774 research outputs found
Thermalization through Hagedorn states - the importance of multiparticle collisions
Quick chemical equilibration times of hadrons within a hadron gas are
explained dynamically using Hagedorn states, which drive particles into
equilibrium close to the critical temperature. Within this scheme master
equations are employed for the chemical equilibration of various hadronic
particles like (strange) baryon and antibaryons. A comparison of the Hagedorn
model to recent lattice results is made and it is found that for both Tc =176
MeV and Tc=196 MeV, the hadrons can reach chemical equilibrium almost
immediately, well before the chemical freeze-out temperatures found in thermal
fits for a hadron gas without Hagedorn states.Comment: 8 pages, 3 figures, talk presented at the International Conference on
Strangeness in Quark Matter, Buzios, Rio de Janeiro, Brazil, Sept. 27 - Oct.
2, 200
Particle Ratios and the QCD Critical Temperature
We show how the measured particle ratios at RHIC can be used to provide
non-trivial information about the critical temperature of the QCD phase
transition. This is obtained by including the effects of highly massive
Hagedorn resonances on statistical models, which are used to describe hadronic
yields. Hagedorn states are relevant close to and have been shown to
decrease to the KSS limit and allow for quick chemical equilibrium
times in dynamical calculations of hadrons. The inclusion of Hagedorn states
creates a dependence of the thermal fits on the Hagedorn temperature, ,
which is assumed to be equal to , and leads to an overall improvement of
thermal fits. We find that for Au+Au collisions at RHIC at
GeV the best square fit measure, , occurs at MeV and
produces a chemical freeze-out temperature of 170.4 MeV and a baryon chemical
potential of 27.8 MeV.Comment: 6 pages, 2 figures, talk presented at the International Conference on
Strangeness in Quark Matter, Buzios, Rio de Janeiro, Brazil, Sept. 27 - oct.
2, 200
Monitoramento de doenças como fator de redução do uso de fungicidas no controle da pinta-preta (Asperisporium caricae) do mamoeiro.
Pela alta freqüência que ocorre e pelos danos que pode ocasionar ao mamoeiro, particularmente diminuindo o valor comercial dos frutos, a pinta preta, causada pelo fungo Asperisporium caricae constitui um dos mais sérios problemas dessa fruteira. As medidas de controle recomendadas baseiam-se em práticas onerosas e, algumas delas, potencialmente agressivas ao meio ambiente, como é o caso da aplicação de fungicidas. A diminuição do número de aplicações minimizaria o impacto na entomofauna benéfica, possibilitando a melhoria na qualidade dos frutos produzidos e a preservação ambiental.Disponível em: Acesso em: 21 fev. 2011
Impacto econômico da cultivar de batata-doce BRS Amélia na agricultura familiar do Sul do Brasil.
A avaliação de impacto seguiu metodologia do excedente econômico.Trabalho 252. Sessão ePôster I
Estudo da microfracturação do maciço granítico de Castelo Branco através dos Planos de Inclusões Fluidas
The main objective of this study was to determine the geometry of the FIP, in the Castelo
Branco granite massif. This study showed that in addition to FIP in Mode I, are also present Mode II,
suggesting that the directions found NE-SW to NNE-SSW and E-W to ESE-WNW can be interpreted as
related to a maximum stress (σ1) oriented NE-SW. The NNW-SSE orientation corresponds to a late
syste
Sarcosine oxidase composite screen-printed electrode for sarcosine determination in biological samples
XIX Meeting of the Portuguese Electrochemical Society - XVI Iberic Meeting of ElectrochemistryProstate Cancer (PCa) is the most common form of cancer in men in Europe with a 61.4 % incidence among all cancer cases and a 12.1 % mortality [1] and, therefore, its early detection is fundamental for increasing the survival rate. Currently, diagnosis and management of patients with PCa is only based on the determination of the biomarker Prostate Specific Antigen (PSA). However, the method used for PCa detection has poor sensitivity and specificity, leading to false negative and false positive test results and many patients are sent to unnecessary biopsy procedures [2]. Therefore, there is a need to seek for new biomarkers and more effective screening. In this work, a biosensor device was developed for the quantification of sarcosine via electrochemical detection of H2O2 (at 0.6 V) generated from the catalyzed oxidation of sarcosine. The detection was carried out after the modification of carbon screen printed electrodes (SPEs) by immobilization of sarcosine oxidase (SOX) on the electrode surface. The strategies used herein included the activation of the carbon films by an electrochemical step and the formation of an NHS/EDAC layer to bond the enzyme to the electrode, the use of metallic or semiconductor nanoparticles layer previously or during the enzyme immobilization. In order to improve the sensor stability and selectivity a polymeric layer with extra enzyme content was further added. The proposed methodology for the detection of sarcosine allowed obtaining a limit of detection (LOD) of 1.6x10-5 mM, using a linear concentration range between 1x10-5 and 1x10-4 mM. The biosensor was successfully applied to the analysis of sarcosine in urine samples.
Parasitismo de cochonilhas em camucamuzeiro no município de Belém, Pará.
Dentre os insetos fitófagos associados ao camucamuzeiro (Myrciaria dubia) no estado do Pará, espécies de cochonilhas (Hemiptera) foram relatadas em áreas de várzea e terra firme. Parasitoides (Hymenoptera) pertencentes às famílias Eupelmidae e Pteromalidae foram observados parasitando a cochonilha Parasaissetia nigra, coletada em folhas e hastes. Este estudo tem o objetivo identificar parasitoides em associação com cochonilhas presentes em M. dubia no município de Belém, PA. Foram realizadas coletas de folhas e hastes com a presença de cochonilhas em área experimental da Embrapa Amazônia Oriental. Em laboratório foram obtidos 313 parasitoides, com espécimes pertencentes às famílias (gêneros) Aphelinidae (Aphytis, Coccophagus e Encarsia), Braconidae (Rhysipolis), Encyrtidae (Metaphycus), Eupelmidae (Lecaniobius), Pteromalidae (Scutellista), Signiphoridae, além de 13 morfoespécies. A maior diversidade de parasitoides está associada à cochonilha P. nigra
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