99 research outputs found

    Preparation of high crystalline nanoparticles of rare-earth based complex pervoskites and comparison of their structural and magnetic properties with bulk counterparts

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    A simple route to prepare Gd0.7_{0.7}Sr0.3_{0.3}MnO3_3 nanoparticles by ultrasonication of their bulk powder materials is presented in this article. For comparison, Gd0.7_{0.7}Sr0.3_{0.3}MnO3_3 nanoparticles are also prepared by ball milling. The prepared samples are characterized by X-ray diffraction (XRD),field emission scanning electron microscope (FESEM), energy dispersive X-ray (EDX), X-ray photoelectron spectroscope (XPS), and Superconducting Quantum Interference Device (SQUID) magnetometer. XRD Rietveld analysis is carried out extensively for the determination of crystallographic parameters and the amount of crystalline and amorphous phases. FESEM images demonstrate the formation of nanoparticles with average particle size in the range of 50-100 nm for both ultrasonication and 4 hours (h) of ball milling. The bulk materials and nanoparticles synthesized by both ultrasonication and 4 h ball milling exhibit a paramagnetic to spin-glass transition. However, nanoparticles synthesized by 8 h and 12 h ball milling do not reveal any phase transition, rather show an upturn of magnetization at low temperature. The degradation of the magnetic properties in ball milled nanoparticles may be associated with amorphization of the nanoparticles due to ball milling particularly for milling time exceeding 8 h. This investigation demonstrates the potential of ultrasonication as a simple route to prepare high crystalline rare-earth based manganite nanoparticles with improved control compared to the traditional ball milling technique.Comment: 9 pages, 6 figure

    Evaluasi Kinerja Peternak Mitra Ayam Ras Pedaging

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    Broiler chicken had a great performance with unique characteristics like rapid growth, had a thick meat, and also had a relatively short breeding time. The breeding management became one of the farmers key success in describing their management system effectively. One of the management function was the evaluation, thus the research purpose was to evaluate the performance of partnership farmers as the partner of PT XYZ. This research was using the observation and interview methods to the company’s side and also the ones who was involved in the farmers performance evaluation process. The data that was used in this research was the secondary data that was gathered from the company’s yearly report, and was seen  by the farmers index performance (IP). This study took 36 breeders as the sample, 216 periods in 2017 for 6 production cycles. Data were analyzed using a control chart. Data analysis indicates IP Score less than 300 goes to underperformed, 301-325 is considered enough, while a score of 326 - 350 goes to good. As for great and outstanding there are no farmers yet in those segments. The highest IP score for partnership farmers is 335 and the lowest was 277. Partnership farmers in category "enough" are 69,44%, "good" 11,11% and "underperformed" 10,44%. Upper Control Limit (UCL) is 344,36 and Low Control Limit (LCL) is 278,65 wit Mean value of 311,50. There are two points less than LCL, in 19th  and 210th points, scoring 277 and 278

    Simple top-down preparation of magnetic Bi0.9_{0.9}Gd0.1_{0.1}Fe1x_{1-x}Tix_xO3_3 nanoparticles by ultrasonication of multiferroic bulk material

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    We present a simple technique to synthesize ultrafine nanoparticles directly from bulk multiferroic perovskite powder. The starting materials, which were ceramic pellets of the nominal compositions of Bi0.9_{0.9}Gd0.1_{0.1}Fe1x_{1-x}Tix_xO3_3 (x = 0.00-0.20), were prepared initially by a solid state reaction technique, then ground into micrometer-sized powders and mixed with isopropanol or water in an ultrasonic bath. The particle size was studied as a function of sonication time with transmission electron microscopic imaging and electron diffraction that confirmed the formation of a large fraction of single-crystalline nanoparticles with a mean size of 11-13 nm. A significant improvement in the magnetic behavior of Bi0.9_{0.9}Gd0.1_{0.1}Fe1x_{1-x}Tix_xO3_3 nanoparticles compared to their bulk counterparts was observed at room temperature. This sonication technique may be considered as a simple and promising route to prepare ultrafine nanoparticles for functional applications.Comment: 7 pages, 5 figure

    Performance studies of the Belle II Silicon Vertex Detector with data taken at the DESY test beam in April 2016

