam was in the range of 10-8 m2/pa-s orders. The results were significantly helpful in decision-making for mining water prevention and prediction in practice.

Identification of Wnt Pathway Target Genes Regulating the Division and Differentiation of Larval Seam Cells and Vulval Precursor Cells in Caenorhabditis elegans.

Science.gov (United States)

Gorrepati, Lakshmi; Krause, Michael W; Chen, Weiping; Brodigan, Thomas M; Correa-Mendez, Margarita; Eisenmann, David M

2015-06-05

The evolutionarily conserved Wnt/β-catenin signaling pathway plays a fundamental role during metazoan development, regulating numerous processes including cell fate specification, cell migration, and stem cell renewal. Wnt ligand binding leads to stabilization of the transcriptional effector β-catenin and upregulation of target gene expression to mediate a cellular response. During larval development of the nematode Caenorhabditis elegans, Wnt/β-catenin pathways act in fate specification of two hypodermal cell types, the ventral vulval precursor cells (VPCs) and the lateral seam cells. Because little is known about targets of the Wnt signaling pathways acting during larval VPC and seam cell differentiation, we sought to identify genes regulated by Wnt signaling in these two hypodermal cell types. We conditionally activated Wnt signaling in larval animals and performed cell type-specific "mRNA tagging" to enrich for VPC and seam cell-specific mRNAs, and then used microarray analysis to examine gene expression compared to control animals. Two hundred thirty-nine genes activated in response to Wnt signaling were identified, and we characterized 50 genes further. The majority of these genes are expressed in seam and/or vulval lineages during normal development, and reduction of function for nine genes caused defects in the proper division, fate specification, fate execution, or differentiation of seam cells and vulval cells. Therefore, the combination of these techniques was successful at identifying potential cell type-specific Wnt pathway target genes from a small number of cells and at increasing our knowledge of the specification and behavior of these C. elegans larval hypodermal cells. Copyright © 2015 Gorrepati et al.

Feature extraction and classification in automatic weld seam radioscopy

International Nuclear Information System (INIS)

Heindoerfer, F.; Pohle, R.

1994-01-01

The investigations conducted have shown that automatic feature extraction and classification procedures permit the identification of weld seam flaws. Within this context the favored learning fuzzy classificator represents a very good alternative to conventional classificators. The results have also made clear that improvements mainly in the field of image registration are still possible by increasing the resolution of the radioscopy system. Since, only if the flaw is segmented correctly, i.e. in its full size, and due to improved detail recognizability and sufficient contrast difference will an almost error-free classification be conceivable. (orig./MM) [de

Fluid migration through geo-membrane seams and through the interface between geo-membrane and geo-synthetic clay liner

International Nuclear Information System (INIS)

Barroso, M.

2005-03-01

Composite liners are used to limit the contamination migration from landfills. Their successful performance is closely related with the geo-membrane as it provides the primary barrier to diffusive and advective transport of contaminants. Critical issues on the performance of the geo-membranes are the seams between geo-membrane panels and the inevitable defects resulting, for instance, from inadequate installation activities. In landfills, where high density polyethylene geo-membranes are usually used, seams are typically made by the thermal-hot dual wedge method. A literature review on quality control of the seams showed that, in situ, fluid-tightness of seams is evaluated in qualitative terms (pass/failure criteria), despite their importance to ensure appropriate performance of the geo-membranes as barriers. In addition, a synthesis of studies on geo-membrane defects indicated that defects varying in density from 0.7 to 15.3 per hectare can be found in landfills. Defects represent preferential flow paths for leachate. Various authors have developed analytical solutions and empirical equations for predicting the flow rate through composite liners due to defects in the geo-membrane. The validity of these methods for composite liners comprising a geo-membrane over a geo-synthetic clay liner (GCL) over a compacted clay liner (CCL) has never been studied from an experimental point of view. To address the problem of fluid migration through the geo-membrane seams, an attempt is made to provide a test method, herein termed as 'gas permeation pouch test', for assessing the quality of the thermal-hot dual wedge seams. This test consists of pressurizing the air channel formed by the double seam with a gas to a specific pressure and, then, measuring the decrease in pressure over time. From the pressure decrease, both the gas permeation coefficients, in steady state conditions, and the time constant, in unsteady state conditions, can be estimated. Experiments were carried out

Paleoenvironmental implications from biomarker and stable isotope investigations on the Pliocene Velenje lignite seam (Slovenia)

Energy Technology Data Exchange (ETDEWEB)

Bechtel, A.; Sachsenhofer, R.F.; Markic, M.; Gratzer, R.; Lucke, A.; Puttmann, W. [Montan University of Leoben, Leoben (Austria)

2003-07-01

A Pliocene lignite seam up to 160 m thick occurs in the Velenje basin (Slovenia). The seam originated in a topogenous mire and evolved within a non-marine, transgressive setting. Differences in soluble organic matter yield and hydrocarbon content of borehole samples from the lignite are related to differences in the composition of free lipids of microbial origin and/or hydrocarbons derived from the biogeochemical degradation of plant tissue. Variations of the redox conditions within the mire are reflected by pristane/phytane ratios. The abundance of terpenoid biomarkers indicates the predominance of gymnosperms over angiosperms, which is consistent with palynomorphic spectra dominated by pollen of the Sequoia-Taxodium-Metasequoia plant community rather than by angiosperms. Evidence is also provided that the content of land plant derived biomarkers and the preservation of plant tissue is controlled by the input of resin-rich, decay-resistant conifers.

Preparation and extraction of sloping seams without leaving inter-drift coal pillars

Energy Technology Data Exchange (ETDEWEB)

Artamonov, N S; Bormotov, I N; Brovko, I I

1977-10-01

A description is given of mining three coal seams in the Kuznetsk Basin without leaving coal pillars because they could not withstand the stress of the induced reference pressure. This system reduced coal losses in 1976 in comparison to 1970 and eliminated local accumulations of methane by withdrawing it through the excavated area. The system was noted to have the disadvantage of additional expenditures for timber supports. 2 figures.

Effects of torpedo blasting on rockburst prevention during deep coal seam mining in the Upper Silesian Coal Basin

Directory of Open Access Journals (Sweden)

Ł. Wojtecki

2017-08-01

Full Text Available In the Upper Silesian Coal Basin (USCB, coal seams are exploited under progressively more difficult geological and mining conditions (greater depth, higher horizontal stress, more frequent occurrence of competent rock layers, etc.. Mining depth, dislocations and mining remnants in coal seams are the most important factors responsible for the occurrence of rockburst hazards. Longwall mining next to the mining edges of neighbouring coal seams is particularly disadvantageous. The levels of rockburst hazards are minimised via the use of rockburst prevention methods. One active prevention method is torpedo blasting in roof rocks. Torpedo blastings are performed in order to decrease local stress concentrations in rock masses and to fracture the roof rocks to prevent or minimise the impact of high-energy tremors on excavations. The estimation of the effectiveness of torpedo blasting is particularly important when mining is under difficult geological and mining conditions. Torpedo blasting is the main form of active rockburst prevention in the assigned colliery in the Polish part of the USCB. The effectiveness of blasting can be estimated using the seismic effect method, in which the seismic monitoring data and the mass of explosives are taken into consideration. The seismic effect method was developed in the Czech Republic and is always being used in collieries in the Czech part of the coal basin. Now, this method has been widely adopted for our selected colliery in the Polish part of the coal basin. The effectiveness of torpedo blastings in the faces and galleries of the assigned longwall in coal seam 506 has been estimated. The results show that the effectiveness of torpedo blastings for this longwall was significant in light of the seismic effect method, which corresponds to the in situ observations. The seismic effect method is regularly applied to estimating the blasting effectiveness in the selected colliery.

Probabilistic modelling and uncertainty analysis of flux and water balance changes in a regional aquifer system due to coal seam gas development.

Science.gov (United States)

Sreekanth, J; Cui, Tao; Pickett, Trevor; Rassam, David; Gilfedder, Mat; Barrett, Damian

2018-09-01

Large scale development of coal seam gas (CSG) is occurring in many sedimentary basins around the world including Australia, where commercial production of CSG has started in the Surat and Bowen basins. CSG development often involves extraction of large volumes of water that results in depressurising aquifers that overlie and/or underlie the coal seams thus perturbing their flow regimes. This can potentially impact regional aquifer systems that are used for many purposes such as irrigation, and stock and domestic water. In this study, we adopt a probabilistic approach to quantify the depressurisation of the Gunnedah coal seams and how this impacts fluxes to, and from the overlying Great Artesian Basin (GAB) Pilliga Sandstone aquifer. The proposed method is suitable when effects of a new resource development activity on the regional groundwater balance needs to be assessed and account for large scale uncertainties in the groundwater flow system and proposed activity. The results indicated that the extraction of water and gas from the coal seam could potentially induce additional fluxes from the Pilliga Sandstone to the deeper formations due to lowering pressure heads in the coal seams. The median value of the rise in the maximum flux from the Pilliga Sandstone to the deeper formations is estimated to be 85ML/year, which is considered insignificant as it forms only about 0.29% of the Long Term Annual Average Extraction Limit of 30GL/year from the groundwater management area. The probabilistic simulation of the water balance components indicates only small changes being induced by CSG development that influence interactions of the Pilliga Sandstone with the overlying and underlying formations and with the surface water courses. The current analyses that quantified the potential maximum impacts of resource developments and how they influences the regional water balance, would greatly underpin future management decisions. Copyright © 2018 Elsevier B.V. All rights

Coal petrology of coal seams from the Leao-Butia Coalfield, Lower Permian of the Parana Basin, Brazil - Implications for coal facies interpretations

Energy Technology Data Exchange (ETDEWEB)

Silva, M.B. [Laboratorio de Oceanografia Geologica, Departamento de Geociencias, Fundacao Universidade Federal do Rio Grande, FURG, Av. Italia km 08, Campus Carreiros, 96201-900, Rio Grande, RS (Brazil); Kalkreuth, W.; Holz, M. [Instituto de Geociencias, UFRGS, Av. Bento Goncalves, 9500 91501-970 Porto Alegre, RS (Brazil)

2008-02-01

In the Leao-Butia Coalfield, Rio Grande do Sul the coal seams occur in the Rio Bonito Formation, Guata Group, Tubarao Supergroup of the Parana Basin, Brazil and are of Permian (Artinskian-Kungurian) age. This study is the first detailed investigation on the coal petrographic characterization of the coal-bearing sequence in relation to the depositional settings of the precursor mires, both in terms of whole seam characterization and in-seam variations. The study is based on the analyses of nine coal seams (I2, CI, L4, L3, L2, L1, S3, S2, S1), which were selected from core of borehole D-193, Leao-Butia and represent the entire coal-bearing sequence. The interpretation of coal facies and depositional environment is based on lithotype, maceral and microlithotype analyses using different facies-critical petrographic indices, which were displayed in coal facies diagrams. The seams are characterized by the predominance of dull lithotypes (dull, banded dull). The dullness of the coal is attributed to relatively high mineral matter, inertinite and liptinite contents. The petrographic composition is dominated by vitrinite (28-70 vol.% mmf) and inertinite (> 30 vol.% mmf) groups. Liptinite contents range from 7 to 30 vol.% (mmf) and mineral matter from 4-30 vol.%. Microlithotypes associations are dominated by vitrite, duroclarite, carbominerite and inertite. It is suggested that the observed vertical variations in petrographic characteristics (lithotypes, microlithotypes, macerals, vitrinite reflectance) were controlled by groundwater level fluctuations in the ancient mires due to different accommodation/peat accumulation rates. Correlation of the borehole strata with the general sequence-stratigraphical setting suggests that the alluvial fan system and the coal-bearing mudstone succession are linked to a late transgressive systems tract of sequence 2. Based on average compositional values obtained from coal facies diagrams, a deposition in a limno-telmatic to limnic coal

Detecting voids in a 0. 6m coal seam, 7m deep, using seismic reflection

Energy Technology Data Exchange (ETDEWEB)

Miller, R.D.; Steeples, D.W. (University of Kansas, Lawrence, KS (USA). Kansas Geological Survey)

1991-07-01

Surface collapse over abandoned subsurface coal mines is a problem in many parts of the world. High-resolution P-wave reflection seismology was successfully used to evaluate the risk of an active sinkhole to a main north-south railroad line in an undermined area of southeastern Kansas, USA. Water-filled cavities responsible for sinkholes in this area are in a 0.6 m thick coal seam, 7 m deep. Dominant reflection frequencies in excess of 200 Hz enabled reflections from the coal seam to be discerned from the direct wave, refractions, air wave, and ground roll on unprocessed field files. Repetitive void sequences within competent coal on three seismic profiles are consistent with the 'room and pillar' mining technique practiced in this area near the turn of the century. The seismic survey showed that the apparent active sinkhole was not the result of reactivated subsidence but probably the results of erosion. 14 refs., 6 figs.

Field trials of aquifer protection in longwall mining of shallow coal seams in China

Energy Technology Data Exchange (ETDEWEB)

Zhang, D.S.; Fan, G.W.; Liu, Y.D.; Ma, L.Q. [State Key Laboratory of Coal Resource & Mine Safety, Xuzhou (China)

2010-09-15

The large-scale mining of shallow coal seams has a significant impact on the overlying aquifers and surface ecological environment. To protect the aquifers and maximize the coal resource recovery, field trials were undertaken during the operation of the LW32201 in Bulianta coal mine, Shendong, China. With a severely weathered rock (SWR) layer and two key strata (KS) in the overlying strata, aquifer protection in longwall mining (APLM) relies mainly on the rapid advance. In some localized zones, special measures should be taken to achieve the APLM, including lowering mining height, backfill and slurry injection. To further understand the mechanism and applicable conditions of the APLM and validate the effectiveness of the APLM, variation of the water table in the aquifer was observed as the longwall face passed through the zone. This paper also discusses the mechanism and basic requirements of the APLM and the relationship between the fall of the water table and the surface subsidence. The results of the field trials indicated that APLM in shallow coal seams could be successful under suitable conditions.

Apparatus and process for ultrasonic seam welding stainless steel foils

Science.gov (United States)

Leigh, Richard W.

1992-01-01

An ultrasonic seam welding apparatus having a head which is rotated to form contact, preferably rolling contact, between a metallurgically inert coated surface of the head and an outside foil of a plurality of layered foils or work materials. The head is vibrated at an ultrasonic frequency, preferably along a longitudinal axis of the head. The head is constructed to transmit vibration through a contacting surface of the head into each of the layered foils. The contacting surface of the head is preferably coated with aluminum oxide to prevent the head from becoming welded to layered stainless steel foils.

Ploughs for difficult seams of Bergbau AG Niederrhein

Energy Technology Data Exchange (ETDEWEB)

Klimek, K.-H.

1989-06-29

Ploughs for difficult seams have been used in five panels at collieries of Bergbau AG Niederrhein. It was determined during operation that short or standard ploughs achieve a 30% higher area rate of advance than double ploughs. Differences in pitch in the plough chain lead to regenerative operation of the motor with the greater chain pitch in the case of deviations over 1.5%. An excessively high pretensioning force depending on the wire diameter may lead to an increase in the no-load power up to 100%. In future special attention must be paid to observance of a defined cutting depth; systems for load equalisation and the tensioner for the plough chain which can be used during continuous operation, must be further developed. 6 refs., 4 figs., 1 tab.

Geological evaluation on productibility of coal seam gas; Coal seam gas no chishitsugakuteki shigen hyoka ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Fujii, K [University of Shizuoka, Shizuoka (Japan). Faculty of Education

1996-09-01

Coal seam gas is also called coal bed methane gas, indicating the gas existing in coal beds. The gas is distinguished from the oil field based gas, and also called non-conventional type gas. Its confirmed reserve is estimated to be 24 trillion m {sup 3}, with the trend of its development seen worldwide as utilization of unused resource. For the necessity of cultivating relevant technologies in Japan, this paper considers processes of production, movement, stockpiling, and accumulation of the gas. Its productibility is controlled by thickness of a coal bed, degree of coalification, gas content, permeability, groundwater flow, and deposition structure. Gas generation potential is evaluated by existing conditions of coal and degree of coalification, and methane production by biological origin and thermal origin. Economically viable methane gas is mainly of the latter origin. Evaluating gas reserve potential requires identification of the whole mechanism of adsorption, accumulation and movement of methane gas. The gas is expected of effect on environmental aspects in addition to availability as utilization of unused energy. 5 figs.

Development of the first coal seam gas exploration program in Indonesia: Reservoir properties of the Muaraenim Formation, south Sumatra

Energy Technology Data Exchange (ETDEWEB)

Sosrowidjojo, I.B. [R and D Centre for Oil and Gas Technology, LEMIGAS, Jakarta (Indonesia); Saghafi, A. [CSIRO Energy Technology, P O Box 330, Newcastle, NSW, 2300 (Australia)

2009-09-01

The Late Miocene Muaraenim Formation in southern Sumatra contains thick coal sequences, mostly of low rank ranging from lignite to sub-bituminous, and it is believed that these thick low rank coals are the most prospective for the production of coal seam gas (CSG), otherwise known as coalbed methane (CBM), in Indonesia. As part of a major CSG exploration project, gas exploration drilling operations are being undertaken in Rambutan Gasfields in the Muaraenim Formation to characterize the CSG potential of the coals. The first stage of the project, which is described here, was designed to examine the gas reservoir properties with a focus on coal gas storage capacity and compositional properties. Some five CSG exploration boreholes were drilled in the Rambutan Gasfield, south of Palembang. The exploration boreholes were drilled to depths of {proportional_to} 1000 m into the Muaraenim Formation. Five major coal seams were intersected by these holes between the depths of 450 and 1000 m. The petrography of coal samples collected from these seams showed that they are vitrinite rich, with vitrinite contents of more than 75% (on a mineral and moisture free basis). Gas contents of up to 5.8 m{sup 3}/t were measured for the coal samples. The gas desorbed from coal samples contain mainly methane (CH{sub 4}) ranging from 80 to 93% and carbon dioxide (CO{sub 2}) ranging from 6 to 19%. The composition of the gas released into the production borehole/well is, however, much richer in CH{sub 4} with about 94 to 98% CH{sub 4} and less than 5% CO{sub 2}. The initial results of drilling and reservoir characterization studies indicate suitable gas recovery parameters for three of the five coal seams with a total thickness of more than 30 m. (author)

Geological storage of carbon dioxide in the coal seams: from material to the reservoir

International Nuclear Information System (INIS)

Nikoosokhan, S.

2012-01-01

CO 2 emissions into the atmosphere are recognized to have a significant effect on global warming. Geological storage of CO 2 is widely regarded as an essential approach to reduce the impact of such emissions on the environment. Moreover, injecting carbon dioxide in coal bed methane reservoirs facilitates the recovery of the methane naturally present, a process known as enhanced coal bed methane recovery (ECBM). But the swelling of the coal matrix induced by the preferential adsorption by coal of carbon dioxide over the methane in place leads to a closure of the cleat system (a set of small natural fractures) of the reservoir and therefore to a loss of injectivity. This PhD thesis is dedicated to a study of how this injectivity evolves in presence of fluids. We derive two poro-mechanical dual-porosity models for a coal bed reservoir saturated by a pure fluid. The resulting constitutive equations enable to better understand and model the link between the injectivity of a coal seam and the adsorption-induced swelling of coal. For both models, the pore space of the reservoir is considered to be divided into the macroporous cleats and the pores of the coal matrix. The two models differ by how adsorption of fluid is taken into account: the first model is restricted to surface adsorption, while the second model can be applied for adsorption in a medium with a generic pore size distribution and thus in a microporous medium such as coal, in which adsorption mostly occurs by micropore filling. The latter model is calibrated on two coals with different sorption and swelling properties. We then perform simulations at various scales (Representative Elementary Volume, coal sample, coal seam). In particular, we validate our model on experimental data of adsorption-induced variations of permeability of coal. We also perform simulations of seams from which methane would be produced (CBM) or of methane-free seams into which CO 2 would be injected. We study the effect of various

Physical simulation method for the investigation of weld seam formation during the extrusion of aluminum alloys

NARCIS (Netherlands)

Fang, G; Zhou, J.

2017-01-01

Extrusion through the porthole die is a predominant forming process used in the production of hollow aluminum alloy profiles across the aluminum extrusion industry. Longitudinal weld seams formed during the process may negatively influence the quality of extruded profiles. It is therefore of

49 CFR 178.61 - Specification 4BW welded steel cylinders with electric-arc welded longitudinal seam.

Science.gov (United States)

2010-10-01

... Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS... inspection must conform to the techniques and acceptability criteria set forth in CGA Pamphlet C-3. When... prescribed tests to be acceptable. Repair of welded seams by welding is authorized provided that all...

Rock burst prevention at steep seam mining

Energy Technology Data Exchange (ETDEWEB)

Efremov, G D

1988-09-01

At steep shield longwalls one method of preventing rock bursts is to avoid sharp angles during working. Stress in coal and rock body that appears when steep seams are worked where rock bursts occur at corners of set-up entries is discussed. The dynamic interaction between gas and rock pressure is assessed. Maintains that in order to avoid rock bursts at these places it is necessary to turn the protruding coal wall by 20-30 degrees towards the coal body to divert the action of shift forces. At the same time the face should also be inclined (by 10-15 degrees) to move the zones of increased stress away from the corner into the coal and rock body. Stress at workings with round cross-sections is 3-4 times lower than at square cross-sections. Recommendations are given that concern shearer loader operation (semi-spherical shape of the face), borehole drilling and water injection. Initial distance of 10-15 m between boreholes is suggested. 3 refs.

Some aspects of the development of the Vaal Reef uranium-gold carbon seams, Witwatersrand sequence: organic geochemical and microbiological considerations

International Nuclear Information System (INIS)

Zumberge, J.E.; Nagy, B.; Nagy, L.A.

1981-01-01

The solvent-insoluble organic matter (kerogen) that is the predominant syngenetic component of the Vaal Reef carbon seams was analyzed by combined high-vacuum pyrolysis gas-chromatography mass spectrometry, combined electron microprobe-scanning electron microscopy and electron paramagnetic resonance spectroscopy. The pyrolysis results indicate that the Vaal Reef carbon is a random polymer-type matter consisting mainly of aromatic and short-chain aliphatic hydrocarbons, as well as aromatic and other organic-sulfur constituents. Scanning electron microscopy revealed coccoid and filamentous microstructures in the carbonaceous seams. These structures are conceivably of biological affinity and may be fossil blue-green algae and (or) bacteria. Gold is often concentrated at the interfaces of admixed clay-carbon microenvironments. This implies physical and chemical interactions between clays and organic matter conducive to the entrapment of detrital gold during deposition and the crystallization of colloidal/dissolved gold in the carbon seams. High concentrations of organic free radicals (molecules with unpaired electrons) in the carbonaceous matter, deduced from electron paramagnetic resonance spectroscopy, suggest that radiation emitted from uranium played a unique role in the reconstitution and polymerization of the progenitor biochemicals

An Efficient Seam Elimination Method for UAV Images Based on Wallis Dodging and Gaussian Distance Weight Enhancement.

Science.gov (United States)

Tian, Jinyan; Li, Xiaojuan; Duan, Fuzhou; Wang, Junqian; Ou, Yang

2016-05-10

The rapid development of Unmanned Aerial Vehicle (UAV) remote sensing conforms to the increasing demand for the low-altitude very high resolution (VHR) image data. However, high processing speed of massive UAV data has become an indispensable prerequisite for its applications in various industry sectors. In this paper, we developed an effective and efficient seam elimination approach for UAV images based on Wallis dodging and Gaussian distance weight enhancement (WD-GDWE). The method encompasses two major steps: first, Wallis dodging was introduced to adjust the difference of brightness between the two matched images, and the parameters in the algorithm were derived in this study. Second, a Gaussian distance weight distribution method was proposed to fuse the two matched images in the overlap region based on the theory of the First Law of Geography, which can share the partial dislocation in the seam to the whole overlap region with an effect of smooth transition. This method was validated at a study site located in Hanwang (Sichuan, China) which was a seriously damaged area in the 12 May 2008 enchuan Earthquake. Then, a performance comparison between WD-GDWE and the other five classical seam elimination algorithms in the aspect of efficiency and effectiveness was conducted. Results showed that WD-GDWE is not only efficient, but also has a satisfactory effectiveness. This method is promising in advancing the applications in UAV industry especially in emergency situations.

COVERING THE SEAMS IN U.S. NATIONAL SECURITY BY APPLYING NETWORK AND TEAM ATTRIBUTES

Science.gov (United States)

2017-04-06

Today, one such weakness is the seams that exist in the system. Organizational criteria like geography, functions, and responsibilities often create...climate change are a potential “’threat multiplier’ that intensifies instability around the world by worsening water shortages, food insecurity...system. One significant study, the Project on National Security Reform (PNSR), developed a recommendation “that the president selectively shift

A case study of multi-seam coal mine entry stability analysis with strength reduction method.

Science.gov (United States)

Tulu, Ihsan Berk; Esterhuizen, Gabriel S; Klemetti, Ted; Murphy, Michael M; Sumner, James; Sloan, Michael

2016-03-01

In this paper, the advantage of using numerical models with the strength reduction method (SRM) to evaluate entry stability in complex multiple-seam conditions is demonstrated. A coal mine under variable topography from the Central Appalachian region is used as a case study. At this mine, unexpected roof conditions were encountered during development below previously mined panels. Stress mapping and observation of ground conditions were used to quantify the success of entry support systems in three room-and-pillar panels. Numerical model analyses were initially conducted to estimate the stresses induced by the multiple-seam mining at the locations of the affected entries. The SRM was used to quantify the stability factor of the supported roof of the entries at selected locations. The SRM-calculated stability factors were compared with observations made during the site visits, and the results demonstrate that the SRM adequately identifies the unexpected roof conditions in this complex case. It is concluded that the SRM can be used to effectively evaluate the likely success of roof supports and the stability condition of entries in coal mines.

Novel pre-treatment of zeolite materials for the removal of sodium ions: potential materials for coal seam gas co-produced wastewater.

Science.gov (United States)

Santiago, Oscar; Walsh, Kerry; Kele, Ben; Gardner, Edward; Chapman, James

2016-01-01

Coal seam gas (CSG) is the extraction of methane gas that is desorbed from the coal seam and brought to the surface using a dewatering and depressurisation process within the saturated coalbed. The extracted water is often referred to as co-produced CSG water. In this study, co-produced water from the coal seam of the Bowen Basin (QLD, Australia) was characterised by high concentration levels of Na(+) (1156 mg/L), low concentrations of Ca(2+) (28.3 mg/L) and Mg(2+) (5.6 mg/L), high levels of salinity, which are expected to cause various environmental problems if released to land or waters. The potential treatment of co-produced water using locally sourced natural ion exchange (zeolite) material was assessed. The zeolite material was characterized for elemental composition and crystal structure. Natural, untreated zeolite demonstrated a capacity to adsorb Na(+) ions of 16.16 mEq/100 g, while a treated zeolite using NH4 (+) using a 1.0 M ammonium acetate (NH4C2H3O2) solution demonstrated an improved 136 % Na(+) capacity value of 38.28 mEq/100 g after 720 min of adsorption time. The theoretical exchange capacity of the natural zeolite was found to be 154 mEq/100 g. Reaction kinetics and diffusion models were used to determine the kinetic and diffusion parameters. Treated zeolite using a NH4 (+) pre-treatment represents an effective treatment to reduce Na(+) concentration in coal seam gas co-produced waters, supported by the measured and modelled kinetic rates and capacity.

Vadose Zone Fate and Transport Simulation of Chemicals Associated with Coal Seam Gas Extraction

Science.gov (United States)

Simunek, J.; Mallants, D.; Jacques, D.; Van Genuchten, M.

2017-12-01

The HYDRUS-1D and HYDRUS (2D/3D) computer software packages are widely used finite element models for simulating the one-, and two- or three-dimensional movement of water, heat, and multiple solutes in variably-saturated media, respectively. While the standard HYDRUS models consider only the fate and transport of individual solutes or solutes subject to first-order degradation reactions, several specialized HYDRUS add-on modules can simulate far more complex biogeochemical processes. The objective of this presentation is to provide an overview of the HYDRUS models and their add-on modules, and to demonstrate applications of the software to the subsurface fate and transport of chemicals involved in coal seam gas extraction and water management operations. One application uses the standard HYDRUS model to evaluate the natural soil attenuation potential of hydraulic fracturing chemicals and their transformation products in case of an accidental release. By coupling the processes of retardation, first-order degradation and convective-dispersive transport of the biocide bronopol and its degradation products, we demonstrated how natural attenuation reduces initial concentrations by more than a factor of hundred in the top 5 cm of the vadose zone. A second application uses the UnsatChem module to explore the possible use of coal seam gas produced water for sustainable irrigation. Simulations with different irrigation waters (untreated, amended with surface water, and reverse osmosis treated) provided detailed results regarding chemical indicators of soil and plant health, notably SAR, EC and sodium concentrations. A third application uses the coupled HYDRUS-PHREEQC module to analyze trace metal transport involving cation exchange and surface complexation sorption reactions in the vadose zone leached with coal seam gas produced water following some accidental water release scenario. Results show that the main process responsible for trace metal migration is complexation of

Coal forming conditions for coal seams and coal measures of the Heshan Group Upper Permian Series in Guangxi Province (part 1)

Energy Technology Data Exchange (ETDEWEB)

Li, Y.

1980-10-01

Coal forming conditions for the coal measures of the Heshan Group are discussed based on the analysis of the historical background and paleogeographical environment of the Permian in Guangxi Province. The roof, floor, and partings of the seams are composed of algal micritic limestone, therefore affirming that the central part of Guangxi Province in the late Permian was a typical epi-continental sea. The compensative deposit of algea on the carbonate platform in very shallow water created the conditions for the occurrence of the peat swamp and established the supra-tidal swampy facies. The environment for the accumulation of the major coal seams are analyzed. (In Chinese)

Seam gap bridging of laser based processes for the welding of aluminium sheets for industrial applications

NARCIS (Netherlands)

Aalderink, B.J.; Aalderink, Benno; Pathiraj, B.; Aarts, Ronald G.K.M.

2010-01-01

Laser welding has a large potential for the production of tailor welded blanks in the automotive industry, due to the low heat input and deep penetration. However, due to the small laser spot and melt pool, laser-based welding processes in general have a low tolerance for seam gaps. In this paper,

Use of neutron activation analysis to measure the variation in trace element concentrations in a coal seam

International Nuclear Information System (INIS)

Fardy, J.J.; Swaine, D.J.

1985-01-01

Trace element concentrations were measured by neutron activation on 57 run-of-mine coal samples from several locations in seven mines located in the Lithgow seam in the Western Coalfield, Sydney Basin. Results were tabulated as ratios of the highest to the lowest variance for each element

Case study on ground surface deformation induced by CO2 injection into coal seam

International Nuclear Information System (INIS)

Li Hong; Tang Chun'an

2010-01-01

To monitor a geomechanical response of injecting CO 2 into relatively shallow coal seams, tiltmeters were set as an array to cover the ground surface area surrounding the injection well, and to measure the ground deformation during a well fracturing stimulation and a short-term CO 2 injection test. In this paper, an attempt to establish a quantitative relationship between the in-situ coal swelling and the corresponding ground deformation was made by means of numerical simulation study. (authors)

Numerical Study on 4-1 Coal Seam of Xiaoming Mine in Ascending Mining

Science.gov (United States)

Tianwei, Lan; Hongwei, Zhang; Sheng, Li; Weihua, Song; Batugin, A. C.; Guoshui, Tang

2015-01-01

Coal seams ascending mining technology is very significant, since it influences the safety production and the liberation of dull coal, speeds up the construction of energy, improves the stability of stope, and reduces or avoids deep hard rock mining induced mine disaster. Combined with the Xiaoming ascending mining mine 4-1, by numerical calculation, the paper analyses ascending mining 4-1 factors, determines the feasibility of ascending mining 4-1 coalbed, and proposes roadway layout program about working face, which has broad economic and social benefits. PMID:25866840

Behaviors of overlying strata in extra-thick coal seams using top-coal caving method

Directory of Open Access Journals (Sweden)

Bin Yu

2016-04-01

Full Text Available Accidents such as support failure and excessive deformation of roadways due to drastic changes in strata behaviors are frequently reported when mining the extra-thick coal seams Nos. 3–5 in Datong coal mine with top-coal caving method, which significantly hampers the mine's normal production. To understand the mechanism of strata failure, this paper presented a structure evolution model with respect to strata behaviors. Then the behaviors of strata overlying the extra-thick coal seams were studied with the combined method of theoretical analysis, physical simulation, and field measurement. The results show that the key strata, which are usually thick-hard strata, play an important role in overlying movement and may influence the mining-induced strata behaviors in the working face using top-coal caving method. The structural model of far-field key strata presents a “masonry beam” type structure when “horizontal O-X” breakage type happens. The rotational motion of the block imposed radial compressive stress on the surrounding rock mass of the roadway. This can induce excessive deformation of roadway near the goaf. Besides, this paper proposed a pre-control technology for the hard roof based on fracture holes and underground roof pre-splitting. It could effectively reduce stress concentration and release the accumulated energy of the strata, when mining underground coal resources with top-coal caving method.

Multifrequency eddy-current inspection of seam weld in steel sheath

Energy Technology Data Exchange (ETDEWEB)

Smith, J.H.; Dodd, C.V.; Chitwood, L.D.

1985-04-01

Multifrequency eddy-current techniques were used to perform a continuous on-line inspection of the seam weld in the steel jacket for a superconducting cable. The inspection was required to detect both surface and internal weld flaws in the presence of a large, highly conductive central conductor. Raw eddy-current data were recorded on magnetic tape, and test properties such as discontinuity size and weld penetration were determined by mathematically fitting these data to coefficients developed with representative standards. A sophisticated computer-controlled scanning technique was applied, and a unique scanning device was developed to provide full coverage of the weld and heat-affected zone. The techniques used to develop this multifrequency eddy-current examination are described in this report along with the test equipment, test procedures, and computer programs.

Multifrequency eddy-current inspection of seam weld in steel sheath

International Nuclear Information System (INIS)

Smith, J.H.; Dodd, C.V.; Chitwood, L.D.

1985-04-01

Multifrequency eddy-current techniques were used to perform a continuous on-line inspection of the seam weld in the steel jacket for a superconducting cable. The inspection was required to detect both surface and internal weld flaws in the presence of a large, highly conductive central conductor. Raw eddy-current data were recorded on magnetic tape, and test properties such as discontinuity size and weld penetration were determined by mathematically fitting these data to coefficients developed with representative standards. A sophisticated computer-controlled scanning technique was applied, and a unique scanning device was developed to provide full coverage of the weld and heat-affected zone. The techniques used to develop this multifrequency eddy-current examination are described in this report along with the test equipment, test procedures, and computer programs

Prior infusion of water into the seam and its effects in the behavior of methane

Energy Technology Data Exchange (ETDEWEB)

Degueldre, G

1975-01-01

Infusion of the seam is carried out in advance of the face to control dust but it has been found that it also reduces the rate of desorption of methane. Since the methane is retained in the coal, less is present in the mine air. Guidelines for the infusion process are given, and experience in using it is described. The effect on the water content of the coal and on the dust is described.

A sequential approach to control gas for the extraction of multi-gassy coal seams from traditional gas well drainage to mining-induced stress relief

International Nuclear Information System (INIS)

Kong, Shengli; Cheng, Yuanping; Ren, Ting; Liu, Hongyong

2014-01-01

Highlights: • The gas reservoirs characteristics are measured and analyzed. • A sequential approach to control gas of multi-gassy coal seams is proposed. • The design of gas drainage wells has been improved. • The utilization ways of different concentrations of gas production are shown. - Abstract: As coal resources become exhausted in shallow mines, mining operations will inevitably progress from shallow depth to deep and gassy seams due to increased demands for more coal products. However, during the extraction process of deeper and gassier coal seams, new challenges to current gas control methods have emerged, these include the conflict between the coal mine safety and the economic benefits, the difficulties in reservoirs improvement, as well as the imbalance between pre-gas drainage, roadway development and coal mining. To solve these problems, a sequential approach is introduced in this paper. Three fundamental principles are proposed: the mining-induced stress relief effect of the first-mined coalbed should be sufficient to improve the permeability of the others; the coal resource of the first-mined seams must be abundant to guarantee the economic benefits; the arrangement of the vertical wells must fit the underground mining panel. Tunlan coal mine is taken as a typical example to demonstrate the effectiveness of this approach. The approach of integrating surface coalbed methane (CBM) exploitation with underground gas control technologies brings three major benefits: the improvement of underground coal mining safety, the implementation of CBM extraction, and the reduction of greenhouse gas emissions. This practice could be used as a valuable example for other coal mines having similar geological conditions

Technique for reinforcing development working in lower strata of thick coal seams

Energy Technology Data Exchange (ETDEWEB)

Andranovich, V A; Gromov, Yu V; Kurglikov, V P

1981-01-15

This device is to be used by mining industry, specifically for reinforcing development work in bottom strata of thick coal seams having a layer depression. Reinforcing consists of drilling a hole, or making cutting slits and lowering support props for the stratum below through them, as well as lowering the roof timber on the ground. To cut back expenditures on installation and removal of equipment, drilling or making cutting slits is done to a depth equal to the total height of the substrata, and the support props are laid for all of the substrata. Only the roof timber is lowered on the ground during work on the layers.

缓倾斜严重突出煤层快速揭煤优化研究%Research on Optimization of Fast Exposing Gently-inclined Serious Outburst Coal Seam by a Crosscut

Institute of Scientific and Technical Information of China (English)

王建; 张荻; 李正刚

2015-01-01

为了提高缓倾斜严重突出煤层的揭煤效率,采用缩短揭煤巷道距离、水力压裂增透结合底板穿层钻孔预抽的方法,优化揭煤步骤. 现场应用表明,该方法可以减少2次区域验证次数,减少施工9~24个钻孔,揭煤时间平均缩短5. 0~15. 4 d,费用减少50%,实现了安全快速石门揭煤.%In order to improve the efficiency of exposing the gently-inclined serious outburst coal seam by a crosscut, the steps of exposing the outburst coal seam by a crosscut were optimized by adopting the measures of shortening the distance of the roadway exposing the outburst coal seam, gas permeability enhancement by hydraulic fracturing and gas pre-drainage by floor crossing holes. The site application showed that this method can reduce two regional verifications, reduce the drilling construction of 9~24 holes, the average time for exposing the outburst coal seam was shortened by 5. 0~15. 4 d and the costs were reduced by 50%, as a result, the fast exposing outburst coal seam by a crosscut was realized.

Organic petrology, mineralogy and depositional environment of the Kipra lignite seam, Maritza-West basin, Bulgaria

Energy Technology Data Exchange (ETDEWEB)

Kostova, Irena [Department of Geology and Palaeontology, Sofia University ' ' St. Kliment Ohridski' ' , 1000, Sofia (Bulgaria); Zdravkov, Alexander [Department of Economic Geology, University of Mining and Geology ' ' St. Ivan Rilski' ' , 1700, Sofia (Bulgaria)

2007-08-01

The aim of the present study is to provide additional information about the properties and depositional environment of the Kipra lignite seam, which was deposited during the regressive stage of development of the Maritza-West basin. Petrographical and mineralogical data, along with ash yields and sulphur contents of 24 samples from a seam profile, have been used to study the vertical variation of the depositional settings during peat accumulation and subsequent coalification. The Kipra lignite is characterized by high ash yields and sulphur contents. It formed in a rheotrophic, low-lying mire with alkaline pH value. Vegetation with low preservation potential dominated within the palaeomire. During peat formation, frequent changes of the water level controlled the depositional environment. During the deposition of units 1 and 2, high water energy caused the transportation of high amounts of inorganic material into the mire, resulting in the formation of weakly gelified mineral-rich lignite. The organic matter from units 3 and 4 is characterized by enhanced gelification, which probably reflects the decreasing energy of the system. Good positive correlation between sulphur contents and the GI values was established in units 4, indicating that the gelification of the tissues was probably mainly controlled by the bacterial activity. In contrast, the gelification of the samples from unit 3 of the Kipra seam was probably governed by the redox conditions. The organic matter deposited under relatively wet conditions, in which the thermal and oxidative destruction of the tissues, was limited. A variety of major, minor and accessory minerals are present in Maritza-West lignite. The mineral composition is dominated mainly by pyrite, gypsum and calcite, and to a lesser extent limonite, quartz, kaolinite, montmorillonite, illite, chlorite and plagioclase. Jarosite, hematite, halloysite, mica, K-feldspar, aragonite, siderite, and dolomite were also determined in very low

Increasing the effectiveness of the hydraulic fracturing of seams with the use of the pattern recognition method

Energy Technology Data Exchange (ETDEWEB)

Rasizade, Ya M; Nagiev, T M; Kuznetsov, V I; Mikerin, B P

1977-08-01

An examination is made of using a sequential diagnostic procedure for increasing the effectiveness of the hydraulic fracturing of seams in boreholes of the gas and oil drilling administration of the Khadyzhenneft' association. The use of the pattern recognition method was shown to make it possible to increase the effectiveness of hydraulic fracturing by up to 80%. 4 references, 1 figure, 3 tables.

Managing produced water from coal seam gas projects: implications for an emerging industry in Australia.

Science.gov (United States)

Davies, Peter J; Gore, Damian B; Khan, Stuart J

2015-07-01

This paper reviews the environmental problems, impacts and risks associated with the generation and disposal of produced water by the emerging coal seam gas (CSG) industry and how it may be relevant to Australia and similar physical settings. With only limited independent research on the potential environmental impacts of produced water, is it necessary for industry and government policy makers and regulators to draw upon the experiences of related endeavours such as mining and groundwater extraction accepting that the conclusions may not always be directly transferrable. CSG is widely touted in Australia as having the potential to provide significant economic and energy security benefits, yet the environmental and health policies and the planning and regulatory setting are yet to mature and are continuing to evolve amidst ongoing social and environmental concerns and political indecision. In this review, produced water has been defined as water that is brought to the land surface during the process of recovering methane gas from coal seams and includes water sourced from CSG wells as well as flowback water associated with drilling, hydraulic fracturing and gas extraction. A brief overview of produced water generation, its characteristics and environmental issues is provided. A review of past lessons and identification of potential risks, including disposal options, is included to assist in planning and management of this industry.

Coal seam gas-supply and impact on U.S. markets and Canadian producers

International Nuclear Information System (INIS)

Kelafant, J.

1992-01-01

The basic ways in which coalbed methane differs from natural gas are described. Coalbed methane is stored at a higher capacity in the coal seam, has a different production curve, and exploration costs are lower. Comparing a conventional gas well having 2 billion ft 3 reserves with coalbed methane wells in the San Juan and Warrior basins, gas from the conventional well costs $1.90 per 1,000 ft 3 and methane from the San Juan and Warrior wells costs $1.50 and $2.40 per 1,000 ft 3 respectively. A 90 cent per 1,000 ft 3 tax credit on coalbed methane reduces the two latter costs significantly and is without doubt the driving force behind the coalbed methane industry in some areas. Examples from the Warrior and San Juan basins are described to illustrate the technology driven economics of coalbed methane. Substantial improvements in gas production can be achieved by such means as multiple seam completion technologies, improved well stimulation, optimum well spacing, and the use of cavitation completion. Technically recoverable coalbed methane resources in the USA are estimated at 145 trillion ft 3 , concentrated in the western coal basins. At a wellhead price of $2 per 1,000 ft 3 , the economically recoverable potential is ca 13 trillion ft 3 . Examining future production potential, by developing new technologies or bringing more basins on stream, production could be increased to ca 3 billion ft 3 /d in the late 1990s. It is suggested that the increased volumes of coalbed methane have had minimal impact on gas prices. 9 figs., 12 tabs

Simulating the Fate and Transport of Coal Seam Gas Chemicals in Variably-Saturated Soils Using HYDRUS

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Dirk Mallants

2017-05-01

Full Text Available The HYDRUS-1D and HYDRUS (2D/3D computer software packages are widely used finite element models for simulating the one-, and two- or three-dimensional movement of water, heat, and multiple solutes in variably-saturated media, respectively. While the standard HYDRUS models consider only the fate and transport of individual solutes or solutes subject to first-order degradation reactions, several specialized HYDRUS add-on modules can simulate far more complex biogeochemical processes. The objective of this paper is to provide a brief overview of the HYDRUS models and their add-on modules, and to demonstrate possible applications of the software to the subsurface fate and transport of chemicals involved in coal seam gas extraction and water management operations. One application uses the standard HYDRUS model to evaluate the natural soil attenuation potential of hydraulic fracturing chemicals and their transformation products in case of an accidental release. By coupling the processes of retardation, first-order degradation and convective-dispersive transport of the biocide bronopol and its degradation products, we demonstrated how natural attenuation reduces initial concentrations by more than a factor of hundred in the top 5 cm of the soil. A second application uses the UnsatChem module to explore the possible use of coal seam gas produced water for sustainable irrigation. Simulations with different irrigation waters (untreated, amended with surface water, and reverse osmosis treated provided detailed results regarding chemical indicators of soil and plant health, notably SAR, EC and sodium concentrations. A third application uses the HP1 module to analyze trace metal transport involving cation exchange and surface complexation sorption reactions in a soil leached with coal seam gas produced water following some accidental water release scenario. Results show that the main process responsible for trace metal migration in soil is complexation of

Towards Sensor-Actuator Coupling in an Automated Order Picking System by Detecting Sealed Seams on Pouch Packed Goods

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Frank Weichert

2014-10-01

Full Text Available In this paper, a novel concept of coupling the actuators of an automated order picking system for pouch packed goods with an embedded CCD camera sensor by means of image processing and machine learning is presented. The picking system mechanically combines the conveyance and singularization of a still-connected chain of pouch packed goods in a single machinery. The proposed algorithms perform a per-frame processing of the captured images in real-time to detect the sealed seams of the ongoing pouches. The detections are used to deduce cutting decisions in order to control the system’s actuators, namely the drive pulley for conveyance and the cutting device for the separation. Within this context, two controlling strategies are presented as well which specify the interaction of the sensor and the actuators. The detection is carried out by two different marker detection strategies: enhanced Template Matching as a heuristic and Support Vector Machines as a supervised classification based concept. Depending on the employed marker, detection rates of almost 100% with a calculation time of less than 40 ms are possible. From a logistic point of view, sealed seam widths of 20 mm prove feasible.

Phosphorus minerals in tonstein; coal seam 405 at Sośnica-Makoszowy coal mine, Upper Silesia, southern Poland

Science.gov (United States)

Kokowska-Pawłowska, Magdalena; Nowak, Jacek

2013-06-01

Kokowska-Pawłowska, M. and Nowak, J. 2013. Phosphorus minerals in tonstein; coal seam 405 at Sośnica- Makoszowy coal mine, Upper Silesia, southern Poland. Acta Geologica Polonica, 63 (2), 271-281. Warszawa. The paper presents results of research on tonstein, which constitutes an interburden in coal seam 405 at the Sośnica- Makoszowy coal mine, Makoszowy field (mining level 600 m), Upper Silesia, southern Poland. The mineral and chemical compositions of the tonstein differ from the typical compositions described earlier for tonsteins from Upper Silesia Coal Basin area. Additionally, minerals present in the tonsteins include kaolinite, quartz, kaolinitised biotite and feldspars. The presence of the phosphatic minerals apatite and goyazite has been recognized. The presence of gorceixite and crandallite is also possible. The contents of CaO (5.66 wt%) and P2O5 (6.2 wt%) are remarkably high. Analysis of selected trace elements demonstrated high contents of Sr (4937 ppm) and Ba (4300 ppm), related to the phosphatic minerals. On the basis of mineral composition the tonstein has been identified as a crystalline tonstein, transitional to a multiplied one.

Numerical modelling of surface subsidence arising from longwall mining of steeply inclined coal seams

Energy Technology Data Exchange (ETDEWEB)

Nejad, M.A.; Reddish, D.J. [University of Nottingham, Nottingham (United Kingdom). School of Chemical, Environmental and Mining Engineering

1998-12-31

The paper presents results from and the methodology of a numerical modelling investigation into the surface ground movements above longwall mining of inclined and steep seams with varying panel configurations. A modelling approach was developed using a finite difference numercial model Fast Lagrangian Analysis of Continua (FLAC). On the basis of this methodology, representative surface subsidence profiles were simulated and the results of simulations were validated against the UK data using the Subsidence Engineer`s Handbook (SEH) and influence function methods. Furthermore, the proposed methodology was applied to two UK case histories for validation purposes. 15 refs., 7 figs., 3 tabs.

Characterization of Rare Earth Elements in in Clay Deposits Associated with Central Appalachian Coal Seams

Science.gov (United States)

Scott, M.; Verba, C.; Falcon, A.; Poston, J.; McKoy, M.

2017-12-01

Because of their multiple uses in clean energy technologies, rare earth elements (REE) are critical for national economic and energy security. With no current domestic source, supply remains a major concern for domestic security. Underclay - specifically the layer of stratum beneath a coal bed - is a potentially rich source of REE. This study focuses on the characterization and ion exchange recovery of REE from underclay samples from the Lower Freeport, Middle Kittanning, and Pittsburgh coal seams in West Virginia. Multimodal techniques provided quantitative assessments of REE-bearing mineral phases in select underclays and the influence of organic acid rock treatment on the recovery of REE from both exchangeable and crystalline mineral phases present. All samples are from extensively weathered horizons that contain abundant kaolinite and illite. Total REE concentrations range from 250-450 ppm and all samples have a HREE/LEEE ratio >20%. Rare earth element bearing minerals identified in the clay are monazite, xenotime, florencite, and crandallite. Our selective recovery approach is designed to isolate and recover REE through partial dissolution of the clay matrix and ion exchange rather than dissolution/recovery of phosphate or aluminosilicate bound REE. These results provide a better understanding of coal seam underclay, the affinity of REEs for specific ligands and colloids, and how the rock and ligands respond to different chemical treatments. These processes are important to the development and commercialization of efficient and cost effective methods to extract REE from domestic geologic deposits and recover into salable forms.

Community perspectives of natural resource extraction: coal-seam gas mining and social identity in Eastern Australia

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David Lloyd

2013-01-01

Full Text Available Using a recent case study of community reaction to proposed coal-seam gas mining in eastern Australia, we illustrate the role of community views in issues of natural resource use. Drawing on interviews, observations and workshops, the paper explores the anti-coal-seam gas social movement from its stages of infancy through to being a national debate linking community groups across and beyond Australia. Primary community concerns of inadequate community consultation translate into fears regarding potential impacts on farmland and cumulative impacts on aquifers and future water supply, and questions regarding economic, social and environmental benefits. Many of the community activists had not previously been involved in such social action. A recurring message from affected communities is concern around perceived insufficient research and legislation for such rapid industrial expansion. A common citizen demand is the cessation of the industry until there is better understanding of underground water system interconnectivity and the methane extraction and processing life cycle. Improved scientific knowledge of the industry and its potential impacts will, in the popular view, enable better comparison of power generation efficiency with coal and renewable energy sources and better comprehension of the industry as a transition energy industry. It will also enable elected representatives and policy makers to make more informed decisions while developing appropriate legislation to ensure a sustainable future.

Analysis of the Harmfulness of Water-Inrush from Coal Seam Floor Based on Seepage Instability Theory

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

A theory of seepage instability was used to estimate the harmfulness of water-inrush from a coal seam floor in a particular coal mine of the Mining Group, Xuzhou.Based on the stratum column chart in this coal mine, the distribution of stress in mining floors when the long-wall mining was respectively pushed along to 100 m and to 150 m was simulated by using the numerical software (RFPA2D).The permeability parameters of the coal seam floor are described given the relationship between permeability parameters.Strain and the water-inrush-indices were calculated.The water-inrush-index was 67.2% when the working face was pushed to 100 m, showing that water-inrush is possible and it was 1630% when the working face was pushed to 150 m, showing that water-inrush is quite probable.The results show that as long-wall mining is pushed along, the failure zone is enlarged, the strain increased, and fissures developed correspondingly, resulting in the formation of water-inrush channels.Accompanied by the failure of the strata, the permeability increased exponentially.In contrast, the non-Darcy flow β factor and the acceleration coefficient decreased exponentially, while the increase in the water-inrush-index was nearly exponential and the harmfulness of water-inrush in the coal mine increased accordingly.

