Pergerakan Tanah Lateral Akibat Proses Pemancangan Tiang

Pemancangan pondasi tiang pada tanah mengakibatkan desakan butiran tanah kearah lateral serta menimbulkan kenaikan tekanan air pori tanah. Hal ini memberikan pengaruh hingga jarak tertentu dan berpotensi merusak bangunan di sekitar. Pada proyek X, lokasi pemancangan soldier pile berdekatan dengan pemukiman padat penduduk. Oleh karena itu, perlu diprediksi jarak yang aman dari pengaruh proses pemancangan.Penelitian ini dilakukan dengan prediksi teoritis besarnya pergerakan tanah kearah lateral akibat pemancangan di jarak tertentu dari titik tiang yang dipancang dengan formula tertentu. Hasil prediksi secara teori ini kemudian dibandingkan dengan hasil pengukuran pergerakan tanah kearah lateral yang dilakukan menggunakan instrumentasi berupa inclinometer. Hasil keduanya akan dibandingkan sebagai kesimpulan.Soldier pile pada proyek X menggunakan jenis tiang pancang beton open ended spun pile Ø800 mm yang ditekan masuk kedalam tanah sedalam 28 meter dengan hydraulic jack. Sebelum pemancangan, terlebih dahulu dilaksanakan preboring Ø500 mm dengan kedalaman 12 meter. Menurut teori ini disimpulkan bahwa radius pengaruh pemancangan adalah sama dengan kedalaman tiang. Pengaruh tapak alat hydraulic jack terekam di inclinometer pada jarak sepertiga kedalaman tiang. Hal ini menyebabkan kesulitan prediksi secara teoritis. Pengaruh ini akan dihilangkan agar dapat dibandingkan dengan hasil prediksi. Setelah koreksi, dijumpai hasil prediksi secara teori mendekati hasil inclinometer

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

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

Anomalous Stability of nu=1 Bilayer Quantum Hall State

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

<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