WorldWideScience

Sample records for camera-based seam tracking

  1. Using active contour models for feature extraction in camera-based seam tracking of arc welding

    DEFF Research Database (Denmark)

    Liu, Jinchao; Fan, Zhun; Olsen, Søren

    2009-01-01

    In the recent decades much research has been performed in order to allow better control of arc welding processes, but the success has been limited, and the vast majority of the industrial structural welding work is therefore still being made manually. Closed-loop and nearly-closed-loop control...... of the processes requires the extraction of characteristic parameters of the welding groove close to the molten pool, i.e. in an environment dominated by the very intense light emission from the welding arc. The typical industrial solution today is a laser-scanner containing a camera as well as a laser source....... It is highly desirable to extract groove features closer to the arc and thus facilitate for a nearly-closed-loop control situation. On the other hand, for performing seam tracking and nearly-closed-loop control it is not necessary to obtain very detailed information about the molten pool area as long as some...

  2. Visual Tracking System for Welding Seams

    Institute of Scientific and Technical Information of China (English)

    Zeng-shun ZHAO; Ji-zhen WANG; Xue-Zhen CHENG

    2010-01-01

    To track the narrow butt welding seams in container manufacture, a visual tracking system based on smart camera is proposed in this paper. A smart camera is used as the sensor to detect the welding seam. The feature extraction algorithm is designed with the consideration of the characteristics of the smart camera, which is used to compute the error between the welding torch and the welding seam. Visual control system based on image is presented, which employs a programmable controller to control a stepper motor to eliminate the tracking error detected by the smart camera. Experiments are conducted to demonstrate the effectiveness of the vision system.

  3. Seam Tracking Technology for Hyperbaric Underwater Welding

    Institute of Scientific and Technical Information of China (English)

    JIAO Xiangdong; YANG Yongyong; ZHOU Canfeng

    2009-01-01

    Automatic weld seam tracking technology to be used in hyperbaric underwater damaged pipeline repair welding is much more important, because of poor bevel preparation and severe working condition. A weld seam tracking system based on digital signal processing(DSP) passive light weld image processing technology has been established. A convenient charge coupled device(CCD) camera system was used in the high pressure environment with the help of an aperture and focus altering mechanism to guarantee overall image visibility in the scope of pressure below 0.7 MPa. The system can be used in the hyperbaric environment to pick up the real welding image of both the welding arc and the welding pool. The newly developed DSP technology was adopted to achieve the goal of system real time characteristics. An effective weld groove edge recognition technique including narrow interesting window opening, middle value wave filtering, Sobel operator weld edge detecting and edge searching in a defined narrow area was proposed to remove the guide error and system accuracy was ensured. The results of tracking simulation and real tracking application with arc striking have proved the validity and the accuracy of the mentioned system and the image processing method.

  4. Seam tracking with texture based image processing for laser materials processing

    Science.gov (United States)

    Krämer, S.; Fiedler, W.; Drenker, A.; Abels, P.

    2014-02-01

    This presentation deals with a camera based seam tracking system for laser materials processing. The digital high speed camera records interaction point and illuminated work piece surface. The camera system is coaxially integrated into the laser beam path. The aim is to observe interaction point and joint gap in one image for a closed loop control of the welding process. Especially for the joint gap observation a new image processing method is used. Basic idea is to detect a difference between the textures of the surface of the two work pieces to be welded together instead of looking for a nearly invisible narrow line imaged by the joint gap. The texture based analysis of the work piece surface is more robust and less affected by varying illumination conditions than conventional grey scale image processing. This technique of image processing gives in some cases the opportunity for real zero gap seam tracking. In a condensed view economic benefits are simultaneous laser and seam tracking for self-calibrating laser welding applications without special seam pre preparation for seam tracking.

  5. Real-time seam tracking for rocket thrust chamber manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, D.J.; Novak, J.L. [Sandia National Labs., Albuquerque, NM (United States); Starr, G.P. [New Mexico Univ., Albuquerque, NM (United States); Maslakowski, J.E. [Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.

    1993-11-01

    A sensor-based control approach for real-time seam tracking of rocket thrust chamber assemblies has been developed to enable automation of a braze paste dispensing process. This approach utilizes a non-contact Multi-Axis Seam Tracking (MAST) sensor to track the seams. Thee MAST sensor measures capacitance variations between the sensor and the workpiece and produces four varying voltages which are read directly into the robot controller. A PID control algorithm which runs at the application program level has been designed based upon a simple dynamic model of the combined robot and sensor plant. The control algorithm acts on the incoming sensor signals in real-time to guide the robot motion along the seam path. Experiments demonstrate that seams can be tracked at 100 mm/sec within the accuracy required for braze paste dispensing.

  6. Empirical Study on Designing of Gaze Tracking Camera Based on the Information of User's Head Movement.

    Science.gov (United States)

    Pan, Weiyuan; Jung, Dongwook; Yoon, Hyo Sik; Lee, Dong Eun; Naqvi, Rizwan Ali; Lee, Kwan Woo; Park, Kang Ryoung

    2016-08-31

    Gaze tracking is the technology that identifies a region in space that a user is looking at. Most previous non-wearable gaze tracking systems use a near-infrared (NIR) light camera with an NIR illuminator. Based on the kind of camera lens used, the viewing angle and depth-of-field (DOF) of a gaze tracking camera can be different, which affects the performance of the gaze tracking system. Nevertheless, to our best knowledge, most previous researches implemented gaze tracking cameras without ground truth information for determining the optimal viewing angle and DOF of the camera lens. Eye-tracker manufacturers might also use ground truth information, but they do not provide this in public. Therefore, researchers and developers of gaze tracking systems cannot refer to such information for implementing gaze tracking system. We address this problem providing an empirical study in which we design an optimal gaze tracking camera based on experimental measurements of the amount and velocity of user's head movements. Based on our results and analyses, researchers and developers might be able to more easily implement an optimal gaze tracking system. Experimental results show that our gaze tracking system shows high performance in terms of accuracy, user convenience and interest.

  7. An adaptive sliding mode control technology for weld seam tracking

    Science.gov (United States)

    Liu, Jie; Hu, Youmin; Wu, Bo; Zhou, Kaibo; Ge, Mingfeng

    2015-03-01

    A novel adaptive sliding mode control algorithm is derived to deal with seam tracking control problem of welding robotic manipulator, during the process of large-scale structure component welding. The proposed algorithm does not require the precise dynamic model, and is more practical. Its robustness is verified by the Lyapunov stability theory. The analytical results show that the proposed algorithm enables better high-precision tracking performance with chattering-free than traditional sliding mode control algorithm under various disturbances.

  8. Single camera-based object detection and tracking for mobile robots

    Science.gov (United States)

    Anderson, J. Keith; Iftekharuddin, Khan M.; Threlkeld, Elizabeth; Montgomery, Brad

    2008-09-01

    In order for a mobile robot to successfully navigate its environment, it must have knowledge about the objects in its immediate vicinity. The robot can use this information for localization, navigation and object avoidance. Among many sensors available for object detection we are primarily interested in camera-based vision for indoor robot navigation. In this work, we focus on using a single camera to detect objects in the field of view of the robot for the purpose of obstacle avoidance. In order to obtain an integrated robot obstacle avoidance and navigation technique, we investigate a modular approach. In the first module, we extend an appearance based object detection (ABOD) technique to automatically identify individual objects. We then extract strong corner features, overlaying them over the identified objects. This allows us to select a few representative corners for each object. In the second module, we attempt to group these strong corner features using a planar homography technique to define more natural features such as 'planes' for further processing. As an added feature, we utilize the strong corner features generated from module 1, the corresponding features in the next frame from module 2 and a basic optical flow technique for tracking these identified objects. In the third and final module, we obtain distance and heading information for each of obstacles as the robot avoids and navigates in an indoor environment. We show both simulation and actual results on a mobile robot for each of these three modules. We hope to integrate these three modules to obtain a single camera-based integrated robot obstacle avoidance and navigation technique in future.

  9. Development of seam tracking system with ultrasonic sensor using self-tuning fuzzy control

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    One kind of the SAW seam tracking system with contactless ultrasonic sensor is presented in this paper. The new contactless ultrasonic sensor for seam tracking and the working principle of the seam tracking with the sensor are introduced. Based on the experiments, the optimal values of the fuzzy control parameters α and k3 are defined by means of the off-line adjusting method. Because the self-tuning fuzzy control is adopted in the seam tracking system, the overshoot of the system is restrained, the steady-state error is reduced, and the system’s response speed is improved effectively. The results of the SAW seam tracking experiments show that this system’s tracking accuracy is up to ±0.5mm and the system can satisfy the requirements of the engineering application.

  10. Computer automation on an electron-beam welder with automatic, stored seam tracking

    Energy Technology Data Exchange (ETDEWEB)

    Burkhardt, J.H. Jr.; Bowers, G.L.; Davenport, C.M.; Turner, P.C.; Greene, L.M.

    1978-05-10

    A Hamilton Standard 7.5-kW electron-beam welder has been extensively rebuilt, upgraded, and computer automated to provide accurate, repeatable, multipass, wirefed welds with stored seam tracking. Tests have shown that the seam-tracking system can keep the beam on a true line within approximately +-0.05 millimeter, even in the presence of a strongly deflecting magnet.

  11. Real-time seam tracking for robotic laser welding using trajectory-based control

    NARCIS (Netherlands)

    Graaf, de Menno; Aarts, Ronald; Jonker, Ben; Meijer, Johan

    2010-01-01

    In this paper a real-time seam tracking algorithm is proposed that can cope with the accuracy demands of robotic laser welding. A trajectory-based control architecture is presented, which had to be developed for this seam tracking algorithm. Cartesian locations (position and orientation) are added t

  12. Vision-based weld seam tracking in gas metal arc welding

    Institute of Scientific and Technical Information of China (English)

    GAO Jinqiang; WU Chuansong; LIU Xizhang; XIA Dianxiu

    2007-01-01

    A low-cost visual sensmg system is developed to realize weld seam tracking in gas metal arc welding(GMAW).The system consists of a commercial CCD camera,narrow-band composite filter lens,an image capturing card,an industrial computer,a welding control unit,a GMAW power source,and a worktable.Images of root gap and its vicinity are captured in the GMAW welding process by the system.The captured images arc processed by an algorithm on the basis of the analysis of gray characteristics of the root gap to get the offsetting information between torch and root gap centerline.The offsetting information is then used to realize weld seam tracking in the GMAW process.Welding seam tracking experiment is conducted by a simple proportional(P)controller.The results show that tracking error is basically less than ±0.5 mm.

  13. A machine vision approach to seam tracking in real-time in PAW of large-diameter stainless steel tube

    Institute of Scientific and Technical Information of China (English)

    葛景国; 朱政强; 何德孚; 陈立功

    2004-01-01

    Manual monitoring and seam tracking through watching weld pool images in real-time, by naked eyes or by industrial TV, are experience-depended, subjective, labor intensive, and sometimes biased. So it is necessary to realize the automation of computer-aided seam tracking. A PAW (plasma arc welding) seam tracking system was developed, which senses the molten pool and the seam in one frame by a vision sensor, and then detects the seam deviation to adjust the work piece motion adaptively to the seam position sensed by vision sensor. A novel molten pool area image-processing algorithm based on machine vision was proposed. The algorithm processes each image at the speed of 20 frames/second in real-time to extract three feature variables to get the seam deviation. It is proved experimentally that the algorithm is very fast and effective. Issues related to the algorithm are also discussed.

  14. Camera-based stereo laser-tracking system for robot-positioning applications

    Science.gov (United States)

    Allen, Charles R.; Mistry, Nilesh

    1993-08-01

    This paper describes the theory behind laser tracking measurement systems (LTMS) and the development of a prototype LTMS system at Newcastle. An assessment is made of the accuracy of positioning achieved by the system in the control of the end-effector position of a Puma 560 robot manipulator using a CCD camera positioning sensor and a hollow cube retro- reflector placed on the robot wrist.

  15. Development a Vision Based Seam Tracking System for None Destructive Testing Machines

    Directory of Open Access Journals (Sweden)

    Nasser moradi

    2013-04-01

    Full Text Available The automatic weld seam tracking is an important challenge in None Destructive Testing (NDT systems for welded pipe inspection. In this Study, a machine vision based seam tracker, is developed and implemented, instead of old electro-mechanical system. A novel algorithm based on the weld image centered is presented, to reduce Environment conditions and improve the seam tracking accuracy. The weld seam images are taken by a camera arranged ahead of the machine and the centered is extracted as a parameter to detect the weld position, and offset between this point and central axis is computed and used as control parameter of servomotors. Adaptive multi step segmentation t technique is employed to increase the probable of real edge of the welds and improve the line fitting accuracy. This new approach offers some important technical advantages over the existing solutions to weld seam detection: Its based on natural light and does not need any auxiliary light. The adaptive threshold segmentation technique applied, decrease Environmental lighting condition. Its accurate and stable in real time NDT testing machines. After a series of experiments in real industrial environment, it is demonstrated that accuracy of this method can improve the quality of NDT machines. The average tracking error is 1.5 pixels approximately 0.25mm..

  16. Developing selective mining capability for longwall shearers using thermal infrared-based seam tracking

    Institute of Scientific and Technical Information of China (English)

    Jonathon C. Ralston; Andrew D.Strange

    2013-01-01

    Longwall mining continues to remain the most efficient method for underground coal recovery.A key aspect in achieving safe and productive longwall mining is to ensure that the shearer is always correctly positioned within the coal seam.At present,this machine positioning task is the role of longwall personnel who must simultaneously monitor the longwall coal face and the shearer's cutting drum position to infer the geological trends of the coal seam.This is a labour intensive task which has negative impacts on the consistency and quality of coal production.As a solution to this problem,this paper presents a sensing method to automatically track geological coal seam features on the longwall face,known as marker bands,using thermal infrared imaging.These non-visible marker bands are geological features that link strongly to the horizontal trends present in layered coal seams.Tracking these line-like features allows the generation of a vertical datum that can be used to maintain the shearer in a position for optimal coal extraction.Details on the theory of thermal infrared imaging are given,as well as practical aspects associated with machine-based implementation underground.The feature detection and tracking tasks are given with real measurements to demonstrate the efficacy of the approach.The outcome is important as it represents a new selective mining capability to help address a long-standing limitation in longwall mining operations.

  17. Study of image processing for V-shape groove and robotic weld seam tracking based on laser vision

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Single-stripe laser was applied to acquire V-shape groove contour information. Most of arc light and splash noise was removed and stripe laser image was kept by wavelet transform. Half-threshold algorithm was used for image segmentation and stripe laser image was gotten after refining. Weld seam center position was identified and extracted by extreme curvature corner detection method. The location of torch was detected to accord the frequency of computer program with robot program and serial communication program. The tracking experiments of sidelong, reflex and curve weld line show that the system can meet the demand of the tracking precision under normal welding conditions.

  18. Adaptive welding of fillet welds using a fast seam-tracking sensor in combination with a standard industrial robot

    Science.gov (United States)

    Pischetsrieder, Alexandra

    1996-08-01

    In laser welding, problems often arise from the accuracy required by the laser process, particularly where joints have narrow tolerance limits, e.g. with a fillet weld at an overlap joint. In a number of applications seam-tracking sensors can improve this situation. They are able to detect and follow the joint geometry autonomously. In addition to the tolerances, a varying gap between the parts to weld can cause welding flaws. To solve the problems caused by the height of the gap a functionality for adaptive welding can be integrated into the tracking sensor, rendering possible a determined influence on process parameters. Functional dependencies between the height of the gap and the welding parameters are presented in this paper. To further enhance the accuracy of path tracking the dynamic behavior of the system is investigated. With the integration of these dependencies into the tracking sensor, an algorithm for adaptive welding has been obtained, which takes another step towards the raise of profitability of laser installations by a simplified weld seam preparation and an enhanced stability of the welding process.

  19. Stereoscopic Video Weld-Seam Tracker

    Science.gov (United States)

    Kennedy, Larry Z.

    1991-01-01

    Stereoscopic video camera and laser illuminator operates in conjunction with image-data-processing computer to locate weld seam and to map surface features in vicinity of seam. Intended to track seams to guide placement of welding torch in automatic welding system and to yield information on qualities of welds. More sensitive than prior optical seam trackers and suitable for use in production environment. Tracks nearly invisible gap between butted machined edges of two plates.

  20. 焊缝跟踪FUZZY—P控制规则的研究%STUDY ON THE FUZZY—P CONTROLRULES IN THE SEAM TRACKING

    Institute of Scientific and Technical Information of China (English)

    胡绳荪; 孟英谦; 单平

    2000-01-01

    A seam tracking system with contactless ultrasonic sensor is introduced. Fuzzy P control theory is used in the seam tracking system. That is: the P control(pro portional control) is adopted when the error of the seam position is great, and the self-tuning fuzzy control is adopted when the error of the seam position is small. Firstly, the threshold value of the FuzzyP control and the control rule s of the proportional control are studied. Then,the principle of the self-tuning fuzzy control is presented. The two factors self-tuning fuzzy control method is put on the seam tracking. And the fuzzy control rules are generated by checking the table. Based on the experiments, the values of factors are determined. Mean while, it is analyzed which the system's dynamic characteristics are influenced by the scale factor. The scale factor value in the system is determined by the e xperiments. The experimental results show that the system has highly response sp eed, precision and stability and the system can satisfy the requirements of the engineering application.%介绍了一种非接触超声传感焊缝跟踪系统。该焊缝跟踪系统采用 了Fuzzy—P控制理论,即在大偏差时采用比例控制,在小偏差时采用自调整模糊控制。研究 了Fuzzy—P控制的阈值和比例控制的规则。介绍了自调整模糊控制的原理,提出了焊缝跟踪 中的双因数自调整模糊控制方法。在试验的基础上确定了双因数的数值。应用公式法生成了 模糊控制规则表。同时分析了自调整模糊控制中的比例系数对系统动态特性的影响。通过试 验确定了该系统中的比例系数的数值。试验证明,该跟踪系统具有快速、准确、稳定的特点 ,完全能够满足实际工程应用的需要。

  1. CAMERA-BASED SOFTWARE IN REHABILITATION/THERAPY INTERVENTION

    DEFF Research Database (Denmark)

    Brooks, Anthony Lewis

    2014-01-01

    Use of an affordable, easily adaptable, ‘non-specific camera-based software’ that is rarely used in the field of rehabilitation is reported in a study with 91 participants over the duration of six workshop sessions. ‘Non-specific camera-based software’ refers to software that is not dependent...... on specific hardware. Adaptable means that human tracking and created artefact interaction in the camera field of view is relatively easily changed as one desires via a user-friendly GUI. The significance of having both available for contemporary intervention is argued. Conclusions are that the mature, robust...

  2. Study on welded seam recognition using circular laser vision sensor

    Institute of Scientific and Technical Information of China (English)

    Peiquan Xu; Xinhua Tang; Ri Na; Shun Yao

    2007-01-01

    A novel visual robotic arc welding system based on circular laser vision sensor is developed. After image de-noising, image segmentation, and image thinning, the relation of depth value of workpiece and off-axis angle γ, three-dimensional (3D) calculation, and seam tracking experiments are carried out. Finally, the error for seam tracking system is analyzed. The results show that 1) 3D information can be obtained using the proposed visual robotic arc welding system and the real-time seam tracking is realized; 2) the seam tracking error is small enough for gas tungsten arc welding (GTAW) process, and this system can be used for seam location and seam tracking or seam finder.

  3. A Robust Camera-Based Interface for Mobile Entertainment.

    Science.gov (United States)

    Roig-Maimó, Maria Francesca; Manresa-Yee, Cristina; Varona, Javier

    2016-02-19

    Camera-based interfaces in mobile devices are starting to be used in games and apps, but few works have evaluated them in terms of usability or user perception. Due to the changing nature of mobile contexts, this evaluation requires extensive studies to consider the full spectrum of potential users and contexts. However, previous works usually evaluate these interfaces in controlled environments such as laboratory conditions, therefore, the findings cannot be generalized to real users and real contexts. In this work, we present a robust camera-based interface for mobile entertainment. The interface detects and tracks the user's head by processing the frames provided by the mobile device's front camera, and its position is then used to interact with the mobile apps. First, we evaluate the interface as a pointing device to study its accuracy, and different factors to configure such as the gain or the device's orientation, as well as the optimal target size for the interface. Second, we present an in the wild study to evaluate the usage and the user's perception when playing a game controlled by head motion. Finally, the game is published in an application store to make it available to a large number of potential users and contexts and we register usage data. Results show the feasibility of using this robust camera-based interface for mobile entertainment in different contexts and by different people.

  4. The integrated intelligent system for welding seam error and penetration depth identification

    Institute of Scientific and Technical Information of China (English)

    张华; 胡静; 彭绍彬; 邹春华

    2003-01-01

    A integrated intelligent system for seam tracking and penetration control is given. The system received information of welding seam error and penetration depth from only one sensor, then, it realized seam tracking and penetration control simultaneously. This paper introduces constitution of the system, methods of information recognition, design of the neural-fuzzy controller and results practically.

  5. 基于LabVIEW的窄间隙GTAW焊缝跟踪研究%Research on Seam Tracking System of NG-GTAW by LabVIEW

    Institute of Scientific and Technical Information of China (English)

    颜厚银; 唐新华

    2012-01-01

    A seam tracking system of NG-GTAW was designed based on Lab VIEW, and its model was "multi-function card plus PC". It could achieve data collection and processing, PWM pulse output and Fuzzy-PID control. To solve the problem that the check point was ahead of tungsten electrode, the system could operate arrays by storage and deleting quickly. The producer/consumer data pattern was designed to achieve collection and control output synchronization. The results show that procedures have friendly interface, high reliability and good extensibility. It provides a good experimental platform for the succeeding research on narrow gap GTAW welding.%设计了基于LabVIEW的窄间隙GTAW焊缝跟踪系统,系统采用“数据采集卡+PC机”模式,包括数据采集、数据处理、模糊PID控制和PWM输出等功能.通过数组的数据动态存储,有效解决了检测点超前的问题,采用生产者/消费者的用户界面时间处理器设计模式,实现了采集和同步控制输出的实时控制.结果表明,系统的跟踪精度达到了使用要求,为窄间隙GTAW焊的深入研究提供了良好的实验平台.

  6. Detection of seam tracking offset based on infrared image during high-power fiber laser welding%大功率光纤激光焊焊缝跟踪偏差红外检测方法

    Institute of Scientific and Technical Information of China (English)

    高向东; 莫玲; 仲训杲; 游德勇; Katayama Seiji

    2011-01-01

    精确控制激光束使其始终对准并跟踪焊缝是保证激光焊接质量的前提.针对大功率(激光功率10kW)光纤激光焊接304型不锈钢紧密对接焊缝(间隙为0—0.1mm),研究一种基于红外热像的焊缝跟踪偏差检测新方法.采用红外传感高速摄像机摄取焊接区域熔池红外动态热像,分析激光束对准和偏离焊缝中心时的熔池温度分布和红外辐射特性,以熔池匙孔形变参数和热堆积效应参数作为激光束与焊缝中心偏差检测特征值,通过图像识别技术研究和分析特征值与焊缝偏差之间的关系.激光焊接试验结果表明,熔池匙孔形变参数和热堆积效应参数与焊缝偏差之间存在%Seam tracking is a significant precondition to obtain good welding quality.During the laser welding,the laser beam focus must be controlled to follow the welding seam accurately.A novel approach to detecting the offset between the laser beam focus and the welding seam based on infrared image processing is investigated during high-power fiber laser butt-joint welding of type 304 austenitic stainless steel plates at a continuous wave fiber laser power of 10 kW.The joint gap width is less than 0.1 mm.An infrared sensitive high speed camera arranged in off-axis direction of laser beam is used to capture the dynamic thermal images of a molten pool.The characteristics of thermal distribution and infrared radiation of the molten pool,when the laser beam focus is deviated from the welding seam center,are analyzed.Two parameters called the keyhole morphological parameter and the heat accumulation effect parameter are defined as the characteristic values of seam tracking offset to determine the offset between the laser beam focus and the desired welding seam.Also,the image processing technique is used to analyze the infrared images of the molten pool,which indicates the presence of mathematic correlation between the defined two parameters and the seam tracking

  7. NIR-camera-based online diagnostics of laser beam welding processes

    Science.gov (United States)

    Dorsch, Friedhelm; Braun, Holger; Keßler, Steffen; Pfitzner, Dieter; Rominger, Volker

    2012-03-01

    We have developed an on-axis camera-based online sensor system for laser beam welding diagnostics that detects the thermal radiation in the near-infrared (NIR) spectral range between 1200 and 1700 nm. In addition to a sensor in the visible (VIS) range, our camera detects the thermal radiation of the weld pool more clearly, and it is also sensible to the radiation of the solidified weld seam. The NIR images are analyzed by real-time image processing. Features are extracted from the images and evaluated to characterize the welding process. Keyhole and weld pool analysis complement VIS diagnostics, whereas the observation of the weld seam and heat affected zone with an NIR camera allows online heat flux thermography. By this means we are able to detect bad joints in overlap weldings ("false friends") online during the welding process.

  8. A cooperative control algorithm for camera based observational systems.

    Energy Technology Data Exchange (ETDEWEB)

    Young, Joseph G.

    2012-01-01

    Over the last several years, there has been considerable growth in camera based observation systems for a variety of safety, scientific, and recreational applications. In order to improve the effectiveness of these systems, we frequently desire the ability to increase the number of observed objects, but solving this problem is not as simple as adding more cameras. Quite often, there are economic or physical restrictions that prevent us from adding additional cameras to the system. As a result, we require methods that coordinate the tracking of objects between multiple cameras in an optimal way. In order to accomplish this goal, we present a new cooperative control algorithm for a camera based observational system. Specifically, we present a receding horizon control where we model the underlying optimal control problem as a mixed integer linear program. The benefit of this design is that we can coordinate the actions between each camera while simultaneously respecting its kinematics. In addition, we further improve the quality of our solution by coupling our algorithm with a Kalman filter. Through this integration, we not only add a predictive component to our control, but we use the uncertainty estimates provided by the filter to encourage the system to periodically observe any outliers in the observed area. This combined approach allows us to intelligently observe the entire region of interest in an effective and thorough manner.

  9. Vasomotor assessment by camera-based photoplethysmography

    Directory of Open Access Journals (Sweden)

    Trumpp Alexander

    2016-09-01

    Full Text Available Camera-based photoplethysmography (cbPPG is a novel technique that allows the contactless acquisition of cardio-respiratory signals. Previous works on cbPPG most often focused on heart rate extraction. This contribution is directed at the assessment of vasomotor activity by means of cameras. In an experimental study, we show that vasodilation and vasoconstriction both lead to significant changes in cbPPG signals. Our findings underline the potential of cbPPG to monitor vasomotor functions in real-life applications.

  10. 弧焊机器人焊缝跟踪神经网络控制器%Application of Neural Network Controller in the Seam Tracking of Arc-Welding Robot

    Institute of Scientific and Technical Information of China (English)

    高向东; 黄石生; 毛利彰; 山本元司

    1999-01-01

    介绍一种能提高弧焊机器人焊缝跟踪精度的神经网络控制器.通过神经网络的补偿作用,弥补了由于无法知道机器人精确模型所造成的控制上的误差.不同于机器人控制中传统的神经网络控制器,本文提出并应用了基于笛卡尔空间轨迹控制的机器人焊缝跟踪神经网络,大大简化了控制算法.计算机模拟及实验结果表明,该控制器非常适用于机器人的实际焊接,对于现有的机器人,无须改变其控制器内部结构,即可应用该技术.与常用的机器人关节力矩控制法相比,有效地提高了跟踪精度并具有较强的鲁棒性.%A neural network(NN) controller which improves the accuracy of seam tracking of an arc-welding robot is presented in this paper. The improvement of tracking accuracy can be achieved by applying the NN controller for compensating for model uncertainties of robot manipulator. Unlike the traditional NN compensation of model uncertainties which was carried through by modifying the joint/force of the robot, the proposed NN compensation is used to modify the reference Cartesian seam trajectory, which is easily applied in practice. The required internal signal level of proposed NN for the seam modification is much smaller. Simulations and experiments have been performed on an actual arc-welding robot manipulator to test the effectiveness of NN control scheme. It has been found that NN can generate better tracking performance than the traditional computed torque(CT) control method which is based on the manipulator dynamics only. One goal of this paper is to stimulate further discussion of application of NN in the arc-welding robot control.

  11. Seam 2 Web Development LITE

    CERN Document Server

    Salter, David

    2011-01-01

    Packed with illustrations and examples, this book will make the task of improving your Seam application simple and straightforward. This book is for Java EE application developers who have a Seam web application set up and ready to go, and are looking for information on the key areas of Seam that this book covers. You will need a basic understanding of Java EE and also to be aware of EJB3, although you do not need to know it in any detail. Experience with JBoss AS would be great, but all you really need is to be comfortable using any application server. Knowledge of AJAX and JavaScript would a

  12. Multi-seam carving via seamlets

    Science.gov (United States)

    Conger, David D.; Kumar, Mrityunjay; Radha, Hayder

    2011-03-01

    Seam carving is a powerful retargeting algorithm for mapping images to arbitrary sizes with arbitrary aspect ratios. Meanwhile, the seamlet transform has been introduced as an efficient image representation for seam-carving-based retargeting over heterogeneous multimedia devices with a broad range of display sizes. The original seamlet transform was developed using Haar filters, and hence it enabled traditional single-seam carving by removing a single seam at a time in a recursive manner until the desired image size was reached. In this paper, we develop a more efficient approach for seam carving by enabling multi-seam carving, where at each step of the retargeting algorithm, multiple seams are carved simultaneously. We achieve multi-seam carving by (a) extending the seamlet transform to allow for larger filters, and (b) employing local circular convolution in the vicinity of the selected seams. We show that by extending the seamlet transform we can employ popular filterbanks such as Daubechies' wavelets to achieve efficient multi-seam carving with visual quality that is comparable to single-seam carving using the Haar transform. Furthermore, with multi-seam carving, the number of iterations needed to achieve a given target size can be reduced significantly.

  13. Process for the extraction of thick coal seams

    Energy Technology Data Exchange (ETDEWEB)

    Barsi, K.; Salamon, H.; Solymos, A.; Takacs, J.; Toth, I.

    1983-08-23

    There is disclosed a process for the extraction of thick coal seams by means of which coal seams not extractable in one bank or slice and/or located at peripheral areas may also be extracted under improved mine safety conditions and with high productivity. According to the invention the thick coal seam is if required, divided horizontally and/or vertically into extraction blocks which are bounded and separated by stowing pillars arranged according to the direction of advance of the extraction. The cavity of the pillars is advanced at a level higher than the level of the roof of the extraction space, after which the cavity of the pillar is back-filled. Then the block is extracted by means of block caving in a manner known per se. In a preferred embodiment of the invention incombustible material that agglomerates under the effect of the static pressure of the rock is used for stowing. The utilization of the process for extraction according to the invention results in a considerable increase of intensity. Whether the extraction is in one or more slices and whether using individual self-advancing supports, using track-bound or independent loading/conveyor equipment, an economic extraction of coal seams is achieved.

  14. Spectral Camera based on Ghost Imaging via Sparsity Constraints

    Science.gov (United States)

    Liu, Zhentao; Tan, Shiyu; Wu, Jianrong; Li, Enrong; Shen, Xia; Han, Shensheng

    2016-05-01

    The image information acquisition ability of a conventional camera is usually much lower than the Shannon Limit since it does not make use of the correlation between pixels of image data. Applying a random phase modulator to code the spectral images and combining with compressive sensing (CS) theory, a spectral camera based on true thermal light ghost imaging via sparsity constraints (GISC spectral camera) is proposed and demonstrated experimentally. GISC spectral camera can acquire the information at a rate significantly below the Nyquist rate, and the resolution of the cells in the three-dimensional (3D) spectral images data-cube can be achieved with a two-dimensional (2D) detector in a single exposure. For the first time, GISC spectral camera opens the way of approaching the Shannon Limit determined by Information Theory in optical imaging instruments.

  15. Spectral Camera based on Ghost Imaging via Sparsity Constraints.

    Science.gov (United States)

    Liu, Zhentao; Tan, Shiyu; Wu, Jianrong; Li, Enrong; Shen, Xia; Han, Shensheng

    2016-05-16

    The image information acquisition ability of a conventional camera is usually much lower than the Shannon Limit since it does not make use of the correlation between pixels of image data. Applying a random phase modulator to code the spectral images and combining with compressive sensing (CS) theory, a spectral camera based on true thermal light ghost imaging via sparsity constraints (GISC spectral camera) is proposed and demonstrated experimentally. GISC spectral camera can acquire the information at a rate significantly below the Nyquist rate, and the resolution of the cells in the three-dimensional (3D) spectral images data-cube can be achieved with a two-dimensional (2D) detector in a single exposure. For the first time, GISC spectral camera opens the way of approaching the Shannon Limit determined by Information Theory in optical imaging instruments.

  16. Spectral Camera based on Ghost Imaging via Sparsity Constraints

    CERN Document Server

    Liu, Zhentao; Wu, Jianrong; Li, Enrong; Shen, Xia; Han, Shensheng

    2015-01-01

    The information acquisition ability of conventional camera is far lower than the Shannon Limit because of the correlation between pixels of image data. Applying sparse representation of images to reduce the abundance of image data and combined with compressive sensing theory, the spectral camera based on ghost imaging via sparsity constraints (GISC spectral camera) is proposed and demonstrated experimentally. GISC spectral camera can acquire the information at a rate significantly below Nyquist, and the resolution of the cells in the three-dimensional (3D) spectral image data-cube can be achieved with a two-dimensional (2D) detector in a single exposure. For the first time, GISC spectral camera opens the way of approaching the Shannon Limit determined by Information Theory in optical imaging instruments.

  17. Discussion of the indexes of nonoutburst coal seam upgrade and its corresponding critical values

    Institute of Scientific and Technical Information of China (English)

    WEI dian-ping; LIU Yan-wei; LIU Ming-ju; MENG Lei

    2009-01-01

    In view of the measurement difficulties of indexes recommended by the 50 Items Experience of Coal Mine Gas Prevention in the process of the nonoutburst coal seam upgrade, this paper took the No.8 coal seam of Huainan Mining Group as research object. Discussed the suitability of indexes and corresponding critical values, put forward method in determining the indexes and its critical values by analysis and investigation of the gas geological condition and the-spot tracking near position where an outburst occurred combined with laboratory experiment, and established the indexes and its critical values of nonoutburst coal seam upgrade in No.8 coal seam of Huainan Mining Group. The results show that it is suitable to take gas content and tectonic soft coal thickness easily to gain in routine production as primary upgrade indexes that its critical values are 7.5 m3/t and 0.8 m, respectively. In addition, takefvalue and Ap value as auxiliary indexes.

  18. Goal-oriented rectification of camera-based document images.

    Science.gov (United States)

    Stamatopoulos, Nikolaos; Gatos, Basilis; Pratikakis, Ioannis; Perantonis, Stavros J

    2011-04-01

    Document digitization with either flatbed scanners or camera-based systems results in document images which often suffer from warping and perspective distortions that deteriorate the performance of current OCR approaches. In this paper, we present a goal-oriented rectification methodology to compensate for undesirable document image distortions aiming to improve the OCR result. Our approach relies upon a coarse-to-fine strategy. First, a coarse rectification is accomplished with the aid of a computationally low cost transformation which addresses the projection of a curved surface to a 2-D rectangular area. The projection of the curved surface on the plane is guided only by the textual content's appearance in the document image while incorporating a transformation which does not depend on specific model primitives or camera setup parameters. Second, pose normalization is applied on the word level aiming to restore all the local distortions of the document image. Experimental results on various document images with a variety of distortions demonstrate the robustness and effectiveness of the proposed rectification methodology using a consistent evaluation methodology that encounters OCR accuracy and a newly introduced measure using a semi-automatic procedure.

  19. A bionic camera-based polarization navigation sensor.

    Science.gov (United States)

    Wang, Daobin; Liang, Huawei; Zhu, Hui; Zhang, Shuai

    2014-07-21

    Navigation and positioning technology is closely related to our routine life activities, from travel to aerospace. Recently it has been found that Cataglyphis (a kind of desert ant) is able to detect the polarization direction of skylight and navigate according to this information. This paper presents a real-time bionic camera-based polarization navigation sensor. This sensor has two work modes: one is a single-point measurement mode and the other is a multi-point measurement mode. An indoor calibration experiment of the sensor has been done under a beam of standard polarized light. The experiment results show that after noise reduction the accuracy of the sensor can reach up to 0.3256°. It is also compared with GPS and INS (Inertial Navigation System) in the single-point measurement mode through an outdoor experiment. Through time compensation and location compensation, the sensor can be a useful alternative to GPS and INS. In addition, the sensor also can measure the polarization distribution pattern when it works in multi-point measurement mode.

  20. Small prototype gamma camera based on wavelength-shifting fibres

    Science.gov (United States)

    Castro, I. F.; Soares, A. J.; Moutinho, L. M.; Veloso, J. F. C. A.

    2012-01-01

    We are studying and developing a small field of view gamma camera based on wavelength-shifting optical fibres coupled to both sides of an inorganic scintillation crystal and using for the light readout highly sensitive photon detectors, namely silicon photomultipliers (SiPMs) and high efficiency multi-anode photomultiplier tubes (MaPMTs). The coupling of the fibres in orthogonal directions allows obtaining 2D position information, while the energy signal is provided by a PMT. A first prototype laboratory system has been developed using a custom-made 50 × 50 × 3 mm3 CsI(Na) crystal with embedded 1 mm diameter fibres and reading out the light from several fibres in each direction, both with individual SiPMs and with a MaPMT. Proof-of-concept studies and results obtained with these systems using 57Co are presented and compared. The application of optical fibres combined with highly sensitive SiPMs or MaPMTs as light sensors in a compact gamma camera has the potential to improve the spatial resolution to the 1-2 mm FWHM level, thus improving the sensitivity of typical scintigraphy techniques and making such camera clinically useful. Results demonstrate the feasibility and imaging capability of the system using both types of photon detectors for imaging. In the case of SiPMs, a temperature cooling system is necessary to improve the SNR and consequently achieve a better imaging performance. The development of larger prototypes with 10 × 10 cm2 and 12 × 12 cm2 is under way, using 1 mm2 SiPMs and 64 anode PMTs, respectively.

  1. CAMERA-BASED SOFTWARE IN REHABILITATION/THERAPY INTERVENTION (extended)

    DEFF Research Database (Denmark)

    Brooks, Anthony Lewis

    2014-01-01

    on specific hardware. Adaptable means that human tracking and created artefact interaction in the camera field of view is relatively easily changed as one desires via a user-friendly GUI. The significance of having both available for contemporary intervention is argued. Conclusions are that the mature, robust...

  2. Geomorphology of coal seam fires

    Science.gov (United States)

    Kuenzer, Claudia; Stracher, Glenn B.

    2012-02-01

    Coal fires occur in underground natural coal seams, in exposed surface seams, and in coal storage or waste piles. The fires ignite through spontaneous combustion or natural or anthropogenic causes. They are reported from China, India, USA, South Africa, Australia, and Russia, as well as many other countries. Coal fires lead to loss of a valuable resource (coal), the emission of greenhouse-relevant and toxic gases, and vegetation deterioration. A dangerous aspect of the fires is the threat to local mines, industries, and settlements through the volume loss underground. Surface collapse in coal fire areas is common. Thus, coal fires are significantly affecting the evolution of the landscape. Based on more than a decade of experience with in situ mapping of coal fire areas worldwide, a general classification system for coal fires is presented. Furthermore, coal seam fire geomorphology is explained in detail. The major landforms associated with, and induced by, these fires are presented. The landforms include manifestations resulting from bedrock surface fracturing, such as fissures, cracks, funnels, vents, and sponges. Further manifestations resulting from surface bedrock subsidence include sinkholes, trenches, depressions, partial surface subsidence, large surface subsidence, and slides. Additional geomorphologic coal fire manifestations include exposed ash layers, pyrometamorphic rocks, and fumarolic minerals. The origin, evolution, and possible future development of these features are explained, and examples from in situ surveys, as well as from high-resolution satellite data analyses, are presented. The geomorphology of coal fires has not been presented in a systematic manner. Knowledge of coal fire geomorphology enables the detection of underground coal fires based on distinct surface manifestations. Furthermore, it allows judgments about the safety of coal fire-affected terrain. Additionally, geomorphologic features are indicators of the burning stage of fires

  3. Spectrally-Tunable Infrared Camera Based on Highly-Sensitive Quantum Well Infrared Photodetectors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a SPECTRALLY-TUNABLE INFRARED CAMERA based on quantum well infrared photodetector (QWIP) focal plane array (FPA) technology. This will build on...

  4. Handheld Longwave Infrared Camera Based on Highly-Sensitive Quantum Well Infrared Photodetectors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a compact handheld longwave infrared camera based on quantum well infrared photodetector (QWIP) focal plane array (FPA) technology. Based on...

  5. Camera-based platform and sensor motion tracking for data fusion in a landmine detection system

    NARCIS (Netherlands)

    Mark, W. van der; Heuvel, J.C. van den; Breejen, E. den; Groen, F.C.A.

    2003-01-01

    Vehicles that serve in the role as landmine detection robots could be an important tool for demining former conflict areas. On the LOTUS platform for humanitarian demining, different sensors are used to detect a wide range of landmine types. Reliable and accurate detection depends on correctly combi

  6. Weld repair method for aluminum lithium seam

    Science.gov (United States)

    McGee, William Floyd (Inventor); Rybicki, Daniel John (Inventor)

    1998-01-01

    Aluminum-lithium plates are butt-welded by juxtaposing the plates and making a preliminary weld from the rear or root side of the seam. An initial weld is then made from the face side of the seam, which may cause a defect in the root portion. A full-size X-ray is made and overlain over the seam to identify the defects. The defect is removed from the root side, and rewelded. Material is then removed from the face side, and the cavity is rewelded. The procedure repeats, alternating from the root side to the face side, until the weld is sound.

  7. Video-Camera-Based Position-Measuring System

    Science.gov (United States)

    Lane, John; Immer, Christopher; Brink, Jeffrey; Youngquist, Robert

    2005-01-01

    A prototype optoelectronic system measures the three-dimensional relative coordinates of objects of interest or of targets affixed to objects of interest in a workspace. The system includes a charge-coupled-device video camera mounted in a known position and orientation in the workspace, a frame grabber, and a personal computer running image-data-processing software. Relative to conventional optical surveying equipment, this system can be built and operated at much lower cost; however, it is less accurate. It is also much easier to operate than are conventional instrumentation systems. In addition, there is no need to establish a coordinate system through cooperative action by a team of surveyors. The system operates in real time at around 30 frames per second (limited mostly by the frame rate of the camera). It continuously tracks targets as long as they remain in the field of the camera. In this respect, it emulates more expensive, elaborate laser tracking equipment that costs of the order of 100 times as much. Unlike laser tracking equipment, this system does not pose a hazard of laser exposure. Images acquired by the camera are digitized and processed to extract all valid targets in the field of view. The three-dimensional coordinates (x, y, and z) of each target are computed from the pixel coordinates of the targets in the images to accuracy of the order of millimeters over distances of the orders of meters. The system was originally intended specifically for real-time position measurement of payload transfers from payload canisters into the payload bay of the Space Shuttle Orbiters (see Figure 1). The system may be easily adapted to other applications that involve similar coordinate-measuring requirements. Examples of such applications include manufacturing, construction, preliminary approximate land surveying, and aerial surveying. For some applications with rectangular symmetry, it is feasible and desirable to attach a target composed of black and white

  8. Using vector building maps to aid in generating seams for low-attitude aerial orthoimage mosaicking: Advantages in avoiding the crossing of buildings

    Science.gov (United States)

    Wang, Dongliang; Cao, Wei; Xin, Xiaoping; Shao, Quanqin; Brolly, Matthew; Xiao, Jianhua; Wan, Youchuan; Zhang, Yongjun

    2017-03-01

    A novel seam detection approach based on vector building maps is presented for low-attitude aerial orthoimage mosaicking. The approach tracks the centerlines between vector buildings to generate the candidate seams that avoid crossing buildings existing in maps. The candidate seams are then refined by considering their surrounding pixels to minimize the visual transition between the images to be mosaicked. After the refinement of the candidate seams, the final seams further bypass most of the buildings that are not updated into vector maps. Finally, three groups of aerial imagery from different urban densities are employed to test the proposed approach. The experimental results illustrate the advantages of the proposed approach in avoiding the crossing of buildings. The computational efficiency of the proposed approach is also significantly higher than that of Dijkstra's algorithm.

  9. Technology and means of a coal seam interval hydraulic fracturing for the seam degassing intensification

    Science.gov (United States)

    Klishin, VI; Opruk, GY; Tatsienko, AL

    2017-02-01

    Interval hydraulic fracturing use for the seam degassing intensification actuality is explained. The known methods of degassing are reviewed. Technological scheme of the interval coal seam hydraulic fracturing implementation is worked out. The equipment to fulfill degassing intensification measures is suggested.

  10. Research on New Method of Full-Seam Mining for Gently Inclined Thick Coal Seams

    Institute of Scientific and Technical Information of China (English)

    赵景礼; 郭志飙; 柳慧鹏; 赵立军

    2002-01-01

    The recovery ratio of top-coal caving mining plays a key role in the development of this mining method. For the proposes to raise the recovery ratio and considering heading advance and roadway maintenance, a new method of full - seam mining for gently inclined thick coal seams is put forward on the basis of a theoretic research and engineering practice.

  11. Roadway failure and support in a coal seam underlying a previously mined coal seam

    Institute of Scientific and Technical Information of China (English)

    Lu Yinlong; Wang Lianguo; Zhang Bei

    2012-01-01

    The influence of an upper,mined coal seam on the stability of rock surrounding a roadway in a lower coal seam is examined.The technical problems of roadway control are discussed based on the geological conditions existing in the Liyazhuang Mine No.2 coal seam.The stress distribution and floor failure in the lower works after mining the upper coal is studied through numerical simulations.The failure mechanism of the roof and walls of a roadway located in the lower coal seam is described.The predicted deformation and failure of the roadway for different distances between the two coal seams are used to design two ways of supporting the lower structure.One is a combined support consisting of anchors with a joist steel tent and a combined anchor truss.A field test of the design was performed to good effect.The results have significance for the design of supports for roadways located in similar conditions.

  12. Induced polarization signature of coal seam fires

    Science.gov (United States)

    Shao, Zhenlu; Revil, André; Mao, Deqiang; Wang, Deming

    2017-03-01

    Coal seam fires are a worldwide disaster of both ecological and economic importance. Their remote detection from the ground surface or using airborne techniques is required for developing efficient strategies to extinguish them. We investigate here the use of time-domain-induced polarization to localize coal seam fires. For laboratory experiments, we first introduce a modified time-domain-induced polarization methodology to quickly acquire and invert the secondary voltage distribution mapped after the shutdown of the primary current. A set of sandbox experiments is conducted in which coal is embedded into humidified sand. Raw coal alone generates significant induced polarization anomalies, above those shown by the sand. Even higher induced polarization anomalies are detected in presence of a coal seam fire. We postulate that the higher chargeability is due to the pyrolysis, which may enhance electronic polarization or the polarization associated with the cation exchange capacity (CEC) of the material. The position of the coal seam fire is well recovered inside the tank by inverting the secondary voltages in term of a source current density distribution. We also collected field data over a recognized coal seam fire in Colorado, USA. A chargeability anomaly (˜800 mV V-1) and a resistivity anomaly (˜1 Ohm m) are observed at the position of the coal seam fire. We propose a normalized burning front index (a scaled normalized chargeability) to image and localize, without ambiguity, the position of the coal seam fire in the subsurface. The 3-D reconstructed target is located below a negative self-potential anomaly (similarly to what is observed in laboratory experiments) and a temperature anomaly recorded at a depth of 30 cm.

  13. Modelling of Rayleigh-type seam waves in disturbed coal seams and around a coal mine roadway

    Science.gov (United States)

    Essen, Katja; Bohlen, Thomas; Friederich, Wolfgang; Meier, Thomas

    2007-08-01

    Wave propagation in coal seams is numerically modelled in order to identify approaches towards the reconnaissance beyond the heading face of an advancing coal mine roadway. Complete synthetic wavefields including P-SV body waves and Rayleigh-type seam waves are calculated using a Green's function approach for simple, laterally homogeneous models and a parallel elastic 2-D/3-D finite difference modelling code for more realistic geometries. For a simple three-layer model the wavefield within the seam is dominated by a fundamental Rayleigh seam mode symmetrical with respect to the centre of the seam on the vertical component and antisymmetrical on the horizontal component. If the seam contains an interleaved dirt band with higher velocities and density, higher modes dominate the wave propagation, depending on the thickness of the dirt band. Wave propagation in laterally inhomogeneous coal seam models with disturbances like seam ends, faults, thinning, washouts and seam splitting is strongly influenced by the type of disturbance. Amplitudes of seam waves reflected from these disturbances strongly depend on the fault throw and the degree of thinning or washout. In some cases, conversion to higher modes can occur. In all investigated models, those Rayleigh seam wave phases are preferably reflected, which have frequencies above the fundamental mode Airy phase. Lower frequency phases are preferably transmitted. However, seam waves are not reflected from a seam splitting disturbance. Thus a detection of seam splitting with reflected seam waves appears to be impossible. FD computations for 3-D models containing an ending tunnel parallel to the seam and a source beyond the heading face of the tunnel show that seam waves are converted into Rayleigh waves at the tunnel face. They propagate along the surface of the tunnel and interfere with the seam waves propagating beside the tunnel. This effect has to be taken into account for subsequent treatment of experimental data, where

  14. Coal seam clue to Abbeystead disaster

    Energy Technology Data Exchange (ETDEWEB)

    1985-04-01

    The Health and Safety Executive Report on the Abbeystead valve house explosion is critically studied. The body of evidence is examined which suggests that the tunnel could have crossed the line of a coal seam. Coal outcrops, bell pit making suggest that a coal seam following the 99 m contour crosses the tunnel near the Rowton Portal, and hence provided a source of methane. Also the formation of stalactites in the tunnel is discussed. Whether or not these mainly mineral formations can grow under water is a matter of debate. If they cannot then significant voids must have been present.

  15. iCaCoT: Interactive camera-based coaching and training

    NARCIS (Netherlands)

    D'Acunto, L.; Redi, J.A.; Niamut, O.A.

    2015-01-01

    This paper reports on the evaluation of the concept of interactive camera-based coaching and training (iCaCoT), which focuses on using interactive video navigation for coaching and training purposes. The iCaCoT concept leverages tiled streaming technology, which allows users to navigate freely throu

  16. Applied on bolting-cable anchor support of full-seam roadway in weaker thick coal seam

    Institute of Scientific and Technical Information of China (English)

    赵庆彪; 张生华; 郭励生

    2003-01-01

    The designing method and the supporting mechanism of both bolt and small cable anchor for full-seam roadway in the weaker thick coal seam are systematically analyzed, and the construction technology and the supporting results are briefly summarized.

  17. The conceptual design of SeamFrame

    NARCIS (Netherlands)

    Wal, van der T.; Rizolli, A.; Svensson, M.; Villa, F.; Knapen, R.; Athanasiadis, I.

    2005-01-01

    This project deliverable provides the underlying architecture of a concept for linking models and databases and it provides the design of SeamFrame, delivering its architecture to provide an integration framework for models and simulation algorithms, supported by procedures for data handling and spa

  18. Seam tracking for laser welding with an industrial robot

    NARCIS (Netherlands)

    Römer, G.R.B.E.; Amerongen, van J.; Jonker, J.B.; Regtien, P.P.L.

    2001-01-01

    Because of their construction and flexibility, industrial robots are suitable to be used, with a laser source and an optical fiber, for laser welding of 3D products. However, the positioning accuracy of robots are insufficient for laser welding. Also the product and clamping tolerances are too wide

  19. Friction assisted solid state lap seam welding and additive manufacturing method

    Institute of Scientific and Technical Information of China (English)

    Prasad Rao KALVALA; Javed AKRAM; Mano MISRA

    2016-01-01

    This paper describes results of seam welding of relatively high temperature melting materials, AISI 304, C-Mn steels, Ni-based alloys, CP Cu, CP Ni, Ti6Al4V and relatively low temperature melting material, AA6061. It describes the seam welding of multi-layered similar and dissimilar metallic sheets. The method described and involved advancing a rotating non-consumable rod (CP Mo or AISI 304) toward the upper sheet of a metallic stack clamped under pressure. As soon as the distal end of the rod touched the top portion of the upper metallic sheet, an axial force was applied. After an initial dwell time, the metallic stack moved horizontally relative to the stationery non-consumable rod by a desired length, thereby forming a metallurgical bond between the metallic sheets. Multi-track and multi-metal seam welds of high temperature metallic sheets, AISI 304, C-Mn steel, Nickel-based alloys, Cp Cu, Ti6Al4V and low temperature metallic sheets, AA6061 were obtained. Optical and scanning electron microscopy examination and 180 degree U-bend test indicated that defect free seam welds could be obtained with this method. Tensile-shear testing showed that the seam welds of AISI 304, C-Mn steel, Nickel-based alloy were stronger than the starting base metal counterparts while AA6061 was weaker due to softening. The metallurgical bonding at the interface between the metallic sheets was attributed to localized stick and slip at the interface, dynamic recrystallization and diffusion. The method developed can be used as a means of welding, cladding and additive manufacturing.

