203 research outputs found

    Analysis of Concentric Split Ring Square Element for Broadband Reflectarray Antenna

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    An investigation of phase variation and phase range of concentric split ring square element for broadband reflectarray antenna is presented in this paper. This is realized by exploiting the physical geometry of three element shapes namely square element, concentric ring square element and concentric split ring square element. Modifying the current distribution of basic concentric ring square element, leads to a less steep phase variation and also the bandwidth performance. An analysis of frequency response is described and analysed. The physical interpretation of the elements is also discussed. The proposed antenna element effectively covers two frequency operations (13.44 GHz and 18.36 GHz) in Ku-band range. Bandwidth broadening is achieved by introducing the ring square combination of element and the practical phase range is achieved through the use of RF 35 (thickness = 1.524 mm) as the substrate. The new concept of split initiates to a wider bandwidth (up to 67.6 %) for the antenna and can applied to any two frequency operations of Ku-band applications

    A Comparative Study of Enhanced Nonlinear PI to Multivariable Nonlinear Plant

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    The static gains of PI controller have limitation to handle the process nonlinearities of the system. This suggests the development of enhanced nonlinear PI controller where a nonlinear gain function is cascaded to PI parameters. Two nonlinear gain functions are developed and the effectiveness of the control performance is investigated for two different control structures for a multivariable nonlinear wastewater treatment plant (WWTP). It was proved that superior output with the lower mean error was obtained by developed nonlinear PI specifically in the multivariable control structure. The developed nonlinear PI offers simpler control structure and easy implementation hence offering alternative control strategy for the multivariable system

    Does Inhalation of Virgin Coconut Oil Accelerate Reversal of Airway Remodelling in an Allergic Model of Asthma?

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    Many studies have been done to evaluate the effect of various natural products in controlling asthma symptoms. Virgin coconut oil (VCO) is known to contain active compounds that have beneficial effects on human health and diseases.The objective of this study was to evaluate the effect of VCO inhalation on airway remodelling in a rabbit model of allergic asthma.The effects of VCO inhalation on infiltration of airway inflammatory cells, airway structures, goblet cell hyperplasia, and cell proliferation following ovalbumin induction were evaluated. Allergic asthma was induced by a combination of ovalbumin and alum injection and/or followed by ovalbumin inhalation.The effect ofVCOinhalationwas then evaluated via the rescue or the preventive route. Percentage of inflammatory cells infiltration, thickness of epithelium and mucosa regions, and the numbers of goblet and proliferative cells were reduced in the rescue group but not in preventive group. Analysis using a gas chromatography-mass spectrometry found that lauric acid and capric acid were among themost abundant fatty acids present in the sample. Significant improvement was observed in rescue route in alleviating the asthma symptoms, which indicates the VCO was able to relieve asthma-related symptoms more than preventing the onset of asthma

    Throughfall at an abandoned skid trail in a tropical rain forest in Peninsular Malaysia

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    Knowledge of throughfall at abandoned skid trails in tropical forests is extremely scarce. Thus, throughfall was measured using 120 storage rain gauges set on a skid trail left abandoned 41 years after forest harvesting in the Bukit Tarek Experimental Watershed (BTEW) in Peninsular Malaysia. All trees of ≥ 1 m height in the plot were identified to the species level, and their diameter at breast height (DBH) and height were measured. Vegetation along the skid trail comprises trees with smaller DBH (0.2-31.0 cm, with a mean of 2.0 cm) and shorter height (1.0-20.0 m, with a mean of 2.8 m) than those in the regenerated secondary forests of BTEW. The diversity (i.e. 43 families, 131 species) at the skid trail was similar to that in an old tropical forest at BTEW. The ratio of throughfall to gross rainfall (Th/Rg) for 84 rain events ranged from 27.4% to 204.7% with a mean and standard deviation of 98.1% and 33.2%, respectively. We found that a considerable amount of rainwater dropped under bertam (i.e. Eugeissona tristis) and rattan (i.e. Daemonorops callicarpa, Calamus insignis) vegetation. The Th/Rg ratio weakly correlated with canopy openness. The mean Th/Rg ratio is the largest mean ratio ever reported for forests in Malaysia

