Protonospheric electron concentration profiles Final report

Protonospheric electron concentration profiles based on Doppler and Faraday effect

The Brown-dwarf Atmosphere Monitoring (BAM) Project II: Multi-epoch monitoring of extremely cool brown dwarfs

With the discovery of Y dwarfs by the WISE mission, the population of field brown dwarfs now extends to objects with temperatures comparable to those of Solar System planets. To investigate the atmospheres of these newly identified brown dwarfs, we have conducted a pilot study monitoring an initial sample of three late T-dwarfs (T6.5, T8 and T8.5) and one Y-dwarf (Y0) for infrared photometric variability at multiple epochs. With J-band imaging, each target was observed for a period of 1.0h to 4.5h per epoch, which covers a significant fraction of the expected rotational period. These measurements represent the first photometric monitoring for these targets. For three of the four targets (2M1047, Ross 458C and WISE0458), multi-epoch monitoring was performed, with the time span between epochs ranging from a few hours to ~2 years. During the first epoch, the T8.5 target WISE0458 exhibited variations with a remarkable min-to-max amplitude of 13%, while the second epoch light curve taken ~2 years later did not note any variability to a 3% upper limit. With an effective temperature of ~600 K, WISE0458 is the coldest variable brown dwarf published to-date, and combined with its high and variable amplitude makes it a fascinating target for detailed follow-up. The three remaining targets showed no significant variations, with a photometric precision between 0.8% and 20.0%, depending on the target brightness. Combining the new results with previous multi-epoch observations of brown dwarfs with spectral types of T5 or later, the currently identified variables have locations on the colour-colour diagram better matched by theoretical models incorporating cloud opacities rather than cloud-free atmospheres. This preliminary result requires further study to determine if there is a definitive link between variability among late-T dwarfs and their location on the colour-colour diagram.Comment: 9 pages, 6 figures, 3 tables, accepted for publication in MNRA

Resonant electron heating and molecular phonon cooling in single C60_{60} junctions

We study heating and heat dissipation of a single \c60 molecule in the junction of a scanning tunneling microscope (STM) by measuring the electron current required to thermally decompose the fullerene cage. The power for decomposition varies with electron energy and reflects the molecular resonance structure. When the STM tip contacts the fullerene the molecule can sustain much larger currents. Transport simulations explain these effects by molecular heating due to resonant electron-phonon coupling and molecular cooling by vibrational decay into the tip upon contact formation.Comment: Accepted in Phys. Rev. Let

Avaliação de genótipos de soja submetidos ao encharcamento.

Levando-se em consideração a grande variedade de cultivares no mercado e também os impactos das mudanças climáticas sobre a produção agrícola, torna-se necessário a seleção dos genótipos de soja adaptados ao alagamento imediato dos solos e também aqueles que melhor se recuperam após este estresse. Assim, o objetivo deste trabalho foi avaliar o comportamento de genótipos de soja quando submetidos a período de encharcamento do solo. O ensaio foi conduzido na safra 2008/09 na Granja Quatro Irmãos (Município de Rio Grande), no delineamento de blocos ao acaso, com quatro repetições, sendo a parcela composta por quatro linhas com 5 m de comprimento e 0,50 m de espaçamento entre linhas, sendo descartadas as duas linhas externas e 50 cm na extremidade de cada linha. Os genótipos avaliados foram: BRS 255 RR,BMX Apolo RR e FUNDACEP 53 RR (ciclo precoce); BRS 244 RR, BRS 246 RR e BRS Taura RR (ciclo médio);BRS Pampa RR, CD 219 RR e FUNDACEP 59 RR (ciclo tardio). Dentre os genótipos de ciclo precoce o que apresentou a menor perda para rendimentos de grãos quando submetido ao encharcamento foi Fundacep 53 RR, dentre os de ciclo médio foi BRS 246 RR. Na avaliação dos genótipos de ciclo tardio observou-se que na média durante o encharcamento no reprodutivo eles foram mais produtivos que os genótipos de ciclo precoce e médio

Synthetic spectra of H Balmer and HeI absorption lines. I: Stellar library

We present a grid of synthetic profiles of stellar H Balmer and HeI lines at optical wavelengths with a sampling of 0.3 A. The grid spans a range of effective temperature 4000 K < Teff < 50000 K, and gravity 0.0 < log g < 5.0 at solar metallicity. For Teff > 25000 K, NLTE stellar atmosphere models are computed using the code TLUSTY (Hubeny 1988). For cooler stars, Kurucz (1993) LTE models are used to compute thesynthetic spectra. The grid includes the profiles of the high-order hydrogen Balmer series and HeI lines for effective temperatures and gravities that have not been previously synthesized. The behavior of H8 to H13 and HeI 3819 with effective temperature and gravity is very similar to that of the lower terms of the series (e.g. Hb) and the other HeI lines at longer wavelengths; therefore, they are suited for the determination of the atmospheric parameters of stars. These lines are potentially important to make predictions for these stellar absorption features in galaxies with active star formation. Evolutionary synthesis models of these lines for starburst and post-starburst galaxies are presented in a companion paper. The full set of the synthetic stellar spectra is available for retrieval at our website http://www.iaa.es/ae/e2.html and http://www.stsci.edu/science/starburst/ or on request from the authors at [email protected]: To be published in ApJS. 28 pages and 12 figure

