2,313 research outputs found
The 5C 6 and 5C 7 surveys of radio sources
5C 6 and 5C 7 continue the series of deep surveys made at 408 and 1407 MHz with the One-Mile telescope at Cambridge. They were intended (1) to provide a sample of faint radio sources suitable for further study; (2) to improve the statistics of source counts N(S) and spectral-index distributions at low flux densities; (3) to study the isotropy of the distribution of faint sources. Each observed field is about 4° in diameter at 408 MHz and 1° in diameter at 1407 MHz, and the field-centres are a α = 02ʰ14ᵐ, δ = 32° (5C 6) and α = 08ᵏ17ᵐ, δ = 27° (5C 7). The synthesized beamwidths (FWHM) are 80 arcsec (408 MHz) and 23 arcsec (1407 MHz). The techniques of observation and data-analysis followed closely those used for 5C 5 (Pearson, T. J., 1975. Mon. Not. R. astr. Soc., 171, 475), with some minor variations which are noted in Section 2
Superconducting properties of MgB2 thin films prepared on flexible plastic substrates
Superconducting MgB2 thin films were prepared on 50-micrometer-thick,
flexible polyamide Kapton-E foils by vacuum co-deposition of Mg and B
precursors with nominal thickness of about 100 nm and a special ex-situ rapid
annealing process in an Ar or vacuum atmosphere. In the optimal annealing
process, the Mg-B films were heated to approximately 600 C, but at the same
time, the backside of the structures was attached to a water-cooled radiator to
avoid overheating of the plastic substrate. The resulting MgB2 films were
amorphous with the onset of the superconducting transition at T_(c,on) about 33
K and the transition width of approximately 3 K. The critical current density
was > 7x10^5 A/cm^2 at 4.2 K, and its temperature dependence indicated a
granular film composition with a network of intergranular weak links. The films
could be deposited on large-area foils (up to 400 cm^2) and, after processing,
cut into any shapes (e.g., stripes) with scissors or bent multiple times,
without any observed degradation of their superconducting properties.Comment: 3 figure
Evidence for the Validity of the Berry-Robnik Surmise in a Periodically Pulsed Spin System
We study the statistical properties of the spectrum of a quantum dynamical
system whose classical counterpart has a mixed phase space structure consisting
of two regular regions separated by a chaotical one. We make use of a simple
symmetry of the system to separate the eigenstates of the time-evolution
operator into two classes in agreement with the Percival classification scheme
\cite{Per}. We then use a method firstly developed by Bohigas et. al.
\cite{BoUlTo} to evaluate the fractional measure of states belonging to the
regular class, and finally present the level spacings statistics for each class
which confirm the validity of the Berry-Robnik surmise in our model.Comment: 15 pages, 9 figures available upon request, Latex fil
Phonons in MgB2 by Polarized Raman Scattering on Single Crystals
The paper presents detailed Raman scattering study of the unusually broad E2g
phonon mode in MgB2 crystal. For the first time, it is shown by the polarized
Raman scattering on few-micron-size crystallites with natural faces that the
observed broad Raman feature really does obey the selection rules of an E2g
mode. Raman spectra on high quality polycrystalline superconducting MgB2 wires
reveal a very symmetric E2g phonon line near 615 1/cm with the room temperature
linewidth of 260 1/cm only. Additional scattering of different polarization
dependence, observed in certain crystallites is interpreted as weighted phonon
density of states induced by lattice imperfections.Comment: 4 pages + 7 figure
The 5C 6 and 5C 7 surveys of radio sources
5C 6 and 5C 7 continue the series of deep surveys made at 408 and 1407 MHz with the One-Mile telescope at Cambridge. They were intended (1) to provide a sample of faint radio sources suitable for further study; (2) to improve the statistics of source counts N(S) and spectral-index distributions at low flux densities; (3) to study the isotropy of the distribution of faint sources. Each observed field is about 4° in diameter at 408 MHz and 1° in diameter at 1407 MHz, and the field-centres are a α = 02ʰ14ᵐ, δ = 32° (5C 6) and α = 08ᵏ17ᵐ, δ = 27° (5C 7). The synthesized beamwidths (FWHM) are 80 arcsec (408 MHz) and 23 arcsec (1407 MHz). The techniques of observation and data-analysis followed closely those used for 5C 5 (Pearson, T. J., 1975. Mon. Not. R. astr. Soc., 171, 475), with some minor variations which are noted in Section 2
PENGEMBANGAN MEDIA KERETA BUDAYA UNTUK MENANAMKAN KARAKTER CINTA TANAH AIR SISWA KELAS IV SD
