4,961 research outputs found

    Improved Microseismic Signal Detection Using Weighted Particle Motion Linearity Measures

    Get PDF
    Microseismic data provides important information about the subsurface during hydraulic fracturing jobs. However, microseismic signals are not as easy to identify as conventional seismic signals. I developed a new technique to detect microseismic signals by measuring displacement information along with the three-dimensional time coherence analysis of the 3D particles motion (linearity). It was tested on microseismic data from a horizontal well in the Marcellus Shale. The method multiplies the linearity calculation with a function of the amplitude of oscillation that is generated using the envelope. In addition, I developed techniques to detect signals from the new, weighted linearity (or the traditional, unweighted linearity) that help with the goal of more effective signal detection. The results from the new method show that it can detect 16 signals from two microseismic datasets, including barely noticeable (amplitude of 0.0003), weak (amplitude of 0.002), and strong (amplitude of 0.02) signals. These were compared with the results from the traditional, unweighted linearity calculation, where I detect only 9 signals and give results contaminated with noise. This indicates that there is a 40% improvement in signal detection using the new approach. Furthermore, the weighted linearity showed more detail in the signals and less noise compared to unweighted linearity results. With this new approach, I am able to detect signals that unweighted linearity cannot identify, while not compromising the quality of signals detectable by linearity

    Endoscopic Third Ventriculostomy, Indications and Challenges

    Get PDF
    Endoscopic third ventriculostomy (ETV) allows the cerebrospinal fluid (CSF) to flow directly from the third ventricle through the fashioned ventriculostoma to the interpeduncular cistern, by passing the site of obstruction. In spite of the wide variety of indications where ETV is implemented, its success rate is still debatable especially in certain age groups, where it is most successful in adult patients with obstructive hydrocephalus and it has an identifiable failure rate in children less than 6 months of age. Several factors would affect the success rate of ETV, which are related to the patient’s age, pathology, and intraoperative findings. This chapter covers most of the current debates considering ETV

    Economic Feasibility of using by-products in soil stabilization, Saudi Arabia

    Full text link
    Composite is stated as constituent of two or more materials which retain their own physical and chemical property during the time of application, but produce a component which inherent the properties of its constituent materials and makes it better for the real time USAge. There are varieties of processing techniques for fabricating composite parts or structures such as: (1) Resin Transfer Moulding, (2) Pultrusion, (3) Filament Winding, (4) Autoclave Moulding. Among all these technique of exercising composite materials, the filament winding technique is the most appropriate because it avails the user with the ease of USAge, as well as gives wide range of degree of freedom for fabricating or manufacturing objects. In the paper we basically reveal the maximum approach made to study basic theory related to the filament winding technique or method, which provides initial platform for the new learner

    The Effect of Recombinant Human Bone Morphogenetic Protein-7 on the Osteoblast-like Cells Cultured on Implant

    Get PDF
    AIM: The aim of the study was to study the effect of recombinant human bone morphogenetic protein-7 (rhBMP-7) on the osteoblast-like cells cultured on implant. MATERIALS AND METHODS: The osteoblast-like osteo-1 cell line was used in this experiment and derived from the parietal bone tissue of newborn albino rats. The cells were incubated in a humid atmosphere of 95% air and 5% carbon dioxide at 37°C. The medium was changed every 2 days. Four groups were conducted as follows osteoclast-like cell (machined), implanted osteoclast-like cell on titanium (Ti) (modified), osteoclast-like cell supplemented with BMP-7 (Machined + BMP-7), and implanted osteoclast-like cell on Ti and supplemented with BMP-7 (Modified + BMP-7). RESULTS: Cell proliferation was influenced by rhBMP-7, as demonstrated by a significant increase in collagen content after 7 and 21 days of culture (p = 0.005) and a significant increase in alkaline phosphatase (ALP) activity after 7 days (p < 0.001). The addition of rhBMP-7 influenced ALP activity, and a significant increase was observed after 21 days (p < 0.001). CONCLUSION: Within the limitations of the study, we concluded that the presence of rhBMP-7 did not influence cell adhesion to chemically modified Ti surfaces but provided an additional stimulus during the differentiation of rat osteo-1 cells cultured on this type of surface

    Runoff Curves Development for Al-Adhaim Catchment Using Digital Simulation Models

    Get PDF
    A rainfall-runoff model is used to develop runoff curves through simulating runoff processes. The runoff curves are developed by inserting various equations related to runoff calculations and runoff coefficients. The runoff model used in this study is the Stanford Watershed Model after it has been properly modified. Application of the various parameters and their effects on runoff rates are investigated. Based on the results of this application, the monthly simulated runoff rate indicated significant level of sensitivity to various model parameters. The Modified Stanford Watershed Model is operated and applied on Al-Adhaim catchment. The relationship between runoff coefficients and rainfall concentration times is explained for different variables and parameters. Runoff curves accordingly provide a better and more accurate estimate for runoff coefficients

    FSM-F: finite state machine based framework for denial of service and intrusion detection in manet

