281 research outputs found

    TRImP - A new facility to produce and trap radioactive isotopes

    Get PDF
    At the Kernfysisch Vensneller Institiutr (KVI) in Groningen, NL, a new facility (TRImP) is under development. It aims for producing, slowing down, and trapping of radioactive isotopes in order to perform accurate measurements on fundamental symmetries and interactions. A production target station and a dual magnetic separator installed and commissioned. We will slow down the isotopes of interest using an ion catcher and in a further stage a radiofrequency quadropole gas cooler (RFQ). The isotopes will finally be trapped in an atomic trap for precision studies.Comment: Proceedings of the XXIX Mazurian Lakes Conference on Physics (Sep. 2005, Piaski, Poland

    Virulence determination of Beauveria bassiana isolates on a predatory hemipteran, Andrallus spinidens Fabricius (Hemiptera: Pentatomidae)

    Get PDF
    Virulence of the two isolates of Beauveria bassiana, BB2 and AM-118, were evaluated on adults of a predatory hemipteran, Andrallus spinidens Fabricius by conidial bioassay and enzymatic activities. Results of the bioassay revealed LC50 of 37×104 and 15×103 spore/ml for isolates BB2 and AM-118, respectively. Activities of chitinase, lipase and ALP showed the higher activity in the media inoculated by AM-118 while no statistical differences were observed in activity of ACP. Although no statistical differences were found in general protease and Pr1 activities but activity of Pr2 in AM-118 was significantly higher than that of BB2. Activity of general esterases demonstrated no statistical differences when α- and β-naphtyl acetate were used as substrates but activity of glutathione S-transferase in AM-118 was higher than that of BB2 by using CDNB and DCNB as specific reagents. Results of the current study indicated higher virulence of isolate AM-118 against adults of A. spinidens by lower LC50 value and higher activities of the enzymes involved in pathogenicity. Recruiting of these isolates against C. suppressalis must be considered by their adaptability of A. spinidens. Moreover, AM-118 has been isolated from rice fields of northern Iran, so it may somehow indicate a type of host-microorganism interaction

    Production of Radioactive Nuclides in Inverse Reaction Kinematics

    Get PDF
    Efficient production of short-lived radioactive isotopes in inverse reaction kinematics is an important technique for various applications. It is particularly interesting when the isotope of interest is only a few nucleons away from a stable isotope. In this article production via charge exchange and stripping reactions in combination with a magnetic separator is explored. The relation between the separator transmission efficiency, the production yield, and the choice of beam energy is discussed. The results of some exploratory experiments will be presented.Comment: 10 pages, 4 figures, to be submitted to Nucl. Instr. and Met

    UWB Microwave Imaging for Inclusions Detection: Methodology for Comparing Artefact Removal Algorithms

    Get PDF
    An investigation is presented on Artefact Removal Methods for Ultra-Wideband (UWB) Microwave Imaging. Simulations have been done representing UWB signals transmitted onto a cylindrical head-mimicking phantom containing an inclusion having dielectric properties imitating an haemorrhagic stroke. The ideal image is constructed by applying a Huygens’ Principle based imaging algorithm to the difference between the electric field outside the cylinder with an inclusion and the electric field outside the same cylinder with no inclusion. Eight different artefact removal methods are then applied, with the inclusion positioned at \u1d70b and −\u1d70b/4 radians, respectively. The ideal image is then used as a reference image to compare the artefact removal methods employing a novel Image Quality Index, calculated using a weighted combination of image quality metrics. The Summed Symmetric Differential method performed very well in our simulations

    Free space operating microwave imaging device for bone lesion detection: a phantom investigation

    Get PDF
    In this letter, a phantom validation of a low complexity microwave imaging device operating in free space in the 1-6.5 GHz frequency band is presented. The device, initially constructed for breast cancer detection, measures the scattered signals in a multi-bistatic fashion and employs an imaging procedure based on Huygens principle. Detection has been achieved in both bone fracture lesion and bone marrow lesion scenarios using the superimposition of five doublet transmitting positions, after applying the rotation subtraction artefact removal method. A resolution of 5 mm and a signal to clutter ratio (3.35 in linear scale) are achieved confirming the advantage of employing multiple transmitting positions on increased detection capability

    Ft values of the T = 1/2 mirror beta transitions

    Get PDF
    A complete survey is presented of all half-life and branching-ratio measurements related to the isospin T = 1/2 mirror beta transitions ranging from 3He to 83Mo. No measurements are ignored, although some are rejected for cause. Using the decay energies obtained in the 2003 Mass Evaluation experimental ft values are then determined for the transitions up to 45V. For the first time also all associated theoretical corrections needed to convert these results into "corrected" Ft values, similar to the superallowed 0+ -> 0+ pure Fermi beta transitions, were calculated. Precisions of the resulting values are in most cases between 0.1 % and 0.4 %. These Ft(mirror) values can now be used to extract precise weak interaction information from past and ongoing correlation measurements in the beta decay of the T = 1/2 mirror beta transitions

    Developing Artefact Removal Algorithms to Process Data from a Microwave Imaging Device for Haemorrhagic Stroke Detection

    Get PDF
    In this paper, we present an investigation of different artefact removal methods for ultra-wideband Microwave Imaging (MWI) to evaluate and quantify current methods in a real environment through measurements using an MWI device. The MWI device measures the scattered signals in a multi-bistatic fashion and employs an imaging procedure based on Huygens principle. A simple two-layered phantom mimicking human head tissue is realised, applying a cylindrically shaped inclusion to emulate brain haemorrhage. Detection has been successfully achieved using the superimposition of five transmitter triplet positions, after applying different artefact removal methods, with the inclusion positioned at 0°, 90°, 180°, and 270°. The different artifact removal methods have been proposed for comparison to improve the stroke detection process. To provide a valid comparison between these methods, image quantification metrics are presented. An “ideal/reference” image is used to compare the artefact removal methods. Moreover, the quantification of artefact removal procedures through measurements using MWI device is performed

    The road to developing economically feasible plans for green, comfortable and energy efficient buildings

    Get PDF
    Owing to the current challenges in energy and environmental crises, improving buildings, as one of the biggest concerns and contributors to these issues, is increasingly receiving attention from the world. Due to a variety of choices and situations for improving buildings, it is important to review the building performance optimization studies to find the proper solution. In this paper, these studies are reviewed by analyzing all the different key parameters involved in the optimization process, including the considered decision variables, objective functions, constraints, and case studies, along with the software programs and optimization algorithms employed. As the core literature, 44 investigations recently published are considered and compared. The current investigation provides sufficient information for all the experts in the building sector, such as architects and mechanical engineers. It is noticed that EnergyPlus and MATLAB have been employed more than other software for building simulation and optimization, respectively. In addition, among the nine different aspects that have been optimized in the literature, energy consumption, thermal comfort, and economic benefits are the first, second, and third most optimized, having shares of 38.6%, 22.7%, and 17%, respectively
    corecore