84 research outputs found

    Improving the Students\u27 Writing Competence in a Second Language Acquisition Through the Implementation of Lesson Study

    Full text link
    Writing is the most difficult skill for second language learners. It can be seen, for example, they always make ageneralization, simplification, less of knowing vocabularies, punctuation, spelling, and grammar. This paper will describe improving the students\u27 writing competence in second language acquisition through the implementation of lesson study in faculty of language education of Indraprasta PGRI University of Jakarta. This research uses qualitative approach and the data taken from the students who are studying writing in the class. In applying lesson study, lecturer model explains about the materials based on the syllabus of the subject. The students are also given tasks in their groups. The observers watch and write about the students and assist them. After doing this, the observers discuss about the class with the lecturer model. By doing the implementation of Lesson Study, the students can work in group together, the class is so inspiring, they feel satisfied with the explanation of the lecturer model and havegood impact to improve the students\u27 writing competence

    A Monte-Carlo-based study of a single-2D-detector proton-radiography system

    Get PDF
    PURPOSE: To assess the feasibility of a proton radiography (pRG) system based on a single thin pixelated detector for water-equivalent path length (WEPL) and relative stopping power (RSP) measurements.METHODS: A model of a pRG system consisting of a single pixelated detector measuring energy deposition and proton fluence was investigated in a Geant4-based Monte Carlo study. At the position directly after an object traversed by a broad proton beam, spatial 2D distributions are calculated of the energy deposition in, and the number of protons entering the detector. Their ratio relates to the 2D distribution of the average stopping power of protons in the detector. The system response is calibrated against the residual range in water of the protons to provide the 2D distribution of the WEPL of the object. The WEPL distribution is converted into the distribution of the RSP of the object. Simulations have been done, where the system has been tested on 13 samples of homogeneous materials of which the RSPs have been calculated and compared with RSPs determined from simulations of residual-range-in-water, which we refer to as reference RSPs.RESULTS: For both human-tissue- and non-human-tissue-equivalent materials, the RSPs derived with the detector agree with the reference values within 1%.CONCLUSION: The study shows that a pRG system based on one thin pixelated detection screen has the potential to provide RSP predictions with an accuracy of 1%.</p

    Analisis Kesalahan Berbahasa Indonesia Dalam Karangan Eksposisi Siswa Sekolah Menengah Atas

    Full text link
    : The purpose of this research is : (1) to describes the error of Indonesian language in exposition text by the students at class X of SMA Negeri in Karanganyar in the academic year 2011/2012; (2) causes of error, and (3) the effort which is done by the teacher and student to solve the error. This research is a qualitative descriptive research with a sample student text SMA Negeri 1 Karanganyar and SMA Negeri Kebakkramat. The sampling technique used was purposive sampling. Data collection techniques used were in-depth interviews and document analysis. Data analysis technique used is the interactive analytical model that includes four components, namely data collection, data reduction, data presentation, and verification. The conclusions of this study are as follows. Firstly, the linguistic elements of language errors that often occur in the student text is divided into four errors : spelling error, diction, sentence, and paragraph. Secondly, language errors that often occur in a student text exposition caused by several factors, among others: is inadequate of language mastery, lack of examples by the teachers, the influence of foreign language, lack of writing peactice, and lack of writing time. Thirdly, the efforts have been made to minimize errors include: improving students\u27 language mastery, having more practices in writing, implementing appropriate correction technique, and implementing a process approach to teaching writing

    Pusat Informasi Pariwisata dan Kebudayaan Kalimantan Timur di Samarinda

    Full text link
    Samarinda sekarang merupakan ibukota dari Kalimantan Timur yang didalamnya memiliki potensi pariwisata dan kebudayaan. Hadirnya fasilitas pusat informasi ini bertujuan untuk memenuhi kebutuhan kota atas potensi dan penjawaban salah satu permasalahan kota yang ada. Pusat Informasi ini di desain untuk memberikan informasi serta pemasaran tentang pariwisata dan kebudayaan yang ada di wilayah Kalimantan Timur. tidak hanya berupa data saja tetapi dari fasilitas gallery, workshop, ampitheatre, perpustakaan sampai informasi yang berupa kuliner dari resotran yang di desain.informasi juga dipaparkan lewat puisi semiotika yaitu pada ekspresi bangunan yang menggunakan pendekatan simbolik dengan tema “Genesis of East Borneo Culture”. Tidak semata-mata mentah mengambil bentuk dari arsitektur Kalimantan Timur tetapi dimodernisasikan mengikuti perkembangan dunia arsitektur disertai dengan Kubahan bentuk melalui proses simbolik

