18,602 research outputs found

    A study into the effect of concentration process on the yield of rotenone from the extract of local plant species (Derris elliptica)

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    Bio-pesticides are becoming increasingly important as pest management tools in various cropping systems in the tropics essentially to remedy problems associated with the indiscriminate use of ‘hard’ inorganic pesticide and interest in organic agriculture. In the few decades, many bio-pesticidal products, both microbial-based (bacteria, fungi, microsprodia, entomopathogenic nematodes, viruses) and plant-based botanicals (rotenone and azadiracthin) had been studied for use against insect pests in the tropics. In this paper, the effect of the concentration process towards the yield of rotenone; mg and its concentration; mg/ml are studied extensively. The raw plants were collected from Kota Johor Lama, Johor and sorted to collect the root and stem. Only the root and stem were utilized as a raw material of the extraction process. The root and stem were extracted using the Normal Soaking Extraction (NSE) at 28 0C to 30 0C with 95 % (v/v) of acetone as a solvent and the solvent-to-solid ratio of 10 ml/g). The extraction was carried out for 24 hours. The liquid crude extract was concentrated further (the solvent removed under reduced pressure) using the rotary evaporator at 50 0C and 80 mbar of vacuum pressures. The fractions of the liquid crude extract were collected for each interval time (15 mins/1.0 ml/fraction). Each fractions were diluted 1/100 with acetone and further cleaned up prior to determination of rotenone content; mg and concentration; mg/ml by using the High Performance Liquid Chromatography (HPLC). Significant effect of the concentration process against the yield of rotenone; mg was recorded and shows a significant thermal degradation or dissipation of rotenone content at higher operating temperature. The possibilities for better exploitation and identification of the effective operating parameters will be discussed

    Standardization of the bio-active compounds (rotenoids) from the extract of local plant species (derris elliptica) using the internal standard method of high performance liquid chromatography (HPLC)

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    It is well known now that some plant species represent an efficient factory of chemicals, which are manufactured and used as bio-weapons against pest attacks. Extensive work has been done during the last few decades on these potentially useful compounds. During the last few decades a growing interest has been paid for safe agricultural production i.e free residual toxicity hazards to human beings and to the environment. Plant extracts-based biocides possess a great advantage compared with the chemical ones. Their efficacies are also acceptable. Research carried out was to standardize and determine the bio-active compounds from the extract of local plant species (Derris elliptica) using the internal standard method of the isocratic High Performance Liquid Chromatography (HPLC) analysis system. The raw plants were collected from Kota Johor Lama, Johor and sorted to collect the root and stem. Only the root and stem were utilized as a raw material of the extraction process. The root and stem were extracted by using the Normal Soaking Extraction (NSE) method at 28 0C to 30 0C with 95.0 % (v/v) of acetone as a solvent and the solvent-to-solid ratio of the extraction is (10.0 ml/g). The extraction was carried out for 24 hours and further cleaned up to remove fine debris of root and stem prior to determination of the rotenone and its derivatives content. The rotenone cube resin of SAPHYR S.A.R.L (France) was used to verify the appearances of the compounds in the extract. The employed method of analysis shows significant appearances of the bio-active compounds in the extract compared with the commercial grade of rotenone cube resin

    The EU Sugar Policy Regime and Implications of Reform

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    The European Union’s sugar policy, in place since 1968, underwent its first major reform in 2005 in response to mounting and unsustainable imbalances in supply and demand. The reform, however, targeted only a few policy instruments (intervention price cut, voluntary production quota buyout, and restrictions on nonquota sugar exports), while leaving other key policies unchanged (interstate quota trading, sugar-substitute competition, and import barriers). Consequently, the extent of the reform’s impact is limited, compared with more far-reaching alternatives, particularly when the oligopolistic nature of the industry and its noncompetitive pricing behavior are taken into account. A model-based analysis suggests that the reforms by themselves are unlikely to induce price adjustments sufficient to reduce overproduction unless quotas and/or high tariffs are reduced.European Union, EU, sugar CMO, Common Market Organization, policy reform, trade, economic model, Agricultural and Food Policy, International Relations/Trade,

    Monopolizing force?: police legitimacy and public attitudes towards the acceptability of violence

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    Why do people believe that violence is acceptable? In this paper we study people’s normative beliefs about the acceptability of violence to achieve social control (as a substitute for the police, for self-protection and the resolution of disputes) and social change (through violent protests and acts to achieve political goals). Addressing attitudes towards violence among young men from various ethnic minority communities in London, we find that procedural justice is strongly correlated with police legitimacy, and that positive judgments about police legitimacy are associated with more negative views about the use of violence. We conclude with the idea that police legitimacy has an additional, hitherto unrecognized, empirical property – by constituting the belief that the police monopolise rightful force in society, legitimacy has a ‘crowding out’ effect on positive views of private violence

    Blind image separation based on exponentiated transmuted Weibull distribution

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    In recent years the processing of blind image separation has been investigated. As a result, a number of feature extraction algorithms for direct application of such image structures have been developed. For example, separation of mixed fingerprints found in any crime scene, in which a mixture of two or more fingerprints may be obtained, for identification, we have to separate them. In this paper, we have proposed a new technique for separating a multiple mixed images based on exponentiated transmuted Weibull distribution. To adaptively estimate the parameters of such score functions, an efficient method based on maximum likelihood and genetic algorithm will be used. We also calculate the accuracy of this proposed distribution and compare the algorithmic performance using the efficient approach with other previous generalized distributions. We find from the numerical results that the proposed distribution has flexibility and an efficient resultComment: 14 pages, 12 figures, 4 tables. International Journal of Computer Science and Information Security (IJCSIS),Vol. 14, No. 3, March 2016 (pp. 423-433

    Structural response of SSME turbine blade airfoils

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    Reusable space propulsion hot gas-path components are required to operate under severe thermal and mechanical loading conditions. These operating conditions produce elevated temperature and thermal transients which results in significant thermally induced inelastic strains, particularly, in the turbopump turbine blades. An inelastic analysis for this component may therefore be necessary. Anisotropic alloys such as MAR M-247 or PWA-1480 are being considered to meet the safety and durability requirements of this component. An anisotropic inelastic structural analysis for an SSME fuel turbopump turbine blade was performed. The thermal loads used resulted from a transient heat transfer analysis of a turbine blade. A comparison of preliminary results from the elastic and inelastic analyses is presented

    Penggunaan Model Pembelajaran Kooperatif Dan Kompetitif Dalam Mengembangkan Kreativitas Siswa

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    Both cooperative and competitive methods are influence the student creativity. However, base on the research study the cooperative method understood is more effective than competitive method in developing student creativity. Therefore, using both methods (cooperative and competitive) should be tried in learning process in classes
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