  20. Camera-based model to predict the total difference between effect coatings under directional illumination

    Institute of Scientific and Technical Information of China (English)

    Zhongning Huang; Haisong Xu; M.Rounier Luo

    2011-01-01

    @@ A camera-based model is established to predict the total difference for samples of metallic panels with effect coatings under directional illumination,and the testing results indicate that the model can precisely predict the total difference between samples with metallic coatings with satisfactory consistency to the visual data.Due to the limited amount of testing samples,the model performance should be further developed by increasing the training and testing samples.%A camera-based model is established to predict the total difference for samples of metallic panels with effect coatings under directional illumination, and the testing results indicate that the model can precisely predict the total difference between samples with metallic coatings with satisfactory consistency to the visual data. Due to the limited amount of testing samples, the model performance should be further developed by increasing the training and testing samples.

  1. Methods and costs of thin-seam mining. Final report, 25 September 1977-24 January 1979. [Thin seam in association with a thick seam

    Energy Technology Data Exchange (ETDEWEB)

    Finch, T.E.; Fidler, E.L.

    1981-02-01

    This report defines the state of the art (circa 1978) in removing thin coal seams associated with vastly thicker seams found in the surface coal mines of the western United States. New techniques are evaluated and an innovative method and machine is proposed. Western states resource recovery regulations are addressed and representative mining operations are examined. Thin seam recovery is investigated through its effect on (1) overburden removal, (2) conventional seam extraction methods, and (3) innovative techniques. Equations and graphs are used to accommodate the variable stratigraphic positions in the mining sequence on which thin seams occur. Industrial concern and agency regulations provided the impetus for this study of total resource recovery. The results are a compendium of thin seam removal methods and costs. The work explains how the mining industry recovers thin coal seams in western surface mines where extremely thick seams naturally hold the most attention. It explains what new developments imply and where to look for new improvements and their probable adaptability.

  2. Nature of electromagnetic radiation of a coal seam

    Energy Technology Data Exchange (ETDEWEB)

    Frid, V.I.; Shabarov, A.N.; Proskuryakov, V.M.; Baranov, V.A. (Rossiiskaya Akademiya Nauk (Russian Federation))

    1992-03-01

    Analyzes feasibility of forecasting rock burst hazards on the basis of electromagnetic radiation of a coal seam. Electromagnetic radiation emitted by coal seams situated at depths from 300 to 750 m in a number of coal mines in the Kuzbass was investigated. The investigations were carried out both in coal seams prone to rock bursts and in those without rock burst hazards. Effects of the following factors on the level of electromagnetic radiation were analyzed: moisture content in coal seams, coal mechanical properties, porosity, state of stress, microcracking of coal seams caused by stress concentration, gas desorption from coal. Analyses show that electromagnetic emission supplied reliable information on rock burst hazards. Use of a frequency of about 100 Hz for measuring electromagnetic radiation is recommended. Rock burst forecasting based on measuring electromagnetic radiation of a coal seam was compared to methods based on measuring the rate of cuttings leaving test boreholes and the velocity of gas emitted from the boreholes. 11 refs.

  3. 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.

  4. Stability of Roadway in Upper Seam of Deep Multiple Rich Gas Coal Seams through Ascending Stress-relief Mining

    OpenAIRE

    2015-01-01

    The first mining of a protective coal seam through ascending stress-relief mining is one of the most effective techniques for eliminating the risk of coal and gas outburst during the exploitation of multiple coal seams containing high rich gas. However, the difficulty of controlling roadway stability in the upper protected coal seam above the goaf increases greatly after ascending mining. Based on the geological conditions in Guqiao Coal Mine in China, a numerical simulation model is establis...

  5. Detection of occult disease in breast cancer using fluorodeoxyglucose camera-based positron emission tomography.

    Science.gov (United States)

    Pecking, A P; Mechelany-Corone, C; Bertrand-Kermorgant, F; Alberini, J L; Floiras, J L; Goupil, A; Pichon, M F

    2001-10-01

    An isolated increase of blood tumor marker CA 15.3 in breast cancer is considered a sensitive indicator for occult metastatic disease but by itself is not sufficient for initiating therapeutic intervention. We investigated the potential of camera-based positron emission tomography (PET) imaging using [18F]-fluorodeoxyglucose (FDG) to detect clinically occult recurrences in 132 female patients (age, 35-69 years) treated for breast cancer, all presenting with an isolated increase in blood tumor marker CA 15.3 without any other evidence of metastatic disease. FDG results were correlated to pathology results or to a sequentially guided conventional imaging method. One hundred nineteen patients were eligible for correlations. Positive FDG scans were obtained for 106 patients, including 89 with a single lesion and 17 with 2 or more lesion. There were 92 true-positive and 14 false-positive cases, 10 of which became true positive within 1 year. Among the 13 negative cases, 7 were false negative and 6 were true negative. Camera-based PET using FDG has successfully identified clinically occult disease with an overall sensitivity of 93.6% and a positive predictive value of 96.2%. The smallest detected size was 6 mm for a lymph node metastasis (tumor to nontumor ratio, 4:2). FDG camera-based PET localized tumors in 85.7% of cases suspected for clinically occult metastatic disease on the basis of a significant increase in blood tumor marker. A positive FDG scan associated with an elevated CA 15.3 level is most consistent with metastatic relapse of breast cancer.

  6. Volumetric Diffuse Optical Tomography for Small Animals Using a CCD-Camera-Based Imaging System

    Directory of Open Access Journals (Sweden)

    Zi-Jing Lin

    2012-01-01

    Full Text Available We report the feasibility of three-dimensional (3D volumetric diffuse optical tomography for small animal imaging by using a CCD-camera-based imaging system with a newly developed depth compensation algorithm (DCA. Our computer simulations and laboratory phantom studies have demonstrated that the combination of a CCD camera and DCA can significantly improve the accuracy in depth localization and lead to reconstruction of 3D volumetric images. This approach may present great interests for noninvasive 3D localization of an anomaly hidden in tissue, such as a tumor or a stroke lesion, for preclinical small animal models.

  7. Note: Tormenta: An open source Python-powered control software for camera based optical microscopy

    Science.gov (United States)

    Barabas, Federico M.; Masullo, Luciano A.; Stefani, Fernando D.

    2016-12-01

    Until recently, PC control and synchronization of scientific instruments was only possible through closed-source expensive frameworks like National Instruments' LabVIEW. Nowadays, efficient cost-free alternatives are available in the context of a continuously growing community of open-source software developers. Here, we report on Tormenta, a modular open-source software for the control of camera-based optical microscopes. Tormenta is built on Python, works on multiple operating systems, and includes some key features for fluorescence nanoscopy based on single molecule localization.

  8. Filter properties of seam material from paved urban soils

    Directory of Open Access Journals (Sweden)

    T. Nehls

    2007-08-01

    Full Text Available We studied pavement seam material. This is the soil substrate in joints of pervious pavements in urban areas. It is mostly 1 cm thick and develops from the original seam filling by depositions of all kinds of urban residues, including anthropogenic organic substances. It was investigated, how this unique form of organic matter influences the filter properties of seam material and how the seam material influences heavy metal transport through the pavement. The seam material is characterised by a darker munsell colour, higher organic carbon content, higher surface areas, higher cation exchange capacities, but a lower fraction of high adsorption energy sites compared to the original seam filling. The deposited anthropogenic organic matter itself could be characterised as particulate and non-polar. Compared to natural soils, it has a small surface area and a low surface charge density resulting in a small cation exchange capacity of only 75 cmol(+ kg−1C. The seam material shows stronger sorption of Pb and Cd compared to the original construction sand. The retardation capacity of seam material towards Pb is similar, towards Cd it is much smaller compared to natural soils. The simulated long term displacement scenarios for a street in Berlin do not indicate an acute contamination risk for Pb. For Cd the infiltration from ponds can lead to a displacement of Cd during only one decade.

  9. 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...

  10. The geomechanics of gas recovery from coal seams

    Science.gov (United States)

    Klimov, D. M.; Karev, V. I.; Kovalenko, Yu. F.

    2015-05-01

    A new approach for the creation of scientific foundations for effective and environmentally safe recovery of methane from coal seams is proposed. A virgin coal seam possesses very low permeability. Free gas is contained in isolated microscopic pores and cracks of the coal seam under a pressure close to the rock pressure. An oriented system of cracks, which forms a coupled system of filtration channels, can be formed by means of directed unloading of the rock pressure from the seam due to expanding gas energy. The parameters of the manufacturing effect on the seam are determined based on physical modeling of actual mechanical and filtration processes using the experimental installation of truly three-axial loading and mathematical modeling.

  11. 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%.

  12. A Camera-Based Target Detection and Positioning UAV System for Search and Rescue (SAR) Purposes.

    Science.gov (United States)

    Sun, Jingxuan; Li, Boyang; Jiang, Yifan; Wen, Chih-Yung

    2016-10-25

    Wilderness search and rescue entails performing a wide-range of work in complex environments and large regions. Given the concerns inherent in large regions due to limited rescue distribution, unmanned aerial vehicle (UAV)-based frameworks are a promising platform for providing aerial imaging. In recent years, technological advances in areas such as micro-technology, sensors and navigation have influenced the various applications of UAVs. In this study, an all-in-one camera-based target detection and positioning system is developed and integrated into a fully autonomous fixed-wing UAV. The system presented in this paper is capable of on-board, real-time target identification, post-target identification and location and aerial image collection for further mapping applications. Its performance is examined using several simulated search and rescue missions, and the test results demonstrate its reliability and efficiency.

  13. Grooving corrosion of seam welded oil pipelines

    Directory of Open Access Journals (Sweden)

    Mohamed Hanafy El-Sayed

    2014-10-01

    Full Text Available 24” pipeline carrying oil was failed in the form of longitudinal crack at the 6 O’clock position resulting in oil spill. The failed pipe was investigated to reveal the main cause of its failure. The procedure of investigation was built on studying the intact pipe, rupture area, parent material, and intact weld. Results of chemical analysis, mechanical properties, and microstructure of the pipe material were confirmed with the specified standard. Cracks were originated from weld defected sites, initiated by grooving corrosion, propagated by inertia at the normal designed pressure condition, and stopped when stress relief is attained. It is recommended to use high quality ERW pipe, with its seam weld line positioned around the 12 O’clock during installation, to minimize and decelerate grooving corrosion. It is also important to perform regular or routine inspection, on suitable intervals, determined by past experience.

  14. Prediction of Coal Seam Methane Enriched Areas Using Seismic Data

    Institute of Scientific and Technical Information of China (English)

    CHEN Tong-jun; CUI Ruo-fei; LIU En-ru; LANG Yu-quan

    2006-01-01

    All coal mine disasters are dynamic geological phenomenon and affected by many factors. However, locating the enriched areas of CSM (coal seam methane) may be the precondition for the successful prediction of such disasters. Traditional methods of investigating CSM enriched areas use limited data and only consider a few important factors. Their success rate is low and cannot meet practical needs. In this paper, an alternative method is proposed. The procedure is given as follows: 1) fracture attributes derived from azimuth variations of P-wave data in coal seams and wall rocks can be extracted; 2) AVO attributes, such as the intercept P and gradient G parameters can be extracted from different azimuths from 3D seismic data; 3) seismic cubes can be inverted and the relative attributes of impedance cubes can be extracted; 4) using a GIS platform, multi-source information can be obtained and analyzed; these include fracture attributes of coal seams and wall rocks, the thickness of coal seams, the distribution of faults and structures, the depth of coal seams, the inclination and exposure of coal seams and the coal rank. Through this processing procedure, methane enriched areas can be systematically detected.

  15. Greenhouse gas emissions from shallow uncovered coal seams

    Institute of Scientific and Technical Information of China (English)

    Saghafi Abouna

    2014-01-01

    This study discusses a method of quantifying emissions from surface coal mining that has been trialled in Australia. The method is based on direct measurement of surface emissions from uncovered coal seams in mine pits, concurrent measurement of residual gas content of blasted coal in mine pits, and measurement of pre-mining gas content of the same seam from cores retrieved from exploration boreholes drilled away from active mining. The results from one of the mines studied are presented in this paper. In this mine, the pre-mining gas content of the target seam was measured using cores from an exploration borehole away from active mining. Gas content varied from 0.7 to 0.8 m3/t and gas composition varied from 16% to 21% CH4 (84-79% CO2). In-pit measurements included seam surface emissions and residual gas content of blasted and ripped coal. Residual gas content varied from 0.09 to 0.15 m3/t, less than twofold across the mine pit. Composition of the residual gas was in general 90%CO2 and 10%CH4, with slight var-iation between samples. Coal seam surface emissions varied from 1.03 to 7.50 mL of CO2-e per minute and per square meter of the coal seam surface, a sevenfold variation across the mine pit.

  16. Persons with multiple disabilities select environmental stimuli through a smile response monitored via camera-based technology

    NARCIS (Netherlands)

    Lancioni, G.E.; Bellini, D.; Oliva, D.; Singh, N.N.; O'Reilly, M.F.; Lang, R.; Didden, H.C.M.; Bosco, A.

    2011-01-01

    Objective: To assess whether two persons with multiple disabilities could use smile expressions and new camera-based microswitch technology to select environmental stimuli. Method: Within each session, a computer system provided samples/reminders of preferred and non-preferred stimuli. The camera-ba

  17. Probing of two-dimensional grid patterns by means of camera-based image processing

    Science.gov (United States)

    Schroeck, Martin; Doiron, Theodore D.

    2000-03-01

    Camera based probes and machine vision have found increased use in coordinate measuring machines over the past years and the calibration of artifacts for these probes has become an important task for NIST. Until recently these artifacts have been calibrated using one or two dimensional measuring machines with electro-optic microscopes or scanning devices as probes. These sensors evaluate only a small section of the edge of a grid mark, and irregularities in this particular spot from local deformations or contamination influence the measurement result. Since these measurements result in a single number based on the entire field of view, the influence of small irregularities are not easily detected. Since different probes scan different parts of the grid mark edge they may give systematically different positions of the mark. The conversion to video based sensors has allowed more flexibility it edge detection, although most instruments still use least squares fits as the substitute geometry of straight edges. This method is very susceptible to noise and edge irregularities. We present some experiments for finding the sub-pixel edge point locations and fitting the set of edge points to a line using a fairly simple least sum of absolute deviations fit. Data from a high accuracy 2D measuring machine is used to show the strengths of the algorithms.

  18. The determination of the intrinsic and extrinsic parameters of virtual camera based on OpenGL

    Science.gov (United States)

    Li, Suqi; Zhang, Guangjun; Wei, Zhenzhong

    2006-11-01

    OpenGL is the international standard of 3D image. The 3D image generation by OpenGL is similar to the shoot by camera. This paper focuses on the application of OpenGL to computer vision, the OpenGL 3D image is regarded as virtual camera image. Firstly, the imaging mechanism of OpenGL has been analyzed in view of perspective projection transformation of computer vision camera. Then, the relationship between intrinsic and extrinsic parameters of camera and function parameters in OpenGL has been analysed, the transformation formulas have been deduced. Thereout the computer vision simulation has been realized. According to the comparison between the actual CCD camera images and virtual camera images(the parameters of actual camera are the same as virtual camera's) and the experiment results of stereo vision 3D reconstruction simulation, the effectiveness of the method with which the intrinsic and extrinsic parameters of virtual camera based on OpenGL are determined has been verified.

  19. Carded Tow Real-Time Color Assessment: A Spectral Camera-Based System.

    Science.gov (United States)

    Furferi, Rocco; Governi, Lapo; Volpe, Yary; Carfagni, Monica

    2016-08-31

    One of the most important parameters to be controlled during the production of textile yarns obtained by mixing pre-colored fibers, is the color correspondence between the manufactured yarn and a given reference, usually provided by a designer or a customer. Obtaining yarns from raw pre-colored fibers is a complex manufacturing process entailing a number of steps such as laboratory sampling, color recipe corrections, blowing, carding and spinning. Carding process is the one devoted to transform a "fuzzy mass" of tufted fibers into a regular mass of untwisted fibers, named "tow". During this process, unfortunately, the correspondence between the color of the tow and the target one cannot be assured, thus leading to yarns whose color differs from the one used for reference. To solve this issue, the main aim of this work is to provide a system able to perform a spectral camera-based real-time measurement of a carded tow, to assess its color correspondence with a reference carded fabric and, at the same time, to monitor the overall quality of the tow during the carding process. Tested against a number of differently colored carded fabrics, the proposed system proved its effectiveness in reliably assessing color correspondence in real-time.

  20. Carded Tow Real-Time Color Assessment: A Spectral Camera-Based System

    Directory of Open Access Journals (Sweden)

    Rocco Furferi

    2016-08-01

    Full Text Available One of the most important parameters to be controlled during the production of textile yarns obtained by mixing pre-colored fibers, is the color correspondence between the manufactured yarn and a given reference, usually provided by a designer or a customer. Obtaining yarns from raw pre-colored fibers is a complex manufacturing process entailing a number of steps such as laboratory sampling, color recipe corrections, blowing, carding and spinning. Carding process is the one devoted to transform a “fuzzy mass” of tufted fibers into a regular mass of untwisted fibers, named “tow”. During this process, unfortunately, the correspondence between the color of the tow and the target one cannot be assured, thus leading to yarns whose color differs from the one used for reference. To solve this issue, the main aim of this work is to provide a system able to perform a spectral camera-based real-time measurement of a carded tow, to assess its color correspondence with a reference carded fabric and, at the same time, to monitor the overall quality of the tow during the carding process. Tested against a number of differently colored carded fabrics, the proposed system proved its effectiveness in reliably assessing color correspondence in real-time.

  1. A method of color correction of camera based on HSV model

    Science.gov (United States)

    Zhao, Rujin; Wang, Jin; Yu, Guobing; Zhong, Jie; Zhou, Wulin; Li, Yihao

    2014-09-01

    A novel color correction method of camera based on HSV (Hue, Saturation, and Value) model is proposed in this paper, which aims at the problem that spectrum response of camera differs from the CIE criterion, and that the image color of camera is aberrant. Firstly, the color of image is corrected based on HSV model to which image is transformed from RGB model. As a result, the color of image accords with the human vision for the coherence between HSV model and human vision; Secondly, the colors checker with 24 kinds of color under standard light source is used to compute correction coefficient matrix, which improves the spectrum response of camera and the CIE criterion. Furthermore, the colors checker with 24 kinds of color improves the applicability of the color correction coefficient matrix for different image. The experimental results show that the color difference between corrected color and color checker is lower based on proposed method, and the corrected color of image is consistent with the human eyes.

  2. High-resolution Compton cameras based on Si/CdTe double-sided strip detectors

    Energy Technology Data Exchange (ETDEWEB)

    Odaka, Hirokazu, E-mail: odaka@astro.isas.jaxa.jp [Department of High Energy Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); Ichinohe, Yuto [Department of High Energy Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); Department of Physics, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo, Tokyo 113-0033 (Japan); Takeda, Shin' ichiro [Department of High Energy Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); Fukuyama, Taro; Hagino, Koichi; Saito, Shinya; Sato, Tamotsu [Department of High Energy Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); Department of Physics, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo, Tokyo 113-0033 (Japan); Sato, Goro; Watanabe, Shin; Kokubun, Motohide [Department of High Energy Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); Takahashi, Tadayuki [Department of High Energy Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); Department of Physics, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo, Tokyo 113-0033 (Japan); Yamaguchi, Mitsutaka [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency (JAEA), 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); and others

    2012-12-11

    We have developed a new Compton camera based on silicon (Si) and cadmium telluride (CdTe) semiconductor double-sided strip detectors (DSDs). The camera consists of a 500-{mu}m-thick Si-DSD and four layers of 750-{mu}m-thick CdTe-DSDs all of which have common electrode configuration segmented into 128 strips on each side with pitches of 250{mu}m. In order to realize high angular resolution and to reduce size of the detector system, a stack of DSDs with short stack pitches of 4 mm is utilized to make the camera. Taking advantage of the excellent energy and position resolutions of the semiconductor devices, the camera achieves high angular resolutions of 4.5 Degree-Sign at 356 keV and 3.5 Degree-Sign at 662 keV. To obtain such high resolutions together with an acceptable detection efficiency, we demonstrate data reduction methods including energy calibration using Compton scattering continuum and depth sensing in the CdTe-DSD. We also discuss imaging capability of the camera and show simultaneous multi-energy imaging.

  3. Carded Tow Real-Time Color Assessment: A Spectral Camera-Based System

    Science.gov (United States)

    Furferi, Rocco; Governi, Lapo; Volpe, Yary; Carfagni, Monica

    2016-01-01

    One of the most important parameters to be controlled during the production of textile yarns obtained by mixing pre-colored fibers, is the color correspondence between the manufactured yarn and a given reference, usually provided by a designer or a customer. Obtaining yarns from raw pre-colored fibers is a complex manufacturing process entailing a number of steps such as laboratory sampling, color recipe corrections, blowing, carding and spinning. Carding process is the one devoted to transform a “fuzzy mass” of tufted fibers into a regular mass of untwisted fibers, named “tow”. During this process, unfortunately, the correspondence between the color of the tow and the target one cannot be assured, thus leading to yarns whose color differs from the one used for reference. To solve this issue, the main aim of this work is to provide a system able to perform a spectral camera-based real-time measurement of a carded tow, to assess its color correspondence with a reference carded fabric and, at the same time, to monitor the overall quality of the tow during the carding process. Tested against a number of differently colored carded fabrics, the proposed system proved its effectiveness in reliably assessing color correspondence in real-time. PMID:27589765

  4. Effect of Some Fabric and Sewing Conditions on Apparel Seam Characteristics

    Directory of Open Access Journals (Sweden)

    A. K. Choudhary

    2013-01-01

    Full Text Available Many previous studies showed that seam appearance as well as performance depends on the interrelationship of fabrics, threads, and the stitch/seam selection and lastly on the sewing conditions, which include the needle size, needle thread tension, stitch density, and the appropriate operation and maintenance of the sewing machine. Present investigation elucidates the effect of blend composition, sewing thread size, and sewing needle parameters on garment seam characteristics (i.e., seam strength, seam strength efficiency, seam puckering, seam stiffness, and drape coefficient. The seam quality characterization is studied through the L9 orthogonal design methodology. In good quality apparels, compatibility of the seams with the functional requirement is very important for serviceability and life of the apparel. Reversibility as well as repairing of seams in the apparel is very limited in the condition of seam failure. Seam strength efficiency is higher for the uniform fiber matrix in the structure of fabrics. The polyester dominated suiting fabrics give minimum seam stiffness because polyester component has low flexural rigidity. The cotton dominated suiting fabrics have less seam puckering due to increase in fabric stiffness.

  5. IP Camera Based Video Surveillance Using Object’s Boundary Specification

    Directory of Open Access Journals (Sweden)

    Natalia Chaudhry

    2016-08-01

    Full Text Available The ability to detect and track object of interest from sequence of frames is a critical and vital problem of many vision systems developed as yet. This paper presents a smart surveillance system that tracks objects of interest in a sequence of frames in their own defined respective boundaries. The objects of interest are registered or saved within the system. We have proposed a unique tracking algorithm using combination of SURF feature matching, Kalman filtering and template matching approach. Moreover, an efficient technique is proposed that is used to refine registered object image, extract object of interest and remove extraneous image area from it. The system will track registered objects in their respective boundaries using real time video generated through two IP cameras positioned in front of each other.

  6. An upgraded camera-based imaging system for mapping venous blood oxygenation in human skin tissue

    Science.gov (United States)

    Li, Jun; Zhang, Xiao; Qiu, Lina; Leotta, Daniel F.

    2016-07-01

    A camera-based imaging system was previously developed for mapping venous blood oxygenation in human skin. However, several limitations were realized in later applications, which could lead to either significant bias in the estimated oxygen saturation value or poor spatial resolution in the map of the oxygen saturation. To overcome these issues, an upgraded system was developed using improved modeling and image processing algorithms. In the modeling, Monte Carlo (MC) simulation was used to verify the effectiveness of the ratio-to-ratio method for semi-infinite and two-layer skin models, and then the relationship between the venous oxygen saturation and the ratio-to-ratio was determined. The improved image processing algorithms included surface curvature correction and motion compensation. The curvature correction is necessary when the imaged skin surface is uneven. The motion compensation is critical for the imaging system because surface motion is inevitable when the venous volume alteration is induced by cuff inflation. In addition to the modeling and image processing algorithms in the upgraded system, a ring light guide was used to achieve perpendicular and uniform incidence of light. Cross-polarization detection was also adopted to suppress surface specular reflection. The upgraded system was applied to mapping of venous oxygen saturation in the palm, opisthenar and forearm of human subjects. The spatial resolution of the oxygenation map achieved is much better than that of the original system. In addition, the mean values of the venous oxygen saturation for the three locations were verified with a commercial near-infrared spectroscopy system and were consistent with previously published data.

  7. 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.

  8. Conical intersection seams in polyenes derived from their chemical composition

    Energy Technology Data Exchange (ETDEWEB)

    Nenov, Artur; Vivie-Riedle, Regina de [Department Chemie, Ludwig-Maximilians-Univerisitaet, Muenchen Butenandtstr. 11, 81377 Muenchen (Germany)

    2012-08-21

    The knowledge of conical intersection seams is important to predict and explain the outcome of ultrafast reactions in photochemistry and photobiology. They define the energetic low-lying reachable regions that allow for the ultrafast non-radiative transitions. In complex molecules it is not straightforward to locate them. We present a systematic approach to predict conical intersection seams in multifunctionalized polyenes and their sensitivity to substituent effects. Included are seams that facilitate the photoreaction of interest as well as seams that open competing loss channels. The method is based on the extended two-electron two-orbital method [A. Nenov and R. de Vivie-Riedle, J. Chem. Phys. 135, 034304 (2011)]. It allows to extract the low-lying regions for non-radiative transitions, which are then divided into small linear segments. Rules of thumb are introduced to find the support points for these segments, which are then used in a linear interpolation scheme for a first estimation of the intersection seams. Quantum chemical optimization of the linear interpolated structures yields the final energetic position. We demonstrate our method for the example of the electrocyclic isomerization of trifluoromethyl-pyrrolylfulgide.

  9. Conical intersection seams in polyenes derived from their chemical composition

    Science.gov (United States)

    Nenov, Artur; de Vivie-Riedle, Regina

    2012-08-01

    The knowledge of conical intersection seams is important to predict and explain the outcome of ultrafast reactions in photochemistry and photobiology. They define the energetic low-lying reachable regions that allow for the ultrafast non-radiative transitions. In complex molecules it is not straightforward to locate them. We present a systematic approach to predict conical intersection seams in multifunctionalized polyenes and their sensitivity to substituent effects. Included are seams that facilitate the photoreaction of interest as well as seams that open competing loss channels. The method is based on the extended two-electron two-orbital method [A. Nenov and R. de Vivie-Riedle, J. Chem. Phys. 135, 034304 (2011)], 10.1063/1.3608924. It allows to extract the low-lying regions for non-radiative transitions, which are then divided into small linear segments. Rules of thumb are introduced to find the support points for these segments, which are then used in a linear interpolation scheme for a first estimation of the intersection seams. Quantum chemical optimization of the linear interpolated structures yields the final energetic position. We demonstrate our method for the example of the electrocyclic isomerization of trifluoromethyl-pyrrolylfulgide.

  10. Polycyclic aromatic hydrocarbon formation under simulated coal seam pyrolysis conditions

    Institute of Scientific and Technical Information of China (English)

    Liu Shuqin; Wang Yuanyuan; Wang Caihong; Bao Pengcheng; Dang Jinli

    2011-01-01

    Coal seam pyrolysis occurs during coal seam fires and during underground coal gasification.This is an important source of polycyclic aromatic hydrocarbon (PAH) emission in China.Pyrolysis in a coal seam was simulated in a tubular furnace.The 16 US Environmental Protection Agency priority controlled PAHs were analyzed by HPLC.The effects of temperature,heating rate,pyrolysis atmosphere,and coal size were investigated.The results indicate that the 3-ring PAHs AcP and AcPy are the main species in the pyrolysis gas.The 2-ring NaP and the 4-ring Pyr are also of concern.Increasing temperature caused the total PAH yield to go through a minimum.The lowest value was obtained at the temperature of 600 ℃ Higher heating rates promote PAH formation,especially formation of the lower molecular weight PAHs.The typical heating rate in a coal seam,5 ℃/min,results in intermediate yields of PAHs.The total PAHs yield in an atmosphere of N2 is about 1.81 times that seen without added N2,which indicates that an air flow through the coal seam accelerates the formation of PAHs.An increase in coal particle size reduces the total PAHs emission but promotes the formation of 5- and 6-ring PAHs.

  11. Multi-Kinect v2 Camera Based Monitoring System for Radiotherapy Patient Safety.

    Science.gov (United States)

    Santhanam, Anand P; Min, Yugang; Kupelian, Patrick; Low, Daniel

    2016-01-01

    3D kinect camera systems are essential for real-time imaging of 3D treatment space that consists of both the patient anatomy as well as the treatment equipment setup. In this paper, we present the technical details of a 3D treatment room monitoring system that employs a scalable number of calibrated and coregistered Kinect v2 cameras. The monitoring system tracks radiation gantry and treatment couch positions, and tracks the patient and immobilization accessories. The number and positions of the cameras were selected to avoid line-of-sight issues and to adequately cover the treatment setup. The cameras were calibrated with a calibration error of 0.1 mm. Our tracking system evaluation show that both gantry and patient motion could be acquired at a rate of 30 frames per second. The transformations between the cameras yielded a 3D treatment space accuracy of < 2 mm error in a radiotherapy setup within 500mm around the isocenter.

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

    OpenAIRE

    2016-01-01

    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 a...

  13. Theory of gas extraction from coal seams and its use

    Institute of Scientific and Technical Information of China (English)

    FAN Xi-sheng

    2012-01-01

    Gas extraction is one of the main measures of control and use of gas of coal mines.At present,the design method is under the experimental period and do not satisfy the need of practice.In this paper,the theory of gas extraction of coal seams based upon Darcy law was studied.Mathematical model of gas extraction of coal seams was established and two kinds of solving approaches based on computer software and linear approximation were given.The rightness and the validities of the model were examined with a practical example.Results obtained can be used to determine and optimize the parameters related etc.

  14. 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...

  15. Entry roof truss-bolt system test under the gob of contiguous seams

    Institute of Scientific and Technical Information of China (English)

    LIAN Chuan-jie; XU Wei-ya; WANG Ya-jie

    2007-01-01

    Roof bolt support system has been widely applied in the No.7.9 seam in Caozhuang coal mine.However,it has not been able to be applied in the NO.10-2 seam since the small interburden(2m)between NO.9 and NO.10-2 seam.The NO.9 and NO.10-2 seams are contiguous seams.The NO.9 seam has been mined out and the NO.10-2 seam will be mined under the gob of the NO.9 seam.The roof strata of the NO.10-2 seam may have been weakened and fractured due to the shear failure caused by the NO.9 seam mining activities.The steel beam sets spaced at 0.8 m have been used to support the entry of the NO.10-2 seam.In order to speed up the advance rate and cut entry development cost,a test area,using roof bolt in conjunction with truss-system,was successfully conducted.This paper presents the support system design,application of designed system,and the test results.Test results provide a cheaper,quicker,and safer way to support entry for the No.10-2 seam.

  16. Study on ascending mining roadway layout of close distance coal seams in deep mine

    Institute of Scientific and Technical Information of China (English)

    SHI Yong-kui; MO Ji

    2007-01-01

    To solve the problems appeared in mining process of No.2 seam, the ascending stress-releasing mining method was adopted. Studying on the reasonable layout of actual mining roadway in upper coal seams is the precondition of successful ascending mining.By using "device of leak measuring by blocking up double ends", it detected the height of overburden water flowing fractured zone originated from sub-coal seams mining. Thus it proved that the actual mining roadway of No.2 upper ascending seam was located in the smooth sagging zone. On the basis of analyzing the stress-releasing effect of sub-coal seams mining to upper coal seams by using RFPA software, it analyzed the stability of up-face coal seams and the reasonable location of starting cut in up-face coal seams. It also analyzed the reasonable gateway location in upper coal seams, which ensured the crossheading in upper coal seams out of the effect of sub-coal work face mining by using theory of underground pressure. Meanwhile, the reasonable pillars dimensions in upper coal seams by building the structure mechanics model of stope were researched. It can make the roadway driven along next goaf to be located in low stress zone, and be beneficial to keeping roads stable owing to less stress of surrounding rock. Finally, it tested the rationality of the layout method of roads in upper coal seams by engineering field measurement in 3221 working face.

  17. Real-time camera-based face detection using a modified LAMSTAR neural network system

    Science.gov (United States)

    Girado, Javier I.; Sandin, Daniel J.; DeFanti, Thomas A.; Wolf, Laura K.

    2003-03-01

    This paper describes a cost-effective, real-time (640x480 at 30Hz) upright frontal face detector as part of an ongoing project to develop a video-based, tetherless 3D head position and orientation tracking system. The work is specifically targeted for auto-stereoscopic displays and projection-based virtual reality systems. The proposed face detector is based on a modified LAMSTAR neural network system. At the input stage, after achieving image normalization and equalization, a sub-window analyzes facial features using a neural network. The sub-window is segmented, and each part is fed to a neural network layer consisting of a Kohonen Self-Organizing Map (SOM). The output of the SOM neural networks are interconnected and related by correlation-links, and can hence determine the presence of a face with enough redundancy to provide a high detection rate. To avoid tracking multiple faces simultaneously, the system is initially trained to track only the face centered in a box superimposed on the display. The system is also rotationally and size invariant to a certain degree.

  18. Palaeoenvironmental reconstruction of Hüsamlar coal seam, SW Turkey

    Indian Academy of Sciences (India)

    Zeynep Büçkün; HüLya İnaner; Riza Görkem Oskay; Kimon Christanis

    2015-06-01

    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 many sharp alternations of matrix lignite beds and inorganic, lacustrine sediment layers. The coal is a medium-to-high ash lignite (10.47–31.16 wt%, on dry basis) with high total sulphur content (up to 10 wt%, on dry, ash-free basis), which makes it prone to self-combustion. The maceral composition indicates that the peat-forming vegetation consisted of both arboreal and herbaceous plants, with the latter being predominant in the upper part of the seam. Mica and feldspars contribute to the low part of the seam; carbonates are dominant in the upper part, whereas quartz and pyrite are present along the entire coal profile. The sudden transitions of the telmatic to the lacustrine regime and reverse is attributed to tectonic movements that controlled water table levels in the palaeomire, which affected surface runoff and hence, clastic deposition.

  19. Characteristics of fracture development and gas extraction of a lower protected seam

    Institute of Scientific and Technical Information of China (English)

    王海锋

    2009-01-01

    To ensure the mining safety of working face in the protective seam and meanwhile extract pressure-relief gas of the lower protected seam and eliminate its outburst risk,the present study researched into fracture development of floor coal-rock mass of the protective seam and migration rule of pressure-relief gas from a protected seam so as to obtain an effective pressure- relief gas extraction method.The results show that after the upper protective seam was mined,mining-induced fracturing floor coal-rock mas...

  20. Coal seam methane distribution and its significance in Pingdingshan mining area

    Institute of Scientific and Technical Information of China (English)

    郭德勇; 周心权; 沈少川; 张晓萍

    2002-01-01

    A study aimed at the coal seam group E and F in Pingdingshan mining area has been completed. This study is on the relationship of the coal-seam methane reserve to coal thickness, coal rank, coal seam depth, surrounding rock and geological structure and other factors. The study indicates that different geological factor plays different role in controlling the law of coal-seam methane reserve. The coal-seam methane rich area, which was formed because of various factors and comprehensive effect, is the coal and methane outburst-prone area, and also the key area for coal-bed methane recovery. Among all factors, coal seam depth and geological structure is more important factor in affecting coal-seam methane content in Pingdingshan mining area.

  1. Study on the economic mining method for the close quarter coal seams with thin rock sheet

    Institute of Scientific and Technical Information of China (English)

    GOU Pan-feng; CHEN Zhao-qiang; YUN Xiao-you

    2001-01-01

    The paper presents the mining method for the close quarter coal seams with thin rock sheet, that is mining the low coal seam, recovering the top coal seam aft er putting down the roof rock of the low coal seam. Practice has proved that in recovering the top coal outside the face width after the rock between seams fall s naturally or is demolished, the technology is simple, easy to operate and doe s not make a great demand for technical equipment. In the process of recovering t he top coal, the low seam support could not be affected seriously, and two seams mining could be coordinated. Compared with the individual mining method, this m ining method can produce a better economic benefit.

  2. Study on the economic mining method for the close quarter coal seams with thin rock sheet

    Institute of Scientific and Technical Information of China (English)

    勾攀峰; 陈兆强; 员小有

    2001-01-01

    The paper presents the mining method for the close quarter coal seams with thin rock sheet, that is mining the low coal seam, recovering the top coal seam after putting down the roof rock of the low coal seam. Practice has proved that in recovering the top coal outside the face width after the rock between seams falls naturally or is demolished, the technology is simple, easy to operate and does not make a great demand for technical equipment. In the process of recovering the top coal, the low seam support could not be affected seriously, and two seams mining could be coordinated. Compared with the individual mining method, this mining method can produce a better economic benefit.

  3. Camera-based measurement for transverse vibrations of moving catenaries in mine hoists using digital image processing techniques

    Science.gov (United States)

    Yao, Jiannan; Xiao, Xingming; Liu, Yao

    2016-03-01

    This paper proposes a novel, non-contact, sensing method to measure the transverse vibrations of hoisting catenaries in mine hoists. Hoisting catenaries are typically moving cables and it is not feasible to use traditional methods to measure their transverse vibrations. In order to obtain the transverse displacements of an arbitrary point in a moving catenary, by superposing a mask image having the predefined reference line perpendicular to the hoisting catenaries on each frame of the processed image sequence, the dynamic intersecting points with a grey value of 0 in the image sequence could be identified. Subsequently, by traversing the coordinates of the pixel with a grey value of 0 and calculating the distance between the identified dynamic points from the reference, the transverse displacements of the selected arbitrary point in the hoisting catenary can be obtained. Furthermore, based on a theoretical model, the reasonability and applicability of the proposed camera-based method were confirmed. Additionally, a laboratory experiment was also carried out, which then validated the accuracy of the proposed method. The research results indicate that the proposed camera-based method is suitable for the measurement of the transverse vibrations of moving cables.

  4. Automated methods and control when mining seams prone to outburst

    Energy Technology Data Exchange (ETDEWEB)

    Kolesov, O.A.; Agaphonov, A.V.; Kolchin, G.I. [Makeyevka Safety in Mines Research Institute (Ukraine)

    1995-12-31

    Drawbacks in existing methods of predicting outburst zones in Donbas (Russia) thin coal seams led specialists at MakNII to investigate methods based on artificial excited acoustic signals, with processing by personnal computers. The paper describes investigations to correlate different acoustic signal parameters with stress and strained state of the massif preface. The method proved reliable in determining the relief zone in 12 Donbas mines. The paper goes on to describe development of a control method for another widely used method of coal and gas outburst prevention in Donbas, that of water injection into the coal seam known as `hydroripping`. This method includes acoustic signals recording and preface part parameters determination in the drilling process for infusion and recording and processing of the acoustic signal in real time, which is created during water infusion. 8 refs.

  5. Innovative technology summary report: Sealed-seam sack suits

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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).

  6. Radiation and annealing response of WWER 440 beltline welding seams

    Science.gov (United States)

    Viehrig, Hans-Werner; Houska, Mario; Altstadt, Eberhard

    2015-01-01

    The focus of this paper is on the irradiation response and the effect of thermal annealing in weld materials extracted from decommissioned WWER 440 reactor pressure vessels of the nuclear power plant Greifswald. The characterisation is based on the measurement of the hardness, the yield stress, the Master Curve reference temperature, T0, and the Charpy-V transition temperature through the thickness of multi-layer beltline welding seams in the irradiated and the thermally annealed condition. Additionally, the weld bead structure was characterised by light microscopic studies. We observed a large variation in the through thickness T0 values in the irradiated as well as in thermally annealed condition. The T0 values measured with the T-S-oriented Charpy size SE(B) specimens cut from different thickness locations of the multilayer welding seams strongly depend on the intrinsic weld bead structure along the crack tip. The Master Curve, T0, and Charpy-V, TT47J, based ductile-to-brittle transition temperature progressions through the thickness of the multi-layer welding seam do not correspond to the forecast according to the Russian code. In general, the fracture toughness values at cleavage failure, KJc, measured on SE(B) specimens from the irradiated and large-scale thermally annealed beltline welding seams follow the Master Curve description, but more than the expected number lie outside the curves for 2% and 98% fracture probability. In this case the test standard ASTM E1921 indicates the investigated multi-layer weld metal as not uniform. The multi modal Master Curve based approach describes the temperature dependence of the specimen size adjusted KJc-1T values well. Thermal annealing at 475 °C for 152 h results in the expected decrease of the hardness and tensile strength and the shift of Master Curve and Charpy-V based ductile-to-brittle transition temperatures to lower values.

  7. PHYSICAL SIMULATION AND ANALYSIS OF METHANE TRANSPORT IN COAL SEAM

    Institute of Scientific and Technical Information of China (English)

    罗新荣; 俞启香

    1994-01-01

    This paper studies the effect of ground stress, pore gas pressure and adsorbed methane on methane transport in coal seam, and researches into the applicability of Darcy's law to methane transport. The additional expansion stress of coal induced by adsorbed methane is measured. The paper establishes the constitutive equation of methane transport, taking ground stress, pore gas pressure and Klinkcnburg's effects into considcration, The features of methane transport under the condition of given stress or strain have been analyzed.

  8. 高频焊接钢管焊缝的超声波自动检测工艺%Automated Ultrasonic Inspection Technology for Weld Seam of High Frequency Welding Pipes

    Institute of Scientific and Technical Information of China (English)

    张志刚

    2011-01-01

    在高频焊接钢管焊缝自动超声波检测的实际工作中,精确的焊缝跟踪较难实现,易影响检测的可靠性.通过对超声波检测技术进行分析,利用6 dB声束全壁厚覆盖区进行检测,提出了一套超声波检测新工艺.实践证明:该工艺可以在焊缝跟踪不精确的情况下实现可靠的超声波检测,为高频焊接钢管焊缝自动超声波检测提供了一套有效的检测方法.%During the automated ultrasonic inspection of weld seam of high frequency welding(HFW) pipes,it is very difficult to track the weld seam accurately, which will affect the reliability of inspection easily. Through the analysis of ultrasonic inspection techniques, and inspecting with 6 dB sound beam full wall thickness overlap area, a new set of ultrasonic inspection technology was put forward. Practice showed that, in the event of inexact seam track, the technology can assure the reliable inspection result, and provided a effective method for the automated ultrasonic inspection of weld seams of HFW pipes.

  9. Modeling and simulation of strata movement for protective seam mining with large interburden

    Institute of Scientific and Technical Information of China (English)

    SONG Chang-sheng; LI De-hai; LI Hua-min

    2009-01-01

    Based on simulated material scale modeling and numerical simulation,the pro-tective seam mining method was conducted at one coal mine.After extracting the No.15 seam,the overlying strata movement and the deformation of the No.9-10 protected seam were studied.The experiment results show that it is feasible to destress the protected seams with large interburden thickness.When the face had advanced 200 m from the setup room,the No.9-10 seam was fully destressed,resulting in easy gas drainage in the destressed zone.Recommendations on mining sequence of multiple seams mining in the same coal areas were made.

  10. Variation in gas drainage rate from a coal seam during mining

    Institute of Scientific and Technical Information of China (English)

    Li; Gang; Qi; Qingxin; Li; Hongyan; Fan; Xisheng

    2012-01-01

    Gas flow patterns during draining of gas from a coal seam during mining are discussed.The coal seam is treated as a dual medium with both pores and cracks.The seepage,diffusion,and desorption processes are treated using a gas flow equation that describes flow around drill holes.MATLAB is used to solve the differential equations.The permeability tracer test results from a mined coal seam are used to study the variation in gas drainage from a coal seam during mining.The results show that mining can increase the permeability of a coal seam,which then increases the gas drainage.There are inflection points in this variation over time.A close relationship between this variation and the rate of change in coal seam permeability is observed.

  11. Radiation and annealing response of WWER 440 beltline welding seams

    Energy Technology Data Exchange (ETDEWEB)

    Viehrig, Hans-Werner, E-mail: h.w.viehrig@hzdr.de; Houska, Mario; Altstadt, Eberhard

    2015-01-15

    Highlights: • Investigation of the beltline welding seam from decommissioned reactor pressure vessels. • The Master Curve based reference temperature varies strongly through the thickness. • This variation is mainly caused by the intrinsic weld bead structure. • The Charpy-V based ductile-to-brittle temperature shift does not correspond to the prediction. • The mitigation of the irradiation induced embrittlement by annealing has been confirmed. - Abstract: The focus of this paper is on the irradiation response and the effect of thermal annealing in weld materials extracted from decommissioned WWER 440 reactor pressure vessels of the nuclear power plant Greifswald. The characterisation is based on the measurement of the hardness, the yield stress, the Master Curve reference temperature, T{sub 0}, and the Charpy-V transition temperature through the thickness of multi-layer beltline welding seams in the irradiated and the thermally annealed condition. Additionally, the weld bead structure was characterised by light microscopic studies. We observed a large variation in the through thickness T{sub 0} values in the irradiated as well as in thermally annealed condition. The T{sub 0} values measured with the T–S-oriented Charpy size SE(B) specimens cut from different thickness locations of the multilayer welding seams strongly depend on the intrinsic weld bead structure along the crack tip. The Master Curve, T{sub 0}, and Charpy-V, TT{sub 47J}, based ductile-to-brittle transition temperature progressions through the thickness of the multi-layer welding seam do not correspond to the forecast according to the Russian code. In general, the fracture toughness values at cleavage failure, K{sub Jc}, measured on SE(B) specimens from the irradiated and large-scale thermally annealed beltline welding seams follow the Master Curve description, but more than the expected number lie outside the curves for 2% and 98% fracture probability. In this case the test standard ASTM

  12. Guided modes in coal seams and their application to underground seismic surveying

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, P.E.; Mason, I.M.

    1975-01-01

    Underground seismic surveying of coal seams can be performed using the channel waves guided by the low velocity coal layer. The roadway modes, i.e. the modes guided by the free face of the coal seam, are analysed. The knowledge of channel modes and roadway modes are shown to be fundamental to the interpretation of any survey data. Detailed calculations of the channel modes and the pulse propagation in a particular coal seam are presented.

  13. Gray Comprehensive Evaluation Method on Coal Seam Water Injection in Order of Difficulty

    OpenAIRE

    2016-01-01

    In order to evaluate the coal mine water injection accurately, the gray comprehensive evaluation is applied in this paper, the depth of coal seam, the development degree of coal seam crack, porosity, gas pressure in coal seam, wetting edge of coal, firmness coefficient of coal are chosen as the main index to evaluate the method of water injection into coal mine. The results show that the gray comprehensive evaluation model has a relatively high reliability and accuracy, which can be used to p...

  14. 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.

  15. Coal and rock fissure evolution and distribution characteristics of multi-seam mining

    Institute of Scientific and Technical Information of China (English)

    Zhang Dongming; Qi Xiaohan; Yin Guangzhi; Zheng Binbin

    2013-01-01

    Henan Pingdingshan No.10 mine is prone to both coal and gas outbursts. The E9-10 coal seam is the main coal-producing seam but has poor quality ventilation, thus making it relatively difficult for gas extraction. The F15 coal seam, at its lower section, is not prone to coal and gas outbursts. The average seam separa-tion distance of 150 m is greater than the upper limit for underside protective seam mining. Based on borehole imaging technology for field exploration of coal and rock fracture characteristics and discrete element numerical simulation, we have studied the evolution laws and distribution characteristics of the coal and rock fissure field between these two coal seams. By analysis of the influential effect of group F coal mining on the E9-10 coal seam, we have shown that a number of small fissures also develop in the area some 150 m above the overlying strata. The width and number of the fissures also increase with the extent of mining activity. Most of the fissures develop at a low angle or even parallel to the strata. The results show that the mining of the F15 coal seam has the effect of improving the permeability of the E9-10 coal seam.

  16. Definition of Locked-up Stresses around a Rectilinear Welding Seam

    Science.gov (United States)

    Velikanov, N. L.; Koryagin, S. I.; Sharkov, O. V.

    2016-04-01

    In article one of the ways of modelling of the locked-up stresses caused by imposing of a welding seam in a plate is described. These stresses are caused by residual deformations of welding seams. In the settlement scheme the welding seam is presented in the form of an element by the thickness equal to the thickness of a plate, inserted in it with a longitudinal and cross-section tightness. The field of locked-up stresses around the welding seam experiences longitudinal and cross-section shrinkage under cooling and it is defined in work with the use of complex potentials of the theory of elasticity.

  17. Effect of Heat Treatment on High Temperature Stress Rupture Strength of Brazing Seam for Nickel-base Superalloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to enhance the high-temperature stress rupture strength of brazing seam by heat treatment, it was diffusion treated, then solution heat treated, and finally aging treated. The microstructure of brazing seam especially morphology of phase and boride was observed and the strength of brazing seam was measured in this process. The results show that heat treatment can enhance high-temperature stress rupture strength by improving the microstructure of brazing seam. The strength of brazing seam after solution heat treatment decreases in comparison with that only after diffusion treatment while aging treatment after solution heat treatment increases the strength of brazing seam.

  18. Deep coal seams as a greener energy source: a review

    Science.gov (United States)

    Ranathunga, A. S.; Perera, M. S. A.; Ranjith, P. G.

    2014-12-01

    Today, coal and oil are the main energy sources used in the world. However, these sources will last for only a few decades. Hence, the investigation of possible energy sources to meet this crisis has become a crucial task. Coal bed methane (CBM) is a potential energy source which can be used to fulfil the energy demand. Since the amount of carbon dioxide (CO2) emitted to the atmosphere from the use of CBM is comparatively very low compared to conventional energy sources, it is also a potential mitigation option for global warming. This paper reviews CBM recovery techniques with particular emphasis on CO2-enhanced coal bed methane (CO2-ECBM) recovery. The paper reviews (1) conventional CBM recovery techniques and problems associated with them, (2) CBM production-enhancement methods, including hydro-fracturing and enhanced CBM recovery techniques, such as N2-ECBM and CO2-ECBM, (3) the importance of the CO2-ECBM technique compared to other methods and problems with it, (4) the effect of CO2 injection during the CO2-ECBM process on coal seam permeability and strength and (5) current CO2-ECBM field projects and their progress. Although conventional CBM recovery methods are simple (basically related to the drawdown of the reservoir pressure to release methane from it), they are inefficient for the recovery of a commercially viable amount of methane from coal seams. Therefore, to enhance methane production, several methods are used, such as hydro-fracturing and ECBM (N2-ECBM and CO2-ECBM). The CO2-ECBM process has a number of advantages compared to other methane recovery techniques, as it contributes to the mitigation of the atmospheric CO2 level, is safer and more economical. However, as a result of CO2 injection into the coal seam during the CO2-ECBM process, coal mass permeability and strength may be crucially changed, due to the coal matrix swelling associated with CO2 adsorption into the coal matrix. Both injecting CO2 properties (gas type, CO2 phase and pressure

  19. Gas drainage technology of high gas and thick coal seam

    Institute of Scientific and Technical Information of China (English)

    HE Tian-cai; LI Hai-gui; ZHANG Hai-jun

    2009-01-01

    Gas drainage in Jincheng Mining Group Co., Ltd. was introduced briefly and the importance of gas drainage in gas control was analyzed. Combined with coal-bed gas oc-currence and gas emission, the double system of gas drainage was optimized and a pro-gressive gas drainage model was experimented on. For guaranteed drainage, excavation and mining and realization of safety production and reasonable exploitation of gas in coal seams, many drainage methods were adopted to solve the gas problem of the working face.

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

    Directory of Open Access Journals (Sweden)

    Y. Li

    2016-04-01

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

  1. An overview of lithotype associations of Miocene lignite seams exploited in Poland

    Science.gov (United States)

    Widera, Marek

    2016-09-01

    Currently, three stratigraphically distinct lignite seams of Early to Middle Miocene age are exploited in Poland, namely the third Ścinawa lignite seam (ŚLS-3), the second Lusatian lignite seam (LLS-2) and the first Mid-Polish lignite seam (MPLS-1). All of these are composed of numerous macroscopically distinguishable layers defined as lignite lithotypes. In the present paper, the lithotypes of Polish lignites are grouped into seven major lithotype associations that originated in various types of mire. Therefore, an approximate reconstruction of mire type can be based on lignite lithotypes. Within the Polish lignite seams examined, the commonest in order of importance are: xylodetritic (XDL), detroxylitic (DXL), detritic (DL) and xylitic (XL) lithotype associations, mostly with a massive (m) or horizontal (h) structure. They are particularly dominant in lignite opencasts belonging to the Konin and Adamów mines. However, in the lowermost seams at the Turów and Bełchatów mines, a substantial part of the seams comprises the bitumen-rich (BL) lithotype association. These seams also lignite lithotypes that in large quantities have a gelified (g) and/or nodular (n) structure. In contrast, lignites from the Sieniawa mine are characterised by an admixture of the best-developed lithotype associations of both fusitic (FL) and weathered (WL) lignites. Moreover, the vast majority of these lignites have a folded (fo) and/or faulted (fa) structure, because they were completely deformed by glaciotectonics.

  2. The innovational mining technology of fully mechanized mining on thin coal seam

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, G.; Sun, Q.; Song, H. [China Ocean University, Qingdao (China)

    2007-03-15

    The paper describes the innovational fully mechanized mining technology practised on thin coal seams in Tianchen coal mine. This mining technology combined fully mechanized mining and orthodox working face mining. The technology is suitable for mining of particularly thin coal seams. 7 refs., 1 fig., 1 tab.