    Influence of biofertilizer on growth improvement of aerobic rice genotypes

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    Biofertilizers have emerged as a potential environment friendly inputs that are supplemented for proper plant growth.Two field experiments were conductedat University Putra Malaysia (UPM), Selangor, Malaysia during 1st season (Mayto September 2015) and 2nd season (September to December 2015)to evaluate the performance of aerobic rice genotypes under different combinations of bioandchemical fertilizer. The experiment consisted of five (5)biofertilizer combinations (chemical fertilizer recommended rate (CFRR) (150 N; 60 P2O5;60 K2O kg ha-1) 100%,biofertilizer 1 ton+ 75%CFRR,biofertilizer 2 tons + 50%CFRR,biofertilizer 3tons+ 25%CFRR,and biofertilizer 4 tons)and three aerobic rice genotypes (MRIA1, MR219-4 and MR219-9)laid out in a split-plot in randomized complete block design(RCBD) with 3 replicates.Results revealed that application of biofertilizer 1 ton + 75%CFRR produced the highest plant height (102.65 cm) and an umberof tillers (20.38) in the 2nd season, the highest grain yield (4.30 t ha-1) than theother biofertilizer treatments in the 1st season. MR219-4 produced the highest number of tillers, leaf area and leaf photosynthesis rate in both seasons,grain yield (5.02 t ha-1) in 1st season while MR219-9 produced the highestcropbiomass (52.76 g hill-1) and crop growth rate (8.00 g hill-1week-1) at 12 WAS,grain yield (3.86 tha-1) than the other genotypes in the 2nd season.The trend in these results indicated that biofertilizer tend to be more effective with limited chemical fertilizer in the 1st season of low rainfall.These results concluded that 1 ton biofertilizer + 75% CFRR andMR219-4enhancesrice growth and grain yield in aerobic condition

    The design of IPT system for multiple kitchen appliances using class E LCCL circuit

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    Since many years ago, kitchen appliances are powered up by cable connected. This create a troublesome case as wire might tangle together and cause kitchen table messy. Due to this, wireless power technology (WPT) is introduced as its ability is to transmit power to load without physical contact. This leads to cordless solution better in safety as the product can be completely seal, highly expandable power range. This work focuses on the design of WPT based on inductive approach to power up multiple kitchen appliances. The selection of inductive approach over its partners capacitive and acoustic is mainly due to high power efficiency. Class E inverter is proposed here to convert the DC to AC current to drive the inductive link. A 1 MHz operating frequency is used. To ensure the circuit is robust with load variations, an LCCL impedance matching is proposed. This solution is table to maintain the output power if there is a slight change in load impedance. Finally, the developed prototype is able to supply 50V utput which can achieve power transmission up to 81.76%

    A parametric study of textile artificial magnetic conductor with wire dipole at 2.45GHZ and 5.8GHZ

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    Textile Artificial Magnetic Conductor (AMC) with wire dipole is presented. The AMCs are made of fleece and Shieldit fabrics and were designed to have in-phase reflections at 2.45GHz and 5.8GHz. Thorough parametric studies based on AMC unit cell have been performed to obtain the optimized design. Performance comparison between different types of environments, fabrics and arrays size were also conducted. The proposed AMC and wire dipole are designed, simulated, fabricated and tested. Results of return loss, radiation pattern and gain are presented. Results show that forward directive radiation pattern with improved gain are achieved with the introduction of the AMC at both 2.45GHz and 5.8GHz. The proposed textile AMC is suitable for body centric communication systems

    Effect of fertilizer management on growth and yield of fragrant fine rice varieties in rainfed condition

