3,648 research outputs found

    Foolproof quick-release locking pin

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    Locking pin can be withdrawn only when stress on the joint is negligible. Pin consists of a forward-pointing sleeve, a spring-loaded sliding handle, and a sliding plunger. Plunger movement controls installation and withdrawal of pin

    The Reproductive Characters of Four Varieties of Groundnuts (Arachis hypogaea L.)

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    The reproductive characters of 4 groundnut varieties, Nudong V-13, Matjam and Alabama. were studied. All varieties showed similar patterns of flowering, pegging and podding. Only 15 percent of the flowers produced developed mature pods. The .low yield ,was attributed to inefficient pollination and abortion of developing kernels due to adverse envzronmental mfluences

    Preventing crystal agglomeration of pharmaceutical crystals using temperature cycling and a novel membrane crystallization procedure for seed crystal generation

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    In this work, a novel membrane crystallization system was used to cr ystallize micro-sized seeds of piroxicam monohydrate by reverse antisolvent addition. Membrane crystallization seeds were compared with seeds produced by conventional antisolvent addition and polymorphic transformation of a fine powdered sample of piroxicam form I in water. The membrane crystallization process allowed for a consistent production of pure monohydrate crystals with narrow size distribution and without significant agglomeration. The seeds were grown in 350 g of 20:80 w/w acetone-water mixture. Different seeding loads were tested and temperature cycling was applied in order to avoid agglomeration of the growing crystals during the process. Focused beam reflectance measurement (FBRM); and particle vision and measurement (PVM) were used to monitor crystal growth; nucleation and agglomeration during the seeded experiments. Furthermore; Raman spectroscopy was used to monitor solute concentration and estimate the overall yield of the process. Membrane crystallization was proved to be the most convenient and consistent method to produce seeds of highly agglomerating compounds; which can be grown via cooling crystallization and temperature cycling

    A new degree six modified chordal ring network topology

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    The performance of a parallel or distributed network depends on the design of its interconnection topology. One good network interconnection topology that has been the focus of various researchers is the chordal ring. In this paper, a new degree six modified chordal ring is presented, the optimised degree six 3-modified chordal ring (CHR6o3), with the aim of comparing its performance parameters in terms of optimal diameter and optimal average path length to existing degree six chordal rings. Formulae to generate the data for each different chordal ring were derived from its corresponding tree visualisation or used from previous work. Network sizes tested were from 1200 to 12000 nodes. Large networks of CHR6o3 were shown to perform better than those of previous degree six chordal rings. This gives CHR6o3 an added advantage for its implementation in large distributive networks, such as Fibre to the Home (FTTH) networks, since it offers redundancies at higher network layers

    Measurement and modeling of the influence of grain size and pressure gradients on swash zone sediment transport

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    The paper examines the dependency between sediment transport rate, q, and grain size, D, (i.e. q∝Dp) in the swash zone. Experiments were performed using a dam break flow as a proxy for swash overtopping on a mobile sediment beach. The magnitude and nature of the dependency (i.e. p value) is inferred for different flow parameters; the initial dam depth (or initial bore height), do, the integrated depth averaged velocity, ∫u3 dt, and against the predicted transport, qp using the Meyer-Peter Muller (MPM) transport model. Experiments were performed over both upward sloping beds and a horizontal bed. The data show that negative dependencies (p0) are obtained for ∫u3 dt. This indicates that a given do and qp transport less sediment as grain size increases, whereas transport increases with grain size for a given ∫u3 dt. The p value is expected to be narrow ranged, 0.5≤ p≤-0.5. A discernible difference observed between the measured and predicted transport on horizontal and sloping beds suggests different modes of transport. The incorporation of a pressure gradient correction, dp/dx, using the surface water slope (i.e. piezometric head), in the transport calculation greatly improved the transport predictions on the horizontal bed, where dp/dx is positive. On average, the incorporation of a pressure gradient term into the MPM formulation reduces qp in the uprush by 4% (fine sand) to 18% (coarse sand) and increases qp over a horizontal bed by 1% (fine sand) to two orders of magnitude (coarse sand). The measured transport for fine and coarse sand are better predicted using MPM and MPM+dp/dx respectively. Poor predictions are obtained using Nielsen (2002) because the pressure gradient in the uprush is of opposite sign to that inferred from velocity data in that paper. It is suggested that future swash sediment transport models should incorporate the grain size effect, partly through the pressure gradient, although the dp/dx influence is small for fine sands because of the grain size scaling contained in the stress term

    Opportunity for using WLAN with IEC 61850 and the future of this protocol

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    The unified protocols are unified in application interface, models, and seamless. They generate one standard protocol, one world called IEC 61850. IEC 61850 integrate the security, interoperability, modelling, mapping to a substation, and reliability. Presently, the more expensive fiber based Ethernet LAN is the most prevalent technology for medium and low voltage distribution substations. To circumvent this problem Wireless Local Area Network (WLAN) has been investigated for its suitability for applications that are compliant to IEC 61850: automation and metering; control and monitoring; and over-current protection. In this paper the IEEE 802.11n WLAN is studied when used in various IEC 61850 supported applications for substation automation. It also discusses the benefits of using GOOSE message to protect and control applications and the use of IEC 61850

    Characterisation of plant growth-promoting bacteria from Kacip Fatimah (Labisia pumila) under natural tropical forest

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    Medicinal plants play a major role in many cultures, not only as medicines, but also as trade commodities to fulfil the demands of distant markets. A study was conducted to characterise growth-promoting bacteria from two varieties of Kacip Fatimah (Labisia pumila) found at two different locations, Sungai Tekala, Semenyih, Selangor for Labisia pumila var. lanceolate and Bukit Slim Permanent Forest Reserve, Perak for Labisia pumila var. alata. Soil and plant samples were taken for the physico-chemical analyses and characterisation of the indigenous plant growth-promoting bacteria (PGPB). Both Labisia varieties were found to thrive in areas with quite similar soil chemical and physical properties in natural forest environments except for altitude, where Labisia pumila var. alata was found in higher elevation compared to Labisia pumila var. lanceolata. The soil in both places was found to be slightly acidic and low in nutrient content. Total bacterial population found on var. alata was higher than in var. lanceolata and the highest population was found in the root endosphere (8.68 × 107 cfu g-1 soil). Morphologically-isolated bacteria were circular in shape, with flat/raised elevation, entire margin, moist texture and smooth and glistening surface but varied in colour and size. Most of the bacterial strains showed several plant-growth promoting traits like plant-growth hormones (indole acetic acid (IAA)), N2 fixation and P solubilisation activities and beneficial enzymes. Two of the bacterial isolates showing most of the beneficial properties were identified as Exiguobacterium sp. and Stenotrophomonas sp. These PGPB have the potential to enhance the growth of Kacip Fatimah

    Circle grid fractal plate as a turbulent generator for premixed flame: an overview

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    This review paper focuses to ascertain a new approach in turbulence generation on the structure of premixed flames and external combustion using a fractal grid pattern. This review paper discusses the relationship between fractal pattern and turbulence flow. Many researchers have explored the fractal pattern as a new concept of turbulence generators, but researchers rarely study fractal turbulence generators on the structure premixed flame. The turbulent flow field characteristics have been studied tand investigated in a premixed combustion application. In terms of turbulence intensity, most researchers used fractal grid that can be tailored so that they can design the characteristic needed in premixed flame. This approach makes it extremely difficult to determine the exact turbulent burning velocity on the velocity fluctuation of the flow. The decision to carry out additional research on the effect circle grid fractal plate as a turbulent generator for premixed flame should depends on the blockage ratio and fractal pattern of the grid. 1
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