Spray stability of outwards opening pintle injectors for stratified direct injection spark ignition engine operation

The spray characteristics and spray stability from three prototype piezoelectric pintle-type injectors were investigated under different operating conditions in an optical direct injection engine designed for stratified combustion. The pintle-type outwards opening injector has the potential to address and overcome many of the typical problems related to close-spacing, spray-guided configurations owing to its hollow cone spray, exhibiting better air utilization than multihole sprays, with good penetration during early injection, and a spray angle almost independent of cylinder backpressure. The three prototype injectors have different nozzle exit geometries for optimization of spray stability under all engine operating conditions. The emerging fuel sprays for both single- and double-injection operation were visualized using Mie scattering and a high-speed CCD camera. The performance of the injectors was assessed by constructing mean and RMS images at different operating conditions of injection pressure, backpressure, injector needle lift, and engine speed. From these images, a spray angle analysis was performed by comparing the mean, standard deviation, maximum, and minimum cone angle under different operating conditions; the spray stability was quantified by analysing the mean and RMS images and the mean and RMS spray cone angles. Evaluation of the three prototypes has revealed that the positive-step inward seal band design produces the most robust spray angle ideally suited for stratified fuel/air mixture formation and combustion in spray-guided direct injection spark ignition (DISI) gasoline engines

Caracterização direta da transpiração em vinhedo da Campanha Gaúcha através de medidores de fluxo de seiva.

Considerando a carência de informações técnicas para o manejo hídrico em vinhedos da Campanha, esse trabalho teve por objetivo testar medidores de fluxo de seiva para obter uma caracterização direta da transpiração diária (Td) das videiras nestas condições edafoclimáticas

Contribution of White Dwarfs to Cluster Masses

I present a literature search through 31 July 1997 of white dwarfs (WDs) in open and globular clusters. There are 36 single WDs and 5 WDs in binaries known among 13 open clusters, and 340 single WDs and 11 WDs in binaries known among 11 globular clusters. From these data I have calculated WD mass fractions for four open clusters (the Pleiades, NGC 2168, NGC 3532, and the Hyades) and one globular cluster (NGC 6121). I develop a simple model of cluster evolution that incorporates stellar evolution but not dynamical evolution to interpret the WD mass fractions. I augment the results of my simple model with N-body simulations incorporating stellar evolution (Terlevich 1987; de la Feunte Marcos 1996; Vesperini & Heggie 1997). I find that even though these clusters undergo moderate to strong kinematical evolution the WD mass fraction is relatively insensitive to kinematical evolution. By comparing the cluster mass functions to that of the Galactic disk, and incorporating plausibility arguments for the mass function of the Galactic halo, I estimate the WD mass fraction in these two populations. I assume the Galactic disk is ~10 Gyrs old (Winget et al. 1987; Liebert, Dahn, & Monet 1988; Oswalt et al. 1996) and that the Galactic halo is ~12 Gyrs old (Reid 1997b; Gratton et al. 1997; Chaboyer et al. 1998), although the WD mass fraction is insensitive to age in this range. I find that the Galactic halo should contain 8 to 9% (alpha = -2.35) or perhaps as much as 15 to 17% (alpha = -2.0) of its stellar mass in the form of WDs. The Galactic disk WD mass fraction should be 6 to 7% (alpha = -2.35), consistent with the empirical estimates of 3 to 7% (Liebert, Dahn, & Monet 1988; Oswalt et al. 1996). (abridged)Comment: 20 pages, uuencoded gunzip'ed latex + 3 postscrip figures, to be published in AJ, April, 199

Sensores de fluxo de seiva para avaliação da transpiração direta em vinhedo da campanha gaúcha e sua relação com evapotranspiração de referência.

Esse trabalho teve por objetivo testar medidores de fluxo de seiva para obter uma caracterização direta da transpiração diária das videiras (Td), relacionando-se com valores de Evapotranspiração de Referência (ETo). O experimento foi realizado no ciclo 2013/2014 em vinhedo de Merlotl/S04 conduzido em espaldeira e poda em cordão esporonado da Cooperativa Vinícola Nova Aliança Ltda/Filial 03 localizado no município de Santana do Livramento - RS (latitude 30°53'27" Sul e longitude 55°31'58 Oeste, altitude de 208 metros) observando 4 dias durante o mês de janeiro

Deep Photometry of the Globular Cluster M5: Distance Estimates from White Dwarf and Main Sequence Stars

