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Sample records for resistance series seam

Resistance seam welding

International Nuclear Information System (INIS)

Schueler, A.W.

1977-01-01

The advantages and disadvantages of the resistance seam welding process are presented. Types of seam welds, types of seam welding machines, seam welding power supplies, resistance seam welding parameters and seam welding characteristics of various metals
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.
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...
Performance of mesh seam welds in tailor welded blanks; Terado blank yo mash seam yosetsubu no tokusei

Energy Technology Data Exchange (ETDEWEB)

Uchihara, M; Takahashi, M; Kurita, M; Hirose, Y; Fukui, K [Sumitomo Metal Industries, Ltd., Osaka (Japan)

1997-10-01

Formability, fatigue properties and corrosion behavior of mash seam welded steel sheets were investigated and the results were compared with laser weld. The stretch formability of mash seam weld and laser weld were same level. Mash seam weld however, showed slightly smaller formability in hole expansion test. The fatigue strength of mash seam welds was lower than that of laser welds in case of differential thickness joints. Corrosion was apt to initiate at weld in both mash seam and laser weld with E-coat. The corrosion resistance of welds was improved by using zinc coated steel. 3 refs., 14 figs., 2 tabs.
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
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)
Design guidelines for multi-seam mining at Elliot Lake

International Nuclear Information System (INIS)

Hedley, D.G.F.

1978-04-01

With the current expansion in uranium mining, multi-seam mining could again be practised at Elliot Lake as it was in the 1960s. Information on the dimensions of stopes, pillars, and parting zone was gathered from plans and sections of the relevant closed mines. Discussions were held with personnel familiar with these mines to establish instances of pillar, roof, and parting zone failures. Design guidelines are formulated for stope and pillar dimensions in multi-seam mining for a range of orebody configurations using past practice in a back-analysis approach. Constraints imposed by dip and seam thickness on the choice of equipment and mining layout are evaluated. An attempt is made to bring together the engineering aspects, including rock mechanics, of multi-seam mine design with uranium recovery and other economic factors for three alternative mine layouts: single-seam mining, double-seam mining, and seams-and-parting mining. A series of examples are worked through, showing how the design guidelines can be applied for typical orebody configurations
Cryogenic Testing of Different Seam Concepts for Multilayer Insulation Systems

Science.gov (United States)

Johnson, Wesley L.; Fesmire, J. E.

2009-01-01

Recent testing in a cylindrical, comparative cryostat at the Cryogenics Test Laboratory has focused on various seam concepts for multilayer insulation systems. Three main types of seams were investigated: straight overlap, fold-over, and roll wrapped. Each blanket was comprised of 40 layer pairs of reflector and spacer materials. The total thickness was approximately 12.5-mm, giving an average layer density of 32 layers per centimeter. The blankets were tested at high vacuum, soft vacuum, and no vacuum using liquid nitrogen to maintain the cold boundary temperature at 77 K. Test results show that all three seam concepts are all close in thermal performance; however the fold-over method provides the lowest heat flux. For the first series of tests, seams were located 120 degrees around the circumference of the cryostat from the previous seam. This technique appears to have lessened the degradation of the blanket due to the seams. In a follow-on test, a 20 layer blanket was tested in a roll wrapped configuration and then cut down the side of the cylinder, taped together, and re-tested. This test result shows the thermal performance impact of having the seams all in one location versus having the seams clocked around the vessel. This experimental investigation indicates that the method of joining the seams in multilayer insulation systems is not as critical as the quality of the installation process.
Thin seam mining

Energy Technology Data Exchange (ETDEWEB)

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

1989-06-01

Discusses thin seam mining in Poland and its prospects. There were 194 working faces in coal seams to 1.5 m thick in Poland in 1988. Of them, 115 fell on faces with powered supports, 79 on faces with SHC-40 and Valent props; 108 shearer loaders and 45 coal plows were used for longwall mining of thin coal seams. Drilling and blasting was used to mine 21 working faces. Longwall faces in seams to 1.0 m thick gave 2.0% coal output, faces in coal seams 1.01-1.5 m thick gave 12.2% of daily coal output of underground mining. Structure of daily coal output of faces in thin seams was the following: 52 faces below 300 t/day, 42 from 301-500 t/day, 63 from 501 to 1,000 t/day, 17 faces above 1,000 t/day. Prospects for increasing coal output of faces in thin seams are discussed. 7 refs.
Java Persistence Dengan JBoss Seam

OpenAIRE

Utomo, Wiranto Herry; Istiyanto, Jazi Eko

2009-01-01

Seam is based on Java EE, so it satisfies its framework duties in two fundamental ways: 1) Seam simplifies Java EE: Seam provides a number of shortcuts and simplifications to the standard Java EE framework, making it even easier to effectively use Java EE web and business components, 2) Seam extends Java EE: Seam integrates a number of new concepts and tools into the Java EE framework. These extensions b...
Integration of vertical and in-seam horizontal well production analyses with stochastic geostatistical algorithms to estimate pre-mining methane drainage efficiency from coal seams: Blue Creek seam, Alabama.

Science.gov (United States)

Karacan, C Özgen

2013-07-30

Coal seam degasification and its efficiency are directly related to the safety of coal mining. Degasification activities in the Black Warrior basin started in the early 1980s by using vertical boreholes. Although the Blue Creek seam, which is part of the Mary Lee coal group, has been the main seam of interest for coal mining, vertical wellbores have also been completed in the Pratt, Mary Lee, and Black Creek coal groups of the Upper Pottsville formation to degasify multiple seams. Currently, the Blue Creek seam is further degasified 2-3 years in advance of mining using in-seam horizontal boreholes to ensure safe mining. The studied location in this work is located between Tuscaloosa and Jefferson counties in Alabama and was degasified using 81 vertical boreholes, some of which are still active. When the current long mine expanded its operation into this area in 2009, horizontal boreholes were also drilled in advance of mining for further degasification of only the Blue Creek seam to ensure a safe and a productive operation. This paper presents an integrated study and a methodology to combine history matching results from vertical boreholes with production modeling of horizontal boreholes using geostatistical simulation to evaluate spatial effectiveness of in-seam boreholes in reducing gas-in-place (GIP). Results in this study showed that in-seam wells' boreholes had an estimated effective drainage area of 2050 acres with cumulative production of 604 MMscf methane during ~2 years of operation. With horizontal borehole production, GIP in the Blue Creek seam decreased from an average of 1.52 MMscf to 1.23 MMscf per acre. It was also shown that effective gas flow capacity, which was independently modeled using vertical borehole data, affected horizontal borehole production. GIP and effective gas flow capacity of coal seam gas were also used to predict remaining gas potential for the Blue Creek 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.…
In-seam seismics for coal

Energy Technology Data Exchange (ETDEWEB)

Saviron Cidon, L [OCICARBON, Madrid (Spain)

1989-11-01

The project objective is to assess the degree of applicability of in-seam seismic technology in Spanish coal mines for use as a tool to predict the presence of irregularities in coal seams. By the very nature of coal mining, a large number of in-seam seismic research results are put directly to the test by the ensuing underground operations. The statistics from this continuous process of verification in other countries show this method to be extremely successful. Indeed, the use of the method has become habitual and it is recognised as an efficient instrument for aiding the location of faults and other irregularities in coal seams. 3 figs., 2 tabs.
A novel weld seam detection method for space weld seam of narrow butt joint in laser welding

Science.gov (United States)

Shao, Wen Jun; Huang, Yu; Zhang, Yong

2018-02-01

Structured light measurement is widely used for weld seam detection owing to its high measurement precision and robust. However, there is nearly no geometrical deformation of the stripe projected onto weld face, whose seam width is less than 0.1 mm and without misalignment. So, it's very difficult to ensure an exact retrieval of the seam feature. This issue is raised as laser welding for butt joint of thin metal plate is widely applied. Moreover, measurement for the seam width, seam center and the normal vector of the weld face at the same time during welding process is of great importance to the welding quality but rarely reported. Consequently, a seam measurement method based on vision sensor for space weld seam of narrow butt joint is proposed in this article. Three laser stripes with different wave length are project on the weldment, in which two red laser stripes are designed and used to measure the three dimensional profile of the weld face by the principle of optical triangulation, and the third green laser stripe is used as light source to measure the edge and the centerline of the seam by the principle of passive vision sensor. The corresponding image process algorithm is proposed to extract the centerline of the red laser stripes as well as the seam feature. All these three laser stripes are captured and processed in a single image so that the three dimensional position of the space weld seam can be obtained simultaneously. Finally, the result of experiment reveals that the proposed method can meet the precision demand of space narrow butt joint.
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
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…
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.
Outwitting the series resistance in scanning spreading resistance microscopy

International Nuclear Information System (INIS)

Schulze, A.; Cao, R.; Eyben, P.; Hantschel, T.; Vandervorst, W.

2016-01-01

The performance of nanoelectronics devices critically depends on the distribution of active dopants inside these structures. For this reason, dopant profiling has been defined as one of the major metrology challenges by the international technology roadmap of semiconductors. Scanning spreading resistance microscopy (SSRM) has evolved as one of the most viable approaches over the last decade due to its excellent spatial resolution, sensitivity and quantification accuracy. However, in case of advanced device architectures like fins and nanowires a proper measurement of the spreading resistance is often hampered by the increasing impact of parasitic series resistances (e.g. bulk series resistance) arising from the confined nature of the aforementioned structures. In order to overcome this limitation we report in this paper the development and implementation of a novel SSRM mode (fast Fourier transform-SSRM: FFT-SSRM) which essentially decouples the spreading resistance from parasitic series resistance components. We show that this can be achieved by a force modulation (leading to a modulated spreading resistance signal) in combination with a lock-in deconvolution concept. In this paper we first introduce the principle of operation of the technique. We discuss in detail the underlying physical mechanisms as well as the technical implementation on a state-of-the-art atomic force microscope (AFM). We demonstrate the performance of FFT-SSRM and its ability to remove substantial series resistance components in practice. Eventually, the possibility of decoupling the spreading resistance from the intrinsic probe resistance will be demonstrated and discussed. - Highlights: • A novel electrical AFM mode for carrier profiling in confined volumes is presented. • Thereby the force and hence the contact area between AFM probe and sample is modulated. • Information on the spreading resistance is derived using a lock-in approach. • Bulk series resistance components are
Analysis of US underground thin seam mining potential. Volume 1. Text. Final technical report, December 1978. [In thin seams

Energy Technology Data Exchange (ETDEWEB)

Pimental, R. A; Barell, D.; Fine, R. J.; Douglas, W. J.

1979-06-01

An analysis of the potential for US underground thin seam (< 28'') coal mining is undertaken to provide basic information for use in making a decision on further thin seam mining equipment development. The characteristics of the present low seam mines and their mining methods are determined, in order to establish baseline data against which changes in mine characteristics can be monitored as a function of time. A detailed data base of thin seam coal resources is developed through a quantitative and qualitative analysis at the bed, county and state level. By establishing present and future coal demand and relating demand to production and resources, the market for thin seam coal has been identified. No thin seam coal demand of significance is forecast before the year 2000. Current uncertainty as to coal's future does not permit market forecasts beyond the year 2000 with a sufficient level of reliability.
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)

Aluminized film, seam sealing tests and observations. Final report

Energy Technology Data Exchange (ETDEWEB)

1994-06-16

The purpose of this work was to investigate various seam sealing techniques, reinforcing methods, fitting installations, seam tolerances and geometric configurations pertinent to an aluminized plastic laminate. The program seeks a successful fabricating method for producing low-diffusion, cylindrical, spar liners to contain pressurized GH{sub 2} and GO{sub 2}. The test plan included: (1) seaming techniques on metallized Mylar film; (2) ``double patches`` for end fittings; (3) stainless steel bulkhead fitting assembly with seals; (4) minimum run tolerance on linear shear seam; (5) peel seam vs. inverted seal seam fabrication.
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.
Investigation of subsidence event over multiple seam mining area

International Nuclear Information System (INIS)

Kohli, K.K.

1999-01-01

An investigation was performed to determine the sequence of events which caused the 1987 surface subsidence and related damage to several homes in Walker County, Alabama, USA. Surface affects compared to mine maps indicated the subsidence to be mine related. However, two coal seams had been worked under this area. The upper seam, the American seam, ranged from 250 to 280 feet beneath the surface in the area in question. It was mined-out before 1955 by room-and-pillar method leaving in place narrow-long pillars to support the overburden strata, and abandoned in 1955. The lower seam, the Mary Lee seam, ranged from 650 to 700 feet beneath the surface. The Mary Lee seam had been abandoned in 1966 and subsequently became flooded. The dewatering of the Mary Lee seam workings in 1985 caused the submerged pillars to be exposed to the atmosphere. Due to multiple seam mining and the fact that workings had been inundated then dewatered, a subsurface investigation ensued to determine the sequence and ultimate cause of surface subsidence. Core sample tests with fracture analysis in conjunction with down-the-hole TV camera inspections provided necessary information to determine that the subsidence started in the lower seam and progressed through the upper coal seam to the surface. Evidence from the investigation program established that dewatering of the lower seam workings caused the marginally stable support pillars and the roof to collapse. This failure triggered additional subsidence in the upper seam which broadened the area of influence at the surface
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.
Effect of Seams on Drape of Fabrics | Sukumar | African Research ...

African Journals Online (AJOL)

In this study drape of ten fabrics are analyzed with three types of seams and three stitch densities. Sample without seam is a control sample and drape of seamed samples are compared with control sample to analyse the drape behavior of seamed fabrics. This paper presents a fundamental drape analysis of seamed fabrics ...
49 CFR 230.30 - Lap-joint seam boilers.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Lap-joint seam boilers. 230.30 Section 230.30..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Inspection and Repair § 230.30 Lap-joint seam boilers. Every boiler having lap-joint longitudinal seams...
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)
Mining the 510 coal seam prone to rock bursts and below a coal support pillar in a seam above

Energy Technology Data Exchange (ETDEWEB)

Major, M; Gebala, W

1983-10-01

The 510 coal seam, situated at a depth of 760 m below a support pillar left in an overlying coal seam, was mined by a system of longwall faces from 1979 to 1982. The seam was prone to rock bursts. Energy of rock bursts which occurred in the mine ranged from 10/SUP/5 to 10/SUP/6 J. The coal seam, 10 m thick, was mined by slicing. Faces were 140 m long. Stress concentrations caused by the suppport pillar left in the overlying coal seam were calculated. Curves which describe stress fluctuations were plotted. Rock burst hazards were determined by drilling. Drilling intervals depended on hazard degree and position of the test site in relation to the support pillar in the overlying coal seam. The face was 3 m high. Supports used in 2 gate roads were reinforced by steel and timber supports. Strong timber boards were placed at canopies of powered supports used at the working face. The face was situated at an angle of 10 degrees to the pillar axis. In the zone of critical stresses water infusion and shock blasting were used for rock burst prevention. These methods, plus reinforcement of the supports in gate roads and at the working face, guaranteed safe mining and prevented rock bursts. (8 refs.)
Seam Pucker

CSIR Research Space (South Africa)

Galuszynski, S

1986-05-01

Full Text Available pucker. The bestexam~leofsucha stitch is the lockstitch lFie.4). Astitch withabilitv to stretch and react to thread contraction without prk&kg ~ i g ~ c a n t changes in stitch length, is unlikely to produce seam pucker. The double locked chain...
Effects of clay-seam behavior on WIPP repository design

International Nuclear Information System (INIS)

Stone, C.M.; Krieg, R.D.; Branstetter, L.J.

1981-07-01

The geology at the southeastern New Mexico WIPP site consists of bedded layers of rock salt, anhydrite, polyhalite, mixtures of those materials, and thin clay seams. In spite of their very small (0.005 m to 0.05 m) thickness, clay seams are important to structural characterization of the WIPP stratigraphy since slip might possibly take place across them. Results of a study to determine the effects of clay seam frictional slip on the closure of a well-defined drift configuration are described. A Mohr-Coulomb dry friction model was used to model the active clay seams. The main thrust of the study was to determine the effects of friction coefficient variability on drift closure. Results show that the drift closure varies by a factor of 3.0 over the range of friction coefficients studied. The maximum slip observed along any clay seam was 0.12 m. For values of μ > .7, virtually no slip occurs along any clay seam
Current status of thin seam longwall mining in the US

Energy Technology Data Exchange (ETDEWEB)

Peng, S.S. [West Virginia Univ., Morgantown, WV (United States); Orndorff, A.

1996-12-31

Thin seams in this paper refers to those seams the economic mining height of which is below 50-55 in. that are traditionally considered to be the proprietary of plowing and present a whole net set of problems for longwall mining. In thin seams it is difficult to design and manufacture an efficient high capacity cutting machine for maintenance and production operations. Thin seam mining by longwall plowing began in the late fifties in southern West Virginia, and continues to the present time. In the seventies when longwall mining began to take off a large percentage of U.S. longwalls were operating in the thin seams. Tables 1 and 2 show the historical trends of cutting machines used for seams less than 55 in and 50 in, respectively. In addition to the plow system, the single-ended fixed drum and single-ended ranging drum shearers were introduced in the mid and late seventies and operated continuously until 2-4 years ago. The double-ended ranging drum shearers have also been employed for thin seam longwall mining during this period including several in-web (or off-pan) shearers between late seventies and early eighties. In this paper three thin-seam longwalls in three states employing the latest thin-seam longwall technology will be reviewed. However only two of them are still in operation while the third one ceased operation recently.
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.
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.
A new optimal seam method for seamless image stitching

Science.gov (United States)

Xue, Jiale; Chen, Shengyong; Cheng, Xu; Han, Ying; Zhao, Meng

2017-07-01

A novel optimal seam method which aims to stitch those images with overlapping area more seamlessly has been propos ed. Considering the traditional gradient domain optimal seam method and fusion algorithm result in bad color difference measurement and taking a long time respectively, the input images would be converted to HSV space and a new energy function is designed to seek optimal stitching path. To smooth the optimal stitching path, a simplified pixel correction and weighted average method are utilized individually. The proposed methods exhibit performance in eliminating the stitching seam compared with the traditional gradient optimal seam and high efficiency with multi-band blending algorithm.
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.
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.
"Feeling" Series and Parallel Resistances.

Science.gov (United States)

Morse, Robert A.

1993-01-01

Equipped with drinking straws and stirring straws, a teacher can help students understand how resistances in electric circuits combine in series and in parallel. Follow-up suggestions are provided. (ZWH)
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.
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)
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.
Determination of internal series resistance of PV devices: repeatability and uncertainty

International Nuclear Information System (INIS)

Trentadue, Germana; Pavanello, Diego; Salis, Elena; Field, Mike; Müllejans, Harald

2016-01-01

The calibration of photovoltaic devices requires the measurement of their current–voltage characteristics at standard test conditions (STC). As the latter can only be reached approximately, a curve translation is necessary, requiring among others the internal series resistance of the photovoltaic device as an input parameter. Therefore accurate and reliable determination of the series resistance is important in measurement and test laboratories. This work follows standard IEC 60891 ed 2 (2009) for the determination of the internal series resistance and investigates repeatability and uncertainty of the result in three aspects for a number of typical photovoltaic technologies. Firstly the effect of varying device temperature on the determined series resistance is determined experimentally and compared to a theoretical derivation showing agreement. It is found that the series resistance can be determined with an uncertainty of better than 5% if the device temperature is stable within ±0.1 °C, whereas the temperature range of ±2 °C allowed by the standard leads to much larger variations. Secondly the repeatability of the series resistance determination with respect to noise in current–voltage measurement is examined yielding typical values of ±5%. Thirdly the determination of the series resistance using three different experimental set-ups (solar simulators) shows agreement on the level of ±5% for crystalline Silicon photovoltaic devices and deviations up to 15% for thin-film devices. It is concluded that the internal series resistance of photovoltaic devices could be determined with an uncertainty of better than 10%. The influence of this uncertainty in series resistance on the electrical performance parameters of photovoltaic devices was estimated and showed a contribution of 0.05% for open-circuit voltage and 0.1% for maximum power. Furthermore it is concluded that the range of device temperatures allowed during determination of series
Distributed series resistance effects in solar cells

DEFF Research Database (Denmark)

Nielsen, Lars Drud

1982-01-01

A mathematical treatment is presented of the effects of one-dimensional distributed series resistance in solar cells. A general perturbation theory is developed, including consistently the induced spatial variation of diode current density and leading to a first-order equivalent lumped resistance...
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.
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.
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.
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.
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

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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

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

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

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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.
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

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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.
Series Resistance Analysis of Passivated Emitter Rear Contact Cells Patterned Using Inkjet Printing

Directory of Open Access Journals (Sweden)

Martha A. T. Lenio

2012-01-01

Full Text Available For higher-efficiency solar cell structures, such as the Passivated Emitter Rear Contact (PERC cells, to be fabricated in a manufacturing environment, potentially low-cost techniques such as inkjet printing and metal plating are desirable. A common problem that is experienced when fabricating PERC cells is low fill factors due to high series resistance. This paper identifies and attempts to quantify sources of series resistance in inkjet-patterned PERC cells that employ electroless or light-induced nickel-plating techniques followed by copper light-induced plating. Photoluminescence imaging is used to determine locations of series resistance losses in these inkjet-patterned and plated PERC cells.
The Investigation of Knitted Materials Bonded Seams Behaviour upon Cyclical Fatigue Loading

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

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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.
Sources of series resistance in the Harwell solid state alpha detector

International Nuclear Information System (INIS)

Rawlings, K.J.

1985-12-01

The metal-semiconductor contacts to the Harwell solid state alpha detector have been characterized and the effect of the contact geometry has been assessed. To a reasonable approximation the latter gives rise to an emitter series resistance with an expected range of 20 +- 8 ohms. The contacts behave like parallel RC networks which become noticeably frequency dependent above ca. 100 kHz. Up to this frequency the emitter contact is likely to add 6 +- 4 ohms to the series resistance and the contribution from the base contact varies inversely with the square of the diode's diameter, being 5 +- 3 ohms for a diode with a diameter of 30 mm. (author)
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
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.
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.
Experimental Study of Drag Resistance using a Laboratory Scale Rotary Set-Up

DEFF Research Database (Denmark)

Erik Weinell, Claus; Olsen, Kenneth N.; Christoffersen, Martin W.

2003-01-01

This work covers an experimental study of the drag resistance of different painted surfaces and simulated large-scale irregularities, viz. dry spraying, weld seams, barnacle fouling and paint remains. A laboratory scale rotary set-up was used to determine the drag resistance, and the surface...
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)
Analysis of series resistance effects on forward I - V and C - V characteristics of mis type diodes

International Nuclear Information System (INIS)

Altindal, S.; Tekeli, Z.; Karadeniz, S.; Tugluoglu, N.; Ercan, I.

2002-01-01

In order to determine the series resistance R s , we have followed Lie et al., Cheung et al. and Kang et al., from the plot of I vs dV/dLn(I) which was linear curve over a wide range of current values at each temperature. The values of Rs were obtained from the slope of the linear parts of the curves and then the series resistance at each temperature has been evaluated at Ln(I) vs (V-IR s ) curves. The curves are linear over a wide range of voltage. The most reliable values of ideality factor n and reverse saturation current Is were then determined. In addition to role of series resistance on the C-V and G-V characteristics of diode have been investigated. Both C-V and G-V measurements show that the measured capacitance and conductance seriously varies with applied bias and frequency due to presence of R s . The density of interface states, barrier height and series resistance from the forward bias I-V characteristics using this method agrees very well with that obtained from the capacitance technique. It is clear that ignoring the series resistance (device with high series resistance) can lead to significant errors in the analysis of the I-V-T, C-V-f and G-V-f characteristics
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.

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.
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%.
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.
A Laboratory Exercise in Physics: Determining the Resistance of Single Resistors and Series and Parallel Combinations of Resistance.

Science.gov (United States)

Schlenker, Richard M.

Presented is a secondary level physics unit which introduces students to electrical resistance in series and parallel combinations, use of the voltmeter and ammeter, wiring simple circuits, and writing scientific reports. (SL)
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.
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.
Investigation of series resistance and surface states in Au/n - GaP structures

International Nuclear Information System (INIS)

Kiymaz, A.; Onal, B.; Ozer, M.; Acar, S.

2009-01-01

The variation in series resistance and surface state density of Au/n - GaP Schottky diodes have been systematically investigated at room temperature by using capacitance-voltage C-V and conductance-voltage G/w-V measurements techniques. The C-V and G/w-V characteristics of these devices were investigated by considering series resistance effects in a wide frequency range. It is shown that the capacitance of the Au/n - GaP Schottky diode decreases with increasing frequency. It is assumed that the surface states were responsible for this behaviour. The distribution profile of Rs-V gives a peak in the depletion region at low frequencies and disappears with increasing frequencies
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.
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.
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...
Laser beam joining of non-oxidic ceramics for ultra high temperature resistant joints

International Nuclear Information System (INIS)

Lippmann, W.; Knorr, J.; Wolf, R.; Reinecke, A.M.; Rasper, R.

2004-01-01

The excellent technical properties of silicon carbide (SiC) and silicon nitride (Si 3 N 4 ) ceramics, such as resistance to extreme temperatures, oxidation, mechanical wear, aggressive chemical substances and radioactive radiation and also its high thermal conductivity and good temperature-shock resistance, make these ceramics ideally suited for use in the field of nuclear technology. However, their practical use has been limited so far because of the unavailability of effective joining techniques for these ceramics, especially for high temperature applications. A new joining technology (CERALINK registered ) has been developed in a network project which allowed high temperature resistant and vacuum-tight joining of SiC or Si 3 N 4 ceramics. A power laser is used as heat source, which makes it possible to join ceramic components in free atmosphere in combination with a pure oxidic braze filler. As no furnace is necessary, there are no limitations on the component dimensions by the furnace-geometry. During the joining process, the heated area can be limited to the seam area so that this technology can also be used to encapsulate materials with a low melting point. The seam has a high mechanical strength, it is resistant to a wide range of chemicals and radiation and it is also vacuum-tight. The temperature resistance can be varied by variation of the braze filler composition - usually between 1,400 C and >1,600 C. Beside the optimum filler it is also important to select the suitable laser wavelength. The paper will demonstrate the influence of different wave lengths, i. e. various laser types, on the seam quality. Examples are chosen to illustrate the strengths and limitations of the new technology
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.
Series Resistance Monitoring for Photovoltaic Modules in the Vicinity of MPP

DEFF Research Database (Denmark)

Sera, Dezso

2010-01-01

Faults and performance deterioration issues related to increases of the series resistance in PV modules or arrays are one of the most common causes to decrease the energy yield of photovoltaic installations. Therefore, the early detection of such failure types is very important in order to minimize...
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.

In-mine electrical resistance tomography for imaging the continuity of tabular orebodies

CSIR Research Space (South Africa)

Van Schoor, Abraham M

2006-09-01

Full Text Available One of the strengths of the electrical resistance tomography (ERT) technique is its flexibility in terms of survey geometries. In this paper an unconventional and novel ERT application that is geometrically analogous to in-seam seismic tomography...
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.
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.
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)
"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…
Modeling of the Channel Thickness Influence on Electrical Characteristics and Series Resistance in Gate-Recessed Nanoscale SOI MOSFETs

Directory of Open Access Journals (Sweden)

A. Karsenty

2013-01-01

Full Text Available Ultrathin body (UTB and nanoscale body (NSB SOI-MOSFET devices, sharing a similar W/L but with a channel thickness of 46 nm and lower than 5 nm, respectively, were fabricated using a selective “gate-recessed” process on the same silicon wafer. Their current-voltage characteristics measured at room temperature were found to be surprisingly different by several orders of magnitude. We analyzed this result by considering the severe mobility degradation and the influence of a huge series resistance and found that the last one seems more coherent. Then the electrical characteristics of the NSB can be analytically derived by integrating a gate voltage-dependent drain source series resistance. In this paper, the influence of the channel thickness on the series resistance is reported for the first time. This influence is integrated to the analytical model in order to describe the trends of the saturation current with the channel thickness. This modeling approach may be useful to interpret anomalous electrical behavior of other nanodevices in which series resistance and/or mobility degradation is of a great concern.
In situ analysis of coal from single electrode resistance, self-potential and gamma-ray logs

International Nuclear Information System (INIS)

Kayal, J.R.

