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Direct neutron capture reactions play an important role in nuclear astrophysics and applied physics. Since for most unstable short-lived nuclei it is not possible to measure the $(n, \gamma)$ cross sections, $(d,p)$ reactions have been used as an alternative indirect tool. We analyze simultaneously $^{48}{\rm Ca}(d,p)^{49}{\rm Ca}$ at deuteron energies $2, 13, 19$ and 56 MeV and the thermal $(n,\gamma)$ reaction at 25 meV. We include results for the ground state and the first excited state of $^{49}$Ca. From the low-energy $(d,p)$ reaction, the neutron asymptotic normalization coefficient (ANC) is determined. Using this ANC, we extract the spectroscopic factor (SF) from the higher energy $(d,p)$ data and the $(n, \gamma)$ data. The SF obtained through the 56 MeV $(d,p)$ data are less accurate but consistent with those from the thermal capture. We show that to have a similar dependence on the single particle parameters as in the $(n, \gamma)$, the (d,p) reaction should be measured at 30 MeV., Comment: 5 pg, 4 figs, Phys. Rev. C (rapid) in press

A methodology for extracting neutron direct capture rates from Coulomb dissociation data is developed and applied to the Coulomb dissociation of 15C on 208Pb at 68 MeV/nucleon. Full Continuum Discretized Coupled Channel calculations are performed and an asymptotic normalization coefficient is determined from a fit to the breakup data. Direct neutron capture calculations using the extracted asymptotic normalization coefficient provide $(n,��)$ cross sections consistent with direct measurements. Our results show that the Coulomb Dissociation data can be reliably used for extracting the cross section for 14C(n,g)15C if the appropriate reaction theory is used. The resulting error bars are of comparable magnitude to those from the direct measurement. This procedure can be used more generally to extract capture cross sections from breakup reactions whenever the desired capture process is fully peripheral., submitted to Phys. Rev. C (R)

Coulomb excitation is a standard method used to extract quadrupole excitation strengths of even-even nuclei. In typical analyses the reaction is assumed to be one-step, Coulomb only, and is treated within a semi-classical model. In this work, fully-quantal coupled-channel calculations are performed for three test cases in order to determine the importance of multi-step effects, nuclear contributions, feeding from other states and corrections to the semi-classical approximation. We study the excitation of 30S, 58Ni and 78Kr on 197Au at ~ 50 AMeV. We find that nuclear effects may contribute more than 10% and that feeding contributions can be larger than 15%. These corrections do not alter significantly the published B(E2) values, however an additional theoretical error of up to 13% should be added to the experimental uncertainty if the semi-classical model is used. This theoretical error is reduced to less than 7% when performing a quantal coupled-channel analysis., Comment: 9 pages, accepted for publication in J. Phys. G: Nucl. Phys

The elastic scattering and breakup of $^{11}$Be from a proton target at intermediate energies is studied. We explore the role of core excitation in the reaction mechanism. Comparison with the data suggests that there is still missing physics in the description., 5 pages, 4 figures, submitted to Phys. Rev. C

Esta pesquisa foi realizada com o objetivo de avaliar o valor nutritivo de silagens de capim-elefante contendo níveis crescentes de subproduto desidratado de maracujá (SDM). Foram testados cinco níveis de adição de SDM (0,0; 3,5; 7,0; 10,5 e 14,0%) na dieta de 20 ovinos machos, não-castrados, segundo delineamento experimental inteiramente casualizado, com cinco tratamentos (níveis de adição) e quatro repetições. Foram estimados os consumos de MS (CMS), PB (CPB), FDN (CFDN) e FDA (CFDA), as digestibilidades aparentes da MS (DAMS), PB (DAPB), FDN (DAFDN), FDA (DAFDA) e hemicelulose (DAHEM), além dos valores de nutrientes digestíveis totais (NDT) e do balanço de nitrogênio (BN). Com a inclusão de SDM na ensilagem do capim-elefante, ocorreram elevações nos CMS e CPB, sem, no entanto, alterar os valores de CFDN e CFDA. As DAMS, DAPB e os valores de NDT e BN elevaram com a adição de SDM, mas as DAFDN, DAFDA e DAHEM não foram alteradas. A adição de SDM na ensilagem de capim-elefante é uma prática recomendável, pois o uso dessas silagens aumentou o consumo e a digestibilidade dos nutrientes e elevou a densidade energética da dieta. Palavras- Made available in DSpace on 2011-04-09T15:19:43Z (GMT). No. of bitstreams: 1 APIValornutritivodesilagensdecapimelefanteenriquecidascomsubproduto.pdf: 204217 bytes, checksum: deec9f539b271b503d4d82c79bc95fc5 (MD5) Previous issue date: 2007-10-24

