738 research outputs found
Quiescent Radio Emission from Southern Late-type M Dwarfs and a Spectacular Radio Flare from the M8 Dwarf DENIS 1048-3956
We report the results of a radio monitoring program conducted at the
Australia Telescope Compact Array to search for quiescent and flaring emission
from seven nearby Southern late-type M and L dwarfs. Two late-type M dwarfs,
the M7 V LHS 3003 and the M8 V DENIS 1048-3956, were detected in quiescent
emission at 4.80 GHz. The observed emission is consistent with optically thin
gyrosynchrotron emission from mildly relativistic (~1-10 keV) electrons with
source densities n_e ~ 10 G magnetic fields. DENIS
1048-3956 was also detected in two spectacular, short-lived flares, one at 4.80
GHz (peak f_nu = 6.0+/-0.8 mJy) and one at 8.64 GHz (peak f_nu = 29.6+/-1.0
mJy) approximately 10 minutes later. The high brightness temperature (T_B >~
10^13 K), short emission period (~4-5 minutes), high circular polarization
(~100%), and apparently narrow spectral bandwidth of these events imply a
coherent emission process in a region of high electron density (n_e ~
10^11-10^12 cm^-3) and magnetic field strength (B ~ 1 kG). If the two flare
events are related, the apparent frequency drift in the emission suggests that
the emitting source either moved into regions of higher electron or magnetic
flux density; or was compressed, e.g., by twisting field lines or gas motions.
The quiescent fluxes from the radio-emitting M dwarfs violate the Gudel-Benz
empirical radio/X-ray relations, confirming a trend previously noted by Berger
et al. (abridged)Comment: 28 pages, 8 figures, accepted for publication in Ap
Landowning, Status and Population Growth
This paper considers the effects of the landowning and land reforms on economic and demographic growth by a family-optimization model with endogenous fertility and status-seeking. A land reform provides the peasant with strong incentives to limit their family size and to improve the productivity of the land. Even though the income effect due to the land reform tends to raise fertility, a strong enough status-effect outweighs it, thus generating a decrease in population growth. The European demographic history provides supporting anecdotal evidence for this theoretical result
Semi-Hard Scattering Unraveled from Collective Dynamics by Two-Pion Azimuthal Correlations in 158 A GeV/c Pb + Au Collisions
Elliptic flow and two-particle azimuthal correlations of charged hadrons and
high- pions ( 1 GeV/) have been measured close to mid-rapidity in
158A GeV/ Pb+Au collisions by the CERES experiment. Elliptic flow ()
rises linearly with to a value of about 10% at 2 GeV/. Beyond
1.5 GeV/, the slope decreases considerably, possibly indicating
a saturation of at high . Two-pion azimuthal anisotropies for
1.2 GeV/ exceed the elliptic flow values by about 60% in mid-central
collisions. These non-flow contributions are attributed to near-side and
back-to-back jet-like correlations, the latter exhibiting centrality dependent
broadening.Comment: Submitted to Phys. Rev. Letters, 4 pages, 5 figure
e+e--pair production in Pb-Au collisions at 158 GeV per nucleon
We present the combined results on electron-pair production in 158 GeV/n
{Pb-Au} (= 17.2 GeV) collisions taken at the CERN SPS in 1995 and
1996, and give a detailed account of the data analysis. The enhancement over
the reference of neutral meson decays amounts to a factor of 2.31 for semi-central collisions (28%
) when yields are integrated over 200 MeV/ in
invariant mass. The measured yield, its stronger-than-linear scaling with
, and the dominance of low pair strongly suggest an
interpretation as {\it thermal radiation} from pion annihilation in the
hadronic fireball. The shape of the excess centring at 500
MeV/, however, cannot be described without strong medium modifications of
the meson. The results are put into perspective by comparison to
predictions from Brown-Rho scaling governed by chiral symmetry restoration, and
from the spectral-function many-body treatment in which the approach to the
phase boundary is less explicit.Comment: 39 pages, 40 figures, to appear in Eur.Phys.J.C. (2005
SPOrt: an Experiment Aimed at Measuring the Large Scale Cosmic Microwave Background Polarization
SPOrt (Sky Polarization Observatory) is a space experiment to be flown on the
International Space Station during Early Utilization Phase aimed at measuring
the microwave polarized emission with FWHM = 7deg, in the frequency range 22-90
GHz. The Galactic polarized emission can be observed at the lower frequencies
and the polarization of Cosmic Microwave Background (CMB) at 90 GHz, where
contaminants are expected to be less important. The extremely low level of the
CMB Polarization signal (< 1 uK) calls for intrinsically stable radiometers.