1981-01-01

Single electrode resistance, self-potential and gamma-ray logging have been carried out in North Karanpura, West Bokaro and Jharia coalfields of Gondwana basin in Eastern India. Correlation of these geophysical logs is found to be very useful in locating the coal beds, determining their accurate depths and thickness and approximate quality. Coal seams have been detected as very high resistive formations compared to sandstone/shale which are interbedded in the coal basin. High or low self-potential values are obtained against the coal beds depending on the borehole fluid conditions. Burnt coals (Jhama) are characterised as highly conductive beds. Gamma ray logs have been effectively used alongwith electrical logs for correlation and identification of coal seams. Further analysis of gamma-ray log data determines a linear relationship with ash content of coal. (author)
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.
A grid-voltage-sensorless resistive active power filter with series LC-filter

DEFF Research Database (Denmark)

Bai, Haofeng; Wang, Xiongfei; Blaabjerg, Frede

2017-01-01

Voltage-sensorless control has been investigated for Voltage Source Inverters (VSIs) for many years due to the reduced system cost and potentially improved system reliability. The VSI based Resistive Active Power Filters (R-APFs) are now widely used to prevent the harmonic resonance in power...... distribution network, for which the voltage sensors are needed in order to obtain the current reference. In this paper a grid-voltage-sensorless control strategy is proposed for the R-APF with series LC-filter. Unlike the traditional resistance emulation method, this proposed control method re...
A Grid-Voltage-Sensorless Resistive Active Power Filter with Series LC-Filter

DEFF Research Database (Denmark)

Bai, Haofeng; Wang, Xiongfei; Blaabjerg, Frede

2018-01-01

Voltage-sensorless control has been investigated for Voltage Source Inverters (VSIs) for many years due to the reduced system cost and potentially improved system reliability. The VSI based Resistive Active Power Filters (R-APFs) are now widely used to prevent the harmonic resonance in power...... distribution network, for which the voltage sensors are needed in order to obtain the current reference. In this paper a grid-voltage-sensorless control strategy is proposed for the R-APF with series LC-filter. Unlike the traditional resistance emulation method, this proposed control method re...
Chaotic characteristic of electromagnetic radiation time series of coal or rock under different scales

Energy Technology Data Exchange (ETDEWEB)

Zhen-Tang Liu; En-Lai Zhao; En-Yuan Wang; Jing Wang [China University of Mining and Technology, Xuzhou (China). School of Safety Engineering

2009-02-15

Based on chaos theory, the chaotic characteristics of electromagnetic radiation time series of coal or rock under different loads was studied. The results show that the correlation of electromagnetic radiation time series of small-scale coal or rock and coal mine converges to a stable saturation value, which shows that these electromagnetic radiation time series have chaos characteristics. When there is danger of coal seam burst, the value of the saturation correlation dimension D{sub 2} of the electromagnetic radiation time series is bigger and it changes greatly; when there is no danger, its value is smaller and changes smoothly. The change of saturation correlation of electromagnetic radiation time series can be used to forecast coal or rock dynamic disasters. 11 refs., 4 figs.
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.
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.
Modeling and control of a DC upset resistance butt welding process

NARCIS (Netherlands)

Naus, G.J.L.; Meulenberg, R.; Molengraft, van de M.J.G.

2007-01-01

This paper presents the analysis and synthesis of modeling and control of the DC upset resistance butt welding process used in rim production lines. A new control strategy is developed, enabling active control of the welding seam temperature and the upset size. As a result, set-up times and energy
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.

Accurate calibration of resistance ratios between 1 MΩ and 1 GΩ using series resistors

International Nuclear Information System (INIS)

Yu, Kwang Min; Ihm, G

2011-01-01

As shown in high-resistance key comparisons carried out by the Consultative Committee for Electricity and Magnetism (CCEM), Inter-American Metrology System (SIM) and European Association of National Metrology Institutes (EURAMET), the accuracy of 10 MΩ and 1 GΩ resistances depends on ratio values between the reference resistance and unknown resistance and the accuracy of the reference resistance, which is determined with a quantized Hall resistance standard. This paper presents a method for calibrating 10:1 ratios in a high-resistance bridge using series resistors simply and accurately. By applying the 10:1 ratio errors determined using the presented method, the combined relative standard uncertainty for 1 GΩ resistance measurements using a modified Wheatstone bridge was estimated to be on the 1 × 10 −6 level. The method was also applied to 1 GΩ resistance measurements using a direct-current comparator resistance bridge. It was found that the 1 GΩ resistances determined by the two bridges agreed within 2.4 × 10 −6 Ω/Ω. We expect that the presented method can also be used to calibrate arbitrary resistance ratios
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
Time-series analysis in imatinib-resistant chronic myeloid leukemia K562-cells under different drug treatments.

Science.gov (United States)

Zhao, Yan-Hong; Zhang, Xue-Fang; Zhao, Yan-Qiu; Bai, Fan; Qin, Fan; Sun, Jing; Dong, Ying

2017-08-01

Chronic myeloid leukemia (CML) is characterized by the accumulation of active BCR-ABL protein. Imatinib is the first-line treatment of CML; however, many patients are resistant to this drug. In this study, we aimed to compare the differences in expression patterns and functions of time-series genes in imatinib-resistant CML cells under different drug treatments. GSE24946 was downloaded from the GEO database, which included 17 samples of K562-r cells with (n=12) or without drug administration (n=5). Three drug treatment groups were considered for this study: arsenic trioxide (ATO), AMN107, and ATO+AMN107. Each group had one sample at each time point (3, 12, 24, and 48 h). Time-series genes with a ratio of standard deviation/average (coefficient of variation) >0.15 were screened, and their expression patterns were revealed based on Short Time-series Expression Miner (STEM). Then, the functional enrichment analysis of time-series genes in each group was performed using DAVID, and the genes enriched in the top ten functional categories were extracted to detect their expression patterns. Different time-series genes were identified in the three groups, and most of them were enriched in the ribosome and oxidative phosphorylation pathways. Time-series genes in the three treatment groups had different expression patterns and functions. Time-series genes in the ATO group (e.g. CCNA2 and DAB2) were significantly associated with cell adhesion, those in the AMN107 group were related to cellular carbohydrate metabolic process, while those in the ATO+AMN107 group (e.g. AP2M1) were significantly related to cell proliferation and antigen processing. In imatinib-resistant CML cells, ATO could influence genes related to cell adhesion, AMN107 might affect genes involved in cellular carbohydrate metabolism, and the combination therapy might regulate genes involved in cell proliferation.
The effect of the series resistance in dye-sensitized solar cells explored by electron transport and back reaction using electrical and optical modulation techniques

International Nuclear Information System (INIS)

Liu Weiqing; Hu Linhua; Dai Songyuan; Guo Lei; Jiang Nianquan; Kou Dongxing

2010-01-01

The influence of the series resistance on the electron transport and recombination processes in dye-sensitized solar cells (DSC) has been investigated. The series resistances induced by some parts of DSC, such as the transparent conductive oxide (TCO), the electrolyte layer and the counter electrode, influence the performance of DSC. By combining three frequency-domain techniques, specifically electrochemical impedance spectroscopy (EIS), intensity modulated photocurrent spectroscopy (IMPS) and intensity modulated photovoltage spectroscopy (IMVS), we studied the relationship between the series resistance and the dynamic response of DSC. The results show that the series resistance induced by the TCO or counter electrode predominantly affects the electron transport under short circuit conditions and has no significant influence on the recombination under open circuit conditions. However, the resistance related to the electrolyte layer not only limits the carrier transport but also influences the recombination. Possible reasons for the influence of the series resistance on the electron transport and recombination processes in DSC are also discussed.
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.)
Photovoltaic module diagnostics by series resistance monitoring and temperature and rated power estimation

DEFF Research Database (Denmark)

Sera, Dezso; Teodorescu, Remus; Rodriguez, Pedro

2008-01-01

One of the most important parameters, which characterize a photovoltaic panel health state, is its series resistance. An increase of this normally indicates bad contacts between cells or panels. Another important property, which characterizes the aging of the panel is the reduction of its MPP power...
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.
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.
Thin stillage fractionation using ultrafiltration: resistance in series model.

Science.gov (United States)

Arora, Amit; Dien, Bruce S; Belyea, Ronald L; Wang, Ping; Singh, Vijay; Tumbleson, M E; Rausch, Kent D

2009-02-01

The corn based dry grind process is the most widely used method in the US for fuel ethanol production. Fermentation of corn to ethanol produces whole stillage after ethanol is removed by distillation. It is centrifuged to separate thin stillage from wet grains. Thin stillage contains 5-10% solids. To concentrate solids of thin stillage, it requires evaporation of large amounts of water and maintenance of evaporators. Evaporator maintenance requires excess evaporator capacity at the facility, increasing capital expenses, requiring plant slowdowns or shut downs and results in revenue losses. Membrane filtration is one method that could lead to improved value of thin stillage and may offer an alternative to evaporation. Fractionation of thin stillage using ultrafiltration was conducted to evaluate membranes as an alternative to evaporators in the ethanol industry. Two regenerated cellulose membranes with molecular weight cut offs of 10 and 100 kDa were evaluated. Total solids (suspended and soluble) contents recovered through membrane separation process were similar to those from commercial evaporators. Permeate flux decline of thin stillage using a resistance in series model was determined. Each of the four components of total resistance was evaluated experimentally. Effects of operating variables such as transmembrane pressure and temperature on permeate flux rate and resistances were determined and optimum conditions for maximum flux rates were evaluated. Model equations were developed to evaluate the resistance components that are responsible for fouling and to predict total flux decline with respect to time. Modeling results were in agreement with experimental results (R(2) > 0.98).
Studies of axon-glial cell interactions and periaxonal K+ homeostasis--II. The effect of axonal stimulation, cholinergic agents and transport inhibitors on the resistance in series with the axon membrane.

Science.gov (United States)

Hassan, S; Lieberman, E M

1988-06-01

The small electrical resistance in series with the axon membrane is generally modeled as the intercellular pathway for current flow through the periaxonal glial (Schwann cell) sheath. The series resistance of the medial giant axon of the crayfish, Procambarus clarkii, was found to vary with conditions known to affect the electrical properties of the periaxonal glia. Series resistance was estimated from computer analysed voltage waveforms generated by axial wire-constant current and space clamp techniques. The average series resistance for all axons was 6.2 +/- 0.5 omega cm2 (n = 128). Values ranged between 1 and 30 omega cm2. The series resistance of axons with low resting membrane resistance (less than 1500 omega cm2) increased an average of 30% when stimulated for 45 s to 7 min (50 Hz) whereas the series resistance of high membrane resistance (greater than 1500 omega cm2) axons decreased an average of 10%. Carbachol (10(-7) M) caused the series resistance of low membrane resistance axons to decrease during stimulation but had no effect on high membrane resistance axons. d-Tubocurare (10(-8) M) caused the series resistance of high membrane resistance axons to increase during stimulation but had no effect on low membrane resistance axons. Bumetanide, a Na-K-Cl cotransport inhibitor and low [K+]o, prevented the stimulation-induced increase in series resistance of low membrane resistance axons but had no effect on the high membrane resistance axons. The results suggest that the series resistance of axons varies in response to the activity of the glial K+ uptake mechanisms stimulated by the appearance of K+ in the periaxonal space during action potential generation.(ABSTRACT TRUNCATED AT 250 WORDS)
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
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
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)
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
Nanofluidic Devices with Two Pores in Series for Resistive-Pulse Sensing of Single Virus Capsids

DEFF Research Database (Denmark)

Harms, Zachary D.; Mogensen, Klaus Bo; Rodrigues de Sousa Nunes, Pedro André

2011-01-01

We report fabrication and characterization of nanochannel devices with two nanopores in series for resistive-pulse sensing of hepatitis B virus (HBV) capsids. The nanochannel and two pores are patterned by electron beam lithography between two microchannels and etched by reactive ion etching....... The two nanopores are 50-nm wide, 50-nm deep, and 40-nm long and are spaced 2.0-μm apart. The nanochannel that brackets the two pores is 20 wider (1 μm) to reduce the electrical resistance adjacent to the two pores and to ensure the current returns to its baseline value between resistive-pulse events...
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
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
Temperature dependence and effects of series resistance on current and admittance measurements of Al/SnO2/p-Si MIS diode

International Nuclear Information System (INIS)

Altindal, S.; Tekeli, Z.; Karadeniz, S.; Sahingoez, R.

2002-01-01

Temperature dependency and the series resistance effect on I-V, C-V and G-V characteristics of Al/SnO 2 /p-Si MIS diode were investigated in the temperature range 150-350 K. The current-voltage (I-V) analysis in this temperature range gives the saturation current (10''-''9 - 10''-''5 A), the ideality factor (6-1.8), the barrier height Φ B (I-V) (0.3-0.65 eV) the density of interface states D it (8x10''1''3 - 1x10''1''3 eV''-''1cm''-''2) and the series resistance R s (500-100 Ω). The decreases with increasing temperature of density of interface states is the result of molecular restructuring and reordering at the metal-semiconductor interface. The value of series resistance 520 Ω was calculated from the admittance measurement at room temperature and enough high frequency (500 khz) when the diode is biased in strong accumulation region. The admittance frequency (C-V and G-V) measurement confirmed that the measured capacitance (C m ) and conductance (G m ) varies with applied voltage and frequency due to the presence of density of interface states in the MIS diode, interfacial insulator layer and enough high series resistance. Similar results have been observed on MIS type Schottky diodes
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.
Stress corrosion cracking resistance of aluminum alloy 7000 series after two-step aging

Directory of Open Access Journals (Sweden)

Jegdić Bore V.

2015-01-01

Full Text Available The effect of one step-and a new (short two-step aging on the resistance to stress corrosion cracking of an aluminum alloy 7000 series was investigated, using slow strain rate test and fracture mechanics method. Aging level in the tested alloy was evaluated by means of scanning electron microscopy and measurements of electrical resistivity. It was shown that the alloy after the new two-step aging is significantly more resistant to stress corrosion cracking. Values of tensile properties and fracture toughness are similar for both thermal states. Processes that take place at the crack tip have been considered. The effect of the testing solution temperature on the crack growth rate on the plateau was determined. Two values of the apparent activation energy were obtained. These values correspond to different processes that control crack growth rate on the plateau at higher and lower temperatures. [Projekat Ministarstva nauke Republike Srbije, br. TR 34028 i br. TR 34016
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.
Analysis of frequency-dependent series resistance and interface states of In/SiO{sub 2}/p-Si (MIS) structures

Energy Technology Data Exchange (ETDEWEB)

Birkan Selcuk, A. [Department of Nuclear Electronics and Instrumentation, Saraykoey Nuclear Research and Training Center, 06983 Saray, Ankara (Turkey); Tugluoglu, N. [Department of Nuclear Electronics and Instrumentation, Saraykoey Nuclear Research and Training Center, 06983 Saray, Ankara (Turkey)], E-mail: ntuglu@taek.gov.tr; Karadeniz, S.; Bilge Ocak, S. [Department of Nuclear Electronics and Instrumentation, Saraykoey Nuclear Research and Training Center, 06983 Saray, Ankara (Turkey)

2007-11-15

In this work, the investigation of the interface state density and series resistance from capacitance-voltage (C-V) and conductance-voltage (G/{omega}-V) characteristics in In/SiO{sub 2}/p-Si metal-insulator-semiconductor (MIS) structures with thin interfacial insulator layer have been reported. The thickness of SiO{sub 2} film obtained from the measurement of the oxide capacitance corrected for series resistance in the strong accumulation region is 220 A. The forward and reverse bias C-V and G/{omega}-V characteristics of MIS structures have been studied at the frequency range 30 kHz-1 MHz at room temperature. The frequency dispersion in capacitance and conductance can be interpreted in terms of the series resistance (R{sub s}) and interface state density (D{sub it}) values. Both the series resistance R{sub s} and density of interface states D{sub it} are strongly frequency-dependent and decrease with increasing frequency. The distribution profile of R{sub s}-V gives a peak at low frequencies in the depletion region and disappears with increasing frequency. Experimental results show that the interfacial polarization contributes to the improvement of the dielectric properties of In/SiO{sub 2}/p-Si MIS structures. The interface state density value of In/SiO{sub 2}/p-Si MIS diode calculated at strong accumulation region is 1.11x10{sup 12} eV{sup -1} cm{sup -2} at 1 MHz. It is found that the calculated value of D{sub it} ({approx}10{sup 12} eV{sup -1} cm{sup -2}) is not high enough to pin the Fermi level of the Si substrate disrupting the device operation.
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
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
Shunt and series resistance of photovoltaic module evaluated from the I-V curve; I-V tokusei kara hyokashita taiyo denchi no shunt teiko to chokuretsu teiko

Energy Technology Data Exchange (ETDEWEB)

Asano, K; Kawamura, H; Yamanaka, S; Kawamura, H; Ono, H [Meijo University, Nagoya (Japan)

1997-11-25

With an objective of discussing I-V characteristics when a shadow has appeared on part of a photovoltaic module, evaluations were given as a first stage of the study on saturation current, shunt resistance and series resistance for the solar cell module. As a result of measuring change in amount of power generated in a sunny day with a shadow appearing over the solar cell module, reduction in power generation capability of about 23% was verified. In other words, the I-V characteristics of the solar cell module change largely because of existence of the shadow caused on the module. The I-V characteristics curve may be expressed and calculated as a function of the shunt resistance and series resistance. By curve-fitting measurement data for a case of changing insolation without existence of partial shadow, values of the shunt resistance and series resistance were derived. As a result, it was found that the calculations agree well with measurements. It was made also clear that each parameter shows temperature dependence. 6 refs., 10 figs., 1 tab.
Effects of series and parallel resistances on the C-V characteristics of silicon-based metal oxide semiconductor (MOS) devices

Science.gov (United States)

Omar, Rejaiba; Mohamed, Ben Amar; Adel, Matoussi

2015-04-01

This paper investigates the electrical behavior of the Al/SiO2/Si MOS structure. We have used the complex admittance method to develop an analytical model of total capacitance applied to our proposed equivalent circuit. The charge density, surface potential, semiconductor capacitance, flatband and threshold voltages have been determined by resolving the Poisson transport equations. This modeling is used to predict in particular the effects of frequency, parallel and series resistance on the capacitance-voltage characteristic. Results show that the variation of both frequency and parallel resistance causes strong dispersion of the C-V curves in the inversion regime. It also reveals that the series resistance influences the shape of C-V curves essentially in accumulation and inversion modes. A significant decrease of the accumulation capacitance is observed when R s increases in the range 200-50000 Ω. The degradation of the C-V magnitude is found to be more pronounced when the series resistance depends on the substrate doping density. When R s varies in the range 100 Ω-50 kΩ, it shows a decrease in the flatband voltage from -1.40 to -1.26 V and an increase in the threshold voltage negatively from -0.28 to -0.74 V, respectively. Good agreement has been observed between simulated and measured C-V curves obtained at high frequency. This study is necessary to control the adverse effects that disrupt the operation of the MOS structure in different regimes and optimizes the efficiency of such electronic device before manufacturing.
Optimum design of matrix fault current limiters using the series resistance connected with shunt coil

Science.gov (United States)

Chung, D. C.; Choi, H. S.; Lee, N. Y.; Nam, G. Y.; Cho, Y. S.; Sung, T. H.; Han, Y. H.; Kim, B. S.; Lim, S. H.

2007-10-01

In this paper we described the improved design for the matrix fault current limiters (MFCL). To do this, we used thin film-type superconducting elements. therefore it means that we can make the MFCL with minimized size and high switching speed because of the high current density and the high indexing value of superconducting thin film. Also we could minimize the bulky shunt coil using the connection of a series resistance with a shunt coil. Also we could effectively block up a leakage current in shunt coils under no-fault condition and simply control total impedances of a current-limiting part using this method. After we designed an appropriated 1 × 2 basic MFCL module with an applied voltage of 160 V, we enlarged it to a 2 × 2 MFCL module and a 3 × 2 MFCL module where applied voltages were 320 V and 480 V, respectively. Experimental results for our MFCL were reported in terms of various fault currents, variation of series resistance and so on. We think that these methods will be useful in the optimum design of an m × n MFCL.
Optimum design of matrix fault current limiters using the series resistance connected with shunt coil

International Nuclear Information System (INIS)

Chung, D.C.; Choi, H.S.; Lee, N.Y.; Nam, G.Y.; Cho, Y.S.; Sung, T.H.; Han, Y.H.; Kim, B.S.; Lim, S.H.

2007-01-01

In this paper we described the improved design for the matrix fault current limiters (MFCL). To do this, we used thin film-type superconducting elements. therefore it means that we can make the MFCL with minimized size and high switching speed because of the high current density and the high indexing value of superconducting thin film. Also we could minimize the bulky shunt coil using the connection of a series resistance with a shunt coil. Also we could effectively block up a leakage current in shunt coils under no-fault condition and simply control total impedances of a current-limiting part using this method. After we designed an appropriated 1 x 2 basic MFCL module with an applied voltage of 160 V, we enlarged it to a 2 x 2 MFCL module and a 3 x 2 MFCL module where applied voltages were 320 V and 480 V, respectively. Experimental results for our MFCL were reported in terms of various fault currents, variation of series resistance and so on. We think that these methods will be useful in the optimum design of an m x n MFCL
Magnetic Field Emission Comparison for Series-Parallel and Series-Series Wireless Power Transfer to Vehicles – PART 2/2

DEFF Research Database (Denmark)

Batra, Tushar; Schaltz, Erik

2014-01-01

Series-series and series-parallel topologies are the most favored topologies for design of wireless power transfer system for vehicle applications. The series-series topology has the advantage of reflecting only the resistive part on the primary side. On the other hand, the current source output...... characteristics of the series-parallel topology are more suited for the battery of the vehicle. This paper compares the two topologies in terms of magnetic emissions to the surroundings for the same input power, primary current, quality factor and inductors. Theoretical and simulation results show that the series...
Density of interface states, excess capacitance and series resistance in the metal-insulator-semiconductor (MIS) solar cells

Energy Technology Data Exchange (ETDEWEB)

Altindal, Semsettin; Tataroglu, Adem; Dokme, Ilbilge [Faculty of Arts and Sciences, Physics Department, Gazi University, 06500, Ankara (Turkey)

2005-01-31

Dark and illuminated current-voltage (I-V) characteristics of Al/SiO{sub x}/p-Si metal-insulator-semiconductor (MIS) solar cells were measured at room temperature. In addition to capacitance-voltage (C-V) and conductance-voltage (G-V), characteristics are studied at a wide frequency range of 1kHz-10MHz. The dark I-V characteristics showed non-ideal behavior with an ideal factor of 3.2. The density of interface states distribution profiles as a function of (E{sub ss}-E{sub v}) deduced from the I-V measurements at room temperature for the MIS solar cells on the order of 10{sup 13}cm{sup -2}eV{sup -1}. These interface states were responsible for the non-ideal behavior of I-V, C-V and G-V characteristics. Frequency dispersion in capacitance for MIS solar cells can be interpreted only in terms of interface states. The interface states can follow the a.c. signal and yield an excess capacitance, which depends on the relaxation time of interface states and the frequency of the a.c. signal. It was observed that the excess capacitance C{sub o} caused by an interface state decreases with an increase of frequency. The capacitances characteristics of MIS solar cells are affected not only in interface states but also series resistance. Analysis of this data indicated that the high interface states and series resistance leads to lower values of open-circuit voltage, short-circuit current density, and fill factor. Experimental results show that the location of interface states and series resistance have a significant effect on I-V, C-V and G-V characteristics.
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.
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.
Impact of Nickel silicide Rear Metallization on Series Resistance of Crystalline Silicon Solar Cells

KAUST Repository

Bahabry, Rabab R

2018-01-11

The Silicon-based solar cell is one of the most important enablers toward high efficiency and low-cost clean energy resource. Metallization of silicon-based solar cells typically utilizes screen printed silver-Aluminium (Ag-Al) which affects the optimal electrical performance. To date, metal silicide-based ohmic contacts are occasionally used as an alternative candidate only to the front contact grid lines in crystalline silicon (c-Si) based solar cells. In this paper, we investigate the electrical characteristics of nickel mono-silicide (NiSi)/Cu-Al ohmic contact on the rear side of c-Si solar cells. We observe a significant enhancement in the fill factor of around 6.5% for NiSi/Cu-Al rear contacts leading to increasing the efficiency by 1.2% compared to Ag-Al. This is attributed to the improvement of the parasitic resistance in which the series resistance decreased by 0.737 Ω.cm². Further, we complement experimental observation with a simulation of different contact resistance values, which manifests NiSi/Cu-Al rear contact as a promising low-cost metallization for c-Si solar cells with enhanced efficiency.
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.
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.)
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

Directory of Open Access Journals (Sweden)

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

Directory of Open Access Journals (Sweden)

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.
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

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

Directory of Open Access Journals (Sweden)

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.
Fabrics for fire resistant passenger seats in aircraft

Science.gov (United States)

Tesoro, G. C.

1978-01-01

The essential elements of the problem and of approaches to improved fire resistance in aircraft seats are reviewed. The performance requirements and availability of materials, delay in the ignition of upholstery fabric by a small source are considered a realistic objective. Results of experimental studies on the thermal response of fabrics and fabric/foam combinations suggest significant conclusions regarding: (1) the ignition behavior of a commercial 90/10 wool/nylon upholstery fabric relative to fabrics made from thermally stable polymers; (2) the role of the foam backing; (3) the behavior of seams. These results, coupled with data from other sources, also confirm the importance of materials' interactions in multicomponent assemblies, and the need for system testing prior to materials' selection. The use of an interlinear or thermal barrier between upholstery fabric and foam is a promising and viable approach to improved fire resistance of the seat assembly, but experimental evaluation of specific combinations of materials or systems is an essential part of the selection process.
Analysis of interface states and series resistance at MIS structure irradiated under {sup 60}Co {gamma}-rays

Energy Technology Data Exchange (ETDEWEB)

Tataroglu, A. [Department of Physics, Faculty of Arts and Sciences, Gazi University, 06500 Ankara (Turkey)], E-mail: ademt@gazi.edu.tr; Altindal, S. [Department of Physics, Faculty of Arts and Sciences, Gazi University, 06500 Ankara (Turkey)

2007-10-11

In this research, we investigated the effect of {sup 60}Co {gamma}-ray exposure on the electrical properties of Au/SnO{sub 2}/n-Si (MIS) structures using current-voltage (I-V) measurements. The fabricated devices were exposed to {gamma}-ray doses ranging from 0 to 300 kGy at a dose rate of 2.12 kGy h{sup -1} in water at room temperature. The density of interface states N{sub ss} as a function of E{sub c}-E{sub ss} is deduced from the forward bias I-V data for each dose by taking into account the bias dependence effective barrier height and series resistance of device at room temperature. Experimental results show that the {gamma}-irradiation gives rise to an increase in the zero bias barrier height {phi}{sub BO}, as the ideality factor n and N{sub ss} decrease with increasing radiation dose. In addition, the values of series resistance were determined using Cheung's method. The R{sub s} increases with increasing radiation dose. The results show that the main effect of the radiation is the generation of interface states with energy level within the forbidden band gap at the insulator/semiconductor interface.
Resistant plasmid profile analysis of multidrug resistant Escherichia ...

African Journals Online (AJOL)

Multiple drug resistance isolates causing UTI has seri- ous implications for the empiric therapy against patho- genic isolates and for the possible co-selection of antimicrobial resistant mediated by multi drug resistant plasmids21,22. E. coli from clinical isolates are known to harbour plasmids of different molecular sizes23.
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
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
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..
Monitoring groundwater-surface water interaction using time-series and time-frequency analysis of transient three-dimensional electrical resistivity changes

Science.gov (United States)

Johnson, Timothy C.; Slater, Lee D.; Ntarlagiannis, Dimitris; Day-Lewis, Frederick D.; Elwaseif, Mehrez

2012-01-01

Time-lapse resistivity imaging is increasingly used to monitor hydrologic processes. Compared to conventional hydrologic measurements, surface time-lapse resistivity provides superior spatial coverage in two or three dimensions, potentially high-resolution information in time, and information in the absence of wells. However, interpretation of time-lapse electrical tomograms is complicated by the ever-increasing size and complexity of long-term, three-dimensional (3-D) time series conductivity data sets. Here we use 3-D surface time-lapse electrical imaging to monitor subsurface electrical conductivity variations associated with stage-driven groundwater-surface water interactions along a stretch of the Columbia River adjacent to the Hanford 300 near Richland, Washington, USA. We reduce the resulting 3-D conductivity time series using both time-series and time-frequency analyses to isolate a paleochannel causing enhanced groundwater-surface water interactions. Correlation analysis on the time-lapse imaging results concisely represents enhanced groundwater-surface water interactions within the paleochannel, and provides information concerning groundwater flow velocities. Time-frequency analysis using the Stockwell (S) transform provides additional information by identifying the stage periodicities driving groundwater-surface water interactions due to upstream dam operations, and identifying segments in time-frequency space when these interactions are most active. These results provide new insight into the distribution and timing of river water intrusion into the Hanford 300 Area, which has a governing influence on the behavior of a uranium plume left over from historical nuclear fuel processing operations.
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.
Cell shunt resistance and photovoltaic module performance

Energy Technology Data Exchange (ETDEWEB)

McMahon, T.J.; Basso, T.S.; Rummel, S.R. [National Renewable Energy Lab., Golden, CO (United States)

1996-05-01

Shunt resistance of cells in photovoltaic modules can affect module power output and could indicate flawed manufacturing processes and reliability problems. The authors describe a two-terminal diagnostic method to directly measure the shunt resistance of individual cells in a series-connected module non-intrusively, without deencapsulation. Peak power efficiency vs. light intensity was measured on a 12-cell, series-connected, single crystalline module having relatively high cell shunt resistances. The module was remeasured with 0.5-, 1-, and 2-ohm resistors attached across each cell to simulate shunt resistances of several emerging technologies. Peak power efficiencies decreased dramatically at lower light levels. Using the PSpice circuit simulator, the authors verified that cell shunt and series resistances can indeed be responsible for the observed peak power efficiency vs. intensity behavior. The authors discuss the effect of basic cell diode parameters, i.e., shunt resistance, series resistance, and recombination losses, on PV module performance as a function of light intensity.
‘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.
Analysis of temperature-dependant current–voltage characteristics and extraction of series resistance in Pd/ZnO Schottky barrier diodes

Energy Technology Data Exchange (ETDEWEB)

Mayimele, M A, E-mail: meehleketo@gmail.com; Rensburg, J P van. Janse; Auret, F D; Diale, M

2016-01-01

We report on the analysis of current voltage (I–V) measurements performed on Pd/ZnO Schottky barrier diodes (SBDs) in the 80–320 K temperature range. Assuming thermionic emission (TE) theory, the forward bias I–V characteristics were analysed to extract Pd/ZnO Schottky diode parameters. Comparing Cheung’s method in the extraction of the series resistance with Ohm’s law, it was observed that at lower temperatures (T<180 K) the series resistance decreased with increasing temperature, the absolute minimum was reached near 180 K and increases linearly with temperature at high temperatures (T>200 K). The barrier height and the ideality factor decreased and increased, respectively, with decrease in temperature, attributed to the existence of barrier height inhomogeneity. Such inhomogeneity was explained based on TE with the assumption of Gaussian distribution of barrier heights with a mean barrier height of 0.99 eV and a standard deviation of 0.02 eV. A mean barrier height of 0.11 eV and Richardson constant value of 37 A cm{sup −2} K{sup −2} were determined from the modified Richardson plot that considers the Gaussian distribution of barrier heights.
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.
A Case Study of Damage Energy Analysis and an Early Warning by Microseismic Monitoring for Large Area Roof Caving in Shallow Depth Seams

Directory of Open Access Journals (Sweden)

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

Directory of Open Access Journals (Sweden)

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.
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.
Meta-analysis and time series modeling allow a systematic review of primary HIV-1 drug-resistant prevalence in Latin America and Caribbean.

