Polarimetric Properties of Flux-Ropes and Sheared Arcades in Coronal Prominence Cavities

The coronal magnetic field is the primary driver of solar dynamic events. Linear and circular polarization signals of certain infrared coronal emission lines contain information about the magnetic field, and to access this information, either a forward or an inversion method must be used. We study three coronal magnetic configurations that are applicable to polar-crown filament cavities by doing forward calculations to produce synthetic polarization data. We analyze these forward data to determine the distinguishing characteristics of each model. We conclude that it is possible to distinguish between cylindrical flux ropes, spheromak flux ropes, and sheared arcades using coronal polarization measurements. If one of these models is found to be consistent with observational measurements, it will mean positive identification of the magnetic morphology that surrounds certain quiescent filaments, which will lead to a greater understanding of how they form and why they erupt.Comment: 22 pages, 8 figures, Solar Physics topical issue: Coronal Magnetis

Tomographic 3D-Modeling of the Solar Corona with FASR

The "Frequency-Agile Solar Radiotelescope" (FASR) litteraly opens up a new dimension in addition to the 3D Euclidian geometry: the frequency dimension. The 3D geometry is degenerated to 2D in all images from astronomical telescopes, but the additional frequency dimension allows us to retrieve the missing third dimension by means of physical modeling. We call this type of 3D reconstruction "Frequency Tomography". In this study we simulate a realistic 3D model of an active region, composed of 500 coronal loops with the 3D geometry [x(s),y(s),z(s)] constrained by magnetic field extrapolations and the physical parameters of the density n_e(s) and temperature T_e(s) given by hydrostatic solutions. We simulate a series of 20 radio images in a frequency range of f=0.1-10 GHz, anticipating the capabilities of FASR, and investigate what physical information can be retrieved from such a dataset. We discuss also forward-modeling of the chromospheric and Quiet Sun density and temperature structure, another primary goal of future FASR science.Comment: 10 Figure

PROFIL WISATAWAN MUSEUM RADYA PUSTAKA SURAKARTA

Anggit Margaret, C9407031 2011. Profil Wisatawan Museum Radya Pustaka Surakarta. Program Studi Diploma III Usaha Perjalanan Wisata Fakultas Sastra Dan Seni Rupa Universitas Sebelas Maret Surakarta. Penelitian tugas akhir ini mengkaji tentang Profil Wisatawan di Museum Radya Pustaka Surakarta. Tujuan dari penelitian ini adalah untuk mengetahui dari daerah mana saja wisatawan yang berkunjung ke Museum Radya Pustaka, bagaimana ciri-ciri wisatawan yang berkunjung ke Museum Radya Pustaka serta harapan-harapan yang diinginkan wisatawan terhadap Museum Radya Pustaka. Penelitian dilakukan dengan metode kualitatif. Pengumpulan data dilakukan melalui wawancara dengan narasumber wisatawan yang berkujung di Museum Radya Pustaka Surakarta tempat penulis melakukan penelitian, serta studi pustaka dan studi dokumen guna menambah sumber data. Hasil penelitian menunjukkan bahwa (1) Sebagian besar wisatawan yang datang berasal dari Semarang sebesar 32%. (2) Mayoritas wisatawan yang berkunjung ke Museum Radya Pustaka berusia antara 17-25 tahun dan kebanyakan dari mereka adalah pelajar atau mahasiswa dengan prosentase 52%. (3) Sebagian besar wisatawan yang datang ke Museum Radya Pustaka adalah bertujuan untuk melakukan penelitian yaitu sebesar 34%. (4) Harapan wisatawan yang berkunjung terhadap kelangsungan Museum Radya Pustaka sebagian besar adalah agar ditingkatkan lagi pengelolaan dan keamanan museum, agar kejadian hilangnya benda-benda koleksi museum tidak terulang lagi dikemudian hari. Kesimpulan dari hasil penelitian ini bahwa wisatawan yang berkujung ke Museum Radya Pustaka Surakarta mayoritas berasal dari Semarang, mayoritas berusia 17-25 tahun dan kebanyakan dari mereka adalah berprofesi sebagai pelajar dan mahasiswa. Kebanyakan wisatawan yang datang bertujuan untuk melakukan penelitian, serta harapan wisatawan terhadap Museum Radya Pustaka adalah supaya lebih ditingkatkan lagi pengelolaan dan keamanan museum

Xerogels of ammonium polyvanadatomolybdate as starting material for ammonia gas sensors

The various gas sensors were designed for detection of different gases in the air using different oxides and impurities [1-3]. For example the manufacturing of ammonia sensors on the basis of CuxS-micro-porous-Si structure includes manufacture of micro-porous silicon, drawing on it of SiO2 isolating layer, and then the CuxS layer [4, 5]. The special equipment for all these processes is needed. More usable method for sensor production is so-called soft chemistry or sol–gel synthesis [6, 7]Fizinių ir technologijos mokslų centro Puslaidininkių fizikos institutasVytauto Didžiojo universitetasŠvietimo akademij

Microwave tomography of solar magnetic fields

We present a new technique for the measurement of magnetic fields in the solar chromosphere - corona through observations of its free-free microwave emission in intensity and polarization. We derive the decoupled radiation transfer equations for Stoke's parameters of I and V for circular polarized emission in plane-layer inhomogeneous atmospheres and present a model solutions of inversion problem. We discuss the discrimination between contributions from the corona and the chromosphere to the observed brightness spectra from the quiet Sun and plage regions and propose a practical method of magnetic field estimates, which was used both with single frequency (the Nobeyama Radioheliograph at 17 GHz) and multi frequency (RATAN at $1 - 16$ GHz) observations and discuss the preliminary results. The proposed techniques may be useful as microwave magnetography at the corona base and for checks and improvements in the current problem of extrapolating magnetic fields from photosphere to corona.


Sol-Gel Production and XPS Study of Sodium-Vanadium Oxide Bronze β-Phase

A β-phase of sodium-vanadium oxide bronze thin film has been synthesized by using sol-gel technology from $V_2O_5$ and $Na_2SO_4$. The powders of these materials in suitable proportion were dissolved in hydrogen peroxide and heated up to 350 K for the dissociation of peroxide complexes. The obtained gel was deposited onto a metallic substrate and dried in air at room temperature. The produced xerogel was heated up to 580 K in air atmosphere for the removal of water from xerogel. Starting materials, xerogel, as well as a final product were investigated by means of X-ray photoelectron spectroscopy method. X-ray photoelectron spectra testify that the chemical bonds of vanadium, oxygen and sodium in the bronze differ from the similar bonds in the starting materials. The sulphur presence was detected in the xerogel but not in the final bronze composition