WorldWideScience

Sample records for camera-based seam tracking

  1. 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.

  2. 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.

  3. 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.

  4. Seam-Tracking for Friction Stir Welded Lap Joints

    Science.gov (United States)

    Fleming, Paul A.; Hendricks, Christopher E.; Cook, George E.; Wilkes, D. M.; Strauss, Alvin M.; Lammlein, David H.

    2010-11-01

    This article presents a method for automatic seam-tracking in friction stir welding (FSW) of lap joints. In this method, tracking is accomplished by weaving the FSW tool back-and-forth perpendicular to the direction of travel during welding and monitoring force and torque signals. Research demonstrates the ability of this method to automatically track weld seam positions. Additionally, tensile and S-bend test result comparisons demonstrate that weaving most likely does not reduce weld quality. Finally, benefits of this weave-based method to FSW of lap joints are discussed and methods for incorporating it into existing friction stir welding control algorithms (such as axial load control) are examined.

  5. 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

    2016-01-01

    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. PMID:27589768

  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. 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...

  8. 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.

  9. 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

  10. Algorithm For Simplified Robotic Tracking Of Weld Seams

    Science.gov (United States)

    Gutow, David A.; Paternoster, Vincent Y.

    1992-01-01

    Algorithm computes small cross-seam corrections to programmed path of welding robot. Intended for use with add-on vision system loosely coupled to robot, transmitting small amount of information about weld seam ahead of torch. Position of welding torch in reference frame of moving window estimated on basis of data on weld seam and speed of torch. Does not need data on position of torch, and does not transform data on seam to another reference frame.

  11. Seam tracking for laser welding with an industrial robot

    OpenAIRE

    Römer, G.R.B.E.; Amerongen, van, W.E.; 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 for laser welding. These problems can be solved by applying sensors, which measure the location of the seam in real-time. This paper describes the integration and performance of a commercial seam 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. 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.

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

    Science.gov (United States)

    van der Mark, Wannes; van den Heuvel, Johan C.; den Breejen, Eric; Groen, Frans C. A.

    2003-09-01

    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 combining the observations from the different sensors on the moving platform. Currently a method based on odometry is used to merge the readings from the sensors. In this paper a vision based approach is presented which can estimate the relative sensor pose and position together with the vehicle motion. To estimate the relative position and orientation of sensors, techniques from camera calibration are used. The platform motion is estimated from tracked features on the ground. A new approach is presented which can reduce the influence of tracking errors or other outliers on the accuracy of the ego-motion estimate. Overall, the new vision based approach for sensor localization leads to better estimates then the current odometry based method.

  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. Development of seam tracking control using monitoring system for laser welding (iL-Viewer)

    Science.gov (United States)

    Takahashi, Hideo; Oowaki, Katsura; Morita, Ichiro; Tsuchiya, Kazuyuki

    2003-03-01

    Automatic or semi-automatic welding methods are required for improving efficiency and safety, then various seam tracking technologies have been developed as an important part of them. For laser welding, although industrial application is magnifying widely, traditional seam-tracking technologies are difficult to apply. We have developed new monitoring system of weld zone and its around at the same time under high luminosity of laser welding, using the 2nd harmonics generator of pulsed YAG laser for illuminating the situation of weld. Using this system, we can observe the welding situations clearly in monitors, even for especially high luminous welding phenomenon, such a laser welding. Using this system, we have developed the seam tracking control system of laser welding by analyzing the images in computer in order to decide the position of the weld line and beam point and conducting tbe feedback coontrol of laser torch position. For examining this system, we conducted the I-bat welding on stainless steel plate changing welding track and welding speed. Through the experiment, followings were understood. This system can use high speed welding and works sufficiently in laser welding.

  18. 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.

  19. 波纹管焊缝跟踪检测技术%Tracking measurement technology for welding seam of bellows

    Institute of Scientific and Technical Information of China (English)

    段振云; 蒋卫卫; 赵文辉; 任仲伟

    2011-01-01

    In order to improve the seam quality and welding speed for bellows, an automatic welding technique with real-time tracking measurement system was presented according to the welding seam characteristics of bellows.The infrared laser sensor was used for performing the non-contact and real-time detection of welded joint center.The profile data of welding seam was transmitted by IEEE-1384 fire wire communication.Through pre-processing the data and combining with least square method, the coordinates of welding points were storaged and forecasted.Then the data was transmitted to the moving control card to control the welding gun.The experimental results show that the present tracking measurement technology for welding seam is stable and reliable, and is effective for improving the welding quality and efficiency of bellows.%为了提高波纹管焊缝的焊接质量和焊接速度,根据波纹管焊缝的特点,提出了一种实时跟踪检测波纹管焊缝的自动焊接技术.采用红外激光传感器对焊缝中心进行非接触式实时检测,通过1394火线通讯传输焊缝轮廓数据,经焊缝数据点预处理后结合最小二乘法直线拟合原理对焊点坐标进行存储与预测,再向运动控制卡发送数据控制焊枪跟踪焊接.实验结果表明,此焊缝跟踪检测技术稳定可靠,能够有效地提高波纹管的焊接质量和生产效率.

  20. 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.

  1. Application of a seam weld tracking system for robot welding under hyperbar conditions. Einsatz eines Nahtfuehrungssystems fuer das hyperbare Schweissen mit einem Industrieroboter

    Energy Technology Data Exchange (ETDEWEB)

    Kober, J.; Santos, J.F. dos; Thomas-Jeromin, J.; Szelagowski, P.; Schultheiss, G.; Seeger, G.

    1989-01-01

    It is reported about first experiences with an optical weld seam tracking system under hyperbar conditions. Thus it was possible in two compression phases of 6 and 31 bar abs to safely weld, for the first time sensor-aided, root passes (weave-bead technique) which would pass the final inspection. (MM).

  2. Accuracy and Precision of a Custom Camera-Based System for 2-D and 3-D Motion Tracking during Speech and Nonspeech Motor Tasks

    Science.gov (United States)

    Feng, Yongqiang; Max, Ludo

    2014-01-01

    Purpose: Studying normal or disordered motor control requires accurate motion tracking of the effectors (e.g., orofacial structures). The cost of electromagnetic, optoelectronic, and ultrasound systems is prohibitive for many laboratories and limits clinical applications. For external movements (lips, jaw), video-based systems may be a viable…

  3. 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。

  4. 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.

  5. Application of laser seam tracking system in robotic welding of stainless steel thin plate%激光焊缝跟踪系统在汽车薄板机器人GTAW中的应用

    Institute of Scientific and Technical Information of China (English)

    李妍; 林涛; 陈华斌

    2012-01-01

    A high reliable laser seam tracking system for robotic welding was proposed and applied to the butt welding in the lip of stainless steel thin plate. Laser sensor is used effectively to adjust the torch position,and make the torch move forward along the seam center,which can greatly improve the welding quality. Finally the practical experiments were demonstrated that the developed system can meet the seam tracking accuracy requirements and engineering application.%根据不锈钢薄板卷边对接焊缝的特点,设计了一种具有可靠性高、能够在工业现场长期应用的机器人GTAW焊接跟踪系统.系统采用激光传感器进行初始焊位识别及焊缝跟踪,有效地调节焊枪位置的变化,使焊枪始终沿着焊缝中心前进,从而大大提高了焊接质量.试验结果表明,所设计的机器人焊缝跟踪系统能够满足焊缝跟踪的精度要求,具有实际应用价值.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. Research of welding seam tracking system using laser vision and double queues%双队列控制的激光视觉焊缝跟踪系统研究

    Institute of Scientific and Technical Information of China (English)

    王秀平; 白瑞林

    2015-01-01

    设计与实现了一套激光视觉引导的焊缝自动跟踪系统,包括系统的整体硬件构成和关键算法。在工业机器人末端安装激光视觉传感器构成焊缝跟踪系统的硬件部分。采用小波变换滤除焊缝图像噪声,采用改进的Steger算法和Hough变换方法提取激光条纹中心直线,进一步提取出焊缝位置。提出一种双队列控制策略,在采集的焊缝特征点的基础上进一步插值,从而实现激光视觉引导的焊缝自动与平滑跟踪。实验结果表明,该系统具有较好的跟踪精度,能满足工业实际需求。%It designs and realizes a set of laser vision guided automatic seam tracking system, including overall system structure and key algorithms. A laser vision sensor is installed at the end of an industrial robot. Wavelet transform is used to filter image noise and improved Steger algorithm and Hough transform method are applied to extract the laser stripe center line. Then the position of welding seam is located. A strategy of dual queues is put forward to control the move-ment of the manipulator, and a series of intermediate points among welding points are obtained by interpolation, so as to realize the automatic and smooth tracking of weld laser visual guide. The experimental results show the system has good tracking accuracy and can meet the industrial requirement.

  11. 线结构光视觉传感器二维机器人焊缝跟踪系统%2-D Robot seam tracking system based on structured-light visual sensor

    Institute of Scientific and Technical Information of China (English)

    林嘉睿; 吴斌; 高鹏; 叶声华

    2009-01-01

    提出了一种基于线结构光视觉传感器示教及纠偏的二维机器人焊缝跟踪方法.利用简单快速的系统标定,视觉传感器分别对焊缝上示教特征点和实际特征点坐标进行测量记录,同时采用模板匹配进行图像处理,测出它们之间的偏差,ABB机器人根据得到的偏差实时调整焊枪位置,从而实现自动跟踪.利用线结构光视觉传感器和ABB机器人设计了实验系统,对所提的方法进行了验证.%A method for 2-D robot seam tracking based on structured-light visual sensor is presented which combines visual teaching and correcting. The visual sensor is used to measure and record the coor-dinates of the teaching points and real points on the seam by template matching,then the deviations be-tween teaching path and real path can be figured out. According to the deviations,the ABB robot can ad-just the position of welding gun automatically to realize the real-time tracking. At last,an experimental system that consists of the structured-light visual sensor and ABB robot has been designed,and the ex-perimental results prove that this method is available.

  12. Camera Based Navigation System with Augmented Reality

    Directory of Open Access Journals (Sweden)

    M. Marcu

    2012-06-01

    Full Text Available Nowadays smart mobile devices have enough processing power, memory, storage and always connected wireless communication bandwidth that makes them available for any type of application. Augmented reality (AR proposes a new type of applications that tries to enhance the real world by superimposing or combining virtual objects or computer generated information with it. In this paper we present a camera based navigation system with augmented reality integration. The proposed system aims to the following: the user points the camera of the smartphone towards a point of interest, like a building or any other place, and the application searches for relevant information about that specific place and superimposes the data over the video feed on the display. When the user moves the camera away, changing its orientation, the data changes as well, in real-time, with the proper information about the place that is now in the camera view.

  13. Gamma camera based FDG PET in oncology

    International Nuclear Information System (INIS)

    Positron Emission Tomography(PET) was introduced as a research tool in the 1970s and it took about 20 years before PET became an useful clinical imaging modality. In the USA, insurance coverage for PET procedures in the 1990s was the turning point, I believe, for this progress. Initially PET was used in neurology but recently more than 80% of PET procedures are in oncological applications. I firmly believe, in the 21st century, one can not manage cancer patients properly without PET and PET is very important medical imaging modality in basic and clinical sciences. PET is grouped into 2 categories; conventional (c) and gamma camera based (CB) PET. CBPET is more readily available utilizing dual-head gamma cameras and commercially available FDG to many medical centers at low cost to patients. In fact there are more CBPET in operation than cPET in the USA. CBPET is inferior to cPET in its performance but clinical studies in oncology is feasible without expensive infrastructures such as staffing, rooms and equipments. At Ajou university Hospital, CBPET was installed in late 1997 for the first time in Korea as well as in Asia and the system has been used successfully and effectively in oncological applications. Our was the fourth PET operation in Korea and I believe this may have been instrumental for other institutions got interested in clinical PET. The following is a brief description of our clinical experience of FDG CBPET in oncology

  14. 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......, and accessible software EyeCon is a potent and significant tool in the field of rehabilitation/therapy and warrants wider exploration....

  15. Laser Seam welding method

    International Nuclear Information System (INIS)

    The present invention provides a laser seam welding method for welding spacers to be used in nuclear fuel assemblies at a stable quality. Namely, the laser seam welding method comprises irradiating, while moving, laser beams to a portion to be welded. In this case, data of the shapes and characteristics of the portion to be welded are inputted to restrict the range of the welding of the portion to be welded. The power, moving speed, distance to a focal point and energy of the laser beams are controlled in the midway of the range for the welding. Then, a welding nugget having a shape defined to a portion to be welded can be formed thereby enabling to keep the portion to be welded to stable quality. As a result, failed welding can be eliminated, and strength of joint can be guaranteed. In addition, auxiliary products of portions to be welded, for example, springs are not failed by laser beams. As a result, satisfactory spacers can be provided. (I.S.)

  16. 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

  17. Mouse Control using a Web Camera based on Colour Detection

    OpenAIRE

    2014-01-01

    In this paper we present an approach for Human computer Interaction (HCI), where we have tried to control the mouse cursor movement and click events of the mouse using hand gestures. Hand gestures were acquired using a camera based on colour detection technique. This method mainly focuses on the use of a Web Camera to develop a virtual human computer interaction device in a cost effective manner.

  18. A Bionic Camera-Based Polarization Navigation Sensor

    OpenAIRE

    Daobin Wang; Huawei Liang; Hui Zhu; Shuai Zhang

    2014-01-01

    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 ...

  19. Working adjacent seams separated by thin interbeddings

    Energy Technology Data Exchange (ETDEWEB)

    Batmanov, Yu.K.; Bakhtin, A.F.; Bulavka, E.I. (Donetskii Nauchno-Issledovatel' skii Ugol' nyi Institut (Ukraine))

    1992-10-01

    Discusses problems related to working pairs of seams separated by thin interbeddings in Ukrainian black coal mines. Working pairs of seams in descending or ascending order is considered. Exemplary cases of working closely lying seams in five mines are studied. It was found that excavation of under- or overworked seams causes deterioration of the immediate roof and caving of draw roof. It is concluded that very close lying seams should not be worked in ascending order; pillarless working of the upper seam is indispensable in the case of working in descending order. Caving of unstable roofs can be prevented by roof bolting and consolidation by fluid injection. 4 refs.

  20. IMRT verification with a camera-based electronic portal imaging system

    International Nuclear Information System (INIS)

    An evaluation of the capabilities of a commercially available camera-based electronic portal imaging system for intensity-modulated radiotherapy verification is presented. Two modifications to the system are demonstrated which use a novel method to tag each image acquired with the delivered dose measured by the linac monitor chamber and reduce optical cross-talk in the imager. A detailed performance assessment is presented, including measurements of the optical decay characteristics of the system. The overall geometric accuracy of the system is determined to be ±2.0 mm, with a dosimetric accuracy of ±1.25 MU. Finally a clinical breast IMRT treatment, delivered by dynamic multileaf collimation, is successfully verified both by tracking the position of each leaf during beam delivery and recording the integrated intensity observed over the entire beam. (author)

  1. 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.

  2. Noninvasive particle sizing using camera-based diffuse reflectance spectroscopy

    DEFF Research Database (Denmark)

    Abildgaard, Otto Højager Attermann; Frisvad, Jeppe Revall; Falster, Viggo;

    2016-01-01

    Diffuse reflectance measurements are useful for noninvasive inspection of optical properties such as reduced scattering and absorption coefficients. Spectroscopic analysis of these optical properties can be used for particle sizing. Systems based on optical fiber probes are commonly employed, but...... their low spatial resolution limits their validity ranges for the coefficients. To cover a wider range of coefficients, we use camera-based spectroscopic oblique incidence reflectometry. We develop a noninvasive technique for acquisition of apparent particle size distributions based on this approach....... Our technique is validated using stable oil-in-water emulsions with a wide range of known particle size distributions. We also measure the apparent particle size distributions of complex dairy products. These results show that our tool, in contrast to those based on fiber probes, can deal with a range...

  3. 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.

  4. 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.

  5. 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.

  6. Setup of precise camera based solar tracker systems and greenhouse gas measurements using a modified portable spectrometer

    OpenAIRE

    Gisi, Michael

    2012-01-01

    Methods for correcting errors in solar absorption FTIR spectroscopy using the Sun as the light source were developed. A novel camera-based solar tracker is presented, providing robust tracking accuracies better than 30 arc sec. A method for correcting mis-sampling artifacts in the interferograms is shown. A portable and robust low-resolution FTIR spectrometer was developed for measuring total column CO2 values. An agreement of 0.1% was reached compared to a co-located TCCON reference instrument.

  7. 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. PMID:20876019

  8. 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.

  9. 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

  10. 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......, and accessible software EyeCon is a potent and significant user-friendly tool in the field of rehabilitation/therapy and warrants wider exploration....

  11. 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.

  12. 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

  13. 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...

  14. 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...

  15. 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.

  16. Mining vertical coal seams in France

    Energy Technology Data Exchange (ETDEWEB)

    Schneiderman, S.J.

    1981-05-01

    French coal miners in the Lorraine Basin coalfields of Charbonnages de France, work under extremely difficult mining conditions. The coal seams are located in two parallel anticlines dipping to the southwest. On the northwest flanks the coal dips at angles up to 40/sup 0/; on the southeast flanks the coal dips as steep as 90/sup 0/. In addition to the problems associated with steeply dipping coal seams, the coal is often more than 3 meters (10 feet) thick, thus contributing the additional problems that are associated with thick seams. A cut-and-fill mining method is used and production of up to 400 tons per day for a three-shift working face has been achieved. The cut-and-fill mining method employed at Puit Reumaux, rising horizontal rooms with hydraulic stowing, is used in areas of the mine where seam dips exceed 45/sup 0/ and where seam thickness is from 2 to 5 meters (6.5 to 16.5 feet). Hydraulic stowing has many advantages for the Merlebach mine: The coalis located under urbanized areas and is also covered by water-bearing strata with hydraulic sand stowing there is little subsidence, so disturbances to the surface and the aquiferous zones are minimized. Hydraulic sand stowing also helps prevent eating and combustion.

  17. 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.

  18. Development of a stereo-laser-profile-system for the optical inspection of welding seams

    OpenAIRE

    Ekkel, T.; Meyer, A. M.; T. Luhmann; H. Hastedt; F. Bethmann

    2013-01-01

    This research project focuses on the development of an optical 3D measuring system that enables high accurate surface measurements of welding seams in order to detect impurities. The systems concept is based on a stereo camera system in conjunction with a projecting line laser. A second camera system is used as tracking or positioning component to obtain the position of the measuring systems in object space. The complete stereo laser-profile system will be used as a hand-held system....

  19. 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.

  20. Economic assessment of utilizing protective properties of level coal seams

    Energy Technology Data Exchange (ETDEWEB)

    Bakhtin, A.F.; Batmanov, Yu.K.; Gainutdinov, I.A.

    1982-12-01

    Increasing mining depth negatively influences mining efficiency and safety. At depths to 600 m 10% of coal comes from seams prone to rock bursts. At depths exceeding 600 m proportion of coal from seams prone to rock bursts increases to 40%. Investigations carried out in Ukrainian coal mines show that coal losses (due to rock burst hazard) in level seams mined by a longwall system amount to 4.6 Mt per year. Cost of rock burst prevention and repairs after rock bursts amounts to 12 million rubles per year. About 68% of coal from level coal seams comes from long coal pillars mined by a longwall system. In level coal seams prone to rock bursts this proportion is 40% lower (proportion of longwall mining is reduced due to increased rock burst hazards). Only 10% of coal seams prone to rock bursts are mined using a system of stress relaxation by cutting another overlying or underlying coal seam (utilizing protective properties of a coal seam). A method for economic analysis of protective properties of coal seams in seam groups is described. Using the method the optimum order of mining coal seams in a seam group is determined. Examples of the method's use are analyzed. (3 refs.) (In Russian)

  1. 49 CFR 230.30 - Lap-joint seam boilers.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Inspection and Repair § 230.30 Lap-joint seam boilers. Every boiler having lap-joint longitudinal seams... 49 Transportation 4 2010-10-01 2010-10-01 false Lap-joint seam boilers. 230.30 Section...

  2. 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

  3. 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.

  4. A BINARIZATION TECHNIQUE FOR EXTRACTION OF DEVANAGARI TEXT FROM CAMERA BASED IMAGES

    Directory of Open Access Journals (Sweden)

    Rajesh K. Bawa

    2014-04-01

    Full Text Available This paper presents a binarization method for camera based natural scene (NS images based on edge analysis and morphological dilation. Image is converted to grey scale image and edge detection is carried out using canny edge detection. The edge image is dilated using morphological dilation and analyzed to remove edges corresponding to non-text regions. The image is binarized using mean and standard deviation of edge pixels. Post processing of resulting images is done to fill gaps and to smooth text strokes. The algorithm is tested on a variety of NS images captured using a digital camera under variable resolutions, lightening conditions having text of different fonts, styles and backgrounds. The results are compared with other standard techniques. The method is fast and works well for camera based natural scene images.

  5. 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.

  6. Stress transfer between multi-seam longwall mines

    OpenAIRE

    Ganguli, Rajive

    1995-01-01

    The future of most underground coal mining in the USA will entail the extraction of coal under multi-seam mining conditions. Mine design in such an environment will require the accurate prediction of stress transfer between adjacent seams. The available knowledge on criteria controlling stress transfer has been exhaustively reviewed and critical factors affecting multi-seam mining investigated. Young's Moduli of rock layers, thickness of rock layers, number of these layers a...

  7. Mining adjacent inclined coal seams of varying thickness

    Energy Technology Data Exchange (ETDEWEB)

    Batmanov, Yu.K.; Bakhtin, A.F.; Bulavka, E.I.

    1980-01-01

    In the Donbass coal basin a large number of thin coal seams located near other thicker coal seams are left. It is suggested that coal output from the Donbass could be increased by 100% and cost of mining could be lowered by 0.4-1.1 roubles per 1 ton of coal if thinner coal seams were also mined. Mining methods in the Donbass are analyzed from the point of view of reducing the cost of mining and increasing coal production. Recommendations on methods of mining thin inclined coal seams are given. (6 refs.) (In Russian)

  8. A quality problem in seam welds in aluminum extrusion

    Directory of Open Access Journals (Sweden)

    M.S. Keskin

    2007-07-01

    Full Text Available Purpose: Seam welds occur during the hollow profile extrusion; the billet’s material is divided into separate metal streams by the bridges of the die which support a mandrel, and then these metal streams are welded in welding chamber behind the bridges. When the desired conditions have not been provided, the required quality in seam welds may not occur. One of the possible reasons for this situation is a poor metal feed. In this study, an insufficient pressure problem occurring in seam welds on an aluminum extrusion profile section is investigated.Design/methodology/approach: The study was realized on a hollow extrusion profile type which has seam weld zones. The experimental profile was produced by a real extrusion press which has a capacity of 1460 tones.Findings: The poor metal feed occurring on specimen is shown by microstructural pictures. Microstructure of the main region has a homogenous appearance. In the microstructure, containing seam weld region, only a slight change was observed in seam weld region. However, there was no significant change in near of seam weld regions. This points out that there has been no metallurgical problem. Therefore, the problem is an insufficient pressure problem and this caused poor metal feeding. In the other hand, micro hardness tests are realized on seam weld region, main region and defective region’s surround of specimen’s section. After the micro hardness tests important differences are shown among these regions’ strength. Hardness values of seam weld region were lower than the main material’s hardness values, but higher than the defective region’s.Practical implications: In application, seam welds occur on hollow profiles produced by aluminum extrusion.Originality/value: As a result, this study shows a quality problem in seam welds in aluminum extrusion.

