308 research outputs found

    Improving Students' Activeness In Speaking Using Jigsaw II Of Sman 1 Kendawangan

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    This research was aimed to improve students' activeness in speaking using Jigsaw II to class XI IPA 1 of SMAN 1 Kendawangan in academic 2016/2017. In this research, the researcher implemented Jigsaw II as the technique. The actions were designed in order to improve students' activeness in speaking by discussing and presenting the material. The subject of this research were the students from class XI IPA 1 of SMAN 1 Kendawangan in academic year 2016/2017. The method of this research was a classroom action research. The researcher observed the improvement of students' activeness in speaking by collecting the data through observation and measurement technique. The data were in the form of observation checklist, and field notes. The data were collected by analyzing field notes and observation guidelines during the research and by measuring the students' mean score. This research was done in three cycles. The result of this research showed that Jigsaw II was effective to improve students' activeness in speaking. The students' mean score improved from 2.1 in the first cycle, 3 in the second cycle to 3.3 in the third cycle. It can be concluded that students' activeness in speaking taught by Jigsaw II was improved. In other words, this technique can help the students to speak actively

    Pengembangan Model Peningkatan Kompetensi Pekerja Domestik Indonesia Di Malaysia

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    . ASEAN Economic Community is an ASEAN Economic Integration in free trade system all around ASEAN. Indonesia as one of ASEAN Country has a role to compete with other countries, but one of the problems is competitiveness issues. Unskilled domestic workers from Indonesia being the background of miscommunication, workers abuse and many criminality problems in Malaysia. But in fact, placing Indonesian domestic workers in other countries is the best solution to unemployment issues in Indonesia. This study aimed to analyze the problematic situations and create a model that may affect the competency strategies to increase the competitiveness of Indonesian domestic workers in Malaysia. Data from the experts was analyzed using Rich Picture and The House Model. The result showed that in planning the vision for five years term is needed to Enhancing the relevant Governmental Authorities, Establishing the individual reputation and Collaborating between Government and agencies involved. This strategies had been formulated to increase the human resource competencies with Competency-Based Training (CBT). Training and development conducted in Indonesia before placement in abroad is the ways to build workers\u27 quality and then could compete with domestic workers from the Philippines and other countries in Malaysia. The research findings are expected to have implications on government and institutions in the process competency based training models. The government was expected to make the findings as a reference for the Competency-Based Training (CBT) to Indonesian domestic workers fairly and effectively to support its competitiveness strategies

    Low Energy Electron and Nuclear Recoil Thresholds in the DRIFT-II Negative Ion TPC for Dark Matter Searches

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    Understanding the ability to measure and discriminate particle events at the lowest possible energy is an essential requirement in developing new experiments to search for weakly interacting massive particle (WIMP) dark matter. In this paper we detail an assessment of the potential sensitivity below 10 keV in the 1 m^3 DRIFT-II directionally sensitive, low pressure, negative ion time projection chamber (NITPC), based on event-by-event track reconstruction and calorimetry in the multiwire proportional chamber (MWPC) readout. By application of a digital smoothing polynomial it is shown that the detector is sensitive to sulfur and carbon recoils down to 2.9 and 1.9 keV respectively, and 1.2 keV for electron induced events. The energy sensitivity is demonstrated through the 5.9 keV gamma spectrum of 55Fe, where the energy resolution is sufficient to identify the escape peak. The effect a lower energy sensitivity on the WIMP exclusion limit is demonstrated. In addition to recoil direction reconstruction for WIMP searches this sensitivity suggests new prospects for applications also in KK axion searches

    Design Feed Forward Neural Network To Solve Boundary Value Problems

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    The aim of this paper is to design fast feed forward neural network to present a method to solve second order boundary value problem for ordinary differential equations. That is to develop an algorithm which can speedup the solution times, reduce solver failures, and increase possibility of obtaining the globally optimal solution and we use several different training algorithms many of them having a very fast convergence rate for reasonable size networks.Finally, we illustrate the method by solving model problem and present comparison with solutions obtained using other different method

    First measurement of the Head-Tail directional nuclear recoil signature at energies relevant to WIMP dark matter searches

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    We present first evidence for the so-called Head-Tail asymmetry signature of neutron-induced nuclear recoil tracks at energies down to 1.5 keV/amu using the 1m^3 DRIFT-IIc dark matter detector. This regime is appropriate for recoils induced by Weakly Interacting Massive Particle (WIMPs) but one where the differential ionization is poorly understood. We show that the distribution of recoil energies and directions induced here by Cf-252 neutrons matches well that expected from massive WIMPs. The results open a powerful new means of searching for a galactic signature from WIMPs.Comment: 4 pages, 6 figures, 1 tabl

    The ZEPLIN-III dark matter detector: instrument design, manufacture and commissioning