Science.gov (United States)

Coelho, Antonio Victor Campos; De Moura, Ronald Rodrigues; Da Silva, Ronaldo Celerino; Kamada, Anselmo Jiro; Guimarães, Rafael Lima; Brandão, Lucas André Cavalcanti; Coelho, Hemílio Fernandes Campos; Crovella, Sergio

2015-01-01

Here we review the prevalence of HIV-1 primary drug resistance in Latin America and Caribbean using meta-analysis as well as time-series modeling. We also discuss whether there could be a drawback to HIV/AIDS programs due to drug resistance in Latin America and Caribbean in the next years. We observed that, although some studies report low or moderate primary drug resistance prevalence in Caribbean countries, this evidence needs to be updated. In other countries, such as Brazil and Argentina, the prevalence of drug resistance appears to be rising. Mutations conferring resistance against reverse transcriptase inhibitors were the most frequent in the analyzed populations (70% of all mutational events). HIV-1 subtype B was the most prevalent in Latin America and the Caribbean, although subtype C and B/F recombinants have significant contributions in Argentina and Brazil. Thus, we suggest that primary drug resistance in Latin America and the Caribbean could have been underestimated. Clinical monitoring should be improved to offer better therapy, reducing the risk for HIV-1 resistance emergence and spread, principally in vulnerable populations, such as men who have sex with men transmission group, sex workers and intravenous drug users.
Has the emergence of community-associated methicillin-resistant Staphylococcus aureus increased trimethoprim-sulfamethoxazole use and resistance?: a 10-year time series analysis.

Science.gov (United States)

Wood, Jameson B; Smith, Donald B; Baker, Errol H; Brecher, Stephen M; Gupta, Kalpana

2012-11-01

There are an increasing number of indications for trimethoprim-sulfamethoxazole use, including skin and soft tissue infections due to community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA). Assessing the relationship between rates of use and antibiotic resistance is important for maintaining the expected efficacy of this drug for guideline-recommended conditions. Using interrupted time series analysis, we aimed to determine whether the 2005 emergence of CA-MRSA and recommendations of trimethoprim-sulfamethoxazole as the preferred therapy were associated with changes in trimethoprim-sulfamethoxazole use and susceptibility rates. The data from all VA Boston Health Care System facilities, including 118,863 inpatient admissions, 6,272,661 outpatient clinic visits, and 10,138 isolates were collected over a 10-year period. There was a significant (P = 0.02) increase in trimethoprim-sulfamethoxazole prescriptions in the post-CA-MRSA period (1,605/year) compared to the pre-CA-MRSA period (1,538/year). Although the overall susceptibility of Escherichia coli and Proteus spp. to trimethoprim-sulfamethoxazole decreased over the study period, the rate of change in the pre- versus the post-CA-MRSA period was not significantly different. The changes in susceptibility rates of S. aureus to trimethoprim-sulfamethoxazole and to methicillin were also not significantly different. The CA-MRSA period is associated with a significant increase in use of trimethoprim-sulfamethoxazole but not with significant changes in the rates of susceptibilities among clinical isolates. There is also no evidence for selection of organisms with increased resistance to other antimicrobials in relation to increased trimethoprim-sulfamethoxazole use.

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

Directory of Open Access Journals (Sweden)

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.
Laboratory-scale thyristor controlled series capacitor

Energy Technology Data Exchange (ETDEWEB)

Matsuki, J.; Ikeda, K.; Abe, M. [Kyoto University, Kyoto (Japan)

1996-10-20

This paper describes the results of an experimental study on the characteristics of a thyristor controlled series capacitor (TCSC). At present, there are two major thyristor controlled series compensation projects in the U.S.: the Kayenta ASC and the Slatt TCSC. However, there has been little operating experience and thus further understanding of the characteristics of TCSC is still to be sought. Therefore, a laboratory-scale TCSC was produced and installed in a laboratory power system. The impedance characteristics, waveshapes of voltages and currents in the TCSC circuit, and harmonics, for various thyristor firing angles, and insertion responses were measured and analyzed. In particular, effects of the size of the circuit components, i.e., parasitic resistance, additional damping resistance and series reactor, on the overall TCSC performances were investigated. The results were compared with EMTP simulations. 10 refs., 7 figs.
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.
Detection of increased series losses in PV arrays using Fuzzy Inference Systems

DEFF Research Database (Denmark)

Spataru, Sergiu; Sera, Dezso; Kerekes, Tamas

2012-01-01

There are well-defined methods to measure the (increased) series resistance of PV panels in controlled laboratory conditions. However, the presence of various irradiance levels and partial shadows, in case of an outdoor installation, may affect the series resistance estimation. This paper focuses...
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
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)
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.
Effect of electroless nickel on the series resistance of high-efficiency inkjet printed passivated emitter rear contacted solar cells

Energy Technology Data Exchange (ETDEWEB)

Lenio, Martha A.T. [REC Technology US, Inc., 1159 Triton Dr., Foster City, CA 94301 (United States); Lennon, A.J.; Ho-Baillie, A.; Wenham, S.R. [ARC Photovoltaics Centre of Excellence, University of NSW, Sydney, NSW 2052 (Australia)

2010-12-15

Many existing and emerging solar cell technologies rely on plated metal to form the front surface contacts, and aluminium to form the rear contact. Interactions between the metal plating solutions and the aluminium rear can have a significant impact on cell performance. This paper describes non-uniform nickel deposition on the sintered aluminium rear surface of passivated emitter and rear contacted (PERC) cells patterned using an inkjet printing technique. Rather than being plated homogeneously over the entire rear surface as is observed on an alloyed aluminium rear, the nickel is plated only in the vicinity of the point openings in the rear surface silicon dioxide dielectric layer. Furthermore, this non-uniform nickel deposition was shown to increase the contact resistance of the rear point contacts by an order of magnitude, resulting in higher series resistance values for these fabricated PERC cells. (author)
Resistance to fracture of carbon weldable structural steel with ferrite-pearlite and widmanstaetten structure

International Nuclear Information System (INIS)

Gulyaev, A.P.; Guzovskaya, M.A.

1977-01-01

Consideration is given to mechanical properties of St3 steel with varying ferritic-peartilic and widmanstaetten structures typical of a weld seam and adjacent zones. It has been found that mechanical properties determined at static tension are sensitive to structure variation in the limits under study. A considerable difference has been detected during impact tests CT 50 , asub(p)). The highest resistance to breakage is observed for the steel with a fine-grain ferritic-pearlitic structure (T 50 =-10 deg C, asub(p)=4.3 kgxm/cm 2 ). The enlargement of such a structure enhances transition temperature (T 50 =+20 deg C) and reduces resistance to crack development (asub(p)2.4 kgxm/cm 2 ). The appearance of widmanstaetten zones in the fine-grain structure leads also to a higher T 50 , up to +10 deg C, and at a completely widmanstaetten structure T 50 =+25 deg C. An especially unfavorable effect on the resistance of steel to breakage is produced by structure nonuniformity, i.e. accumulation of loop-like pearlitic and ferritic zones
Corrosion resistant properties and weldabilities of ASTM Grade 12 titanium alloy

International Nuclear Information System (INIS)

Tsumori, Yoshikatsu; Itoh, Hideo

1988-01-01

Plates, sheets, bars, wires and thinner seam-welded tubings were manufactured from large-scaled ingot of ASTM Grade 12 alloy (Ti-0.8Ni-0.3Mo). The processability of G-12 alloy has proved almost similar to that of conventional commercially pure titanium grades. It has been clarified that the G-12 alloy showed several advantageous features: Chlorides-Crevice corrosion resistance of the alloy was almost equals to G-7 and Pd0/TiO 2 coated titanium, and the maximum allowable stress was able to be designed higher than that of commercially pure titanium. This alloy has been in applications also offers where such environments as seawater, brines and moist chlorine, various oil refinery and chemical industries, and others. (author)
Epidemiology meets econometrics: using time-series analysis to observe the impact of bed occupancy rates on the spread of multidrug-resistant bacteria.

Science.gov (United States)

Kaier, K; Meyer, E; Dettenkofer, M; Frank, U

2010-10-01

Two multivariate time-series analyses were carried out to identify the impact of bed occupancy rates, turnover intervals and the average length of hospital stay on the spread of multidrug-resistant bacteria in a teaching hospital. Epidemiological data on the incidences of meticillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase (ESBL)-producing bacteria were collected. Time-series of bed occupancy rates, turnover intervals and the average length of stay were tested for inclusion in the models as independent variables. Incidence was defined as nosocomial cases per 1000 patient-days. This included all patients infected or colonised with MRSA/ESBL more than 48h after admission. Between January 2003 and July 2008, a mean incidence of 0.15 nosocomial MRSA cases was identified. ESBL was not included in the surveillance until January 2005. Between January 2005 and July 2008 the mean incidence of nosocomial ESBL was also 0.15 cases per 1000 patient-days. The two multivariate models demonstrate a temporal relationship between bed occupancy rates in general wards and the incidence of nosocomial MRSA and ESBL. Similarly, the temporal relationship between the monthly average length of stay in intensive care units (ICUs) and the incidence of nosocomial MRSA and ESBL was demonstrated. Overcrowding in general wards and long periods of ICU stay were identified as factors influencing the spread of multidrug-resistant bacteria in hospital settings. Copyright 2010 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved.
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.
The role of {sup 60}Co gamma-ray irradiation on the interface states and series resistance in MIS structures

Energy Technology Data Exchange (ETDEWEB)

Tascioglu, Ilke [Department of Physics, Faculty of Science and Arts, Gazi University, 06500 Ankara (Turkey); Tataroglu, Adem, E-mail: ademt@gazi.edu.t [Department of Physics, Faculty of Science and Arts, Gazi University, 06500 Ankara (Turkey); Ozbay, Akif; Altindal, Semsettin [Department of Physics, Faculty of Science and Arts, Gazi University, 06500 Ankara (Turkey)

2010-04-15

The effect of gamma-ray exposure on the metal-insulator-semiconductor (MIS) structures has been investigated using the electrical characteristics at room temperature. The MIS structures are irradiated with {sup 60}Co gamma-ray source. The energy distribution of interface states was determined from the forward bias I-V characteristics by taking into account the bias dependence of the effective barrier height and ideality factor. The value of series resistance decreases with increasing dose. Experimental results confirmed that gamma-ray irradiation have a significant effect on electrical characteristics of MIS structures.
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.
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).
On the profile of frequency and voltage dependent interface states and series resistance in MIS structures

Energy Technology Data Exchange (ETDEWEB)

Doekme, Ilbilge [Science Education Department, Faculty of Kirsehir Education, Gazi University, Kirsehir (Turkey)]. E-mail: ilbilgedokme@gazi.edu.tr; Altindal, Semsettin [Physics Department, Faculty of Arts and Sciences, Gazi University, 06500, Teknikokullar, Ankara (Turkey)

2007-04-30

The variation in the capacitance-voltage (C-V) and conductance-voltage (G/{omega}-V) characteristics of Au/SiO{sub 2}/n-Si metal-insulator-semiconductor (MIS) structure have been systematically investigated as a function of frequencies in the frequency range 0.5 kHz-10 MHz at room temperature. In addition, the forward and reverse bias current-voltage (I-V) characteristics of this structure were measured at room temperature. The high value of ideality factor was attributed to the high density of interface states localized at Si/SiO{sub 2} interface and interfacial oxide layer. The density of interface states (N{sub ss}) and the series resistance (R{sub ss}) were calculated from I-V and C-V measurements using different methods and the effect of them on C-V and G/{omega}-V characteristics were deeply researched. At the same energy position near the top of valance band, the calculated N{sub ss} values, obtained without taking into account the series resistance of the devices almost one order of magnitude larger than N{sub ss} values obtained by taking into account R{sub ss} values. It is found that the C-V and G/{omega}-V curves exhibit a peak at low frequencies and the peak values of C and G/{omega} decrease with increasing frequency. Also, the plots of R {sub s} as a function of bias give two peaks in the certain voltage range at low frequencies. These observations indicate that at low frequencies, the charges at interface states can easily follow an AC signal and the number of them increases with decreasing frequency. The I-V, C-V and G/{omega}-V characteristics of the MIS structure are affected not only with R {sub s} but also N {sub ss}. Experimental results show that both the R{sub s} and C{sub o} values should be taken into account in determining frequency-dependent electrical characteristics.

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.
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.
Module Five: Relationships of Current, Voltage, and Resistance; Basic Electricity and Electronics Individualized Learning System.

Science.gov (United States)

Bureau of Naval Personnel, Washington, DC.

This module covers the relationships between current and voltage; resistance in a series circuit; how to determine the values of current, voltage, resistance, and power in resistive series circuits; the effects of source internal resistance; and an introduction to the troubleshooting of series circuits. This module is divided into five lessons:…
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.
Analysis of interface states and series resistance for Al/PVA:n-CdS nanocomposite metal-semiconductor and metal-insulator-semiconductor diode structures

Energy Technology Data Exchange (ETDEWEB)

Sharma, Mamta; Tripathi, S.K. [Panjab University, Centre of Advanced Study in Physics, Department of Physics, Chandigarh (India)

2013-11-15

This paper presents the fabrication and characterization of Al/PVA:n-CdS (MS) and Al/Al{sub 2}O{sub 3}/PVA:n-CdS (MIS) diode. The effects of interfacial insulator layer, interface states (N{sub ss}) and series resistance (R{sub s}) on the electrical characteristics of Al/PVA:n-CdS structures have been investigated using forward and reverse bias I-V, C-V, and G/w-V characteristics at room temperature. Al/PVA:n-CdS diode is fabricated with and without insulator Al{sub 2}O{sub 3} layer to explain the effect of insulator layer on main electrical parameters. The values of the ideality factor (n), series resistance (R{sub s}) and barrier height ({phi} {sub b}) are calculated from ln(I) vs. V plots, by the Cheung and Norde methods. The energy density distribution profile of the interface states is obtained from the forward bias I-V data by taking into account the bias dependence ideality factor (n(V)) and effective barrier height ({phi} {sub e}) for MS and MIS diode. The N{sub ss} values increase from mid-gap energy of CdS to the bottom of the conductance band edge for both MS and MIS diode. (orig.)
CVD-graphene for low equivalent series resistance in rGO/CVD-graphene/Ni-based supercapacitors

Science.gov (United States)

Kwon, Young Hwi; Kumar, Sunil; Bae, Joonho; Seo, Yongho

2018-05-01

Reduced equivalent series resistance (ESR) is necessary, particularly at a high current density, for high performance supercapacitors, and the interface resistance between the current collector and electrode material is one of the main components of ESR. In this report, we have optimized chemical vapor deposition-grown graphene (CVD-G) on a current collector (Ni-foil) using reduced graphene oxide as an active electrode material to fabricate an electric double layer capacitor with reduced ESR. The CVD-G was grown at different cooling rates—20 °C min‑1, 40 °C min‑1 and 100 °C min‑1—to determine the optimum conditions. The lowest ESR, 0.38 Ω, was obtained for a cell with a 100 °C min‑1 cooling rate, while the sample without a CVD-G interlayer exhibited 0.80 Ω. The CVD-G interlayer-based supercapacitors exhibited fast CD characteristics with high scan rates up to 10 Vs‑1 due to low ESR. The specific capacitances deposited with CVD-G were in the range of 145.6 F g‑1–213.8 F g‑1 at a voltage scan rate of 0.05 V s‑1. A quasi-rectangular behavior was observed in the cyclic voltammetry curves, even at very high scan rates of 50 and 100 V s‑1, for the cell with optimized CVD-G at higher cooling rates, i.e. 100 °C min‑1.
Analysis of cyclical behavior in time series of stock market returns

Science.gov (United States)

Stratimirović, Djordje; Sarvan, Darko; Miljković, Vladimir; Blesić, Suzana

2018-01-01

In this paper we have analyzed scaling properties and cyclical behavior of the three types of stock market indexes (SMI) time series: data belonging to stock markets of developed economies, emerging economies, and of the underdeveloped or transitional economies. We have used two techniques of data analysis to obtain and verify our findings: the wavelet transform (WT) spectral analysis to identify cycles in the SMI returns data, and the time-dependent detrended moving average (tdDMA) analysis to investigate local behavior around market cycles and trends. We found cyclical behavior in all SMI data sets that we have analyzed. Moreover, the positions and the boundaries of cyclical intervals that we found seam to be common for all markets in our dataset. We list and illustrate the presence of nine such periods in our SMI data. We report on the possibilities to differentiate between the level of growth of the analyzed markets by way of statistical analysis of the properties of wavelet spectra that characterize particular peak behaviors. Our results show that measures like the relative WT energy content and the relative WT amplitude of the peaks in the small scales region could be used to partially differentiate between market economies. Finally, we propose a way to quantify the level of development of a stock market based on estimation of local complexity of market's SMI series. From the local scaling exponents calculated for our nine peak regions we have defined what we named the Development Index, which proved, at least in the case of our dataset, to be suitable to rank the SMI series that we have analyzed in three distinct groups.
High-performance carbon nanotube-implanted mesoporous carbon spheres for supercapacitors with low series resistance

Energy Technology Data Exchange (ETDEWEB)

Yi, Bin [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China); Chen, Xiaohua, E-mail: hudacxh62@yahoo.com.cn [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China); Guo, Kaimin [College of Physics and Electronic Science, Changsha University of Science and Technology (China); Xu, Longshan [Department of Mechanical Engineering, Xiamen University of Technology, Xiamen 361024 (China); Chen, Chuansheng [College of Physics and Electronic Science, Changsha University of Science and Technology (China); Yan, Haimei; Chen, Jianghua [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China)

2011-11-15

Research highlights: {yields} CNTs-implanted porous carbon spheres are prepared by using gelatin as soft template. {yields} Homogeneously distributed CNTs form a well-develop network in carbon spheres. {yields} CNTs act as a reinforcing backbone assisting the formation of pore structure. {yields} CNTs improve electrical conductivity and specific capacitance of supercapacitor. -- Abstract: Carbon nanotube-implanted mesoporous carbon spheres were prepared by an easy polymerization-induced colloid aggregation method using gelatin as a soft template. Scanning electron microscopy, transmission electron microscopy and nitrogen adsorption-desorption measurements reveal that the materials are mesoporous carbon spheres, with a diameter of {approx}0.5-1.0 {mu}m, a specific surface area of 284 m{sup 2}/g and average pore size of 3.9 nm. Using the carbon nanotube-implanted mesoporous carbon spheres as electrode material for supercapacitors in an aqueous electrolyte solution, a low equivalent series resistance of 0.83 {Omega} cm{sup 2} and a maximum specific capacitance of 189 F/g with a measured power density of 8.7 kW/kg at energy density of 6.6 Wh/kg are obtained.
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.
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.
Novel series of 1,2,4-trioxane derivatives as antimalarial agents.

Science.gov (United States)

Rudrapal, Mithun; Chetia, Dipak; Singh, Vineeta

2017-12-01

Among three series of 1,2,4-trioxane derivatives, five compounds showed good in vitro antimalarial activity, three compounds of which exhibited better activity against P. falciparum resistant (RKL9) strain than the sensitive (3D7) one. Two best compounds were one from aryl series and the other from heteroaryl series with IC 50 values of 1.24 µM and 1.24 µM and 1.06 µM and 1.17 µM, against sensitive and resistant strains, respectively. Further, trioxane derivatives exhibited good binding affinity for the P. falciparum cysteine protease falcipain 2 receptor (PDB id: 3BPF) with well defined drug-like and pharmacokinetic properties based on Lipinski's rule of five with additional physicochemical and ADMET parameters. In view of having antimalarial potential, 1,2,4-trioxane derivative(s) reported herein may be useful as novel antimalarial lead(s) in the discovery and development of future antimalarial drug candidates as P. falciparum falcipain 2 inhibitors against resistant malaria.
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
Effects of laminations in pipes to resistance and working life of pipelines; Auswirkung von Doppelungen in Rohren auf die Festigkeit und die Lebensdauer von Mineraloelfernleitungen

Energy Technology Data Exchange (ETDEWEB)

Camp, H.J. de la; Feser, G; Schmidt, H [Technischer Ueberwachungs-Verein Bayern Hessen Sachsen e.V., Muenchen (Germany)

1998-03-01

The effect of load cycles on pipes with laminations was examined to obtain information about the effects on resistance and working life. Material tests carried out in connection with threshold load tests showed that laminations or also segregations in pipes welded with longitudinal seams always run parallel to the surface and that even with the slight enlargement that sometimes occurs under threshold loading, resistance and working life are not reduced. (orig.) [Deutsch] Die Auswirkung von dynamischen Belastungen auf dopplungsbehaftete Rohre wurde untersucht, um Erkenntnisse hinsichtlich der Beeinflussung auf die Festigkeit der Lebensdauer zu gewinnen. Durchgefuehrte Werkstoffuntersuchungen im Zusammenhang mit Schwelllastversuchen zeigten, dass Doppelungen oder auch Seigerungen in laengsnahtgeschweissten Rohren immer oberflaechenparallel verlaufen und dass selbst bei der unter Schwellastbeanspruchung teilweise eingetretenen geringfuegigen Vergroesserung die Festigkeit und die Lebensdauer nicht eingeschraenkt wird. (orig.)
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.
Resistance Fluctuations in GaAs Nanowire Grids

Directory of Open Access Journals (Sweden)

Ivan Marasović

2014-01-01

Full Text Available We present a numerical study on resistance fluctuations in a series of nanowire-based grids. Each grid is made of GaAs nanowires arranged in parallel with metallic contacts crossing all nanowires perpendicularly. Electrical properties of GaAs nanowires known from previous experimental research are used as input parameters in the simulation procedure. Due to the nonhomogeneous doping, the resistivity changes along nanowire. Allowing two possible nanowire orientations (“upwards” or “downwards”, the resulting grid is partially disordered in vertical direction which causes resistance fluctuations. The system is modeled using a two-dimensional random resistor network. Transfer-matrix computation algorithm is used to calculate the total network resistance. It is found that probability density function (PDF of resistance fluctuations for a series of nanowire grids changes from Gaussian behavior towards the Bramwell-Holdsworth-Pinton distribution when both nanowire orientations are equally represented in the grid.
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.
Test of 6-inch-thick pressure vessels. Series 2. Intermediate test vessels V-3, V-4, and V-6

International Nuclear Information System (INIS)

Bryan, R.H.; Merkle, J.G.; Raftenberg, M.N.; Robinson, G.C.; Smith, J.E.

1975-11-01

The second series of intermediate vessel tests were crack initiation fracture tests of 6-in.-thick 39-in.-OD steel vessels with sharp surface flaws approximately 2 1 / 2 in. deep by 8 in. long in the longitudinal weld seams of the test cylinders. Fracture was initiated by means of hydraulic pressurization. One vessel was tested at each of three temperatures: 75, 130, and 190 0 F. Pretest analyses were made to predict the failure pressures and strains. Fracture toughness data obtained by equivalent-energy analysis of precracked Charpy-V tests and compact-tension specimen tests were used in the fracture analyses. The vessels behaved generally as had been expected. Posttest fracture analyses were also performed for each vessel. Detailed discussions of the fracture analysis methods developed in support of the vessel tests described are included. 34 references

Report on series 3 reflood experiment

International Nuclear Information System (INIS)

Murao, Yoshio; Iguchi, Tadashi; Sudoh, Takashi; Sudo, Yukio; Sugimoto, Jun

1977-03-01

Series 3 reflood experiment was carried out from December 1975 to January 1976. The purpose was to confirm temperature response and durability of the improved thermocouple installation and to examine system effect with parameters, flow housing temperature and primary loop flow resistance. The results are : 1) The improved thermocouples installation still has some problems, but is generally satisfactory up to 1000 0 C. 2) The flow housing temperature has large influence on the reflood phenomena, especially oscillation. 3) The primary loop resistance determines the flooding rate, and so influences the reflood phenomena. (auth.)
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
On the interface trap density and series resistance of tin oxide film prepared on n-type Si (1 1 1) substrate: Frequency dependent effects before and after 60Co γ-ray irradiation

International Nuclear Information System (INIS)

Karadeniz, S.; Selcuk, A. Birkan; Tugluoglu, N.; Ocak, S. Bilge

2007-01-01

We report the first investigation of the frequency dependent effects of gamma irradiation on interface state density and series resistance determined from capacitance-voltage (C-V) and conductance-voltage (G-V) characteristics in SnO 2 /n-Si structures prepared by spray deposition method. The samples were irradiated using a 60 Co γ-ray source at 500 kGy at room temperature. The C-V and G-V measurements of the samples were performed in the voltage range -6 V to 2 V and at 10 kHz, 100 kHz, 500 kHz and 1 MHz at room temperature before and after 500 kGy irradiation. The measurement capacitance and conductance are corrected for series resistance. It has been seen that the value of the series resistance R s of sample decreases from 204 Ω to 55.4 Ω with increasing the frequency before irradiation while it decreases from 248 Ω to 60 Ω with increasing frequency at 500 kGy irradiation. It has been found that and D it values of MOS structure increases up to 100 kHz and then decreases up to 1 MHz while the R s increases with increasing irradiation dose for our sample. The interface state density D it ranges from 1.83 x 10 13 cm -2 eV -1 for before irradiation to 1.54 x 10 13 cm -2 eV -1 for 500 kGy irradiation dose at 500 kHz and decreases with increasing frequency
Characterization of Series Resistance and Mobility Degradation Parameter and Optimizing Choice of Oxide Thickness in Thin Oxide N-Channel MOSFET

Directory of Open Access Journals (Sweden)

Noureddine Maouhoub

2011-01-01

Full Text Available We present two methods to extract the series resistance and the mobility degradation parameter in short-channel MOSFETs. The principle of the first method is based on the comparison between the exponential model and the classical model of effective mobility and for the second method is based on directly calculating the two parameters by solving a system of two equations obtained by using two different points in strong inversion at small drain bias from the characteristic (. The results obtained by these techniques have shown a better agreement with data measurements and allowed in the same time to determine the surface roughness amplitude and its influence on the maximum drain current and give the optimal oxide thickness.
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...
Quantitative trait loci associated with anthracnose resistance in sorghum

Science.gov (United States)

With an aim to develop a durable resistance to the fungal disease anthracnose, two unique genetic sources of resistance were selected to create genetic mapping populations to identify regions of the sorghum genome that encode anthracnose resistance. A series of quantitative trait loci were identifi...
Predictions of fire behavior and resistance to control: for use with photo series for the ponderosa pine type, ponderosa pine and associated species type, and lodgepole pine type.

Science.gov (United States)

Franklin R. Ward; David V. Sandberg

1981-01-01

This publication presents tables on the behavior of fire and the resistance of fuels to control. The information is to be used with the publication, "Photo Series for Quantifying Forest Residues in the Ponderosa Pine Type, Ponderosa Pine and Associated Species Type, Lodgepole Pine Type" (Maxwell, Wayne G.; Ward, Franklin R. 1976. Gen. Tech. Rep. PNW-GTR-052....
Accelerating resistance breeding in wheat by integrating marker ...