  9. Systematic solutions for thick seam mining

    Energy Technology Data Exchange (ETDEWEB)

    Zitz, A.

    1986-06-01

    Room and pillar method and rib pillar extraction in thick seams are analysed for non European coal mining and available equipment, the resulting weaknesses are shown - The analysis forms the basis for the development of the model of an integrated machinery system, consisting of excavating machine, continuous transport system and fully mechanised mobile support. Because the continuous conveyor system still remains to be put to underground tests, comprehensive results from applications of other system components only are available. They are the basis for improvement and source of efficiency improvement of the mentioned mining methods. (orig./MOS). With 21 figs.

  10. Camera Based Closed Loop Control for Partial Penetration Welding of Overlap Joints

    Science.gov (United States)

    Abt, F.; Heider, A.; Weber, R.; Graf, T.; Blug, A.; Carl, D.; Höfler, H.; Nicolosi, L.; Tetzlaff, R.

    Welding of overlap joints with partial penetration in automotive applications is a challenging process, since the laser power must be set very precisely to achieve a proper connection between the two joining partners without damaging the backside of the sheet stack. Even minor changes in welding conditions can lead to bad results. To overcome this problem a camera based closed loop control for partial penetration welding of overlap joints was developed. With this closed loop control it is possible to weld such configurations with a stable process result even under changing welding conditions.

  11. 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.

  12. 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.

  13. 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%.

  14. Influences Determining European Coal Seam Gas Deliverability

    Science.gov (United States)

    Clark, G.

    2009-04-01

    Technically the coal basins of Europe have generated significant Gas In Place figures that has historically generated investor's interest in the development of this potential coal seam gas (CSG) resource. In the early 1980's, a wave of international, principally American, companies arrived, established themselves, drilled and then left with a poor record of success and disappointed investors. Recently a second wave of investment started after 2002, with the smaller companies leading the charge but have the lesson been learned from the past failures? To select a CSG investment project the common European approach has been to: 1. Find an old mining region; 2. Look to see if it had a coal mine methane gas problem; 3. Look for the non-mined coal seams; and 4. Peg the land. This method is perhaps the reason why the history of CSG exploration in Europe is such a disappointment as generally the coal mining regions of Europe do not have commercial CSG reservoir attributes. As a result, investors and governments have lost confidence that CSG will be a commercial success in Europe. New European specific principles for the determination of commercial CSG prospects have had to be delineated that allow for the selection of coal basins that have a strong technical case for deliverability. This will result in the return of investor confidence.

  15. Camera-based noncontact metrology for static/dynamic testing of flexible multibody systems

    Science.gov (United States)

    Pai, P. Frank; Ramanathan, Suresh; Hu, Jiazhu; Chernova, DarYa K.; Qian, Xin; Wu, Genyong

    2010-08-01

    Presented here is a camera-based noncontact measurement theory for static/dynamic testing of flexible multibody systems that undergo large rigid, elastic and/or plastic deformations. The procedure and equations for accurate estimation of system parameters (i.e. the location and focal length of each camera and the transformation matrix relating its image and object coordinate systems) using an L-frame with four retroreflective markers are described in detail. Moreover, a method for refinement of estimated system parameters and establishment of a lens distortion model for correcting optical distortions using a T-wand with three markers is described. Dynamically deformed geometries of a multibody system are assumed to be obtained by tracing the three-dimensional instantaneous coordinates of markers adhered to the system's outside surfaces, and cameras and triangulation techniques are used for capturing marker images and identifying markers' coordinates. Furthermore, an EAGLE-500 motion analysis system is used to demonstrate measurements of static/dynamic deformations of six different flexible multibody systems. All numerical simulations and experimental results show that the use of camera-based motion analysis systems is feasible and accurate enough for static/dynamic experiments on flexible multibody systems, especially those that cannot be measured using conventional contact sensors.

  16. 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.

  17. Submap joining smoothing and mapping for camera-based indoor localization and mapping

    Science.gov (United States)

    Bjärkefur, J.; Karlsson, A.; Grönwall, C.; Rydell, J.

    2011-06-01

    Personnel positioning is important for safety in e.g. emergency response operations. In GPS-denied environments, possible positioning solutions include systems based on radio frequency communication, inertial sensors, and cameras. Many camera-based systems create a map and localize themselves relative to that. The computational complexity of most such solutions grows rapidly with the size of the map. One way to reduce the complexity is to divide the visited region into submaps. This paper presents a novel method for merging conditionally independent submaps (generated using e.g. EKF-SLAM) by the use of smoothing. Using this approach it is possible to build large maps in close to linear time. The method is demonstrated in two indoor scenarios, where data was collected with a trolley-mounted stereo vision camera.

  18. A new depth measuring method for stereo camera based on converted relative extrinsic parameters

    Science.gov (United States)

    Song, Xiaowei; Yang, Lei; Wu, Yuanzhao; Liu, Zhong

    2013-08-01

    This paper presents a new depth measuring method for the dual-view stereo camera based on the converted relative extrinsic parameters. The relative extrinsic parameters between left and right cameras, which obtained by the stereo camera calibration, can indicate the geometric relationships among the left principle point, right principle point and convergent point. Furthermore, the geometry which consists of the corresponding points and the object can be obtained by making conversion between the corresponding points and principle points. Therefore, the depth of the object can be calculated based on the obtained geometry. The correctness of the proposed method has been proved in 3ds Max, and the validity of the method has been verified on the binocular stereo system of flea2 cameras. We compared our experimental results with the popular RGB-D camera (e.g. Kinect). The comparison results show that our method is reliable and efficient, without epipolar rectification.

  19. Development of a stereo-laser-profile-system for the optical inspection of welding seams

    Science.gov (United States)

    Ekkel, T.; Meyer, A. M.; Luhmann, T.; Hastedt, H.; Bethmann, F.

    2013-10-01

    This research project focuses on the development of an optical 3D measuring system that enables high accurate surface measurements of welding seams in order to detect impurities. The systems concept is based on a stereo camera system in conjunction with a projecting line laser. A second camera system is used as tracking or positioning component to obtain the position of the measuring systems in object space. The complete stereo laser-profile system will be used as a hand-held system. The development, optimization and testing of the system components (stereo camera system with projecting laser line and tracking component) for surface measurements as well as calibration and accuracy evaluations are the main objectives within this research project. Testing procedures and probes are constructed and evaluated to verify the results. The development considers conditions for a future adaption to underwater use.

  20. Systems of pillarless working of adjacent, sloped and inclined seams

    Energy Technology Data Exchange (ETDEWEB)

    Batmanov, Yu.K.; Bakhtin, A.F.; Bulavka, E.I.

    1979-01-01

    An analysis is made (advantages and disadvantages) of existing and recommended (pillarless) systems of working adjacent, sloped, and inclined seams. The economic benefits, area and extent of those systems are indicated. 8 references, 4 figures.

  1. Interactive prediction software for underlying multi-seam design

    OpenAIRE

    Kanniganti, Ravi S.

    1996-01-01

    An extensive review of multi-seam under-mining literature was conducted and a data base of case studies was compiled. A critical review of the design principles outlined in this literature resulted in the compilation of specific design criteria for the design of lower seam mines. Analysis of this criteria demonstrated the necessity for a protocol for the design of unsymmetrically loaded pillars. Such a design criteria was developed using finite element methods for a wide ra...

  2. Properties of seam welds produced with different extrusion parameters

    OpenAIRE

    A. Bozacl; M.S. Keskin; S. Bingol

    2007-01-01

    Purpose: This study focuses to investigate the effects of different extrusion parameters on microstructural properties of seam (longitudinal) welds in aluminum extrusion profiles.Design/methodology/approach: To realize the study, it is studied on a hollow extrusion profile type which has seam weld zones. The experimental profile was produced in different temperatures, billet temperatures and ram speeds by a real extrusion press which has a capacity of 1460 tones. These parameters are some of ...

  3. 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.

  4. Brazilian experience in characterization of solitary pulmonary nodules using 18-fluorodeoxyglucose on camera-based PET

    International Nuclear Information System (INIS)

    Introduction: Positron emission tomography (PET) using 18-fluorodeoxyglucose (18F-FDG), showing increased 18F-FDG uptake and retention in malignant cells, has proved useful to differentiate malignant from benign pulmonary nodules. An accurate diagnosis of pulmonary cancer represents a clinical challenge. This could be even more significant in Latin America, where the incidence of infectious granulomas is high. However, the high cost of dedicated- PET studies has prevented widespread application of this technique. Hybrid PET is a new approach to tumor imaging using 18F-FDG. In our country, such a system was introduced in 1998. These systems offer the possibility to produce diagnostic quality images of 18F-FDG body distribution, making metabolic scans potentially available. Objective : The aim of this study was to determine the diagnostic value of F-18-FDG scan using a hybrid PET in characterizing pulmonary nodules as benign or malignant. Methods: We evaluated 62 patients (50 male, 38-79y) with indeterminate solitary pulmonary nodules after computed tomography (CT) screening. 18F-FDG scans were performed on a camera-based PET (MCD Vertex-plus Adac) after injection of 18-F-fluorodeoxyglucose intravenously. Image acquisition began after 1 hour. Qualitative analysis of the images was performed by visual identification of areas of increase (positive) or absence (negative)of FDG uptake. All results were assessed on basis of histology or clinical/radiological follow-up. Results : Twenty-one patients (33.9%) showed a marked increase in FDG uptake and underwent invasive intervention (biopsy or thoracotomy). Histopathological evaluation revealed malignant disease in eighteen of these patients and benign disease in three of them (positive predictive value = 85.7%). Forty-one patients (66.1%) showed absence of FDG uptake. Fourteen of them underwent surgical procedure. Malignancy was found in only one. Twenty-seven patients with negative FDG studies are being followed up with a

  5. Two Persons with Multiple Disabilities Use Camera-Based Microswitch Technology to Control Stimulation with Small Mouth and Eyelid Responses

    Science.gov (United States)

    Lancioni, Giulio E.; Bellini, Domenico; Oliva, Doretta; Singh, Nirbhay N.; O'Reilly, Mark F.; Sigafoos, Jeff; Lang, Russell

    2012-01-01

    Background: A camera-based microswitch technology was recently developed to monitor small facial responses of persons with multiple disabilities and allow those responses to control environmental stimulation. This study assessed such a technology with 2 new participants using slight variations of previous responses. Method: The technology involved…

  6. Camera-Based Microswitch Technology for Eyelid and Mouth Responses of Persons with Profound Multiple Disabilities: Two Case Studies

    Science.gov (United States)

    Lancioni, Giulio E.; Bellini, Domenico; Oliva, Doretta; Singh, Nirbhay N.; O'Reilly, Mark F.; Sigafoos, Jeff

    2010-01-01

    These two studies assessed camera-based microswitch technology for eyelid and mouth responses of two persons with profound multiple disabilities and minimal motor behavior. This technology, in contrast with the traditional optic microswitches used for those responses, did not require support frames on the participants' face but only small color…

  7. 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.

  8. 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.

  9. A novel approach to accurate portal dosimetry using CCD-camera based EPIDs

    International Nuclear Information System (INIS)

    A new method for portal dosimetry using CCD camera-based electronic portal imaging devices (CEPIDs) is demonstrated. Unlike previous approaches, it is not based on a priori assumptions concerning CEPID cross-talk characteristics. In this method, the nonsymmetrical and position-dependent cross-talk is determined by directly imaging a set of cross-talk kernels generated by small fields ('pencil beams') exploiting the high signal-to-noise ratio of a cooled CCD camera. Signal calibration is achieved by imaging two reference fields. Next, portal dose images (PDIs) can be derived from electronic portal dose images (EPIs), in a fast forward-calculating iterative deconvolution. To test the accuracy of these EPI-based PDIs, a comparison is made to PDIs obtained by scanning diode measurements. The method proved accurate to within 0.2±0.7% (1 SD), for on-axis symmetrical and asymmetrical fields with different field widths and homogeneous phantom thicknesses, off-axis Alderson thorax fields and a strongly modulated IMRT field. Hence, the proposed method allows for fast, accurate portal dosimetry. In addition, it is demonstrated that the CEPID cross-talk signal is not only induced by optical photon reflection and scatter within the CEPID structure, but also by high-energy back-scattered radiation from CEPID elements (mirror and housing) towards the fluorescent screen

  10. 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

  11. Calibration and disparity maps for a depth camera based on a four-lens device

    Science.gov (United States)

    Riou, Cécile; Colicchio, Bruno; Lauffenburger, Jean Philippe; Haeberlé, Olivier; Cudel, Christophe

    2015-11-01

    We propose a model of depth camera based on a four-lens device. This device is used for validating alternate approaches for calibrating multiview cameras and also for computing disparity or depth images. The calibration method arises from previous works, where principles of variable homography were extended for three-dimensional (3-D) measurement. Here, calibration is performed between two contiguous views obtained on the same image sensor. This approach leads us to propose a new approach for simplifying calibration by using the properties of the variable homography. Here, the second part addresses new principles for obtaining disparity images without any matching. A fast algorithm using a contour propagation algorithm is proposed without requiring structured or random pattern projection. These principles are proposed in a framework of quality control by vision, for inspection in natural illumination. By preserving scene photometry, some other standard controls, as for example calipers, shape recognition, or barcode reading, can be done conjointly with 3-D measurements. Approaches presented here are evaluated. First, we show that rapid calibration is relevant for devices mounted with multiple lenses. Second, synthetic and real experimentations validate our method for computing depth images.

  12. 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

  13. 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.

  14. 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.

  15. Morphogenetic classification of coal seam washouts in Donbass mines

    Energy Technology Data Exchange (ETDEWEB)

    Shul' ga, V.F.; Vashchenko, V.I.

    1982-09-01

    The paper evaluates washout types in coal seams in Donbass mines. Five washout types are characterized: trough-shaped, V-shaped or U-shaped, lentil-shaped, consisting of groups of small lentils and discontinuous washouts which consist of a number of coal and rock partings. Each of the 5 washout types is shown in a scheme. The following aspects of coal seam washouts are discussed: dimensions, shape, angle of inclination of trough walls, washout dimensions in relation to coal seam thickness, rock types filling washout zones. Effects of seam washouts on longwall mining are analyzed. Morphogenetic characteristics of 5 washout groups are given. Investigations show that trough-shaped, U or V-shaped washouts are of epigenetic origin and lentil-shaped, discontinuous washouts consisting of a number of rock and coal partings and washouts with groups of rock lentils are of syngenetic origin. Washout classification is shown in a table. Classification is aimed at optimizing the mining system in washout zones. It considers washout dimensions, washout dimensions in relation to coal seam thickness and rock type filling the washout (sandstone, agrillite or aleurite). System for coding information on washouts is described.

  16. 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.

  17. 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.

  18. 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.

  19. Evaluation of gamma camera-based measurement of individual kidney function using iodine-123 orthoiodohippurate

    International Nuclear Information System (INIS)

    To evaluate the accuracy of these techniques, we measured RUR by an optimized procedure and compared it with standard ERPF. Iodine-123 orthoiodohippurate (OIH) scintigraphy and simultaneous para-aminohippurate clearance study for measuring standard ERPF were performed in three hospitals in 24 patients with normal or mildly impaired renal function. 123I-OIH was injected intravenously and 10-s consecutive imaging of the kidneys was started when the abdominal aorta was seen. The attenuation coefficient for 123I was measured in each hospital using the same water-equivalent absorption materials and used for the attenuation correction. After subtracting background radioactivity, RURs were defined as the count ratios of fractional renal uptakes based on the integral from 1 to 2, 2 to 3, 1.5 to 2.5 and 1 to 3 min after the injection of 123I-OIH in relation to injected doses using the following three procedures in respect of attenuation correction: (1) RUR without attenuation correction, (2) RUR with fractional renal uptake corrected by the measured attenuation coefficient, (3) RUR with the total injected dose corrected by the absorption material. To decide upon the appropriate correction method and time interval, RURs were compared with standard ERPF. Among the three correction methods, procedure 2 showed the highest correlation between RUR and standard ERPF, but the correlation coefficient was low (r=0.75). No significant difference was observed among the RURs of each time interval. Individual kidney function measured from early renal uptake may be inaccurate even when appropriate correction is made for attenuation, background activity or time lag between injection and data acquisition. Gamma camera-based measurement of renal function using 123I-OIH is limited with regard to accuracy and reproducibility, though it is convenient and non-invasive. (orig.). With 2 figs., 2 tabs

  20. Calibration of high resolution digital camera based on different photogrammetric methods

    International Nuclear Information System (INIS)

    This paper presents method of calibrating high-resolution digital camera based on different configuration which comprised of stereo and convergent. Both methods are performed in the laboratory and in the field calibration. Laboratory calibration is based on a 3D test field where a calibration plate of dimension 0.4 m × 0.4 m with grid of targets at different height is used. For field calibration, it uses the same concept of 3D test field which comprised of 81 target points located on a flat ground and the dimension is 9 m × 9 m. In this study, a non-metric high resolution digital camera called Canon Power Shot SX230 HS was calibrated in the laboratory and in the field using different configuration for data acquisition. The aim of the calibration is to investigate the behavior of the internal digital camera whether all the digital camera parameters such as focal length, principal point and other parameters remain the same or vice-versa. In the laboratory, a scale bar is placed in the test field for scaling the image and approximate coordinates were used for calibration process. Similar method is utilized in the field calibration. For both test fields, the digital images were acquired within short period using stereo and convergent configuration. For field calibration, aerial digital images were acquired using unmanned aerial vehicle (UAV) system. All the images were processed using photogrammetric calibration software. Different calibration results were obtained for both laboratory and field calibrations. The accuracy of the results is evaluated based on standard deviation. In general, for photogrammetric applications and other applications the digital camera must be calibrated for obtaining accurate measurement or results. The best method of calibration depends on the type of applications. Finally, for most applications the digital camera is calibrated on site, hence, field calibration is the best method of calibration and could be employed for obtaining accurate

  1. 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.

  2. 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. PMID:27046604

  3. 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.

  4. Feasibility of an Integrated Thin Seam Coal Mining and Waste Disposal System

    OpenAIRE

    Basu, Kohinoor

    1997-01-01

    The depletion of more attractive thicker and easily accessible coal seams in the central Appalachia will direct attention towards the extraction of coal seams thinner than 28 in. This thesis investigates the feasibility of an integrated mining and backfilling system applicable to thin seams. Two conceptual mining systems, namely Auger mining and Self Advancing Miner, have been proposed for this purpose. Both these systems are designed to remotely mine coal from the seams. Several ...

  5. 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.

  6. 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.

  7. 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...

  8. Assessment of reliability and efficiency of mining coal seams located above or below extracted coal seams with support coal pillars. [USSR

    Energy Technology Data Exchange (ETDEWEB)

    Batmanov, Yu.K.; Bakhtin, A.F.; Bulavka, E.I.

    1981-04-01

    Mining thin (under 1.1 m) coal seams located above or below extracted thicker coal seams in which coal support pillars were left is one of the ways of increasing coal output without major investment in Donbass coal mines. It is planned that by 1985 25 thin coal seams will be mined in the Donbass. Investigations show that mining thin coal seams with gradients up to 12 degrees by a system of raise faces without leaving coal pillars is economical using mining systems available at present. This mining scheme is economical also in the case of coal seams located in zones of geologic dislocations. Using integrated mining systems (coal cutter, powered supports and face conveyor) in this coal seams would reduce mining cost from 0.2 to 0.3 rubles/t. Using automated integrated mining systems is economical in working faces with coal output exceeding 900 t/d. (3 refs.) (In Russian)

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

    Science.gov (United States)

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

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

  10. 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.

  11. 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...

  12. 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.

  13. In-mine geoelectric investigations for detecting tectonic disturbances in coal seam structures

    Science.gov (United States)

    Gyulai, Ákos; Dobróka, Mihály; Ormos, Tamás; Turai, Endre; Sasvári, Tibor

    2013-10-01

    The methods of in-mine seam-sounding and transillumination (geoelectric tomography) for the detection of tectonic disturbances of coal seams were developed by the Department of Geophysics of the University of Miskolc in the 1970-80's with the effective support of the former "Borsod" Coal Mines Ltd. The paper gives an overview about the theory of seam-sounding and a special geoelectric tomographic inversion, and introduces the in-mine geoelectric seam-sounding and transillumination measurement systems using vertical electrode dipoles. In the second part the paper, the results of an in-mine geoelectric measurement are presented, which was carried out in order to detect tectonic disturbances of the Miocene aged coal seams situated in Slovakia. As results of the geophysical investigation, the authors forecasted the tectonic features in the coal seam. The company confirmed the results by independent information about seam disturbances and tectonic features arising from the excavation of the investigated area.

  14. Tracking objects, Tracking agents

    OpenAIRE

    Bullot, Nicolas J.; Rysiew, Patrick

    2005-01-01

    Animals and humans have to keep track of individuals in their environment, both in perception (sensorimotor tracking) and in cognition (e.g., spatio-temporal localization and linguistic reference via memory, communication and reasoning). Items that are typical targets for tracking are things such as stationary physical objects (e.g., rocks, plants, trees, buildings, or attached artifacts), moving physical objects (e.g., animals, certain artifacts) and human beings. All such items are located ...

