oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 32 )

2019 ( 353 )

2018 ( 411 )

2017 ( 454 )

Custom range...

Search Results: 1 - 10 of 351699 matches for " G. P.;Krug "
All listed articles are free for downloading (OA Articles)
Page 1 /351699
Display every page Item
Melhoramento do milho: II - Germoplasma utilizado nos trabalhos de sele??o
Viegas, G. P.;Krug, C. A.;
Bragantia , 1952, DOI: 10.1590/S0006-87051952000300002
Abstract: in order to diversify the maize germplasm utilized in the breeding work conducted at the instituto agron?mico, at campinas, s?o paulo, brazil, efforts were made to obtain corn samples from the most diversified origins. seeds of numerous varieties, inbred lines and hybrids were introduced and their performance observed under local conditions. until 1951, a total of 1405 samples were introduced, most of them being derived from various parts of brazil. from the united states, colombia, peru, bolivia also numerous samples were obtained. recently, single crosses from colombia, and mexican inbred lines crossed to brazilian single hybrids, were introduced, and are being tested under local conditions. yellow flint and dent varieties were tested in trials conducted at campinas, ribeir?o preto and pindorama. the best ones were : 1-catêto, 333-creóle yellow flint and 417-assis brasil among the yellow flint and 373-itaici and 986-tuxpan, among the yellow dent varieties. plants from more than 50 distinct varieties were selfed to get inbred lines. lines from about 20 varieties are still available. most of these were derived from catêto, some having now been selfed for 20 generations. l. 483 is the most outstanding one, as it has excelent agronomic features and high combining ability. from tuxpan the line l. 94-956 was obtained in vi?osa, minas gerais. in the years 1941 and 1942, 153 inbred lines and many hybrids were introduced from the united states. their performance is not satisfactory under local conditions, as they are too early, the ears having poor husk protection.
Melhoramento do milho: III - Ensaios de híbridos
Viegas, G. P.;Krug, C. A.;Penteado, Marcos P.;
Bragantia , 1952, DOI: 10.1590/S0006-87051952000300003
Abstract: comparative trials with experimental corn hybrids are being conducted, in the state of s?o paulo, brazil, by the instituto agron?mico, at its experiment stations, at campinas, ribeir?o prêto and pindorama. during the years from 1938 to 1950 a total of 119 trials were planted, only twelve of them having been eliminated due to severe insect attacks. except 21 trials in randomized blocks and 2 in incomplete block designs, all the others were planted in simple lattice, with 4 replications. the individual plots, with few exceptions, had one or usually two 5 m rows each. among the yellow flint unes tested, l. 483 is, no doubt, the best. it has high combining ability and also excellent agronomic characters. the performance of some other lines, as l.278-1-1, l.606, l.334, l.445 and l. 422, is also briefly described. hybrid h.3531 [(483 x 581)x(278-1-1 x 429-2)] gave, on the average, an increase of 780 kg/ha over the "cateto" variety, having been tested in a total of 51 trials conducted at 3 different localities. some lines of yellow dent corn were also obtained from local and introduced varieties. among the lines received from different places of the united states, only hy and 38-11 furnished reasonably good results. however even these are too early for local conditions, the ears being poorly protected, exposing them to severe weevil damage. l.2051-1-2-3 derived from "amarel?o" and l.2761, from "tuxpan", are, so far, the best ones. at apresent, h.4624 [(2051-1-2-3 x 2761)x(278-1-1x483)j is being produced, as a good, medium dent double hybrid.
Híbridos comerciais de milho
Krug, C. A.;Viégas, G. P.;Paoliéri, L.;
Bragantia , 1943, DOI: 10.1590/S0006-87051943001100001
Abstract: in the present bulletin the authors present the details of a 10 year's corn improvement project to produce hybrid varieties, which has been conducted by the genetics division of the instituto agron?mico, campinas, s. p., brasil. a general description is given of the basic material which has been used ; the various methods of isolating and selecting pure lines, methods of hybridization and of the study of hybrids are described. in the main chapter the details of the breeding work is outlined, year by year general comments of the results obtained always being added. for the isolation of pure lines a total of 17 varieties, several hybrids and other types were used, more than 26.000 