Model Data Fusion: developing Bayesian inversion to constrain equilibrium and mode structure

Recently, a new probabilistic "data fusion" framework based on Bayesian principles has been developed on JET and W7-AS. The Bayesian analysis framework folds in uncertainties and inter-dependencies in the diagnostic data and signal forward-models, together with prior knowledge of the state of the plasma, to yield predictions of internal magnetic structure. A feature of the framework, known as MINERVA (J. Svensson, A. Werner, Plasma Physics and Controlled Fusion 50, 085022, 2008), is the inference of magnetic flux surfaces without the use of a force balance model. We discuss results from a new project to develop Bayesian inversion tools that aim to (1) distinguish between competing equilibrium theories, which capture different physics, using the MAST spherical tokamak; and (2) test the predictions of MHD theory, particularly mode structure, using the H-1 Heliac.Comment: submitted to Journal of Plasma Fusion Research 10/11/200

Three view electronically scanned interferometer for plasma electron density measurements on the H-1 heliac

We report the development of a three view electronically scanned millimeter-wave interferometer for plasma electron density profile measurement on the H-1 heliac. The system utilizes an electronically tunable backward-wave oscillator whose output is incident on a fixed blazed diffraction grating such that sweeping the source frequency effects a spatial scan of the plasma cross section. Two diagonal views essentially span most of the plasma cross section, while the horizontal arm views the lower half of the plasma. The diffracted beams traverse the plasma in <1ms with a spatial resolution ∼20mm. A study of the density projection dependence on magnetic configuration shows that the presence of low-order rational surfaces in the plasma gives rise to sharp density gradients in the vicinity of the surface

Cytotoxicity of Alpinia Galanga Rhizome Crude Extract on NIH-3T3 Cells

BACKGROUND: Alpinia galanga (A. galanga) was reported as a potential medicinal source due to its wide effect. A. galanga rhizome crude extract (ARCE) was reported to have high cytotoxic effect in cancer cells, but low in normal cells. However half maximal inhibitory concentration (IC50) of ARCE is not clearly known yet. Hence, current study was conducted to investigate the IC50 of ARCE in normal standard fibroblast cell line, NIH-3T3 cells.METHODS: Rhizomes of A. galanga were collected, peeled, dried, milled and weighed. Extraction was performed using maceration method, then filtered and evaporated. ARCE with various concentrations were applied in NIH-3T3 cells for 24 or 48 hours. Cells were documented and counted with 3-(4,5-dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium bromide (MTT) assay.RESULTS: Five hundreds grams of simplicia were macerated with ethanol and evaporated, 1 mg/mL crude extract with total volume of 114 mL was obtained. By addition of ARCE in NIH-3T3 cell culture, number of NIH-3T3 cells were shown less when treated with higher concentration of ARCE. Cell numbers of 0, 3.125, 6.25, 12.5, 25 and 50% ARCE treatment for 24 hours are 11,531, 11,352, 10,920, 10,365, 9,471, 8,360, respectively, meanwhile for 48 hours are 13,219, 12,686, 12,278, 11,390, 10,279, 8,390, respectively.CONCLUSION: IC50 of ARCE in 24 hours treatment was 620.5 mg/mL, while in 48 hours treatment was 666.6 mg/mL. Hence, ARCE is suggested to have low cytotoxic effect in NIH-3T3 cells

Ideal MHD theory of low-frequency Alfven waves in the H-1 Heliac

A part analytical, part numerical ideal MHD analysis of low-frequency Alfven wave physics in the H-1 stellarator is given. The three-dimensional, compressible ideal spectrum for H-1 is presented and it is found that despite the low beta (approx. 10^-4) of H-1 plasmas, significant Alfven-acoustic interactions occur at low frequencies. Several quasi-discrete modes are found with the three-dimensional linearised ideal MHD eigenmode solver CAS3D, including beta-induced Alfven eigenmode (BAE)- type modes in beta-induced gaps. The strongly shaped, low-aspect ratio magnetic geometry of H-1 causes CAS3D convergence difficulties requiring the inclusion of many Fourier harmonics for the parallel component of the fluid displacement eigenvector even for shear wave motions. The highest beta-induced gap reproduces large parts of the observed configurational frequency dependencies in the presence of hollow temperature profiles