  15. Motion Tracker: Camera-Based Monitoring of Bodily Movements Using Motion Silhouettes.

    Directory of Open Access Journals (Sweden)

    Jacqueline Kory Westlund

    Full Text Available Researchers in the cognitive and affective sciences investigate how thoughts and feelings are reflected in the bodily response systems including peripheral physiology, facial features, and body movements. One specific question along this line of research is how cognition and affect are manifested in the dynamics of general body movements. Progress in this area can be accelerated by inexpensive, non-intrusive, portable, scalable, and easy to calibrate movement tracking systems. Towards this end, this paper presents and validates Motion Tracker, a simple yet effective software program that uses established computer vision techniques to estimate the amount a person moves from a video of the person engaged in a task (available for download from http://jakory.com/motion-tracker/. The system works with any commercially available camera and with existing videos, thereby affording inexpensive, non-intrusive, and potentially portable and scalable estimation of body movement. Strong between-subject correlations were obtained between Motion Tracker's estimates of movement and body movements recorded from the seat (r =.720 and back (r = .695 for participants with higher back movement of a chair affixed with pressure-sensors while completing a 32-minute computerized task (Study 1. Within-subject cross-correlations were also strong for both the seat (r =.606 and back (r = .507. In Study 2, between-subject correlations between Motion Tracker's movement estimates and movements recorded from an accelerometer worn on the wrist were also strong (rs = .801, .679, and .681 while people performed three brief actions (e.g., waving. Finally, in Study 3 the within-subject cross-correlation was high (r = .855 when Motion Tracker's estimates were correlated with the movement of a person's head as tracked with a Kinect while the person was seated at a desk (Study 3. Best-practice recommendations, limitations, and planned extensions of the system are discussed.

  16. Motion Tracker: Camera-Based Monitoring of Bodily Movements Using Motion Silhouettes.

    Science.gov (United States)

    Kory Westlund, Jacqueline; Westlund, Jacqueline Kory; D'Mello, Sidney K; Olney, Andrew M

    2015-01-01

    Researchers in the cognitive and affective sciences investigate how thoughts and feelings are reflected in the bodily response systems including peripheral physiology, facial features, and body movements. One specific question along this line of research is how cognition and affect are manifested in the dynamics of general body movements. Progress in this area can be accelerated by inexpensive, non-intrusive, portable, scalable, and easy to calibrate movement tracking systems. Towards this end, this paper presents and validates Motion Tracker, a simple yet effective software program that uses established computer vision techniques to estimate the amount a person moves from a video of the person engaged in a task (available for download from http://jakory.com/motion-tracker/). The system works with any commercially available camera and with existing videos, thereby affording inexpensive, non-intrusive, and potentially portable and scalable estimation of body movement. Strong between-subject correlations were obtained between Motion Tracker's estimates of movement and body movements recorded from the seat (r =.720) and back (r = .695 for participants with higher back movement) of a chair affixed with pressure-sensors while completing a 32-minute computerized task (Study 1). Within-subject cross-correlations were also strong for both the seat (r =.606) and back (r = .507). In Study 2, between-subject correlations between Motion Tracker's movement estimates and movements recorded from an accelerometer worn on the wrist were also strong (rs = .801, .679, and .681) while people performed three brief actions (e.g., waving). Finally, in Study 3 the within-subject cross-correlation was high (r = .855) when Motion Tracker's estimates were correlated with the movement of a person's head as tracked with a Kinect while the person was seated at a desk (Study 3). Best-practice recommendations, limitations, and planned extensions of the system are discussed. PMID:26086771

  17. 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).

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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. (paper)

  20. 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.

  1. Forced circular seam welding of tubes automated with orbital heads

    International Nuclear Information System (INIS)

    The MG process with pulse width modulated current and cold wire filler is suitable mainly for the production of high-quality welded joints. Three orbital welding heads adapted to requirements of the nuclear power station constructor have been designed for the mechanized forced circular seam welding of tubes. They differ in respect of their scope, in the structural height and in the number of the motor - controllable functions and the maximal values of the parameters defined by the functions. (orig.)

  2. 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.

  3. 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

  4. High resolution processing of 3D seismic data for thin coal seam in Guqiao coal mine

    Science.gov (United States)

    Li, Qiaoling; Peng, Suping; Zou, Guangui

    2015-04-01

    Accurate identification of small faults for coal seams is very important for coal-field exploration, which can greatly improve mining efficiency and safety. However, coal seams in China are mostly thin layers, ranging from 2-5 m. Moreover, the shallow coal seam with strong reflection forms a shield underneath thin coal seam which is only about 40 m deeper. This causes great difficulty in seismic processing and interpretation. The primary concern is to obtain high-resolution seismic image of underneath thin coal seam for mining safety. In this paper, field data is carefully analyzed and fit-for-purpose solutions are adopted in order to improve the quality of reprocessed data and resolution of target coal seam. Identification of small faults has been enhanced significantly.

  5. 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.

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

    OpenAIRE

    Liu Xiao Li; Zhang Zhi Ye; Li Meng Qian

    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...

  7. 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.

  8. 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.

  9. 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.

  10. A large surface X-ray camera based on XPAD3/CdTe single chip hybrids

    Science.gov (United States)

    Cassol, F.; Blanc, N.; Bompard, F.; Boudet, N.; Boursier, Y.; Buton, C.; Clémens, J.-C.; Dawiec, A.; Debarbieux, F.; Delpierre, P.; Dupont, M.; Graber-Bolis, J.; Hustache, S.; Morel, C.; Perez-Ponce, H.; Portal, L.; Vigeolas, E.

    2015-11-01

    The XPAD3 chip bump-bonded to a Si sensor has been widely used in preclinical micro-computed tomography and in synchrotron experiments. Although the XPAD3 chip is linear up to 60 keV, the performance of the XPAD3/Si hybrid detector is limited to energies below 30 keV, for which detection efficiencies remain above 20%. To overcome this limitation on detection efficiency in order to access imaging at higher energies, we decided to develop a camera based on XPAD3 single chips bump-bonded to high-Z CdTe sensors. We will first present the construction of this new camera, from the first tests of the single chip hybrids to the actual mechanical assembly. Then, we will show first images and stability tests performed on the D2AM beam line at ESRF synchrotron facility with the fully assembled camera.

  11. 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

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

    International Nuclear Information System (INIS)

    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

  13. Introducing dolomite seams: hybrid compaction-dissolution bands in dolomitic limestones

    Science.gov (United States)

    Tavani, Stefano; Vitale, Stefano; Grifa, Celestino; Iannace, Alessandro; Parente, Mariano; Mazzoli, Stefano

    2016-04-01

    Anastomosing dolomite seams occur at different stratigraphic levels of a clay-poor Mesozoic carbonate platform succession of the Apennines. Millimeter-thick seams, roughly parallel to bedding, are composed of a high concentration of dolomite crystals compared to the hosting dolomitic limestone micrite. Rare calcite veins emanating from the seams are observed in thin-section, while m-thick micro-stylolites frequently occur within the seams. Veins and micro-stylolites are perpendicular and parallel to the dolomite seams, respectively. Scanning electron microscope images and energy dispersive x-ray spectroscopy analysis document crushing and fragmentation of dolomite crystals, and accumulation of non-carbonate insoluble material along stylolites and around dolomite crystals of the seams. All these features suggest that the described seams are hybrid structures between pressure dissolution seams and compaction bands, and formed parallel to bedding during sedimentary burial. The dolomite crystals scattered in the micritic matrix represent the main body of the insoluble residue produced by the progressive dissolution of calcite. As calcite dissolution proceeds, the concentration of dolomite crystals increases, eventually resulting in a dolomite seam in which locally a dolomite crystal-supported texture is attained. At this stage, the dolomite crystals within the seam start to collide, crush and fragment, so that the dolomite seam behaves like a compaction band for high dolomite crystals concentrations. This new type of compaction structure is likely to be widespread in clay-poor dolomitic limestones, where it may have a significant role in controlling syn-burial porosity evolution and post-dolomitization calcite to dolomite ratio decrease.

  14. THE UTILIZATION TECHNOLOGIES OF METHANE PRODUCED FROM UNDERGRAUND COAL SEAMS

    OpenAIRE

    Gökhan AYDIN; Karakurt, İzzet

    2009-01-01

    A few coal mines use coalbed methane recovered from coal seams. As well as being unable to use gas means waste of an economically valuable source, it contributes to global warming. Gases recovered from coal mines can be used for various applications as an alternative source to natural gas or such as generation of power related to methane concentration. In cases the sale and/or use of gas would not be profitable, the best way for decreasing gas emissions is to destroy methane via flaring. In t...

  15. THE UTILIZATION TECHNOLOGIES OF METHANE PRODUCED FROM UNDERGRAUND COAL SEAMS

    Directory of Open Access Journals (Sweden)

    Gökhan AYDIN

    2009-01-01

    Full Text Available A few coal mines use coalbed methane recovered from coal seams. As well as being unable to use gas means waste of an economically valuable source, it contributes to global warming. Gases recovered from coal mines can be used for various applications as an alternative source to natural gas or such as generation of power related to methane concentration. In cases the sale and/or use of gas would not be profitable, the best way for decreasing gas emissions is to destroy methane via flaring. In this study, the utilization technologies of methane are defined in detail and the examples being in practice are given.

  16. 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.

  17. A penetrative addictive for water infusion in coal seams

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The manufacturing process, characteristics, and application results of a rod-like penetrative additive (the penetrative rod)were discussed. The components and functions of the penetrative rod were studied carefully. A large number of orthogonal combinedtests were carried out and over 100 sample molds were made. Ultimately the components were decided after careful selection amongthese molds, mainly including hygroscopic major components and auxiliary material. The results of on-site practical applicationshow that such an addictive can increase the water penetrative ability effectively and has a remarkable effect on preventing dust pro-duction during coal seam excavation. The penetrating radius, the infusing velocity and the dust-preventive effect were systematicallystudied.

  18. 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.

  19. Model-based Translucency in Middleware: Supporting Seamful Development

    DEFF Research Database (Denmark)

    Schougaard, Kari Rye; Langdal, Jakob

    2010-01-01

    that the actual adaptability needs at some point differs from the ones predicted. We argue that the seams, which are hidden in middleware with seamless design, should be accessible for pervasive computing application developers. It cannot be foreseen which aspects of a seam the domain or application need. We...

  20. 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..

  1. 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.

  2. 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.

  3. 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%.

  4. 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.

  5. 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.

  6. 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.

  7. 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)

  8. 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.

  9. 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.

  10. System for detecting interfaces between mineral seams and the surrounding earth formations

    International Nuclear Information System (INIS)

    The present invention contemplates a system for detecting an interface between a mineral seam and the surrounding earth formation utilizing a radiation source and a radiation receiver mounted on a miner having a positionable cutter assembly. As the miner is moved into the coal seam, a first distance is continuously sensed between one surface formed in the mineral seam by the miner cutter assembly and the surrounding earth formation and the miner cutter assembly is positioned in response to the sensed first distance. As the miner is withdrawn from the coal seam, a second distance is continuously sensed between one surface formed in the mineral seam by the miner cutter assembly and the surrounding earth formation and the miner cutter assembly is positioned in response to the sensed second distance. A substantial portion of the space between the wall formed in the mineral seam by the miner cutter assembly and the radiation source and radiation receiver is substantially filled with a material having a density greater than the density of air to direct a substantial portion of the radiation through the mineral seam

  11. 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.

  12. Three-dimensional strata movement around coal face of steeply dipping seam group

    Institute of Scientific and Technical Information of China (English)

    WU Yong-ping; XIE Pan-shi; REN Shi-guang; LI Rui-bin

    2008-01-01

    Steeply dipping seam group, which has complex occurrence conditions, belongs to the steeply dipping seam. The research on the strata movement around the coalface not only improves safe production technology in practice, but also develops the mining theory. By using physical simulation experiments, numerical simulation and site test,the deformation, failure and movement of surrounding rock in Iongwall working face wereanalyzed. According to the analysis, characteristics of the seam group were formed whichis different from the single seam. Asymmetry mechanics, sequential changes and imbalance of strata movement along the tendency working face were summarized. Furthermore,the features of upper and lower seams were different. The mining of the lower seam induced more complex strata movement along the strike. Multi-section mining disturbedsurrounding rocks in larger areas than the single section mining did, which had an impacton and dynamic loading function to the support when mining the lower seam, and produced a great influence on the stability of support-rock system.

  13. Seam-line determination for image mosaicking: A technique minimizing the maximum local mismatch and the global cost

    Science.gov (United States)

    Chon, Jaechoon; Kim, Hyongsuk; Lin, Chun-Shin

    2010-01-01

    This paper presents a novel algorithm that selects seam-lines for mosaicking image patches. This technique uses Dijkstra's algorithm to find a seam-line with the minimal objective function. Since a segment of seam-line with significant mismatch, even if it is short, is more visible than a lengthy one with small differences, a direct summation of the mismatch scores is inadequate. Limiting the level of the maximum difference along a seam-line should be part of the objective in the seam-line selection process. Our technique first determines this desired level of maximum difference, then applies Dijkstra's algorithm to find the best seam-line. A quantitative measure to evaluate a seam-line is proposed. The measure is defined as the sum of a fixed number of top mismatch scores. The proposed algorithm is compared with other techniques quantitatively and visually about various types of images.

  14. 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.

  15. 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.

  16. 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.

  17. 基于FPGA的数字认证相机设计%Design of digital authentication camera based on FPGA

    Institute of Scientific and Technical Information of China (English)

    潘晓中; 罗鹏; 刘方明; 雷雨

    2012-01-01

    A model of digital authentication camera based on semi-fragile watermarking was proposed, which is imple- mented on FPGA. Our watermarking algorithm was based on two invariant properties of DCT coefficients before and af- ter JPEG compressions, resisting JPEG compression under certain quality factor. At the same time, attacks were detec- ted and located. The hardware structure of the proposed model was designed and implemented upon the multimedia ex- ploitation platform of DE2 _ 70 + TRDB _ D5M + LTM. Watermarking is real-timely generated and then inserted con- comitantly with image capture, and thus authentication is guaranteed from beginning of image obtainment.%提出了一种基于图像半脆弱水印的数字认证相机模型,并在FPGA平台上予以实现。水印算法根据图像DCT系数在JPEG压缩过程中的两个不变特性进行设计,可以抵抗一定程度的JPEG压缩,同时检测恶意篡改并定位。模型的硬件结构在DE2_70+TRDB_D5M+LTM的FPGA多媒体开发平台上进行了设计实现,水印信息可伴随图像的采集过程实时生成和嵌入,从而在图像获取的源头保证了其可认证性。

  18. Numerical investigation of coal seam gas detection using airborne electromagnetics

    Science.gov (United States)

    Abdulla, Mohamed

    The use of airborne electromagnetic (AEM) techniques has been mostly utilized in the mining industry. The various AEM systems enable fast data acquisition to detect zones of interest in exploration and in some cases are used to delineate targets on a production scale. For coal seam gas (CSG) reservoirs, reservoir thickness and the resistivity contrast present a new challenge to the present AEM systems in terms of detectability. Our research question began with the idea of using AEM methods in the detection of thin reservoirs. CSG reservoirs resemble thin reservoirs that have been and are currently being produced. In this thesis we present the results of a feasibility analysis of AEM study on coal seam reservoirs using synthetic models. The aim of the study is to contribute and bridge the gap of the scientific literature on AEM systems in settings such as CSG exploration. In the models we have chosen to simulate both in 1-D and 3-D, the CSG target resistivity was varied from a resistive to a conductive target (4 ohm.m, 150 ohm.m, and 667 ohm.m) to compare the different responses while the target thickness was fixed to resemble a stack of coal seams at that interval. Due to the differences in 1-D and 3-D modelling, we also examine the differences resulting from each modelling set up. The results of the 1-D forward modeling served as a first order understanding of the detection depths by AEM for CSG reservoirs. Three CSG reservoir horizontally layered earth model scenarios were examined, half-space, conductive/resistive and resistive/conductive. The response behavior for each of the three scenarios differs with the differing target resistivities. The 1-D modeling in both the halfspace and conductive/resistive models shows detection at depths beyond 300 m for three cases of target resistivity outlined above. After the 300-m depth, the response falls below the assumed noise floor level of 5% response difference. However, when a resistive layer overlies a conductive host

  19. 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.

  20. 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.

  1. 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.

  2. 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%.

  3. Mechanism on simulation and experiment of pre-crack seam formation in stope roof

    Institute of Scientific and Technical Information of China (English)

    胡建华; 雷涛; 周科平; 刘浪; 劳德正

    2014-01-01

    The pre-crack blast technology has been used to control the induction caving area in the roof. The key is to form the pre-crack seam and predict the effect of the seam. The H-J-C blast model was built in the roof. Based on the theories of dynamic strength and failure criterion of dynamic rock, the rock dynamic damage and the evolution of pre-crack seam were simulated by the tensile damage and shear failure of the model. According to the actual situation of No. 92 ore body test stope at Tongkeng Mine, the formation process of the pre-crack blast seam was simulated by Ansys/Ls-dyna software, the pre-crack seam was inspected by a system of digital panoramic borehole camera. The pre-crack seam was inspected by the system of digital panoramic borehole in the roof. The results of the numerical simulation and inspection show that in the line of centers of pre-hole, the minimum of the tensile stress reaches 20 MPa, which is much larger than 13.7 MPa of the dynamic tensile strength of rock. The minimum particle vibration velocity reaches 50 cm/s, which is greater than 30-40 cm/s of the allowable vibration velocity. It is demonstrated that the rock is destroyed near the center line and the pre-crack is successfully formed by the large diameters and large distances pre-crack holes in the roof.

  4. Assessment of the Influence of Fractures on the Dynamics of Coal Seam Fires by Numerical Experiments

    Science.gov (United States)

    Wuttke, Manfred W.; Zeng, Qiang

    2016-04-01

    Uncontrolled burning coal seam fires still constitute major problems for the coal industry by destroying the resource, a serious hazard for the local people by severe environmental pollution, and a tremendous threat to the global environment by the emission of greenhouse gases and aerosols. In particular when the seams are lying shallow the alteration of the immediate surrounding of the coal seam fire feeds back on the dynamics of the fire. Thermal stress induced fracturing produces direct connections of the fire zone with the atmosphere. This influences the supply with oxygen, the venting of the exhaust gases, and the dissipation of heat. The first two processes are expected to enhance the fire propagation whereas the latter effect should slow it down. With our dedicated coal seam fire code ACME ("Amendable Coal-fire Modeling Exercise") we study these coupled effects of fractures in simulations of typical coal seam fire scenarios based on data from Xinjiang, China. Fractures are predefined as 1D/2D objects in a 2D/3D model geometry and are opened depending on the passage of the heat wave produced by the coal seam fire.

  5. 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.

  6. 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.

  7. 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.

  8. 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

    2015-01-01

    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. PMID:25580901

  9. 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.

  10. Maceral and geochemical characteristics of coal seam 1 and oil shale 1 in fault-controlled Huangxian Basin, China

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Y.Z.; Wang, B.S.; Lin, M.Y. [University of Petroleum, Beijing (China)

    1998-12-31

    Seven samples of coal seam 1 and oil shale 1 from the fault-controlled Hangxiang Basin were analysed by coal petrographic and geochemical methods. High huminite ratios and high contents of sesquiterpenoids and diterpenoids indicate that coal seam 1 and oil shale 1 are predominantly composed of terrestrial higher plant material. Two ternary diagrams of `facies diagnostic` macerals and biomarkers were used to interpret the depositional environments of organic matter in coal seam 1 and oil shale 1.

  11. 基于全局图像结构信息的Seam Carving算法%Seam Carving algorithm based on global image structure

    Institute of Scientific and Technical Information of China (English)

    聂栋栋; 马勤勇

    2011-01-01

    This paper presented a Seam Carving algorithm based on global image structure,which changed the sizes and scales of images by the importance of each pixel.It defined a new pixel energy function from both global and local information by extracting special image edges and computing each pixel gradients, which prevented seams from crossing image edges, avoided the pixels on edges moving differently and preserved image edge structures.Experiments confirm that this algorithm reduces the structure distortion and improves the visual effect of images by Seam Carving process effectively.%提出了一种基于全局图像结构信息的Seam Carving算法,它根据像素的重要性修改图像尺寸和比例.通过从图像提取特定方向的边缘结构信息,再利用每个像素的梯度信息,从全局和局部两方面定义新的像素能量计算函数,以此来阻止seam通路与特定方向图像边缘的交叉,避免边缘像素的不一致位移,以此保持图像的边缘结构.实验结果证明,算法减少了处理后图像的结构形变,有效改进了Seam Carving算法的处理效果.

  12. Improved schemes and methods of working closely lying flat seams. [USSR - Ukrainian SSR

    Energy Technology Data Exchange (ETDEWEB)

    Batmanov, Yu.K.; Bakhtin, A.F.; Bulavka, E.I. (DonUGI (USSR))

    1990-08-01

    Presents requirements that must be met in order to improve working of closely lying coal seams in the Ukraine. These requirements are: the working order should ensure effective utilization of protective seams for rock burst prevention, gas should be reduced by natural degassing during under- and overworking, and rock pressure should be controlled. A mixed order of seam working is recommended that combines the advantages of ascending and descending working order. Two working schemes that suit the requirements are presented: descending working order in a pillar system with countercurrent ventilation, and ascending working with combined system and concurrent ventilation. Three more improved schemes with air-flow freshening intended for deep highly methane bearing coal seams are considered to meet the requirements still better. Cost effectiveness of the working schemes is compared and an economic effect of 0.8-1.2 rubles/t is claimed. A method of seam grouping into winning and basic workings is recommended that allows the volume and maintenance cost of basic workings to be reduced by 30-40%. Application criteria of the working schemes are discussed. 7 refs.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Study on improving the permeability of soft coal seam with high pressure pulsed water jet

    Energy Technology Data Exchange (ETDEWEB)

    Xiao-Hong Li; Yi-Yu Lu; Yu Zhao; Yong Kang; Dong-Ping Zhou [Chongqing University (China)

    2008-12-15

    A new idea of improving the permeability of soft coal seams and increasing the rate of gas release by drilling and splitting the coal seam is presented. Based on the rock dynamic damage model, the dynamic damage properties and the fracture field's dynamic evolution mechanism were studied by theoretical analyses and numerical simulation of the condition of instantaneous dynamic load and flexible impact of a high pressure pulsed water jet. The results show that the effect of the impact, denudation and vibration caused coal to crack and improved permeability. A pulsed water jet gas drainage system has been developed and applied successfully in a typical mine rich in gas and of low permeability in Chongqing. The application demonstrates the high pressure pulsed water jet has effectively improved seam permeability with the drainage flux amounting to 7.8 times per 100 m of drainage hole. 8 refs., 6 figs.

  19. 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.

  20. Design and trial of a multi lift Wongawilli mining method for thick coal seams. [Australia

    Energy Technology Data Exchange (ETDEWEB)

    O' Beirne, T.J.