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    We present details of the technical design and manufacture of the ZEPLIN-III dark matter experiment. ZEPLIN-III is a two-phase xenon detector which measures both the scintillation light and the ionisation charge generated in the liquid by interacting particles and radiation. The instrument design is driven by both the physics requirements and by the technology requirements surrounding the use of liquid xenon. These include considerations of key performance parameters, such as the efficiency of scintillation light collection, restrictions placed on the use of materials to control the inherent radioactivity levels, attainment of high vacuum levels and chemical contamination control. The successful solution has involved a number of novel design and manufacturing features which will be of specific use to future generations of direct dark matter search experiments as they struggle with similar and progressively more demanding requirements.Comment: 25 pages, 19 figures. Submitted to Astropart. Phys. Some figures down sampled to reduce siz

    First Results from the DRIFT-IIa Dark Matter Detector

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    Data from the DRIFT-IIa directional dark matter experiment are presented, collected during a near continuous 6 month running period. A detailed calibration analysis comparing data from gamma-ray, x-ray and neutron sources to a GEANT4 Monte Carlo simulations reveals an efficiency for detection of neutron induced recoils of 94+/-2(stat.)+/-5(sys.)%. Software-based cuts, designed to remove non-nuclear recoil events, are shown to reject 60Co gamma-rays with a rejection factor of better than 8x10-6 for all energies above threshold. An unexpected event population has been discovered and is shown here to be due to the alpha-decay of 222Rn daughter nuclei that have attached to the central cathode. A limit on the flux of neutrons in the Boulby Underground Laboratory is derived from analysis of unshielded and shielded data.Comment: 43 pages, 14 figures, submitted to Astroparticle Physic

    Track Reconstruction and Performance of DRIFT Directional Dark Matter Detectors using Alpha Particles

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    First results are presented from an analysis of data from the DRIFT-IIa and DRIFT-IIb directional dark matter detectors at Boulby Mine in which alpha particle tracks were reconstructed and used to characterise detector performance--an important step towards optimising directional technology. The drift velocity in DRIFT-IIa was [59.3 +/- 0.2 (stat) +/- 7.5 (sys)] m/s based on an analysis of naturally-occurring alpha-emitting background. The drift velocity in DRIFT-IIb was [57 +/- 1 (stat) +/- 3 (sys)] m/s determined by the analysis of alpha particle tracks from a Po-210 source. 3D range reconstruction and energy spectra were used to identify alpha particles from the decay of Rn-222, Po-218, Rn-220 and Po-216. This study found that (22 +/- 2)% of Po-218 progeny (from Rn-222 decay) are produced with no net charge in 40 Torr CS2. For Po-216 progeny (from Rn-220 decay) the uncharged fraction is (100 +0 -35)%.Comment: 27 pages, 12 figures, 5 tables. Submitted to Nuclear Instruments and Methods in Physics Research, Section A. Subj-class: Instrumentation and Detector

    Changes in Histone H3 Acetylation on Lysine 9 Accompany Aβ 1-40 Overexpression in an Alzheimer’s Disease Yeast Model

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    Alzheimer’s Disease (AD), the most common type of dementia, is a neurodegenerative disease characterized by plaques of amyloid-beta (Aβ) peptides found in the cerebral cortex of the brain. The pathological mechanism by which Aβ aggregation leads to neurodegeneration remains unknown. Interestingly, genetic mutations do not explain most AD cases suggesting that other mechanisms are at play. Epigenetic mechanisms, such as histone post-translational modifications (PTMs), may provide insight into the development of AD. Here, we exploit a yeast Aβ overexpression model to map out the histone PTM landscape associated with AD. We find a modest decrease in the acetylation levels on lysine 9 of histone H3 in the context of Aβ 1-40 overexpression. This change is accompanied by a decrease in RNA levels. Our results support a potential role for H3K9ac in AD pathology and allude to the role of epigenetics in AD and other neurodegenerative diseases

    Alterations in Antioxidant Defense System in the Plasma of Female Khat Chewers of Thamar City, Yemen

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    Abstract * Corresponding author. e-mail: [email protected]. * Abbreviations used: BChE, Butyrylcholinesterase; GSH, Reduced glutathione; T-SH, Total thiols; OPs, Organophosphate compounds; CAT, Catalase Chewing Khat leaves (Catha edulis) is highly prevalent in Yemen and East African countries. Unfortunately, farmers use to apply pesticide for the better product of Khat. The present study has been designed to investigate the activity of plasma butyrylcholinesterase (BChE) and to assess the antioxidant defense system in the plasma of female Khat chewers in Thamar city, Yemen. Plasma of twenty female Khat chewers and twenty controls (non Khat chewers) were prepared and the activities of BChE and catalase (CAT) were estimated along with the measuring levels of reduced glutathione, total thiols and cholesterol. At biochemical level a significant decrease in the activities of BChE and CAT were observed in the plasma of female Khat chewers (P < 0.05) concomitant with reductions in the levels of reduced glutathione and total thiols (P < 0.05) as compared to non Khat chewers. This alterations on the antioxidants resulted in decrease of plasma cholesterol in Khat chewers group (P < 0.05). The present data show that the production of oxidants which are responsible for reduction in antioxidant defense system might be due to chewing Khat plant with more attention to the pesticide applied to the plant
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