Analysis of anomalous high concentration of lead and selenium and their origin in the main minable coal seam in the Junger coalfield

Energy Technology Data Exchange (ETDEWEB)

Li Sheng-sheng; Ren De-yi [State Administration of Work Safety, Beijing (China)

2006-07-01

The concentration, occurrence, and geological origin of lead and selenium in the main minable coal seam from the Junger coalfield were studied using inductively coupled plasma mass spectrometry (CICP-MS), instrumental neutron activation analysis (CINAA), scanning electron microscope equipped with an energy-dispersive X-ray spectrometer (SEM-EDX), and optical microscope. The results show that the average concentrations of Pb and Se are as high as 35.7 {mu}g/g and 8.2 {mu}g/g, respectively, which are much higher than those of coals from North China, Guizhou, China, and USA. In addition, their enrichment factors are up to 2.4 and 68.1, respectively. Lead and selenium are significantly enriched in the seam. Lead and selenium mainly exist in galena, clausthalite, and selenio-galena which occur as cell-filling of coal-forming plants and are of chemical-sedimentary origin. 22 refs., 3 figs., 1 tab.

Determining the hydraulic and fracture properties of the Coal Seam Gas well by numerical modelling and GLUE analysis

Science.gov (United States)

Askarimarnani, Sara; Willgoose, Garry; Fityus, Stephen

2017-04-01

Coal seam gas (CSG) is a form of natural gas that occurs in some coal seams. Coal seams have natural fractures with dual-porosity systems and low permeability. In the CSG industry, hydraulic fracturing is applied to increase the permeability and extract the gas more efficiently from the coal seam. The industry claims that it can design fracking patterns. Whether this is true or not, the public (and regulators) requires assurance that once a well has been fracked that the fracking has occurred according to plan and that the fracked well is safe. Thus defensible post-fracking testing methodologies for gas generating wells are required. In 2009 a fracked well HB02, owned by AGL, near Broke, NSW, Australia was subjected to "traditional" water pump-testing as part of this assurance process. Interpretation with well Type Curves and simple single phase (i.e. only water, no gas) highlighted deficiencies in traditional water well approaches with a systemic deviation from the qualitative characteristic of well drawdown curves (e.g. concavity versus convexity of drawdown with time). Accordingly a multiphase (i.e. water and methane) model of the well was developed and compared with the observed data. This paper will discuss the results of this multiphase testing using the TOUGH2 model and its EOS7C constitutive model. A key objective was to test a methodology, based on GLUE monte-carlo calibration technique, to calibrate the characteristics of the frack using the well test drawdown curve. GLUE involves a sensitivity analysis of how changes in the fracture properties change the well hydraulics through and analysis of the drawdown curve and changes in the cone of depression. This was undertaken by changing the native coal, fracture, and gas parameters to see how changing those parameters changed the match between simulations and the observed well drawdown. Results from the GLUE analysis show how much information is contained in the well drawdown curve for estimating field scale

Study on Resources Assessment of Coal Seams covered by Long-Distance Oil & Gas Pipelines

Science.gov (United States)

Han, Bing; Fu, Qiang; Pan, Wei; Hou, Hanfang

2018-01-01

The assessment of mineral resources covered by construction projects plays an important role in reducing the overlaying of important mineral resources and ensuring the smooth implementation of construction projects. To take a planned long-distance gas pipeline as an example, the assessment method and principles for coal resources covered by linear projects are introduced. The areas covered by multiple coal seams are determined according to the linear projection method, and the resources covered by pipelines directly and indirectly are estimated by using area segmentation method on the basis of original blocks. The research results can provide references for route optimization of projects and compensation for mining right..

Coal seam gas water: potential hazards and exposure pathways in Queensland.

Science.gov (United States)

Navi, Maryam; Skelly, Chris; Taulis, Mauricio; Nasiri, Shahram

2015-01-01

The extraction of coal seam gas (CSG) produces large volumes of potentially contaminated water. It has raised concerns about the environmental health impacts of the co-produced CSG water. In this paper, we review CSG water contaminants and their potential health effects in the context of exposure pathways in Queensland's CSG basins. The hazardous substances associated with CSG water in Queensland include fluoride, boron, lead and benzene. The exposure pathways for CSG water are (1) water used for municipal purposes; (2) recreational water activities in rivers; (3) occupational exposures; (4) water extracted from contaminated aquifers; and (5) indirect exposure through the food chain. We recommend mapping of exposure pathways into communities in CSG regions to determine the potentially exposed populations in Queensland. Future efforts to monitor chemicals of concern and consolidate them into a central database will build the necessary capability to undertake a much needed environmental health impact assessment.

‘Cut in two’, Part 1: Exposing the Seam in Q 12:42−46

Directory of Open Access Journals (Sweden)

Llewellyn Howes

2015-06-01

Full Text Available This publication argues for the existence of a seam between verses 44 and 45 of the parable in Q 12:42–46. In the process, a case is also made for identifying the second half of the parable (Q 12:45–46 as a redactional addition to a more original first half (Q 12:42–44. The arguments that make up this article form the basis for a follow-up article on the redaction of Q 12:42–46 within the context of the Sayings Gospel as a whole.

A Case Study of Damage Energy Analysis and an Early Warning by Microseismic Monitoring for Large Area Roof Caving in Shallow Depth Seams

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Like Wei

2015-01-01

Full Text Available Shallow depth coal seams are widely spread in Shendong mining area, which is located in the Northwestern region of China. When working face is advanced out of concentrated coal pillar in upper room and pillar goaf, strong strata behaviors often cause support crushing accidents, and potentially induce large area residual pillars instability and even wind blast disaster. In order to predict the precise time when the accident happens, guaranteeing life-safety of miner, microseismic monitoring system was for the first time applied in shallow coal seam. Based on damage mechanics correlation theory, the damage energy model is established to describe relationship between damage level and cumulative energy of microseismic events. According to microseismic monitoring data of two support crushing accidents, the damage energy model is verified and an effective early warning method of these accidents is proposed. The field application showed that the early warning method had avoided miners suffering from all support crushing accidents in Shigetai coal mine.

Control Mechanism of Rock Burst in the Floor of Roadway Driven along Next Goaf in Thick Coal Seam with Large Obliquity Angle in Deep Well

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Yunhai Cheng

2015-01-01

Full Text Available This paper deals with the theoretical aspects combined with stress analysis over the floor strata of coal seam and the calculation model for the stress on the coal floor. Basically, this research presents the relevant results obtained for the rock burst prevention in the floor of roadway driven along next goaf in the exploitation of thick coal seam with large obliquity in deep well and rock burst tendency. The control mechanism of rock burst in the roadway driven along next goaf is revealed in the present work. That is, the danger of rock burst can be removed by changing the stress environment for the energy accumulation of the floor and by reducing the impact on the roadway floor from the strong dynamic pressure. This result can be profitable being used at the design stage of appropriate position of roadway undergoing rock burst tendency in similar conditions. Based on the analysis regarding the control mechanism, this paper presents a novel approach to the prevention of rock burst in roadway floor under the above conditions. That is, the return airway is placed within the goaf of the upper working face that can prevent the rock burst effectively. And in this way, mining without coal pillar in the thick coal seam with large obliquity and large burial depth (over a thousand meters is realized. Practice also proves that the rock burst in the floor of roadway driven along next goaf is controlled and solved.

GMR-based eddy current probe for weld seam inspection and its non-scanning detection study

Science.gov (United States)

Gao, Peng; Wang, Chao; Li, Yang; Wang, Libin; Cong, Zheng; Zhi, Ya

2017-04-01

Eddy current testing is one of the most important non-destructive testing methods for welding defects detection. This paper presents the use of a probe consisting of 4 giant magneto-resistive (GMR) sensors to detect weld defects. Information from four measuring points above and on both sides of the weld seam is collected at the same time. By setting the GMR sensors' sensing axes perpendicular to the direction of the excitation magnetic field, the information collected mainly reflects the change in the eddy current which is caused by defects. Digital demodulation technology is applied to extract the real part and imaginary part of the GMR sensors' output signals. The variables containing directional information of the magnetic field are introduced. Based on the data from the four GMR (4-GMR) sensors' output signals, four values, Ran, Mean, Var and k are selected as the feature quantities for defect recognition. Experiments are carried out on weld seams with and without defects, and the detection outputs are given in this paper. The 4-GMR probe is also employed to investigate non-scanning weld defect detection and the four feature quantities (Ran, Mean, Var and k) are studied to evaluate weld quality. The non-scanning weld defect detection is presented. A support vector machine is used to classify and discriminate welds with and without defects. Experiments carried out show that through the method in this paper, the recognition rate is 92% for welds without defects and 90% for welds with defects, with an overall recognition rate of 90.9%, indicating that this method could effectively detect weld defects.

Block Slides on Extremely Weak Tectonic Clay Seams in Openly Folded Tertiary Mud-Rocks at Auckland and the Rangitikei Valley, North Island, New Zealand

Science.gov (United States)

Prebble, Warwick M.; Williams, Ann L.

2016-06-01

Block slides have developed on extremely weak, thin clay seams of tectonic origin, parallel to bedding in gently dipping sandstones and mudstones of Tertiary age. Two areas of noted instability are investigated at Auckland and the Rangitikei valley. Dimensions range from 100 m across × 100 m long for short displacement block slides up to 4 km across × 3 km long for large landslide complexes in which block slides are a major component. Displacements of blocks range from incipient (cm) through short (30 m) to 2 or 3 km for large slides. Many of the Auckland slides are dormant but likely to move in a 2000 year return period earthquake or 100 year high intensity rain storm. At Rangitikei there are many active, younger slides. Sliding rates for active failures vary from a few cm/year to 50 m in 30 min. Host rocks are weak to very weak clayey sandstones and sandy mudstones. The seams are rich in smectite. They have polished and crushed walls, may have slickensides and some contain rounded rock fragments. Laboratory shear strength of the seams is 13 kPa cohesion and 13° friction, with a lower bound of 8° at zero cohesion. Strength is increased at the field scale by waviness, steps and splays. Continuity can be demonstrated over distances of hundreds of metres. Key investigation methods were mapping, shafts and trenches. Tectonic uplift, folding and faulting of the weak Tertiary strata and river down-cutting are perpetuating block slide development.

Chemistry and palynology of carbon seams and associated rocks from the Witwatersrand goldfields, South Africa

Science.gov (United States)

Ebert, L.B.; Robbins, E.I.; Rose, K.D.; Kastrup, R.V.; Scanlon, J.C.; Gebhard, L.A.; Garcia, A.R.

1990-01-01

Carbon seams in the Witwatersrand System of South Africa host some of the richest gold concentrations in the world. A study of the microscopic characteristics in thin sections and acid residues, and of the chemical and physical nature of the carbon-bearing phases, was undertaken to gain some understanding of the biological precursors and thermal changes that have occurred since the seams were buried. The HClHF acid-resistant organic tissues in this Early Proterozoic coal are filamentous and spherical, which are typical morphologies for microorganisms. The tissues are carbonized black as would be expected for metamorphic rocks, so usual palynological techniques were of limited use. Therefore, the chemical and physical nature of the organic remains was studied by H C ratios, X-ray diffraction (XRD), 13C nuclear magnetic resonance (NMR), reductive chemistry, crosspolarization/magic angle spinning NMR (CP/MAS), and electron spin resonance (ESR). The H C ratios of the samples examined are similar to those of semi-anthracite and petroleum cokes from delayed cokers. XRD shows graphite is not present and that the gold is in elemental form, not chemically bound or intercalated between carbon planes. NMR shows that both aromatic and paraffinic carbons are present. Integration of the carbon NMR spectra suggests that 80% of the carbon is sp2-hybridized and 20% is sp3-hybridized. Reductive chemistry shows that the benzenoid entities are larger than common polynuclear aromatic hydrocarbons such as perylene and decacyclene. Dipolar dephasing CP/MAS NMR suggests the presence of two types of paraffinic carbons, a rigid methylene group and a rotating methyl group. The narrowing of the ESR linewidth between room temperature and 300??C shows that the materials examined have not previously been subjected to temperatures as high as 300??C. ?? 1990.

Chemokine Signaling during Midline Epithelial Seam Disintegration Facilitates Palatal Fusion

Science.gov (United States)

Suttorp, Christiaan M.; Cremers, Niels A.; van Rheden, René; Regan, Raymond F.; Helmich, Pia; van Kempen, Sven; Kuijpers-Jagtman, Anne M.; Wagener, Frank A.D.T.G.

2017-01-01

Disintegration of the midline epithelial seam (MES) is crucial for palatal fusion, and failure results in cleft palate. Palatal fusion and wound repair share many common signaling pathways related to epithelial-mesenchymal cross-talk. We postulate that chemokine CXCL11, its receptor CXCR3, and the cytoprotective enzyme heme oxygenase (HO), which are crucial during wound repair, also play a decisive role in MES disintegration. Fetal growth restriction and craniofacial abnormalities were present in HO-2 knockout (KO) mice without effects on palatal fusion. CXCL11 and CXCR3 were highly expressed in the disintegrating MES in both wild-type and HO-2 KO animals. Multiple apoptotic DNA fragments were present within the disintegrating MES and phagocytized by recruited CXCR3-positive wt and HO-2 KO macrophages. Macrophages located near the MES were HO-1-positive, and more HO-1-positive cells were present in HO-2 KO mice compared to wild-type. This study of embryonic and palatal development provided evidence that supports the hypothesis that the MES itself plays a prominent role in palatal fusion by orchestrating epithelial apoptosis and macrophage recruitment via CXCL11-CXCR3 signaling. PMID:29164113

Chemokine Signaling during Midline Epithelial Seam Disintegration Facilitates Palatal Fusion

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Christiaan M. Suttorp

2017-10-01

Full Text Available Disintegration of the midline epithelial seam (MES is crucial for palatal fusion, and failure results in cleft palate. Palatal fusion and wound repair share many common signaling pathways related to epithelial-mesenchymal cross-talk. We postulate that chemokine CXCL11, its receptor CXCR3, and the cytoprotective enzyme heme oxygenase (HO, which are crucial during wound repair, also play a decisive role in MES disintegration. Fetal growth restriction and craniofacial abnormalities were present in HO-2 knockout (KO mice without effects on palatal fusion. CXCL11 and CXCR3 were highly expressed in the disintegrating MES in both wild-type and HO-2 KO animals. Multiple apoptotic DNA fragments were present within the disintegrating MES and phagocytized by recruited CXCR3-positive wt and HO-2 KO macrophages. Macrophages located near the MES were HO-1-positive, and more HO-1-positive cells were present in HO-2 KO mice compared to wild-type. This study of embryonic and palatal development provided evidence that supports the hypothesis that the MES itself plays a prominent role in palatal fusion by orchestrating epithelial apoptosis and macrophage recruitment via CXCL11-CXCR3 signaling.

Significance of the Resonance Condition for Controlling the Seam Position in Laser-assisted TIG Welding

Science.gov (United States)

Emde, B.; Huse, M.; Hermsdorf, J.; Kaierle, S.; Wesling, V.; Overmeyer, L.; Kozakov, R.; Uhrlandt, D.

As an energy-preserving variant of laser hybrid welding, laser-assisted arc welding uses laser powers of less than 1 kW. Recent studies have shown that the electrical conductivity of a TIG welding arc changes within the arc in case of a resonant interaction between laser radiation and argon atoms. This paper presents investigations on how to control the position of the arc root on the workpiece by means of the resonant interaction. Furthermore, the influence on the welding result is demonstrated. The welding tests were carried out on a cooled copper plate and steel samples with resonant and non-resonant laser radiation. Moreover, an analysis of the weld seam is presented.

Coal Mining and Coal Seam Gas on Gomeroi country: Sacred lands, economic futures and shifting alliances

International Nuclear Information System (INIS)

Norman, Heidi

2016-01-01

North western NSW has seen a host of interest groups working in alliance opposing coal and coal seam gas mining. These groups - farmers, residents and environmentalists share concerns about the impact on the unique black soil and aquifer, of fossil fuel more broadly. While these shared alliances across class, gender and generations are emergent, Aboriginal citizens are uniquely placed in this contest over land, environment and resources. This paper sets out to show the historical and contemporary significance of the place of Aboriginal people in the debate over land use, arguing that, for the first time in history, Aboriginal worlds are central to community futures. In this space, new relationships are being forged and new discourse is required to comprehend the complex position Aboriginal citizens have as custodians of place and at the same time, the responsibility to provide for families and communities, otherwise excluded from the prevailing modern economy. With reference to the history of both relationship to land and land usage over Gomeroi country, and drawing on ethnographic along with archival research, this article seeks to contribute to a critical understanding of Aboriginal people's dealings in relation to their land, their cultural and economic interests with in an emerging regional coal economy, and in turn how they are redefining the context for energy resource extraction, and energy policy. - Highlights: • Aboriginal worlds are central to community futures in Australia. • Prospecting for coal and coal seam gas is forcing Aboriginal land holders into new relationships. • The nexus between the coal economy & Aboriginal self-determination is deeply contested. • New discourses are emerging to comprehend the custodianship of place in the context of mining.

A Gas–Solid–Liquid Coupling Model of Coal Seams and the Optimization of Gas Drainage Boreholes

Directory of Open Access Journals (Sweden)

Yuexia Chen

2018-03-01

Full Text Available For a gas–solid–liquid coupling model of coal seams, previous permeability models basically supposed uniaxial strains as the boundary condition for coal reservoirs without considering the deformation caused by changes in humidity. The permeability model varies under different boundary conditions. According to the true triaxial stress state of coal reservoirs, a permeability model considering the effective stress, sorption and desorption, and wet strain was established. Based on the permeability model, the continuity equation of gas and water and the stress field equation were coupled. Then, the model was incorporated in the COMSOL suite to simulate gas drainage from boreholes in floor roadways passing through seams in a coal mine. By comparing with the measured gas flow on site, the model was verified as being reliable. Moreover, the spacing and layout shape of boreholes in floor roadways were simulated. To achieve the aim of eliminating regional outburst within 180 days and decreasing the number of boreholes so as to reduce the cost, the spacing and shape of boreholes were optimized. When the superimposed effect of the boreholes was not considered, the optimal spacing of boreholes was 3 r; if the superimposed effect was taken into account, the spacing could be set to within 3 r ≤ L ≤ R, where r and R represent the effective gas drainage radius and the influence radius of gas drainage, respectively. The borehole spacing could be appropriately increased when the boreholes were arranged in rhomboidal form. To achieve the same range of outburst elimination, the rhomboidal layout can decrease the number of boreholes to reduce cost, thus realizing the objective of this optimization process.

Conditions of Antonin seam exploitation in the open pit Druzba near Sokolov with regard to the protection of thermal and mineral water resources in Karlovy Vary

International Nuclear Information System (INIS)

Grmela, A.; Sterba, J.

1997-01-01

From new structural-tectonic findings concerning the extent and character of the Nove Sedlo fault in the area of the Druzba open pit in the Sokolov Basin, it is evident that it is a form of listric fault of shallow range, ending in an intermediate slip. This finding has a decisive relevance for deciding as to the current placement of the pit in the protection zone of Karlovy Vary's thermal springs. For the purposes of the exploitation of the Antonin seam, it is necessary to create a network of multipurpose bore holes at the bottom of the pit and in front of the working face for the regulation of pressure in the basal aquifer and to ensure unity of monitoring and its complex evaluation on the basis of numerical modelling of the hydrodynamic state of the basal aquifer and the geotechnical processes of the seam's impermeable bedrock. 4 refs

Robotic complex for the development of thick steeply-inclined coal seams and ore deposits

Science.gov (United States)

Nikitenko, M. S.; Malakhov, Yu V.; Neogi, Biswarup; Chakraborty, Pritam; Banerjee, Dipesu

2017-09-01

Proposal for the formulation of robotic complexes for steeply inclined coal seams as a basis of the supportive-enclosing walking module and power support with a controlled outlet for mining industry has been represented in this literature. In mining industry, the available resource base reserves and mineral deposits are concentrated deep down the earth crust leading towards a complicated geological condition i.e. abrupt ore bedding and steeply inclined strata with the high gas content and fire hazard of thick coal stratum, heading against an unfavorable and sometimes human labor life risk during subversive mining. Prevailing towards the development of effective robotic complexes based on the means of “unmanned technologies” for extraction of minerals from hard-to-reach deposits and make sure the safety of underground staff during sublevel mining technology.

A Novel Acoustic Liquid Level Determination Method for Coal Seam Gas Wells Based on Autocorrelation Analysis

Directory of Open Access Journals (Sweden)

Ximing Zhang

2017-11-01

Full Text Available In coal seam gas (CSG wells, water is periodically removed from the wellbore in order to keep the bottom-hole flowing pressure at low levels, facilitating the desorption of methane gas from the coal bed. In order to calculate gas flow rate and further optimize well performance, it is necessary to accurately monitor the liquid level in real-time. This paper presents a novel method based on autocorrelation function (ACF analysis for determining the liquid level in CSG wells under intense noise conditions. The method involves the calculation of the acoustic travel time in the annulus and processing the autocorrelation signal in order to extract the weak echo under high background noise. In contrast to previous works, the non-linear dependence of the acoustic velocity on temperature and pressure is taken into account. To locate the liquid level of a coal seam gas well the travel time is computed iteratively with the non-linear velocity model. Afterwards, the proposed method is validated using experimental laboratory investigations that have been developed for liquid level detection under two scenarios, representing the combination of low pressure, weak signal, and intense noise generated by gas flowing and leakage. By adopting an evaluation indicator called Crest Factor, the results have shown the superiority of the ACF-based method compared to Fourier filtering (FFT. In the two scenarios, the maximal measurement error from the proposed method was 0.34% and 0.50%, respectively. The latent periodic characteristic of the reflected signal can be extracted by the ACF-based method even when the noise is larger than 1.42 Pa, which is impossible for FFT-based de-noising. A case study focused on a specific CSG well is presented to illustrate the feasibility of the proposed approach, and also to demonstrate that signal processing with autocorrelation analysis can improve the sensitivity of the detection system.

A reactive transport modelling approach to assess the leaching potential of hydraulic fracturing fluids associated with coal seam gas extraction

Science.gov (United States)

Mallants, Dirk; Simunek, Jirka; Gerke, Kirill

2015-04-01

Coal Seam Gas production generates large volumes of "produced" water that may contain compounds originating from the use of hydraulic fracturing fluids. Such produced water also contains elevated concentrations of naturally occurring inorganic and organic compounds, and usually has a high salinity. Leaching of produced water from storage ponds may occur as a result of flooding or containment failure. Some produced water is used for irrigation of specific crops tolerant to elevated salt levels. These chemicals may potentially contaminate soil, shallow groundwater, and groundwater, as well as receiving surface waters. This paper presents an application of scenario modelling using the reactive transport model for variably-saturated media HP1 (coupled HYDRUS-1D and PHREEQC). We evaluate the fate of hydraulic fracturing chemicals and naturally occurring chemicals in soil as a result of unintentional release from storage ponds or when produced water from Coal Seam Gas operations is used in irrigation practices. We present a review of exposure pathways and relevant hydro-bio-geo-chemical processes, a collation of physico-chemical properties of organic/inorganic contaminants as input to a set of generic simulations of transport and attenuation in variably saturated soil profiles. We demonstrate the ability to model the coupled processes of flow and transport in soil of contaminants associated with hydraulic fracturing fluids and naturally occurring contaminants.

Nonlinear coupling analysis of coal seam floor during mining based on FLAC3D

Institute of Scientific and Technical Information of China (English)

YAO Duo-xi; XU Ji-ying; LU Hai-feng

2011-01-01

Based on the hydro-geological conditions of 1028 mining face in Suntuan Coal Mine, mining seepage strain mechanism of seam floor was simulated by a nonlinear coupling method, which applied fluid-solid coupling analysis module of FLAC3D. The results indicate that the permeability coefficient of adjoining rock changes a lot due to mining. The maximum value reaches 1 379.9 times to the original value, where it is at immediate roof of the mined-out area. According to the analysis on the seepage field, mining does not destroy water resistance of the floor aquiclude. The mining fissure does not conduct lime-stone aquifer, and it is less likely to form damage. The plastic zone does not exactly correspond to the seepage area, and the scope of the altered seepage area is much larger than the plastic zone.

The peculiarities of structurizing enclosing rock massif while developing a coal seam

Science.gov (United States)

Kozyreva, E. N.; Shinkevich, M. V.

2017-09-01

Different concepts of the development of geo-mechanical processes during longwall mining of a seam which are fundamentally different from the conventional ones are introduced in the article. Fundamental principles of the model for structurizing enclosing rock mass while longwall mining along the strike are described. The model was developed on the bases of non-linear geomechanical laws. According to the model, rock mass in the area of mining operation is organized as rock geomechanical layers with shifting arches. And the formation period of shifting arches in disintegrated rock mass is divisible by the length of the stope. Undulate characteristic of a massif as a peculiarity of man-made structurization of a massif is defined. It is shown that structuring the broken massif causes the formation of block-structured system and it can be detected while monitoring the ground pressure in powered support props. The results of the research allow decreasing the negative influence of a ground pressure and can be applied to specify parameters for controlling the roof, defining geometrical dimensions of a mining section and positioning of holing chute (face entry).

Rock mechanics investigations of structural stability in the Bulli seam at West Cliff Colliery

Energy Technology Data Exchange (ETDEWEB)

Jaggar, F

1978-03-01

Rock mechanics investigations were conducted at West Cliff colliery to obtain rock properties and stress measurements and study the stability of mining structures. The roof and floor were drilled in order to obtain core for rock testing and lump samples of coal were collected in order to measure the coal properties. Absolute stress measurements were obtained using CSIR cells. The strata were sufficiently uniform and competent to overcore the emplaced cells. Testing revealed that the rocks were better than average for coal measure sedimentary strata and the stresses indicated the existence of a moderately high horizontal stress field. The coal is of average strength only with some marked variation relating to the very banded nature of the seam. Finite element analyses showed that the rectangular roadways driven using roof bolts and timber supports were stable and adequately stable by an indicative factor of safety of about l.5.

Molecular and elemental analyses of the carbonaceous matter in the gold and uranium bearing Vaal Reef carbon seams, Witwatersrand sequence

International Nuclear Information System (INIS)

Zumberge, J.E.; Sigleo, A.C.; Nagy, B.

1978-01-01

The thin Vaal Reef carbon seams consist of a complex, solid, and solvent insoluble, polymer-like substance, containing mainly hydrocarbons and some organic sulphur and oxygen compounds. These carbon seams are not pure carbon, e.g. graphite, and do not contain only hydrocarbons. According to modern terminology the Vaal Reef carbonaceous matter is most appropriately referred to as kerogen rather than carbon or thucholite. This kerogen is not the result of the polymerization of gaseous or liquid hydrocarbons, but rather of the polymerization of biochemicals from decayed, primitive Precambrian micro-organisms. These microbiota formed mats in which uranium minerals and gold became incorporated before burial under younger sediments. Organic geochemistry was first developed as a means to elucidate the nature and composition of petroleum and coal. Later it was successfully used in lunar sample, planetary surface, and meteorite studies as well as in investigations of kerogens in terrestrial sediments of various ages. Considering economic geology, organic geochemistry holds promise for elucidating the origin and helping in the exploration of carbonaceous ore deposits. The purpose of this report is to review some of the major current organic geochemical methods and to illustrate these by the analysis of the Vaal Reef kerogen. The samples were analysed by a directly connected high vacuum pyrolysis system-gas chromatograph-organic mass spectrometer. Additional analyses were performed by a combined scanning electron microscope-electron microprobe, by the techniques of electron paramagnetic resonance spectroscopy, and by neutron activation analysis

Grade Distribution Modeling within the Bauxite Seams of the Wachangping Mine, China, Using a Multi-Step Interpolation Algorithm

Directory of Open Access Journals (Sweden)

Shaofeng Wang

2017-05-01

Full Text Available Mineral reserve estimation and mining design depend on a precise modeling of the mineralized deposit. A multi-step interpolation algorithm, including 1D biharmonic spline estimator for interpolating floor altitudes, 2D nearest neighbor, linear, natural neighbor, cubic, biharmonic spline, inverse distance weighted, simple kriging, and ordinary kriging interpolations for grade distribution on the two vertical sections at roadways, and 3D linear interpolation for grade distribution between sections, was proposed to build a 3D grade distribution model of the mineralized seam in a longwall mining panel with a U-shaped layout having two roadways at both sides. Compared to field data from exploratory boreholes, this multi-step interpolation using a natural neighbor method shows an optimal stability and a minimal difference between interpolation and field data. Using this method, the 97,576 m3 of bauxite, in which the mass fraction of Al2O3 (Wa and the mass ratio of Al2O3 to SiO2 (Wa/s are 61.68% and 27.72, respectively, was delimited from the 189,260 m3 mineralized deposit in the 1102 longwall mining panel in the Wachangping mine, Southwest China. The mean absolute errors, the root mean squared errors and the relative standard deviations of errors between interpolated data and exploratory grade data at six boreholes are 2.544, 2.674, and 32.37% of Wa; and 1.761, 1.974, and 67.37% of Wa/s, respectively. The proposed method can be used for characterizing the grade distribution in a mineralized seam between two roadways at both sides of a longwall mining panel.

Geostatistical modeling of the gas emission zone and its in-place gas content for Pittsburgh-seam mines using sequential Gaussian simulation

Science.gov (United States)

Karacan, C.O.; Olea, R.A.; Goodman, G.

2012-01-01

Determination of the size of the gas emission zone, the locations of gas sources within, and especially the amount of gas retained in those zones is one of the most important steps for designing a successful methane control strategy and an efficient ventilation system in longwall coal mining. The formation of the gas emission zone and the potential amount of gas-in-place (GIP) that might be available for migration into a mine are factors of local geology and rock properties that usually show spatial variability in continuity and may also show geometric anisotropy. Geostatistical methods are used here for modeling and prediction of gas amounts and for assessing their associated uncertainty in gas emission zones of longwall mines for methane control.This study used core data obtained from 276 vertical exploration boreholes drilled from the surface to the bottom of the Pittsburgh coal seam in a mining district in the Northern Appalachian basin. After identifying important coal and non-coal layers for the gas emission zone, univariate statistical and semivariogram analyses were conducted for data from different formations to define the distribution and continuity of various attributes. Sequential simulations performed stochastic assessment of these attributes, such as gas content, strata thickness, and strata displacement. These analyses were followed by calculations of gas-in-place and their uncertainties in the Pittsburgh seam caved zone and fractured zone of longwall mines in this mining district. Grid blanking was used to isolate the volume over the actual panels from the entire modeled district and to calculate gas amounts that were directly related to the emissions in longwall mines.Results indicated that gas-in-place in the Pittsburgh seam, in the caved zone and in the fractured zone, as well as displacements in major rock units, showed spatial correlations that could be modeled and estimated using geostatistical methods. This study showed that GIP volumes may

Permeability Increase with Deep Borehole Controlled Pre-cracking Blasting Technology in Low Permeability and High Gassy Seam"%低透气性高瓦斯煤层深孔控制预裂爆破增透技术

Institute of Scientific and Technical Information of China (English)

弓美疆; 池鹏; 张明杰

2012-01-01

为了解决低透气性高瓦斯煤层难抽采问题,运用RFPA2D数值模拟软件,建立了2种深孔控制预裂爆破力学模型,通过对模拟结果进行对比分析,得出一套适用于鹤煤八矿底板抽采的爆破参数,并进行了现场试验,爆破后煤层透气性系数平均值达到了2.23 m2/（MPa2.d）,比爆破前测定的煤层原始透气性平均值提高了近3.05倍,说明该技术可以明显提高钻孔周围煤体裂隙发育程度,煤体透气性增加,达到了提高煤层瓦斯抽采量和抽采率的目的。%In order to solve the difficult gas drainage problem in low permeability and high gassy seam, the RFPA2D numerical simulation software was applied to establish two deep borehole controlled pre-cracking blasting mechanics models. With the comparison and analysis on the simulation results, a set of blasting parameters obtained which were suitable for floor gas drainage in No. 8 mine of Hegang Coal Mining and the site trial with the parameters was conducted. The results showed that after the blasting, the average value of the seam per- meability coefficient reached at 2. 23 m2/ ( MPa2 ·d) and 3.05 times higher than the average value of the seam in-situ permeability be- fore the blasting conducted. Thus the technology could obviously improve the cracking development degree of coal around the borehole and could improve the permeability of the seam. The target to improve the seam gas drainage value and the gas drainage rate could be reached.

SULPHIDE MINERALIZATION IN UPPER WESTPHALIAN COAL SEAMS FROM THE EASTERN PART OF THE UPPER SILESIAN COAL BASIN

Directory of Open Access Journals (Sweden)

Lipiarski Ireneusz

1997-10-01

Full Text Available Morphologically diversified sulphide mineralization has been found in No. 301 and 302 coal seams (Westphalian B. The main sulphide is pyrite which forms veinlets cross-cutting the sedimentary fabrics of the coal, encrusts the cellular structures and intergrowths with oxysulphides. Two generations of pyrites were observed: the preceding and the following the oxysulphides. Pyrite composition is stoichiometric, rare admixtures are up to(in wt.%: Mn - 0.19, Co - 0.48, Ni - 0.42 and As - 1.41. Iron oxysulphides contain up to 35.06 wt.% oxygen. Their composition varies between FeS2O and FeS2O3. Increased contents of As (up to 1.46 wt.% and Pb (up to 0.96 wt.% were detected.

Drag resistance of ship hulls: Effects of surface roughness of newly applied fouling control coatings, coating water absorption, and welding seams

DEFF Research Database (Denmark)

Wang, Xueting; Olsen, Stefan Møller; Andrés, Eduardo

2018-01-01

selected, that a so-called fouling release (FR) coating caused approximately 5.6 % less skin friction (torque) over time than traditional biocide-based antifouling (AF) coatings at a tangential speed of 12 knots. Furthermore, results of immersion experiments and supporting “standard” water absorption......Fouling control coatings (FCCs) and irregularities (e.g. welding seams) on ship hull surfaces have significant effects on the overall drag performance of ships. In this work, skin frictions of four newly applied FCCs were compared using a pilot-scale rotary setup. Particular attention was given...

Analysis and mapping of post-fire hydrologic hazards for the 2002 Hayman, Coal Seam, and Missionary Ridge wildfires, Colorado

Science.gov (United States)

Elliott, J.G.; Smith, M.E.; Friedel, M.J.; Stevens, M.R.; Bossong, C.R.; Litke, D.W.; Parker, R.S.; Costello, C.; Wagner, J.; Char, S.J.; Bauer, M.A.; Wilds, S.R.

2005-01-01

Wildfires caused extreme changes in the hydrologic, hydraulic, and geomorphologic characteristics of many Colorado drainage basins in the summer of 2002. Detailed assessments were made of the short-term effects of three wildfires on burned and adjacent unburned parts of drainage basins. These were the Hayman, Coal Seam, and Missionary Ridge wildfires. Longer term runoff characteristics that reflect post-fire drainage basin recovery expected to develop over a period of several years also were analyzed for two affected stream reaches: the South Platte River between Deckers and Trumbull, and Mitchell Creek in Glenwood Springs. The 10-, 50-, 100-, and 500-year flood-plain boundaries and water-surface profiles were computed in a detailed hydraulic study of the Deckers-to-Trumbull reach. The Hayman wildfire burned approximately 138,000 acres (216 square miles) in granitic terrain near Denver, and the predominant potential hazard in this area is flooding by sediment-laden water along the large tributaries to and the main stem of the South Platte River. The Coal Seam wildfire burned approximately 12,200 acres (19.1 square miles) near Glenwood Springs, and the Missionary Ridge wildfire burned approximately 70,500 acres (110 square miles) near Durango, both in areas underlain by marine shales where the predominant potential hazard is debris-flow inundation of low-lying areas. Hydrographs and peak discharges for pre-burn and post-burn scenarios were computed for each drainage basin and tributary subbasin by using rainfall-runoff models because streamflow data for most tributary subbasins were not available. An objective rainfall-runoff model calibration method based on nonlinear regression and referred to as the ?objective calibration method? was developed and applied to rainfall-runoff models for three burned areas. The HEC-1 rainfall-runoff model was used to simulate the pre-burn rainfall-runoff processes in response to the 100-year storm, and HEC-HMS was used for runoff

Structural evaluation of WIPP disposal room raised to Clay Seam G

International Nuclear Information System (INIS)

Park, Byoung Yoon; Holland, John F.

2004-01-01

This report summarizes a series of structural calculations that examine effects of raising the Waste Isolation Pilot Plant repository horizon from the original design level upward 2.43 meters. These calculations allow evaluation of various features incorporated in conceptual models used for performance assessment. Material presented in this report supports the regulatory compliance re-certification, and therefore begins by replicating the calculations used in the initial compliance certification application. Calculations are then repeated for grid changes appropriate for the new horizon raised to Clay Seam G. Results are presented in three main areas: 1. Disposal room porosity, 2. Disturbed rock zone characteristics, and 3. Anhydrite marker bed failure. No change to the porosity surface for the compliance re-certification application is necessary to account for raising the repository horizon, because the new porosity surface is essentially identical. The disturbed rock zone evolution and devolution are charted in terms of a stress invariant criterion over the regulatory period. This model shows that the damage zone does not extend upward to MB 138, but does reach MB 139 below the repository. Damaged salt would be expected to heal in nominally 100 years. The anhydrite marker beds sustain states of stress that promote failure and substantial marker bed deformation into the room assures fractured anhydrite will sustain in the proximity of the disposal rooms

Research into methods of dust prevention in mechanised winning in thin coal seams. Investigacion de metodos de prevencion del polvo, en el arranque mecanizado de capas estrechas de carbon

Energy Technology Data Exchange (ETDEWEB)

Martinez Fidalgo, M.; Alvarez Santullano, L.; Eguidazu Pujades, J.L.; Gonzalez del Valle, S.; Cordera Fernandez, J.V.; De Arriba de la Iglesia, J. (Instituto Nacional de Silicosis (Spain))

1989-09-01

Concerns the research work carried out jointly by HUNOSA and the National Institute of Silicosis regarding dust prevention on mechanised faces in thin coal seams using shearers with a drum diameter of less than 600 mm. This work was supported by the Directorate General for mines and Ocicarbon. 10 figs., 1 tab.

Study on Gas Drainage by Pressure Relief for Floor Through Beds Holes in Far Distance Lower Protective Coal Seam%远距离下保护层底板穿层钻孔卸压瓦斯抽采研究

Institute of Scientific and Technical Information of China (English)

刘军; 李生舟; 姚明柱

2017-01-01

This paper takes the remote lower protective layer 11# coal seam mining to protect main 3# coal seam as the research object in Songshuping Coal Mine.It is concluded that it is reasonable to arrange 3314 floor gas drainage roadway at the bottom 15 m of the 3# coal seam through arranging through beds grid format upholes in floor roadway to extract the protective layer and carry out pressure relief gas.The actual extraction data show that during the mining of the long-distance protective layer,the influence of the mining can effectively relieve the pressure and improve the permeability of the protective layer.The pre-pumping rate of the drainage area is about 65.6％.According to the effect analysis of pressure relief gas extraction,11# coal seam after the protection of the working layer in front of 10 m to the protective layer of the face of 60 m within the corresponding overlying 3# coal seam is the best pressure relief gas extraction area.%以桑树坪煤矿远距离下保护层11#煤层开采保护主采3#煤层为研究对象,利用底板巷布置上向穿层网格式钻孔抽采被保护层卸压瓦斯,研究得出将3314底板瓦斯抽放巷布置在3#煤层底部法距15 m处较为合理.实际抽采数据表明,在远距离下保护层开采期间,采动影响能够有效卸压,提高被保护层的透气性,底抽巷预抽区域瓦斯预抽率约为65.6％.从卸压瓦斯抽采效果分析,11#煤层回采后保护层工作面前方10m至保护层工作面后方60 m范围内对应的上覆3#煤层区域为最佳卸压瓦斯抽采区域.

Mechanism of selective corrosion in electrical resistance seam welded carbon steel pipe

Energy Technology Data Exchange (ETDEWEB)

Lopez Fajardo, Pedro; Godinez Salcedo, Jesus; Gonzalez Velasquez, Jorge L. [Instituto Politecnico Nacional, Mexico D.F., (Mexico). Escuela Superior de Ingenieria Quimica e Industrias Extractivas. Dept. de Ingenieria Metalurgica

2009-07-01

In this investigation the studies of the mechanism of selective corrosion in electrical resistance welded (ERW) carbon steel pipe was started. Metallographic characterizations and evaluations for inclusions were performed. The susceptibility of ERW pipe to selective corrosion in sea water (NACE 1D182, with O{sub 2} or CO{sub 2} + H{sub 2}S) was studied by the stepped potential Potentiostatic electrochemical test method in samples of 1 cm{sup 3} (ASTM G5) internal surface of the pipe (metal base-weld). The tests were looking for means for predicting the susceptibility of ERW pipe to selective corrosion, prior to placing the pipeline in service. Manganese sulfide inclusions are observed deformed by the welding process and they are close to the weld centerline. A slight decarburization at the weld line is observed, and a distinct out bent fiber pattern remains despite the post-weld seam annealing. The microstructure of the weld region consists of primarily polygonal ferrite grains mixed with small islands of pearlite. It is possible to observe the differences of sizes of grain of the present phases in the different zones. Finally, scanning electron microscopic observation revealed that the corrosion initiates with the dissolution of MnS inclusions and with small crack between the base metal and ZAC. (author)

Study on Mg/Al Weld Seam Based on Zn–Mg–Al Ternary Alloy

Directory of Open Access Journals (Sweden)

Liming Liu

2014-02-01

Full Text Available Based on the idea of alloying welding seams, a series of Zn–xAl filler metals was calculated and designed for joining Mg/Al dissimilar metals by gas tungsten arc (GTA welding. An infrared thermography system was used to measure the temperature of the welding pool during the welding process to investigate the solidification process. It was found that the mechanical properties of the welded joints were improved with the increasing of the Al content in the Zn–xAl filler metals, and when Zn–30Al was used as the filler metal, the ultimate tensile strength could reach a maximum of 120 MPa. The reason for the average tensile strength of the joint increasing was that the weak zone of the joint using Zn–30Al filler metal was generated primarily by α-Al instead of MgZn2. When Zn–40Al was used as the filler metal, a new transition zone, about 20 μm-wide, appeared in the edge of the fusion zone near the Mg base metal. Due to the transition zones consisting of MgZn2- and Al-based solid solution, the mechanical property of the joints was deteriorated.

Development of and horizontal seams wining system by means of galleries and chambers; Demostracion de un Sistema de Explotacion de Capas Horizontales por el Metodo de Pilares y Galerias Trazadas Integramente con Maquinas de Ataque Puntual

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

The project Development of an horizontal seams wining system by means of galleries and chambers aimed on the solution of a mining problem kept unresolved during the last 35 years in Carrasconte mine, owned by the society Minero Siderurgica de Ponferrada, in the coal yield of Villablino, Leon, Spain. The problem was a horizontal seam, with a width from 2,5 to 3,5 m, with two specific characteristics; one, roof and floor extremely rigid, with a 30 m sandstone stratum by roof that practically could highly restrict the long wall face conventional system, and the other, an intercalation of shale with a width of 1,2 m and a hardness of near 400 kg/cm2 that required a suitable winning system. By means of investigation with galleries carried out by continuous miners the real width of shale intercalation was stated, an then suitable systems adopted as this width varied. So, short wall faces in areas with minimum shale were disposed, and in t areas with maximum shale width, two long wall faces each one in each different vein were designed. At the end, the borders of reserves were recovered by the conventional system of galleries and chambers. This development project has allowed to recover more than a million tons in three years by systems suitable to the different conditions of the seam. (Author)

复杂瓦斯地质条件下煤层透气性评价及抽采对策研究%Study on coal seam gas permeability evaluation and drainage countermeasures in complex gas geological conditions

Institute of Scientific and Technical Information of China (English)

易汉华

2017-01-01

针对煤层瓦斯地质条件复杂的米箩煤矿在生产过程中瓦斯抽采难、预抽时间长、矿区范围内可采煤层透气性不确定的问题,采用煤层透气性系数现场测定的方法,对米箩煤矿1号、3号、9号、10号、16号、26号、27号、29号、31号和40号煤层施工测压钻孔进行了煤层透气性系数相关参数的测定,并依据钻孔径向流量法计算公式,对米箩煤矿各煤层透气性系数进行了评价,得出了米箩煤矿矿区范围内1号、3号、9号、10号、16号、26号、27号、29号、31号和40号煤层均为低透气性煤层.通过优化瓦斯抽采钻孔直径和钻孔间距的方式,改善了煤层透气性,并在1108底板瓦斯抽放巷两侧每隔15 m分别增设一个高位钻场,在钻场内向3号煤层布置19个斜向穿层抽采钻孔,有效缩短了110310回采工作面瓦斯预抽时间.%The geological conditions of Miluo Coal Mine is complex,in the production process,gas is difficult to drain,the time of gas drainage is long,and permeability of minable seam was uncertain,aimed at these problems,the permeability coefficient measuring on site was applied,thus,pressure drilling were constructed in No.1,3,9,10,16,26,27,29,31 and No.40 coal seam,whose purpose was to evaluate the permeability coefficient of coal seams.It was proposed that No.1,3,9,10,16,26,27,29,31 and No.40 are of low permeability coal seam.Through the optimization of diameter and spacing of holes for gas drainage,the permeability of coal seam was improved,high-level drilling field was added on two side of 1108 floor drainage roadway,and the spacing of drilling field was 15 m.19 oblique layer-through boreholes were laid out into No.3 coal seam in the drilling field,and this has effectively reduced the pre-pumping time of the gas on 110310 working face.

Fluid migration through geo-membrane seams and through the interface between geo-membrane and geo-synthetic clay liner; Contribution a l'etude des transferts de masse au niveau des joints de geomembrane et a l'interface entre geomembrane et geosynthetique bentonitique

Energy Technology Data Exchange (ETDEWEB)

Barroso, M

2005-03-15

Composite liners are used to limit the contamination migration from landfills. Their successful performance is closely related with the geo-membrane as it provides the primary barrier to diffusive and advective transport of contaminants. Critical issues on the performance of the geo-membranes are the seams between geo-membrane panels and the inevitable defects resulting, for instance, from inadequate installation activities. In landfills, where high density polyethylene geo-membranes are usually used, seams are typically made by the thermal-hot dual wedge method. A literature review on quality control of the seams showed that, in situ, fluid-tightness of seams is evaluated in qualitative terms (pass/failure criteria), despite their importance to ensure appropriate performance of the geo-membranes as barriers. In addition, a synthesis of studies on geo-membrane defects indicated that defects varying in density from 0.7 to 15.3 per hectare can be found in landfills. Defects represent preferential flow paths for leachate. Various authors have developed analytical solutions and empirical equations for predicting the flow rate through composite liners due to defects in the geo-membrane. The validity of these methods for composite liners comprising a geo-membrane over a geo-synthetic clay liner (GCL) over a compacted clay liner (CCL) has never been studied from an experimental point of view. To address the problem of fluid migration through the geo-membrane seams, an attempt is made to provide a test method, herein termed as 'gas permeation pouch test', for assessing the quality of the thermal-hot dual wedge seams. This test consists of pressurizing the air channel formed by the double seam with a gas to a specific pressure and, then, measuring the decrease in pressure over time. From the pressure decrease, both the gas permeation coefficients, in steady state conditions, and the time constant, in unsteady state conditions, can be estimated. Experiments were

Thermodynamic and hydrochemical controls on CH4 in a coal seam gas and overlying alluvial aquifer: new insights into CH4 origins

OpenAIRE

Owen, D. Des. R.; Shouakar-Stash, O.; Morgenstern, U.; Aravena, R.

2016-01-01

Using a comprehensive data set (dissolved CH4, ?13C-CH4, ?2H-CH4, ?13C-DIC, ?37Cl, ?2H-H2O, ?18O-H2O, Na, K, Ca, Mg, HCO3, Cl, Br, SO4, NO3 and DO), in combination with a novel application of isometric log ratios, this study describes hydrochemical and thermodynamic controls on dissolved CH4 from a coal seam gas reservoir and an alluvial aquifer in the Condamine catchment, eastern Surat/north-western Clarence-Moreton basins, Australia. ?13C-CH4 data in the gas reservoir (?58? to ?49?) and sha...

Analysis on Development of Transverse - Sectioned Weld Zone using FEM Verified with Multipulsed Resistance Seam Welding

Directory of Open Access Journals (Sweden)

N Muhammad

2013-12-01

Full Text Available This paper details an investigation, through an experimental study, of the development of weld nuggets and a heat-affected zone (HAZ in resistance seam welding(RSEW using a numerical simulation approach. SYSWELD software for the simulation of heat treatment, welding, and welding assembly was utilized for the simulation process. The integrated Spot Weld Advisor (SWA in SYSWELD was applied to simulate the RSEW model using a two-dimensional axis-symmetric FE model with customized electrode meshing. The thermal-mechanical-electrical characteristic and contact condition were taken into account throughout this study. The developed model comprised a transverse cross section for welding two layers of low carbon steel with a thickness of 1 mm. For the experimental verification, three-pulsed RSEW with two different current stages was carried out. It was discovered that this program code, Spotweld Advisor, when used with the meshing method, was capable of offering results that were in agreement with physical experiments.

Influence of coal mining on the deformation-failure and permeability of seam floor%煤炭开采对煤层底板变形破坏及渗透性的影响

Institute of Scientific and Technical Information of China (English)

孟召平; 王保玉; 徐良伟; 吴志远; 白刚; 路波涛

2012-01-01

Except the geological factors, the deformation and failure of seam floor are also controlled by mining factors. The influence of coal mining on stress-strain and permeability of seam floor in working face and its failure regularities were studied through theoretical analysis and the experiment. The research result shows that the permeability of the rock with different lithology is a function of strain in the process of complete stress-strain. In the micro-fracture closure and elastic deformation stage, the primary pores and cracks of rocks are easily compacted, it is obviously that rock permeability decreases with the increase of stress, when the stress intensity increases to the limit, the rock sample is destroyed and cracks through the sample are formed,, the rock permeability rapidly increases to the maximum. There are some differences between rocks with different lithology. With advancement of working face, the seam floor rocks are divided into four areas horizontally, they are initial stress area, advanced stress compression area, direct damaged area of mining stress and stress recovery area of floor rock mass. Permeability of seam floor rock shows regular variation with the deformation and failure of seam floor rock during coal mining.%煤层底板变形破坏除受地质因素控制外,还受开采因素影响.通过试验和理论分析,系统研究了煤炭开采对回采工作面底板应力、应变和破坏及渗透性的影响.研究结果表明,不同岩性岩石的渗透性在全应力-应变过程中为应变的函数,在微裂隙闭合和弹性变形阶段,岩石的原生孔隙和裂隙容易被压密,岩石的渗透率随应力的增加由大变小明显,当应力增大至极限强度时岩石试件破坏形成贯穿�

Influence of lithological characters of coal bearing formation on stability of roof of coal seams

Energy Technology Data Exchange (ETDEWEB)

Meng Zhao-ping; Peng Su-ping; Li Guo-qing; Huang Wei; Lu Jun; Lei Zhi-yong [CUMT, Beijing (China). School of Resources and Safety Engineering

2003-07-01

Lithology is one of the important factors influencing the stability of roof of coal seams. In order to investigate this, the phenomenon of underground pressure and distribution of pressure were studied by using the local observation and simulation test with similar materials. The observation results show that the distance of initial weighting and periodic weighting of the mudstone roof is shorter than that of sandstone roofs. The sandstone roof with a high strength has a longer distance of initial weighting and periodic weighting, the abutment stress on the working face is big and the height of caving and fracture zone is high. The peak point of abutment stress in the sandstone roof is near to the working face and the pressure bump is inclined to occur. The result is contrary to that in case of the mudstone roof with a low strength. While in the transition zone of nipped sandstone, roof rock-mass is broken and is poor in stability, therefore, it is difficult to hold the roof.

