34,386 research outputs found
Self-similar solutions with fat tails for Smoluchowski's coagulation equation with locally bounded kernels
The existence of self-similar solutions with fat tails for Smoluchowski's
coagulation equation has so far only been established for the solvable and the
diagonal kernel. In this paper we prove the existence of such self-similar
solutions for continuous kernels that are homogeneous of degree and satisfy . More precisely,
for any we establish the existence of a continuous weak
self-similar profile with decay as
Cultivos da cebola e do tomate industrial.
Manejo da cultura. Recomendacoes tecnicas e coeficientes tecnico para o plantio.bitstream/item/137803/1/ID-7006.pdfApostila do Curso de Atualizacao Tecnica para Engenheiros Agronomos do Banco do Brasil, Petrolina, 1995
FUSE Observations of the Magellanic Bridge Gas toward Two Early-Type Stars: Molecules, Physical Conditions, and Relative Abundance
We discuss FUSE observations of two early-type stars, DI1388 and DGIK975, in
the low density and low metallicity gas of Magellanic Bridge (MB). Toward
DI1388, the FUSE observations show molecular hydrogen, O VI, and numerous other
atomic or ionic transitions in absorption, implying the presence of multiple
gas phases in a complex arrangement. The relative abundance pattern in the MB
is attributed to varying degrees of depletion onto dust similar to that of halo
clouds. The N/O ratio is near solar, much higher than N/O in damped Ly-alpha
systems, implying subsequent stellar processing to explain the origin of
nitrogen in the MB. The diffuse molecular cloud in this direction has a low
column density and low molecular fraction. H2 is observed in both the
Magellanic Stream and the MB, yet massive stars form only in the MB, implying
significantly different physical processes between them. In the MB some of the
H2 could have been pulled out from the SMC via tidal interaction, but some also
could have formed in situ in dense clouds where star formation might have taken
place. Toward DGIK975, the presence of neutral, weakly and highly ionized
species suggest that this sight line has also several complex gas phases. The
highly ionized species of O VI, C IV, and Si IV toward both stars have very
broad features, indicating that multiple components of hot gas at different
velocities are present. Several sources (a combination of turbulent mixing
layer, conductive heating, and cooling flows) may be contributing to the
production of the highly ionized gas in the MB. Finally, this study has
confirmed previous results that the high-velocity cloud HVC 291.5-41.2+80 is
mainly ionized composed of weakly and highly ions. The high ion ratios are
consistent with a radiatively cooling gas in a fountain flow model.Comment: Accepted for publication in the ApJ (October 10, 2002). Added
reference (Gibson et al. 2000
Modelling a Particle Detector in Field Theory
Particle detector models allow to give an operational definition to the
particle content of a given quantum state of a field theory. The commonly
adopted Unruh-DeWitt type of detector is known to undergo temporary transitions
to excited states even when at rest and in the Minkowski vacuum. We argue that
real detectors do not feature this property, as the configuration "detector in
its ground state + vacuum of the field" is generally a stable bound state of
the underlying fundamental theory (e.g. the ground state-hydrogen atom in a
suitable QED with electrons and protons) in the non-accelerated case. As a
concrete example, we study a local relativistic field theory where a stable
particle can capture a light quantum and form a quasi-stable state. As
expected, to such a stable particle correspond energy eigenstates of the full
theory, as is shown explicitly by using a dressed particle formalism at first
order in perturbation theory. We derive an effective model of detector (at
rest) where the stable particle and the quasi-stable configurations correspond
to the two internal levels, "ground" and "excited", of the detector.Comment: 13 pages, references added, final versio
Doses e períodos de aplicação de nitrogênio na melancia no Submédio São Francisco.
O trabalho constou de três experimentos que foram realizados num Agrissolo Vermelho Amarelo, arenoso, em Petrolina - PE, nos anos de 2000, 2001 e 2002, com o objetivo de avaliar os efeito de doses e períodos de aplicação de nitrogênio, via fertirrigação, na cultura da melancia (Citrullus lanatus). O delineamento experimental foi em blocos ao acaso, com esquema em faixa, com três e quatro repetições. Em 2000 houve uma resposta quadrática às aplicações de N, sendo 45,7 kg/ha a dose que proporcionou a produtividade máxima esperada (111,57 t.ha-1). Em 2001, as aplicações de N proporcionaram um peso médio dos frutos (PMF) superior ao da testemunha (sem N). Nos outros experimentos não houve resposta para o PMF, cujos valores variaram de 6,945 a 7,706 kg em 2000 e de 7,204 a 8,176 kg em 2002. Os teores de sólidos solúveis totais dos frutos, avaliados em 2002, com oscilações de 12,1 a 12,5%, não foram influenciados pelos tratamentos. Os períodos de aplicação de N só exerceram efeito significativo na produtividade em 2002
Doses de potássio na melancia no Submédio São Francisco.
O trabalho constou de um experimentos realizado num Argissolo Vermelho Amarelo, arenoso, em Petrolina - PE, em 2002, com o objetivo de avaliar os efeitos da aplicação de potássio, via fertirrigação, na cultura da melancia (Citrullus lanatus). O delineamento experimental foi em blocos ao acaso, com quatro repetições e quatro tratamentos: 0, 40, 120, e 160 kg.ha-1 de K2O. Verificou-se efeito positivo do potássio no peso médio dos frutos (PMF), mas não houve influência para a produtividade (43,06 a 49,68 t.ha-1)e o teor de sólidos solúveis (11,7 a 12,6%). Com 65,8 kg.ha-1 de K2O obteve-se o PMF máximo esperado, 7,97 kg.Suplemento. Edição de resumos expandidos e palestras do 43. Congresso Brasileiro de Olericultura, Recife, jul. 2003
Aplicação de nitrogênio via água de irrigação em meloeiro.
Real;izou-se um estudo para avaliar os efeitos da aplicação de nitrogênio via fertirrigação na cultura do melão. O experimento foi conduzido na Embrapa, em Petrolina, PE. Adotaram-se quatro doses de nitrogênio: 45, 90, 135 e 180 kg.ha -1. O sistema de irrigação utilizado foi o gotejamento. A produção máxima de frutos, obtida pela equação de regressão, foi de 38,06 kgt.ha -1, para a dose de 129 kg.ha -1 de N. Na colheita, as características químicas, teor de sólidos solúveis, pH e acidez total foram: 10,47 oBrix, 5,65 e 0,15%, respectivamente. O teor de sólidos solúveis dos frutos produzidos atende às exigências dos mercados internos e externos. Trinta dias após a colheita, os valores de teor de sólidos solúveis, acidez total e pH foram a 11,00 oBrix, 0,14% e 5,75, respectivamente, que os mantinha aptos à comercialização
A bibliometric based analysis to identify promising domains of decarbonisation technologies
The high volume of research outputs related to technologies and strategies for decarbonisation can make it challenging to understand the relevance of the presented proposals. In this paper, a bibliometric-based analysis is proposed to understand better the domains and subdomains of decarbonisation technologies that have given more attention by the scientific community. The results show that carbon capture technologies, renewable energy sources, electric mobility, green hydrogen, and storage systems are the technology innovations that have received the most attention in the period 2013 to 2021. These results confirm the traditional supply-side orientation of research on technology innovations.info:eu-repo/semantics/acceptedVersio
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