The SPOrt instrument is expressly devoted to CMB polarization measurements and
the whole design has been optimized for minimizing instrumental polarization
effects. In this contribution we present the receiver architecture based on
correlation techniques, the analysis showing its intrinsic stability and the
custom hardware development carried out to detect such a low signal.Comment: 9 pages, 5 figures, conference proceeding, to appear in "Polarimetry
in Astronomy", SPIE Symposium on 'Astronomical Telescopes and
Instrumentation', Waikoloa, August 22-28 200
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The small open-economy New Keynesian Phillips Curve: empirical evidence and implied inflation dynamics
In this paper we apply GMM estimation to assess the relevance of domestic versus external determinants of CPI inflation dynamics in a sample of OECD countries typically classified as open economies. The analysis is based on a variant of the small open-economy New Keynesian Phillips Curve derived in Galí and Monacelli (Rev Econ Stud 72:707–734, 2005), where the novel feature is that expectations about fluctuations in the terms of trade enter explicitly. For most countries in our sample the expected relative change in the terms of trade emerges as the more relevant inflation driver than the contemporaneous domestic output gap
Тепличное хозяйство – обзор текущего состояния отрасли АПК России
Relevance. Population growth and income growth, especially in urban areas, are already causing an increase in market demand as consumers seek to optimize their nutrition. Increased vegetable production to meet this demand creates important economic opportunities, especially for greenhouses.Materials and methods. The purpose of the research is to analyze the stages of development of domestic vegetable growing in greenhouses and the problems of organic greenhouse farming in the Russian Federation. The methods used in economic science were used. The research information base was compiled by official state statistics; normative legal acts of federal and regional levels; data of the Ministry of Agriculture of the Russian Federation; reference materials of specialized publications on the subject under study; materials from participants in the market of vegetables of greenhouses, own research and other.Results. The development of protected ground in Russia has repeatedly been given the attention of state bodies. The main stages of the formation of domestic vegetable growing of protected soil are considered; trends characteristic of the domestic market, which is subject to the influence of external and internal factors. Currently, in general, vegetable growing in closed ground is showing positive dynamics. Since 2000, the production of greenhouse vegetables has increased by 3.6 times. The gross growth of vegetables is due to the positive dynamics of two components: an increase in the area of new generation greenhouses and an increase in yield per meter of inventory. Most of the greenhouses being built and commissioned are high-tech complexes, the construction of which was made possible thanks to state support. The competitiveness of domestic vegetable products is possible in the formation of a favorable investment climate for the development of innovative technologies and increase the profitability of greenhouse plants. This can be achieved by limiting the growth of prices for material and technical resources (equipment, fertilizers, protective equipment, energy, etc.); increase in the share of vegetable producers in the final market price; stabilization of decent prices for vegetables; increasing incomes (to maintain consumer demand); accelerated technical and technological modernization of production; maintaining state support; a ban on the return of unsold products. Pursuant to Federal Law No. 280-ФЗ “On Organic Production and Amending Certain Legislative Acts of the Russian Federation” dated January 1, 2020, it is necessary to provide public and private financing for organic greenhouse farming as part of the research program of the Federal Research Center for Vegetable Production as the only state research institute for vegetable growing.