artificial selfings having been made. an attempt has also been made to adapt lines introduced from other countries, mainly from the united states of america. the selection of pure lines has been based on their morphological characters as well as on their combining ability (general and specific) which was determined by top-crosses with open pollinated varieties and whith other lines. that way it was succeeded to isolate lines with good vegetative characters and producing high yielding hybrids. up to 1941-42 more than 3.700 hybrids were studied in a total of 47 field trials (single, three-way, double and inter-varietal crosses), of which 133 (3,5%), yielded significantly higher than the control varieties at campinas, ribeir?o preto and pindorama, three different ecological zones in the state of s?o paulo. the differences in yield varied between 7 and 92%, most of the hybrids being of the yellow flint type. some of these hybrids showed significant higher yields at the three above mentioned regions and during two to three years. it is concluded that the preliminary part of the project has now come to an end and steps are taken to produce hybrid corn seeds on a commercial scale.
Step bunching during Si(001) homoepitaxy caused by the surface diffusion anisotropy
J. Myslivecek,C. Schelling,F. Schaffler,G. Springholz,P. Smilauer,J. Krug,B. Voigtlander
Physics , 2002,
Abstract: Scanning tunneling microscopy experiments show that the unstable growth morphology observed during molecular beam homoepitaxy on slightly vicinal Si(001) surfaces consists of straight step bunches. The instability occurs under step- flow growth conditions and vanishes both during low-temperature island growth and at high temperatures. An instability with the same characteristics is observed in a 2D Kinetic Monte Carlo model of growth with incorporated Si(001)- like diffusion anisotropy. This provides strong evidence that the diffusion anisotropy destabilizes growth on Si(001) and similar surfaces towards step bunching. This new instability mechanism is operational without any additional step edge barriers.
Second layer nucleation and the shape of wedding cakes
J. Krug,P. Kuhn
Physics , 2001,
Abstract: The rate of second layer nucleation -- the formation of a stable nucleus on top of a two-dimensional island -- determines both the conditions for layer-by-layer growth, and the size of the top terrace of multilayer mounds in three-dimensional homoepitaxial growth. It was recently shown that conventional mean field nucleation theory overestimates the rate of second layer nucleation by a factor that is proportional to the number of times a given site is visited by an adatom during its residence time on the island. In the presence of strong step edge barriers this factor can be large, leading to a substantial error in previous attempts to experimentally determine barrier energies from the onset of second layer nucleation. In the first part of the paper simple analytic estimates of second layer nucleation rates based on a comparison of the relevant time scales will be reviewed. In the main part the theory of second layer nucleation is applied to the growth of multilayer mounds in the presence of strong but finite step edge barriers. The shape of the mounds is obtained by numerical integration of the deterministic evolution of island boundaries, supplemented by a rule for nucleation in the top layer. For thick films the shape converges to a simple scaling solution. The scaling function is parametrized by the coverage $\theta_c$ of the top layer, and takes the form of an inverse error function cut off at $\theta_c$. The surface width of a film of thickness $d$ is $\sqrt{(1- \theta_c) d}$. Finally, we show that the scaling solution can be derived also from a continuum growth equation.
Poly-MTO, {(CH_3)_{0.92} Re O_3}_\infty, a Conducting Two-Dimensional Organometallic Oxide
R. Miller,E. -W. Scheidt,G. Eickerling,C. Helbig,F. Mayr,R. Herrmann,W. Scherer,H. -A. Krug von Nidda,V. Eyert,P. Schwab
Physics , 2005, DOI: 10.1103/PhysRevB.73.165113