    Get PDF
    Due to the continuous advancements in wireless communication in terms of quality of communication and affordability of the technology, the application area of Mobile Adhoc Networks (MANETs) significantly growing particularly in military and disaster management. Considering the sensitivity of the application areas, security in terms of detection of Denial of Service (DoS) and intrusion has become prime concern in research and development in the area. The security systems suggested in the past has state recognition problem where the system is not able to accurately identify the actual state of the network nodes due to the absence of clear definition of states of the nodes. In this context, this paper proposes a framework based on Finite State Machine (FSM) for denial of service and intrusion detection in MANETs. In particular, an Interruption Detection system for Adhoc On-demand Distance Vector (ID-AODV) protocol is presented based on finite state machine. The packet dropping and sequence number attacks are closely investigated and detection systems for both types of attacks are designed. The major functional modules of ID-AODV includes network monitoring system, finite state machine and attack detection model. Simulations are carried out in network simulator NS-2 to evaluate the performance of the proposed framework. A comparative evaluation of the performance is also performed with the state-of-theart techniques: RIDAN and AODV. The performance evaluations attest the benefits of proposed framework in terms of providing better security for denial of service and intrusion detection attacks

    Water catchment area and management method

    Get PDF
    Due to critical and obvious effect of the wastewater comes from the industry, agriculture and industrial activity nearby the dam has led to environmental issues in Sembrong dam, Kluang Johor which caused negative impacts to the biological, chemical and physical properties of water river environments. The dam itself contained a large number of algae which caused the blocking of sunlight, could not enter directly to the water surface and it threatening to the aquatic life. The dam also traps sediments, which are crucial for maintaining physical progressions and habitats of the dam. The chapter introduce “G.E.T” formula as management method to overcome the pollution problems. The implementation of “G.E.T” formula is basically to improve the urban environmental condition as key for urban policy and environmental management. Sustainable management and utilisation of resources is a guidance in pursuing the development of agricultural and forestry activity at dam area

    Critical Review on Waqf Experiences: Lessons From Muslim and Non-Muslim

    Full text link
    The purpose of this paper is to critically assess current practices in waqf institution based on Middle East, Asia and some selected non-Muslim countries experience. Muslims countries have their own ways of managing waqf. Some ways are similar to one another and some are different. The methodology used in this study is in depth review analysis of the literature of waqf practices in various countries. The paper could conclude that differences of waqf institution based on legal factors, historic of establishment and current implementation. The paper identifies, that the objective establishment of Waqf institution is benefit to the society and development of the country. This paper is based on critical analysis review of the waqf experiences literature review in selected countries. Future research might integrate this review with empirical methodology. There is a limit number of countries waqf experiences have been included in this study, future research might include more experiences. In term of the implications of findings, it hopes that the findings give more comprehensive and cross countries picture of waqf experience and practice. Which is, it will assist the related waqf regulators in the evaluation process of waqf management practices and determine best practice as well set up a benchmark waqf management practices

    Intelligent Control of Switched Reluctance Motor for Electrical Vehicle Applications with Different Controller

    Get PDF
    تستخدم محركات المعاوقي المفتاحي لإنتاج الكثير من  عزم الدوران والتي تعمل عند التشبع المغناطيسي العالي. وبالنظر إلى التشبع المغناطيسي العالي، فإن العلاقة بين تيار الطور، وموقع الدوار هي علاقة غير خطية. لذلك فان  الضجيج، الاضطرابات، وعزم القصور الذاتي  عند  التحميل يمكن أن يكون لها جميعا تأثير سلبي على أداء المحرك المعاوقي المفتاحي. في هذه الدراسة تم تطوير وحدة التحكم الانزلاقي. وقد استخدم وحدة التحكم الانزلاقي في تنظيم السرع على مدى واسع  بما في ذلك المحرك المعاوقي المفتاحي في السرع العالية والسرع الواطئة وتقارن هذه الدراسة وحدة التحكم الانزلاقي مع وحدة التحكم التناسبي المتكامل التفاضلي في المحرك المعاوقي المفتاحي ذو 4/6 اقطاب باستعمال  الطرق الامثل للتحكم . ومقارنة  سرعة الجزء الدوار مع السرعة المضبوطة .فان وحدة التحكم الانزلاقي المتسارع هو الافضل من حيث الاداء والمتانة في  تطبيق السيارات الكهربائية  تبعا لنظام السيمولنك المستخدم Switched reluctance motors (SRM) are used to produce a lot of torque when they are operating at high magnetic saturation. Due to the high magnetic saturation, the relationship between phase current, rotor position, and the flux linkage of SRM is nonlinear. Noise, disturbances, and inertia of load torque can all have a negative impact on the SRM driver system's speed controller performance. In this study, the SRM driver system's sliding mode controller was developed .The sliding mode controller( SMC) speed controller was used to regulate speeds of the SRM throughout a wide range speeds, including high and low speeds. This study compares (SMC) with a modified reaching law and a Proportional Integral Divertive Control (PID) controller for a 6/4 pole SRM using an optimization technique for switching controllers. Furthermore, the rotor speed was simulated and compared to the reference speed. The Exponential Sliding Mode Controller (ExpSMC) is the best in terms of performance and robustness for an electric vehicle application, depending on a simulation of an established test bench using the two controllers

    Chatter-Free Distributed Control for Multi-agent Nonholonomic Wheeled Mobile Robot

    Get PDF
    This paper proposes to design a chatter-free distributed control for multiagent nonholonomic wheeled mobile robot systems employing terminal exponential functions with graph theory. The terminal tracking criteria are estimated using the Lyapunov approach. The development of distributed control for nonholonomic multiagent wheeled robot systems is defined in the paper along with consensus tracking for undirected fixed/switched topologies. Numerical simulations have been done in order to assess the efficacy and efficiency of the proposed distributed control method in multiple scenarios
    corecore