Актуальность. Рост населения и увеличение доходов, особенно в городских районах, вызывают увеличение спроса на рынке, поскольку потребители стремятся оптимизировать свое питание. Увеличение производства овощей для удовлетворения этого спроса создает важные экономические возможности, особенно для тепличных хозяйств.Методы. В работе проанализированы этапы развития отечественного овощеводства защищенного грунта и проблемы органического хозяйства в РФ. Для анализа использованы методы, применяемые в экономической науке. Информационную базу исследования составили данные официальной государственной статистики; нормативные акты федеральных и региональных уровней; данные Министерства сельского хозяйства Российской Федерации; справочные материалы специализированных изданий по исследуемой тематике; материалы, поступающие от участников рынка овощей защищенного грунта, собственные исследования; данные отраслевых порталов, сайты производителей продукции защищенного грунта, статьи и обзоры.Результаты. В целом овощеводство защищенного грунта демонстрирует положительную динамику: за период с 2000 года производство овощей защищенного грунта увеличилось в 3,6 раза. Валовой рост овощей происходит благодаря положительной динамике двух составляющих: увеличения площадей теплиц нового поколения и роста урожайности с метра инвентарной площади. Большая часть строящихся и вводимых теплиц является высокотехнологичными комплексами, строительство которых стало возможным благодаря государственной поддержке. Передовые агротехнологии стали ведущим фактором развития тепличного овощеводства и позволили решать вопросы урожайности и качества продукции, а также насыщения российского рынка овощами отечественного производства. Конкурентоспособность отечественной овощной продукции возможна при формировании благоприятного инвестклимата для освоения инновационных технологий и повышения доходности тепличных комбинатов. Это может быть достигнуто через ограничение роста цен на материально-технические ресурсы; увеличение доли овощепроизводителей в конечной рыночной цене; стабилизацию достойных цен на овощи; повышение доходов населения (для поддержания потребительского спроса); ускоренную технико-технологическую модернизацию производства; сохранение государственной поддержки; запрет на возврат нереализованной продукции. Во исполнение Федерального закона №280-ФЗ «Об органической продукции и о внесении изменений в отдельные законодательныеакты Российской Федерации» от 1 января 2020 года необходимо предусмотреть государственное и частное финансирование по органическому тепличному хозяйству в рамках исследовательской программы ФГБНУ «Федеральный научный центр овощеводства», как единственного государственного научно-исследовательского института по овощеводству
Recoil Polarization Measurements of the Proton Electromagnetic Form Factor Ratio to Q^2 = 8.5 GeV^2
Among the most fundamental observables of nucleon structure, electromagnetic
form factors are a crucial benchmark for modern calculations describing the
strong interaction dynamics of the nucleon's quark constituents; indeed, recent
proton data have attracted intense theoretical interest. In this letter, we
report new measurements of the proton electromagnetic form factor ratio using
the recoil polarization method, at momentum transfers Q2=5.2, 6.7, and 8.5
GeV2. By extending the range of Q2 for which GEp is accurately determined by
more than 50%, these measurements will provide significant constraints on
models of nucleon structure in the non-perturbative regime
Azimuthal anisotropy and correlations in the hard scattering regime at RHIC
Azimuthal anisotropy () and two-particle angular correlations of high
charged hadrons have been measured in Au+Au collisions at
=130 GeV for transverse momenta up to 6 GeV/c, where hard
processes are expected to contribute significantly. The two-particle angular
correlations exhibit elliptic flow and a structure suggestive of fragmentation
of high partons. The monotonic rise of for GeV/c is
consistent with collective hydrodynamical flow calculations. At \pT>3 GeV/c a
saturation of is observed which persists up to GeV/c.Comment: As publishe
Azimuthal anisotropy of K0S and Lambda + Lambda -bar production at midrapidity from Au+Au collisions at sqrt[sNN]=130 GeV