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    A field experiment was carried out at the Banglasesh Institute of Nuclear Agriculture (BINA) farm, Mymensingh during July to December 2010, to find out optimum variety and optimum fertility management of aromatic fine rice grown in transplant rainfed condition. The experiment was laid out in split-plot design with three replications assigning the variety in the main plot and different fertilizer management in the sub-plot. Results indicated that the effect of aromatic fine rice varieties and fertilizer management showed significant variation in respect of yield contributing characters and yield. At harvest, maximum number of effective tillers/hill (12.7 and 12.5), number of grains/panicle (105.6 and 115.2), 1000 grain weight (13.25 and 19.97 g), grain yield (3.29 and 3.30 t/ha) and straw yield (5.0 and 5.7 t/ha) were obtained from the application of T6 (NPKSZn; RD BARC, 2005) @ 126.9, 19.81, 65, 43.3 and 1.8 kg/ha+Cow dung at 5.0 t/ha) and T9 (Urea super granules (USG) @ 1 (1.8 g) granules/spot) + PKSZn; (RD BARC, 2005 @19.81, 65, 43.3 and 1.8 kg/ha). The fertilizer management T6 (NPKSZn; RD BARC, 2005) @ 126.9, 19.81, 65, 43.3 and 1.8 kg/ha+Cow dung at 5.0 t/ha) and T9 (Urea super granules (USG) @ 1 (1.8 g) granules/spot)+PKSZn; (RD BARC,2005 @ 19.81, 65, 43.3 and 1.8 kg/ha) produced the highest grain yield of Ukunimadhu (2.95 t/ha) and Kataribhog (3.96 t/ha)

    Identification of genotypes resistant to blast, bacterial leaf blight, sheath blight and tungro and efficacy of seed treating fungicides against blast disease of rice

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    A total of 35 inbred and 13 hybrid varieties including susceptible checks were screened against the 4 major diseases of rice (blast, bacterial leaf blight, sheath blight and tungro) as well as experiments on management of blast were conducted in the rain-fed and irrigated rice ecosystems during 1999 to 2003. Results showed that none of the tested high yielding varieties (HYV) were resistant to blast, while the hybrids, sonarbangla1, aalock6201, KRH2, IR71101H, IR68877H and IR76901H, and inbreds BR12, BR15 and IR72 were moderately resistant in the irrigated rice ecosystem. On the other hand, all the varieties tested against bacterial leaf blight (BLB) and sheath blight (ShB) were moderately susceptible in the same ecosystem. The inbred varieties BR22, BR25, BRRI dhan31, BRRI dhan32, BRRI dhan33, BRRI dhan34, BRRI dhan38 and BRRI dhan39 demonstrated moderately resistant reactions but all the hybrids were moderately susceptible to BLB in the rain-fed ecosystem. Eight inbreds, predominantly, BR22, BR23, BRRI dhan27, BRRI dhan31, BRRI dhan32, BRRI dhan37, BRRI dhan38 and BRRI dhan40 were moderately resistant to tungro disease. Among the 3 fungicides tested in 2 different trials, adivistin and haydazim 50 WP (carbendazim) at the rate of 0.4% were more effective as seed-treating fungicides for the control of rice blast disease

    Study of genetic variation of some eggplant cultivars through RAPD-PCR molecular markers and its relatedness to phomopsis blight disease reaction

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    Disease susceptibility and genetic variability in 10 eggplant genotypes were studied after inoculating Phomopsis vexans under confined field conditions. Random amplified polymorphic DNA (RAPD) markers were used to assess genetic variation and relationships among eggplant genotypes. The disease index of leaves ranged 0.208-13.79%, while fruit infection ranged 2.15-42.76%. Two varieties, Dohazari G and Laffa S, were found to be susceptible, 6 were moderately resistant, 1 was moderately susceptible, and BAU Begun-1 was resistant to P. vexans. Amplification of genomic DNA by using 3 RAPD primers produced 20 bands: 14 (70%) were polymorphic and 6 (30%) were monomorphic. The highest intra-variety similarity indices values were found in ISD 006, Ishurdi L, Jessore L, and BAU Begun-1 (100%), while the lowest was in Dohazari G (90%). The lowest genetic distance (0.0513) and the highest genetic identity (0.9500) were observed between the ISD 006 and Ishurdi L combinations. A comparatively higher genetic distance (0.3724) and the lowest genetic identity (0.6891) were observed between the ISD 006 and Dohazari G combinations. A dendogram was constructed based on Nei’s genetic distance, which produced 2 main clusters of the genotypes - Cluster I: ISD 006, Ishurdi L, Marich begun L, BAU Begun-1, Marich begun S, and Chega and Cluster 2: Laffa S, Dohazari G, Jessore L, and Singhnath. Genetic variation and its relationship with disease susceptibility were assessed using RAPD markers, to develop disease-resistant varieties and improve eggplant crops
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