    Real-Time PET Imaging for Range Verification of Helium Radiotherapy

    Get PDF
    Real-time range verification of particle beams is important for optimal exploitation of the tissue-sparing advantages of particle therapy. Positron Emission Tomography (PET) of the beam-induced positron emitters such as 15O (T1/2 = 122 s) and 11C (T1/2 = 1223 s) has been used for monitoring of therapy in both clinical and preclinical studies. However, the half-lives of these nuclides preclude prompt feedback, i.e., on a sub-second timescale, on dose delivery. The in vivo verification technique relying on the in-beam PET imaging of very short-lived positron emitters such as 12N (T1/2 = 11 ms), recently proposed and investigated in feasibility experiments with a proton beam, provides millimeter precision in range measurement a few tens of milliseconds after the start of an irradiation. With the increasing interest in helium therapy, it becomes relevant to study the feasibility of prompt feedback using PET also for helium beams. A recent study has demonstrated the production of very short-lived nuclides (T1/2 = 10 ms attributed to 12N and/or 13O) during irradiation of water and graphite with helium ions. This work is aimed at investigating the range verification potential of imaging these very short-lived nuclides. PMMA targets were irradiated with a 90 AMeV 4He pencil beam consisting of a series of pulses of 10 ms beam-on and 90 ms beam-off. Two modules of a modified Siemens Biograph mCT PET scanner (21 × 21 cm2), installed 25 cm apart, were used to image the beam-induced PET activity during the beam-off periods. For the irradiation of PMMA, we identify the very short-lived activity earlier observed to be 12N (T1/2 = 11.0 ms). The range precision determined from the 12N activity profile that is measured after just one beam pulse was found to be 9.0 and 4.1 mm (1σ) with 1.3 × 1074He ions per pulse and 6.6 × 1074He ions per pulse, respectively. When considering 4.0 × 1074He ions, which is about the intensity of the most intense distal layer spot in a helium therapy plan, a range verification precision in PMMA of 5.7 mm (1σ) can be realized. The range precision scales approximately with the inverse square root of the number of 4He ions, i.e., the relative statistical accuracy of the number of coincidence events. Thus, when summing data over about 10 distal layer spots, this study shows good prospects for obtaining 1.8 mm (1σ) precision in range verification, within 50 ms after the start of a helium irradiation by in-beam PET imaging (scanner 29% solid angle) of 12N

    A simple microscopy setup for visualizing cellular responses to DNA damage at particle accelerator facilities

    Get PDF
    Cellular responses to DNA double-strand breaks (DSBs) not only promote genomic integrity in healthy tissues, but also largely determine the efficacy of many DNA-damaging cancer treatments, including X-ray and particle therapies. A growing body of evidence suggests that activation of the mechanisms that detect, signal and repair DSBs may depend on the complexity of the initiating DNA lesions. Studies focusing on this, as well as on many other radiobiological questions, require reliable methods to induce DSBs of varying complexity, and to visualize the ensuing cellular responses. Accelerated particles of different energies and masses are exceptionally well suited for this task, due to the nature of their physical interactions with the intracellular environment, but visualizing cellular responses to particle-induced damage - especially in their early stages - at particle accelerator facilities, remains challenging. Here we describe a straightforward approach for real-time imaging of early response to particle-induced DNA damage. We rely on a transportable setup with an inverted fluorescence confocal microscope, tilted at a small angle relative to the particle beam, such that cells can be irradiated and imaged without any microscope or beamline modifications. Using this setup, we image and analyze the accumulation of fluorescently-tagged MDC1, RNF168 and 53BP1—key factors involved in DSB signalling—at DNA lesions induced by 254 MeV α-particles. Our results provide a demonstration of technical feasibility and reveal asynchronous initiation of accumulation of these proteins at different individual DSBs

    Investigating the lateral dose response functions of point detectors in proton beams

    Get PDF
    Objective Point detector measurements in proton fields are perturbed by the volume effect originating from geometrical volume-averaging within the extended detector's sensitive volume and density perturbations by non-water equivalent detector components. Detector specific lateral dose response functions K(x) can be used to characterize the volume effect within the framework of a mathematical convolution model, where K(x) is the convolution kernel transforming the true dose profile D(x) into the measured signal profile of a detector M(x). The aim of this work is to investigate K(x) for detectors in proton beams. Approach The K(x) for five detectors were determined by iterative deconvolution of measurements of D(x) and M(x) profiles at 2 cm water equivalent depth of a narrow 150 MeV proton beam. Monte Carlo simulations were carried out for two selected detectors to investigate a potential energy dependence, and to study the contribution of volume-averaging and density perturbation to the volume effect. Main results The Monte Carlo simulated and experimentally determined K(x) agree within 2.1% of the maximum value. Further simulations demonstrate that the main contribution to the volume effect is volume-averaging. The results indicate that an energy or depth dependence of K(x) is almost negligible in proton beams. While the signal reduction from a Semiflex 3D ionization chamber in the center of a gaussian shaped field with 2 mm sigma is 32% for photons, it is 15% for protons. When measuring the field with a microDiamond the trend is less pronounced and reversed with a signal reduction for protons of 3.9% and photons of 1.9%. Significance The determined K(x) can be applied to characterize the influence of the volume effect on detectors measured signal profiles at all clinical proton energies and measurement depths. The functions can be used to derive the actual dose distribution from point detector measurements
    corecore