Biological action of coal dust formed during excavation of seams after physicochemical treatment

Energy Technology Data Exchange (ETDEWEB)

Sukhanov, V V; Gadzhiev, G P

1982-03-01

Destruction of the self-cleansing function of lungs by dust is important in the development of pneumoconiosis. It is expedient to study the influence of chemical substances, injected into coal seams to prevent methane bursts and reduce dust formation, on the physiologic mechanisms for the protection of the lungs from dust (macrophageal reaction of lungs, function of mucociliary transport). An investigation using 15, 24 and 50% solutions of binder KM/SUB/2 modified by polyvinyl alcohol, and 3% hydrochloric acid solution was conducted on 200 white rats. Reaction of rats treated with solutions of binder in different concentrations proved that accumulation of dust in lungs and lymph nodes was directly related to the strength of the solution. Three percent hydrochloric acid solution diminished dust accumulation in paratracheal lymph nodes and content of lipids and collagen in the lungs. Inhalation of dust treated with a 50% solution of binder KM/SUB/2 increases the deposit of dust in the lungs and increases fiber production. Therefore, solutions of more than 24% binder should not be used to treat coal. Solutions of 15% and 24% do not significantly affect the process of dust accumulation in the lungs. A 3% solution of hydrochloric acid reduces the dust-forming capacity of the coal mass. (13 refs.) (In Russian)

Adaptive removal of background and white space from document images using seam categorization

Science.gov (United States)

Fillion, Claude; Fan, Zhigang; Monga, Vishal

2011-03-01

Document images are obtained regularly by rasterization of document content and as scans of printed documents. Resizing via background and white space removal is often desired for better consumption of these images, whether on displays or in print. While white space and background are easy to identify in images, existing methods such as naïve removal and content aware resizing (seam carving) each have limitations that can lead to undesirable artifacts, such as uneven spacing between lines of text or poor arrangement of content. An adaptive method based on image content is hence needed. In this paper we propose an adaptive method to intelligently remove white space and background content from document images. Document images are different from pictorial images in structure. They typically contain objects (text letters, pictures and graphics) separated by uniform background, which include both white paper space and other uniform color background. Pixels in uniform background regions are excellent candidates for deletion if resizing is required, as they introduce less change in document content and style, compared with deletion of object pixels. We propose a background deletion method that exploits both local and global context. The method aims to retain the document structural information and image quality.

Laser vision seam tracking system based on image processing and continuous convolution operator tracker

Science.gov (United States)

Zou, Yanbiao; Chen, Tao

2018-06-01

To address the problem of low welding precision caused by the poor real-time tracking performance of common welding robots, a novel seam tracking system with excellent real-time tracking performance and high accuracy is designed based on the morphological image processing method and continuous convolution operator tracker (CCOT) object tracking algorithm. The system consists of a six-axis welding robot, a line laser sensor, and an industrial computer. This work also studies the measurement principle involved in the designed system. Through the CCOT algorithm, the weld feature points are determined in real time from the noise image during the welding process, and the 3D coordinate values of these points are obtained according to the measurement principle to control the movement of the robot and the torch in real time. Experimental results show that the sensor has a frequency of 50 Hz. The welding torch runs smoothly with a strong arc light and splash interference. Tracking error can reach ±0.2 mm, and the minimal distance between the laser stripe and the welding molten pool can reach 15 mm, which can significantly fulfill actual welding requirements.

Linear Mathematical Model for Seam Tracking with an Arc Sensor in P-GMAW Processes.

Science.gov (United States)

Liu, Wenji; Li, Liangyu; Hong, Ying; Yue, Jianfeng

2017-03-14

Arc sensors have been used in seam tracking and widely studied since the 80s and commercial arc sensing products for T and V shaped grooves have been developed. However, it is difficult to use these arc sensors in narrow gap welding because the arc stability and sensing accuracy are not satisfactory. Pulse gas melting arc welding (P-GMAW) has been successfully applied in narrow gap welding and all position welding processes, so it is worthwhile to research P-GMAW arc sensing technology. In this paper, we derived a linear mathematical P-GMAW model for arc sensing, and the assumptions for the model are verified through experiments and finite element methods. Finally, the linear characteristics of the mathematical model were investigated. In torch height changing experiments, uphill experiments, and groove angle changing experiments the P-GMAW arc signals all satisfied the linear rules. In addition, the faster the welding speed, the higher the arc signal sensitivities; the smaller the groove angle, the greater the arc sensitivities. The arc signal variation rate needs to be modified according to the welding power, groove angles, and weaving or rotate speed.

Determination of Parachute Joint Factors using Seam and Joint Testing

Science.gov (United States)

Mollmann, Catherine

2015-01-01

This paper details the methodology for determining the joint factor for all parachute components. This method has been successfully implemented on the Capsule Parachute Assembly System (CPAS) for the NASA Orion crew module for use in determining the margin of safety for each component under peak loads. Also discussed are concepts behind the joint factor and what drives the loss of material strength at joints. The joint factor is defined as a "loss in joint strength...relative to the basic material strength" that occurs when "textiles are connected to each other or to metals." During the CPAS engineering development phase, a conservative joint factor of 0.80 was assumed for each parachute component. In order to refine this factor and eliminate excess conservatism, a seam and joint testing program was implemented as part of the structural validation. This method split each of the parachute structural joints into discrete tensile tests designed to duplicate the loading of each joint. Breaking strength data collected from destructive pull testing was then used to calculate the joint factor in the form of an efficiency. Joint efficiency is the percentage of the base material strength that remains after degradation due to sewing or interaction with other components; it is used interchangeably with joint factor in this paper. Parachute materials vary in type-mainly cord, tape, webbing, and cloth -which require different test fixtures and joint sample construction methods. This paper defines guidelines for designing and testing samples based on materials and test goals. Using the test methodology and analysis approach detailed in this paper, the minimum joint factor for each parachute component can be formulated. The joint factors can then be used to calculate the design factor and margin of safety for that component, a critical part of the design verification process.

A New Tree-Type Fracturing Method for Stimulating Coal Seam Gas Reservoirs

Directory of Open Access Journals (Sweden)

Qian Li

2017-09-01

Full Text Available Hydraulic fracturing is used widely to stimulate coalbed methane production in coal mines. However, some factors associated with conventional hydraulic fracturing, such as the simple morphology of the fractures it generates and inhomogeneous stress relief, limit its scope of application in coal mines. These problems mean that gas extraction efficiency is low. Conventional fracturing may leave hidden pockets of gas, which will be safety hazards for subsequent coal mining operations. Based on a new drilling technique applicable to drilling boreholes in coal seams, this paper proposes a tree-type fracturing technique for stimulating reservoir volumes. Tree-type fracturing simulation experiments using a large-scale triaxial testing apparatus were conducted in the laboratory. In contrast to the single hole drilled for conventional hydraulic fracturing, the tree-type sub-boreholes induce radial and tangential fractures that form complex fracture networks. These fracture networks can eliminate the “blank area” that may host dangerous gas pockets. Gas seepage in tree-type fractures was analyzed, and gas seepage tests after tree-type fracturing showed that permeability was greatly enhanced. The equipment developed for tree-type fracturing was tested in the Fengchun underground coal mine in China. After implementing tree-type fracturing, the gas extraction rate was around 2.3 times greater than that for traditional fracturing, and the extraction rate remained high for a long time during a 30-day test. This shortened the gas drainage time and improved gas extraction efficiency.

Setting reinspection intervals for seam welded piping by use of probabilistic fracture mechanics and target reliability values

International Nuclear Information System (INIS)

Harris, D.O.; Dedhia, D.

1995-01-01

The purpose of this paper is to describe a procedure for the selection of a reinspection interval for defects found during an inspection. The procedure is based on probabilistic fracture mechanics calculations of the reliability of the component into the future and selection of an inspection time based on maintaining the target value reliability. The selection of a target value based on the risk of everyday activities is discussed. The procedure is applied to high temperature seam welded piping as an example, because the probabilistic fracture mechanics tools are relatively readily available and this is a problem of great current interest. The results obtained in the example problem indicate reinspection intervals much shorter than field experience would suggest. This indicates a conservatism in the fracture mechanics procedures and/or lack of accurate characterization of scatter in material properties due to lack of data. The general procedure should prove useful in the disposition of detected cracks in a wide variety of situations

Mechanical model of water inrush from coal seam floor based on triaxial seepage experiments

Institute of Scientific and Technical Information of China (English)

Yihui Pang; Guofa Wang; Ziwei Ding

2014-01-01

In order to study the mechanism of confined water inrush from coal seam floor, the main influences on permeability in the process of triaxial seepage experiments were analyzed with methods such as laboratory experiments, theoretical analysis and mechanical model calculation. The crack extension rule and the ultimate destruction form of the rock specimens were obtained. The mechanism of water inrush was explained reasonably from mechanical point of view. The practical criterion of water inrush was put forward. The results show that the rock permeability ‘‘mutation’’ phe-nomenon reflects the differences of stress state and cracks extension rate when the rock internal crack begins to extend in large-scale. The rock ultimate destruction form is related to the rock lithology and the angle between crack and principal stress. The necessary condition of floor water inrush is that the mining pressure leads to the extension and transfixion of the crack. The sufficient condition of floor water inrush is that the confined water’s expansionary stress in normal direction and shear stress in tangential direction must be larger than the internal stress in the crack. With the two conditions satisfied at the same time, the floor water inrush accident will occur.

Exploring the determinants of health and wellbeing in communities living in proximity to coal seam gas developments in regional Queensland.

Science.gov (United States)

Mactaggart, Fiona; McDermott, Liane; Tynan, Anna; Gericke, Christian A

2017-08-03

There is some concern that coal seam gas mining may affect health and wellbeing through changes in social determinants such as living and working conditions, local economy and the environment. The onward impact of these conditions on health and wellbeing is often not monitored to the same degree as direct environmental health impacts in the mining context, but merits attention. This study reports on the findings from a recurrent theme that emerged from analysis of the qualitative component of a comprehensive Health Needs Assessment (HNA) conducted in regional Queensland: that health and wellbeing of communities was reportedly affected by nearby coal seam gas (CSG) development beyond direct environmental impacts. Qualitative analysis was initially completed using the Framework Method to explore key themes from 11 focus group discussions, 19 in-depth interviews, and 45 key informant interviews with health and wellbeing service providers and community members. A key theme emerged from the analysis that forms the basis of this paper. This study is part of a larger comprehensive HNA involving qualitative and quantitative data collection to explore the health and wellbeing needs of three communities living in proximity to CSG development in regional Queensland, Australia. Communities faced social, economic and environmental impacts from the rapid growth of CSG development, which were perceived to have direct and indirect effects on individual lifestyle factors such as alcohol and drug abuse, family relationships, social capital and mental health; and community-level factors including social connectedness, civic engagement and trust. Outer regional communities discussed the effects of mining activity on the fabric of their town and community, whereas the inner regional community that had a longer history of industrial activity discussed the impacts on families and individual health and wellbeing. The findings from this study may inform future health service planning in

Mining a coal seam with caving in a protective pillar of a mine shaft. [Poland

Energy Technology Data Exchange (ETDEWEB)

Szymura, G; Dilling, R; Kowalski, A

1984-01-01

Mining the 620 seam is evaluated (from 1.5 to 1.7 m thick at a depth of 468 m in the protective pillar of the upcast mine shaft used for ventilation, manriding and transport of materials in the Pstrowski mine in Upper Silesia). The shaft is 496 m deep, has a diameter of 3.5 m and its liners are made of bricks. Ground subsidence caused by underground mining influenced: the head frame above the shaft, residential buildings, a church, railway tracks and a river bed. A system of shortwall mining with caving was used. Deformation of shaft liners was reduced by advanced cutting of a coal block 30x30 m around the shaft. A system of timber cribbings and yielding elements was used. Design of support systems used around the shaft is shown in 3 schemes. Shaft deformation was within permissible limits. The maximum ground subsidence (0.95 m) occurred in the river area. Ground subsidence in the area of the church ranged from 0.75 to 0.81 m and in the head frame area 0.84 m. Accuracy of ground subsidence and shaft deformation forecasting was high. 4 references.

Caenorhabditis elegans BAH-1 is a DUF23 protein expressed in seam cells and required for microbial biofilm binding to the cuticle.

Directory of Open Access Journals (Sweden)

Kevin Drace

2009-08-01

Full Text Available The cuticle of Caenorhabditis elegans, a complex, multi-layered extracellular matrix, is a major interface between the animal and its environment. Biofilms produced by the bacterial genus Yersinia attach to the cuticle of the worm, providing an assay for surface characteristics. A C. elegans gene required for biofilm attachment, bah-1, encodes a protein containing the domain of unknown function DUF23. The DUF23 domain is found in 61 predicted proteins in C. elegans, which can be divided into three distinct phylogenetic clades. bah-1 is expressed in seam cells, which are among the hypodermal cells that synthesize the cuticle, and is regulated by a TGF-beta signaling pathway.

Degassification and methane drainage in thick and vertical coal seams worked by horizontal sublevel caving method; Drenaje y Desgasificacion de Grisu en Capas de Carbon Potentes y Verticales, Explotadas por subniveles Horizontales con sutiraje

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

The present trend of the working in spanish coal underground mines is directed towards the utilization, if the deposit characteristics permit it, of mining method by horizontal sublevels with caving. The application of this method involves an important coal volume in specific situations inside the workings cycle (shots, roof cavings, workings beginning, etc). Therefore, those considerable quantities of coal put into circulation, joined to high firedamp concentration desorbable of coal seam, produce in a instantaneous way large volumes of firedamp in the mine atmosphere with the consequent associated risk for the mine people, the stoppage of the works and its evacuation. These aforementioned risks could be avoided, or at least decreased to a great extent, through a methane capture before its circulation in openings caused by the mining works or by draining from accumulation rooms. During the last years, basically in EU countries, some researches have been accomplished about previous Degassification and methane capture in longwall faces of horizontal seams. In these researches have been studied the methane capture both from surface and from underground. In sublevel caving workings, substantially different from longwall faces workings, the techniques and capture systems utilized in the first one are not applicable to the second. The field works and measurements of this project have been mainly carried out in two mining companies located at the north of Spain, the Mina la Camocha S. A. and the S. A. Hullera Vasco Leonesa. Many methane capture tests by means of boreholes in coal seam have been carried out to determine the influence that capture boreholes exert in degassification of coal panel. Otherwise, many firedamp drainage tests in accumulation rooms have been also carried out, and a small-scale system that makes possible the capture in safe conditions have been defined and tested. (Author)

Engineering research on coal and gas outburst control for outburst coal seam floor roadway in deep mine%深井突出煤层底板巷防治煤与瓦斯突出工程研究

Institute of Scientific and Technical Information of China (English)

吕有厂; 王玉杰

2017-01-01

文章针对平煤股份首山一矿突出煤层结构复杂、渗透性低,致使预抽煤层瓦斯效果差、效率低的问题,以平煤股份首山一矿突出煤层底板岩巷瓦斯治理工程典型应用模式为研究对象,现场观测分析上覆突出煤层采掘过程中低板岩巷围岩应力变化规律,观测分析卸压瓦斯抽采效果,优化煤岩巷层位关系、为深部突出煤层巷道支护和抽采瓦斯提供指导,对提高深井突出煤层瓦斯治理效果具有重要的借鉴意义.%Aiming at the complex structure and low permeability of outburst coal seam in Shouyishan Coal Mine,resulting in poor effect in the gas pre-drainage,based on the typical application mode of gas control engineering in floor rock roadway of the outburst coal seam,surrounding rock stress variation law of floor rock roadway was observed and analyzed in the field during mining and tunneling in the overlying outburst coal seam.The pressure-relieving gas drainage effect was analyzed,and the position arrangement of coal and rock roadway was optimized.

Study on the change law of soil in subsidence area of horizontal coal seam

Science.gov (United States)

Li, Pengfeng; Wang, Shugang; Liu, Wei

2017-11-01

In order to provide theoretical basis for land reclamation in subsidence area, the mining subsidence area is divided into three areas: zone I (stretching zone), zone II (compression zone) and zone III (neutral zone). On this basis, the change characteristics of the soil in the three areas of the horizontal coal seam mining subsidence area are studied. The results show that: due to stretching, soil of zone I cracks was developed, the soil continuity damage, poor integrity, serious leakage of soil Water Leakage fertilizer, the area shows the soil water holding capacity decreased, the decline of soil fertility, soil coarsening and barren trend. The soil mass in zone II is compressed and the soil structure is relatively complete, but the soil bulk density increases correspondingly, while the soil porosity decreases gradually and the permeability decreases. The main soil layer in the zone III is vertical deformation, and the soil integrity is better. But the influence of mined out area leads to the movement of water and nutrients to the lower part of the soil. This paper suggests that in the land reclamation process should adopt corresponding reclamation method based on the variation law of the three soil area of reclamation area of mining subsidence, for improving soil physicochemical properties, so as to achieve the purpose of effective reclamation.

Segmentation of Pollen Tube Growth Videos Using Dynamic Bi-Modal Fusion and Seam Carving.

Science.gov (United States)

Tambo, Asongu L; Bhanu, Bir

2016-05-01

The growth of pollen tubes is of significant interest in plant cell biology, as it provides an understanding of internal cell dynamics that affect observable structural characteristics such as cell diameter, length, and growth rate. However, these parameters can only be measured in experimental videos if the complete shape of the cell is known. The challenge is to accurately obtain the cell boundary in noisy video images. Usually, these measurements are performed by a scientist who manually draws regions-of-interest on the images displayed on a computer screen. In this paper, a new automated technique is presented for boundary detection by fusing fluorescence and brightfield images, and a new efficient method of obtaining the final cell boundary through the process of Seam Carving is proposed. This approach takes advantage of the nature of the fusion process and also the shape of the pollen tube to efficiently search for the optimal cell boundary. In video segmentation, the first two frames are used to initialize the segmentation process by creating a search space based on a parametric model of the cell shape. Updates to the search space are performed based on the location of past segmentations and a prediction of the next segmentation.Experimental results show comparable accuracy to a previous method, but significant decrease in processing time. This has the potential for real time applications in pollen tube microscopy.

Reactor cooling water expansion joint bellows: The role of the seam weld in fatigue crack development

International Nuclear Information System (INIS)

West, S.L.; Nelson, D.Z.; Louthan, M.R. Jr.

1992-01-01

The secondary cooling water system pressure boundary of Savannah River Site reactors includes expansion joints utilizing a thin-wall bellows. While successfully used for over thirty years, an occasional replacement has been required because of the development of small, circumferential fatigue cracks in a bellows convolute. One such crack was recently shown to have initiated from a weld heat-affected zone liquation microcrack. The crack, initially open to the outer surface of the rolled and seam welded cylindrical bellows section, was closed when cold forming of the convolutes placed the outer surface in residual compression. However, the bellows was placed in tension when installed, and the tensile stresses reopened the microcrack. This five to eight grain diameter microcrack was extended by ductile fatigue processes. Initial extension was by relatively rapid propagation through the large-grained weld metal, followed by slower extension through the fine-grained base metal. A significant through-wall crack was not developed until the crack extended into the base metal on both sides of the weld. Leakage of cooling water was subsequently detected and the bellows removed and a replacement installed

The effect of zeolite treatment by acids on sodium adsorption ratio of coal seam gas water.

Science.gov (United States)

Wang, Xiaoyu; Ozdemir, Orhan; Hampton, Marc A; Nguyen, Anh V; Do, Duong D

2012-10-15

Many coal seam gas (CSG) waters contain a sodium ion concentration which is too high relative to calcium and magnesium ions for environment acceptance. Natural zeolites can be used as a cheap and effective method to control sodium adsorption ratio (SAR, which is a measure of the relative preponderance of sodium to calcium and magnesium) due to its high cation exchange capacity. In this study, a natural zeolite from Queensland was examined for its potential to treat CSG water to remove sodium ions to lower SAR and reduce the pH value. The results demonstrate that acid activated zeolite at 30%wt solid ratio can reduce the sodium content from 563.0 to 182.7 ppm; the pH from 8.74 to 6.95; and SAR from 70.3 to 18.5. Based on the results of the batch experiments, the sodium adsorption capacity of the acid-treated zeolite is three times greater than that of the untreated zeolite. Both the untreated and acid-treated zeolite samples were characterized using zeta potential, surface characterization, DTA/TG and particle size distribution in order to explain their adsorption behaviours. Copyright © 2012 Elsevier Ltd. All rights reserved.

Exploring the determinants of health and wellbeing in communities living in proximity to coal seam gas developments in regional Queensland

Directory of Open Access Journals (Sweden)

Fiona Mactaggart

2017-08-01

Full Text Available Abstract Background There is some concern that coal seam gas mining may affect health and wellbeing through changes in social determinants such as living and working conditions, local economy and the environment. The onward impact of these conditions on health and wellbeing is often not monitored to the same degree as direct environmental health impacts in the mining context, but merits attention. This study reports on the findings from a recurrent theme that emerged from analysis of the qualitative component of a comprehensive Health Needs Assessment (HNA conducted in regional Queensland: that health and wellbeing of communities was reportedly affected by nearby coal seam gas (CSG development beyond direct environmental impacts. Methods Qualitative analysis was initially completed using the Framework Method to explore key themes from 11 focus group discussions, 19 in-depth interviews, and 45 key informant interviews with health and wellbeing service providers and community members. A key theme emerged from the analysis that forms the basis of this paper. This study is part of a larger comprehensive HNA involving qualitative and quantitative data collection to explore the health and wellbeing needs of three communities living in proximity to CSG development in regional Queensland, Australia. Results Communities faced social, economic and environmental impacts from the rapid growth of CSG development, which were perceived to have direct and indirect effects on individual lifestyle factors such as alcohol and drug abuse, family relationships, social capital and mental health; and community-level factors including social connectedness, civic engagement and trust. Conclusions Outer regional communities discussed the effects of mining activity on the fabric of their town and community, whereas the inner regional community that had a longer history of industrial activity discussed the impacts on families and individual health and wellbeing. The

Environmental impact of coal mining and coal seam gas production on surface water quality in the Sydney basin, Australia.

Science.gov (United States)

Ali, A; Strezov, V; Davies, P; Wright, I

2017-08-01

The extraction of coal and coal seam gas (CSG) will generate produced water that, if not adequately treated, will pollute surface and groundwater systems. In Australia, the discharge of produced water from coal mining and related activities is regulated by the state environment agency through a pollution licence. This licence sets the discharge limits for a range of analytes to protect the environment into which the produced water is discharged. This study reports on the impact of produced water from coal mine activities located within or discharging into high conservation environments, such as National Parks, in the outer region of Sydney, Australia. The water samples upstream and downstream from the discharge points from six mines were taken, and 110 parameters were tested. The results were assessed against a water quality index (WQI) which accounts for pH, turbidity, dissolved oxygen, biochemical oxygen demand, total dissolved solids, total phosphorus, nitrate nitrogen and E .coli. The water quality assessment based on the trace metal contents against various national maximum admissible concentration (MAC) and their corresponding environmental impacts was also included in the study which also established a base value of water quality for further study. The study revealed that impacted water downstream of the mine discharge points contained higher metal content than the upstream reference locations. In many cases, the downstream water was above the Australia and New Zealand Environment Conservation Council and international water quality guidelines for freshwater stream. The major outliers to the guidelines were aluminium (Al), iron (Fe), manganese (Mn), nickel (Ni) and zinc (Zn). The WQI of surface water at and downstream of the discharge point was lower when compared to upstream or reference conditions in the majority of cases. Toxicology indices of metals present in industrial discharges were used as an additional tool to assess water quality, and the newly

Enrichment of radon and carbon dioxide in the open atmosphere of an Australian coal seam gas field.

Science.gov (United States)

Tait, Douglas R; Santos, Isaac R; Maher, Damien T; Cyronak, Tyler J; Davis, Rachael J

2013-04-02

Atmospheric radon ((222)Rn) and carbon dioxide (CO2) concentrations were used to gain insight into fugitive emissions in an Australian coal seam gas (CSG) field (Surat Basin, Tara region, Queensland). (222)Rn and CO2 concentrations were observed for 24 h within and outside the gas field. Both (222)Rn and CO2 concentrations followed a diurnal cycle with night time concentrations higher than day time concentrations. Average CO2 concentrations over the 24-h period ranged from ~390 ppm at the control site to ~467 ppm near the center of the gas field. A ~3 fold increase in maximum (222)Rn concentration was observed inside the gas field compared to outside of it. There was a significant relationship between maximum and average (222)Rn concentrations and the number of gas wells within a 3 km radius of the sampling sites (n = 5 stations; p gas field related to both point (well heads, pipelines, etc.) and diffuse soil sources. Radon may be useful in monitoring enhanced soil gas fluxes to the atmosphere due to changes in the geological structure associated with wells and hydraulic fracturing in CSG fields.

Structural evaluation of WIPP disposal room raised to clay seam G

International Nuclear Information System (INIS)

Park, Byoung Yoon; Holland, John F.

2007-01-01

An error was discovered in the ALGEBBRA script used to calculate the disturbed rock zone around the disposal room and the shear failure zone in the anhydrite layers in the original version. To correct the error, a memorandum of correction was submitted according to the Waste Isolation Pilot Plant (WIPP) Quality Assurance program. The recommended course of action was to correct the error, to repeat the post-process, and to rewrite Section 7.4, 7.5, 8, and Appendix B in the original report. The sections and appendix revised by the post-process using the corrected ALGEBRA scripts are provided in this revision. The original report summarizes a series of structural calculations that examine effects of raising the WIPP repository horizon from the original design level upward 2.43 meters. Calculations were then repeated for grid changes appropriate for the new horizon raised to Clay Seam G. Results are presented in three main areas: (1) Disposal room porosity, (2) Disturbed rock zone characteristics, and (3) Anhydrite marker bed failure. No change to the porosity surface for the compliance re-certification application is necessary to account for raising the repository horizon, because the new porosity surface is essentially identical. The disturbed rock zone evolution and devolution are charted in terms of a stress invariant criterion over the regulatory period. This model shows that the propagation of the DRZ into the surrounding rock salt does not penetrate through MB 139 in the case of both the original horizon and the raised room. Damaged salt would be expected to heal in nominally 150 years. The shear failure does not occur in either the upper or lower anhydrite layers at the moment of excavation, but appears above and below the middle of the pillar one day after the excavation. The damaged anhydrite is not expected to heal as the salt in the DRZ is expected to

Sequential simulation approach to modeling of multi-seam coal deposits with an application to the assessment of a Louisiana lignite

Science.gov (United States)

Olea, Ricardo A.; Luppens, James A.

2012-01-01

There are multiple ways to characterize uncertainty in the assessment of coal resources, but not all of them are equally satisfactory. Increasingly, the tendency is toward borrowing from the statistical tools developed in the last 50 years for the quantitative assessment of other mineral commodities. Here, we briefly review the most recent of such methods and formulate a procedure for the systematic assessment of multi-seam coal deposits taking into account several geological factors, such as fluctuations in thickness, erosion, oxidation, and bed boundaries. A lignite deposit explored in three stages is used for validating models based on comparing a first set of drill holes against data from infill and development drilling. Results were fully consistent with reality, providing a variety of maps, histograms, and scatterplots characterizing the deposit and associated uncertainty in the assessments. The geostatistical approach was particularly informative in providing a probability distribution modeling deposit wide uncertainty about total resources and a cumulative distribution of coal tonnage as a function of local uncertainty.

Hiawatha Aircraft Anti-Collision System, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — For Small Unmanned Aerial Vehicles (SUAVs), the FAA mandate to equip all aircraft with ADS-B Out transmitters by 1 January 2020 to support NextGen goals presents...

Hiawatha Aircraft Anti-Collision System, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — For SUAVs, the FAA mandate to equip all aircraft with ADS-B Out transmitters by 1 January 2020 to support NextGen goals presents both logistical and mission security...

Determining basic parameters of shafts with cage hoisting systems in mines with steep seams

Energy Technology Data Exchange (ETDEWEB)

Durov, E.M.

1982-05-01

This paper analyzes problems associated with increasing depth of mine shafts in operating coal mines. Schemes of shaft excavation in mines with steep coal seams are analyzed. Removal of mine rock and the ground surface by existing mine shafts is most economical in most cases. Yuzhgiproshakht has investigated a number of hoisting schemes during mine shaft excavation in order to select the optimum shaft diameter which permits shaft reconstruction and deepening to be optimized. The following conditions are analyzed: coal output of a coal mine ranges from 0.9 megatons (Mt) to 1.8 Mt/year, mining depth ranges from 600 m to 1600 m (with intermediary depth of 800, 1000, 1200 and 1400 m also considered). Separate hoisting of coal and rock waste is used. Shaft sinking rate ranges from 10 to 50 m/month. The following hoisting schemes are analyzed: two independent systems which consist of a cage with counterweight, three systems of a cage with counterweight, double cage system and a cage with counterweight. Hoisting schemes are shown in 9 diagrams. Investigations show that a 7 to 8 m diameter of mine shafts is most economic. In mine shafts 7 m in diameter equipped with two cages with counterweights one of the cages is removed to form a free space for the hoisting bucket. In the 8 m shaft equipped with a double cage system and a cage with counterweight the cage with counterweight is removed to form a free place for the hoisting bucket used during shaft excavation.

Prediction of mining conditions from bore core information: rock mechanics investigations in the Whybrow Seam at Wambo Colliery

Energy Technology Data Exchange (ETDEWEB)

Richmond, A.; Levers, R.; Smith, K.

1979-12-01

Rock mechanics investigations were conducted at Wambo Colliery as part of the series designed to study the stability of mining structures and obtain geomechanical properties. The roof and floor were drilled in order to obtain core for rock testing and samples of coal were collected to measure the coal properties. A successful overcoring of a CSIR strain cell was achieved to determine the absolute stress field. The core which was recovered was logged prior to laboratory testing to determine a C index (modified RQD index based on core fragmentation). This was used to estimate the in-situ strata properties from the laboratory results. The roof material was found to consist predominantly of a competent laminite. The Whybrow seam above the Cow Manure band had an average uniaxial strength of 26 MPa. The Cow Manure band was extremely weak with a strength of 1 MPa, while the coal below this band was much weaker than the upper section coal with a strength of 7 MPa. The floor strata was made up of competent carbonaceous siltstone and alternate bands of shale and sandstone. Finite element analyses indicate very stable roof, floor and rib, corresponding closely to the in-situ conditions.

Methane production from coal seams and CO2 uptake capability of the Mecsek mountain range, Hungary; Die Methangewinnung aus Kohlefloezen und das CO{sub 2}-Aufnahmevermoegen des Mecsek-Gebirges in Ungarn

Energy Technology Data Exchange (ETDEWEB)

Varga, Z.N. [Univ. Miskolc (Hungary); Lakatos, I. [Forschungsinstitut der angewandten Chemie (Hungary); Foeldessy, J.; Toth, J.; Fodor, B.; Csecsei, T. [Ungarischer Geologischer Dienst, Rotaqua KFT (Hungary)

2006-06-15

Methane from the Mecsek mountain range coal seams is of vast economic importance. Modified geological models focusing on zones of enhanced permeability may be useful in the development of practicable winning technologies. High gas volumes are assumed in stowed material, which may be recovered by a simple technology. There is a power station in the vicinity which produces waste gases that may be used for injection, so the Mecsek region offers promising conditions for CO2 CBM production. The same power plant is also a potential consumer of the recovered methane. (orig.)

Social licence, corporate social responsibility and coal seam gas: framing the new political dynamics of contestation

International Nuclear Information System (INIS)

Curran, Giorel

2017-01-01

This paper explores the contestation dynamics between the unconventional gas mining sector and its challengers through the prism of the social licence to operate. Social licence is a dominant narrative in the mining sector today and as a signifier of the sector's CSR credentials, the term is an influential one. Its capacity to confer project legitimacy, and hence avoid the risks of community opposition, helps explain why most companies seek to gain one. Today both gas proponents and opponents talk the language of social licence: the former to defend their projects, the latter to challenge them. Yet, beyond rhetoric, the precise meaning of social licence remains elusive. This paper uses a case study of community opposition to primarily coal seam gas projects in an eastern Australian region to explore how the absence of a precise meaning for social licence has created a strategic opportunity space for the industry's opponents to invest social licence with a potent democracy frame. This democracy framing has proved particularly effective as a contestation tool and helps explain the outcomes in this case. - Highlights: • Unconventional gas exploration and mining is becoming increasingly contested. • A key way of managing this contestation is through the social licence to operate. • Both proponents and opponents of gas mining use social licence strategically. • Social licence has become increasingly politicised. • A democratic frame assists the effectiveness of contestation.

Comparison analysis on permeability improved effect of single and multi section hydraulic fracturing in deep depth seam%深部煤层单段/多段水力压裂增透效果对比

Institute of Scientific and Technical Information of China (English)

张春华; 张勇志; 李江涛; 李腾达

2017-01-01

为对比深部煤层钻孔内单段和多段水力压裂增透效果,基于谢桥煤矿待揭8煤层赋存条件,分别建立了单段和多段水力压裂增透模型,运用RFPA2D-Flow软件,模拟分析了水力压裂影响区内煤层水压场、应力场、裂隙场和渗透场特征和规律,并进行了效果验证.结果表明:单段压裂起裂时的煤体孔隙水压为7 MPa,多段压裂起裂时的煤体孔隙水压为16 MPa;煤层起裂后,单段压裂时钻孔中部煤体产生了明显的应力集中,而多段压裂时煤体应力分布虽有起伏但无明显应力集中;单段压裂时裂隙主要在钻孔中部位置向顶底板萌发延伸,有效压裂面积较小,多段压裂时各压裂段均可产生类似的裂隙场,有效压裂面积大;单段压裂时煤体渗透系数最大可达初值的249倍,多段水力压裂时最大可达初值的263倍.与钻孔单段水力压裂工艺相比,多段水力压裂可有效提高钻孔瓦斯抽采效果.%In order to compare the permeability effects of a single section and multi section hvdraulic fracturing in the deep seam boreholes,based on the deposition conditions of the proposed opened No.8 seam in Xieqiao Mine,a single section and multi section hydraulic fracturing and permeability improved models were individually established.A RFPA2D-Flow software was applied to simulate and analyze the features and law of the in-seam water pressure field,stress field,crack field and permeability field within the hydraulic fracturing influence zone and the effect verifications were conducted.The results showed that the pore pressure in the coal mass at the initial fracturing of the single section fracturing was 7 MPa and the pore pressure of the coal mass at the initial fracturing of the multi section fracturing was 16 MPa.When the fracturing operation started in the seam,during the single section fracturing,there was an obvious stress concentration occurred in the borehole middle part of the seam.And when a multi

Source and Enrichment of Toxic Elements in Coal Seams around Mafic Intrusions: Constraints from Pyrites in the Yuandian Coal Mine in Anhui, Eastern China

Directory of Open Access Journals (Sweden)

Yanfei An

2018-04-01

Full Text Available Pyrite, a mineral that can cause potential environmental issues in coal mining, is commonly found in coal seams around intrusions. In this paper, pyrites from the Yuandian Coal Mine (Huaibei Coalfield, Anhui, Eastern China were studied using SEM, Raman and LA-ICP-MS. The pyrite morphologic and geochemical data suggest that (1 four pyrite generations are present (framboidal sedimentary pyrites (Py I in the original coal, coarse-grained magmatic pyrites (Py II in the intruding diabase, fine-grained metamorphic pyrites (Py III in the intrusive contact aureole, and spheroid/vein hydrothermal pyrites (Py IV in the cokeite; and (2 concentrations of cobalt, nickel, arsenic, selenium, lead and copper in the metamorphic pyrites are much higher than the other pyrite generations. We propose that mafic magmatism is the main contributor of the toxic elements to the intrusion-related cokeite at Yuandian.

Probabilistic assessment of the impact of coal seam gas development on groundwater: Surat Basin, Australia

Science.gov (United States)

Cui, Tao; Moore, Catherine; Raiber, Matthias

2018-05-01

Modelling cumulative impacts of basin-scale coal seam gas (CSG) extraction is challenging due to the long time frames and spatial extent over which impacts occur combined with the need to consider local-scale processes. The computational burden of such models limits the ability to undertake calibration and sensitivity and uncertainty analyses. A framework is presented that integrates recently developed methods and tools to address the computational burdens of an assessment of drawdown impacts associated with rapid CSG development in the Surat Basin, Australia. The null space Monte Carlo method combined with singular value decomposition (SVD)-assisted regularisation was used to analyse the uncertainty of simulated drawdown impacts. The study also describes how the computational burden of assessing local-scale impacts was mitigated by adopting a novel combination of a nested modelling framework which incorporated a model emulator of drawdown in dual-phase flow conditions, and a methodology for representing local faulting. This combination provides a mechanism to support more reliable estimates of regional CSG-related drawdown predictions. The study indicates that uncertainties associated with boundary conditions are reduced significantly when expressing differences between scenarios. The results are analysed and distilled to enable the easy identification of areas where the simulated maximum drawdown impacts could exceed trigger points associated with legislative `make good' requirements; trigger points require that either an adjustment in the development scheme or other measures are implemented to remediate the impact. This report contributes to the currently small body of work that describes modelling and uncertainty analyses of CSG extraction impacts on groundwater.

单一低透突出煤层底抽巷煤气共采技术及实践%Application and Practice of Coal-gas Co-extraction Technology by Floor Drainage Roadway in Single Low-permeability Outburst Seam

Institute of Scientific and Technical Information of China (English)

冀超辉

2015-01-01

To counter to the serious gas troubles and low mining efficiency present in a single low-permeability outburst coal seam, based on the analysis of the distribution of stress and permeability in the working face, a coal-gas co-extraction technology by floor drainage roadway in a single low-permeability outburst seam was proposed, that is: gas extraction by hydraulic flushing in hole in the original pressure area before mining, gas extraction in the stress reduced area during mining and the gas extraction from gob after mining. The application in Ligou Mine showed that three gas extraction methods can be coordinated and complemented each other, the outburst hazard in the working face was not only eliminated, but also the gas extraction volume increased, as a result, the safe and efficient mining of the single low-permeability outburst seam was realized.%针对单一低透突出煤层存在瓦斯灾害严重、开采效率低等问题，在分析回采工作面应力分布和渗透率分布的基础上，提出了单一低透突出煤层底抽巷煤气共采模式，即采前未卸压区水力冲孔抽采、采中影响区的应力降低区瓦斯抽采和采后的采空区瓦斯抽采模式。李沟煤矿的工程应用结果表明：3种抽采方法互相协调、互为补充，不但消除了工作面突出危险性，而且大大地增加了瓦斯抽采量，实现了单一低透突出煤层煤与瓦斯的安全高效开采。

Evaluation of a Compact Coaxial Underground Coal Gasification System Inside an Artificial Coal Seam

Directory of Open Access Journals (Sweden)

Fa-qiang Su

2018-04-01

Full Text Available The Underground Coal Gasification (UCG system is a clean technology for obtaining energy from coal. The coaxial UCG system is supposed to be compact and flexible in order to adapt to complicated geological conditions caused by the existence of faults and folds in the ground. In this study, the application of a coaxial UCG system with a horizontal well is discussed, by means of an ex situ model UCG experiment in a large-scale simulated coal seam with dimensions of 550 × 600 × 2740 mm. A horizontal well with a 45-mm diameter and a 2600-mm length was used as an injection/production well. During the experiment, changes in temperature field and product gas compositions were observed when changing the outlet position of the injection pipe. It was found that the UCG reactor is unstable and expands continuously due to fracturing activity caused by coal crack initiation and extension under the influence of thermal stress. Therefore, acoustic emission (AE is considered an effective tool to monitor fracturing activities and visualize the gasification zone of coal. The results gathered from monitoring of AEs agree with the measured data of temperatures; the source location of AE was detected around the region where temperature increased. The average calorific value of the produced gas was 6.85 MJ/Nm3, and the gasification efficiency, defined as the conversion efficiency of the gasified coal to syngas, was 65.43%, in the whole experimental process. The study results suggest that the recovered coal energy from a coaxial UCG system is comparable to that of a conventional UCG system. Therefore, a coaxial UCG system may be a feasible option to utilize abandoned underground coal resources without mining.

The age, palaeoclimate, palaeovegetation, coal seam architecture/mire types, paleodepositional environments and thermal maturity of syn-collision paralic coal from Mukah, Sarawak, Malaysia

Science.gov (United States)

Sia, Say-Gee; Abdullah, Wan Hasiah; Konjing, Zainey; Koraini, Ahmad Munif

2014-02-01

The Mukah coal accumulated in the Balingian Formation where the time-stratigraphic position is poorly defined by fauna, though a probable Late Miocene age has always been assigned to this formation. Samples collected in the present study that yielded an abundance of Casuarina pollen associated with occurrences of Dacrydium, Stenochlaena palustris, Florschuetzia levipoli and also Stenochlaena areolaris spores, compare closely to zone PR9 of the palynological zonation of the Malay Basin, and can be tied to depositional sequences of Malay Basin Seismic sequences I2000/I3000, indicating an Early Miocene age for the studied coal. The Early Miocene age shows that the Mukah coal was formed during the collision between Luconia Block-Dangerous Grounds with the Borneo that lasted from Late Eocene to late Early Miocene. The rapid increase of deposition base-level caused by the collision is clearly reflected by the architecture of the Mukah coal seams that were generally thin, and also by the reverse order of the paleo-peat bodies.

76 FR 19970 - Hiawatha East Resource Advisory Committee

Science.gov (United States)

2011-04-11

... and Community Self-Determination Act (Pub. L. 110-343) and in compliance with the Federal Advisory... chairperson by the committee members. (3) Receive materials explaining roles of the RAC and process for...

Research on comprehensive gas permeability improvement technology by hydraulic fracturing and slotting in coal seam with complex geological conditions and low permeability%复杂地质低渗煤层水力压裂-割缝综合瓦斯增透技术研究

Institute of Scientific and Technical Information of China (English)

贾同千; 饶孜; 何庆兵; 宋润权; 白鑫

2017-01-01

Aiming at the problem of gas drainage in the coal seam with complex geological conditions and low permeability in Baijiao Coal Mine,the hydraulic fracturing technology was applied to carry out the regional gas permeability improvement,and its application effect was analyzed according to the situation of field gas drainage.Aiming at the blind area of regional gas permeability improvement by hydraulic fracturing,the technical measure of localized gas permeability improvement by hydraulic slotting was put forward,then the comprehensive gas permeability improvement technology by hydraulic fracturing and slotting in coal seam with complex geological conditions and low permeability was formed,and the field verification was conducted.The results showed that the average pure flow rate of gas drainage for three fracturing boreholes in the hydraulic fracturing zone increased by 15.8 times than that of regular single borehole gas drainage in 238 floor laneway,and the gas drainage concentration increased by 4％.The pure flow rate of gas drainage in the fractured area increased by 2.1 times than that of the comparison zone,but there existed the blind area by the regional measures of hydraulic fracturing due to the restriction of geological conditions such as fault and coal seam hardness.The gas concentration of drainage borehole in the hydraulic slotting permeability improvement zone increased by 4.9 times on the average,and the pure flow rate of gas increased by 3.3 times on the average.It has strong adaptability to different geological conditions,but the influence range of slotting is small,and the drainage time is short.The comprehensive gas permeability improvement technology by hydraulic fracturing and slotting in coal seam with complex geological conditions and low permeability integrates the advantages of hydraulic fracturing and slotting,and it has strong adaptability to coal seam with complex geological conditions,which improves the gas control level greatly.The field

Geological Factors and Reservoir Properties Affecting the Gas Content of Coal Seams in the Gujiao Area, Northwest Qinshui Basin, China

Directory of Open Access Journals (Sweden)

Zhuo Zou

2018-04-01

Full Text Available Coalbed methane (CBM well drilling and logging data together with geological data were adopted to provide insights into controlling mechanism of gas content in major coal seams and establish gas accumulation models in the Gujiao area, Northwest Qinshui Basin, China. Gas content of targeted coals is various in the Gujiao area with their burial depth ranging from 295 to 859 m. Highly variable gas content of coals should be derived from the differences among tectonism, magmatism, hydrodynamism, and sedimentation. Gas content preserved in the Gujiao area is divided into two parts by the geological structure. Gas tends to accumulate in the groundwater stagnant zone with a total dissolved solids (TDS value of 1300–1700 ppm due to water pressure in the Gujiao area. Reservoir properties including moisture content, minerals, and pore structure also significantly result in gas content variability. Subsequently, the gray correlation statistic method was adopted to determine the most important factors controlling gas content. Coal metamorphism and geological structure had marked control on gas content for the targeted coals. Finally, the favorable CBM exploitation areas were comprehensively evaluated in the Gujiao area. The results showed that the most favorable CBM exploitation areas were in the mid-south part of the Gujiao area (Block I.

Numerical simulation of head top coal's stability control of fully mechanized longwall mining with sublevel caving face in large dip seam

Energy Technology Data Exchange (ETDEWEB)

Li, W.; Wan, Z.; Jiang, F.; Jia, P. [Beijing Science and Technology University, Beijing (China)

2008-07-01

Stability control of the head face's top-coal is one of the key techniques of realising high production and high efficiency in coal mining in fully mechanized top-coal caving face. The characteristics of the stress in the overlying strata of the fully mechanized top-coal caving face and the top coal were analysed using FLAC{sup 3D}. The results show that the tip-to-face top-coal generates a large deformation while it is in the stress-relaxed area. The top-coal in the front of the wall appears to be the failure area for the effect of the abutment pressure that spreads over the coal seam. The surrounding rock of the upper face end is the key part strengthened the control of the rib spalling. The first and frequent appearing phenomenon of losing stability of the powered supports is that the back base of the hydraulic power supports in the top of the face slips. Increasing the quality of support and so on can maintain the stability of surrounding rock. 4 refs., 7 figs., 1 tab.

FY 1998 basic survey for coal resource development. Data collection of the joint research of new technology in the geophysical exploration of coal resources (land area shallow seam survey); 1998 nendo sekitan shigen kaihatsu kiso chosa shiryoshu. Shintansa gijutsu chosa kaihatsu (rikuiki senso tansa)

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

This is a compilation of the data on the coal resource land area shallow seam survey conducted in FY 1998 as the basic survey for coal resource development. The trend survey was made from July 26 to August 6, 1998. The purposes of the survey are to study the image analysis method, examples of application of the reflection seismic survey to coal, and inversion technology. The data compilation includes the following: 1. Minutes of the proceedings of the FY 1998 Japan-Australia steering committee (in English). 2. Data/proceedings of the FY 1998 Japan-Australia technical study committee (in English). 3. Results of the GPS measurement of reflection seismic survey traverse lines in Caroona district. 4. List of parameters in the FY 1998 reflection seismic survey data processing. 5. Report on the work of inspection/repair of seismic pulse generator. 6. List of the data on diameter of the test boring conducted in FY 1998. 7. NEDO-DMR CAROONA DDH borehole core pictures. 8. Estimated curves. 9. Report on the trend survey of the FY 1998 coal resource development basic survey (land area shallow seam survey). 10. Pictures. 11. Data on the 1st (FY 1998) new exploration technology study committee. (NEDO)

Introduction to South African coal mining and exploration

CSIR Research Space (South Africa)

Jeffrey, L

2015-01-01

Full Text Available , such as is mined at the No. 2 Mine at Kriel Colliery9. Klip River The Bottom Seam in the Klip River Coalfield (equivalent to the Gus Seam) is high in sulphur & phosphorus, with sulphur usually ranging from 1.3% to 1.8%1, 10. The Top Seam (corresponding... to the Alfred Seam) has a smaller bright coal proportion than the Bottom Seam1, but like the Bottom Seam, the rank of the Top Seam ranges from bituminous to anthracitic with generally high sulphur & phosphorus content. In general, the Klip River Coalfield...

Development of basic engineering to investigate dust prevention methods in the mechanised winning of thin coal seams. Proyecto de desarrollo de la ingenieria basica para la investigacion de metodos de prevencion del pulvo en el arranque mecanizado de capas estrechas de carbon

Energy Technology Data Exchange (ETDEWEB)

Martinez Fidalgo, M; Alvarez Santullano, L; Eguidazu Pujades, J L; Gonzalez del Valle, S; Cordera Fernandez, J V; Arriba de la Iglesia, J.

1990-02-01

The article concerns research work carried out jointly by HUNOSA and the National Institute of Silicosis on dust prevention on mechanised faces where thin seams are cut by shearers with a drum diameter of less than 600 mm. Under these conditions, it is not possible to use the conventional dust suppression systems employed for high-output shearers with larger drum diameters where the large quantities of sprayed water are easily absorbed by the coal. 11 figs., 1 tab.

瓦斯抽放煤层增透深孔聚能爆破钻孔参数%Drilling parameters of deep-hole cumulative blasting to improve coal seam permeability in gas drainage

Institute of Scientific and Technical Information of China (English)

郭德勇; 吕鹏飞; 单智勇; 谢安

2013-01-01

以焦作煤业集团九里山矿煤层深孔聚能爆破试验为基础,利用数值模拟分析了爆破煤体应力变化规律,发现聚能爆破效应导致应力峰值增大,扩大了煤体裂隙区范围.同时对聚能爆破钻孔参数进行优化,确定了合理的炮孔直径、爆破孔间距、爆破孔与邻近抽放孔及煤层顶底板间距.现场试验结果表明:优化的钻孔参数不仅使聚能爆破增透效果显著而且保证了爆破过程的安全.%Based on coal seam deep-hole cumulative blasting experiments in Jiulishan Coal Mine of Jiaozuo Coal Group, the law of stress change in a blasting coal body was analyzed by numerical simulation. It is found that cumulative blasting effect leads to the increase of peak stress and enlarges the crack zone range of the coal body. Drilling parameters for cumulative blasting, such as blast hole diameter, blast hole spacing, distance between the blast hole and the adjacent gas drainage hole, and distance from the blast hole to the coal seam roof and floor, were determined by optimization. Field experimental results show that after using these optimized drilling parameters the cumulative blasting not only gets remarkable permeability increasing effect but also ensures blasting safety.

Synchronous separation, seaming, sealing and sterilization (S4) using brazing for sample containerization and planetary protection

Science.gov (United States)

Bar-Cohen, Yoseph; Badescu, Mircea; Sherrit, Stewart; Bao, Xiaoqi; Lindsey, Cameron; Kutzer, Thomas; Salazar, Eduardo

2018-03-01

The return of samples back to Earth in future missions would require protection of our planet from the risk of bringing uncontrolled biological materials back with the samples. This protection would require "breaking the chain of contact (BTC)", where any returned material reaching Earth for further analysis would have to be sealed inside a container with extremely high confidence. Therefore, the acquired samples would need to be contained while destroying any potential biological materials that may contaminate the external surface of the container. A novel process that could be used to contain returning samples has been developed and demonstrated in a quarter scale size. The process consists of brazing using non-contact induction heating that synchronously separates, seams, seals and sterilizes (S4) the container. The use of brazing involves melting at temperatures higher than 500°C and this level of heating assures sterilization of the exposed areas since all carbon bonds (namely, organic materials) are broken at this temperature. The mechanism consists of a double wall container with inner and outer shells having Earth-clean interior surfaces. The process consists of two-steps, Step-1: the double wall container halves are fabricated and brazed (equivalent to production on Earth); and Step-2 is the S4 process and it is the equivalent to the execution on-orbit around Mars. In a potential future mission, the double wall container would be split into two halves and prepared on Earth. The potential on-orbit execution would consist of inserting the orbiting sample (OS) container into one of the halves and then mated to the other half and brazed. The latest results of this effort will be described and discussed in this manuscript.

Fiscal 1998 overseas geological structure survey. Japan-China joint coal survey Mei-Xian project; 1998 nendo kaigai chishitsu kozo nado chosa hokokusho. Nippon Chugoku sekitan kyodo tansa Mei-Xian project

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

Japan-China joint coal survey was made through seismic prospecting by Japanese group and drilling prospecting by Chinese group. Mei-Xian mine property includes coal seams of the Jurassic period, and is covered with the quaternary period stratum without any coal seam. The base of the quaternary period stratum exists at depth of 50-400m, while the coal seams at depth of 300-700m. Among 11 existing seams, the 1st and 5th seams are main objects for prospecting. The 5th seam of 0.2-8.96m (2.95m in average) thick is the most expected important one, distributing all over the mine property. The 5th seam also has branch seams spreading over 2.5km from east to west and 1.2km from south to north in the center part of the mine property. The 1st seam of 0-8.62m (2.90m in average) thick is most thick in the south part of the mine property. The theoretical amount of coal deposits in the whole coal seam is estimated to be nearly 290,000,000t by Chinese group (nearly 50% of it in the 5th seam). That is also estimated to be nearly 346,000,000t by Japanese group (155,000,000t in the 5th seam). Both 1st and 5th seams are composed of sub-bituminous coal. (NEDO)

76 FR 16603 - Hiawatha West Resource Advisory Committee; Meeting

Science.gov (United States)

2011-03-24

... Schools and Community Self-Determination Act (Pub. L. 110- 343) and in compliance with the Federal... explaining roles of the RAC and process for considering and recommending Title II projects; and (4) Public...