  3. An overview of lithotype associations of Miocene lignite seams exploited in Poland

    Directory of Open Access Journals (Sweden)

    Widera Marek

    2016-09-01

    Full Text Available Currently, three stratigraphically distinct lignite seams of Early to Middle Miocene age are exploited in Poland, namely the third Ścinawa lignite seam (ŚLS-3, the second Lusatian lignite seam (LLS-2 and the first Mid-Polish lignite seam (MPLS-1. All of these are composed of numerous macroscopically distinguishable layers defined as lignite lithotypes. In the present paper, the lithotypes of Polish lignites are grouped into seven major lithotype associations that originated in various types of mire. Therefore, an approximate reconstruction of mire type can be based on lignite lithotypes. Within the Polish lignite seams examined, the commonest in order of importance are: xylodetritic (XDL, detroxylitic (DXL, detritic (DL and xylitic (XL lithotype associations, mostly with a massive (m or horizontal (h structure. They are particularly dominant in lignite opencasts belonging to the Konin and Adamów mines. However, in the lowermost seams at the Turów and Bełchatów mines, a substantial part of the seams comprises the bitumen-rich (BL lithotype association. These seams also lignite lithotypes that in large quantities have a gelified (g and/or nodular (n structure. In contrast, lignites from the Sieniawa mine are characterised by an admixture of the best-developed lithotype associations of both fusitic (FL and weathered (WL lignites. Moreover, the vast majority of these lignites have a folded (fo and/or faulted (fa structure, because they were completely deformed by glaciotectonics.

  4. Relative Performance of Lockstitch and Chainstitch at the Seat Seam of Military Trouser

    Directory of Open Access Journals (Sweden)

    Arunangshu Mukhopadhyay, Ph.D.

    2008-03-01

    Full Text Available An experimental investigation of the effect of two different type of stitches viz., lockstitch and chainstitch at the seat seam of trouser for military armed forces has been reported. Performance of chainstitched seam is found to be much better as regards lower value of force at low level of strain, higher value of force at break, strain at break and work of rapture. In general with the change in thread linear density, greater improvement in seam strength, seam strain at break and work up to fracture are obtained in case of chainstitched seam. On laundering, in general force at small strain and force at break increases, the change being more in case of lockstitched fabric. However, strain at break decrease marginally on laundering in case of both the stitches.

  5. Kalman filter of the force signal of identifying weld seam in remote teaching

    Institute of Scientific and Technical Information of China (English)

    Liu Lijun; Zhu Ronghua; Zhang Guangjun; Gao Hongming; Wu Lin

    2008-01-01

    For reasons of the vibration of robot, the rough surface of weld seam and electromagnetic disturbance of welding machine, the force signals of identifying weld seam become unstable. The position error of remote teaching point is too big to meet teaching requirements in remote welding. The force signals of identifying weld seam can be filtered by Kalman. The force signals of identifying weld seam of next teaching point is accurately predicted according to predicting algorithms, such as the equation of the state, the equation of the observation, the gain matrix of the filter and the covariance matrix of predicting state. The experimental results show that the precision of identifying weld seam is improved by Kalman filter.

  6. New development of longwall mining equipment based on automation and intelligent technology for thin seam coal

    Institute of Scientific and Technical Information of China (English)

    Guo-fa WANG

    2013-01-01

    The paper introduced complete sets of automatic equipment and technology used in thin seam coal face,and proposed the comprehensive mechanization and automation of safe and high efficiency mining models based on the thin seam drum shearer.The key technology of short length and high power thin seam drum shearer,and new type roof support with big extension ratio and plate canopy were introduced.The new research achievement on automatic control system of complete sets of equipment for the thin seam coal,which composed of electronic-hydraulic system,compact thin seam roof supports,high effective shearer with intelligent control system,and characterized by automatical follow-up and remote control technology,was described in this paper..

  7. Path Planning of Planar Kinked Line Seam by Visual Servoing for Robotic Welding

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Welding path planning can substitute for the manual teaching process of the robot and can promote the autonomous level of the robotic welding. A path planning method by visual servoing was presented, in which the optimal angle of charge-coupled device (CCD) camera was also planned. Aiming at planning two forms of kinked line seams, obtuse angle seam and right angle seam, a practicable solution was put forward. In this solution, the intersection of two adjacent straight segments is detected in each local seam image, and if intersection is found, theseam errors are calculated using the next straight segment. The experimental results show that kinked line seam can be well planned using this solution.

  8. Beyond leaf color: Comparing camera-based phenological metrics with leaf biochemical, biophysical, and spectral properties throughout the growing season of a temperate deciduous forest

    Science.gov (United States)

    Yang, Xi; Tang, Jianwu; Mustard, John F.

    2014-03-01

    Plant phenology, a sensitive indicator of climate change, influences vegetation-atmosphere interactions by changing the carbon and water cycles from local to global scales. Camera-based phenological observations of the color changes of the vegetation canopy throughout the growing season have become popular in recent years. However, the linkages between camera phenological metrics and leaf biochemical, biophysical, and spectral properties are elusive. We measured key leaf properties including chlorophyll concentration and leaf reflectance on a weekly basis from June to November 2011 in a white oak forest on the island of Martha's Vineyard, Massachusetts, USA. Concurrently, we used a digital camera to automatically acquire daily pictures of the tree canopies. We found that there was a mismatch between the camera-based phenological metric for the canopy greenness (green chromatic coordinate, gcc) and the total chlorophyll and carotenoids concentration and leaf mass per area during late spring/early summer. The seasonal peak of gcc is approximately 20 days earlier than the peak of the total chlorophyll concentration. During the fall, both canopy and leaf redness were significantly correlated with the vegetation index for anthocyanin concentration, opening a new window to quantify vegetation senescence remotely. Satellite- and camera-based vegetation indices agreed well, suggesting that camera-based observations can be used as the ground validation for satellites. Using the high-temporal resolution dataset of leaf biochemical, biophysical, and spectral properties, our results show the strengths and potential uncertainties to use canopy color as the proxy of ecosystem functioning.

  9. CO2 Sequestration in Unmineable Coal Seams: Potential Environmental Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Hedges, S.W.; Soong, Yee; McCarthy Jones, J.R.; Harrison, D.K.; Irdi, G.A.; Frommell, E.A.; Dilmore, R.M.; Pique, P.J.; Brown, T.D

    2005-09-01

    An initial investigation into the potential environmental impacts of CO2 sequestration in unmineable coal seams has been conducted, focusing on changes in the produced water during enhanced coalbed methane (ECBM) production using a CO2 injection process (CO2-ECBM). Two coals have been used in this study, the medium volatile bituminous Upper Freeport coal (APCS 1) of the Argonne Premium Coal Samples series, and an as-mined Pittsburgh #8 coal, which is a high volatile bituminous coal. Coal samples were reacted with either synthetic produced water or field collected produced water and gaseous carbon dioxide at 40 οC and 50 bar to evaluate the potential for mobilizing toxic metals during CO2-ECBM/sequestration. Microscopic and x-ray diffraction analysis of the post-reaction coal samples clearly show evidence of chemical reaction, and chemical analysis of the produced water shows substantial changes in composition. These results suggest that changes to the produced water chemistry and the potential for mobilizing toxic trace elements from coalbeds are important factors to be considered when evaluating deep, unmineable coal seams for CO2 sequestration.

  10. Pressure relief, gas drainage and deformation effects on an overlying coal seam induced by drilling an extra-thin protective coal seam

    Institute of Scientific and Technical Information of China (English)

    LIU Hai-bo; CHENG Yuan-ping; SONG Jian-cheng; SHANG Zheng-jie; WANG Liang

    2009-01-01

    Numerical simulations and field tests were used to investigate the changes in ground stress and deformation of, and gas flow from, a protected coal seam under which an extra-thin coal seam was drilled. The geological conditions were: 0.5 meter min-ing height, 18.5 meter coal seam spacing and a hard limestone/fine sandstone inter-stratum. For these conditions we conclude: 1) the overlying coal-rock mass bends and sinks without the appearance of a caving zone, and 2) the protected coal seam is in the bending zone and undergoes expansion deformation in the stress-relaxed area. The deformation was 12 mm and the relative defor-mation was 0.15%. As mining proceeds, deformation in the protected layer begins as compression, then becomes a rapid expansion and, finally, reaches a stable value. A large number of bed separation crannies are created in the stress-relaxed area and the perme-ability coefficient of the coal seam was increased 403 fold. Grid penetration boreholes were evenly drilled toward the protected coal seam to affect pressure relief and gas drainage. This made the gas pressure decrease from 0.75 to 0.15 Mpa, the gas content de-crease from 13 to 4.66 m3/t and the gas drainage reach 64%.

  11. Optimization of a mini-gamma camera based on a 2x2 array of Hamamatsu H8500 PSPMTs

    Energy Technology Data Exchange (ETDEWEB)

    Majewski, Stan [Jefferson Laboratory, 12000 Jefferson Ave., Newport News, VA 23606 (United States); Popov, Vladimir [Jefferson Laboratory, 12000 Jefferson Ave., Newport News, VA 23606 (United States); Wojcik, Randolph [Jefferson Laboratory, 12000 Jefferson Ave., Newport News, VA 23606 (United States): Ray Visions, Inc., 317 Blacksmith Arch, Yorktown, VA 23693 (United States)]. E-mail: wojcik@jlab.org; Weisenberger, Andrew [Jefferson Laboratory, 12000 Jefferson Ave., Newport News, VA 23606 (United States)

    2006-12-20

    We present the results of a comparative study between several scintillation sensors with the goal of optimizing the spatial resolution of a practical mini-gamma camera based on a 2x2 array of Hamamatsu H8500 flat panel position sensitive photomultiplier tubes (PSPMTs) with 64 anode pads per PSPMT. The readout of this 256 pad imager was achieved by a special in-house designed and optimized pad-decoupling strip readout reducing the number of readout channels to 32. Pixellated NaI(Tl) and CsI(Tl) scintillator arrays, as well as thin continuous GSO, GSOZ, CsI(Na) and CsI(Tl) scintillator plates were coupled to this PSPMT array to form a compact mini-gamma camera. This round of tests, following extensive prior experience with this type of imager, was intended to investigate the possibility of achieving an intrinsic spatial resolution of under 1.0 mm FWHM across the whole surface of the mini-gamma camera. We confirmed the results of our previous studies that the best overall performance is achieved with pixellated NaI(Tl) arrays. The present resolution limit attainable with the H8500 PSPMT array is approaching 1.2 mm FWHM, which is equivalent to the smallest available pixel pitch of these arrays.

  12. Feasibility study of a ``4H'' X-ray camera based on GaAs:Cr sensor

    Science.gov (United States)

    Dragone, A.; Kenney, C.; Lozinskaya, A.; Tolbanov, O.; Tyazhev, A.; Zarubin, A.; Wang, Zhehui

    2016-11-01

    A multilayer stacked X-ray camera concept is described. This type of technology is called `4H' X-ray cameras, where 4H stands for high-Z (Z>30) sensor, high-resolution (less than 300 micron pixel pitch), high-speed (above 100 MHz), and high-energy (above 30 keV in photon energy). The components of the technology, similar to the popular two-dimensional (2D) hybrid pixelated array detectors, consists of GaAs:Cr sensors bonded to high-speed ASICs. 4H cameras based on GaAs also use integration mode of X-ray detection. The number of layers, on the order of ten, is smaller than an earlier configuration for single-photon-counting (SPC) mode of detection [1]. High-speed ASIC based on modification to the ePix family of ASIC is discussed. Applications in X-ray free electron lasers (XFELs), synchrotrons, medicine and non-destructive testing are possible.

  13. SPLASSH: Open source software for camera-based high-speed, multispectral in-vivo optical image acquisition.

    Science.gov (United States)

    Sun, Ryan; Bouchard, Matthew B; Hillman, Elizabeth M C

    2010-08-02

    Camera-based in-vivo optical imaging can provide detailed images of living tissue that reveal structure, function, and disease. High-speed, high resolution imaging can reveal dynamic events such as changes in blood flow and responses to stimulation. Despite these benefits, commercially available scientific cameras rarely include software that is suitable for in-vivo imaging applications, making this highly versatile form of optical imaging challenging and time-consuming to implement. To address this issue, we have developed a novel, open-source software package to control high-speed, multispectral optical imaging systems. The software integrates a number of modular functions through a custom graphical user interface (GUI) and provides extensive control over a wide range of inexpensive IEEE 1394 Firewire cameras. Multispectral illumination can be incorporated through the use of off-the-shelf light emitting diodes which the software synchronizes to image acquisition via a programmed microcontroller, allowing arbitrary high-speed illumination sequences. The complete software suite is available for free download. Here we describe the software's framework and provide details to guide users with development of this and similar software.

  14. Mathematical modeling for coupled solid elastic-deformation and gas leak flow in multi-coal-seams

    Institute of Scientific and Technical Information of China (English)

    孙培德

    2002-01-01

    Based on the new viewpoint of solid and gas interaction mechanics, gas leakage in a double deformable coal seam can be understood. That is, under the action of geophysical fields, the methane flow in a double deformable coal seam can be essentially considered to be compressible with time-dependent and mixed permeation and diffusion through a pore-cleat deformable heterogeneous and anisotropy medium. Based on this new viewpoint, a coupled mathematical model for coal seam deformation and gas leakage in a double coal seam was formulated and numerical simulations for gas emission from the coal seam are presented. It is found that coupled models might be closer to reality.

  15. A new straight line detection method in images for robot seam tracking

    Institute of Scientific and Technical Information of China (English)

    Chen Qiang; Zhang Wenzeng; Du Dong; Sun Zhenguo; Zhang Guoxian

    2006-01-01

    A new efficient straight line detection algorithm, GPI ( Gray Projecting Integral) method is proposed. The gray values of a sub-window are projected onto a line, and sum the gray values which are projected onto one same point to shape a special vector, then rotate the projecting direction, obtain many such vectors corresponding to different projecting directions.The vectors can form a matrix, a GPI matrix of the sub-image. The problem of lines detection is converted into maxima or minima searching problem in the GPI matrix. Based on the GPI matrix, the lines can be calculated. Different from traditional methods, the algorithm can detect the positions of lines accurately, quickly without previous edge detection, which costs less time, and avoids the error resulted from the poor threshold with traditional methods. This algorithm is useful and efficient for numerous image understanding applications and robot visual navigation, especially for welded joint position detection in heavy noise.

  16. Arc sensing system for automatic weld seam tracking (II) ——Signal processing

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Due to violent disturbance of the welding arc, signal processingis the key problem of application of the sensor. By means of the new technique the arc sensor can recognize not only V-groove but also lap joint and butt joint. The sensor has good recognition ability even for welding process with very large current disturbance, e.g. pulsed arc and short circuit welding process, etc. The proposed technique is developed on the basis of modern digital filtering theory and mathematic transformation of the signals from time domain into frequency domain.

  17. Research on the Sensor of Welding Seam Tracking Based on the Same Plane Electrode

    Science.gov (United States)

    Shang, Zhendong; Wang, Weiguang

    2016-11-01

    Capacitive sensors have a wide range of applications, but its edge effect is severely restricted by the detection accuracy. In this paper, we put forward a kind of capacitance sensor based on the edge of capacitance. It has a wide range of static and dynamic measurement (mm) and high measurement accuracy. And its mathematical modeling, through the analysis proves that the model is correct and feasible.At the same time also used in the finite element analysis software ANSYS, three-dimensional model of the sensor was established, and the optimization and analysis of the sensor's output characteristic of sensor specific structural parameters, the final determination of the optimal structure parameters of the capacitive sensor. Finally, the experimental results show that the output signal of the sensor is good.

  18. Evaluation of cold bending and mechanical properties of helical (SAWH) and longitudinal (SAWL) seam pipes

    Energy Technology Data Exchange (ETDEWEB)

    Batista, Gilmar Zacca; Sanandres, Simon Ricardo [PETROBRAS, Rio de Janeiro, RJ (Brazil). Pipeline Engineering Division; Pinto, Percy Saavedra; Mello, Marcelo [Tubos Soldados Atlantico, Sao Paulo, SP (Brazil)

    2009-07-01

    The present work is a part of a comprehensive program that aims to evaluate the helical seam pipe application in pipeline construction and compare with the traditional longitudinal seam pipe that have been used in Brazil. One of the biggest concerns is the cold bending process once the Brazilian land profile is very sinuous, different than other countries where helical seam pipes have been used successfully. At this work, two pipes were used, one helical seam and one longitudinal seam, both API 5L X70 with 28 inch of diameter and 0.469 inch wall thickness. The results of cold bending tests comparing both types of pipe and the mechanical properties from the straight pipe with the bend section are shown. The research methodology includes dimensional analysis, microstructural evaluation and mechanical tests that were performed on the straight pipe and bend areas. The cold bending parameters used to obtain a bend according the design and construction standards requirements are also presented. The results showed that the cold bending process produces a helical seam pipe bend with the most critical radius allowed by the standards, without presenting any evidence of wrinkles, out-of-roundness above the limits or any type of mechanical damage. Both pipes tested met the standards requirements in terms of bending and mechanical properties. The results of this study provide technical information for future helical seam pipe application in Brazil. (author)

  19. Thermal effects of magmatic sills on coal seam metamorphism and gas occurrence

    Science.gov (United States)

    Wang, Liang; Cheng, Long-biao; Cheng, Yuan-ping; Yin, Guang-zhi; Cai, Chun-cheng; Xu, Chao; Jin, Kan

    2014-04-01

    Igneous intrusions in coal seams are found in 80 % of coal mines in the Huaibei coalfield, China, and coal and gas outburst accidents have occurred 11 times under a 120-m-thick sill in the Haizi mining field. The magma's heat had a significant controlling effect on coal seam gas occurrence. Based on theoretical analysis, experimental tests and site validation, we analyzed the temperature distribution following magma intrusion into coal measure strata and the variations in multiple physical parameters and adsorption/desorption characteristics between the underlying coal seams beneath the sill in the Haizi mining field and coal seams uninfluenced by magma intrusion in the adjacent Linhuan mining field. The research results show that the main factors controlling the temperature distribution of the magma and surrounding rocks in the cooling process include the cooling time and the thickness and initial temperature of the magmatic rock. As the distance from sill increases, the critical effective temperature and the duration of sustained high temperatures decrease. The sill in the Haizi mining field significantly promoted coal seam secondary hydrocarbon generation in the thermally affected area, which generated approximately 340 m3/t of hydrocarbon. In the magma-affected area, the metamorphic grade, micropore volume, amount of gas adsorption, initial speed of gas desorption, and amount of desorption all increase. Fluid entrapment by sills usually causes the gas pressure and gas content of the underlying coal seams to increase. As a result, the outburst risks from coal seams increases as well.

  20. Improving methods of extracting thick seams in the Kuzbass. Sovershenstvovanie sposobov razrabotki moshchnykh plastov v Kuzbasse

    Energy Technology Data Exchange (ETDEWEB)

    Tomashevskii, L.P.

    1985-01-01

    This report reviews mining conditions in the Prokop'evsk-Kiselevsk coal fields characterized by tectonic faults, well developed foldings, convergence of seams and propensity to spontaneous ignition. Discusses trends in the development of new and the improvement of old extraction methods (mining machines KPK, AK3 for 35-65 degree inclined seams up to 10 m thick, KNK, 20 KP-70 for seams over 10 m thick and KGS3, KV3 for extraction with stowing). Analyzes improved mining machines for use with flexible canopies (KMS cutter-loaders incorporating powered supports used for extracting 5 m thick 35-75 degree inclined seams); complex type 2ANShch for extraction of coal and erection of flexible canopies. Discusses method of extracting coal under flexible canopies by long diagonal faces with cutting advanced kerfs; mining thick seams and fold ridges by horizontal slicing employing FRG and Soviet props ('Tolstyi' seam, 35 m thick inclined 32-43 degrees and 45 m longwalls cutting 3 m slices); air supplies through diagonal boreholes. Describes trials of new double and diagonal canopies; extraction of faulted seams by horizontal layers with caving. Detailed discussion of the dynamics of pillar fragmentation and methods of erecting interhorizontal isolation strips to prevent spontaneous fires using consolidated rock and solidifying stowing.

  1. Law of surface movement for multi-coal seam strip mining 

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li-ya; ZHANG Hong-mei

    2014-01-01

    It is an important part of green mining to control the disasters of coal mining which have caused irreversible damages to buildings and ecological environment. Strip mining is one of the efficient measures to control surface subsidence and mining damage. However, the research on the laws of the surface subsidence are still deficient in multi-coal seam strip mining at present. Based on the Fast Lagrangian Analysis of Continua (short for FLAC3D) numerical simulation software, the laws of the surface subsidence and horizontal movement were systematically studied for different depths, different mining widths, different distances between seams, different mining thickness, different parameters between seams and the special relations of the upper pillar and the lower pillar in the vertical direction in multi-seam strip mining. The function relation between the maximum subsidence and the maximum horizontal movement with the depth, the mining width, the seam distance, mining thickness, different parameters between seams and the partial offset are summarized respectively. Finally the formula integrating the surface maximum subsidence value and the maximum horizontal movement was deduced. The results can be used for reference theory and measure in forecasting the surface displacement in multi-coal seam strip mining.

  2. Microcosmic analysis of ductile shearing zones of coal seams of brittle deformation domain in superficial lithosphere

    Institute of Scientific and Technical Information of China (English)

    JU; Yiwen; WANG; Guiliang; JIANG; Bo; HOU; Quanlin

    2004-01-01

    The ductile shearing zones of coal seams in a brittle deformation domain in superficial lithosphere are put forward based on the study on bedding shearing and ductile rheology of coal seams. The macrocosmic and microcosmic characteristics include wrinkle fold, mymonitized zones and ductile planar structure of coal seams, etc., while the microcosmic characteristics may also include different optic-axis fabrics and the anisotropy of vitrinite reflectance as well as the change of chemical structure and organic geochemistry components. The forming mechanism is analyzed and the strain environment of ductile shearing zones of coal seams discussed. The result indicates that, in the superficial brittle deformation domain, the coal seams are easy to be deformed, resulting in not only brittle deformation but also ductile shearing deformation under the action of force. Because of simple shearing stress, the interlayer gliding or ductile rheology may take place between coal seams and wall rocks. Therefore, many ductile shearing zones come into being in superficial lithosphere (<5 km). The research on ductile shearing zone of brittle deformation domain in superficial lithosphere is significant not only theoretically for the study of ductile shearing and ductile rheology of the lithosphere but also practically for the structural movement of coal seams, the formation and accumulation of coal-bed methane, and the prevention and harness of gas burst in coal mine.

  3. Gas seepage equation of deep mined coal seams and its application

    Institute of Scientific and Technical Information of China (English)

    HU Guo-zhong; WANG Hong-tu; TAN Hai-xiang; FAN Xiao-gang; YUAN Zhi-gang

    2008-01-01

    In order to obtain a gas seepage law of deep mined coal seams, according to the properties of eoalbed methane seepage in in-situ stress and geothermal temperature fields, the gas seepage equation of deep mined coal seams with the Klinkenberg effect was obtained by confirming the coalbed methane permeability in in-situ stress and geothermal temperature fields. Aimed at the condition in which the coal seams have or do not have an outcrop and outlet on the ground, the application of the gas seepage equation of deep mined coal seams in in-situ stress and geothermal temperature fields on the gas pressure calculation of deep mined coal seams was investigated. The comparison between calculated and measured results indicates that the calculation method of gas pressure, based on the gas seepage equation of deep mined coal seams in in-situ stress and geothermal temperature fields can accurately be identical with the measured values and theoretically perfect the calculation method of gas pressure of deep mined coal seams.

  4. Methodology for lens transmission measurement in the 8-13 micron waveband: integrating sphere versus camera-based

    Science.gov (United States)

    Schuster, Norbert; Verplancke, Jan; Salethaiyan, Bergeron; Franks, John

    2014-05-01

    Transmission is a key parameter in describing an IR-lens, but is also often the subject of controversy. One reason is the misinterpretation of "transmission" in infrared camera practice. If the camera lens is replaced by an alternative one the signal will be affected by two parameters: proportional to the square of the effective aperture based F-number and linearly to the transmission. The measure to collect energy is defined as the Energy Throughput ETP, and the signal level of the IR-camera is proportional to ETP. Most published lens transmission values are based on spectrophotometric measurement of plane-parallel witness pieces obtained from coating processes. Published aperture based F-numbers derive very often from ray tracing values in the on-axis bundle. The following contribution is about transmission measurement. It highlights the bulk absorption and coating issues of infrared lenses. Two different setups are built and tested, an Integrating Sphere (IS)-based setup and a Camera-Based (CB) setup. The comparison of the two principles also clarifies the impact of the F-number. One difficulty in accurately estimating lens transmission lies in measuring the ratio between the signal of ray bundles deviated by the lens under test and the signal of non-deviated ray bundles without lens (100% transmission). There are many sources for errors and deviations in LWIR-region including: background radiation, reflection from "rough" surfaces, and unexpected transmission bands. Care is taken in the set up that measured signals with and without the lens are consistent and reproducible. Reference elements such as uncoated lenses are used for calibration of both setups. When solid angle-based radiometric relationships are included, both setups yield consistent transmission values. Setups and their calibration will be described and test results on commercially available lenses will be published.

  5. The seam offset identification based on support vector regression machines

    Institute of Scientific and Technical Information of China (English)

    Zeng Songsheng; Shi Yonghua; Wang Guorong; Huang Guoxing

    2009-01-01

    The principle of the support vector regression machine(SVR) is first analysed. Then the new data-dependent kernel function is constructed from information geometry perspective. The current waveforms change regularly in accordance with the different horizontal offset when the rotational frequency of the high speed rotational arc sensor is in the range from 15 Hz to 30 Hz. The welding current data is pretreated by wavelet filtering, mean filtering and normalization treatment. The SVR model is constructed by making use of the evolvement laws, the decision function can be achieved by training the SVR and the seam offset can be identified. The experimental results show that the precision of the offset identification can be greatly improved by modifying the SVR and applying mean filtering from the longitudinal direction.

  6. In-Orbit Construction with a Helical Seam Pipe Mill

    Science.gov (United States)

    Gilhooley, N.

    The challenges of building large structures in space, and in particular a torus habitat, require novel processes. One potential method is to manufacture helical seam (also called spiral) pipe in orbit using a pipe mill. These machines turn rolls of steel or alloy into fully formed, welded and inspected pipe, pressure vessels and silos of various diameters. Pipe mills are highly automated and efficient in a factory environment and are increasingly being used for in-situ repair. By constructing in-orbit (on-orbit assembly) the launch vehicle can supply full payloads of compact, robust rolls of material; and the installation design is less restricted by fairing constraints and modular limitations. The use of a pipe mill is discussed as a possible construction method, for comparison an example design envelope is shown and further pipe mill products are considered.

  7. Some approaches to handling hydrogen sulphide in coal seams

    Energy Technology Data Exchange (ETDEWEB)

    Gillies, A.D.S.; Kizil, M.S.; Wu, H.W.; Harvey, T. [University of Queensland, Qld. (Australia). Department of Mining, Minerals and Materials Engineering

    2001-07-01

    The study addresses Hydrogen Sulphide (H{sub 2}S) in coal seams. The objectives of the project were to undertake a comprehensive series of interrelated studies to gain a full understanding of this complex mine production problem. The goal was to understand how, where and why high concentration zones of H{sub 2}S occur, how does gas release from the coal mass occur, can concentrations be diluted or neutralised through improved ventilation, water, chemical or microbiological infusion, chemical solution sprays and can mining approaches be modified to contain the problem. A multidisciplined approach has been used for related investigations. Systems and the output streams available for H{sub 2}S detection and monitoring have been examined. The large variations in H{sub 2}S concentration measurements from different face sources and the physical differences in the longwall face, ventilation plan, and operating procedures make the interpretation of gas concentration data difficult. Respiratory filters represent a cost-effective and short-term safe way to protect miners from potentially lethal environment. A selection of cartridge and Racal airstream helmet filters has been described and some tests into filter life and efficiency undertaken. The mine ventilation system can be modified to allow safe production through H{sub 2}S affected zones. Designs for maximising safe production through affected mine panel or development headings have been tested. Mining options to reduce H{sub 2}S emissions have also been examined. A major program of in-seam chemical neutralisation infusion trials was undertaken. The basic aim of the chemical infusion process is to prestrip a significant proportion of H{sub 2}S to allow coal mining to proceed in a safe working environment at an economic production rate. Some approaches to analysis of results and evaluating the efficiency of the approach have been given. 12 refs., 8 figs.

  8. Characteristics of ground behavior of fully mechanized caving faces in hard thick seams

    Institute of Scientific and Technical Information of China (English)

    SUO Yong-lu(索永录)

    2003-01-01

    It is showed in practice that the support load and its fluctuation is large, the periodic weighting is obvious and can be divided into two kinds, the large and small pressure, sometimes the behavior of the large pressure is very violent in hard thick seam caving faces. These are obviously different from those of the generally soft or medium hard seam caving feces. All above these are summarized, and the causes aroused these are researched. Finally the powered support selection of hard thick seam caving faces is discussed.

  9. Roof structure theory and support resistance determination of longwall face in shallow seam

    Institute of Scientific and Technical Information of China (English)

    HUANG Qing-xiang(黄庆享)

    2003-01-01

    This paper presents the structure models founded in shallow seam, the roof asymmetry arch with three articulations in roof first weighting and the step voussoir beam in roof periodic weighting. These structure models are differ from classic theory, it establishes the new roof control theory of instability structure roof, especially in shallow seam. Based on the new roof structure theory, the support working state of "given sliding load" is put forward, and the factor of load transmitting is introduced to determine the load on roof structure. Therefore, the proper and accurate calculating methods of support resistance are established. Based on this, the dynamic structure theory in shallow seam could be predicted.

  10. Stress-strain distribution at the boundary area of coal seams containing nonuniformities

    Energy Technology Data Exchange (ETDEWEB)

    Khaimova-Mal' kova, R.I.

    1986-01-01

    Discusses results of investigations carried out with the help of the finite element method in a 2 m thick coal seam at 400 m level, having varying properties and nonuniformities. Shows that considerable areas with horizontal deformation appear in soft coal which may result in vertical fissuring parallel to headings. States that presence of soft and hard inclusions in coal seams affect stress-strain state and stability of boundary areas and lead to spasmodic changes in stress-strain intensity which result in dynamic phenomena particularly in coal seams which are prone to sudden gas and coal outbursts. 3 refs.

  11. The estimation of coal thickness based on Kriging technique and 3D coal seam modeling

    Energy Technology Data Exchange (ETDEWEB)

    Li, X.; Hu, J.; Zhu, H.; Ding, X. [Tongji University, Shanghai (China)

    2008-07-15

    Based on borehole data, the spatial variation of coal seam thickness was studied. Using contour data, a Triangulated Irregular Network (TIN) model was constructed with a strip algorithm. By using the Kriging method, the thickness at each point of the TIN was calculated. The thickness of coal has the characteristic of uncertainties. The top TIN of the coal seam can be acquired through mapping the bottom TIN with the calculated thickness. A 3D model of the coal seam was constructed by building the corresponding relationship between the top and bottom TIN. 15 refs., 6 figs., 1 tab.

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

    Directory of Open Access Journals (Sweden)

    Z. Kiss

    2012-01-01

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

  13. Gray Comprehensive Evaluation Method on Coal Seam Water Injection in Order of Difficulty

    Directory of Open Access Journals (Sweden)

    Liu Xiao Li

    2016-01-01

    Full Text Available In order to evaluate the coal mine water injection accurately, the gray comprehensive evaluation is applied in this paper, the depth of coal seam, the development degree of coal seam crack, porosity, gas pressure in coal seam, wetting edge of coal, firmness coefficient of coal are chosen as the main index to evaluate the method of water injection into coal mine. The results show that the gray comprehensive evaluation model has a relatively high reliability and accuracy, which can be used to predict the difficulty degree of water injection.

  14. Exploration possibilities of Oligocene brown coal seams in the Vertessomio - Majkpuszta - Orosziany region

    Energy Technology Data Exchange (ETDEWEB)

    Gidai, L.

    1986-01-01

    The history of exploration, the stratigraphic conditions of the Oligocene formations together with the tectonics of the region are discussed. Based on exploration borehole data the expected thickness and distribution of the coal seams are presented. As demonstrated by the isopach lines the depth of the Oligocene coal seams varies between 50 and 300 mm below the surface, i.e. the beds lie somewhat higher than the Eocene coal-bearing strata. For this very reason the region seems to be extractable though the thickness of the coal seams falls behind the Eocene ones.

  15. Floral assemblage of the `D` coal seam (Cretaceous): implications for banding characteristics in New Zealand coal seams

    Energy Technology Data Exchange (ETDEWEB)

    Ward, S.D.; Moore, T.A.; Newman, J. [University of Canterbury, Christchurch (New Zealand). Dept. of Geology

    1995-09-01

    Two complete vertical sections were studied from the uppermost Cretaceous `D` coal seam near Greymouth, New Zealand. The thickest and most concentrated vitrain bands occur in the paleomire centre and bands are thinner and less abundant at the paleomire margin. Botanical analysis of the vitrain bands indicates they formed entirely from the secondary xylem (wood) of gymnosperms. Palynomorphs indicate that there is no consistent correlation between conifer pollen abundance and the degree of vitrain banding. However, maximum preservation of vitrain bands coincides with an inferred transition from a rheotrophic mire (as indicated by Phyllocladidites mawsonii pollen) to an acidic and possibly ombrotrophic system (as indicated by the abundance of Gleicheniaceae spores). This suggests that the presence/absence of gymnosperm secondary xylem as vitrain bands is controlled at least in part by mire chemistry.

  16. Combined ANN prediction model for failure depth of coal seam floors

    Institute of Scientific and Technical Information of China (English)

    WANG Lian-guo; ZHANG Zhi-kang; LU Yin-long; YANG Hong-bo; YANG Sheng-qiang; SUN Jian; ZHANG Jin-yao

    2009-01-01

    Failure depth of coal seam floors is one of the important considerations that must be kept in mind when mining is carried out above a confined aquifer. In order to study the factors that affect the failure depth of coal seam floors such as mining depth, coal seam pitch, mining thickness, workface length and faults, we propose a combined artificial neural networks (ANN) prediction model for failure depth of coal seam floors on the basis of existing engineering data by using genetic algorithms to train the ANN. A practical engineering application at the Taoyuan Coal Mine indicates that this method can effectively determine the network struc-ture and training parameters, with the predicted results agreeing with practical measurements. Therefore, this method can be applied to relevant engineering projects with satisfactory results.

  17. Distribution of Heavy Hydrocarbon in Coal Seams and Its Use in Predicting Outburst of Coal

    Institute of Scientific and Technical Information of China (English)

    蒋承林; 李增华; 韩颖

    2003-01-01

    In order to verify whether any special gas component exists in outburst samples or not, coal samples from both outburst coal seams and non-outburst coal seams were collected. Some gases were extracted from the samples and analyzed qualitatively and quantitatively on chromatogram-mass spectrograph. The qualitative analysis show that there is no special gases in coal seams. And the quantitative analysis indicates that the heavy hydrocarbon content in coal samples from outburst coal seams is apparently higher than that from non-outburst district ones, which reflects the damage of geological tectonic movement to coal body in history. Therefore, the heavy hydrocarbon content of coal sample can be used as an index to predict coal outburst.

  18. 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.

  19. Investigation into the deformation of a large span roadway in soft seams and its support technology

    Institute of Scientific and Technical Information of China (English)

    Fu Jianqiu; Feng Chao; Shi Jianjun

    2011-01-01

    We investigated the deformation failure mechanism of surrounding rock from the aspect of engineering support for a roadway in seams with soft roofs and soft floors and observed the large displacement of the roadway in these soft seams.The result shows that the deformation area is quite large,and settlement of the roof is evident and displacement of the side walls is also obvious.We considered rock bolt-cable coupling for roadway support in seams with soft roofs and floors,in which the cable should be fixed at key positions.As well,we designed an optimal scheme to support a roadway in soft seams of the Shizuishan Second Mine in Ningxia,China.Field monitoring results show that bolt-cable coupling support has achieved the aims of roadway stability control and minimizes deformation.

  20. Extracting a very thick seam at the Stara Jama mine in Yugoslavia

    Energy Technology Data Exchange (ETDEWEB)

    Bijelic, V.

    1986-01-01

    The Stara Jama mine is located in a brown coal field in the Northern part of the central Bosnian coal reserves. The main seam in the West Field attains an average seam thickness of 13.20 mm. On account of its major thickness, good calorific value and relatively low depth the extraction of the seam is of interest in economic terms. This article describes a fully mechanised longwall installation at Stara Jama mine for the complete extraction of thick coal seams. Analysis of the operating results of this method with the extraction method previously used leads to the conclusion that the longwalling applied at Stara Jama mine in conjunction with the top slicing method facilitates exploitation of the deposit, high operating results and a low safety risk.

  1. Working of spontaneously combustible coal seams with automatic air pressure regulation in the excavation field

    Energy Technology Data Exchange (ETDEWEB)

    Golik, A.S.; Churikov, Yu.V.; Troyan, N.P.

    1980-01-01

    A demonstration is made of the effectiveness of using an automatic air pressure control system during the working of spontaneously combustible coal seams in order to control endogenic fires and gas. 2 figures.

  2. Intramolecular fluorescence correlation spectroscopy in a feedback tracking microscope

    CERN Document Server

    McHale, Kevin

    2009-01-01

    We derive the statistics of the signals generated by shape fluctuations of large molecules studied by feedback tracking microscopy. We account for the influence of intramolecular dynamics on the response of the tracking system, and derive a general expression for the fluorescence autocorrelation function that applies when those dynamics are linear. We show that tracking provides enhanced sensitivity to translational diffusion, molecular size, heterogeneity and long time-scale decays in comparison to traditional fluorescence correlation spectroscopy. We demonstrate our approach by using a three-dimensional tracking microscope to study genomic $\\lambda$-phage DNA molecules with various fluorescence label configurations. We conclude with a discussion of related techniques, including computation of the relevant statistics for camera-based intramolecular correlation measurements.

  3. A novel track imaging system as a range counter

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Z. [National Institute of Radiological Sciences (Japan); Matsufuji, N. [National Institute of Radiological Sciences (Japan); Tokyo Institute of Technology (Japan); Kanayama, S. [Chiba University (Japan); Ishida, A. [National Institute of Radiological Sciences (Japan); Tokyo Institute of Technology (Japan); Kohno, T. [Tokyo Institute of Technology (Japan); Koba, Y.; Sekiguchi, M.; Kitagawa, A.; Murakami, T. [National Institute of Radiological Sciences (Japan)

    2016-05-01

    An image-intensified, camera-based track imaging system has been developed to measure the tracks of ions in a scintillator block. To study the performance of the detector unit in the system, two types of scintillators, a dosimetrically tissue-equivalent plastic scintillator EJ-240 and a CsI(Tl) scintillator, were separately irradiated with carbon ion ({sup 12}C) beams of therapeutic energy from HIMAC at NIRS. The images of individual ion tracks in the scintillators were acquired by the newly developed track imaging system. The ranges reconstructed from the images are reported here. The range resolution of the measurements is 1.8 mm for 290 MeV/u carbon ions, which is considered a significant improvement on the energy resolution of the conventional ΔE/E method. The detector is compact and easy to handle, and it can fit inside treatment rooms for in-situ studies, as well as satisfy clinical quality assurance purposes.

  4. 无针缝服装接缝性能研究分析%Seam Performance Analysis of No-Stitched Seam Apparels

    Institute of Scientific and Technical Information of China (English)

    寿弘毅

    2012-01-01

    以3种无针缝服装防水透气面料为研究对象,在一定时间、温度、压力条件下通过热压或超声波熔接,与同面料的针缝接口部位进行断裂强力、耐水压和水洗脱胶的比较。结果显示:3种面料不管用进口还是国产热熔胶膜,也不论是热压或超声波熔接,其接口部位强力均超出常规形式针缝的强力。因此无针缝加工不仅能做到防水透气,赋予接缝良好的弹性,同时能很好地保证户外运动服装对接缝强力的要求,水洗牢度也完全符合要求。%Three typical types of water proof and breathable fabrics are selected for the study. Fabrics are seamed by press bonding or ultrasonic waves at certain conditions of time, temperature and pressure. Performances such as fracture strength, water pressure resistance and debonding are compared to stitched seams on same fabrics. Test results indicate that no-stitched seams on all three fabrics have higher fracture strength than regular stitched seams, whether imported or domestic hot melt adhesives are used, or press bonding or ultrasonic waves are adopted. No-stitched seams are not only water proof and breathable but also flexible, and can guarantee the required seam strength and washing fastness.

  5. Research on drawing coal effects in the dipping and steep--dipping coal seams

    Institute of Scientific and Technical Information of China (English)

    胡伟; 王窈惠

    2002-01-01

    Controllable drawing roof coal mining method is applied either to rently inclined seam or to big dipping seam. This paper sums up four corresponding methods according to conditions of our country, and analyses the coal-recovering effects and proves applicated conditions and measures for improving by "drawing coal theory of the ellipsoid". Its conclusion basically consists with practice. This work is of guiding meaning for designing drawing coal technology.

  6. Stimulation of commercial coal seam methane production aimed at improving mining technology

    OpenAIRE

    2016-01-01

    The relevance of the current research is due to the urgent need to revise the existing normative bases and procedures involved in intensive development of coal-methane deposits and commercial production of coal seam methane. The article presents the analysis of data on coal production volume and amount of methane emitted into the atmosphere in Kuzbass. There is a need to develop the exploration techniques that would allow implementing pre-mining gas drainage of coal seams and provide the comp...

  7. Heatshield for Extreme Entry Environment Technology: Results from Acreage and Integrated Seams Arcjet Testing

    Science.gov (United States)

    Venkatapathy, Ethiraj

    2016-01-01

    This invited talk will give a brief overview of the integrated heat-shield system design that requires seams and the extreme environment conditions that HEEET should be demonstrated to be capable of thermal performance without fail. We have tested HEEET across many different facilities and at conditions that are extreme. The presentation will highlight the performance of both the acreage as well as integrated seam at these conditions. The Invite talks are 10 min and hence this presentation will be short.

  8. Extracting a very thick seam at the Stara Jama mine in Yugoslavia

    Energy Technology Data Exchange (ETDEWEB)

    Bijelic, V.

    1986-08-01

    With the general call for a high degree of exploitation of coal deposits, the complete extraction of thick seams is increasingly growing in importance. The following article shows, that the solution of this problem nowadays with fully mechanised longwall installations, as are available at the Stara Jama mine in Zenica, Yugoslavia, can be regarded as an example for the complete extraction of thick coal seams. Since the installation was first put into operation in 1978, the production results have been considerably improved upon.

  9. Forecasting Fractures in Coal Seams by Using Azimuthal Anisotropy from P-Wave Seismic Data

    Institute of Scientific and Technical Information of China (English)

    DONG Shou-hua; YUE Jian-hua; ZHANG Fen-xuan

    2007-01-01

    If the thickness of coal seams and the lithology of both roofs and floors of coal seams have not changed at all or only a little, then it is thought that the elastic anisotropy of coal seams depends mainly on fractures and obeys the horizontally symmetric model of an azimuth anisotropy. For a fixed offset, the amplitude A of the reflection P-wave and the cosine of 2 (ψ) has an approximately linear relation, ( (ψ) is the source-detector azimuth with respect to the fracture strike. Based on this relationship, many things can be done, such as the extraction of macro bins, the correction of residual normal moveout, the formation of azimuth gather, the transformation and normalization of azimuth gathers and the extraction of reflection wave amplitudes of coal seams. The least squares method was used to inverse theoretically the direction and density of fractures of coal seams. The result is in good agreement with the regional geological structure, indicating that the azimuth anisotropic analysis of the P-wave is feasible in evaluating the density and direction of fractures in coal seams.

  10. Influence of Light Rare Earth on Toughness of Welded Seam of LAHS Steel

    Institute of Scientific and Technical Information of China (English)

    李慕勤; 马臣; 刘冬梅

    2003-01-01

    The influence mechanism of light rare earth elements, which are transited to the welding seam of low-alloy high strength (LAHS) steel through the covering of the electrode, on the toughness of the welding seam was studied. The experimental results show that proper amount of rare earth elements can desulfurate, dehydrogenate, reduce inclusions and purify the structure of the welding seam. Rare earth element additions have the effect on welding seam and, at the same time, the transformation of side-batten ferrite is resisted while the pin-ferrite structure is promoted. The improvement of the toughness of the welding seam is due to the purifying action of rare earth elements as well as their refining effect on the structure. However, the toughness of the welding seam can decrease when the amount of light rare earth elements are added excessively because the crystal grains become coarser, porosities appear and the inclusions increase as well. The experimental results show that the suitable amount of light rare earth element additions is about 2%.

  11. Comparison of external motion tracking systems for PET list-mode reconstruction

    DEFF Research Database (Denmark)

    Olesen, Oline Vinter; Paulsen, Rasmus Reinhold; Keller, Sune H.

    2011-01-01

    attachment of markers to the subject introducing image artifacts on human scans. We have previously designed a camera-based structured light (SL) system for 3D head tracking used with the high resolution research tomograph (HRRT, Siemens, Knoxville, USA) [5]. The system was modified to use invisible light...... markerless tracking system is not trivial to provide and to our knowledge not presently existent. The Polaris Vicra optical tracking system (Northern Digital Inc.) is generally used with PET brain imaging and has been demonstrated to work very well on phantoms [4]. However, it suffers from the necessary...

  12. Depth camera-based 3D hand gesture controls with immersive tactile feedback for natural mid-air gesture interactions.

    Science.gov (United States)

    Kim, Kwangtaek; Kim, Joongrock; Choi, Jaesung; Kim, Junghyun; Lee, Sangyoun

    2015-01-08

    Vision-based hand gesture interactions are natural and intuitive when interacting with computers, since we naturally exploit gestures to communicate with other people. However, it is agreed that users suffer from discomfort and fatigue when using gesture-controlled interfaces, due to the lack of physical feedback. To solve the problem, we propose a novel complete solution of a hand gesture control system employing immersive tactile feedback to the user's hand. For this goal, we first developed a fast and accurate hand-tracking algorithm with a Kinect sensor using the proposed MLBP (modified local binary pattern) that can efficiently analyze 3D shapes in depth images. The superiority of our tracking method was verified in terms of tracking accuracy and speed by comparing with existing methods, Natural Interaction Technology for End-user (NITE), 3D Hand Tracker and CamShift. As the second step, a new tactile feedback technology with a piezoelectric actuator has been developed and integrated into the developed hand tracking algorithm, including the DTW (dynamic time warping) gesture recognition algorithm for a complete solution of an immersive gesture control system. The quantitative and qualitative evaluations of the integrated system were conducted with human subjects, and the results demonstrate that our gesture control with tactile feedback is a promising technology compared to a vision-based gesture control system that has typically no feedback for the user's gesture inputs. Our study provides researchers and designers with informative guidelines to develop more natural gesture control systems or immersive user interfaces with haptic feedback.

  13. Depth Camera-Based 3D Hand Gesture Controls with Immersive Tactile Feedback for Natural Mid-Air Gesture Interactions

    Directory of Open Access Journals (Sweden)

    Kwangtaek Kim

    2015-01-01

    Full Text Available Vision-based hand gesture interactions are natural and intuitive when interacting with computers, since we naturally exploit gestures to communicate with other people. However, it is agreed that users suffer from discomfort and fatigue when using gesture-controlled interfaces, due to the lack of physical feedback. To solve the problem, we propose a novel complete solution of a hand gesture control system employing immersive tactile feedback to the user’s hand. For this goal, we first developed a fast and accurate hand-tracking algorithm with a Kinect sensor using the proposed MLBP (modified local binary pattern that can efficiently analyze 3D shapes in depth images. The superiority of our tracking method was verified in terms of tracking accuracy and speed by comparing with existing methods, Natural Interaction Technology for End-user (NITE, 3D Hand Tracker and CamShift. As the second step, a new tactile feedback technology with a piezoelectric actuator has been developed and integrated into the developed hand tracking algorithm, including the DTW (dynamic time warping gesture recognition algorithm for a complete solution of an immersive gesture control system. The quantitative and qualitative evaluations of the integrated system were conducted with human subjects, and the results demonstrate that our gesture control with tactile feedback is a promising technology compared to a vision-based gesture control system that has typically no feedback for the user’s gesture inputs. Our study provides researchers and designers with informative guidelines to develop more natural gesture control systems or immersive user interfaces with haptic feedback.

  14. Calculation of gas content in coal seam influenced by in-situ stress grads and ground temperature

    Institute of Scientific and Technical Information of China (English)

    王宏图; 李时雨; 吴再生; 杨晓峰; 秦大亮; 杜云贵

    2002-01-01

    On the basis of the analysis of coal-bed gas pressure in deep mine, and the coal-bed permeability (k) and the characteristic of adsorption parameter (b) changing with temperature, the author puts forward a new calculating method of gas content in coal seam influenced by in-situ stress grads and ground temperature. At the same time, the contrast of the measuring results of coal-bed gas pressure with the computing results of coal-bed gas pressure and gas content in coal seam in theory indicate that the computing method can well reflect the authenticity of gas content in coal seam,and will further perfect the computing method of gas content in coal seam in theory,and have important value in theory on analyzing gas content in coal seam and forecasting distribution law of gas content in coal seam in deep mine.

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    Peng Xu

    2015-01-01

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

  17. Geomechanics of subsidence above single and multi-seam coal mining

    Institute of Scientific and Technical Information of China (English)

    A.M. Suchowerska Iwanec; J.P. Carter; J.P. Hambleton

    2016-01-01

    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.

  18. Fracture mechanics characterisation of the WWER-440 reactor pressure vessel beltline welding seam

    Energy Technology Data Exchange (ETDEWEB)

    Viehrig, Hans-Werner [Forschungszentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany)], E-mail: H.W.Viehrig@fzd.de; Schuhknecht, Jan [Forschungszentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany)

    2009-04-15

    The master curve (MC) approach as standardised in the ASTM Standard Test Method E1921 was applied to weld metal of the reactor pressure vessel (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 orientation of the specimens within the welding seam is TL and TS according to ASTM E399. The fracture toughness values measured on the SE(B) specimens with both orientations follow the course of the master curve. Nearly all values lie within the fracture toughness curves for 2% and 98% fracture probability. There is a strong variation of the reference temperature T{sub 0} through the thickness of the welding seam, which can be explained by microstructural differences. The scatter is more pronounced for the TS SE(B) specimens. It can be shown that specimens with TL and TS orientation in the welding seam have a differentiating and integrating behaviour, respectively.

  19. Research on Protective Area of Exploiting Lower Protective Coal Seam and its Feasibility

    Directory of Open Access Journals (Sweden)

    Wang Kai

    2014-02-01

    Full Text Available Based on the reasonable consideration of the role of the second main stress in D-P criterion, the distribution of stress and deformation with the method of finite difference was simulated. And the stress relief angles along incline and strike according to the rules of stress and deformation were obtained. Then the protective area resulted from exploiting the lower protective coal seam were acquired. The results show that the stress relief angles along incline are 75.5 and 77.7 degrees, the ones along strike are 78.4 and 83.5 degrees in the sense of protection when the advancing distance is 300m. But the real effective protective area is much smaller. The largest degree of stress relief locates in the protected coal seam corresponding to the upper and middle of the working face. According the simulation results and the water inrush coefficient method of effective water-resisting seam, the water inrush risk area of lower protective coal seam was divided, and the feasibility of exploiting protective coal seam was analysed and judged. Research results are of certain guidance and reference significance in the layout of mining and gas extraction for the similar coal mines.

  20. The development of a geosteering tool for in-seam drilling

    Energy Technology Data Exchange (ETDEWEB)

    Ian Gray; Paul Clemence; Gary Paradise; Sean Charlton; Robert Dixon; Peter Hatherly [Sigra (Australia)

    2002-06-01

    In 1996, Sigra and CMTE began a joint research project aimed at developing a tool to provide geosteering options for in-seam drilling. The tool was to provide a survey capability, drill torque, thrust and rpm measurements, and geophysical measurements of rock resistivity and the spectrum of the natural gamma radiation. It was intended that the tool could reside behind the drill bit and communicate through the drill string via existing communication systems or a cableless system that Sigra was proposing to develop. The development of geosteering tools has proved to be far more difficult than originally expected. The results from various tests, however, are extremely encouraging. Sigra has demonstrated the acquisition of rock resistivity and drill parameters - torque, pressure and thrust while drilling is underway. The expectation is that the resistivity measurements can indicate the approach of the coal seam roof or floor from the borehole. CMTE has established through the logging of in-seam and vertical boreholes, that spectrometric analysis of natural gamma radiation allows a characteristic seam profile to be monitored and that stone bands in the seam can be distinguished from the roof and floor. The ratio of the counts due to thorium and potassium is particularly diagnostic when combined with the information on the total radiation. All tools have been designed and constructed in consideration of the rigours of the down-hole environment, the needs for intrinsic safety, the needs for power, modularity, down-hole processing and communications.

  1. 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.

