Penentuan Daerah Penangkapan Ikan Tongkol (Euthynnus Affinis) Berdasarkan Sebaran Suhu Permukaan Laut Di Perairan Idi Rayeuk Kabupaten Aceh Timur

This study aimed to determine the potential fishing ground for tuna by remote sensing based on sea surface temperature in the waters of Idi Rayeuk, East Aceh regency. The Collection of field data in such as the number of catches and the coordinates of the fishing conducted from March to April 2016. Sea surface temperature downloadable on the site http://oceancolorgsfc.nasa.gov. Then processed using the device Seadas 7.3. The result showed that the distribution of sea surface temperatures in the waters of Idi Rayeuk from March to April 2016 ranges from 28°C to 30°C with the average of sea surface temperature was 29°C. There were two potential fishing ground identified during the study in East Aceh regency District of Idi Rayeuk, e.i 1) at the coordinates 5°04'88"N-98°23'51"E by the number of catches amounting to 13.293 kg and the sea surface temperature of 29°C 2) potential fishing ground at coordinates 5°29'46"N-98°28'09"E by the number of catches amounting to 13.310 kg with sea surface temperature of 30°C. Penelitian ini bertujuan untuk menentukan daerah penangkapan yang potensial untuk ikan tongkol dengan penginderaan jarak jauh berdasarkan suhu permukaan laut di perairan Idi Rayeuk Kabupaten Aceh Timur. Pengambilan data seperti jumlah hasil tangkapan dan koordinat daerah penangkapan ikan dilaksanakan pada bulan Maret sampai April 2016. Suhu permukaan laut diunduh pada situs http://oceancolorgsfc.nasa.gov. Selanjutnya diolah menggunakan perangkat SeaDas 7.3. Hasil penelitian diperoleh bahwa sebaran suhu permukaan laut di perairan Idi Rayeuk pada bulan Maret sampai April 2016 berkisar antara 28°C sampai 30°C dengan suhu permukaan laut rata-rata adalah 29°C. Dua daerah penangkapan yang potensial diindetifikasi selama penelitian di perairan Kabupaten Aceh Timur Kecamatan Idi Rayeuk, yaitu 1) pada daerah penangkapan dengan koordinat 5°04'88"LU-98°23'51"BT dengan jumlah hasil tangkapan sebesar 13.293 kg serta suhu permukaan laut 29°C dan 2) pada koordinat 5°29'462"LU-98°28'09"BT dengan jumlah hasil tangkapan sebesar 13.310 kg dengan suhu permukaan laut 30°C

Uji selektivitas fraksi Rf < 0,5 ekstrak MeOH biji putat air (Barringtonia racemosa) terhadap ikan mujair (Oreochromis mossambicus)

Abstract. The objective of the present study was to evaluate the selectivity of the Rf 0.5 fraction of MeOH extract of putat air kernels (Barringtonia racemosa) on golden snail (Pomacea canaliculata) and tilapia (Oreochromis mossambicus). The research was conducted on November 2011 to February 2012 at Chemical Laboratory of Teacher Training and Education Facultyand Marine Chemical Laboratory of Coordinatorate of Marine and Fisheries of Syiah Kuala University. Thin-layer chromatography was used as the separation technique towards component compounds in the extract samples. The research was used five levels concentration of Rf 0.5 fraction of MeOH solution (20 ppm, 40 ppm, 60 ppm, 80 ppm, 100 ppm) with three repetitions. Mortality rates of golden snails and tilapia were detected when they were exposure to Rf 0.5 fraction of MeOH extract of B. racemosa kernels. The data were analyzed by Probit, and selectivity value (S) was calculated by Feng and Wang formula. The results revealed that Rf 0.5 fraction of MeOH extract of putat air kernels was selective to golden apple snails.Key words. Thin-layer chromatography, mortality, Probit, and moluscid