Mineral composition of sediments underlying the Velenje lignite seam in the P-9k/92 borehole (Slovenia

Directory of Open Access Journals (Sweden)

Teja Čeru

2015-07-01

Full Text Available The paper presents the results of granulometrical, geochemical and mineralogical characterisation of sediments underlying the Velenje lignite seam as drilled through the P-9k/92 borehole in the central part of the Pliocene intermontane Velenje Basin. This study of differently lithified sediments/sedimentary rocks is based on analyses of 32 samples from 21 core intervals at the depth of 562.6–580.0 m (end of the borehole. Grain size was analysed on 12 samples, 24 samples were investigated geochemically, while mineral composition was obtained with X-ray diffraction (XRD on 23 samples, and optical microscopy was performed on 7 samples. Granulometry of very low lithified samples revealed that they are mostly clayey silts (>85 % of the silt fraction, only two are silty sands and one is pebbly/rubbly sandstone. Well-lithified clastics are all sandstones cemented by calcite, siderite and/or marcasite. Geochemical analysis indicated that most samples are SiO2 + Al2O3 rich (>60–80 %. Some sediments, mostly at the base of the profile, are enriched in Fe2O3 and inorganic C both indicating the presence of siderite. At the top of the profile, thin limestone and gravelly sandstone beds contain a high CaO content and have high loss on ignition (LOI. Qualitative XRD analysis and microscopy showed that all clastic sediments consist of quartz, kaolinite and muscovite/illite. Feldspars occur sporadically, mainly in sands and sandstones. Gypsum was found in some samples of siltstones. Pyrite occurs only in a sample of limestone at the top of the profile. Also marcasite was found only in one sample.

Report on the FY 1998 geological structure survey. North Hay Gulch area, State of Colorado, the U.S.; 1998 nendo kaigaitan kaihatsu kanosei chosa hojo jigyo chishitsu kozo chosa hokokusho. Beikoku Colorado shu North Hay Gulch chiiki

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-02-01

Test boring at 21 places and core sampling were conducted during September-November 1998 along the ridge to the west of Hay Gulch and in the direction crossing the northwest of the drainage canal and National King Coal Mine (NKC coal mine). It was found that A layer which NKC coal mine is now drilling is the upper part of A coal seam where the seam bifurcates. The boundary to the west of the thick A coal seam is not clear, and there is a possibility that more reserve from the thick coal seam and single seam exists toward Cherry Creek. In the existing coal drilling area, the lower A seam existing under the upper A seam becomes thin rapidly, and the seam thickness becomes less than 1 foot. The average thickness of thick coal seams is 9.9 feet, and the area is 780 acres along the ridge. The upper A coal seam except the above is 5.5 feet in average seam thickness and 910 acres in area. The reserve is 23 million tons. As to the quality of thick coal seam, the average heating value is 7,089 kcal/kg, sulfur content 0.68%, and ash content 7.50%. As coal drilling conditions, the same level as or higher than those of NKC coal mine is expected. (NEDO)

Dissolved radon and uranium in groundwater in a potential coal seam gas development region (Richmond River Catchment, Australia).

Science.gov (United States)

Atkins, Marnie L; Santos, Isaac R; Perkins, Anita; Maher, Damien T

2016-04-01

The extraction of unconventional gas resources such as shale and coal seam gas (CSG) is rapidly expanding globally and often prevents the opportunity for comprehensive baseline groundwater investigations prior to drilling. Unconventional gas extraction often targets geological layers with high naturally occurring radioactive materials (NORM) and extraction practices may possibly mobilise radionuclides into regional and local drinking water resources. Here, we establish baseline groundwater radon and uranium levels in shallow aquifers overlying a potential CSG target formation in the Richmond River Catchment, Australia. A total of 91 groundwater samples from six different geological units showed highly variable radon activities (0.14-20.33 Bq/L) and uranium levels (0.001-2.77 μg/L) which were well below the Australian Drinking Water Guideline values (radon; 100 Bq/L and uranium; 17 μg/L). Therefore, from a radon and uranium perspective, the regional groundwater does not pose health risks to consumers. Uranium could not explain the distribution of radon in groundwater. Relatively high radon activities (7.88 ± 0.83 Bq/L) in the fractured Lismore Basalt aquifer coincided with very low uranium concentrations (0.04 ± 0.02 μg/L). In the Quaternary Sediments aquifers, a positive correlation between U and HCO3(-) (r(2) = 0.49, p uranium was present as uranyl-carbonate complexes. Since NORM are often enriched in target geological formations containing unconventional gas, establishing radon and uranium concentrations in overlying aquifers comprises an important component of baseline groundwater investigations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Detecting content adaptive scaling of images for forensic applications

Science.gov (United States)

Fillion, Claude; Sharma, Gaurav

2010-01-01

Content-aware resizing methods have recently been developed, among which, seam-carving has achieved the most widespread use. Seam-carving's versatility enables deliberate object removal and benign image resizing, in which perceptually important content is preserved. Both types of modifications compromise the utility and validity of the modified images as evidence in legal and journalistic applications. It is therefore desirable that image forensic techniques detect the presence of seam-carving. In this paper we address detection of seam-carving for forensic purposes. As in other forensic applications, we pose the problem of seam-carving detection as the problem of classifying a test image in either of two classes: a) seam-carved or b) non-seam-carved. We adopt a pattern recognition approach in which a set of features is extracted from the test image and then a Support Vector Machine based classifier, trained over a set of images, is utilized to estimate which of the two classes the test image lies in. Based on our study of the seam-carving algorithm, we propose a set of intuitively motivated features for the detection of seam-carving. Our methodology for detection of seam-carving is then evaluated over a test database of images. We demonstrate that the proposed method provides the capability for detecting seam-carving with high accuracy. For images which have been reduced 30% by benign seam-carving, our method provides a classification accuracy of 91%.

FY 1997 basic survey for coal resource development. Data collection of the joint research of new technology in the geophysical exploration of coal resources (water area medium depth seam survey); 1997 nendo sekitan shigen kaihatsu kiso chosa shiryoshu. Shintansa gijutsu chosa kaihatsu (suiiki chushindoso tansa)

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

In 'the new exploration technology test on coal resource' (water area medium depth seam exploration) jointly conducted between Japan and China, tests have been carried out for 5 years on the BDR-5 test boring measurement monitoring system and the diamond bit which are items of the technology development of high resolution seismic survey system and high efficiency test boring system. As a result, the new technology test was successful, and technical economic effects were obtained. The situation of the test was summarized. The following data were compiled as shown in Data No.1-12. 1. The proceedings of the FY 1997 Japan-China steering committee (No.9). 2. Report on the survey of China verification field South Sihu water level situation. 3. The proceedings of the FY 1997 Japan-China steering committee (final). 4. Report on the FY 1997 reflection seismic exploration survey. 5. Report on the FY 1997 No.2 test boring survey. 6. Summarization of the test on 'the new exploration technology of coal source' conducted between Japan and China. 7. Report on the drilling data measurement. 8. Various sections of the reflection seismic survey data processing. 9. Traverse line chart. 10. T3 isochrone chart. 11. T3 depth structural chart. 12. Report on the new exploration technology survey development (water area medium depth seam exploration) geological model making. (NEDO)

Petrography, palynology, and paleoecology of the Lower Pennsylvanian Bon Air coal, Franklin County, Cumberland Plateau, southeast Tennessee

Energy Technology Data Exchange (ETDEWEB)

Shaver, Stephen A.; Saussy, Frederick L. [Department of Forestry and Geology, University of the South, Sewanee, TN 37383 (United States); Eble, Cortland F. [Kentucky Geological Survey, 228 MMRB, University of Kentucky, Lexington, KY 40506-0107 (United States); Hower, James C. [Center for Applied Energy Research, University of Kentucky, 2540 Research Park Drive, Lexington, KY 40511-8433 (United States)

2006-05-03

Stratigraphy, palynology, petrography, and geochemistry of the Bon Air coal from the Armfield, Dotson, Rutledge, and Shakerag mine sites of Franklin County, Tennessee suggest that Bon Air seams at all sites were small (=1.0 mile, 1.6 km), spatially distinct paleomires that evolved from planar to domed within the fluviodeltaic Lower Pennsylvanian Raccoon Mountain Formation. Of observed palynoflora, 88?97% are from lycopsids prevalent in the Westphalian. Densosporites palynomorphs of small lycopsids (e.g., Omphalophloios) dominate at the shale-hosted Armfield site, while Lycospora palynoflora of large arboreous lycopsids (especially Lepidodendron, with lesser Lepidophloios harcourtii and Lepidophloios hallii) dominate where intercalated siltstone/sandstone/shale hosts the coal (all other sites). Palynoflora of other lycopsids (Sigillaria and Paralycopodites), tree ferns, seed ferns, small ferns, calamites, and cordaites are generally minor. Genera of clastic-associated Paralycopodites are most common in Shakerag's coal (=10%), yet quite rare in Rutledge or Dotson coals. Overall, the palynomorph assemblages suggest that the Bon Air paleomires were forest swamps, and Early Pennsylvanian in age (Westphalian A, Langsettian). Dominant macerals at all sites are vitrinites, with fine collodetrinite (from strongly decomposed plant debris) more common than coarser collotelinite (from well-preserved plant fragments), and with lesser inertinites (fusinite and semifusinite) and liptinites (dominantly sporinite). Shakerag's coal has greatest abundance (mineral-matter-free) of collotelinite (up to 47%) and total vitrinite (74?79%) of any sites, but lowest liptinite (12?14.5%) and inertinite (7?11%). The Dotson and Rutledge seams contain moderate liptinite (21?23%) and highest inertinite (36?37%), lowest vitrinite (=41%), and lowest collotelinite (13?15%). Armfield's seam has relatively high liptinite (26?28%) and vitrinite (56.5?62%), but rather low inertinite (12

Forecast fire damp emission in thin, steep coal bed; Prevision de Desprendimiento de Grisu en Capas Estrechas e Inclindas

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-12-31

A model to forecast fire damp emission in thin, steep coal bed, mining in advance and backfill works, has been developed and validated. The model estimates the amount of methane released towards the works, including fire damp proceeding from the actually mined seam, as well as methane coming from adjacent seams layers, depending on easy-to find parameters. Methane coming from the mined seam is determined as a function of the methane concentration in the seam and methane from adjacent seams is assessed by the degassification degree. This parameter depends also on the distance to the mined seam. The influence volume of a thin, steep mined coal bed has been determined, in order to study which seams and layers release methane towards the works. The works to develop the methane emission model were done in a coal face on Maria seam, in San Antonio mine, belonging to HUNOSA. The validation works were carried out in 24 left south seam, in the belonging to Minas de Figaredo, S. A. (Author)

Coal plows in underground mines in Czechoslovakia

Energy Technology Data Exchange (ETDEWEB)

Vasek, J.; Klimek, M.

1980-05-01

This article discusses factors which influence the possibility of using coal plows for mining black coal seams in Czechoslovakia. Seams inclined at angles up to 40 degrees can be mined by plows. Another factor which influences plow work is ease of separating coal seam from the direct roof: the plow can be used in seams with good or average separation, and can not be used in seams with roofs difficult to separate from the seam. Quality of rocks surrounding the coal seam: If the stability of the roof is low and strength of rock is low and roof falls occur easily coal plows can not be used. From among three classes of rock in Czechoslovakia plows can be used only in the class characterized by the highest strength. Intense seam dislocations are one of the most important difficulties in using coal plows. Plows can be used if height of seam dislocations is not greater than 40% of the seam thickness. Further factors which influence the possibility of using coal plows (coal resistance to cutting, features of cutting elements of the plow, specific features of the plow mechanism etc.) are also discussed. A method for assessing advantages and disadvantages of using coal plows in given circumstances is presented. (10 refs.) (In Czech)

Geochemical Characteristics of Trace Elements in the No. 6 Coal Seam from the Chuancaogedan Mine, Jungar Coalfield, Inner Mongolia, China

Directory of Open Access Journals (Sweden)

Lin Xiao

2016-03-01

Full Text Available Fourteen samples of No. 6 coal seam were obtained from the Chuancaogedan Mine, Jungar Coalfield, Inner Mongolia, China. The samples were analyzed by optical microscopic observation, X-ray diffraction (XRD, scanning electron microscope equipped with an energy-dispersive X-ray spectrometer (SEM-EDS, inductively coupled plasma mass spectrometry (ICP-MS and X-ray fluorescence spectrometry (XRF methods. The minerals mainly consist of kaolinite, pyrite, quartz, and calcite. The results of XRF and ICP-MS analyses indicate that the No. 6 coals from Chuancaogedan Mine are higher in Al2O3, P2O5, Zn, Sr, Li, Ga, Zr, Gd, Hf, Pb, Th, and U contents, but have a lower SiO2/Al2O3 ratio, compared to common Chinese coals. The contents of Zn, Sr, Li, Ga, Zr, Gd, Hf, Pb, Th, and U are higher than those of world hard coals. The results of cluster analyses show that the most probable carrier of strontium in the coal is gorceixite; Lithium mainly occurs in clay minerals; gallium mainly occurs in inorganic association, including the clay minerals and diaspore; cadmium mainly occurs in sphalerite; and lead in the No. 6 coal may be associated with pyrite. Potentially valuable elements (e.g., Al, Li, and Ga might be recovered as byproducts from coal ash. Other harmful elements (e.g., P, Pb, and U may cause environmental impact during coal processing.

Silicified conifer forests and potential mining problems in seam M2 of the Gore Lignite Measures (Miocene), Southland, New Zealand

Energy Technology Data Exchange (ETDEWEB)

Lindqvist, J K; Isaac, M J [New Zealand Geological Survey, Dunedin (New Zealand). Dept. of Scientific and Industrial Research

1991-04-01

Silicified conifer ({ital Podocarpus cf. hallii}) stumps up to 0.8 m in diameter are present at two levels in seam M2 of the Miocene Gore Lignite Measures, Mataura Coalfield, eastern Southland. The in situ stumps are believed to be the remains of forests which grew during pauses in peat accumulation, when groundwater levels were depressed as a result of climatic change or local basinal processes. Growth-ring measurements show the trees increased in radius between 0.16 and 1 mm per year. In two of six specimens, the growth-rates halved during their final 30-40 years of life; rising water levels may have resulted in less favourable growth conditions. Within the stumps, much of the wood structure is well preserved. Progressive diagenesis involved impregnation of the cell walls by silica, infilling of the cell lumens with length-slow chalcedony and opaline silica, and deposition of opal, length-fast chalcedony, and minor siderite in fractures. Radial and axial parenchyma contain coalified organic material and minor chalcedony. Filaments of wood-rotting fungi and probable root masses of epiphytes are present in some fossil wood. However, by analogy with modern Podocarpus hallii, the stumps were probably preserved for later silicification because the wood was highly resistant to fungal and bacterial decay. The stumps presumably functioned as conduits to ascending silica-saturated meteoric groundwater and water released during compaction, because of the contrasts in permeability between the vertical stumps and the surrounding peat. 25 refs., 12 figs.

Case Studies of Rock Bursts Under Complicated Geological Conditions During Multi-seam Mining at a Depth of 800 m

Science.gov (United States)

Zhao, Tong-bin; Guo, Wei-yao; Tan, Yun-liang; Yin, Yan-chun; Cai, Lai-sheng; Pan, Jun-feng

2018-05-01

A serious rock burst ("4.19" event) occurred on 19 April 2016 in the No. 4 working face of the No. 10 coal seam in Da'anshan Coal Mine, Jingxi Coalfield. According to the China National Seismological Network, a 2.7 magnitude earthquake was simultaneously recorded in this area. The "4.19" event resulted in damage to the entire longwall face and two gateways that were 105 m in long. In addition, several precursor bursts and mine earthquakes had occurred between October 2014 and April 2016 in the two uphill roadways and the No. 4 working face. In this paper, the engineering geological characteristics and in situ stress field are provided, and then the rock burst distributions are introduced. Next, the temporal and spatial characteristics, geological and mining conditions, and other related essential information are reviewed in detail. The available evidence and possible explanations for the rock burst mechanisms are also presented and discussed. Based on the description and analysis of these bursts, a detailed classification system of rock burst mechanisms is established. According to the main causes and different disturbance stresses (i.e., high/low disturbance stresses and far-field/near-field high disturbance stresses), there are a total of nine types of rock bursts. Thus, some guidelines for controlling or mitigating different types of rock bursts are provided. These experiences and strategies not only provide an essential reference for understanding the different rock burst mechanisms, but also build a critical foundation for selecting mitigation measures and optimizing the related technical parameters during mining or tunnelling under similar conditions.

Similar Simulation Test on Permeability Evolution of Floor During Upper Protective Layer Mining in "Three Soft" Coal Seam%“三软”煤层上保护层开采底板围岩透气性演化相似试验研究

Institute of Scientific and Technical Information of China (English)

撒占友; 李磊; 卢守青; 刘杰; 张辉

2017-01-01

In order to investigate the permeability evolution law of floor surrounding rock in "three soft" coal seam of high stress zone during the upper protective seam mining,taking the protective seam mining in Ji15-23130 working face of Henan Pingdingshan No.4 mine as the research object,similar experiments are carried out.The results show that the closer distance of the protective layers are,the larger displacement of the bottom is,the higher peak value of the stress curve is,and the smaller the minimum value is,the higher the permeability coefficient is.The permeability coefficient of floor in upper protective layer mining process has successively experienced three stages,they are "slow down-increase dramatically-slow down again",and there is little difference in the improvement of permeability coefficient at different positions of the same layer.The test also shows that the abrupt change and pressure relief in the process of upper protection layer mining is the important reason for the abnormal gas emission in the mining face.%为了探讨高应力区“三软”煤层上保护层开采底板围岩透气性演化规律,以河南平顶山四矿己15-23130工作面作上保护层煤层开采为研究对象,进行相似试验研究.结果表明,距保护层越近,底板位移量越大,应力曲线峰值越高,极小值越小,透气性系数提升越显著;底板透气性系数在上保护层开采过程中依次经历“缓慢下降-大幅提高-再次缓慢降低”3个阶段,同一层位不同水平位置底板透气性系数提高程度差别不大;上保护层开采过程中底板压力陡变卸压是导致工作面瓦斯异常涌出的重要原因.

Depositional setting, petrology and chemistry of Permian coals from the Parana Basin: 2. South Santa Catarina Coalfield, Brazil

Energy Technology Data Exchange (ETDEWEB)

Kalkreuth, W.; Mexias, A.; Balbinot, M.; Levandowski, J. [Instituto de Geociencias, UFRGS, Porto Alegre (Brazil); Holz, M. [Inst. de Geociencias, UFBA, Salvador, Bahia (Brazil); Willett, J.; Finkelman, R. [U.S. Geological Survey, Reston, VA (United States); Burger, H. [Freie Universitaet Berlin, Geoinformatik, (Germany)

2010-12-01

In Brazil economically important coal deposits occur in the southern part of the Parana Basin, where coal seams occur in the Permian Rio Bonito Formation, with major coal development in the states of Rio Grande de Sul and Santa Catarina. The current paper presents results on sequence stratigraphic interpretation of the coal-bearing strata, and petrological and geochemical coal seam characterization from the South Santa Catarina Coalfield, Parana Basin. In terms of sequence stratigraphic interpretation the precursor mires of the Santa Catarina coal seams formed in an estuarine-barrier shoreface depositional environment, with major peat accumulation in a high stand systems tract (Pre-Bonito and Bonito seams), a lowstand systems tract (Ponta Alta seam, seam A, seam B) and a transgressive systems tract (Irapua, Barro Branco and Treviso seams). Seam thicknesses range from 1.70 to 2.39 m, but high proportions of impure coal (coaly shale and shaley coal), carbonaceous shale and partings reduce the net coal thickness significantly. Coal lithoypes are variable, with banded coal predominant in the Barro Branco seam, and banded dull and dull coal predominantly in Bonito and Irapua seams, respectively. Results from petrographic analyses indicate a vitrinite reflectance range from 0.76 to 1.63 %Rrandom (HVB A to LVB coal). Maceral group distribution varies significantly, with the Barro Branco seam having the highest vitrinite content (mean 67.5 vol%), whereas the Irapua seam has the highest inertinite content (33.8 vol%). Liptinite mean values range from 7.8 vol% (Barro Branco seam) to 22.5 vol% (Irapua seam). Results from proximate analyses indicate for the three seams high ash yields (50.2 - 64.2 wt.%). Considering the International Classification of in-Seam Coals, all samples are in fact classified as carbonaceous rocks (> 50 wt.% ash). Sulfur contents range from 3.4 to 7.7 wt.%, of which the major part occurs as pyritic sulfur. Results of X-ray diffraction indicate the

Report on the FY 1993 basic survey for industrialization related to the survey of overseas geological structure (Muara Lakitan area, Indonesia). Tables and drawings; 1993 nendo kaigai chishitsu kozo nado chosa ni kakawaru kigyoka kiso chosa hokokusho (Indonesia Muara Lankin chiku). Hyo oyobi zumen

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-03-01

These are tables and drawings for the FY 1993 basic survey for the coal mine development/industrialization in the Muara Lakitan area of Indonesia. The geological structure in the survey area is under six sets of the anticline/syncline structure which have an NW-SE axis of fold, and exposes the Muaraenim seam repeatedly. The theoretical coal reserve in the depth down to 200m of each of the seams, Nos. 1, 2, 5, 12 and 13, which are great in coal seam change and exist relatively stably, is 143 million tons. The depth for adoption of the shovel/truck system open pit mining seems to be 50m or shallower, and the production is to be approximately 70 million tons. The coal is classified into a subbituminous coal-brown coal rank of the JIS classification. As tables, included were a table of the calculation of coal amount by seam and a table of the analytical result of coal by seam. As drawings, included were borehole logs of coal seam by boring, diagrams of thickness by seam such as the seam thickness/diagrams of thickness by seam such as the coal thickness, diagrams of range of calculating the coal amount, etc. Besides, in relation to coal properties, the report included value diagrams by seam of the inherent moisture, the ash, the volatile matter, the fixed carbon, the heating value, and the total sulfur content. (NEDO)

Multiscale Characterization and Quantification of Arsenic Mobilization and Attenuation During Injection of Treated Coal Seam Gas Coproduced Water into Deep Aquifers

Science.gov (United States)

Rathi, Bhasker; Siade, Adam J.; Donn, Michael J.; Helm, Lauren; Morris, Ryan; Davis, James A.; Berg, Michael; Prommer, Henning

2017-12-01

Coal seam gas production involves generation and management of large amounts of co-produced water. One of the most suitable methods of management is injection into deep aquifers. Field injection trials may be used to support the predictions of anticipated hydrological and geochemical impacts of injection. The present work employs reactive transport modeling (RTM) for a comprehensive analysis of data collected from a trial where arsenic mobilization was observed. Arsenic sorption behavior was studied through laboratory experiments, accompanied by the development of a surface complexation model (SCM). A field-scale RTM that incorporated the laboratory-derived SCM was used to simulate the data collected during the field injection trial and then to predict the long-term fate of arsenic. We propose a new practical procedure which integrates laboratory and field-scale models using a Monte Carlo type uncertainty analysis and alleviates a significant proportion of the computational effort required for predictive uncertainty quantification. The results illustrate that both arsenic desorption under alkaline conditions and pyrite oxidation have likely contributed to the arsenic mobilization that was observed during the field trial. The predictive simulations show that arsenic concentrations would likely remain very low if the potential for pyrite oxidation is minimized through complete deoxygenation of the injectant. The proposed modeling and predictive uncertainty quantification method can be implemented for a wide range of groundwater studies that investigate the risks of metal(loid) or radionuclide contamination.

Is Increasing Coal Seam Gas Well Development Activity Associated with Increasing Hospitalisation Rates in Queensland, Australia? An Exploratory Analysis 1995-2011.

Science.gov (United States)

Werner, Angela K; Cameron, Cate M; Watt, Kerrianne; Vink, Sue; Jagals, Paul; Page, Andrew

2017-05-18

The majority of Australia's coal seam gas (CSG) reserves are in Queensland, where the industry has expanded rapidly in recent years. Despite concerns, health data have not been examined alongside CSG development. This study examined hospitalisation rates as a function of CSG development activity in Queensland, during the period 1995-2011. Admissions data were examined with CSG well numbers, which served as a proxy for CSG development activity. Time series models were used to assess changes in hospitalisation rates for periods of "low", "medium", "high", and "intense" activity compared to a period of "very low" activity, adjusting for covariates. "All-cause" hospitalisation rates increased monotonically with increasing gas well development activity in females (324.0 to 390.3 per 1000 persons) and males (294.2 to 335.4 per 1000 persons). Hospitalisation rates for "Blood/immune" conditions generally increased for both sexes. Female and male hospitalisation rates for "Circulatory" conditions decreased with increasing CSG activity. Hospitalisation rates were generally low for reproductive and birth outcomes; no clear associations were observed. This study showed some outcomes were associated with increasing CSG development activity. However, as a condition of data access, the population and outcomes were aggregated to a broad geographic study area rather than using higher geographic resolution data. Higher resolution data, as well as other data sources, should be explored. Further research should be conducted with an expanded time period to determine if these trends continue as the industry grows.

Taxonomically-linked growth phenotypes during arsenic stress among arsenic resistant bacteria isolated from soils overlying the Centralia coal seam fire.

Science.gov (United States)

Dunivin, Taylor K; Miller, Justine; Shade, Ashley

2018-01-01

Arsenic (As), a toxic element, has impacted life since early Earth. Thus, microorganisms have evolved many As resistance and tolerance mechanisms to improve their survival outcomes given As exposure. We isolated As resistant bacteria from Centralia, PA, the site of an underground coal seam fire that has been burning since 1962. From a 57.4°C soil collected from a vent above the fire, we isolated 25 unique aerobic As resistant bacterial strains spanning seven genera. We examined their diversity, resistance gene content, transformation abilities, inhibitory concentrations, and growth phenotypes. Although As concentrations were low at the time of soil collection (2.58 ppm), isolates had high minimum inhibitory concentrations (MICs) of arsenate and arsenite (>300 mM and 20 mM respectively), and most isolates were capable of arsenate reduction. We screened isolates (PCR and sequencing) using 12 published primer sets for six As resistance genes (AsRGs). Genes encoding arsenate reductase (arsC) and arsenite efflux pumps (arsB, ACR3(2)) were present, and phylogenetic incongruence between 16S rRNA genes and AsRGs provided evidence for horizontal gene transfer. A detailed investigation of differences in isolate growth phenotypes across As concentrations (lag time to exponential growth, maximum growth rate, and maximum OD590) showed a relationship with taxonomy, providing information that could help to predict an isolate's performance given As exposure in situ. Our results suggest that microbiological management and remediation of environmental As could be informed by taxonomically-linked As tolerance, potential for resistance gene transferability, and the rare biosphere.

Liquefaction of Warukin Formation Coal, Barito Basin, South Kalimantan on Low Pressure and Low Temperature

Directory of Open Access Journals (Sweden)

Edy Nursanto

2013-06-01

Full Text Available Research focusing on the quality of coal in Warukin Formation has been conducted in coal outcrops located on Tabalong area, particularly in 3 coal seams, namely Wara 120 which consists of low rank coal (lignite. Meanwhile, coals in seam Tutupan 210 and Paringin 712 are medium rank coal (sub-bituminous. Coal liquefaction is conducted in an autoclave on low pressure and temperature. Pressure during the process is 14 psi and temperature is 120oC. Catalyst used are alumina, hydrogen donor NaOH and water solvent. Liquefaction is conducted in three times variables of 30 minutes, 60 minutes and 90 minutes. This process shows following yield : Wara seam 120: 25.37% - 51.27%; Tutupan seam 210: 3.02%-15.45% and seam Paringin 712:1.99%-11.95%. The average result of yield shows that coals in seam Wara has higher yield conversion than coals in seam Tutupan and Paringin.

Non-mine technology of hydrocarbon resources production at complex development of gas and coal deposits

International Nuclear Information System (INIS)

Saginov, A.S.; Adilov, K.N.; Akhmetbekov, Sh.U.

1997-01-01

Non-mine technology of coal gas seams exploitation is new geological technological method of complex exploitation of coal gas deposits. The method allows sequentially to extract hydrocarbon resources in technological aggregative-mobile condensed states. According to natural methane content in seams the technology includes: methane extraction from sorption volume where it is bounded up with coal; gas output intensification of coal is due to structural changes of substance at the cost of physico-chemical treatment of seam; increase of seam permeability by the methods of active physical and physico-chemical actions on coal seam (hydro-uncovering, pneumatic hydro action etc.). Pilot testing shows efficiency of well mastering with help of depth pumps. In this case works of action of pumping out of operating liquid and gas extraction from coal seam are integrated

Pillar size optimization design of isolated island panel gob-side entry driving in deep inclined coal seam—case study of Pingmei No. 6 coal seam

Science.gov (United States)

Zhang, Shuai; Wang, Xufeng; Fan, Gangwei; Zhang, Dongsheng; Jianbin, Cui

2018-06-01

There is a perception that deep roadways are difficult to maintain. To reverse this and to improve the recovery rate of coal resources, gob-side entry driving is widely used in coal mines, especially deep-mining coal mines, in China. Determination of the reasonable pillar size through in situ observation and experimentation plays a vital role for roadway maintenance. Based on the geological conditions of Pingmei No.6 coal seam, a theoretical analysis, numerical simulation, and industrial experiments are carried out to calculate the reasonable width of chain pillars, analyze the lateral support stress distribution law near the gob side, investigate the relationship between the coal pillar stress distribution, roadway surrounding rock stress distribution, roadway surrounding rock deformation and the coal pillar width. The results indicate that 5 m wide coal pillars can ensure that the chain pillars are at a lower stress level and the deformation of roadway surrounding rock is in a more reasonable range. Industrial experiments show that when the chain pillar width is 5 m, the deformation of roadway surrounding rock can meet the requirements of working face safe production. The numerical results agreed well with field measurement and observations, and the industrial experiments results further validated the results of the numerical simulation.

FY 1999 report on the survey of the overseas geological structure, etc. Japan-Indonesia joint Tanjung Enim coal exploration project; 1999 nendo kaigai chishitsu kozo nado chosa hokokusho. Nippon Indonesia sekitan kyodo tansa Tanjung Enim project

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

The paper summed up the FY 1999 results of the survey conducted based on the agreement on the Tanjung Enim IV coal exploration project which was concluded between NEDO and Indonesia's Ministry of Mining Energy. The survey was made for an area of approximately 40km{sup 2} which is a north block of the south Arahan region, Tanjung Enim, South Sumatra, Indonesia. To grasp the succession of strata/rock facies/geological structure and the state of existence of the coal seams to be drilled, surveys were conducted on ground surface and boreholes. A total of 10 holes was test-drilled, and all the boreholes were physically logged. As a result of the survey, each of A1, A2, B, C and E coal seams was confirmed as main seams. A1, A2 and B seams are low in ash and sulfur contents with heating values of approximately 4,800 kcal/kg, C seam is high in sulfur content, and E seam is high in heating value, 6,000 kcal/kg. As coal seams for open pit mining, existence of A, B and C seams is expected which lay in the shallow part from ground surface to sea level of 0m and in the range of depth of approximately 100m. The proved coal reserves of these coals were estimated at 189 million tons. (NEDO)

Mechanization of operations in underground workings in coal mines and research project trends. [Poland

Energy Technology Data Exchange (ETDEWEB)

Reich, K; Skoczynski, W; Sikora, W

1985-01-01

Structure of black coal reserves of Poland, imported and Polish made equipment for underground mining, prospects for mechanization of selected operations in underground mines and research programs of the KOMAG Center for Mechanization of Mining are evaluated. Prospects for longwall mining with caving or stowing in thick coal seams (slice mining), thin (0.8 to 1.2 m), level or inclined coal seams and steep seams are analyzed. The following equipment for mechanization of underground mining is evaluated: integrated face systems, shearer loaders, chain conveyors, belt conveyors, coal plows, equipment for mine drivage, hoists, drive systems for mining equipment. The following research programs of the KOMAG Center are reviewed: modernization of face systems for coal seams with uncomplicated mining conditions, development of equipment for thin seam mining, development of types of mining equipment for coal seams from 1.5 to 3.0 m thick with dip angles to 25 degrees, modernization of equipment for thick seam mining, increasing efficiency of mine drivage (new types of heading machines, materials handling equipment for mine drivage), mechanization of auxiliary operations in underground coal mines, improving quality of mining equipment, development of equipment for coal preparation, increasing occupational safety in underground mining.

System of the creation of a model for the coal deposit, and the subsequent

Directory of Open Access Journals (Sweden)

Staněk František

1996-09-01

Full Text Available In the paper, methodics of creating a model for different type of the coal deposit is described, including the processing of reserves text and graphic outputs. It is also useful in cases of the deposit with a great number of seams of various thicknesses that is heavily tectonically disturbed and divided into tectonic blocks. The development of seams is variable in both the thickness and quality. Splitting of the seams occurs, separate benches are formed and, on the contrary, connected into one seam.

Cell fate determination in the Caenorhabditis elegans epidermal lineages

NARCIS (Netherlands)

Soete, G.A.J.

2007-01-01

The starting point for this work was to use the hypodermal seam of C. elegans as a model system to study cell fate determination. Even though the seam is a relatively simple developmental system, the mechanisms that control cell fate determination in the seam lineages are connected in a highly

Control of firedamp emission (Report on ECSC contract 6220-04/2/042)

Energy Technology Data Exchange (ETDEWEB)

Boxho, J [INIEX; Degueldre, G [Institut d' Hygiene des Mines

1977-01-01

The effects of remote pre-infusion of water into coal seams to reduce gas drainage is discussed. Its effects on overall gas emission are less easy to demonstrate as it can only affect the drainage of the seam being worked (10 to 20% of overall emission) and the variable parameters of the seam being infused can distort the effect of infusion. It would be possible to increase the effect of remote pre-infusion by subjecting adjacent seams to the same process. It is better to apply the method to an entire district so that the water can escape into former workings. Remote pre-infusion is a very good means of dust control and it renders the seam more accessible to ploughing by helping the cleavages to open up. (In French)

Effects of increased rock strata stresses on coal gettability

Energy Technology Data Exchange (ETDEWEB)

Sikora, W; Skoczynski, W [Politechnika Slaska, Gliwice (Poland). Instytut Mechanizacji Gornictwa

1988-01-01

Analyzes effects of rock strata pressure on a coal seam, its cracking and on energy consumption of coal cutting by shearer loaders and coal plows. Effects of mining depth on stresses in a coal seam rib side were analyzed using formulae developed by Budryk, Chudek and Borecki. Formulae used for selecting optimum yield strength of powered supports at working faces are reviewed. Four types of spontaneous separation of coal seam blocks caused by rock strata stresses are evaluated: layers parallel to the face with constant thickness, coal blocks with thickness decreasing in the direction of the floor or roof (blocks with a planar triangle cross-cut), blocks situated in the seam layer adjacent to the floor or roof. Causes of each type of coal seam separation are analyzed. 9 refs.

Characterization of coals from the Ravenscrag Formation, southern Saskatchewan, Canada

Energy Technology Data Exchange (ETDEWEB)

McDougall, W.J. (University of Regina, Regina, SK (Canada). Faculty of Science)

1989-10-30

Samples of economically important lignite reserves in the Ravenscrag Formation (Paleocene) of southern Saskatchewan are characterized by lithotype, maceral, microlithotype, and chemical analysis. The samples are from two cores and five reverse circulation drill boreholes from the Hart seam, Willow Bunch coalfield. Samples from four reverse circulation boreholes from the Souris seam, Estevan coalfield are characterized by maceral and chemical analysis. Coals from the Hart and Souris seams differ in rank, because of different thermal histories. A microlithotype classification developed for low rank coals is presented for Hart seam coals. 74 refs., 35 figs., 12 tabs.

Analysis on the Initial Cracking Parameters of Cross-Measure Hydraulic Fracture in Underground Coal Mines

Directory of Open Access Journals (Sweden)

Yiyu Lu

2015-07-01

Full Text Available Initial cracking pressure and locations are important parameters in conducting cross-measure hydraulic fracturing to enhance coal seam permeability in underground coalmines, which are significantly influenced by in-situ stress and occurrence of coal seam. In this study, stress state around cross-measure fracturing boreholes was analyzed using in-situ stress coordinate transformation, then a mathematical model was developed to evaluate initial cracking parameters of borehole assuming the maximum tensile stress criterion. Subsequently, the influences of in-situ stress and occurrence of coal seams on initial cracking pressure and locations in underground coalmines were analyzed using the proposed model. Finally, the proposed model was verified with field test data. The results suggest that the initial cracking pressure increases with the depth cover and coal seam dip angle. However, it decreases with the increase in azimuth of major principle stress. The results also indicate that the initial cracking locations concentrated in the second and fourth quadrant in polar coordinate, and shifted direction to the strike of coal seam as coal seam dip angle and azimuth of maximum principle stress increase. Field investigation revealed consistent rule with the developed model that the initial cracking pressure increases with the coal seam dip angle. Therefore, the proposed mathematical model provides theoretical insight to analyze the initial cracking parameters during cross-measure hydraulic fracturing for underground coalmines.

Microstructure evolution of Al/Mg butt joints welded by gas tungsten arc with Zn filler metal

International Nuclear Information System (INIS)

Liu Fei; Zhang Zhaodong; Liu Liming

2012-01-01

Based on the idea of alloying welding seam, Gas tungsten arc welding method with pure Zn filler metal was chosen to join Mg alloy and Al alloy. The microstructures, phases, element distribution and fracture morphology of welding seams were examined. The results indicate that there was a transitional zone in the width of 80–100 μm between the Mg alloy substrate and fusion zone. The fusion zone was mainly composed of MgZn 2 , Zn-based solid solution and Al-based solid solution. The welding seam presented distinct morphology in different location owning to the quite high cooling rate of the molten pool. The addition of Zn metal could prevent the formation of Mg–Al intermetallics and form the alloyed welding seam during welding. Therefore, the tensile strengths of joints have been significantly improved compared with those of gas tungsten arc welded joints without Zn metal added. Highlights: ► Mg alloy AZ31B and Al alloy 6061 are welded successfully. ► Zinc wire is employed as a filler metal to form the alloyed welding seam. ► An alloyed welding seam is benefit for improving of the joint tensile strength.

FY 1999 Report on overseas geological structure surveys. Joint Japan-China Yu Xian exploitation project; 1999 nendo kaigai chishitsu kozo nado chosa hokokusho. Nippon Chugoku sekitan kyodo tansa Yu Xian project

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

This project is based on the (agreement of the joint exploitation project for Yu Xian block in Yu Xian coal mine, Province of Hepei by Japan's NEDO and China's Coal Geological Bureau), signed on October 4, 1996. The joint project mainly comprises seismic exploitation and test drilling, Japan being mainly responsible for the former and China for the latter. The final report will be drawn jointly for the geological survey results necessary for designing coal mines. The Yu Xian block contains the Jurassic coal seams, which are covered by the Quaternary bed and not exposed to the surface. The Quaternary bed base is 50 to 400 m deep from the surface, and coal seams are 300 to 700 m deep also from the surface. A total of 11 coal seams are located in the Xiahuayuan strata as the coal-bearing strata. The first and fifth seams are most promising ones. In particular, the fifth seam is thick (0.2 to 6.91 m thick) and distributed throughout the block. It is estimated that 8 coal seams have a total coal quantity of approximately 346 million tons. (NEDO)

Data base for the analysis of compositional characteristics of coal seams and macerals. Final report - Part 10. Variability in the inorganic content of United States' coals: a multivariate statistical study

Energy Technology Data Exchange (ETDEWEB)

Glick, D.C.; Davis, A.

1984-07-01

The multivariate statistical techniques of correlation coefficients, factor analysis, and cluster analysis, implemented by computer programs, can be used to process a large data set and produce a summary of relationships between variables and between samples. These techniques were used to find relationships for data on the inorganic constituents of US coals. Three hundred thirty-five whole-seam channel samples from six US coal provinces were analyzed for inorganic variables. After consideration of the attributes of data expressed on ash basis and whole-coal basis, it was decided to perform complete statistical analyses on both data sets. Thirty variables expressed on whole-coal basis and twenty-six variables expressed on ash basis were used. For each inorganic variable, a frequency distribution histogram and a set of summary statistics was produced. These were subdivided to reveal the manner in which concentrations of inorganic constituents vary between coal provinces and between coal regions. Data collected on 124 samples from three stratigraphic groups (Pottsville, Monongahela, Allegheny) in the Appalachian region were studied using analysis of variance to determine degree of variability between stratigraphic levels. Most variables showed differences in mean values between the three groups. 193 references, 71 figures, 54 tables.

The influence of macroscopic texture on biogenically-derived coalbed methane, Huntly coalfield, New Zealand

Energy Technology Data Exchange (ETDEWEB)

Mares, Tennille E. [Department of Geological Sciences, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Moore, Tim A. [Department of Geological Sciences, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Solid Energy NZ Ltd., P.O. Box 1303, Christchurch (New Zealand)

2008-10-02

Secondary biogenic gas content can be related to textural characteristics in Eocene age subbituminous coals from the Huntly coalfield, New Zealand. However, the relationships between the two major coal seams in the basin are considerably different despite their close stratigraphic proximity (less than 25 m). In this study, 163 coal samples were collected and desorbed from eight drill holes. Gas adsorption capacity and proximate analyses were conducted as well as macroscopic logging for coal type and vitrain banding characteristics. Vitrain bands were quantitatively point counted and the longest dimension of the shortest axis measured. Three coal types were recognized: bright luster non-banded, bright moderately banded and bright highly banded. Vitrain band thickness, converted to the phi (- log{sub 2}) scale, was found to increase across the coal types with the thickest bands being associated with the most banded coal type. Overall, when normalized by seam and location, the dataset reveals a relationship between coal type and gas content with the non-banded coal type having the highest gas contents and conversely, the coal types with the most vitrain bands having the lowest gas contents. However, when the seams are considered separately, it can be seen that in the stratigraphically higher Renown coal seam, gas has an indirect association with increasing band thickness, in agreement with the overall trend, while the stratigraphically lower Kupakupa coal seam appears to have a direct relationship. Interestingly the Renown seam, which has a greater percentage of non-banded material, generally has a greater methane adsorption capacity as well as a greater gas content compared to the Kupakupa seam. It is believed these differences are related to macroscopic texture and that the differing proportions of the coal types between the two seams has a fundamental effect on microporosity, ultimately controlling the available surface area for gas adsorption. (author)

Study on robot motion control for intelligent welding processes based on the laser tracking sensor

Science.gov (United States)

Zhang, Bin; Wang, Qian; Tang, Chen; Wang, Ju

2017-06-01

A robot motion control method is presented for intelligent welding processes of complex spatial free-form curve seams based on the laser tracking sensor. First, calculate the tip position of the welding torch according to the velocity of the torch and the seam trajectory detected by the sensor. Then, search the optimal pose of the torch under constraints using genetic algorithms. As a result, the intersection point of the weld seam and the laser plane of the sensor is within the detectable range of the sensor. Meanwhile, the angle between the axis of the welding torch and the tangent of the weld seam meets the requirements. The feasibility of the control method is proved by simulation.

Refinement of Out of Circularity and Thickness Measurements of a Cylinder for Finite Element Analysis

Science.gov (United States)

2016-09-01

refined finite element model. Note that the longitudinal seam weld at θ = 0° (= 360°) runs along the green area and through the centre of the red...Longitudinal seam weld is a theta = 0/360 deg UNCLASSIFIED DST-Group-TN-1521 UNCLASSIFIED 7 Figure 2. Example of thickness distribution in the... weld seam at 0° is clearly evident. Inspection of similar graphs for all sections indicates similarly good comparison between the measured and

A Comparison between Model Base Hardconstrain, Bandlimited, and Sparse-Spike Seismic Inversion: New Insights for CBM Reservoir Modelling on Muara Enim Formation, South Sumatra

Science.gov (United States)

Mohamad Noor, Faris; Adipta, Agra

2018-03-01

Coal Bed Methane (CBM) as a newly developed resource in Indonesia is one of the alternatives to relieve Indonesia’s dependencies on conventional energies. Coal resource of Muara Enim Formation is known as one of the prolific reservoirs in South Sumatra Basin. Seismic inversion and well analysis are done to determine the coal seam characteristics of Muara Enim Formation. This research uses three inversion methods, which are: model base hard- constrain, bandlimited, and sparse-spike inversion. Each type of seismic inversion has its own advantages to display the coal seam and its characteristic. Interpretation result from the analysis data shows that the Muara Enim coal seam has 20 (API) gamma ray value, 1 (gr/cc) – 1.4 (gr/cc) from density log, and low AI cutoff value range between 5000-6400 (m/s)*(g/cc). The distribution of coal seam is laterally thinning northwest to southeast. Coal seam is seen biasedly on model base hard constraint inversion and discontinued on band-limited inversion which isn’t similar to the geological model. The appropriate AI inversion is sparse spike inversion which has 0.884757 value from cross plot inversion as the best correlation value among the chosen inversion methods. Sparse Spike inversion its self-has high amplitude as a proper tool to identify coal seam continuity which commonly appears as a thin layer. Cross-sectional sparse spike inversion shows that there are possible new boreholes in CDP 3662-3722, CDP 3586-3622, and CDP 4004-4148 which is seen in seismic data as a thick coal seam.

Coalbed Methane prospect of Jamalganj Coalfield Bangladesh

International Nuclear Information System (INIS)

Imam, M. Badrul; Rahman, M.; Akhtar, Syed Humayun

2002-01-01

Five major Gondwana coalfields have been discovered in the half-graben type basins in the subsurface in the Precambrian platform area of the Northwest Bangladesh. The Jamalganj coalfields with an estimated reserve of about 1053 millions tons of coal, has seven coal seams in the depth range between 640 to 1158m below the ground surface. Compared to the other coalfields of the area, with coal occurring at 150 to 500m depth, Jamalganj coal is considered to be too deep to be exploited by conventional underground or open pit mining. Instead, developing coal bed methane from Jamalganj coalfield may be considered as a viable option for its exploitation. The positive factors of Jamalganj coal bed methane development include high net thickness of coal with at least one very thick (40m+) and widely developed seam, coal seam burial depth within optimum range, large coal reserves, indication of significant gas content from drilling data, and poor permeability in the rocks above and surrounding the coal layers. The thickest seam III can be primary target for CBM development especially where it combines with seam IV in the eastern part of coalfield. However, there are a number of unknown factors like actual gas content of coal, permeability, and in-seam pressure that need to be evaluated before deciding the viability of the project. An initial attempt to collect these base line data should include drilling test well or wells in the primary target area where seam III is most thick and widely developed. (author)

Electrical and gamma-ray logging in Gondwana and Tertiary coal fields of India

International Nuclear Information System (INIS)

Kayal, J.R.

1979-01-01

Electrical and gamma-ray logging have been very useful for identification and accurate determination of depth and thickness of coal seams in Gondwana and Tertiary coal fields of India. The characteristic resistance/resistivity peaks of coal seams in a particular area have been correlated, thus providing a picture of the subsurface structure. Physico-chemical properties of layers or sections of coal seams are responsive to electrical logs. Gamma-ray logs are found to be very useful for correlation and have sometimes been the only logs used in cased and dry boreholes for detection of coal seams. Under favourable conditions a single-point resistance log reveals a detailed picture of the formations and picks up thin coal seams as well as thin shale bands within the coal seam. But in some cases it fails to differentiate between coal and sandstone beds in spite of high contrast in true resistivities. Multi-electrode long-normal and lateral logs are found to be more useful in differentiating such formations because of higher penetration in this system. Long-normal and lateral curves can also be used to determine true resisvity of the formation. But long normal logs cannot pick up thin coal bands and/or thin shale partings within the coal seam because of the 'adjacent bed effect'. Gamma-ray logging can be done in both cased and uncased bore-holes or even in a dry borehole but its resolution for shaly coal or thin coal is not sufficient. Combined study has been found to yield the best results. (Auth.)

Influence of Laundering on the Quality of Sewn Cotton and Bamboo Woven Fabrics

Directory of Open Access Journals (Sweden)

Jurgita KOŽENIAUSKIENĖ

2013-03-01

Full Text Available In the presented study the effect of laundering on the quality of sewn cotton and bamboo plain woven fabrics was investigated considering both the textile parameters and the type of chemical treatment. Quality parameters of sewn cotton and bamboo woven fabrics such as: fabric strength, seam strength and seam slippage at the moment of 4 mm seam opening were evaluated before and after washing with “Tide” washing powder without softeners or with softeners: “Surcare” and “Pflege Weicspuler”. There was also determined surface density, warp and weft densities as well as thicknesses under the pressures 0.625 kPa and 3.125 kPa, and calculated the comparative thickness that was considered as softness or porosity of fabrics. Notwithstanding that both the investigated fabrics were cellulosic their behavior after laundering was different. Under the tested conditions, unwashed and laundered with or without chemical softeners cotton fabric didn’t demonstrate seam slippage. The seam slippage resistance of laundered without or with softener specimens of bamboo fabric was increased in respect to control fabric. The larger changes in seam efficiency and seam strength because of laundering were determined for bamboo woven fabric then for cotton fabric. They could be influenced by the higher changes in bamboo fabric’s structure. The highest difference between the structure parameters of both fabrics was determined for comparative thickness. It was significantly increased for cotton fabric and decreased for bamboo fabric after chemical softening comparing to untreated fabrics.DOI: http://dx.doi.org/10.5755/j01.ms.19.1.3831

The state of hydraulic mining in China and suggestions for future development

Energy Technology Data Exchange (ETDEWEB)

Anon, A.

1996-11-01

This paper discusses the state of development of hydraulic mining technology in China. The paper conceives that the seam conditions most suitable for hydraulic mining are: geologic faults with many cuts, inclined or gradually inclined thick and very thick seams with stable or moderately stable roofs, where longwall mining cannot be employed or pushed far; inclined or steeply inclined strata of inclination angle above 30{degree} with moderately stable roof, where the roof is stable or moderately stable, the inclination angle is greater than 7{degree}, with irregular production pattern and great variation in the seam thickness, or medium to thick coal seam of relatively more geologic damages and poor stability. Some suggestions are proposed for the future development of hydraulic mining.

A Case Study of Effective Support Working Resistance and Roof Support Technology in Thick Seam Fully-Mechanized Face Mining with Hard Roof Conditions

Directory of Open Access Journals (Sweden)

Wei-bin Guo

2017-06-01

Full Text Available This paper presents the engineering geological properties and roof control tecnology for a thick coal seam fully-mechanized face mining with hard roof conditions (THC at the Jinhuagong Coal Mine (JCM, northwest China. The effective support working resistance and appropriate roof control technology are two critical factors for safe and productive mining in the THC. The load-estimate-method (LOEM is the effective method to determine the support working resistance for normal working conditions (the mining height less than 3.5 m. In order to prevent support crushing accidents from happening and to ensure the safety and high-efficiency in the THC, the LOEM was modified based on the structure of the overlying strata in the THC. The strata which can form the voussoir beam structure in normal working conditions and will break in the form of cantilever beam in the THC is defined as the key strata in the immediate roof. Therefore, the hanging length of the key strata in the immediate roof was considered in the LOEM. Furthermore, a method for calculating the hanging length of the key strata in the immediate roof and its influencing factors were proposed using cantilever beam theory analysis of the structure of the overlying strata. Moreover, in order to fully fill the goaf area with caving roof to reduce the energy accumulation of main roof movement, it was decided to apply destress blasting technique (DEBT at the JCM to control the large hanging length of the hard roof, so as to reduce the impact of the hard main roof movement on the working face. The key technique parameters of the roof caving borehole were also proposed. The obtained results demonstrated that the theoretical analysis is reasonable, and the chosen support type and the DEBT could meet the roof control requirements. The THC has achieved safety and high-efficiency mining.