  2. A fuzzy logic model to predict the out-of-seam dilution in longwall mining

    Institute of Scientific and Technical Information of China (English)

    Ali Bahri Najafi; Golam Reza Saeedi

    2015-01-01

    The longwall mining method is often affected by the out-of-seam dilution (OSD). Therefore, predicting and controlling of dilution are important factors for reducing mining costs. In this study, the fuzzy set theory and multiple regression models with parameters, including variation in seam thickness, dip of seam, seam thickness, depth of seam, and hydraulic radius as inputs to the models were applied to pre-dict the OSD in the longwall coal panels. Field data obtained from Kerman and Tabas coal mines, Iran were used to develop and validate the models. Three indices including coefficient of determination (R2), root mean square error (RMSE) and variance account for (VAF) were used to evaluate the perfor-mance of the models. With 10 randomly selected datasets, for the linear, polynomial, power, exponential, and fuzzy logic models, R2, RSME and VAF are equal to (0.85, 4.4, 84.4), (0.61, 7.5, 59.6), (0.84, 4.5, 72.7), (0.80, 4.1, 79.6), and (0.97, 2.1, 95.7), respectively. The obtained results indicate that the fuzzy logic model predictor with R2=0.97, RMSE=2.1, and VAF=95.7 performs better than the other models.

  3. Phenomenon of methane driven caused by hydraulic fracturing in methane-bearing coal seams

    Institute of Scientific and Technical Information of China (English)

    Huang Bingxiang; Cheng Qingying; Chen Shuliang

    2016-01-01

    The methane concentration of the return current will always be enhanced to a certain degree when hydraulic fracturing with bedding drilling is implemented to a gassy coal seam in an underground coal mine. The methane in coal seam is driven out by hydraulic fracturing. Thus, the phenomenon is named as methane driven effect of hydraulic fracturing. After deep-hole hydraulic fracturing at the tunneling face of the gassy coal seam, the coal methane content exhibits a‘low-high-low”distribution along exca-vation direction in the following advancing process, verifying the existence of methane driven caused by hydraulic fracturing in methane-bearing coal seam. Hydraulic fracturing causes the change of pore-water and methane pressure in surrounding coal. The uneven distribution of the pore pressure forms a pore pressure gradient. The free methane migrates from the position of high pore (methane) pressure to the position of low pore (methane) pressure. The methane pressure gradient is the fundamental driving force for methane-driven coal seam hydraulic fracturing. The uneven hydraulic crack propagation and the effect of time (as some processes need time to complete and are not completed instantaneously) will result in uneven methane driven. Therefore, an even hydraulic fracturing technique should be used to avoid the negative effects of methane driven; on the other hand, by taking fully advantage of methane driven, two technologies are presented.

  4. Applicable conditions for a classification system of aquifer-protective mining in hallow coal seams

    Institute of Scientific and Technical Information of China (English)

    Liu Yude; Zhang Dongsheng; Fan Gangwei; Yan Shoufeng

    2011-01-01

    Based on the conclusions of domestic and foreign research,we have analyzed the collapse-fall characteristics of overlying strata and the mechanism of aquifer-protective mining in shallow coal seam working faces at the Shendong Mine.We have selected the height of the water-conducting fracture zone in overlying strata as a composite index and established the applicable conditions of aquifer-protective mining in shallow coal seams with a multi-factor synthetic-index classification method.From our calculations and analyses of variance,we used factors such as the overlying strata strength,mining disturbing factors and rock integrity as related factors of the composite index.We have classified the applicable conditions of aquifer-protective mining in shallow coal seams into seven types by comparing the result of the height of water-conducting fractured zones of long-wall and short-wall working faces with the thickness of the bedrock.the thickness of the weathered zone and the size of safety coal-rock pillars.As a result,we propose the preliminary classification system of aquifer-protective mining in shallow coal seams.It can provide a theoretical guidance for safe applications of aquifer-protective mining technology in shallow coal seams under similar conditions.

  5. A Valence Bond Description of the Prefulvene Extended Conical Intersection Seam of Benzene.

    Science.gov (United States)

    Blancafort, Lluís; Robb, Michael A

    2012-12-11

    The permutational isomers of the prefulvene-like minimum energy conical intersection lie on an extended conical intersection seam, where they are connected by higher symmetry structures. Here, we present a VB analysis of the electronic states involved along this extended seam. The VB method produces a spin-exchange density (ie. a bonding pattern) that provides the basis to assign resonance structures to the states. The results show that in the high symmetry region of the seam, the character of the states is dominated by the positive and negative combination of the Kekulé structures, (A+B) and (A-B). The low energy parts of the seam, comprised of lower symmetry conical intersection structures, are stabilized by mixing with the Dewar resonance structures. This feature is responsible for the stability of the benzvalene-like conical intersections. The validity of the VB model is confirmed by calculating the branching space vectors at this level of theory, which are in good agreement with the CASSCF calculated vectors. The VB analysis has also allowed us to complete our picture of the global seam, since it has provided the clue to locate a conical intersection saddle point that interconverts two minima of the prefulvene conical intersection where the carbon bent out of the plane is inverted and rotated by 60°. This saddle point has a benzvalene-like geometry, in agreement with the VB picture.

  6. Post-trial anatomical frame alignment procedure for comparison of 3D joint angle measurement from magnetic/inertial measurement units and camera-based systems.

    Science.gov (United States)

    Li, Qingguo; Zhang, Jun-Tian

    2014-11-01

    Magnetic and inertial measurement units (MIMUs) have been widely used as an alternative to traditional camera-based motion capture systems for 3D joint kinematics measurement. Since these sensors do not directly measure position, a pre-trial anatomical calibration, either with the assistance of a special protocol/apparatus or with another motion capture system is required to establish the transformation matrices between the local sensor frame and the anatomical frame (AF) of each body segment on which the sensors are attached. Because the axes of AFs are often used as the rotational axes in the joint angle calculation, any difference in the AF determination will cause discrepancies in the calculated joint angles. Therefore, a direct comparison of joint angles between MIMU systems and camera-based systems is less meaningful because the calculated joint angles contain a systemic error due to the differences in the AF determination. To solve this problem a new post-trial AF alignment procedure is proposed. By correcting the AF misalignments, the joint angle differences caused by the difference in AF determination are eliminated and the remaining discrepancies are mainly from the measurement accuracy of the systems themselves. Lower limb joint angles from 30 walking trials were used to validate the effectiveness of the proposed AF alignment procedure. This technique could serve as a new means for calibrating magnetic/inertial sensor-based motion capture systems and correcting for AF misalignment in scenarios where joint angles are compared directly.

  7. Explanation for peat-forming environments of coal seam 2 and 9-2 based on the maceral composition and aromatic compounds in the Xingtai coalfield, China

    Institute of Scientific and Technical Information of China (English)

    SUN Yu-zhuang; QIN Shen-jun; LI Yan-heng; LIN Ming-yue; DING Shu-li

    2009-01-01

    Maceral composition and aromatic compounds were determined on column samples to study the peat-forming environments of Permian coal seam 2 and Carbonifer-ous coal seam 9-2 from the Xingtai coalfield,China.The macerals were dominated by iner-tinite in seam 2 and by vitrinite in seam 9-2.Three maceral groups were selected as indi-cators of peat-forming environments.Two triangle diagrams were drawn based on the in-dicators to explicate the peat-forming environments of permian seam 2 and Carboniferous seam 9-2.The results indicate that the peat of carboniferous seam 9-2 formed dominantly in wet swamps,whereas the peat of Permian seam 2 formed dominantly in dry swamps and open moor environments.

  8. Stimulation of commercial coal seam methane production aimed at improving mining technology

    Science.gov (United States)

    Shubina, E. A.; Lukyanov, V. G.

    2016-09-01

    The relevance of the current research is due to the urgent need to revise the existing normative bases and procedures involved in intensive development of coal-methane deposits and commercial production of coal seam methane. The article presents the analysis of data on coal production volume and amount of methane emitted into the atmosphere in Kuzbass. There is a need to develop the exploration techniques that would allow implementing pre-mining gas drainage of coal seams and provide the companies with the guidance on coal seam methane drainage in very gassy coal mines. Commercial production of methane should become an integral part of economy and energy balance of the Russian Federation, which, in its turn, would enhance environmental protection due to reducing methane emissions, the largest source of greenhouse effect.

  9. Evaluation of coal bed methane potential of coal seams of Sawang Colliery, Jharkhand, India

    Indian Academy of Sciences (India)

    Anil M Pophare; Vinod A Mendhe; A Varade

    2008-04-01

    The coal seams of Sawang Colliery, East Bokaro Coalfields are bituminous to sub-bituminous in nature and categorized as high gaseous seams (degree II to degree III level). These seams have the potential for coal bed methane (CBM) and their maturity increases with increasing depth, as a result of enhanced pressure-temperature conditions in the underground. The vitrinite maceral group composition of the investigated coal seams ranges from 62.50-83.15%, whereas the inertinite content varies from 14.93-36.81%. The liptinite content varies from 0.66% to 3.09%. The maximum micro-pores are confined within the vitrinite group of macerals. The coal seams exhibit vitrinite reflectance values (Ro% calculated) from 0.94% (sample CG-97) to 1.21% (sample CG-119). Proximate analyses of the investigated coal samples reveal that the moisture content (M%) ranges from 1.28% to 2.98%, whereas, volatile matter (VM%) content is placed in the range of 27.01% to 33.86%. The ash content (A%) ranges from 10.92% to 30.01%. Fixed carbon (FC%) content varies from 41.53% to 55.93%. Fuel ratio variation shows a restricted range from 1.53 to 1.97. All the coal samples were found to be strongly caking and forming coke buttons. The present study is based on the adsorption isotherm experiments carried out under controlled P-T conditions for determination of actual gas adsorption capacity of the coal seams. This analysis shows that the maximum methane gas adsorbed in the coal sample CG-81 is 17m3/t (Std. daf), at maximum pressure of 5.92MPa and experimental temperature of 30°C. The calculated Langmuir regression parameters PL and VL range from 2.49 to 3.75MPa and 22.94 to 26.88m3/t (Std. daf), respectively.

  10. Impacts of Coal Seam Gas (Coal Bed Methane) and Coal Mining on Water Resources in Australia

    Science.gov (United States)

    Post, D. A.

    2013-12-01

    Mining of coal bed methane deposits (termed ';coal seam gas' in Australia) is a rapidly growing source of natural gas in Australia. Indeed, expansion of the industry is occurring so quickly that in some cases, legislation is struggling to keep up with this expansion. Perhaps because of this, community concern about the impacts of coal seam gas development is very strong. Responding to these concerns, the Australian Government has recently established an Independent Expert Scientific Committee (IESC) to provide advice to the Commonwealth and state regulators on potential water-related impacts of coal seam gas and large coal mining developments. In order to provide the underlying science to the IESC, a program of ';bioregional assessments' has been implemented. One aim of these bioregional assessments is to improve our understanding of the connectivity between the impacts of coal seam gas extraction and groundwater aquifers, as well as their connection to surface water. A bioregional assessment can be 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 now being carried out across large portions of eastern Australia which are underlain by coal reserves. This presentation will provide an overview of the issues related to the impacts of coal seam gas and coal mining on water resources in Australia. The methodology of undertaking bioregional assessments will be described, and the application of this methodology to six priority bioregions in eastern Australia will be detailed. Preliminary results of the program of research to date will be assessed in light of the requirements of the IESC to provide independent advice to the Commonwealth and State governments. Finally, parallels between the expansion of the industry in Australia with that

  11. 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

  12. 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…

  13. Experimental Study on the Feasibility of Methane Drainage in Coal Seams with Compound Technique of Perforating and Fracturing

    Institute of Scientific and Technical Information of China (English)

    Luo Yong; Shen Zhaowu

    2007-01-01

    Compound technique of perforating and fracturing can effectively control the perforating direction and the fracturing expansion. The feasibility of this technique used in fracturing coal seams is analyzed. In this paper, the experiments of perforating and fracturing are carried out on samples of coal and the experimental effects are satisfactory. Compound technique of perforating and fracturing is promising in coal seams.

  14. Facies conditions of the 2. Lusatian seam horizon in the area East of Peitz

    Energy Technology Data Exchange (ETDEWEB)

    Boenisch, R.; Liskow, C.

    1988-07-01

    Characterizes the Miocene brown coal deposit in the area Peitz, Jaenschwalde and Guben (GDR) by methods of paleobotany and paleogeography. Results of macropetrographic facies analysis and geophysical borehole measurements were employed in the study. Geologic profiles of the region as well as maps of seam distribution were drawn up. The analysis proves that prehistoric river meanders divide the brown coal moor into a northern and a southern section. A description of the paleoenvironment and the sedimentation process is given. A correlation between coal facies and technological coal quality is pointed out. The study is being used to develop a geologic seam model for this brown coal mining area. 9 refs.

  15. Laser-welded Dissimilar Steel-aluminum Seams for Automotive Lightweight Construction

    Science.gov (United States)

    Schimek, M.; Springer, A.; Kaierle, S.; Kracht, D.; Wesling, V.

    By reducing vehicle weight, a significant increase in fuel efficiency and consequently a reduction in CO 2 emissions can be achieved. Currently a high interest in the production of hybrid weld seams between steel and aluminum exists. Previous methods as laser brazing are possible only by using fluxes and additional materials. Laser welding can be used to join steel and aluminum without the use of additives. With a low penetration depth increases in tensile strength can be achieved. Recent results from laser welded overlap seams show that there is no compromise in strength by decreasing penetration depth in the aluminum.

  16. Exploration possibilities of Oligocene coal seams in the vicinity of Mogyorosbanya and Szarkaspuszta

    Energy Technology Data Exchange (ETDEWEB)

    Gidai, L.

    1986-01-01

    In the Dorog Basin (North Trabnsdanubia) the Oligocene coal seams lie in much smaller depths than the Eocene ones, thus the prospective coal reserves could be mined under less dangerous conditions (water inrush etc.). A review of the history of exploration is given together with the demonstration of the structural-tectonic position of the area in question. The distribution and extension as well as the quality and thickness of the Oligocene coal seams are discussed with special reference to the strata columns. Eight regions are distinguished that may be suitable for economic use.

  17. Automatic assessment of the appearance of seam pucker on textiles using Hough transform

    Science.gov (United States)

    Ichikawa, Koji; Aibara, Tsunehiro; Muranaka, Maki; Izumide, Masanori; Murakami, Kenji

    1996-02-01

    Two methods of automated assessment of the appearance of seam pucker based on the Hough transform are proposed. We treat this problem as a pattern recognition problem. From the given standard photographs of suits, which are classified into five classes, we determine a template pattern for each class. These patterns are separated well in the feature space. Although there are several items to be assessed, we focus our attention on the seam of the back of suits. Using a few test samples we made an experiment on the assessment. The results suggest the possibility of practical use.

  18. Application of Seismic Anisotropy Caused by Fissures in Coal Seams to the Detection of Coal-bed Methane Reservoirs

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Coal-bed methane is accumulated in micro-fissures and cracks in coal seams. The coal seam is the source terrace and reservoir bed of the coal-bed methane (Qian et al., 1996). Anisotropy of coal seams is caused by the existence of fissures. Based on the theory of S wave splitting: an S wave will be divided into two S waves with nearly orthogonal polarization directions when passing through anisotropic media, i.e. the fast S wave with its direction of propagation parallel to that of the fissure and slow S wave with the direction of propagation perpendicular to that of the fissure.This paper gives the results of laboratory research and field test on the S wave splitting caused by coal-seam fissures. The results show that it is feasible to detect fissures in coal seams by applying the converted S wave and finally gives the development zone and development direction of these fissures.

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

    OpenAIRE

    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 tem...

  20. De-stressed mining of multi-seams: Surrounding rock control during the mining of a roadway in the overlying protected seam

    Institute of Scientific and Technical Information of China (English)

    Wang Cheng; Zhang Nong; Li Guichen; Zhang Nianchao

    2011-01-01

    Surrounding rock control in the overlying protective coal seam is a challenging topic for de-stressed mining of multi-seamed coal. Current research findings on roadway control were used in the design of a physical model of a complex textured roof having a varying thickness. The model was used to study roadway instability and collapse caused by dynamic pressure. The results show that when the thickness of the roof exceeds the bolted depth the roadway security is least and the roof has the greatest possibility for collapse. Numerical simulations were also carried out to study stress redistribution before and after roadway excavation during underlying protective seam mining. The evolution of roadway displacement and fracture, as affected by support methods, has been well studied. A series of support principles and technologies for mining affected roadways has been proposed after demonstration of successful practical application in the Huainan Mines. These principles and technologies are of extended value to deep coal mining support in China.

  1. Molecular characterization of microbial communities in deep coal seam groundwater of northern Japan

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, S.; Akiyama, M.; Naganuma, T.; Fujioka, M.; Nako, M.; Ishijima, Y. [Northern Advancement Center for Science and Technology, Hokkaido (Japan)

    2007-12-15

    We investigated microbial methanogenesis and community structure based on 16S rRNA gene sequences from a coal seam aquifer located 843-907 m below ground level in northern Japan; additionally, we studied the {delta}{sup 13}C and {delta} {sup 2}H ({delta}D) of coal-bed gases and other physicochemical parameters. Although isotopic analysis suggested a thermocatalytic origin for the gases, the microbial activity and community structure strongly implied the existence of methanogenic microbial communities in situ. Methane was generated in the enrichment cultures of the hydrogenotrophic and methylotrophic microorganisms obtained from coal seam groundwater. Methanogen clones dominated the archaeal 16S rRNA gene libraries and were mostly related to the hydrogenotrophic genus Methanoculleus and the methylotrophic genus Methanolobus. Bacterial 16S rRNA gene libraries were dominated by the clones related to the genera Acetobacterium and Syntrophus which have a symbiotic association with methanogens. LIBSHUFF analysis revealed that N{sub 2} gas injected into the coal seam (for enhanced methane production) does not affect the coverage of archaeal and bacterial populations. However, AMOVA analysis does provide evidence for a change in the genetic diversity of archaeal populations that are dominated by methanogens. Therefore, N{sub 2} injection into the coal seam might affect the cycling of matter by methanogens in situ.

  2. Installed capacity of coal seam gas power generation exceeds 480 MW under SGCC s coverage

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The journalist learned from the "National Gas Security Working Conference" held recently that the coal seam gas power generation has been rapidly developed in recent years.As of July 2009,within the SGCC's business area,the power generation units

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

    NARCIS (Netherlands)

    Aalderink, Bernard Johan; Pathiraj, B.; Aarts, R.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, f

  4. Draft Genome Sequence of Clostridium sp. Maddingley, Isolated from Coal-Seam Gas Formation Water.

    Science.gov (United States)

    Rosewarne, Carly P; Greenfield, Paul; Li, Dongmei; Tran-Dinh, Nai; Bradbury, Mark I; Midgley, David J; Hendry, Philip

    2013-01-01

    Clostridium sp. Maddingley was isolated as an axenic culture from a brown coal-seam formation water sample collected from Victoria, Australia. It lacks the solventogenesis genes found in closely related clostridial strains. Metabolic reconstructions suggest that volatile fatty acids are the main fermentation end products.

  5. Principle and engineering application of pressure relief gas drainage in low permeability outburst coal seam

    Institute of Scientific and Technical Information of China (English)

    LIU lin; CHENG Yuan-ping; WANG Hai-feng; WANG Liang; MA Xian-qin

    2009-01-01

    With the increase in mining depth, the danger of coal and gas outbursts increases. In order to drain coal gas effectively and to eliminate the risk of coal and gas outbursts, we used a specific number of penetration boreholes for draining of pressure relief gas. Based on the principle of overlying strata movement, deformation and pressure relief, a good effect of gas drainage was obtained. The practice in the Panyi coal mine has shown that, after mining the Cllcoal seam as the protective layer, the relative expansion deformation value of the protected layer C13 reached 2.63%, The permeability coefficient increased 2880 times, the gas drainage rate of the C13 coal seam increased to more than 60%, the amount of gas was reduced from 13.0 to 5.2 m3/t and the gas pressure declined from 4.4 to 0.4 MPa, which caused the danger the outbursts in the coal seams to be eliminated. The result was that we achieved a safe and highly efficient mining operation of the C 13 coal seam.

  6. Numerical investigations on mapping permeability heterogeneity in coal seam gas reservoirs using seismo-electric methods

    Science.gov (United States)

    Gross, L.; Shaw, S.

    2016-04-01

    Mapping the horizontal distribution of permeability is a key problem for the coal seam gas industry. Poststack seismic data with anisotropy attributes provide estimates for fracture density and orientation which are then interpreted in terms of permeability. This approach delivers an indirect measure of permeability and can fail if other sources of anisotropy (for instance stress) come into play. Seismo-electric methods, based on recording the electric signal from pore fluid movements stimulated through a seismic wave, measure permeability directly. In this paper we use numerical simulations to demonstrate that the seismo-electric method is potentially suitable to map the horizontal distribution of permeability changes across coal seams. We propose the use of an amplitude to offset (AVO) analysis of the electrical signal in combination with poststack seismic data collected during the exploration phase. Recording of electrical signals from a simple seismic source can be closer to production planning and operations. The numerical model is based on a sonic wave propagation model under the low frequency, saturated media assumption and uses a coupled high order spectral element and low order finite element solver. We investigate the impact of seam thickness, coal seam layering, layering in the overburden and horizontal heterogeneity of permeability.

  7. Fully mechanised working of vertical and thin coal seams in the Central Asturian coalfield

    Energy Technology Data Exchange (ETDEWEB)

    Arsuaga, J.; Luque, V.; Garcia Arguelles, A.; Beckmann, K.

    1984-01-01

    This describes integrated mechanisation trials on a coal face in a thin vertical seam with geological irregularities. The mining company used a shearer of its own design, HUNOSA-1, and Westfalia-Lunen and Mackina Westfalia hydraulically powered supports. Excellent results were obtained.

  8. Physical Simulation Method for the Investigation of Weld Seam Formation During the Extrusion of Aluminum Alloys

    Science.gov (United States)

    Fang, Gang; Nguyen, Duc-Thien; Zhou, Jie

    2016-12-01

    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 great importance to understand the formation of weld seams inside the welding chamber during extrusion, as affected by extrusion process variables and die design. Previously developed physical simulation methods could not fully reproduce the thermomechanical conditions inside the welding chamber of porthole die. In this research, a novel physical simulation method for the investigation of weld seam formation during extrusion was developed. With a tailor-designed tooling set mounted on a universal testing machine, the effects of temperature, speed, and strain on the weld seam quality of the 6063 alloy were investigated. The strains inside the welding chamber were found to be of paramount importance for the bonding of metal streams, accompanied by microstructural changes, i.e., recovery or recrystallization, depending on the local deformation condition. The method was shown to be able to provide guidelines for the design of porthole dies and choice of extrusion process variables, thereby reducing the scrap rate of aluminum extrusion operation.

  9. Forward Modeling of Azimuthal Anisotropy to the Reflected P Wave of Coal Seam

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun-gong; DONG Shou-hua; YUE Jian-hua

    2006-01-01

    Under the condition of weak anisotropy, the relation of P-wave anisotropy in direction to fractures of coal seams was researched in order to forecast the density and the direction of the fractures. Although the approximate solution by Rüger is suitable for thick reservoirs, it has some limitations for the composite reflected wave from both roofs and floors of coal seams, as well as multiple reflections. So first, the phase velocity and group velocity as well as their travel time were calculated about the reflected P-wave of the coal seam. Then, the anisotropic coefficients of both roofs and floors were calculated by Rüger formulae and last, the section versus azimuth in fixed offset can be gotten by convolution. In addition, the relation of amplitude of the composite reflected wave to azimuth angle was discussed. The forward modelling results of the coal azimuth anisotropy show these: 1) the coal seam is the strong reflecting layer, but the change of the reflectivity caused by the azimuth anisotropy is smaller; 2) if the azimuth angle is parallel to the crack strike, the reflectivity reaches up to the maximum absolute value, however, if the azimuth angle is perpendicular to the crack strike, the absolute value of the reflection coefficient is minimum; and 3)the reflection coefficient is the cosine function of the azimuth angle and the period is π.

  10. Nitrogen Injection To Flush Coal Seam Gas Out Of Coal: An Experimental Study

    Science.gov (United States)

    Zhang, Lei; Aziz, Naj; Ren, Ting; Nemcik, Jan; Tu, Shihao

    2015-12-01

    Several mines operating in the Bulli seam of the Sydney Basin in NSW, Australia are experiencing difficulties in reducing gas content within the available drainage lead time in various sections of the coal deposit. Increased density of drainage boreholes has proven to be ineffective, particularly in sections of the coal seam rich in CO2. Plus with the increasing worldwide concern on green house gas reduction and clean energy utilisation, significant attention is paid to develop a more practical and economical method of enhancing the gas recovery from coal seams. A technology based on N2 injection was proposed to flush the Coal Seam Gas (CSG) out of coal and enhance the gas drainage process. In this study, laboratory tests on CO2 and CH4 gas recovery from coal by N2 injection are described and results show that N2 flushing has a significant impact on the CO2 and CH4 desorption and removal from coal. During the flushing stage, it was found that N2 flushing plays a more effective role in reducing adsorbed CH4 than CO2. Comparatively, during the desorption stage, the study shows gas desorption after N2 flushing plays a more effective role in reducing adsorbed CO2 than CH4.

  11. Seam-wave measurements in the pits of Nogrod coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Toros, E.; Bodoky, T.

    1988-01-01

    The principle of measuring seismic seam-waves is shortly reviewed and measurement examples are given from the coal mines of Nograd County. Reflection measurements and time sections are exemplified by different figures from different pits. The preliminary results of the method obtained in these mines as well as further application possibilities of the method are described.

  12. The mechanics of intersecting echelon veins and pressure solution seams in limestone

    Science.gov (United States)

    Seyum, Solomon; Pollard, David D.

    2016-08-01

    Many studies that describe the formation of echelon vein arrays relate the causative stresses implicitly to the deformation, reliant on simple shear kinematics, such that the vein-to-array angle and the array width are the primary physical quantities. In contrast, we identify twelve physical quantities to describe echelon veins in two dimensions, including coeval, vein-intersecting, pressure solution seams. A finite element method is used to reproduce vein shapes in linear elastic and elastic-perfectly plastic model limestone. Model vein geometries are designed using values within the range of geometries measured from echelon veins at Raplee Anticline and Comb Monocline, Utah. Four physical quantities are significant for describing echelon vein shapes: vein spacing, vein-array angle, limestone elastic stiffness, and closing of orthogonal pressure solution seams. Pressure solution seam closing influences the mechanical interaction between adjacent veins, and for a range of conditions, causes a nearly linear vein opening distribution (triangular shapes) and encourages straight vein propagation, both of which approximate field measurements. Model results show that small spacing of veins with seams and large vein-array angles promote straight vein traces in limestone with stiffness typical of laboratory measurements, given the physical geologic conditions inferred from the burial history of the limestone strata.

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

    Directory of Open Access Journals (Sweden)

    Nam JaeYeal

    2010-09-01

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

  14. A poromechanical model for coal seams saturated with binary mixtures of CH4 and CO2

    Science.gov (United States)

    Nikoosokhan, Saeid; Vandamme, Matthieu; Dangla, Patrick

    2014-11-01

    Underground coal bed reservoirs naturally contain methane which can be produced. In parallel of the production of this methane, carbon dioxide can be injected, either to enhance the production of methane, or to have this carbon dioxide stored over geological periods of time. As a prerequisite to any simulation of an Enhanced Coal Bed Methane recovery process (ECBM), we need state equations to model the behavior of the seam when cleats are saturated with a miscible mixture of CH4 and CO2. This paper presents a poromechanical model of coal seams exposed to such binary mixtures filling both the cleats in the seam and the porosity of the coal matrix. This model is an extension of a previous work which dealt with pure fluid. Special care is dedicated to keep the model consistent thermodynamically. The model is fully calibrated with a mix of experimental data and numerical data from molecular simulations. Predicting variations of porosity or permeability requires only calibration based on swelling data. With the calibrated state equations, we predict numerically how porosity, permeability, and adsorbed amounts of fluid vary in a representative volume element of coal seam in isochoric or oedometric conditions, as a function of the pressure and of the composition of the fluid in the cleats.

  15. Dynamic effects of high-pressure pulsed water jet in low-permeability coal seams

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-hong; ZHOU Dong-ping; LU Yi-yu; KANG Yong; ZHAO Yu; WANG Xiao-chuan

    2009-01-01

    Mine gas extraction in China is difficult due to the characteristics such as mi-cro-porosity, low-permeability and high adsorption of coal seams. The pulsed mechanism of a high-pressure pulsed water jet was studied through theoretical analysis, experiment and field measurement. The results show that high-pressure pulsed water jet has three dynamic properties. What's more, the three dynamic effects can be found in low-perme-ability coal seams. A new pulsed water jet with 200-1 000 Hz oscillation frequency and peak pressure 2.5 times than average pressure was introduced. During bubble collapsing, sound vibration and instantaneous high pressures over 100 MPa enhanced the cutting ability of the high-pressure jet. Through high-pressure pulsed water jet drilling and slotting, the exposure area of coal bodies was greatly enlarged and pressure of the coal seams rapidly decreased. Therefore, the permeability of coal seams was improved and gas ab-sorption rate also decreased. Application results show that gas adsorption rate decreased by 30%-40% and the penetrability coefficient increased 100 times. This proves that high-pressure pulsed water is more efficient than other conventional methods.

  16. 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.

  17. 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.

  18. Determining areas in an inclined coal seam floor prone to water-inrush by micro-seismic monitoring

    Institute of Scientific and Technical Information of China (English)

    Sun Jian; Wang Lianguo; Wang Zhansheng; Hou Huaqiang; Shen Yifeng

    2011-01-01

    The failure depth of the coal seam floor is one important consideration that must be kept in mind when mining is carried out above a confined aquifer. Determining the floor failure depth is the essential precondition for predicting the water-resisting ability of the floor. We have used a high-precision microseismic monitoring technique to overcome the limited amount of data available from field measurements. The failure depth of a coal seam floor, especially an inclined coal seam floor, may be more accurately estimated by monitoring the continuous, dynamic failure of the floor. The monitoring results indicate the failure depth of the coal seam floor near the workface conveyance roadway (the lower crossheading) is deeper and that the failure range is wider here compared to the coal seam floor near the return airway (the upper crossheading). The results of micro-seismic monitoring show that the dangerous area for water-inrush from the coal seam floor may be identified. This provides an important field measurement that helps ensure safe and highly efficient mining of the inclined coal seam above the confined aquifer at the Taoyuan Coal Mine.

  19. Study on the countermeasures against methane outburst of mining multiple upper protective layers in coal seams cluster

    Institute of Scientific and Technical Information of China (English)

    XIE Guang-xiang; LUO Yong

    2005-01-01

    In order to prevent coal and methane outbursts, mining protective layers is an effective means, yet no precedents of mining multiple protective layers is discoveried in seams which includes several seams are prone to outburst like Xinzhuangzi Mine. This paper perfected the related theories through analyzing mining multiple upper protective layers. By means of examining several parameters, it synthetically analyzed and ascertains the protected effectiveness and scope and reasonable parameters, finally obtained the specific indexes and effectiveness of mining multiple protective layers in coal seams cluster.

  20. Fuzzy Evaluation of Coal Seam Geological Condition of Fully-Mechanized Face in Ten-Million-Ton Mine

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Based on coal seam geological condition and mining technological characteristic in Jisan Mine, coal seam geological condition is quantitative evaluated by using fuzzy evaluation with the view of coal mining and coalface production. The structure and index system of evaluation factor, the membership functions and weights of evaluation factor, evaluation model and reliability in the coal seam geological conditions are expounded in detail. Eighty-two coalfaces which will be exploited is classified. All of these have provided a theoretical foundation for the selection of coal mining technology and for sustainable development of the coal mine.

  1. Pose tracking for augmented reality applications in outdoor archaeological sites

    Science.gov (United States)

    Younes, Georges; Asmar, Daniel; Elhajj, Imad; Al-Harithy, Howayda

    2017-01-01

    In recent years, agencies around the world have invested huge amounts of effort toward digitizing many aspects of the world's cultural heritage. Of particular importance is the digitization of outdoor archaeological sites. In the spirit of valorization of this digital information, many groups have developed virtual or augmented reality (AR) computer applications themed around a particular archaeological object. The problem of pose tracking in outdoor AR applications is addressed. Different positional systems are analyzed, resulting in the selection of a monocular camera-based user tracker. The limitations that challenge this technique from map generation, scale, anchoring, to lighting conditions are analyzed and systematically addressed. Finally, as a case study, our pose tracking system is implemented within an AR experience in the Byblos Roman theater in Lebanon.

  2. Tracking Porters

    DEFF Research Database (Denmark)

    Bruun, Maja Hojer; Krause-Jensen, Jakob; Nielsen, Margit Saltofte

    2015-01-01

    Anthropology attempts to gain insight into people's experiential life-worlds through long-term fieldwork. The quality of anthropological knowledge production, however, does not depend solely on the duration of the stay in the field, but also on a particular way of seeing social situations. The an...... the students followed the work of a group of porters. Drawing on anthropological concepts and research strategies the students gained crucial insights about the potential effects of using tracking technologies in the hospital....

  3. Assessment of uncertainty and degasification efficiency in coal seam gas drainage through stochastic reservoir simulation

    Science.gov (United States)

    Özgen Karacan, C.

    2016-04-01

    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 bed reservoir simulation, as a reservoir management and forecasting tool, is one of the most effective ways to help with these two main objectives. However, as in all modeling and simulation studies, reservoir description and whether observed productions can be predicted are important considerations. Using geostatistical realizations as spatial maps of different coal reservoir properties is a more realistic approach than assuming uniform properties across the field. In fact, this approach can help with simultaneous history matching of multiple wellbores to enhance the confidence in spatial models of different coal properties that are pertinent to degasification. The problem that still remains, however, is the uncertainty in geostatistical, and thus reservoir, simulations originating from partial sampling of the seam that does not properly reflect the stochastic nature of coal property realizations. This study demonstrates the use of geostatistical realizations generated through sequential Gaussian simulation and co-simulation techniques and assesses the uncertainty in coal seam reservoir simulations with history matching errors. 100 individual realizations of 10 coal properties were generated using geostatistical techniques. These realizations were used to create 100 realization bundles (property datasets). Each of these bundles was then used in coal seam reservoir simulations for simultaneous history matching of degasification wells. History matching errors for each bundle were evaluated and the single set of realizations that would minimize the error for all wells was defined. Errors were compared with those of E-type and the average realization of the best matches. The study helped to determine the realization bundle that consisted of the spatial maps of coal properties, which resulted in minimum error. In

  4. 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

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

    Science.gov (United States)

    Post, David

    2016-04-01

    While extraction of methane from shale gas deposits has been the principal source of the recent expansion of the industry in the United States and Europe, 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. Surface water and groundwater modelling is now complete for two regions where coal seam gas development may proceed, namely the Clarence-Moreton and Gloucester regions in eastern New South Wales. This presentation will discuss how the results of these

  6. Forward Modeling of the Relationship Between Reflection Coefficient and Incident Angle of the P Wave in a Coal Seam

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Although the Zoeppritz equation is suitable for a single interface in a thick deposit, it has some limitations for composite reflection waves from both the floor and the roof of coal seams. Based on the ray model, the relationship of the overall reflection coefficient of composite reflection P waves, from coal seam versus incidence angle (AVO), is discussed. The result shows that: 1) the overall reflection coefficient of composite reflection waves from coal seams is a negative value and is determined mainly by the lithology of roof and floor, which is different from the reflection coefficient of a single interface; 2) if the incidence angle ranges from 0° to 6°, the reflection coefficient of composite waves of a coal seam does not change with the incidence angle and 3) if the incidence angle ranges from 6-60° , the reflection coefficient increases monotonically.

  7. Hydraulic support stability control of fully mechanized top coal caving face with steep coal seams based on instable critical angle

    Institute of Scientific and Technical Information of China (English)

    TO Shi-hao; YUAN Yong; LI Nai-liang; DOU Feng-jin; WANG Fang-tian

    2008-01-01

    Analyzed the support instable mode of sliding, tripping, and so on, and believedthe key point of the support stability control of fully mechanized coal caving face with steepcoal seams was to maintain that the seam true angle was less than the hydraulic supportinstability critical angle. Through the layout of oblique face, the improvement of supportsetting load, the control of mining height and nonskid platform, the group support systemof end face, the advance optimization of conveyor and support, and the other control tech-nical measures, the true angle of the seam is reduced and the instable critical angle of thesupport is increased, the hydraulic support stability of fully mechanized coal caving facewith steep coal seams is effectively controlled.

  8. Methane conditions in the coal seam of the Stara Jama mine in Zenica. Metanonosnost - Gasonosnost ugljenog sloja Stara Jama Zenica

    Energy Technology Data Exchange (ETDEWEB)

    Adilovic, A.; Micevic, S. (Rudarski Institut, Tuzla (Yugoslavia))

    1990-01-01

    Reviews methane emission at the Stara Jama underground coal mine in the Zenica coal basin (Yugoslavia). Geologic and tectonic conditions of the mine are described, as well as the mechanized longwall mining and mine ventilation system. Sorption properties of the coal seam in 11.7 m mean thickness were determined, methane released from the coal seam was measured by a special container, a manometer and the AOP-1 vacuum apparatus. Methane losses during the sampling procedure were taken into account. Measurement results for the upper, medium and lower sections of the coal seam are presented separately in a table. An average methane content of 3.5 m{sup 3}/t of coal in intact coal seams was determined. 4 refs.

  9. Study on the non-linear forecast method for water inrush from coal seam floor based on wavelet neural network

    Institute of Scientific and Technical Information of China (English)

    ZHOU Rong-yi; LIU Ai-qun; LI Shu-qing

    2007-01-01

    Directing at the non-linear dynamic characteristics of water inrush from coal seam floor and by the analysis of the shortages of current forecast methods for water inrush from coal seam floor,a new forecast method was raised based on wavelet neural network(WNN)that was a model combining wavelet function with artificiaI neural network.Firstly basic principle of WNN was described.then a forecast model for water inrush from coal seam floor based on WNN was established and analyzed,finally an example of forecasting the quantity of water inrush from coal floor was illustrated to verify the feasibility and superiority of this method.Conclusions show that the forecast result based on WNN is more precise and that using WNN model to forecast the quantity of water inrush from coal seam floor is feasible and practical.

  10. Note: Time-gated 3D single quantum dot tracking with simultaneous spinning disk imaging

    Energy Technology Data Exchange (ETDEWEB)

    DeVore, M. S.; Stich, D. G.; Keller, A. M.; Phipps, M. E.; Hollingsworth, J. A.; Goodwin, P. M.; Werner, J. H., E-mail: jwerner@lanl.gov [Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Mail Stop G755, Los Alamos, New Mexico 87545 (United States); Cleyrat, C.; Lidke, D. S.; Wilson, B. S. [Department of Pathology and Cancer Research and Treatment Center, University of New Mexico, Albuquerque, New Mexico 87131 (United States)

    2015-12-15

    We describe recent upgrades to a 3D tracking microscope to include simultaneous Nipkow spinning disk imaging and time-gated single-particle tracking (SPT). Simultaneous 3D molecular tracking and spinning disk imaging enable the visualization of cellular structures and proteins around a given fluorescently labeled target molecule. The addition of photon time-gating to the SPT hardware improves signal to noise by discriminating against Raman scattering and short-lived fluorescence. In contrast to camera-based SPT, single-photon arrival times are recorded, enabling time-resolved spectroscopy (e.g., measurement of fluorescence lifetimes and photon correlations) to be performed during single molecule/particle tracking experiments.

  11. Note: Time-gated 3D single quantum dot tracking with simultaneous spinning disk imaging.

    Science.gov (United States)

    DeVore, M S; Stich, D G; Keller, A M; Cleyrat, C; Phipps, M E; Hollingsworth, J A; Lidke, D S; Wilson, B S; Goodwin, P M; Werner, J H

    2015-12-01

    We describe recent upgrades to a 3D tracking microscope to include simultaneous Nipkow spinning disk imaging and time-gated single-particle tracking (SPT). Simultaneous 3D molecular tracking and spinning disk imaging enable the visualization of cellular structures and proteins around a given fluorescently labeled target molecule. The addition of photon time-gating to the SPT hardware improves signal to noise by discriminating against Raman scattering and short-lived fluorescence. In contrast to camera-based SPT, single-photon arrival times are recorded, enabling time-resolved spectroscopy (e.g., measurement of fluorescence lifetimes and photon correlations) to be performed during single molecule/particle tracking experiments.

  12. Investigations of changes in the physical state of the formations covering coal seams with the aid of geophysical methods

    Energy Technology Data Exchange (ETDEWEB)

    Takacs, E.; Egerszegi, P.

    1987-01-01

    Testing measurements were carried out using surface frequence probes and applying electric transillumination between various levels of two drill holes in order to observe the effect of the overburden of a face passing through the section. Having applied the apparent specific resistances determined for each depth interval, measurable changes could be observed. The greatest change occured in the surroundings of the coal seam where the resistance decreased, and in a sand layer overlying the seam where resistance increased.

  13. The development of three dimensional inspection and tracking system for the maintenance of pipes in the nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Suk Young; Kim, Chul Jung; Baik, Sung Hoon; Cho, Jai Wan; Park, Seung Kyu

    1999-12-01

    We developed 3D laser camera sensors for weld seam tracking and inspection of radioactive NPP pipes. The developed sensor's optical system adopts the optical triangulation method with the line beam generation and imaging optics. A laser line extraction algorithm accompanying preprocessing of noise reduction has been developed on images captured from the sensor. Experimental results validate the physical accuracy of the sensor hardware and the robustness of the image processing algorithms. A 3D shape reconstruction algorithm from multiple laser lines was proposed and the resulting 3D shape was visualized on the developed 3D graphic program environment utilizing OpenGL graphic libraries. And also, two D.O.F precise servo controlled mechanism was developed. The experimental results on weld seam tracking and inspection tasks show the practical feasibility of the developed sensors and the image processing algorithms. (author)

  14. Numerical simulation and damage analysis of fissure field evolution law in a single coal seam mining

    Institute of Scientific and Technical Information of China (English)

    Feng; Gao; Xingguang; Liu; Chaofeng; Ge; Hongmei; Cheng

    2012-01-01

    Based on the different deformation and failure laws of coal and rock materials under tensile or compressive loads,the damage variable was defined to divide three phases from the damage and rupture point of view in order to reveal the fissured field evolution characteristics and spatial distribution of coal and rock in the single coal seam mining with low permeability and rich methane.According to the corresponding damage constitutive equations,the secondary development of the finite element program was completed.The fissures field evolution law of a coal mine with single coal seam mining was calculated and analyzed by this new program and the distribution areas and failure degree of the surrounding coal and rock structures with damage,fissure or rupture are given on the condition of mining.This paper provides a scientific basis for quantitative research and evaluation of the safe simultaneous production of coal and gas.

  15. 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.

  16. Organic geochemical study of sequences overlying coal seams: example from the Mansfield Formation (Lower Pennsylvania), Indiana

    Energy Technology Data Exchange (ETDEWEB)

    Mastalerz, M.; Stankiewicz, A.B.; Salmon, G.; Kvale, E.P.; Millard, C.L. [Indiana University, Bloomington, IN (United States). Indiana Geological Survey

    1997-09-01

    Roof successions above two coal seams from the Mansfield Formation (Lower Pennsylvanian) in the Indiana portion of the Illinois basin were studied with regard to sedimentary structures, organic petrology and organic geochemistry. The succession above the Blue Creek Member of the Mansfield Formation is typical of the lithologies covering low-sulphur coals ({lt} 1%) in the area studied, whereas the succession above the unnamed Mansfield coal is typical of high-sulphur coal({gt} 2%). The transgressive-regressive packages above both seams reflect the periodic inundation of coastal mires by tidal flats and creeks. Geochemistry and petrology of organic facies above the Blue Creek coal suggest that tidal flats formed inland in fresh-water environments. Above the unnamed coal, trace fossils and geochemical and petrological characteristics of organic facies suggest more unrestricted seaward depositional. 55 refs., 11 figs., 3 tabs.

  17. Ultrasonic seam welding technologies of copper plate and tube for collecting solar energy

    Institute of Scientific and Technical Information of China (English)

    汤勇; 万珍平; 刘亚俊; 刘树道

    2003-01-01

    The ultrasonic welding is applied more and more extensively due to its advantages such as environmental protection, cleaning and energy saving. By researching the mechanism on ultrasonic seam welding of copper plates and tubes for collecting solar energy, it is put forward that the ultrasonic metal welding process can be divided into two stages, and two factors make functions jointly to join the welded metal specimens. In order to successfully join the welding, three basic conditions must be satisfied, that is, there should be high frequency friction vibration in the contact interface; pressure must be imposed on the plate specimen during friction vibration; the time of friction vibration and pressure imposed should be proper. Furthermore, how to select the hardness of copper plate and tube and ultrasonic seam welding parameters is analyzed by experiments.

  18. In-situ coal seam and overburden permeability characterization combining downhole flow meter and temperature logs.

    Directory of Open Access Journals (Sweden)

    Busse Julia

    2016-06-01

    Full Text Available The planning and design of any coal mine development requires among others a thorough investigation of the geological, geotechnical and hydrogeological subsurface conditions. As part of a coal mine exploration program we conducted heat pulse vertical flow meter testing. The flow data were combined with absolute and differential temperature logging data to gain information about the hydraulic characteristics of two different coal seams and their over- and interburden. For the strata that were localised based on geophysical logging data including density, gamma ray and resistivity hydraulic properties were quantified. We demonstrate that the temperature log response complements the flow meter log response. A coupling of both methods is therefore recommended to get an insight into the hydraulic conditions in a coal seam and its overburden.

  19. Impact of longwall mining on groundwater above the longwall panel in shallow coal seams

    Directory of Open Access Journals (Sweden)

    Yang Li

    2015-06-01

    Full Text Available Since longwall mining causes subsidence through the overlying strata to the ground surface, the surface water and groundwater above the longwall panels may be affected and drained into the lower levels. Therefore, loss or interruption of streams and overburden aquifers is a common concern in coal industry. This paper analyzed the potential effects of longwall mining on subsurface water system in shallow coal seam. In order to monitor different water level fluctuations throughout the mining period, three water wells were drilled down to the proposed deformation zone above the longwall panel. A GGU-SS-FLOW3D model was used to predict water table contours for the periods of pre- and post-mining conditions. The field data from the three water wells were utilized to calibrate the model. The field test and numerical model can help to better understand the dewatering of shallow aquifers and surface waters related to ground subsidence from longwall mining in shallow coal seam.

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

    Institute of Scientific and Technical Information of China (English)

    WANG En-yuan; LIU Xiao-fei; ZHAO En-lai; LIU Zhen-tang

    2009-01-01

    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 elimi-nating abnormal gas emission by eliminating the occurrence of rock burst or depressing the magnitude of rock burst was considered. The No.237 working face was selected as the typical working face contacting gas in deep mining; aimed at this working face, a sys-tem of rock burst prediction and control for coal seam contacting gas in deep mining was established. 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 burst control.

  1. Impact of longwall mining on groundwater above the longwall panel in shallow coal seams

    Institute of Scientific and Technical Information of China (English)

    Yang Li; Syd S. Peng; Jinwang Zhang

    2015-01-01

    Since longwall mining causes subsidence through the overlying strata to the ground surface, the surface water and groundwater above the longwall panels may be affected and drained into the lower levels. Therefore, loss or interruption of streams and overburden aquifers is a common concern in coal industry. This paper analyzed the potential effects of longwall mining on subsurface water system in shallow coal seam. In order to monitor different water level fluctuations throughout the mining period, three water wells were drilled down to the proposed deformation zone above the longwall panel. A GGU-SS-FLOW3D model was used to predict water table contours for the periods of pre-and post-mining conditions. The field data from the three water wells were utilized to calibrate the model. The field test and numerical model can help to better understand the dewatering of shallow aquifers and surface waters related to ground subsidence from longwall mining in shallow coal seam.

  2. 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.)

  3. Supporting Seamful Development of Positioning Applications through Model Based Translucent Middleware

    DEFF Research Database (Denmark)

    Jensen, Jakob Langdal

    design for context aware applications in general are advocating that seams (problem areas caused by technologies interconnecting) can be exploited by end-users if they are made available to them. A system allowing this kind of interaction is said to be seamfully designed as opposed to the traditional...... goal of ubiquitous computing where seamlessness is advocated. Another challenge is to provide middleware designers a set of tools that allow them to build translucent middleware, i.e., middleware where the level of openness can be differentiated. Such middleware should provide application developers......Positioning technologies are becoming ever more pervasive, and they are used for a growing number of applications in a broad range of fields. We aim to support software developers who create position based applications. More specifically, how support can be provided through the use of specialized...

  4. Numerical simulation of influence of Langmuir adsorption constant on gas drainage radius of drilling in coal seam

    Institute of Scientific and Technical Information of China (English)

    Lin Haifei; Huang Meng; Li Shugang; Zhang Chao; Cheng Lianhua

    2016-01-01

    To determine reasonable distance of gas pre-drainage drillings in coal seams, a solid–gas coupling model that takes gas adsorption effect into account was constructed. In view of different adsorption constants, the paper conducted the numerical simulation of pre-drainage gas in drillings along coal seam, studied the relationship of adsorption constants and permeability, gas pressure, and effective drainage radius of coal seams, and applied the approach to the layout of pre-drainage gas drillings in coal seams. The results show that the permeability of coal seams is on the gradual increase with time, which is divided into three sections according to the increase rate:the drainage time 0–30 d is the sharp increase section;30–220 d is the gradual increase section;and the time above 200 d is the stable section. The permeability of coal seams is in negative linear and positive exponent relation with volume adsorption constant VL and pressure adsorption constant PL, respectively. The effective drainage radius is in negative linear relation with VL and in positive exponent relation with PL. Compared with the former design scheme, the engi-neering quantity of drilling could be reduced by 25%.

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

    Institute of Scientific and Technical Information of China (English)

    WANG; Wenfeng; QIN; Yong; SONG; Dangyu; SANG; Shuxun; JIAN

    2005-01-01

    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 conclusions are drawn as follows. 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, and that the kaolinite changes into illite and montmorillonite in the coal-sublayer near the roof. 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 kaolintie, 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, Al, 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.

  6. 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)

    Guo, Pinkun; Cheng, Yuanping

    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.

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

    Directory of Open Access Journals (Sweden)

    Pinkun Guo

    2013-01-01

    Full Text Available 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.

  8. Model test of the overburden deformation and failure law in close distance multi-seam mining

    Institute of Scientific and Technical Information of China (English)

    YANG Wei-feng; SUI Wang-hua; XIA Xiao-hong

    2008-01-01

    Based on characteristic of the associated mining of multi-coal seam and the engineering geological characteristics of overburden, the mining impact pattern of multiseam mining and the dynamic fracture mechanism of overburden were characterized by applying the engineering geological mechanical model test. The related strata movement arameters and influence area of multi-seam mining were obtained, the strike boundary angle is 61°, the full extraction coefficient is 0.93, the greatest subsidence angle is 81°, the horizontal movement factor is 0.38, the deviation of inflection point/mining deep is 0.11.The development height of caving zone and water flowing fractured zone of multi-seam mining were calculated, is 32 m and 81.5 m separatly. The assess of influence degree of coal layer safety mining is that, there exists the possibility of water and sand inflow when mining, some messures for mine water prevention and control should be used, and the mining thickness should be local strictly limit.

  9. A New Accumulation Model of Coal Seams in France Extensional Basins

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper, based on the sedimentary features of the coal seams in the typical extensional (faulted) coal basins between two inland mountainous areas of the Central Massif (France) deals with the accumulation mechanism and the corresponding sedimentary-tectonic conditions of these thick coalbeds, and proposes a new coal accumulation model for the inland lacustrine-basin thick coalbeds. The presence of a great number of gravity-flow sediments such as detrital flow, diluted slurry flow or turbidity-current sediments in the coal seams, and that of the contemporaneous gravity slump and deformation structure in the coal seam itself bath indicate that thelacustrine environment in the accumulation of the thick coalbeds was characterized by the relatively deep flood and violent sedimentation. This model can not only interpret reasonably the accumulation mecha nism of the thick coalbeds developed in the fault basins in the Central Massif, France, but also show its features distinctively from those of the accumulation model of the traditional thick coalbeds.

  10. Guiding-controlling technology of coal seam hydraulic fracturing fractures extension

    Institute of Scientific and Technical Information of China (English)

    Zhai; Cheng; Li; Min; Sun; Chen; Zhang; Jianguo; Yang; Wei; Li; Quangui

    2012-01-01

    Aiming at the uncontrollable problem of extension direction of coal seam hydraulic fracturing,this study analyzed the course of fractures variation around the boreholes in process of hydraulic fracturing,and carried out the numerical simulations to investigate the effect of artificial predetermined fractures on stress distribution around fractured holes.The simulation results show that partial coal mass occurs relatively strong shear failure and forms weak surfaces,and then fractures extended along the desired direction while predetermined fractures changed stress distribution.Directional fracturing makes the fractures link up and the pressure on coal mass is relieved within fractured regions.Combining deep hole controlling blasting with hydraulic fracturing was proposed to realize the extension guiding-controlling technology of coal seam fractures.Industrial experiments prove that this technology can avoid local stress concentration and dramatically widen the pressure relief scope of deep hole controlling blasting.The permeability of fractured coal seam increased significantly,and gas extraction was greatly improved.Besides,regional pressure relief and permeability increase was achieved in this study.