The $B$(E1;$1/2^+\to1/2^-$) strength for $^{11}$Be has been extracted from intermediate energy Coulomb excitation measurements, over a range of beam energies using a new reaction model, the extended continuum discretized coupled channels (XCDCC) method. In addition, a measurement of the excitation cross section for $^{11}$Be+$^{208}$Pb at 38.6 MeV/nucleon is reported. The $B$(E1) strength of 0.105(12) e$^2$fm$^2$ derived from this measurement is consistent with those made previously at 60 and 64 MeV/nucleon, i n contrast to an anomalously low result obtained at 43 MeV/nucleon. By coupling a multi-configuration description of the projectile structure with realistic reaction theory, the XCDCC model provides for the first time a fully quantum mechanical description of Coulomb excitation. The XCDCC calculations reveal that the excitation process involves significant contributions from nuclear, continuum, and higher-order effects. An analysis of the present and two earlier intermediate energy measurements yields a combined B(E1) strength of 0.105(7) e$^2$fm$^2$. This value is in good agreement with the value deduced independently from the lifetime of the $1/2^-$ state in $^{11}$Be, and has a comparable p recision., Comment: 5 pages, 2 figures, accepted for publication in Phys. Lett. B

The concept of reproductive health implies that individuals and couples have the right to a satisfying safe sexual life. The drug Viagra has the potential to be as liberating to men as the Pill was to women 30 years ago. Viagra distribution offers an excellent opportunity for family planning associations to attract men to their programs and expand education around male sexuality. The availability of Viagra raises complex ethical issues however related to whether a drug that increases sexual enjoyment should be covered by medical insurance. Insurance coverage for people without physical problems who want to use the drug for enhancement of sexual pleasure does not seem justified. Without insurance coverage Viagra will remain a remedy available only to those who can afford its high price.

11Li is studied within a three-body model 9Li+n+n where the core is allowed to be deformed and/or excite. In particular, we include reorientation couplings and couplings between the two bound states of 9Li. Contrary to the other examples studied within this model, we find that core excitation does not affect the structure of 11Li significantly. Reorientation couplings of the deformed 9Li can change the ground state of 11Li from a predominantly two neutron s1/2^2 configuration into a p1/2^2. In addition, we see no evidence for the existence of significant d-wave strength in its ground state, as opposed to the prediction by shell model. A comparison with shell model is presented., 13 pages, 9 figures

The eXtended Continuum Discretized Coupled Channel (XCDCC) method is developed to treat reactions where core degrees of freedom play a role. The projectile is treated as a multi-configuration coupled channels system generated from a valence particle coupled to a deformed core which is allowed to excite. The coupled channels initial state breaks up into a coupled channels continuum which is discretized into bins, similarly to the original CDCC method. Core collective degrees of freedom are also included in the interaction of the core and the target, so that dynamical effects can occur during the reaction. We present results for the breakup of $^{17}$C=$^{16}$C+n and $^{11}$Be=$^{10}$Be+n on $^{9}$Be. Results show that the total cross section increases with core deformation. More importantly, the relative percentage of the various components of the initial state are modified during the reaction process through dynamical effects. This implies that comparing spectroscopic factors from structure calculations with experimental cross sections requires more detailed reaction models that go beyond the single particle model., 14 pages, revtex, submitted to Phys Rev C

Supressão de doenças de plantas por microrganismos endofíticos tem sido demonstrada em diversos patossistemas. Neste trabalho foram selecionados isolados de bactérias endofíticas de folhas e ramos de cafeeiro com potencial para o controle biológico da ferrugem do cafeeiro, pois é conhecido que esses microrganismos podem possuir essa característica. Bactérias endofíticas isoladas previamente de folhas e ramos de Coffea arabica L e Coffea robusta L foram avaliadas quanto ao seu potencial de biocontrole da ferrugem do café causada pelo fungo Hemileia vastatrix Berk. & Br., raça 2. As bactérias foram testadas para a inibição da germinação de urediniosporos do fungo e em bioensaios para o controle do desenvolvimento da ferrugem alaranjada do cafeeiro em discos de folhas, folhas destacadas e mudas da cv. Mundo Novo. Os isolados de bactérias endofíticas testados demonstraram eficácia na inibição da germinação de urediniosporos e/ou no desenvolvimento da ferrugem, com valores acima de 50%, embora os resultados obtidos nos testes de germinação de urediniosporos tenham sido inferiores ao tratamento com propiconazole (testemunha padrão). Nos testes em discos de folhas, folhas destacadas e em plantas de cafeeiro, os isolados endofíticos TG4-Ia, TF2-IIc, TF9-Ia, TG11-IIa e TF7-IIa demonstraram melhor controle da ferrugem do cafeeiro. Os isolados endofíticos TG4-Ia e TF9-Ia foram identificados como Bacillus lentimorbus Dutky e Bacillus cereus Frank. & Frank., respectivamente. De acordo com os resultados verifica-se que alguns isolados foram eficientes em controlar a ferrugem do cafeeiro, embora alguns tenham aumentado a severidade da doença. Apesar do número relativamente baixo de bactérias endofíticas testadas, resultados promissores foram obtidos em relação ao controle biológico da ferrugem, sendo que esses poderão no futuro apresentar uma alternativa aos fungicidas.