We present deep VI photometry of stars in the globular cluster M5 (NGC 5904) based on images taken with the Hubble Space Telescope. The resulting color-magnitude diagram reaches below V ~ 27 mag, revealing the upper 2-3 magnitudes of the white dwarf cooling sequence, and main sequence stars eight magnitudes and more below the turn-off. We fit the main sequence to subdwarfs of known parallax to obtain a true distance modulus of (m-M)_0 = 14.45 +/- 0.11 mag. A second distance estimate based on fitting the cluster white dwarf sequence to field white dwarfs with known parallax yielded (m-M)_0 = 14.67 +/- 0.18 mag. We couple our distance estimates with extensive photometry of the cluster's RR Lyrae variables to provide a calibration of the RR Lyrae absolute magnitude yielding M_V(RR) = 0.42 +/- 0.10 mag at [Fe/H] = -1.11 dex. We provide another luminosity calibration in the form of reddening-free Wasenheit functions. Comparison of our calibrations with predictions based on recent models combining stellar evolution and pulsation theories shows encouraging agreement. (Abridged)Comment: AASTeX, 29 pages including 5 figures. Complete photometry data and FITS-format images are available at http://physics.bgsu.edu/~layden/ASTRO/PUBL/published.html . Accepted for publication in the Astrophysical Journal, 2005 October 20. Replaced errant wording in last sentence of paragraph 4 of conclusion

Reservas de amido em sarmentos de videira 'Isabel precoce' submetida a diferentes épocas de poda e duas safras no ciclo.

Na região sul do Brasil, onde o clima é temperado, tradicionalmente colhe-se apenas uma safra/ciclo por ano. Alguns locais, como na Depressão Central do RS estão adotando manejo de dupla poda a fim de obter duas safras e oferecendo uma maior viabilidade financeira para o produtor que além de obter uma segunda safra, poderá ofertar em um período de baixa oferta de uva no mercado, recebendo mais pela produção. O objetivo deste trabalho foi avaliar as reservas de amido em sarmentos que se desenvolveram a partir de distintas datas de poda e em videiras com ou sem a prática de dupla colheita. O vinhedo de Isabel Precoce onde foi realizado o experimento está localizado no município de Eldorado do Sul-RS. A quantificação do amido foi por processo enzimático com posterior leitura em espectrofotômetro. Concluiu-se que a precocidade na poda de inverno auxilia no acúmulo de reservas de amido em sarmentos da videira por aumentar o ciclo vegetativo fotossinteticamente ativo das plantas e a dupla poda/colheita reduz os conteúdos de amido presentes no sarmento, principalmente no segundo período de crescimento, podendo debilitar a planta caso esta prática seja associada a podas tardias e realizada em anos sucessivos

An aqueous one-pot route to gold/quantum rod heterostructured nanoparticles functionalized with DNA

International audienc

DDO Photometry of M71: Carbon and Nitrogen Patterns Among Evolving Giants

We present V, B-V, and DDO C(41-42) and C(42-45) photometry for a sample of 75 red giants down to M_V = +2 in the relatively metal-rich Galactic globular cluster M71. The C(41-42) colors reveal a bimodal distribution of CN band strengths generally anticorrelated with CH band strength as measured by the C(42-45) color. Both DDO colors agree well with those found in 47 Tucanae -- a nearby globular cluster of similar metallicity -- and suggest nearly identical C and N abundance patterns among the giants of both clusters. A comparison with synthetic DDO colors demonstrates that little change in surface C or N abundance is required to match the colors of the M71 giants over the entire luminosity range observed. Apparently like 47 Tuc (a cluster of much greater mass and central concentration), M71 exhibits an abundance pattern which cannot be solely the result of internal mixing.Comment: To appear in the Astronomical Journal, November 2001. 17 Pages, 5 Figure

Prospecção de reguladores de crescimento para o controle de vigor em Cabernet Sauvignon (Vitis vinifera L) na Serra Gaúcha-RS.

O presente trabalho teve por objetivo caracterizar o efeito da época de aplicação de dois inibidores de giberelina, Prohexadiona de Cálcio (Viviful®, V) e Etil-trinexapac (Moddus®, M), sobre o crescimento vegetativo e produtivo da videira. Utilizou-se um vinhedo comercial de Cabernet Sauvignon/Paulsen 1103, conduzido em espaldeira e poda em cordão esporonado