  11. Hydraulic Flushing Technology and Its Practice in Outburst Coal Seam with High Gas and Low Permeability

    Directory of Open Access Journals (Sweden)

    Qing Ye

    2015-10-01

    Full Text Available Hydraulic flushing technology can rapidly and effectively eliminate coal and gas outbursts and improve the permeability of a coal seam. Its effect mainly depends on the technical parameters of hydraulic flushing. To solve the problems on technical parameters that exist in the application of hydraulic flushing technology, the outburst elimination mechanism of hydraulic flushing technology was expatiated, the hydraulic flushing process was introduced, and a field test was performed on the B1 coal seam in Yi’an Coal Mine by using the pressure drop method. Moreover, the effective influence radius of hydraulic flushing measure was determined, and the technical parameters were analyzed. Finally, a series of relationships was obtained, including the relationships between hydraulic pressure and coal output, critical breaking coal pressure and firmness coefficient, flushing time and coal output, drilling hole angle and coal output, and coal output and effective influence radius. Results showed that the effective influence radius of hydraulic flushing in B1 coal seam was 9 m, and the outburst risk of the coal within the influence region was eliminated. In addition, the time of outburst elimination was shortened and the production rate was improved. The research results could provide technical support for the optimization of the technical parameters and the test scheme of hydraulic flushing measures.

  12. Relations between coal petrology and gas content in the Upper Newlands Seam, Central Queensland, Australia

    Science.gov (United States)

    Walker, R.; Glikson, M.; Mastalerz, Maria

    2001-01-01

    The Upper Newlands Seam in the northern Bowen Basin, Queensland Australia consists of six benches (A-F) that have different petrographic assemblages. Benches C and E contain relatively abundant inertodetrinite and mineral matter, as well as anomalously high reflectance values; these characteristics support a largely allochthonous, detrital origin for the C and E benches. Fractures and cleats in the seam show a consistent orientation of northeast-southwest for face cleats, and a wide range of orientations for fractures. Cleat systems are well developed in bright bands, with poor continuity in the dull coal. Both maceral content and cleat character are suggested to influence gas drainage in the upper Newlands Seam. A pronounced positive correlation between vitrinite abundance and gas desorption data suggests more efficient drainage from benches with abundant vitrinite. Conversely, inertinite-rich benches are suggested to have less efficient drainage, and possibly retain gas within pore spaces, which could increase the outburst potential of the coal. ?? 2001 Elsevier Science B.V. All rights reserved.

  13. Laser ultrasound: a flexible tool for the inspection of complex CFK components and welded seams

    Science.gov (United States)

    von Kopylow, Christoph; Focke, Oliver; Kalms, Michael

    2007-06-01

    Modern production processes use more and more components made of new materials like carbon fiber reinforced plastics (CFRP). These components have different sizes, functionalities, high assembly complexity and high security requirements. In addition optimized joining processes, especially during welding are implemented in manufacturing processes. The increasing requirements during the manufacturing of complex products like cars and aircrafts demand new solutions for the quality assurance. The main focus is to find a measurement strategy that is cost effective, flexible and adaptive. The extension of the conventional ultrasound technique for non destructive testing with the laser ultrasound method brings new possibilities into the production processes for example for the inspection of small complex CFRP-parts like clips and the online observation during seam welding. In this paper we describe the principle of laser ultrasound, especially the adaptation of a laser ultrasound system to the requirements of non destructive testing of CFRP-components. An important point is the generation of the ultrasound wave in the surface of the component under investigation. We will show experimental results of different components with complex shape and different defects under the surface. In addition we will present our results for the detection of defects in metals. Because the online inspection of welded seams is of high interest experiments for the investigation of welded seams are demonstrated.

  14. INNER TRACKING

    CERN Multimedia

    P. Sharp

    The CMS Inner Tracking Detector continues to make good progress. The Objective for 2006 was to complete all of the CMS Tracker sub-detectors and to start the integration of the sub-detectors into the Tracker Support Tube (TST). The Objective for 2007 is to deliver to CMS a completed, installed, commissioned and calibrated Tracking System (Silicon Strip and Pixels) aligned to < 100µ in April 2008 ready for the first physics collisions at LHC. In November 2006 all of the sub-detectors had been delivered to the Tracker Integration facility (TIF) at CERN and the tests and QA procedures to be carried out on each sub-detector before integration had been established. In December 2006, TIB/TID+ was integrated into TOB+, TIB/TID- was being prepared for integration, and TEC+ was undergoing tests at the final tracker operating temperature (-100 C) in the Lyon cold room. In February 2007, TIB/TID- has been integrated into TOB-, and the installation of the pixel support tube and the services for TI...

  15. 论煤层的加积方式%On Accreation Pattern of Coal Seams

    Institute of Scientific and Technical Information of China (English)

    赵万福

    2012-01-01

    The origin of coal seams is the kernel of coal geology. Coal seam is a kind of sedimentary stratum, it adheres to the basic principles of the sedimentology, stratigraphy, petrology and study of ore deposits, but still has its particularity, and its origin differs from origin of coal. Classic kernel viewpoint of coal geology is coal seam evolving from peat bog; its essence is vertical accretion of coal-forming material. Through coal seam vertical and lateral accretions contrastive analyses and large area stable distributed thick coal seam low gamma-ray multi-crest phenomenon, sedimentary features of bedding and banded structure studies have considered that the coal-forming material is mechanically deposited, while coal seam likes most sedimentary strata is laterally accreted. As to thick coal seams, multi -stage lateral accretions bring on secondary vertical accretions; their formation process is not a simple, consecutive, linear vertical progressive process, but a rather complicated, inconsecutive, nonlinear lateral superimposed process. Coal-forming material is inconsecutive, multi -staged and multi -sourced, ubiquitous parting in thick coal seams is the evidence of inconsequence, moreover, thick coal seams are diachronous. Coal seam lateral accretion coexisting with deeper water or marine deposit, which is an organically consecutive en bloc, in harmony with Walther's law of facies, principle of paleoecology, in harmony with coal seam thickness, changeable configuration, many and varied underlying sedimentary systems, also in harmony with coalforming material super huge industrial enrichment, coal-bearing strata gray, grayish black in color and coal deposit high quality facts.%煤层成因是煤地质学的核心.煤层是一种沉积地层,它遵循沉积学、地层学、岩石学以及矿床学的基本规律,也有其特殊性,其成因并不同于煤的成因.传统煤地质学的核心观点是煤层由泥炭沼泽演化而成,其本质就是成煤物质的

  16. A small-scale comparison of Iceland scallop size distributions obtained from a camera based autonomous underwater vehicle and dredge survey.

    Directory of Open Access Journals (Sweden)

    Warsha Singh

    Full Text Available An approach is developed to estimate size of Iceland scallop shells from AUV photos. A small-scale camera based AUV survey of Iceland scallops was conducted at a defined site off West Iceland. Prior to height estimation of the identified shells, the distortions introduced by the vehicle orientation and the camera lens were corrected. The average AUV pitch and roll was 1.3 and 2.3 deg that resulted in <2% error in ground distance rendering these effects negligible. A quadratic polynomial model was identified for lens distortion correction. This model successfully predicted a theoretical grid from a frame photographed underwater, representing the inherent lens distortion. The predicted shell heights were scaled for the distance from the bottom at which the photos were taken. This approach was validated by height estimation of scallops of known sizes. An underestimation of approximately 0.5 cm was seen, which could be attributed to pixel error, where each pixel represented 0.24 x 0.27 cm. After correcting for this difference the estimated heights ranged from 3.8-9.3 cm. A comparison of the height-distribution from a small-scale dredge survey carried out in the vicinity showed non-overlapping peaks in size distribution, with scallops of a broader size range visible in the AUV survey. Further investigations are necessary to evaluate any underlying bias and to validate how representative these surveys are of the true population. The low resolution images made identification of smaller scallops difficult. Overall, the observations of very few small scallops in both surveys could be attributed to low recruitment levels in the recent years due to the known scallop parasite outbreak in the region.

  17. A small-scale comparison of Iceland scallop size distributions obtained from a camera based autonomous underwater vehicle and dredge survey.

    Science.gov (United States)

    Singh, Warsha; Örnólfsdóttir, Erla B; Stefansson, Gunnar

    2014-01-01

    An approach is developed to estimate size of Iceland scallop shells from AUV photos. A small-scale camera based AUV survey of Iceland scallops was conducted at a defined site off West Iceland. Prior to height estimation of the identified shells, the distortions introduced by the vehicle orientation and the camera lens were corrected. The average AUV pitch and roll was 1.3 and 2.3 deg that resulted in <2% error in ground distance rendering these effects negligible. A quadratic polynomial model was identified for lens distortion correction. This model successfully predicted a theoretical grid from a frame photographed underwater, representing the inherent lens distortion. The predicted shell heights were scaled for the distance from the bottom at which the photos were taken. This approach was validated by height estimation of scallops of known sizes. An underestimation of approximately 0.5 cm was seen, which could be attributed to pixel error, where each pixel represented 0.24 x 0.27 cm. After correcting for this difference the estimated heights ranged from 3.8-9.3 cm. A comparison of the height-distribution from a small-scale dredge survey carried out in the vicinity showed non-overlapping peaks in size distribution, with scallops of a broader size range visible in the AUV survey. Further investigations are necessary to evaluate any underlying bias and to validate how representative these surveys are of the true population. The low resolution images made identification of smaller scallops difficult. Overall, the observations of very few small scallops in both surveys could be attributed to low recruitment levels in the recent years due to the known scallop parasite outbreak in the region.

  18. STUDY ON THE RELATIONSHIP BETWEEN THE DIVERSITY COAL MASS STRUCTURE AND LITHOTYPE OF COAL IN MULTI-COAL SEAM MINE

    Institute of Scientific and Technical Information of China (English)

    吴基文; 赵志根; 陈资平

    1999-01-01

    Through site observation and indoor measurements in XieJiaji No.2 Coal Mine in Huainen and Luling Coal Mine in Huaibei, it is discovered that the fragmentation degree are different in different coal seams in same mining district and even in sublevels of the same coal seam, the coal mass structures exist much difference. By analyzing the relationship between the constitution of coal matters and the epigenesis breakage of coal. This paper points out that the internal factor which causes the diversity of the coal mass structure comes from the diversity in the contents of telocollinite and desmocollinite in the vitrinite. The contenet of desmocollinite is higher than that of telocollinite in intact coal seam (sublevel) but the former is less than the later in breaking sublevel, the diversity of constituent content more affects the epigenetic fragmentation degree of coal seam. The content of desrnocollinite proves lower than that of telocollinite in the broken coal seam. The new understanding has directing, and reference for the study of coal petrology, coal mine gas geology and coal methane.

  19. Overlying strata movement rules and safety mining technology for the shallow depth seam proximity beneath a room mining goaf

    Institute of Scientific and Technical Information of China (English)

    Wang Fangtian; Zhang Cun; Zhang Xiaogang; Song Qi

    2015-01-01

    Aiming at the shallow depth seam proximity beneath a room mining goaf, due to that the shallow depth seam is exploited using the longwall mining and overlain by thin bedrock and thick loose sands, many accidents are likely to occur, including roof structure instability, roof step subsidence, damages of shield supports, and the face bumps triggered by the large area roof weighting, resulting in serious threats to the safety of underground miners and equipment. This paper analyses the overlying strata movement rules for the shallow seams using the physical simulation, the 3DEC numerical simulation and the field mea-surements. The results show that, in shallow seam mining, the overburden movement forms caved zone and fractured zone, the cracks develop continuously and reach the surface with the face advancing, and the development of surface cracks generally goes through four stages. With the application of loose blast-ing of residual pillars, reasonable mining height, and roof support and management, the safe, efficient and high recovery rate mining has been achieved in the shallow depth seam proximity beneath a room min-ing goaf.

  20. 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.

  1. Approach to In- Situ Producing Reinforcing Phase Within an Active-Transient Liquid Phase Bond Seam for Aluminum Matrix Composite

    Science.gov (United States)

    Zhang, Guifeng; Liao, Xianjin; Chen, Bo; Zhang, Linjie; Zhang, Jianxun

    2015-06-01

    To optimize the braze composition design route for aluminum matrix composite, the feasibility of in situ producing reinforcing phase within the transient liquid phase bond seam matrix, by adding active melting point increaser (MPI, e.g., Ti) together with general melting point depressant (MPD, e.g., Cu) into the interlayer, was demonstrated. For SiC p /A356 composite, by comparing the wettability, joint microstructure, joint shear strength, and fracture path for the developed Al-19Cu-1Ti, Al-19Cu, Al-33Cu-1Ti, Al-33Cu (wt pct), and commercial Cu foils as interlayer, the feasibility of in situ producing reinforcing phase within the bond seam by adding Ti was demonstrated. Especially for Al-19Cu-1Ti active braze, small and dispersed ternary aluminide of Al-Si-Ti phase was obtained within the bond seam as in situ reinforcement, leading to a favorable fracture path within SiC p /A356, not along the initial interface or within the bond seam. For the formation mechanism of the in situ reinforcing phase of MPI-containing intermetallic compound within the bond seam, a model of repeating concentration-precipitation-termination-engulfment during isothermal solidification is proposed.

  2. INNER TRACKING

    CERN Multimedia

    P. Sharp

    The CMS Inner Tracking Detector continues to make good progress. The successful commissioning of ~ 25% of the Silicon Strip Tracker was completed in the Tracker Integration Facility (TIF) at CERN on 18 July 2007 and the Tracker has since been prepared for moving and installation into CMS at P5. The Tracker will be ready to move on schedule in September 2007. The Installation of the Tracker cooling pipes and LV cables between Patch Panel 1 (PP1) on the inside the CMS magnet cryostat, and the cooling plants and power system racks on the balconies has been completed. The optical fibres from PP1 to the readout FEDs in the USC will be installed in parallel with the installation of the EB/HB services, and will be completed in October. It is planned to install the Tracker into CMS at the end of October, after the completion of the installation of the EB/HB services. The Tracker will then be connected to the pre-installed services on YB0 and commissioned with CMS in December. The FPix and BPix continue to make ...

  3. INNER TRACKING

    CERN Multimedia

    P. Sharp

    The CMS Inner Tracking Detector continues to make good progress. The successful commissioning of ~ 25% of the Silicon Strip Tracker was completed in the Tracker Integration Facility (TIF) at CERN in July 2007 and the Tracker has since been prepared for moving and installation into CMS at P5. The Tracker was ready to move on schedule in September 2007. The Installation of the Tracker cooling pipes and LV cables between Patch Panel 1 (PP1) on the inside the CMS magnet cryostat, and the cooling plants and power system racks on the balconies has been completed. The optical fibres from PP1 to the readout FEDs in the USC have been installed, together with the Tracker cable channels, in parallel with the installation of the EB/HB services. All of the Tracker Safety, Power, DCS and the VME Readout Systems have been installed at P5 and are being tested and commissioned with CMS. It is planned to install the Tracker into CMS before Christmas. The Tracker will then be connected to the pre-installed services on Y...

  4. Patient Treatment Tracking Chart

    Science.gov (United States)

    ... ZIP code here Hepatitis C Treatment Tracking Chart Patient Treatment Tracking Chart Patient Treatment Tracking Chart Sample Chart This chart is ... this website Submit Share this page Related Resource Patient Treatment Tutorial return to top CONNECT Veterans Crisis ...

  5. CEH-20/Pbx and UNC-62/Meis function upstream of rnt-1/Runx to regulate asymmetric divisions of the C. elegans stem-like seam cells

    Directory of Open Access Journals (Sweden)

    Samantha Hughes

    2013-06-01

    Caenorhabditis elegans seam cells divide in the stem-like mode throughout larval development, with the ability to both self-renew and produce daughters that differentiate. Seam cells typically divide asymmetrically, giving rise to an anterior daughter that fuses with the hypodermis and a posterior daughter that proliferates further. Previously we have identified rnt-1 (a homologue of the mammalian cancer-associated stem cell regulator Runx as being an important regulator of seam development, acting to promote proliferation; rnt-1 mutants have fewer seam cells whereas overexpressing rnt-1 causes seam cell hyperplasia. We isolated the interacting CEH-20/Pbx and UNC-62/Meis TALE-class transcription factors during a genome-wide RNAi screen for novel regulators of seam cell number. Animals lacking wild type CEH-20 or UNC-62 display seam cell hyperplasia, largely restricted to the anterior of the worm, whereas double mutants have many additional seam cells along the length of the animal. The cellular basis of the hyperplasia involves the symmetrisation of normally asymmetric seam cell divisions towards the proliferative stem-like fate. The hyperplasia is completely suppressed in rnt-1 mutants, and rnt-1 is upregulated in ceh-20 and unc-62 mutants, suggesting that CEH-20 and UNC-62 function upstream of rnt-1 to limit proliferative potential to the appropriate daughter cell. In further support of this we find that CEH-20 is asymmetrically localised in seam daughters following an asymmetric division, being predominantly restricted to anterior nuclei whose fate is to differentiate. Thus, ceh-20 and unc-62 encode crucial regulators of seam cell division asymmetry, acting via rnt-1 to regulate the balance between proliferation and differentiation.

  6. Huge thick conglomerate movement induced by full thick longwall mining huge thick coal seam

    Institute of Scientific and Technical Information of China (English)

    Ma Liqiang; Qiu Xiaoxiang; Dong Tao; Zhang Jixiong; Huang Yanli

    2012-01-01

    A discrete elemental method was used to study the thickness of conglomerate layer in a full thick seam mining activities under the influence of the law,pointing out the thickness of the conglomerate at different seam mining,and during the destruction and instability of existing state of laws.At 21141 thick seam mining,the face toward the direction of separation between the thick layer of conglomerate rock and the next bit after reaching its maximum capacity due to pull from the bottom of the plastic zone,formed a stratified and hierarchical down collapse.The shape of caving area is a "triangular block",the length of the plastic zone and face advancement from the linear fit between the height of the plastic zone and the advancing face is a quadratic function of distance,while the top layer of thick gravel layer is the overall bending subsidence trend.Tilting the direction of the face,a thick gob of collapsed conglomerate layer is formed in the coal gob entity on both sides of the thick conglomerate at the top of the overall fracture morphology performance,thus forming a mutual extrusion of articulated block structure.The instability,separation and balance of the thick conglomerate layer in the hinged block stope stress leads to abnormal occurrence of rock burst induced by face as the major factor in the accident.This research reveals the form of stress distribution in the destroyed layer of the thick conglomerate rock,analyzes the stope law of coupling for the pressure burst behavior law for the mining work face,and the choice of preventive measures to provide a theoretical basis and implementation.

  7. Research on image segmentation of weld seam of oil derrick welded by arc welding robot

    Institute of Scientific and Technical Information of China (English)

    Cai Guangyu; Cui Shilin; Wu Changlin

    2009-01-01

    This paper puts forward a new method of PCNN (pulse-coupled neural networks) image segmentation, in which the binary matrix of the ignition frequency matrix is employed, for the first time, to act as the final result of image segmentation. It gives the principles of PCNN parameter selection under the guidance of this process. The new method reduces the dependence of PCNN on parameters, improves the effect of image segmentation, and produces good results after being applied to image recognition of weld seam of oil derrick welded by arc welding robot.

  8. Layout and support design of a coal roadway in ultra-close multiple-seams

    Institute of Scientific and Technical Information of China (English)

    严红; 翁明月; 冯锐敏; 李伟康

    2015-01-01

    A roadway within ultra-close multiple-seams (RUCMSs) is one of the most difficult supported coal roadways to deal with in underground coal mines. This is usually due to the unknown stress distributions, improper roadway layout, and unreasonable support parameters. In order to solve this support problem and effectively save RUCMSs from frequent and abrupt disasters (such as serious deformation of the surrounding rock, roof cave ins, and coal side collapse), a comprehensive method is adopted here which includes theoretical analysis, numerical simulation, and field monitoring. A mechanical model was constructed to determine the stress distribution in the coal pillar after two sides of a longwall panel had been mined. Based on this model, the horizontal, vertical, and tangential stress equations for the plane below the floor of the upper-left coal pillar were deduced. In addition, a typical coal mine (the Jinggonger colliery, located in Shuozhou city, Shanxi province, China) with an average distance between its 9# and 11# coal seams of less than 8.0 was chosen to conduct research on the proper layout and reasonable support required for a typical coal roadway located within coal seam 11#. Using FLAC3D (Fast Lagrangian Analysis of Continua in 3-Dimensions) numerical software, eight schemes were designed with different horizontal distances (d) between the center lines of the coal pillar and the roadway in the lower coal seam (RLCS). The simulations and detailed analysis indicate that the proper distances required are between 22.5 and 27.5 m. A total of 20 simulation schemes were used to investigate the factors influencing the support provided by the key bolts (bolt length, spacing, distance between two rows, installation angle, and pre-tightening force). The results were analyzed and used to determine reasonable values for the support parameters. Field results show that the stability and strength of the RLCS can be effectively safeguarded using a combination of researched

  9. Understanding the effect of seams on the aerodynamics of an association football

    OpenAIRE

    Carrè, M. J.; Goodwill, S. R.; Haake, S. J.

    2005-01-01

    The aerodynamic properties of an association football were measured using a wind tunnel arrangement. A third scale model of a generic football (with seams) was used in addition to a 'mini-football'. As the wind speed was increased, the drag coefficient decreased from 0.5 to 0.2, suggesting a transition from laminar to turbulent behaviour in the boundary layer. For spinning footballs, the Magnus effect was observed and it was found that reverse Magnus effects were possible at low Reynolds numb...

  10. Research on Protective Area of Exploiting Lower Protective Coal Seam and its Feasibility

    OpenAIRE

    2014-01-01

    Based on the reasonable consideration of the role of the second main stress in D-P criterion, the distribution of stress and deformation with the method of finite difference was simulated. And the stress relief angles along incline and strike according to the rules of stress and deformation were obtained. Then the protective area resulted from exploiting the lower protective coal seam were acquired. The results show that the stress relief angles along incline are 75.5 and 77.7 deg...

  11. Comparison of outburst danger criteria of coal seams for acoustic spectral and instrumental forecast methods

    Science.gov (United States)

    Shadrin, A. V.; Bireva, Yu A.

    2016-10-01

    Outburst danger criteria for the two methods of current coal seam outburst forecast are considered: instrumental - by the initial outgassing rate and chippings outlet during test boreholes drilling, and geo-physical - by relation of high frequency and low frequency components of noise caused by cutting tool of operating equipment probing the face area taking into consideration the outburst criteria correction based on methane concentration at the face area and the coal strength. The conclusion is made on “adjustment” possibility of acoustic spectral forecast method criterion amended by control of methane concentration at the coal face and the coal strength taken from the instrumental method forecast results.

  12. Investigation of exploiting thick coal seams and the possibilities of increasing the vertical concentration

    Energy Technology Data Exchange (ETDEWEB)

    Pera, F.

    1987-01-01

    In underground coal mines the efficiency of exploiting thick coal seams can be increased first of all by increasing the vertical concentration. The most suitable method can be chosen by simple modelling. In cases where both the natural and technical conditions allow the use of the sub-caving method on long-wall faces, and on the basis of comparisons between the technical and economic parameters, the method discussed can be recommended. The shield support system with single scraper and overhead tapping is one of the most adequate ones. The Hungarian made VHP 730 type shields provided good results in the Ajka coal fields.

  13. APPLICATION OF EXPERT SYSTEM BASED ON NEURAL NETWORK IN MINING THE GENTLE INCLINED THICK SEAM

    Institute of Scientific and Technical Information of China (English)

    朱川曲; 施式亮

    1997-01-01

    This paper presents a new method for the correct selection of mining methods and prediction of main technological and economic indexes of the face in the gentle inclined thick seams with the application of the artificial neural network theory and the expert system. The theory analysis and calculating results indicate that the method is reliable, practical and precise. This method has strongly capabilities of self-study and non-linear dynamic data process. It is expected to be widely applied in the policy decision and prediction of mining technology in coal mine.

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

    Directory of Open Access Journals (Sweden)

    Lan Tianwei

    2015-01-01

    Full Text Available 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.

  15. Numerical study on 4-1 coal seam of Xiaoming mine in ascending mining.

    Science.gov (United States)

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

    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.

  16. Layout and support design of a coal roadway in ultra-close multiple-seams

    Institute of Scientific and Technical Information of China (English)

    严红; 翁明月; 冯锐敏; 李伟康

    2015-01-01

    A roadway within ultra-close multiple-seams(RUCMSs) is one of the most difficult supported coal roadways to deal with in underground coal mines. This is usually due to the unknown stress distributions, improper roadway layout, and unreasonable support parameters. In order to solve this support problem and effectively save RUCMSs from frequent and abrupt disasters(such as serious deformation of the surrounding rock, roof cave ins, and coal side collapse), a comprehensive method is adopted here which includes theoretical analysis, numerical simulation, and field monitoring. A mechanical model was constructed to determine the stress distribution in the coal pillar after two sides of a longwall panel had been mined. Based on this model, the horizontal, vertical, and tangential stress equations for the plane below the floor of the upper-left coal pillar were deduced. In addition, a typical coal mine(the Jinggonger colliery, located in Shuozhou city, Shanxi province, China) with an average distance between its 9# and 11# coal seams of less than 8.0 was chosen to conduct research on the proper layout and reasonable support required for a typical coal roadway located within coal seam 11#. Using FLAC3D(Fast Lagrangian Analysis of Continua in 3-Dimensions) numerical software, eight schemes were designed with different horizontal distances(d) between the center lines of the coal pillar and the roadway in the lower coal seam(RLCS). The simulations and detailed analysis indicate that the proper distances required are between 22.5 and 27.5 m. A total of 20 simulation schemes were used to investigate the factors influencing the support provided by the key bolts(bolt length, spacing, distance between two rows, installation angle, and pre-tightening force). The results were analyzed and used to determine reasonable values for the support parameters. Field results show that the stability and strength of the RLCS can be effectively safeguarded using a combination of researched stress

  17. Controllable theory and applications for the wall bolting reinforcement in the roadway of seam

    Institute of Scientific and Technical Information of China (English)

    TAN Yun-liang; ZHANG Li-jun; XIAO Ya-xun

    2007-01-01

    By using the Radar penetrating technology and numerical simulations, the fractured zone could be easily determined. Both wall fractured zone and mining action of coal seam roadway were considered, and the bolt reinforcing criteria for wall including low limit condition and up limit condition were put up, which supply a basis for the bolt reinforcement design. For a particular engineering, there existed a bolt reinforcing controllable range which can be determined by the method put up in this paper. For the out of controllable range of bolt reinforcement in engineering, it is necessary to seek for other kind reinforcing technology, because the bolt reinforcing technology is not omnipotent.

  18. 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

  19. Study on stress distribution and failure criterion of the roof for the severely inclined coal seam under long wall working

    Institute of Scientific and Technical Information of China (English)

    MENG Xiang-rui; GAO Zhao-ning; WANG Xiang-qian

    2012-01-01

    By turning to the theory of elastic thin plates,a mechanical model of the main roof breaking for severely inclined seam under long wall working was esbalished,in which formulaes were deduced for the calculation of the stress distribution.When the main roof stress distribution was characterized,the failure form of the roof in the long wall coal seam under work was given with the failure criterion deduced.The deduced failure criterion was then applied to the No.3232(3) face of the Lizuizi Coal Mine; the first pressure for the working face was accurately predicted.Results of the field application show that the main roof of the severely inclined coal seam under long wall working breaks in the O-X pattern,which is basically in accordance with the reality.

  20. Forecasting the degree of rock burst hazard in areas of gas bearing coal seams by the electromagnetic radiation method

    Energy Technology Data Exchange (ETDEWEB)

    Proskuryakov, V.M.; Shabarov, A.N.; Frid, V.I. (Vsesoyuznyi Nauchno-Issledovatel' skii Institut Gornoi Geomekhaniki i Marksheiderskogo Dela (USSR))

    1991-02-01

    Presents results of investigations into emission of electromagnetic waves in zones of increased rock burst hazard conducted during drivage of a ventilation gallery in the Anzherskaya mine (Severokuzbassugol' association). Relationships between the emission of electromagnetic impulses, yield of drilling, gas yield rate, the distance between increased stress zones and seam denudation and time are discussed and presented in diagrams. Regularities of variation in electromagnetic radiation at various stress states in coal seam boundary parts with the gas yield factor taken into account were found. Suitability of recording electromagnetic radiation for forecasting rock burst hazards was shown and criteria for evaluating the degree of rock burst hazard for a coal seam in the Anzherskaya mine are presented. 3 refs.

  1. Experiments in the full mechanisation of vertical seams at La Camocha Colliery (MSP, Ponferrada Mine and Steel Company)

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Arguelles, A.; Torano, J.; Tejuca, L.; Gonzalez, A.; Gutierrez, S.

    1987-05-01

    Limited production methods afforded by conventional coal-winning systems in vertical seams with series of borehole samples taken at 5 m vertical intervals and by the use of pneumatic picks and wooden props has forced coal mining companies, including the Ponferrada Mine and Steel Company, to introduce mechanised winning in this type of seam, in order to achieve a clear improvement in production levels. This article describes the experiences and the results obtained during full mechanisation of vertical seams at La Camocha colliery, by the combined use of a drum shearer and powered supports and by stowing of the goaf. The article is divided into two sections. The first section, given here, describes the methods and equipment used.

  2. Experiments in the full mechanisation of vertical seams at La Camocha colliery (MSP), Ponferrado Mine and Steel Company

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Arguelles, A.; Torano, J.; Tejuca, L.; Gonzalez, A.; Gutierrez, S.

    1987-06-01

    Limited production methods afforded by conventional coal-winning systems in vertical seams with series of borehole samples taken at 5 m vertical intervals and by the use of pneumatic picks and wooden props has forced coal mining companies, including the Ponferrada Mine and Steel Company, to introduce mechanised winning in this type of seam, in order to achieve a clear improvement in production levels. This article describes the experiences and the results obtained during full mechanisation of vertical seams at La Camocha colliery, by the combined use of a drum shearer and powered supports and by stowing of the goaf. The article is divided into two sections. The second section given here, gives the results obtained after seven months of operating the new system. 7 figs., 1 tab.

  3. "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…

  4. Back-and-forth mining for hard and thick coal seams-research about the mining technology for fully mechanized caving working face of Datong Mine

    Institute of Scientific and Technical Information of China (English)

    JIN Zhi-xin; YU Hong; YU Bin; SONG Hua-ling

    2005-01-01

    The article introduced the key technology, mining process, and back-and-forth mining method for the caving working face of hard-thick coal seams in Datcng mine, and researched this innovations process, optimized the systemic design and working face outplay, tried to perfect the caving mining technology of hard-thick coal seams further.

  5. A new numerical approach of coupled modeling for solid deformation and gas leak flow in multi-coal-seams

    Institute of Scientific and Technical Information of China (English)

    SUN Pei-de; GUO Mao-xin

    2005-01-01

    From the viewpoint of interaction mechanics for solid and gas, a coupled mathematical model was presented for solid coal/rock deformation and gas leak flow in parallel deformable coal seams. Numerical solutions using the SIP (Strong Implicit Procedure) method to the coupled mathematical model for double parallel coal seams were also developed in detail. Numerical simulations for the prediction of the safety range using protection layer mining were performed with experimental data from a mine with potential danger of coal/gas outbursts. Analyses show that the numerical simulation results are consistent with the measured data in situ.

  6. Dynamic destabilization analysis based on AE experiment of deep-seated, steep-inclined and extra-thick coal seam

    Institute of Scientific and Technical Information of China (English)

    Fenhua Ren; Xingping Lai; Meifeng Cai

    2008-01-01

    No. 5 coal seam in Huating Coal Mine is a deep-seated, steep-inclined extra-thick coal seam where excavation disturbance is quite frequent. The maximum and minimum principal stresses differ widely. During mining, dynamical destabilization happens frequently and induce tragedies. Based on the comparison between the acoustic emission (AE) experiment on dynamical destabilization of coal rock and the related in situ testing results, this article provides comprehensive analysis on the regular quantificational AE patterns (energy rate, total events) of coal rock destabilization in complex-variable environment. The comparison parameters include dynamic tension energy rate, deformation resistance to compression, and shear stress.

  7. 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

  8. Organic geochemical study of sequences overlying coal seams; example from the Mansfield Formation (Lower Pennsylvanian), Indiana

    Science.gov (United States)

    Mastalerz, Maria; Stankiewicz, A.B.; Salmon, G.; Kvale, E.P.; Millard, C.L.

    1997-01-01

    Roof successions above two coal seams from the Mansfield Formation (Lower Pennsylvanian) in the Indiana portion of the Illinois Basin have been studied with regard to sedimentary structures, organic petrology and organic geochemistry. The succession above the Blue Creek Member of the Mansfield Formation is typical of the lithologies covering low-sulphur coals ( 2.%). The transgressive-regressive packages above both seams reflect the periodic inundation of coastal mires by tidal flats and creeks as inferred from bioturbation and sedimentary structures such as tidal rhythmites and clay-draped ripple bedforms. Geochemistry and petrology of organic facies above the Blue Creek coal suggest that tidal flats formed inland in fresh-water environments. These overlying fresh water sediments prevented saline waters from invading the peat, contributing to low-sulphur content in the coal. Above the unnamed coal, trace fossils and geochemical and petrological characteristics of organic facies suggest more unrestricted seaward depositional environment. The absence of saline or typically marine biomarkers above this coal is interpreted as evidence of very short periods of marine transgression, as there was not enough time for establishment of the precursor organisms for marine biomarkers. However, sufficient time passed to raise SO42- concentration in pore waters, resulting in the formation of authigenic pyrite and sulphur incorporation into organic matter.

  9. Transitional geology and its effects on development and longwall mining in Pittsburgh Seam

    Institute of Scientific and Technical Information of China (English)

    Lu Jun; Van Dyke Mark; Su Daniel W.H; Hasenfus Greg

    2016-01-01

    This paper presents the geologic and ground control challenges that were encountered by Consol Energy’s coal mining operations in southwestern Pennsylvania, USA. Geologic encounters, such as sandstone-to-limestone geology transition, massive sandstone channels, shale channels, pyritic rich green claystone, laminated roof, and soft floor, have significantly impacted the development and longwall mining in Consol’s Pittsburgh Seam coal mines. Experience from different mines shows that, in the sandstone-to-limestone geology transition zone, 1.83 m high-tension, fully-grouted primary bolts employed along with 4.88 m cen-ter cable bolts at every other strap greatly improved beam building and ensured proper anchorage into the competent roof. Hydraulic fracturing of the massive sandstone was often necessary to enhance caving of the massive sandstone behind the shields to relieve pressure at the face. The presence of soft floor coupled with presence of thick floor coal and deep cover, induced excessive headgate convergence during retreat of the first right hand longwall panel. In all, it is important to explore the roof and in-seam geology in detail to delineate normal and anomalous geologic conditions prior to and during development. With diligent geologic reconnaissance, geotechnical monitoring, and assessment, site-specific geotechnical solutions have been provided to mine operations to improve safety and productivity.

  10. Research on forced gas draining from coal seams by surface well drilling

    Institute of Scientific and Technical Information of China (English)

    Wu Dongmei; Wang Haifeng; Ge Chungui; An Fenghua

    2011-01-01

    Surface drilling was performed at the Luling Coal Mine, in Huaibei, to shorten the period required for gas draining. The experimental study was designed to reduce the cost of gas control by efficiently draining gas from the upper protected layer. The structural arraignment and technical principles of pressure relief via surface drilling are discussed. Results from the trial showed that gas drained from the surface system over a period of 10 months. The total amount of collected gas was 248.4 million m3. The gas draining occurred in three stages: a growth period; a period of maximum gas production; and an attenuation period. The period of maximum gas production lasted for 4 months. During this time the methane concentration ranged from 60% to 90% and the average draining rate was 10.6 m3/min. Combined with other methods of draining it was possible to drain 70.6% of the gas from middle coal seam groups. The amount of residual gas dropped to 5.2 m3/ton, and the pressure of the residual gas fell to 0.53 MPa,thereby eliminating the outburst danger in the middle coal seam groups. The factors affecting pressure relief gas draining by surface drilling were analysed.

  11. 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.

  12. Recycling of coal seam gas-associated water using vacuum membrane distillation.

    Science.gov (United States)

    Heidarpour, Farideh; Shi, Jeffrey; Chae, So-Ryong

    2015-01-01

    Coal seam gas-associated water (CSGAW), which is a by-product of coal seam gas (CSG) production typically contains significant amounts of salts and has potential environmental issues. In this study, we optimized a bench-scale vacuum membrane distillation (VMD) process with flat-sheet hydrophobic polytetrafluoroethylene (PTFE) membranes for the treatment of synthetic CSGAW (conductivity = 15 mS/cm). To study performance of the VMD process, we explored the effects of feed temperature (T(f) = 60, 70, and 80°C), feed flow rate (V(f) = 60, 120, and 240 mL/min), and vacuum pressure (P(v) = 3, 6, and 9 kPa) on water permeability through the PTFE membrane in the VMD process. Under the optimum conditions (i.e. T(f) = 80°C, V(f) = 240 mL/min, P(v) = 3 kPa), water permeability and rejection efficiency of salts by the VMD process were found to be 5.5 L/m(2)/h (LMH) and 99.9%, respectively, after 2 h filtration. However, after 8 h operation, the water permeability decreased by 70% compared with the initial flux due to the formation of fouling layer of calcium, chloride, sodium, magnesium, and potassium on the membrane surface.

  13. Experimental research of overburden movement and subsurface water seeping in shallow seam mining

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Shallow seam coal field has the largest coal reserve in China. Mining in shallow depth causes serious problems, and subsurface dewatering is a major issue. In this paper, the physical simulating models were prepared to study overburden movement and aquiclude stability in the shallow seam mining of Yushuwan Coalfield, China. According to the characteristic of clay aquiclude and bedrock in the overburden, the proper simulation materials for simulating the plastic clay aquiclude layers and brittle bedrock layers were determined by the stress-strain tests and hydrophilic tests. The physical simulating models of solid medium and two phases of solid-liquid medium were carried out to simulate the failure and caving process of the roof and overburden, as well as the subsurface water seeping. Based on the simulation, it was found that the movement of clay aquiclude follows the movement of the underlying bedrock layers. The stability of aquiclude is mainly affected by cracks in fracture zone. The tests also showed that the best way to control the stability of aquiclude is to reduce the subsiding gradient, and there is a possibility of ground water conservation under longwall mining in Yushuwan Mine. This research provides a foundation for further study on mining dewatering and water conservation.

  14. Journey to the centre of the earth: coal seam gas in Queensland

    Energy Technology Data Exchange (ETDEWEB)

    Dighton, P.

    1998-12-31

    Coal Seam Gas (CSG) is potentially an important energy source of the future. In addition to being a valuable energy source, the utilisation of CSG will also decrease significantly the adverse greenhouse effects of venting CSG to the atmosphere. Although CSG is presently being recovered and utilised in both Queensland and New South Wales, its economic viability at the moment is marginal. However technological advances or fiscal incentives could see this change rapidly. At present most of the Queensland coal fields have overlapping petroleum tenures. While this has not presented significant conflicts to date, holders of Authorities To Prospect are automatically entitled to production leases from discovery of petroleum, including coal seam gas, deposits. The Queensland government has addressed this potential conflict by producing a `final position` paper. One of the main proposals is to protect the coal mining industry by the declaration of CSG areas and strata titling of the relevant interests. The legislation, presently being drafted for submission to the new Queensland Parliament, is outlined.

  15. Auxiliary transportation mode in a fully-mechanized face in a nearly horizontal thin coal seam

    Institute of Scientific and Technical Information of China (English)

    Wang Chen; Tu Shihao; Zhang Lei; Yang Qianlong; Tu Hongsheng

    2015-01-01

    On fully-mechanized faces in nearly horizontal thin coal seams (NHTCS), the selection of the auxiliary transportation mode is difficult. Generally, auxiliary transportation mainly includes trackless or rail transportation. Combined with a familiar NHTCS fully-mechanized face, a multi-attribute decision-making model was set up for the decision. The index weight was objectively determined with the fuzzy number and entropy method. The priority order of auxiliary transportation modes was obtained from the Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE). The results show that: the net flow of the mode can be expressed by the function of the surrounding rock deformation of the roadway, the dimension of equipment and the thickness of the coal seam;Based on the cost type index, there is a positive correlation between the net flow with the height and width of the trackless aux-iliary transportation equipment, respectively. The trackless auxiliary transportation equipment selection principle should be‘height first then width”. Combined with the field application of the trackless auxil-iary transportation in Liangshuijing coal mine, the proper method to achieve the safe and high-efficient exploitation of a NHTCS fully-mechanized face is trackless tyred vehicle auxiliary transportation.

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

    Institute of Scientific and Technical Information of China (English)

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

    2016-01-01

    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 vari-able 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 quan-tify the stability factor of the supported roof of the entries at selected locations. The SRM-calculated sta-bility 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.

  17. 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.

  18. Solar tracking system

    Energy Technology Data Exchange (ETDEWEB)

    Okandan, Murat; Nielson, Gregory N.

    2016-07-12

    Solar tracking systems, as well as methods of using such solar tracking systems, are disclosed. More particularly, embodiments of the solar tracking systems include lateral supports horizontally positioned between uprights to support photovoltaic modules. The lateral supports may be raised and lowered along the uprights or translated to cause the photovoltaic modules to track the moving sun.

  19. 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.

  20. 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)

  1. Fracture evolution and pressure relief gas drainage from distant protected coal seams under an extremely thick key stratum

    Institute of Scientific and Technical Information of China (English)

    WANG Liang; CHENG Yuan-ping; LI Feng-rong; WANG Hai-feng; LIU Hai-bo

    2008-01-01

    When an extremely thick rock bed exists above a protected coal seam in the bending zone given the condition of a mining protective seam, this extremely thick rock bed controls the movement of the entire overlying stratum. This extremely thick rock bed, called a "main key stratum", will not subside nor break for a long time, causing lower fractures and bed separations not to close and gas can migrate to the bed separation areas along the fractures. These bed separations become gas enrichment areas. By analyzing the rule of fracture evolution and gas migration under the main key stratum after the deep protective coal seam has been mined, we propose a new gas drainage method which uses bore holes, drilled through rock and coal seams at great depths for draining pressure relief gas. In this method, the bores are located at a high level suction roadway (we can also drill them in the drilling field located high in an air gateway). Given the practice in the Halzi mine, the gas drainage rate can reach 73% in the middie coal group, with a gas drainage radius over 100 m.

  2. A method of determining the permeability coefficient of coal seam based on the permeability of loaded coal

    Institute of Scientific and Technical Information of China (English)

    Li Bo; Wei Jianping; Wang Kai; Li Peng; Wang Ke

    2014-01-01

    This study developed the equipment for thermo-fluid-solid coupling of methane-containing coal, and investigated the seepage character of loaded coal under different working conditions. Regarding the effective pressure as a variable, the variation characteristics of the gas permeability of loaded meth-ane-containing coal has been studied under the conditions of different confining pressures and pore pres-sures. The qualitative and quantitative relationship between effective stress and permeability of loaded methane-containing coal has been established, considering the adsorption of deformation, amount of pore gas compression and temperature variation. The results show that the permeability of coal samples decreases along with the increasing effective stress. Based on the Darcy law, the correlation equation between the effective stress and permeability coefficient of coal seam has been established by combining the permeability coefficient of loaded coal and effective stress. On the basis of experimental data, this equation is used for calculation, and the results are in accordance with the measured gas permeability coefficient of coal seam. In conclusion, this method can be accurate and convenient to determine the gas permeability coefficient of coal seam, and provide evidence for forecasting that of the deep coal seam.

  3. Facies, dissolution seams and stable isotope compositions of the Rohtas Limestone (Vindhyan Supergroup) in the Son valley area, central India

    Indian Academy of Sciences (India)

    S Banerjee; S K Bhattacharya; S Sarkar

    2005-02-01

    The early Mesoproterozoic Rohtas Limestone in the Son valley area of central India represents an overall shallowing-upward carbonate succession. Detailed facies analysis of the limestone reveals outer- to inner-shelf deposition in an open marine setting. Wave-ripples, hummocky cross strat- ifications and edgewise conglomerates argue against a deep marine depositional model for the Rohtas Limestone proposed earlier. Stable isotope analysis of the limestone shows that 13C and 18O values are compatible with the early Mesoproterozoic open seawater composition. The ribbon limestone facies in the Rohtas Limestone is characterized by micritic beds, each decoupled in a lower band enriched and an upper band depleted in dissolution seams. Band-wise isotopic analysis reveals systematic short-term variations. Comparative enrichment of the heavier isotopes in the upper bands is attributed to early cementation from sea water and water derived from the lower band undergoing dissolution because of lowering of pH at depth. The short-term positive shifts in isotopic compositions in almost every upward gradational transition from a seamed band to a non-seamed band support the contention that dissolution seams here are of early diagenetic origin, although their formation was accentuated under overburden pressure.

  4. 40 CFR Table 28 to Subpart G of... - Deck Seam Length Factors a (SD) for Internal Floating Roof Tanks

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Deck Seam Length Factors a (SD) for Internal Floating Roof Tanks 28 Table 28 to Subpart G of Part 63 Protection of Environment ENVIRONMENTAL... specific information is available, these factors can be assumed to represent the most common bolted...

  5. Current status and technical challenges of CO2 storage in coal seams and enhanced coalbed methane recovery:an overview

    Institute of Scientific and Technical Information of China (English)

    Xiaochun Li; Zhi-ming Fang

    2014-01-01

    In the past two decades, research on CO2 storage in coal seams and simultaneously enhanced coalbed methane recovery (ECBM) has attracted a lot of attention due to its win–win effect between greenhouse gas (CO2) emission reduction and coalbed methane recovery enhancement. This paper presents an overview on the current status of research on CO2-ECBM in the past two decades, which involves CO2 storage capacity evaluations, laboratory investigations, mod-elings and pilot tests. The current status shows that we have made great progress in the ECBM technology study, especially in the understanding of the ECBM mechanisms. However, there still have many technical challenges, such as the definition of unmineable coal seams for CO2 storage capacity evaluation and storage site characterization, methods for CO2 injec-tivity enhancement, etc. The low injectivity of coal seams and injectivity loss with CO2 injection are the major technique challenges of ECBM. We also search several ways to promote the advancement of ECBM technology in the present stage, such as integrating ECBM with hydraulic fracturing, using a gas mixture instead of pure CO2 for injection into coal seams and the application of ECBM to underground coal mines.

  6. Modeling of air-gas and dynamic processes in driving development workings in the gas-bearing coal seams

    Energy Technology Data Exchange (ETDEWEB)

    Presler, V.T. [Russian Academy of Science, Kemerovo (Russian Federation). Siberian Branch, Inst. of Coal & Coal Fuel Chemistry

    2002-04-01

    The models for air-gas processes of different hierarchical level are considered in designing and driving development workings in the coal seams. The procedure is proposed for model adaptation according to the on-line data, which makes it possible to estimate the state of medium and working capacity of measuring equipment.

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

    Energy Technology Data Exchange (ETDEWEB)

    Viehrig, Hans-Werner; Schuhknecht, Jan [Forschungszentrum Dresden-Rossendorf (Germany)

    2008-07-01

    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{sub 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

  8. Origin of banded structure and coal lithotype cycles in Kargali coal seam of East Bokaro sub-basin, Jharkhand, India: Environmental implications

    Indian Academy of Sciences (India)

    Ram Chandra Tewari; Zahid A Khan

    2015-04-01

    The Kargali seam of Early Permian Barakar cyclothems of East Bokaro sub-basin of Jharkhand, India is 12–30 m thick, splits into two parts, and extends throughout the length of the basin. It is made up of interbedded sequences and variable proportions of Vitrain, Clarain, Durain and Fusain. Application of embedded Markov chain model rejects the phenomenon of randomness in the repetition of coal lithotypes. The preferential upward transition path for coal lithotypes that can be derived for the Kargali top coal seam is: Vitrain → Clarain → Durain ↔ Fusain → Vitrain, and for the Kargali bottom coal seam is: Clarain ↔ Vitrain → Fusain → Durain → Clarain. By and large, the cyclic repetition of coal lithotypes is similar in the Kargali bottom and top seams. Among the noteworthy features are two-way transitions between Durain and Fusian in Kargali top and between Clarain and Vitrain in the case of Kargali bottom coal seam. Entropy analysis corroborates Markov chain and indicates the presence of type A-4 asymmetrical cycles of coal lithotypes. It is suggested that the banded structure of a coal seam is not a random feature and follows a definite cyclic pattern in the occurrence of coal lithotypes in vertical order and is similar to that described in Australian and European coal seams. Asymmetrical cyclic sequences are a normal, rather than an unusual condition, within coal seams. It is visualized that a gradual decline of toxic environment and ground water level resulted in the coal lithotype cycles in the Kargali seam of East Bokaro sub-basin. The close interbedding of Vitrain and Clarain is suggestive of seasonal fluctuation in anaerobic and aerobic conditions during peat formation.

  9. 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.

  10. 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.

  11. Test studies of gas flow in rock and coal surrounding a mined coal seam

    Institute of Scientific and Technical Information of China (English)

    Lv Youchang

    2012-01-01

    An analysis of the variation rule of abutment pressure at the mining working face in a single coal seam and the mechanical behavior of surrounding rock during stoping is presented.Consideration of the elastic and plastic deformation zones that develop during the mining process allowed the determination of a relationship between horizontal stress and vertical stress.Based on this,a confined pressure unloading test was conducted by the use of the "gas-containing coal thermo-fluid-solid coupling 3-axis servo seepage" experimental apparatus.Thus,gas flow patterns in the elastic and plastic zones were derived from an experimental point of view.Darcy's law and the Klinkenberg effect were used to derive a gas flow equation for the elastic and plastic stress fields.The study of gas flow phenomena at the working face during coal mining is of great importance for the study of gas migration and enrichment oatterns.

  12. Parametric optimization of seam welding of stainless steel (SS 304) sheets

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, Muthuraman Pandi; Sait, Abdullah Naveen; Ravichandran, Manickam [Chendhuran College of Engineering and Technology, Pudukkottai, Tamilnadu (India)

    2015-06-01

    In the present study, seam welding process parameters were optimized for joining 306 stainless steel plates. Welding pressure, welding speed and welding temperature combinations were carefully selected with the objective of producing a weld joint with maximum impact strength and hardness. Taguchi technique was applied for optimizing the selected welding parameters. The factors used in this study consisted of pressure, welding speed and welding temperature, each of which had three levels in the study. L{sub 27} orthogonal array and corresponding levels were selected according to the aforementioned factors and experimental tests were performed. Signal-to-noise (S/N) ratio was used to evaluate the experimental results. The results indicate that the welding speed has the greatest influence on impact strength, followed by welding pressure and temperature. Experiments have also been conducted to validate the optimized parameters.

  13. 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.

  14. Forecast of Geological Gas Hazards for "Three-Soft" Coal Seams in Gliding Structural Areas

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Gas outbursts from "three-soft" coal seams (soft roof, soft floor and soft coal) constitute a very serious problem in the Ludian gliding structure area in western Henan.By means of theories and methods of gas geology, structural geology, coal petrology and rock tests, we have discussed the effect of control of several physical properties of soft roof on gas preservation and proposed a new method of forecasting gas geological hazards under open structural conditions.The result shows that the areas with type Ⅲ or Ⅳ soft roofs are the most dangerous areas where gas outburst most likely can take place.Therefore, countermeasures should be taken in these areas to prevent gas outbursts.

  15. Rapid evaluation of the condition of a rock burst endangered seam

    Energy Technology Data Exchange (ETDEWEB)

    Proskuryakov, V.M.; Shabarov, A.N.; Frid, V.I. (VNIMI (USSR))

    1990-03-01

    Reports on the EMI rapid geophysical method for forecasting the degree of rock burst hazard. The method was developed at VNIMI and is based on recording electromagnetic radiation trends. Curves of electromagnetic radiation trends are compared with curves that represent the amount of drillings obtained from exploratory boreholes. The dependence of electromagnetic radiation on borehole depth is also shown. Investigations showed that the intensity of electromagnetic radiation depends primarily on the volume of rock that is in the process of transition to a critical state. Increased radiation intensity reflects growing stress in boundary parts of rock burst endangered seams. An index that characterizes the energy of the coal disintegration process is discussed. The index permits the electromagnetic radiation intensity that characterizes elevated rock burst hazards to be calculated along with the threshold of amplitude discrimination at which measurements must be performed. The index also allows the most suitable sensitivity of the measuring apparatus (EG-9) to be determined. 3 refs.

  16. The NC Power Supply Design of Large Current and Wide Frequency Pulse in SEAM

    Directory of Open Access Journals (Sweden)

    Jianping Zhou

    2013-07-01

    Full Text Available There are a lot of ways to achieve large current pulse power supply, and the more common way is to adopt the inverter switching circuit to achieve pulse power supply. The core of the NC power supply design of large current and wide frequency pulse in SEAM is using two-stage modulation. Combined with inverter technology, DC chopper technology and NC technology, it not only can achieve the adjustability of the output pulse amplitude, but also can realize continuous adjustment of the output pulses and the duty cycle. The front stage of power supply uses DC/DC transformation circuit with the UC3879 integrated control chip as the core. With the microcontroller as the control core, the backward stage uses DC chopper circuit to achieve the NC power supply of multi-parameter adjustable output large current pulse.

  17. Planning of excavation of seams characterized by complicated structure with the aim of coal mixing

    Energy Technology Data Exchange (ETDEWEB)

    Belyakov, Yu.I.; Pushkin, S.P. (Kievskii Inzhenerno-Stroitel' nyi Institut (USSR))

    1990-07-01

    Discusses use of mathematical modeling for optimization of surface mining in mines with a complicated coal deposit structure and changing coal quality. The modeling is aimed at stabilizing coal quality, especially ash content. Surface mines with bucket wheel excavators for overburden removal and mining and locomotives and railroad cars for mine haulage are modeled. The mines supply 2 classes of coal: with 47% ash and with 55%. The modeling is aimed at determining optimum advance rates of the bucket wheel excavators. Effects of mine haulage system, coal yard capacity, coal seam structure, fluctuations of coal quality in a coal deposit, requirements for optimum geometry of the working faces, benches and other elements that influence slope stability are considered. 2 refs.