    1981-01-01

    The Australian Coal Industry Research Laboratories (ACIRL) designed a system of mining coal seams over 5 m thick with near complete extraction using a multi-slice Wongawilli operation. As conceived, the seam was divided into three slices with the top slice worked first and the bottom slice following some distance behind. During retreat of the bottom slice the middle section would be cut down with the raised head of the continuous miner. Field trials began at Collinsville, Australia, in 5.4 m thick seam in July 1978 and ceased in August 1981. Details of the original model are presented, and the performance under field conditions is assessed. The applications and limitations of the system are assessed. (16 refs.)

  1. 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.

  2. 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

  3. 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.

  4. 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…

  5. 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.

  6. 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.

  7. The division of coal species in seams by the digital logs in Juye coalfield

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Z. [Shandong Coal Geologic Engineering Surveying Institute, Jinan (China)

    1997-12-31

    The division of coal species is based generally on the sampling and analysis. For coal seams with complex texture and higher degree of metamorphism, the qualitative division of coal species is more complex. Using the geophysical characters of coal seams reflected by logging data, combined with the data obtained from the geological description of cores, coal-petrologic identification and coal quality analysis and so on, the better effects are obtained in the comprehensive qualitative classification of coal species. 2 refs., 5 figs., 2 tabs.

  8. IMPROVING METHODS OF MODELING CANAL WAVES PROPAGATION PROCESS IN COAL SEAMS

    Directory of Open Access Journals (Sweden)

    SMIRNOV YU.M.

    2012-01-01

    Full Text Available There has been analyzed the principal methods of modeling the process of canal waves propagation in coal seams when carrying out mining geophysical studies. There has been established that the wave guide moving into the surface of the elastic half-space doesn’t practically change the main properties of the interferential waves propagating in them. There has been recommended to use Fourier integral describing the single pulse spectrum for studying the registered seismograms. There have been formulated the main problems of improving physical processes modeling in coal seams when carrying out their geological studying

  9. 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.

  10. 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.

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

    OpenAIRE

    Pinkun Guo; Yuanping Cheng

    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...

  12. A versatile new mineralized bone stain for simultaneous assessment of tetracycline and osteoid seams.

    Science.gov (United States)

    Villanueva, A R; Lundin, K D

    1989-05-01

    A versatile mineralized bone stain (MIBS) for demonstrating osteoid seams and tetracycline fluorescence simultaneously in thin or thick undecalcified sections has been developed. Bone specimens are fixed in 70% ethanol, but 10% buffered formalin is permissible. Depending upon one's preference, these specimens can be left unstained or be prestained before plastic embedding. Osteoid seams are stained green to jade green, or light to dark purple. Mineralized bone matrix is unstained or green. Osteoblast and osteoclast nuclei are light to dark purple, cytoplasm varies from slightly gray to pink. The identification of osteoid seams by this method agrees closely with identification by in vivo tetracycline uptake using the same section from the same biopsy. The method demonstrates halo volumes, an abnormal, lacunar, low density bone around viable osteocytes in purple. This phenomenon is commonly seen in vitamin D-resistant rickets, fluorosis, renal osteodystrophy, hyperparathyroidism, and is sometimes seen in fluoride treated osteoporotic patients. In osteomalacic bone, most osteoid seams are irregularly stained as indicated by the presence of unmineralized osteoid between mineralized lamellae. The method has been used effectively in staining new bone formation in hydroxyapatite implants and bone grafts. Old, unstained, plastic embedded undecalcified sections are stained as well as fresh sections after removal of the coverslip. This stain also promises to be valuable in the study of different metabolic bone diseases from the point of view of remodeling, histomorphometry, and pathology. PMID:2480003

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

    Energy Technology Data Exchange (ETDEWEB)

    Li, X.; Zhou, D.; Lu, Y.; Kang, Y.; Zhao, Y.; Wang, X. [Chongqing University, Chongqing (China)

    2009-09-15

    Mine gas extraction in China is difficult due to the as micro-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. The three dynamic effects can be found in low-permeability coal seams. A new pulsed water jet with 200-1000 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 absorption 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. 11 refs., 5 figs., 2 tabs.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. "3-Section" Technology of Full-Dimension Mining in Flat Thick-Seam

    Institute of Scientific and Technical Information of China (English)

    赵景礼

    2004-01-01

    To raise coal recovery ratio and solve the key problem of full-dimension mining, a new "3-section" technology of full-dimension mining is put forward in flat thick-seam according to the theory and mining practice. This technology is proved to be rational and feasible in rodway layout system of stagger arrangement.

  1. In situ determination of sulphur in coal seams and overburden rock by PGNAA

    Science.gov (United States)

    Borsaru, M.; Berry, M.; Biggs, M.; Rojc, A.

    2004-01-01

    The prompt gamma neutron activation analysis technique was tested successfully for the determination of sulphur in coal seams and overburden rock. The logging tool employs a 3 μg 252Cf neutron source and a 50 mm dia × 100 mm BGO detector.

  2. In situ determination of sulphur in coal seams and overburden rock by PGNAA

    Energy Technology Data Exchange (ETDEWEB)

    Borsaru, M. E-mail: mihai.borsaru@csiro.au; Berry, M.; Biggs, M.; Rojc, A

    2004-01-01

    The prompt gamma neutron activation analysis technique was tested successfully for the determination of sulphur in coal seams and overburden rock. The logging tool employs a 3 {mu}g {sup 252}Cf neutron source and a 50 mm dia x 100 mm BGO detector.

  3. 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.

  4. 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

  5. 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.

  6. Real-time tracking for virtual environments using scaat kalman filtering and unsynchronised cameras

    DEFF Research Database (Denmark)

    Rasmussen, Niels Tjørnly; Störring, Morritz; Moeslund, Thomas B.;

    2006-01-01

    This paper presents a real-time outside-in camera-based tracking system for wireless 3D pose tracking of a user’s head and hand in a virtual environment. The system uses four unsynchronised cameras as sensors and passive retroreflective markers arranged in rigid bodies as targets. In order...... to achieve high update rates and to cope with the unsynchronised data a single-constraint-at-a-time (SCAAT) Extended Kalman Filtering approach is used that recursively integrates measurements as soon as they are available one-at-a-time. Tests show that this approach is more robust to occlusions and provides...

  7. Cracks in the joints of superheated steam tubing in the area of welding seams. Pt. 1

    International Nuclear Information System (INIS)

    The authors furnish, on the basis of extensive bibliography, an introductory review of the materials utilised in the construction of power plants and of the crack damage thereby observed in the joints of superheated steam tubing in various areas of the welding seams. The properties of the alloyed materials used in the construction of superheated steam tubing are elucidated. An optimum in creep strength with simultaneous sufficiency in toughness can only be achieved by careful heat treatment. In recent years, cracks have occurred to an ever-increasing extent in superheated steam tubing joints in the area of the welding seams. The incidents of damage dealt with from the bibliography drawn-upon primarily concern welding seam cracks and cracks running parallel to the circumferential welds in the area of the heat-affected zone. On the basis of a detailed illustration, thirteen recent occurrences of damage to the joints of superheated steam tubing in the area of welding seams are discussed; these were the subject of detailed expertises conducted at the Allianz Centre for Technology. The authors also furnish a review of the processes leading up to the occurrence of crack damage in various areas of the welding seams of joints. This is followed by pointers and recommendations for the prevention of such cracks, based on the experience gained from hitherto known incidents of damage. In summing up, the authors find that it should be feasible to avoid crack damage of this nature by means of appropriate material forming and commensurate application of welding techniques. (orig.)

  8. Improved Continuous Tube Welding Due to Unique Process Sensor System and Process Control

    Science.gov (United States)

    Dorsch, F.; Pfitzner, D.; Braun, H.

    A unique camera-based triple sensor system increases productivity, yield and quality of continuous welding of tubes and profiles. It combines high-precision seam tracking and beam positioning with weld spot visualization and characterization, and seam geometry measurement. The higher overall precision allows operating the process closer to its limits, online quality monitoring detects faults immediately. The process setup time is greatly reduced, and also the waste during startup is reduced. Finally, full documentation sets the basis for data traceability.

  9. 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.

  10. 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 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. PMID:25303243

  11. 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.

  12. Tracks Revisited.

    Science.gov (United States)

    Scarnati, James T.

    1993-01-01

    Describes a contemporary adaptation of the "Footprint Puzzle," whigh was first developed in the 1960s for the Earth Science Curriculum Project. Students sequentially look at three frames of track drawings. For each frame, students first list observations and then make inferences about the observations. (PR)

  13. 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

  14. 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

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. Mining a coal seam below a heating goaf with a force auxiliary ventilation system at Longhua underground coal mine, China

    Institute of Scientific and Technical Information of China (English)

    Wang Gang; Xie Jun; Xue Sheng; Wang Haiyang

    2015-01-01

    Extraction of a coal seam which lies not far below a heating goaf can be a major safety challenge. A force auxiliary ventilation system was adopted as a control method in successful extraction and recovery of the panel 30110 of the #3?1 coal seam, which is about 30–40 m below the heating goaf of the #2?2 seam at Longhua underground coal mine, Shanxi Province, China. Booster fans and ventilation control devices such as doors and regulators were used in the system. The results show that, provided that a force auxiliary ventilation system is properly designed to achieve a pressure balance between a panel and its overlying goaf, the system can be used to extract a coal seam overlain by a heating goaf. This paper describes the design, installation and performance of the ventilation system during the extraction and recovery phases of the panel 30110.

  20. 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.

  1. 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.

  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. Laser Ablation Cleaning of Self-Reacting Friction Stir Weld Seam Surfaces: A Preliminary Evaluation

    Science.gov (United States)

    Nunes, A. C., Jr.; Russell, C. K.; Brooke, S. A.; Parry, Q.; Lowrey, N. M.

    2014-01-01

    Anodized aluminum panels were cleaned by three lasers at three separate sites with a view to determining whether more economical laser cleaning might supplant current manual cleaning methods for preparation of surfaces to be welded by the self-reacting friction stir process. Uncleaned panels yielded welds exhibiting residual oxide defect (ROD) and failing at very low stresses along the trace of the weld seam. Manually cleaned panels yielded welds without ROD; these welds failed at nominal stress levels along an angled fracture surface not following the weld seam trace. Laser cleaned panels yielded welds failing at intermediate stress levels. The inadequacy of the laser cleaning processes leaves questions: Was the anodized aluminum test too stringent to represent actual cleaning requirements? Were the wrong laser cleaning techniques/parameters used for the study? Is the laser cleaning mechanism inadequate for effective preweld surface cleaning?

  4. 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.

  5. 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. PMID:24396293

  6. 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%.

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

    OpenAIRE

    Chen Wang; Shihao Tu

    2015-01-01

    Mechanized mining technical process (MMTP) related to the control method of the shearer is a vital process in thin coal seam mining operations. An appropriate MMTP is closely related to safety, productivity, labour intensity, and efficiency. Hence, the evaluation of alternative MMTP is an important part of the mining design. Several parameters should be considered in MMTP evaluation, so the evaluation is complex and must be compliant with a set of criteria. In this paper, two multiple criteri...

  8. Practical methodology to evaluate the fatigue life of seam welded joints

    OpenAIRE

    K.C.Goes; G.F. Batalha; M.V. Pereira; A.F. Camarao

    2011-01-01

    Purpose: of this paper is to present a practical and robust methodology developed to evaluate the fatigue life of seam welded joints under combined cyclic loading.Design/methodology/approach: Fatigue analysis was conducted in virtual environment. The finite element stress results from each loading were imported to fatigue code FE-Fatigue and combined to perform the fatigue life prediction using the S x N (stress x life) method. A tube-to-plate specimen was submitted to a combined cyclic loadi...

  9. 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.

  10. IMPROVING METHODS OF MODELING CANAL WAVES PROPAGATION PROCESS IN COAL SEAMS

    OpenAIRE

    SMIRNOV YU.M.; КЕNZHIN B.М.

    2012-01-01

    There has been analyzed the principal methods of modeling the process of canal waves propagation in coal seams when carrying out mining geophysical studies. There has been established that the wave guide moving into the surface of the elastic half-space doesn’t practically change the main properties of the interferential waves propagating in them. There has been recommended to use Fourier integral describing the single pulse spectrum for studying the registered seismograms. There have been fo...

  11. 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.

  12. 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.

  13. 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.

  14. Laser welding process in PP moulding parts: Evaluation of seam performance

    Science.gov (United States)

    Oliveira, N.; Pontes, A. J.

    2015-12-01

    The Polypropylene is one of the most versatile polymer materials used in the industry. Due to this versatility, it is possible to use it in different products. This material can also be mixed with several additives namely glass fiber, carbon nanotubes, etc. This compatibility with different additives allows also obtaining products with characteristics that goes from an impact absorber to an electricity conductor. When is necessary to join components in PP they could be welded through hot plate, ultrasonic weld and also by laser. This study had the objective of study the influence of several variables, capable of influence the final quality of the seam. In this case were studied variables of the injection molding process as mold temperature and cooling time. Was also studied laser welding variables and different materials. The results showed that the variables that have the most influence were mould temperature, laser velocity and laser diameter. The seams were analyzed using Optical Microscopy technique. The seams showed perfect contact between the materials analyzed, despite the high standard variation presented in the mechanical testes.

  15. An analysis of injury claims from low-seam coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, S.; Moore, S.; Dempsey, P.G. [NIOSH, Pittsburgh, PA (United States)

    2009-07-01

    The restricted workspace present in low-seam coal mines forces workers to adopt awkward working postures (kneeling and stooping), which place high physical demands on the knee and lower back. This article provides an analysis of injury claims for eight mining companies operating low-seam coal mines during calendar years 1996-2008. All cost data were normalized using data on the cost of medical care (MPI) as provided by the U.S. Bureau of Labor Statistics. Results of the analysis indicate that the knee was the body part that led in terms of claim cost ($4.2 million), followed by injuries to the lower back ($2.7 million). While the average cost per injury for these body parts was $13,100 and $14,400, respectively (close to the average cost of an injury overall), the high frequency of these injuries resulted in their pre-eminence in terms of cost. Analysis of data from individual mining companies suggest that knee and lower back injuries were a consistent problem across companies, as these injuries were each among the top five most costly part of body for seven out of eight companies studied. Results of this investigation suggest that efforts to reduce the frequency of knee and low back injuries in low-seam mines have the potential to create substantial cost savings.

  16. 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.

  17. Determination of Fracture Initiation Locations during Cross-Measure Drilling for Hydraulic Fracturing of Coal Seams

    Directory of Open Access Journals (Sweden)

    Yiyu Lu

    2016-05-01

    Full Text Available When drilling coal-bearing sequences to enhance coal seam permeability by hydraulic fracturing (HF, the location where fractures are initiated is important. To date, most research on fracture initiation has studied the problem in two dimensions. In this study, a three-dimensional model to assess initiation location is developed. The model analyzes the stress state of both the borehole wall and the coal-rock interface and the model shows that the fracture initiation location is affected by in situ stress, the dip of the coal seam, and the angle between the borehole and the coal seam. How the initiation location changes near different types of geological faults is calculated by assuming typical in situ stresses for the faults. Following these calculations, physical experiments were carried out to emulate cross-measure hydraulic fracturing under stress conditions equivalent to those in the Chongqing Tonghua coal mine, China. Fracture initiation during the experiments was monitored by an acoustic emission system. The experimental results were consistent with the theoretical calculations. This implies that the three-dimensional model for assessing the locations of fracture initiation can be applied to forecast the initiation location of fractures generated by cross-measure drilling. The assessment model provides reference values for this type of drilling in underground mines.

  18. The influence of hydrogeological disturbance and mining on coal seam microbial communities.

    Science.gov (United States)

    Raudsepp, M J; Gagen, E J; Evans, P; Tyson, G W; Golding, S D; Southam, G

    2016-03-01

    The microbial communities present in two underground coal mines in the Bowen Basin, Queensland, Australia, were investigated to deduce the effect of pumping and mining on subsurface methanogens and methanotrophs. The micro-organisms in pumped water from the actively mined areas, as well as, pre- and post-mining formation waters were analyzed using 16S rRNA gene amplicon sequencing. The methane stable isotope composition of Bowen Basin coal seam indicates that methanogenesis has occurred in the geological past. More recently at the mine site, changing groundwater flow dynamics and the introduction of oxygen in the subsurface has increased microbial biomass and diversity. Consistent with microbial communities found in other coal seam environments, pumped coal mine waters from the subsurface were dominated by bacteria belonging to the genera Pseudomonas and the family Rhodocyclaceae. These environments and bacterial communities supported a methanogen population, including Methanobacteriaceae, Methanococcaceae and Methanosaeta. However, one of the most ubiquitous micro-organisms in anoxic coal mine waters belonged to the family 'Candidatus Methanoperedenaceae'. As the Archaeal family 'Candidatus Methanoperedenaceae' has not been extensively defined, the one studied species in the family is capable of anaerobic methane oxidation coupled to nitrate reduction. This introduces the possibility that a methane cycle between archaeal methanogenesis and methanotrophy may exist in the anoxic waters of the coal seam after hydrogeological disturbance. PMID:26541089

  19. Design and trial of a multilift Wongawilli mining method for thick coal seams

    Energy Technology Data Exchange (ETDEWEB)

    O' Beirne, T.

    1980-01-01

    ACIRL designed a system of mining coal seams over 5.0 metres thick with near complete extraction using a multislice Wongawilli operation. As conceived, the seam was divided into three slices with the top slice worked first and the bottom slice following some distance behind. During retreat of the bottom slice the middle section would be cut down with the raised head of the continuous miner. Physical and mathematical model studies were performed to test the concept and in general showed that: development headings should be superimposed for maximum stability; the central portion between the top and lower lifts, known as the septum, benefits from reinforcement; top and lower workings could be worked simultaneously or as totally separate workings; when working both slices simultaneously an optimum separation distance existed (dependent on geotechnical environment); coal pillars remaining amongst the top slice goaf adversely affected the lower workings; and the septum could be successfully extracted whilst retreating the lower workings. A full scale trial of the method on a coal block 300 x 300 m was held at the Collinsville Coal Company mine, in the 5.3 m thick Bowen Seam between July 1978 and August 1981.

  20. 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.

  1. 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.

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

    International Nuclear Information System (INIS)

    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)

  3. 基于BP神经网络的数码相机颜色特征化%Color Characterization for Digital Camera Based on BP Neural Network

    Institute of Scientific and Technical Information of China (English)

    蒋飞飞; 徐兰萍; 郑立扬

    2012-01-01

    Color characterization method for digital cameras based on BP neural network was proposed after comparison of color characterization methods using the color theory and neural network theory.Color space conversion from RGB to XYZ and Lab was realized by using MATLAB.The precision of the two models was compared and the main causes of training and test error were analyzed statistically.The results showed that RGB to Lab color space version is better than RGB to XYZ.%以色度学理论和神经网络为基础,在综合比较数码相机颜色特征化方法之后,采用了基于BP神经网络的颜色特征化方法。利用MATLAB实现了从RGB到XYZ及Lab的颜色空间转换,比较了2种转换模型的精度,统计分析了该模型产生训练误差和测试误差的主要原因,验证了RGB→Lab转换算法是一种较优和可靠的方法。

  4. 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

  5. INNER TRACKING

    CERN Document Server

    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...

  6. 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......’ that differs from the standardized procedures of normal science. To establish our points we use an example of problem-based project work conducted by a group of Techno-Anthropology students at Aalborg University, we focus on key aspects of this craft and how the students began to learn it: For two weeks...... 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....

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Track Construction Manual.

    Science.gov (United States)

    Banke, Ron; Di Gennaro, Guy; Ediger, Rick; Garner, Lanny; Hersom, Steve; Miller, Jack; Nemeth, Ron; Petrucelli, Jim; Sierks, Donna; Smith, Don; Swank, Kevin; West, Kevin

    This book establishes guidelines for the construction and maintenance of tracks by providing information for building new tracks or upgrading existing tracks. Subjects covered include running track planning and construction, physical layout, available surfaces, and maintenance. General track requirements and construction specifications are…

  13. 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.

  14. 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.

  15. A method of working a coal seam which has coal and gas outbursts

    Energy Technology Data Exchange (ETDEWEB)

    Batmanov, Y.K.; Bakhtin, A.F.; Mochseev, M.A.; Petukhov, I.M.; Saratikyants, S.A.; Voronin, V.A.

    1983-01-01

    The purpose of this invention is to reduce expenditures on the working of an outburst-prone formation. This is achieved by using the method of working a coal seam which is prone to coal and gas outbursts; this method involves local safety excavation in the protection formation and opening air passage and ventilation workings; the ventilation working proceeds through the formation which is prone to gas and coal outbursts, while the local protection excavation in the protection formation is performed on both sides of the air passage working simultaneously with the ventilation working which is connected occasionally to the air passage working by blind shafts.

  16. 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.

  17. 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.

  18. 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.

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

    International Nuclear Information System (INIS)

    CO2 emissions into the atmosphere are recognized to have a significant effect on global warming. Geological storage of CO2 is widely regarded as an essential approach to reduce the impact of such emissions on the environment. Moreover, injecting carbon dioxide in coal bed methane reservoirs facilitates the recovery of the methane naturally present, a process known as enhanced coal bed methane recovery (ECBM). But the swelling of the coal matrix induced by the preferential adsorption by coal of carbon dioxide over the methane in place leads to a closure of the cleat system (a set of small natural fractures) of the reservoir and therefore to a loss of injectivity. This PhD thesis is dedicated to a study of how this injectivity evolves in presence of fluids. We derive two poro-mechanical dual-porosity models for a coal bed reservoir saturated by a pure fluid. The resulting constitutive equations enable to better understand and model the link between the injectivity of a coal seam and the adsorption-induced swelling of coal. For both models, the pore space of the reservoir is considered to be divided into the macroporous cleats and the pores of the coal matrix. The two models differ by how adsorption of fluid is taken into account: the first model is restricted to surface adsorption, while the second model can be applied for adsorption in a medium with a generic pore size distribution and thus in a microporous medium such as coal, in which adsorption mostly occurs by micropore filling. The latter model is calibrated on two coals with different sorption and swelling properties. We then perform simulations at various scales (Representative Elementary Volume, coal sample, coal seam). In particular, we validate our model on experimental data of adsorption-induced variations of permeability of coal. We also perform simulations of seams from which methane would be produced (CBM) or of methane-free seams into which CO2 would be injected. We study the effect of various

  20. 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

  1. Geometric characterization of a circumferential seam by automatic segmentation of digitized radioscopic images

    International Nuclear Information System (INIS)

    The present study deals with the nondestructive control of a circumferential seam by digital radioscopy. A series of images for one complete revolution of the welded component is available. We first resort to a joint approach by simulation and experimentation. This approach allows the detection of the molten zone limits for an initial image. We then develop a segmentation method that permits automatic extraction of the geometric characteristics of the set of images representative of the weld. These measures supply fast and automatic control of the weld quality. Results are shown for real components. (author)

  2. 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.

