9,262 research outputs found
Vibrations on pulse tube based Dry Dilution Refrigerators for low noise measurements
Dry Dilution Refrigerators (DDR) based on pulse tube cryo-coolers have
started to replace Wet Dilution Refrigerators (WDR) due to the ease and low
cost of operation. However these advantages come at the cost of increased
vibrations, induced by the pulse tube. In this work, we present the vibration
measurements performed on three different commercial DDRs. We describe in
detail the vibration measurement system we assembled, based on commercial
accelerometers, conditioner and DAQ, and examined the effects of the various
damping solutions utilized on three different DDRs, both in the low and high
frequency regions. Finally, we ran low temperature, pseudo-massive (30 and 250
g) germanium bolometers in the best vibration-performing system under study and
report on the results
Control of fluorescence in quantum emitter and metallic nanoshell hybrids for medical applications
We study the light emission from quantum emitter and double metallic
nanoshell hybrid systems. Quantum emitters act as local sources which transmit
their light efficiently due to a double nanoshell near field. The double
nanoshell consists a dielectric core and two outer nanoshells
Amostragem das pragas do algodoeiro com auxilio de ficha pictografica.
A ficha pctografica; Implantacao do metodo.bitstream/item/33300/1/CNPA-DOCUMENTOS-06-AMOSTRAGEM-DAS-PRAGAS-DO-ALGODOEIRO-COM-AUXILIO-DE-FICHA-PICTOGRAFICA-FL-02978.pd
Inseticidas e intervalos de pulverizacao para o controle lagarta rosada (Pectinophora gossypiela (Saund) (Lepidoptera, gelechiidae) no algodoeiro herbaceo.
bitstream/item/33358/1/INSETICIDAS-INTERVALOS.pd
Infestação de Cosmopolites sordidus em genótipos de bananeira.
A broca do rizoma da bananeira é a principal praga da cultura, causando severos prejuízos à produção (Fancelli & Mesquita, 2008). O adulto geralmente efetua a postura na região de contato entre o rizoma e as bainhas foliares, a uma profundidade de 2 mm. Em função do habitat da larva, torna-se difícil a visualização dos danos e, portanto, medidas indiretas são utilizadas para determinação do nível de controle, como é o caso das iscas confeccionadas com pseudocaule de bananeiras colhidas, com o objetivo de atrair adultos da broca (Cordeiro & Fancelli, 2007). No entanto, a contagem do número de adultos não reflete o nível de dano encontrado no rizoma e, desse modo, a adoção de medidas de controle pode ser efetivada desnecessariamente ou o inverso (Vilardebo, 1973). Como o comportamento de ambas as formas larval e adulta, bem como o desenvolvimento larval podem não ser dependentes dos mesmos estímulos provenientes da planta hospedeira, fica claro que, ao se estudar a resistência de plantas a insetos, deve-se avaliar os efeitos do hospedeiro sobre as diferentes fases do inseto (Lara, 2001). Estudos sobre a biologia do inseto em condições de laboratório podem representar um longo tempo e alto investimento, além da demanda de mão-de-obra. Por outro lado, avaliações em condições de campo exigem grandes áreas e homogeneidade da infestação. Desse modo, esse trabalho foi realizado com o objetivo de avaliar uma metodologia que permita discriminar, precocemente, genótipos de bananeira quanto à infestação pela broca do rizoma, visando aplicação em estudos de resistência de plantas a insetos.pdf 234
OH rotational lines as a diagnostic of the warm neutral gas in galaxies
We present Infrared Space Observatory (ISO) observations of several OH, CH
and H2O rotational lines toward the bright infrared galaxies NGC253 and
NGC1068. As found in the Galactic clouds in SgrB2 and Orion, the extragalactic
far-IR OH lines change from absorption to emission depending on the physical
conditions and distribution of gas and dust along the line of sight. As a
result, most of the OH rotational lines that appear in absorption toward NGC253
are observed in emission toward NGC1068. We show that the far-IR spectrum of OH
can be used as a powerful diagnostic to derive the physical conditions of
extragalactic neutral gas. In particular, we find that a warm (Tk~150 K, n(H2)<
5 10^4 cm^-3) component of molecular gas with an OH abundance of 10^{-7} from
the inner <15'' can qualitatively reproduce the OH lines toward NGC253. Similar
temperatures but higher densities (5 10^5 cm^-3) are required to explain the OH
emission in NGC1068.Comment: 5 pages, 4 figures, accepted in ApJ Part I (2004, October 6