  18. Small-scale explosive seam welding. [using ribbon explosive encased in lead sheath

    Science.gov (United States)

    Bement, L. J.

    1972-01-01

    A unique small scale explosive seam welding technique is reported that has successfully joined a variety of aluminum alloys and alloy combinations in thicknesses to 0.125 inch, as well as titanium in thicknesses to 0.056 inch. The explosively welded joints are less than one-half inch in width and apparently have no long length limitation. The ribbon explosive developed in this study contains very small quantities of explosive encased in a flexible thin lead sheath. The evaluation and demonstration of this welding technique was accomplished in three phases: evaluation and optimization of ten major explosive welding variables, the development of four weld joints, and an applicational analysis which included photomicrographs, pressure integrity tests, vacuum effects, and fabrication of some potentially useful structures in aluminum and titanium.

  19. 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.

  20. Optical Tracking With Two Markers for Robust Prospective Motion Correction for Brain Imaging

    Science.gov (United States)

    Singh, Aditya; Zahneisen, Benjamin; Keating, Brian; Herbst, Michael; Chang, Linda; Zaitsev, Maxim; Ernst, Thomas

    2017-01-01

    Object Prospective motion correction (PMC) during brain imaging using camera-based tracking of a skin-attached marker may suffer from problems including loss of marker visibility due to the coil and false correction due to non-rigid-body facial motion, such as frowning or squinting. A modified PMC system is introduced to mitigate these problems and increase the robustness of motion correction. Materials and Methods The method relies on simultaneously tracking two markers, each providing six degrees of freedom, that are placed on the forehead. This allows us to track head motion when one marker is obscured, and detect skin movements to prevent false corrections. Experiments were performed to compare the performance of the two-marker motion correction technique to the previous single-marker approach. Results Experiments validate the theory developed for adaptive marker tracking and skin movement detection, and demonstrate improved image quality during obstruction of the line-of-sight of one marker, when subjects squint, or when subjects squint and move simultaneously. Conclusion The proposed methods eliminate two common failure modes of PMC and substantially improve the robustness of PMC and can be applied to other optical tracking systems capable of tracking multiple markers. The methods presented can be adapted to the use of more than two markers. PMID:26121941

  1. Forward tracking detectors

    Indian Academy of Sciences (India)

    Klaus Mönig

    2007-11-01

    Forward tracking is an essential part of a detector at the international linear collider (ILC). The requirements for forward tracking are explained and the proposed solutions in the detector concepts are shown.

  2. An infra-red finger tracking system used in the assessment and remediation of “graph-as-picture” misconceptions

    OpenAIRE

    2012-01-01

    The workshop presentation will describe a specialized ap- plication of Lee’s “Wiimote Whiteboard” [7] an infra-red camera based tracking system which uses the Nintendo Wii wireless remote control unit and Bluetooth. Young students wear a very small infra-red LED on their index finger with a forefinger/thumb operated micro-switch for produ- cing “mouse clicks”. This system is combined with a vertically mounted data projector or a horizontally mounted regular computer LCD display, creating a co...

  3. Bayesian multiple target tracking

    CERN Document Server

    Streit, Roy L

    2013-01-01

    This second edition has undergone substantial revision from the 1999 first edition, recognizing that a lot has changed in the multiple target tracking field. One of the most dramatic changes is in the widespread use of particle filters to implement nonlinear, non-Gaussian Bayesian trackers. This book views multiple target tracking as a Bayesian inference problem. Within this framework it develops the theory of single target tracking, multiple target tracking, and likelihood ratio detection and tracking. In addition to providing a detailed description of a basic particle filter that implements

  4. Track finding efficiency in

    Energy Technology Data Exchange (ETDEWEB)

    Allmendinger, T.; Bhuyan, B.; Brown, D. N.; Choi, H.; Christ, S.; Covarelli, R.; Davier, M.; Denig, A. G.; Fritsch, M.; Hafner, A.; Kowalewski, R.; Long, O.; Lutz, A. M.; Martinelli, M.; Muller, D. R.; Nugent, I. M.; Lopes Pegna, D.; Purohit, M. V.; Prencipe, E.; Roney, J. M.; Simi, G.; Solodov, E. P.; Telnov, A. V.; Varnes, E.; Waldi, R.; Wang, W. F.; White, R. M.

    2012-12-10

    We describe several studies to measure the charged track reconstruction efficiency and asymmetry of the BaBar detector. The first two studies measure the tracking efficiency of a charged particle using τ and initial state radiation decays. The third uses the τ decays to study the asymmetry in tracking, the fourth measures the tracking efficiency for low momentum tracks, and the last measures the reconstruction efficiency of K$0\\atop{S}$ particles. The first section also examines the stability of the measurements vs. BaBar running periods.

  5. Geochemistry and Modes of Occurrence of Hazardous Trace Elements in the No.11 Coal Seam, Antaibao Surface Mine, Shanxi Province

    Institute of Scientific and Technical Information of China (English)

    SONG Dangyu; QIN Yong; WANG Wenfeng; ZHANG Junying; ZHENG Chuguang

    2007-01-01

    Concentrations of seventeen hazardous trace elements including As, Pb, Hg, Se, Cd, Cr, Co,Mo, Mn, Ni, U, V, Th, Be, Sb, Br and Zn in the No.11 coal seam, Antaibao surface mine, Shanxi Province were determined using Instrumental Neutron Activation Analysis (INAA), Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), Cold-Vapor Atomic Absorption Spectrometry (CV-AAS) and Graphite Furnace Atomic Absorption Spectrometry (GF-AAS).Comparisons with average concentrations of trace elements in Chinese coal show that the concentrations of Hg and Cd in the No. 11 coal seam, Antaibao surface mine are much higher. They may be harmful to the environment in the process of utilization. The variations of the trace elements contents and pyritic sulfur in vertical section indicated that: (a) the concentrations of As, Pb, Mn, and pyritic sulfur decrease from roof to floor; (b) the concentrations of Cr, Zn and Mo are higher in roof,floor and lower in coal seam; (c) the concentration of Br, Sb, and Hg are higher in coal seam and lower in roof and floor; (d) the concentrations of Mo, V, Th and Al vary consistently with the ash yield.Cluster analysis of trace elements, pyritic sulfur, ash yield and major elements, such as Al, Fe, P, Ca shows that: (a) pyritic sulfur, Fe, As, Mn, Ni, Be are closely associated and reflect the influence of pyrite; (b) Mo, Se, Pb, Cr, Th, Co, Ca and Al are related to clay mineral, which is the main source of ash; (c) U, Zn, V, Na, P maybe controlled by phosphate or halite; (d) Hg, Br, Sb and Cd may be mainly organic-associated elements which fall outside the three main groups. The concentration distribution characteristics of trace elements in coal seam and the cluster analysis of major and trace elements showed that the contents of trace elements in the No. 11 coal seam, Antaibao surface mine, are mainly controlled by detrital input and migration from roof and floor.

  6. Advanced Tracking of Vehicles

    DEFF Research Database (Denmark)

    Jensen, Christian Søndergaard; Li, K.-J.; Pakalnis, Stardas

    2005-01-01

    With the continued advances in wireless communications, geo-location technologies, and consumer electronics, it is becoming possible to accurately track the time-varying location of each vehicle in a population of vehicles. This paper reports on ongoing research that has as it objective to develop...... efficient tracking techniques. More specifically, while almost all commercially available tracking solutions simply offer time-based sampling of positions, this paper's techniques aim to offer a guaranteed tracking accuracy for each vehicle at the lowest possible costs, in terms of network traffic...... and server-side updates. This is achieved by designing, prototyping, and testing novel tracking techniques that exploit knowledge of the road network and past movement. These resulting tracking techniques are to support mobile services that rely on the existence of a central server that continuously tracks...

  7. Draft Genome Sequence of Methanobacterium sp. Maddingley, Reconstructed from Metagenomic Sequencing of a Methanogenic Microbial Consortium Enriched from Coal-Seam Gas Formation Water.

    Science.gov (United States)

    Rosewarne, Carly P; Greenfield, Paul; Li, Dongmei; Tran-Dinh, Nai; Midgley, David J; Hendry, Philip

    2013-01-01

    The draft genome of Methanobacterium sp. Maddingley was reconstructed from metagenomic sequencing of a methanogenic microbial consortium enriched from coal-seam gas formation water. It is a hydrogenotrophic methanogen predicted to grow using hydrogen and carbon dioxide.

  8. Tracks: Nurses and the Tracking Network

    Centers for Disease Control (CDC) Podcasts

    2012-06-06

    This podcast highlights the utility of the National Environmental Public Health Tracking Network for nurses in a variety of work settings. It features commentary from the American Nurses Association and includes stories from a public health nurse in Massachusetts.  Created: 6/6/2012 by National Center for Environmental Health (NCEH)/Division of Environmental Hazards and Health Effects (DEHHE)/Environmental Health Tracking Branch (EHTB).   Date Released: 6/6/2012.

  9. Study on Gas Cubic Drainage Technology in Contiguous Seams%近距离煤层群瓦斯立体抽采技术研究

    Institute of Scientific and Technical Information of China (English)

    刘珂铭; 张勇; 许力峰; 张江利; 张西斌; 李艳君; 杨维帅

    2012-01-01

    According to the mining in contiguous seams of Tongzi Mine, a seam with low gas content and low outburst danger was selected as a protective seam for coal mining. The mining disturbance role was applied to improve the permeability of the below pressure released seam. The borehole drilled along seam, low level strike borehole drilled through seam, pipeline buried in goaf, floor upward borehole drilled through seam and other measures were applied to comprehensive cubic gas drainage of the seam group. The experiment showed that the gas drainage rate of the coal mining face in protective seam was over 55% , coal and gas outburst danger was eliminated and the upper corner gas volume fraction was controlled below 1% after mining operation of the coal mining face completed. After the pressure released by the protective seam, the permeability coefficient of No. 6, No. 7 and No. 9 seam was individually increased by 392,320 and 289 times, the gas drainage rate was over 60% and the safe and efficient coal and gas jointly mining realized.%针对桐梓煤矿近距离煤层群开采,首先选择瓦斯含量较小、突出危险性低的煤层作为保护层进行开采,利用其开采扰动作用提高下部卸压煤层的透气性。采用顺层钻孔、低位走向穿层钻孔、采空区埋管和底板上向穿层钻孔等措施对煤层群进行立体化综合抽采,试验表明:保护层工作面瓦斯预抽采率在55%以上,消除了煤与瓦斯突出危险性,工作面开采后上隅角瓦斯体积分数控制在1%以下;6号、7号和9号被保护煤层经卸压后透气性系数分别增加了392、320和289倍,瓦斯抽采率超过60%,实现了煤与瓦斯安全高效共采

  10. The application of OpenCV on the real -time detection system of the seam%OpenCV在焊缝实时检测系统中的应用

    Institute of Scientific and Technical Information of China (English)

    冯染宝; 徐自越

    2012-01-01

    机器视觉系统是集机械、光电、控制、计算机和数字图像处理等技术于一体的高度自动化系统,广泛应用于工业当中.焊缝实时检测系统主要针对焊接自动跟踪技术中的在线检测焊缝并进行相关处理的系统.该文在VC ++6.0开发环境中设计了一种采用Gauss小波检测边缘,基于OpenCV的焊缝实时检测与处理算法,实验结果表明该算法实时性高、效果好、检测正确快速.%The machine vision system is a high automation system in the integration of the machinery, photoelectricity, control, computer and digital image processing, widely used in industry. The real-time detection and processing system of the seam is used for on-line detection and related image processing of welding automation tracking technology. In the VC + + 6. 0 development environment this paper design a kind of the real-time seam detection algorithm based on OpenCV, adopting Gauss wavelet to detect edge. Experimental results show that the algorithm has high real-time, good effect and correct and fast detection.

  11. Ground pressure law of fully mechanized large cutting height face in extremely-soft thick seam and stability control in tip-to-face area

    Institute of Scientific and Technical Information of China (English)

    LIU Chang-you; CHANG Xing-min; HUANG Bing-xiang; WEI Min-tao; WANG Jun; WANG Jian-shu

    2007-01-01

    When stepped coal getting technology was applied to high seam mining working face, with field observations the following aspects of working face were analyzed based on the inherent conditions of extremely soft thick seam mined by Liangbei Mine, such as the brokenness and activity law of rock seam in the working face, the law of load-bearing of its supports, and the instability character of coal or rock in tip-to-face area.The following are the major laws. Pressure intensity of roof in high seam mining with extremely soft thick seam is stronger than one in slicing and sublevel-caving as a whole. But the greater crushing deformation of coal side makes pressure intensity of roof in the middle of working face be equivalent to one in sublevel-caving. In the middle of working face the roof brokenness has less dynamic load effect than roof brokenness in the two ends of working face. The brokenness instability of distinct pace of roof brings several load-bearings to supports. In condition of extremely soft thick seam, the ratio of resistance increment of supports in two ends of working face is obviously greater than that of supports in the middle. Most sloughing in coal side is triangular slop sloughing caused by shear slipping in high seam mining with extremely soft thick seam. Ultrahigh mining is the major reason for roof fall. Instability of coal or rock in tip-to-face area can be controlled effectively with the methods such as improving setting load of supports, mining along roof by reinforcing floor and protecting the immediate roof in time, and so on.

  12. Outburst control in soft and outburst prone coal seam using the waterjet slotting technique from modeling to field work

    Institute of Scientific and Technical Information of China (English)

    LU Ting-kan; YAO Zai-feng; CHANG Fang-tao; ZHAO Zhi-jian

    2012-01-01

    The paper discussed a comprehensive numerical simulation and field work by the usage of waterjet slotting technique to prevent the occurrence of outbursts in soft and outburst prone coal seams.This was based on the geological and geomechanical conditions of Jinjiachong Colliery,Guizhou Province,associated with varied waterjet slotting parameters such as slotting penetration,slotting thickness and slotting distance along the length of borehole.Also,to understand the variation of internal stress of coal seams after waterjet slotting application,the internal stress levels were compared with and without slotting application,and the results indicate that the internal effective stress levels can be reduced to 70% and 45% for the vertical and horizontal stresses,respectively,and the gas concentration can be increased up to 5 times when the waterjet slotting is applied.

  13. Fully mechanised experimental face in a seam with a dip of over 80 degrees at Sotan Colliery, HUNOS

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Arguelles Martinez, A.; Lugue Cabal, V.

    1984-01-01

    As is well known, mining is being carried out in the Central Asturian coalfield in seams which are mostly vertical, thin and of irregular hypsometry. 58% of the reserves are at a dip of more than 60 degrees and 35% are between 30 and 60 degrees. Average seam thickness is 0.93 m. Faults and geological disturbances are common. In the 1970s drum shearers were tested and installed underground, principally the Russian TEMP and KT models, which allowed 25% of the winning faces to be mechanised. The remainder was won with pneumatic picks. Mechanisation of the winning operations with the machines commercially available was not sufficient however, as production potential had reched its maximum.

  14. Mining seams liable to spontaneous combustion using a system of automatic regulation of air pressure in a ventilation section

    Energy Technology Data Exchange (ETDEWEB)

    Golik, A.S.; Churikov, Yu.V.; Troyan, N.P.

    1980-01-01

    In mining coal seams liable to spontaneous combustion, the possibility of underground fire increases with growing depth of mining, as air depression in lower seams can suck the air from the goaf of upper levels through cracks and fissures in the roof. To preclude this possibility a system of automatic control of air pressure in a ventilated section of a coal mine has been worked out. The system, called SReDA-1, consists in complete isolation of the ventilated section from other workings by conventional means and in exact maintenance of air pressure equal to atmospheric pressure. Technical specifications of ventilating machines used in the SReDA-1 system are given. Scheme of ventilated section using the system is also shown. (In Russian)

  15. Study on the effect of welding current during laser beam-resistance seam welding of aluminum alloy 5052

    Institute of Scientific and Technical Information of China (English)

    Li Yongqiang; Zhao Xihua; Zhao He; Cao Haipeng; Zhao Huanling

    2008-01-01

    The effect of welding current on the weld shape and tensile shear load during laser beam-resistance seam welding (LB-RSW) of aluminum alloy 5052 is studied. Experimental results show that the penetration depth, weld width,tensile shear load and the ratio of penetration depth to weld width of LB-RSW are bigger than those of laser beam welding(LBW) under the same conditions and the former three parameters increase as welding current rises. The weld shape of LB-RSW below 5 kA welding current is nearly the same as that of LBW. The weld morphology is protuberant under the condition of 5 kA welding current and 0.8 m/min welding speed. Furthermore, the microstructure of the weld seam of LB-RSW is coarser than that of LBW.

  16. The Caenorhabditis elegans GATA factor ELT-1 works through the cell proliferation regulator BRO-1 and the Fusogen EFF-1 to maintain the seam stem-like fate.

    Science.gov (United States)

    Brabin, Charles; Appleford, Peter J; Woollard, Alison

    2011-08-01

    Seam cells in Caenorhabditis elegans provide a paradigm for the stem cell mode of division, with the ability to both self-renew and produce daughters that differentiate. The transcription factor RNT-1 and its DNA binding partner BRO-1 (homologues of the mammalian cancer-associated stem cell regulators RUNX and CBFβ, respectively) are known rate-limiting regulators of seam cell proliferation. Here, we show, using a combination of comparative genomics and DNA binding assays, that bro-1 expression is directly regulated by the GATA factor ELT-1. elt-1(RNAi) animals display similar seam cell lineage defects to bro-1 mutants, but have an additional phenotype in which seam cells lose their stem cell-like properties and differentiate inappropriately by fusing with the hyp7 epidermal syncytium. This phenotype is dependent on the fusogen EFF-1, which we show is repressed by ELT-1 in seam cells. Overall, our data suggest that ELT-1 has dual roles in the stem-like seam cells, acting both to promote proliferation and prevent differentiation.

  17. The Caenorhabditis elegans GATA factor ELT-1 works through the cell proliferation regulator BRO-1 and the Fusogen EFF-1 to maintain the seam stem-like fate.

    Directory of Open Access Journals (Sweden)

    Charles Brabin

    2011-08-01

    Full Text Available Seam cells in Caenorhabditis elegans provide a paradigm for the stem cell mode of division, with the ability to both self-renew and produce daughters that differentiate. The transcription factor RNT-1 and its DNA binding partner BRO-1 (homologues of the mammalian cancer-associated stem cell regulators RUNX and CBFβ, respectively are known rate-limiting regulators of seam cell proliferation. Here, we show, using a combination of comparative genomics and DNA binding assays, that bro-1 expression is directly regulated by the GATA factor ELT-1. elt-1(RNAi animals display similar seam cell lineage defects to bro-1 mutants, but have an additional phenotype in which seam cells lose their stem cell-like properties and differentiate inappropriately by fusing with the hyp7 epidermal syncytium. This phenotype is dependent on the fusogen EFF-1, which we show is repressed by ELT-1 in seam cells. Overall, our data suggest that ELT-1 has dual roles in the stem-like seam cells, acting both to promote proliferation and prevent differentiation.

  18. A creative design of robotic visual tracking system in tailed welded blanks based on TRIZ

    Institute of Scientific and Technical Information of China (English)

    Zhang Lei; Zhao Mingyang; Zou Yuanyuan; Zhao Lihua

    2006-01-01

    According to the main tools of TRIZ, the theory of inventive problem solving, a new flowchart of the product conceptual design process to solve contradiction in TRIZ is proposed. In order to realize autonomous moving and automatic weld seam tracking for welding robot in Tailed Welded Blanks, a creative design of robotic visual tracking system based on CMOS has been developed by using the flowchart. The new system is not only used to inspect the workpiece ahead of a welding torch and measure the joint orientation and lateral deviation caused by curvature or discontinuity in the joint part, but also to record and measure the image size of the weld pool. Moreover, the hardware and software components are discussed in brief.

  19. Application of mathematical methods to determine the field parameters related to diffusion of methane gas in a Bulli seam

    Energy Technology Data Exchange (ETDEWEB)

    Basu, A.; Lama, R.D.

    1986-01-01

    The application of a mathematical model to describe gas drainage in coal seams is presented. The mechanisms of gas flow from coal can either follow Darcy's law or Fick's law of diffusion. At the earlier stages where the gas pressure is high, Darcy's law applies. At later stages when gas pressure is stabilized, Fick's law of diffusion is applicable. In this study Fick's law was applied.

  20. Characteristics of lignite seams in the Visonta opencast mine and analysis of relationships between their qualitative indices

    Energy Technology Data Exchange (ETDEWEB)

    Varga, J.

    1985-01-01

    Intercalations among the lignite seams consisting of clays and sandy clays considerably affect the quality indices of lignites themselves. The parameters (calorific value, ash content, etc.) show no homogeneous distribution in the opencast mine, thus their spatial changes should be followed. The analysis of the relationship of these parameters, e.g. the change of density as a function of water content, provides a useful tool to rationalize the lignite production.

  1. Computer determination of the extent of displacements of under-worked surfaces in case of steeply inclined seams

    Energy Technology Data Exchange (ETDEWEB)

    Martos, F.; Hegedus, G.

    1986-01-01

    Based on the problems related to the characteristics of the displacement of surface over faces in horizontal seams, the possibilities of the computer representation of the process of sinking for displacement elements with dipping angle over 30 degrees are presented. The importance of proper relationships between model and reality is emphasized. The limits of the method suggested are discussed on the basis of case studies of some Hungarian mines.

  2. Influence of the Laser-Beam Distribution on the Seam Dimensions for Laser-Transmission Welding: A Simulative Approach

    Science.gov (United States)

    Aden, Mirko

    2016-06-01

    Radiation propagation and temperature development are simulated for laser-transmission welding of polycarbonate and polybutylene terephthalate parts. The simulations are carried out for a Gaussian- and an M-shape laser beam. For polycarbonate the shape of the laser beam is preserved, while for polybutylene terephthalate it is altered due to scattering processes. The resulting intensity and integrated intensity distribution in the joining zone are calculated for both polymers. They give rise to different temperature fields. The dimensions of the model seam are approximated by the dimensions of the melt isotherm. For polycarbonate the seam generated by a Gaussian beam has a non-homogeneous thickness and a width that is smaller than the beam diameter. For an M-shape beam it has a homogeneous thickness and its width scales with the width of the integrated intensity. For polybutylene terephthalate volumetric scattering destroys the original beam shape in the joining zone. The distributions of the integrated intensities and the dimensions of the seam are similar for both types of beams.

  3. 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

    2016-01-01

    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. PMID:27171091

  4. Mobile hydrocarbon microspheres from >2-billion-year-old carbon-bearing seams in the South African deep subsurface.

    Science.gov (United States)

    Wanger, G; Moser, D; Hay, M; Myneni, S; Onstott, T C; Southam, G

    2012-11-01

    By ~2.9 Ga, the time of the deposition of the Witwatersrand Supergroup, life is believed to have been well established on Earth. Carbon remnants of the microbial biosphere from this time period are evident in sediments from around the world. In the Witwatersrand Supergroup, the carbonaceous material is often concentrated in seams, closely associated with the gold deposits and may have been a mobile phase 2 billion years ago. Whereas today the carbon in the Witwatersrand Supergroup is presumed to be immobile, hollow hydrocarbon spheres ranging in size from 50 μm were discovered emanating from a borehole drilled through the carbon-bearing seams suggesting that a portion of the carbon may still be mobile in the deep subsurface. ToF-SIMS and STXM analyses revealed that these spheres contain a suite of alkane, alkenes, and aromatic compounds consistent with the described organic-rich carbon seams within the Witwatersrand Supergroup's auriferous reef horizons. Analysis by electron microscopy and ToF-SIMS, however, revealed that these spheres, although most likely composed of biogenic carbon and resembling biological organisms, do not retain any true structural, that is, fossil, information and were formed by an abiogenic process.

  5. Prediction of methane emissions during the extraction of close-to-roof layer of a seam of large thickness

    Institute of Scientific and Technical Information of China (English)

    KRAUSE Eugeniusz; QU Xian-chao

    2012-01-01

    Prediction of methane emissions at the stage of longwall planning constitutes the basis for the determination of the appropriate method and parameters of ventilation and selection of prevention means including the methane drainage technology.The growth of methane saturation of coal seams with the extraction depth,with simultaneously increasing output concentration,contributes to the increase of the quantity of methane emitted into longwall areas.The subject matter of the article has been directed at the predicted quantity of methane emissions into planned longwalls with roof caving in the layer of seams adjacent to the roof of large thickness.The performed prognostic calculations of methane emissions into the longwall working were referred to two sources,i.e.methane liberated during coal mining by means of a cutter-loader and methane originating from the degasification of the floor layer destressed by the longwall conducted in the close-to-roof layer.The calculations of predictions allow to refer to the planned longwall,on account of the emitting methane,with possible and safe output quantity.Planning of extraction in the close-to-roof layer of a seam of large thickness with roof caving is especially important in conditions of increasing methane saturation with the depth of deposition and should be preceded by a prognostic analysis for determining the extraction possibilities of the planned longwall.

  6. An evaluation of deep thin coal seams and water-beating/resisting layers in the quaternary system using seismic inversion

    Institute of Scientific and Technical Information of China (English)

    XU Yong-zhong; HUANG Wei-chuan; CHEN Tong-jun; CUI Ruo-fei; CHEN Shi-zhong

    2009-01-01

    Non-liner wave equation inversion, wavelet analysis and artificial neural networks were used to obtain stratum parame-ters and the distribution of thin coal seams. The lithology of the water-bearing/resisting layer in the Quaternary system was also predicted. The implementation process included calculating the well log parameters, stratum contrasting the seismic data and the well logs, and extracting, studying and predicting seismic attributes. Seismic inversion parameters, including the layer velocity and wave impedance, were calculated and effectively used for prediction and analysis. Prior knowledge and seismic interpretation were used to remedy a dearth of seismic data during the inversion procedure. This enhanced the stability of the inversion method. Non-linear seismic inversion and artificial neural networks were used to interpret coal seismic lithology and to study the wa-ter-bearing/resisting layer in the Quaternary system. Interpretation of the 1-2 m thin coal seams, and also of the wa-ter-bearing/resisting layer in the Quaternary system, is provided. The upper mining limit can be lifted from 60 m to 45 m. The pre-dictions show that this method can provide reliable data useful for thin coal seam exploitation and for lifting the upper mining limit, which is one of the principles of green mining.

  7. Technology of back stoping from level floors in gateway and pillar mining areas of extra-thick seams

    Institute of Scientific and Technical Information of China (English)

    Tu Hongsheng; Tu Shihao; Zhang Xiaogang; Li Zhaoxin; Jia Shuai

    2014-01-01

    According to the special requirements of secondary mining of resources in gateway-and-pillar goaf in extra-thick seams of Shanxi, this paper presents a technical proposal of back stoping from level floors. Numerical simulation and theoretical analysis are used to investigate the compaction characteristics of cavities under stress as well as an appropriate mining height of the primary-mining layer based on dif-ferent mining widths and pillar widths. For Yangjian coal mine, the mining thickness of the first seam during back stoping from level floor is determined to be 3 m, which meets the relevant requirements. Gateway-and-pillar goaf of a single layer has a range of influence of 9 m vertically. If gateway-and-pillar goaf occurs both in 9-1 and 9-5 layers, the range is extended to within 11.2 m. When the mining width of a gateway is less than 2 m or larger than 5 m, the gateway-and-pillar goaf in the upper layer of the primary-mining seam can be filled in and compacted after stoping. When the working face is 2 m away from the gateway and pillar before entering into it and after passing through it, the coal body under the gateway and pillar is subjected to relatively high stress. During mining of the upper layer, moreover, the working face should interlock the goaf in primary-mining layer for 20 m.

  8. Influence of Surface Coatings of Filler Wires on Weld Seam Properties of Laser Beam Welded Copper Connections

    Science.gov (United States)

    Mann, Vincent; Holzer, Matthias; Hofmann, Konstantin; Özkaya, Esra; Hugger, Florian; Roth, Stephan; Schmidt, Michael

    In laser beam welding of copper its material properties require high intensities of the laser beam for a stable process, which are often realized by small focal diameters. Thus conventional laser beam welding of copper is accompanied by small bridgeable gap widths. A way to increase tolerable gap widths is the use of filler wires, which leads to higher energy consumption per unit length of the process, as extra energy is necessary to melt the filler wire. As some surface coatings are known to reduce energy consumption in laser beam welding of copper, this paper investigates the influence of surface coated filler wires on weld seam properties of laser beam welded of copper alloys with the aim of improved usage of the energy provided for the process. For this reason different coating materials and thicknesses of the filler wires are used within the experiments. The resulting weld seams are evaluated by means of geometrical, electrical and mechanical properties of the joints, e.g. seam width, cross-sectional area, electrical resistance, tensile strength and strain.

  9. Matter Composition and Two Stage Evolution of a Liangshan Super High-Sulfur Coal Seam in Kaili, Eastern Guizhou

    Institute of Scientific and Technical Information of China (English)

    YI Tong-sheng; QIN Yong; ZHANG Jing; WU Yan-yan; LI Zhuang-fu

    2007-01-01

    Super-high sulfur coal resultes in serious coal-derived pollution but might have a particular genesis. Thus, a columnar section of an Early Permian Liangshan Formation coal seam. weight average sulfur content 5.80%, from Kaili, eastern Guizhou, was studied using the methods of coal petrology and geochemistry. The results show that the seam was apparently formed in seawater-effected peat bogs that developed in two distinct stages. During the first stage various layers were formed in a supratidal bog and have a composition characteristic of a bog with a gradually decreasing seawater effect, decreasing water dynamics, and an increasingly reductive environment. Layers in the upper seam formed during a second stage in an intertidal bog. These layers are very high in total and inorganic sulfur, the ratios of organic/inorganic sulfur and V/I drop, they are high in coal ash yield and have a high ash component index, considerable barkinite, oxidized and detrital macerals, have a porphyroclatic micro-structure and are rich in pyrite, all of which indicate the coal-forming environment had higher oxidation potential, strong and roiling water dynamics, and intermittent exposure to a sulfur rich environment.

  10. Membrane solutions for coal seam methane produced water : case history at Origin Energy, Spring Gully Gas Plant, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Wines, T. [Pall Corp., Port Washington, NY (United States); Blyth, G.; Chalmers, S. [Pall Australia, Melbourne (Australia); Karlapudi, R. [Pall Industrial Water, Port Washington, NY (United States)

    2009-07-01

    Coal seam methane is a significant and emerging source of energy that can be found in Australia, western Canada, the United States, China and India. However, the extraction of methane from coal seams has one particular problem whereby, in many cases, large volumes of water with high levels of dissolved salts are produced along with the gas. This produced water poses an environmental liability, but with proper treatment can be converted into an asset. This paper discussed the use of an integrated membrane system (IMS) consisting of microfiltration coupled with reverse osmosis filtration. A case history at Origin Energy was evaluated where pilot testing was first conducted and later followed by a commercial installation treating nine million liters per day, creating a purified water product that can be used for industrial processes as well as irrigation or discharge into the environment. The paper also presented lessons learned from the pilot phase and explained the experience of the full scale operation demonstrating the advantages of this newly applied technology for coal seam methane production. The IMS system has met Origin Energy's requirements for producing high quality water, and has continued to operate effectively, producing treated water that is well within the Queensland Environmental Protection Agency's guidelines. 6 refs., 1 tab., 11 figs.

  11. Critical hydraulic pressure forecasting of water inrush in coal seam floors based on a genetic algorithm-neural network

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, M.; Shi, C.; Liu, T. [China Academy of Safety Science and Technology, Beijing (China); Fu, T. [Tsinghua Univ., Beijing (China). Dept. of Thermal Engineering

    2008-08-15

    This paper presented a method of forecasting water inrush in coal seam floors. The theoretical forecasting method used a combined genetic algorithm-neural network method to analyze the relationships between the critical pressure of water inrush and the different conditions in coal seam floors. Actual measurement data from Chinese coal mines were used to train the multi-layer feedforward neural network. Genetic algorithms were used to train the neural networks and optimize the neural network topology. The topology structure of the network was selected by considering population size, mutation rate, and crossing rates. The critical hydraulic pressure of water inrush was then predicted, and predictions were compared with measurements taken to validate the method. Results of the study showed that the forecasting method improved learning efficiency and the prediction capacity of the network. It was concluded that the combined method can be used to accurately predict the critical hydraulic pressure of water inrush on coal seam floors. 28 refs., 1 tab., 7 figs.

  12. 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.

  13. Origin of Minerals and Elements in the Late Permian Coal Seams of the Shiping Mine, Sichuan, Southwestern China

    Directory of Open Access Journals (Sweden)

    Yangbing Luo

    2016-07-01

    Full Text Available Volcanic layers in coal seams in southwestern China coalfields have received much attention given their significance in coal geology studies and their potential economic value. In this study, the mineralogical and geochemical compositions of C19 and C25 coal seams were examined, and the following findings were obtained. (1 Clay minerals in sample C19-r are argillized, and sedimentary layering is not observed. The acicular idiomorphic crystals of apatite and the phenocrysts of Ti-augite coexisting with magnetite in roof sample C19-r are common minerals in basaltic rock. The rare earth elements (REE distribution pattern of C19-r, which is characterized by positive Eu anomalies and M-REE enrichment, is the same as that of high-Ti basalt. The concentrations of Ti, V, Co, Cr, Ni, Cu, Zn, Nb, Ta, Zr, and Hf in C19-r are closer to those of high-Ti basalt. In conclusion, roof sample C19-r consists of tuffaceous clay, probably with a high-Ti mafic magma source. (2 The geochemical characteristics of the C25 coals are same as those reported for coal affected by alkali volcanic ash, enrichment in Nb, Ta, Zr, Hf, and REE, causing the C25 minable coal seams to have higher potential value. Such a vertical study of coals and host rocks could provide more information for coal-forming depositional environment analysis, for identification of volcanic eruption time and magma intrusion, and for facilitating stratigraphic subdivision and correlation.

  14. Conical intersection seam and bound resonances embedded in continuum observed in the photodissociation of thioanisole-d3.

    Science.gov (United States)

    Han, Songhee; Lim, Jeong Sik; Yoon, Jun-Ho; Lee, Jeongmook; Kim, So-Yeon; Kim, Sang Kyu

    2014-02-07

    Herein, the multi-dimensional nature of the conical intersection seam has been experimentally revealed in the photodissociation reaction of thioanisole-d3 (C6H5SCD3) excited on S1, giving C6H5S·(Ã or X̃]) +·CD3 products. The translational energy distribution of the nascent·CD3 fragment, reflecting the relative yields of the C6H5S·(Ã) and C6H5S·(X̃) products, was measured at each S1 vibronic band using the velocity map ion imaging technique. Direct access of the reactant flux to the conical intersection seam leads to the increase of the nonadiabatic transition probability resulting in sharp resonances in the X̃/ÃC6H5S·product branching ratio at several distinct S1 vibronic bands. The nature of the S1 vibronic bands associated with such dynamic resonances was clarified by the mass-analyzed threshold ionization spectroscopy. The bound state embedded in continuum generated by the conical intersection is observed as a distinct dynamic resonance, revealing the nature of the nuclear motion responsible for the nonadiabatic coupling of two potential energy surfaces at the conical intersection. The multi-dimensional facets of the conical intersection seam in terms of its detailed structure and dynamic role are discussed with the aid of theoretical calculations.

  15. On Not Losing Track

    OpenAIRE

    Washburn, A.R.

    1990-01-01

    IEEE Transactions on Automatic Control, Vol. 35, 1990, pp. 852-855. This paper uses tracking time as an explicit objective in designing tracking algorithms that function in clutter. Implications of using "time to the first mistake" as a measure of tracking time are explored. An optimal tracker is derived for a special circukstance where there is clutter, but no measurement error, and is compared to a tracker based on the Maximum Likelihood principle.

  16. DCS Budget Tracking System

    Data.gov (United States)

    Social Security Administration — DCS Budget Tracking System database contains budget information for the Information Technology budget and the 'Other Objects' budget. This data allows for monitoring...

  17. Method of mining heavy coal seams in two or more benches

    Energy Technology Data Exchange (ETDEWEB)

    Barsi, K.; Dorombozi, L.; Forisek, I.; Kuburczik, G.; Stuber, G.

    1982-07-20

    In mining a heavy coal seam that must be excavated in several benches, the excavation of the uppermost bench is accompanied by the introduction of a cementitious slurry into the resulting stope for consolidating the waste rock present therein, preparatorily to the excavation of the next-lower bench, and proceeding in like manner with the second bench if a third one is to follow. The cementitious slurry comprises burnt or slaked lime, and/or Portland cement, suspended in water in a quantity of about 10 to 60% by weight and preferably together with a small percentage of chlorides of one or more alkali or alkaline-earth metals, to which ceramic aggregates at large specific surface such as mineral ashes, slag, sand or dolomite powder may be added in a quantity of up to about 30% of the weight of the water. The slurry, on being admitted to the stope in an amount of at least 10% of the volume thereof, causes the waste rock to swell and form a solid layer of up to approximately a meter in thickness which allows the next-lower bench to be excavated after only about a month's delay.

  18. Variable frequency of pulse hydraulic fracturing for improving permeability in coal seam

    Institute of Scientific and Technical Information of China (English)

    Li Quangui; Lin Baiquan; Zhai Cheng; Ni Guanhua; Peng Shen; Sun Chen; Cheng Yanying

    2013-01-01

    Variable frequency, a new pattern of pulse hydraulic fracturing, is presented for improving permeability in coal seam. A variable frequency pulse hydraulic fracturing testing system was built, the mould with triaxial loading was developed. Based on the monitor methods of pressure sensor and acoustic emission, the trials of two patterns of pulse hydraulic fracturing of single frequency and variable frequency were carried out, and at last fracturing mechanism was analyzed. The results show that the effect of variable frequency on fracture extension is better than that of single frequency based on the analysis of macro-scopic figures and AE. And the shortage of single frequency is somewhat remedied when the frequency is variable. Under variable frequency, the pressure process can be divided into three stages: low fre-quency band, pressure stability band and high frequency band, and rupture pressure of the sample is smaller than that of the condition of single frequency. Based on the Miner fatigue theory, the effect of different loading sequences on sample rupture is discussed and the results show that it is better to select the sequence of low frequency at first and then high frequency. Our achievements can give a basis for the improvement and optimization of the pulse hydraulic fracturing technology.

  19. Evolution of a mining induced fracture network in the overburden strata of an inclined coal seam

    Institute of Scientific and Technical Information of China (English)

    Wei; Xiujun; Gao; Mingzhong; Lv; Youchang; Shi; Xiangchao; Gao; Hailian; Zhou; Hongwei

    2012-01-01

    The geological conditions of the Pingdingshan coal mining group were used to construct a physical model used to study the distribution and evolution of mining induced cracks in the overburden strata.Digital graphics technology and fractal theory are introduced to characterize the distribution and growth of the mining induced fractures in the overburden strata of an inclined coal seam.A relationship between fractal dimension of the fracture network and the pressure in the overburden strata is suggested.Mining induced fractures spread dynamically to the mining face and up into the roof as the length of advance increases.Moreover,the fractal dimension of the fracture network increases with increased mining length,in general,but decreases during a period from overburden strata separation until the main roof collapses.It is a1so shown that overburden strata pressure plays an important role in the evolution of mining induced fractures and that the fractal dimension of the fractures increases with the pressure of the overburden.

  20. 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)

  1. Influence of Lithological Characters of Coal Bearing Formation on Stability of Roof of Coal Seams

    Institute of Scientific and Technical Information of China (English)

    孟召平; 彭苏萍; 李国庆; 黄为; 芦俊; 雷志勇

    2003-01-01

    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.

  2. Effects of gully terrain on stress field distribution and ground pressure behavior in shallow seam mining

    Institute of Scientific and Technical Information of China (English)

    Li Jianwei; Liu Changyou; Zhao Tong

    2016-01-01

    This study proposes a novel approach to study stress field distribution and overlying ground pressure behavior in shallow seam mining in gully terrain. This approach combines numerical simulations and field tests based on the conditions of gully terrain in the Chuancao Gedan Mine. The effects of gully ter-rain on the in situ stress field of coal beds can be identified by the ratio of self-weight stress to vertical stress (g) at the location corresponding to the maximum vertical stress. Based on the function g=f(h), the effect of gully terrain on the stress field of overlying strata of the entire field can be characterized as a significantly affected area, moderately affected area, or non-affected area. Working face 6106 in the Chuancao Gedan Mine had a coal bed depth<80 m and was located in what was identified as a signifi-cantly affected area. Hence, mining may cause sliding of the gully slope and increased loading (including significant dynamic loading) on the roof strata. Field tests suggest that significant dynamic pressures were observed at the body and foot of the gully slope, and that dynamic loadings were observed upslope of the working face expansion, provided that the expanding direction of the working face is parallel to the gully.

  3. 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.

  4. Chemical variability of groundwater samples collected from a coal seam gas exploration well, Maramarua, New Zealand.

    Science.gov (United States)

    Taulis, Mauricio; Milke, Mark

    2013-03-01

    A pilot study has produced 31 groundwater samples from a coal seam gas (CSG) exploration well located in Maramarua, New Zealand. This paper describes sources of CSG water chemistry variations, and makes sampling and analytical recommendations to minimize these variations. The hydrochemical character of these samples is studied using factor analysis, geochemical modelling, and a sparging experiment. Factor analysis unveils carbon dioxide (CO(2)) degassing as the principal cause of sample variation (about 33%). Geochemical modelling corroborates these results and identifies minor precipitation of carbonate minerals with degassing. The sparging experiment confirms the effect of CO(2) degassing by showing a steady rise in pH while maintaining constant alkalinity. Factor analysis correlates variations in the major ion composition (about 17%) to changes in the pumping regime and to aquifer chemistry variations due to cation exchange reactions with argillaceous minerals. An effective CSG water sampling program can be put into practice by measuring pH at the wellhead and alkalinity at the laboratory; these data can later be used to calculate the carbonate speciation at the time the sample was collected. In addition, TDS variations can be reduced considerably if a correct drying temperature of 180 °C is consistently implemented.

  5. Atmospheric radon, CO2 and CH4 dynamics in an Australian coal seam gas field

    Science.gov (United States)

    Tait, D. R.; Santos, I. R.; Maher, D. T.

    2013-12-01

    Atmospheric radon (222Rn), carbon dioxide (CO2), and methane concentrations (CH4) as well as carbon stable isotope ratios (δ13C) were used to gain insight into atmospheric chemistry within an Australian coal seam gas (CSG) field (Surat Basin, Tara region, Queensland). A˜3 fold increase in maximum 222Rn concentration was observed inside the gas field compared to outside of it. There was a significant relationship between maximum and average 222Rn concentrations and the number of gas wells within a 2 km to 4 km radius of the sampling sites (n = 5 stations; p gas field related to point sources (well heads, pipelines, etc.) and diffse soil sources due to changes in the soil structural and hydrological characteristics. A rapid qualitative assessment of CH4 and CO2 concentration, and carbon isotopes using a mobile cavity ring-down spectrometer system showed a widespread enrichment of both CH4 and CO2 within the production gas field. Concentrations of CH4 and CO2 were as high as 6.89 ppm and 541 ppm respectively compared average concentrations of 1.78 ppm (CH4) and 388 ppm (CO2) outside the gas field. The δ13C values showed distinct differences between areas inside and outside the production field with the δ13C value of the CH4 source within the field matching that of the methane in the CSG.

  6. 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.

  7. Method for stabilizing quality of coal extracted from seams with a complicated structure

    Energy Technology Data Exchange (ETDEWEB)

    Belyakov, Yu.I.; Pushkin, S.P. (Kievskii Inzhenerno-Stroitel' nyi Institut (Ukraine))

    1992-02-01

    Discusses methods for stabilizing coal quality (ash content) under conditions of complicated coal deposit structure (coal seams separated by thin rock layers). Computerized simulation of operation of a set of equipment for coal surface mining and mine haulage (bucket wheel excavators, locomotives and mine cars) is discussed. Output of individual excavators, ash content in coal from the face mined by each excavator and effects of coal mixing during haulage and handling on fluctuations of ash content in run-of-mine coal are analyzed. Computerized simulation shows that under conditions of the Ehkibastuz an optimum system for coal mixing and haulage should consist of bucket wheel excavators with output reserves ranging from 10 to 20% and haulage systems with 4 to 5 reserve train routes to coal yards. Such a system guarantees a reduction of ash content (mean square deviation) by 30-35%, reduction of idle time of mine cars by 35-40% and reduction of coal mining cost by 4-6%. 3 refs.

  8. Structural evaluation of WIPP disposal room raised to Clay Seam G.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Wide pillar roadway retained in the deep high gas coal seam

    Institute of Scientific and Technical Information of China (English)

    Pan; Liyou; Feng; Enhu; Zhao; Qingshou; Chen; Liqiang; Kong; Fanpeng

    2012-01-01

    According to the geological and mining conditions of deep high gas coal seam,this paper established the mechanical model of stope surrounding rock,and analyzed the stress distribution and deformation failure mechanism of working face and coal pillar.The research determined the arrangement mode that adjacent working faces retain wide pillar,and the reasonable support method of roadway that the combined support of roof and grouting combined together.The reasonable time of reinforced roadway was determined.Through analyzing the mechanical model of the ways of roadway supporting,this research drew the conclusions as follows:the combined support of roof and working slope improved the support strength and range of surrounding rock,optimized the support by adjusting the angle of anchor,and reached the support requirements by using cement grouting in working slope and chemical grout in roof.The technology was applied in 15104 working face of Baoan Mine,and obtained good results.

  10. 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.

  11. Deformation effect of lateral roof roadway in close coal seams after repeated mining

    Institute of Scientific and Technical Information of China (English)

    Xie Jianlin; Xu Jialin; Wang Feng; Guo Jiekai; Liu Donglin

    2014-01-01

    This paper analyzed the deformation mechanism in lateral roof roadway of the Ding Wu-3 roadway which was disturbed by repeated mining of close coal seams Wu-8 and Wu-10 in Pingdingshan No. 1 Mine. To determine the strata disturbance scope, the strata displacement angle was used to calculate the protection pillar width. A numerical model was built considering the field geological conditions. In simulation, the mining stress borderline was defined as the contour where the induced stress is 1.5 times of the original stress. Simulation results show the mining stress borderline of the lateral roadway extended 91.7 m outward after repeated mining. Then the original stress increased, deforming the road-way of interest. This deformation agreed with the in situ observations. Moreover, the strata displacement angle changed due to repeated mining. Therefore, reselection of the displacement angle was required to design the protective pillar width. Since a constant strata displacement angle was used in traditional design, the proposed method was beneficial in field cases.

  12. The Complex Function Method Roadway Section Design of the Soft Coal Seam

    Directory of Open Access Journals (Sweden)

    Shihao Tu

    2016-01-01

    Full Text Available As for the sophisticated advanced support technique of vertical wall semicircle arch roadway in the three-soft coal seam, a design of flat top U-shape roadway section was put forward. Based on the complex function method, the surrounding rock displacement and stress distribution laws both of vertical wall semicircle arch roadway and of flat top U-shape roadway were obtained. The results showed that the displacement distribution laws in the edge of roadway surrounding rock were similar between the two different roadways and the area of plasticity proportion of flat top U-shape roadway approximately equals that of vertical wall semicircle arch roadway. Based on finite element method, the bearing behaviors of the U-type steel support under the interaction of surrounding rock in vertical wall semicircle arch roadway and flat top U-shape roadway were analyzed. The results showed that, from a mechanics perspective, U-type steel support can fulfill the requirement of surrounding rock supporting in flat top U-shape roadway and vertical wall semicircle arch roadway. The field measurement of mining roadway surrounding rock displacement in Zouzhuang coal mine working face 3204 verified the accuracy of theoretical analysis and numerical simulation.

  13. 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.

  14. Major and Trace Element Geochemistry of Coals and Intra-Seam Claystones from the Songzao Coalfield, SW China

    Directory of Open Access Journals (Sweden)

    Lei Zhao

    2015-12-01

    Full Text Available Silicic, mafic and alkali intra-seam tonsteins have been known from SW China for a number of years. This paper reports on the geochemical compositions of coals and tonsteins from three seam sections of the Songzao Coalfield, SW China, and evaluates the geological factors responsible for the chemical characteristics of the coal seams, with emphasis on the influence from different types of volcanic ashes. The roof and floor samples of the Songzao coal seams mostly have high TiO2 contents, consistent with a high TiO2 content in the detrital sediment input from the source region, namely mafic basalts from the Kangdian Upland on the western margin of the coal basin. The coals from the Songzao Coalfield generally have high ash yields and are highly enriched in trace elements including Nb, Ta, Zr, Hf, rare earth elements (REE, Y, Hg and Se; some variation occurs among different seam sections due to input of geochemically different volcanic ash materials. The geochemistry of the Songzao coals has also been affected by the adjacent tonstein/K-bentonite bands. The relatively immobile elements that are enriched in the altered volcanic ashes also tend to be enriched in the adjacent coal plies, possibly due to leaching by groundwaters. The coals near the alkali tonstein bands in the Tonghua and Yuyang sections of the Songzao Coalfield are mostly high in Nb, Ta, Zr, Hf, Th, U, REE and Y. Coal samples overlying the mafic K-bentonite in the Tonghua section are high in V, Cr, Zn and Cu. The Datong coal, which has neither visible tonstein layers nor obvious volcanogenic minerals, has high TiO2, V, Cr, Ni, Cu and Zn concentrations in the intervals between the coal plies affected by mafic and alkaline volcanic ashes. This is consistent with the suggestion that a common source material was supplied to the coal basin, derived from the erosion of mafic basaltic rocks of the Kangdian Upland. Although the Songzao coal is generally a high-sulfur coal, most of the

  15. CWI at TREC 2012, KBA track and Session Track

    NARCIS (Netherlands)

    Araújo, S.; Boscarino, C.; Gebremeskel, G.G.; He, J.; Vries, A.P. de; Voorhees, E.M.; Buckland, L. P.

    2013-01-01

    We participated in two tracks: Knowledge Base Acceleration (KBA) Track and Session Track. In the KBA track, we focused on experi- menting with different approaches as it is the first time the track is launched. We experimented with supervised and unsupervised re- trieval models. Our supervised appro

  16. Eye-Tracking

    Directory of Open Access Journals (Sweden)

    Gabriela GROSSECK

    2006-01-01

    Full Text Available Eye-tracking: one of the newest and most efficient methods of improving on-line marketing communication is called eye-tracking. Marketers have borrowed this technique, usually used in psychological and medical research, in order to study web users with the help of a video camera incorporated in the monitor.

  17. Large scale tracking algorithms.

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Ross L.; Love, Joshua Alan; Melgaard, David Kennett; Karelitz, David B.; Pitts, Todd Alan; Zollweg, Joshua David; Anderson, Dylan Z.; Nandy, Prabal; Whitlow, Gary L.; Bender, Daniel A.; Byrne, Raymond Harry

    2015-01-01

    Low signal-to-noise data processing algorithms for improved detection, tracking, discrimination and situational threat assessment are a key research challenge. As sensor technologies progress, the number of pixels will increase signi cantly. This will result in increased resolution, which could improve object discrimination, but unfortunately, will also result in a significant increase in the number of potential targets to track. Many tracking techniques, like multi-hypothesis trackers, suffer from a combinatorial explosion as the number of potential targets increase. As the resolution increases, the phenomenology applied towards detection algorithms also changes. For low resolution sensors, "blob" tracking is the norm. For higher resolution data, additional information may be employed in the detection and classfication steps. The most challenging scenarios are those where the targets cannot be fully resolved, yet must be tracked and distinguished for neighboring closely spaced objects. Tracking vehicles in an urban environment is an example of such a challenging scenario. This report evaluates several potential tracking algorithms for large-scale tracking in an urban environment.

  18. Can Tracking Improve Learning?

    Science.gov (United States)

    Duflo, Esther; Dupas, Pascaline; Kremer, Michael

    2009-01-01

    Tracking students into different classrooms according to their prior academic performance is controversial among both scholars and policymakers. If teachers find it easier to teach a homogeneous group of students, tracking could enhance school effectiveness and raise test scores of both low- and high-ability students. If students benefit from…

  19. Large scale tracking algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Ross L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Love, Joshua Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Melgaard, David Kennett [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Karelitz, David B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pitts, Todd Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zollweg, Joshua David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Anderson, Dylan Z. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nandy, Prabal [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Whitlow, Gary L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bender, Daniel A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Byrne, Raymond Harry [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-01-01

    Low signal-to-noise data processing algorithms for improved detection, tracking, discrimination and situational threat assessment are a key research challenge. As sensor technologies progress, the number of pixels will increase signi cantly. This will result in increased resolution, which could improve object discrimination, but unfortunately, will also result in a significant increase in the number of potential targets to track. Many tracking techniques, like multi-hypothesis trackers, suffer from a combinatorial explosion as the number of potential targets increase. As the resolution increases, the phenomenology applied towards detection algorithms also changes. For low resolution sensors, "blob" tracking is the norm. For higher resolution data, additional information may be employed in the detection and classfication steps. The most challenging scenarios are those where the targets cannot be fully resolved, yet must be tracked and distinguished for neighboring closely spaced objects. Tracking vehicles in an urban environment is an example of such a challenging scenario. This report evaluates several potential tracking algorithms for large-scale tracking in an urban environment.

