540,403 research outputs found

    Development of a hydraulic component leakage detecting system using pressure decay signal

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    It is preferable to detect leakage at the earliest phase in the manufacturing process, and then further assembly of hydraulic components with leakage problems can be avoided. Integrating a USB based microcontroller and a pressure sensor; this study developed a hydraulic leakage detection system in using air instead of hydraulic oil as medium, through measuring pressure decay signals captured by a real time data acquisition system. Compared with the conventional hydraulic system using oils, this system shows advantages in safety operation and little environmental concerns due to use a lower pressure clean air. The low-cost hydraulic leakage detection system was developed can record and visualize the system pressure in real time. Experimental tests were conducted to test this system performance. The pressure decay of the hydraulic system inserted in good hydraulic tubes were tested as the system pressure holding performance baseline, and then compared with the pressure decay of the same system when the tube was installed with connection errors. The experiments were repeated when the system was set up at different operating pressure levels to test if the system can consistently fulfill its designed functionality. Through statistical analysis it was found that the developed prototype system can capture and visualize the pressure decay curve in real time, and two signals, the pressure drop from the test start to end point and the pressure drop rate in the testing period, can be used as featured characteristics to quickly detect hydraulic leakage components’ status

    Antiproton beam parameters measurement by a new digital-receiver-based system

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    The Antiproton Decelerator (AD) provides the users with very low intensity beams, in the 107 particles range, hence prompting the development of an innovative measuring system, which was completed in early 2000. This system measures antiproton beam intensity for bunched and debunched beams, together with momentum spread and mean momentum for debunched beams. It uses a state-of-the-art Digital Receiver board, which processes data obtained from two ultra-low-noise, wide-band AC beam transformers. These have a combined bandwidth in the range 0.02 MHz - 30 MHz and are used to measure AC beam current modulation. For bunched beams, the intensity is obtained by measuring the amplitude of the fundamental and second RF Fourier components. On the magnetic plateaus the beam is debunched for stochastic or electron cooling and longitudinal beam properties (intensity, momentum spread and mean momentum) are measured by FFT-based spectral analysis of Schottky signals. The system provides real-time information characterising the machine performance; it has been used for troubleshooting and to fine-tune the AD, thus allowing further improved performance. This system has been operating since May 2000 and providing beam intensity data to the users on a routine basis since late 2000. A dedicated software package was expressly developed to take care of the control, data acquisition and processing phases. It consists of three main codes, namely a GUI, a Real Time Task and a Low Level Code. This report gives an overview of both the hardware and software developed

    The New Digital-Receiver-Based System for Antiproton Beam Diagnostics

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    An innovative system to measure antiproton beam intensity, momentum spread and mean momentum in CERN's Antiproton Decelerator (AD) is described. This system is based on a state-of-the-art Digital Receiver (DRX) board, consisting of 8 Digital Down-Converter (DDC) chips and one Digital Signal Processor (DSP). An ultra-low-noise, wide-band AC beam transformer (0.2 MHz - 30 MHz) is used to measure AC beam current modulation. For bunched beams, the intensity is obtained by measuring the amplitude of the fundamental and second RF Fourier components. On the magnetic plateaus the beam is debunched for stochastic or electron cooling and longitudinal beam properties (intensity, momentum spread and mean momentum) are measured by FFT-based spectral analysis of Schottky signals. The system thus provides real time information characterising the machine performance; it has been used for troubleshooting and to fine-tune the AD, thus achieving further improved performances. This system has been operating since May 2000 and typical results are presented

    Water Systems towards New Future Challenges

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    This book comprises components associated with smart water which aims at the exploitation and building of more sustainable and technological water networks towards the water–energy nexus and system efficiency. The implementation of modeling frameworks for measuring the performance based on a set of relevant indicators and data applications and model interfaces provides better support for decisions towards greater sustainability and more flexible and safer solutions. The hydraulic, management, and structural models represent the most effective and viable way to predict the behavior of the water networks under a wide range of conditions of demand and system failures. The knowledge of reliable parameters is crucial to develop approach models and, therefore, positive decisions in real time to be implemented in smart water systems. On the other hand, the models of operation in real-time optimization allow us to extend decisions to smart water systems in order to improve the efficiency of the water network and ensure more reliable and flexible operations, maximizing cost, environmental, and social savings associated with losses or failures. The data obtained in real time instantly update the network model towards digital water models, showing the characteristic parameters of pumps, valves, pressures, and flows, as well as hours of operation towards the lowest operating costs, in order to meet the requirement objectives for an efficient system