This research aims to produce a learning media. The product is about “a train culture” which can be used properly as a learning material of cultural diversity to embed nationalism character for fourth grade students of SD N Golo Yogyakarta. This research’s using Research and Development (RnD) Borg and Gall model. The data resources were collected from interview, observation, and questionnaire. This product was passed planning step, validation step (by two experts), and trial steps. Final validation by material expert got average score 4,3 with ‘very high’ validity and quality. Final validation by media expert got average score 5 with ‘very high’ validity and quality. Initial field trials were conducted on 3 students and 1 teacher in class IV B, while the main field test was conducted on 12 students and 1 teacher in class IV A, SD N Golo Yogyakarta. Preliminary field testing result got average score 4,2 in teacher testing ‘very high’ validity and quality, and got average score 4,38 in student testing ‘very high’ validity and quality. Main field testing result got average score 4,8 in teacher testing ‘very high’ validity and quality, and got average score 4,36 in student testing ‘very high’ validity and quality. So, overall, this media train of culture can be used properly into a social science lessons. AbstrakPenelitian ini bertujuan untuk menghasilkan media pembelajaran Kereta Budaya (train of culture) yang layak digunakan pada materi keberagaman budaya Indonesia sebagai upaya untuk menanamkan karakter cinta tanah air bagi siswa kelas IV SDN Golo Yogyakarta. Penelitian ini merupakan penelitian pengembangan yang mengacu pada model yang dikembangkan Borg & Gall. Teknik pengumpulan data menggunakan wawancara, observasi, studi pustaka, dan angket. Teknik analisis data menggunakan statistik deskriptif kuantitatif. Hasil penelitian menunjukkan bahwa media pembelajaran Kereta Budaya layak digunakan dan mempunyai kualitas tinggi sehingga dapat digunakan di Sekolah Dasar. Hasil validasi materi memperoleh skor rata-rata 4,3 memiliki tingkat validitas dan kualitas “sangat tinggi”. Hasil validitas terakhir dari segi media, memperoleh skor rata-rata 5 (memiliki tingkat validitas dan kualitas “sangat tinggi”). Uji coba lapangan awal dilakukan kepada 3 siswa dan 1 guru kelas IVB; sedangkan uji coba lapangan utama dilakukan kepada 12 siswa dan 1 guru kelas IVA SDN Golo Yogyakarta. Hasil uji coba lapangan awal kepada guru memperoleh skor rata-rata 4,2 (tingkat validitas dan kualitas “sangat tinggi”; sedangkan kepada siswa memperoleh skor rata-rata 4,38 (tingkat validitas dan kualitas “sangat tinggi”). Hasil uji coba lapangan utama kepada guru memperoleh skor rata-rata 4,8 (tingkat validitas dan kualitas “sangat tinggi”); sedangkan kepada siswa memperoleh skor rata-rata 4,36 (tingkat validitas dan kualitas “sangat tinggi”).
Pola Pertumbuhan dan Produksi Tanaman Cabai Merah Keriting Terhadapaplikasi Kalium Nitrat (Kno3) pada Daerah Dataran Tinggi
Tanaman cabai merupakan salah satu komoditas hortikultura yang memiliki nilai ekonomi penting di Indonesia, namun jumlah produksi nasional belum mampu memenuhi kebutuhan masyarakat yang tinggi akan tingkat konsumsi cabai. Untuk meningkatkan produksi tanaman cabai merah perlu adanya teknologi budidaya yang tepat, salah satunya adalah pemupukan. Penelitian ini bertujuan untuk: (1) mengetahui pengaruh aplikasi KNO3 tehadap pola pertumbuhan dan produksi tanaman cabai merah (Capsicum annuum L.) pada daerah dataran tinggi, (2) mengetahui konsentrasi KNO3 terbaik untuk produksi tanaman cabai merah (C. annuum) pada daerah dataran tinggi. Perlakuan ini disusun secara tunggal dalam rancangan acak kelompok (RAK) dengan tiga ulangan. Adapun faktor perlakuan dosis kalium nitrat (KNO3) terdiri dari 5 taraf yaitu K0 (kontrol 0 g l-1), K1 (2 g l1), K2 (4 g l-1, K3 (6 g l-1), dan K4 (8 g l-1). Setiap taraf dosis perlakuan diulang sebanyak tiga kali.Homogenitas ragam antar perlakuan diuji dengan uji Bartlet dan additifitas data diuji dengan uji Tukey. Analisis data dilanjutkan dengan menggunakan analisis ragam kemudian pola pertumbuhan dan produksi tanaman cabai dianalisis dengan menggunakan analisis regresi dan polinomial ortogonal. Hasil penelitian menunjukkan bahwa pemberian konsentrasi KNO3 pada fase vegetatif menunjukkan pola pertumbuhan tanaman cabai yang relatif sama khususnya tinggi tanaman dan tingkat percabangan. Sedangkan pada fase generatif pemberian konsentrasi KNO3 pada tanaman cabai sampai dengan 4 g l-1 dapat meningkatkan jumlah bunga dan panjang buah dan dapat meningkatkan hasil produksi (jumlah buah dan bobot buah panen). Secara kualitatif pemberian konsentrasi KNO3 2 g l-1 dan 4 g l-1 memberikan penampilan yang cukup baik dibandingkan dengan pemberian konsentarsi KNO3 6 g l-1 dan 8 g l-1
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