Anastomosing river deposits: palaeoenvironmental control on coal quality and distribution, Northern Karoo Basin

Energy Technology Data Exchange (ETDEWEB)

Cairncross, B

1980-01-01

Borehole data from an area close to the northern margin of the Karoo Basin 110 m thick coal reveal a bearing succession of the Vryheid Formation overlying Dwyka tillite. The lowermost sediments reflect processes of deglaciation with a complex array of glaciolacustrine, glaciofluvial and alluvial-outwash fan deposits. Above this paraglacial milieu, tundra-type peat bogs developed in inactive areas and account for the two thick basal coal seams (No. 1 and 2 seams). During accumulation of peat which was later to form the extensive No. 2 coal seam, active clastic sedimentation was confined to laterally restricted river channels which incised into the underlying peat. Lateral migration was inhibited by vegetation stabilized river banks and channel deposits are characterized by vertically accreted upward-fining cycles. Channel fill consists of coarse-grinder bedload sediment deposited in anastomosing streams. Flood episodes are marked by widespread, but thin (< 1 m), shale zones that intercalate with the channel sandstones. Both sandstone and shale units are completely enveloped by No. 2 coal seams. This clastic parting influences No. 2 coal seam distribution and ash content. 23 references

U.S. Pacific Command > Resources > Travel Requirements

Science.gov (United States)

- NIPRNet: https://jkodirect.jten.mil/Atlas2/faces/page/login/Login.seam - SIPRNet: https ://jkolms.jwfc.smil.mil/Atlas2/faces/page/login/Login.seam ***Record Completion Date*** 6. Complete/Verify/Review ISOPREP

SHRIMP zircon U–Pb ages from coal beds across the Permian–Triassic boundary, eastern Yunnan, southwestern China

Directory of Open Access Journals (Sweden)

Juan Wang

2018-04-01

Full Text Available The first SHRIMP zircon U–Pb ages from coal beds close to the end-Permian mass extinction are reported from the C1 coal seam in the Yantang Mine in Laibin Town, Xuanwei County, eastern Yunnan Province. Zircons were extracted from kaolinite claystone layers, defined as tonsteins (volcanic ash deposits, in the sub-seam B1 and B3 of the coal seam C1. The U–Pb ages are 252.0 ± 2.3 Ma and 250.3 ± 2.1 Ma for the sub-seam B1 and B3, respectively. Within analytical uncertainties, these U–Pb ages include the time period of the onset of the mass extinction at 251.941 ± 0.037 Ma, which was obtained from the marine Meishan section in Zhejiang Province, ∼1600 km away from the Yantang Mine. These new ages represent not only the first and closest ages to the PTB mass extinction in terrestrial coal beds, but also ages from the nearest site to the Emeishan volcanoes investigated so far. Therefore these new data provide the most accurate stratigraphic horizon of terrestrial facies of the end-Permian extinction in South China. The Emeishan volcanoes were likely the source of volcanic ash in the coal seams at the Xuanwei County and broader areas in South China. Furthermore, the minerals and geochemistry characteristics of the C1 coal seam also implied the influences of contemporaneous volcanic activities. Keywords: PTB mass extinction, C1 coal seam, SHRIMP U–Pb isotope age, Xuanwei County, Yunnan Province

Surrounding rock abutment pressure distribution and thickness effect of dynamic catastrophic in fully mechanized sublevel mining stope

Energy Technology Data Exchange (ETDEWEB)

Xie, G.; Yang, K.; Chang, J.; Wang, L. [Anhui University of Science and Technology, Huainan (China)

2006-12-15

Numerical simulation was carried out to analyse the distribution of surrounding rock stress with coal seams of different thickness (3.0, 5.4, 8.0, 12.0 m) based on engineering geology and exploitation technology of the 151(3) fully mechanized sublevel caving face in Xieqiao colliery. The research indicates that the variation of abutment pressure has obvious difference in coal seams of different thickness. The effect of abutment pressure distribution in seams of different thickness on coal-methane outbursts was analysed. With an increase in thickness of the caving seam, the research illustrates that the elastic energy resilience is reduced and the capability of resisting damage and deformation is strengthened in coal around the stope. The results show that fully mechanized sublevel caving slows down dynamic catastrophes. 7 refs., 4 figs.

Airborne nanoparticle concentrations in the manufacturing of polytetrafluoroethylene (PTFE) apparel.

Science.gov (United States)

Vosburgh, Donna J H; Boysen, Dane A; Oleson, Jacob J; Peters, Thomas M

2011-03-01

One form of waterproof, breathable apparel is manufactured from polytetrafluoroethylene (PTFE) membrane laminated fabric using a specific process to seal seams that have been sewn with traditional techniques. The sealing process involves applying waterproof tape to the seam by feeding the seam through two rollers while applying hot air (600 °C). This study addressed the potential for exposure to particulate matter from this sealing process by characterizing airborne particles in a facility that produces more than 1000 lightweight PTFE rain jackets per day. Aerosol concentrations throughout the facility were mapped, breathing zone concentrations were measured, and hoods used to ventilate the seam sealing operation were evaluated. The geometric mean (GM) particle number concentrations were substantially greater in the sewing and sealing areas (67,000 and 188,000 particles cm⁻³)) compared with that measured in the office area (12,100 particles cm⁻³). Respirable mass concentrations were negligible throughout the facility (GM = 0.002 mg m⁻³) in the sewing and sealing areas). The particles exiting the final discharge of the facility's ventilation system were dominated by nanoparticles (number median diameter = 25 nm; geometric standard deviation of 1.39). The breathing zone particle number concentrations of the workers who sealed the sewn seams were highly variable and significantly greater when sealing seams than when conducting other tasks (p < 0.0001). The sealing workers' breathing zone concentrations ranged from 147,000 particles cm⁻³ to 798,000 particles cm⁻³, and their seam responsibility significantly influenced their breathing zone concentrations (p = 0.03). The finding that particle number concentrations were approximately equal outside the hood and inside the local exhaust duct indicated poor effectiveness of the canopy hoods used to ventilate sealing operations.

Detection of Coal Fires: A Case Study Conducted on Indian Coal Seams Using Neural Network and Particle Swarm Optimization

Science.gov (United States)

Singh, B. B.

2016-12-01

India produces majority of its electricity from coal but a huge quantity of coal burns every day due to coal fires and also poses a threat to the environment as severe pollutants. In the present study we had demonstrated the usage of Neural Network based approach with an integrated Particle Swarm Optimization (PSO) inversion technique. The Self Potential (SP) data set is used for the early detection of coal fires. The study was conducted over the East Basuria colliery, Jharia Coal Field, Jharkhand, India. The causative source was modelled as an inclined sheet like anomaly and the synthetic data was generated. Neural Network scheme consists of an input layer, hidden layers and an output layer. The input layer corresponds to the SP data and the output layer is the estimated depth of the coal fire. A synthetic dataset was modelled with some of the known parameters such as depth, conductivity, inclination angle, half width etc. associated with causative body and gives a very low misfit error of 0.0032%. Therefore, the method was found accurate in predicting the depth of the source body. The technique was applied to the real data set and the model was trained until a very good correlation of determination `R2' value of 0.98 is obtained. The depth of the source body was found to be 12.34m with a misfit error percentage of 0.242%. The inversion results were compared with the lithologs obtained from a nearby well which corresponds to the L3 coal seam. The depth of the coal fire had exactly matched with the half width of the anomaly which suggests that the fire is widely spread. The inclination angle of the anomaly was 135.510 which resembles the development of the geometrically complex fracture planes. These fractures may be developed due to anisotropic weakness of the ground which acts as passage for the air. As a result coal fires spreads along these fracture planes. The results obtained from the Neural Network was compared with PSO inversion results and were found in

Leak test fixture and method for using same

Science.gov (United States)

Hawk, Lawrence S.

1976-01-01

A method and apparatus are provided which are especially useful for leak testing seams such as an end closure or joint in an article. The test does not require an enclosed pressurized volume within the article or joint section to be leak checked. A flexible impervious membrane is disposed over an area of the seamed surfaces to be leak checked and sealed around the outer edges. A preselected vacuum is applied through an opening in the membrane to evacuate the area between the membrane and the surface being leak checked to essentially collapse the membrane to conform to the article surface or joined adjacent surfaces. A pressure differential is concentrated at the seam bounded by the membrane and only the seam experiences a pressure differential as air or helium molecules are drawn into the vacuum system through a leak in the seam. A helium detector may be placed in a vacuum exhaust line from the membrane to detect the helium. Alternatively, the vacuum system may be isolated at a preselected pressure and leaks may be detected by a subsequent pressure increase in the vacuum system.

Investigation on localized corrosion of 304 stainless steel joints brazed using Sn-plated Ag alloy filler in NaCl aqueous solution

Science.gov (United States)

Wang, Xingxing; Li, Shuai; Peng, Jin

2018-03-01

Novel AgCuZnSn filler metal with high Sn contents was prepared from BAg50CuZn filler metal by a process of electroplating and thermal diffusion, and the prepared filler metal was applied to induction brazing of 304 stainless steel. The corrosion behavior of the brazed joints was evaluated based on localized corrosion analysis, the morphology of the joints were analyzed by SEM after immersion in a 3.5 vol% NaCl aqueous solution. The results indicated that corrosion groove occurred near the interface between the stainless steel base metal and the brazing seam. A wide range of defects such as holes and cracks appeared on the surface of the base metal, while the brazing seam zone almost no corrosion defects occur. With the increase of corrosion time, the corrosion rates of both the brazing seam and the base metal first exhibited an increasing trend, followed by a decreasing trend, and the corrosion rate of the base metal was slightly greater than that of the brazing seam. The corrosion potential of the brazing seam and 304 stainless steel were -0.7758 V and -0.7863 V, respectively.

STUDY REGARDING THE STITCHING STRENGTH OF MATERIALS USED FOR FOOTWEAR UPPERS MANUFACTURING

Directory of Open Access Journals (Sweden)

HARNAGEA Florentina

2016-05-01

Full Text Available The shoes manufacturing implies the use of various types of leathers, leather substitutes and fabric. The sewing plays a very important role in shoe making, having an impact both in terms of functionality and outlook. One of the most important indicators of the sewed products quality is seam strength, which is influenced by a series of technological parameters such as: the shape of the needle’s top, the needle’s diameter, the seam thickness, the number of seams, the gauge of the thread, the type of seam and the material type. This paper studies the stitching strength of the full grain leather and full grain leather shiny surface used for footwear uppers, in order to improve productivity and seam quality.The experimental researches obtained for the stitching strength allow calculating the weakening coefficient of the material in the process of sewing (a= 0.33-0.48. The “a” coefficient is dependent on the stitch density, the shape of the needle’s top and the joined materials. In terms of stitching strength, the results indicate that the full grain leather obtains higher values than the full grain leather shiny surface.

Site qualification studies of the UCG-SDB at North Knobs, Wyoming

Energy Technology Data Exchange (ETDEWEB)

Davis, B.E.; Krajewski, S.A.; Ahner, P.F.; Avasthi, J.M.; Dolde, M.E.; Greenman, C.A.; Miranda, J.E.

1979-01-01

The site qualification program for the North Knobs UCG site near Rawlins, Wyoming has been completed. This site will be the location for the field tests of Underground Coal Gasification of Steeply Dipping Beds undertaken by Gulf Research and Development Company for DOE in a cost shared contract. Site characterization included a comprehensive geotechnical analysis along with vegetation, historical, and archeological studies. The G coal seam chosen for these tests is a subbituminous B coal with a true seam thickness of 22 feet and has thin coal benches above and below the main seam. The water table is at 90 feet below the surface. Hydrologic studies have defined the seam as an aquiclude (non-aquifer). The site is deemed restorable to regulatory requirements. Evaluation of this site indicates total acceptability for the three-test program planned by GR and DC.

Making transducers and sensors which lead to safer mining

Energy Technology Data Exchange (ETDEWEB)

Laird, R

1977-10-20

MRDE work on transducers and sensors is described. A device containing a radioactive source has already been developed for detecting the edge of a coal seam; on a device which senses the edge of the seam by measuring natural radiation form the neighbouring rocks. Hard bands or dirt in a seam can be located by measuring pick force or pick vibrations. Environmental monitors, sensors for measuring pressure and flow in methane drainage pipes, vibration monitors for fans, means of detecting cage position in pit shaft, and bunker control systems are also mentioned.

Drill machine guidance using natural occurring radiation

International Nuclear Information System (INIS)

Dahl, H.D.; Schroeder, R.L.; Williams, B.J.

1980-01-01

A drilling machine guidance system is described which uses only the naturally occuring radiation within the seam or stratum of interest. The apparatus can be used for guiding horizontal drilling machines through coal seams and the like. (U.K.)

Developments in mechanization of operations of comprehensively mechanized longwalls in the USSR and abroad. Sovershenstvovanie sredstv mekhanizatsii kontsevykh operatsii v kompleksno-mekhanizirovannykh lavakh v SSSR i za rubezhom

Energy Technology Data Exchange (ETDEWEB)

Bodrunov, L D

1985-01-01

This paper discusses construction and introduction of equipment for mining at junctions of longwalls and roadways. Design and operation of a Soviet made narrow web shearer loader with chainless advance, enabling coal extraction by side cutting without the provision of stables in seams 2-4.1 m thick and up to 30 degrees inclination are described along with two types (520 mm and 630 mm high) of narrow web shearer loaders for extracting 0.7-0.95 m and 0.8-1.2 m thick seams with inclinations up to 35 degrees. Three types of machines constructed to operate in thin seams are presented. They are designed to extract coal from seams: 0.6-1.3 m thick with shear strength of 2.5 kN/cm, 0.65-1.2 m thick with shear strength up to 3.0 kN/cm and seams 0.8-1.8 m thick also with 3.0 kN/sm shear strength. Stableless extraction is also possible due to developments which have taken place in face scraper conveyors with shortened driving heads. Some of the new conveyors can be used in normal complexes to extract flat and inclined seams 1-2.5 m thick, whilst others are used to extract flat and inclined thin seams (0.7-1.2 m). The use of two shearer loaders has resulted in reduction in stable size or stableless extraction. Mechanization of supports at junctions of longwalls and mine roadways by means of metal supporting beams in conjunction with hydraulic or friction props is described. Mechanization of similar operations in foreign mines is also described, e.g. stableless extraction in the UK, where up to 80% of coal is extracted by the longwall system and 20% by the pillar system using the two shearer loader method. Machines produced by Anderson Strathclyde, Mining Supplies, and British Jeffrey Diamond and props manufactured by Dowty and Gullick Dobson are described. FRG coal extraction is carried out chiefly (95%) from inclined seams more than 4 m thick, using a pillar mining system (25%), longwall system (58%) and combined (17%).

18 CFR 270.101 - General definitions.

Science.gov (United States)

2010-04-01

..., DEPARTMENT OF ENERGY PROCEDURES GOVERNING DETERMINATIONS FOR TAX CREDIT PURPOSES DETERMINATION PROCEDURES... gas produced from coal seams means naturally occurring natural gas released from entrapment from the fractures, pores and bedding planes of coal seams. (7) Natural gas produced from Devonian shale means...

Modelling Project Feasibility Robustness by Use of Scenarios

DEFF Research Database (Denmark)

Moshøj, Claus Rehfeld; Leleur, Steen

1998-01-01

, SEAM secures a consistent inclusion of actual scenario elements in the quantitative impact modelling and facilitates a transparent project feasibility robustness analysis. SEAM is implemented as part of a decision support system with a toolbox structure applicable to different types of transport...

Capacitive system detects and locates fluid leaks

Science.gov (United States)

1966-01-01

Electronic monitoring system automatically detects and locates minute leaks in seams of large fluid storage tanks and pipelines covered with thermal insulation. The system uses a capacitive tape-sensing element that is adhesively bonded over seams where fluid leaks are likely to occur.

Distribution and sedimentary arrangement of carbon in South African proterozoic placer deposits

International Nuclear Information System (INIS)

Minter, W.E.L.

1981-01-01

Carbon, which occurs as grains, films, and thin seams in Witwatersrand Proterozoic placer deposits, is generally confined to carbon-seam reefs that were deposited in distal environments. The distribution of carbon on paleosurfaces, on sedimentary accumulation surfaces like pebble layers, on trough-shaped bedforms of pi-crossbedded units and foresets, and on the winnowed top of placer sediments implies that its growth took place contemporaneously with placer deposition in an aquatic fluvial environment. The areal distribution of carbon seams in distal environments is patchy, and its sparsity or total absence in some areas does not affect either the gold or the uranium content of the placer. High gold and uranium contents that appear to be associated with carbon seams are at the base of the reef because that position represents both the stable consolidated paleosurface upon which the plant material anchored itself and also the surface of bedload concentration

Sensor integration for robotic laser welding processes

NARCIS (Netherlands)

Iakovou, D.; Aarts, Ronald G.K.M.; Meijer, J.; Ostendorf, A; Hoult, A.; Lu, Y.

2005-01-01

The use of robotic laser welding is increasing among industrial applications, because of its ability to weld objects in three dimensions. Robotic laser welding involves three sub-processes: seam detection and tracking, welding process control, and weld seam inspection. Usually, for each sub-process,

Leslie Cemetery and Francisco distributary fluvial channels in the Petersburg Formation (Pennsylvanian) of Gibson County, Indiana, USA

Energy Technology Data Exchange (ETDEWEB)

Eggert, D L

1984-01-01

The Leslie Cemetery Channel is a small distributary fluvial channel that is partly contemporaneous with the Springfield Coal member of the Petersburg Formation (Pennsylvanian) and splits the seam into two seams. This channel is 1-6 miles (1.6-10 km) wide and extends 30 miles (48 km) in the subsurface. Overbank and channel fill deposits consisting of sandstone, siltstone, and mudstone split the coal into two seams up to 40-50 ft (12-15 m) apart in places. The lower seam is a low-sulphur coal. Adjacent to this channel is the unsplit coal, which is as much as 9 ft (3 m) thick. Beneath the Leslie Cemetery Channel and the Springfield coal is the slightly older Francisco Channel (new name), which is younger than the next lower coal. This channel is filled with a fining-upward sandstone as much as 75 ft (23 m) thick. The positions of these stacked channels were determined by the differential compaction of earlier sediments. 20 references.

78 FR 52967 - Notice of Intent To Initiate Public Scoping and Prepare an Environmental Impact Statement for...

Science.gov (United States)

2013-08-27

..., the overburden (sedimentary rock material covering the coal seams) would be drilled and blasted... pass. After the dragline exposes the coal seam in each pass, the coal would be drilled and blasted. A...) Sediment control, (2) soil salvage, (3) access and haul roads, (4) blasting, (5) overburden removal, (6...

Raton basin assessment of coalbed methane resources. [USA - Colorado and New Mexico

Energy Technology Data Exchange (ETDEWEB)

Stevens, S H; Kelso, B S; Lombardi, T E; Coates, J -M [Advanced Research International, Arlington, VA (USA)

1993-02-01

Coalbed methane resources of the Raton basin were assessed through an analysis of public and proprietary sources encompassing stratigraphic, structural, hydrologic, coal rank, and gas-content data. Mapping of coal seams within the Vermejo Formation and Raton Formation revealed several net-coal thickness maxima of 80 ft along the synclinal axis of the basin. However, this sizable coal resource is distributed among multiple, thin, laterally discontinuous coal seams; approximately 60 percent of the total coal in the Raton Formation and 50 percent in the Vermejo Formation occur in seams thinner than 4 ft. Coal rank of the basal Vermejo Formation ranges from high-volatile C to low-volatile bituminous, indicating adequate thermal maturity for methane-generation. Coal seam gas contents show considerable scatter, ranging from 4 to 810 CF/T (ash free), and vary more closely with depth below the hydrologic potentiometric surface than with depth below ground level. Exclusive of shallow and intruded coal seams, in-place coalbed methane resources are estimated at 8.4 to 12.1 TCF, with a mean average of 10.2 TCF. The apparent highest concentration of coalbed methane (24 BCF/mi[sup 2]) occurs along the La Veta trough in Colorado in an area that is geologically less well studied. A second maximum of 8 BCF/mi[sup 2] occurs southeast of Vermejo Park in New Mexico. Successful coalbed methane development in the Raton basin will require favourable coal seam geometry, depth, and reservoir properties in addition to sufficient in-place resources. Local fracturing and enhanced permeability may occur along folds, such as the Vermejo anticline, that splay off the Sangre de Cristo thrust belt. 16 refs., 9 figs.

Geostatistics applied in mine production planning

Energy Technology Data Exchange (ETDEWEB)

Zerdin, F.; Markic, S.; Subelj, A. [NTF, Ljubljana (Slovenia)

1998-07-01

Long-term plan for lignite mine Velenje has been made by using a technical 'parametrisation' method where the basis for periodic, middle-term and short-term plans as well as for scheduling has already been fixed. Plans are presented by grade (heating value in GJ), quantity of ROM coal in tons and quantity of excavated material in cubic metre for each sequence of the seam or whole seam as well as for all working seams in the mines as a whole which correspond to a defined time period. Grade planning aims at achieving uniform product quality to meet contractual obligations. 17 refs., 10 figs.

Sensor development and integration for robotized laser welding

NARCIS (Netherlands)

Iakovou, D.

2009-01-01

Laser welding requires fast and accurate positioning of the laser beam over the seam trajectory. The task of accurate positioning of the laser tools is performed by robotic systems. It is therefore necessary to teach the robot the path it has to follow. Seam teaching is implemented in several ways:

Dirt absorbing heading at Whitwick Colliery

Energy Technology Data Exchange (ETDEWEB)

Ash, J W

1977-07-01

Paper describes a method of developing a roadway in the Yard Seam at Whitwick Colliery using modified mining equipment integrated to form a mining system capable of extracting coal from a thin seam and mechanically packing the ripping dirt. Acceptable rates of advance were achieved and a costing assessment is given.

The C. elegans embryonic fate specification factor EGL-18 (GATA) is reutilized downstream of Wnt signaling to maintain a population of larval progenitor cells.

Science.gov (United States)

Gorrepati, Lakshmi; Eisenmann, David M

2015-01-01

In metazoans, stem cells in developing and adult tissues can divide asymmetrically to give rise to a daughter that differentiates and a daughter that retains the progenitor fate. Although the short-lived nematode C. elegans does not possess adult somatic stem cells, the lateral hypodermal seam cells behave in a similar manner: they divide once per larval stage to generate an anterior daughter that adopts a non-dividing differentiated fate and a posterior daughter that retains the seam fate and the ability to divide further. Wnt signaling pathway is known to regulate the asymmetry of these divisions and maintain the progenitor cell fate in one daughter, but how activation of the Wnt pathway accomplished this was unknown. We describe here our recent work that identified the GATA transcription factor EGL-18 as a downstream target of Wnt signaling necessary for maintenance of a progenitor population of larval seam cells. EGL-18 was previously shown to act in the initial specification of the seam cells in the embryo. Thus the acquisition of a Wnt-responsive cis-regulatory module allows an embryonic fate specification factor to be reutilized later in life downstream of a different regulator (Wnt signaling) to maintain a progenitor cell population. These results support the use of seam cell development in C. elegans as a simple model system for studying stem and progenitor cell biology.

Fast and safe gas detection from underground coal fire by drone fly over.

Science.gov (United States)

Dunnington, Lucila; Nakagawa, Masami

2017-10-01

Underground coal fires start naturally or as a result of human activities. Besides burning away the important non-renewable energy resource and causing financial losses, burning coal seams emit carbon dioxide, carbon monoxide, sulfur oxide and methane, and is a leading cause of smog, acid rain, global warming, and air toxins. In the U.S. alone, the combined cost of coal-fire remediation projects that have been completed, budgeted, or projected by the U.S. Department of the Interior's Office of Surface Mining Remediation and Enforcement (OSM), exceeds $1 billion. It is estimated that these fires generate as much as 3% of the world's annual carbon dioxide emissions and consume as much as 5% of its minable coal. Considering the magnitude of environmental impact and economic loss caused by burning underground coal seams, we have developed a new, safe, reliable surface measurement of coal fire gases to assess the nature of underground coal fires. We use a drone mounted with gas sensors. Drone collected gas concentration data provides a safe alternative for evaluating the rank of a burning coal seam. In this study, a new method of determining coal rank by gas ratios is developed. Coal rank is valuable for defining parameters of a coal seam such as burn temperature, burn rate, and volume of burning seam. Copyright © 2017 Elsevier Ltd. All rights reserved.

Constitutive model of friction stir weld with consideration of its inhomogeneous mechanical properties

Science.gov (United States)

Zhang, Ling; Min, Junying; Wang, Bin; Lin, Jianping; Li, Fangfang; Liu, Jing

2016-03-01

In practical engineering, finite element(FE) modeling for weld seam is commonly simplified by neglecting its inhomogeneous mechanical properties. This will cause a significant loss in accuracy of FE forming analysis, in particular, for friction stir welded(FSW) blanks due to the large width and good formability of its weld seam. The inhomogeneous mechanical properties across weld seam need to be well characterized for an accurate FE analysis. Based on a similar AA5182 FSW blank, the metallographic observation and micro-Vickers hardness analysis upon the weld cross-section are performed to identify the interfaces of different sub-zones, i.e., heat affected zone(HAZ), thermal-mechanically affected zone(TMAZ) and weld nugget(WN). Based on the rule of mixture and hardness distribution, a constitutive model is established for each sub-zone to characterize the inhomogeneous mechanical properties across the weld seam. Uniaxial tensile tests of the AA5182 FSW blank are performed with the aid of digital image correlation(DIC) techniques. Experimental local stress-strain curves are obtained for different weld sub-zones. The experimental results show good agreement with those derived from the constitutive models, which demonstrates the feasibility and accuracy of these models. The proposed research gives an accurate characterization of inhomogeneous mechanical properties across the weld seam produced by FSW, which provides solutions for improving the FE simulation accuracy of FSW sheet forming.

76 FR 22148 - Petitions for Modification of Application of Existing Mandatory Safety Standards

Science.gov (United States)

2011-04-20

... (Top of the slope belt); (ii) 11 seam dump point (Approximately 950 feet down the slope); (iii) 9 seam dump point (Located at the bottom of the slope), and additional fire hose will be kept at strategic... trained in the location and operation procedures of valves and pumps necessary to pressurize the waterline...

The mechanism and field test of permeability improvement by hydraulic flushing in three-soft and single coal seam%“三软”单一煤层水力冲孔卸压增透机理及现场试验

Institute of Scientific and Technical Information of China (English)

冯文军; 苏现波; 王建伟; 秦俊宾; 李贤忠

2015-01-01

Hydraulic flushing is the most effective way for high-efficient extraction in three-soft coal seam. In this paper, the mechanism was studied by laboratory experiment, theoretical analysis and field test for pressure relief and permeability improvement in three-soft coal seam after hydraulic flushing. The coupling experiment of stress and strain-coal structure-permeability revealed the evolution of permeability along with the change of the structure and stress, and found that permeability of soft coal was improved on a large scale after pressure relief. Based on Hoek-Brown criterion theory, the numerical simulation results show that the relief range increased significantly af-ter hydraulic flushing in coal. The hydraulic flushing tests using self-developed machine for gas drainage borehole in 21141 floor drainage tunnel of Daping Mine shows, the machine made hydraulic flushing more secure and effi-cient, and made it possible to repair the old drainage borehole . The field tests fully tested the reliability of the equipment and the accuracy of the above theoretical analysis, and improved the extraction efficiency significantly.%水力冲孔是实现“三软”煤层瓦斯高效抽采的有效途径之一。通过应力应变–煤体结构–渗透率的耦合实验，揭示了“三软”煤层渗透率随煤体结构和应力变化的演化规律，发现软煤在卸压后渗透率得到大规模提升。以Hoek-Brown准则为理论依据，通过数值模拟，发现水力冲孔出煤后的卸压增透范围显著增加。采用自主研发的“瓦斯抽采孔水力作业机”，在郑煤集团大平煤矿21141底板抽放巷进行了水力冲孔试验，使得水力冲孔更加安全、高效，并使得老孔的修复成为现实。现场试验充分检验了装备的可靠性和理论分析的准确性，显著提高了煤层瓦斯的抽采效率。

The Source Equivalence Acceleration Method

International Nuclear Information System (INIS)

Everson, Matthew S.; Forget, Benoit

2015-01-01

Highlights: • We present a new acceleration method, the Source Equivalence Acceleration Method. • SEAM forms an equivalent coarse group problem for any spatial method. • Equivalence is also formed across different spatial methods and angular quadratures. • Testing is conducted using OpenMOC and performance is compared with CMFD. • Results show that SEAM is preferable for very expensive transport calculations. - Abstract: Fine-group whole-core reactor analysis remains one of the long sought goals of the reactor physics community. Such a detailed analysis is typically too computationally expensive to be realized on anything except the largest of supercomputers. Recondensation using the Discrete Generalized Multigroup (DGM) method, though, offers a relatively cheap alternative to solving the fine group transport problem. DGM, however, suffered from inconsistencies when applied to high-order spatial methods. While an exact spatial recondensation method was developed and provided full spatial consistency with the fine group problem, this approach substantially increased memory requirements for realistic problems. The method described in this paper, called the Source Equivalence Acceleration Method (SEAM), forms a coarse-group problem which preserves the fine-group problem even when using higher order spatial methods. SEAM allows recondensation to converge to the fine-group solution with minimal memory requirements and little additional overhead. This method also provides for consistency when using different spatial methods and angular quadratures between the coarse group and fine group problems. SEAM was implemented in OpenMOC, a 2D MOC code developed at MIT, and its performance tested against Coarse Mesh Finite Difference (CMFD) acceleration on the C5G7 benchmark problem and on a 361 group version of the problem. For extremely expensive transport calculations, SEAM was able to outperform CMFD, resulting in speed-ups of 20–45 relative to the normal power

Coal-bed methane water effects on dill and essential oils

Science.gov (United States)

Pumping water from coal seams decreases the pressure in the seam and in turn releases trapped methane; this is the most common and economic way of methane extraction. The water that is pumped out is known as coal-bed methane water (CBMW), which is high in sodium and other salts. In past 25 years, th...

Q-switch Nd:YAG laser welding of AISI 304 stainless steel foils

Energy Technology Data Exchange (ETDEWEB)

P' ng, Danny [Laboratory for Lasers, MEMS and Nanotechnology, Department of Mechanical Engineering, Iowa State University, Ames, IA 50011-2161 (United States); Molian, Pal [Laboratory for Lasers, MEMS and Nanotechnology, Department of Mechanical Engineering, Iowa State University, Ames, IA 50011-2161 (United States)], E-mail: molian@iastate.edu

2008-07-15

Conventional fusion welding of stainless steel foils (<100 {mu}m thickness) used in computer disk, precision machinery and medical device applications suffer from excessive distortion, formation of discontinuities (pore, void and hot crack), uncontrolled melting (melt-drop through) and poor aesthetics. In this work, a 15 ns pulsed, 400 mJ Nd:YAG laser beam was utilized to overcome these barriers in seam welding of 60 {mu}m thin foil of AISI 304 stainless steel. Transmission electron microscopy was used to characterize the microstructures while hardness and tensile-shear tests were used to evaluate the strengths. Surface roughness was measured using a DekTak profilometer while porosity content was estimated using the light microscope. Results were compared against the data obtained from resistance seam welding. Laser welding, compared to resistance seam welding, required nearly three times less heat input and produced welds having 50% narrower seam, 15% less porosity, 25% stronger and improved surface aesthetics. In addition, there was no evidence of {delta}-ferrite in laser welds, supporting the absence of hot cracking unlike resistance welding.

DMAIC Application and Fault Analysis of Metal Packaging in the Canning Industry

Directory of Open Access Journals (Sweden)

Rafael Santos de Souza

2017-11-01

Full Text Available In the food industry, quality assurance is strongly associated with consumer safety and the risk of compromising the purity of products. Specifically, in the canning industries, rusty, dented or bulging cans may contain bacteria and cause foodborne illness. This article discusses the application of DMAIC and failure analysis to reduce the number of crushed cans in a canning industry. The methodology was of an applied nature, with an exploratory objective, a qualitative and quantitative approach and a case study method used. Through statistical analysis, it was found that the amount of dented packaging in the production process, which comprises the steps of filling, seaming and basketing, was high. The step with the highest number of crushed cans between three stages was seaming. This was followed by the application of FMEA failure analysis related to the use of an automated seaming machine. Finally, an action plan was roposed to solve the problem of cans crushed in the seaming step and the results demonstrate the improvements obtained before the target after 4 months (August-November 2015.

Geological control in computer-based resource estimation

International Nuclear Information System (INIS)

Cram, A.A.

1992-01-01

The economic assessment of mineral deposits potentially involves a number of phases from initial assessment through to detailed orebody evaluation and subsequently to estimation of bench or stope grades in an operational mine. Obviously the nature and quantity of information varies significantly from one extreme to the other. This paper reports on geological interpretation which obviously plays a major part during the early phases of assessment and it logically follows that computerized orebody assessment techniques must be able to effectively utilize this information. Even in an operational mine the importance of geological control varies according to the type of orebody. The method of modelling coal seams is distinctly different from those techniques used for a massive sulphide deposit. For coal seams significant reliance is placed on the correlation of seam intercepts from holes which are widely spaced in relation to the seam (i.e.) orebody) thickness. The use of geological interpretation in this case is justified other experience gained in the past, compared to the cost of reliance only on samples from a very dense drill hole pattern

Assessing dynamics of ash content formation in coal at a working face in mines

Energy Technology Data Exchange (ETDEWEB)

Maidukov, G L; Lobkin, V M

1983-05-01

Factors which influence ash content in coal mined at a working face are analyzed: ash content in coal, stability of rock layers surrounding a coal seam, mechanical and physical properties of the direct roof. A mathematical model of ash content formation at a working face is described. On the basis of the model a computer program has been constructed. The program is used for calculating the mean value of ash content in coal and the standardized deviation. The program considers all causes of ash fluctuation in coal such as mining conditions, coal seam thickness, fluctuations in coal seam thickness, mechanical and physical properties of rocks surrounding a coal seam, particularly in the direct roof, mining systems, narrow or wide web shearer loaders, powered supports, hydraulic props, timber friction props with timber roof bars or with steel roof bars. A classification of rocks considering roof stability used by the program is described. A scheme of the program is given. Examples of using the program for forecasting ash content in coal and ash content fluctuations in Donbass mines are evaluated. (In Russian)

Results of using engineering and technological measures for rock burst prevention. [USSR

Energy Technology Data Exchange (ETDEWEB)

Kulikov, A P; Nechaev, A V; Khmara, O I

1980-01-01

The paper evaluates methods for rock burst forecasting and rock burst prevention used in the Donbass, Kuzbass, Karaganda and Pechora basins. Forecasting methods are based on measuring the initial velocity of gas flow from test boreholes and/or quantity ratio of drillings leaving a test borehole and monitoring seismoacoustic signals. Number of working faces at which each of the methods for rock burst forecasting is used is given. Methods for rock burst prevention are comparatively evaluated: explosive fracturing of rocks in seam roof or seam floor, fluid injection (water and surfactants), drilling destressing boreholes, cutting destressing slots using cutting machines or water jets, mining protective coal seams first for reducing rock burst hazard in protected coal seams, using narrow web coal cutter loaders, remote control of coal cutters at working faces with extremely high rock burst hazard, using mining schemes which reduce rock burst hazards (e.g. long pillar mining system). From 1976 to 1979 number of rock bursts in underground coal mines in the USSR decreased by 5 times in comparison to the period 1961 to 1965. (3 refs.) (In Russian)

Eddy-current guidance of the automatic inspection machine for the main vessel of the superphenix reactor

International Nuclear Information System (INIS)

David, B.; Pigeon, M.

1985-01-01

The weld detector device is an eddy-current measurement system consisting of four dual sensors (absolute + differential types), and a control cabinet with eight analog channels. The system delivers all the signals required for computing the correct track of the MIR machine along the welds, irrespective of bend, temperature, width and type of the seam, junctions of seams

Possibility of designing television control system for welded joint formation on electron beam welding

International Nuclear Information System (INIS)

Lifshits, M.L.; Lobanova, N.G.

1987-01-01

Regression equations (models), connecting seam characteristics: width and depth with the welding bath leading front in joint gap and seam width respectively - are obtained at electron beam welding of circular articles with guaranteed clearance with application of television control system. Dispersion analysis showed the models adequancy to the process in the range, where they were identified

FY 2000 report on the survey of the overseas geological structure. Japan-China joint coal exploration - Yu Xian project; 2000 nendo kaigai chishitsu kozo nado chosa hokokusho. Nippon Chugoku sekitan kyodo tansa Yu Xian project

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

The geological survey was carried out which is needed for coal mine design in the Yu Xian coal mine area, Yu Xian coal field, Hebei province, China. The term of survey was 5 years from 1996 to 2000. Activities are mainly for seismic survey and boring survey. Japan was in charge of the seismic survey, and China in charge of the boring survey. Both attained the goal. The results of the activities were summed up in the following 7 items: 1) outline of the survey; 2) general investigation; 3) state of the exploration related materials/machinery; 4) field survey; 5) items of survey; 6) results of the survey; 7) conclusion. In 6), the geological analysis, coal quality survey and coal amount survey were conducted. In the geological analysis, analyzed were the succession of strata, geological structure, and the situation of existence of coal seams. In 7), the following were made clear: geological structure of the survey area, coal seam, coal quality, hydrological geology, other conditions of drilling technology, and coal amount. The coal amount was 328.34 million tons in a total of A/B/C class coals. The total coal amount of Nos. 1 and 5 coal seams was 259.79 million tons, which was 79.1% of the total coal amount in all area. The average thickness of Nos. 1 and 5 coal seams, which are the main minable coal seams, was 3.10m and 2.66m, respectively. (NEDO)

Comprehensive geological report on Yu Hsien mining area, Yu Hsien coalfield, Hopeh Province in the People's Republic of China

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

This is a detailed geological survey report on Yu Hsien coalfield for the period beginning in 1987 and ending in March, 2001. The survey elucidated the structures, beds, coal seams, coal property, hydro-geological features, and other mining technological conditions in Beiyang Zhuang mining area. In addition, as a result of coal reserves calculation, the total of A, B and C class coal reserves was 328.34 million tons, of which No.1 and No.5 coal seams were 259.79 million tons, taking 79.1% of the entire reserves. The average coal seam thickness of the No.1 and No.5 coal seams, which are the principal minable coal seams, are each 3.10 m and 2.66 m, with the existing depth usually 300-711 m; the coal properties are classified into low-medium ash, low sulfur, low phosphorus, and medium heating value. The coal category is long flame coal, with the use applicable to cement, electric power, gasification, etc. As the infrastructure, Beiyang Zhuang mining area is one of the three mines for which development has been decided in Yu Hsien coalfield. with the planned coal output scheduled for 1.8 million tons, and with a road or a dedicated railroad for coal maintained leading to large and medium cities such as Changkiakow, Suanhwa and Beijing. Further, railway construction is in progress, so that transportation conditions are extremely favorable. Preliminary investigation of industries and construction of coal pits should be considered. (NEDO)

A Poromechanical Model for Coal Seams Injected with Carbon Dioxide: From an Isotherm of Adsorption to a Swelling of the Reservoir Un modéle poromécanique pour l’injection de dioxyde de carbone dans des veines de charbon : d’une isotherme d’adsorption à un gonflement du réservoir

Directory of Open Access Journals (Sweden)

Nikoosokhan S.

2012-11-01

Full Text Available Injecting carbon dioxide into deep unminable coal seams can enhance the amount of methane recovered from the seam. This process is known as CO2-Enhanced Coal Bed Methane production (CO2-ECBM. The seam is a porous medium whose porous system is made of cleats (small natural fractures and of coal pores (whose radius can be as small as a few angström. During the injection process, the molecules of CO2 get adsorbed in the coal pores. Such an adsorption makes the coal swell, which, in the confined conditions that prevail underground, induces a closure of the cleat system of the coal bed reservoir and a loss of injectivity. In this work, we develop a poromechanical model which, starting from the knowledge of an adsorption isotherm and combined with reservoir simulations, enables to estimate the variations of injectivity of the coal bed reservoir over time during the process of injection. The model for the coal bed reservoir is based on poromechanical equations that explicitly take into account the effect of adsorption on the mechanical behavior of a microporous medium. We consider the coal bed reservoir as a dual porosity (cleats and coal porosity medium, for which we derive a set of linear constitutive equations. The model requires as an input the adsorption isotherm on coal of the fluid considered. Reversely, the model provides a way to upscale an adsorption isotherm into a meaningful swelling of the coal bed reservoir at the macroscopic scale. The parameters of the model are calibrated on data on coal samples available in the literature. Reservoir simulations of an injection of carbon dioxide in a coal seam are performed with an in-house finite volume and element code. The variations of injection rate over time during the process of injection are obtained from the simulations. The effect of the compressibility of the coal matrix on those variations is discussed. L’injection de dioxyde de carbone dans des veines de charbon profondes peut augmenter

Hydrochemical processes in a shallow coal seam gas aquifer and its overlying stream–alluvial system: implications for recharge and inter-aquifer connectivity

International Nuclear Information System (INIS)

Duvert, Clément; Raiber, Matthias; Owen, Daniel D.R.; Cendón, Dioni I.; Batiot-Guilhe, Christelle; Cox, Malcolm E.

2015-01-01

Highlights: • Major ions and isotopes used to study inter-aquifer mixing in a shallow CSG setting. • Considerable heterogeneity in the water composition of the coal-bearing aquifer. • Rapid recharge of the coal-bearing aquifer through highly fractured igneous rocks. • Potential mixing between the coal-bearing aquifer and downstream alluvial aquifer. • Need to consider the seasonal influences on inter-aquifer mixing in CSG settings. - Abstract: In areas of potential coal seam gas (CSG) development, understanding interactions between coal-bearing strata and adjacent aquifers and streams is of highest importance, particularly where CSG formations occur at shallow depth. This study tests a combination of hydrochemical and isotopic tracers to investigate the transient nature of hydrochemical processes, inter-aquifer mixing and recharge in a catchment where the coal-bearing aquifer is in direct contact with the alluvial aquifer and surface drainage network. A strong connection was observed between the main stream and underlying alluvium, marked by a similar evolution from fresh Ca–Mg–HCO 3 waters in the headwaters towards brackish Ca–Na–Cl composition near the outlet of the catchment, driven by evaporation and transpiration. In the coal-bearing aquifer, by contrast, considerable site-to-site variations were observed, although waters generally had a Na–HCO 3 –Cl facies and high residual alkalinity values. Increased salinity was controlled by several coexisting processes, including transpiration by plants, mineral weathering and possibly degradation of coal organic matter. Longer residence times and relatively enriched carbon isotopic signatures of the downstream alluvial waters were suggestive of potential interactions with the shallow coal-bearing aquifer. The examination of temporal variations in deuterium excess enabled detection of rapid recharge of the coal-bearing aquifer through highly fractured igneous rocks, particularly at the catchment

Ultrasonic inspection recess in heat exchanger and nuclear steam generator tubesheets

International Nuclear Information System (INIS)

Parkinson, J.K.; Ruhe, A.

1975-01-01

A vessel with a butted weld seam is provided with an access slot in its surface at a selected distance from the weld seam. An ultrasonic probe engages with a wall of the slot which is aligned with the weld and signals generated by the probe cross the axis of the weld frontally without substantial reflection from adjacent vessel surfaces

Ring Fusion of Fisheye Images Based on Corner Detection Algorithm for Around View Monitoring System of Intelligent Driving

Directory of Open Access Journals (Sweden)

Jianhui Zhao

2018-01-01

Full Text Available In order to improve the visual effect of the around view monitor (AVM, we propose a novel ring fusion method to reduce the brightness difference among fisheye images and achieve a smooth transition around stitching seam. Firstly, an integrated corner detection is proposed to automatically detect corner points for image registration. Then, we use equalization processing to reduce the brightness among images. And we match the color of images according to the ring fusion method. Finally, we use distance weight to blend images around stitching seam. Through this algorithm, we have made a Matlab toolbox for image blending. 100% of the required corner is accurately and fully automatically detected. The transition around the stitching seam is very smooth, with no obvious stitching trace.

东滩煤矿煤层底板岩层阻水能力试验研究%Experiment of reduction infiltration ability of rock formation under the coal seam floor at Dongtan Coal Mine

Institute of Scientific and Technical Information of China (English)

张维建; 张新武; 张冬

2015-01-01

底板岩层压水试验能够获得可靠的底板岩层阻水能力实测数据, 为深部煤层开采底板岩层阻水能力提供量化依据,对东滩煤矿深部煤层底板岩层进行压水测试,获得了大量的实测数据并依此计算出岩层的渗透系数. 试验结果表明测试底板岩层段在原始状态下的渗透性很低,阻水能力较强.研究结果可为矿区深部工作面的安全开采提供重要的参考依据.%The reliable reduction infiltration characteristics of rock mass could be obtained by the water injection experiment under the coal seem floor. The data of water injection experimnt were obtained and permeability coefficient of floor formation were deduced through water in-jection experiment at Dongtan Coal Mine. Result shows that the test rock formations are all low-permeability, which mean they have high re-duction infiltration ability. The results make a important reference for safety-mining of deep coal seam working face.

THE OHIO RIVER VALLEY CO2 STORAGE PROJECT - PRELIMINARY ASSESSMENT OF DEEP SALINE RESERVOIRS AND COAL SEAMS

Energy Technology Data Exchange (ETDEWEB)

Michael J. Mudd; Howard Johnson; Charles Christopher; T.S. Ramakrishnan, Ph.D.

2003-08-01

This report describes the geologic setting for the Deep Saline Reservoirs and Coal Seams in the Ohio River Valley CO{sub 2} Storage Project area. The object of the current project is to site and design a CO{sub 2} injection facility. A location near New Haven, WV, has been selected for the project. To assess geologic storage reservoirs at the site, regional and site-specific geology were reviewed. Geologic reports, deep well logs, hydraulic tests, and geologic maps were reviewed for the area. Only one well within 25 miles of the site penetrates the deeper sedimentary rocks, so there is a large amount of uncertainty regarding the deep geology at the site. New Haven is located along the Ohio River on the border of West Virginia and Ohio. Topography in the area is flat in the river valley but rugged away from the Ohio River floodplain. The Ohio River Valley incises 50-100 ft into bedrock in the area. The area of interest lies within the Appalachian Plateau, on the western edge of the Appalachian Mountain chain. Within the Appalachian Basin, sedimentary rocks are 3,000 to 20,000 ft deep and slope toward the southeast. The rock formations consist of alternating layers of shale, limestone, dolomite, and sandstone overlying dense metamorphic continental shield rocks. The Rome Trough is the major structural feature in the area, and there may be some faults associated with the trough in the Ohio-West Virginia Hinge Zone. The area has a low earthquake hazard with few historical earthquakes. Target injection reservoirs include the basal sandstone/Lower Maryville and the Rose Run Sandstone. The basal sandstone is an informal name for sandstones that overlie metamorphic shield rock. Regional geology indicates that the unit is at a depth of approximately 9,100 ft below the surface at the project site and associated with the Maryville Formation. Overall thickness appears to be 50-100 ft. The Rose Run Sandstone is another potential reservoir. The unit is located approximately 1

Effects of Nd:YAG laser pulse frequency on the surface treatment of Ti 6Al 4V alloys

Energy Technology Data Exchange (ETDEWEB)

Gursel, Ali [International University of Sarajevo (Bosnia and Herzegovina). Dept. of Mechanical Engineering

2016-07-01

The desirable properties of titanium and titanium alloys, including excellent corrosion resistance, high strength to weight ratio and high operating temperature, have led to their successful application in various fields such as the medical and aerospace industries. Among the reliable treatment techniques, laser welding can provide significant advantages for the titanium alloys because of its precision, rapid processing capability and ability to control the welding parameters and their effects. The morphology and the quality of pulsed seam welds are directly or synergistically influenced by the Nd:YAG laser parameters of pulse shape, energy, duration, travel speed, peak power and frequency of repetition. In this study, a 1.5 mm thick Ti-6Al-4V alloy sheet surface was treated by SigmaLaser {sup registered} 300 Nd:YAG pulsed laser. The influence of the pulse frequency on seam morphology and surface effects was then investigated. The seam and surface quality were characterized in terms of weld morphology and microhardness. The results showed that, for Nd:YAG laser seams used for surface treatment, pulse repetition was more effective on the cooling rate than had been expected.

Evaluation of geological conditions for coalbed methane occurrence based on 3D seismic information: a case study in Fowa region, Xinjing coal mine, China

Science.gov (United States)

Li, Juanjuan; Li, Fanjia; Hu, Mingshun; Zhang, Wei; Pan, Dongming

2017-04-01

The research on geological conditions of coalbed methane (CBM) occurrence is of great significance for predicting the high abundance CBM rich region and gas outburst risk area pre-warning. The No. 3 coal seam, in Yangquan coalfield of Qinshui basin, is the research target studied by 3D seismic exploration technique. The geological factors which affect CBM occurrence are interpreted based on the 3D seismic information. First, the geological structure (faults, folds, and collapse columns) is found out by the 3D seismic structural interpretation and the information of buried depth and thickness of the coal seam is calculated by the seismic horizons. Second, 3D elastic impedance (EI) and natural gamma attribute volumes are generated by prestack EI inversion and multi-attribute probabilistic neural network (PNN) inversion techniques which reflect the information of coal structure types and lithology of the roof and floor. Then, the information of metamorphic degree of seam and hydrogeology conditions can be obtained by the geological data. Consequently, geological conditions of CBM occurrence in No. 3 coal seam are evaluated which will provide scientific reference for high abundance CBM rich region prediction and gas outburst risk area pre-warning.

Stability Criteria of Fullerene-like Nanoparticles: Comparing V2O5 to Layered Metal Dichalcogenides and Dihalides

Directory of Open Access Journals (Sweden)

Yehiam Prior

2010-08-01

Full Text Available Numerous examples of closed-cage nanostructures, such as nested fullerene-like nanoparticles and nanotubes, formed by the folding of materials with layered structure are known. These compounds include WS2, NiCl2, CdCl2, Cs2O, and recently V2O5. Layered materials, whose chemical bonds are highly ionic in character, possess relatively stiff layers, which cannot be evenly folded. Thus, stress-relief generally results in faceted nanostructures seamed by edge-defects. V2O5, is a metal oxide compound with a layered structure. The study of the seams in nearly perfect inorganic "fullerene-like" hollow V2O5 nanoparticles (NIF-V2O5 synthesized by pulsed laser ablation (PLA, is discussed in the present work. The relation between the formation mechanism and the seams between facets is examined. The formation mechanism of the NIF-V2O5 is discussed in comparison to fullerene-like structures of other layered materials, like IF structures of MoS2, CdCl2, and Cs2O. The criteria for the perfect seaming of such hollow closed structures are highlighted.

Effect of coal stress on grain size of the gotten

Energy Technology Data Exchange (ETDEWEB)

Sikora, W; Tront, A

1988-09-01

Presents investigation results on the effect of seam stress and strain state on winning as measured by the grain size of the gotten. The investigations were carried out at the Institute of Mining Mechanization of the Silesian Politechnical where the relations between parameters of seams and cutters and their effect on coal grain size and energy consumption have been studied for several years. The effect was examined on coal samples taken from 4 mines in the Upper Silesian coal basin using a model of the system: seam - cutter. Cubic samples (400x400x400 mm) were tested on the CMG KOMAG test stand equipped with the POS-1 cutting apparatus. Two types of coal were distinguished: that particularly sensitive to increased pressure on seam and that only negligibly susceptible. Corresponding graphs of coal grain size versus vertical pressure are shown. A function has been developed that characterizes this sensitivity depending on a material parameter that can be determined by workability tests. The relationship between coal strength and grain size yield greater than 10 mm in the gotten depending on dynamic crushability of coal is shown in graphs. 6 refs.

Analysis of electromagnetic scattering by nearly periodic structures: an LDRD report.

Energy Technology Data Exchange (ETDEWEB)

Johnson, William Arthur; Warne, Larry Kevin; Jorgenson, Roy Eberhardt; Wilton, Donald R. (University of Houston, Houston, TX); Basilio, Lorena I.; Peters, David William; Capolino, F. (University of Houston, Houston, TX)

2006-10-01

In this LDRD we examine techniques to analyze the electromagnetic scattering from structures that are nearly periodic. Nearly periodic could mean that one of the structure's unit cells is different from all the others--a defect. It could also mean that the structure is truncated, or butted up against another periodic structure to form a seam. Straightforward electromagnetic analysis of these nearly periodic structures requires us to grid the entire structure, which would overwhelm today's computers and the computers in the foreseeable future. In this report we will examine various approximations that allow us to continue to exploit some aspects of the structure's periodicity and thereby reduce the number of unknowns required for analysis. We will use the Green's Function Interpolation with a Fast Fourier Transform (GIFFT) to examine isolated defects both in the form of a source dipole over a meta-material slab and as a rotated dipole in a finite array of dipoles. We will look at the numerically exact solution of a one-dimensional seam. In order to solve a two-dimensional seam, we formulate an efficient way to calculate the Green's function of a 1d array of point sources. We next formulate ways of calculating the far-field due to a seam and due to array truncation based on both array theory and high-frequency asymptotic methods. We compare the high-frequency and GIFFT results. Finally, we use GIFFT to solve a simple, two-dimensional seam problem.

A review of nickel toxicity to marine and estuarine tropical biota with particular reference to the South East Asian and Melanesian region.

Science.gov (United States)

Gissi, Francesca; Stauber, Jennifer L; Binet, Monique T; Golding, Lisa A; Adams, Merrin S; Schlekat, Christian E; Garman, Emily R; Jolley, Dianne F

2016-11-01

The South East Asian Melanesian (SEAM) region contains the world's largest deposits of nickel lateritic ores. Environmental impacts may occur if mining operations are not adequately managed. Effects data for tropical ecosystems are required to assess risks of contaminant exposure and to derive water quality guidelines (WQG) to manage these risks. Currently, risk assessment tools and WQGs for the tropics are limited due to the sparse research on how contaminants impact tropical biota. As part of a larger project to develop appropriate risk assessment tools to ensure sustainable nickel production in SEAM, nickel effects data were required. The aim of this review was to compile data on the effects of nickel on tropical marine, estuarine, pelagic and benthic species, with a particular focus on SEAM. There were limited high quality chronic nickel toxicity data for tropical marine species, and even fewer for those relevant to SEAM. Of the data available, the most sensitive SEAM species to nickel were a sea urchin, copepod and anemone. There is a significant lack of high quality chronic data for several ecologically important taxonomic groups including cnidarians, molluscs, crustaceans, echinoderms, macroalgae and fish. No high quality chronic nickel toxicity data were available for estuarine waters or marine and estuarine sediments. The very sparse toxicity data for tropical species limits our ability to conduct robust ecological risk assessment and may require additional data generation or read-across from similar species in other databases (e.g. temperate) to fill data gaps. Recommendations on testing priorities to fill these data gaps are presented. Copyright © 2016 Elsevier Ltd. All rights reserved.