    The In-Orbit Performance of Four Microsat Spacecraft

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    On January 22, 1990, Ariane V-35 placed four Microsat spacecraft into orbit. The orbit achieved is nearly perfectly sun synchronous at 800 km altitude. The satellites, cubic structures measuring only 23 cm per side, were developed by the Radio Amateur Satellite Corporation of North America (AMSAT-NA). The time required to complete the project, from conception to delivery of the four satellites to Kourou, was exactly two years. Each satellite in orbit has a different mission and is performing in accordance with its intended design, although additional software is still being written to enhance the operating characteristics for each mission. This paper reviews the design objectives of the four spacecraft and summarizes their in-orbit performance against these prelaunch technical objectives. The level of technology employed by the Microsat spacecraft is briefly discussed and the software approach taken in implementing a real-time, multitasking operating system is summarized. The paper reviews the AMSAT experience as the first payload user group of the Ariane ASAP structure. Some of the findings regarding the current technology and how it may be expanded to fulfill other mission needs has been touched upon

    Simulation of fault detection in photovoltaic arrays

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    In solar systems, faults in the module and inverter occur in proportion to increased operating time. The identification of fault types and their effects is important information not only for manufacturers but also for investors, solar operators and researchers. Monitoring and diagnosing the condition of photovoltaic (PV) systems is becoming essential to maximize electric power generation, increase the reliability and lifetime of PV power plants. Any faults in the PV modules cause negative economic and safety impacts, reducing the performance of the system and making unwanted electric connections that can be dangerous for the user. In this paper have been classified all possible faults that happen in the PV system, and is presented to detect common PV array faults, such as open-circuit fault, line-to-line fault, ground fault, shading condition, degradation fault and bypass diode fault. In this studies examines the equivalent circuits of PV arrays with different topological configurations and fault conditions to evaluate the effects of these faults on the performance of a solar system, taking into account the influence of temperature and solar radiation. This work presents the validation of a simulated solar network by measuring the output curves of a low-power photovoltaic array system under real outdoor conditions. This method can be useful in future solar systems

    Emerging melt quality control solution technologies for aluminium melt

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    The newly developed “MTS 1500” Melt Treatment System is performing the specifi cally required melt treatment operations like degassing, cleaning, modification and/or grain refinement by an automated process in one step and at the same location. This linked process is saving time, energy and metal losses allowing - by automated dosage of the melt treatment agents - the production of a consistent melt quality batch after batch. By linking the MTS Metal Treatment System with sensors operating on-line in the melt, i.e., with a hydrogen sensor “Alspek H”, a fully automated control of parts of the process chain like degassing is possible. This technology does guarantee a pre-specifi ed and documented melt quality in each melt treatment batch. Furthermore, to ensure that castings are consistent and predictable there is a growing realization that critical parameters such as metal cleanliness must be measured prior to casting. There exists accepted methods for measuring the cleanliness of an aluminum melt but these can be both slow and costly. A simple, rapid and meaningful method of measuring and bench marking the cleanliness of an aluminum melt has been developed to offer the foundry a practical method of measuring melt cleanliness. This paper shows the structure and performance of the integrated MTS melt treatment process and documents achieved melt quality standards after degassing, cleaning, modifi cation and grain refi nement operations under real foundry conditions. It also provides an insight on a melt cleanliness measuring device “Alspek MQ” to provide foundry men better tools in meeting the increasing quality and tighter specifi cation demand from the industry

    Instrumentation for in-field measurements of energy inputs to tractor-powered agricultural implements