Use of principal component analysis to evaluate thermal properties and combustibility of coffee-pine wood briquettes
Submitted: February 1st, 2021 ; Accepted: March 30th, 2021 ; Published: May 21st, 2021 ; Correspondence: [email protected] coffee production chain is a potential source of residual biomass inherent to the
high productivity that can contribute to the generation of value-added products. The residues from
the coffee sector are typically disposed to landfill without treatment causing potential
environmental inconveniences. Briquetting presents an alternative process to produce a uniform
fuel with high energy density. Briquettes facilitates easy transportation, enables better handling
and storage of biomass residues. Properties such as low equilibrium moisture content, high energy
density and compressive strength were reported for different coffee-pine wood briquettes
treatments. Moreover, understanding of the thermal properties of the briquettes during
combustion is crucial to evaluate their final application. This research is the first study that
investigates the combustibility properties and kinetic parameters of the thermal decomposition of
briquettes from coffee-pine wood using differential and integral thermal analysis under
non-isothermal conditions. Multivariate analysis of the collected parameters through principal
components analysis (PCA), was implemented to reduce the dimensionality of the data.
The desired profile in the combustibility is directly related to high temperatures and long burning
times, thus, the tested briquettes displayed a significant combustibility potential, reporting peak
temperatures and burnout times around 600 °C and 27 minutes, respectively. Activation energy
kinetic parameter in the range of 12–42 kJ mol-1
and average reactivity of 0.14–0.22 min-1
, were
also found. The results revealed the not thermally hard material to degrade when compared to
biomasses typically used for combustion
Estudo de caso da avaliação dos riscos ambientais do trigo geneticamente modificado: método GMP-RAM para avaliação caso a caso de plantas geneticamente modificadas.
Desenvolvimento de linhagens de mamoeiro geneticamente modificadas para resistência a vírus.
O mamoeiro (Carica papaya L.) é umas das fruteiras mais comuns nos países da América Tropical, além de ser cultivado amplamente por vários países do mundo como Sri-Lanka, Malásia, Havaí, Austrália, Ásia e África do Sul. O mamoeiro tem grande importância na alimentação humana, bem como em usos medicinal, indústria têxtil e cosmético. O ataque de viroses ao mamoeiro tem papel fundamental na diminuição da produtividade e, consequentemente, dos lucros gerados pela cultura
Control of mucocutaneous leishmaniasis, a neglected disease: results of a control programme in Satipo Province, Peru.
Mucocutaneous leishmaniasis (MCL) is an important health problem in many rural areas of Latin America, but there are few data on the results of programmatic approaches to control the disease. We report the results of a control programme in San Martin de Pangoa District, which reports one of the highest prevalences of MCL in Peru. For 2 years (2001--2002), the technicians at the health post were trained in patient case management, received medical support and were supplied with antimonials. An evaluation after 2 years showed the following main achievements: better diagnosis of patients, who were confirmed by microscopy in 34% (82/240) of the cases in 2001 and 60% of the cases (153/254) in 2002; improved follow-up during treatment: 237 of 263 (90%) patients who initiated an antimonial therapy ended the full treatment course; improved follow-up after treatment: 143 of 237 (60%) patients who ended their full treatment were correctly monitored during the required period of 6 (cutaneous cases) or 12 (mucosal cases) months after the end of treatment. These achievements were largely due to the human and logistical resources made available, the constant availability of medications and the close collaboration between the Ministry of Health, a national research institute and an international non-governmental organization. At the end of this period, the health authorities decided to register a generic brand of sodium stibogluconate, which is now in use. This should allow the treatment of a significant number of additional patients, while saving money to invest in other facets of the case management
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