Abstract: Polymeric methyltrioxorhenium, {(CH_{3})_{0.92}ReO_{3}}_{\infty} (poly-MTO), is the first member of a new class of organometallic hybrids which adopts the structural pattern and physical properties of classical perovskites in two dimensions (2D). We demonstrate how the electronic structure of poly-MTO can be tailored by intercalation of organic donor molecules, such as tetrathiafulvalene (TTF) or bis-(ethylendithio)-tetrathiafulvalene (BEDT-TTF), and by the inorganic acceptor SbF$_3$. Integration of donor molecules leads to a more insulating behavior of poly-MTO, whereas SbF$_3$ insertion does not cause any significant change in the resistivity. The resistivity data of pure poly-MTO is remarkably well described by a two-dimensional electron system. Below 38 K an unusual resistivity behavior, similar to that found in doped cuprates, is observed: The resistivity initially increases approximately as $\rho \sim$ ln$(1/T$) before it changes into a $\sqrt{T}$ dependence below 2 K. As an explanation we suggest a crossover from purely two-dimensional charge-carrier diffusion within the \{ReO$_2$\}$_{\infty}$ planes at high temperatures to three-dimensional diffusion at low temperatures in a disorder-enhanced electron-electron interaction scenario (Altshuler-Aronov correction). Furthermore, a linear positive magnetoresistance was found in the insulating regime, which is caused by spatial localization of itinerant electrons at some of the Re atoms, which formally adopt a $5d^1$ electronic configuration. X-ray diffraction, IR- and ESR-studies, temperature dependent magnetization and specific heat measurements in various magnetic fields suggest that the electronic structure of poly-MTO can safely be approximated by a purely 2D conductor.
Magnetization and specific heat of the dimer system CuTe2O5
R. M. Eremina,T. P. Gavrilova,A. Günther,Zhe Wang,R. Lortz,M. Johnsson,H. Berger,H. -A. Krug von Nidda,J. Deisenhofer,A. Loidl
Physics , 2011, DOI: 10.1140/epjb/e2011-20263-2
Abstract: We report on magnetization and specific heat measurements on single-crystalline CuTe2O5. The experimental data are directly compared to theoretical results for two different spin structures, namely an alternating spin-chain and a two-dimensional (2D) coupled dimer model, obtained by Das et al. [Phys. Rev. B 77, 224437 (2008)]. While the analysis of the specific heat does not allow to distinguish between the two models, the magnetization data is in good agreement with the 2D coupled dimer model.
Violência: um problema global de saúde pública
Dahlberg,Linda L.; Krug,Etienne G.;
Ciência & Saúde Coletiva , 2006, DOI: 10.1590/S1413-81232006000500007
Abstract: this article is a version of the introduction to the world report on violence and health, published by the world health organization (who). it presents a general description about this phenomenon and points some basic questions: concepts and definitions about the theme; the state of knowledge about it; nature and typology on violence; proposal of a quantitative and qualitative approach of an ecological model; responsibilities and functions of the public health sector and its potentiality to prevent and reduce violence in the world; the responsibilities of the nations and the policy makers in a intersetorial point of view; difficulties and obstacles for actuation and challenges for the health sector.
Violence a global public health problem
Dahlberg,Linda L.; Krug,Etienne G.;
Ciência & Saúde Coletiva , 2006, DOI: 10.1590/S1413-81232006000200007
Abstract: this article is a version of the introduction to the world report on violence and health, published by the world health organization (who). it presents a general description about this phenomenon and points some basic questions: concepts and definitions about the theme; the state of knowledge about it; nature and typology on violence; proposal of a quantitative and qualitative approach of an ecological model; responsibilities and functions of the public health sector and its potentiality to prevent and reduce violence in the world; the responsibilities of the nations and the policy makers in a intersetorial point of view; difficulties and obstacles for actuation and challenges for the health sector.
Correlations of record events as a test for heavy-tailed distributions
J. Franke,G. Wergen,J. Krug
Physics , 2011, DOI: 10.1103/PhysRevLett.108.064101
Abstract: A record is an entry in a time series that is larger or smaller than all previous entries. If the time series consists of independent, identically distributed random variables with a superimposed linear trend, record events are positively (negatively) correlated when the tail of the distribution is heavier (lighter) than exponential. Here we use these correlations to detect heavy-tailed behavior in small sets of independent random variables. The method consists of converting random subsets of the data into time series with a tunable linear drift and computing the resulting record correlations.
Page 1 /351699
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.