Coupled channels calculations are performed for the 12C(d,p)13C and 13C(p,d)12C reactions between 7 and 60 MeV to study the effect of inelastic couplings in transfer reactions. The effect of treating transfer beyond Born approximation is also addressed. The coupling to the 12C 2+ state is found to change the peak cross-section by up to 15 %. Effects beyond Born approximation lead to a significant renormalization of the cross-sections, between 5 and 10 % for deuteron energies above 10 MeV, and larger than 10 % for lower energies. We also performed calculations including the remnant term in the transfer operator, which has a small impact on the 12C(d,p)13C(g.s.) and 13C(p,d)12C(g.s.) reactions. Above 30 MeV deuteron energy, the effect of the remnant term is larger than 10 % for the 12C(d,p)13C(3.09 MeV) reaction and is found to increase with decreasing neutron separation energy for the 3.09 MeV state of 13C. This is of importance for transfer reactions with weakly bound nuclei., 7 pages, 7 figures, submitted to Phys. Rev. C

A deficiência de Fe em plantas de café cultivadas em Latossolos ricos em Fe pode ser causada por condições que afetam o transporte deste nutriente no solo, como teores de P, valores de pH elevados e déficit hídrico no solo. O fluxo difusivo do Fe (FFe) em solos foi avaliado como variável de doses de P e de níveis de acidez e umidade. Para isso, amostras superficiais de dois solos, um Latossolo Vermelho distroférrico típico A moderado textura muito argilosa e um Latossolo Vermelho-Amarelo distroférrico A moderado textura média, receberam 20 mg dm-3 de Fe na forma de FeSO4 e, posteriormente, foram submetidas aos tratamentos: sem ou com calagem (para V = 60 %), sem ou com P (500 mg dm-3, na forma de NH4H2PO4) e três níveis de umidade correspondentes aos potenciais: -0,01, -0,04 e -0,1 MPa, constituindo um fatorial 2 × 2 × 2 × 3, com três repetições distribuídas em blocos inteiramente casualizados. Para a determinação do FFe foram montadas câmaras de difusão que receberam uma lâmina de resina de troca catiônica como dreno de Fe. O Fe total adsorvido às lâminas foi extraído após 10 dias de contato com os solos, estimando-se o FFe. Os resultados mostraram que, em ambos os solos, o FFe mostrou-se altamente dependente da umidade e da acidez do solo (calagem) e que, no Latossolo Vermelho distroférrico, foi muito influenciado pela adição de P. O FFe aumentou com a umidade e com a acidez do solo, mas diminuiu com a adição de P no solo mais argiloso, possivelmente pela formação de compostos Fe-P insolúveis neste solo. Iron deficiency in coffee plants cultivated in ferric Latosols may be induced by conditions that affect the transport of this nutrient in soils, such as P concentration, high pH values and low soil moisture content. The iron diffusive flux (FeF) in soils was evaluated as a function of P rates and levels of acidity and moisture. Surface soil samples of a clayey dystroferric Red Latosol and a loamy-sand dystroferric Yellow Red Latosol were supplied with 20 mg dm-3 Fe as FeSO4, and then submitted to the following treatments: absence and presence of liming (60 % of base saturation), absence and presence of P fertilization (500 mg dm-3 as NH4H2PO4) and three moisture levels, corresponding to water potentials of -0.01, -0.04, and -0.1 MPa. Treatments were arranged in a 2 × 2 × 2 × 3 factorial combination, in a complete randomized block design, with three replications. To determine FeF, diffusion chambers were assembled. Each chamber with treated soil received a strip of cation exchange resin that acts as a Fe sink. After 10 days of soil contact, the total Fe adsorbed by the resin strip was extracted and the FeF estimated. Results showed that the FeF was highly dependent on soil moisture and acidity (liming) in both soils and in the clayey ferric Red Latosol it was also greatly influenced by P addition. The FeF increased with soil moisture and acidity, but decreased with P addition in the clayey soil, possibly due to the formation of insoluble Fe-P compounds in this soil.

In this paper we present all-order quantum mechanical calculations of 7Be breakup on heavy (208Pb) and light (12C) targets. We examine the issues concerning the extraction of the astrophysical S-factor from the breakup data. We discuss the interplay between Coulomb and nuclear breakup, and the importance of higher-order couplings on the cross section. We show that nuclear and Coulomb contributions are not separable using the standard angular selection criterion as nuclear breakup remains large for small scattering angles, even for the heavy target. However, by selecting an upper limit on the relative energy between the final fragments, the contribution from the nuclear breakup can be significantly reduced such that Coulomb breakup is the main reaction mechanism. We show that the extraction of the asymptotic normalization coefficient may require more careful consideration of the nuclear interior than previously used., Comment: 5 pages, 8 figures