Analisa Perkuatan Geotekstil Pada Timbunan Konstruksi Jalan Dengan Plaxis 2d

Permasalahan yang sering terjadi pada timbunan adalah terjadinya penurunan yang besar. Oleh karena itu diperlukan perkuatan untuk memperbaiki kondisi tersebut. Salah satu USAha perkuatan tanah yang dapat dilakukan adalah dengan memasang geotekstil. Tujuan penelitian ini untuk menganalisa kuat tarik geotekstil yang digunakan serta menentukan kuat tarik optimum geotekstil yang akan digunakan sebagai perkuatan dengan memperhatikan nilai angka keamanan dan penurunan. Penelitian ini menggunakan tiga pemodelan yaitu, yang pertama pengujian pada timbunan yang tidak menggunakan geotekstil. Pengujian kedua yaitu untuk menentukan panjang geotekstil yang akan digunakan. Pengujian ketiga, pengujian pada timbunan yang menggunakan geotekstil dengan kuat tarik yang bervariasi, dengan panjang yang ditentukan berdasarkan hasil pola keruntuhan yang terjadi pada pengujian kedua.Hasil dari penelitian ini menunjukkan bahwa dengan adanya penggunaan geotekstil, pola keruntuhan yang terjadi mengalami Perubahan, dimana bagian yang runtuh hanya pada timbunan saja.Penurunan yang terjadi pada timbunan dengan perkuatan geotekstil semakin kecil dan nilai angka keamanan yang diperoleh melebihi batas minimum nilai angka keamanan ijin

A multichannel magnetic probe system for analysing magnetic fluctuations in helical axis plasmas

The need to understand the structure of magnetic fluctuations in H-1NF heliac [S. Hamberger et al., Fusion Technol. 17, 123 (1990)] plasmas has motivated the installation of a sixteen former, tri-axis helical magnetic probe Mirnov array (HMA). The new array complements two existing poloidal Mirnov arrays by providing polarisation information, higher frequency response, and improved toroidal resolution. The helical placement is ideal for helical axis plasmas because it positions the array as close as possible to the plasma in regions of varying degrees of favourable curvature in the magnetohydrodynamic sense, but almost constant magnetic angle. This makes phase variation with probe position near linear, greatly simplifying the analysis of the data. Several of the issues involved in the design, installation, data analysis, and calibration of this unique array are presented including probe coil design, frequency response measurements, mode number identification, orientation calculations, and mapping probe coil positions to magnetic coordinates. Details of specially designed digitally programmable pre-amplifiers, which allow gains and filters to be changed as part of the data acquisition initialisation sequence and stored with the probe signals, are also presented. The low shear heliac geometry [R. Jiménez-Gómez et al., Nucl. Fusion 51, 033001 (2011)], flexibility of the H-1NF heliac, and wealth of information provided by the HMA create a unique opportunity for detailed study of Alfvén eigenmodes, which could be a serious issue for future fusion reactors.This work was supported by the Education Investment Fund under the Super Science Initiative of the Australian Government. S.R.H. wishes to thank AINSE Ltd. for providing financial assistance to enable this work on H-1NF to be conducted

Are people who participate in cultural activities more satisfied with life?

The influence of various aspects of life on wellbeing has been extensively researched. However, despite little empirical evidence, participation in leisure activities has been assumed to increase subjective wellbeing. Leisure is important because it is more under personal control than other sources of life satisfaction. This study asked whether people who participate in cultural leisure activities have higher life satisfaction than people who do not, if different types of leisure have the same influence on life satisfaction and if satisfaction is dependent on the frequency of participation or the number of activities undertaken. It used data from UKHLS Survey to establish associations between type, number and frequency of participation in leisure activities and life satisfaction. Results showed an independent and positive association of participation in sport, heritage and active-creative leisure activities and life satisfaction but not for participation in popular entertainment, theatre hobbies and museum/galleries. The association of reading hobbies and sedentary-creative activities and life satisfaction was negative. High life satisfaction was associated with engaging in a number of different activities rather than the frequency of participation in each of them. The results have implications for policy makers and leisure services providers, in particular those associated with heritage recreation. Subjective wellbeing measures, such as life satisfaction, and not economic measures alone should be considered in the evaluation of services. The promotion of leisure activities which are active and promote social interaction should be considered in programmes aimed at improving the quality of life