  3. 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

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

    OpenAIRE

    Jianping Zhou; Yan Xu; Qiang He; Bisheng Zhou

    2013-01-01

    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 puls...

  5. 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.

  6. 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

  7. 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 ...

  8. 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...

  9. 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.

  10. Classification of conditions for short-wall continuous mechanical mining in shallowly buried coal seam with thin bedrock

    Institute of Scientific and Technical Information of China (English)

    LIU Yu-de; ZHANG Dong-sheng; MA Li-qiang; ZHAO Yong-feng; WANG Hong-sheng

    2008-01-01

    The room and pillar method is usually used to extract coal from shallowly buried seams with thin bedrock. This results in a very low production efficiency and in a low degree of extraction. In recent years short-wall continuous mechanical mining has been extensively used in many situations except shallowly buried coal seams with thin bedrock. The principles governing movement of the overlying strata above the 2.35 m, which was done using fuzzy clustering results. A series of reasonable,relative parameters in each category have been calculated and analyzed. One proposed way to perform short-wall continuous mechanical mining in shallowly buried coal seams is given. This is significant for coal mines with similar geological conditions.

  11. Depillaring of total thickness of a thick coal seam in single lift using cable bolts:A case study

    Institute of Scientific and Technical Information of China (English)

    Kumar Rakesh; Mishra Arvind Kumar; Singh Arun Kumar; Singh Amit Kumar; Ram Sahendra; Singh Rajendra

    2016-01-01

    Explaining fundamentals of application of cable bolting for a thick seam depillaring, this paper summa-rizes the results of field studies conducted during adoption of this approach in more than fifteen panels of Madhusudanpur 7 pit and incline mine. Nearly 7.0 m thick Kajora top coal seam of this mine is developed on pillars along the floor horizon to an average height of 3.0 m, leaving a coal band of around 4.0 m along the roof. Analysis of procured core samples showed that roof strata are easily caveable with a caveability index value of around 2000 only. Easily caveable overlying strata and shallow depth of cover alleviated most of the expected strata mechanics problems of the thick seam mining. However, extraction of total thickness at shallow cover caused differential-subsidence and cracks on the surface. These manifestations were immediately tackled to avoid creation of a breathing path for spontaneous heating in the extracted area.

  12. 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......The present improvement that we see III 3D medical scanner technology including increasing spatio-temporal resolution and increasing signal-to-noise ratio underlines the need for reliable motion correction. Many motion correction schemes assume that the motions are known [1-3]. However, a reliable...

  13. 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.

  14. Petrographic and geochemical contrasts and environmentally significant trace elements in marine-influenced coal seams, Yanzhou mining area, China

    Science.gov (United States)

    Liu, Gaisheng; Yang, P.; Peng, Z.; Chou, C.-L.

    2004-01-01

    The Yanzhou mining area in west Shandong Province, China contains coals of Permian and Carboniferous age. The 31 and 32 seams of the Permian Shanxi Formation and seams 6, 15-17 of the Carboniferous Taiyuan Formation were analyzed for coal petrology, mineralogy and geochemical parameters. The parameters indicate that the coal is high volatile bituminous in rank. The coal is characterized by high vitrinite and low to medium inertinite and liptinite contents. These properties may be related to evolution of the coal forming environment from more reducing conditions in a marine influenced lower delta plain environment for the early Taiyuan coals to more oxidizing paleoenvironments in an upper delta plain for the upper Shanxi coal seams. The major mineral phases present in the coal are quartz, kaolinite, pyrite and calcite. Sulfur is one of the hazardous elements in coal. The major forms of sulfur in coal are pyritic, organic and sulfate sulfur. Pyritic and organic sulfur generally account for the bulk of the sulfur in coal. Elemental sulfur also occurs in coal, but only in trace to minor amounts. In this paper, the distribution and concentration of sulfur in the Yanzhou mining district are analyzed, and the forms of sulfur are studied. The sulfur content of the Taiyuan coal seams is considerably higher than that of the Shanxi coals. Organic sulfur content is positively correlated to total and pyritic sulfur. The vertical variation of Cu, Zn, Pb, As, Th, U and sulfur contents in coal seam 3 of the Shanxi Formation in the Xinglongzhuang mine show that all these trace elements, with the exception of Th, are enriched in the top and bottom plies of the seam, and that their concentrations are also relatively high in the dirt bands within the seam. The pyritic sulfur is positively correlated with total sulfur, and both are enriched in the top, bottom and parting plies of the seam. The concentrations of the trace elements are closely related to sulfur and ash contents. Most of

  15. Solution of underground mine gas emissions on surface of abandoned mining sites where steep deposited coal seams have been exploited

    Energy Technology Data Exchange (ETDEWEB)

    Takla, G.; Froml, K. [OKD, DPB, Paskov (Czech Republic)

    2005-07-01

    The solution of uncontrolled gas emissions from abandoned underground coal mine sites in Ostrava-Karvina coal-field to surface ground in connection with old mine shafts and drifts and with old mining workings in horizontal and inclined coal seams has many forms. It varies according to geological and mining conditions and the disposition of the site surface. Since four years the gas emission risk has appeared in the area of former exploited vertical coal seams within the historical centre of Orlova town, which is protected by State Monument Protection office. A project based on such special nature of mining-geological and urban conditions was elaborated and already implemented. (authors)

  16. 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.

  17. Schemes for development and mining of level coal seams without leaving support coal pillars

    Energy Technology Data Exchange (ETDEWEB)

    Bakhtin, A.F.; Batmanov, Yu.K.; Taratuta, N.K.

    1982-07-01

    Methods are illustrated for longwall mining without leaving support pillars for strata control. Comparative evaluations in Soviet coal mines show that with increasing mining depth coal losses associated with support pillars increase. Use of support pillars also increases rock burst hazard and increases cost of support repairs in mine roadways. Proportion of coal from longwall mining without leaving coal support pillars increased from 36 % in 1976 to 52% in 1980. Two variants of longwall mining without support pillars are analyzed: with repeated use of longwall gate roads and without their repeated use. Comparative investigations show that longwall mining with the repeated use of the gates (one of the gate roads) is used in coal seams with the most convenient mining and geological conditions, whereas the second system is used under more difficult conditions. Schemes with repeated use are designed for thin coal seams, at a depth not exceeding 600 m, under conditions of stable roof and floor (when the floor consists of less stable rocks absence of water influx is the condition). Repeated use of gate roads is economical when, in spite of repeated gate road use, cost of support repair and maintenance is low. Fifteen schemes for longwall mining with and without repeated use of gateroads are compared. The results of evaluations are shown in a table. Recommendations on the most economical mining schemes are made.

  18. Strata behavior investigation for high-intensity mining in the water-rich coal seam

    Institute of Scientific and Technical Information of China (English)

    Ding Huande; Miao Xiexing; Ju Feng; Wang Xiulin; Wang Qingcang

    2014-01-01

    This paper describes a specific case of mining in a water-rich coal seam in western China. Water inrushes, roof caving and other disasters induced by intensive mining operation could pose great threats to the safety of coal mines. The strata behavior during the high-intensity extraction in the water-rich coal seam is analyzed by employing the numerical simulation method and in situ monitoring. The results show that about 10 m ahead of the workface, the front abutment pressure peaks is at 34.13 MPa, while the peak of the side abutment pressure is located about 8 m away from the gateway with the value of 12.41 MPa;the height of the fracture zone, the first weighting step and the cycle weighting step are calculated to be 45, 50 and 20.8 m, respectively; pressure distribution in the workface is characterized by that the vertical pressure in the center occurs earlier and is stronger than those on both ends. Then, the results above are verified by in situ measurement, which may provide a basis for safe mining under similar conditions.

  19. The effect of the fracture distribution on CO2 injection into a coal seam

    Institute of Scientific and Technical Information of China (English)

    Yao Banghua; Wu Yu; Liu Jishan

    2012-01-01

    The effect of the fracture distribution on CO2 injection into coal seams was studied with a heterogeneous model having dual porosity to represent both the primary medium (the coal matrix) and the secondary medium (the fractures) under variable stress conditions.A numerical generation method and a digital image processing method were used to model the heterogeneous fracture distribution in the coal.The model solutions demonstrate that:(1) the fractures are the main channel for gas flow and their distribution has an important impact on the gas injection rate; (2) the fractures only affect the injection rate of CO2 into the coal but not the final storage amount; (3) when gas is injected into coal the fractures will first expand and then close due to the changing effective stresses and the adsorption induced swelling of coal grains.This fully coupled dual-porosity model with a heterogeneous fracture distribution provides a way to predict the CO2 injection into a coal seam.

  20. 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.

  1. Interpretation of Coal-Seam Sequestration Data Using a New Swelling and Shrinkage Model

    Energy Technology Data Exchange (ETDEWEB)

    Siriwardane, H.J.; Smith, D.H.

    2006-10-01

    This paper deals with the influence of swelling and shrinkage of coal on the production of methane from, and sequestration of carbon dioxide in, a coalbed reservoir. A three-dimensional swelling and shrinkage model was developed. It is based on constitutive equations that account for coupled fluid pressure-deformation behavior of a porous medium that undergoes swelling and shrinkage. The swelling and shrinkage strains are computed on the basis of the amounts of different gases (e.g., CO2, CH4) sorbed or desorbed. The amounts of sorption and desorption are computed from measured isotherms with the aid of the Ideal Adsorbed Solution model for mixed gases. The permeability of the reservoir is modified according to the swelling-shrinkage model. The paper presents numerical results for the influence of swelling and shrinkage on reservoir performance during injection of carbon dioxide. The paper includes results from a number of examples, and analysis of a field injection into a coal seam at a site in the San Juan basin. Results show that with the incorporation of swelling and shrinkage into the analysis, it is possible to get a better history-match of production data. Results also show that coal swelling can reduce the injection volumes of carbon dioxide significantly. The interpretation of field data with the new swelling-shrinkage model shows that the coal swelling during carbon dioxide sequestration in coal-seams is an important factor that can influence field performance.

  2. 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.

  3. 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.

  4. 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.

  5. 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. PMID:25783163

  6. The effect of mineral matrix and seam thickness on reflectance of vitrinite in high coals

    Energy Technology Data Exchange (ETDEWEB)

    Gentzis, T. (Alberta Research Council, Devon (Canada)); Goodarzi, F.; Snowdon, L.R.; Labonte, M. (Geological Survey of Canada, Calgary, Alberta (Canada)); Bustin, R.M. (Univ. of British Columbia, Vancouver (Canada))

    1991-06-01

    The variation of vitrinite reflectance with respect to mineral matrix (lithology), thickness of coal seams and coal lenses, as well as type of organic matter was studied from two cores in a 550-m sedimentary succession from the Upper Jurassic-Lower Cretaceous Kootenay Group. The data obtained indicate that reflectance in high- to low-volatile bituminous coals (% R{sub o}, max = 0.8 - 1.35) with depth of burial is affected by the percentage of organic matter in the samples. A positive correlation between the % R{sub o} and the percent of organic matter and a negative correlation with the percent of mineral matter were shown to exist. It was also observed that the thicker the coal interval, the higher the reflectance. Thick coal seams (greater than 1 m) with mineral content of less than 20% generally exhibited higher vitrinite reflectance than thin coaly lenses (15-30 cm thick) with mineral content of greater than 20%. Vitrinite dispersed in sandstone - and, to a lesser extent, siltstone and carbonaceous shale - had the lowest reflectance. Variations in vitrinite reflectance were attributed to chemical differences in the organic matter, possibly induced by degradation and diagenesis syn- or postdepositionally, the effect of geocatalysts present in the sediments, and possibly variations in thermal conductivity in the succession. Any differences in vitrinite reflectance of organic matter observed would be of great significance in the time-temperature history of a sediment needed to generate hydrocarbons.

  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. Data base for the analysis of compositional characteristics of coal seams and macerals. Part 7. Petrographic variation due to depositional setting of the lower Kittanning seam, western Pennsylvania. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Allshouse, S.D.; Davis, A.

    1984-01-01

    Detailed megascopic and microscopic petrographic analyses were conducted on samples of the Lower Kittanning seam from western Pennsylvania. Relationships were sought between the paleoenvironmental setting of the coal swamp and the vertical and lateral variability of lithotypes, maceral composition and vitrinite types. Megascopically, the four samples collected from the freshwater facies of the seam are similar in appearance and relative lithotype composition, and display no distinct vertical zonations. The sample from the marine-influenced central portion of the basin (PSOC-1340) possesses a marked vertical zonation into a bright lower zone and a dull upper zone. The lower zone is similar in appearance to the freswater samples. Detailed microscopic analyses revealed that the vertical zonation of PSOC-1340 is apparent in both the maceral and vitrinite type composition. No similar zonation is apparent in the microscopic analysis of the four freshwater facies samples. Similarities between the lower zone of PSOC-1340 and the whole seam of the freshwater samples are most apparent in the vitrinite-type analysis. The lower zone of PSOC-1340 and the whole seam from the freshwater facies are considered to be laterally equivalent coal types. The dull upper zone of PSOC-1340 is considered to have formed in response to a major change in the paleoenvironment of the swamp, probably a marine transgression. 49 references, 25 figures, 15 tables.

  9. 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.

  10. 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.

  11. 极近距离煤层下位巷道变形机理及控制%Deformation mechanism and control of lower seam roadway of contiguous seams

    Institute of Scientific and Technical Information of China (English)

    于洋; 神文龙; 高杰

    2016-01-01

    In order to solve the support problem of roadway locating in the lower seam of contiguous coal seams, this paper, taking Beiyu coalmine in Pu County, Shanxi Province as a case, has studied the stress field in the floor of gob belonging to upper seam and characteristics of deformation and instability for roadway locating in lower seam by means of numerical simulation. Principles of ground control for roadway roof in lower seam have been determined and different roof control methods have been tested in field. According to this research, three-dimensional combined roof control techniques based on hy-draulic expansion bolt and advancing insertion of tube on roof have been put forward with corres-ponding key parameters being determined through theoretical analysis and field test. Field test has sug-gested that control techniques raised in this paper are effective for the ground control of roadway in lower seam of contiguous coal seams and the general condition of roadway is good, which has provided great reference value for ground control of roadway in similar conditions.%为了解决极近距离煤层下位巷道围岩维护的难题,以山西蒲县北峪煤矿工程地质条件为背景,通过数值计算研究了极近距离上位煤层采空区下底板岩层的应力分布规律及下位煤层巷道变形破坏特征,确定了下位巷道顶板控制原则,并对不同顶板控制方式进行了现场测试;在此基础上,提出了基于水力膨胀锚杆全长锚固和顶板超前插管法的三维联合控顶技术,并依据力学计算和现场测试结果确定了关键参数。工业性试验表明,研究开发的控制技术对极近距离煤层下位巷道围岩的控制作用显著,巷道整体维护状况良好,给类似条件下的巷道围岩控制提供了有益的参考。

  12. Deformation mechanism and control of lower seam roadway of contiguous seams%极近距离煤层下位巷道变形机理及控制

    Institute of Scientific and Technical Information of China (English)

    于洋; 神文龙; 高杰

    2016-01-01

    为了解决极近距离煤层下位巷道围岩维护的难题,以山西蒲县北峪煤矿工程地质条件为背景,通过数值计算研究了极近距离上位煤层采空区下底板岩层的应力分布规律及下位煤层巷道变形破坏特征,确定了下位巷道顶板控制原则,并对不同顶板控制方式进行了现场测试;在此基础上,提出了基于水力膨胀锚杆全长锚固和顶板超前插管法的三维联合控顶技术,并依据力学计算和现场测试结果确定了关键参数。工业性试验表明,研究开发的控制技术对极近距离煤层下位巷道围岩的控制作用显著,巷道整体维护状况良好,给类似条件下的巷道围岩控制提供了有益的参考。%In order to solve the support problem of roadway locating in the lower seam of contiguous coal seams, this paper, taking Beiyu coalmine in Pu County, Shanxi Province as a case, has studied the stress field in the floor of gob belonging to upper seam and characteristics of deformation and instability for roadway locating in lower seam by means of numerical simulation. Principles of ground control for roadway roof in lower seam have been determined and different roof control methods have been tested in field. According to this research, three-dimensional combined roof control techniques based on hy-draulic expansion bolt and advancing insertion of tube on roof have been put forward with corres-ponding key parameters being determined through theoretical analysis and field test. Field test has sug-gested that control techniques raised in this paper are effective for the ground control of roadway in lower seam of contiguous coal seams and the general condition of roadway is good, which has provided great reference value for ground control of roadway in similar conditions.

  13. 76 FR 30241 - Pipeline Safety: Notice of Public Meetings on Managing Challenges With Pipeline Seam Welds and...

    Science.gov (United States)

    2011-05-24

    ... Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477) or view the... Managing Challenges With Pipeline Seam Welds and Improving Pipeline Risk Assessments and Recordkeeping... recordkeeping are driving a stronger focus on better managing these challenges. PHMSA is holding...

  14. 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.

  15. Coal-ball floras of maritime Canada and palynology of the Foord seam: geologic paleobotanical and paleoecogical implications

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, P.C.; Zodrow, E.L.; Millay, M.A.; Dolby, G.; Gillis, K.S.; Cross, A.T. [US Geological Survey, Reston, VA (United States). National Center

    1997-01-01

    Coal balls in the Canadian Carboniferous System are known from the Clifton Formation (late Bolsovian) of New Brunswick and from the Foord seam (Stellarton Formation, late Bolsovian) of the Stellarton Basin of Nova Scotia. Coal balls from these two units are dominated by arborescent lycopods but ferns, seed ferns, calamiteans, and cordaiteans also occur. Baxter`s 1960 list of coal-ball plants from New Brunswick is updated. The palynomorphs and coal-ball plants of the Foord seam of the Stellarton Basin are illustrated and their paleoecology is discussed. Five genera of arborescent lycopods were present in the Foord swamp: Diaphorodendron, Paralycopodites, Lepidophloios, Sigillaria and Lepidodendron. The first three genera are represented in coal balls; the second two are also represented as compressions in the Foord seam; and all genera are represented in the spore assemblages from the Foord seam. The palynostratigraphy indicates that Sigillaria and Diaphorodendron were almost exclusively confined to the upper bench, whereas the other three genera were probably present in the Foord mire throughout its entire history. Palynomorphic changes in the Foord mire probably reflect gradual changes in wet and dry conditions.

  16. 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.

  17. 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...

  18. Concept for the monitoring of weld seams on pressure pipes made of austenitic steel using ultrasonic processes

    International Nuclear Information System (INIS)

    A concept for the repeat testing of weld seams in pipelines made of Austenitic steel using ultrasonic processes is developed and tested. Even with varying sound attenuation in the material and on the occurence of 'ghost' indications, it ensures certain indication of faults. Further, the depth of cracks can be assessed, for example by the height of echos, even for large extents. (orig.)

  19. 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.

  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 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

  2. Selection of development and working methods of coal seams in complicated mining and geological conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kaufman, L.L.; Bakhtin, A.F.; Zel' vyanskii, M.Sh. (Donetskaya Proektnaya Kontora (USSR))

    1991-07-01

    Presents the design and technological patterns developed at the Donetsk Design Office for planning mining work in difficult mining conditions. The recommended patterns of working are based on the following principles. The most progressive panel development of mine-take and horizon layout methods are used. The main workings are driven as rock drifts with support pillars or they are driven in stress relaxed zones. Seams are worked with pillars or in a combined way. The pillarless technology is based on conducting workings with coal cutting along the excavated space or on repeated utilization of workings. Reduction in stone hoisting to the surface is achieved by execution of drifts that follow the longwalls. Variants of pillar systems with panel development of mine-take and horizon layout development are shown and described.

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

    DEFF Research Database (Denmark)

    Jensen, Jakob Langdal

    middleware, and how that middleware can provide developers with methods for controlling application qualities that are related to the positioning process. One key challenge is to understand how to support application development in a heterogeneous domain like that of positioning. Recent trends in application...... with sufficient control over the positioning technologies while maximizing the number of responsibilities that can be delegated to the middleware. We address these challenges by proposing model based translucency as a technique for building middleware that supports run-time inspection, is open to adaptation...... and extension, and can be used to realize a seamfully designed middleware. For position based applications, overall application quality often depends on properties that are orthogonal to the core positioning functionality; there- fore, quality management tend to cross-cut various abstractions of the positioning...

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. The algebra of bipartite graphs and Hurwitz numbers of seamed surfaces

    Science.gov (United States)

    Alekseevskii, A. V.; Natanzon, S. M.

    2008-08-01

    We extend the definition of Hurwitz numbers to the case of seamed surfaces, which arise in new models of mathematical physics, and prove that they form a system of correlators for a Klein topological field theory in the sense defined in [1]. We find the corresponding Cardy-Frobenius algebras, which yield a method for calculating the Hurwitz numbers. As a by-product, we prove that the vector space generated by the bipartite graphs with n edges possesses a natural binary operation that makes this space into a non-commutative Frobenius algebra isomorphic to the algebra of intertwining operators for a representation of the symmetric group S_n on the space generated by the set of all partitions of a set of n elements.

  9. Multifrequency eddy-current inspection of seam weld in steel sheath

    International Nuclear Information System (INIS)

    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

  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. Influence on the soldered seam properties with large gap widths by heat treatment

    International Nuclear Information System (INIS)

    Soldering tests were performed on the nickel base alloy NiCr 20 TiAl with the soldering material NiCrSi. It is seen that soldered seams of over 100 μm width are very brittle. The brittleness is due to the silicides formed during soldering. The ductility behaviour can be considerably improved by an annealing treatment after soldering which does not affect the properties of the basic material. This ductility-increasing heat treatment can also be applied to other soldered joints, the optimum temperatures and annealing times being determined by metallographic and technological investigations. Spot sampling under the actual operational conditions is recommended prior to introducing this heat treatment step into the fabrication. (orig./LH)

  12. Significance of Coal Seam in Recognition of Sequence Boundaries and Systems Tract of the Jurassic in East Fukang Slope, Junggar Basin, China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The Jurassic in the East Fukang Slope can be divided into six sequences based on sequence stratigraphy by combining logging, core and seismic data. The indicators of sequence boundaries include unconformity, coal seams,change of spore and pollen abundance, scour surfaces and base conglomerate, change of logging curve and sedimentary facies. How to determine the location of the first flooding surfaces and the maximum flooding surface is the key step to divide the systems tract. There occurred a topographic slope break in the East Fukang Slope when the Jurassic was deposited, and therefore we can recognize the location of the first flooding surface and establish the sequence stratigraphic framework with the slope break in the study area. Coal seams regionally distributed are correlatable and isochronic, and record the termination of a depositional event or episode. So, the regional coal seam (more than 60percent coverage) can be used as the genetic stratigraphic sequence boundary, while locally distributed coal seam (less than 60 percent coverage) can be used as the systems tract boundary. The thick coal seams distributed regionally in the middle of the Badaowan Formation and the lower part of the Xishanyao Formation in the study area act as the sequence boundaries, while the thin and locally distributed coal seam acts as the systems tract boundary, which results in the correlation of the division of sequence stratigraphy of the Jurassic to the whole basin where coal seams are developed extensively.

