429 research outputs found

    The environment effect on operation of in-vessel mirrors for plasma diagnostics in fusion devices

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    First mirrors will be the plasma facing components of optical diagnostic systems in ITER. Mirror surfaces will undergo modification caused by erosion and re-deposition processes [1,2]. As a consequence, the mirror performance may be changed and may deteriorate [3,4]. In the divertor region it may also be obscured by deposition [5-7]. The limited access to in-vessel components of ITER calls for testing the mirror materials in present day devices in order to gather information on the material damage and degradation of the mirror performance, i.e. reflectivity. A dedicated experimental programme, First Mirror Test (FMT), has been initiated at the JET tokamak within the framework Tritium Retention Studies (TRS).Comment: 12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France).Submitted by B. Schunke on behalf of V. Voytseny

    Pengaruh Penggunaan Fly Ash Pada Soil – Cement

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    Soil cement telah umum digunakan untuk meningkatkan kondisi tanah liat lunak yang mempunyai daya dukung rendah dan penurunan yang besar. Penggunan semen dalam jumlah besar menyebabkan metode ini menjadi mahal. Pada penelitian ini, kadar semen dikurangi dengan penggunaan fly ash dengan kadar tertentu. 8 tangki dengan diameter 46 cm diisi dengan tanah liat lunak setinggi 75 cm, lalu soil cement column dibuat pada tanah liat lunak pada setiap tangki. Pencampuran soil cement dan variasi kadar fly ash menggunakan dua cara yaitu dengan bubuk semen + fly ash (BS) dan semen cair + fly ash (SC). Untuk kadar fly ash yang diteliti adalah 10%, 15%, 20%, dan 25% dari berat semen. Sampel dari tiap campuran soil cement dilakukan pengetesan UC test dan CBR test. Hasil UC test pada sampel 28 hari, untuk campuran BS dengan kadar 10%, 15%, 20%, dan 25% mencapai kekuatan sebesar 20.8, 14.3, 22.8, dan 17.3 (kg/cm2), sedangkan campuran SC mencapai kekuatan sebesar 15.9, 12.71, 10.83, dan 17.3 (kg/cm2). Selanjutnya nilai CBR dengan kadar fly ash 10%, 15%, 20%, dan 25% menghasilkan nilai sebesar 72.5%, 55.4%, 60.7%, dan 44.3% untuk BS, dan 52.3%, 53.9%, 60.7%, dan 42.7% untuk SC

    Anomalous Stability of nu=1 Bilayer Quantum Hall State

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    We have studied the fractional and integer quantum Hall (QH) effects in a high-mobility double-layer two-dimensional electron system. We have compared the "stability" of the QH state in balanced and unbalanced double quantum wells. The behavior of the n=1 QH state is found to be strikingly different from all others. It is anomalously stable, though all other states decay, as the electron density is made unbalanced between the two quantum wells. We interpret the peculiar features of the nu=1 state as the consequences of the interlayer quantum coherence developed spontaneously on the basis of the composite-boson picture.Comment: 5 pages, 6 figure

    Parkinsonism secondary to metastatic lesions within the central nervous system: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Colorectal cancer is one of the most common human diseases worldwide, and metastases are detected in approximately 20% of patients at diagnosis. Brain metastases occur in only 4% of cases, however, and usually present with hemiparesis or other motor or sensory symptoms. There have been only a few reports of parkinsonism secondary to a brain tumor-related mass effect.</p> <p>Case presentation</p> <p>We present an unusual case of parkinsonism secondary to multiple brain metastases. A 57-year-old Caucasian man had recently been diagnosed with primary carcinoma of the colon and had multiple metastases in the lungs and liver. He subsequently developed bilateral symmetrical parkinsonism, and multiple brain tumors were detected by computed tomography scanning. The condition of our patient deteriorated rapidly, and he became akinetic and dependent for all activities of daily living. He was followed up and treated at home by our palliative care unit team and died two weeks after the onset of his neurologic symptoms.</p> <p>Conclusion</p> <p>Although primary and secondary brain tumors are uncommon causes of parkinsonism, their clinical presentation may resemble that of idiopathic Parkinson's disease. An awareness of this rare differential diagnosis is therefore important in ensuring early diagnosis and treatment, thus improving prognosis and quality of life. A rapid progression in neurologic symptoms was observed in our patient, and clinicians should be alert to this atypical presentation of secondary parkinsonism.</p

    Allele-Specific Expression Analysis of PEG1/MEST in Head and Neck Squamous Cell Carcinomas

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    Genomic imprinting is an epigenetic feature that plays a significant role in carcinogenesis. In this study, we examined the expression status of an imprinted gene, paternally expressed gene 1/mesoderm-specific transcript PEG1/MEST, in 38 cases of head and neck squamous cell carcinomas (HNSCCs) and in 17 oral squamous cancer cell lines. Loss of imprinting (LOI) of PEG1/MEST was found in 8 of 10 (80%) in tumor specimens, and 6 of 10 (60%) informative cases even in the extracted normal tissue specimens. As for the oral squamous cancer cell lines, LOI was detected in 5 of 8 (62.5%) informative cases in PEG1/MEST. Thus, these data showed that abnormal expression of PEG1/MEST was found at a high frequency in the tumor, the extracted normal tissue specimens and the oral squamous cancer cell lines. PEG1/MEST LOI in extracted normal tissue specimens may have a potential individual cancer risk for HNSCC
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