African Journals Online (AJOL)

Genetic resistance is the simplest and most cost-effective way to guard against disease in plants. The pyramiding of resistance genes is a useful practice in bringing about durable resistance. This study aimed to develop a series of doubled haploid (DH) wheat lines containing combinations of wild species genes for rust ...
Collateral Resistance and Sensitivity Modulate Evolution of High-Level Resistance to Drug Combination Treatment in Staphylococcus aureus

DEFF Research Database (Denmark)

de Evgrafov, Mari Cristina Rodriguez; Gumpert, Heidi; Munck, Christian

2015-01-01

As drug-resistant pathogens continue to emerge, combination therapy will increasingly be relied upon to treat infections and to help combat further development of multidrug resistance. At present a dichotomy exists between clinical practice, which favors therapeutically synergistic combinations......, to reflect drug concentrations more likely to be encountered during treatment. We performed a series of adaptive evolution experiments using Staphylococcus aureus. Interestingly, no relationship between drug interaction type and resistance evolution was found as resistance increased significantly beyond wild......-type levels. All drug combinations, irrespective of interaction types, effectively limited resistance evolution compared with monotreatment. Cross-resistance and collateral sensitivity were found to be important factors in the extent of resistance evolution toward a combination. Comparative genomic analyses...
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.
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.
Measurements of time average series resonance effect in capacitively coupled radio frequency discharge plasma

International Nuclear Information System (INIS)

Bora, B.; Bhuyan, H.; Favre, M.; Wyndham, E.; Chuaqui, H.; Kakati, M.

2011-01-01

Self-excited plasma series resonance is observed in low pressure capacitvely coupled radio frequency discharges as high-frequency oscillations superimposed on the normal radio frequency current. This high-frequency contribution to the radio frequency current is generated by a series resonance between the capacitive sheath and the inductive and resistive bulk plasma. In this report, we present an experimental method to measure the plasma series resonance in a capacitively coupled radio frequency argon plasma by modifying the homogeneous discharge model. The homogeneous discharge model is modified by introducing a correction factor to the plasma resistance. Plasma parameters are also calculated by considering the plasma series resonances effect. Experimental measurements show that the self-excitation of the plasma series resonance, which arises in capacitive discharge due to the nonlinear interaction of plasma bulk and sheath, significantly enhances both the Ohmic and stochastic heating. The experimentally measured total dissipation, which is the sum of the Ohmic and stochastic heating, is found to increase significantly with decreasing pressure.
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.

Low-level quinolone-resistance in multi-drug resistant typhoid

Energy Technology Data Exchange (ETDEWEB)

Mirza, S H; Khan, M A [Armed Forces Inst. of Pathology, Rawalpindi (Pakistan). Dept. of Microbiolgy

2008-01-15

To find out the frequency of low-level quinolone-resistance in Multi-Drug Resistant (MDR) typhoid using nalidixic acid screening disc. Blood was obtained from suspected cases of typhoid fever and cultured in to BacT/ALERT. The positive blood cultures bottles were subcultured. The isolates were identified by colony morphology and biochemical tests using API-20E galleries. Susceptibility testing of isolates was done by modified Kirby-Bauer disc diffusion method on Muellar Hinton Agar. For the isolates, which were resistant to nalidixic acid by disc diffusion method, Minimal Inhibitory Concentrations (MICs) of ciprofloxacin and nalidixic acid were determined by using the E-test strips. Disc diffusion susceptibility tests and MICs were interpreted according to the guidelines provided by National Committee for Control Laboratory Standard (NCCLS). A total of 21(65.5%) out of 32 isolates of Salmonellae were nalidixic acid-resistant by disk diffusion method. All the nalidixic acid-resistant isolates by disc diffusion method were confirmed by MICs for both ciprofloxacin and nalidixic acid. All the nalidixic acid-resistant isolates had a ciprofloxacin MIC of 0.25-1 microg/ml (reduced susceptibility) and nalidixic acid MICs > 32 microg (resistant). Out of all Salmonella isolates, 24 (75%) were found to be MDR, and all were S. typbi. Low-level quinolone-resistance in typhoid was high in this small series. Screening for nalidixic acid resistance with a 30 microg nalidixic acid disk is a reliable and cost-effective method to detect low-level fluoroquinolone resistance, especially in the developing countries. (author)
Low-level quinolone-resistance in multi-drug resistant typhoid

International Nuclear Information System (INIS)

Mirza, S.H.; Khan, M.A.

2008-01-01

To find out the frequency of low-level quinolone-resistance in Multi-Drug Resistant (MDR) typhoid using nalidixic acid screening disc. Blood was obtained from suspected cases of typhoid fever and cultured in to BacT/ALERT. The positive blood cultures bottles were subcultured. The isolates were identified by colony morphology and biochemical tests using API-20E galleries. Susceptibility testing of isolates was done by modified Kirby-Bauer disc diffusion method on Muellar Hinton Agar. For the isolates, which were resistant to nalidixic acid by disc diffusion method, Minimal Inhibitory Concentrations (MICs) of ciprofloxacin and nalidixic acid were determined by using the E-test strips. Disc diffusion susceptibility tests and MICs were interpreted according to the guidelines provided by National Committee for Control Laboratory Standard (NCCLS). A total of 21(65.5%) out of 32 isolates of Salmonellae were nalidixic acid-resistant by disk diffusion method. All the nalidixic acid-resistant isolates by disc diffusion method were confirmed by MICs for both ciprofloxacin and nalidixic acid. All the nalidixic acid-resistant isolates had a ciprofloxacin MIC of 0.25-1 microg/ml (reduced susceptibility) and nalidixic acid MICs > 32 microg (resistant). Out of all Salmonella isolates, 24 (75%) were found to be MDR, and all were S. typbi. Low-level quinolone-resistance in typhoid was high in this small series. Screening for nalidixic acid resistance with a 30 microg nalidixic acid disk is a reliable and cost-effective method to detect low-level fluoroquinolone resistance, especially in the developing countries. (author)
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
Fate of antibiotic resistant bacteria and genes during wastewater chlorination: implication for antibiotic resistance control.

Directory of Open Access Journals (Sweden)

Qing-Bin Yuan

Full Text Available This study investigated fates of nine antibiotic-resistant bacteria as well as two series of antibiotic resistance genes in wastewater treated by various doses of chlorine (0, 15, 30, 60, 150 and 300 mg Cl2 min/L. The results indicated that chlorination was effective in inactivating antibiotic-resistant bacteria. Most bacteria were inactivated completely at the lowest dose (15 mg Cl2 min/L. By comparison, sulfadiazine- and erythromycin-resistant bacteria exhibited tolerance to low chlorine dose (up to 60 mg Cl2 min/L. However, quantitative real-time PCRs revealed that chlorination decreased limited erythromycin or tetracycline resistance genes, with the removal levels of overall erythromycin and tetracycline resistance genes at 0.42 ± 0.12 log and 0.10 ± 0.02 log, respectively. About 40% of erythromycin-resistance genes and 80% of tetracycline resistance genes could not be removed by chlorination. Chlorination was considered not effective in controlling antimicrobial resistance. More concern needs to be paid to the potential risk of antibiotic resistance genes in the wastewater after chlorination.
An Annotated Bibliography of MANPRINT-Related Assessments and Evaluations Conducted by the U.S. Army, 2nd Edition: 1953 to 2009. Volume 3 - Test and Evaluation Reports

Science.gov (United States)

2010-02-01

way stretch capability. All gannents have an abrasion resistant exterior and full FR construction including zippers, thread , cord, Velcro, and...liner of fully-sewn, fire -retardant, self-extinguishing fabric; outer glove stitching of heat- resistant Kevlar™ 303 thread ; and seams on index, middle...FREE Ensemble-FREE Fire Resistant Environmental Ensemble (FREE) System Integrator - ADS 2008 Aircraft- Helicopter- Aircrew- Knife- ASEK Knife
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
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.
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.
Resistive RAMs as analog trimming elements

Science.gov (United States)

Aziza, H.; Perez, A.; Portal, J. M.

2018-04-01

This work investigates the use of Resistive Random Access Memory (RRAM) as an analog trimming device. The analog storage feature of the RRAM cell is evaluated and the ability of the RRAM to hold several resistance states is exploited to propose analog trim elements. To modulate the memory cell resistance, a series of short programming pulses are applied across the RRAM cell allowing a fine calibration of the RRAM resistance. The RRAM non volatility feature makes the analog device powers up already calibrated for the system in which the analog trimmed structure is embedded. To validate the concept, a test structure consisting of a voltage reference is evaluated.
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
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.
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.
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
Semiconductor resistance thermometer for the temperature range 300-0.3 K

International Nuclear Information System (INIS)

Zinov'eva, K.N.; Zarubin, L.I.; Nemish, I.Yu.; Vorobkalo, F.M.; Boldarev, S.T.; AN Ukrainskoj SSR, Kiev. Inst. Poluprovodnikov)

1979-01-01

Thermometric characteristics of semiconductor resistor thermometers for the temperature range from 300 to 0.3 K and from 77 to 0.3 K are given. Temperature dependence of thermometer resistances in the 300-1.3 K range was measured in cryostats with pumping-out of N 2 , H 2 and 4 He. For measurements below 1.3 K use was made of a 3 H- 4 He dissolving cryostat. The accuracy of measuring temperatures in the 1.3-0.3 K range is not below +-0.003 K, the error in determining thermometer resistances does not exceed 1%. The analysis of obtained thermometric characteristics of several series of semiconductor resistance thermometers showed that observed insignificant spread of resistances of thermometers in one series and identity of characteristics allows them to be used without preliminary calibration for relatively coarse measurements in the range from 3O0 to 0.3 K. Besides, it has been found that in the 4.2-0.3 K range the thermometric characteristics represent a straight line in the lgR-Tsup(-n) coordinates, where R is the thermometer resistance, T is the temperature and n=0.5. Thus, the thermometers of the same series can be calibrated only in 2 or 3 reference point measurements
Adding Resistances and Capacitances in Introductory Electricity

Science.gov (United States)

Efthimiou, C. J.; Llewellyn, R. A.

2005-09-01

All introductory physics textbooks, with or without calculus, cover the addition of both resistances and capacitances in series and in parallel as discrete summations. However, none includes problems that involve continuous versions of resistors in parallel or capacitors in series. This paper introduces a method for solving the continuous problems that is logical, straightforward, and within the mathematical preparation of students at the introductory level.
47 CFR 73.54 - Antenna resistance and reactance measurements.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Antenna resistance and reactance measurements... measurements. (a) The resistance of an omnidirectional series fed antenna is measured at either the base of the... the point of common radiofrequency input to the directional antenna system after the antenna has been...

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.
Dealing with antimicrobial resistance - the Danish experience

DEFF Research Database (Denmark)

Bager, Flemming; Aarestrup, Frank Møller; Wegener, Henrik Caspar

2000-01-01

(DANMAP), which monitors resistance among bacteria from food animals, food and humans. A programme to monitor all use of prescription medicine in food animals at the herd level is presently being implemented. Another initiative was the elaboration of a series of practical recommendations to veterinarians...... on the prudent use of antimicrobials in order to reduce the development of resistance without compromising therapeutic efficacy. Our experience with avoparcin shows that a restrictive policy on the use of antimicrobials can curb the development of resistance. However, the occurrence and persistence of specific...
Comparing spatial series of soil bulk electrical conductivity as obtained by Time Domain Reflectometry and Electrical Resistivity Tomography

Science.gov (United States)

Saeed, Ali; Dragonetti, Giovanna; Comegna, Allessandro; Garre, Sarah; Lamaddalena, Nicola; Coppola, Antonio

2016-04-01

Conventional ground survey of soil root zone salinity by direct soil sampling are time consuming, costly and destructive. Alternatively, soil salinity can be evaluated by measuring the bulk electrical conductivity, σb, in the field. This approach is faster and cheaper, and allows a more intensive surveying. Measurements of σb can be made either in situ or with remote devices. Time domain reflectometry (TDR) sensors allow simultaneous measurements of water content, θ, and σb. They may be calibrated for estimating the electrical conductivity of the soil solution (σw). However, they have a relatively small observation window and thus they are thought to only provide local-scale measurements. The spatial range of the sensors is limited to tens of centimeters and extension of the information to a large area can be problematic. Also, information on the vertical distribution of the σb soil profile may only be obtained by installing sensors at different depths. In this sense, the TDR may be considered as an invasive technique. Compared to the TDR, other geophysical methods based for example on the Electrical Resistivity Tomography (ERT) techniques represent an alternative in respect to those traditional for soil salinity characterization. In order to deduce the actual distribution of the bulk electrical conductivity, σb, in the soil profile, one needs to invert the signal coming from ERT sensors. The latter, in turn, depends on the specific depth distribution of the σb, as well as on the electrical configuration of the sensor used. With these premises, the main aim of this study is to estimate the vertical σb distribution starting from resistivity data series measured using the ERT method under different salinity conditions and using TDR data as ground-truth data for calibration and validation of the ERT sensor. This way, limited measured TDR data may be used for translating extensive ERT apparent electrical conductivity, σa, measurements to estimate depth
Study of self-compliance behaviors and internal filament characteristics in intrinsic SiOx-based resistive switching memory

International Nuclear Information System (INIS)

Chang, Yao-Feng; Zhou, Fei; Chen, Ying-Chen; Lee, Jack C.; Fowler, Burt

2016-01-01

Self-compliance characteristics and reliability optimization are investigated in intrinsic unipolar silicon oxide (SiO x )-based resistive switching (RS) memory using TiW/SiO x /TiW device structures. The program window (difference between SET voltage and RESET voltage) is dependent on external series resistance, demonstrating that the SET process is due to a voltage-triggered mechanism. The program window has been optimized for program/erase disturbance immunity and reliability for circuit-level applications. The SET and RESET transitions have also been characterized using a dynamic conductivity method, which distinguishes the self-compliance behavior due to an internal series resistance effect (filament) in SiO x -based RS memory. By using a conceptual “filament/resistive gap (GAP)” model of the conductive filament and a proton exchange model with appropriate assumptions, the internal filament resistance and GAP resistance can be estimated for high- and low-resistance states (HRS and LRS), and are found to be independent of external series resistance. Our experimental results not only provide insights into potential reliability issues but also help to clarify the switching mechanisms and device operating characteristics of SiO x -based RS memory
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
Capacitors and Resistance-Capacitance Networks.

Science.gov (United States)

Balabanian, Norman; Root, Augustin A.

This programed textbook was developed under a contract with the United States Office of Education as Number 5 in a series of materials for use in an electrical engineering sequence. It is divided into three parts--(1) capacitors, (2) voltage-current relationships, and (3) simple resistance-capacitance networks. (DH)
Treatment Options for Carbapenem-Resistant and Extensively Drug-Resistant Acinetobacter baumannii Infections

Science.gov (United States)

Viehman, J. Alexander; Nguyen, Minh-Hong; Doi, Yohei

2014-01-01

Acinetobacter baumannii is a leading cause of healthcare-associated infections worldwide. Due to various intrinsic and acquired mechanisms of resistance, most β-lactam agents are not effective against many strains, and carbapenems have played an important role in therapy. Recent trends show many infections are caused by carbapenem-resistant, or even extensively drug-resistant (XDR) strains, for which effective therapy is not well established. Evidence to date suggests that colistin constitutes the backbone of therapy, but the unique pharmacokinetic properties of colistin have led many to suggest the use of combination antimicrobial therapy. However, the combination of agents and dosing regimens that delivers the best clinical efficacy while minimizing toxicity is yet to be defined. Carbapenems, sulbactam, rifampin and tigecycline have been the most studied in the context of combination therapy. Most data regarding therapy for invasive, resistant A. baumannii infections come from uncontrolled case series and retrospective analyses, though some clinical trials have been completed and others are underway. Early institution of appropriate antimicrobial therapy is shown to consistently improve survival of patients with carbapenem-resistant and XDR A. baumannii infection, but the choice of empiric therapy in these infections remains an open question. This review summarizes the most current knowledge regarding the epidemiology, mechanisms of resistance, and treatment considerations of carbapenem-resistant and XDR A. baumannii. PMID:25091170
Accurate measurement of junctional conductance between electrically coupled cells with dual whole-cell voltage-clamp under conditions of high series resistance.

Science.gov (United States)

Hartveit, Espen; Veruki, Margaret Lin

2010-03-15

Accurate measurement of the junctional conductance (G(j)) between electrically coupled cells can provide important information about the functional properties of coupling. With the development of tight-seal, whole-cell recording, it became possible to use dual, single-electrode voltage-clamp recording from pairs of small cells to measure G(j). Experiments that require reduced perturbation of the intracellular environment can be performed with high-resistance pipettes or the perforated-patch technique, but an accompanying increase in series resistance (R(s)) compromises voltage-clamp control and reduces the accuracy of G(j) measurements. Here, we present a detailed analysis of methodologies available for accurate determination of steady-state G(j) and related parameters under conditions of high R(s), using continuous or discontinuous single-electrode voltage-clamp (CSEVC or DSEVC) amplifiers to quantify the parameters of different equivalent electrical circuit model cells. Both types of amplifiers can provide accurate measurements of G(j), with errors less than 5% for a wide range of R(s) and G(j) values. However, CSEVC amplifiers need to be combined with R(s)-compensation or mathematical correction for the effects of nonzero R(s) and finite membrane resistance (R(m)). R(s)-compensation is difficult for higher values of R(s) and leads to instability that can damage the recorded cells. Mathematical correction for R(s) and R(m) yields highly accurate results, but depends on accurate estimates of R(s) throughout an experiment. DSEVC amplifiers display very accurate measurements over a larger range of R(s) values than CSEVC amplifiers and have the advantage that knowledge of R(s) is unnecessary, suggesting that they are preferable for long-duration experiments and/or recordings with high R(s). Copyright (c) 2009 Elsevier B.V. All rights reserved.
Drug-resistant tuberculosis in Sindh

International Nuclear Information System (INIS)

Almani, S.A.; Memon, N.M.; Qureshi, A.F.

2002-01-01

Objective: To assess the prevalence of primary and secondary drug resistance amongst the clinical isolates of M.tuberculosis, to identify risk factors and how to overcome this problem. Design: A case series of 50 indoor patients with sputum smear-positive pulmonary tuberculosis. Place and duration of Study: Department of Medicine, Liaquat University of Medical and Health Sciences Jamshoro, Sindh, (Pakistan) from January 1999 to December 2000. Patients and methods: Four first line anti-tuberculous drugs rifampicine, ethambutol and streptomycin were tested for sensitivity pattern. Results: Twelve (26.66%) were sensitive to all four drugs, 12(26.66%) were resistant to one drug, 14 (31.11%) were resistant to two drugs, 2 (4.44%) were resistant to three drugs, and 5(11.11%) were resistant to all four drugs. Resistance to isoniazid was the most common in 27 cases (60%) with primary resistance in 6(13.33%) and secondary resistance in 21(46.66%), followed by resistance to streptomycin in 17 cases (37.77%) with primary resistance in 5(11.11%) and secondary resistance in 12 (26.66%). Resistance to ethambutol in 10 cases (22.22%) and rifampicine in 11 (24.44%) and all cases were secondary. Similarly multi-drugs resistance (MRD) TB was found in 11(24.44%) isolates. Conclusion: This study showed high prevalence of drug resistance among clinical isolates of M. tuberculosis. Their is a need to establish centers at number of places with adequate facilities for susceptibility testing so that the resistant pattern could be ascertained and treatment regimens tailored accordingly. (author)
Transition edge sensor series array bolometer

Energy Technology Data Exchange (ETDEWEB)

Beyer, J, E-mail: joern.beyer@ptb.d [Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, D-10587 Berlin (Germany)

2010-10-15

A transition edge sensor series array (TES-SA) is an array of identical TESs that are connected in series by low-inductance superconducting wiring. The array elements are equally and well thermally coupled to the absorber and respond to changes in the absorber temperature in synchronization. The TES-SA total resistance increases compared to a single TES while the shape of the superconducting transition is preserved. We are developing a TES-SA with a large number, hundreds to thousands, of array elements with the goal of enabling the readout of a TES-based bolometer operated at 4.2 K with a semiconductor-based amplifier located at room temperature. The noise and dynamic performance of a TES-SA bolometer based on a niobium/aluminum bilayer is analyzed. It is shown that stable readout of the bolometer with a low-noise transimpedance amplifier is feasible.
Transition edge sensor series array bolometer

International Nuclear Information System (INIS)

Beyer, J

2010-01-01

A transition edge sensor series array (TES-SA) is an array of identical TESs that are connected in series by low-inductance superconducting wiring. The array elements are equally and well thermally coupled to the absorber and respond to changes in the absorber temperature in synchronization. The TES-SA total resistance increases compared to a single TES while the shape of the superconducting transition is preserved. We are developing a TES-SA with a large number, hundreds to thousands, of array elements with the goal of enabling the readout of a TES-based bolometer operated at 4.2 K with a semiconductor-based amplifier located at room temperature. The noise and dynamic performance of a TES-SA bolometer based on a niobium/aluminum bilayer is analyzed. It is shown that stable readout of the bolometer with a low-noise transimpedance amplifier is feasible.
A Series Active Damper with Closed-loop Control for Stabilizing Single-phase Power-Electronics-Based Power System

DEFF Research Database (Denmark)

Lu, Dapeng; Wang, Xiongfei; Bai, Haofeng

2016-01-01

resistance through detection and resonant controller, the series active damper can suppress the resonance with its external damping character in closed-loop damping character are carried out. Simulation and experimental results are presented to verify the effectiveness of the proposed series active damper....
Optimization study on inductive-resistive circuit for broadband piezoelectric energy harvesters

Directory of Open Access Journals (Sweden)

Ting Tan

2017-03-01

Full Text Available The performance of cantilever-beam piezoelectric energy harvester is usually analyzed with pure resistive circuit. The optimal performance of such a vibration-based energy harvesting system is limited by narrow bandwidth around its modified natural frequency. For broadband piezoelectric energy harvesting, series and parallel inductive-resistive circuits are introduced. The electromechanical coupled distributed parameter models for such systems under harmonic base excitations are decoupled with modified natural frequency and electrical damping to consider the coupling effect. Analytical solutions of the harvested power and tip displacement for the electromechanical decoupled model are confirmed with numerical solutions for the coupled model. The optimal performance of piezoelectric energy harvesting with inductive-resistive circuits is revealed theoretically as constant maximal power at any excitation frequency. This is achieved by the scenarios of matching the modified natural frequency with the excitation frequency and equating the electrical damping to the mechanical damping. The inductance and load resistance should be simultaneously tuned to their optimal values, which may not be applicable for very high electromechanical coupling systems when the excitation frequency is higher than their natural frequencies. With identical optimal performance, the series inductive-resistive circuit is recommended for relatively small load resistance, while the parallel inductive-resistive circuit is suggested for relatively large load resistance. This study provides a simplified optimization method for broadband piezoelectric energy harvesters with inductive-resistive circuits.
Optimization study on inductive-resistive circuit for broadband piezoelectric energy harvesters

Science.gov (United States)

Tan, Ting; Yan, Zhimiao

2017-03-01

The performance of cantilever-beam piezoelectric energy harvester is usually analyzed with pure resistive circuit. The optimal performance of such a vibration-based energy harvesting system is limited by narrow bandwidth around its modified natural frequency. For broadband piezoelectric energy harvesting, series and parallel inductive-resistive circuits are introduced. The electromechanical coupled distributed parameter models for such systems under harmonic base excitations are decoupled with modified natural frequency and electrical damping to consider the coupling effect. Analytical solutions of the harvested power and tip displacement for the electromechanical decoupled model are confirmed with numerical solutions for the coupled model. The optimal performance of piezoelectric energy harvesting with inductive-resistive circuits is revealed theoretically as constant maximal power at any excitation frequency. This is achieved by the scenarios of matching the modified natural frequency with the excitation frequency and equating the electrical damping to the mechanical damping. The inductance and load resistance should be simultaneously tuned to their optimal values, which may not be applicable for very high electromechanical coupling systems when the excitation frequency is higher than their natural frequencies. With identical optimal performance, the series inductive-resistive circuit is recommended for relatively small load resistance, while the parallel inductive-resistive circuit is suggested for relatively large load resistance. This study provides a simplified optimization method for broadband piezoelectric energy harvesters with inductive-resistive circuits.
Evaluation of a series of 2-napthamide derivatives as inhibitors of the drug efflux pump AcrB for the reversal of antimicrobial resistance.

Science.gov (United States)

Wang, Yinhu; Mowla, Rumana; Guo, Liwei; Ogunniyi, Abiodun D; Rahman, Taufiq; De Barros Lopes, Miguel A; Ma, Shutao; Venter, Henrietta

2017-02-15

Drug efflux pumps confer multidrug resistance to dangerous pathogens which makes these pumps important drug targets. We have synthesised a novel series of compounds based on a 2-naphthamide pharmacore aimed at inhibiting the efflux pumps from Gram-negative bacteria. The archeatypical transporter AcrB from Escherichia coli was used as model efflux pump as AcrB is widely conserved throughout Gram-negative organisms. The compounds were tested for their antibacterial action, ability to potentiate the action of antibiotics and for their ability to inhibit Nile Red efflux by AcrB. None of the compounds were antimicrobial against E. coli wild type cells. Most of the compounds were able to inhibit Nile Red efflux indicating that they are substrates of the AcrB efflux pump. Three compounds were able to synergise with antibiotics and reverse resistance in the resistant phenotype. Compound A3, 4-(isopentyloxy)-2-naphthamide, reduced the MICs of erythromycin and chloramphenicol to the MIC levels of the drug sensitive strain that lacks an efflux pump. A3 had no effect on the MIC of the non-substrate rifampicin indicating that this compound acts specifically through the AcrB efflux pump. A3 also does not act through non-specific mechanisms such as outer membrane or inner membrane permeabilisation and is not cytotoxic against mammalian cell lines. Therefore, we have designed and synthesised a novel chemical compound with great potential to further optimisation as inhibitor of drug efflux pumps. Copyright © 2017 Elsevier Ltd. All rights reserved.
Anomaly effects of arrays for 3d geoelectrical resistivity imaging ...

African Journals Online (AJOL)

user

The effectiveness of using a net of orthogonal or parallel sets of two-dimensional (2D) profiles for three- dimensional (3D) geoelectrical resistivity imaging has been evaluated. A series of 2D apparent resistivity data were generated over two synthetic models which represent geological or environmental conditions for a ...
Nanoscale study on water damage for different warm mix asphalt binders

Directory of Open Access Journals (Sweden)

Kefei Liu

2016-11-01

Full Text Available In order to analyze the water damage to different warm mix asphalt binders from the micro scale, five kinds of asphalt binders, 70#A base asphalt, sasobit warm mix asphalt, energy champion 120 °C (EC120 warm mix asphalt, aspha-min warm mix asphalt, sulfur-extended asphalt modifier (SEAM warm mix asphalt, under different conditions (dry/wet, original/aging are prepared for laboratory tests. The atomic force microscope (AFM is used to observe the surface properties and measure the adhesion force between the asphalt and the mineral aggregate. The obtained results show that under the dry condition aspha-min warm mix asphalt and SEAM warm mix asphalt show stronger adhesive ability with the mineral aggregate compared with other asphalt binders, but also have relatively large dispersion and fluctuation in the tested results; under the wet condition, aspha-min warm mix asphalt and SEAM warm mix asphalt show stronger water damage resistance ability. The EC120 warm mix asphalt and aspha-min warm mix asphalt are less sensitive to moist, and their corresponding adhesion force is less susceptible to the change of external moisture conditions, leading to a better ability to resist water erosion. The aging process significantly lowers the moisture erosion resistance ability, which further impairs the water damage resistance ability. The base asphalt is more sensitive to moisture and more vulnerable to water damage, no matter whether it is under original or aging conditions. The aging aspha-min warm mix asphalt has the least loss of adhesion force, the smallest dispersion of the tested adhesion force, the strongest water damage resistance ability, no matter it is dry or wet. Keywords: Road engineering, Warm mix asphalt, Moisture damage, Atomic force microscope, Microcosmic

Field performance assessment of synthetic liners for uranium tailings ponds: a status report

International Nuclear Information System (INIS)

Mitchell, D.H.; Spanner, G.E.

1984-03-01

The objective of this study is to provide a database to support US Nuclear Regulatory Commission (NRC) licensing of uranium tailings leachate isolation impoundments. This objective is being accomplished by determining the effectiveness of design, installation, and quality assurance practices associated with uranium mill tailings impoundments with flexible membrane liners. The program includes testing of chemical resistance and physical performance of liners, leak detection systems, and seam inspection techniques. This report presents the status of the program through September 1983. The report addresses impoundment design, installation, and inspection techniques used by the uranium milling industry. To determine the relative successes of these techniques, information has been collected from consultants, mill operators, and the synthetic liner industry. Progress in experimental tasks on chemical resistance of liners, physical properties of liners, and nondestructive examination of seams is reported. 25 references, 9 figures, 13 tables
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
Experimental determination of fuel-cladding thermal contact resistance

International Nuclear Information System (INIS)

Maglic, K.; Zivotic, Z.

1968-01-01

Thermal resistance of the UO 2 fuel - Zr-2 cladding was measure by the same experimental apparatus which was used for measuring the thermal conductivity of ceramic fuel. Thermal resistance was measure for a series of heat flux values and the dependence of thermal resistance on the flux is given within in the range from 0.66 W/cm 2 to 13.3 W/cm 2 . The temperature drop on the contact surface was between 39 deg C and 181.7 deg C, proportional to the increase of the heat flux [sr
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.
Antiplasmodial activity of a series of 1,3,5-triazine-substituted polyamines

OpenAIRE

Klenke, Burkhard; Barrett, Michael P.; Brun, Reto; Gilbert, Ian H.

