2,871 research outputs found

    Overcoming self-interference in SM-OFDMA with ESINR and dynamic subcarrier allocation

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    A spatial interference minimization strategy for the correlated LTE downlink channel

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    Wind tunnel pressurization and recovery system

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    The high density, low toxicity characteristics of refrigerant-12 (dichlorofluoromethane) make it an ideal gas for wind tunnel testing. Present limitations on R-12 emissions, set to slow the rate of ozone deterioration, pose a difficult problem in recovery and handling of large quantities of R-12. This preliminary design is a possible solution to the problem of R-12 handling in wind tunnel testing. The design incorporates cold temperature condensation with secondary purification of the R-12/air mixture by adsorption. Also discussed is the use of Freon-22 as a suitable refrigerant for the 12 foot wind tunnel

    Normal soaking extraction (NSE) of rotenone from Derris elliptica

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    Derris elliptica or the tuba plant contains rotenone, bio-active compound known that has the potential to be used as bio-pesticide. Bio-pesticide is the best-known alternative bio-pesticide which has the potential to replace the use of conventional pesticides, as it is more environmentally friendly. The main objective of the paper is to obtain the best extraction solvent for optimizing the yield in rotenone extraction. Rotenone was extracted from Derris root using three different parts of roots and three types of solvent in Normal Soaking Extraction (NSE). The types of Derris roots are: (1) Fine root (2) Coarse root (3) Stem. The three types of solvent system are: (1) Acetone 95 % (v/v), (2) Chloroform 99.9 % (v/v) and (3) a mixture of ethanol: H2O (9:1) added with oxalic acid (1mg/ml). The liquid crude extracts were further cleaned up to remove the fine debris of roots. The presence of rotenone was confirmed using qualitative analysis Thin Layer Chromatography (TLC) and thereupon the determination of rotenone content was carried out using High Performance Liquid Chromatography (HPLC). From the results obtained, it was found that the Normal Soaking Extraction (NSE) using acetone 95 % (v/v) was the best method to extract the highest yield of rotenone; 1.14 % (w/w)

    Future Community-Based Ecotourism (CBET) development

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    Ecotourism is an alternative form of tourism and is usually confused with natural and cultural tourism.CBET is fast becoming a popular biodiversity conservation tool that develops and benefits the local community. Based on the context of conservation theory and practice, Community-Based Ecotourism (CBET) is a form of community-based natural resource management. However, a sustainable CBET development through Community Capacity Building (CCB)programs is not something that it easily achievable. Local community’s capacity varies from one culture to another. It takes a high level of community participation, in order for it to come to a level where the community members themselves are motivated to participate and contribute to the development of the program. This fully qualitative research involved 15 respondents from the community of Kg. Selai, Bekok in Johor, Malaysia. The result show there are five factors that sustained the ecotourism development based for Orang Asli Community in Kg. Selai, namely, existing CBET development, past CBET development, local community participation in planning stage of tourism, local participation in implementation stage of tourism and participation in nature conservation

    The room temperature phosphine-free synthesis of near-infrared emitting HgSe quantum dots

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    Luminescent mercury selenide (HgSe) quantum dots have been synthesised by a phosphine-free method using oleic acid as a capping agent. The modification of experimental conditions such as temperature resulted in particles of various sizes (15–100 nm) and morphologies not previously seen in HgSe, with emission tuneable between 1000 nm and 1350 nm

    Type Ia supernova Hubble diagram with near-infrared and optical observations

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    We main goal of this paper is to test whether the NIR peak magnitudes of SNe Ia could be accurately estimated with only a single observation obtained close to maximum light, provided the time of B band maximum and the optical stretch parameter are known. We obtained multi-epoch UBVRI and single-epoch J and H photometric observations of 16 SNe Ia in the redshift range z=0.037-0.183, doubling the leverage of the current SN Ia NIR Hubble diagram and the number of SNe beyond redshift 0.04. This sample was analyzed together with 102 NIR and 458 optical light curves (LCs) of normal SNe Ia from the literature. The analysis of 45 well-sampled NIR LCs shows that a single template accurately describes them if its time axis is stretched with the optical stretch parameter. This allows us to estimate the NIR peak magnitudes even with one observation obtained within 10 days from B-band maximum. We find that the NIR Hubble residuals show weak correlation with DM_15 and E(B-V), and for the first time we report a possible dependence on the J_max-H_max color. The intrinsic NIR luminosity scatter of SNe Ia is estimated to be around 0.10 mag, which is smaller than what can be derived for a similarly heterogeneous sample at optical wavelengths. In conclusion, we find that SNe Ia are at least as good standard candles in the NIR as in the optical. We showed that it is feasible to extended the NIR SN Ia Hubble diagram to z=0.2 with very modest sampling of the NIR LCs, if complemented by well-sampled optical LCs. Our results suggest that the most efficient way to extend the NIR Hubble diagram to high redshift would be to obtain a single observation close to the NIR maximum. (abridged)Comment: 39 pages, 15 figures, accepted by A&

    Pengaruh Latihan Barbell Pullover terhadap Kekuatan Otot Lengan dan Bahu pada Tim Voli Putra SMP Negeri 6 Pekanbaru

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    , the purpose of this research is want to know is there the effect of Barbell Pullover exercise toward strenght of arm and shoulder musclus of smpn 6 pekanbaru man vollyball club, so when do under servise, the ball can pass over the net. Type of this research is experimental, the population in this research was the students of smpn 6 pekanbaru man vollyball club who actively doing exercise, the total was 10 students. Sampling technique used as sample ( sugiyono 2008 : 124 ). Total sample of this research is 10 students of smpn 6 pekanbaru man vollyball club. Data tecnique used was surfaited sampling, it is determination of the sample when all members are the population are used as sample. The instruments was used in this research was expanding dynamometer, which is aimed to measure the strength og arm and shoulder muscles. After that, the data was analysis by using statistic to examine the normality with liliefors test on the significant level 0,05a. The subritted hypothesis was there is the effect of Barbell Pullover exercise toward strength of arm and shoulder muscles. Based on the data analysis t test showed T count was 21,95 and T table was 1,812, it means that T count > T table. Based on the statistic data analysis, the average of preetest was 12,1 and the average of posttest 15,7 was it. Shows that the data was normal. In conclution , there was the effect of Barbell Pullover exercise toward strength of arm and shoulder of smpn 6 pekanbaru man vollyball club
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