3D photospheric velocity field of a Supergranular cell

We investigate the plasma flow properties inside a Supergranular (SG) cell, in particular its interaction with small scale magnetic field structures. The SG cell has been identified using the magnetic network (CaII wing brightness) as proxy, applying the Two-Level Structure Tracking (TST) to high spatial, spectral and temporal resolution observations obtained by IBIS. The full 3D velocity vector field for the SG has been reconstructed at two different photospheric heights. In order to strengthen our findings, we also computed the mean radial flow of the SG by means of cork tracing. We also studied the behaviour of the horizontal and Line of Sight plasma flow cospatial with cluster of bright CaII structures of magnetic origin to better understand the interaction between photospheric convection and small scale magnetic features. The SG cell we investigated seems to be organized with an almost radial flow from its centre to the border. The large scale divergence structure is probably created by a compact region of constant up-flow close to the cell centre. On the edge of the SG, isolated regions of strong convergent flow are nearby or cospatial with extended clusters of bright CaII wing features forming the knots of the magnetic network.Comment: 7 pages, submitted to A&A, referee's comments include

Discovery of inward moving magnetic enhancements in sunspot penumbrae

Sunspot penumbrae show a fine structure in continuum intensity that displays considerable dynamics. The magnetic field, in contrast, although also highly structured, has appeared to be relatively static. Here we report the discovery of inward moving magnetic enhancements in the penumbrae of two regular sunspots based on time series of SOHO/MDI magnetograms. Local enhancements of the LOS component of the magnetic field in the inner part of the penumbral region move inward to the umbra-penumbra boundary with a radial speed of about 0.3 km s$^{-1}$. These local inward-moving enhancements of the LOS component of the magnetic fields appear to be relatively common. They are associated with dark structures and tend to display downflows relatively to the penumbral background. Possible explanations are discussed.Comment: 4 pages, 4 figures, submitted to ApJ Letter

Seismology of the Sun : Inference of Thermal, Dynamic and Magnetic Field Structures of the Interior

Recent overwhelming evidences show that the sun strongly influences the Earth's climate and environment. Moreover existence of life on this Earth mainly depends upon the sun's energy. Hence, understanding of physics of the sun, especially the thermal, dynamic and magnetic field structures of its interior, is very important. Recently, from the ground and space based observations, it is discovered that sun oscillates near 5 min periodicity in millions of modes. This discovery heralded a new era in solar physics and a separate branch called helioseismology or seismology of the sun has started. Before the advent of helioseismology, sun's thermal structure of the interior was understood from the evolutionary solution of stellar structure equations that mimicked the present age, mass and radius of the sun. Whereas solution of MHD equations yielded internal dynamics and magnetic field structure of the sun's interior. In this presentation, I review the thermal, dynamic and magnetic field structures of the sun's interior as inferred by the helioseismology.Comment: To be published in the proceedings of the meeting "3rd International Conference on Current Developments in Atomic, Molecular, Optical and Nano Physics with Applications", December 14-16, 2011, New Delhi, Indi

Spatial variations in the field of velocities and real solar granulation

In this paper, the physical conditions within the inhomogeneous solar atmosphere have been reconstructed by means of solving the inverse problem of Non Local Thermodynamic Equilibrium (NLTE) radiative transfer. The profiles of $\lambda=523.42$ nm FeI spectral line of high spatial and time resolution were used as observational data. The velocity field has been studied for the real solar granulation in superadiabatic layer and overshooting convection region. Also, we investigate the vertical structure of inhomogeneous solar photosphere and consider penetration of granules from convective region into upper layers of stable atmosphere. The microturbulent velocity appears to be minimal at the bottom of overshooting convection region and increases sharply through superadiabatic layer and upper photosphere. High-turbulent layers emerge either in the central part of a flow or at the boundary of an incipient flow with following drift toward the centre of the flow. Wide descending flows tend to disintegrate into structures having turbulence augmented, these structures correspond to the flows of matter. High microturbulence of the intensive flows provokes steep temperature depression in upper photosphere leading to the second inversion of temperature for the intergranules. The inversion of vertical velocities is observed to be frequent in the solar granulation. Some of the convective flows reach the minimum temperature region. Vertical convective velocities of the matter flows were found to be smaller in the middle and upper photosphere. Also, the effect of finite resolution on the spacial variations of the velocities in solar photosphere has been estimated.Comment: 8 pages, 7 figure