We report STAR results on the azimuthal anisotropy parameter v2 for strange particles K0S, Lambda , and Lambda -bar at midrapidity in Au+Au collisions at sqrt[sNN]=130 GeV at the Relativistic Heavy Ion Collider. The value of v2 as a function of transverse momentum, pt, of the produced particle and collision centrality is presented for both particles up to pt~3.0 GeV/c. A strong pt dependence in v2 is observed up to 2.0 GeV/c. The v2 measurement is compared with hydrodynamic model calculations. The physics implications of the pt integrated v2 magnitude as a function of particle mass are also discussed.Alle Autoren: C. Adler, Z. Ahammed, C. Allgower, J. Amonett, B. D. Anderson, M. Anderson, G. S. Averichev, J. Balewski, O. Barannikova, L. S. Barnby, J. Baudot, S. Bekele, V. V. Belaga, R. Bellwied, J. Berger, H. Bichsel, A. Billmeier, L. C. Bland, C. O. Blyth, B. E. Bonner, A. Boucham, A. Brandin, A. Bravar, R. V. Cadman, H. Caines, M. Calderón de la Barca Sánchez, A. Cardenas, J. Carroll, J. Castillo, M. Castro, D. Cebra, P. Chaloupka, S. Chattopadhyay, Y. Chen, S. P. Chernenko, M. Cherney, A. Chikanian, B. Choi, W. Christie, J. P. Coffin, T. M. Cormier, J. G. Cramer, H. J. Crawford, W. S. Deng, A. A. Derevschikov, L. Didenko, T. Dietel, J. E. Draper, V. B. Dunin, J. C. Dunlop, V. Eckardt, L. G. Efimov, V. Emelianov, J. Engelage, G. Eppley, B. Erazmus, P. Fachini, V. Faine, K. Filimonov, E. Finch, Y. Fisyak, D. Flierl, K. J. Foley, J. Fu, C. A. Gagliardi, N. Gagunashvili, J. Gans, L. Gaudichet, M. Germain, F. Geurts, V. Ghazikhanian, O. Grachov, V. Grigoriev, M. Guedon, E. Gushin, T. J. Hallman, D. Hardtke, J. W. Harris, T. W. Henry, S. Heppelmann, T. Herston, B. Hippolyte, A. Hirsch, E. Hjort, G. W. Hoffmann, M. Horsley, H. Z. Huang, T. J. Humanic, G. Igo, A. Ishihara, Yu. I. Ivanshin, P. Jacobs, W. W. Jacobs, M. Janik, I. Johnson, P. G. Jones, E. G. Judd, M. Kaneta, M. Kaplan, D. Keane, J. Kiryluk, A. Kisiel, J. Klay, S. R. Klein, A. Klyachko, A. S. Konstantinov, M. Kopytine, L. Kotchenda, A. D. Kovalenko, M. Kramer, P. Kravtsov, K. Krueger, C. Kuhn, A. I. Kulikov, G. J. Kunde, C. L. Kunz, R. Kh. Kutuev, A. A. Kuznetsov, L. Lakehal-Ayat, M. A. C. Lamont, J. M. Landgraf, S. Lange, C. P. Lansdell, B. Lasiuk, F. Laue, A. Lebedev, R. Lednický, V. M. Leontiev, M. J. LeVine, Q. Li, S. J. Lindenbaum, M. A. Lisa, F. Liu, L. Liu, Z. Liu, Q. J. Liu, T. Ljubicic, W. J. Llope, G. LoCurto, H. Long, R. S. Longacre, M. Lopez-Noriega, W. A. Love, T. Ludlam, D. Lynn, J. Ma, R. Majka, S. Margetis, C. Markert, L. Martin, J. Marx, H. S. Matis, Yu. A. Matulenko, T. S. McShane, F. Meissner, Yu. Melnick, A. Meschanin, M. Messer, M. L. Miller, Z. Milosevich, N. G. Minaev, J. Mitchell, V. A. Moiseenko, C. F. Moore, V. Morozov, M. M. de Moura, M. G. Munhoz, J. M. Nelson, P. Nevski, V. A. Nikitin, L. V. Nogach, B. Norman, S. B. Nurushev, G. Odyniec, A. Ogawa, V. Okorokov, M. Oldenburg, D. Olson, G. Paic, S. U. Pandey, Y. Panebratsev, S. Y. Panitkin, A. I. Pavlinov, T. Pawlak, V. Perevoztchikov, W. Peryt, V. A Petrov, M. Planinic, J. Pluta, N. Porile, J. Porter, A. M. Poskanzer, E. Potrebenikova, D. Prindle, C. Pruneau, J. Putschke, G. Rai, G. Rakness, O. Ravel, R. L. Ray, S. V. Razin, D. Reichhold, J. G. Reid, F. Retiere, A. Ridiger, H. G. Ritter, J. B. Roberts, O. V. Rogachevski, J. L. Romero, A. Rose, C. Roy, V. Rykov, I. Sakrejda, S. Salur, J. Sandweiss, A. C. Saulys, I. Savin, J. Schambach, R. P. Scharenberg, N. Schmitz, L. S. Schroeder, A. Schüttauf, K. Schweda, J. Seger, D. Seliverstov, P. Seyboth, E. Shahaliev, K. E. Shestermanov, S. S. Shimanskii, V. S. Shvetcov, G. Skoro, N. Smirnov, R. Snellings, P. Sorensen, J. Sowinski, H. M. Spinka, B. Srivastava, E. J. Stephenson, R. Stock, A. Stolpovsky, M. Strikhanov, B. Stringfellow, C. Struck, A. A. P. Suaide, E. Sugarbaker, C. Suire, M. Šumbera, B. Surrow, T. J. M. Symons, A. Szanto de Toledo, P. Szarwas, A. Tai, J. Takahashi, A. H. Tang, J. H. Thomas, M. Thompson, V. Tikhomirov, M. Tokarev, M. B. Tonjes, T. A. Trainor, S. Trentalange, R. E. Tribble, V. Trofimov, O. Tsai, T. Ullrich, D. G. Underwood, G. Van Buren, A. M. VanderMolen, I. M. Vasilevski, A. N. Vasiliev, S. E. Vigdor, S. A. Voloshin, F. Wang, H. Ward, J. W. Watson, R. Wells, G. D. Westfall, C. Whitten, Jr., H. Wieman, R. Willson, S. W. Wissink, R. Witt, J. Wood, N. Xu, Z. Xu, A. E. Yakutin, E. Yamamoto, J. Yang, P. Yepes, V. I. Yurevich, Y. V. Zanevski, I. Zborovský, H. Zhang, W. M. Zhang, R. Zoulkarneev, and A. N. Zubarev (STAR Collaboration
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