185,750 research outputs found

    Detection of water leakage in buried pipes using infrared technology; a comparative study of using high and low resolution infrared cameras for evaluating distant remote detection

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    Water is one of the most precious commodities around the world. However, significant amount of water is lost daily in many countries through broken and leaking pipes. This paper investigates the use of low and high resolution infrared systems to detect water leakage in relatively dry countries. The overall aim is to develop a non-contact and high speed system that could be used to detect leakage in pipes remotely via the effect of the change in humidity on the temperature of the ground due to evaporation. A small scale experimental test rig has been constructed to simulate water leakage in The Great Man- Made River Project in Libya, taking into consideration the dryness level of the desert sand and the scaled dimensions of the system. The results show that the infrared technology is an effective technology in detecting water leakage in pipes. The low resolution system has been found as valuable as the high resolution system in detecting water leakage. The results indicate the possibility of distant remote detection of leakage in water systems using infrared technologies which could be mobilised using drones, helium balloons, aeroplanes or other similar technologies

    The Adjectival construct in Arabic

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    We propose an analysis of the adjectival construct in Arabic in LFG, building on previous work in LFG on a Welsh construction which shows several similarities to the Arabic (Mittendorf and Sadler, 2008) and work on the MSA and cognate Hebrew constructions by Hazout (2000); Kremers (2005); Siloni (2002); Heller (2002); Kim (2002). The construction involves an adjective occurring with an immediately following definite nominal, which denotes a property, part or quality of the noun that the adjectivemodifies (in attributive use) or is predicated of (in predicative constructions). The major characteristics of this construction are that the post-adjectival nominal serves to delimit the respect in which the adjective denotes a property of the external nominal, and the adjectival head and the GEN complement are subject to a very strict adjacency requirement. We present a syntactic analysis, showing that the construction is formed in the syntax rather than the morphology, and sketch out a proposal as to how the semantics of the construction might be captured

    March CRF: an Efficient Test for Complex Read Faults in SRAM Memories

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    In this paper we study Complex Read Faults in SRAMs, a combination of various malfunctions that affect the read operation in nanoscale memories. All the memory elements involved in the read operation are studied, underlining the causes of the realistic faults concerning this operation. The requirements to cover these fault models are given. We show that the different causes of read failure are independent and may coexist in nanoscale SRAMs, summing their effects and provoking Complex Read Faults, CRFs. We show that the test methodology to cover this new read faults consists in test patterns that match the requirements to cover all the different simple read fault models. We propose a low complexity (?2N) test, March CRF, that covers effectively all the realistic Complex Read Fault

    Heat absorption properties of ground material for solar chimney power plants

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    One of the major challenges to the widespread application of the solar chimney power plant is its low-power conversion efficiency because of the three technological processes involved. The chimney efficiency is difficult to improve, and thus enhancing the collector or turbine performance can considerably improve the total plant efficiency. This work focused on enhancing the energy conversion efficiency of the collector and also extending the operation time using a heat storage medium. The solar to thermal conversion and thermal storage capabilities of six ground materials that are potentially available in Malaysia were studied experimentally and numerically. The experimental model was designed such that the six materials were exposed to the same operation boundary conditions. The numerical studies were conducted using ANSYS software, where the geometrical models were developed and simulated using FLUENT for the fluid flow and energy/thermal field studies. The selected ground materials were ceramic, black stones, sawdust, dark-green painted wood, sand, and pebbles. The simulation and experimental results are in good agreement in terms of air stream velocity and energy conversion efficiency. The results showed that the different materials have different heat storage capacities, and that ceramics extend the operation with improved efficiency until nighttime. The results also showed that ceramic and black stones have better performance than the other materials. However, black stones are recommended as the absorbing material for solar chimney power plants in Malaysia and regional countries because they are readily available
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