Radon monitoring for the prediction of mine outbursts

International Nuclear Information System (INIS)

Lebecka, J.; Wysocka, M.; Chalupnik, S.

1993-01-01

Observations of changes of concentrations of radon in gases occurring in coal seams prone to instantaneous outbursts of coal and gas have been performed. Gas samples have been taken from specially drilled boreholes. In coal seams prone to outbursts strong variations of radon concentration have been found, while in seams where no outbursts occurred radon concentration was much more stable. In all cases outbursts were always preceded by very low concentrations of radon, which raised again afterwards. Similar observations are performed in coal mines where a strong hazard of shocks accompanied by rock bursts occur which is caused by mining activity. Obtained results indicate the possibility of using radon as supporting indicator for prediction of instantaneous outbursts and rock bursts and may be worth-while for prevention of these catastrophes. (author). 9 refs, 2 figs

Microstructure and phase constitution near the interface of Cu/3003 torch brazing using Al Si La Sr filler

International Nuclear Information System (INIS)

Yan, Fei; Wang, Chun Ming; Wang, Ya Jun; Xu, Dao Rong; Wu, S.C.; Sun, Qin De

2012-01-01

It has been mainly studied in this paper on brazing of Cu to Al using Al.Si filler metal. The optimized scanning rate of 2.5 mm/s is first obtained through simulating the temperature field of Cu Al brazing process based on ANSYS software. Then the brazing of Cu C11000 to Al 3003 using Al.Si.La.Sr filler is carried out by torch brazing technology. It is found that the brazing seam region is mainly consisted of α Al solid solution and CuAl2 IMC. Further experimental results also show that the rare earth element La in filler metal can not only refine the grain, but also promote the dispersion of intermetallic compounds into the brazing seam, which significantly improves the brazing seam microstructure and mechanical properties of the joints

The effect of axial external magnetic field on tungsten inert gas welding of magnesium alloy

Science.gov (United States)

Li, Caixia; Zhang, Xiaofeng; Wang, Jing

2018-04-01

The influences of axial external magnetic field on the microstructure and mechanical property of the AZ31 magnesium (Mg) alloy joints were studied. The microstructure of Mg alloy joint consisted of the weld seam, heat affected zone and base metal zone. The average grain size of weld seam welded with magnetic field is 39 μm, which is 38% smaller than that of the joint welded with absence of magnetic field. And the microhardness of weld seam increases with the help of magnetic field treatment, owing to the coarse grain refinement. With coil current of 2.0A, the maximum mechanical property of joint increases 6.7% to 255 MPa over the specimen without magnetic field treatment. Furthermore, fracture location is near heat affected area and the fracture surface is characterized with ductile fracture.

Laser welding closed-loop power control

DEFF Research Database (Denmark)

Bagger, Claus; Olsen, Flemming Ove

2003-01-01

A closed-loop control system is developed to maintain an even seam width on the root side of a laser weld by continually controlling the output laser power of a 1500 W CO2 laser.......A closed-loop control system is developed to maintain an even seam width on the root side of a laser weld by continually controlling the output laser power of a 1500 W CO2 laser....

Structural pathway of regulated substrate transfer and threading through an Hsp100 disaggregase.

Science.gov (United States)

Deville, Célia; Carroni, Marta; Franke, Kamila B; Topf, Maya; Bukau, Bernd; Mogk, Axel; Saibil, Helen R

2017-08-01

Refolding aggregated proteins is essential in combating cellular proteotoxic stress. Together with Hsp70, Hsp100 chaperones, including Escherichia coli ClpB, form a powerful disaggregation machine that threads aggregated polypeptides through the central pore of tandem adenosine triphosphatase (ATPase) rings. To visualize protein disaggregation, we determined cryo-electron microscopy structures of inactive and substrate-bound ClpB in the presence of adenosine 5'- O -(3-thiotriphosphate), revealing closed AAA+ rings with a pronounced seam. In the substrate-free state, a marked gradient of resolution, likely corresponding to mobility, spans across the AAA+ rings with a dynamic hotspot at the seam. On the seam side, the coiled-coil regulatory domains are locked in a horizontal, inactive orientation. On the opposite side, the regulatory domains are accessible for Hsp70 binding, substrate targeting, and activation. In the presence of the model substrate casein, the polypeptide threads through the entire pore channel and increased nucleotide occupancy correlates with higher ATPase activity. Substrate-induced domain displacements indicate a pathway of regulated substrate transfer from Hsp70 to the ClpB pore, inside which a spiral of loops contacts the substrate. The seam pore loops undergo marked displacements, along with ordering of the regulatory domains. These asymmetric movements suggest a mechanism for ATPase activation and substrate threading during disaggregation.

Influence of the post-weld surface treatment on the corrosion resistance of the duplex stainless steel 1.4062

Science.gov (United States)

Rosemann, P.; Müller, C.; Baumann, O.; Modersohn, W.; Halle, T.

2017-03-01

The duplex stainless steel 1.4062 (X2CrNiN22-2) is used as alternative material to austenitic stainless steels in the construction industry. The corrosion resistance of welded seams is influenced by the base material, the weld filler material, the welding process and also by the final surface treatment. The scale layer next to the weld seam can be removed by grinding, pickling, electro-polished or blasting depending on the application and the requested corrosion resistance. Blasted surfaces are often used in industrial practice due to the easier and cheaper manufacturing process compared to pickled or electro-polished surfaces. Furthermore blasting with corundum-grain is more effective than blasting with glass-beads which also lower the process costs. In recent years, stainless steel surfaces showed an unusually high susceptibility to pitting corrosion after grinding with corundum. For this reason, it is now also questioned critically whether the corrosion resistance is influenced by the applied blasting agent. This question was specifically investigated by comparing grinded, pickled, corundum-grain- and glass-bead-blasted welding seams. Results of the SEM analyses of the blasting agents and the blasted surfaces will be presented and correlated with the different performed corrosion tests (potential measurement, KorroPad-test and pitting potential) on welding seams with different surface treatments.

Evaluation of asbestos exposure within the automotive repair industry: a study involving removal of asbestos-containing body sealants and drive clutch replacement.

Science.gov (United States)

Blake, Charles L; Dotson, G Scott; Harbison, Raymond D

2008-12-01

Two independent assessments were performed of airborne asbestos concentrations generated during automotive repair work on vintage vehicles . The first involved removal of asbestos-containing seam sealant, and the second involved servicing of a drive clutch. Despite the relatively high concentrations (5.6-28%) of chrysotile fibers detected within bulk samples of seam sealant, the average asbestos concentration for personal breathing zone (PBZ) samples during seam sealant removal was 0.006 f/cc (fibers/cubic centimeter of air). Many other air samples contained asbestos at or below the analytical limit of detection (LOD). Pneumatic chiseling of the sealant material during removal resulted in 69% of area air samples containing asbestos. Use of this impact tool liberated more asbestos than hand scraping. Asbestos fibers were only detected in air samples collected during the installation of a replacement clutch. The highest asbestos corrected airborne fiber concentration observed during clutch installation was 0.0028 f/cc. This value is approximately 100 times lower than Occupational Safety and Health Administration's (OSHA) permissible exposure limit (PEL) of 0.1f/cc. The airborne asbestos concentrations observed during the servicing of vintage vehicles with asbestos-containing seam sealant and clutches are comparable to levels reported for repair work involving brake components and gaskets.

A novel orthoimage mosaic method using the weighted A* algorithm for UAV imagery

Science.gov (United States)

Zheng, Maoteng; Zhou, Shunping; Xiong, Xiaodong; Zhu, Junfeng

2017-12-01

A weighted A* algorithm is proposed to select optimal seam-lines in orthoimage mosaic for UAV (Unmanned Aircraft Vehicle) imagery. The whole workflow includes four steps: the initial seam-line network is firstly generated by standard Voronoi Diagram algorithm; an edge diagram is then detected based on DSM (Digital Surface Model) data; the vertices (conjunction nodes) of initial network are relocated since some of them are on the high objects (buildings, trees and other artificial structures); and, the initial seam-lines are finally refined using the weighted A* algorithm based on the edge diagram and the relocated vertices. The method was tested with two real UAV datasets. Preliminary results show that the proposed method produces acceptable mosaic images in both the urban and mountainous areas, and is better than the result of the state-of-the-art methods on the datasets.

Portable rapid gas content measurement - an opportunity for a step change in the coal industry?

International Nuclear Information System (INIS)

Beamish, Basil; Kizil, Mehmet; Gu, Ming

2013-01-01

The last major advance in gas content measurement for coal seams was the introduction of the quick crush technique in the early 1990s. This is a laboratory test method that has proven very reliable over the years. Recent laboratory testing using a portable quick crushing device, known as the portable gas content analyser, has produced consistent gas content results for a set of core samples obtained from a single borehole that intersected four coal seams. The retained gas content values obtained for the seams show the same increasing gas content pattern and gas composition change with depth as the standard quick crush technique. Use of the portable gas content analyser provides the opportunity to produce rapid, reliable gas content measurement of coal that could be developed for assessing gas compliance cores and outburst-prone conditions at a mine site.

Palynostratigraphical correlation of the excavated Miocene lignite seams of the Yataǧan basin (Muǧla Province, south-western Turkey)

Science.gov (United States)

Bouchal, Johannes Martin; Grímsson, Friðgeir; Denk, Thomas

2016-04-01

The excavated main lignite seams and overlying lacustrine sediments of the opencast mines Eskihisar, Salihpaşalar, and Tı naz, Muǧla Province, south-western Turkey were investigated using a high taxonomic resolution palynological approach. The Eskihisar section comprises 47m and 56 samples of which 30 were usable for palynological analysis. The Tı naz section comprises 75 m and 29 samples of which 15 were usable for palynological analysis. Finally, the Salihpaşalar section comprises 25 m and 26 samples of which 16 were usable for palynological analysis. The age of the palynological sections is middle to late Miocene based on radiometric dating and vertebrate fossils. In order to investigate dispersed pollen and spores and their botanical affinities a combined light microscopy and scanning electron microscopy approach was used. The rich palynoflora comprises: seven types of algal cysts (Botryococcus, Zygnemataceae), seventeen spore types belonging to Lycopsida (club mosses), Marsileaceae (water-clover), Osmundaceae, Pteridaceae (brake), and Polypodiaceae; 14 types of gymnosperm pollen belonging to Ephedraceae (Mormon tea), Cupressaceae, Pinaceae (Cathaya, cedar, hemlock, pine, spruce); five types of monocotyledone pollen belonging to Poaceae (grasses, common reed), and Typhaceae (bulrush, bur-reed); ca 90 dicotyledone pollen types belonging to Altingiaceae (sweet gum), Amaranthaceae (goosefoot), Anacardiaceae (sumac family), Apiaceae (parsley family), Aquifoliaceae (holly), Asteraceae (sunflower family), Betulaceae (alder, birch, hazel, hophornbeam, hornbeam), Campanulaceae (bellflower family), Cannabaceae (hackberries), Caprifoliaceae (honeysuckle, teasel family), Caryophyllaceae (pink family), Ericaceae (heather family), Eucommiaceae, Euphorbiaceae (spurge family), Fabaceae (bean family), Fagaceae (beech, oak), Geraniaceae (storkbills), Juglandaceae (hickory, walnut, wingnut), Lamiaceae (bagflower), Linaceae (flax), Lythraceae (waterwillow), Malvaceae

The narrow-gap TIG welding concerns the electric power plants manufacturers; Le soudage en joint etroit suscite l'interet des constructeurs de centrales electriques

Energy Technology Data Exchange (ETDEWEB)

Anon

2009-05-15

Polysoude, France, played host to an expert forum on narrow gap welding from 5-7 November 2008. The successful event welcomed around one hundred experts.The power plant construction sector is currently booming worldwide. For plant construction this means using more pressure-resistant, thick-walled pipes made from high temperature steels. The key quality features of this new steel grade are the values for high creep rupture strength that also apply without restriction as the benchmark for every weld seam on these pipes. In particular, the forum on narrow gap welding addressed this area of automated welding technology. During the forum, Mr Hans-Peter Mariner (Polysoude's CEO), has offered an in-depth insight into the latest developments in narrow gap welding. This presentation highlighted that with wall thicknesses of over 60 mm, welding time is shortened by a factor of five to ten in comparison to conventional TIG processes with a traditional V seam. The welding characteristics of the parent material are the decisive factor in the application of the narrow gap process. Technical advances in equipment technology such as automatic centring, HF-free ignition, seam preparation and optimised gas protection further increase the application limits. The geometry and gap width of the weld groove are based on the mechanical properties of the materials being joined, with the shrinkage characteristics of the seam being particularly important. Another key part of the programme was a presentation on the three different narrow gap-welding techniques. The first involves a single pass weld per layer and torch or work-piece revolution. The second is dual pass welding next to one another, when the seam preparation or positioning exceed the required narrow tolerances of a few tenths of a millimetre for one stringer bead per layer. TIG narrow gap welding with a shuttle-motion electrode is ideal with very large wall thicknesses of 150-200 mm. This is particularly the case if the

The narrow-gap TIG welding concerns the electric power plants manufacturers

International Nuclear Information System (INIS)

Anon.

2009-01-01

Polysoude, France, played host to an expert forum on narrow gap welding from 5-7 November 2008. The successful event welcomed around one hundred experts.The power plant construction sector is currently booming worldwide. For plant construction this means using more pressure-resistant, thick-walled pipes made from high temperature steels. The key quality features of this new steel grade are the values for high creep rupture strength that also apply without restriction as the benchmark for every weld seam on these pipes. In particular, the forum on narrow gap welding addressed this area of automated welding technology. During the forum, Mr Hans-Peter Mariner (Polysoude's CEO), has offered an in-depth insight into the latest developments in narrow gap welding. This presentation highlighted that with wall thicknesses of over 60 mm, welding time is shortened by a factor of five to ten in comparison to conventional TIG processes with a traditional V seam. The welding characteristics of the parent material are the decisive factor in the application of the narrow gap process. Technical advances in equipment technology such as automatic centring, HF-free ignition, seam preparation and optimised gas protection further increase the application limits. The geometry and gap width of the weld groove are based on the mechanical properties of the materials being joined, with the shrinkage characteristics of the seam being particularly important. Another key part of the programme was a presentation on the three different narrow gap-welding techniques. The first involves a single pass weld per layer and torch or work-piece revolution. The second is dual pass welding next to one another, when the seam preparation or positioning exceed the required narrow tolerances of a few tenths of a millimetre for one stringer bead per layer. TIG narrow gap welding with a shuttle-motion electrode is ideal with very large wall thicknesses of 150-200 mm. This is particularly the case if the

Ge distribution in the Wulantuga high-germanium coal deposit in the Shengli coalfield, Inner Mongolia, northeastern China

Energy Technology Data Exchange (ETDEWEB)

Du, Gang [Key Laboratory of Marginal Sea Geology, Chinese Academy of Sciences (China)]|[Coal Geology Bureau of Inner Mongolia, Hohhot, 010051 (China); Zhuang, Xinguo [Institute of Sedimentary Basin and Mineral, Faculty of Earth Resources, China University of Geosciences, Hubei, 430074 (China)]|[State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Hubei, 430074 (China); Querol, Xavier; Izquierdo, Maria; Alastuey, Andres; Moreno, Teresa; Font, Oriol [Institute of Earth Science ' Jaume Almera' , CSIC, C/ LLuis Sole Sabaris s/n, 08028 Barcelona (Spain)

2009-03-01

The geological and geochemical controls of the Ge distribution in the Cretaceous Wulantuga high-Germanium coal deposit in the Shengli coal field, Inner Mongolia are investigated. This paper focuses mainly on the spatial distribution of the Ge contents in coal. The high-Ge coals mainly occur in three splits of the 6 coal in the southwestern part of the Shengli coal field. Mean germanium contents in the coal range from 32 to 820 {mu}g/g, with a mean value of 137 {mu}g/g, on a bulk coal basis (mean of 939 coal samples from 75 boreholes in the 6 coal seam) in an area of 2.2 km{sup 2}. The highest Ge content occurs SW of 6 coal seam, close to the margins of the coal basin, decreasing with a fan-shaped trend towards NW, the direction of the coal basin. There is an negative correlation between the mean Ge content and the thickness of the coal seam. Different distribution patterns of Ge content were found in vertical profiles. High Ge concentrations may occur in the middle parts of coal seams, at the bottom and/or the top of thick coal seams and inconspicuous variation. A major organic affinity was determined for Ge, with a special enriched in the banded bright and semibright coal. The high-Ge coals and the coalified wood in the sandstone overlaying the 6-1 coal highly enriched in Ge, As, Sb, W, Cs, Tl, Be, and Hg. The Late Jurassic silicified volcanic rocks in the NW of the Ge coal deposit relatively high enriched in Ge, Ga, Sb, As, Cs, Be, Ge and Hg. The correlation coefficients among the elements enriched showed marked variations at close sites in this deposit, suggesting a possible diagenetic origin of the geochemical anomaly. The main Ge anomaly was attributed to early Cretaceous hydrothermal fluids circulating through the fault systems and porous volcanic rocs, probably from the subjacent granitoid rocks. The fault systems, the porous coarse clastic rocks overlying coal seam and the lithotype of coal played an important role in the transport and trapping of Ge. A

Prevention of rock bursts at the West mine; Gebirgsschlagverhuetung auf dem Bergwerk West

Energy Technology Data Exchange (ETDEWEB)

Braick, Helmut; Bartel, Ralf [RAG Deutsche Steinkohle AG, Bergwerk West, Kamp-Lintfort (Germany); Baltz, Ruediger [DMT GmbH und Co. KG, Essen (Germany). Fachsstelle fuer Gebirgsschlagverhuetung

2011-08-15

An unusually comprehensive stress-relief measure to eliminate a detected rock burst hazard in the Girondelle seam at the West mine clearly shows that an increase in the stress-relief cases must also be anticipated in the seam horizons, which were regarded as relatively uncritical in the recent past. An overall depth trend is recognisable in the Ruhr district. The combination of greater depth and higher strength of the enclosing rock and the more extensive pressure-increasing factors such as working boundaries and residual pillars clearly increases the probability of critical rock stresses in the vicinity of mine workings. The system applied in the German coal mining industry to detect and eliminate critical rock stresses ensures with a correct expert procedure that rock bursts do not occur and protection of personnel can thus be ensured despite extremely difficult conditions as in the stress-relief case in the Girondelle seam. (orig.)

Effects of water infusions on mechanical properties of carboniferous rocks

Energy Technology Data Exchange (ETDEWEB)

Vavro, M; Chlebik, J

1977-01-01

Method of water infusion is used in the Ostrava-Karvina coal region in Czechoslovakia, where the roof of the extracted coal seam consists of thick rock layers (sandstone, Namurian B series) characterized by high resistance to compression, high coefficient of linear elasticity and high capacity of accumulating energy. When the resistance boundary is crossed and the rocks are disturbed this energy is suddenly released and transferred to the surrounding rock masses, coal seam and support system. On the basis of laboratory experiments the physico-mechanical and energy properties of carboniferous rocks together with calculation of their energy coefficient and other parameters are described and calculated. The results of research and theoretical solutions are presented. Practical use of water infusions to influence mechanical properties of sandstone in the roof of coal seams is described with the example of the Dukla coal mine. (5 refs.) (In Polish)

Atom probe tomography of intermetallic phases and interfaces formed in dissimilar joining between Al alloys and steel

International Nuclear Information System (INIS)

Lemmens, B.; Springer, H.; Duarte, M.J.; De Graeve, I.; De Strycker, J.; Raabe, D.; Verbeken, K.

2016-01-01

While Si additions to Al are widely used to reduce the thickness of the brittle intermetallic seam formed at the interface during joining of Al alloys to steel, the underlying mechanisms are not clarified yet. The developed approach for the site specific atom probe tomography analysis revealed Si enrichments at grain and phase boundaries between the θ (Fe 4 Al 13 ) and η (Fe 2 Al 5 ) phase, up to about ten times that of the concentration in Al. The increase in Si concentration could play an important role for the growth kinetics of the intermetallic phases formed for example in hot-dip aluminizing of steel. - Highlights: •Si additions to Al reduce thickness of intermetallic seam in joining with steel. •Approach developed for the site specific APT analysis of the intermetallic seam •Si enrichment at grain and phase boundaries possibly affects growth of intermetallics.

The underground coal gasification First step of community collaboration; Gasification Subterranea del Carbon. Primer Intento en el Ambito de una Colaboracion Comunitaria

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

The objective of the project was to demonstrate the technical feasibility of underground coal gasification in coal seams at 600 metre depth, in order to asses its potential as a means of energy exploitation in Europe. The trial was based on the use of deviated boreholes and a retractable injection system techniques, which have both been developed by the oil and gas industries. One borehole, the injection well, was drilled in the coal seam. The other, the vertical production well, was run to intercept it in the lower part of the coal seam as closely as possible, in order to construct a continuous channel for gasification. The well were completed with casing and concentric tubing to provide the necessary paths for production, injection, purging gas and cooling water flows. A coiled tubing located in the injection well was used to execute the retraction (or CRIP) manoeuvre, which is a process in which the injector head for the gasification agents, i. e. oxygen and water, and the ignitor, are directed to a specific section of the coal seam. The gasification products passes to a surface production line for flow measurement and sampling of gas and condensate products. Production gases were either flared or incinerated, while the liquids were collected for appropriate disposal. The first trial achieved its principal objectives of in seam drilling, channel communication, the CRIP manoeuvres and the gasification of significant quantity of coal. The post-gasification study also identified the shape and extent of the cavity. The study has demonstrated the technical feasibility of underground coal gasification at the intermediate depths of European coal and proposals are made for further development and semi-commercial exploitation of this promising extraction technology. (Author) 11 refs.

Geochemistry of trace elements in coals from the Zhuji Mine, Huainan Coalfield, Anhui, China

Science.gov (United States)

Sun, R.; Liu, Gaisheng; Zheng, Lingyun; Chou, C.-L.

2010-01-01

The abundances of nine major elements and thirty-eight trace elements in 520 samples of low sulfur coals from the Zhuji Mine, Huainan Coalfield, Anhui, China, were determined. Samples were mainly collected from 10 minable coal seams of 29 boreholes during exploration. The B content in coals shows that the influence of brackish water decreased toward the top of coal seams; marine transgression and regression occurred frequently in the Lower Shihezi Formation. A wide range of elemental abundances is found. Weighted means of Na, K, Fe, P, Be, B, Co, Ni, Cr, Se, Sb, Ba, and Bi abundances in Zhuji coals are higher, and the remainder elements are either lower or equal to the average values of elements in coals of northern China. Compared to the Chinese coals, the Zhuji coals are higher in Na, K, Be, B, Cr, Co, Se, Sn, Sb, and Bi, but lower in Ti, P, Li, V and Zn. The Zhuji coals are lower only in S, P, V and Zn than average U.S. and world coals. Potassium, Mg, Ca, Mn, Sr, As, Se, Sb and light rare earth elements (LREE) had a tendency to be enriched in thicker coal seams, whereas Fe, Ti, P, V, Co, Ni, Y, Mo, Pb and heavy rare earth elements (HREE) were inclined to concentrate in thinner coal seams. The enrichment of some elements in the Shanxi or Upper Shihezi Formations is related to their depositional environments. The elements are classified into three groups based on their stratigraphic distributions from coal seams 3 to 11-2, and the characteristics of each group are discussed. Lateral distributions of selected elements are also investigated. The correlation coefficients of elemental abundances with ash content show that the elements may be classified into four groups related to modes of occurrence of these elements. ?? 2009 Elsevier B.V. All rights reserved.

Steeply Inclined Coal Floor Impermeability Probing in Mining under Safe Water Pressure of Aqui fer%带压开采条件下急倾斜煤层底板隔水性能探查研究

Institute of Scientific and Technical Information of China (English)

杜占良

2016-01-01

急倾斜煤层带压开采较水平及缓倾斜煤层存在的突水潜在威胁较大。为了有效防范底板突水情况的发生，昌华煤矿在带压开采急倾斜5号煤层时，于井下布置了三个钻孔，采用了钻孔“三量”观测、压水试验和岩石力学测试等方法，对煤层底板隔水层进行了探查。探查成果表明：5号煤层底板至奥灰顶界隔水层隔水性能较好，厚度适中，且奥灰顶面下约50 m亦可作为相对隔水层，对防护开采5号煤层突水危险较为有利。%Comparing with horizontal and gently inclined coal seams, the water bursting potential threat is larger during steeply inclined coal seam mining under safe water pressure of aquifer. To effectively prevent floor water bursting, during the steeply inclined coal seam No.5 mining under safe water pressure in the Changhua coalmine has laid out 3 boreholes underground, using“3 items”observation, packer permeability test and rock mechanical test carried out coal floor aquifuge exploring. The result has shown that the impermeabili⁃ty of aquifuge between coal seam No.5 floor to top of Ordovician limestone is rather good with moderate thickness. Besides, 50m below Ordovician limestone top can be a relative aquifuge propitious to prevent water bursting hazard during the mining of coal seam No. 5.

Fast and safe gas detection from underground coal fire by drone fly over

International Nuclear Information System (INIS)

Dunnington, Lucila; Nakagawa, Masami

2017-01-01

Underground coal fires start naturally or as a result of human activities. Besides burning away the important non-renewable energy resource and causing financial losses, burning coal seams emit carbon dioxide, carbon monoxide, sulfur oxide and methane, and is a leading cause of smog, acid rain, global warming, and air toxins. In the U.S. alone, the combined cost of coal-fire remediation projects that have been completed, budgeted, or projected by the U.S. Department of the Interior's Office of Surface Mining Remediation and Enforcement (OSM), exceeds $1 billion. It is estimated that these fires generate as much as 3% of the world's annual carbon dioxide emissions and consume as much as 5% of its minable coal. Considering the magnitude of environmental impact and economic loss caused by burning underground coal seams, we have developed a new, safe, reliable surface measurement of coal fire gases to assess the nature of underground coal fires. We use a drone mounted with gas sensors. Drone collected gas concentration data provides a safe alternative for evaluating the rank of a burning coal seam. In this study, a new method of determining coal rank by gas ratios is developed. Coal rank is valuable for defining parameters of a coal seam such as burn temperature, burn rate, and volume of burning seam. - Graphical abstract: Concluding Figure for Gas Ratios: Plotted points and ranges of adjusted literature data. Stars represent bituminous and subbituminous coal types; Ovals represent lignite. - Highlights: • Recognize underground coal fire as a potential source of energy. • Developed a creative, safe, reliable and fast gas detection method. • Developed a concept of gas ratio measurement method that can provide more accurate description of underground burning coal resource.

Genesis of natural cokes: Some Indian examples

Energy Technology Data Exchange (ETDEWEB)

Singh, Ashok K.; Sharma, Mamta [Central Institute of Mining and Fuel Research, Dhanbad, PIN-828108 (India); Singh, Mahendra P. [Banaras Hindu University, Varanasi, PIN-221005 (India)

2008-06-13

In Indian coalfields huge amounts of natural coke have been produced due to magmatic intrusions. Jharia Coalfield in eastern part of India alone contains approximately 2000 Mt of baked coking coal as a consequence of these intrusions in the form of discordant and concordant bodies. This paper is an effort to investigate the effect of carbonization in two intrusion affected coal seams of Ena (seam XIII) and Alkusa (seam XIV) collieries of Jharia Coalfield. Natural coke is derived from coking coal under in-situ conditions due to intense magmatic induced heat and overburden pressure. Natural coke is characterized by the presence of low volatile matter and high ash contents and organic constituents showing isotropy and anisotropy. Through physical, petrographic and chemical properties of natural coke or 'jhama' as determined by various methods it has been established that the reactives in the unaltered coals (vitrinite, liptinite, pseudovitrinite, reactive semifusinite, etc.) are < 25.0 vol.%, moisture < 2.5%, volatile matter < 15.0% and hydrogen < 4.0%. The temperatures attained in the coal seams have been deciphered using some standard models, which indicate that a temperature {proportional_to} 1000 C was attained. This produced huge amount of anisotropic and deposited carbons. An attempt has been made to understand the factors that influence the genesis of natural coke and heat altered maceral products in coals in Indian coalfields. (author)

Lithostratigraphy, depositional environments and sedimentology of the Permian Vryheid Formation (Karoo Supergroup), Arnot North, Witbank Coalfield, South Africa

OpenAIRE

2009-01-01

M.Sc. This work documents the lithostratigraphy and interpreted depositional environments of the Permian Vryheid Formation in the most northern proximal setting yet studied in the Witbank Coalfield. Data from 924 boreholes from two mining companies (Anglo Operations Ltd. and Xstrata Coal Ltd.) drilled over 50 years, covering an area of 910km2 revealed a 35m sequence of terrigenous clastic sedimentary rocks containing two coal seams. These seams are numbered No. 1 at the base and No. 2 at t...

Automatic pickup of arrival time of channel wave based on multi-channel constraints

Science.gov (United States)

Wang, Bao-Li

2018-03-01

Accurately detecting the arrival time of a channel wave in a coal seam is very important for in-seam seismic data processing. The arrival time greatly affects the accuracy of the channel wave inversion and the computed tomography (CT) result. However, because the signal-to-noise ratio of in-seam seismic data is reduced by the long wavelength and strong frequency dispersion, accurately timing the arrival of channel waves is extremely difficult. For this purpose, we propose a method that automatically picks up the arrival time of channel waves based on multi-channel constraints. We first estimate the Jaccard similarity coefficient of two ray paths, then apply it as a weight coefficient for stacking the multichannel dispersion spectra. The reasonableness and effectiveness of the proposed method is verified in an actual data application. Most importantly, the method increases the degree of automation and the pickup precision of the channel-wave arrival time.

Automatic weld torch guidance control system

Science.gov (United States)

Smaith, H. E.; Wall, W. A.; Burns, M. R., Jr.

1982-01-01

A highly reliable, fully digital, closed circuit television optical, type automatic weld seam tracking control system was developed. This automatic tracking equipment is used to reduce weld tooling costs and increase overall automatic welding reliability. The system utilizes a charge injection device digital camera which as 60,512 inidividual pixels as the light sensing elements. Through conventional scanning means, each pixel in the focal plane is sequentially scanned, the light level signal digitized, and an 8-bit word transmitted to scratch pad memory. From memory, the microprocessor performs an analysis of the digital signal and computes the tracking error. Lastly, the corrective signal is transmitted to a cross seam actuator digital drive motor controller to complete the closed loop, feedback, tracking system. This weld seam tracking control system is capable of a tracking accuracy of + or - 0.2 mm, or better. As configured, the system is applicable to square butt, V-groove, and lap joint weldments.

Demonstration of superconducting micromachined cavities

Energy Technology Data Exchange (ETDEWEB)

Brecht, T., E-mail: teresa.brecht@yale.edu; Reagor, M.; Chu, Y.; Pfaff, W.; Wang, C.; Frunzio, L.; Devoret, M. H.; Schoelkopf, R. J. [Department of Applied Physics, Yale University, New Haven, Connecticut 06511 (United States)

2015-11-09

Superconducting enclosures will be key components of scalable quantum computing devices based on circuit quantum electrodynamics. Within a densely integrated device, they can protect qubits from noise and serve as quantum memory units. Whether constructed by machining bulk pieces of metal or microfabricating wafers, 3D enclosures are typically assembled from two or more parts. The resulting seams potentially dissipate crossing currents and limit performance. In this letter, we present measured quality factors of superconducting cavity resonators of several materials, dimensions, and seam locations. We observe that superconducting indium can be a low-loss RF conductor and form low-loss seams. Leveraging this, we create a superconducting micromachined resonator with indium that has a quality factor of two million, despite a greatly reduced mode volume. Inter-layer coupling to this type of resonator is achieved by an aperture located under a planar transmission line. The described techniques demonstrate a proof-of-principle for multilayer microwave integrated quantum circuits for scalable quantum computing.

Expediency of using pneumatic balloons at the junction of a working face and gate roads

Energy Technology Data Exchange (ETDEWEB)

Kolokolov, O V; Litvinov, Yu G; Ozerova, A S

1983-02-01

The paper discusses strata control at longwall faces in thin coal seams. Use of pneumatic balloons instead of timber cribbing at the junction of the face and ventilation road is evaluated. The seam is 0.68 m thick at a depth of 980 m and has gradients from 60 to 63 degrees. The face mined by the Poisk coal cutter is 126 m long. The ventilation road is protected by strips of stowing. Use of pneumatic balloons with an initial pressure of 150 kN instead of timber cribbing with an initial pressure of 30 kN reduces convergence of the roof and the floor at the working face by 39%. Damage to hydraulic props at the working face caused by roof subsidence decreases by 10 to 15%. Convergence rate (measured in mm/d) decreases by 41%. Use of pneumatic balloons for strata control at working faces in thin coal seams is recommended.

Computer Tomography 3-D Imaging of the Metal Deformation Flow Path in Friction Stir Welding

Science.gov (United States)

Schneider, Judy; Beshears, Ronald; Nunes, Arthur C., Jr.

2004-01-01

In friction stir welding, a rotating threaded pin tool is inserted into a weld seam and literally stirs the edges of the seam together. This solid-state technique has been successfully used in the joining of materials that are difficult to fusion weld such as aluminum alloys. To determine optimal processing parameters for producing a defect free weld, a better understanding of the resulting metal deformation flow path is required. Marker studies are the principal method of studying the metal deformation flow path around the FSW pin tool. In our study, we have used computed tomography (CT) scans to reveal the flow pattern of a lead wire embedded in a FSW weld seam. At the welding temperature of aluminum, the lead becomes molten and thus tracks the aluminum deformation flow paths in a unique 3-dimensional manner. CT scanning is a convenient and comprehensive way of collecting and displaying tracer data. It marks an advance over previous more tedious and ambiguous radiographic/metallographic data collection methods.

Experience in landslide control

Energy Technology Data Exchange (ETDEWEB)

Koz' min, L S

1983-06-01

The problems of slope stability in the Krasnoyarskugol' surface mines are discussed. Methods used for slide prevention and slide control from 1977 to 1982 are analyzed. Landslides were caused by weathering of the argillite layer in the coal seam roof. Sliding plane was parallel to the coal seam roof. At a later stage of landslide prevention sliding planes were in the coal seam floor (which consisted of weak rock layers). Range of landslides was evaluated. Losses caused by landslides were discussed: working time losses, losses of coal, damaged equipment. Landslide hazards were controlled by reducing slope angle and by changing cut geometry. Cross section of the cut with a spoil bank prone to landslides is shown in a scheme. Reducing angle of slope inclination, using strong rock layers as the spoil bank base and changing cut geometry eliminated landslides in 1982. Recommendations on landslide control in coal surface mines with layers of weak rocks influenced by weathering are made.

Experimental use of road header (AM-50) as face cutting machine for extraction of coal in longwall panel

Energy Technology Data Exchange (ETDEWEB)

Passi, K.K.; Kumar, C.R.; Prasad, P. [DGMS, Dhanbad (India)

2001-07-01

The scope of this paper has been limited to the use of available machines and techniques for attaining higher and more efficient production in underground coal mines. Under certain conditions of strata and higher degree of gassiness, the longwall method with hydraulic sand stowing is the only appropriate method of work for extraction of thick seam. In Moonidih Jitpur Colliery of M/S IISCO, No. 14 seam, Degree III gassy seam, 9.07 m thick, is extracted in multilift system with hydraulic sand stowing. In general, the bottom lift is extracted by Single Ended Ranging Arm Shearer and the middle and top lift are extracted by conventional method. However, in one of the panels spare road header machine was used as face cutting machine in bottom lift, on an experimental basis. This paper presents a successful case study of extraction of bottom lift coal by the longwall method with hydraulic sand stowing using road header (AM 50) as the face cutting machines. 9 figs.

COALVAL

International Nuclear Information System (INIS)

Plis, M.N.; Rohrbacher, T.J.; Teeters, D.D.

1992-01-01

This paper highlights COALVAL, a coal property evaluation software package developed by the U.S. Bureau of Mines (USBM) on Lotus 1-2-3, version 2.2, spreadsheet. The software is also compatible with version 3.1, and provisionally with version 2.01. COALVAL is a menu-driven program that produces a prefeasibility-level cost analysis of mine-planned coal resources. The software contains cost models for each of five coal mining methods commonly employed in Appalachia: auger, contour strip, mountain top removal, continuous miner and longwall. COALVAL allows individuals to input resource data and the various production, operating, and cost variables that pertain to their property The program can evaluate up to 25 seams, each to be mined with up to 5 different mining methods, within a given area. Summary spreadsheet listing the cost per clean ton to mine the resources, F.O.B. The tipple, are produced for each property, seam, and mining method/seam combination

A novel orthoimage mosaic method using a weighted A∗ algorithm - Implementation and evaluation

Science.gov (United States)

Zheng, Maoteng; Xiong, Xiaodong; Zhu, Junfeng

2018-04-01

The implementation and evaluation of a weighted A∗ algorithm for orthoimage mosaic with UAV (Unmanned Aircraft Vehicle) imagery is proposed. The initial seam-line network is firstly generated by standard Voronoi Diagram algorithm; an edge diagram is generated based on DSM (Digital Surface Model) data; the vertices (conjunction nodes of seam-lines) of the initial network are relocated if they are on high objects (buildings, trees and other artificial structures); and the initial seam-lines are refined using the weighted A∗ algorithm based on the edge diagram and the relocated vertices. Our method was tested with three real UAV datasets. Two quantitative terms are introduced to evaluate the results of the proposed method. Preliminary results show that the method is suitable for regular and irregular aligned UAV images for most terrain types (flat or mountainous areas), and is better than the state-of-the-art method in both quality and efficiency based on the test datasets.

Computed Tomography 3-D Imaging of the Metal Deformation Flow Path in Friction Stir Welding

Science.gov (United States)

Schneider, Judy; Beshears, Ronald; Nunes, Arthur C., Jr.

2005-01-01

In friction stir welding (FSW), a rotating threaded pin tool is inserted into a weld seam and literally stirs the edges of the seam together. To determine optimal processing parameters for producing a defect free weld, a better understanding of the resulting metal deformation flow path is required. Marker studies are the principal method of studying the metal deformation flow path around the FSW pin tool. In our study, we have used computed tomography (CT) scans to reveal the flow pattern of a lead wire embedded in a FSW weld seam. At the welding temperature of aluminum, the lead becomes molten and is carried with the macro-flow of the weld metal. By using CT images, a 3-dimensional (3D) image of the lead flow pattern can be reconstructed. CT imaging was found to be a convenient and comprehensive way of collecting and displaying tracer data. It marks an advance over previous more tedious and ambiguous radiographic/metallographic data collection methods.

Mathematical simulation of the behaviour of the spent organic extractive solution near the injection well area in the case of underground disposal

International Nuclear Information System (INIS)

Istomin, A.D.; Noskov, M.D.; Balakhonov, V.G.; Zubkov, A.A.; Egorov, G.F.

2005-01-01

A mathematical model is presented of the processes in the collector seam under combined disposal of organic and radioactive wastes in porous geological strata of deep bedding. The model describes filtration, mass transfer, sorption and desorption of radionuclides, radioactive decay, decomposition of organic components and heat transfer. The computer software is developed. The results of simulating the thermal field dynamics, behaviour of the components of the spent organic extractive solution and water radioactive wastes in the collector seam of deep bedding are presented [ru

Unraveling the Processing Parameters in Friction Stir Welding

Science.gov (United States)

Schneider, Judy; Nunes, Arthur C., Jr.

2005-01-01

In friction stir welding (FSW), a rotating threaded pin tool is translated along a weld seam, literally stirring the edges of the seam together. To determine optimal processing parameters for producing a defect free weld, a better understanding of the resulting metal deformation flow path or paths is required. In this study, various markers are used to trace the flow paths of the metal. X-ray radiographs record the segmentation and position of the wire. Several variations in the trajectories can be differentiated within the weld zone.

Depositional controls on coal distribution and quality in the Eocene Brunner Coal Measures, Buller Coalfield, South Island, New Zealand

Science.gov (United States)

Flores, R.M.; Sykes, R.

1996-01-01

The Buller Coalfield on the West Coast of the South Island, New Zealand, contains the Eocene Brunner Coal Measures. The coal measures unconformably overlie Paleozoic-Cretaceous basement rocks and are conformably overlain by, and laterally interfinger with, the Eocene marine Kaiata Formation. This study examines the lithofacies frameworks of the coal measures in order to interpret their depositional environments. The lower part of the coal measures is dominated by conglomeratic lithofacies that rest on a basal erosional surface and thicken in paleovalleys incised into an undulating peneplain surface. These lithofacies are overlain by sandstone, mudstone and organic-rich lithofacies of the upper part of the coal measures. The main coal seam of the organic-rich lithofacies is thick (10-20 m), extensive, locally split, and locally absent. This seam and associated coal seams in the Buller Coalfield are of low- to high-volatile bituminous rank (vitrinite reflectance between 0.65% and 1.75%). The main seam contains a variable percentage of ash and sulphur. These values are related to the thickening and areal distribution of the seam, which in turn, were controlled by the nature of clastic deposition and peat-forming mire systems, marine transgression and local tidal incursion. The conglomeratic lithofacies represent deposits of trunk and tributary braided streams that rapidly aggraded incised paleovalleys during sea-level stillstands. The main seam represents a deposit of raised mires that initially developed as topogenous mires on abandoned margins of inactive braidbelts. Peat accumulated in mires as a response to a rise in the water table, probably initially due to gradual sea-level rise and climate, and the resulting raised topography served as protection from floods. The upper part of the coal measures consists of sandstone lithofacies of flu vial origin and bioturbated sandstone, mudstone and organic-rich lithofacies, which represent deposits of paralic (deltaic

Investigation of Standing Seam Metal Roofing.

Science.gov (United States)

1986-06-01

assembly is critical to avoid a gap where rain could which a leak will result in expensive water damage to enter. (Vulcraft Nucor Corp.) the building’s...flexible (EPDM) (Vulcraft/ Nucor Corp.) membrane that allows for differential thermal move- ment between the two parts. Connection between the 3...joint design would and possibly the building contents. (ACS Pacific. become critical. ( Vulcraft Nucor (orp.) Inc.) 34 % ,,% 1 %t ASLREQUIRE G/UTTER

Casting and dozing recovers deep seams

Energy Technology Data Exchange (ETDEWEB)

1992-04-01

Juliana Mining Co. has combined cast blasting with a team of dozers to maintain a competitive position at its Amos mine in West Virgina. Up to 100 ft of cover is removed with trucks and loaders, and then the pit is bridged, so the upper material can be placed on top of the spoil. Cast blasting creates two major advantages: short distances and downhill pushes. 5 figs.

FY 2000 survey of the geological structure overseas, etc. Japan-China joint coal exploration - Yu Xian project; 2000 nendo kaigai chishitsu kozo nado chosa - futai shiryoshu. Nippon Chugoku sekitan kyodo tansa Yu Xian project

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

This data book summarized the proceedings and the technical report of the management committee on the Japan-China geological structure survey based on the consultation concluded between NEDO and China's bureau of coal field geology and a report meeting on the Yu Xian project. In the exploration, conducted were the boring survey of 10 boreholes, seismic survey of 2D (71 traverse lines, 180.105km) and 3D (1.5km{sup 2}), VSP (6 holes (345 shots)) and the low velocity band survey (2,072 shots). The geological structure of the area presented the syncline structure with a gentle line associated with foldings and a number of faults and was classified into the medium class or the class of a little complication in the Chinese standard. The number of the faults confirmed in this exploration totaled 57. Coal reserves by coal seam were 157.22 million tons at No. 5 seam and 102.57 million tons at No. 1 seam. The total amount of the two seams was 79.1% of the total coal amount in all area. The coal quality of Nos. 1 and 5 was brown coal - flame coal in the Chinese classification, and subbituminous coal B - subbituminous coal C in the ASTM classification. The coal, however, cannot be used for process raw coal. There is a technical potentiality of the fixed bed pressurized gasification. (NEDO)

PRACTICAL CONTRIBUTIONS TO THE STUDY OF RESISTANCE ASSEMBLIES MADE WITH WARP KNITS

Directory of Open Access Journals (Sweden)

OANA Ioan-Pavel

2014-05-01

Full Text Available Based on the principle that a body to be obtained by sewing the material to provide resistance and the like in the stitching assembly, the experimental study of which developed resistance is compared with the resistance materials to effectively assembled by the assembly line. The experimental values resistance for assemblies were obtained in the testing for resistance to sliding stitch ASTM D 434 using Tinius Olsen HK5T test type machine. The assembly strength was determined for warp knitted fabric and satin charmeuse, made of poly-filamentary wires and mono-filament polyester and polyamide. Resistance assembling is one of the major determinants of the quality of the stitching. It is defined as "the tensile strength or friction." Tenacity stitching seam rupture is the force recorded at its weakest point. Seam abrasion resistance is the number of cycles required friction mesh destruction of seam. It can be said that the strength of the used assembly, the seam 301 is achieved by, in most of the cases, lower resistance knitted studied. In these cases, the primary findings presented, it is clear that the assembly is not appropriate in terms of reliability and maintainability of the product. Such a situation requires a first step to change the type (class of stitch used. Another way to remedy the deficiencies could be using a sewing thread with a lower finesse or strength in grain, especially in the upper loop of wire used in the study-specific.

Report on achievements of research and development of an automatic sewing system in fiscal 1988. High-tech assembling sub-system; 1998 nendo jido hosei system no kenkyu kaihatsu seika hokokusho. Haiteku assemble sub system

Energy Technology Data Exchange (ETDEWEB)

NONE

1989-03-01

The Automatic Sewing System Technology Research Association was commissioned from the Agency of Industrial Science and Technology on research of a production system by apparel types and systematization of an experiment plant. As the research on systematizing the experiment plant, the association is tackling with the researches on a high-speed laser cutting sub-system, a flexible sewing sub-system, a hi-tech assembling sub-system, and a three-dimensional flexible pressing sub-system. This paper reports the achievement of the research and development on the hi-tech assembling sub-system. This system was studied by grouping the system into a seam sewing technology and a three-dimensional sewing technology. The former technology deals with the processes of seam sewing of the side of the left body part in a model wear, sew-up margin division, straightening, and back center seam sewing. The latter technology deals with the sleeve fitting process. Although these processes are the subject of automated system, it is difficult to automate the back collar sewing, shoulder sewing and front collar sewing after the back center seam sewing process to just before the sleeve fitting process. Therefore, these processes are processed by retrofitting and three-dimensional sewing devices, and a control computer to transmit, receive and control the information required for the devices. The utilizing conditions of the sub-system constituting devices and the component technologies are tabulated in a table. (NEDO)

Aerodynamics in the classroom and at the ball park

Science.gov (United States)

Cross, Rod

2012-04-01

Experiments suitable for classroom projects or demonstrations are described concerning the aerodynamics of polystyrene balls. A light ball with sufficient backspin can curve vertically upward through the air, defying gravity and providing a dramatic visual demonstration of the Magnus effect. A ball projected with backspin can also curve downward with a vertical acceleration greater than that due to gravity if the Magnus force is negative. These effects were investigated by filming the flight of balls projected in an approximately horizontal direction so that the lift and drag forces could be easily measured. The balls were also fitted with artificial raised seams and projected with backspin toward a vertical target in order to measure the sideways deflection over a known horizontal distance. It was found that (a) a ball with a seam on one side can deflect either left or right depending on its launch speed and (b) a ball with a baseball seam can also deflect sideways even when there is no sideways component of the drag or lift forces acting on the ball. Depending on the orientations of the seam and the spin axis, a sideways force on a baseball can arise either if there is rough patch on one side of the ball or if there is a smooth patch. A scuff ball with a rough patch on one side is illegal in baseball. The effect of a smooth patch is a surprising new observation.

Welding induced residual stress evaluation using laser-generated Rayleigh waves

Science.gov (United States)

Ye, Chong; Zhou, Yuanlai; Reddy, Vishnu V. B.; Mebane, Aaron; Ume, I. Charles

2018-04-01

Welding induced residual stress could affect the dimensional stability, fatigue life, and chemical resistance of the weld joints. Ultrasonic method serves as an important non-destructive tool for the residual stress evaluation due to its easy implementation, low cost and wide application to different materials. Residual stress would result in the ultrasonic wave velocity variation, which is the so called acoustoelastic effect. In this paper, Laser/EMAT ultrasonic technique was proposed to experimentally study the relative velocity variation ΔV/V of Rayleigh wave, which has the potential to evaluate surface/subsurface longitudinal residual stress developed during the Gas Metal Arc Welding process. Broad band ultrasonic waves were excited by pulsed Q-Switched Nd: YAG laser. An electromagnetic acoustic transducer (EMAT) attached to the welded plates was used to capture the Rayleigh wave signals propagating along the weld seam direction. Different time of flight measurements were conducted by varying the distance between the weld seam and Rayleigh wave propagating path in the range of 0 to 45 mm. The maximum relative velocity difference was found on the weld seam. With the increasing distance away from the weld seam, the relative velocity difference sharply decreased to negative value. With further increase in distance, the relative velocity difference slowly increased and approached zero. The distribution of relative velocity variations indicates that tensile stress appears in the melted zone as it becomes compressive near the heat-affected zone.

Modeling of carbon sequestration in coal-beds: A variable saturated simulation

International Nuclear Information System (INIS)

Liu Guoxiang; Smirnov, Andrei V.

2008-01-01

Storage of carbon dioxide in deep coal seams is a profitable method to reduce the concentration of green house gases in the atmosphere while the methane as a byproduct can be extracted during carbon dioxide injection into the coal seam. In this procedure, the key element is to keep carbon dioxide in the coal seam without escaping for a long term. It is depended on many factors such as properties of coal basin, fracture state, phase equilibrium, etc., especially the porosity, permeability and saturation of the coal seam. In this paper, a variable saturation model was developed to predict the capacity of carbon dioxide sequestration and coal-bed methane recovery. This variable saturation model can be used to track the saturation variability with the partial pressures change caused by carbon dioxide injection. Saturation variability is a key factor to predict the capacity of carbon dioxide storage and methane recovery. Based on this variable saturation model, a set of related variables including capillary pressure, relative permeability, porosity, coupled adsorption model, concentration and temperature equations were solved. From results of the simulation, historical data agree with the variable saturation model as well as the adsorption model constructed by Langmuir equations. The Appalachian basin, as an example, modeled the carbon dioxide sequestration in this paper. The results of the study and the developed models can provide the projections for the CO 2 sequestration and methane recovery in coal-beds within different regional specifics

The coal cleat system: A new approach to its study

Directory of Open Access Journals (Sweden)

C.F. Rodrigues

2014-06-01

Full Text Available After a general analysis regarding the concept of coal “cleat system”, its genetic origin and practical applications to coalbed methane (CBM commercial production and to CO2 geological sequestration projects, the authors have developed a method to answer, quickly and accurately in accordance with the industrial practice and needs, the following yet unanswered questions: (1 how to define the spatial orientation of the different classes of cleats presented in a coal seam and (2 how to determine the frequency of their connectivites. The new available and presented techniques to answer these questions have a strong computer based tool (geographic information system, GIS, able to build a complete georeferentiated database, which will allow to three-dimensionally locate the laboratory samples in the coalfield. It will also allow to better understand the coal cleat system and consequently to recognize the best pathways to gas flow through the coal seam. Such knowledge is considered crucial for understanding what is likely to be the most efficient opening of cleat network, then allowing the injection with the right spatial orientation, of pressurized fluids in order to directly drain the maximum amount of gas flow to a CBM exploitation well. The method is also applicable to the CO2 geological sequestration technologies and operations corresponding to the injection of CO2 sequestered from industrial plants in coal seams of abandoned coal mines or deep coal seams.