  13. High temperature properties of the seam weld portion in 1% Cr-0.5% Mo ERW boiler tubing after long-term aging

    International Nuclear Information System (INIS)

    This study is aimed at the evaluation of reliability of the seam weld portion of 1% Cr-0.5% Mo ERW (Electric Resistance Welding) boiler tubings for high temperature use. High temperature properties of materials aged in the temperature between 500 and 6000C for 5000 h were evaluated by a slow extension rate test (SERT) and a low cycle fatigue test at high temperatures. Microscopic observation was also made with a scanning electron microscope and a transmission electron microscope. Proof stress and tensile strength obtained by SERT tend to decrease with an increase in aging temperature. It is confirmed that the strength of the seam weld portion is higher than that of the base metal. The fatigue crack propagation rates studied by test pieces with a side-notch either at the base metal or at the seam weld portion were found to be lower at the seam weld portion compared with that at the base metal. Dislocations of high density and fine precipitates of carbides were observed with electron microscopy in the seam weld portion. It is also found that the size of dislocation cells formed during fatigue is smaller in the seam weld portion than in the base metal. It is concluded that higher strength of the seam weld portion is closely related to the above mentioned microstructure originated in the dissolution of carbides during ERW process. 10 figures, 3 tables

  14. Calculating crawler track plates for surface mining equipment - part 2

    Energy Technology Data Exchange (ETDEWEB)

    Schoenemann, F.

    1988-02-01

    Demonstrates calculation procedures for static stress, steel fatigue strength and buckling resistance of crawler track links on heavy surface mining equipment according to the VBK 0052 instruction of the TAKRAF manufacturer in the GDR. Maximum permissible stresses (139 to 355 N/mm/sup 2/) for 3 locations at the link's cross section are listed. Static stress calculations concern the welded joints of the link to the sheet metal body and the buckling of the link's bottom plate. A formula for bottom plate deformation forces is provided. Stresses are different for driving on solid overburden or on dumped spoil surfaces. Values derived from fatigue experiments are provided for permanent fatigue strength of welded seams of the link. Buckling resistance has to be determined only for load conditions of partial link contact to the ground surface.

  15. Structure instability forecasting and analysis of giant rock pillars in steeply dipping thick coal seams

    Institute of Scientific and Technical Information of China (English)

    Xing-ping Lai; Huan Sun; Peng-fei Shan; Ming Cai; Jian-tao Cao; Feng Cui

    2015-01-01

    Structure stability analysis of rock masses is essential for forecasting catastrophic structure failure in coal seam mining. Steeply dipping thick coal seams (SDTCS) are common in the Urumqi coalfield, and some dynamical hazards such as roof collapse and min-ing-induced seismicity occur frequently in the coal mines. The cause of these events is mainly structure instability in giant rock pillars sand-wiched between SDTCS. Developing methods to predict these events is important for safe mining in such a complex environment. This study focuses on understanding the structural mechanics model of a giant rock pillar and presents a viewpoint of the stability of a trend sphenoid fractured beam (TSFB). Some stability index parameters such as failure surface dips were measured, and most dips were observed to be between 46° and 51°. We used a digital panoramic borehole monitoring system to measure the TSFB’s height (ΔH), which varied from 56.37 to 60.50 m. Next, FLAC3D was used to model the distribution and evolution of vertical displacement in the giant rock pillars;the re-sults confirmed the existence of a TSFB structure. Finally, we investigated the acoustic emission (AE) energy accumulation rate and ob-served that the rate commonly ranged from 20 to 40 kJ/min. The AE energy accumulation rate could be used to anticipate impeding seismic events related to structure failure. The results presented provide a useful approach for forecasting catastrophic events related to structure in-stability and for developing hazard prevention technology for mining in SDTCS.

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

    International Nuclear Information System (INIS)

    The basic ways in which coalbed methane differs from natural gas are described. Coalbed methane is stored at a higher capacity in the coal seam, has a different production curve, and exploration costs are lower. Comparing a conventional gas well having 2 billion ft3 reserves with coalbed methane wells in the San Juan and Warrior basins, gas from the conventional well costs $1.90 per 1,000 ft3 and methane from the San Juan and Warrior wells costs $1.50 and $2.40 per 1,000 ft3 respectively. A 90 cent per 1,000 ft3 tax credit on coalbed methane reduces the two latter costs significantly and is without doubt the driving force behind the coalbed methane industry in some areas. Examples from the Warrior and San Juan basins are described to illustrate the technology driven economics of coalbed methane. Substantial improvements in gas production can be achieved by such means as multiple seam completion technologies, improved well stimulation, optimum well spacing, and the use of cavitation completion. Technically recoverable coalbed methane resources in the USA are estimated at 145 trillion ft3, concentrated in the western coal basins. At a wellhead price of $2 per 1,000 ft3, the economically recoverable potential is ca 13 trillion ft3. Examining future production potential, by developing new technologies or bringing more basins on stream, production could be increased to ca 3 billion ft3/d in the late 1990s. It is suggested that the increased volumes of coalbed methane have had minimal impact on gas prices. 9 figs., 12 tabs

  17. 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.

  18. Gas Control Technology of Coal Mining in Upper Protective Seam of Contiguous Outburst Seams Group%近距离突出煤层群上保护层开采瓦斯治理技术

    Institute of Scientific and Technical Information of China (English)

    刘震; 李增华; 杨永良; 唐一博; 季淮君

    2012-01-01

    In combination with the mining conditions of the upper protective seam in Qingdong Mine, the FLAC3D software was applied to the simulation of the floor pressure releasing law in the upper protective seam mining. The study results showed that the pressure released gas emission rate of the protected seam was 30. 0% -36. 5%. After the upper protective seam mined, the in-situ ground stress of the protected seam would be reduced from i0. 5 N i0. 8 Mpa to I. 0 ~ 1.5 Mpa. The initial pressure released location in the protected seam would be 40 - 50 m to the coal mining face. According to the study results, stereo gas control technology with roof rock roadway in coal layer, bedding drainage, a roof high level gas drainage gateway, tubing buried at the up corner, downward borehole through strata with fracturing in the air retuning gateway in the upper protective seam was set up. The engineering application showed that the pressure re- leased gas would account for 86. 8% of the total gas emission of the coal mining face, the gas emission rate of the protected seam was 30. 4% and the initial pressure releasing location of the protected seam was the location that the coal mining face advanced at 40 m.%结合青东煤矿上保护层开采条件,采用FLAC3D软件模拟了上保护层开采底板卸压规律。研究结果表明:被保护煤层卸压瓦斯涌出率为30.0%~36.5%;上保护层开采后被保护煤层原始地应力由10.5~10.8 MPa降低为1.0~1.5 MPa;被保护煤层初始卸压位置为工作面回采至40~50m。根据研究结果制定了顶板岩巷穿层钻孔、顺层预抽、顶板高抽巷、上隅角埋管及上保护层回风巷下向穿层增裂钻孔的立体瓦斯治理技术。工程应用表明,卸压瓦斯占工作面瓦斯涌出总量的86.8%,被保护煤层瓦斯涌出率为30.4%,被保护煤层初始卸压位置为工作面回采至40 m位置。

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

    OpenAIRE

    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 Ca2+ (28.3 mg/L) and Mg2+ (5.6 mg/L), high levels of salini...

  20. 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.

  1. 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.

  2. APPLICATION FOR AIRCRAFT TRACKING

    OpenAIRE

    Ostroumov, Ivan; Kuz’menko, Natalia

    2011-01-01

    Abstract. In the article the important problems of software development for aircraft tracking have beendiscussed. Position reports of ACARS have been used for aircraft tracking around the world.An algorithm of aircraft coordinates decoding and visualization of aircraft position on the map has beenrepresented.Keywords: ACARS, aircraft, internet, position, software, tracking.

  3. Advanced Tracking of Vehicles

    DEFF Research Database (Denmark)

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

    2005-01-01

    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...

  4. Track and Field Facilities.

    Science.gov (United States)

    Wood, Tony

    2001-01-01

    Discusses planning and design tips that help ensure track and field facilities are successful and well-suited to both school and community use. Examines approaches to determining the best track surface and ways to maximize track and field flexibility with limited space. (GR)

  5. 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

  6. 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

  7. Rapid disappearance of the medial epithelial seam during palatal fusion occurs by multifocal breakdown that is preceded by expression of alpha smooth muscle actin in the epithelium.

    Science.gov (United States)

    Gibbins, J R; Brent, S; Srivastava, M; Garibotto, N; Tazawa, Y M; Cameron, A; Hunter, N

    2000-02-01

    Breakdown of the medial epithelial seam (MES) is essential to allow bridging of the mesenchyme during palatal fusion. Evidence exists for three mechanisms for this breakdown that are incompatible at the level of individual cells in the seam. To determine if breakdown of the seam was regionally restricted, 3-dimensional reconstructions were generated using volume rendering software from 1 micron serial sections in the sagittal plane of rat palates fixed during the process of fusion. The earliest break detected in electron micrographs was cell separation and in reconstructions was a discrete defect, with a rounded outline, nearer to the nasal than to the oral margin of the seam. Further breakdown produced a pattern of rounded defects along the nasal margin of the seam resulting in interconnected columns of cells preferentially attached to the oral epithelium. Computer generated slicing of reconstructed seams showed that groups of cells evident in cross-sections as islands at this stage of breakdown of the MES could be artifacts. Unequivocal islands of epithelial cells formed later in fusion had a rounded outline, an incomplete basal lamina and a halo of cells containing phagocytosed apoptotic debris. The pattern of breakdown indicated that the MES breaks down under tension. Laser confocal microscopy of sections and whole-mounts of palates demonstrated alpha-smooth muscle actin preferentially localized in the epithelial cells of the palatal shelves immediately before and during formation of the seam. Expression in epithelial cells of the isoform of actin normally restricted to smooth muscle cells engaged in tonic contraction supported an interpretation that the epithelial cells of the seam may be capable of generating tension during the palatal fusion event. PMID:10794080

  8. Annual Change Detection by ASTER TIR Data and an Estimation of the Annual Coal Loss and CO2 Emission from Coal Seams Spontaneous Combustion

    OpenAIRE

    Xiaomin Du; Suping Peng; Haiyan Wang; Sergio Bernardes; Guang Yang; Zhipeng Li

    2014-01-01

    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 f...

  9. 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.

  10. Smart Vehicle Tracking System

    Directory of Open Access Journals (Sweden)

    K.P.Kamble

    2012-08-01

    Full Text Available It is amazing to know how simple ideas can give a whole new dimension to the tracking and navigation industry and smart vehicle tracking system is used for tracking the vehicles. You can optimize driver routes, save petrol or gas and time, reduce theft and control the vehicle functions. Many a times it is not required to track your vehicle or target globally. In majority of cases tracking is more restricted to local purposes only, such as tracking movement of vehicle within city, tracking the raw materials within industrial estate or to know the present position of your daughter or son within city. But unfortunately in the pursuit of making things complex this simple idea is forgotten. This simple yet powerful idea forms the basis of this revolutionary project. All this coupled with a very low cost, a robust design and tremendous market potential makes this model even more attractive.

  11. Tracking by Neural Nets

    CERN Document Server

    Jofrehei, Arash

    2015-01-01

    Current track reconstruction methods start with two points and then for each layer loop through all possible hits to find proper hits to add to that track. Another idea would be to use this large number of already reconstructed events and/or simulated data and train a machine on this data to find tracks given hit pixels. Training time could be long but real time tracking is really fast. Simulation might not be as realistic as real data but tracking efficiency is 100 percent for that while by using real data we would probably be limited to current efficiency. The fact that this approach can be a lot faster and even more efficient than current methods by using simulation data can make it a great alternative for current track reconstruction methods used in both triggering and tracking.

  12. 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.

  13. 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.

  14. Modeling and finite element analysis of the nonstationary action on a multi-layer poroelastic seam with nonlinear geomechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Nasedkina, A.A.; Nasedkin, A.V.; Iovane, G. [Southern Federal University, Rostov Na Donu (Russian Federation)

    2009-07-15

    The paper discusses modeling of a multi-layer coal seam under hydrodynamic action based on the coupled equations of poroelasticity and filtration with the nonlinear relationship of permeability and porous pressure. The calculations by the finite element method use correspondence between the poroelasticity and thermoelasticity equations. The influence of input data on the size of a degassing hole area is analyzed for the couple problem and pure filtration problem.

  15. Thermodynamic and kinetic processes associated with CO 2-sequestration and CO 2-enhanced coalbed methane production from unminable coal seams

    OpenAIRE

    Busch, Andreas

    2005-01-01

    The present thesis investigates the thermodynamic and kinetic processes associated with gas sorption (CO2, CH4) on coal. It is incorporated into a research field which studies CO2-sequestration in combination with CO2-enhanced coalbed methane production in unminable coal seams. This combination is regarded as a viable and promising option to reduce anthropogenic CO2-emissions. At the moment numerous world-wide research projects investigate the feasibility of this concept under different geolo...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-09-01

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

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  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. 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.

  6. 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. PMID:22901282

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

    Directory of Open Access Journals (Sweden)

    Jinyan Tian

    2016-05-01

    Full Text Available 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.

  8. Assessment of mining horizontal seams at depth considering strata stress factor

    Energy Technology Data Exchange (ETDEWEB)

    Bakhtin, A.F.

    1983-04-01

    This paper discusses systems of mining level coal seams at large depths in the light of increasing mining depth in the Donbass, where about 50% of mined coal comes from depths exceeding 600 m. Mining systems used in underground mining in the Donbass are evaluated: 77.4% of production is from long pillar mining, 8.6% from longwall mining and 14% from combined systems. Seventeen variants of long pillar mining and longwall mining schemes used in the Donbass are compared. Effects of strata movement and strata control in mine roadways on mining cost are analyzed. A mathematical model is used for comparative evaluations of mining cost at large depths. Analyses show that long pillar mining combined with repeated use of gate roads is associated with considerable cost of support repair and support replacement. Recommendations on support systems suitable for strata control in mine roadways influenced by longwall mining are made. When roof subsidence does not exceed 500 mm, use of three-element yielding arched supports is recommended. In mine roadways with strata subsidence from 500 to 1200 mm, yielding arched supports consisting of five elements should be used. When forecast roof subsidence exceeds 1200 mm, additional support systems (such as friction props or hydraulic props) should be used. (6 refs.) (In Russian)

  9. 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.

  10. Methanolobus zinderi sp nov., a methylotrophic methanogen isolated from a deep subsurface coal seam

    Energy Technology Data Exchange (ETDEWEB)

    Doerfert, S.N.; Reichlen, M.; Iyer, P.; Wang, M.Y.; Ferry, J.G. [Penn State University, University Park, PA (United States)

    2009-05-15

    A methanogenic organism from the domain Archaea (SD1{sup T}) was isolated from saline water released from a coal seam located 926 m below the surface via a methane-producing well near Monroe, Louisiana, USA. Growth and methanogenesis were supported with methanol, monomethylamine, dimethylamine or trimethylamine, but not with dimethylsulfide, formate, acetate or H{sub 2}/CO{sub 2}. Cells grew in high-salt minimal medium but growth was stimulated with yeast extract or tryptone. Cells were single, non-motile, irregular coccoids 0.5-1.0 {mu} m in diameter and the cell wall contained protein. Conditions for the maximum rate of growth were 40-50{sup o}C, 0.2-0.6 M NaCl, 100- {ge} 200 mM MgCl{sub 2}, and pH 7.0-8.0. The G + C content of the genomic DNA was 42 {+-} 1 mol%. A comparison of 16S rRNA gene sequences indicated that strain SD1{sup T} was most closely related to Methanolobus oregonensis DSM 5435{sup T} with 96% gene sequence similarity. It is proposed that strain SD1{sup T} represents a novel species, Methanolobus zinderi sp. nov. The type strain is SD1{sup T} (=ATCC BAA-1601P{sup T}=DSM 21339{sup T}).

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Tomographic 3D-radiometry for the visualisation and measurement of the defects of girth seams

    International Nuclear Information System (INIS)

    Tomographic Computer Aided Radiology (TomoCAR) is based on the mechanical position control of an X-ray tube in front of a weld seam and the application of a Dgital Detector Array (DDA) behind it. Several hundred radiometric projections in small angle steps are acquired. The tomographical reconstruction allows the three-dimensional (3D) representation of the defects. A new radiometric detector array with small internal unsharpness and high image contrast was used for the 2- and 3-dimensional visualization and sizing of planar defects with a defect opening of less than 100 μm. This detector is based on a CMOS-flat panel with a direct converting CdTe-single crystal layer. The small design allows the application of the mobile testing equipment for mechanized X-ray inspection in industrial plants. The physical pixel size of the detector amounts to 0,1 x 0,1 mm2. Nevertheless, this system yields a better spatial resolution than indirect converting detectors (e.g. cameras with fluorescence layers of Gd2O2S). It allows the reliable detection of planar defects with openings far below the detector pixel size by subpixel resolution. A German pilot study was successfully carried out on the basis of the ENIQ guidelines. In this context 'TomoCAR' was qualified for application in the nuclear power industry. (orig.)

  17. 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. PMID:22841594

  18. 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.

  19. 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.

  20. Experimental validation of the influence of lamination defects in electrical resistance seam welded pipelines

    International Nuclear Information System (INIS)

    Experimental results from seven strain gaged instrumented hydrostatic tests on ex-service tubes from a 350 mm diameter, 6.3 mm thickness electrical resistance seam welded oil pipeline are presented. Lamination defects had been detected in these sectors by means of transversal magnetic flow in-line inspection and the FAST ultrasonic technique. Five tubes failed in the weld, these yielded the lowest burst pressures. The largest laminations found in the base material reduced the burst pressure by less than 25%. Defects propagated in the weld reduced the burst strength by up to 50%. Fracture mechanics modelling of the most representative defect shows that an inclined lamination defect with a through-thickness depth of up to 3 mm is not critical; test results show that this prediction is conservative. These results show that the location of the defect is more important than its size, the main reason being the low toughness of the weld. The results of this study confirm the validity of the restrictions of Section 8 of API RP 579

  1. 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.

  2. 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)

  3. 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 also 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.

  4. Research on downward crack closing of clay aquiclude in shallow coal seam safety mining

    Institute of Scientific and Technical Information of China (English)

    HUANG Qing-xiang; ZHANG Wen-zhong

    2011-01-01

    The water resisting property ofaquiclude is the key factor of water conservation and safety mining,and the mining induced cracks in aquiclude is major factor of water resisting property.The aquiclude is composed by loess layer and red clay layer in Yushuwan Coal Mine,and the water reaction property of clay and loess of aquiclude was tested by soil mechanics method.The permeability coefficient of the loess is 0.856 m/d and the clay is 0.434 rn/d.The dilatability coefficient of the loess is 16.1% and the clay is 14.6%.Through physical solid-liquid simulation with whole stress-stain similarity,the distribution of "downward crack zone" and "upward crack zone" was found to be the major factor of aquiclude stability.The downward crack closing length is about 30% of the downward crack length.The expanding of clay and loess with water are principal factors of downward crack closing.At last,the mechanical model of downward crack closing was constructed,and the criterion of crack closing was put forward at all.This work will provides the theoretical base for aquiclude stability research and safety mining in shallow seam.

  5. Investigation on displacement field characteristics of tunnel's surrounding rock and coal seam at FMTC face

    Institute of Scientific and Technical Information of China (English)

    XIE Guang-xiang; CHANG Ju-cai; YANG Ke

    2006-01-01

    The change rules of displacement field characteristics of coal seam and tunnel's surrounding rock were obtained by means of numerical simulation-FLAC3D and site observation, and according to engineering geology and exploitation technology of 1151 (3)fully mechanized top coal caving (FMTC) face in Xieqiao colliery. The research's results show that the top coal displacement on the top of FMTC face is apparently larger than those of the middle and the bottom, the top coal begins to move in the front of the face's wall, and the sub-level top coal-rock moves ahead of the Iow-level top coal-rock, the verticai displacement of top coal-rock increases gradually as the decreasing of distance to face.Top coal and overlying strata in vertical direction are always in compressed state in the front of face, then the top coal begins to separate from the overlying strata at the upside of face. The support loading at face is mainly the deformation pressure due to top coal and main roof's movement, and it is not suitable for the FMTC face with traditional support design. Surrounding rock movement of the face is of near-field effect, the surrounding rock deformation is acute greatly near to the face, the ideas of supporting design for the tailentry and headentry should be changed from loading control to deformation control.

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

    International Nuclear Information System (INIS)

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

  7. 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.

  8. 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.

  9. Adsorption-induced coal swelling and stress: Implications for methane production and acid gas sequestration into coal seams

    Science.gov (United States)

    Cui, Xiaojun; Bustin, R. Marc; Chikatamarla, Laxmi

    2007-10-01

    Sequestration of CO2 and H2S into deep unminable coal seams is an attractive option to reduce their emission into atmosphere and at the same time displace preadsorbed CH4 which is a clean energy resource. High coal seam permeability is required for efficient and practical sequestration of CO2 and H2S and recovery of CH4. However, adsorption of CO2 and H2S into coals induces strong swelling of the coal matrix (volumetric strain) and thus reduces significantly coal permeability by narrowing and even closing fracture apertures. Our experimental data on three western Canadian coals show that the adsorption-induced volumetric strain is approximately linearly proportional to the volume of adsorbed gas, and for the same gas, different coals have very similar volumetric strain coefficient. Impacts of adsorption-induced swelling on stress and permeability around wellbores were analytically investigated using our developed stress and permeability models. Our model results indicate that adsorption-induced volumetric strain has significant controls on stress and permeability of producing and sequestrating coal seams and consequently the potential of acid gas sequestration. Coal seams may undergo >10 times enhancement of permeability around CH4-producing wellbores due to a reduction in effective stress as a result of coal shrinking caused by methane desorption accompanying a reduction in reservoir pressure. Injection of H2S and CO2 on the other hand results in strong sorption-induced swelling and a marked increase in effective stress which in turn leads to a reduction of coal seam permeability of up to several orders of magnitude. Injection of mixtures of N2 and CO2 such as found in flue gas results in weaker swelling, the amount of which varies with gas composition, and provides the greatest opportunity of sequestering CO2 and secondary recovery of CH4 for most coals. Because of the marked swelling of coal in the presence of H2S, even minor amounts of H2S result in a marked

  10. Visual identification by signature tracking

    OpenAIRE

    Munich, Mario E.; Perona, Pietro

    2003-01-01

    We propose a new camera-based biometric: visual signature identification. We discuss the importance of the parameterization of the signatures in order to achieve good classification results, independently of variations in the position of the camera with respect to the writing surface. We show that affine arc-length parameterization performs better than conventional time and Euclidean arc-length ones. We find that the system verification performance is better than 4 percent error on skilled fo...