2017-01-01

Polyamine biosynthesis and function has been shown to be a good drug target in some parasitic protozoa and it is proposed that the pathway might also represent a target in the malaria parasite Plasmodium falciparum. A series of 1,3,5-triazine-substituted polyamine analogues were tested for activity against Plasmodium falciparum in vitro. The series showed activity against the parasites and were generally more active against the chloroquine-resistant line K1 than the chloroquine-susceptible li...
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.
Case Series.

Science.gov (United States)

Vetrayan, Jayachandran; Othman, Suhana; Victor Paulraj, Smily Jesu Priya

2017-01-01

To assess the effectiveness and feasibility of behavioral sleep intervention for medicated children with ADHD. Six medicated children (five boys, one girl; aged 6-12 years) with ADHD participated in a 4-week sleep intervention program. The main behavioral strategies used were Faded Bedtime With Response Cost (FBRC) and positive reinforcement. Within a case-series design, objective measure (Sleep Disturbance Scale for Children [SDSC]) and subjective measure (sleep diaries) were used to record changes in children's sleep. For all six children, significant decrease was found in the severity of children's sleep problems (based on SDSC data). Bedtime resistance and mean sleep onset latency were reduced following the 4-week intervention program according to sleep diaries data. Gains were generally maintained at the follow-up. Parents perceived the intervention as being helpful. Based on the initial data, this intervention shows promise as an effective and feasible treatment.
ANSYS Simulation of Residual Strains in Butt-welded Joints

Directory of Open Access Journals (Sweden)

A. Atroshenko

2014-07-01

Full Text Available The effect of thermal-strain cycle on residual strains in thin-walled circular seams of cylindrical shells using TIG butt welds was studied. Estimates were calculated using numerical modelling. The structure was made of corrosion-resistant austenitic steels.
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.
Evaluation of resistivity meters for concrete quality assurance.

Science.gov (United States)

2015-06-01

This research evaluated a series of MoDOT concrete mixtures to verify existing relationships between surface resistivity (SR), rapid : chloride permeability (RCP), chloride ion diffusion, and the AASHTO penetrability classes. The research also perfor...
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.
Development of large area resistive electrodes for ATLAS NSW Micromegas

Science.gov (United States)

Ochi, Atsuhiko

2018-02-01

Micromegas with resistive anodes will be used for the NSW upgrades of the ATLAS experiment at LHC. Resistive electrodes are used in MPGD devices to prevent sparks in high-rate operation. Large-area resistive electrodes for Micromegas have been developed using two different technologies: screen printing and carbon sputtering. The maximum resistive foil size is 45 × 220 cm with a printed pattern of 425-μm pitch strips. These technologies are also suitable for mass production. Prototypes of a production model series have been successfully produced. In this paper, we report the development, the production status, and the test results of resistive Micromegas.
Coke fouling monitoring by electrical resistivity

Energy Technology Data Exchange (ETDEWEB)

Bombardelli, Clovis; Mari, Livia Assis; Kalinowski, Hypolito Jose [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil). Programa de Pos-Graduacao em Engenharia Eletrica e Informatica Industrial (CPGEI)

2008-07-01

An experimental method to simulate the growth of the coke fouling that occurs in the oil processing is proposed relating the thickness of the encrusted coke to its electrical resistivity. The authors suggest the use of the fouling electrical resistivity as a transducer element for determining its thickness. The sensor is basically two electrodes in an electrically isolated device where the inlay can happen in order to compose a purely resistive transducer. Such devices can be easily constructed in a simple and robust form with features capable to face the high temperatures and pressures found in relevant industrial processes. For validation, however, it is needed a relationship between the electrical resistivity and the fouling thickness, information not yet found in the literature. The present work experimentally simulates the growth of a layer of coke on an electrically insulating surface, equipped with electrodes at two extremities to measure the electrical resistivity during thermal cracking essays. The method is realized with a series of consecutive runs. The results correlate the mass of coke deposited and its electrical resistivity, and it can be used to validate the coke depositions monitoring employing the resistivity as a control parameter. (author)
Triazole biotin: a tight-binding biotinidase-resistant conjugate.

Science.gov (United States)

Germeroth, Anne I; Hanna, Jill R; Karim, Rehana; Kundel, Franziska; Lowther, Jonathan; Neate, Peter G N; Blackburn, Elizabeth A; Wear, Martin A; Campopiano, Dominic J; Hulme, Alison N

2013-11-28

The natural amide bond found in all biotinylated proteins has been replaced with a triazole through CuAAC reaction of an alkynyl biotin derivative. The resultant triazole-linked adducts are shown to be highly resistant to the ubiquitous hydrolytic enzyme biotinidase and to bind avidin with dissociation constants in the low pM range. Application of this strategy to the production of a series of biotinidase-resistant biotin-Gd-DOTA contrast agents is demonstrated.
Studies on stem and leaf rust resistance in wheat

International Nuclear Information System (INIS)

Knott, D.R.

1983-01-01

Stem and leaf rust resistance was successfully transferred from Agropyron to wheat by radiation-induced translocations. Mutation induction subsequently proved to be useful in separating an undesired gene for yellow pigment from the resistance. The homoeologous pairing mutant obtained by Sears was also used successfully in obtaining transfers through crossing-over between wheat and Agropyron chromosomes. Another experimental series succeeded in accumulating minor genes for rust resistance, after eliminating major genes for specific resistance. The resistance is polygenic and widely effective although not general. It is recessively inherited, and hoped to be more durable than major gene resistance used so far in the Canadian prairies. An attempt to induce mutations for leaf rust resistance in a small-scale experiment with leading Canadian wheat varieties Manitou and Neepawa using gamma rays and EMS has not been successful. (author)
Effect of electrode shape on grounding resistances - Part 2

DEFF Research Database (Denmark)

Tomaskovicova, Sonia; Ingeman-Nielsen, Thomas; Christiansen, Anders V.

2016-01-01

Although electric resistivity tomography (ERT) is now regarded as a standard tool in permafrost monitoring, high grounding resistances continue to limit the acquisition of time series over complete freeze-thaw cycles. In an attempt to alleviate the grounding resistance problem, we have tested three...... electrode designs featuring increasing sizes and surface area, in the laboratory and at three different field sites in Greenland. Grounding resistance measurements showed that changing the electrode shape (using plates instead of rods) reduced the grounding resistances at all sites by 28%-69% during...... unfrozen and frozen ground conditions. Using meshes instead of plates (the same rectangular shape and a larger effective surface area) further improved the grounding resistances by 29%-37% in winter. Replacement of rod electrodes of one entire permanent permafrost monitoring array by meshes resulted...
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.
The Internal Resistance of Supercapacitors

Science.gov (United States)

Costa, G. G. G.; Pietronero, R. C.; Catunda, T.

2012-01-01

In this paper we study the transient behaviour of RC circuits with supercapacitors, varying R between 1 and 100 [omega]. We demonstrate that supercapacitors behave as ideal capacitors in series with an internal resistance (r [similar to] 8 [omega] for C = 0.2 F, 5.5 V). This result is important to optimize the demonstration of RC circuits using a…
Position-sensitive proportional counter with low-resistance metal-wire anode

International Nuclear Information System (INIS)

Kopp, M.K.

1980-01-01

A position-sensitive proportional counter circuit is provided which uses a conventional (low-resistance, metal-wire anode) proportional counter for spatial resolution of an ionizing event along the anode of the counther. A pair of specially designed activecapacitance preamplifiers terminate the anode ends wherein the anode is treated as an RC line. The preamplifiers act as stabilized active capacitance loads and each is composed of a series-feedback, lownoise amplifier, a unity-gain, shunt-feedback amplifier whose output is connected through a feedback capacitor to the series-feedback amplifier input. The stabilized capacitance loading of the anode allows distributed RC-line position encoding and subsequent time difference decoding by sensing the difference in rise times of pulses at te anode ends where the difference is primarily in response to the distributed capacitance along the anode. This allows the use of lower resistance wire anodes for spatial radiation detection which simplifies the counter construction and handling of the anodes, and stabilizes the anode resistivity at high count rates
Salt Concentration Differences Alter Membrane Resistance in Reverse Electrodialysis Stacks

KAUST Repository

Geise, Geoffrey M.

2014-01-14

Membrane ionic resistance is usually measured by immersing the membrane in a salt solution at a single, fixed concentration. While salt concentration is known to affect membrane resistance when the same concentration is used on both sides of the membrane, little is known about membrane resistance when the membrane is placed between solutions of different concentrations, such as in a reverse electrodialysis (RED) stack. Ionic resistance measurements obtained using Selemion CMV and AMV that separated sodium chloride and ammonium bicarbonate solutions of different concentrations were greater than those measured using only the high-concentration solution. Measured RED stack resistances showed good agreement with resistances calculated using an equivalent series resistance model, where the membranes accounted for 46% of the total stack resistance. The high area resistance of the membranes separating different salt concentration solutions has implications for modeling and optimizing membranes used in RED systems.

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.)
Hierarchical Composite Membranes with Robust Omniphobic Surface Using Layer-By-Layer Assembly Technique

KAUST Repository

Woo, Yun Chul; Kim, Youngjin; Yao, Minwei; Tijing, Leonard Demegilio; Choi, Juneseok; Lee, Sangho; Kim, Seunghyun; Shon, Hokyong

2018-01-01

gave the LBL membrane an omniphobic property, as indicated by its good wetting resistance. The membrane performed a stable air gap membrane distillation (AGMD) flux of 11.22 L/m2h with very high salt rejection using reverse osmosis brine from coal seam
Insulin resistance alters islet morphology in nondiabetic humans

DEFF Research Database (Denmark)

Mezza, Teresa; Muscogiuri, Giovanna; Sorice, Gian Pio

2014-01-01

Type 2 diabetes is characterized by poor glucose uptake in metabolic tissues and manifests when insulin secretion fails to cope with worsening insulin resistance. In addition to its effects on skeletal muscle, liver, and adipose tissue metabolism, it is evident that insulin resistance also affects...... pancreatic β-cells. To directly examine the alterations that occur in islet morphology as part of an adaptive mechanism to insulin resistance, we evaluated pancreas samples obtained during pancreatoduodenectomy from nondiabetic subjects who were insulin-resistant or insulin-sensitive. We also compared...... insulin sensitivity, insulin secretion, and incretin levels between the two groups. We report an increased islet size and an elevated number of β- and α-cells that resulted in an altered β-cell-to-α-cell area in the insulin- resistant group. Our data in this series of studies suggest that neogenesis from...
An evaluation of the resistivity anisotropy of the clays at the Down Ampney fault research site

International Nuclear Information System (INIS)

Raines, M.G.; Jackson, P.D.; Evans, C.J.; Meldrun, P.; Rainsbury, M.

1991-01-01

The anisotropy of electrical resistivity of the Oxford clay at Down Ampney was examined by a series of measurements of resistivity on the core with current flowing horizontally and vertically. As expected the horizontal resistivity core data was found to agree with the downhole resistivity logs. This observation enabled a methodology to be implemented where both horizontal and vertical resistivities were assessed in the field
Invasive carbapenem-resistant Enterobacteriaceae infection at a ...

African Journals Online (AJOL)

Background. There are no paediatric reports of invasive infection caused by carbapenem-resistant Enterobacteriaceae (CRE) from Africa. Objectives. To document a series of cases of CRE infections at a tertiary children's hospital in Cape Town, South Africa, describing the clinical and microbiological findings in these ...
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.
Development of large area resistive electrodes for ATLAS NSW MicroMEGAS

CERN Document Server

Ochi, Atsuhiko; The ATLAS collaboration

2015-01-01

MicroMegas with resistive anode will be used for the NSW upgrade of the ATLAS experiment at LHC. The resistive electrode is one of key technology for MPGDs to prevent sparks. Large area resistive electrodes for the MM have been developed using two different technology; screen printing and carbon sputtering. Maximum size of each resistive foil is 45cm x 220cm with printed pattern of 425 micron pitch strips. Those technologies are also suitable to mass production. The prototypes of series production model have been produced successfully. We will report the development and production status and test results of the resistive MicroMegas.
Pb5Bi24Se41: A new member of the homologous series forming topological insulator heterostructures

International Nuclear Information System (INIS)

Segawa, Kouji; Taskin, A.A.; Ando, Yoichi

2015-01-01

We have synthesized Pb 5 Bi 24 Se 41 , which is a new member of the (PbSe) 5 (Bi 2 Se 3 ) 3m homologous series with m=4. This series of compounds consist of alternating layers of the topological insulator Bi 2 Se 3 and the ordinary insulator PbSe. Such a naturally-formed heterostructure has recently been elucidated to give rise to peculiar quasi-two-dimensional topological states throughout the bulk, and the discovery of Pb 5 Bi 24 Se 41 expands the tunability of the topological states in this interesting homologous series. The trend in the resistivity anisotropy in this homologous series suggests an important role of hybridization of the topological states in the out-of-plane transport. - Graphical abstract: X-ray diffraction profiles taken on cleaved surfaces of single-crystal samples of the (PbSe) 5 (Bi 2 Se 3 ) 3m homologous series with various m values up to 4, which realizes topological insulator heterostructures. Schematic crystal structure of the new phase, m=4, is also shown. - Highlights: • We have synthesized a new member of the homologous series related to topological insulators. • In this compound, a heterostructure of topological and ordinary insulators naturally forms. • Resistivity anisotropy suggests an important role of hybridization of the topological states. • This compound expands the tunability of the topological states via chemical means
Mechanical characteristics of heterogeneous structures obtained by high-temperature brazing of corrosion-resistant steels with rapidly quenched non-boron nickel-based alloys

Science.gov (United States)

Kalin, B.; Penyaz, M.; Ivannikov, A.; Sevryukov, O.; Bachurina, D.; Fedotov, I.; Voennov, A.; Abramov, E.

2018-01-01

Recently, the use rapidly quenched boron-containing nickel filler metals for high temperature brazing corrosion resistance steels different classes is perspective. The use of these alloys leads to the formation of a complex heterogeneous structure in the diffusion zone that contains separations of intermediate phases such as silicides and borides. This structure negatively affects the strength characteristics of the joint, especially under dynamic loads and in corrosive environment. The use of non-boron filler metals based on the Ni-Si-Be system is proposed to eliminate this structure in the brazed seam. Widely used austenitic 12Cr18Ni10Ti and ferrite-martensitic 16Cr12MoSiWNiVNb reactor steels were selected for research and brazing was carried out. The mechanical characteristics of brazed joints were determined using uniaxial tensile and impact toughness tests, and fractography was investigated by electron microscopy.
A nonlinear resistive MHD-code in cylindrical geometry

International Nuclear Information System (INIS)

Jakoby, A.

1987-11-01

A computer code has been developed which solves the full compressible resistive magnetohydrodynamic (MHD) equations in cylindrical geometry. The variables are expanded in Fourier series in the poloidal and axial directions while finite differences are used in the radial direction. The time advance is accomplished by using a semi-implicit predictor-corrector-scheme. Applications to the ideal m=1 ideal kink saturation in the nonlinear regime and the subsequent decay of the singular current layer due to resistivity are presented. (orig.)
The Role of Interface States and Series Resistance on the Current Voltage (I-V) Characterises of Au/n-CdTe Solar Cells

International Nuclear Information System (INIS)

Fiat, S.

2008-01-01

In order to well interpret the experimentally observed nonideal Au/n-CdTe solar cells parameters such as the zero-bias barrier height ( Φ B o), ideality factor (n), interface states (Nss) and series resistance. The energy distribution profile of Nss was obtained from forward bias I-V characteristics by taking in to account the bias dependent of the effective barrier height (Φ e )at room temperature.The values of Rs obtained from Cheung's functions. The higher values of n and Rs were attributed to the existence of a native insulator layer on CdTe surface and to high density of Nss localized at semiconductor/ insulator layer interface. The experimental I-V characteristics confirmed that the the thickness of insulator layer (δ o x) ,magnitude or Rs and Nss and a particular distribution of Nss in the band gap are important parameters that influence the electrical parameters of Au/n-CdTe solar cells
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
Distribution of Microorganisms and Antibiotic Resistance in Children with Urinary Tract Infections, Retrospective Case Series.

Directory of Open Access Journals (Sweden)

Didem Kaya

2017-04-01

Full Text Available Aim Urinary tract infection is one of the most common serious bacterial infections in children. Due to regional differences and past infections, the use of antibiotics has problems such as variability in microorganisms and antibiotic susceptibility. In this study, we aimed to determine the microorganisms detected in urinary tract infections in children and their antibiotic resistance status.Methods A retrospective observational study was planned. Demographic data, urine microscopy and urine culture results of patients who were hospitalized with urinary tract infection diagnosis in our pediatric clinic at hospital were recorded retrospectively through hospital automation system. The first culture results of the patients were used in the evaluation of the data. Results In the study group of 112 patients, Escherichia coli (E. coli and Klebsiella were the most identified microorganisms in patients with urinary culture. Under 2 years old, Klebsiella was more frequent, and at 2 years of age there was a noticeable increase in the frequency of E-coli. The most common resistance of both microorganisms was found to be ampicillin. Conclusions: Regional infectious agents and antibiotic resistance should be revised at regular intervals, appropriate empiric therapy should be considered. Thus, is predicted that the chance of success in treatment will increase and the speed of resistance development will decrease.
Antimalarial activity of HIV-1 protease inhibitor in chromone series.

Science.gov (United States)

Lerdsirisuk, Pradith; Maicheen, Chirattikan; Ungwitayatorn, Jiraporn

2014-12-01

Increasing parasite resistance to nearly all available antimalarial drugs becomes a serious problem to human health and necessitates the need to continue the search for new effective drugs. Recent studies have shown that clinically utilized HIV-1 protease (HIV-1 PR) inhibitors can inhibit the in vitro and in vivo growth of Plasmodium falciparum. In this study, a series of chromone derivatives possessing HIV-1 PR inhibitory activity has been tested for antimalarial activity against P. falciparum (K1 multi-drug resistant strain). Chromone 15, the potent HIV-1 PR inhibitor (IC50=0.65μM), was found to be the most potent antimalarial compound with IC50=0.95μM while primaquine and tafenoquine showed IC50=2.41 and 1.95μM, respectively. Molecular docking study of chromone compounds against plasmepsin II, an aspartic protease enzyme important in hemoglobin degradation, revealed that chromone 15 exhibited the higher binding affinity (binding energy=-13.24kcal/mol) than the known PM II inhibitors. Thus, HIV-1 PR inhibitor in chromone series has the potential to be a new class of antimalarial agent. Copyright © 2014 Elsevier Inc. All rights reserved.
Preparation of two series of materials with perovskite structure and investigation of their physical properties

International Nuclear Information System (INIS)

Mohamed, H.S.R.

2010-01-01

Results on structural, electric transport and magnetic properties of a series of (Al / In) doped Ca-series and (Al / In) doped Sr-series are presented and discussed.The polycrystalline ceramic samples were prepared by the solid state reaction technique. Elemental analysis showed a reasonable agreement between nominal and actual sample compositions. The grain size (G.S) of the Ca doped series increased with In content (G.S. (x = 0.2) = 79.5 nm and G.S. (x = 0.8) = 95.4 nm). For the Sr-series it has values in the range of 40 - 42 nm.Room temperature structural analysis using the Rietveld refinement technique,showed no structural transitions with the variation of the Al / In ratio. The doped Ca-series had an orthorhombic symmetry with space group Pnma. The Sr -doped series is rhombohedral with space group ( R3C ). In both series the Mn-O bond distance was found to increase whereas the mean Mn-O-Mn bond angle decreased with x. This was ascribed to the size mismatch between the divalent A- site ions and the B- site as a result of the introduction of the large In 3+ ion size. The tolerance factor varies from 0.918-0.933 for the Ca-series and from 0.932 - 0.948 for the Sr-series as x varies from 0.0 to 1.0. The temperature dependence of the magnetic susceptibility and electric resistivity of the Ca-doped series showed distinct ferromagnetic metallic (FMM) to a paramagnetic insulator (PMI) transitions near the Curie point (T C ), which ranges from T C ∼ 210 - 100 K for x = 0.0 to 1.0 respectively. The temperature dependence of the resistivity for the Sr-doped series showed distinct FMM to PMI transitions for samples with x = 0.0, 0.2 and 1.0, whereas samples with x = 0.4, 0.6 and 0.8 showed FMM to PMM. The transition temperature variation is not linear and lies within a narrow temperature range T p ∼ 344 - 367 K The results of the Sr-series showed that the size mismatch between the A- and B- sites is the major factor that controls the magnetic and electric properties
On the energy distribution profile of interface states obtained by taking into account of series resistance in Al/TiO2/p-Si (MIS) structures

International Nuclear Information System (INIS)

Pakma, O.; Serin, N.; Serin, T.; Altindal, S.

2011-01-01

The energy distribution profile of the interface states (N ss ) of Al/TiO 2 /p-Si (MIS) structures prepared using the sol-gel method was obtained from the forward bias current-voltage (I-V) characteristics by taking into account both the bias dependence of the effective barrier height (φ e ) and series resistance (R s ) at room temperature. The main electrical parameters of the MIS structure such as ideality factor (n), zero-bias barrier height (φ b0 ) and average series resistance values were found to be 1.69, 0.519 eV and 659 Ω, respectively. This high value of n was attributed to the presence of an interfacial insulator layer at the Al/p-Si interface and the density of interface states (N ss ) localized at the Si/TiO 2 interface. The values of N ss localized at the Si/TiO 2 interface were found with and without the R s at 0.25-E v in the range between 8.4x10 13 and 4.9x10 13 eV -1 cm -2 . In addition, the frequency dependence of capacitance-voltage (C-V) and conductance-voltage (G/ω-V) characteristics of the structures have been investigated by taking into account the effect of N ss and R s at room temperature. It can be found out that the measured C and G/ω are strongly dependent on bias voltage and frequency. -- Research highlights: →We successfully fabricated Al/TiO 2 /p-Si device with interlayer by a sol-gel method. The facts: (i) that the technology of the fabrication of a Al/TiO 2 /p-Si MIS structure much simpler and economical than that for the Si p-n junction and (b) the main advantages of TiO 2 films are low densities of the surface states when compared to SiO 2 .
Fourier series

CERN Document Server

Tolstov, Georgi P

1962-01-01

Richard A. Silverman's series of translations of outstanding Russian textbooks and monographs is well-known to people in the fields of mathematics, physics, and engineering. The present book is another excellent text from this series, a valuable addition to the English-language literature on Fourier series.This edition is organized into nine well-defined chapters: Trigonometric Fourier Series, Orthogonal Systems, Convergence of Trigonometric Fourier Series, Trigonometric Series with Decreasing Coefficients, Operations on Fourier Series, Summation of Trigonometric Fourier Series, Double Fourie
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.
NMR spectroscopy up to 35.2T using a series-connected hybrid magnet.

Science.gov (United States)

Gan, Zhehong; Hung, Ivan; Wang, Xiaoling; Paulino, Joana; Wu, Gang; Litvak, Ilya M; Gor'kov, Peter L; Brey, William W; Lendi, Pietro; Schiano, Jeffrey L; Bird, Mark D; Dixon, Iain R; Toth, Jack; Boebinger, Gregory S; Cross, Timothy A

2017-11-01

The National High Magnetic Field Laboratory has brought to field a Series-Connected Hybrid magnet for NMR spectroscopy. As a DC powered magnet it can be operated at fields up to 36.1T. The series connection between a superconducting outsert and a resistive insert dramatically minimizes the high frequency fluctuations of the magnetic field typically observed in purely resistive magnets. Current-density-grading among various resistive coils was used for improved field homogeneity. The 48mm magnet bore and 42mm outer diameter of the probes leaves limited space for conventional shims and consequently a combination of resistive and ferromagnetic shims are used. Field maps corrected for field instabilities were obtained and shimming achieved better than 1ppm homogeneity over a cylindrical volume of 1cm diameter and height. The magnetic field is regulated within 0.2ppm using an external 7 Li lock sample doped with paramagnetic MnCl 2 . The improved field homogeneity and field regulation using a modified AVANCE NEO console enables NMR spectroscopy at 1 H frequencies of 1.0, 1.2 and 1.5GHz. NMR at 1.5GHz reflects a 50% increase in field strength above the highest superconducting magnets currently available. Three NMR probes have been constructed each equipped with an external lock rf coil for field regulation. Initial NMR results obtained from the SCH magnet using these probes illustrate the very exciting potential of ultra-high magnetic fields. Copyright © 2017 Elsevier Inc. All rights reserved.

Climatic factors and community - associated methicillin-resistant Staphylococcus aureus skin and soft-tissue infections - a time-series analysis study.

Science.gov (United States)

Sahoo, Krushna Chandra; Sahoo, Soumyakanta; Marrone, Gaetano; Pathak, Ashish; Lundborg, Cecilia Stålsby; Tamhankar, Ashok J

2014-08-29

Skin and soft tissue infections caused by Staphylococcus aureus (SA-SSTIs) including methicillin-resistant Staphylococcus aureus (MRSA) have experienced a significant surge all over the world. Changing climatic factors are affecting the global burden of dermatological infections and there is a lack of information on the association between climatic factors and MRSA infections. Therefore, association of temperature and relative humidity (RH) with occurrence of SA-SSTIs (n = 387) and also MRSA (n = 251) was monitored for 18 months in the outpatient clinic at a tertiary care hospital located in Bhubaneswar, Odisha, India. The Kirby-Bauer disk diffusion method was used for antibiotic susceptibility testing. Time-series analysis was used to investigate the potential association of climatic factors (weekly averages of maximum temperature, minimum temperature and RH) with weekly incidence of SA-SSTIs and MRSA infections. The analysis showed that a combination of weekly average maximum temperature above 33 °C coinciding with weekly average RH ranging between 55% and 78%, is most favorable for the occurrence of SA-SSTIs and MRSA and within these parameters, each unit increase in occurrence of MRSA was associated with increase in weekly average maximum temperature of 1.7 °C (p = 0.044) and weekly average RH increase of 10% (p = 0.097).
Investigating Corrosion, Wear Resistance and Friction of AA5454-O Series after its Severe Deformation by Rolling

Directory of Open Access Journals (Sweden)

Sinan SEZEK

2017-02-01

Full Text Available AA5454-O is an easily wrought, or in other words, a ductile aluminium alloy, however, its mechanical properties are inferior as compared to those of other alloys. The change taking place in corrosion resistance of AA5454-O alloy as a result of its severe plastic deformation (SPD by rolling has been investigated in this study. It has been observed that significant changes occurred in abrasion wear and corrosion resistances of AA5454-O alloy, which was severely deformed up to 80 % by rolling process. Corrosion resistance of the alloy that was severely deformed by rolling has increased. The effect of deformation rate on corrosion has been investigated by applying potentiodynamic test whereas on the other hand such change has been evidenced also through corrosion test. It has been observed that friction coefficient of severely deformed AA5454-O alloy varied by around 10 %, and that, associated with such change, its wear resistance also increased considerably. It has been determined that, as a result of severe deformation by rolling, hardness values rose in areas where the alloy was in contact with rolling surface. In this study, wear resistance of severely deformed alloy has been investigated as well. It has been observed that deformation value contributed positively to the increase in wear resistance.DOI: http://dx.doi.org/10.5755/j01.ms.23.1.14650
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。
Report on series 4 reflood experiment

International Nuclear Information System (INIS)

Murao, Yoshio; Iguchi, Tadashi; Sudoh, Takashi; Sudo, Yukio; Sugimoto, Jun

1977-03-01

Series 4 reflood experiment was carried out from June to July 1976. The purpose was to examine system-pressure effect and system effect with heater rods having about the same heat capacity as the real ones and flow resistance of the primary loop. The results are: 1) The core flood velocity increases and the quench time decreases with system pressure. 2) The relation between core differential pressure (accumulation head of the core) and core power density, which indicates coolability of the core, is obtainable in map with the system pressure as a parameter. 3) The steady-state thermal condition occurs in the test section with constant power density. (auth.)
Empirical mode decomposition and k-nearest embedding vectors for timely analyses of antibiotic resistance trends.

Science.gov (United States)

Teodoro, Douglas; Lovis, Christian

2013-01-01

Antibiotic resistance is a major worldwide public health concern. In clinical settings, timely antibiotic resistance information is key for care providers as it allows appropriate targeted treatment or improved empirical treatment when the specific results of the patient are not yet available. To improve antibiotic resistance trend analysis algorithms by building a novel, fully data-driven forecasting method from the combination of trend extraction and machine learning models for enhanced biosurveillance systems. We investigate a robust model for extraction and forecasting of antibiotic resistance trends using a decade of microbiology data. Our method consists of breaking down the resistance time series into independent oscillatory components via the empirical mode decomposition technique. The resulting waveforms describing intrinsic resistance trends serve as the input for the forecasting algorithm. The algorithm applies the delay coordinate embedding theorem together with the k-nearest neighbor framework to project mappings from past events into the future dimension and estimate the resistance levels. The algorithms that decompose the resistance time series and filter out high frequency components showed statistically significant performance improvements in comparison with a benchmark random walk model. We present further qualitative use-cases of antibiotic resistance trend extraction, where empirical mode decomposition was applied to highlight the specificities of the resistance trends. The decomposition of the raw signal was found not only to yield valuable insight into the resistance evolution, but also to produce novel models of resistance forecasters with boosted prediction performance, which could be utilized as a complementary method in the analysis of antibiotic resistance trends.
From 1 Sun to 10 Suns c-Si Cells by Optimizing Metal Grid, Metal Resistance, and Junction Depth

International Nuclear Information System (INIS)

Chaudhari, V.A.; Solanki, C.S.