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    A second generation data acquisition system, integrally mounted on a two-wheel drive 75-PTO kW agricultural tractor, was interfaced to various sensors which measured: (1) time, (2) implement draft, (3) left and right drive axle torque, (4) left and right drive wheel rotation, (5) ground surface displacement, (6) fuel flow, (7) PTO torque, and (8) engine flywheel rotation. This data gathering system was centered around a DEC PDP11/03-LK microcomputer using the RT-11 operating system and having a linkage of MACRO-11 and FORTRAN IV data acquisition routines. Magnetic memory, of the same capacity as two RXOl floppy disks, was subdivided into the system device and the data storage device. Real-time data were displayed in engin-eering units on the operator CRT console. Physical transfer of archived test data for mainframe statistical analysis was accomplished using a TUBS tape drive. Sensors were simultaneously sampled once per second using a crystal controlled hardware interrupt. Before sampling by an A/D board, each analog signal was passed through an active low-pass filter having a one-half Hz cutoff frequency to satisfy the Nyquist Criterion of the Sampling Theorem. Digital signals were counted by an in-house designed counterboard. Digital count values were read and subsequently cleared through software. Digital sensors were (1) two bi-directional optical shaft encoders measuring rear axle speeds, (2) a transducer sensing fuel consumption rates, (3) a single-beam radar unit measuring true ground speeds, and (4) a passive magnetic sensor monitoring engine speeds. Analog sensors included mounted strain gauges detecting drive wheel torques and implement drafts, and a commercial load cell sensing PTO torques. The revised data acquisition system has been field tested for three growing seasons with repeatable results. Specific tests included gathering energy consumption data of tillage operations, and acquiring data showing the energy used throughout the formation of a round bale. In addition, the performance of three ground speed sensors was determined while traversing selected ground surfaces at various operating speeds. Further work is needed on the sensor used for measuring the drafts produced by towed PTO-driven implements. Also, minor adjust-ments to the counterboard are required

    Systems for characterizing Internet routing

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    2018 Spring.Includes bibliographical references.Today the Internet plays a critical role in our lives; we rely on it for communication, business, and more recently, smart home operations. Users expect high performance and availability of the Internet. To meet such high demands, all Internet components including routing must operate at peak efficiency. However, events that hamper the routing system over the Internet are very common, causing millions of dollars of financial loss, traffic exposed to attacks, or even loss of national connectivity. Moreover, there is sparse real-time detection and reporting of such events for the public. A key challenge in addressing such issues is lack of methodology to study, evaluate and characterize Internet connectivity. While many networks operating autonomously have made the Internet robust, the complexity in understanding how users interconnect, interact and retrieve content has also increased. Characterizing how data is routed, measuring dependency on external networks, and fast outage detection has become very necessary using public measurement infrastructures and data sources. From a regulatory standpoint, there is an immediate need for systems to detect and report routing events where a content provider's routing policies may run afoul of state policies. In this dissertation, we design, build and evaluate systems that leverage existing infrastructure and report routing events in near-real time. In particular, we focus on geographic routing anomalies i.e., detours, routing failure i.e., outages, and measuring structural changes in routing policies

    Nondestructive in-line sub-picomolar detection of magnetic nanoparticles in flowing complex fluids

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    Over the last decades, the use of magnetic nanoparticles in research and commercial applications has increased dramatically. However, direct detection of trace quantities remains a challenge in terms of equipment cost, operating conditions and data acquisition times, especially in flowing conditions within complex media. Here we present the in-line, non-destructive detection of magnetic nanoparticles using high performance atomic magnetometers at ambient conditions in flowing media. We achieve sub-picomolar sensitivities measuring ∌\sim30 nm ferromagnetic iron and cobalt nanoparticles that are suitable for biomedical and industrial applications, under flowing conditions in water and whole blood. Additionally, we demonstrate real-time surveillance of the magnetic separation of nanoparticles from water and whole blood. Overall our system has the merit of inline direct measurement of trace quantities of ferromagnetic nanoparticles with so far unreached sensitivities and could be applied in the biomedical field (diagnostics and therapeutics) but also in the industrial sector
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