  20. Bewegingsvolgsysteem = Monitor tracking system

    NARCIS (Netherlands)

    Slycke, Per Johan; Veltink, Petrus Hermanus; Roetenberg, Daniel

    2006-01-01

    A motion tracking system for tracking an object composed of object parts in a three-dimensional space. The system comprises a number of magnetic field transmitters; a number of field receivers for receiving the magnetic fields of the field transmitters; a number of inertial measurement units for rec

  1. Bewegingsvolgsysteem = Monitor tracking system

    NARCIS (Netherlands)

    Slycke, Per Johan; Veltink, Petrus Hermanus; Roetenberg, Daniel

    2007-01-01

    A motion tracking system for tracking an object composed of object parts in a three-dimensional space. The system comprises a number of magnetic field transmitters; a number of field receivers for receiving the magnetic fields of the field transmitters; a number of inertial measurement units for rec

  2. On the Wrong Track?

    Science.gov (United States)

    Gursky, Daniel

    1990-01-01

    Discusses problems with student tracking. Although supporters consider tracking the best way for teachers to handle classroom diversity, many minorities say that it condemns their children to an inferior education. Studies show that heterogeneous classes benefit all students if the teachers adopt flexible instructional methods to handle the…

  3. TRACKED VEHICLE Rev 75

    Energy Technology Data Exchange (ETDEWEB)

    2007-05-08

    Revision 75 of the Tracked Vehicle software is a soft real-time simulation of a differentially steered, tracked mobile robot, which, because of the track flippers, resembles the iRobot PackBot (http://www.irobot.com/). Open source libraries are used for the physics engine (http://www.ode.org/), the display and user interface (http://www.mathies.com/cpw/), and the program command line and configuration file parameters (http://www.boost.org/). The simulation can be controlled by a USB joystick or the keyboard. The configuration file contains demonstration model parameters of no particular vehicle. This simulation can be used as a starting point for those doing tracked vehicle simulations. This simulation software is essentially a research tool which can be modified and adapted for certain types of tracked vehicle research. An open source license allows an individual researchers to tailor the code to their specific research needs.

  4. Sparse Hashing Tracking.

    Science.gov (United States)

    Zhang, Lihe; Lu, Huchuan; Du, Dandan; Liu, Luning

    2016-02-01

    In this paper, we propose a novel tracking framework based on a sparse and discriminative hashing method. Different from the previous work, we treat object tracking as an approximate nearest neighbor searching process in a binary space. Using the hash functions, the target templates and the candidates can be projected into the Hamming space, facilitating the distance calculation and tracking efficiency. First, we integrate both the inter-class and intra-class information to train multiple hash functions for better classification, while most classifiers in previous tracking methods usually neglect the inter-class correlation, which may cause the inaccuracy. Then, we introduce sparsity into the hash coefficient vectors for dynamic feature selection, which is crucial to select the discriminative and stable features to adapt to visual variations during the tracking process. Extensive experiments on various challenging sequences show that the proposed algorithm performs favorably against the state-of-the-art methods.

  5. Persistent Aerial Tracking

    KAUST Repository

    Mueller, Matthias

    2016-04-13

    In this thesis, we propose a new aerial video dataset and benchmark for low altitude UAV target tracking, as well as, a photo-realistic UAV simulator that can be coupled with tracking methods. Our benchmark provides the rst evaluation of many state of-the-art and popular trackers on 123 new and fully annotated HD video sequences captured from a low-altitude aerial perspective. Among the compared trackers, we determine which ones are the most suitable for UAV tracking both in terms of tracking accuracy and run-time. We also present a simulator that can be used to evaluate tracking algorithms in real-time scenarios before they are deployed on a UAV "in the field", as well as, generate synthetic but photo-realistic tracking datasets with free ground truth annotations to easily extend existing real-world datasets. Both the benchmark and simulator will be made publicly available to the vision community to further research in the area of object tracking from UAVs. Additionally, we propose a persistent, robust and autonomous object tracking system for unmanned aerial vehicles (UAVs) called Persistent Aerial Tracking (PAT). A computer vision and control strategy is applied to a diverse set of moving objects (e.g. humans, animals, cars, boats, etc.) integrating multiple UAVs with a stabilized RGB camera. A novel strategy is employed to successfully track objects over a long period, by \\'handing over the camera\\' from one UAV to another. We integrate the complete system into an off-the-shelf UAV, and obtain promising results showing the robustness of our solution in real-world aerial scenarios.

  6. Understanding the self-assembly process and behavior of metal-seamed pyrogallol[4]arene nanocapsules

    Science.gov (United States)

    Mossine, Andrew V.

    C-alkylpyrogallol[4]arenes (PgCs) are bowl-shaped compounds that are commonly used as supramolecular building blocks in the construction of larger entities such as capsules, nanotubes, and layered networks. Many of these assemblies are constructed using non-covalent means and, as such, are inherently unstable in polar media. Although metal coordination with the hydroxyl-rich PgC upper rim can be exploited to synthesize assemblies with enhanced stability, few reports of this can be found in the literature. Thus, a thorough investigation of these metal-seamed assemblies and their manipulation is of importance. Prior work in the Atwood lab has produced three examples of metal-organic nanocapsules (MONCs) based on PgCs. These include two hexameric MONCs (based on Cu2+ and Ga3+) as well as a single example of a dimeric MONC (based on Zn2+). As it was unknown whether other metal cations could lead to the formation of similar entities, PgC complexation experiments were conducted with other first series transition metal cations, notably Ni2+, Co2+ and Mn2+. All of these led to nanocapsular materials, which were identified and studied using single crystal X-ray diffraction (scXRD). Once the foundational studies were complete, syntheses were also performed under varied conditions, specifically with Ni2+ and Cu2+. This led to the characterization of both dimeric and hexameric MONCs with these two metals, as well as the characterization of many other capsular materials. The information collected from these experiments also led to an intriguing question: which specific conditions lead to the formation of dimeric vs. hexameric MONCs? To answer this question, solid-state analysis using scXRD was coupled to in situ analysis utilizing small angle neutron scattering (SANS). This work showed that the formation of the dimer is typically favored at higher temperatures while the formation of the hexamer is favored at lower temperatures for both of the metals tested. Studies that varied

  7. CO2 sequestration in deep coal seams: experimental characterization of the fundamental underlying mechanisms

    Science.gov (United States)

    Pini, R.; Mazzotti, M.

    2012-04-01

    The process of injecting and storing carbon dioxide (CO2) into suitable deep geological formations, such as saline aquifers, (depleted) oil or gas reservoirs, and unmineable coal seams, is referred to as CO2 sequestration. In little more than a decade, this technology has emerged as one of the most important options for reducing CO2 emissions. Among the different options, unmineable coal seams are not as broadly distributed as saline aquifers or oil/gas reservoirs, but their peculiarity resides in the proven capacity of retaining significant amount of gas (mainly methane, CH4) for a very long time. Additionally, the injection of CO2 into the coal reservoir would enhance the recovery of this natural gas, a source of energy that will most likely play a key role in the power sector over the next 20 years from now. This process is called Enhanced Coal Bed Methane (ECBM) recovery and, as for enhanced oil recovery, it allows in principle offsetting the costs associated to the storage operation. A study was undertaken aimed at the experimental characterization of the fundamental mechanisms that take place during the process of injection and storage in coal reservoirs, namely adsorption and swelling (Pini et al 2010), and of their effects on the coal's permeability (Pini et al. 2009), the property that plays a dominant role in controlling fluid transport in a porous rock. An apparatus has been built that allows measuring the permeability of rock cores under typical reservoir conditions (high pressure and temperature) by the so-called transient step method. For this study, a coal core from the Sulcis coal mine in Sardinia (Italy) has been used. In the experiments, an inert gas (helium) was used to investigate the effects of the effective pressure on the permeability of the coal sample, whereas two adsorbing gases (CO2 and N2) to quantify those of adsorption and swelling. The experiments have been interpreted by a one-dimensional model that describes the fluid transport

  8. 松软低透煤层群开采保护层工作面瓦斯综合治理技术%Comprehensive Gas Control Technology for Mining Protective Seam Face in Soft Coal Seams with Low Permeability

    Institute of Scientific and Technical Information of China (English)

    胡明; 张玉明; 雷洪波; 姚峰

    2014-01-01

    In order to solve the problem of gas emission during the extraction of the protective seam in Yuyang Coal Mine, comprehensive gas control measures such as “U+ tailing way drainage” ventilation, gas pre-drainage from the seam being mined by large-diameter deep holes, gas drainage by crossing hole in the floor and so on were taken. The result showed that the gas concentration in return air of the working face was controlled below 0. 7% during coal mining and the month coal output of the face raised by 50%. This thus solved the gas overrun problem in the protective seam working face, improved the drawing rate of the face and realized safe production of the mine.%为了解决渝阳煤矿突出矿井煤层群开采保护层工作面时瓦斯涌出的问题,采取了“U+尾排”通风、大直径深孔预抽本煤层瓦斯、底板穿层钻孔抽采瓦斯等综合治理措施,治理效果表明:回采期间工作面回风流中瓦斯体积分数控制在0.7%以下,工作面月产量提高了50%。解决了保护层工作面的瓦斯超限问题,同时提高了工作面的回采速度,实现了安全生产。

  9. Dynamic failure in coal seams:Implications of coal composition for bump susceptibility

    Institute of Scientific and Technical Information of China (English)

    Lawson Heather; Weakley Andrew; Miller Arthur

    2016-01-01

    As a contributing factor in the dynamic failure (bumping) of coal pillars, a bump-prone coal seam has been described as one that is ‘uncleated or poorly cleated, strong. . .that sustains high stresses.”Despite extensive research regarding engineering controls to help reduce the risk for coal bumps, there is a paucity of research related to the properties of coal itself and how those properties might contribute to the mechanics of failures. Geographic distribution of reportable dynamic failure events reveals a highly localized clustering of incidents despite widespread mining activities. This suggests that unique, contributing geologic characteristics exist within these regions that are less prevalent elsewhere. To investigate a new approach for identifying coal characteristics that might lead to bumping, a principal component analysis (PCA) was performed on 306 coal records from the Pennsylvania State Coal Sample database to determine which characteristics were most closely linked with a positive history of reportable bumping. Selected material properties from the data records for coal samples were chosen as variables for the PCA and included petrographic, elemental, and molecular properties. Results of the PCA suggest a clear correlation between low organic sulfur content and the occurrence of dynamic failure, and a secondary correlation between volatile matter and dynamic failure phenomena. The ratio of vola-tile matter to sulfur in the samples shows strong correlation with bump-prone regions, with a minimum threshold value of approximately 20, while correlations determined for other petrographic and elemental variables were more ambiguous. Results suggest that the composition of the coal itself is directly linked to how likely a coal is to have experienced a reportable dynamic failure event. These compositional controls are distinct from other previously established engineering and geologic criteria and represent a missing piece to the bump prediction puzzle.

  10. Geological controls on the sulphur content of coal seams in the Northumberland Coalfield, Northeast England

    Energy Technology Data Exchange (ETDEWEB)

    Turner, Brian R. [Department of Earth Sciences, Science Laboratories, University of Durham, South Road, Durham DH1 3LE (United Kingdom); Richardson, David [H.J. Banks and Co. Ltd, Bishop Auckland DL13 4HG (United Kingdom)

    2004-12-03

    The sulphur content of coal is an important consideration when developing reserves for exploitation, driven by emission limits from power stations becoming more stringent. Variations in the sulphur content of Westphalian A and B coals from the predominantly freshwater Northumberland Coalfield, Northeast England, were studied according to their regional, stratigraphic and in-seam location. The observed variation in sulphur content spatially increases towards the source area away from more marine influenced areas, with increased sulphur content through time linked to changes in the general depositional environment as conditions became more marine-influenced. A model of basinal surface water and groundwater flow driven by post-depositional source area tectonism is thought to have played only a minor role in contributing secondary sulphur to the coal. However, the isotopic composition of coal pyrite shows a similar range in composition to that of pyrite and other sulphides from the North Pennine Orefield along the southern margin of the coalfield, suggesting an additional potential source of secondary sulphur, as sulphur-rich fluids were expelled northwards through the coal measures during early Permian Variscan transpression from the south. The Westphalian A and B are interpreted as third-order depositional sequences, defined by third-order maximum flooding surfaces. Each sequence is made up of several coal-bearing fourth-order parasequences, which tend to be more brackish to marine in character, on either side of the third-order maximum flooding surfaces when base level was relatively high. The lowest sulphur coals are confined to the lower to middle, relative low stand part of the Westphalian A third-order base level curve and the lowest part of the Westphalian B third-order base level curve. This difference is attributed to a more rapid rise of base level in the Westphalian B. The stratigraphic and spatial distribution of coal sulphur has been used as a guide to

  11. Rheological Behaviors of Bio-degradable Drilling Fluids in Horizontal Drilling of Unconsolidated Coal Seams

    Directory of Open Access Journals (Sweden)

    Cai Jihua

    2011-06-01

    Full Text Available In China, horizontal drilling techniques have been widely used in the exploration of coalbed methane (CBM. The drill-in fluids, especially in unconsolidated coal seams, are typically comprised of cellulose polymers, xanthan polymers and guar gums. However, testing and experience have shown that insufficient degradation of filter cakes resulting from even this “clean” drill-in fluids can significantly impede flow capacity at the wellbore wall. Past approaches to minimizing the damage have been the application of strong acids or oxidative breakers systems. They are often only marginally successful, particularly when applied in extended length intervals. Therefore, this paper introduced an engineered technique incorporating non-toxic, environment friendly and economically attractive bio-degradable drilling fluids (BDF.Extensive lab tests were conducted to evaluate the effects of substrate (polymer type, substrate concentration, enzyme type and enzyme concentration on the viscosity breaking behaviors of BDFs. We got the conclusions as follows. (1 Power Law model was the best model to matching the rheological properties of BDFs; (2 Compared with konjak, the degradations of Na-CMC and guar gum were easier to be controlled; (3 In the degradation of CMC by enzyme SE-1, the optimal weight concentration ratio of CMC to SE-1 was 3 to 1; (4 Of the three enzymes, enzyme SE-2 had the highest activity and could be used to degrade polymer in shorter time; (5 Higher enzyme concentration could speed up the degradation reaction; (6 Viscosity breaking times fluctuating from 13.5 hours to 74.5 hours and viscosity breaking ratios varying from 20% to 100% could be achieved by modifying the formulations of BDFs.

  12. Permeability variation characteristics of coal after injecting carbon dioxide into a coal seam

    Institute of Scientific and Technical Information of China (English)

    Ni Xiaoming; Li Quanzhong; Wang Yanbin; Gao Shasha

    2015-01-01

    A theoretical basis for the optimization of carbon dioxide injection parameters and the development of the drainage system can be provided by identifying the permeability change characteristic of coal and rock after injection of carbon dioxide into the coal seam. Sihe, Yuwu, and Changcun mines were used as research sites. Scanning electron microscopy and permeability instruments were used to measure coal properties such as permeability and surface structure of the coal samples at different pH values of carbon dioxide solution and over different timescales. The results show that the reaction between minerals in coal and carbonate solution exhibit positive and negative aspects of permeability-the dissolution reaction between carbonate minerals in coal and acid solution improves the conductivity of coal whilst, on the other hand, the clay minerals in the coal (mainly including montmorillonite, illite and kaolinite) exhibit expansion as a result of ion exchange with the H+in acid solution, which has a negative effect on the per-meability of the coal. The permeability of coal samples increased at first and then decreased with immer-sion time, and when the soaking time is 2–3 months the permeability of the coal reached a maximum. In general, for coals with permeabilities less than 0.2 mD or greater than 2 mD, the effect on the permeabil-ity is low;when the permeability of the coal is in the range 0.2–2 mD, the effect on the permeability is highest. Research into permeability change characteristics can provide a theoretical basis for carbon diox-ide injection under different reservoir permeability conditions and subsequent drainage.

  13. Structural evaluation of WIPP disposal room raised to Clay Seam G.

    Energy Technology Data Exchange (ETDEWEB)

    Park, Byoung Yoon (Sandia National Laboratories, Carlsbad, NM); Holland, John F. (Sandia National Laboratories, Albuquerque, NM)

    2007-09-01

    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.

  14. 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.

  15. Application of pressure relief and permeability increased by slotting a coal seam with a rotary type cutter working across rock layers

    Institute of Scientific and Technical Information of China (English)

    Shen Chunming; Lin Baiquan; Meng Fanwei; Zhang Qizhi; Zhai Cheng

    2012-01-01

    Pressure relief to increase permeability significantly improves gas extraction efficiency from coal seams.In this paper we report results from simulations using FLAC3D code to analyze changes in coal displacement and stress after special drill slots were formed.We investigated the mechanism of pressure relief and permeability increase in a high-gas and low-permeability coal seam through the modeling of gas flow.This allows the development of the technology.Slotting across rock layers in the coal seam with a rotary type cutter was then applied in the field.The results show that pressure relief and permeability increases from slotting the coal seam can increase the transport and the fracture of the coal.This expands the range of pressure relief from the drilling and increases the exposed area of the seam.The total quantity of gas extracted from slotted bore holes was three times that seen with ordinary drilling.The concentration of gas extracted from the slotted drills was from two to three times that seen using ordinary drills.The gas flow was stable at 80%.Improved permeability and more efficient gas extraction are the result of the slotting.The roadway development rate is increased by 30-50% after gas drainage.This technology diminishes the lag between longwall production and roadway development and effectively prevents coal and gas outburst,which offers the prospect of broad application.

  16. The Caenorhabditis elegans GATA factor elt-1 is essential for differentiation and maintenance of hypodermal seam cells and for normal locomotion.

    Science.gov (United States)

    Smith, Judith A; McGarr, Pamela; Gilleard, John S

    2005-12-15

    The Caenorhabditis elegans GATA transcription factor elt-1 has previously been shown to have a central role in the specification of hypodermal (epidermal) cell fates and acts several cell divisions before the birth of hypodermal cells. Here we report that elt-1 also has essential functions during subsequent development. Reporter gene studies show that elt-1 expression is maintained in lateral seam cells throughout development and elt-1 RNA interference experiments support an essential role for elt-1 in the differentiation of lateral seam cells in the embryo. The maintenance of seam-cell fates in all larval stages including L2d and dauer also requires elt-1. The elt-1 RNAi phenotype shows that seam cells are essential for the structural integrity of adult hermaphrodites in the vulval region and for diametric shrinkage during dauer larval formation. By contrast, severe seam-cell loss in the larval stages has little effect on moulting, indicating that the presence of these cells is not essential for this process. The elt-1 reporter gene is also expressed in neurones of the locomotory circuit. Loss of elt-1 function during postembryonic development results in a hypermotility phenotype whereas overexpression of elt-1 leads to a reciprocal phenotype of reduced motility and paralysis. These results suggest that elt-1 is a key regulator of neuronal function in larvae and adult worms.

  17. 提高免烫衬衫袖窿起皱级别的方法%Methods to Improve the Seam Grade of Non-iron Fabric

    Institute of Scientific and Technical Information of China (English)

    宋海燕; 李凤霞

    2012-01-01

    免烫面料由于其特殊的整理方式,容易出现袖窿缝口缩皱的问题,严重影响了衬衣的品质和外观而达不到客户要求。以实例说明改良前后的接缝起皱级别的对比,经检测分析表明:缝纫线的调整;线迹密度的适当调节;对袖窿进行熨烫整理;对衣片含湿率进行调整等有利于提高衬衣袖窿接缝起皱级别,解决了免烫衬衣袖窿接缝起皱低的问题。%The seam pucker is easily appeared in garment processing by using non-iron fabric for its special finishing. It affected the shirtts quality and outlook seriousiy, which could not meet the customls request. The seam grade was contrasted with examples before and after the improvements. The results by examining and analyzing the weak seam pucker showed that: adjusting threads, ad- justing sewing stitches properly, ironing armhole and adjusting the cloth moisture ratio could increase the seam grade, then the weak seam pucker could be solved.

  18. Technique of coal mining and gas extraction without coal pillar in multi-seam with low permeability

    Institute of Scientific and Technical Information of China (English)

    YUAN Liang

    2009-01-01

    Aimed at the low mining efficiency in deep multi-seams because of high crustal stress, high gas content, low permeability, the compound "three soft" roof and the trouble-some safety situation encountered in deep level coal exploitation, proposed a new idea of gob-side retaining without a coal-pillar and Y-style ventilation in the first-mined key pres-sure-relieved coal seam and a new method of coal mining and gas extraction. The follow-ing were discovered: the dynamic evolution law of the crannies in the roof is influenced by mining, the formative rule of "the vertical cranny-abundant area" along the gob-side, the distribution of air pressure field in the gob, and the flowing rule of pressure-relieved gas in a Y-style ventilation system. The study also established a theoretic basis for a new mining method of coal mining and gas extraction which is used to extract the pressure-relieved gas by roadway retaining boreholes instead of roadway boreholes. Studied and resolved many difficult key problems, such as, fast roadway retaining at the gob-side without a coal-pillar, Y-style ventilation and extraction of pressure-relieved gas by roadway retaining boreholes, and so on. The study innovated and integrated a whole set of technical sys-tems for coal and pressure relief gas extraction. The method of the pressure-relieved gas extraction by roadway retaining had been successfully applied in 6 typical working faces in the Huainan and Huaibei mining areas. The research can provide a scientific and reliable technical support and a demonstration for coal mining and gas extraction in gaseous deep multi-seams with low permeability.

  19. A Combined Micro-CT Imaging/Microfluidic Approach for Understating Methane Recovery in Coal Seam Gas Reservoirs

    Science.gov (United States)

    Mostaghimi, P.; Armstrong, R. T.; Gerami, A.; Lamei Ramandi, H.; Ebrahimi Warkiani, M.

    2015-12-01

    Coal seam methane is a form of natural gas stored in coal beds and is one of the most important unconventional resources of energy. The flow and transport in coal beds occur in a well-developed system of natural fractures that are also known as cleats. We use micro-Computed Tomography (CT) imaging at both dry and wet conditions to resolve the cleats below the resolution of the image. Scanning Electron Microscopy (SEM) is used for calibration of micro-CT data. Using soft lithography technique, the cleat system is duplicated on a silicon mould. We fabricate a microfluidic chip using Polydimethylsiloxane (PDMS) to study both imbibition and drainage in generated coal structures for understating gas and water transport in coal seam reservoirs. First, we use simple patterns observed on coal images to analyse the effects of wettability, cleat size and distribution on flow behaviour. Then, we study transport in a coal by injecting both distilled water and decane with a rate of 1 microliter/ min into the fabricated cleat structure (Figure 1), initially saturated with air. We repeat the experiment for different contact angles by plasma treating the microfluidic chip, and results show significant effects of wettability on the displacement efficiency. The breakthrough time in the imbibition setup is significantly longer than in the drainage. Using rapid video capturing, and high resolution microscopy, we measure the saturation of displacing fluid with respect to time. By measuring gas and liquid recovery in the outlet at different saturation, we predict relative permeability of coal. This work has important applications for optimising gas recovery and our results can serve as a benchmark in the verification of multiphase numerical models used in coal seam gas industry.

  20. Numerical analysis of the destruction of water-resisting strata in a coal seam floor in mining above aquifers

    Institute of Scientific and Technical Information of China (English)

    Jiang Zhihai

    2011-01-01

    With the increase in mining depth many mining areas in China have entered a period necessitating mining above aquifers.Production safety in coal mines in northern China is under serious threat from Ordovician karst water on coal seam floors.In order to analyze the destruction of water-resisting strata in floors of coal seams being mined and to achieve safe mining above deep aquifers,we established a numerical model of water-resisting strata,considering the structural characteristics and mechanical properties of a floor layered with hard and soft rock.We simulated the distribution characteristics of deformation,failure and seepage using the analytical module of fluid-structure interaction of FLAC.We also obtained the corresponding stress distribution,deformation and flow vectors.Our results indicate that:(1) the advance of the working face causes water-resisting strata in goaf floors to form a deep double-clamped beam,subject to homogeneous loading at the bottom; (2) the two sides of the rock beam are subject to shear failure; (3) both sides of the rock seam at the bottom of the water-resisting strata are subject to tension and the greater the working face advance,the more serious the failure; (4) the original balance of the stress and seepage fields are broken and redistributed due to mining activities,especially the interaction of the abutment pressure in both sides of the goaf; the lateral pressure on the goaf floor and the water pressure on the floor of the aquifer promote floor heave and shear failure on both sides of the floor,forming a water-inrush passage.Our study results can provide references for the mechanism of water-inrush on mine floors.

  1. Technique of coal mining and gas extraction without coal pillar in multi-seam with low permeability

    Energy Technology Data Exchange (ETDEWEB)

    Liang Yuan [Huainan Mining (Group) Co. Ltd., Huainan (China)

    2009-06-15

    Aimed at the low mining efficiency in deep multi-seams because of high crustal stress, high gas content, low permeability, the compound 'three soft' roof and the troublesome safety situation encountered in deep level coal exploitation, a new idea of gob-side retaining without a coal-pillar and Y-style ventilation in the first-mined key pressure-relieved coal seam and a new method of coal mining and gas extraction was proposed. The following were discovered: the dynamic evolution law of the crannies in the roof is influenced by mining, the formative rule of 'the vertical cranny-abundant area' along the gob-side, the distribution of air pressure field in the gob, and the flowing rule of pressure-relieved gas in a Y-style ventilation system. The study also established a theoretic basis for a new mining method of coal mining and gas extraction which is used to extract the pressure-relieved gas by roadway retaining boreholes instead of roadway boreholes. Studied and resolved many difficult key problems, such as, fast roadway retaining at the gob-side without a coalpillar, Y-style ventilation and extraction of pressure-relieved gas by roadway retaining boreholes, and so on. The study innovated and integrated a whole set of technical systems for coal and pressure relief gas extraction. The method of the pressure-relieved gas extraction by roadway retaining had been successfully applied in 6 typical working faces in the Huainan and Huaibei mining areas. The research can provide a scientific and reliable technical support and a demonstration for coal mining and gas extraction in gaseous deep multi-seams with low permeability. 9 refs., 7 figs.

  2. Complex methods to determine zones liable to sudden outbursts during prospecting and mining of gassy coal seams

    Energy Technology Data Exchange (ETDEWEB)

    Sergeev, I.V.; Ivanov, B.M. [Skochinsky Institute of Mining, Lyubertsy (Russian Federation)

    1995-12-31

    Greater depth of mining and speed of development driving results in greater number of coal seams liable to outbursts. A concept for coal and gas outbursts prevention worked out in Russia provides the main idea and a practical combination of a reliable forecast of the zones liable to outbursts with optimum parameters for the technological impact on the mining of gassy coal seams. The main idea for a reliable forecast of the coal seam zones liable to outbursts allows a complex estimation of the potential outburst hazard outside the mine development impact zone depending upon the geological and geophysical investigations of the prospecting boreholes and true outburst hazard as a function of the potential outburst hazard and energy capacity and its effects upon the technology of the development of faces. Main idea of complex forecast can be developed by forming a criteria for the outburst hazard which is a function of the basic outburst hazard factors conditioned by the energy-power theory for sudden outbursts. The basic outburst hazard factors are considered as a function of empirical outburst hazard indices which make it possible to determine the forecast criteria on a statistical basis by using computers and the image recognition theory. It is possible to develop a regional (geological prospecting) and a local (periodical - in the development faces) forecast of the outburst hazard zones, and to determine the reduction degree for gas content and gas pressure on applying anti-outburst measures. Resorting to the seismoacoustic (apparatus ZUA type) and gas-dynamic (methane-control equipment) automated forecasting makes it possible to continuously control the reactions of the near-face rock mass to the technological influence. The information through the telemetry reaches the mine computer at the switchboard and is translated into a forecast. 1 tab.

  3. Procurement Tracking System (PTS)

    Data.gov (United States)

    Office of Personnel Management — The Procurement Tracking System (PTS) is used solely by the procurement staff of the Office of the Inspector General (OIG) at the U.S. Office of Personnel Management...

  4. LHCb VELO Tracking Resolutions

    CERN Multimedia

    Alexander, Michael

    2011-01-01

    The excellent tracking performance of the Vertex Locator (VELO) at LHCb is presented. The resolutions it achieves on single hits, impact parameters, and primary vertex positions are shown, with particular attention paid to measurement of impact parameters.

  5. Human Capital Tracking Tool -

    Data.gov (United States)

    Department of Transportation — AVS is now required to collect, track, and report on data from the following Flight, Business and Workforce Plan. The Human Resource Management’s Performance Target...

  6. Financial Disclosure Tracking System

    Data.gov (United States)

    US Agency for International Development — USAID's FDTS identifies personal service contractors and local employees who should file disclosure reports. It tracks late filers and identifies those who must take...

  7. 1996 : Track Count Protocol

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The goal of St. Vincent National Wildlife Refuge's Track Count Protocol is to provide an index to the population size of game animals inhabiting St. Vincent Island.

  8. Case Analysis Tracking System

    Data.gov (United States)

    National Archives and Records Administration — CATS tracks Public and Federal Agency Reference Requests for OPF (Official Personnel Folder) , EMF (Employee Medical Folder), and eOPF (electronic Official Personnel...

  9. Matter Tracking Information System -

    Data.gov (United States)

    Department of Transportation — The Matter Tracking Information System (MTIS) principle function is to streamline and integrate the workload and work activity generated or addressed by our 300 plus...

  10. Jet Car Track Site

    Data.gov (United States)

    Federal Laboratory Consortium — Located in Lakehurst, New Jersey, the Jet Car Track Site supports jet cars with J57 engines and has a maximum jet car thrust of 42,000 pounds with a maximum speed of...

  11. Energy Tracking Software Platform

    Energy Technology Data Exchange (ETDEWEB)

    Ryan Davis; Nathan Bird; Rebecca Birx; Hal Knowles

    2011-04-04

    Acceleration has created an interactive energy tracking and visualization platform that supports decreasing electric, water, and gas usage. Homeowners have access to tools that allow them to gauge their use and track progress toward a smaller energy footprint. Real estate agents have access to consumption data, allowing for sharing a comparison with potential home buyers. Home builders have the opportunity to compare their neighborhood's energy efficiency with competitors. Home energy raters have a tool for gauging the progress of their clients after efficiency changes. And, social groups are able to help encourage members to reduce their energy bills and help their environment. EnergyIT.com is the business umbrella for all energy tracking solutions and is designed to provide information about our energy tracking software and promote sales. CompareAndConserve.com (Gainesville-Green.com) helps homeowners conserve energy through education and competition. ToolsForTenants.com helps renters factor energy usage into their housing decisions.

  12. LHCb on track

    CERN Multimedia

    2006-01-01

    On 7 and 8 June 2006, the last large component of the LHCb experiment was lowered into the cavern. This 10-tonne, 18-metre long metal structure known as 'the bridge' will support the LHCb tracking system.

  13. Applied eye tracking research

    NARCIS (Netherlands)

    Jarodzka, Halszka

    2011-01-01

    Jarodzka, H. (2010, 12 November). Applied eye tracking research. Presentation and Labtour for Vereniging Gewone Leden in oprichting (VGL i.o.), Heerlen, The Netherlands: Open University of the Netherlands.

  14. Neonate turtle tracking data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The objectives of this project are to use novel satellite tracking methods to provide improved estimation of threats at foraging areas and along migration routes for...

  15. Track Loading Vehicle - TLV

    Data.gov (United States)

    Federal Laboratory Consortium — The TLV is designed to apply forces close to the strength limits of the rails and other track structure components, such as ties, rail fasteners, and ballast, while...

  16. Study on the law of methane seepage in the wall of drainage roadway in mining seam-group

    Institute of Scientific and Technical Information of China (English)

    LIU Jian; LUO Yong; LIU Ze-gong; SHI Bi-ming

    2005-01-01

    Based on the equation of the gas flow continuity and state, Darcy law and Langmuir equation, the law of methane seepage in the wall of drainage roadway was studied. The governing equation of methane one-way seepage in the seam was founded.By solving the equation, the calculation of methane seepage velocity in the coal wall was worked out. The result has really applied worth and will give beneficial references to related research, it provides preventing coal and gas outbursts with theoretical gist.

  17. Role of tectonic movements in the origin of gas outburst hazards of black coal seams in the Mecsek Area

    Energy Technology Data Exchange (ETDEWEB)

    Nemedi; Varga, Z.

    1985-01-01

    The tectonics and the major structural elements of the lower Liassic black coal seams of the Mecsek Area are reviewed. The folded and faulted tectonic elements play a predominant role in the process of gas migration and trap formation. Since these elements are of primary importance from the point of view of gas outburst hazard, the knowledge of the distribution and peculiarities of these elements is very important. The investigations needed to forecast the gas outbursts both from the local and from the areal point of view are comprehensively discussed.

  18. Determining coal reserves in a mine field, accounting for the random nature of the change in the seam thickness. [USSR

    Energy Technology Data Exchange (ETDEWEB)

    Smirenskii, M.M.; Rozhkova, N.B.

    1979-01-01

    A method is proposed for calculating the balanced coal reserves (shales) based on the probability distribution of values corresponding to the seam thickness. The approval tests for the method, which were performed in accordance with the conditions at the ''Osinnikovsk'' mine of the ''Yuzhkuzbassgol'' Production Union demonstrated that it is no less accurate than traditional methods, while the labor expended and volume of calculations are, on the average, cut in half. Additionally, the proposed method makes it possible to numerically evaluate the reliability of the calculations performed.

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

    Directory of Open Access Journals (Sweden)

    Llewellyn Howes

    2015-03-01

    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.

  20. Vehicle Tracking and Security

    Science.gov (United States)

    Scorer, A. G.

    1998-09-01

    This paper covers the wide area and short range locational technologies that are available for vehicle tracking in particular and mobile user security in general. It also summarises the radio communications services that can deliver information to the user. It considers the use that can be made of these technologies, when combined with procedures for delivering a response, in the security field, notably in relation to personal security, high-value load protection and the after-theft tracking markets.

  1. MATERIAL TRACKING USING LANMAS

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, F.

    2010-06-07

    LANMAS is a transaction-based nuclear material accountability software product developed to replace outdated and legacy accountability systems throughout the DOE. The core underlying purpose of LANMAS is to track nuclear materials inventory and report transactions (movement, mixing, splitting, decay, etc.) to the Nuclear Materials Management and Safeguards System (NMMSS). While LANMAS performs those functions well, there are many additional functions provided by the software product. As a material is received onto a site or created at a site, its entire lifecycle can be tracked in LANMAS complete to its termination of safeguards. There are separate functions to track material movements between and within material balance areas (MBAs). The level of detail for movements within a MBA is configurable by each site and can be as high as a site designation or as detailed as building/room/rack/row/position. Functionality exists to track the processing of materials, either as individual items or by modeling a bulk process as an individual item to track inputs and outputs from the process. In cases where sites have specialized needs, the system is designed to be flexible so that site specific functionality can be integrated into the product. This paper will demonstrate how the software can be used to input material into an account and track it to its termination of safeguards.

  2. The adjusting mining technology of combining fully mechanized with individual prop, rotating, hilt, irregular form, and double unit face on thin coal seam of Tianchen Mine

    Institute of Scientific and Technical Information of China (English)

    SONG Hua-ling; WEN Guo-feng; LI Jin-ke

    2008-01-01

    Analyzed the situations and characteristics of thin coal seam mining and its mining technologies, and introduced the mining innovation technology used by Tianchen Coal Mine of Zhaozhuang Coal Company of China. This innovation technology combined the fully mechanized mining with individual props, and the working face of mining is over length, irregular form and double units. The rotational adjusting mining technology on thin coal seam is also practiced in this new mining technology. The detail technologies, such as outlays of working face and ways, mining methods, equipments of cutting, transporting and sporting, have been introduced. So that, using the synthetic and creative mining tech-nologies, Tianchen Coal Mine solves the mining problems of thin coal seam successfully.

  3. Numerical simulation and experiment analysis of improving permeability by deep-hole presplitting explosion in high gassy and low permeability coal seam

    Institute of Scientific and Technical Information of China (English)

    CAI Feng; LIU Ze-gong; LIN Bai-quan; LI Wei

    2009-01-01

    Created a new damage model for explosive for LS-DYNA3D, taking advantage of the Taylor method aimed at the high gassy and low permeability coal seam, and nu-merically simulated and analyzed the deep-hole presplitting explosion. The entire process of explosion was represented, including cracks caused by dynamic pressure, transmission and vibration superposition of stress waves, as well as cracks growth driven by gas gen-erated by explosion. The influence of the cracks generated in the process of explosion and the performance of improving permeability caused by the difference of interval between explosive holes were analyzed. A reasonable interval between explosive holes of deep-hole presplitting explosions in high gassy and low permeability coal seams was proposed, and the resolution of gas drainage in high gassy and low permeability coal seam was put forward.

  4. Modelling of a coal seam of the deposit Đurđevik (BiH) by means of 2D reflection seismic imaging

    Science.gov (United States)

    Arsenović, Siniša; Urošević, Milovan; Sretenović, Branislav; Cvetkov, Vesna; Životić, Dragana

    2016-06-01

    A low cost 2D reflection seismic survey was used to map the continuity of the main seams as well as the numerous faults at the Đurđevik sub-bituminous coal deposit (BiH). A 24-channel seismic data acquisition system was available for this survey. The natural high reflectivity of the coal seams and a favourable geometry of seismic profiles enabled the identification and correlation of major faults across the area. Rugged terrain presented challenges to both data acquisition and processing. Stacks of acceptable quality were obtained only after the application of surface consistent statics and careful application of multi-channel filtering. A set of recorded 2D lines was interpreted in a 3D environment. Inferred structural elements disrupting the seam continuity were identified and were in agreement with available drilling results and mine workings. The result of this work was used to reduce mining hazards and also to help optimise mine planning.

  5. Characteristics of Extra Narrow Gap Weld of HSLA Steel Welded by Single-Seam per Layer Pulse Current GMA Weld Deposition

    Science.gov (United States)

    Agrawal, B. P.; Ghosh, P. K.

    2017-03-01

    Butt weld joints are produced using pulse current gas metal arc welding process by employing the technique of centrally laid multi-pass single-seam per layer weld deposition in extra narrow groove of thick HSLA steel plates. The weld joints are prepared by using different combination of pulse parameters. The selection of parameter of pulse current gas metal arc welding is done considering a summarized influence of simultaneously interacting pulse parameters defined by a dimensionless hypothetical factor ϕ. The effect of diverse pulse parameters on the characteristics of weld has been studied. Weld joint is also prepared by using commonly used multi-pass multi-seam per layer weld deposition in conventional groove. The extra narrow gap weld joints have been found much superior to the weld joint prepared by multi-pass multi-seam per layer deposition in conventional groove with respect to its metallurgical characteristics and mechanical properties.

  6. 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.

  7. 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

  8. 复合土工膜防渗施工接缝加固方法%Seam-reinforcing Method for Composite Geomembrane in Seepage Control Construction

    Institute of Scientific and Technical Information of China (English)

    蒋学行; 李翠玲; 李娟; 李晓红

    2012-01-01

    Currently, seams of PE membrane are fused and seams of non-woven geo-fabric are sewed for joining of membrane and non-woven geo-fabrics. The test results indicate that tensile failure strength of the bonded seams is only 20 %~40 % of the tensile strength of parent materials. On the basis of a series of experimental study, a new method is proposed for strengthening the seams of geomembrane and geo-fabrics. With the new method, KS hot melt adhesive is used for binding seams of PE membrane and non-woven geofabric and seams of non-woven geofabric following welding of PE membrane. Being strengthened with KS hot melt adhesive the tensile failure strength of the bonded seams could be similar to the tensile strength of parent materials, which satisfies technical requirement that tensile strength of seams should not be lower than 80 % of the tensile strength of parent materials as specified in Standard for Application of Geosynthetics in Hydraulic and Hydro-power Engineering.%目前两布一膜型PE复合土工膜施工中多采用膜焊接、非织造土工布缝合的接缝方法,测得接缝拉伸断裂强度仅为母材强度的20%~40%.在试验研究基础上提出了膜焊接后,膜与非织造土工布、非织造土工布与非织造土工布之间采用KS热熔胶粘剂粘合的接缝加固方法.加固后的接缝强度接近母材强度,满足SL/T 225-98《水利水电工程土工合成材料应用技术规范》中,接缝强度不低于母材强度80%的技术要求.

  9. Role of igneous rocks in the development of the gas outburst-prone nature of the black coal seams in the Mecsek area

    Energy Technology Data Exchange (ETDEWEB)

    Nemedi Varga, Z.

    1986-01-01

    In addition to the rank and structural conditions of coal seams the role of volcanic dykes is primordial from the point of view of the development of gas outburst of coal seams. The Mesco-Cenozoic volcanism of the Mecsek Mountains (South Transdanubia) is reviewed including the areal distribution of volcanics. The rock types and their frequency of occurrence are described with special emphasis to the contact metamorphism produced by the interaction of igneous and sedimentary rocks. The possibilities of gas migration as a function of the tectonic conditions are outlined exemplified by the Komlo region most famous for its gas outburst events.

  10. Sensitivity of detection of fugitive methane emissions from coal seam gas fields

    Science.gov (United States)

    Feitz, A. J.; Berko, H.; Wilson, P.; Jenkins, C.; Loh, Z. M.; Etheridge, D.

    2013-12-01

    There is increasing recognition that minimising methane emissions from the oil and gas sector is a key step in reducing global greenhouse gas emissions in the near term. Atmospheric monitoring techniques are likely to play an important future role in measuring the extent of existing emissions and verifying emission reductions. They can be very suitable for monitoring gas fields as they are continuous and integrate emissions from a number of potential point and diffuse sources that may vary in time. Geoscience Australia and CSIRO Marine & Atmospheric Research have collected three years of continuous methane and carbon dioxide measurements at their atmospheric composition monitoring station ('Arcturus') in the Bowen Basin, Australia. Methane signals in the Bowen Basin are likely to be influenced by cattle production, landfill, coal production, and conventional and coal seam gas (CSG) production. Australian CSG is typically 'dry' and is characterised by a mixed thermogenic-biogenic methane source with an absence of C3-C6+ alkanes. The range of δ13C isotopic signatures of the CSG is similar to methane from landfill gas and cattle emissions. The absence of standard in-situ tracers for CSG fugitive emissions suggests that having a comprehensive baseline will be critical for successful measurement of fugitive emissions using atmospheric techniques. In this paper we report on the sensitivity of atmospheric techniques for the detection of fugitive emissions from a simulated new CSG field against a three year baseline signal. Simulation of emissions was performed for a 1-year period using the coupled prognostic meteorological and air pollution model TAPM at different fugitive emission rates (i.e. estimates of <1% to up to 10% of production lost) and distances (i.e. 10 - 50 km) from the station. Emissions from the simulated CSG field are based on well density, production volumes, and field size typical of CSG fields in Australia. The distributions of the perturbed and

  11. Empirical-analytical method for evaluating the pressure distribution in the hard coal seams

    Institute of Scientific and Technical Information of China (English)

    KABIESZ Józef; MAKóWKA Janusz

    2009-01-01

    At present, numerical modelling of distributions of many rock mass characteristics plays more and more important role in many geomechanical questions. In the issues related to seismic and rockburst hazards, the analyses of distributions of stress component values in the rock strata are performed, similarly as those of deformation parameters of the strata. To do this, commercial computer programs are used which function on the basis of the finite element-, separate element-, finite difference-, boundary element methods, or individually designed computer programs. They enable to obtain information, unattainable with other methods, being of importance for further concluding on those hazards. The programs based on applying those methods have contributed to important progress and development of science in the domain of analyzing and predicting the hazards. To this end, the commercial computer programs are used that are based on the methods of: finite elements, separate elements, finite differences, boundary elements, etc., or on individually developed computer programs. They enable to obtain information, unavailable using other methods, being of vital importance for further concluding on these hazards. The programs based on these methods have contributed to essential progress and development of science in the field of analysing and predicting the hazards. Apart from their obvious advantages, they have many drawbacks that hinder their practical, routine application. To allow making these type of analyses, without the necessity of constructing complicated models and knowing the detailed geomechanical parameters of rocks, together with laborious computation using a high-rank computer hardware, an analytical-empirical method has been developed at Central Mining Institute, Poland, to make prediction (modelling) of the distribution of pressure values (vertical component of stress) in SIGMAZ coal seams. It is based on geophysical measurements, generalized for the conditions of

  12. Ensuring efficient dust abatement without impregnation in low-rank seams worked by stripping winning; Sicherstellung der Wirksamkeit der Staubbekaempfungsmassnahmen bei Verzicht auf Traenkarbeit in Betrieben der schaelenden Gewinnung in niedrig inkohlten Floezen

    Energy Technology Data Exchange (ETDEWEB)

    Armbruster, L.; Eichholtz, P.; Suedhofer, F. [Deutsche Steinkohle AG, Herne (Germany). Hauptabteilung BA

    2001-10-01

    Waterinfusion in to coal before winning is an obligatory measure to reduce dust, both with a view to health protection and to fire and explosion safety. The effect of infusion is, however, greater in high-rank seams than in low-rank ones. The highly effective dust control measures applied when winning coal are now causing the infusion effect to recede. It is now possible to dispense with this in low-rank seam sections. In operational trials in the P and Erda seams it has been demonstrated that, when modern dust control methods are used, there is no longer any evidence of the infusion effect in the mine. Infusion can now be dispensed with in seams above seam P in stripping winning, provided that the official mining regulations on ensuring lower dust concentrations are observed. (orig.)

  13. 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)

    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.

  14. 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.

  15. 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.

  16. A probe into "mining technique in the condition of floor failure" for coal seam above longwall goafs

    Institute of Scientific and Technical Information of China (English)

    FENG Guo-rui; WANG Xian-xia; KANG Li-xun

    2008-01-01

    Targeting at the coal seam with useful value discarded above goafs, attempted to explore the feasibility of "mining technique in the condition of floor failure" from theoretical point of view, and predicted. It indicated that mining technique in the condition of floor failureused above Longwall Goafs in Baijiazhuang Mining is totally feasible. At law, the deformation of the floor in the mining technique by means of probability-integral method. And it is discov-ered that deformed basin can emerge in the footwall of No.6 coal seam and its maximum subsidence was possibly 1 633 mm or so and its maximum positive curvature is 61.74/10-3.At last, it therefore suggests appropriate ground pressure control measures as strengthening observation of ground pressure and adopting false slope for exploitation and strengthening support for reasonable push and slide based on the adverse ground pressure behaviors possibly occurring in the mining technique. This serves to gather data and lay sturdy founda-tion for further probe into the mining technique, and offers theoretical and technical grounds for concrete implementation of the mining technique.

  17. 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.

  18. Research into comprehensive gas extraction technology of single coal seams with low permeability in the Jiaozuo coal mining area

    Institute of Scientific and Technical Information of China (English)

    Fu Jiangwei; Fu Xuehai; Hu Xiao; Chen Li; Ou Jianchun

    2011-01-01

    For a low permeability single coal seam prone to gas outbursts,pre-drainage of gas is difficult and inefficient,seriously restricting the safety and efficiency of production.Radical measures of increasing gas extraction efficiency are pressure relief and infrared antireflection.We have analyzed the effect of mining conditions and the regularity of mine pressure distribution in front of the working face of a major coal mine of the Jiaozuo Industrial (Group) Co.as our test area,studied the width of the depressurization zone in slice mining and analyzed gas efficiency and fast drainage in the advanced stress relaxation zone.On that basis,we further investigated and practiced the exploitation technology of shallow drilling,fan drilling and grid shape drilling at the working face.Practice and our results show that the stress relaxation zone is the ideal region for quick and efficient extraction of gas.By means of an integrated extraction technology,the amount of gas emitted into the zone was greatly reduced,while the risk of dangerous outbursts of coal and gas was lowered markedly.This exploration provides a new way to control for gas in working faces of coal mines with low permeability and risk of gas outbursts of single coal seams in the Jiaozuo mining area.

  19. Luge Track Safety

    CERN Document Server

    Hubbard, Mont

    2012-01-01

    Simple geometric models of ice surface shape and equations of motion of objects on these surfaces can be used to explain ejection of sliders from ice tracks. Simulations using these can be used to explain why certain design features can be viewed as proximate causes of ejection from the track and hence design flaws. This paper studies the interaction of a particle model for the luge sled (or its right runner) with the ice fillet commonly connecting inside vertical walls and the flat track bottom. A numerical example analyzes the 2010 luge accident at the Vancouver Olympics. It shows that this runner-fillet interaction, and specifically the fillet's positive curvature up the inside wall, can cause a vertical velocity more than sufficient to clear the outside exit wall. In addition its negative curvature along the track, together with large vertical velocity, explains loss of fillet or wall contact and slider ejection. This exposes the fillet along inside walls as a track design flaw. A more transparent design ...

  20. Clean tracks for ATLAS

    CERN Multimedia

    2006-01-01

    First cosmic ray tracks in the integrated ATLAS barrel SCT and TRT tracking detectors. A snap-shot of a cosmic ray event seen in the different layers of both the SCT and TRT detectors. The ATLAS Inner Detector Integration Team celebrated a major success recently, when clean tracks of cosmic rays were detected in the completed semiconductor tracker (SCT) and transition radiation tracker (TRT) barrels. These tracking tests come just months after the successful insertion of the SCT into the TRT (See Bulletin 09/2006). The cosmic ray test is important for the experiment because, after 15 years of hard work, it is the last test performed on the fully assembled barrel before lowering it into the ATLAS cavern. The two trackers work together to provide millions of channels so that particles' tracks can be identified and measured with great accuracy. According to the team, the preliminary results were very encouraging. After first checks of noise levels in the final detectors, a critical goal was to study their re...

  1. AIRSHIP ATTITUDE TRACKING SYSTEM

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-liang; SHAN Xue-xiong

    2006-01-01

    The attitude tracking control problem for an airship with parameter uncertainties and external disturbances was considered in this paper. The mathematical model of the airship attitude is a multi-input/multi-output uncertain nonlinear system. Based on the characteristics of this system, a design method of robust output tracking controllers was adopted based on the upper-bounds of the uncertainties. Using the input/output feedback linearization approach and Liapunov method, a control law was designed, which guarantees that the system output exponentially tracks the given desired output. The controller is easy to compute and complement. Simulation results show that, in the closed-loop system, precise attitude control is accomplished in spite of the uncertainties and external disturbances in the system.

  2. Tracking of deformable objects

    Science.gov (United States)

    Aswani, Parimal; Wong, K. K.; Chong, Man N.

    2000-12-01

    Tracking of moving-objects in image sequences is needed for several video processing applications such as content-based coding, object oriented compression, object recognition and more recently for video object plane extraction in MPEG-4 coding. Tracking is a natural follow-up of motion-based segmentation. It is a fast and efficient method to achieve coherent motion segments along the temporal axis. Segmenting out moving objects for each and every frame in a video sequence is a computationally expensive approach. Thus, for better performance, semi-automatic segmentation is an acceptable compromise as automatic segmentation approaches rely heavily on prior assumptions. In semi-automatic segmentation approaches, motion-segmentation is performed only on the initial frame and the moving object is tracked in subsequent frames using tracking algorithms. In this paper, a new model for object tracking is proposed, where the image features -- edges, intensity pattern, object motion and initial keyed-in contour (by the user) form the prior and likelihood model of a Markov Random Field (MRF) model. Iterated Conditional Mode (ICM) is used for the minimization of the global energy for the MRF model. The motion segment for each frame is initialized using the segment information from the previous frame. For the initial frame, the motion segment is obtained by manually keying in the object contour. The motion-segments obtained using the proposed model are coherent and accurate. Experimental results on tracking using the proposed algorithm for different sequences -- Bream, Alexis and Claire are presented in this paper. The results obtained are accurate and can be used for a variety of applications including MPEG-4 Video Object Plane (VOP) extraction.

  3. Tracking Your Development

    CERN Document Server

    Hennum, Kelly M

    2011-01-01

    This book provides you with the means to set development goals and to track your progress on achieving them. It can help you efficiently gather and make sense of information about your progress and avoid common pitfalls that can block your development. Tracking your development can be captures in a few steps: articulating your goal, creating an action plan, gathering information about your behavior, indentifying barriers and support, and revising your action plan. Taking these steps will greatly increase the likelihood of achieving your goals.

  4. Application of OpenCV on Real-time Detection and Processing System of Seam%OpenCV在焊缝实时检测与处理系统中的应用

    Institute of Scientific and Technical Information of China (English)

    徐自越; 李战明; 李二超

    2012-01-01

    机器视觉系统是集机械、光电、控制、计算机和数字图像处理等技术于一体的高度自动化系统,能够有效地提高产品的质量和产量,现已广泛应用于工业当中.随着科技的发展,对焊接的质量与效率的要求越来越大,为此有必要设计一套行之有效的,在焊接自动跟踪技术中能够在线检测焊缝并进行处理的焊缝实时检测与处理系统.文中在VC++6.0开发环境中设计了一种采用Otsu自动选择阈值和Canny算子检测边缘,基于OpenCV的焊缝实时检测与处理算法,实验结果表明基于该算法的系统实时性高、效果好、检测正确快速.%The machine vision system is a high automation system in the integration of the machinery,photoelectricity,control,computer and digital image processing ,can effectively improve the product quality and production, and now is widely used in industry. With the development of technology,need to design a system that can improve the welding quality and efficiency. For this,develop the real-time detection and processing system of the seam which is used for on-line detection and related image processing of welding automation tracking technology. In the CV++ 6.0 development environment, design a kind of the real-time seam detection and processing algorithm based on OpenCV, adopting automatic value selection by Otsu and edge detection by Canny operator. Experimental results show that the algorithm has high real-time, good effect and correct and fast detection.