2009-01-01

Use of a solar cell in concentrator PV technology requires reduction in its series resistance in order to minimize the resistive power losses. The present paper discusses a methodology of reducing the series resistance of a commercial c-Si solar cell for concentrator applications, in the range of 2 to 10 suns. Step by step optimization of commercial cell in terms of grid geometry, junction depth, and electroplating of the front metal contacts is proposed. A model of resistance network of solar cell is developed and used for the optimization. Efficiency of un optimized commercial cell at 10 suns drops by 30% of its 1 sun value corresponding to resistive power loss of about 42%. The optimized cell with grid optimization, junction optimization, electroplating, and junction optimized with electroplated contacts cell gives resistive power loss of 20%, 16%, 11%, and 8%, respectively. An efficiency gain of 3% at 10 suns for fully optimized cell is estimated
Bacterial strategies of resistance to antimicrobial peptides.

Science.gov (United States)

Joo, Hwang-Soo; Fu, Chih-Iung; Otto, Michael

2016-05-26

Antimicrobial peptides (AMPs) are a key component of the host's innate immune system, targeting invasive and colonizing bacteria. For successful survival and colonization of the host, bacteria have a series of mechanisms to interfere with AMP activity, and AMP resistance is intimately connected with the virulence potential of bacterial pathogens. In particular, because AMPs are considered as potential novel antimicrobial drugs, it is vital to understand bacterial AMP resistance mechanisms. This review gives a comparative overview of Gram-positive and Gram-negative bacterial strategies of resistance to various AMPs, such as repulsion or sequestration by bacterial surface structures, alteration of membrane charge or fluidity, degradation and removal by efflux pumps.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'. © 2016 The Author(s).
`Indoor` series vending machines; `Indoor` series jido hanbaiki

Energy Technology Data Exchange (ETDEWEB)

Gensui, T.; Kida, A. [Fuji Electric Co. Ltd., Tokyo (Japan); Okumura, H. [Fuji Denki Reiki Co. Ltd., Tokyo (Japan)

1996-07-10

This paper introduces three series of vending machines that were designed to match the interior of an office building. The three series are vending machines for cups, paper packs, cans, and tobacco. Among the three series, `Interior` series has a symmetric design that was coated in a grain pattern. The inside of the `Interior` series is coated by laser satin to ensure a sense of superior quality and a refined style. The push-button used for product selection is hot-stamped on the plastic surface to ensure the hair-line luster. `Interior Phase II` series has a bay window design with a sense of superior quality and lightness. The inside of the `Interior Phase II` series is coated by laser satin. `Interior 21` series is integrated with the wall except the sales operation panel. The upper and lower dress panels can be detached and attached. The door lock is a wire-type structure with high operativity. The operation block is coated by titanium color. The dimensions of three series are standardized. 6 figs., 1 tab.
Laboratory methods for diagnosis and detection of drug resistant ...

African Journals Online (AJOL)

Data source: Published series of peer reviewed journals and manuals written on laboratory methods that are currently used for diagnosis and detection of drug resistance of Mycobacterium tuberculosis complex were reviewed using the index medicus, pubmed and medline search. Conventional bacteriological microscopy ...
On Negative Resistance Oscillators as Modified Multi-vibrators

DEFF Research Database (Denmark)

Lindberg, Erik; Murali, K.; Tamasevicius, Arunas

2015-01-01

A tutorial discussion of negative resistance oscillators based on simple RLC circuits is presented. Two cases are based on parallel RLC circuits and two cases are based on series RLC circuits. Distortion is minimized by introducing symmetry in the movement of the complex pole-pair of the small...
Insulin resistance: definition and consequences.

Science.gov (United States)

Lebovitz, H E

2001-01-01

Insulin resistance is defined clinically as the inability of a known quantity of exogenous or endogenous insulin to increase glucose uptake and utilization in an individual as much as it does in a normal population. Insulin action is the consequence of insulin binding to its plasma membrane receptor and is transmitted through the cell by a series of protein-protein interactions. Two major cascades of protein-protein interactions mediate intracellular insulin action: one pathway is involved in regulating intermediary metabolism and the other plays a role in controlling growth processes and mitoses. The regulation of these two distinct pathways can be dissociated. Indeed, some data suggest that the pathway regulating intermediary metabolism is diminished in type 2 diabetes while that regulating growth processes and mitoses is normal.--Several mechanisms have been proposed as possible causes underlying the development of insulin resistance and the insulin resistance syndrome. These include: (1) genetic abnormalities of one or more proteins of the insulin action cascade (2) fetal malnutrition (3) increases in visceral adiposity. Insulin resistance occurs as part of a cluster of cardiovascular-metabolic abnormalities commonly referred to as "The Insulin Resistance Syndrome" or "The Metabolic Syndrome". This cluster of abnormalities may lead to the development of type 2 diabetes, accelerated atherosclerosis, hypertension or polycystic ovarian syndrome depending on the genetic background of the individual developing the insulin resistance.--In this context, we need to consider whether insulin resistance should be defined as a disease entity which needs to be diagnosed and treated with specific drugs to improve insulin action.
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.
Report on series 2B reflood experiment

International Nuclear Information System (INIS)

Murao, Yoshio; Iguchi, Tadashi; Sudoh, Takashi; Sudo, Yukio; Sugimoto, Jun

1976-12-01

Series 2B reflood experiment was carried out from April to May 1975, as follows: 1) injection of coolant water from the downcomer at a constant head into the test section having a flow resistance simulator of the primary loop, 2) under an atmospheric pressure, 3) in constant power density, 4) with heater rod temperature up to 600 0 C. The objectives are to examine quantitatively system effect and to check performance of the reflood test rig. The effect of the coolant injection mode, relation between oscillatory phenomena and core thermo-hydrodynamics, and technological problems of the test rig were observed. (auth.)
Experience of successful treatment of patients with metronidazole-resistant Trichomonas vaginalis with zinc sulfate: A case series

Directory of Open Access Journals (Sweden)

Jung Mi Byun

2015-10-01

Conclusion: Although the exact role of zinc sulfate in metronidazole-resistant trichomoniasis is not clear, our patients experienced a therapeutic effect with zinc sulfate douche treatment. We therefore recommend zinc sulfate douche as an option for the treatment of metronidazole-resistant vaginal trichomoniasis.
On the energy distribution profile of interface states obtained by taking into account of series resistance in Al/TiO{sub 2}/p-Si (MIS) structures

Energy Technology Data Exchange (ETDEWEB)

Pakma, O., E-mail: osman@pakma.co [Department of Physics, Faculty of Sciences and Arts, Batman University, Batman (Turkey); Serin, N.; Serin, T. [Department of Engineering Physics, Faculty of Engineering, Ankara University, 06100 Tandogan, Ankara (Turkey); Altindal, S. [Physics Department, Faculty of Arts and Sciences, Gazi University, Teknikokullar, 06500 Ankara (Turkey)

2011-02-15

The energy distribution profile of the interface states (N{sub ss}) of Al/TiO{sub 2}/p-Si (MIS) structures prepared using the sol-gel method was obtained from the forward bias current-voltage (I-V) characteristics by taking into account both the bias dependence of the effective barrier height ({phi}{sub e}) and series resistance (R{sub s}) at room temperature. The main electrical parameters of the MIS structure such as ideality factor (n), zero-bias barrier height ({phi}{sub b0}) and average series resistance values were found to be 1.69, 0.519 eV and 659 {Omega}, respectively. This high value of n was attributed to the presence of an interfacial insulator layer at the Al/p-Si interface and the density of interface states (N{sub ss}) localized at the Si/TiO{sub 2} interface. The values of N{sub ss} localized at the Si/TiO{sub 2} interface were found with and without the R{sub s} at 0.25-E{sub v} in the range between 8.4x10{sup 13} and 4.9x10{sup 13} eV{sup -1} cm{sup -2}. In addition, the frequency dependence of capacitance-voltage (C-V) and conductance-voltage (G/{omega}-V) characteristics of the structures have been investigated by taking into account the effect of N{sub ss} and R{sub s} at room temperature. It can be found out that the measured C and G/{omega} are strongly dependent on bias voltage and frequency. -- Research highlights: {yields}We successfully fabricated Al/TiO{sub 2}/p-Si device with interlayer by a sol-gel method. The facts: (i) that the technology of the fabrication of a Al/TiO{sub 2}/p-Si MIS structure much simpler and economical than that for the Si p-n junction and (b) the main advantages of TiO{sub 2} films are low densities of the surface states when compared to SiO{sub 2}.
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.
Validity of Wearable Activity Monitors during Cycling and Resistance Exercise.

Science.gov (United States)

Boudreaux, Benjamin D; Hebert, Edward P; Hollander, Daniel B; Williams, Brian M; Cormier, Corinne L; Naquin, Mildred R; Gillan, Wynn W; Gusew, Emily E; Kraemer, Robert R

2018-03-01

The use of wearable activity monitors has seen rapid growth; however, the mode and intensity of exercise could affect the validity of heart rate (HR) and caloric (energy) expenditure (EE) readings. There is a lack of data regarding the validity of wearable activity monitors during graded cycling regimen and a standard resistance exercise. The present study determined the validity of eight monitors for HR compared with an ECG and seven monitors for EE compared with a metabolic analyzer during graded cycling and resistance exercise. Fifty subjects (28 women, 22 men) completed separate trials of graded cycling and three sets of four resistance exercises at a 10-repetition-maximum load. Monitors included the following: Apple Watch Series 2, Fitbit Blaze, Fitbit Charge 2, Polar H7, Polar A360, Garmin Vivosmart HR, TomTom Touch, and Bose SoundSport Pulse (BSP) headphones. HR was recorded after each cycling intensity and after each resistance exercise set. EE was recorded after both protocols. Validity was established as having a mean absolute percent error (MAPE) value of ≤10%. The Polar H7 and BSP were valid during both exercise modes (cycling: MAPE = 6.87%, R = 0.79; resistance exercise: MAPE = 6.31%, R = 0.83). During cycling, the Apple Watch Series 2 revealed the greatest HR validity (MAPE = 4.14%, R = 0.80). The BSP revealed the greatest HR accuracy during resistance exercise (MAPE = 6.24%, R = 0.86). Across all devices, as exercise intensity increased, there was greater underestimation of HR. No device was valid for EE during cycling or resistance exercise. HR from wearable devices differed at different exercise intensities; EE estimates from wearable devices were inaccurate. Wearable devices are not medical devices, and users should be cautious when using these devices for monitoring physiological responses to exercise.
Crystal structure and electrical resistivity studies of Gd(Fe1-x Cox)2 intermetallics

International Nuclear Information System (INIS)

Onak, M.; Guzdek, P.; Stoch, P.; Chmist, J.; Bednarski, M.; Panta, A.; Pszczola, J.

2007-01-01

From X-ray analysis (295 K) it was found that the cubic, MgCu 2 -type, Fd3m crystal structure appears across the Gd(Fe 1-x Co x ) 2 series. Electrical resistivity measurements for the Gd(Fe 1-x Co x ) 2 intermetallics were performed in a wide temperature region and the parameters characterizing the resistivity dependence on temperature and composition were determined. The differential of the electrical resistivity against temperature was used to estimate Curie temperatures. The Curie temperature versus x, high and moderately increasing in the iron-rich area, rapidly drops in the cobalt-rich region. The obtained results are compared with the data known for the Dy(Fe 1-x Co x ) 2 series. The Curie temperature is related to both the number of 3d electrons and the de Gennes factor
Collateral methotrexate resistance in cisplatin-selected murine leukemia cells

Directory of Open Access Journals (Sweden)

Bhushan A.

1999-01-01

Full Text Available Resistance to anticancer drugs is a major cause of failure of many therapeutic protocols. A variety of mechanisms have been proposed to explain this phenomenon. The exact mechanism depends upon the drug of interest as well as the tumor type treated. While studying a cell line selected for its resistance to cisplatin we noted that the cells expressed a >25,000-fold collateral resistance to methotrexate. Given the magnitude of this resistance we elected to investigate this intriguing collateral resistance. From a series of investigations we have identified an alteration in a membrane protein of the resistant cell as compared to the sensitive cells that could be the primary mechanism of resistance. Our studies reviewed here indicate decreased tyrosine phosphorylation of a protein (molecular mass = 66 in the resistant cells, which results in little or no transfer of methotrexate from the medium into the cell. Since this is a relatively novel function for tyrosine phosphorylation, this information may provide insight into possible pharmacological approaches to modify therapeutic regimens by analyzing the status of this protein in tumor samples for a better survival of the cancer patients.
Resistance exercise-induced microinjuries do not depend on 1or 3 minutes rest time interval between series. (Las microlesiones inducidas por el entrenamiento con cargas no dependen de los intervalos de descanso entre series de 1 o 3 minutos.

Directory of Open Access Journals (Sweden)

Rafael Pereira

2008-10-01

Full Text Available AbstractIn order to examine the effects of different rest intervals between sets on the muscle fiber integrity, 14 male subjects volunteered to participate in randomized crossover design methodology. All subjects completed 2 experimental training sessions. Both sessions consisted of 3 sets of 10 repetitions with 10 repetition maximum resistance bench press, cable pulldowns, military press, biceps curl, triceps curl, leg press, leg extension, and lying leg curls. The 2 experimental sessions differed only in the length of the rest period between sets and exercises: 1 session with a 1-minute and the other with a 3-minute rest period. the mechanical stress caused by the proposed training session cause similar damage in the muscle fibers do not depend of the 1 or 3 minutes of rest interval between series. ResumenEl propósito de ese estudio fue comparar los efectos de 2 diferentes períodos de descanso durante una sesión de entrenamiento con cargas en la integridad de la fibra muscular. Participaron de forma voluntaria 14 hombres en un estudio con diseño cruzado aleatorio. Todos los sujetos realizaron 2 sesiones de entrenamiento con cargas. Durante cada sesión, los sujetos completaban 3 series de 10 repeticiones máximas de press de banca, jalón en polea alta para dorsal, press militar, curl de bíceps con barra, extensión de tríceps trasnuca con mancuerna, prensa de piernas en máquina, extensión de rodillas en máquina, y flexión de rodillas en máquina. Las 2 sesiones experimentales diferían sólo en la longitud del período de descanso entre las series y los ejercicios: una sesión con 1 minuto y la otra con 3 minutos en los períodos de descanso. La tensión mecánica causada por las sesiones puede causar daños similares en las fibras musculares y no dependen de hacer 1 o 3 minutos de intervalo de descanso entre las series.

Decentring the Wizard: An Analysis of the Constructed Discourses of Animality in the Harry Potter Series

OpenAIRE

Haugann, Martine Juritzen

2015-01-01

This thesis seeks to explore the way constructions of animality present problematic discourses of race, gender and human ethnic groups in the Harry Potter series. This is done with special emphasis on the third novel, Harry Potter and the Prisoner of Azkaban, the fifth, Harry Potter and the Order of the Phoenix, and the seventh, Harry Potter and the Deathly Hallows. The overall claim is that problematic representations of animality constructions in the series reinforce, rather than resist, st...
Regeneration systems for pyramiding disease resistance into walnut rootstocks

Science.gov (United States)

This study was conducted to regenerate selected walnut rootstocks adventitiously. This is an essential step to be able to produce transgenic walnut rootstocks with superior traits, such as disease resistance. A series of plant tissue culture experiments were conducted on RX1 and VX211 rootstocks wit...
Clinical study of carbapenem sensitive and resistant Gram-negative bacteremia in neutropenic and nonneutropenic patients: The first series from India.

Science.gov (United States)

Ghafur, A K; Vidyalakshmi, P R; Kannaian, P; Balasubramaniam, R

2014-01-01

Carbapenem resistance is a growing global concern. There is a lack of published clinical studies on the topic from Indian subcontinent. Aim of this study was to analyze clinical profile of patients with carbapenem sensitive and resistant bacteremia among neutropenic and nonneutropenic patients. Retrospective analysis of 141 patients who had carbapenem resistant or sensitive Gram-negative bacteremia, identified over a period of 1-year was done by medical records review, in Apollo Specialty Hospital, a 300-bedded tertiary care Oncology, neurosurgical and orthopedic center in South India. Of the total 141 patients with Gram-negative bacteremia, 44 had carbapenem resistant ones. Of these 44 patients, 17 were neutropenics (resistant neutropenic group) and 27 nonneutropenic patients (resistant nonneutropenic group). Of the 97 patients with carbapenem sensitive bacteremia, 43 were neutropenic (sensitive neutropenic group) and 54 nonneutropenics (sensitive nonneutropenic group). The 28 days mortality was significantly higher in carbapenem resistant bacteremic group compared to the sensitive one (P = 0.008). This is the first study from India comparing clinical features of patients with carbapenem sensitive and resistant blood stream infections. Patients with carbapenem resistant bacteremia had higher mortality compared to patients with sensitive bacteremia.
Passivity Enhancement of Grid-Tied Converter by Series LC-Filtered Active Damper

DEFF Research Database (Denmark)

Bai, Haofeng; Wang, Xiongfei; Loh, Poh Chiang

2015-01-01

attention. Also, parasitic capacitance of the grid transmission line brings new challenge for the application of an active damper, which has not been discussed before. In order to fill these gaps, this paper first analyzes the stability of a grid-tied converter with the help of passivity. Based......Series LC-filtered active damper can be used to stabilize the grid-tied voltage source converter in a non-ideal grid. The operation principle of the active damper is to mimic a damping resistance at the resonance frequencies. However, the selection of the damping resistance has not received much...... on the passivity-based-stability analysis, a damping resistance selection method is proposed. Then, an admittance shaping method is developed to ensure the system stability in the presence of parasitic capacitance of the transmission line. Finally, experimental results are provided to show the validity...
Radiation resistance and molecular structure of poly(arylene ether sulphone)s

International Nuclear Information System (INIS)

Hill, D.J.T.; Lewis, D.A.; O'Donnell, J.H.; Pomery, P.J.; Hedrick, J.L.; McGrath, J.E.

1991-01-01

The radiation resistance of a series of aromatic polysulfones comprising alternating units of diphenyl sulfone and various aromatic diols has been investigated by measuring volatile products, soluble fractions and electron spin resonance (ESR) spectra. The yields of radicals at 77 K observed by ESR and of SO 2 at 423 K have indicated that biphenol gives enhanced resistance to γ radiation, and tetramethyl bisphenol-A decreased resistance, relative to bisphenol-A, bisphenol-S and hydroquinone. The protective effect of biphenol was confirmed by lower scission and crosslinking yields determined from the soluble fractions after high doses. (author)
Radiation Resistance and Life Time Estimates at Cryogenic Temperatures of Series Produced By-Pass Diodes for the LHC Magnet Protection

Science.gov (United States)

Denz, R.; Gharib, A.; Hagedorn, D.

2004-06-01

For the protection of the LHC superconducting magnets about 2100 specially developed by-pass diodes have been manufactured in industry and more than one thousand of these diodes have been mounted into stacks and tested in liquid helium. By-pass diode samples, taken from the series production, have been submitted to irradiation tests at cryogenic temperatures together with some prototype diodes up to an accumulated dose of about 2 kGy and neutron fluences up to about 3.0 1013 n cm-2 with and without intermediate warm up to 300 K. The device characteristics of the diodes under forward bias and reverse bias have been measured at 77 K and ambient versus dose and the results are presented. Using a thermo-electrical model and new estimates for the expected dose in the LHC, the expected lifetime of the by-pass diodes has been estimated for various positions in the LHC arcs. It turns out that for all of the by-pass diodes across the arc elements the radiation resistance is largely sufficient. In the dispersion suppresser regions of the LHC, on a few diodes annual annealing during the shut down of the LHC must be applied or those diodes may need to be replaced after some time.
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)
The importance of the neutral region resistance for the calculation of the interface state in Pb/p-Si Schottky contacts

International Nuclear Information System (INIS)

Aydin, M.E.; Akkilic, K.; Kilicoglu, T.

2004-01-01

We have fabricated H-terminated Pb/p-type Si Schottky contacts with and without the native oxide layer to explain the importance of the fact that the neutral region resistance value is considered in calculating the interface state density distribution from the nonideal forward bias current-voltage (I-V) characteristics. The diodes with the native oxide layer (metal-insulating layer-semiconductor (MIS)) showed nonideal I-V behavior with an ideality factor value of 1.310 and the barrier height value of 0.746eV. An ideality factor value of 1.065 and a barrier height value of 0.743eV were obtained for the diodes without the native oxide layer (MS). At the same energy position near the top of the valance band, the calculated interface states density (Nss) values, obtained without taking into account the series resistance of the devices (i.e. without subtracting the voltage drop across the series resistance from the applied voltage values V) is almost one order of magnitude larger than Nss values obtained by taking into account the series resistance
Dynamic modeling and simulation of an induction motor with adaptive backstepping design of an input-output feedback linearization controller in series hybrid electric vehicle

Directory of Open Access Journals (Sweden)

Jalalifar Mehran

2007-01-01

Full Text Available In this paper using adaptive backstepping approach an adaptive rotor flux observer which provides stator and rotor resistances estimation simultaneously for induction motor used in series hybrid electric vehicle is proposed. The controller of induction motor (IM is designed based on input-output feedback linearization technique. Combining this controller with adaptive backstepping observer the system is robust against rotor and stator resistances uncertainties. In additional, mechanical components of a hybrid electric vehicle are called from the Advanced Vehicle Simulator Software Library and then linked with the electric motor. Finally, a typical series hybrid electric vehicle is modeled and investigated. Various tests, such as acceleration traversing ramp, and fuel consumption and emission are performed on the proposed model of a series hybrid vehicle. Computer simulation results obtained, confirm the validity and performance of the proposed IM control approach using for series hybrid electric vehicle.
Experimental dynamical characterization of five autonomous chaotic oscillators with tunable series resistance

Energy Technology Data Exchange (ETDEWEB)

Minati, Ludovico, E-mail: lminati@ieee.org, E-mail: ludovico.minati@unitn.it [MR-Lab, Center for Mind/Brain Science, University of Trento, Trento, Italy and Scientific Department, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan (Italy)

2014-09-01

In this paper, an experimental characterization of the dynamical properties of five autonomous chaotic oscillators, based on bipolar-junction transistors and obtained de-novo through a genetic algorithm in a previous study, is presented. In these circuits, a variable resistor connected in series to the DC voltage source acts as control parameter, for a range of which the largest Lyapunov exponent, correlation dimension, approximate entropy, and amplitude variance asymmetry are calculated, alongside bifurcation diagrams and spectrograms. Numerical simulations are compared to experimental measurements. The oscillators can generate a considerable variety of regular and chaotic sine-like and spike-like signals.
Improved Short-Circuit Protection for Power Cells in Series

Science.gov (United States)

Davies, Francis

2008-01-01

A scheme for protection against short circuits has been devised for series strings of lithium electrochemical cells that contain built-in short-circuit protection devices, which go into a high-resistance, current-limiting state when heated by excessive current. If cells are simply connected in a long series string to obtain a high voltage and a short circuit occurs, whichever short-circuit protection device trips first is exposed to nearly the full string voltage, which, typically, is large enough to damage the device. Depending on the specific cell design, the damage can defeat the protective function, cause a dangerous internal short circuit in the affected cell, and/or cascade to other cells. In the present scheme, reverse diodes rated at a suitably high current are connected across short series sub-strings, the lengths of which are chosen so that when a short-circuit protection device is tripped, the voltage across it does not exceed its rated voltage. This scheme preserves the resetting properties of the protective devices. It provides for bypassing of cells that fail open and limits cell reversal, though not as well as does the more-expensive scheme of connecting a diode across every cell.
On Sums of Numerical Series and Fourier Series

Science.gov (United States)

Pavao, H. Germano; de Oliveira, E. Capelas

2008-01-01

We discuss a class of trigonometric functions whose corresponding Fourier series, on a conveniently chosen interval, can be used to calculate several numerical series. Particular cases are presented and two recent results involving numerical series are recovered. (Contains 1 note.)
Infinite series

CERN Document Server

Hirschman, Isidore Isaac

2014-01-01

This text for advanced undergraduate and graduate students presents a rigorous approach that also emphasizes applications. Encompassing more than the usual amount of material on the problems of computation with series, the treatment offers many applications, including those related to the theory of special functions. Numerous problems appear throughout the book.The first chapter introduces the elementary theory of infinite series, followed by a relatively complete exposition of the basic properties of Taylor series and Fourier series. Additional subjects include series of functions and the app
Earthquake-resistant performance investigation for rural buildings in Zhongxiang area, China

Directory of Open Access Journals (Sweden)

Lei Jingya

2013-02-01

Full Text Available We carried out a census of the rural residential buildings of Zhongxiang area’s 17 towns. Next, we conducted a sample survey in four townships: Huji, Shipai, Zhangji, and Jiuli. According to the census and sample survey data of the rural residence buildings, we evaluated the quality and earthquake-resistant performance of the rural buildings for the various local rural residential structural types. The results showed that there are four main factors affecting the seismic performance of the local rural residences: (1 Foundations are not made appropriately (such as by compaction or some other fill but are built directly in the farming soil. (2 Seismic measures are not completely implemented. Structure construction measures are not in place at the junction of the vertical and horizontal wall. The vertical wall joints are not the result of the same masonry techniques as the horizontal joints. There are no lintels above the door and window openings, or if there are any, the length of the lintels is less than 240 mm. (3 The brick masonry wall has low strength. The greatest housing wall mortar strength is between M0. 4–1.5, much lower than the strength of the brick. (4 The building material and construction quality are poor. The quality of the mortar masonry wall is poor. The cracks between the bricks are uneven, even in the seams.
Changes in Escherichia coli resistance to co-trimoxazole in ...

African Journals Online (AJOL)

In Thyolo district, Malawi, an operational research study is being conducted on the efficacy and feasibility of co-trimoxazole prophylaxis in preventing deaths in HIV-positive patients with tuberculosis (TB). A series of cross-sectional studies were carried out to determine i) whether faecal Escherichia coli (E.coli) resistance to ...
A potent series targeting the malarial cGMP-dependent protein kinase clears infection and blocks transmission

NARCIS (Netherlands)

Baker, D.A.; Stewart, L.B.; Large, J.M.; Bowyer, P.W.; Ansell, K.H.; Jimenez-Diaz, M.B.; Bakkouri, M. El; Birchall, K.; Dechering, K.J.; Bouloc, N.S.; Coombs, P.J.; Whalley, D.; Harding, D.J.; Smiljanic-Hurley, E.; Wheldon, M.C.; Walker, E.M.; Dessens, J.T.; Lafuente, M.J.; Sanz, L.M.; Gamo, F.J.; Ferrer, S.B.; Hui, R.; Bousema, T.; Angulo-Barturen, I.; Merritt, A.T.; Croft, S.L.; Gutteridge, W.E.; Kettleborough, C.A.; Osborne, S.A.

2017-01-01

To combat drug resistance, new chemical entities are urgently required for use in next generation anti-malarial combinations. We report here the results of a medicinal chemistry programme focused on an imidazopyridine series targeting the Plasmodium falciparum cyclic GMP-dependent protein kinase
Insulin Resistance in Alzheimer's Disease

Science.gov (United States)

Dineley, Kelly T; Jahrling, Jordan B; Denner, Larry

2014-01-01

Insulin is a key hormone regulating metabolism. Insulin binding to cell surface insulin receptors engages many signaling intermediates operating in parallel and in series to control glucose, energy, and lipids while also regulating mitogenesis and development. Perturbations in the function of any of these intermediates, which occur in a variety of diseases, cause reduced sensitivity to insulin and insulin resistance with consequent metabolic dysfunction. Chronic inflammation ensues which exacerbates compromised metabolic homeostasis. Since insulin has a key role in learning and memory as well as directly regulating ERK, a kinase required for the type of learning and memory compromised in early Alzheimer's disease (AD), insulin resistance has been identified as a major risk factor for the onset of AD. Animal models of AD or insulin resistance or both demonstrate that AD pathology and impaired insulin signaling form a reciprocal relationship. Of note are human and animal model studies geared toward improving insulin resistance that have led to the identification of the nuclear receptor and transcription factor, peroxisome proliferator-activated receptor gamma (PPARγ) as an intervention tool for early AD. Strategic targeting of alternate nodes within the insulin signaling network has revealed disease-stage therapeutic windows in animal models that coalesce with previous and ongoing clinical trial approaches. Thus, exploiting the connection between insulin resistance and AD provides powerful opportunities to delineate therapeutic interventions that slow or block the pathogenesis of AD. PMID:25237037
Impact of ertapenem on antimicrobial resistance in a sentinel group of Gram-negative bacilli: a 6 year antimicrobial resistance surveillance study.

