20,020 research outputs found
The Policy and Regulatory Environment for Organic Farming in Europe
Organic Farming is one of the key issues in reshaping European agricultural policy. This book clarifies the policy and regulatory environment within which organic farming currently operates in all EU-15 member states and in three non-EU countries (Norway, Switzerland and the Czech Republic). European and national regulations and their implementation are reviewed. Focus is led on agri-environmental and mainstream agricultural support measures, marketing and regional development programmes, certification systems and organic farming support in the form of advice, training and research.
The book aims at policy makers, the private sector, researchers and students in the field of economics and politics of organic farming
GA tuning of pitch controller for small scale MAVs
The paper presents the application of intelligent tuning methods for the control of a prototype MAV in order to address problems associated with bandwidth limited actuators and gust alleviation. Specifically, as a proof of concept, the investigation is focused on the pitch control of a MAV. The work is supported by experimental results from wind tunnel testing that shows the merits of the use of Genetic Algorithm (GA) tuning techniques compared to classical, empirical tuning methodologies. To provide a measure of relative merit, the controller responses are evaluated using the ITAE performance index. In this way, the proposed method is shown to induce far superior dynamic performance compared to traditional approaches
Comparison of single-phase matrix converter and H-bridge converter for radio frequency induction heating
This paper compares the newly developed single-phase matrix converter and the more conventional H- bridge converter for radio frequency induction heating. Both the converters exhibit unity power factor, very low total harmonic distortion at the utility supply interface, good controllability under soft switching condition for a wide range of power, and high efficiencies, whilst still having simple structures. A novel switching control pattern has been proposed for the matrix converter in order to maintain the comparable performance to the H-bridge converter. Simulation and experimental results for both converters are presented. Comparisons between two converters have confirmed the excellent performance of the proposed matrix converter
Recruiting hard-to-reach populations to physical activity studies : evidence and experiences
Most researchers who are conducting research with a public health focus face difficulties in recruiting the segments of the population that they really want to reach. This symposium presented evidence and experiences on recruiting participants to physical activity research, including both epidemiological and intervention based studies. Results from a systematic review of recruitment strategies suggested that we know little about how best to recruit and highlighted the need for researchers to report this in more detail, including metrics of reach into the target population such as number, proportion, and representativeness of participants. Specific strategies used to optimise responses to a population-based mail survey were presented such as study promotion, survey design, multiple mailings, and personal engagement. Finally, using place based recruiting via schools or places of worship to target ethnic minority youth were discussed. Overall the symposium presenters suggested that we need to learn more about how best to recruit participants, in particular those typically under-represented, and that researchers need to apportion a similar amount of planning effort to their recruitment strategies as they do the their research design. Finally we made a plea for researchers to report their recruitment processes in detail
Single phase matrix converter for radio frequency induction heating
Conventional converters for radio frequency induction heating usually follow an AC-DC-AC structure, which can exhibit non-unity power factor and introduce large harmonic currents into the utility supply. The need for a direct converter for radio frequency induction heating, featuring unity power factor, and sinusoidal input current, has motivated the development of a single phase matrix converter as an induction heater. A novel commutation strategy is therefore required to ensure smooth operation of the converter whilst creating a high frequency output under soft switching conditions. The operating principle and features of the proposed converter are described here, and experimentally verifie
Drugs for neglected diseases: a failure of the market and a public health failure?
Infectious diseases cause the suffering of hundreds of millions of people, especially in tropical and subtropical areas. Effective, affordable and easy-to-use medicines to fight these diseases are nearly absent. Although science and technology are sufficiently advanced to provide the necessary medicines, very few new drugs are being developed. However, drug discovery is not the major bottleneck. Today's R&D-based pharmaceutical industry is reluctant to invest in the development of drugs to treat the major diseases of the poor, because return on investment cannot be guaranteed. With national and international politics supporting a free market-based world order, financial opportunities rather than global health needs guide the direction of new drug development. Can we accept that the dearth of effective drugs for diseases that mainly affect the poor is simply the sad but inevitable consequence of a global market economy? Or is it a massive public health failure, and a failure to direct economic development for the benefit of society? An urgent reorientation of priorities in drug development and health policy is needed. The pharmaceutical industry must contribute to this effort, but national and international policies need to direct the global economy to address the true health needs of society. This requires political will, a strong commitment to prioritize health considerations over economic interests, and the enforcement of regulations and other mechanisms to stimulate essential drug development. New and creative strategies involving both the public and the private sector are needed to ensure that affordable medicines for today's neglected diseases are developed. Priority action areas include advocating an essential medicines R&D agenda, capacity-building in and technology transfer to developing countries, elaborating an adapted legal and regulatory framework, prioritizing funding for essential drug development and securing availability, accessibility, distribution and rational use of these drugs
Prompt energization of relativistic and highly relativistic electrons during a substorm interval: Van Allen Probes observations
Abstract On 17 March 2013, a large magnetic storm significantly depleted the multi-MeV radiation belt. We present multi-instrument observations from the Van Allen Probes spacecraft Radiation Belt Storm Probe A and Radiation Belt Storm Probe B at ~6 Re in the midnight sector magnetosphere and from ground-based ionospheric sensors during a substorm dipolarization followed by rapid reenergization of multi-MeV electrons. A 50% increase in magnetic field magnitude occurred simultaneously with dramatic increases in 100 keV electron fluxes and a 100 times increase in VLF wave intensity. The 100 keV electrons and intense VLF waves provide a seed population and energy source for subsequent radiation belt enhancements. Highly relativistic (\u3e2 MeV) electron fluxes increased immediately at L* ~ 4.5 and 4.5 MeV flux increased \u3e90 times at L* = 4 over 5 h. Although plasmasphere expansion brings the enhanced radiation belt multi-MeV fluxes inside the plasmasphere several hours postsubstorm, we localize their prompt reenergization during the event to regions outside the plasmasphere. Key Points Substorm dynamics are important for highly relativistic electron energization Cold plasma preconditioning is significant for rapid relativistic energization Relativistic / highly relativistic electron energization can occur in \u3c 5 hrs
Isolation of ribosomes from Neurospora and their analysis using a vertical rotor
Isolation of ribosomes from Neurospora and their analysis using a vertical roto
Calixarene bulk modified screen-printed electrodes (SPCCEs) as a one-shot disposable sensor for the simultaneous detection of lead(II), copper(II) and mercury(II) ions: Application to environmental samples
Calixarene bulk modified screen-printed electrodes (SPCCEs) have been designed, fabricated and utilized as one-shot disposable electrochemical sensors towards the simultaneous measurement of toxic metal ions lead(II), copper(II) and mercury(II) within environmental samples. These SPCCEs have been fabricated upon polyester strips, which have been modified over a range of different calixarene compositions. These bespoke sensors have been utilized as disposable electrochemical sensors and quantified in model aqueous solution of 0.1 M HCl giving rise to the simultaneous sensing of lead(II), copper(II) and mercury(II) using cyclic voltammetry and differential pulse anodic stripping voltammetry techniques. These SPCCEs have additionally been applied for the sensing of lead(II), copper(II) and mercury(II) within industrial and environmental samples such as industrial effluents and wastewater samples, furthermore the presented method has been subjected to a comprehensive interference study and further validated with an atomic absorption spectrometric method. © 2017 Elsevier B.V
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