  11. Online Supervised Subspace Tracking

    OpenAIRE

    Xie, Yao; Song, Ruiyang; Dai, Hanjun; Li, Qingbin; Song, Le

    2015-01-01

    We present a framework for supervised subspace tracking, when there are two time series $x_t$ and $y_t$, one being the high-dimensional predictors and the other being the response variables and the subspace tracking needs to take into consideration of both sequences. It extends the classic online subspace tracking work which can be viewed as tracking of $x_t$ only. Our online sufficient dimensionality reduction (OSDR) is a meta-algorithm that can be applied to various cases including linear r...

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. On the Wrong Track.

    Science.gov (United States)

    Black, Susan

    1992-01-01

    By any measure--student achievement, social development, or democratic values--ability grouping and tracking practices are indefensible and unsupported by research. Tracking allows schools to practice in-school segregation and perpetuate unequal opportunities and unequal socialization within classrooms. Jonathan Kozol's investigation shows how…

  17. Why we are tracking

    DEFF Research Database (Denmark)

    Tække, Jesper

    2015-01-01

    In this short essay, concerning why we are tracking, I will try to frame tracking as an evolutionary developed skill that humans need to survive. From an evolutionary point zero life must reflect upon itself in regard to its surrounding world as a kind of societal self-synchronization in this...

  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. 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…

  20. Practical methodology to evaluate the fatigue life of seam welded joints

    Directory of Open Access Journals (Sweden)

    K.C.Goes

    2011-11-01

    Full Text Available Purpose: of this paper is to present a practical and robust methodology developed to evaluate the fatigue life of seam welded joints under combined cyclic loading.Design/methodology/approach: Fatigue analysis was conducted in virtual environment. The finite element stress results from each loading were imported to fatigue code FE-Fatigue and combined to perform the fatigue life prediction using the S x N (stress x life method. A tube-to-plate specimen was submitted to a combined cyclic loading (bending and torsion with constant amplitude. The virtual durability analysis result was calibrated based on these laboratory tests and design codes such as BS7608 and Eurocode 3. The feasibility and application of the proposed numerical-experimental methodology and contributions for the technical development are discussed. Major challenges associated with this modelling and improvement proposals are finally presented.Findings: The finite element model was validated due to laboratory results. The analytical stress result presented upper value due to the approach used that considered the fillet weld supported all work. The model presented a good representation of failure and load correlation.Research limitations/implications: The measurement or modelling of the residual stresses resulting from the welding process was not included in this work. However, the thermal and metallurgical effects, such as distortions and residual stresses, were considered indirectly with regard to the corrections performed in the fatigue curves obtained from the investigated samples.Practical implications: Integrating fatigue analysis and finite elements, it is possible to analyse several welded joint configurations in the design phase, providing development time and cost reduction, increasing the project reliability.Originality/value: This methodology will permit, in further studies, the modelling of both stresses, in-service and residual stresses, acting together, which seem

  1. Probabilities of failure of a seam-welded calandria tube after a spontaneous pressure tube rupture

    International Nuclear Information System (INIS)

    This paper describes a methodology for calculating probabilities of seam-welded calandria tube (CT) failure after a sudden pressure tube (PT) rupture for operating conditions of CANDU reactors. Such a calculation is required in certain analyses or design option assessments such as those related to the issue of PT failure with consequential loss of moderator coincident with loss of emergency coolant injection (ECI). This accident scenario is the subject of Generic Action Item (GAl) 95G02 that was raised by the Canadian Nuclear Safety Commission (CNSC) in 1995. The CT failure probabilities were required as part of the resolution process for GAl-95G02. Two modes of CT failure considered are the prompt failure and the delayed creep failure. During the first half-second of CT pressurization by a spontaneous PT rupture, the plausible failure mechanism is the CT circumferential strain caused by a water-hammer type overpressure transient. The probability of prompt CT failure is calculated using a distribution of the measured failure strains for irradiated CTs and the calculated maximum CT strains resulting from water-hammer overpressure transients. If the CT survives the initial transient loading, the CT becomes the temporary pressure boundary to the primary heat transport system. Under certain pressure and temperature conditions the CT can experience slow-strain-rate plastic deformation and eventually fail by plastic strain. A time-to-rupture model is used to calculate the probability of this delayed creep failure within 5 to 15 minutes after a PT rupture. Then, the CT failure probability is calculated by combining prompt failure with delayed creep failure. (author)

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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。

  8. 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.

  9. The roles of melt infiltration and cumulate assimilation in the formation of anorthosite and a Cr-spinel seam in the Rum Eastern Layered Intrusion, NW Scotland

    Science.gov (United States)

    O'Driscoll, Brian; Donaldson, Colin H.; Daly, J. Stephen; Emeleus, C. Henry

    2009-07-01

    Thin (~ 2 mm) Cr-spinel seams are present at the bases of several of the coupled peridotite-troctolite units that comprise the Rum Eastern Layered Intrusion. In some cases, 'subsidiary' Cr-spinel seams have also developed at between 6 and 12 cm below the unit boundaries. The subsidiary seams are thinner than the normal seams (approx. 1 mm), discontinuous, and occur within and at the base of a thin (~ 10 cm) layer of anorthosite, which is sandwiched between peridotite and troctolite. The troctolite contains cumulus olivine, but in the Cr-spinel seam and anorthosite, olivine is intercumulus only. Cr-spinel is scarce in the troctolite, but common in the anorthosite, where it has a different composition (more Fe-and Cr-rich) and crystal size distribution (CSD) profile to the Cr-spinel in the subsidiary seam, suggesting that it represents a different crystal population. A model involving downward infiltration of hot picrite and resulting troctolitic cumulate assimilation is developed here to explain the subsidiary seams. This is based on petrographic observation, quantitative textural measurement and mineral chemical analyses. It is suggested that as the picritic magma was emplaced, downward percolation of this melt occurred into a troctolite mush. The anorthosite represents a layer of almost completely melted troctolite, formed by growth of high-anorthite zones from the contaminated picrite onto residual cumulus plagioclase. Assimilation of large amounts of the troctolite cumulate mush forced the contaminated picrite onto the olivine-spinel cotectic, leading to Cr-spinel crystallisation. Subsequently, the Cr-spinel crystals in the anorthosite have reacted with intercumulus melt over a wider temperature interval and have gained a more Fe 3+-rich composition than the subsidiary seam Mg- and Al-rich Cr-spinels. It is suggested that the separation of a small fraction of immiscible sulphide liquid in the Cr-spinel seams is the result of locally changing SiO 2 and oxygen

  10. 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.

  11. 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.

  12. Microstructure and properties of Mg/Al joint welded by gas tungsten arc welding-assisted hybrid ultrasonic seam welding

    International Nuclear Information System (INIS)

    Graphical abstract: Gas tungsten arc welding (GTAW) was introduced into ultrasonic seam welding of Mg and Al dissimilar metals for the first time as shown in (a). The preceding GTAW can preheat the sheet metal to enhance the weldability. Without improving the ultrasonic power, the direct joining of 1 mm thick Al and Mg alloys sheets was accomplished and the maximum lap shear strength was 1 kN at a GTAW current of 30 A, approximately 40% of AZ31B Mg alloy base metal, as shown in (b). - Highlights: • Mg and Al were joined in solid state by hybrid ultrasonic seam welding. • The preceding GTAW heat source enhanced the acoustic bonding effect. • The maximum lap shear strength was 1 kN at a GTAW current of 30 A. - Abstract: A novel gas tungsten arc welding (GTAW) assisted hybrid ultrasonic seam welding MgAZ31B and Al6061 alloy sheets with satisfactory joint strength were successfully achieved using a previous GTAW preheating heat source. The preceding GTAW reduced the sheet hardness but enhanced the acoustic softening effect and materials plasticity. Therefore, the direct joining of 1 mm thick MgAZ31B and Al6061 alloy sheets can be obtained without improving the ultrasonic power. The effect of GTAW current on the microstructure and mechanical properties was investigated. The tensile shear strength of the joint increased with GTAW current up to a maximum strength and then decreased dramatically with higher GTAW current. The maximum lap shear strength was 1 kN at a GTAW current of 30 A, approximately 40% of AZ31B Mg alloy base metal. The failure occurred by interface fracture mode, and the fracture patterns exhibited brittle fracture mode with cleavage facet feature

  13. 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.

  14. Scale adaptive compressive tracking.

    Science.gov (United States)

    Zhao, Pengpeng; Cui, Shaohui; Gao, Min; Fang, Dan

    2016-01-01

    Recently, the compressive tracking (CT) method (Zhang et al. in Proceedings of European conference on computer vision, pp 864-877, 2012) has attracted much attention due to its high efficiency, but it cannot well deal with the scale changing objects due to its constant tracking box. To address this issue, in this paper we propose a scale adaptive CT approach, which adaptively adjusts the scale of tracking box with the size variation of the objects. Our method significantly improves CT in three aspects: Firstly, the scale of tracking box is adaptively adjusted according to the size of the objects. Secondly, in the CT method, all the compressive features are supposed independent and equal contribution to the classifier. Actually, different compressive features have different confidence coefficients. In our proposed method, the confidence coefficients of features are computed and used to achieve different contribution to the classifier. Finally, in the CT method, the learning parameter λ is constant, which will result in large tracking drift on the occasion of object occlusion or large scale appearance variation. In our proposed method, a variable learning parameter λ is adopted, which can be adjusted according to the object appearance variation rate. Extensive experiments on the CVPR2013 tracking benchmark demonstrate the superior performance of the proposed method compared to state-of-the-art tracking algorithms. PMID:27386298

  15. 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.

  16. TrackPunch

    OpenAIRE

    Weigert, Jonas

    2014-01-01

    TrackPunch is a music streaming service that turns music discovery into a social experience. Our platform provides users with an elegant way to find new music based on their friends' listening habits. We aggregate music data from top music sources to index who influences each user individually. Our users can search, listen to, and share high quality content from GrooveShark, and SoundCloud, and YouTube for free. On TrackPunch, your next favorite song awaits. TrackPunch is a music streaming...

  17. Evaluation of the reliability and effectiveness of plans for finishing off seams influenced by overlying or underlying workings without the use of pillars

    Energy Technology Data Exchange (ETDEWEB)

    Batmanov, Iu.K.; Bakhtin, A.F.; Bulavka, E.I.

    1981-01-01

    The pillar-less plan for finishing off seams using longwalls above thick pillars influenced by overlying or underlying workings earlier without the use of pillars on productive (thicker) seams is effective both from the point of view of its reliability and from the economic point of view (even when present techniques are used, as well as under complex mining-geological conditions. The system described is used on the Ukrainian Donbass mines in a total of 13% of the cases out of the overall number of contiguous, gently sloping and inclined coal seams of various thicknessess; the improvement in the amount of coal obtained can be said to have increased by a factor of 2.

  18. 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.

  19. Mechanism and Application of Coal Seam Water Injection Ability%煤层注水可注性机理及应用

    Institute of Scientific and Technical Information of China (English)

    刘先新

    2016-01-01

    针对煤层注水可注性问题,对煤层注水的可注性机理及鉴定指标进行了论述。通过应用实例,重点介绍了煤样的选取方法以及各鉴定指标的检测过程,为煤层注水可注性工作提供了理论依据和应用经验。%In view of the coal seam water injection problem, discussed the coal seam water injection ability mechanism and appraisal index. Through the example of application, mainly introduced the method of choosing coal sample and the testing process of the appraisal index, provided theoretical basis and application experience for coal seam water injection.

  20. 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.

  1. 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.

  2. Thick coal seam fully mechanized coal face moving method improvement%厚煤层综采工作面搬家方法改进研究

    Institute of Scientific and Technical Information of China (English)

    李燎; 王建

    2015-01-01

    针对晋华宫矿现阶段厚煤层综采工作面搬家方法,提出了高效安全的改进方案,提高了厚煤层综采工作面搬家速度及安全性,为厚煤层综采工作面搬家积累宝贵经验。%For thick seam fully mechanized coal face at the present stage moving method in jinhuagong coal mine, puts forward the effective safety improvement program, improve the thick coal seam fully mechanized coal face, moving speed, and safety for thick coal seam fully mechanized coal face moving accumulated valuable experience.

  3. Practice of Gas Drainage of Relaxed Adjacent Seam from Thin Coal Seam and Use of Gas for Power Generation%极薄煤层卸压瓦斯抽采与发电利用实践

    Institute of Scientific and Technical Information of China (English)

    刘益文

    2011-01-01

    Gas emission from the comer of coal working face always exceeded the specified limitation in min- ing extremely thin coal seam in Shengli coal mine, Sichuan. After building of a fixed gas drainage system on the surface, cross-measure roof (or floor) boreholes were used to extract pressure - relief gas in the adjacent coal seams above (or below) the gob area of the working face, and obtained satisfactory safety and economic benefits, through achieving zero electricity fee for production and living, which is of important significance to mines with similar conditions.%四川胜利煤矿开采极薄煤层,采煤工作面隅角瓦斯经常超限,矿井建立了地面抽采瓦斯系统后,采用顶(底)板穿层钻孔抽采工作面采空区上(下)邻近层卸压瓦斯,有效地治理了瓦斯灾害。瓦斯抽采系统运行稳定后,将瓦斯进行发电利用,实现了矿井生产和生活零电费,取得了很好的安全与经济效益,对相似条件下的煤矿具有重要借鉴意义。

  4. 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...

  5. 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.

  6. 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.

  7. 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...

  8. 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.

  9. 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...

  10. 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.

  11. 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.

  12. 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...

  13. 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...

  14. 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

  15. 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

  16. 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

  17. 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.

  18. Provenance Tracking in UNICORE

    OpenAIRE

    Giesler, André; Hagemeier, Björn; Czekala, Myriam

    2015-01-01

    The automated tracking and storage of provenance information allows users of scientific workflow systems to validate and reproduce results of their experiments. Until now, UNICORE has not been providing comprehensive provenance features. For this reason, we plan to equip UNICORE with a flexible provenance tracking mechanism. Our goal is to ensure a suitable traceability of job and workflow processes into a description format supporting query capabilities and interoperability. In a first step,...

  19. Analysis of alternatives for using cable bolts as primary support at two low-seam coal mines

    Institute of Scientific and Technical Information of China (English)

    Esterhuizen Gabriel S; Tulu Ihsan B

    2016-01-01

    Cable bolts are sometimes used in low-seam coal mines to provide support in difficult ground conditions. This paper describes cable bolting solutions at two low-seam coal mines in similar ground conditions. Both mines used support systems incorporating cable bolts as part of the primary support system. Two original cable bolt based support systems as well as two modified systems are evaluated to estimate their ability to prevent large roof falls. One of the support systems incorporated passive cable bolts, while the other used pre-tensioned cable bolts. The results and experience at the mines showed that the mod-ified systems provided improved stability over the original support systems. The presence of the cable bolts is the most important contribution to stability against large roof falls, rather than the details of the support pattern. It was also found that a heavy steel channel can improve the safety of the system because of the‘sling’ action it provides. Additionally, the analysis showed that fully-grouted rebar bolts load much earlier than the cable bolts, and pre-tensioning of the cable bolts can result in a more uniform distribution of loading in the roof.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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 ...

  6. 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...

  7. Track finding efficiency in BABAR

    International Nuclear Information System (INIS)

    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 KS0 particles. The first section also examines the stability of the measurements vs. BABAR running periods

  8. Design of Wireless Network Interface of Mine-used Camera Based on AR2524 Chip%基于AR2524芯片的矿用摄像仪无线网络接口设计

    Institute of Scientific and Technical Information of China (English)

    刘冬; 王向菊; 于晶晶

    2011-01-01

    In view of demand that some mine field is unconvenient for cable laying and need video transmission by wireless, wireless network interface of camera based on AR2524 chip was designed on platform of network camera. The wireless network interface uses IEEE802.11b/g protocol and can access Ethernet by wireless AP. The experiment result showed that the wireless network interface can realize wireless connection with wireless monitoring and control substation and transmit video signals, and has long transmission distance, clear image, smooth video, which meets with basic demands of mine video transmission.%针对部分煤矿现场有线敷设不方便、需要通过无线传输视频的需求,在网络摄像仪的平台上,基于AR2524芯片设计了摄像仪的无线网络接口.该无线网络接口采用基于IEEE802.11b/g标准的传输协议,可通过矿用无线AP接入局域网中.测试结果表明,该无线网络接口能与无线监控分站实现无线连接并传输视频信号,传输距离远,图像清晰,视频流畅,满足了矿用视频传输的基本需求.

  9. 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.

  10. The STAR Tracking Upgrade

    CERN Document Server

    Simon, Frank

    2007-01-01

    The STAR experiment at the Relativistic Heavy Ion Collider RHIC studies the new state of matter produced in relativistic heavy ion collisions and the spin structure of the nucleon in collisions of polarized protons. In order to improve the capabilities for heavy flavor measurements and the reconstruction of charged vector bosons an upgrade of the tracking system both in the central and the forward region is pursued. The challenging environments of high track multiplicity in heavy ion collisions and of high luminosity in polarized proton collisions require the use of new technologies. The proposed inner tracking system, optimized for heavy flavor identification, is using active pixel sensors close to the collision point and silicon strip technology further outward. Charge sign determination for electrons and positrons from the decay of W bosons will be provide by 6 large-area triple GEM disks currently under development. A prototype of the active pixel detectors has been tested in the STAR experiment, and an e...

  11. 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.

  12. Tracks to therapy

    Science.gov (United States)

    Katz, R.; Cucinotta, F. A.

    1999-01-01

    Studies of the structure of particle tracks have led to models of track effects based on radial dose and radiobiological target theory that have been very successful in describing and predicting track effects in physical, chemical, and biological systems. For describing mammalian cellular inactivation two inactivation modes are required, called gamma-kill and ion-kill, the first due to synergistic effects of delta rays from adjacent ion paths thus resembling the effects from gamma rays, and the second to the effects of single ion transits through a cell nucleus. The ion-kill effect is more severe, where the fraction of cells experiencing ion kill is responsible for a decrease in the oxygen enhancement ratio, and an increase in relative biological effectiveness, but these are accompanied by loss of repair, hence to a reduction in the efficiency of fractionation in high LET therapy, as shown by our calculations for radiobiological effects in the "spread out Bragg Peak".

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. Simple front tracking

    Energy Technology Data Exchange (ETDEWEB)

    Glimm, J.; Grove, J.W.; Li, X.; Zhao, N.

    1999-04-01

    A new and simplified front tracking algorithm has been developed as an aspect of the extension of this algorithm to three dimensions. Here the authors emphasize two main results: (1) a simplified description of the microtopology of the interface, based on interface crossings with cell block edges, and (2) an improved algorithm for the interaction of a tracked contact discontinuity with an untracked shock wave. For the latter question, they focus on the post interaction jump at the contact, which is a purely 1D issue. Comparisons to other methods, including the level set method, are included.

  19. Computationally efficient Bayesian tracking

    Science.gov (United States)

    Aughenbaugh, Jason; La Cour, Brian

    2012-06-01

    In this paper, we describe the progress we have achieved in developing a computationally efficient, grid-based Bayesian fusion tracking system. In our approach, the probability surface is represented by a collection of multidimensional polynomials, each computed adaptively on a grid of cells representing state space. Time evolution is performed using a hybrid particle/grid approach and knowledge of the grid structure, while sensor updates use a measurement-based sampling method with a Delaunay triangulation. We present an application of this system to the problem of tracking a submarine target using a field of active and passive sonar buoys.

  20. Geochemistry of the late Permian No. 30 coal seam, Zhijin Coalfield of Southwest China: influence of a siliceous low-temperature hydrothermal fluid

    International Nuclear Information System (INIS)

    This paper describes the influence of siliceous low-temperature hydrothermal fluid on the elemental concentrations and mineralogical characteristics of the late Permian anthracitic (Ro,max=3.58%) coal seam (No. 30) from the Zhijin Coalfield in western Guizhou Province, SW China. Coal samples were examined using instrumental neutron activation analysis, inductively coupled plasma-mass spectroscopy, inductively coupled plasma-atomic emission spectrometry, X-ray fluorescence, powder X-ray diffraction, scanning electron microscopy equipped with energy-dispersive X-ray, and isotope analysis. The modes of occurrence of elements were determined using a sequential chemical extraction procedure. The studies indicate that the No. 30 coal seam has a very high content of veined quartz (vol. 9.4%), whose isotope values of δ30Si and δ18O are 0.6 per mille and 15.4 per mille, respectively, indicating that the quartz originated from siliceous low-temperature hydrothermal fluid (formation temperature 160-220 deg. C) rather than detrital material of terrigenous origin or magmatic hydrothermal inputs. Results of scanning electron microscopy equipped with energy-dispersive X-ray and sequential chemical extraction procedure show that the veined quartz is the dominant source of Fe, Cu, U, Pd, Pt and Ir, which are as high as 2.31%, 356, 8, 2.1, 2.43, and 0.006 μg/g in this coal seam, respectively. The studies have also found that elements, such as Fe and Cu are mainly in the veined quartz and they do not occur as sulfides in this coal seam, in sharp contrast to many other coal seams in China. The geochemical and mineralogical anomalies of the coal are attributed to the siliceous low-temperature hydrothermal fluid

  1. 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.

  2. Fast frequency tracking

    Directory of Open Access Journals (Sweden)

    Prokopenko I. G.

    2013-12-01

    Full Text Available A method of periodical signal frequency tracking by the frequency-locked loops is proposed. Increasing of frequency adjustment accuracy is achieved by using of a new fast frequency discriminator, based on estimates of an instantaneous frequency. Reasonability of an input signal pre-filtering in case of nonlinear distortions, harmonics interferences and strong noise is proved.

