Phases of granular segregation in a binary mixture

We present results from an extensive experimental investigation into granular segregation of a shallow binary mixture in which particles are driven by frictional interactions with the surface of a vibrating horizontal tray. Three distinct phases of the mixture are established viz; binary gas (unsegregated), segregation liquid and segregation crystal. Their ranges of existence are mapped out as a function of the system's primary control parameters using a number of measures based on Voronoi tessellation. We study the associated transitions and show that segregation can be suppressed is the total filling fraction of the granular layer, $C$, is decreased below a critical value, $C_{c}$, or if the dimensionless acceleration of the driving, $\gamma$, is increased above a value $\gamma_{c}$.Comment: 12 pages, 12 figures, submitted to Phys. Rev.

Vibrational spectroscopic force field studies of dimethyl sulfoxide and hexakis(dimethyl sulfoxide)scandium(III) iodide, and crystal and solution structure of the hexakis(dimethyl sulfoxide)scandium(III) ion

Hexakis(dimethyl sulfoxide) scandium(III) iodide, [Sc(OS(CH3)(2))(6)]I-3 contains centrosymmetric hexasolvated scandium(III) ions with an Sc-O bond distance of 2.069(3) Angstrom. EXAFS spectra yield a mean Sc-O bond distance of 2.09(1) Angstrom for solvated scandium(III) ions in dimethyl sulfoxide solution, consistent with six-coordination. Raman and infrared absorption spectra have been recorded, also of the deuterated compound, and analysed by means of normal coordinate methods, together with spectra of dimethyl sulfoxide. The effects on the vibrational spectra of the weak intermolecular C-H...O interactions and of the dipole dipole interactions in liquid dimethyl sulfoxide have been evaluated, in particular for the S O stretching mode. The strong Raman band at 1043.6 cm(-1) and the intense IR absorption at 1062.6 cm(-1) have been assigned as the S-O stretching frequencies of the dominating species in liquid dimethyl sulfoxide, evaluated as centrosymmetric dimers with antiparallel polar S-O groups. The shifts of vibrational frequencies and force constants for coordinated dimethyl sulfoxide ligands in hexasolvated trivalent metal ion complexes are discussed. Hexasolvated scandium( III) ions are found in dimethyl sulfoxide solution and in [Sc(OSMe2)(6)]I-3. The iodide ion dipole attraction shifts the methyl group C H stretching frequency for (S-)C-H...I- more than for the intermolecular (S-)C-H...O interactions in liquid dimethyl sulfoxide

Universal velocity distributions in an experimental granular fluid

We present experimental results on the velocity statistics of a uniformly heated granular fluid, in a quasi-2D configuration. We find the base state, as measured by the single particle velocity distribution $f(c)$, to be universal over a wide range of filling fractions and only weakly dependent on all other system parameters. There is a consistent overpopulation in the distribution's tails, which scale as $f\propto\exp(\mathrm{const.}\times c^{-3/2})$. More importantly, the high probability central region of $f(c)$, at low velocities, deviates from a Maxwell-Boltzmann by a second order Sonine polynomial with a single adjustable parameter, in agreement with recent theoretical analysis of inelastic hard spheres driven by a stochastic thermostat. To our knowledge, this is the first time that Sonine deviations have been measured in an experimental system.Comment: 13 pages, 15 figures, with minor corrections, submitted to Phys. Rev.

Mancha-púrpura do alho e da cebola: doença difícil de controlar.

bitstream/CNPH-2010/36360/1/cot-71.pd

"Vermelhão" do morangueiro: ameaça misteriosa.

bitstream/CNPH-2010/36361/1/cot-70.pd

Pengaruh Kondisi Tanah Terhadap Kerusakan Jalan Menggunakan Metode (PCI) Tirto Rahhayu Landung Sari Desa Mulyoagung Kecamatan Dau Kabupaten Malang

Tanah adalah suatu himpunan mineral, bahan organik, dan endapan-endapan relatif lepas,salah satunya pada konstruksi jalan raya.tanah sebagai pondasi sangat berpengaruh terhadap kualitas pelayanan dan kondisi konstruksi jalan. Kondisi ini terjadi di Jalan Tirto Rahayu Landung Sari-Desa Mulyoagung Kecamatan Dau Kabupaten Malang yang merupakan obyek penelitian.Dari hasil penelitian yang dilakukan sepanjang 1000 m yang di bagi menjadi 200 m persegmen di Jalan Tirto Rahayu Landung Sari Desa Mulyoagung Kecamatan Dau Kabupaten Malang,kondisi jalan mengalami kerusakan.Hal ini dilihat dari kerusakan permukaan aspal yang terkelupas,retak, dan berlubang.Nilai rata-rata Pavement Condition Index (PCI) jalan Tirto Rahayu Landung Sari Desa Mulyoagung Kecanatan Dau Kabupaten Malang yaitu 44 Cukup (Fair),jenis tanah setelah di lakukan penelitian dan lolos ayakan 200 = 35% tanah berbutir sebagian besar lanau dan lempung.hasil analisa saringan lolos ayakan 200,20,dan 10 yaitu batu pecah,kerikil,dan pasir.hasil analisa kadar air rata-rata yaitu 54,05%,hasil rata-rata nilai plastisitas yaitu 1,1 % < 10 % sehingga rata-rata tingkat plastisitas segmen rendah dengan jenis tanah Lanau.hasil nilai rata-rata CBR dan DDT menggunakan alat DCP yaitu sebesar 2,43 % < 5 % dengan nilai DDT sebesar 3,36. jalan ini perlu dimasukan dalam program pemiliharaan secara berkala dan Pemilihan perkerasan dalam menggulangi kerusakan pada jalan ini yaitu menggunakan perkerasan lentu