  5. Track Reconstruction Performance in CMS

    CERN Document Server

    Azzurri, Paolo

    2008-01-01

    The expected performance of track reconstruction with LHC events using the CMS silicon tracker is presented. Track finding and fitting is accomplished with Kalman Filter techniques that achieve efficiencies above 99\\% on single muons with $p_T >$1~GeV/c. Difficulties arise in the context of standard LHC events with a high density of charged particles, where the rate of fake combinatorial tracks is very large for low $p_T$ tracks, and nuclear interactions in the tracker material reduce the tracking efficiency for charged hadrons. Recent improvements with the CMS track reconstruction now allow to efficiently reconstruct charged tracks with $p_T$ down to few hundred MeV/c and as few as three crossed layers, with a very small fake fraction, by making use of an optimal rejection of fake tracks in conjunction with an iterative tracking procedure.

  6. Underground Coal Mine Methane Displacement by Injecting Low-pressure Gas into the Meta-anthracite Seam: Laboratory and Field Tests

    Directory of Open Access Journals (Sweden)

    Yu Hong

    2014-09-01

    Full Text Available Because of the strong adsorption capacity of meta-anthracite, the gas content of a meta-anthracite seam can be as high as 10 m3/t, with a gas pressure lower than 0.74 MPa; this results in low efficiency of gas extraction in underground mines. To enhance low-pressure methane extraction efficiency in meta-anthracite seams, a new approach – methane displacement by gas injection – has been developed, investigated in the laboratory, and then applied in the field in the Fuyanshan coal mine. Laboratory results show that when the gas content of the coal seam is high, methane displacement by nitrogen injection is difficult. The volume of methane displaced is directly related to the pressure difference between the coal seam gas pressure and the injection gas pressure. If the total gas pressure is greater than 0.5 MPa after nitrogen injection, then the methane displacement efficiency will be greatly enhanced. It is also confirmed that the displacement efficiency can be improved by injecting inert gas to change the partial pressure of the methane. Field test data show quite good methane displacement efficiency.

  7. Research on the Reasonable Spacing of Holes in Gas Drainage along Coal Seams in Consideration of the Superimposed Effect of Drainage

    Directory of Open Access Journals (Sweden)

    Li Bo

    2016-02-01

    Full Text Available o determine the reasonable spacing of holes for gas drainage, an experimental study was conducted on the effective influence radius of drilling hole through the pressure drop method based on the actual condition of coal seams. The coal seam that contains gas is regarded as elastic-plastic dual media. The governing equation of gas transport is established by analyzing the different flow forms of gas in the pore and fissure systems as well as by considering the mass exchange capacity in the pore-fissure system. The equation is embedded into COMSOL Multiphysics (COMSOL software to simulate the gas drainage effect further by drilling along a coal seam under a 3-D space. Upon confirming the effective radius and drainage influence radius of a single pore, the holes for gas drainage can be reasonably spaced along the coal seam by analyzing the change features of coal permeability around the borehole and the functional mechanism of the superimposed effect of drainage, namely, 2r≤L≤R. The study results can reliably guide practical gas drainage theoretically and can also effectively lower the cost of gas drainage as well as ensure the safe production in mines.

  8. Production of gas from coal seams in the Upper Silesian Coal Basin in Poland in the post-injection period of an ECBM pilot site

    NARCIS (Netherlands)

    Bergen, F. van; Krzystolik, P.; Wageningen, N. van; Pagnier, H.; Jura, B.; Skiba, J.; Winthaegen, P.; Kobiela, Z.

    2009-01-01

    A pilot site for CO2 storage in coal seams was set-up in the Upper Silesian Coal Basin in Poland in the scope of the RECOPOL project, funded by the European Commission. About 760 tons CO2 were injected into the reservoir from August 2004 to June 2005. Breakthrough of the injected CO2 was established

  9. Study on‘‘fracturing-sealing’’ integration technology based on high-energy gas fracturing in single seam with high gas and low air permeability

    Institute of Scientific and Technical Information of China (English)

    Zhang Chao; Lin Baiquan; Zhou Yan; Zhai Cheng; Zhu Chuanjie

    2013-01-01

    To improve the gas extraction efficiency of single seam with high gas and low air permeability, we devel-oped the‘fracturing-sealing’ integration technology, and carried out the engineering experiment in the 3305 Tunliu mine. In the experiment, coal seams can achieve the aim of antireflection effect through the following process:First, project main cracks with the high energy pulse jet. Second, break the coal body by delaying the propellant blasting. Next, destroy the dense structure of the hard coal body, and form loose slit rings around the holes. Finally, seal the boreholes with the‘strong-weak-strong’ pressurized sealing technology. The results are as follows:The average concentration of gas extraction increases from 8.3%to 39.5%. The average discharge of gas extraction increases from 0.02 to 0.10 m3/min. The tunneling speeds up from 49.5 to 130 m/month. And the permeability of coal seams improves nearly tenfold. Under the same conditions, the technology is much more efficient in depressurization and antireflection than common methods. In other words, it will provide a more effective way for the gas extraction of single seam with high gas and low air permeability.

  10. Pseudonoise code tracking loop

    Science.gov (United States)

    Laflame, D. T. (Inventor)

    1980-01-01

    A delay-locked loop is presented for tracking a pseudonoise (PN) reference code in an incoming communication signal. The loop is less sensitive to gain imbalances, which can otherwise introduce timing errors in the PN reference code formed by the loop.

  11. Tracking Self into Place

    Science.gov (United States)

    Piersol, Laura

    2010-01-01

    In an effort to figure out what it means to educate "ecologically," I decided to track down some of the stories that I was living, telling and making as an educator. I ended up lost in the house of environmental education, stuck within the rooms of ecological science and political advocacy. Outside on the lawn sat the story of place based…

  12. Energy Tracking Diagrams

    Science.gov (United States)

    Scherr, Rachel E.; Harrer, Benedikt W.; Close, Hunter G.; Daane, Abigail R.; DeWater, Lezlie S.; Robertson, Amy D.; Seeley, Lane; Vokos, Stamatis

    2016-01-01

    Energy is a crosscutting concept in science and features prominently in national science education documents. In the "Next Generation Science Standards," the primary conceptual learning goal is for learners to conserve energy as they "track" the transfers and transformations of energy within, into, or out of the system of…

  13. Tracking Speech Sound Acquisition

    Science.gov (United States)

    Powell, Thomas W.

    2011-01-01

    This article describes a procedure to aid in the clinical appraisal of child speech. The approach, based on the work by Dinnsen, Chin, Elbert, and Powell (1990; Some constraints on functionally disordered phonologies: Phonetic inventories and phonotactics. "Journal of Speech and Hearing Research", 33, 28-37), uses a railway idiom to track gains in…

  14. Fast Passenger Tracks Network

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    China’s fast passenger tracks network consists of four parts:express rail- way with speeds between 300km/h and 350 kin/h,passenger rail lines with speeds between 200 km/h and 250 km/h,intercity high-speed railways that run

  15. Tracking Politics with POWER

    Science.gov (United States)

    Moreira, Silvio; Batista, David S.; Carvalho, Paula; Couto, Francisco M.; Silva, Mario J.

    2013-01-01

    Purpose: POWER is an ontology of political processes and entities. It is designed for tracking politicians, political organizations and elections, both in mainstream and social media. The aim of this paper is to propose a data model to describe political agents and their relations over time. Design/methodology/approach: The authors propose a data…

  16. Apple Shuns Tracking Tool

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Apple Inc. is advising software de- velopers to stop using a feature in software for its iPhones and iPads .that has been linked to privacyconcerns, a move that would also take away a widely used tool for tracking users and their behavior. Developers who write programs for Apple's lOS operating system have been using a unique.

  17. GPS Metric Tracking Unit

    Science.gov (United States)

    2008-01-01

    As Global Positioning Satellite (GPS) applications become more prevalent for land- and air-based vehicles, GPS applications for space vehicles will also increase. The Applied Technology Directorate of Kennedy Space Center (KSC) has developed a lightweight, low-cost GPS Metric Tracking Unit (GMTU), the first of two steps in developing a lightweight, low-cost Space-Based Tracking and Command Subsystem (STACS) designed to meet Range Safety's link margin and latency requirements for vehicle command and telemetry data. The goals of STACS are to improve Range Safety operations and expand tracking capabilities for space vehicles. STACS will track the vehicle, receive commands, and send telemetry data through the space-based asset, which will dramatically reduce dependence on ground-based assets. The other step was the Low-Cost Tracking and Data Relay Satellite System (TDRSS) Transceiver (LCT2), developed by the Wallops Flight Facility (WFF), which allows the vehicle to communicate with a geosynchronous relay satellite. Although the GMTU and LCT2 were independently implemented and tested, the design collaboration of KSC and WFF engineers allowed GMTU and LCT2 to be integrated into one enclosure, leading to the final STACS. In operation, GMTU needs only a radio frequency (RF) input from a GPS antenna and outputs position and velocity data to the vehicle through a serial or pulse code modulation (PCM) interface. GMTU includes one commercial GPS receiver board and a custom board, the Command and Telemetry Processor (CTP) developed by KSC. The CTP design is based on a field-programmable gate array (FPGA) with embedded processors to support GPS functions.

  18. 弹药引信封口机滚轮沟槽曲线的分析及优化%Analysis and Optimization of the First Operation Seaming Curve of Ammunition Fuze with Sealing Machine

    Institute of Scientific and Technical Information of China (English)

    孙莎莎; 赵美宁; 王玉林; 王妮

    2011-01-01

    阐述了弹药引信包装封口机的卷封机构及二重卷边过程,论述了金属罐二重卷封一道滚轮沟槽曲线的设计,通过有限元仿真模拟卷封过程,分析了滚轮沟槽曲线各段在二重卷边中所起的作用,并对4种曲线进行受力分析比较,确定卷封性能最优良的曲线,并对其进行优化,得到一条理想的曲线.%lllustrated ammunition fuze with sealing mechanism and double seam process, expounded double seaming of cans first operation seaming curve design. By finite element simulation of the double seam process analysis and comparing of the four curves of seaming process, determined the best seaming curve, and optimized it to obtain good seaming curve.

  19. 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

  20. 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.

  1. 棉类裤装缝口缩皱的影响因素%Influencing Factors of Cotton Pants Seam Shrinkage

    Institute of Scientific and Technical Information of China (English)

    屠晔

    2011-01-01

    This study aims at analyzing the rule of seam shrinkage through experiment case study on cotton pants. Pants made of 11 kinds of cotton fabrics manufactured in different sewing conditions and washing ways, are tested for seam shrinkage on outseam, front rise, back rise and waistband, the measurements of the four parts are important for pants. The study gets three influencing factors of seam shrinkage through Factor Analysis at first, they are fabric density, fabric structure, washing ways and sewing condition. Then mathematical statistics is used and the result shows that the factors affecting the seam shrinkage of pant, fabric density is in the first place, the interaction of fabric density and sewing condition ranks the second. In addition, grain direction also influences the seam pucker.%以棉类裤装为研究案例,通过实验,分析缝缩产生的规律.选用10种厚薄不同的棉质面料用不同的缝制工艺做成裤装,并选择不同的水洗工艺进行后处理,测量样裤主要部位的尺寸缝缩量.测量部位主要考虑对裤装造型产生重要作用的四个部位:侧缝、前浪、后浪、腰头.通过主成分分析和数理统计显示:面密度、面料组织结构、洗水处理和缝制条件是四个影响缝缩的主要因素;其中影响最大的因素为面密度,其次为面密度和缝纫条件的交互作用,另外,丝缕方向也有一定影响.

  2. 基于TMS320DM365的高速网络摄像机的设计%Design of high speed IP camera based on TMS320DM365

    Institute of Scientific and Technical Information of China (English)

    秦臻; 曹剑中

    2011-01-01

    Trditional network canmeras have many problems, such as complex configration, low effciency and high cost The design of high speed IP camera based on TMS320DM365 and embedded linux. Through the research of hardware and software desing of high speed IP camrea based on TMS320DM365. the video data is collected by writing driver program followingng V4L2standard from a front camera The video is compressed based on H.264 standard, then the compressed video data can be transported in 100M network follow the protocols of RTP and RTCP.%针对传统网络摄像杌的结构复杂、效率低下以及昂贵的成本等问题,提出了基于嵌入式Linux和达芬奇技术TMS320DM365处理器平台的高速网络摄像机系统的设计方案.通过对基于TMS320DM365的高速网络摄像机进行硬件软件设计,从前端摄像头采集视频数据,通过Linux操作系统的V4L2编写驱动程序从而实现视频的采集.经H.264压缩算法对视频数据进行处理,最后通过RTP以及RTCP编码后经由100 M网口完成网络传输.

  3. Key technologies and equipment for a fully mechanized top-coal caving operation with a large mining height at ultra-thick coal seams

    Institute of Scientific and Technical Information of China (English)

    Jinhua Wang; Bin Yu; Hongpu Kang; Guofa Wang; Debing Mao; Yuntao Liang; Pengfei Jiang

    2015-01-01

    Thick and ultra-thick coal seams are main coal seams for high production rate and high efficiency in Chinese coal mines, which accounts for 44%of the total minable coal reserve. A fully mechanized top-coal caving mining method is a main underground coal extraction method for ultra-thick coal seams. The coal extraction technologies for coal seams less than 14 m thick were extensively used in China. However, for coal seams with thickness greater than 14 m, there have been no reported cases in the world for underground mechanical extraction with safe performance, high efficiency and high coal recovery ratio. To deal with this case, China Coal Technology&Engineering Group, Datong Coal Mine Group, and other 15 organizations in China launched a fundamental and big project to develop coal mining technologies and equipment for coal seams with thicknesses greater than 14 m. After the completion of the project, a coal extraction method was developed for top-coal caving with a large mining height, as well as a ground control theory for ultra-thick coal seams. In addition, the mining technology for top-coal caving with a large mining height, the ground support technology for roadway in coal seams with a large cross-section, and the prevention and control technology for gas and fire hazards were developed and applied. Furthermore, a hydraulic support with a mining height of 5.2 m, a shearer with high reliability, and auxiliary equipment were developed and manufactured. Practical implication on the technologies and equipment developed was successfully completed at the No. 8105 coal face in the Tashan coal mine, Datong, China. The major achievements of the project are summarized as follows:1. A top-coal caving method for ultra-thick coal seams is proposed with a cutting height of 5 m and a top-coal caving height of 15 m. A structural mechanical model of overlying strata called cantilever beam-articulated rock beam is established. Based on the model, the load resistance of the

  4. Characteristics and stability of slope movement response to underground mining of shallow coal seams away from gullies

    Institute of Scientific and Technical Information of China (English)

    Zhang Dongsheng; Fan Gangwei; Wang Xufeng

    2012-01-01

    Underground pressure is abnormal during mining of shallow coal seams under gullies.We studied gully slope movements,subject to underground mining,with physical simulation and theoretical analysis.The rules disclose that the slope rock slides horizontally in response to mining in the direction of gullies and rotates reversely with the appearance of a polygon block in mining away from gullies.We focused our attention on the case of mining away from a gully.We built a mechanical model in terms of a polygon block hinged structure and investigated the variation of horizontal thrust and shear force at the hinged point in relation to the rotation angle under different fragmentations.The Sliding-Rotation instability conditions of the polygon block hinged structure are presented based on the analyses of sliding instability and rotation instability.These results can serve as a theoretical guide for roof control during mining away from gullies in a coalfield defined by gullies.

  5. Enhanced recovery of unconventional gas. Volume II. The program. [Tight gas basins; Devonian shale; coal seams; geopressured aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Kuuskraa, V.A.; Brashear, J.P.; Doscher, T.M.; Elkins, L.E.

    1978-10-01

    This study was conducted to assist public decision-makers in selecting among many choices to obtain new gas supplies by addressing 2 questions: 1) how severe is the need for additional future supplies of natural gas, and what is the economic potential of providing part of future supply through enhanced recovery from unconventional natural gas resources. The study also serves to assist the DOE in designing a cost-effective R and D program to stimulate industry to recover this unconventional gas and to produce it sooner. Tight gas basins, Devonian shale, methane from coal seams, and methane from geopressured aquifers are considered. It is concluded that unconventional sources, already providing about 1 Tcf per year, could provide from 3 to 4 Tcf in 1985 and from 6 to 8 Tcf in 1990 (at $1.75 and $3.00 per Mcf, respectively). However, even with these additions to supply, gas supply is projected to remain below 1977 usage levels. (DLC)

  6. Suitable layout of gate roads related to slice mining in an ultra-thick unstable coal seam

    Institute of Scientific and Technical Information of China (English)

    Fan Gangwei; Zhang Dongsheng; Zhou Lei

    2011-01-01

    We determined a suitable gate road layout in slice mining in an ultra-thick unstable coal seam,using theoretical analysis and numerical calculations.Based on plasticity theory in terms of limiting equilibrium,the width of chain pillar in the upper slice was calculated to be 18 m.The stress distribution in the chain pillar after the upper slice was mined out was described with numerical simulation.The extent of the effect of stress on the upper chain pillar on the lower solid coal was obtained on the basis of an elastic solution of a distributed force loaded on a half-plane.Three layout designs for lower gate roads were proposed and a stability factor was introduced to analyze the stability of the lower pillar with numerical calculation.Gate road translation was determined as the most suitable layout method,which maximizes the extraction rate on the basis of the pillar stability.

  7. Early Eocene carbon isotope excursions: Evidence from the terrestrial coal seam in the Fushun Basin, Northeast China

    Science.gov (United States)

    Chen, Zuoling; Ding, Zhongli; Tang, Zihua; Wang, Xu; Yang, Shiling

    2014-05-01

    A series of transient global warming events between 56 and 50 Ma are characterized by a pronounced negative carbon isotope excursion (CIE). However, the documents of these hyperthermals, such as Eocene Thermal Maximum 2 and H2 events, have come chiefly from marine sediments, and their expression in terrestrial organic carbon is still poorly constrained. Here we yield a high-resolution carbon isotope record of terrestrial organic material from the Fushun Basin, which displays four prominent CIEs with magnitudes larger than 2.5‰. Based on age constraint and comparisons with deep-sea records, our data provide the first evidence of the four hyperthermals in coal seams and suggest a global significance of these events. Moreover, the difference of CIE magnitudes between marine and terrestrial records shows a significant linear correlation with the marine carbonate CIE, implying that these events are likely attributable to recurring injections of 13C-depleted carbon from submarine methane hydrates and/or permafrost.

  8. Water inrush evaluation of coal seam floor by integrating the water inrush coefficient and the information of water abundance

    Institute of Scientific and Technical Information of China (English)

    Shi Longqing; Qiu Mei; Wei Wenxue; Xu Dongjing; Han Jin

    2014-01-01

    The method of singular coefficient of water inrush to achieve safety mining has limitation and one sidedness. Aiming at the problem above, large amounts of data about water inrush were collected. Then the data, including the maximum water inrush, water inrush coefficient and water abundance in aquifers of working face, were processed by the statistical analysis. The analysis results indicate that both water inrush coefficient and water abundance in aquifers should be taken into consideration when evaluating the danger of water inrush from coal seam floor. The prediction model of safe-mining evaluation grade was built by using the support vector machine, and the result shows that this model has high classifica-tion accuracy. A feasible classification system of water-inrush safety evaluation can be got by using the data visualization method which makes the implicit support vector machine models explicit.

  9. Quality Assurance Training Tracking (QATTS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — This is metadata documentation for the Quality Assurance Training Tracking System (QATTS) which tracks Quality Assurace training given by R7 QA staff to in-house...

  10. Medullosalean fusain trunk from the roof rocks of a coal seam: Insight from FTIR and NMR (Pennsylvanian Sydney Coalfield, Canada)

    Energy Technology Data Exchange (ETDEWEB)

    Zodrow, Erwin L. [Palaeobotanical Laboratory, Cape Breton University, Sydney, Nova Scotia (Canada); Mastalerz, Maria [Indiana Geological Survey, Indiana University, 611 North Walnut Grove, Bloomington, IN 47405-2208 (United States); Werner-Zwanziger, Ulrike [Department of Chemistry, Dalhousie University, Halifax, Nova Scotia (Canada); D' Angelo, Jose A. [Instituto Argentino de Nivologia, Glaciologia y Ciencias Ambientales (IANIGLA), CCT-CONICET-Mendoza, Avda. Ruiz Leal s/n Parque Gral. San Martin (5500) Mendoza (Argentina); Area de Quimica, Instituto de Ciencias Basicas, Universidad Nacional de Cuyo, Centro Universitario - M5502JMA - Mendoza (Argentina)

    2010-05-01

    Reported for the first time from the Sydney Coalfield, Canada, is a fragmentary fusain (R{sub o} = 2.51%) specimen, 41 cm long, of a medullosalean trunk or massive petiole that originated from the roof rocks of the banded bituminous Hub Seam (R{sub o} {proportional_to} 0.65%). Megascopic characteristics of the flat-preserved specimen include an irregular-cracked fusain surface with secretinite-rodlet structures and sclerenchymatous strands some of which still embedded in the shaly matrix, and locally preserved vitrain (R{sub o} 0.69%). Co-occurrence with a compression flora composed virtually of only the seed-fern taxon Macroneuropteris scheuchzeri (Hoffmann) is noted. The goal of this study is to provide a framework for the phytophysicochemical taphonomic history which includes the perspective on vitrinite/fusinite relationship, formation of fusinite, and on the significance the only fusinized identifiable plant-fossil specimen in the Sydney Coalfield. We use state-of-the-art solid-state FTIR, {sup 13}C, {sup 1}H NMR CP/MAS techniques, and standard reflected-light microscopy and SEM methods as investigative tools. Results indicate that the fusinite is characterized by long and narrow xylem fibers, without fungal signals, and cell structures infilled with pyrite and carbonate. FTIR spectra of the fusinite and secretinite are similar particularly in respect to high absorbance of aromatic and low absorbance of aliphatic compounds, and absorbance of Si-O functionalities relating to kaolinite. {sup 13}C NMR experiments with direct carbon excitation quantify the aromatic to aliphatic ratio as being 20 {+-} 3:1. As part of the taphonomic history, the evidence favors a hot, > 400 C, directional surface-fueled flame palaeofire of local extent that charred trunks of growing arborescent seed ferns on only one side, and that these trunks were transported to comprise part of the roof rocks of the Hub Seam. (author)

  11. Thermal Tracking of Sports Players

    DEFF Research Database (Denmark)

    Gade, Rikke; Moeslund, Thomas B.

    2014-01-01

    We present here a real-time tracking algorithm for thermal video from a sports game. Robust detection of people includes routines for handling occlusions and noise before tracking each detected person with a Kalman filter. This online tracking algorithm is compared with a state-of-the-art offline...... approach. Furthermore, the combined detection and tracking algorithm runs in real time at 33 fps, even with large image sizes of 1920 × 480 pixels....

  12. Track Initiation for Electro-Optical Tracking of Space Objects

    Science.gov (United States)

    Xu, Z. W.; Wang, X.

    2016-03-01

    Aimed at the track initiation for the electro-optical tracking of space objects, and based on modified Hough transformation, a track initiation algorithm without prior information is proposed to realize the fully robotic identification and tracking of moving objects. The method is valid for the tracking of multi-target as well as with a non-continuous sequence. Simulation shows that the method is effective and applicable for operational usage, and is especially good for the search and discovery of new objects.

  13. Tracking change over time

    Science.gov (United States)

    ,

    2011-01-01

    Landsat satellites capture images of Earth from space-and have since 1972! These images provide a long-term record of natural and human-induced changes on the global landscape. Comparing images from multiple years reveals slow and subtle changes as well as rapid and devastating ones. Landsat images are available over the Internet at no charge. Using the free software MultiSpec, students can track changes to the landscape over time-just like remote sensing scientists do! The objective of the Tracking Change Over Time lesson plan is to get students excited about studying the changing Earth. Intended for students in grades 5-8, the lesson plan is flexible and may be used as a student self-guided tutorial or as a teacher-led class lesson. Enhance students' learning of geography, map reading, earth science, and problem solving by seeing landscape changes from space.

  14. Structural Sparse Tracking

    KAUST Repository

    Zhang, Tianzhu

    2015-06-01

    Sparse representation has been applied to visual tracking by finding the best target candidate with minimal reconstruction error by use of target templates. However, most sparse representation based trackers only consider holistic or local representations and do not make full use of the intrinsic structure among and inside target candidates, thereby making the representation less effective when similar objects appear or under occlusion. In this paper, we propose a novel Structural Sparse Tracking (SST) algorithm, which not only exploits the intrinsic relationship among target candidates and their local patches to learn their sparse representations jointly, but also preserves the spatial layout structure among the local patches inside each target candidate. We show that our SST algorithm accommodates most existing sparse trackers with the respective merits. Both qualitative and quantitative evaluations on challenging benchmark image sequences demonstrate that the proposed SST algorithm performs favorably against several state-of-the-art methods.

  15. The track nanotechnology

    Energy Technology Data Exchange (ETDEWEB)

    Waheed, A. [British Institute of Technology and E-Commerce, London E7 9HZ (United Kingdom); Physics Department, University of Reading, Reading RG6 6AF (United Kingdom); Forsyth, D., E-mail: dforsyth@bite.ac.u [British Institute of Technology and E-Commerce, London E7 9HZ (United Kingdom); Watts, A. [Department of Physics, UCL, London Centre of Nanotechnology (LCN), 17-19 Gordon Street, London WC1H OAH (United Kingdom); Saad, A.F. [Physics Department, Faculty of Science, Garyounis University, Benghazi (Libyan Arab Jamahiriya); Mitchell, G.R. [British Institute of Technology and E-Commerce, London E7 9HZ (United Kingdom); Physics Department, University of Reading, Reading RG6 6AF (United Kingdom); Farmer, M. [British Institute of Technology and E-Commerce, London E7 9HZ (United Kingdom); Harris, P.J.F. [Physics Department, University of Reading, Reading RG6 6AF (United Kingdom)

    2009-10-15

    The discipline now called Solid State Nuclear Track Detection (SSNTD) dates back to 1958 and has its roots in the United Kingdom. Its strength stems chiefly from factors such as its simplicity, small geometry, permanent maintenance of the nuclear record and other diversified applications. A very important field with exciting applications reported recently in conjuction with the nuclear track technique is nanotechnology, which has applications in biology, chemistry, industry, medicare and health, information technology, biotechnology, and metallurgical and chemical technologies. Nanotechnology requires material design followed by the study of the quantum effects for final produced applications in sensors, medical diagnosis, information technology to name a few. We, in this article, present a review of past and present applications of SSNTD suggesting ways to apply the technique in nanotechnology, with special reference to development of nanostructure for applications utilising nanowires, nanofilters and sensors.

  16. Issues in Target Tracking

    Science.gov (United States)

    2010-05-01

    the CUSUM (Page) test yields the quickest detection of a change of distribution for the case of i.i.d. observations [3]. In fact, in a (highly...11. Autocorrelation of the CUSUM increments, sn, under H1 (target present). Issues in Target Tracking RTO-EN-SET-157(2010...restrictive condition that the increments of the cumulative sum, sn, be i.i.d. [3], [22]. Fig. 11 plots the autocorrelation of the CUSUM increments as a

  17. Registration and Tracking Report

    Science.gov (United States)

    2006-02-01

    the layer ownership probabilities are maximized. Isard and MacCormick [71] propose joint modelling of the background and foreground regions for...gradients. Isard et. al [71] define the object state in terms of spline shape parameters and affine motion parameters. The measurements consist of image...Conference on Automatic Face and Gesture Recognition May 17 - 19, 2004 Seoul, Korea 86 [7] Michael Isard , Andrew Blake, ”Condensation Tracking By

  18. BESⅢ track fitting algorithm

    Institute of Scientific and Technical Information of China (English)

    WANG Ji-Ke; MAO Ze-Pu; BIAN Jian-Ming; CAO Guo-Fu; CAO Xue-Xiang; CHEN Shen-Jian; DENG Zi-Yan; FU Cheng-Dong; GAO Yuan-Ning; HE Kang-Lin; HE Miao; HUA Chun-Fei; HUANG Bin; HUANG Xing-Tao; JI Xiao-Sin; LI Fei; LI Hai-Bo; LI Wei-Dong; LIANG Yu-Tie; LIU Chun-Xiu; LIU Huai-Min; LIU Suo; LIU Ying-Jie; MA Qiu-Mei; MA Xiang; MAO Ya-Jun; MO Xiao-Hu; PAN Ming-Hua; PANG Cai-Ying; PING Rong-Gang; QIN Ya-Hong; QIU Jin-Fa; SUN Sheng-Sen; SUN Yong-Zhao; WANG Liang-Liang; WEN Shuo-Pin; WU Ling-Hui; XIE Yu-Guang; XU Min; YAN Liang; YOU Zheng-Yun; YUAN Chang-Zheng; YUAN Ye; ZHANG Bing-Yun; ZHANG Chang-Chun; ZHANG Jian-Yong; ZHANG Xue-Yao; ZHANG Yao; ZHENG Yang-Heng; ZHU Ke-Jun; ZHU Yong-Sheng; ZHU Zhi-Li; ZOU Jia-Heng

    2009-01-01

    A track fitting algorithm based on the Kalman filter method has been developed for BESⅢ of BEPCⅡ.The effects of multiple scattering and energy loss when the charged particles go through the detector,non-uniformity of magnetic field (NUMF) and wire sag, etc., have been carefully handled.This algorithm works well and the performance satisfies the physical requirements tested by the simulation data.

  19. Energy Tracking Diagrams

    Science.gov (United States)

    Scherr, Rachel E.; Harrer, Benedikt W.; Close, Hunter G.; Daane, Abigail R.; DeWater, Lezlie S.; Robertson, Amy D.; Seeley, Lane; Vokos, Stamatis

    2016-02-01

    Energy is a crosscutting concept in science and features prominently in national science education documents. In the Next Generation Science Standards, the primary conceptual learning goal is for learners to conserve energy as they track the transfers and transformations of energy within, into, or out of the system of interest in complex physical processes. As part of tracking energy transfers among objects, learners should (i) distinguish energy from matter, including recognizing that energy flow does not uniformly align with the movement of matter, and should (ii) identify specific mechanisms by which energy is transferred among objects, such as mechanical work and thermal conduction. As part of tracking energy transformations within objects, learners should (iii) associate specific forms with specific models and indicators (e.g., kinetic energy with speed and/or coordinated motion of molecules, thermal energy with random molecular motion and/or temperature) and (iv) identify specific mechanisms by which energy is converted from one form to another, such as incandescence and metabolism. Eventually, we may hope for learners to be able to optimize systems to maximize some energy transfers and transformations and minimize others, subject to constraints based in both imputed mechanism (e.g., objects must have motion energy in order for gravitational energy to change) and the second law of thermodynamics (e.g., heating is irreversible). We hypothesize that a subsequent goal of energy learning—innovating to meet socially relevant needs—depends crucially on the extent to which these goals have been met.

  20. The Outburst Risk as a Function of the Methane Capacity and Firmness of a Coal Seam

    Science.gov (United States)

    Wierzbicki, Mirosław; Skoczylas, Norbert

    2014-12-01

    In most coal basins that are currently being exploited, gas and rock outbursts pose a considerable safety threat. The risk of their occurrence is frequently assessed by means of a parameter known as the methane capacity of coal. In a lot of countries, the evaluation of the mechanical properties of coal is conducted by means of another parameter: the firmness of coal. Due to the laboratory investigations and in situ observations carried out by the authors of this paper, it was possible to determine a function space in which the outburst risk can be described as a function of the methane capacity and firmness of a coal seam. This, in turn, made it possible to link the "gas factor" to the "mechanical factor", and thus provide a more comprehensive risk analysis. Wyrzuty gazów i skał stanowią duże zagrożenie w większości obecnie eksploatowanych zagłębi węglowych. Bardzo często wykorzystywanym parametrem oceny stanu zagrożenia wyrzutowego jest zawartość metanu w węglu. W wielu krajach do oceny mechanicznych parametrów węgla wykorzystuje się zwięzłość. Autorzy przeprowadzili badania laboratoryjne polegające na prowokacjach wyrzutów w skali laboratoryjnej. Jako materiał badawczy wykorzystane zostały brykiety węglowe. W trakcie badań wstępnych ustalona została zależność pomiędzy porowatością brykietów, a ich zwięzłością f oraz pomiędzy ciśnieniem nasycania metanem, a wskaźnikiem intensywności desorpcji dP. Pozwoliło to na przygotowywanie eksperymentów o kontrolowanych parametrach gazowych (wskaźnik intensywności desorpcji) oraz wytrzymałościowych (zwięzłość). Opracowana została metoda kontrolowania intensywności prowokacji wyrzutu poprzez określenie tempa spadku ciśnienia gazu przed czołem brykietu. Dzięki temu dla siatki parametrów f-dP możliwe było poszukiwanie minimalnej, skutecznej intensywności prowokacji wyrzutu. Znormalizowana wartość stałej czasowej spadku ciśnienia przed czołem brykietu powoduj

  1. Fuzzy Logic Particle Tracking

    Science.gov (United States)

    2005-01-01

    A new all-electronic Particle Image Velocimetry technique that can efficiently map high speed gas flows has been developed in-house at the NASA Lewis Research Center. Particle Image Velocimetry is an optical technique for measuring the instantaneous two component velocity field across a planar region of a seeded flow field. A pulsed laser light sheet is used to illuminate the seed particles entrained in the flow field at two instances in time. One or more charged coupled device (CCD) cameras can be used to record the instantaneous positions of particles. Using the time between light sheet pulses and determining either the individual particle displacements or the average displacement of particles over a small subregion of the recorded image enables the calculation of the fluid velocity. Fuzzy logic minimizes the required operator intervention in identifying particles and computing velocity. Using two cameras that have the same view of the illumination plane yields two single exposure image frames. Two competing techniques that yield unambiguous velocity vector direction information have been widely used for reducing the single-exposure, multiple image frame data: (1) cross-correlation and (2) particle tracking. Correlation techniques yield averaged velocity estimates over subregions of the flow, whereas particle tracking techniques give individual particle velocity estimates. For the correlation technique, the correlation peak corresponding to the average displacement of particles across the subregion must be identified. Noise on the images and particle dropout result in misidentification of the true correlation peak. The subsequent velocity vector maps contain spurious vectors where the displacement peaks have been improperly identified. Typically these spurious vectors are replaced by a weighted average of the neighboring vectors, thereby decreasing the independence of the measurements. In this work, fuzzy logic techniques are used to determine the true

  2. Thermal Tracking of Sports Players

    Directory of Open Access Journals (Sweden)

    Rikke Gade

    2014-07-01

    Full Text Available We present here a real-time tracking algorithm for thermal video from a sports game. Robust detection of people includes routines for handling occlusions and noise before tracking each detected person with a Kalman filter. This online tracking algorithm is compared with a state-of-the-art offline multi-target tracking algorithm. Experiments are performed on a manually annotated 2-minutes video sequence of a real soccer game. The Kalman filter shows a very promising result on this rather challenging sequence with a tracking accuracy above 70% and is superior compared with the offline tracking approach. Furthermore, the combined detection and tracking algorithm runs in real time at 33 fps, even with large image sizes of 1920 × 480 pixels.

  3. Track Processing Approach for Bearing-Only Target Tracking

    Directory of Open Access Journals (Sweden)

    Hui Chen

    2009-10-01

    Full Text Available This paper mainly studies angle-measurement based track processing approach to overcome the existing problems in the applications of traditional approaches for bearing-only target locating and tracking system. First, this paper gives suited data association algorithms including track initiation and point-track association. Moreover, a new tracking filtering association gate method is presented through analysis of the target motion characteristics in polar coordinates for improving bearing-only measurement confirming efficiency of real target and limiting false track overextension with the dense clutter. Then, by analyzing the feasibility of using multi-model technology, the IMM is adopt as filtering algorithm to solve existing problem in bearing-only tracking for complicated target motion in two dimensional angle plane. As the results, the two dimensional bearing-only tracking accuracy of real target is improved and false tracking is greatly limited. Moreover, computation cost of IMM is analyzed in view of the real-time demand of bearing-only tracking. Finally, this paper gives some concrete summary of multi-model choosing principle. The application of the proposed approach in a simulation system proves its effectiveness and practicability.

  4. Flame front. Evaluation of camera based flame front control in grate furnaces regarding operation and emissions; Flamfront. Utvaerdering av drift och miljoe med hjaelp av kamerabaserad flamfrontsstyrning i rosterpannor

    Energy Technology Data Exchange (ETDEWEB)

    Bubholz, Monika; Myringer, Aase; Nordgren, Daniel

    2007-09-15

    This project aims at showing the usability of camera based flame front control in grate furnaces regarding increased possibilities to use fuels with fluctuating moisture/quality with stable/improved levels of emissions and ash quality. A furnace camera and the human eye make the detection of the flame front movements. Further, the flame front was fixed due to an increase/decrease of the speed of the fuel feeding system. The result is to be generalised for all grate furnaces with a movable grate. During the spring 2007 two weeks of tests were executed at E.ON Heat's plant Hammargaarden at Kungsbacka. Dry and wet fuel pulses of approximately 10 m3, with moisture content of approximately 40 and 60 weights percent, were induced to the grate. At the same time, tries to ward off the flame front movement were carried through. The most important result of the tests were the following: The results is based on a relatively small number of tests and it should be considered to be more of an indication of the usefulness of the control strategy that has been investigated rather than definitive results. The results indicate that the economical and environmental benefits from using a system involving only visual detecting followed by warding off a movement of the flame front mechanically are small, and most likely hard to pay off. It is important to start to ward off the flame front as soon as it seems to be moving. In this way the flame front can be kept stable and often improved emission levels follow. A slight tendency to lower CO-emissions was observed when dry fuel pulses were warded off. When no warding off of dry fuel pulses took place, the combustion took place close to the lower part of the fuel-feeding wall. This was prevented when the dry fuel pulses were warded off. The content of unburnt carbon in ash at wet fuel pulses was lower when warding off in comparison with cases where no warding off took place. An important element of future work is, apart from using a

  5. 49 CFR 213.63 - Track surface.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Track surface. 213.63 Section 213.63..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Geometry § 213.63 Track surface. Each owner of the track to which this part applies shall maintain the surface of its track within the limits prescribed...

  6. Lower Extremity Joint Angle Tracking with Wireless Ultrasonic Sensors during a Squat Exercise.

    Science.gov (United States)

    Qi, Yongbin; Soh, Cheong Boon; Gunawan, Erry; Low, Kay-Soon; Thomas, Rijil

    2015-04-23

    This paper presents an unrestrained measurement system based on a wearable wireless ultrasonic sensor network to track the lower extremity joint and trunk kinematics during a squat exercise with only one ultrasonic sensor attached to the trunk. The system consists of an ultrasound transmitter (mobile) and multiple receivers (anchors) whose positions are known. The proposed system measures the horizontal and vertical displacement, together with known joint constraints, to estimate joint flexion/extension angles using an inverse kinematic model based on the damped least-squares technique. The performance of the proposed ultrasonic measurement system was validated against a camera-based tracking system on eight healthy subjects performing a planar squat exercise. Joint angles estimated from the ultrasonic system showed a root mean square error (RMSE) of 2.85° ± 0.57° with the reference system. Statistical analysis indicated great agreements between these two systems with a Pearson's correlation coefficient (PCC) value larger than 0.99 for all joint angles' estimation. These results show that the proposed ultrasonic measurement system is useful for applications, such as rehabilitation and sports.

  7. Solar Tracking System

    OpenAIRE

    Nguyen, Nam

    2016-01-01

    The goal of this thesis was to develop a laboratory prototype of a solar tracking system, which is able to enhance the performance of the photovoltaic modules in a solar energy system. The operating principle of the device is to keep the photovoltaic modules constantly aligned with the sunbeams, which maximises the exposure of solar panel to the Sun’s radiation. As a result, more output power can be produced by the solar panel. The work of the project included hardware design and implemen...

  8. State of the drilling technology in the conventional tunelling in the target seam Zollverein 6 at the mine Auguste Victoria; Stand der Bohrtechnik im konventionellen Streckenvortrieb im Floezhorizont Zollverein 6 auf dem Bergwerk Auguste Victoria

    Energy Technology Data Exchange (ETDEWEB)

    Rossbach, Stefan [RAG Deutsche Steinkohle, Herne (Germany). Bergwerk Auguste Victoria; Andrzejewski, Michael [RAG Deutsche Steinkohle, Herne (Germany). Servicebereich Technik und Logistik; Gastberg, Ingolf [DMT GmbH und Co. KG, Essen (Germany). Wettertechnik

    2013-06-15

    The future mining activities and activities of advance at the mine Auguste Victoria mainly concentrate in the level of the target seam Zollverein 6. The achievement of a layer depth of nearly 1,400 m in connection with difficult geological conditions imposed particular demands on the planning, technology, organization and security in mining, so that appropriate adjustments were required in mining technology. The contribution under consideration reports on the process characteristics typical for conventional tunneling in the target seam Zollverein 6.

  9. 急倾斜薄煤层采煤方法发展趋势%On development tendency for coal mining methods of inclined thin seams

    Institute of Scientific and Technical Information of China (English)

    迟学海; 孟鑫

    2016-01-01

    The PaPer introduces the develoPment features of the coal mining methods in the inclined thin seams based on the blasting mining tech-nology,exPlores the develoPment of the hydroPower coal mining and mechanized coal mining,and forecasts the develoPment of the coal mining methods of the inclined thin seams,so as to enhance the oPtimization of the coal mining craft.%介绍了基于炮采工艺的急倾斜薄煤层采煤方法的发展特点,并探讨了水力采煤与机械化采煤的发展现状,预测了急倾斜薄煤层采煤方法的发展趋势,有利于促进采煤工艺的不断优化改进。

  10. 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.

  11. Study on fasART neuro-fuzzy networks for distinguishing the difficulty degree of top coal caving in steep seam

    Institute of Scientific and Technical Information of China (English)

    FENG Tao; ZHAO Fu-jun; LIN Jian

    2005-01-01

    Distinguishing the difficulty degree of top coal caving was a precondition of the popularization and application of the roadway sub-level caving in steep seam. Because of complexity and uncertainty of the coal seam, the expression of influence factors was difficulty with exact data. According to the fuzzy and uncertainty of influence factors, triangular fuzzy membership functions were adopted to carry out the factors ambiguity, of which the factors not only have the consistency of semantic meaning, but also dissolve sufficiently expert knowledge. Based on the properties and structures of fasART fuzzy neural networks of fuzzy logic system and practical needs, a simplified fasART model was put forward, stability and reliability of the network were improved, the deficiency of learning sampies and uncertainty of the factors were better treated. The method is of effective and practical value was identified by experiments.

  12. Dust Devil Tracks

    Science.gov (United States)

    Reiss, Dennis; Fenton, Lori; Neakrase, Lynn; Zimmerman, Michael; Statella, Thiago; Whelley, Patrick; Rossi, Angelo Pio; Balme, Matthew

    2016-11-01

    Dust devils that leave dark- or light-toned tracks are common on Mars and they can also be found on the Earth's surface. Dust devil tracks (hereinafter DDTs) are ephemeral surface features with mostly sub-annual lifetimes. Regarding their size, DDT widths can range between ˜1 m and ˜1 km, depending on the diameter of dust devil that created the track, and DDT lengths range from a few tens of meters to several kilometers, limited by the duration and horizontal ground speed of dust devils. DDTs can be classified into three main types based on their morphology and albedo in contrast to their surroundings; all are found on both planets: (a) dark continuous DDTs, (b) dark cycloidal DDTs, and (c) bright DDTs. Dark continuous DDTs are the most common type on Mars. They are characterized by their relatively homogenous and continuous low albedo surface tracks. Based on terrestrial and martian in situ studies, these DDTs most likely form when surficial dust layers are removed to expose larger-grained substrate material (coarse sands of ≥500 μm in diameter). The exposure of larger-grained materials changes the photometric properties of the surface; hence leading to lower albedo tracks because grain size is photometrically inversely proportional to the surface reflectance. However, although not observed so far, compositional differences (i.e., color differences) might also lead to albedo contrasts when dust is removed to expose substrate materials with mineralogical differences. For dark continuous DDTs, albedo drop measurements are around 2.5 % in the wavelength range of 550-850 nm on Mars and around 0.5 % in the wavelength range from 300-1100 nm on Earth. The removal of an equivalent layer thickness around 1 μm is sufficient for the formation of visible dark continuous DDTs on Mars and Earth. The next type of DDTs, dark cycloidal DDTs, are characterized by their low albedo pattern of overlapping scallops. Terrestrial in situ studies imply that they are formed when sand

  13. Hierarchical fringe tracking

    CERN Document Server

    Petrov, Romain G; Boskri, Abdelkarim; Folcher, Jean-Pierre; Lagarde, Stephane; Bresson, Yves; Benkhaldoum, Zouhair; Lazrek, Mohamed; Rakshit, Suvendu

    2014-01-01

    The limiting magnitude is a key issue for optical interferometry. Pairwise fringe trackers based on the integrated optics concepts used for example in GRAVITY seem limited to about K=10.5 with the 8m Unit Telescopes of the VLTI, and there is a general "common sense" statement that the efficiency of fringe tracking, and hence the sensitivity of optical interferometry, must decrease as the number of apertures increases, at least in the near infrared where we are still limited by detector readout noise. Here we present a Hierarchical Fringe Tracking (HFT) concept with sensitivity at least equal to this of a two apertures fringe trackers. HFT is based of the combination of the apertures in pairs, then in pairs of pairs then in pairs of groups. The key HFT module is a device that behaves like a spatial filter for two telescopes (2TSF) and transmits all or most of the flux of a cophased pair in a single mode beam. We give an example of such an achromatic 2TSF, based on very broadband dispersed fringes analyzed by g...

  14. Basic Principles of Seam Design for Pattern Design in Garment Industry%服装工业版型缝份设计的基本原则

    Institute of Scientific and Technical Information of China (English)

    吴正春; 潘力

    2012-01-01

      This article explained the concepts and principles of seam design, emphasizing its importance in pattern design in garment industry.%  本文介绍了服装工业用版型的缝份设计的概念、原则,强调了缝份设计在服装版型设计中的重要性。

  15. Draft Genome Sequence of Cellulosilyticum sp. I15G10I2, a Novel Bacterium Isolated from a Coal Seam Gas Water Treatment Pond

    Science.gov (United States)

    Adelskov, Joseph

    2017-01-01

    ABSTRACT Cellulosilyticum sp. strain I15G10I2 was isolated from a coal seam gas water treatment pond at the Spring Gully water treatment facility, Roma, Queensland, Australia. Analysis of the genome of 4,489,861 bp and G+C content of 35.23% revealed that strain I15G10I2 shared limited similarity to members of the genus Cellulosilyticum, family Lachnospiraceae. PMID:28209824

  16. Differentiation of impregnation by non-impregnation of high volatile coal seams; Differenzierung der Anwendung der Traenkarbeit durch Traenkverzicht in fuer die Traenkung ungeeigneten Floezpartien

    Energy Technology Data Exchange (ETDEWEB)

    Henke, B. [Deutsche Montan Technologie GmbH, Essen (Germany). Gas and Fire Div.

    2004-07-01

    Water infusion into coal seams before winning is a measure as well for dust control as for fire and explosion prevention. The efficiency of water infusion in low volatile coal is much better as in high volatile coal. Highly efficient follow up dust control technologies in plough and shearer faces meanwhile let vanish the effect of water infusion in high volatile coal. So far water infusion no more is necessary in such seams. Underground trials have shown, that the effect of water infusion cannot be recognized any more, if highly efficient follow up dust control techniques are used. In present time water infusion in high volatile coal seams can be dropped, so far the limitations concerning low dust levels, set up by the mining authority, will be matched. By using further developed lab trials for testing coal samples on their behaviour concerning water infusion individual seams or even coal faces can be assessed concerning dropping water infusion. (orig.) [German] Das Traenken der Kohle vor der Gewinnung ist eine Massnahme zur Staubreduzierung sowohl aus der Sicht des Gesundheitsschutzes als auch des Brand- und Explosionsschutzes. Die Effektivitaet des Traenkens ist in hoch inkohlten Floezpartien jedoch hoeher als in niedrig inkohlten Floezpartien. Die hochwirksamen Staubbekaempfungsmassnahmen im Bereich der schneidenden und schaelenden Gewinnung lassen inzwischen den Traenkeffekt in den Hintergrund treten, so dass die Moeglichkeit gegeben ist, auf diese Massnahme in niedrig inkohlten Floezpartien zu verzichten. In Betriebsversuchen konnte nachgewiesen werden, dass die Wirksamkeit der Traenkung nicht mehr nachweisbar ist, wenn optimierte sekundaere Staubbekaempfungstechniken eingesetzt werden. Heute kann in stratigraphisch jungen Floezen bei der Gewinnung auf Traenkbarkeit verzichtet werden, wenn die Einhaltung bergbehoerdlicher Auflagen zur Sicherstellung der niedrigeren Staubbelastung gewaehrleistet ist. Die Weiterentwicklung der vorgeschalteten Laborversuche zur

  17. Fracture mechanics characterisation of the beltline welding seam of the decommissioned WWER-440 reactor pressure vessel of nuclear power plant Greifswald Unit 4

    Energy Technology Data Exchange (ETDEWEB)

    Viehrig, Hans-Werner, E-mail: H.W.Viehrig@hzdr.de [Helmholz Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); Altstadt, Eberhard; Houska, Mario [Helmholz Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); Valo, Matti [VTT Manufacturing Technology, P.O. Box 17042, 02044 VTT (Finland)

    2012-01-15

    The paper presents data measured for trepans sampled from the decommissioned WWER-440 reactor pressure vessel of the NPP Greifswald Unit 4. The main focus of this work is on fracture toughness characterisation according to test standard ASTM E1921. Large variations in the evaluated reference temperature values, T{sub 0}, across the wall of the multilayer beltline welding seam were observed. Generally, the ductile-to-brittle transition temperature shift predicted by the Russian code for the present content of deleterious elements P and Cu and the accumulated neutron fluences lies within the amount of the scatter of the measured T{sub 0} values. Metallographic investigations show that the T{sub 0} values measured with T-S oriented Charpy size SE(B) specimens from different thickness locations of the multilayer welding seams strongly depend on the microstructure at the specimen crack tip, and, consequently, on the initial structure of the multilayer welding seam. The RPV integrity is discussed, taking into account a pressurised thermal shock scenario. - Highlights: Black-Right-Pointing-Pointer The paper presents data of samples from a decommissioned reactor pressure vessel. Black-Right-Pointing-Pointer The main focus is on fracture toughness characterisation of the beltline weld seam. Black-Right-Pointing-Pointer Large variation in the evaluated reference temperatures T{sub 0} was observed. Black-Right-Pointing-Pointer T{sub 0} values strongly depend on the microstructure at the specimen crack tip. Black-Right-Pointing-Pointer RPV integrity is discussed, taking into account a pressurised thermal shock scenario.

  18. Annual Change Detection by ASTER TIR Data and an Estimation of the Annual Coal Loss and CO2 Emission from Coal Seams Spontaneous Combustion

    Directory of Open Access Journals (Sweden)

    Xiaomin Du

    2014-12-01

    Full Text Available Coal fires, including both underground and coal waste pile fires, result in large losses of coal resources and emit considerable amounts of greenhouse gases. To estimate the annual intensity of greenhouse gas emissions and the loss of coal resources, estimating the annual loss from fire-influenced coal seams is a feasible approach. This study assumes that the primary cause of coal volume loss is subsurface coal seam fires. The main calculation process is divided into three modules: (1 Coal fire quantity calculations, which use change detection to determine the areas of the different coal fire stages (increase/growth, maintenance/stability and decrease/shrinkage. During every change detections, the amount of coal influenced by fires for these three stages was calculated by multiplying the coal mining residual rate, combustion efficiency, average thickness and average coal intensity. (2 The life cycle estimate is based on remote sensing long-term coal fires monitoring. The life cycles for the three coal fire stages and the corresponding life cycle proportions were calculated; (3 The diurnal burnt rates for different coal fire stages were calculated using the CO2 emission rates from spontaneous combustion experiments, the coal fire life cycle, life cycle proportions. Then, using the fire-influenced quantity aggregated across the different stages, the diurnal burn rates for the different stages and the time spans between the multi-temporal image pairs used for change detection, we estimated the annual coal loss to be 44.3 × 103 tons. After correction using a CH4 emission factor, the CO2 equivalent emissions resulting from these fires was on the order of 92.7 × 103 tons. We also discovered that the centers of these coal fires migrated from deeper to shallower parts of the coal seams or traveled in the direction of the coal seam strike. This trend also agrees with the cause of the majority coal fires: spontaneous combustion of coalmine goafs.

  19. 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.

  20. 浅埋煤层综采工作面设备选型与配套%Mining machine selection and matching for shallow coal seam

    Institute of Scientific and Technical Information of China (English)

    白如鸿; 王振华; 董康乾; 何鹏程

    2013-01-01

    The shallow coal seam of Shenfu mine area has characteristics of shallow buried depth,thin rock, overlying thick loose sand bed and severe mine pressure reveal, which requires more strict coal mine production safety. Through introduction and analysis of the shallow seam with special geological condition, this paper expounds the selection principle of the main mechanical equipment for shallow coal seam fully-mechanized, the theoretical calculation and related requirement of three machines assortment, then reasonably choose the form,type and technical features of three machines assortment. This paper have a realistic theoretical reference and guidance meaning for the equipment selection and matching work of the north Shaanxi shallow buried coal seam fully mechanized working face.%神府矿区浅埋煤层具有埋深浅、基岩薄、上覆厚松散沙层、矿压显现剧烈等特征,对于煤矿的安全生产提出了更严格的要求.本研究通过对浅埋煤层特殊赋予地质状况的介绍与分析,阐述了浅埋煤层综采工作面主要机械设备的选型原则、理论计算以及三机合理配套的相关要求,合理选择浅埋煤层综采工作面三机配套设备的形式、型号及技术特征.研究对于指导陕北浅埋煤层综采工作面设备选型与配套工作有现实的理论借鉴和指导意义.