  3. 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…

  4. 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…

  5. 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…

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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)

  13. Non-harmonious deformation controlling of gob-side entry in thin coal seam under dynamic pressure

    Institute of Scientific and Technical Information of China (English)

    Kegong Fan; Hongguang Liang; Chishuai Ma; Chuanwei Zang

    2014-01-01

    The behavior of gob-side entry under dynamic pressure is totally different from the one driven after the movement of overlying strata above the adjacent coalface goaf. The gob-side entry will experience severe roof lateral structural adjustments caused by adjacent coalface mining. Thus the deformation and failure characteristics of narrow coal pillar along the gob should be carefully considered. On the basis of the data of the gob-side entry obtained in a thin coal seam under dynamic pressure, the measures to reinforce the narrow coal pillar are put forward. In addition, the non-harmonious controlling of the rock structures and non-equilibrium gob-side entry deformation is proposed to avoid potential failure. Field practices show that the supporting problems of the gob-side entry under dynamic pressure can be well addressed, which could be used in other similar mining cases.

  14. 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)

  15. Gas drainage from different mine areas:optimal placement of drainage systems for deep coal seams with high gas emissions

    Institute of Scientific and Technical Information of China (English)

    Ping Lu; Ping Li; Jian Chen; Chuijin Zhang; Junhua Xue; Tao Yu

    2015-01-01

    The techniques of stress relief mining in low-permeability coal seams and pillarless gob side retained roadway entry using Y-type ventilation and gas drainage systems were developed to control gas outbursts and applied successfully. However, as the mining depth increasing, parts of the gas drainage system are not suitable for mines with high gas emissions. Because larger mining depths cause higher ground stresses, it becomes extremely difficult to maintain long gob side roadways. The greater deformation suffered by the roadway is not favorable for borehole drilling for continuous gas drainage. To solve these problems, Y-type ventilation and gas drainage systems installed from a roof roadway were designed for drainage optimization. This system was designed based on a gas-enrichment zone analysis developed from mining the 11-2 coal seam in the Zhuji Mine at Huainan, Anhui Province, China. The method of Y-type gas extraction from different mine areas was applied to the panel 1112(1) in the Zhuji Mine. The absolute gas emission rate was up to 116.3 m3/min with an average flow of 69.1 m3/min at an average drainage concentration of nearly 85%. After the Y-type method was adopted, the concentration of gas in the return air was 0.15%–0.64%, averaging 0.39%with a ventilation rate of 2100–2750 m3/min. The gas management system proved to be efficient, and the effective gas control allowed safe production to continue.

  16. 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.

  17. Better features to track by estimating the tracking convergence region

    NARCIS (Netherlands)

    Zivkovic, Zoran; Heijden, van der Ferdinand; Deprettere, E.F.; Belloum, A.; Heijnsdijk, J.W.J.; Stappen, van der F.

    2002-01-01

    Reliably tracking key points and textured patches from frame to frame is the basic requirement for many bottomup computer vision algorithms. The problem of selecting the features that can be tracked well is addressed here. The Lucas-Kanade tracking procedure is commonly used. We propose a method to

  18. Better features to track by estimating the tracking convergence region

    NARCIS (Netherlands)

    Zivkovic, Zoran; Heijden, van der Ferdinand; Kasturi, R.; Laurendeau, D.; Suen, C.

    2002-01-01

    Reliably tracking key points and textured patches from frame to frame is the basic requirement for many bottom-up computer vision algorithms. The problem of selecting the features that can be tracked well is addressed. The Lucas-Kanade tracking procedure is commonly used. We propose a method to esti

  19. 无线摄像式智能抄表系统的设计与实现%Design and application of camera-based wireless meter reading system

    Institute of Scientific and Technical Information of China (English)

    吴卫军; 瑚琦; 郑遂; 张祥安

    2012-01-01

    In order to overcome the poor accuracy and low-speed of manual meter reading in power industry, a camera-based low-cost wireless meter reading system is designed. Both the hardware instructions and the operating principle of the system are introduced here. The system combines periodic camera, wireless transmission and image recognition to accomplish intelligent wireless meter reading. The experiment in power grid shows that the system can work successfully as designed. It can greatly improve the picking rate and accuracy compared with manual meter reading, and reduce cost when compared with the all-in-one meter reading machine, particularly suitable for application in the vast rural areas.%针对目前电力行业手工抄表实时性差,精度低的特点,设计了一套低成本的无线摄像式智能抄表系统,并详细地分析了该系统的各个组成部分及其工作原理.系统采用定时摄像、无线传输和数字图像识别相结合的方法,用户无需更换已有的传统电能表,只需在现有的电能表上安装摄像与传输模块即可实现无线智能抄表.与手工抄表方式相比,该系统能提高数据采集速度和精度;与常见的一体化智能电表相比,能降低智能电网建设成本,尤其适合在广大的农村地区使用.

  20. Simple Online and Realtime Tracking

    OpenAIRE

    Bewley, Alex; Ge, ZongYuan; Ott, Lionel; Ramos, Fabio; Upcroft, Ben

    2016-01-01

    This paper explores a pragmatic approach to multiple object tracking where the main focus is to associate objects efficiently for online and realtime applications. To this end, detection quality is identified as a key factor influencing tracking performance, where changing the detector can improve tracking by up to 18.9%. Despite only using a rudimentary combination of familiar techniques such as the Kalman Filter and Hungarian algorithm for the tracking components, this approach achieves an ...

  1. Thermal Tracking of Sports Players

    OpenAIRE

    Rikke Gade; 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 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 chall...

  2. On train track splitting sequences

    CERN Document Server

    Masur, Howard; Schleimer, Saul

    2010-01-01

    We show that the subsurface projection of a train track splitting sequence is an unparameterized quasi-geodesic in the curve complex of the subsurface. For the proof we introduce induced tracks, efficient position, and wide curves. This result is an important step in the proof that the disk complex is Gromov hyperbolic. As another application we show that train track sliding and splitting sequences give quasi-geodesics in the train track graph, generalizing a result of Hamenstaedt [Invent. Math.].

  3. 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.

  4. 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...

  5. The track nanotechnology

    International Nuclear Information System (INIS)

    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.

  6. 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.

  7. 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.

  8. Progressive Fleet tracking systems

    OpenAIRE

    Smětal, Matěj

    2011-01-01

    This bachelor thesis is focused on the importance of vehicle tracking as a part of Fleet management for company's success. The theoretical part contains analysis of positioning systems GPS and GLONASS, describes the structure and principles of its functioning. The practical part contains implementation of Fleet management system into Russian company"Cech č. 1", Ltd. Practical part consists of information gained from internal sources of the company.

  9. Track the talent : methodiekbeschrijving

    OpenAIRE

    Bos, Antoinette; Abdallah, Sebastian

    2008-01-01

    Track the Talent is een beschrijving van een methodiek van Stichting Stedelijk Jongerenwerk Amsterdam en Stichting Hart voor Amsterdam. De beschrijving is uitgevoerd door Youth Spot, een samenwerkingsverband tussen SJA en de Hogeschool van Amsterdam. In het kader van dit project werden twee groepen rechtstreeks met elkaar verbonden: een groep kansarme jongeren die net niet of net wel klaar waren met school en een groep bedrijven die op zoek waren naar nieuwe werknemers. De jongeren gingen op ...

  10. 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.

  11. PARTICLE BEAM TRACKING CIRCUIT

    Science.gov (United States)

    Anderson, O.A.

    1959-05-01

    >A particle-beam tracking and correcting circuit is described. Beam induction electrodes are placed on either side of the beam, and potentials induced by the beam are compared in a voltage comparator or discriminator. This comparison produces an error signal which modifies the fm curve at the voltage applied to the drift tube, thereby returning the orbit to the preferred position. The arrangement serves also to synchronize accelerating frequency and magnetic field growth. (T.R.H.)

  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

    2016-02-01

    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.

  13. 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

  14. 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.

  15. Influence of tracks densities in solid state nuclear track detectors

    International Nuclear Information System (INIS)

    When Solid State Nuclear Track Detectors (SSNTD) is employed to measure nuclear tracks produced mainly by fission fragments and alpha particles, it is considered that the tracks observation work is performed under an efficiency, ε0, which is independent of the track density (number of tracks/area unit). There are not published results or experimental data supporting such an assumption. In this work the dependence of ε0 with track density is studied basing on experimental data. To perform this, pieces of CR-39 cut from a sole 'mother sheet' were coupled to thin uranium films for different exposition times and the resulting ratios between track density and exposition time were compared. Our results indicate that ε0 is constant for track densities between 103 and 105 cm-2. At our etching conditions track overlapping makes impossible the counting for densities around 1.7 x 105 cm-2. For track densities less than 103 cm-2, ε0 , was not observed to be constant. (authors). 4 refs., 2 figs

  16. 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.

  17. 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。

  18. 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.

  19. 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.

  20. JV Task 109 - Risk Assessment and Feasibility of Remedial Alternatives for Coal Seam at Garrison, North Dakota

    Energy Technology Data Exchange (ETDEWEB)

    Jarda Solc

    2008-01-01

    The Energy & Environmental Research Center (EERC) conducted an evaluation of alternative technologies for remediation of hydrocarbon-contaminated coal seam, including impacted soils and groundwater in Garrison, North Dakota. Geotechnical characteristics of the impacted fractured coal seam provide for rapid off-site contaminant transport, with the currently identified impacted zone covering an area of about 40 acres. Regardless of the exposure mechanism (free, dissolved, or vapor phase), results of laboratory tests confirmed secondary release of gasoline-based compounds from contaminated coal to water reaching concentrations documented from the impacted areas. Coal laboratory tests confirmed low risks associated with spontaneous ignition of gasoline-contaminated coal. High contaminant recovery efficiency for the vacuum-enhanced recovery pilot tests conducted at three selected locations confirmed its feasibility for full-scale remediation. A total of 3500 gallons (13.3 m{sup 3}) of contaminated groundwater and over 430,000 ft{sup 3} (12,200 m{sup 3}) of soil vapor were extracted during vacuum-enhanced recovery testing conducted July 17-24, 2007, resulting in the removal of about 1330 lb (603 kg) of hydrocarbons, an equivalent of about 213 gallons of product. The summary of project activities is as follows: (1) Groundwater and vapor monitoring for existing wells, including domestic wells, conducted on a monthly basis from December 12, 2006, to June 6, 2007. This monitoring activity conducted prior to initiation of the EERC field investigation was requested by NDDH in a letter dated December 1, 2006. (2) Drilling of 20 soil borings, including installation of extraction and monitoring wells conducted April 30-May 4 and May 14-18, 2007. (3) Groundwater sampling and water-table monitoring conducted June 11-13, 2007. (4) Evaluation of the feasibility of using a camera survey for delineation of mining voids conducted May 16 and September 10-11, 2007. (5) Survey of all wells

  1. Bearings only naval tracking

    Energy Technology Data Exchange (ETDEWEB)

    Barth, M.J.

    1984-11-01

    Two commonly used Extended Kalman Filter tracking algorithms utilize the Relative Cartesian and Modified Polar coordinate systems. This report compares the two algorithms by exercising a destroyer-Submarine (DD/SS) computer simulation. A simple engagement geometry is employed which encompasses the major DD/SS options available. Error statistics are developed by Monte Carlo methods. Results are presented which show that the circular error depends upon the diagonal values of the error covariance matrix. The results also support (but do not establish) that the optimum DD manuevuer is that which minimizes the range while maximizing the bearing rate. 4 refs., 5 figs., 4 tabs.

  2. 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...

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

    OpenAIRE

    Like Wei; Qingxin Qi; Hongyan Li; Bin Zhang; Yongren Wang; Linghai Kong

    2015-01-01

    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 sy...

  4. Business and IT Design with SEAM: An Illustration with the PhD Hiring Process at École Polytechnique Fédérale de Lausanne

    OpenAIRE

    Popescu, George; Tapandjieva, Gorica; Wegmann, Alain

    2013-01-01

    Companies seek to align their business with their IT. This alignment is important to maximize the return on their IT investment in their business. One major challenge is to develop models that can be understood by both business and IT stakeholders. Without such models, it is difficult for stakeholders to reach a shared understanding and to agree on what the issues and solutions are. We present a method called SEAM: it uses a systemic approach for representing business and IT organizations. Wi...

  5. 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。

  6. 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. PMID:27247868

  7. 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.

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

    International Nuclear Information System (INIS)

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

  9. 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.

  10. 压边力对双焊缝差厚拼焊板拉延成形焊缝移动的影响%Effects on Welding Seams Movement Caused of Blank Holder Force of TWBs with Double Welding Seams and Different Thicknesses on Drawing Process

    Institute of Scientific and Technical Information of China (English)

    夏江梅

    2012-01-01

    拼焊板在拉延成形时焊缝移动受多方面因素的影响,本文模拟分析了不同压边力值和分段压边力对具有两道焊缝的差厚激光拼焊板汽车后纵梁在拉延成形过程中焊缝移动的影响.通过分析在不同压边力下两条焊缝的移动量得出了焊缝最大移动量随压边力的增大而增大的规律.为了减小两条焊缝的移动量,成形过程中在保证总压边力不变的情况下对差厚拼焊板的不同板厚部分设置不同的压边力.通过模拟分析得出了焊缝最大移动量随着薄侧压边力的增大和厚侧压边力的减小而减小.合理的增大薄侧板料压边力,减小厚侧板料压边力可以减小焊缝移动量,提高成形质量.%The weld seam movement of TWB is influenced by some factors during drawing process. The effects on weld seam movement caused by different blank holder forces and segmented blank holder force of back rail of an automobile maded by TWBs with two weld seams and different thicknesses during drawing process was simulated and analyzed The results show that the maximum quantity of weld seam move increases with the blank holder force. In order to reduce the weld seam movement, under invariable blank holder force, the sheet is segmented into parts for they share different thickness, hence receiving different blank holder forces. And the max weld seam movement decreases as the blank holder force of thinner side increases and the thicker side decreases. Increasing the blank holder force of thinner side and decreasing the blank holder force of thicker side reasonable can decrease the weld seam movement and improve the forming quality.

  11. Aspects regarding non-destructive examination of the surface of the ring from the weld root seam of two pipes having small diameter, by replicating method

    International Nuclear Information System (INIS)

    The method has been generated by a real case of breaking of the steel tape from the position control system of the ram 'C' (Fuelling Machine). The paper contains a brief description of the replicating device and of the replicating method proposed. The results obtained are showed at the end of paper. The following conclusions are highlighted: one has initiated un original replicating method of the irregular ring surface of the weld seam into the butt welded assemblies with inner diameter less than 15 mm using an original replicating device (Letters patent no. 121572/Patent application - no.a 2003 0 182 from 30.12.2007); - the tests carried out have proved the workability of the method, the functionality of the device and provided the replicas supported on metal representing the hard copy of the negative of the irregular ring surface corresponding to the weld root seam, making available the dimension examination of the profile; - the visual inspection of the replicas supported on metal gives the information about the geometry of the replicated surface, pointing out the marks which belong to the same inspected surfaces; - the minimum and maximum values have been evaluated as well as the accurate shape of the weld root seam by analyzing the profile graphics. (author)

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

    Science.gov (United States)

    Prebble, Warwick M.; Williams, Ann L.

    2016-06-01

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

  13. 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

    2015-01-01

    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. PMID:25915589

  14. Investigation and Numerical Simulation Study on Mining Effect of Double Protective Seam%双重保护层开采效果考察数值模拟研究

    Institute of Scientific and Technical Information of China (English)

    罗建军

    2015-01-01

    To aim at the problem of the protection range division of the overlying protected seam affected by the mining of the underlying double protective seam in Wulan Coal Mine, calculation was carried out on the change process of the deformation field of the overlying No. 2 and 3 outburst seams after the mining of the underlying No. 7 and 8 seams based on the finite difference method, according to the physical and mechanical parameters and the geological characteristics of roof and floor rock strata of the protective seam and by using FLAC3D simulation software, the roof-to-floor convergence of the protected seam after the mining of the protective seam was obtained, the maximum expansion deformation of the coal seam was calculated and it was greater than the critical point of 3 ‰ thickness of coal seam, and the protection range of the protected seam along the dip and strike after the mining of the protective seam was determined. The results showed the pressure relief angles of the overlying No. 2 and 3 protected seams along their upper and lower boundaries of the dip after the mining of No. 7 and 8 double protective seams were respectively 78° or 57° and 80° or 77°, and that along the their strike were 52° and 61°. The research results have significant theoretical guidance role for the mining effect investigation of the protective seam and the safe mining of overlying No. 2 and 3 outburst seams in the future in Wulan mine.%针对乌兰煤矿下伏双重保护层开采对上覆被保护层保护范围的划分难题,基于有限差分法,结合保护层顶底板煤岩层的物理力学参数和地质特征,采用FLAC3D软件模拟计算了下伏7 #、8 #煤层先行开采后其上覆的2#、3#突出煤层变形场的变化过程,得出保护层开采后被保护层顶底板位移量,进而计算出煤层的最大膨胀变形量大于煤层厚度3‰的临界点,确定出双重保护层开采后被保护层沿倾向和走向的保护范围. 结果表明,7#、8#煤

  15. Study on Coal and Rock Pressure Releasing Effect of Protected Seam Mining Under Long Distance%远程下保护层开采煤岩卸压效应研究

    Institute of Scientific and Technical Information of China (English)

    程详; 赵光明

    2011-01-01

    基于保护层开采覆岩移动破坏特征,分析了远程下保护层开采煤岩卸压的可行性,采用FLAC2D数值模拟软件对被保护煤层的应力分布特征、煤厚变形规律、水平位移规律、卸压范围及卸压角进行了研究。结果表明:下保护层开采时,断裂带高度已发育到被保护层,煤层产生膨胀变形,生成大量的次生裂隙,使被保护煤层产生不同程度的卸压,同时水平位移的产生也有利于煤层透气性增加。在走向方向上,被保护层向保护层采空区方向内错约30 m,煤层进入稳定膨胀变形区,走向有效卸压角的大小为66°左右。研究结果应用于工程实践后,淮南某矿13-1煤层瓦斯压力由原来的4.4 MPa变为卸压后的0.7 MPa,煤层透气性系数增大了1 061倍,表明该方法是较好的区域性防突措施。%Based on the overburden strata movement and failure features of the protected seam mining,the paper had an analysis on the feasibility of the coal and rock pressure releasing in the protected seam mining under long distance.The FLAC2D numerical simulation software was applied to the study on the stress distribution features of the protected seam,seam thickness variation law,the horizontal displacement law,the pressure releasing scope and the pressure releasing angle.The results showed that during the underneath protective seam mining,the height of the crack zone was developed to the protected seam,swelling deformations were occurred in the seam,great secondary cracks were occurred and thus different pressure releasing were occurred in the protected seam.Meanwhile,the horizontal displacement occurred would be favorable to improve the permeability of the seam.On the strike direction,the protected seam was moved about 30 m to the direction of the goaf of the protective seam.The protected seam was in the stable swelling deformation zone and the effective pressure releasing angle in the strike was about 66°.After the study

  16. 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...

  17. Underground pressure characteristics analysis in back-gully mining of shallow coal seam under a bedrock gully slope

    Institute of Scientific and Technical Information of China (English)

    Wang Xufeng; Zhang Dongsheng; Fan Gangwei; Zhang Chengguo

    2011-01-01

    We studied underground pressure and its mechanism during back-gully mining in a shallow coal seam under a bedrock gully slope, by means of physical simulation, numerical modeling and field monitoring.The results show that the intensity of underground pressure is related to its relative position at the coalface. The underground pressure is intensive and the support resistance reaches a maximum when the coalface is at the bottom of the gully, whereas the underground pressure is moderate and decreases gradually when the coalface passes the gully. The mechanism of these changes is analyzed when the slope rotated in a reversed direction to the slope dip during back-gully mining and form an unstable, multilateral block hinged structure, due to slipping. The subsidence of multilateral blocks is considerable when the block fragmentation is small, resulting in enormous changes in the underground pressure. With an increase in the mass of the block body, the block displacement will be reduced in conjunction with an increased clamp effect by both the unbroken rocks and broken rocks in the goaf, resulting in a decrease of the underground pressure.

  18. Induced drill-spray during hydraulic slotting of a coal seam and its influence on gas extraction

    Institute of Scientific and Technical Information of China (English)

    Shen Chunming; Lin Baiquan; Zhang Qizhi; Yang Wei; Zhang Lianjun

    2012-01-01

    Hydraulic slotting can induce drill spray in a gassy,low permeability coal seam.This then influences subsequent gas extraction.This paper describes the drill spray phenomenon from a mechanical perspective and analyzes the effects of water jet damage during slotting.A simulation of the stresses around the drill hole and slot was prepared using FLAC-3D code.It helps explain the induction of drill spray during hydraulic slotting.The stress concentration around the bore increases as the diameter of the hole increases.As the hole enlarges the variation in stress also increases,which introduces an instability into the coal.This allows easy breaking and removal of the coal.Destruction of the coal structure by the water jet is the major factor causing drill spray.Energy stored as either strain or gas pressure is released by the water jet and this causes the coal to fracture and be expelled from the hole.Field tests showed the effect on gas extraction after slotting with drill spray.The concentration of gas increases after drilling.Compared to conventional techniques,the hydraulic slotted bore gives a gas concentration three times higher and has an effective range twice as far.This makes the gas extraction process more efficient and allows reduced construction effort.

  19. Pico-nano bubble column flotation using static mixer-venturi tube for Pittsburgh No. 8 coal seam

    Institute of Scientific and Technical Information of China (English)

    Peng Felicia F.; Yu Xiong

    2015-01-01

    The flotation process is a particle-hydrophobic surface-based separation technique. To improve the essential flotation steps of collision and attachment probabilities, and reduce the step of detachment probabilities between air bubbles and hydrophobic particles, a selectively designed cavitation venturi tube combined with a static mixer can be used to generate very high numbers of pico and nano bubbles in a flotation column. Fully embraced by those high numbers of tiny bubbles, hydrophobic particles readily attract the tiny bubbles to their surfaces. The results of column flotation of Pittsburgh No. 8 seam coal are obtained in a 5.08 cm ID and 162 cm height flotation column equipped with a static mixer and cavitation venturi tube, using kerosene as collector and MIBC as frother. Design of the experimental procedure is combined with a statistical two-stepwise analysis to determine the optimal operating conditions for maximum recovery at a specified grade. The effect of independent variables on the responses has been explained. Combustible material recovery of 85–90% at clean coal product of 10–11%ash is obtained from feed of 29.6%ash, with a much-reduced amount of frother and collector than that used in conventional column flotation. The column flotation process utilizing pico and nano bubbles can also be extended to the lower limit and upper limit of particle size ranges, minus 75 lm and 300–600 lm, respectively, for better recovery.

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

    Directory of Open Access Journals (Sweden)

    Lin Xiao

    2016-03-01

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