Use of the Asturfalia vertical powered support in conjunction with the H-1 shearer in the Centella zone of Polio colliery. Se ha aplicado en la zona conocida por 'Centella' en el Pozo Polio Entibacion Vertical Asturfalia con rozadora H-1 como elemento de arrangue

Energy Technology Data Exchange (ETDEWEB)

1990-06-01

Coaling operations of a 480 metre long panel in the fourth seam in the zone known as Centella at Polio colliery, Spain have now finished. The equipment used was the Asturfalia vertical powered support together with the H-1 shearer. This equipment had been transferred from Fondon colliery and adapted to conditions in the fourth seam. The traditional supports used in Fondon and Samuno collieries were fitted with a base plate and a shield in order to give an operating range of 1,100 mm to 2,060 mm. 1 fig.

Estimating Quartz Reserves Using Compositional Kriging

Directory of Open Access Journals (Sweden)

J. Taboada

2013-01-01

Full Text Available The aim of this study was to determine spatial distribution and volume of four commercial quartz grades, namely, silicon metal, ferrosilicon, aggregate, and kaolin (depending on content in impurities in a quartz seam. The chemical and mineralogical composition of the reserves in the seam were determined from samples collected from outcrops, blasting operations, and exploratory drilling, and compositional kriging was used to calculate the volume and distribution of the reserves. A more accurate knowledge of the deposit ensures better mine planning, leading to higher profitability and an improved relationship with the environment.

Gaining momentum : advanced multilateral technology touted as key to unlocking Manville CBM

International Nuclear Information System (INIS)

Smith, M.

2006-01-01

A new technology developed by a Louisiana-based company called Gardes Energy Services Inc. may be used to develop Canada's Manville coalbed methane (CBM) play. Two Canadian companies have recently agreed to test the patented technology in the Manville play, which has a permeability of only 3 to 4 millidarcies in shallower Manville targets and less than 1 millidarcy in deeper targets. The technology entails the drilling of multiple, radial wells with lateral branches. The 2-string dual injection drilling technique allows non-damaging underbalanced drilling of multiple lateral branches in each seam when combined with the patented Upstock process. The Upstock is then lowered to the lowest seam on a carrier string to redirect the drilling assembly into the first coal seam. Drilling fluid is pumped down the drillstring, activating the drilling assembly's mud motor and guidance system. Injection rates are adjusted according to downhole measurement-while drilling pressure sensors to maintain underbalanced drilling. Continuous circulation through the concentric casing system eliminates the potentially damaging surging that occurs in conventional drilling. By reorienting the bent housing on the drilling motor, branch laterals are added in each coal seam. Once completed, the drilling assembly is pulled, the Upstock is lifted on the carrier string to the next seam of interest, and the process is repeated. The dual annulus process lowers the equivalent circulating density below that of the formation pressure, preventing drilling fluid from invading and damaging the formation. Formation water is typically used as the drilling fluid. Once drilling is completed, an electric submersible pump (ESP) is lowered on tubing to the sump area and water is pumped to surface, allowing the methane to desorb and be produced through perforations into and up the inner annulus. The technique reduces the environmental impact of drilling, as 1 area can be used to drain an area the equivalent of 16

穿层孔吞吐压裂水力强化抽采技术研究及应用%Research and application of gas drainage with hydraulic reinforcement of water stimulation fracture in borehole through strata

Institute of Scientific and Technical Information of China (English)

辛新平; 高建良; 马耕

2014-01-01

为了解决低透气性煤层高效抽采的难题，采用穿层孔吞吐压裂水力强化改善煤层透气性。分析了水力强化工艺穿层孔瓦斯运移产出过程，研究了水力强化对硬煤储层和软煤层中瓦斯渗透率的影响，分析了水力强化对煤体渗透率的作用及增透机理，并进行了现场效果应用。结果表明：穿层孔吞吐压裂技术提高了煤层透气性，形成瓦斯产出通道，在硬煤中水力强化可在顶底板形成“虚拟储层”，瓦斯以渗流为主，软煤中以扩散运移为主；吞吐压裂水力强化通过形成洞穴和裂隙，增加煤层渗透性，减少瓦斯抽采流量衰减系数，提高瓦斯抽采效率。现场实施吞吐压裂水力措施后抽采纯量由14.8 m³增加至31.9~42.8 m³；抽采体积分数由14.1%增加至73.9%~77.5%，该技术具有较高的实际推广应用价值。%In order to solve the problem of how to efficiently extract the coal seam with low permeabil-ity, the hydraulic measures of stimulation fracturing through strata borehole has been adopted to im-prove the permeability of coal seam. The gas migration process through borehole in the hydraulic en-hanced technology has been analyzed. The effect of hydraulic reinforcement measures on hard and soft coal seam permeability has been studied, and the effect and mechanism of hydraulic reinforcement on the permeability of coal mass has been analyzed, and finally, the field experiment of hydraulic fracturing has been carried out. Research results show that the hydraulic measures of stimulation fracturing through strata borehole technology can improve the permeability of coal seam and contribute to form gas flow channel. There is“virtual reservoir”in roof and floor in hard coal seam and the gas shows see-page mainly, while, in soft coal seam gas shows diffusion migration mainly. The hydraulic measures of stimulation fracturing can increase the permeability of coal seam through

The genesis and isotopic composition of carbonates associated with some Permian Australian coals

International Nuclear Information System (INIS)

Gould, K.W.; Smith, J.W.

1979-01-01

Siderite and calcite are the two forms of carbonate commonly associated with Permian Australian coals. The former occurs as disseminated spherulites and is a product of the early post-depositional environment. Isotopic measurements show that the CO 2 fixed as siderite did not result from the direct oxidation of photosynthetically derived materials, but rather from the anaerobic fermentation of these. The higher concentrations of calcite are generally found towards the roofs of coal seams and are characterized by isotopic enrichments to delta 13 C values of +25% PDB. Isotopic exchange between CO 2 and CH 4 within the coal seam is postulated as the mechanism which leads to the formation of isotopically heavy CO 2 . At sites along the seam margins where the CO 2 escapes, interaction with circulating metal ions or preexisting calcite results in the deposition of ''heavy'' calcite. With increasing alteration of coal by thermal metamorphism, the 13 C content of calcites and finally siderites decreases so that it more nearly approaches that of the associated coal. (Auth.)

Fabrication of fine-grain tantalum diffusion barrier tube for Nb3Sn conductors

International Nuclear Information System (INIS)

Hartwig, K. T.; Balachandran, S.; Mezyenski, R.; Seymour, N.; Robinson, J.; Barber, R. E.

2014-01-01

Diffusion barriers used in Nb 3 Sn wire are often fabricated by wrapping Ta sheet into a tube with an overlap seam. A common result of such practice is non-uniform deformation in the Ta sheet as it thins by wire drawing because of non-uniform grain size and texture in the original Ta sheet. Seamless Ta tube with a fine-grain and uniform microstructure would be much better for the diffusion barrier application, but such material is expensive and difficult to manufacture. This report presents results on a new fabrication strategy for Ta tube that shows promise for manufacture of less costly tube with an improved microstructure. The fabrication method begins with seam-welded tube but gives a fine-grain uniform microstructure with little difference between the longitudinal seam weld region and the parent metal after post-weld processing. Severe plastic deformation processing (SPD) applied by area reduction extrusion and tube equal channel angular extrusion (tECAE) are used to refine and homogenize the microstructure. Microstructure and mechanical property results are presented for Ta tubes fabricated by this new processing strategy

Fabrication of fine-grain tantalum diffusion barrier tube for Nb3Sn conductors

Science.gov (United States)

Hartwig, K. T.; Balachandran, S.; Mezyenski, R.; Seymour, N.; Robinson, J.; Barber, R. E.

2014-01-01

Diffusion barriers used in Nb3Sn wire are often fabricated by wrapping Ta sheet into a tube with an overlap seam. A common result of such practice is non-uniform deformation in the Ta sheet as it thins by wire drawing because of non-uniform grain size and texture in the original Ta sheet. Seamless Ta tube with a fine-grain and uniform microstructure would be much better for the diffusion barrier application, but such material is expensive and difficult to manufacture. This report presents results on a new fabrication strategy for Ta tube that shows promise for manufacture of less costly tube with an improved microstructure. The fabrication method begins with seam-welded tube but gives a fine-grain uniform microstructure with little difference between the longitudinal seam weld region and the parent metal after post-weld processing. Severe plastic deformation processing (SPD) applied by area reduction extrusion and tube equal channel angular extrusion (tECAE) are used to refine and homogenize the microstructure. Microstructure and mechanical property results are presented for Ta tubes fabricated by this new processing strategy.

Improved Wallis Dodging Algorithm for Large-Scale Super-Resolution Reconstruction Remote Sensing Images

Directory of Open Access Journals (Sweden)

Chong Fan

2017-03-01

Full Text Available A sub-block algorithm is usually applied in the super-resolution (SR reconstruction of images because of limitations in computer memory. However, the sub-block SR images can hardly achieve a seamless image mosaicking because of the uneven distribution of brightness and contrast among these sub-blocks. An effectively improved weighted Wallis dodging algorithm is proposed, aiming at the characteristic that SR reconstructed images are gray images with the same size and overlapping region. This algorithm can achieve consistency of image brightness and contrast. Meanwhile, a weighted adjustment sequence is presented to avoid the spatial propagation and accumulation of errors and the loss of image information caused by excessive computation. A seam line elimination method can share the partial dislocation in the seam line to the entire overlapping region with a smooth transition effect. Subsequently, the improved method is employed to remove the uneven illumination for 900 SR reconstructed images of ZY-3. Then, the overlapping image mosaic method is adopted to accomplish a seamless image mosaic based on the optimal seam line.

Parallax handling of image stitching using dominant-plane homography

Science.gov (United States)

Pang, Zhaofeng; Li, Cheng; Zhao, Baojun; Tang, Linbo

2015-10-01

In this paper, we present a novel image stitching method to handle parallax in practical application. For images with significant amount of parallax, the more effective approach is to align roughly and globally the overlapping regions and then apply a seam-cutting method to composite naturally stitched images. It is well known that images can be modeled by various planes result from the projective parallax under non-ideal imaging condition. The dominant-plane homography has important advantages of warping an image globally and avoiding some local distortions. The proposed method primarily addresses large parallax problem through two steps: (1) selecting matching point pairs located on the dominant plane, by clustering matching correspondences and then measuring the cost of each cluster; and (2) in order to obtain a plausible seam, edge maps of overlapped area incorporation arithmetic is adopted to modify the standard seam-cutting method. Furthermore, our approach is demonstrated to achieve reliable performance of handling parallax through a mass of experimental comparisons with state-of-the-art methods.

Ruby-Helix: an implementation of helical image processing based on object-oriented scripting language.

Science.gov (United States)

Metlagel, Zoltan; Kikkawa, Yayoi S; Kikkawa, Masahide

2007-01-01

Helical image analysis in combination with electron microscopy has been used to study three-dimensional structures of various biological filaments or tubes, such as microtubules, actin filaments, and bacterial flagella. A number of packages have been developed to carry out helical image analysis. Some biological specimens, however, have a symmetry break (seam) in their three-dimensional structure, even though their subunits are mostly arranged in a helical manner. We refer to these objects as "asymmetric helices". All the existing packages are designed for helically symmetric specimens, and do not allow analysis of asymmetric helical objects, such as microtubules with seams. Here, we describe Ruby-Helix, a new set of programs for the analysis of "helical" objects with or without a seam. Ruby-Helix is built on top of the Ruby programming language and is the first implementation of asymmetric helical reconstruction for practical image analysis. It also allows easier and semi-automated analysis, performing iterative unbending and accurate determination of the repeat length. As a result, Ruby-Helix enables us to analyze motor-microtubule complexes with higher throughput to higher resolution.

High Angle Mining System. Final research report, Sep 80-Jun 83

Energy Technology Data Exchange (ETDEWEB)

Christofferson, D.

1983-06-01

Under Bureau of Mines Contract JO-133925, ESD Corporation developed the High Angle Mining System (HAMS) as a method of extracting coal from seams varying widely in thickness and pitch. The system would normally be employed to extract coal lying beyond the economic limit of a strip or open-pit highwall. It is a surface-controlled operation involving no underground personnel. The HAMS can significantly increase the reserve base of coal that can be economically surface mined. A number of open-pit or surface mines which have moderately or steeply pitched seams were visited and studied. Existing technology was reviewed to identify systems or system components which merited further consideration for the development of the HAMS concept. Conventional and innovative approaches based on augering and two approaches based on slackline excavation were developed in sufficient detail to enable comparison on the basis of operational limitation, recovery ratio, productivity, and economy. The slackline excavator concept employing a projectile bucket was selected as the best approach. The capability of economically mining pitched seams of coal with the HAMS was demonstrated.

New technology for production of granular adding material with nanomodifying additives for steel arc welding

Directory of Open Access Journals (Sweden)

BOLDYREV Alexander Mikhaylovich

2016-12-01

Full Text Available The chemical analysis of metal seam showed that introduction of titanium dioxide with MCA intensifies transition of Al2O3 from slag into metal pool and provides double concentration of titanium in the seam compared to the one which appears in the interaction of bathtub with melted flux AH-47 without TiO2 additives. The presence of oxides of titanium and aluminium of endogenous origin in the melt leads to formation of refractory particles with the center of TiO2 and Al2O3 in it. These particles are the centers of crystallization in the tail part of the molten pool and they remain in seam metal in the form of evenly distributed fine nonmetallic inclusions, which have crystallographic affinity with a matrix (α-iron. That provides the fine-grained seam structure with the raised and stable strength characteristics. This article compares the existing and developed technologies for production of MCA. The granulometric analysis of the powder TiO2 has demonstrated that when MCA is processed in the planetary mill, particles of titanium dioxide are crushed to a nanodimensional order. It is shown that the preparation of MCA in high-energy planetary mill (due to double increase of durability in coupling of the modifier with granulate provides its stable structure, increases the cold resistance (20–25% and stability of strength characteristics along the length of welded seam. Metalgraphic researches determined that the fine-grained structure which linear size of grain is twice smaller than the one obtained in the old technology welding is formed in a seam. However the direct introduction of nanomodifiers in a molten pool through the flux or an electrode wire is not efficient because of their deactivation and high temperature in welding zone. Therefore it was offered to use modifiers in the mix with the cooling macroparticles in case of automatic welding of a bridge metalware under flux using metalchemical additive (MCA. The MCA consists of a chopped

Seismic applications in CBM exploration and development

Energy Technology Data Exchange (ETDEWEB)

Richardson, S.E.; Lawton, D.C. [Calgary Univ., AB (Canada)

2002-07-01

This Power Point presentation reviewed seismic methods, coal seam seismology, seismology and coalbed methane (CBM) development, and time-lapse seismic imaging with reference to numerical modelling and physical testing. The issue of resolution versus detection in various seismic methods was discussed. The thinnest resolvable beds are usually about 1.0 m thick. Coal zones with thin seams can be mapped using seismic reflection, but individual seams are difficult to resolve in field data. In terms of coal seismology, it was noted that seismic surveys make it possible to identify seam thickness, field geometry, subsurface structuring and facies changes. Facies model make it possible to determine the depositional environment, coal type, coal quality and lateral continuity. Some successes in coal seismology include the Cedar Hill and Ferron fields in the San Juan Basin. Numerical modelling methods include digital dipole compressional sonic and density well logs through Ardley Coal Zone, P-wave synthetic seismograms generated in SYNTH (MATLAB), and the alteration of density/velocity values to create new seismograms. Another numerical method is to take the difference between original and altered seismograms. It was shown that dewatering causes a decrease in velocity of about 20 per cent, and a 15 per cent decrease in density. Changes as small as 5 per cent in reservoir properties can be successfully imaged. It was concluded that the identification of dewatered zones allow for optimal positioning of development wells. Further physical testing will involve wet and dry p-wave velocities, s-wave velocities will be tested, and velocities will be measured under pressure. 2 tabs., 10 figs.

Forecast and Prevention of Coal and Gas Outbursts in the Case of Application of a New Mining Method - Drilling of a Coal Pillar

Directory of Open Access Journals (Sweden)

Vlastimil Hudeček

2010-10-01

Full Text Available Coal and gas outbursts are one of risk factors accompanying the mining of coal in low seams in the Ostrava-Karviná Coalfield.At the use of the method of longwall mining, all coal reserves have not been mined out owing to tectonic faults. For mining outthe residual reserves, the application of a new mining method - drilling of a coal pillar was proposed.The method of mining of a coal seam utilizing long large diameter boreholes is verified in the Paskov Mine (company OKD, JSC –Czech Republic under conditions of rock mass with hazard of rock and gas outbursts in localities of residual pillars left in seams afterfinishing the mining operations performed with using the classical method of longwall working along the strike. [5]Forecast and preventive measures applied to the verification of the new method were based on previous experience withthe mining of seams with hazard of coal and gas outbursts. They accepted fully valid legislation, i.e. Ordinance of Ostrava RegionalMining Authority No. 3895/2002 and supplementary materials (Instructions and Guidelines. The proposed measures respectedthe character of the method being verified. [4]For all areas being mined, projects containing also chapters specifying the problems of ensuring the safety of mining worksand operation under conditions of hazard of coal and gas outbursts were prepared.In the contributions, basic proposals for the principles of coal and gas outburst forecast and prevention when applying the newmining method – drilling of a coal pillar are presented

Influence of thickness of zinc coating on CMT welding-brazing with AlSi5 alloy wire

Science.gov (United States)

Jin, Pengli; Wang, Zhiping; Yang, Sinan; Jia, Peng

2018-03-01

Effect of thickness of zinc coating on Cold Mattel Transfer (CMT) brazing of aluminum and galvanized steel is investigated. The thickness of zinc coating is 10 μm, 30 μm, and 60 μm, respectively. A high-speed camera was used to capture images of welding process of different specimens; the microstructure and composition analyses of the welding seam were examined by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS); the mechanical properties were measured in the form of Nano-indentation experiments. The results showed that arc characteristics and metal transfer behavior were unsteady at the beginning of welding process and that became stable after two cycles of CMT. With the thickness of zinc coating thickening, arc characteristics and metal transfer behaviors were more deteriorated. Compared with 10 μm and 30 μm, clad appearance of 60 μm was straight seam edges and a smooth surface which wetting angle was 60°. Zinc-rich zone at the seam edges was formed by zinc dissolution and motel pool oscillating, and zinc content of 10 μm and 30 μm were 5.8% and 7.75%. Zinc content of 60 μm was 14.61%, and it was a belt between galvanized steel and welding seam. The thickness of intermetallic compounds layer was in the range of 1-8 μm, and it changed with the thickness of zinc coating. The average hardness of the reaction layer of 60 μm is 9.197 GPa.

Study on Fluid-solid Coupling Mathematical Models and Numerical Simulation of Coal Containing Gas

Science.gov (United States)

Xu, Gang; Hao, Meng; Jin, Hongwei

2018-02-01

Based on coal seam gas migration theory under multi-physics field coupling effect, fluid-solid coupling model of coal seam gas was build using elastic mechanics, fluid mechanics in porous medium and effective stress principle. Gas seepage behavior under different original gas pressure was simulated. Results indicated that residual gas pressure, gas pressure gradient and gas low were bigger when original gas pressure was higher. Coal permeability distribution decreased exponentially when original gas pressure was lower than critical pressure. Coal permeability decreased rapidly first and then increased slowly when original pressure was higher than critical pressure.

The mechanism and characteristics of ground movement and strata failure caused by mining

Energy Technology Data Exchange (ETDEWEB)

Tianquan, L. (Central Coal Mining Research Institute, Beijing (China))

1988-01-01

Analyzes strata movement and ground subsidence caused by underground coal mining. Five types of strata failure during and after underground coal mining are comparatively evaluated: caving zone, fractured zone, bending zone, arched caving, bending with continuous ground movement, sinkhole formation. Effects of coal seam thickness, dip angle, coal panel dimensions, rock stratification and mechanical properties on dimensions and distribution of failure zones in rock strata are investigated. Strata movement during level and steep seam mining is comparatively evaluated. Causes of continuous ground surface deformation and discontinuous deformation are analyzed. Rock strata properties and water influx, which influence sinkhole hazards, are discussed.

New standards for digital radiography and qualification of detectors; Neue Standards zur Digitalen Radiographie und Qualifizierung von Detektoren

Energy Technology Data Exchange (ETDEWEB)

Ewert, Uwe; Zscherpel, Uwe [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany)

2017-08-01

The contribution describes the most important standards for radiographic examinations that are revised in different committees. Information is given on new requirements esp. on revised parameters that have to be considered in practical testing procedures and classification. Actually for the revision of ISO 17636-1/2 in 2018 user questions are collected concerning weld seam testing. The DIN 25435 standards for weld seam testing in nuclear technology have been translated into English. Revisions of ASTM standards have to be considered in the actual EN and ISO standards. Since several years the International Institute of Welding (IIW) is also revising the international standards.

The Census of Marine Life on Seamounts: results from a global science program

Science.gov (United States)

Stocks, K.; Clark, M.; Rowden, A.; Consalvey, M.

2010-12-01

CenSeam (a Global Census of Marine Life on Seamounts) is a network of more than 500 scientists, policy makers and conservationists around the world. These participants are collaborating to increase our understanding of the factors driving seamount community composition and diversity, such that we can better understand and manage the effects of human activities. The major scientific outcomes of the CenSeam community include the findings that 1) Seamount community composition is often similar to surrounding habitats; however, community structure can be different. 2) Contrary to conventional wisdom, few seamounts follow island biogeography predictions. 3) Seamounts can support a higher benthic biomass than surrounding habitats. 4) Seamounts can support species and communities new to science, and represent range extensions for known species, which are being described from CenSeam voyages. 5) For the first time, the extent of the vulnerability and risk to seamount benthic communities from fishing has been quantified. 6) Whilst long assumed, CenSeam researchers have demonstrated that seamount communities are disturbed by fishing and are slow to recover. And 7) Seamounts might act as repositories of biodiversity during future periods of extreme environmental change, as they have likely done in the past. The major products of Censeam include 1) a book synthesizing seamount knowledge: Seamounts: Ecology, Fisheries and Conservation (from Blackwell Publishing); 2) a recent review of the structure and function of seamount benthic communities, human impacts, and seamount management and conservation (Ann Rev Mar Sci); 3) hundreds of scientific publications, including Special Issues in Marine Ecology and Oceanography (in collaboration with the Seamount Biogeogsciences Network), and a Special Collection in PLoSONE; 4) guidance documents and formal advising for seamount management communities, including the United Nations Environment Program, International Seabed Authority

Test and evaluate the tri-gas low-Btu coal-gasification process. Final report, October 21, 1977-October 31, 1980

Energy Technology Data Exchange (ETDEWEB)

Zabetakis, M.G.

1980-12-01

This report describes the continuation of work done to develop the BCR TRI-GAS multiple fluidized-bed gasification process. The objective is the gasification of all ranks of coals with the only product being a clean, low-Btu fuel gas. Design and construction of a 100 lb/h process and equipment development unit (PEDU) was completed on the previous contract. The process consists of three fluid-bed reactors in series, each having a specific function: Stage 1 - pretreatment; Stage 2- - gasification; Stage 3 - maximization of carbon utilization. Under the present contract, 59 PEDU tests have been conducted. A number of these were single-stage tests, mostly in Stage 1; however, integrated PEDU tests were conducted with a western coal (Rosebud) and two eastern coals (Illinois No. 6 and Pittsburgh seam). Both Rosebud and Pittsburgh seam coals were gasified with the PEDU operating in the design mode. Operation with Illinois No. 6 seam coal was also very promising; however, time limitations precluded further testing with this coal. One of the crucial tasks was to operate the Stage 1 reactor to pretreat and devolatilize caking coals. By adding a small amount of air to the fluidizing gas, the caking properties of the coal can be eliminated. However, it was also desirable to release a high percentage of the volatile matter from the coal in this vessel. To accomplish this, the reactor had to be operated above the agglomerating temperature of caking coals. By maintaining a low ratio of fresh to treated coal, this objective was achieved. Both Illinois No. 6 and Pittsburgh seam coals were treated at temperatures of 800 to 900 F without agglomerating in the vessel.

Optical design and development of a fiber coupled high-power diode laser system for laser transmission welding of plastics

Science.gov (United States)

Rodríguez-Vidal, Eva; Quintana, Iban; Etxarri, Jon; Azkorbebeitia, Urko; Otaduy, Deitze; González, Francisco; Moreno, Fernando

2012-12-01

Laser transmission welding (LTW) of thermoplastics is a direct bonding technique already used in different industrial applications sectors such as automobiles, microfluidics, electronics, and biomedicine. LTW evolves localized heating at the interface of two pieces of plastic to be joined. One of the plastic pieces needs to be optically transparent to the laser radiation whereas the other part has to be absorbent, being that the radiation produced by high power diode lasers is a good alternative for this process. As consequence, a tailored laser system has been designed and developed to obtain high quality weld seams with weld widths between 0.7 and 1.4 mm. The developed laser system consists of two diode laser bars (50 W per bar) coupled into an optical fiber using a nonimaging solution: equalization of the beam parameter product (BPP) in the slow and fast axes by a pair of step-mirrors. The power scaling was carried out by means of a multiplexing polarization technique. The analysis of energy balance and beam quality was performed considering ray tracing simulation (ZEMAX) and experimental validation. The welding experiments were conducted on acrylonitrile/butadiene/styrene (ABS), a thermoplastic frequently used in automotive, electronics and aircraft applications, doped with two different concentrations of carbon nanotubes (0.01% and 0.05% CNTs). Quality of the weld seams on ABS was analyzed in terms of the process parameters (welding speed, laser power and clamping pressure) by visual and optical microscope inspections. Mechanical properties of weld seams were analyzed by mechanical shear tests. High quality weld seams were produced in ABS, revealing the potential of the laser developed in this work for a wide range of plastic welding applications.

Lignite and tin ores exploration in southern part of Thailand by using nuclear track-etch detectors

International Nuclear Information System (INIS)

Chittrakarn, T.; Boonnummar, R.; Pongsuwan, T.; Nuannin, P.; Kaew-On, C.

1993-01-01

Both lignite and tin mines in Southern of Thailand are associated with uranium ore. In lignite exploration, Bangpudum Lignite Mine at Krabi Province was chosen for this studied because we know the exact location and deposition of coal seam by using other geophysical technique and also confirm by borehole. The size 1x2 cm 2 of cellulose nitrate CN-85 films were used, each film was stuck at the inner bottom of a softdrink cup. Each cup was put up side down at the bottom of a borehole about 75 cm depth from the earth surface and laid about 10 m apart. All the cups were put in the hole along the line in order to cover about 280 metre in the cross sectional direction long of the known coal seam. After one month, all the film detectors were collected and etched with 6.25N NaOH at 60 o C about 25 minutes long in order to enlarge the latent alpha registration tracks. These alpha particles were emitted from radon gas (Rn-222) which was generated from uranium associated with lignite ore. The registration track density per area of each CN-85 film was studied by optical microscope at 400x magnifications. We found that the track densities of the films have high correlation with the depth of the known coal seam while high and low track densities will correspond to the shallow and deep coal seam respectively. Also, track density was significantly higher than background. A similar manner of experiment was designed for tin ore exploration at Ronpibul district, Nakorn Si Thammarat province. The result is in progress and will present at the conference. (Author)

Sequence stratigraphic analysis and the origins of Tertiary brown coal lithotypes, Latrobe Valley, Gippsland Basin, Australia

Energy Technology Data Exchange (ETDEWEB)

Holdgate, G R; Kershaw, A P; Sluiter, I R.K. [Monash University, Clayton, Vic. (Australia). Dept. of Earth Sciences

1995-11-01

Sequence analysis methods have been applied to the onshore Gippsland Basin and to the Latrobe Valley Group coal measures. In the east of the Latrobe Valley evidence for marine transgressions into the coal measures are recorded in most of the interseam sediment splits by the presence of contained foraminifer and dinoflagellates. To the west these splits pinch out into continuous coal. However, they can be followed westwards as enhanced organic sulphur levels along sharply defined boundaries between light coal lithotypes below and dark coal lithotypes above. The dark lithotype immediately overlying each of these boundaries contains the highest sulphur value and warmer climate pollen assemblages. Colorimeter and lithotype logging supports an upwards lightening cyclicity to coal colour at 12-20 m intervals through the approx. 100 m thick seams, with cycle boundaries defined at sharp planar to undulating surfaces. The lightening upward lithotype cycles together with their unique boundary conditions are interpreted as parasequences and parasequence boundaries respectively. Each major coal seam can comprise up to five parasequences and is interpreted to represent deposition during an outbuilding high stand systems tract at one of several maximum periods of Tertiary coastal onlap. Stratigraphic correlation of the sequence boundaries identified in the coal measures to the internationally dated marine Seaspray Group, provides a basis for chronostratigraphic correlation of the coal successions to the coastal onlap charts of Haq et al (1989). It appears that each major seam is confined to high standards of third order eustatic cycles. It follows that the lithotype cycles that comprise each seam are related to fourth order eustatic cycles. 49 refs., 11 figs., 1 tab.

Electron beam welding of high-purity copper accelerator cells

International Nuclear Information System (INIS)

Delis, K.; Haas, H.; Schlebusch, P.; Sigismund, E.

1986-01-01

The operating conditions of accelerator cells require high thermal conductivity, low gas release in the ultrahigh vacuum, low content of low-melting metals and an extremely good surface quality. In order to meet these requirements, high-purity copper (OFHC, Grade 1, according to ASTM B 170-82 and extra specifications) is used as structural material. The prefabricated components of the accelerator cells (noses, jackets, flanges) are joined by electron beam welding, the weld seam being assessed on the basis of the same criteria as the base material. The welding procedures required depend, first, on the material and, secondly, on the geometries involved. Therefore experimental welds were made first on standardized specimens in order to study the behaviour of the material during electron beam welding and the influence of parameter variations. The welded joints of the cell design were planned on the basis of these results. Seam configuration, welding procedures and the parameters were optimized on components of original geometry. The experiments have shown that high-quality joints of this grade of copper can be produced by the electron beam welding process, if careful planning and preparation of the seams and adequate containment of the welding pool are assured. (orig.)

Poromechanical response of naturally fractured sorbing media

Science.gov (United States)

Kumar, Hemant

The injection of CO2 in coal seams has been utilized for enhanced gas recovery and potential CO2 sequestration in unmineable coal seams. It is advantageous because as it enhances the production and significant volumes of CO2 may be stored simultaneously. The key issues for enhanced gas recovery and geologic sequestration of CO2 include (1) Injectivity prediction: The chemical and physical processes initiated by the injection of CO2 in the coal seam leads to permeability/porosity changes (2) Up scaling: Development of full scale coupled reservoir model which may predict the enhanced production, associated permeability changes and quantity of sequestered CO2. (3) Reservoir Stimulation: The coalbeds are often fractured and proppants are placed into the fractures to prevent the permeability reduction but the permeability evolution in such cases is poorly understood. These issues are largely governed by dynamic coupling of adsorption, fluid exchange, transport, water content, stress regime, fracture geometry and physiomechanical changes in coals which are triggered by CO 2 injection. The understanding of complex interactions in coal has been investigated through laboratory experiments and full reservoir scale models are developed to answer key issues. (Abstract shortened by ProQuest.).

Service models for remote healthcare monitoring systems.

Science.gov (United States)

Moorman, Bridget A

2010-01-01

These scenarios reflect where the future is heading for remote health monitoring technology and service expectations. Being able to manage a "system of systems" with timely service hand-off over seams of responsibility and system interfaces will become very important for a BMET or clinical engineer. These interfaces will include patient homes, clinician homes, commercial/civilian infrastructure, public utilities, vendor infrastructure as well as internal departmental domains. Concurrently, technology is changing rapidly resulting in newer software delivery modes and hardware appliances as well as infrastructure changes. Those who are able to de-construct the complex systems and identify infrastructure assumptions and seams of servicing responsibility will be able to better understand and communicate the expectations for service of these systems. Moreover, as identified in Case 1, prodigious use of underlying system monitoring tools (managing the "meta-data") could move servicing of these remote systems from a reactive approach to a proactive approach. A prepared healthcare organization will identify their current and proposed future service combination use cases and design service philosophies and expectations for those use cases, while understanding the infrastructure assumptions and seams of responsibility. This is the future of technical service to the healthcare clinicians and patients.

Crosswell Imaging Technology & Advanced DSR Navigation for Horizontal Directional Drilling

Energy Technology Data Exchange (ETDEWEB)

Larry Stolarczyk

2008-08-08

The objective of Phase II is to develop and demonstrate real-time measurement-while-drilling (MWD) for guidance and navigation of drill strings during horizontal drilling operations applicable to both short and long holes. The end product of Phase II is a functional drill-string assembly outfitted with a commercial version of Drill String Radar (DSR). Project Objectives Develop and demonstrate a dual-phase methodology of in-seam drilling, imaging, and structure confirmation. This methodology, illustrated in Figure 1, includes: (1) Using RIM to image between drill holes for seam thickness estimates and in-seam structures detection. Completed, February 2005; and (2) Using DSR for real-time MWD guidance and navigation of drillstrings during horizontal drilling operations. Completed, November 2008. As of November 2008, the Phase II portion of Contract DE-FC26-04NT42085 is about 99% complete, including milestones and tasks original outlined as Phase II work. The one percent deficiency results from MSHA-related approvals which have yet to be granted (at the time of reporting). These approvals are pending and are do not negatively impact the scope of work or project objectives.

Achievement report for fiscal 1989 on the research and development of automatic sewing system. High-tech assemble subsystem; 1989 nendo jido hosei system no kenkyu kaihatsu seika hokokusho. High tech assemble subsystem

Energy Technology Data Exchange (ETDEWEB)

NONE

1990-03-01

A report is compiled about the above-named system being developed under the large-scale industrial technology development project. In the research and development of automatic sewing technologies, the cloth manipulation type module is being improved and the entirety of the automatic sewing system and a cloth opening system are under development, and now they are believed to be usable in the experimental plant. In the research and development of opening seam press technologies, overall design improvement and manufacture are accomplished for the opening seam press system based on the result of systematization researches, and the system is now fit for conveying and positioning the cloth on its way from the previous stage to the next stage. In the research on the ventral coordination control type assemble sewing technology, every unit involved is improved, designed, and manufactured, and software programs for their control are also developed and improved. It is now enhanced in reliability, operationality, workability, and seam quality, and is expected to be usable in the experimental plant. As for the research on retrofitting, it is found in a reliability test that its reliability is still short of the target value of 99.9%. (NEDO)

Analysis on High Temperature Aging Property of Self-brazing Aluminum Honeycomb Core at Middle Temperature

Directory of Open Access Journals (Sweden)

ZHAO Huan

2016-11-01

Full Text Available Tension-shear test was carried out on middle temperature self-brazing aluminum honeycomb cores after high temperature aging by micro mechanical test system, and the microstructure and component of the joints were observed and analyzed using scanning electron microscopy and energy dispersive spectroscopy to study the relationship between brazing seam microstructure, component and high temperature aging properties. Results show that the tensile-shear strength of aluminum honeycomb core joints brazed by 1060 aluminum foil and aluminum composite brazing plate after high temperature aging(200℃/12h, 200℃/24h, 200℃/36h is similar to that of as-welded joints, and the weak part of the joint is the base metal which is near the brazing joint. The observation and analysis of the aluminum honeycomb core microstructure and component show that the component of Zn, Sn at brazing seam is not much affected and no compound phase formed after high temperature aging; therefore, the main reason for good high temperature aging performance of self-brazing aluminum honeycomb core is that no obvious change of brazing seam microstructure and component occurs.

Competitiveness and potentials of UCG-CCS on the European energy market

Science.gov (United States)

Kempka, T.; Nakaten, N.; Schlüter, R.; Fernandez-Steeger, T.; Azzam, R.

2009-04-01

The world-wide coal reserves can satisfy the world's primary energy demand for several hundred years. However, deep coal deposits with seams of low thickness and structural complexity do currently not allow an economic exploitation of many deposits. Here, underground coal gasification (UCG) can offer an economical approach for coal extraction. The intended overall process relies on coal deposit exploitation using directed drillings located at the coal seam base and the subsequent in situ coal conversion into a synthesis gas. The resulting synthesis gas is used for electricity generation in a combined cycle plant at the surface. A reduction of the CO2 emissions resulting from the combined process is realized by subsequent CO2 capture and its injection into the previously gasified coal seams. The scope of the present study was the investigation of UCG-CCS competitiveness on the European energy market and the determination of the impacting factors. For that purpose, a modular model for calculation of UCG-CCS electricity generation costs was implemented and adapted to the most relevant process parameters. Furthermore, the range of energy supply coverage was estimated based on different German energy generation scenarios.

Dispersion calculation method based on S-transform and coordinate rotation for Love channel waves with two components

Science.gov (United States)

Feng, Lei; Zhang, Yugui

2017-08-01

Dispersion analysis is an important part of in-seam seismic data processing, and the calculation accuracy of the dispersion curve directly influences pickup errors of channel wave travel time. To extract an accurate channel wave dispersion curve from in-seam seismic two-component signals, we proposed a time-frequency analysis method based on single-trace signal processing; in addition, we formulated a dispersion calculation equation, based on S-transform, with a freely adjusted filter window width. To unify the azimuth of seismic wave propagation received by a two-component geophone, the original in-seam seismic data undergoes coordinate rotation. The rotation angle can be calculated based on P-wave characteristics, with high energy in the wave propagation direction and weak energy in the vertical direction. With this angle acquisition, a two-component signal can be converted to horizontal and vertical directions. Because Love channel waves have a particle vibration track perpendicular to the wave propagation direction, the signal in the horizontal and vertical directions is mainly Love channel waves. More accurate dispersion characters of Love channel waves can be extracted after the coordinate rotation of two-component signals.

Measurement of sub-surface strata behaviour in bord and pillar mining: a case study

International Nuclear Information System (INIS)

Krishna, R.

1991-01-01

Ranigunj coalfield (India) has been facing significant problems due to subsidence as a result of underground mining of coal seams. The occurrence of the thick seams in close proximity, shallow depth, great variation in the nature of superincumbent strata from site to site, followed by the slow rate of extraction, has aggravated subsidence problems. In the recent past, many such workings have collapsed, damaging a large number of surface structures. In view of the aforesaid need, a comprehensive project financed by the Ministry of Energy (Coal), was undertaken by the Department of Mining Engineering, Indian Institute of Technology, Kharagpur, at a Colliery in Ranigunj Coalfield. This investigation revealed that the caving horizon occurred at 4 times the extracted seam height, which differs from the findings in the UK, USA, and Australia. Also, it appears possible to estimate strata displacements from geological and physicomechanical information from the overlying rocks using the bending moment principle. Further, it was observed that the shallow workings could give rise to a sink hole type of subsidence, which is dangerous and could adversely affect the environment, safety of the public and properties. 11 refs., 13 figs., 1 tab

Customized excavators beat the odds

Energy Technology Data Exchange (ETDEWEB)

1991-10-01

Blackstone Mining, launched in 1983, is based in eastern Ohio, near Cadiz and specializes in stripping small properties for Ohio Edison. Specially modified hydraulic excavators and an efficient mining technique allow the mining of marginal coal deposits. In 1986 Ken McBeth, the company's founder begun using a Cat 245 hydraulic excavator to cleanly and efficiently load coal and also remove overburden. Modifications include: a mass excavator boom 5 feet longer to better reach over the sides of haul trucks and load from higher benches; and larger hydraulic cylinders to maintain earthmoving production. McBeth also devised a fast economical technique for extracting coal from the thin, narrow seams. Soft cover material is removed by excavator; the remaining sand and limestone are blasted to within 2 feet of the seam; the remaining material is removed by an agricultural tractor with a blade; an excavator loads the coal into haul trucks starting at the toe of the face and working backwards. Haul trucks are not placed directly on the seam. This prevents contamination, reducing the price of the coal. There is no wash plant; the coal is hauled direct to the utility. 4 photos.

Analysis and Assessment of Parameters Shaping Methane Hazard in Longwall Areas

Directory of Open Access Journals (Sweden)

Eugeniusz Krause

2013-01-01

Full Text Available Increasing coal production concentration and mining in coal seams of high methane content contribute to its growing emission to longwall areas. In this paper, analysis of survey data concerning the assessment of parameters that influence the level of methane hazard in mining areas is presented. The survey was conducted with experts on ventilation and methane hazard in coal mines. The parameters which influence methane hazard in longwall areas were assigned specific weights (numerical values. The summary will show which of the assessed parameters have a strong, or weak, influence on methane hazard in longwall areas close to coal seams of high methane content.

Plasma Arc Augmented CO2 laser welding

DEFF Research Database (Denmark)

Bagger, Claus; Andersen, Mikkel; Frederiksen, Niels

2001-01-01

In order to reduce the hardness of laser beam welded 2.13 mm medium strength steel CMn 250, a plasma arc has been used simultaneously with a 2.6 kW CO2 laser source. In a number of systematic laboratory tests, the plasma arc current, plasma gas flow and distance to the laser source were varied...... with all laser parameters fixed. The welds were quality assessed and hardness measured transversely to the welding direction in the top, middle and root of the seam. In the seams welded by laser alone, hardness values between 275 and 304 HV1 were measured, about the double of the base material, 150 HV1...

White Flame Energy switches to backhoes

Energy Technology Data Exchange (ETDEWEB)

Fiscor, S.

2005-06-01

The mountaintop coal operator, White Flame Energy has switched to different truck-shovel arrangement. Along with many surface mining operations throughout central Appalachia, the company is using hoe-configured hydraulic excavators as opposed to the traditional front-shovel arrangements. Located in Varney, WV, White Flame Energy uses two Terex O & K mining shovels, an RH170 and an RH 200, which have the capacity to move 2 million cu yards per month from five seams, primarily the Coalburg, Stockton, and No 5 Block and associated rider seams. The article records conversations on the operations with Mike Vines, the general manager, and Don Nicewonder, the owner of White Flame Energy. 2 photos.

Underground gasification of coal. [Newman Spinney

Energy Technology Data Exchange (ETDEWEB)

1950-06-16

This article gives an account of the experimental work on underground gasification at Newman Spinney near Sheffield, England. An attempt was made to develop the percolation technique in flat coal seams but to demonstrate first that gas can be made underground. A borehole system was created on an opencast site where an exposed seam face would allow horizontal drilling to be carried out. Details of trails are given, and drilling techniques, electromagnetic device developed by the Great Britain Post Office Research Branch and radioactive location developed by the Anglo-Iranian Oil Company. An account is given of the inauguration of a series of experiments on May 22, 1950.

ARTIFICIAL NEURAL NETWORK AND FUZZY LOGIC CONTROLLER FOR GTAW MODELING AND CONTROL

Institute of Scientific and Technical Information of China (English)

无

2002-01-01

An artificial neural network(ANN) and a self-adjusting fuzzy logic controller(FLC) for modeling and control of gas tungsten arc welding(GTAW) process are presented. The discussion is mainly focused on the modeling and control of the weld pool depth with ANN and the intelligent control for weld seam tracking with FLC. The proposed neural network can produce highly complex nonlinear multi-variable model of the GTAW process that offers the accurate prediction of welding penetration depth. A self-adjusting fuzzy controller used for seam tracking adjusts the control parameters on-line automatically according to the tracking errors so that the torch position can be controlled accurately.

Theoretical basis for transfer of laboratory test results of grain size distribution of coal to real object

Energy Technology Data Exchange (ETDEWEB)

Sikora, W; Chodura, J [Politechnika Sladska, Gliwice (Poland). Instytut Mechanizacji Gornictwa

1989-01-01

Evaluates a method for forecasting size distribution of black coal mined by shearer loaders in one coal seam. Laboratory tests for determining coal comminution during cutting and haulage along the face are analyzed. Methods for forecasting grain size distribution of coal under operational conditions using formulae developed on the basis of laboratory tests are discussed. Recommendations for design of a test stand and test conditions are discussed. A laboratory stand should accurately model operational conditions of coal cutting, especially dimensions of the individual elements of the shearer loader, geometry of the cutting drum and cutting tools, and strength characteristics of the coal seam. 9 refs.

Production methods and costs of oxygen free copper canisters for nuclear waste disposal

International Nuclear Information System (INIS)

Rajainmaeki, H.; Nieminen, M.; Laakso, L.

1991-08-01

The fabrication technology and costs of various manufacturing alternatives to make large copper canisters for spent fuel repository are discussed. The capsule design is based on the TVO's new advanced cold process concept where a steel canister is surrounded by the oxygen free copper canister. This study shows that already at present there exist several possible manufacturing routes, which result in consistently high quality canisters. Hot rolling, bending and EB-welding the seam is the best way to assure the small grain size which is preferable for the best inspectability of the final EB-welded seam of the lid. The same route turns out also to be the most economical

Production methods and costs of oxygen free copper canisters for nuclear waste disposal

International Nuclear Information System (INIS)

Rajainmaeki, H.; Nieminen, M.; Laakso, L.

1991-06-01

The fabrication technology and costs of various manufacturing alternatives to make large copper canisters for spent fuel repository are discussed. The capsule design is based on the TVO's new advanced cold process concept where a steel canister is surrounded by the oxygen free copper canister. This study shows that already at present there exist several possible manufacturing routes, which results in consistently high quality canisters. Hot rolling, bending and EB-welding the seam is the best way to assure the small grain size which is preferable for the best inspectability of the final EB-welded seam of the lid. The same route turns out also to be the most economical. (au)

Expeditionary Border Security Operations: Eliminating the Seams

National Research Council Canada - National Science Library

Zinno, Michael J

2008-01-01

.... This convergence greatly expands the scope and capability of each individual terrorist or criminal organization and the cumulative effect can overwhelm the security forces of many nations and provide...

Zulia rich coal seams to fuel Venezuela

Energy Technology Data Exchange (ETDEWEB)

1983-06-16

In March, 1982, Carbozulia awarded a contract to Fluor Corp. to provide basic engineering services, including mine planning and geology, for the two-phase project. The open pit mine and ancillary facilities, valued at more than $200 million, will provide steam and metallurgical coal for domestic use. The site, Mina Paso Diablo, is located about 60 miles northwest of Maracaibo. Upon phase one completion sometime in 1987, the mill will start production, gradually increasing to 4 million metric-tons-per-year. This will increase to 6.4 million metric tons when phase two is completed. In addition to the mine, the Venezuelan government plans to build an industrial complex along Lake Maracaibo. Corpozulia will build a steel-rolling mill and add a 350,000 metric tons-per-year coking oven, which will consume about 7% of the mine's metallurgical-coal production. Another government-owned firm, Electric Energy of Venezuela, plans to build a thermo-electric plant nearby. Two 250-megawatt units are planned initially, with potential to add another six units. At full capacity, the plant will burn more than 90% of the coal produced from the mine. Mina Paso Diablo contains one of Latin America's largest proven coal reserves - about 350 million metric tons - with guesstimates running as high as 4 billion metric tons for the Zulia coal basin. The coal is of superior quality, running about 12,000 to 13,000 Btu's per lb. with a low ash and sulphur content.

Dust-control for thick-seam wall mines.

CSIR Research Space (South Africa)

Belle, BK

2002-02-01

Full Text Available configuration and the belt curtains on the shearer. 3. Install, and evaluate the efficiency of, the physical shield curtains (conveyor belt or other flexible material) hanging from the shield structure inside the shield leg area at every 4th shield to reduce... and 1997, coal production hovered around the 50 million tonnes-a-year level (UK DTI, 2001). Currently, there are 16 producing underground mines in the UK, which includes 15 longwall faces, face lengths range from 250 m to 300 m (Creedy, 2001). Most...

The application of a coupled artificial neural network and fault tree analysis model to predict coal and gas outbursts

Energy Technology Data Exchange (ETDEWEB)

Ruilin, Zhang [School of Safety Science and Engineering, Henan Polytechnic University, Jiaozuo, Henan Province, 454003, PR (China); Lowndes, Ian S. [Process and Environmental Research Division, Faculty of Engineering, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom)

2010-11-01

This paper proposes the use of a coupled fault tree analysis (FTA) and artificial neural network (ANN) model to improve the prediction of the potential risk of coal and gas outburst events during the underground mining of thick and deep Chinese coal seams. The model developed has been used to investigate the gas emission characteristics and the geological conditions that exist within the Huaibei coal mining region, Anhui province, China. The coal seams in this region exhibit a high incidence of coal and gas outbursts. An analysis of the results obtained from an initial application of an FTA model, identified eight dominant model parameters related to the gas content or geological conditions of the coal seams, which characterize the potential risk of in situ coal and gas outbursts. The eight dominant model parameters identified by the FTA method were subsequently used as input variables to an ANN model. The results produced by the ANN model were used to develop a qualitative risk index to characterize the potential risk level of occurrence of coal and gas outburst events. Four different potential risk alarm levels were defined: SAFE, POTENTIAL, HIGH and STRONG. Solutions to the prediction model were obtained using a combination of quantitative and qualitative data including the gas content or gas pressure and the geological and geotechnical conditions of coal seams. The application of this combined solution method identified more explicit and accurate model relationships between the in situ geological conditions and the potential risk of coal and gas outbursts. An analysis of the model solutions concluded that the coupled FTA and ANN model may offer a reliable alternative method to forecast the potential risk of coal and gas outbursts. (author)

Petrography and rank of the Bhangtar coals, southeastern Bhutan

Energy Technology Data Exchange (ETDEWEB)

Pareek, H S [BH23, Meerut (India)

1990-07-01

In Bhutan, a potential coal deposit is exposed at Bhangtar in the 'landslide zone'. Nineteen coal seams are encountered in this area, and occur in the Lower Gondwana Supergroup preserved in between the Main Boundary Fault and the Thrust. The coal is low in moisture, {lt}1.76%, but the coal cores show moisture values of 3.16%. The ash content is up to 48.87% and increases substantially in the younger seams. The volatile content (on a pure coal basis) ranges from 23.38% to 41.02%. The sulphur content is less than 0.61%. The coals are non-coking. The amount of trace elements in the coal is quite low. The average petrographic composition of the Bhangtar coal is vitrinite - 31%, exinite - 2%, inertinite - 31%, and mineral and shaly matter - 36%, the vitrinite proportion decreases from the older to the younger seams, which are shaly. an age can be assigned to the Bhangtar coal. Based on oil reflectance, the rank of the coal is metalignitous to hypobituminous. The average microlithotype composition of the coal is vitrite - 30%, clarite - 1%, vitrinertite V - 14%, vitrinertite I - 11%, durite - 3%, fusite - 14%, and carbominerite - 27%. Vitrite decreases in proportion towards the younger seams, 'intermediates' show a concomitant increase, while durite and fusite remain constant. Carbonaceous shale contains fragmentary inertinite and vitrinite macerals and is interlayered with micro-bands of shaly coal which is characterised by abundant fragments of fusinite and vitrinite. The coal is very fragile and thus amenable to economic beneficiation. The coal is used as fuel in electric power plants. The Bhangtar coal is characteristically distinct from the Gondwana coals of India in petrography and rank, but correlates petrographically with the Kameng coals of Arunachal Pradesh, India. 18 refs., 4 figs., 8 tabs., 3 plates.

The use of electromagnetic body forces to enhance the quality of laser welds

Science.gov (United States)

Ambrosy, Guenter; Berger, P.; Huegel, H.; Lindenau, D.

2003-11-01

The use of electromagnetic body forces in laser beam welding of aluminum alloys is a new method to shape the geometry and to enhance the quality of the weld seams. In this new approach, electromagnetic volume forces are utilized by applying magnetic fields and electric currents of various origins. Acting in the liquid metal, they directly affect the flow field and can lead to favourable conditions for the melt dynamics and energy coupling. Numerous welds with full and partial penetration using both CO2 and Nd:YAG lasers demonstrate that this method directly influences the seam geometry and top-bead topography as well as the penetration depth and the evolution of pores and cracks. In the case of full penetration, it is also possible to lift or to lower the weld pool. The method, therefore, can be used to shape the geometry and to enhance the quality of the weld seam. Depending on the orientation of an external magnetic field, significant impacts are achieved in CO2 welding, even without an external current: the shape of the cross-sectional area can be increased of up to 50% and also the seam width is changed. Whereas for such conditions with Nd:YAG lasers no significant effect could be observed, it turned out that, when an external electric current is applied, similar effects are present with both wavelengths. In further investigations, the effect of electromagnetic body forces resulting from the interaction of an external current and its self-induced magnetic field was studied. Hereby, the current was fed into the workpiece via a tungsten electrode or a filler wire. The resulting phenomena are the same independent from wavelength and means of current feed.

Coal Field Fire Fighting - Practiced methods, strategies and tactics

Science.gov (United States)

Wündrich, T.; Korten, A. A.; Barth, U. H.