Science.gov (United States)

Rodriguez-Osorio, Carlos A; Sanchez-Martinez, Cesar O; Araujo-Melendez, Javier; Criollo, Elia; Macias-Hernandez, Alejandro E; Ponce-de-Leon, Alfredo; Ponce-de-Leon, Sergio; Sifuentes-Osornio, Jose

2015-03-01

To determine the association between ertapenem and resistance of Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii-calcoaceticus complex to different antimicrobials while adjusting for relevant hospital factors. This was a retrospective time-series study conducted at a tertiary care centre from September 2002 to August 2008. The specific impact of ertapenem on the resistance of these Gram-negative bacilli (GNB) was assessed by multiple linear regression analysis, adjusting for the average length of stay, rate of hospital-acquired infections and use of 10 other antimicrobials, including type 2 carbapenems. Unadjusted analyses revealed significant increases over the duration of the study in the number of GNB resistant to meropenem/imipenem among 1000 isolates each of E. coli (0.46 ± 0.22, P 0.05) with changes in resistance for any pathogen/antimicrobial combination. After controlling for confounders, ertapenem was not associated with changes in resistance in a group of sentinel GNB, although significant variations in resistance to different antimicrobials were observed in the unadjusted analyses. These results emphasize the importance of implementation of local resistance surveillance platforms and stewardship programmes to combat the global emergence and spread of antimicrobial resistance. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
Strategies for Overcoming Resistance in Tumours Harboring BRAF Mutations

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Nourah Mohammad Obaid

2017-03-01

Full Text Available The development of resistance to previously effective treatments has been a challenge for health care providers and a fear for patients undergoing cancer therapy. This is an unfortunately frequent occurrence for patients undergoing targeted therapy for tumours harboring the activating V600E mutation of the BRAF gene. Since the initial identification of the BRAF mutation in 2002, a series of small molecular inhibitors that target the BRAFV600E have been developed, but intrinsic and acquired resistance to these drugs has presented an ongoing challenge. More recently, improvements in therapy have been achieved by combining the use of BRAF inhibitors with other drugs, such as inhibitors of the downstream effector mitogen activated protein kinase (MAPK/extracellular-signal regulated kinase (ERK kinase (MEK. Despite improved success in response rates and in delaying resistance using combination therapy, ultimately, the acquisition of resistance remains a concern. Recent research articles have shed light on some of the underlying mechanisms of this resistance and have proposed numerous strategies that might be employed to overcome or avoid resistance to targeted therapies. This review will explore some of the resistance mechanisms, compare what is known in melanoma cancer to colorectal cancer, and discuss strategies under development to manage the development of resistance.
Effect of barnacle fouling on ship resistance and powering.

Science.gov (United States)

Demirel, Yigit Kemal; Uzun, Dogancan; Zhang, Yansheng; Fang, Ho-Chun; Day, Alexander H; Turan, Osman

2017-11-01

Predictions of added resistance and the effective power of ships were made for varying barnacle fouling conditions. A series of towing tests was carried out using flat plates covered with artificial barnacles. The tests were designed to allow the examination of the effects of barnacle height and percentage coverage on the resistance and effective power of ships. The drag coefficients and roughness function values were evaluated for the flat plates. The roughness effects of the fouling conditions on the ships' frictional resistances were predicted. Added resistance diagrams were then plotted using these predictions, and powering penalties for these ships were calculated using the diagrams generated. The results indicate that the effect of barnacle size is significant, since a 10% coverage of barnacles each 5 mm in height caused a similar level of added power requirements to a 50% coverage of barnacles each 1.25 mm in height.

Tebufenozide resistance is associated with sex-linked inheritance in Plutella xylostella.

Science.gov (United States)

Cao, Guang-Chun; Han, Zhao-Jun

2015-04-01

The diamondback moth (DBM), Plutella xylostella (L.), is a major pest of cruciferous crops. Tebufenozide, a novel nonsteroidal ecdysone agonist, exhibits good efficacy and has played an increasingly important role in the control of Lepidopteran pests in China. For its resistance management, the genetic basis of tebufenozide resistance was studied using a laboratory selected resistant strain of DBM (resistant ratio, RR = 268). A series of crosses with laboratory susceptible and resistant strains revealed that tebufenozide resistance in this pest was partially biased toward female heredity, with a large difference in RR for F1 (RR = 29) and rF1 progeny (RR = 147). The dominance calculated for these 2 cross progeny was -0.788 and 0.09, respectively. Further analysis showed that the susceptible male and female larvae were similar in their sensitivity to tebufenozide, but the resistant female larvae showed significantly higher resistance than the resistant male larvae. The heredity of tebufenozide resistance in DBM might be linked with the W sex chromosome, which suggested that DBM has the ability to develop high levels of resistance to tebufenozide. This is the first report of sex-linked inheritance of tebufenozide resistance in P. xylostella (L.). © 2013 Institute of Zoology, Chinese Academy of Sciences.
Analysis of the equalizing holes resistance in fuel assembly spike for lead-based reactor

International Nuclear Information System (INIS)

Zhang, Guangyu; Jin, Ming; Wang, Jianye; Song, Yong

2017-01-01

Highlights: • A RELAP5 model for a 10 MWth lead-based reactor was built to study the hydrodynamic characteristics between the equalizing holes in the fuel assembly spike. • Different fuel assembly total blockage scenarios and different resistances for different fuel assemblies were examined. • The inherent safety characteristics of the lead-based reactor was improved by optimizing the configuration of equalizing holes in the fuel assembly spike. - Abstract: To avoid the damage of the fuel rod cladding when a fuel assembly (FA) is totally blocked, a special configuration of the fuel assembly spike was designed with some equalizing holes in the center region which can let the coolant to flow during the totally blockage scenarios of FA. To study the hydrodynamic characteristics between the equalizing holes and an appropriate resistance, a RELAP5 model was developed for a 10 MWth lead-based reactor which used lead-bismuth as coolant. Several FA total blockage and partial core blockage scenarios were selected. The simulation results indicated that when all the FA spike equalizing holes had the same hydraulic resistance, only a narrow range of suitable equalizing holes resistances could be chosen when a FA was blocked. However, in the two or more FA blockage scenarios, there were no appropriate resistances to meet the requirement. In addition, with different FA spike equalizing holes with different resistances, a large range of suitable equalizing hole resistances could be chosen. Especially a series of suitable resistances were selected when the small power FA resistance was 1/2, 1/4, 1/8 of the large one. Under these circumstances, one, two or three FA blockages would not damage the core. These demonstrated that selecting a series of suitable hydraulic resistances for the equalizing holes could improve the safety characteristics of the reactor effectively.
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
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
Chlorpheniramine Analogues Reverse Chloroquine Resistance in Plasmodium falciparum by Inhibiting PfCRT.

Science.gov (United States)

Deane, Karen J; Summers, Robert L; Lehane, Adele M; Martin, Rowena E; Barrow, Russell A

2014-05-08

The emergence and spread of malaria parasites that are resistant to chloroquine (CQ) has been a disaster for world health. The antihistamine chlorpheniramine (CP) partially resensitizes CQ-resistant (CQR) parasites to CQ but possesses little intrinsic antiplasmodial activity. Mutations in the parasite's CQ resistance transporter (PfCRT) confer resistance to CQ by enabling the protein to transport the drug away from its site of action, and it is thought that resistance-reversers such as CP exert their effect by blocking this CQ transport activity. Here, a series of new structural analogues and homologues of CP have been synthesized. We show that these compounds (along with other in vitro CQ resistance-reversers) inhibit the transport of CQ via a resistance-conferring form of PfCRT expressed in Xenopus laevis oocytes. Furthermore, the level of PfCRT-inhibition was found to correlate well with both the restoration of CQ accumulation and the level of CQ resensitization in CQR parasites.
ATHENS SEASONAL VARIATION OF GROUND RESISTANCE PREDICTION USING NEURAL NETWORKS

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S. Anbazhagan

2015-10-01

Full Text Available The objective in ground resistance is to attain the most minimal ground safety esteem conceivable that bodes well monetarily and physically. An application of artificial neural networks (ANN to presage and relegation has been growing rapidly due to sundry unique characteristics of ANN models. A decent forecast is able to capture the dubiousness associated with those ground resistance. A portion of the key instabilities are soil composition, moisture content, temperature, ground electrodes and spacing of the electrodes. Propelled by this need, this paper endeavors to develop a generalized regression neural network (GRNN to predict the ground resistance. The GRNN has a single design parameter and expeditious learning and efficacious modeling for nonlinear time series. The precision of the forecast is applied to the Athens seasonal variation of ground resistance that shows the efficacy of the proposed approach.
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.
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.
Climatic Factors and Community — Associated Methicillin-Resistant Staphylococcus aureus Skin and Soft-Tissue Infections — A Time-Series Analysis Study

Directory of Open Access Journals (Sweden)

Krushna Chandra Sahoo

2014-08-01

Full Text Available Skin and soft tissue infections caused by Staphylococcus aureus (SA-SSTIs including methicillin-resistant Staphylococcus aureus (MRSA have experienced a significant surge all over the world. Changing climatic factors are affecting the global burden of dermatological infections and there is a lack of information on the association between climatic factors and MRSA infections. Therefore, association of temperature and relative humidity (RH with occurrence of SA-SSTIs (n = 387 and also MRSA (n = 251 was monitored for 18 months in the outpatient clinic at a tertiary care hospital located in Bhubaneswar, Odisha, India. The Kirby-Bauer disk diffusion method was used for antibiotic susceptibility testing. Time-series analysis was used to investigate the potential association of climatic factors (weekly averages of maximum temperature, minimum temperature and RH with weekly incidence of SA-SSTIs and MRSA infections. The analysis showed that a combination of weekly average maximum temperature above 33 °C coinciding with weekly average RH ranging between 55% and 78%, is most favorable for the occurrence of SA-SSTIs and MRSA and within these parameters, each unit increase in occurrence of MRSA was associated with increase in weekly average maximum temperature of 1.7 °C (p = 0.044 and weekly average RH increase of 10% (p = 0.097.
Fluoroquinolone Resistance Mechanisms in an Escherichia coli Isolate, HUE1, Without Quinolone Resistance-Determining Region Mutations

Directory of Open Access Journals (Sweden)

Toyotaka eSato

2013-05-01

Full Text Available Fluoroquinolone resistance can cause major clinical problems. Here, we investigated fluoroquinolone resistance mechanisms in a clinical Escherichia coli isolate, HUE1, which had no mutations quinolone resistance-determining regions (QRDRs of DNA gyrase and topoisomerase IV. HUE1 demonstrated MICs that exceeded the breakpoints for ciprofloxacin, levofloxacin, and norfloxacin. HUE1 harbored oqxAB and qnrS1 on distinct plasmids. In addition, it exhibited lower intracellular ciprofloxacin concentrations and higher mRNA expression levels of efflux pumps and their global activators than did reference strains. The genes encoding AcrR (local AcrAB repressor and MarR (MarA repressor were disrupted by insertion of the transposon IS3-IS629 and a frameshift mutation, respectively. A series of mutants derived from HUE1 were obtained by plasmid curing and gene knockout using homologous recombination. Compared to the MICs of the parent strain HUE1, the fluoroquinolone MICs of these mutants indicated that qnrS1, oqxAB, acrAB, acrF, acrD, mdtK, mdfA, and tolC contributed to the reduced susceptibility to fluoroquinolone in HUE1. Therefore, fluoroquinolone resistance in HUE1 is caused by concomitant acquisition of QnrS1 and OqxAB and overexpression of AcrAB−TolC and other chromosome-encoded efflux pumps. Thus, we have demonstrated that QRDR mutations are not absolutely necessary for acquiring fluoroquinolone resistance in E. coli.
Temperature dependence of the electrical resistivity of amorphous Co80-xErxB20 alloys

International Nuclear Information System (INIS)

Touraghe, O.; Khatami, M.; Menny, A.; Lassri, H.; Nouneh, K.

2008-01-01

The temperature dependence of the electrical resistivity of amorphous Co 80-x Er x B 20 alloys with x=0, 3.9, 7.5 and 8.6 prepared by melt spinning in pure argon atmosphere was studied. All amorphous alloys investigated here are found to exhibit a resistivity minimum at low temperature. The electrical resistivity exhibits logarithmic temperature dependence below the temperature of resistivity minimum T min . In addition, the resistivity shows quadratic temperature behavior in the interval T min < T<77 K. At high temperature, the electrical resistivity was discussed by the extended Ziman theory. For the whole series of alloys, the composition dependence of the temperature coefficient of electrical resistivity α shows a change in structural short range occurring in the composition range 8-9 at%
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.
Development of Semi-Stochastic Algorithm for Optimizing Alloy Composition of High-Temperature Austenitic Stainless Steels (H-Series) for Desired Mechanical and Corrosion Properties.

Energy Technology Data Exchange (ETDEWEB)

Dulikravich, George S.; Sikka, Vinod K.; Muralidharan, G.

2006-06-01

The goal of this project was to adapt and use an advanced semi-stochastic algorithm for constrained multiobjective optimization and combine it with experimental testing and verification to determine optimum concentrations of alloying elements in heat-resistant and corrosion-resistant H-series stainless steel alloys that will simultaneously maximize a number of alloy's mechanical and corrosion properties.
Geographic and research center origins of rice resistance to asian planthoppers and leafhoppers: implications for rice breeding and gene deployment

NARCIS (Netherlands)

Horgan, F.G.; Srinivasan, Thanga Suja; Bentur, Jagadish S.; Kumar, R.; Bhanu, K.V.; Singh Sarao, Preetinder; Chien, Ho Van; Almazan, M.L.P.; Bernal, Carmencita C.; Ramal, Angelee Fame; Ferrater, J.B.; Huang, Shou Horng

2017-01-01

This study examines aspects of virulence to resistant rice varieties among planthoppers and leafhoppers. Using a series of resistant varieties, brown planthopper, Nilaparvata lugens, virulence was assessed in seedlings and early-tillering plants at seven research centers in South and East Asia.
Linking the Negative Binomial and Logarithmic Series Distributions via their Associated Series

OpenAIRE

SADINLE, MAURICIO

2008-01-01

The negative binomial distribution is associated to the series obtained by taking derivatives of the logarithmic series. Conversely, the logarithmic series distribution is associated to the series found by integrating the series associated to the negative binomial distribution. The parameter of the number of failures of the negative binomial distribution is the number of derivatives needed to obtain the negative binomial series from the logarithmic series. The reasoning in this article could ...
Fire resistance of prefabricated monolithic slab

Directory of Open Access Journals (Sweden)

Gravit Marina

2017-01-01

Full Text Available A prefabricated monolithic slab (PMS has a number of valuable advantages, they allow to significantly decrease the weight of construction keeping the necessary structural-load capacity, to speed up and cheapen work conduction, to increase the heat isolating properties of an enclosure structure [1]. In order to create a design method of prefabricated monolithic slab fire-resistance, it's necessary to perform a series of PMS testing, one of which is being described in this article. Subjected to the test is a fragment of prefabricated monolithic slab with polystyrene concrete inserts along the beams with bent metal profile 250 mm thick, with a 2.7 m span loaded with evenly spread load equal to 600 kg/m2. After 3 hour testing for fire-resistance [2] no signs of construction ultimate behavior were detected.
Analytic study of resistive instabilities

Energy Technology Data Exchange (ETDEWEB)

Svensson, Magnus

2003-05-01

In a fusion plasma there is always a small amount of resistivity that may cause instabilities. Although their rather slow growth rates they can be of major importance for fusion plasma confinement. In this work a MAPLE-code was rewritten and simplified to make it possible to analytically solve the linearized MHD-equations with resistivity in an RFP-configuration. By using the MHD-equations and expanding the unknown perturbed quantities u{sub 1r}(r) and B{sub 1r}(r) as Taylor series and solving each coefficient we could get eigenvalues, dispersion relations and a relation between the growth rate and the resistivity. The new code was first used to solve two cases with no resistivity and simple unstable equilibria which after running gave the correct expected results. The difference from running the original code with these two cases was the greater speed of the calculations and the less memory needed. Then by using an ideal MHD-stable equilibrium in a plasma with no resistivity the code gave us solutions which unfortunately were not of the expected kind but the time of the calculations was still very fast. The resistivity was finally added to the code with the ideal MHD-stable equilibrium. The program also this time gave incorrect results. We could, however, see from a relation between the growth rate and the resistivity that the solution may be approximately correct in this domain. Although we did not get all the correct results we have to consider the fact that we got results, that were not possible before. Before this work was carried out we could not get any results at all in the resistive cue because of the very long memory demanding expressions. In future work and studies it is not only possible to get the desired eigenvalues {gamma} as function of {eta} but also possible to get expressions for eigenfunctions, dispersion relations and other significant relations with a number of variable parameters. We could also use the method for any geometry and possibly for

Analytic study of resistive instabilities

International Nuclear Information System (INIS)

Svensson, Magnus

2003-05-01

In a fusion plasma there is always a small amount of resistivity that may cause instabilities. Although their rather slow growth rates they can be of major importance for fusion plasma confinement. In this work a MAPLE-code was rewritten and simplified to make it possible to analytically solve the linearized MHD-equations with resistivity in an RFP-configuration. By using the MHD-equations and expanding the unknown perturbed quantities u 1r (r) and B 1r (r) as Taylor series and solving each coefficient we could get eigenvalues, dispersion relations and a relation between the growth rate and the resistivity. The new code was first used to solve two cases with no resistivity and simple unstable equilibria which after running gave the correct expected results. The difference from running the original code with these two cases was the greater speed of the calculations and the less memory needed. Then by using an ideal MHD-stable equilibrium in a plasma with no resistivity the code gave us solutions which unfortunately were not of the expected kind but the time of the calculations was still very fast. The resistivity was finally added to the code with the ideal MHD-stable equilibrium. The program also this time gave incorrect results. We could, however, see from a relation between the growth rate and the resistivity that the solution may be approximately correct in this domain. Although we did not get all the correct results we have to consider the fact that we got results, that were not possible before. Before this work was carried out we could not get any results at all in the resistive cue because of the very long memory demanding expressions. In future work and studies it is not only possible to get the desired eigenvalues γ as function of η but also possible to get expressions for eigenfunctions, dispersion relations and other significant relations with a number of variable parameters. We could also use the method for any geometry and possibly for non
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.
Magnetic Field Emission Comparison for Series-Parallel and Series-Series Wireless Power Transfer to Vehicles – PART 1/2

DEFF Research Database (Denmark)

Batra, Tushar; Schaltz, Erik

2014-01-01

Resonant circuits of wireless power transfer system can be designed in four possible ways by placing the primary and secondary capacitor in a series or parallel order with respect to the corresponding inductor. The two topologies series-parallel and series-series under investigation have been...... already compared in terms of their output behavior (current or voltage source) and reflection of the secondary impedance on the primary side. In this paper it is shown that for the same power rating series-parallel topology emits lesser magnetic fields to the surroundings than its series...
Small Victories: Reflections on Teaching "Harry Potter" to Resistant Prospective Teachers.

Science.gov (United States)

Bercaw, Lynne A.

2003-01-01

Describes the author's interactions with prospective teachers' resistances to books in the "Harry Potter" series and how she dealt with these situations. Recognizes that her role as a teacher educator includes honoring her students' beliefs, upholding the integrity of the academic discipline of children's literature, and adhering to the…
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.
Summation of series

CERN Document Server

Jolley, LB W

2004-01-01

Over 1,100 common series, all grouped for easy reference. Arranged by category, these series include arithmetical and geometrical progressions, powers and products of natural numbers, figurate and polygonal numbers, inverse natural numbers, exponential and logarithmic series, binomials, simple inverse products, factorials, trigonometrical and hyperbolic expansions, and additional series. 1961 edition.
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)
Technology of electron beam welding for Zr-4 alloy spacer grid

International Nuclear Information System (INIS)

Pei Qiusheng; Wu Xueyi; Yang Qishun

1989-10-01

The welding technology for Zr-4 alloy spacer grid by using vacuum electron beam was studied. Through a series of welding technological experiments, metallographic examinations of seam structure and detecting tests for welding defect by X-ray defectoscopy, a good welding technology was selected to meet the requirements. The experimental results indicated that the Zr-4 alloy spacer grid welded by vacuum electron beam welding is feasible
Proliferation resistance assessment of thermal recycle systems

International Nuclear Information System (INIS)

1979-02-01

This paper examines the major proliferation aspects of thermal recycle systems and the extent to which technical or institutional measures could increase the difficulty or detectability of misuse of the system by would-be proliferators. It does this by examining the various activities necessary to acquire weapons-usable material using a series of assessment factors; resources required, time required, detectability. It is concluded that resistance to proliferation could be improved substantially by collecting reprocessing, conversion and fuel fabrication plants under multi national control and instituting new measures to protect fresh MOX fuel. Resistance to theft at sub-national level could be improved by co-location of sensitive facilities high levels of physical protection at plants and during transportation and possibly by adding a radiation barrier to MOX prior to shipment
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)
Testing independence between two Poisson-generated multinomial variables in case-series and cohort studies.

Science.gov (United States)

Hocine, Mounia; Guillemot, Didier; Tubert-Bitter, Pascale; Moreau, Thierry

2005-12-30

In case-series or cohort studies, we propose a test of independence between the occurrences of two types of recurrent events (such as two repeated infections) related to an intermittent exposure (such as an antibiotic treatment). The test relies upon an extension of a recent method for analysing case-series data, in the presence of one type of recurrent event. The test statistic is derived from a bivariate Poisson generated-multinomial distribution. Simulations for checking the validity of the test concerning the type I error and the power properties are presented. The test is illustrated using data from a cohort on antibiotics bacterial resistance in schoolchildren. Copyright 2005 John Wiley & Sons, Ltd.
[Isolation of a carbapenem-resistant K1 serotype Klebsiella pneumonia strain and the study of resistance mechanism].

Science.gov (United States)

Zhang, Rong; Wang, Xuan; Lü, Jianxin

2014-12-16

To study the virulence and mechanism of carbapenem resistance of a clinical isolate of carbapenem-resistant K1 serotype Klebsiella pneumonia strain. Identification of isolate was carried out with VITEK-2 compact system. Antimicrobial susceptibility was determined by E-test; Metallo β-lactamases and carbapenemases screening were conducted by imipenem-EDTA double disc synergy test and modified Hodge test, respectively.Specific polymerehse chain reaction (PCR) and DNA sequencing were preformed to detect the virulence genes including K1, K2, K5, K20, K54, K57, magA, rmpA, wcaG and a series of β-lactamase resistence genes. Conjunction experiment was also performed. The plasmids of transconjugants were submitted to PCR-based replicon typing (PBRT) method. Molecular typing was performed by multilocus sequence typing (MLST). Antimicrobial susceptibility testing revealed that the Klebsiella pneumonia strain was resistant to most of the antibiotics used in clinic. Phynotype confirmary rest revealed the production of carbapanemases, while Metallo β-lactamases were negative; PCR and DNA sequencing confirmed the isolate was positive for blaKPC-2, blaCTX-M-15, blaTEM-1, blaSHV-1 and virulence genes K1, magA, rmpA, wcaG simultaneously; blaKPC-2 was transferred from donor to Escherichia EC600 by conjunction experiment, while no virulence genes were found in the transconjugants. PBRT revealed that Frep plasmid was found in transconjugants. MLST analysis revealed that this strain belonged to ST23. K1 serotype Klebsiella pneumonia strain carries virulence genes and carbapenem resistance gene blaKPC-2, noteworthily the carbapenem resistance genes can be transferred through horizontal transmission on plasmids.
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.
A lifestyle intervention program for successfully addressing major cardiometabolic risks in persons with SCI: a three-subject case series.

Science.gov (United States)

Bigford, Gregory E; Mendez, Armando J; Betancourt, Luisa; Burns-Drecq, Patricia; Backus, Deborah; Nash, Mark S

2017-01-01

This study is a prospective case series analyzing the effects of a comprehensive lifestyle intervention program in three patients with chronic paraplegia having major risks for the cardiometabolic syndrome (CMS). Individuals underwent an intense 6-month program of circuit resistance exercise, nutrition using a Mediterranean diet and behavioral support, followed by a 6-month extension (maintenance) phase involving minimal support. The primary goal was a 7% reduction of body mass. Other outcomes analyzed insulin resistance using the HOMA-IR model, and plasma levels of fasting triglycerides and high-density lipoprotein cholesterol. All participants achieved the goal for 7% reduction of body mass and maintained the loss after the MP. Improvements were observed in 2/3 subjects for HOMA-IR and high-density lipoprotein cholesterol. All participants improved their risk for plasma triglycerides. We conclude, in a three-person case series of persons with chronic paraplegia, a lifestyle intervention program involving circuit resistance training, a calorie-restrictive Mediterranean-style diet and behavioral support, results in clinically significant loss of body mass and effectively reduced component risks for CMS and diabetes. These results were for the most part maintained after a 6-month MP involving minimal supervision.
An analytic solution for numerical modeling validation in electromagnetics: the resistive sphere

Science.gov (United States)

Swidinsky, Andrei; Liu, Lifei

2017-11-01

We derive the electromagnetic response of a resistive sphere to an electric dipole source buried in a conductive whole space. The solution consists of an infinite series of spherical Bessel functions and associated Legendre polynomials, and follows the well-studied problem of a conductive sphere buried in a resistive whole space in the presence of a magnetic dipole. Our result is particularly useful for controlled-source electromagnetic problems using a grounded electric dipole transmitter and can be used to check numerical methods of calculating the response of resistive targets (such as finite difference, finite volume, finite element and integral equation). While we elect to focus on the resistive sphere in our examples, the expressions in this paper are completely general and allow for arbitrary source frequency, sphere radius, transmitter position, receiver position and sphere/host conductivity contrast so that conductive target responses can also be checked. Commonly used mesh validation techniques consist of comparisons against other numerical codes, but such solutions may not always be reliable or readily available. Alternatively, the response of simple 1-D models can be tested against well-known whole space, half-space and layered earth solutions, but such an approach is inadequate for validating models with curved surfaces. We demonstrate that our theoretical results can be used as a complementary validation tool by comparing analytic electric fields to those calculated through a finite-element analysis; the software implementation of this infinite series solution is made available for direct and immediate application.
Induced mutations for disease resistance in wheat and barley

International Nuclear Information System (INIS)

Hanis, M.; Hanisova, A.; Knytl, V.; Cerny, J.; Benc, S.

1977-01-01

The induction of mutations in cultivars of wheat (Triticum aestivum), barley (Hordeum vulgare), and field beans (Phaseolus vulgaris) has been part of the breeding programme at the Plant Breeding Station at Stupice since 1960. A total of 26 cultivars or selections of winter wheat, 4 cultivars or selections of spring wheat, 2 cultivars of field beans, and 43 selections of spring barley have been treated since 1960. A total of 140 mutant lines of wheat and 37 mutant lines of barley with improved disease resistance of a race-specific type have been obtained. Several mutation programme derived cultivars have been registered in Czechoslovakia (''Diamant'', ''Ametyst'', ''Favorit'', ''Hana'', ''Rapid'', and ''Atlas'' in barley, and ''Alfa'' in field beans), but none of them is a mutation for disease resistance. A series of mutants have been used in crossing programmes. Approaches to improve the efficiency of mutation breeding for disease resistance are suggested. (author)
Anthelmintics: From discovery to resistance II (San Diego, 2016

Directory of Open Access Journals (Sweden)

Richard J. Martin

2016-12-01

Full Text Available The second scientific meeting in the series: “Anthelmintics: From Discovery to Resistance” was held in San Diego in February, 2016. The focus topics of the meeting, related to anthelmintic discovery and resistance, were novel technologies, bioinformatics, commercial interests, anthelmintic modes of action and anthelmintic resistance. Basic scientific, human and veterinary interests were addressed in oral and poster presentations. The delegates were from universities and industries in the US, Europe, Australia and New Zealand. The papers were a great representation of the field, and included the use of C. elegans for lead discovery, mechanisms of anthelmintic resistance, nematode neuropeptides, proteases, B. thuringiensis crystal protein, nicotinic receptors, emodepside, benzimidazoles, P-glycoproteins, natural products, microfluidic techniques and bioinformatics approaches. The NIH also presented NIAID-specific parasite genomic priorities and initiatives. From these papers we introduce below selected papers with a focus on anthelmintic drug screening and development.
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

Use of gamma-rays mutagenesis in obtaining chickpea (Cicer arietinum L.) forms resistant to unfavorable environmental factors

International Nuclear Information System (INIS)

Cliciuc, D.

2013-01-01

Following experimental use of γ irradiation on chickpea, mutant forms with a series of morpho-physiological treats were obtained. During the study period, these mutants have been subjected to several stress factors like disease, drought, storm wind in which they presented a different resistance. Some of these mutants showed an increased sensitivity in certain environmental conditions and others have presented an increased resistance.
Statistical analysis and application of quasi experiments to antimicrobial resistance intervention studies.

Science.gov (United States)

Shardell, Michelle; Harris, Anthony D; El-Kamary, Samer S; Furuno, Jon P; Miller, Ram R; Perencevich, Eli N

2007-10-01

Quasi-experimental study designs are frequently used to assess interventions that aim to limit the emergence of antimicrobial-resistant pathogens. However, previous studies using these designs have often used suboptimal statistical methods, which may result in researchers making spurious conclusions. Methods used to analyze quasi-experimental data include 2-group tests, regression analysis, and time-series analysis, and they all have specific assumptions, data requirements, strengths, and limitations. An example of a hospital-based intervention to reduce methicillin-resistant Staphylococcus aureus infection rates and reduce overall length of stay is used to explore these methods.
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%.
From Fourier Series to Rapidly Convergent Series for Zeta(3)

DEFF Research Database (Denmark)

Scheufens, Ernst E

2011-01-01

The article presents a mathematical study which investigates the exact values of the Riemann zeta (ζ) function. It states that exact values can be determined from Fourier series for periodic versions of even power functions. It notes that using power series for logarithmic functions on this such ......The article presents a mathematical study which investigates the exact values of the Riemann zeta (ζ) function. It states that exact values can be determined from Fourier series for periodic versions of even power functions. It notes that using power series for logarithmic functions...
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)
Invariant submanifold for series arrays of Josephson junctions.