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    Belle II is a multipurpose detector currently under construction which will be operated at the next generation B-factory SuberKEKB in Japan. Its main devices for the vertex reconstruction are the Silicon Vertex Detector (SVD) and the Pixel Detector (PXD). In April 2016 a sector of the Belle II SVD and PXD have been tested in a beam of high energetic electrons at the test beam facility at DESY Hamburg (Germany). We report here the results for the hit efficiency estimation and the measurement of the resolution for the Belle II silicon vertex etector. We find that the hit efficiencies are on average above 99.5% and that the measured resolution is within the expectations

    Performance studies of the Belle II Silicon Vertex Detector with data taken at the DESY test beam in April 2016

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    Belle II is a multipurpose detector currently under construction which will be operated at the next generation B-factory SuberKEKB in Japan. Its main devices for the vertex reconstruction are the Silicon Vertex Detector (SVD) and the Pixel Detector (PXD). In April 2016 a sector of the Belle II SVD and PXD have been tested in a beam of high energetic electrons at the test beam facility at DESY Hamburg (Germany). We report here the results for the hit efficiency estimation and the measurement of the resolution for the Belle II silicon vertex etector. We find that the hit efficiencies are on average above 99.5% and that the measured resolution is within the expectations

    The Belle II SVD detector

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    The Silicon Vertex Detector (SVD) is one of the main detectors in the Belle II experiment at KEK, Japan. In combination with a pixel detector, the SVD determines precise decay vertex and low-momentum track reconstruction. The SVD ladders are being developed at several institutes. For the development of the tracking algorithm as well as the performance estimation of the ladders, beam tests for the ladders were performed. We report an overview of the SVD development, its performance measured in the beam test, and the prospect of its assembly and commissioning until installation

    Belle-II VXD radiation monitoring and beam abort with sCVD diamond sensors

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    The Belle-II VerteX Detector (VXD) has been designed to improve the performances with respect to Belle and to cope with an unprecedented luminosity of View the MathML source8 71035cm 122s 121 achievable by the SuperKEKB. Special care is needed to monitor both the radiation dose accumulated throughout the life of the experiment and the instantaneous radiation rate, in order to be able to promptly react to sudden spikes for the purpose of protecting the detectors. A radiation monitoring and beam abort system based on single-crystal diamond sensors is now under an active development for the VXD. The sensors will be placed in several key positions in the vicinity of the interaction region. The severe space limitations require a challenging remote readout of the sensors

    Belle II silicon vertex detector (SVD)

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    The Belle II experiment at the SuperKEKB collider in Japan will operate at an unprecedented luminosity of 8 71035 cm 122s 121, about 40 times larger than its predecessor, Belle. Its vertex detector is composed of a two-layer DEPFET pixel detector (PXD) and a four layer double-sided silicon microstrip detector (SVD). To achieve a precise decay-vertex position determination and excellent low-momentum tracking under a harsh background condition and high trigger rate of 10 kHz, the SVD employs several innovative techniques. In order to minimize the parasitic capacitance in the signal path, 1748 APV25 ASIC chips, which read out signal from 224 k strip channels, are directly mounted on the modules with the novel Origami concept. The analog signal from APV25 are digitized by a flash ADC system, and sent to the central DAQ as well as to online tracking system based on SVD hits to provide region of interests to the PXD for reducing the latter\u2019s data size to achieve the required bandwidth and data storage space. Furthermore, the state-of-the-art dual phase CO2 cooling solution has been chosen for a combined thermal management of the PXD and SVD system. In this proceedings, we present key design principles, module construction and integration status of the Belle II SVD

    Belle II Vertex Detector Performance

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    The Belle II experiment at the SuperKEKB accelerator (KEK, Tsukuba, Japan) collected its first e+e− collision data in the spring 2019. The aim of accumulating a 50 times larger data sample than Belle at KEKB, a first generation B-Factory, presents substantial challenges to both the collider and the detector, requiring not only state-of-the-art hardware, but also modern software algorithms for tracking and alignment. The broad physics program requires excellent performance of the vertex detector, which is composed of two layers of DEPFET pixels and four layers of double sided-strip sensors. In this contribution, an overview of the vertex detector of Belle II and our methods to ensure its optimal performance, are described, and the first results and experiences from the first physics run are presented
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