2009-04-01

Subsurface coal fires destroy millions of tons of coal each year, have an immense impact to the ecological surrounding and threaten further coal reservoirs. Due to enormous dimensions a coal seam fire can develop, high operational expenses are needed. As part of the Sino-German coal fire research initiative "Innovative technologies for exploration, extinction and monitoring of coal fires in Northern China" the research team of University of Wuppertal (BUW) focuses on fire extinction strategies and tactics as well as aspects of environmental and health safety. Besides the choice and the correct application of different extinction techniques further factors are essential for the successful extinction. Appropriate tactics, well trained and protected personnel and the choice of the best fitting extinguishing agents are necessary for the successful extinction of a coal seam fire. The chosen strategy for an extinction campaign is generally determined by urgency and importance. It may depend on national objectives and concepts of coal conservation, on environmental protection (e.g. commitment to green house gases (GHG) reductions), national funding and resources for fire fighting (e.g. personnel, infrastructure, vehicles, water pipelines); and computer-aided models and simulations of coal fire development from self ignition to extinction. In order to devise an optimal fire fighting strategy, "aims of protection" have to be defined in a first step. These may be: - directly affected coal seams; - neighboring seams and coalfields; - GHG emissions into the atmosphere; - Returns on investments (costs of fire fighting compared to value of saved coal). In a further step, it is imperative to decide whether the budget shall define the results, or the results define the budget; i.e. whether there are fixed objectives for the mission that will dictate the overall budget, or whether the limited resources available shall set the scope within which the best possible results shall be

Study of radiosensitivity to gamma irradiation for some important crops in yemen

International Nuclear Information System (INIS)

Saif, A.A.; Zaid, N.M.; Malek, N.M.; Kaid, A.H.; Almaktari, A.

2004-01-01

Dry seeds of six wheat cultivars, one cultivar of lentil, sesame and cotton were irradiated with different doses of gamma rays and compared with untreated control of the same cultivars. Reduction of seed germination percentage with increasing radiation doses was observed over all cultivars of thr studied crops. The doses of 500, 400, 700 and 500 Gy had low percentage of germination for wheat, lentil sesame and cotton respectively. The Ld50 for Wheat, lentil, sesame and cotton seams to be 350,250,500 and 400 Gy respectively. However, varietal l radiosensitivity was found for wheat crop. The GR50 seams to be 250,200,450 and 350 for wheat, lentil, sesame cotton, respectively

“三软”煤层水力冲孔卸压增透技术研究%Study on pressure releasing and permeability improving technology with hydraulic flushing in “three soft”coal seam

Institute of Scientific and Technical Information of China (English)

何志龙; 孙谦; 宋大钊; 高勤琼

2015-01-01

针对糯东煤矿“三软”高瓦斯低透气性煤层易流变、难抽采的问题，提出了底板巷道穿层水力冲孔卸压增透技术，并在糯东煤矿11702掘进工作面进行了现场试验。结果表明：冲孔后比冲孔前抽采瓦斯浓度上升3．4倍，瓦斯抽采流量增加4．4倍，炮掘工作面回风流中的瓦斯（体积分数）由冲孔前0．8％的超限预警状态变成冲孔后的0．4％的安全范围，水力冲孔技术应用效果显著，在糯东煤矿取得了良好的卸压增透效果。%To solve the problem of easy rheology and hard drainage in"three soft"coal seam with high gas concentration and low permeability in Nuodong coal mine,the pressure releasing and permeability improving technology with hydraulic flushing in floor gateway was proposed,and corresponding field test at the No.11702 heading face of Nuodong coal mine was carried out.The re-sults show that the drained gas concentration after hydraulic flushing is 3.4 times as that without hydraulic flushing and the gas flow rate is increased by 4.4 times;and the gas concentration at the blasting working face changes from 0.8% (overrun warning state,before hydraulic flushing)to 0.4% (safety state,after hydraulic flushing).The application of hydraulic flushing technolo-gy is more effective and remarkable in releasing pressure and improving permeability in Nuodong coal mine.

18 CFR 270.201 - Applicability.

Science.gov (United States)

2010-04-01

... OF ENERGY PROCEDURES GOVERNING DETERMINATIONS FOR TAX CREDIT PURPOSES DETERMINATION PROCEDURES... jurisdictional agencies for tight formation gas, occluded natural gas produced from coal seams, and natural gas...

Determination of Destress Blasting Effectiveness Using Seismic Source Parameters

Science.gov (United States)

Wojtecki, Łukasz; Mendecki, Maciej J.; Zuberek, Wacaław M.

2017-12-01

Underground mining of coal seams in the Upper Silesian Coal Basin is currently performed under difficult geological and mining conditions. The mining depth, dislocations (faults and folds) and mining remnants are responsible for rockburst hazard in the highest degree. This hazard can be minimized by using active rockburst prevention, where destress blastings play an important role. Destress blastings in coal seams aim to destress the local stress concentrations. These blastings are usually performed from the longwall face to decrease the stress level ahead of the longwall. An accurate estimation of active rockburst prevention effectiveness is important during mining under disadvantageous geological and mining conditions, which affect the risk of rockburst. Seismic source parameters characterize the focus of tremor, which may be useful in estimating the destress blasting effects. Investigated destress blastings were performed in coal seam no. 507 during its longwall mining in one of the coal mines in the Upper Silesian Coal Basin under difficult geological and mining conditions. The seismic source parameters of the provoked tremors were calculated. The presented preliminary investigations enable a rapid estimation of the destress blasting effectiveness using seismic source parameters, but further analysis in other geological and mining conditions with other blasting parameters is required.

Effects of Different Filler Metals on the Mechanical Behaviors of GTA Welded AA7A52(T6)

Science.gov (United States)

Shu, Fengyuan; Lv, Yaohui; Liu, Yuxin; Lin, Jianjun; Sun, Zhe; Xu, Binshi; He, Peng

2014-06-01

ER4043, ER5356, and AA7A52 on behalf of the Al-Si, Al-Mg, and Al-Zn-Mg-based welding material, respectively, were chosen as the filler metal to weld AA7A52(T6) plates by GTAW. The variance in mechanical performances of the joints caused by the various filler materials was investigated with reference to the SEM and EDS test results for the weld seam and the fracture surface. Failure was found in the seam for all the welded joints. With regard to the joint obtained with ER4043 welding wire, the total elongation was limited by the brittle intergranular compound Mg2Si of which Mg was introduced by convection mass transfer. As for the other two welds, the content ratio of Zn and Mg was found to play the dominant role in deciding the mechanical properties of the intergranular Mg-Zn compounds which were responsible for the tensile behavior of the joints. The content ratio (wt.%) of beyond 2:1 gave birth to the strengthening phase MgZn2 leading to a ductile fracture. Cr in the seam obtained with AA7A52 filler metal was found to enhance the strength of the joint through isolated particles.

Mechanics Evolution Characteristics Analysis of Pressure-arch in Fully-mechanized Mining Field

Directory of Open Access Journals (Sweden)

S.R. Wang

2014-09-01

Full Text Available Based on a practical engineering, the three-dimension computational model was built using FLAC3D under the fullymechanized mining condition. Considering four variation factors, such as the distance of mining advancing, the strength of the surrounding rock, the speed of mining advancing and the dip angle of the coal seam, the mechanics evolution characteristics of the pressure-arch were analyzed. The result showed that for the horizontal seam, the geometric shape of the pressure-arch varied from flat arch to round arch gradually and the height and thickness of the pressure-arch also increased; the maximum principal stress in the skewback also increased with the working face advancing. With the strength of the surrounding rock from soft to hard, the arch thickness reduced, and the arch loading decreased. To improve the mining speed can do some contributions to the stability of the pressure-arch in the mining field. With the increase of dip angle of the seam, the pressure-arch displayed an asymmetric shape, the vault was tilted and moved to the upward direction. At the same time, the thickness of the pressure-arch increased, and the stress concentration in the skewback tended to be further intensified.

Reconstruction of 3D Micro Pore Structure of Coal and Simulation of Its Mechanical Properties

Directory of Open Access Journals (Sweden)

Guang-zhe Deng

2017-01-01

Full Text Available This article takes the low permeability coal seam in the coalfield of South Judger Basin in Xinjiang, as a research object. The pore structure characteristics of coal rock mass in low permeability coal seam were analyzed quantitatively using scanning electron microscopy (SEM through the methods of statistics and digital image analysis. Based on the pore structure parameters and the distribution function of the coal rock mass, a three-dimensional porous cylinder model with different porosity was reconstructed by FLAC3D. The numerical simulation study of reconstructed pore model shows that (1 the porosity and the compressive strength have obvious nonlinear relation and satisfy the negative exponential relation; (2 the porosity significantly affects the stress distribution; with the increase of micro porosity, the stress distribution becomes nonuniform; (3 the compressive failures of different models are mainly shear failures, and the shape of fracture section is related to porosity; (4 the variation of seepage coefficient of the pore reconstruction model is consistent with the development of micro cracks. The micro mechanism of the deformation and failure of coal and the interaction of multiphase flow with porosity are revealed, which provides a theoretical reference for the clean development of the low permeability coal seam.

Fatigue strength of welds and welded materials of high-temperature steels resistant to pressurized hydrogen of the type 2.25% Cr/1% Mo

International Nuclear Information System (INIS)

Burlat, J.; Cheviet, A.; Million, A.

1986-01-01

The aim of the study is to examine systematically the creep strength of welded joints (base material, heat influence zone and welded seam) and of pure welding materials of the type 2 1/4-3% Cr/1% Mo. According to the AD standard rules, the rule which stipulates that the creep strength of welded seams under full stress be calculated with the strength characteristic value reduced by 20% applies to all heat-resistant steels, if no rupture stress values for the welded joints are available. Manufacturers of steel and weld fillers together with the Union of Technical Control Associations (VdTUeV) have prepared a test programme according to which on the one hand welded joints are tested at right angles to their seams, and on the other pure welding material is tested with respect to its creep strength. The development of the testes and their results have been described. The first results are available as VdTUeV material performance sheets, for 2 materials, and as provisional VdTUeV specification sheets, for 3 weld fillers. With the tested materials, it becomes practically feasible to reduce the creep strength of longitudinally welded pressure-bearing components by about 20% of wall thickness. (orig.) [de

Guaranteeing high output of a mine

Energy Technology Data Exchange (ETDEWEB)

Shetser, M G

1983-05-01

Operation of the Im. Kalinina coal mine in the Central Donbass is evluated. Seventeen coal seams, on the average 0.87 m thick, are prone to methane and coal dust explosions and to rock bursts. Some of the seams are also prone to spontaneous combustion. Rock layers in the roofs are prone to rock falls. Mining depth ranges from 740 to 850 m. Another working level is being constructed at a depth of 960 m. The steep coal seams are mined by means of the ANShch shield systems and the KGU system (with the 'Poisk' cutter loader). Strata control methods used in the mine are evaluated. Design of timber cribbings used for strata control in inclined workings is shown in a scheme. Construction of coal chutes and strata control in coal chutes are also described. Operation of KGU-1 powered supports which have been used in the mine for 10 years is evaluated. Improved strata control permitted daily coal output from a working face to be increased from 135 t in 1979 to 169 t in 1982. Yearly coal output increased from 605,000 t to 760,000 t. Labor productivity increased from 21.1 t/month to 25.9 t/month per miner. (In Russian)

CFD Analysis of Swing of Cricket Ball and Trajectory Prediction

Science.gov (United States)

G, Jithin; Tom, Josin; Ruishikesh, Kamat; Jose, Jyothish; Kumar, Sanjay

2013-11-01

This work aims to understand the aerodynamics associated with the flight and swing of a cricket ball and predict its flight trajectory over the course of the game: at start (smooth ball) and as the game progresses (rough ball). Asymmetric airflow over the ball due to seam orientation and surface roughness can cause flight deviation (swing). The values of Drag, Lift and Side forces which are crucial for determining the trajectory of the ball were found with the help of FLUENT using the standard K- ɛ model. Analysis was done to study how the ball velocity, spin imparted to be ball and the tilt of the seam affects the movement of the ball through air. The governing force balance equations in 3 dimensions in combination a MATLAB code which used Heun's method was used for obtaining the trajectory of the ball. The conditions for the conventional swing and reverse swing to occur were deduced from the analysis and found to be in alignment with the real life situation. Critical seam angle for maximum swing and transition speed for normal to reverse swing were found out. The obtained trajectories were compared to real life hawk eye trajectories for validation. The analysis results were in good agreement with the real life situation.

Microstructure and Mechanical Property of 3003 Aluminum Alloy Joint Brazed with Al-Si-Cu-Zn Filler Metal

Directory of Open Access Journals (Sweden)

LI Xiao-qiang

2016-09-01

Full Text Available Al-Si-Cu-Zn filler metal was developed to braze 3003 aluminum alloy. The microstructure and fracture surface of the joint were analyzed by XRD, SEM and EDS, and the effects of brazing temperature on microstructure and property of the joint were investigated. The results show that good joints are obtained at brazing temperature of 540-580℃ for 10min. The brazed joint consists of α(Al solid solution, θ(Al2Cu intermetallic compound, fine silicon phase and AlCuFeMn+Si phase in the central zone of brazed seam, and α(Al solid solution and element diffusion layers at both the sides of brazed seam, and the base metal. The room temperature (RT shear fracture of the joint occurs at the interface between the teeth shape α(Al in the diffusion layer and the center zone of brazed seam, which is mainly characterized as brittle cleavage. As the brazing temperature increases, α(Al solid solution crystals in the diffusion zone grow up, and the interfacial bonding of the joint is in the form of interdigitation. Brazing at 560℃ for 10min, the RT shear strength of the joint reaches the maximum value of 92.3MPa, which is about 62.7% of the base material.

Non-conventional fuel tax credit

International Nuclear Information System (INIS)

Soeoet, P.M.

1988-01-01

Coal-seam methane, along with certain other non-conventional fuels, is eligible for a tax credit. This production tax credit allowed coal-seam methane producers to receive $0.7526 per million Btu of gas sold during 1986. In 1987, this credit rose to $0.78 per million Btu. The tax credit is a very significant element of the economic analysis of current coal-seam methane projects. In today's spot market, gas prices are around $1.50 per million Btu. Allowing for costs of production, the gas producer will net more income from the tax credit than from the sale of the gas. The Crude Oil Windfall Profit Tax Act of 1980 is the source of this tax credit. There were some minor changes made by subsequent legislation, but most of the tax credit has remained intact. Wells must be drilled by 1990 to qualify for the tax credit but the production from such wells is eligible for the tax credit until 2001. Projections have been made, showing that the tax credit should increase to $0.91 per million Btu for production in 1990 and $1.34 per million Btu in 2000. Variables which may decrease the tax credit from these projections are dramatically lower oil prices or general economic price deflation

In-Situ Microbial Conversion of Sequestered Greenhouse Gases

Energy Technology Data Exchange (ETDEWEB)

Scott, A R; Mukhopadhyay, M; Balin, D F

2012-09-06

The objectives of the project are to use microbiological in situ bioconversion technology to convert sequestered or naturally-occurring greenhouse gases, including carbon dioxide and carbon monoxide, into methane and other useful organic compounds. The key factors affecting coal bioconversion identified in this research include (1) coal properties, (2) thermal maturation and coalification process, (3) microbial population dynamics, (4) hydrodynamics (5) reservoir conditions, and (6) the methodology of getting the nutrients into the coal seams. While nearly all cultures produced methane, we were unable to confirm sustained methane production from the enrichments. We believe that the methane generation may have been derived from readily metabolized organic matter in the coal samples and/or biosoluble organic material in the coal formation water. This raises the intriguing possibility that pretreatment of the coal in the subsurface to bioactivate the coal prior to the injection of microbes and nutrients might be possible. We determined that it would be more cost effective to inject nutrients into coal seams to stimulate indigenous microbes in the coal seams, than to grow microbes in fermentation vats and transport them to the well site. If the coal bioconversion process can be developed on a larger scale, then the cost to generate methane could be less than $1 per Mcf

Outburst Prevention Technology with Borehole Hydraulic Jet Through Strata in Floor Gateway%底板巷穿层钻孔水力冲孔防突技术

Institute of Scientific and Technical Information of China (English)

刘明举; 郭献林; 李波; 王冕

2011-01-01

针对新安矿14211运输巷掘进过程中面临的煤与瓦斯突出问题,为了研究和确定适合新安煤田三软煤层赋存特点的水力冲孔工艺和消突评价体系,使其快速消除工作面突出危险性,提高煤巷掘进速度,采用底板巷穿层钻孔水力冲孔防突措施,按照考察出的冲孔影响半径均匀布置钻孔,排出部分煤体和瓦斯,使煤体卸压增透.试验结果表明,底板巷穿层水力冲孔技术较好地适应和利用了三软煤层的赋存特点,消除了工作面的突出危险性,掘进速度也由之前的40 m/月提高到75m/月,提高了87.5%.%According to coal and gas outburst problems occurred in the heading process of the No.14211 transportation gateway in Xin'an Mine, in order to study and set up the borehole hydraulic jet technique and the outburst evaluation system suitable for the three soft seam deposit features in Xin'an Coalfield, to rapidly eliminate the outburst danger of the heading face and to improve the seam gateway heading speed, the outburst prevention measures with borehole hydraulic jet through the strata in the floor gateway were applied.According the investigation of the borehole hydraulic jet influence radius, a layout of the berehole pattern was evenly set up and a partial coal and gas could be discharged.Thus the seam pressure could be released and the permeability of the seam could be improved.The experiment result showed that the borehole hydraulic jet technology passed through strata in the floor gateway would be well suitable for and utilization of the deposit features of the three soft seam and could eliminate the outburst danger of the heading face.Thus the heading speed could be improved from the previous 40 m/month to 75 m/month and the heading efficiency was improved by 87.5％.

The effect of spin in swing bowling in cricket: model trajectories for spin alone

Science.gov (United States)

Robinson, Garry; Robinson, Ian

2015-02-01

In ‘swing’ bowling, as employed by fast and fast-medium bowlers in cricket, back-spin along the line of the seam is normally applied in order to keep the seam vertical and to provide stability against ‘wobble’ of the seam. Whilst spin is normally thought of as primarily being the slow bowler's domain, the spin applied by the swing bowler has the side-effect of generating a lift or Magnus force. This force, depending on the orientation of the seam and hence that of the back-spin, can have a side-ways component as well as the expected vertical ‘lift’ component. The effect of the spin itself, in influencing the trajectory of the fast bowler's delivery, is normally not considered, presumably being thought of as negligible. The purpose of this paper is to investigate, using calculated model trajectories, the amount of side-ways movement due to the spin and to see how this predicted movement compares with the total observed side-ways movement. The size of the vertical lift component is also estimated. It is found that, although the spin is an essential part of the successful swing bowler's delivery, the amount of side-ways movement due to the spin itself amounts to a few centimetres or so, and is therefore small, but perhaps not negligible, compared to the total amount of side-ways movement observed. The spin does, however, provide a considerable amount of lift compared to the equivalent delivery bowled without spin, altering the point of pitching by up to 3 m, a very large amount indeed. Thus, for example, bowling a ball with the seam pointing directly down the pitch and not designed to swing side-ways at all, but with the amount of back-spin varied, could provide a very powerful additional weapon in the fast bowler's arsenal. So-called ‘sling bowlers’, who use a very low arm action, can take advantage of spin since effectively they can apply side-spin to the ball, giving rise to a large side-ways movement, ˜ 20{}^\\circ cm or more, which certainly is

Coal Mine Accidents in Bangladesh: Its Causes and Remedial Measures

Directory of Open Access Journals (Sweden)

MD. MINHAJ UDDIN MONIR

2012-12-01

Full Text Available Barapukuria coal mine (BCM is located at Dinajpur district, NW Bangladesh. Total area is about 6.68 km2 and coal was encountered at a depth ranging between 118 and 509 m. Six major coal seams (seam I to seam VI were identified at BCM, of which, thickest one is the seam-VI (~36 m. The estimated coal reserves is about 390 million tons and of this, nearly 64 million tons of coal is extractable. The annual production of coal is about 1 million ton. In this study several parameters were used to explore minimization of accidents and improvement of coal production in BCM. Considering the geological, hydrological and other technical parameters, longwall mining method is applied for extraction of coal. Longwall retreating mining method is also applied for extraction of coal from single face with the operational area protected by self-advancing hydraulic powered roof support (HPRS system. These supports are moved forward causing the roof behind them to form an extensive abandoned area named goaf, which may lead to collapse with air blast. Coal in BCM is extracted from seam VI, using a multislice Longwall top coal caving method. Average ventilated air composition is ~20.94% oxygen, ~79.00% nitrogen, ~0.04% carbon monoxide, and minor water steam with huge dust. Production of coal was completed from 12 Longwall faces of 1st slice from seam VI. During production period several accidents and troubles within BCM have occurred. Poisonous gases such as carbon monoxide were detected during/after development of 1110 Longwall face, which increases up to 6000 ppm, therefore, sealed-off the face with mining equipments. During the development of belt gate roadway of 1101 Longwall face, maximum temperature and humidity increases up to 37 oC and 100%, respectively. Miners of BCM experienced some difficulties to work in that adverse environment. Air return roadway temperature was always 40 to 41oC in 1101 Longwall face during production period, faces temperature 46o

Method and apparatus for welding workpieces along a seam with the aid of a filler material deposited in the seam

International Nuclear Information System (INIS)

1979-01-01

A method and apparatus for welding a nuclear reactor core barrel in a very precise and controlled manner is given. The power employed to preheat the filler material at its operating level is automatically controlled as a continuous non-linear function of the filler feed speed. (UK)

46 CFR 160.077-5 - Incorporation by reference.

Science.gov (United States)

2010-10-01

...; Soil Burial Method. Federal Standard No. 751, Stitches, Seams, and Stitching. Military Specifications... (NBS) “The Universal Color Language” and “The Color Names Dictionary” in Color: Universal Language and...

Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Suwannee County

Data.gov (United States)

NSGIC Education | GIS Inventory — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Taylor County

Data.gov (United States)

NSGIC Education | GIS Inventory — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Okeechobee County

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NSGIC Education | GIS Inventory — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Baker County

Data.gov (United States)

NSGIC Education | GIS Inventory — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Palm Beach County

Data.gov (United States)

NSGIC Education | GIS Inventory — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Leon County

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NSGIC Education | GIS Inventory — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Sumter County

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NSGIC Education | GIS Inventory — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Alachua County

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NSGIC Education | GIS Inventory — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Putnam County

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NSGIC Education | GIS Inventory — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Lake County

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NSGIC Education | GIS Inventory — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Volusia County

Data.gov (United States)

NSGIC Education | GIS Inventory — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Lee County

Data.gov (United States)

NSGIC Education | GIS Inventory — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Nassau County

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NSGIC Education | GIS Inventory — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Duval County

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NSGIC Education | GIS Inventory — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Indian River County

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NSGIC Education | GIS Inventory — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Gadsden County

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NSGIC Education | GIS Inventory — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

2nd seminar on radioscopy

International Nuclear Information System (INIS)

1991-01-01

This seminar record contains 10 articles on the following subjects: The function and properties of modern radioscopy systems (H. Heidt); systems producing pictures compared to weld seams (R. Limpert); automatic fault assessment on cast parts (D. Filbert); practical experience with computer-aided irradiation tests on car steering housings and crude cast wheels - SABA test system (M. Purschke); concepts and experience in the automatic interpretation of weld seam pictures (P. Rose); the significance of the size and shape of burnt spots in the radioscopy process (E. Kirchner); detector systems in radioscopy (R. Link); radioscopy systems with automatic testing and integrated picture processing (R. Grimm); automatic testing of light alloy wheels for cars in practice (Part 1: K. Doerrich, Part 2: G. Korthals). (HM) [de

An isotopic study of the role of carbon dioxide in outbursts in coal mines

International Nuclear Information System (INIS)

Smith, J.W.; Gould, K.W.

1980-01-01

The occurrence of instantaneous outbursting in the Bulli coal seam at the West Cliff Colliery, Appin, NSW can be correlated directly with an increase in concentration (0.5 to 75%) and a related decrease in the 13 C content (delta 13 C + 16 to -0.8% PDB) of the CO 2 in the seam gas. Two sources of CO 2 are required. The greater incidence of outbursting in CO 2 -rich zones is explained by the conversion to bicarbonate of cleat and fracture filling calcite deep within the coal and the transport of this bicarbonate in water to mine openings. The weakening of the resistance of the coal to shear by this removal of carbonate is an additional factor to be considered in assessing outbursting situations. (author)

Physical properties and strength of cohesive strata from a hazardous area at the Western long-term slope of the Turow surface mine

Energy Technology Data Exchange (ETDEWEB)

Konderla, H; Suchnicka, H [Politechnika Wroclawska (Poland)

1991-01-01

Evaluates landslide hazards in the Turow brown coal mine in the area of a safety pillar of the Neisse river. Physical and mechanical properties of the following types of rocks from the pillar were investigated under laboratory conditions: cohesive Quaternary strata, clay layers adjacent to the coal seams and separating the seams, weathered and disintegrated granite, basalt and tuff (detritus). Rock samples were tested under conditions of tri-axial stresses, with natural water pore pressure, samples with a natural structure without artificial consolidation. The tests showed intensive fluctuations of rock properties. Nonhomogeneity of the samples and structural disturbances were determined. The tests showed the existence of landslide hazards in the Neisse river area. Recommendations for further investigations are made. 3 refs.

Geological structure of strata and the occurence of gas outbursts

Energy Technology Data Exchange (ETDEWEB)

Koewing, K

1977-10-20

Geological conditions which may have an influence on gas outbursts are depth, rank, type of formation, tectonic stresses, and the petrological form of the neighboring rock. The risk of outbursts is greater if there are dirt bands in the seam, since the coal can slide on these. Tectonically disturbed zones in seams containing more than 9 cu m of gas per ton are especially dangerous. Tectonic stress is not necessarily an indication of the severity of outbursts. Gas and sandstone outbursts do not depend on tectonic disturbance; outburst-prone sandstones have a greater pore volume and lower strength than normal. Almost all outbursts from the floor occur where the strata immediately below are impervious to gas and sandstone is present lower down. (In German)

Roof kinematics as a geomechanical basis for selecting the method of working

Energy Technology Data Exchange (ETDEWEB)

Tereskin, A F

1979-03-01

This paper recalls that the development of methods of winning to the rise in steep, thick seams with stowing is hampered by the problem of maintaining stability in the overlying rock mass. Examined in succession are the following factors which affect roof kinematics: seam thickness, abutment pressure, pack-compression characteristics, width of dirt band, the method of winning, the rate of coal-face advance, etc. Plans are under way to evaluate the stability of the overlying solid according to the value of deformation relative to the compression at which the solid breaks-up around its edge. This value amounts to 3-4% for highly-resistant types of coal and 1.2-2% for low-resistant coal. The practical application of the technique is discussed.

Underground Coal Thermal Treatment

Energy Technology Data Exchange (ETDEWEB)

Smith, P. [Univ. of Utah, Salt Lake City, UT (United States); Deo, M. [Univ. of Utah, Salt Lake City, UT (United States); Eddings, E. [Univ. of Utah, Salt Lake City, UT (United States); Sarofim, A. [Univ. of Utah, Salt Lake City, UT (United States); Gueishen, K. [Univ. of Utah, Salt Lake City, UT (United States); Hradisky, M. [Univ. of Utah, Salt Lake City, UT (United States); Kelly, K. [Univ. of Utah, Salt Lake City, UT (United States); Mandalaparty, P. [Univ. of Utah, Salt Lake City, UT (United States); Zhang, H. [Univ. of Utah, Salt Lake City, UT (United States)

2012-01-11

The long-term objective of this work is to develop a transformational energy production technology by insitu thermal treatment of a coal seam for the production of substitute natural gas (SNG) while leaving much of the coal's carbon in the ground. This process converts coal to a high-efficiency, low-GHG emitting gas fuel. It holds the potential of providing environmentally acceptable access to previously unusable coal resources. This topical report discusses the development of experimental capabilities, the collection of available data, and the development of simulation tools to obtain process thermo-chemical and geo-thermal parameters in preparation for the eventual demonstration in a coal seam. It also includes experimental and modeling studies of CO₂ sequestration.

Improvement and qualification of ultrasonic testing of dissimilar welds in the primary circuit of NPPs

International Nuclear Information System (INIS)

Mitzscherling, Steffen; Barth, Enrico; Homann, Tobias; Prager, Jens; Goetschel, Sebastian; Weiser, Martin

2017-01-01

The austenitic and dissimilar welds found in the primary circuit of nuclear power plants are not only extremely relevant to safety but also place very high demands on material testing. In addition to limited accessibility, the macroscopic structure of the weld seam is of paramount importance for ultrasound testing. In order to reliably determine material errors in position and size, the grain orientations and the elastic constants of the anisotropic weld bead structure must be known. The following work steps are used for the imaging representation of possible material defects: First, the weld seam is sounded in order to be able to determine important weld seam parameters, such as, for example, the grain orientation, using an inverse method. On the basis of these parameters, the sound paths are simulated in the next step by means of raytracing (RT). Finally, this RT simulation is assigned the measurement data (A-scans) from different transmitter and receiver positions and superimposed according to the Synthetic Aperature Focusing Technique (SAFT) method. The combination of inverse process, RT and SAFT also ensures a correct visualization of the faults in anisotropic materials. We explain these three methods and present the test arrangement of test specimens with artificial test errors. Measurement data as well as their evaluation are compared with the results of a CIVA simulation. [de

Lacustrine basin evolution and coal accumulation of the Middle Jurassic in the Saishiteng coalfield, northern Qaidam Basin, China

Directory of Open Access Journals (Sweden)

Meng Li

2016-07-01

Full Text Available Based on an extensive borehole survey of the Middle Jurassic coal-bearing sequences in the Saishiteng coalfield, northern Qaidam Basin (NQB, a total of 20 rock types and 5 sedimentary facies were identified, including braided river, meandering river, braided delta, meandering river delta, and lacustrine facies. The distribution of rock types and sedimentary facies contributed to the reconstruction of three periods' sedimentary facies maps of the Middle Jurassic in the Saishiteng coalfield, namely, the Dameigou age, the early Shimengou age and the late Shimengou age. That also provided the basis for the development of a three-stage depositional model of the Middle Jurassic in the NQB, indicating the lacustrine basin of the NQB in the Dameigou age and early Shimengou age were corresponding to an overfill basin, and that in the late Shimengou age was related to a balanced-fill basin. The analysis of the stability and structure of coal seams based on sedimentary facies maps showed that the preferred coal-forming facies in the Saishiteng coalfield were inter-delta bay and interdistributary bay of lower delta plain in the Dameigou age. In particular, the swamps that developed on the subaqueous palaeohigh favored the development of thick coal seams. Thus, minable coal seams may also be found along the Pingtai palaeohigh in the western part of the Saishiteng coalfield.

Welding feasibility study of U-shape lips at ITER Port-Plug with new laser beam sources

Energy Technology Data Exchange (ETDEWEB)

Behr, W., E-mail: w.behr@fz-juelich.de; Faidel, D.; Fischer, K.; Pap, M.; Offermanns, G.

2013-10-15

A “Cut and weld feasibility study of U shape lips” shown on June 2007 was initial of the following investigations. A new solution for Port Plug sealing at ITER was demanded and the experience in laser beam welding of the ZAT (Central Institute of Technology) in Jülich (Research Centre Jülich) offered an alternative solution. Up to now mechanically fixed sealing or sealing by TIG welding is used with typical benefits and problems, as heat input, shrinkage or limited room for tools. New disc-laser application for tight welding (leakage rate < 10{sup −9} mbar l/s) of the sealing lips is presented in the following. Both in the metallographic investigation and by means of leakage rate investigation the suitability of the selected procedure as seal alternative at the ITER Port Plug could be pointed out. The distance between two connections can be reduced to approx. 5 mm. The presented milling process for weld seam removal offers an option additionally to laser beam cutting. Final tests with a new disc-laser source offered additional benefits concerning seam quality, process stability and seam geometry. The distance between two connections will be reduced to less than 3 mm in next investigations. Construction unit near investigations and a demo part in original size underline finally the industrial suitability of the laser-welding-process for Port-Plug sealing at ITER.

Electrochemical corrosion behaviors of the X90 linepipe steel in NS4 solution

Directory of Open Access Journals (Sweden)

Jinheng Luo

2016-10-01

Full Text Available Oil and gas line pipes are laid underground and run through different areas in the laying process, so they will be subjected to different degrees of corrosion and even crack, leading to enormous casualties and economic losses. In order to guarantee the safe operation of line pipes, therefore, it is significant to investigate the electrochemical corrosion behaviors of pipe steel in a simulated soil environment. In this paper, the electrochemical corrosion behaviors of the base metals and welding materials of API 5L X90 steel longitudinally submerged arc welding pipes in near-neutral simulated soil solution (NS4 were studied by means of the electrochemical impedance spectroscopy (EIS and the potentiodynamic polarization testing technology. It is shown that the typical characteristic of anodic dissolution is presented but with no passivation phenomenon when X90 linepipe steel is put in NS4 solution. The base material is thermodynamically more stable than the seam weld material. The base material and seam weld samples were polarized under −850 mV polarization potential for different durations. It is demonstrated that with the proceeding of polarization, the polarization resistance and the corrosion resistance increase while the corrosion current density decreases. And the corrosion resistance of base material is better than that of seam weld material.

Comparative organic petrology of interlayered sandstones, siltstones, mudstones and coals in the Upper Carboniferous Ruhr basin, northwest Germany, and their thermal history and methane generation

Energy Technology Data Exchange (ETDEWEB)

Scheidt, G.; Littke, R. (Harress Geotechnik GmbH, Floersheim (Germany, F.R.))

1989-01-01

In the coal-mining Ruhr-area, Upper Carboniferous rocks consist of interlayered sandstones, siltstones, mudstones and coals. They were deposited in a tropical, paralic environment where alternating fluvial sedimentation, occasional marine ingressions, and swamp growth resulted in an irregular cyclic succession. The total sedimentary package contains on an average 6 Vol.% of organic manner. About 70 Vol. % of the organic matter occurs in coal seams, the rest as dispersed organic matter in clastic rocks. The organic matter is autochthonous in the coals and allochthonous in associated sandstones and siltstones. It consists of about 70% vitrinite, 20% inertinite, and 10% liptinite. The overall maceral group composition is the same for coals and dispersed organic matter. This surprising similarity is caused by a nearly exclusive input of land-plant derived organic matter to swamps and fluvial systems and a similar degree of preservation. Highest average liptinite contents were found in unrooted mudstones, highest average inertinite contents in coarse-grained siltstones and highest average vitrinite percentages in sandstones. Maturities of the sediments studied are well within the hydrocarbon generation window, e.g. vitrinite reflectivities range from 0.6% to 1.6%. Reflectivities measured on dispersed particles in clastic rocks are similar to those measured in coal seams. Calculations of the amount of methane generated indicate that coal seams contributed more to the total hydrocarbon generation than dispersed organic matter. 51 refs., 13 figs.

Simulation based analysis of laser beam brazing

Science.gov (United States)

Dobler, Michael; Wiethop, Philipp; Schmid, Daniel; Schmidt, Michael

2016-03-01

Laser beam brazing is a well-established joining technology in car body manufacturing with main applications in the joining of divided tailgates and the joining of roof and side panels. A key advantage of laser brazed joints is the seam's visual quality which satisfies highest requirements. However, the laser beam brazing process is very complex and process dynamics are only partially understood. In order to gain deeper knowledge of the laser beam brazing process, to determine optimal process parameters and to test process variants, a transient three-dimensional simulation model of laser beam brazing is developed. This model takes into account energy input, heat transfer as well as fluid and wetting dynamics that lead to the formation of the brazing seam. A validation of the simulation model is performed by metallographic analysis and thermocouple measurements for different parameter sets of the brazing process. These results show that the multi-physical simulation model not only can be used to gain insight into the laser brazing process but also offers the possibility of process optimization in industrial applications. The model's capabilities in determining optimal process parameters are exemplarily shown for the laser power. Small deviations in the energy input can affect the brazing results significantly. Therefore, the simulation model is used to analyze the effect of the lateral laser beam position on the energy input and the resulting brazing seam.

Investigation of Wear Behaviour of Sewn Assemblies of Viscose Linings with Different Treatment

Directory of Open Access Journals (Sweden)

Dainora BAČKAUSKAITĖ

2011-07-01

Full Text Available Different types of chemical treatment of textile are widely applied in advanced textile. Finishing of textile can provide additional functional properties for products or/and to improve the appearance of final product as well as to improve their mechanical properties. In this research the influence of the industrial treatment of viscose linings on the parameters of fabric surface friction, on fabric surface appearance as well as on the slippage resistance of yarns at a seam was investigated. Raw, dyed, dyed and softened, dyed and non-slip finished plain weaved linings were investigated. The slippage resistance of yarns at a seam in woven fabrics was evaluated according to standard EN ISO 13936-1:2004. The friction was investigated according to the standard DIN 53375 in a fabric-fabric friction pair. Surface of raw, dyed, dyed and softened viscose lining was investigated using SEM. The obtained results have shown that the friction parameters as well as the parameters of seam slippage resistance of dyed or dyed and softened fabrics were higher than the ones of raw fabric. The highest differences in those parameters were obtained for lining that was dyed and treated with non-slip finishing. That type of finishing influenced the break of lining yarns without typical to the other investigated linings slipping near a stitching line.http://dx.doi.org/10.5755/j01.ms.17.2.485

Causes of coal degradation at working faces

Energy Technology Data Exchange (ETDEWEB)

Sikora, W

1985-01-01

Coal comminution by shearer loaders at working faces and factors influencing it are analyzed. Three groups of factors are evaluated: coal mechanical properties, design and specifications of shearer loaders and mining schemes. On the basis of analyses, recommendations for increasing proportion of coarse coal and reducing coal comminution in underground coal mines in Poland are made. Increasing output of coarse coal in coal seams with a high proportion of dull coal is most economic. Increasing power of drive systems for shearer loaders to 500 kW or more decisively influences grain size distribution of coal and increases proportion of coarse coal, especially in seams of dull coal. Gradually increasing cutting depth of a shearer loader negatively influences haulage speed and coarse coal output. Replacing gradual cutting depth increase by attack at the full cutting depth increases proportion of coarse coal. When medium or thick coal seams are mined a coal bench from 0.3 to 0.5 m thick should be left in the roof or between 2 benches cut by 2 cutting drums. The coal bench left in the face disintegrates under the influence of gravity and the proportion of coarse coal increases. Optimizing yield strength of powered supports at a working face is a further method for improving grain size distribution of coal and increasing proportion of coarse coal. 2 references.

Quantitative prop support estimation and remote monitor early warning for hard roof weighting at the Muchengjian Mine in China

Energy Technology Data Exchange (ETDEWEB)

Tan, Y.; Zhao, T.; Xiao, Y. [Shandong Univ. of Science and Technology, Qingdao, Shandong (China). Key Laboratory of Mine Disaster Prevention and Control

2010-09-15

Pillar extraction is the method used to mine the ore in the Muchengjian Coal Mine in China because the coal seams are too unstable for canopy-powered or shield-powered support. This study involved a retrospective analysis of roof cave-ins to determine the tensile strength by examining the complex coal seam structure and hard roof at the mine. The objective was to ensure workers' safety when hard roof strata cave in. The roof caving span and thickness was analyzed to determine the prop spacing or number of hydraulic props needed per unit area. The study showed that the early warning threshold bedding vertical separation velocity for hard roof caving at the Muchengjian Coal Mine was about 14 mm/day. The newly developed bedding separation remote monitoring system (BSRMS) was used for the first time for early warning of a roof fall. A total of 48 trials of early warning roof weighting were performed at the Muchengjian Mine on the no. 4 face. The roof above the coal seam consists of 3 layers. The roof is supported by hydraulic props connected to an articulated roof beam manufactured in China. It was concluded that the early warnings from the BSRMS proved to be accurate. The BSRMS also indicated that the support system is safe and reliable. 12 refs., 1 tab., 10 figs.

30 CFR 715.13 - Postmining use of land.

Science.gov (United States)

2010-07-01

... water. Land used for storing water for beneficial uses such as stock ponds, irrigation, fire protection..., if the following criteria are met. Proposals to remove an entire coal seam running through the upper...

Compositionally heterogeneous podiform chromitite in the Shetland Ophiolite Complex (Scotland): Implications for chromitite petrogenesis and late-stage alteration in the upper mantle portion of a supra-subduction zone ophiolite

Science.gov (United States)

Derbyshire, E. J.; O'Driscoll, B.; Lenaz, D.; Gertisser, R.; Kronz, A.

2013-03-01

The mantle sequence of the ~ 492 Ma Shetland Ophiolite Complex (SOC; Scotland) contains abundant compositionally heterogeneous podiform chromitite bodies enclosed in elongate dunite lenses in the vicinity of the petrological Moho. Chromitite petrogenesis and late-stage alteration events recorded in these seams are examined here using petrography, mineral chemistry and crystal structural data. The resistant nature of Cr-spinel to serpentinisation and other late-stage alteration means that primary igneous compositions are preserved in unaltered crystal cores. Chromitite mineralogy and texture from five sampled localities at The Viels, Hagdale, Harold's Grave, Nikka Vord and Cliff reveal significant inter-pod chemical heterogeneity. The Cr-spinel mineral chemistry is consistent with supra-subduction zone melt extraction from the SOC peridotites. The occurrence of chromitite seams in the centres of the dunite lenses combined with variable Cr-spinel compositions at different chromitite seam localities supports a model of chromitite formation from spatially (and temporally?) fluctuating amounts of melt-rock interaction through channelised and/or porous melt flow. Pervasive serpentinisation of the SOC has led to the almost complete replacement of the primary (mantle) silicate mineral assemblages with serpentine (lizardite with minor chrysotile and antigorite). Magmatic sulphide (e.g., pentlandite) in dunite and chromitite is locally converted to reduced Ni-sulphide varieties (e.g., heazlewoodite and millerite). A post-serpentinisation (prograde) oxidisation event is recorded in the extensively altered Cliff chromitite seams in the west of the studied area, where chromitite Cr-spinel is extensively altered to ferritchromit. The ferritchromit may comprise > 50% of the volume of the Cliff Cr-spinels and contain appreciable quantities of 1-2 μm inclusions of sperrylite (PtAs2) and Ni-arsenide, signifying the coeval formation of these minerals with ferritchromit at

Bioregional Assessments: Determining the Impacts of Coal Resource Development on Water Resources in Australia through Groundwater, Surface Water and Ecological Modelling

Science.gov (United States)

Peeters, L. J.; Post, D. A.; Crosbie, R.; Holland, K.

2017-12-01

While extraction of methane from shale gas deposits has been the principal source of the recent expansion of the industry in the United States, in Australia extraction of methane from coal bed methane deposits (termed `coal seam gas' in Australia) has been the focus to date. The two sources of methane share many of the same characteristics including the potential requirement for hydraulic fracturing. However, as coal seam gas deposits generally occur at shallower depths than shale gas, the potential impacts of extraction on surface and groundwater resources may be of even greater concern. The Australian Federal Government commissioned a multi-disciplinary programme of bioregional assessments to improve understanding of the potential impacts of coal seam gas and large coal mining activities on water resources and water-dependent assets across six bioregions Australia. A bioregional assessment is a transparent scientific analysis of the ecology, hydrology, geology and hydrogeology of a bioregion with explicit assessment of the potential direct, indirect and cumulative impacts of coal seam gas and large coal mining development on water resources. The first step in the analysis is to establish the most likely scenario for coal development in each region and establish a causal pathway linking coal development to impacts to the social, economic and ecological functioning of water resources. This forms the basis for a sequence of probabilistic geological, hydrogeological, hydrological and ecological models to quantify the probability of potential impacts. This suite of models is developed independent of the proponents and regulators of coal resource developments and so can provide unbiased information to all stakeholders. To demonstrate transparency of the modelling, all inputs, outputs and executables will be available from http://www.bioregionalassessments.gov.au. The analysis delineated a zone of potential hydrological change for each region, outside of which impacts

Dating of authigenic clays related to igneous intrusions in Hunter Valley Coals

International Nuclear Information System (INIS)

Zwingmann, H.

2000-01-01

The Sydney Basin is composed mainly of Permian and Triassic marine and non-marine clastic sedimentary strata together with economically significant coal deposits and volumetrically minor igneous rocks. Many of these igneous rocks are also economically significant not only for their use in the construction industry but also for their deleterious effects on coal mining, particularly in underground mines utilising longwall extraction systems. Igneous activity in the Sydney Basin ranges from Early Permian to Tertiary in age and although episodic in nature, activity was unlikely to have ceased for periods of more than approximately 10 million years (Carr and Facer 1980; Embleton et al. 1982). Dating of the time of emplacement of igneous rocks using the K-Ar isotopic system is a relatively straightforward procedure if suitable analytical facilities and samples of appropriate, fresh, primary minerals are available. In the case of intrusions in coal seams, however, the occurrence of fresh, primary minerals is very rare due to widespread alteration produced by interaction between the igneous rock and fluids in the coal seam. This interaction produces a variety of secondary minerals with most primary minerals and glass being altered to clays (mainly kaolinite) and carbonates. Consequently, relatively few isotopic dates for intrusions into coal seams have been determined. A detailed study of several hundred samples of igneous rocks from the Sydney Basin found only six samples of intrusions into coal seams that were suitable for conventional K-Ar dating (Carr and Facer 1980). Techniques for K-Ar dating of authigenic illite, developed in response to the need by the petroleum industry to understand the timing of diagenesis in petroleum source-rocks and reservoirs, are now well established (Clauer and Chaudhuri 1995). As part of a larger project on the impact of igneous intrusions on coal mining and the alienation of coal reserves, a preliminary investigation of the timing of

Diabatic models with transferrable parameters for generalized chemical reactions

International Nuclear Information System (INIS)

Reimers, Jeffrey R; McKemmish, Laura K; McKenzie, Ross H; Hush, Noel S

2017-01-01

Diabatic models applied to adiabatic electron-transfer theory yield many equations involving just a few parameters that connect ground-state geometries and vibration frequencies to excited-state transition energies and vibration frequencies to the rate constants for electron-transfer reactions, utilizing properties of the conical-intersection seam linking the ground and excited states through the Pseudo Jahn-Teller effect. We review how such simplicity in basic understanding can also be obtained for general chemical reactions. The key feature that must be recognized is that electron-transfer (or hole transfer) processes typically involve one electron (hole) moving between two orbitals, whereas general reactions typically involve two electrons or even four electrons for processes in aromatic molecules. Each additional moving electron leads to new high-energy but interrelated conical-intersection seams that distort the shape of the critical lowest-energy seam. Recognizing this feature shows how conical-intersection descriptors can be transferred between systems, and how general chemical reactions can be compared using the same set of simple parameters. Mathematical relationships are presented depicting how different conical-intersection seams relate to each other, showing that complex problems can be reduced into an effective interaction between the ground-state and a critical excited state to provide the first semi-quantitative implementation of Shaik’s “twin state” concept. Applications are made (i) demonstrating why the chemistry of the first-row elements is qualitatively so different to that of the second and later rows, (ii) deducing the bond-length alternation in hypothetical cyclohexatriene from the observed UV spectroscopy of benzene, (iii) demonstrating that commonly used procedures for modelling surface hopping based on inclusion of only the first-derivative correction to the Born-Oppenheimer approximation are valid in no region of the chemical

Oxidation and carbonisation of coals: a case study of coal fire affected coals from the Wuda coalfield, Inner Mongolia, China

Science.gov (United States)

Kus, Jolanta; Meyer, Uwe; Ma, Jianwei; Chen-Brauchler, Dai

2010-05-01

At the coalfield of Wuda (Inner Mongolia, PR China) extensive underground coal fires cause widespread thermal and oxidative effects in coal seams. Within phase B of the Coal Fire Research Project of the Sino-German Initiative, methods for innovative fire-extinguishing technologies were investigated in multifaceted research approaches. Extensive investigations of oxidative and thermally affected coal seams in coal fire zone 18 were conducted in 2008 prior to application of new fire-extinguishing methods. We present results from the outcrop of coal seam No. 4 in the fire zone 18. The coal of seam No. 4 is of Early Permian age and belongs stratigraphically to the Shanxi Formation. The unaffected coal displays a high volatile bituminous A rank with a background value of random vitrinite reflectance ranging from 0.90 to 0.96 % Rr. Coal channel samples were coallected at actively extracted coal faces along multiple profiles with surface temperatures ranging from about 50° to 600°C. Microscopic examinations revealed a variety of products of coal exposure to the fire. Within coal samples, a marked rise in vitrinite reflectance from background values to 5.55% Rr (6.00 % Rmax) is encountered. In addition, a number of coal samples showed suppressed vitrinite reflectances ranging between 0.82 to 0.88% Rr. Further, seemingly heat unaffected coal samples display intensive development of oxidations rims at coal grain edges and cracks as well as shrinkage cracks and formation of iron oxides/hydroxides. Instead, thermally affected coal samples with higher coalification grade are further characterised by development of macropores (devolatilisation pores) in vitrinitic streaks, transformation of liptinite to meta-liptinite and micrinite as well as by natural coke particles of mostly porous nature and fine to coarse grained anisotropic mosaic. Coal petrographic investigations confirmed a hypothesis that both, oxidations as well as low temperature carbonisation govern the thermal

Determining the economic consequences of natural gas substitution

International Nuclear Information System (INIS)

Rimos, Shaun; Hoadley, Andrew F.A.; Brennan, David J.

2014-01-01

Highlights: • The economics of the extraction and usage of Australian gas and coal are examined. • Effect of feedstock substitution on power, hydrogen and ammonia costs is studied. • Influence of capital cost, transfer price, discount rate and carbon tax is studied. • Black coal has lower transfer price than gas but results in higher overall costs. • Conventional gas and coal seam gas can be substituted with little economic penalty. - Abstract: Resource depletion is a key aspect of sustainability, because the consumption of finite resources impacts on their availability for future generations. There are many proposed methods for accounting for the depletion of a particular resource, amongst which include the proportion of the resource depleted, the rate of resource depletion, and the energy, exergy, or monetary cost of extraction as the resource becomes harder to find or extract. This paper is part of a wider study to measure resource depletion using its environmental and economic impacts for the case of natural gas, where depletion of natural gas requires substitution by black coal or coal seam gas. The capital and operating costs are estimated both for upstream fuel extraction and purification and downstream use of the fuel to produce electricity, hydrogen and ammonia. These costs are based on a commercial scale of operation, using the same basis for economic modelling in each case. Black coal was found to have the lowest transfer price from upstream to downstream processing among the three feedstocks, but the highest capital and operating costs in the downstream processes. Conventional gas produced slightly higher transfer prices and downstream processing costs compared to coal seam gas. The favourable economic and environmental indicators for natural gas and coal seam gas are expected to lead to increased demand for these resources over coal, running the risk of a gas shortage. The economic consequence of a scarcity of either gas resource will be a

Fatigue analysis of welding seams in automotive structures

International Nuclear Information System (INIS)

Halaszi, C.; Gaier, C.; Dannbauer, H.; Hofwimmer, K.

2006-01-01

For lightweight automotive structures, the stiffness and the fatigue behavior is greatly influenced by the properties of the joints. The joining technology used and the number and locations of the joints are of high importance for both engineers and cost accountants. An overview of common computational procedures including European and national standards is given for the assessments of the fatigue behavior of thin sheet structures with arc welds. The influence of the quality and size of finite shell elements on the fatigue results are investigated and it is shown how this influence can be minimized. (author)

Energy losses estimation during pulsed-laser seam welding

Czech Academy of Sciences Publication Activity Database

Šebestová, Hana; Havelková, M.; Chmelíčková, H.

2014-01-01

Roč. 45, č. 3 (2014), s. 1116-1121 ISSN 1073-5615 R&D Projects: GA MŠk(CZ) LG13007 Institutional support: RVO:68378271 Keywords : laser welding * pulsed-laser * Nd:YAG laser Subject RIV: JP - Industrial Processing Impact factor: 1.461, year: 2014

Computer-assisted organization of the weld seam test

International Nuclear Information System (INIS)

Lorenz, H.; Richter, I.; Hansen, W.

1986-01-01

The article describes the task set and the solution found for an EDP program to be used for assisting in non-destructive tests. It covers the activities of test planning, disposition, calculation, test instructions, documentation and quality statistics. The phases of development and implementation have been essentially concluded. The program is not expected to reduce actual test work. Its advantages rather result from complete planning and execution, from early sensing of deviations, easier documentation and fast as well as easily surveyed informations. When the program has been fully integrated into the flow schedule of order handling, it is expected that 'additional work' will be reduced to an extent close to abt. 15 percent of the total work invested. By transferring the invested work from the test and documentation phase to the planning phase, the target of the program system meets the principle of modern quality assurance, namely to intensify measures for preventing errors. (orig.) [de