Science.gov (United States)

Marvel, Seth A; Strogatz, Steven H

2009-03-01

We study the nonlinear dynamics of series arrays of Josephson junctions in the large-N limit, where N is the number of junctions in the array. The junctions are assumed to be identical, overdamped, driven by a constant bias current, and globally coupled through a common load. Previous simulations of such arrays revealed that their dynamics are remarkably simple, hinting at the presence of some hidden symmetry or other structure. These observations were later explained by the discovery of N-3 constants of motion, the choice of which confines the resulting flow in phase space to a low-dimensional invariant manifold. Here we show that the dimensionality can be reduced further by restricting attention to a special family of states recently identified by Ott and Antonsen. In geometric terms, the Ott-Antonsen ansatz corresponds to an invariant submanifold of dimension one less than that found earlier. We derive and analyze the flow on this submanifold for two special cases: an array with purely resistive loading and another with resistive-inductive-capacitive loading. Our results recover (and in some instances improve) earlier findings based on linearization arguments.
3-D nonlinear calculations of resistive tearing modes

International Nuclear Information System (INIS)

Hicks, H.R.; Holmes, J.A.; Lee, D.K.; Carreras, B.; Waddell, B.V.

1981-03-01

Recent numerical calculations of the evolution of resistive tearing modes have been central to the understanding of magnetohydrodynamic activity and disruptions in tokamaks. The nonlinear, 3-D, initial-value computer code RSF has provided many of these results. This code assumes cylindrical geometry with a Fourier series representation in the two periodic coordinates and a finite-difference representation in the radial direction. This choice makes RSF considerably more accurate and efficient than previous codes
Impact of antibiotic restriction on resistance levels of Escherichia coli

DEFF Research Database (Denmark)

Boel, Jonas; Andreasen, Viggo; Jarløv, Jens Otto

2016-01-01

as a retrospective controlled interrupted time series (ITS) at two university teaching hospitals, intervention and control, with 736 and 552 beds, respectively. The study period was between January 2008 and September 2014. We used ITS analysis to determine significant changes in antibiotic use and resistance levels......% CI -177, -126)] and fluoroquinolones [-44.5 DDDs/1000 bed-days (95% CI -58.9, -30.1)]. Resistance of E. coli showed a significant change in slope for cefuroxime [-0.13 percentage points/month (95% CI -0.21, -0.057)] and ciprofloxacin [-0.15 percentage points/month (95% CI -0.26, -0.038)]. CONCLUSIONS......OBJECTIVES: We evaluated the effect of an antibiotic stewardship programme (ASP) on the use of antibiotics and resistance levels of Escherichia coli using a method that allowed direct comparison between an intervention hospital and a control hospital. METHODS: The study was conducted...
Order and turbulence in rf-driven Josephson junction series arrays

International Nuclear Information System (INIS)

Dominguez, D.; Cerdeira, H.A.

1994-01-01

We study underdamped Josephson junction series arrays that are globally coupled through a resistive shunting load and driven by an rf bias current. We find coherent, ordered, partially ordered and turbulent regimes in the IV characteristics. The ordered regime corresponds to giant Shapiro steps. In the turbulent regime there is a saturation of the broad band noise for a large number of junctions. This corresponds to a breaking of the law of large numbers already seen in globally coupled maps. Coexisting with this, we find an emergence of novel pseudo-steps in the IV characteristics. (author). 18 refs, 3 figs
Excellent nonlinearity of a selection device based on anti-series connected Zener diodes for ultrahigh-density bipolar RRAM arrays

International Nuclear Information System (INIS)

Li, Yingtao; Li, Rongrong; Wang, Yang; Tao, Chunlan; Fu, Liping; Gao, Xiaoping

2015-01-01

A crossbar array is usually used for the high-density application of a resistive random access memory (RRAM) device. However, the cross-talk interference limits the increase in the integration density. In this paper, anti-series connected Zener diodes as a selection device are proposed for bipolar RRAM arrays. Simulation results show that, by using the anti-series connected Zener diodes as a selection device, the readout margin is sufficiently improved compared to that obtained without a selection device or with anti-parallel connected diodes as the selection device. The maximum size of the crossbar arrays with anti-series connected Zener diodes as a selection device over 1 TB is estimated by theoretical simulation. In addition, the feasibility of using the anti-series connected Zener diodes as a selection device for bipolar RRAM is demonstrated experimentally. These results indicate that anti-series connected Zener diodes as a selection device opens up great opportunities to realize ultrahigh-density bipolar RRAM arrays. (paper)
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)
Modern Spirometry Supports Anesthetic Management in Small Animal Clinical Practice: A Case Series.

Science.gov (United States)

Calice, Ivana; Moens, Yves

2016-01-01

Modern spirometry, like no other monitoring technique, allows insight into breath-to-breath respiratory mechanics. Spirometers continuously measure volume, airway pressure, and flow while calculating and continuously displaying respiratory system compliance and resistance in the form of loops. The aim of this case series is to show how observation of spirometric loops, similar to electrocardiogram or CO2 curve monitoring, can improve safety of anesthetic management in small animals. Spirometric monitoring cases described in this case series are based on use of the anaesthesia monitor Capnomac Ultima with a side stream spirometry sensor. The cases illustrate how recognition and understanding of spirometric loops allows for easy diagnosis of iatrogenic pneumothorax, incorrect ventilator settings, leaks in the system, kinked or partially obstructed endotracheal tube, and spontaneous breathing interfering with intermittent positive-pressure ventilation. The case series demonstrates the potential of spirometry to improve the quality and safety of anesthetic management, and, hence, its use can be recommended during intermittent positive-pressure ventilation and procedures in which interference with ventilation can be expected.
Three-Dimensional Surface Geophysical Exploration of the 200-Series Tanks at the 241-C Tank Farm

Energy Technology Data Exchange (ETDEWEB)

Crook, N. [HydroGEOPHYSICS, Inc., Tuscon, AZ (United States); McNeill, M. [HydroGEOPHYSICS, Inc., Tuscon, AZ (United States); Dunham, Ralph [Columbia Energy and Environmental Services, Inc., Richland, WA (United States); Glaser, Danney R. [Washington River Protection Solutions, LLC, Richland, WA (United States)

2014-02-26

A surface geophysical exploration (SGE) survey using direct current electrical resistivity was conducted within the C Tank Farm in the vicinity of the 200-Series tanks at the Hanford Site near Richland, Washington. This survey was the second successful SGE survey to utilize the Geotection^TM-180 Resistivity Monitoring System which facilitated a much larger survey size and faster data acquisition rate. The primary objective of the C Tank Farm SGE survey was to provide geophysical data and subsurface imaging results to support the Phase 2 RCRA Facility Investigation, as outlined in the Phase 2 RCRA Facility Investigation/Corrective Measures work plan RPP-PLAN-39114.
Three-Dimensional Surface Geophysical Exploration of the 200-Series Tanks at the 241-C Tank Farm

International Nuclear Information System (INIS)

Crook, N.; McNeill, M.; Dunham, Ralph; Glaser, Danney R.

2014-01-01

A surface geophysical exploration (SGE) survey using direct current electrical resistivity was conducted within the C Tank Farm in the vicinity of the 200-Series tanks at the Hanford Site near Richland, Washington. This survey was the second successful SGE survey to utilize the Geotection(TM)-180 Resistivity Monitoring System which facilitated a much larger survey size and faster data acquisition rate. The primary objective of the C Tank Farm SGE survey was to provide geophysical data and subsurface imaging results to support the Phase 2 RCRA Facility Investigation, as outlined in the Phase 2 RCRA Facility Investigation / Corrective Measures work plan RPP-PLAN-39114
The physics of Resistive Plate Chambers

CERN Document Server

Riegler, Werner

2004-01-01

Over the last 3 years we investigated theoretical aspects of Resistive Plate Chambers (RPC) in order to clarify some of the outstanding questions on space charge effects, high efficiency of small gap RPCs, charge spectra, signal shape and time resolution. In a series of reports we analyzed RPC performance including all detector aspects covering primary ionization, avalanche multiplication, space charge effects, signal induction in presence of resistive materials, crosstalk along detectors with long strips and front-end electronics. Using detector gas parameters entirely based on theoretical predictions and physical models for avalanche development and space charge effects we are able to reproduce measurements for 2 and 0.3 mm RPCs to very high accuracy without any additional assumptions. This fact gives a profound insight into the workings of RPCs and also underlines the striking difference in operation regime when compared to wire chambers. A summary of this work as well as recent results on three-dimensiona...
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.
The Effects of Individualized Resistance Strength Programs on Knee Muscular Imbalances in Junior Elite Soccer Players

Science.gov (United States)

Śliwowski, Robert; Jadczak, Łukasz; Hejna, Rafał; Wieczorek, Andrzej

2015-01-01

The purpose of this study was to investigate the effects of a resistance training program on the muscular strength of soccer players’ knees that initially presented unilateral and bilateral differences. For this study, a team of 24 male well-trained junior soccer players was divided into two strength program training groups: a Resistance Training Control Group (RTCG) composed of 10 players that did not have muscular imbalances and a Resistance Training Experimental Group (RTEG) composed of 14 players that had muscular imbalances. All players followed a resistance training program for six weeks, two times per week, during the transition period. The program of individualized strength training consisted of two parts. The first part, which was identical in terms of the choice of training loads, was intended for both training groups and contained two series of exercises including upper and lower body exercises. The second part of the program was intended only for RTEG and consisted of two additional series for the groups of muscles that had identified unilateral and bilateral differences. The applied program showed various directions in the isokinetic profile of changes. In the case of RTCG, the adaptations related mainly to the quadriceps muscle (the peak torque (PT) change for the dominant leg was statistically significant (p soccer players. PMID:26630271
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.
Research of radiation-resistant microbial organisms

Energy Technology Data Exchange (ETDEWEB)

Kim, Dongho; Lim, Sangyong; Joe, Minho; Park, Haejoon; Song, Hyunpa; Im, Seunghun; Kim, Haram; Kim, Whajung; Choi, Jinsu; Park, Jongchun

2012-01-15

Many extremophiles including radiation-resistant bacteria Deinococcus radiodurans have special characteristics such as novel enzymes and physiological active substances different from known biological materials and are being in the spotlight of biotechnology science. In this research, basic technologies for the production of new genetic resources and microbial strains by a series of studies in radiation-resistant microbial organisms were investigated and developed. Mechanisms required for radiation-resistant in Deinococcus radiodurans were partly defined by analyzing the function of dinB, pprI, recG, DRA{sub 0}279, pprM, and two-component signal transduction systems. To apply genetic resource and functional materials from Deinococcus species, omics analysis in response to cadmium, construction of macroscopic biosensor, and characterization of carotenoids and chaperon protein were performed. Additionally, potential use of D. geothermalis in monosaccharide production from non-biodegradable plant materials was evaluated. Novel radiation resistant yeasts and bacteria were isolated and identified from environmental samples to obtain microbial and genomic resources. An optimal radiation mutant breeding method was set up for efficient and rapid isolation of target microbial mutants. Furthermore, an efficient ethanol producing mutant strain with high production yield and productivity was constructed using the breeding method in collaboration with Korea Research Institute of Bioscience and Biotechnology. Three Deinococcal bioindicators for radiation dosage confirmation after radiation sterilization process were developed. These results provide a comprehensive information for novel functional genetic elements, enzymes, and physiological active substances production or application. Eventually, industrial microbial cell factories based on radiation resistant microbial genomes can be developed and the technologies can be diffused to bioindustry continuously by this project.
Research of radiation-resistant microbial organisms

International Nuclear Information System (INIS)

Kim, Dongho; Lim, Sangyong; Joe, Minho; Park, Haejoon; Song, Hyunpa; Im, Seunghun; Kim, Haram; Kim, Whajung; Choi, Jinsu; Park, Jongchun

2012-01-01

Many extremophiles including radiation-resistant bacteria Deinococcus radiodurans have special characteristics such as novel enzymes and physiological active substances different from known biological materials and are being in the spotlight of biotechnology science. In this research, basic technologies for the production of new genetic resources and microbial strains by a series of studies in radiation-resistant microbial organisms were investigated and developed. Mechanisms required for radiation-resistant in Deinococcus radiodurans were partly defined by analyzing the function of dinB, pprI, recG, DRA 0 279, pprM, and two-component signal transduction systems. To apply genetic resource and functional materials from Deinococcus species, omics analysis in response to cadmium, construction of macroscopic biosensor, and characterization of carotenoids and chaperon protein were performed. Additionally, potential use of D. geothermalis in monosaccharide production from non-biodegradable plant materials was evaluated. Novel radiation resistant yeasts and bacteria were isolated and identified from environmental samples to obtain microbial and genomic resources. An optimal radiation mutant breeding method was set up for efficient and rapid isolation of target microbial mutants. Furthermore, an efficient ethanol producing mutant strain with high production yield and productivity was constructed using the breeding method in collaboration with Korea Research Institute of Bioscience and Biotechnology. Three Deinococcal bioindicators for radiation dosage confirmation after radiation sterilization process were developed. These results provide a comprehensive information for novel functional genetic elements, enzymes, and physiological active substances production or application. Eventually, industrial microbial cell factories based on radiation resistant microbial genomes can be developed and the technologies can be diffused to bioindustry continuously by this project

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.
Divergent Perturbation Series

International Nuclear Information System (INIS)

Suslov, I.M.

2005-01-01

Various perturbation series are factorially divergent. The behavior of their high-order terms can be determined by Lipatov's method, which involves the use of instanton configurations of appropriate functional integrals. When the Lipatov asymptotic form is known and several lowest order terms of the perturbation series are found by direct calculation of diagrams, one can gain insight into the behavior of the remaining terms of the series, which can be resummed to solve various strong-coupling problems in a certain approximation. This approach is demonstrated by determining the Gell-Mann-Low functions in φ 4 theory, QED, and QCD with arbitrary coupling constants. An overview of the mathematical theory of divergent series is presented, and interpretation of perturbation series is discussed. Explicit derivations of the Lipatov asymptotic form are presented for some basic problems in theoretical physics. A solution is proposed to the problem of renormalon contributions, which hampered progress in this field in the late 1970s. Practical perturbation-series summation schemes are described both for a coupling constant of order unity and in the strong-coupling limit. An interpretation of the Borel integral is given for 'non-Borel-summable' series. Higher order corrections to the Lipatov asymptotic form are discussed
Fatigue resistance of engine-driven rotary nickel-titanium endodontic instruments.

Science.gov (United States)

Chaves Craveiro de Melo, Marta; Guiomar de Azevedo Bahia, Maria; Lopes Buono, Vicente Tadeu

2002-11-01

A comparative study of the fatigue resistance of engine-driven nickel-titanium endodontic instruments was performed, aiming to access the influence of the cutting flute design and of the size of the files that reach the working length in curved canal shaping. Geometrical conditions similar to those found in practice were used. Series 29 #5 ProFile, together with #6 and #8 Quantec instruments, were tested in artificial canals with a 45-degree angle of curvature and 5-mm radius of curvature. It was observed that the size of the instrument, which determines the maximum strain amplitude during cyclic deformation, is the most important factor controlling fatigue resistance. The effect of heat sterilization on the fatigue resistance of the instruments was also examined. The results obtained indicate that the application of five sterilization procedures in dry heat increases the average number of cycles to failure of unused instruments by approximately 70%.
Low resistance bakelite RPC study for high rate working capability

International Nuclear Information System (INIS)

Dai, T.; Han, L.; Hou, S.; Liu, M.; Li, Q.; Song, H.; Xia, L.; Zhang, Z.

2014-01-01

This paper presents series efforts to lower resistance of bakelite electrode plate to improve the RPC capability under high rate working condition. New bakelite material with alkali metallic ion doping has been manufactured and tested. This bakelite is found unstable under large charge flux and need further investigation. A new structure of carbon-embedded bakelite RPC has been developed, which can reduce the effective resistance of electrode by a factor of 10. The prototype of the carbon-embedded chamber could function well under gamma radiation source at event rate higher than 10 kHz/cm 2 . The preliminary tests show that this kind of new structure performs as efficiently as traditional RPCs
On the series

Indian Academy of Sciences (India)

2016-08-26

Aug 26, 2016 ... http://www.ias.ac.in/article/fulltext/pmsc/115/04/0371-0381. Keywords. Inverse binomial series; hypergeometric series; polylogarithms; integral representations. Abstract. In this paper we investigate the series ∑ k = 1 ∞ ( 3 k k ) − 1 k − n x k . Obtaining some integral representations of them, we evaluated the ...
Time series analysis time series analysis methods and applications

CERN Document Server

Rao, Tata Subba; Rao, C R

2012-01-01

The field of statistics not only affects all areas of scientific activity, but also many other matters such as public policy. It is branching rapidly into so many different subjects that a series of handbooks is the only way of comprehensively presenting the various aspects of statistical methodology, applications, and recent developments. The Handbook of Statistics is a series of self-contained reference books. Each volume is devoted to a particular topic in statistics, with Volume 30 dealing with time series. The series is addressed to the entire community of statisticians and scientists in various disciplines who use statistical methodology in their work. At the same time, special emphasis is placed on applications-oriented techniques, with the applied statistician in mind as the primary audience. Comprehensively presents the various aspects of statistical methodology Discusses a wide variety of diverse applications and recent developments Contributors are internationally renowened experts in their respect...
A typology and analysis of drug resistance strategies of rural Native Hawaiian youth.

Science.gov (United States)

Okamoto, Scott K; Helm, Susana; Giroux, Danielle; Kaliades, Alexis; Kawano, Kaycee Nahe; Kulis, Stephen

2010-12-01

This study examines the drug resistance strategies described by Native Hawaiian youth residing in rural communities. Sixty-four youth from 7 middle and intermediate schools on the Island of Hawai'i participated in a series of gender-specific focus groups. Youth responded to 15 drug-related problem situations developed and validated from prior research. A total of 509 responses reflecting primary or secondary drug resistance strategies were identified by the youth, which were qualitatively collapsed into 16 different categories. Primary drug resistance strategies were those that participants listed as a single response, or the first part of a two-part response, while secondary drug resistance strategies were those that were used in tandem with primary drug resistance strategies. Over half of the responses reflecting primary drug resistance strategies fell into three different categories ("refuse," "explain," or "angry refusal"), whereas over half of the responses reflecting secondary drug resistance strategies represented one category ("explain"). Significant gender differences were found in the frequency of using different strategies as well as variations in the frequency of using different strategies based on the type of drug offerer (family versus friends/peers). Implications for prevention practice are discussed.
A Novel Series Connected Batteries State of High Voltage Safety Monitor System for Electric Vehicle Application

Directory of Open Access Journals (Sweden)

Qiang Jiaxi

2013-01-01

Full Text Available Batteries, as the main or assistant power source of EV (Electric Vehicle, are usually connected in series with high voltage to improve the drivability and energy efficiency. Today, more and more batteries are connected in series with high voltage, if there is any fault in high voltage system (HVS, the consequence is serious and dangerous. Therefore, it is necessary to monitor the electric parameters of HVS to ensure the high voltage safety and protect personal safety. In this study, a high voltage safety monitor system is developed to solve this critical issue. Four key electric parameters including precharge, contact resistance, insulation resistance, and remaining capacity are monitored and analyzed based on the equivalent models presented in this study. The high voltage safety controller which integrates the equivalent models and control strategy is developed. By the help of hardware-in-loop system, the equivalent models integrated in the high voltage safety controller are validated, and the online electric parameters monitor strategy is analyzed and discussed. The test results indicate that the high voltage safety monitor system designed in this paper is suitable for EV application.
A novel series connected batteries state of high voltage safety monitor system for electric vehicle application.

Science.gov (United States)

Jiaxi, Qiang; Lin, Yang; Jianhui, He; Qisheng, Zhou

2013-01-01

Batteries, as the main or assistant power source of EV (Electric Vehicle), are usually connected in series with high voltage to improve the drivability and energy efficiency. Today, more and more batteries are connected in series with high voltage, if there is any fault in high voltage system (HVS), the consequence is serious and dangerous. Therefore, it is necessary to monitor the electric parameters of HVS to ensure the high voltage safety and protect personal safety. In this study, a high voltage safety monitor system is developed to solve this critical issue. Four key electric parameters including precharge, contact resistance, insulation resistance, and remaining capacity are monitored and analyzed based on the equivalent models presented in this study. The high voltage safety controller which integrates the equivalent models and control strategy is developed. By the help of hardware-in-loop system, the equivalent models integrated in the high voltage safety controller are validated, and the online electric parameters monitor strategy is analyzed and discussed. The test results indicate that the high voltage safety monitor system designed in this paper is suitable for EV application.
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.
Combining Different Conceptual Change Methods within Four-Step Constructivist Teaching Model: A Sample Teaching of Series and Parallel Circuits

Science.gov (United States)

Ipek, Hava; Calik, Muammer

2008-01-01

Based on students' alternative conceptions of the topics "electric circuits", "electric charge flows within an electric circuit", "how the brightness of bulbs and the resistance changes in series and parallel circuits", the current study aims to present a combination of different conceptual change methods within a four-step constructivist teaching…
High efficiency graphene coated copper based thermocells connected in series

Science.gov (United States)

Sindhuja, Mani; Indubala, Emayavaramban; Sudha, Venkatachalam; Harinipriya, Seshadri

2018-04-01

Conversion of low-grade waste heat into electricity had been studied employing single thermocell or flowcells so far. Graphene coated copper electrodes based thermocells connected in series displayed relatively high efficiency of thermal energy harvesting. The maximum power output of 49.2W/m2 for normalized cross sectional electrode area is obtained at 60ºC of inter electrode temperature difference. The relative carnot efficiency of 20.2% is obtained from the device. The importance of reducing the mass transfer and ion transfer resistance to improve the efficiency of the device is demonstrated. Degradation studies confirmed mild oxidation of copper foil due to corrosion caused by the electrolyte.
Connected to TV series: Quantifying series watching engagement.

Science.gov (United States)

Tóth-Király, István; Bőthe, Beáta; Tóth-Fáber, Eszter; Hága, Győző; Orosz, Gábor

2017-12-01

Background and aims Television series watching stepped into a new golden age with the appearance of online series. Being highly involved in series could potentially lead to negative outcomes, but the distinction between highly engaged and problematic viewers should be distinguished. As no appropriate measure is available for identifying such differences, a short and valid measure was constructed in a multistudy investigation: the Series Watching Engagement Scale (SWES). Methods In Study 1 (N Sample1 = 740 and N Sample2 = 740), exploratory structural equation modeling and confirmatory factor analysis were used to identify the most important facets of series watching engagement. In Study 2 (N = 944), measurement invariance of the SWES was investigated between males and females. In Study 3 (N = 1,520), latent profile analysis (LPA) was conducted to identify subgroups of viewers. Results Five factors of engagement were identified in Study 1 that are of major relevance: persistence, identification, social interaction, overuse, and self-development. Study 2 supported the high levels of equivalence between males and females. In Study 3, three groups of viewers (low-, medium-, and high-engagement viewers) were identified. The highly engaged at-risk group can be differentiated from the other two along key variables of watching time and personality. Discussion The present findings support the overall validity, reliability, and usefulness of the SWES and the results of the LPA showed that it might be useful to identify at-risk viewers before the development of problematic use.
Equations describing contamination of run of mine coal with dirt in the Upper Silesian Coalfield

Energy Technology Data Exchange (ETDEWEB)

Winiewski, J J

1977-12-01

Statistical analysis proved that contamination with dirt of run of mine coal from seams in the series 200 to 600 of the Upper Silesian Coalfield depends on the average ash content of a given raw coal. A regression equation is deduced for coarse and fine sizes of each coal. These equations can be used to predict the degree of contamination of run of mine coal to an accuracy sufficient for coal preparation purposes.
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
Short term load forecasting technique based on the seasonal exponential adjustment method and the regression model

International Nuclear Information System (INIS)

Wu, Jie; Wang, Jianzhou; Lu, Haiyan; Dong, Yao; Lu, Xiaoxiao

2013-01-01

Highlights: ► The seasonal and trend items of the data series are forecasted separately. ► Seasonal item in the data series is verified by the Kendall τ correlation testing. ► Different regression models are applied to the trend item forecasting. ► We examine the superiority of the combined models by the quartile value comparison. ► Paired-sample T test is utilized to confirm the superiority of the combined models. - Abstract: For an energy-limited economy system, it is crucial to forecast load demand accurately. This paper devotes to 1-week-ahead daily load forecasting approach in which load demand series are predicted by employing the information of days before being similar to that of the forecast day. As well as in many nonlinear systems, seasonal item and trend item are coexisting in load demand datasets. In this paper, the existing of the seasonal item in the load demand data series is firstly verified according to the Kendall τ correlation testing method. Then in the belief of the separate forecasting to the seasonal item and the trend item would improve the forecasting accuracy, hybrid models by combining seasonal exponential adjustment method (SEAM) with the regression methods are proposed in this paper, where SEAM and the regression models are employed to seasonal and trend items forecasting respectively. Comparisons of the quartile values as well as the mean absolute percentage error values demonstrate this forecasting technique can significantly improve the accuracy though models applied to the trend item forecasting are eleven different ones. This superior performance of this separate forecasting technique is further confirmed by the paired-sample T tests
Novel short chain chloroquine analogues retain activity against chloroquine resistant K1 Plasmodium falciparum.

Science.gov (United States)

Stocks, Paul A; Raynes, Kaylene J; Bray, Patrick G; Park, B Kevin; O'Neill, Paul M; Ward, Stephen A

2002-11-07

A series of short chain chloroquine (CQ) derivatives have been synthesized in one step from readily available starting materials. The diethylamine function of CQ is replaced by shorter alkylamine groups (4-9) containing secondary or tertiary terminal nitrogens. Some of these derivatives are significantly more potent than CQ against a CQ resistant strain of Plasmodium falciparum in vitro. We conclude that the ability to accumulate at higher concentrations within the food vacuole of the parasite is an important parameter that dictates their potency against CQ sensitive and the chloroquine resistant K1 P. falciparum.
Community-Associated Methicillin-Resistant Staphylococcus aureus Infections in Men Who Have Sex With Men: A Case Series

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R Sztramko

2007-01-01

Full Text Available BACKGROUND: The purpose of the present study was to describe the clinical characteristics and management of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA infections among a cohort of men who have sex with men.
Transient, heat-induced thermal resistance in the small intestine of mouse

International Nuclear Information System (INIS)

Hume, S.P.; Marigold, J.C.L.

1980-01-01

Heat-induced thermal resistance has been investigated in mouse jejunum by assaying crypt survival 24 h after treatment. Hyperthermia was achieved by immersing an exteriorized loop of intestine in a bath of Krebs-Ringer solution. Two approaches have been used. In the first, thermal survival curves were obtained following single hyperthermal treatments at temperatures in the range 42 to 44 0 C. Transient thermal resistance, inducted by a plateau in the crypt survival curve, developed during heating at temperatures around 42.5 0 C after 60 to 80 min. In the second series of experiments, a priming heat treatment (40.0, 41.0, 41.5, or 42.0 0 C for 60 min) was followed at varying intervals by a test treatment at 43.0 0 C. A transient resistance to the second treatment was induced, the extent and time of development being dependent upon the priming treatment. Crypt survival curves for thermally resistant intestine showed an increase in thermal D 0 and a decrease in n compared with curves from previously unheated intestine
Exploring glycopeptide-resistance in Staphylococcus aureus: a combined proteomics and transcriptomics approach for the identification of resistance-related markers

Directory of Open Access Journals (Sweden)

Renzoni Adriana

2006-11-01

Full Text Available Abstract Background To unravel molecular targets involved in glycopeptide resistance, three isogenic strains of Staphylococcus aureus with different susceptibility levels to vancomycin or teicoplanin were subjected to whole-genome microarray-based transcription and quantitative proteomic profiling. Quantitative proteomics performed on membrane extracts showed exquisite inter-experimental reproducibility permitting the identification and relative quantification of >30% of the predicted S. aureus proteome. Results In the absence of antibiotic selection pressure, comparison of stable resistant and susceptible strains revealed 94 differentially expressed genes and 178 proteins. As expected, only partial correlation was obtained between transcriptomic and proteomic results during stationary-phase. Application of massively parallel methods identified one third of the complete proteome, a majority of which was only predicted based on genome sequencing, but never identified to date. Several over-expressed genes represent previously reported targets, while series of genes and proteins possibly involved in the glycopeptide resistance mechanism were discovered here, including regulators, global regulator attenuator, hyper-mutability factor or hypothetical proteins. Gene expression of these markers was confirmed in a collection of genetically unrelated strains showing altered susceptibility to glycopeptides. Conclusion Our proteome and transcriptome analyses have been performed during stationary-phase of growth on isogenic strains showing susceptibility or intermediate level of resistance against glycopeptides. Altered susceptibility had emerged spontaneously after infection with a sensitive parental strain, thus not selected in vitro. This combined analysis allows the identification of hundreds of proteins considered, so far as hypothetical protein. In addition, this study provides not only a global picture of transcription and expression adaptations

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