Sistem Pengaturan Lampu Lalu Lintas Berdasarkan Estimasi Panjang Antrian Menggunakan Pengolahan Citra

Saat&nbsp; ini&nbsp; salah&nbsp; satu&nbsp; penyebab&nbsp; kemacetan&nbsp; adalah&nbsp; lampu&nbsp; lalu&nbsp; lintas&nbsp; yang&nbsp; menggunakan&nbsp; waktu&nbsp; yang&nbsp; tetap sedangkan&nbsp; volume&nbsp; kendaraan&nbsp; selalu&nbsp; berubah-,&nbsp; sehingga&nbsp; lampu&nbsp; lalu&nbsp; lintas&nbsp; menjadi&nbsp; kurang&nbsp; efektif.&nbsp; Maka dibutuhkan&nbsp; metode&nbsp; untuk&nbsp; menghitung&nbsp; lama&nbsp; lampu&nbsp; lalu&nbsp; lintas&nbsp; menyala&nbsp; dengan&nbsp; waktu&nbsp; sesuai&nbsp; dengan&nbsp; jumlah kendaraan. Sistem&nbsp; ini&nbsp; mengimplementasikan&nbsp; 4&nbsp; kamera&nbsp; pada&nbsp; persimpangan.&nbsp; Kamera&nbsp; mengambil&nbsp; gambar&nbsp; saat&nbsp; jalur sedang&nbsp; kosong&nbsp; sebagai&nbsp; acuan,&nbsp; dan&nbsp; mengambil&nbsp; gambar&nbsp; setiap&nbsp; sequence&nbsp; sebagai&nbsp; input.&nbsp; Gambar&nbsp; diproses menggunakan&nbsp; pengolahan&nbsp; citra,&nbsp; dari&nbsp; merubah&nbsp; format&nbsp; RGB&nbsp; menjadi&nbsp; grayscale,&nbsp; dilakukan&nbsp; proses&nbsp; subtraction dengan gambar acuan, penambahan brightness, merubah format grayscale menjadi biner dengan Otsu‟s threshold dan menghitung jumlah objek sebagai input dari logika fuzzy tsukamoto yang menghasilkan lama lampu hijau menyala. Sedangkan lama lampu merah menyala dihitung dengan menjumlahkan lama lampu hijau menyala dari jalur lainnnya Penggunaan 4 buah input dimaksudkan agar sistem memperhatikan jumlah antrian dari setiap jalur dan&nbsp; memperhatikan&nbsp; sebaran&nbsp; kepadatan,&nbsp; Sehingga&nbsp; hasil&nbsp; lama&nbsp; lampu&nbsp; merah&nbsp; dan&nbsp; lampu&nbsp; hijau&nbsp; menyala&nbsp; dapat berubah-ubah sesuai dengan sebaran kepadatan antrian. Semakin terang kondisi jalan, semakin tinggi tingkat akurasi yang didapatkan. Pada pagi hari, didapatkan nilai error 1.74%, pada siang hari&nbsp; sebesar 9%, pada&nbsp; malam&nbsp; hari dengan penerangan&nbsp; normal sebesar 21% dan pada malam hari dengan tambahan penerangan sebesar 15%

Synchronisation schemes for two dimensional discrete systems

In this work we consider two models of two dimensional discrete systems subjected to three different types of coupling and analyse systematically the performance of each in realising synchronised states.We find that linear coupling effectively introduce control of chaos along with synchronisation,while synchronised chaotic states are possible with an additive parametric coupling scheme both being equally relevant for specific applications.The basin leading to synchronisationin the initial value plane and the choice of parameter values for synchronisation in the parameter plane are isolatedin each case.Comment: 17 pages 8 figures. submitted to physica script

Balltracking: an highly efficient method for tracking flow fields

We present a method for tracking solar photospheric flows that is highly efficient, and demonstrate it using high resolution MDI continuum images. The method involves making a surface from the photospheric granulation data, and allowing many small floating tracers or balls to be moved around by the evolving granulation pattern. The results are tested against synthesised granulation with known flow fields and compared to the results produced by Local Correlation tracking (LCT). The results from this new method have similar accuracy to those produced by LCT. We also investigate the maximum spatial and temporal resolution of the velocity field that it is possible to extract, based on the statistical properties of the granulation data. We conclude that both methods produce results that are close to the maximum resolution possible from granulation data. The code runs very significantly faster than our similarly optimised LCT code, making real time applications on large data sets possible. The tracking method is not limited to photospheric flows, and will also work on any velocity field where there are visible moving features of known scale length

Caracterização das unidades de produção familiar participante do projeto silvapastoril em Rondônia.

bitstream/item/85766/1/ct126-producaofamiliar.pd