Determination of the Rb ng-series quantum defect by electric-field-induced resonant energy transfer between cold Rydberg atoms

Resonant energy transfer between cold Rydberg atoms was used to determine Rydberg atom energy levels, at precisions approaching those obtainable in microwave spectroscopy. Laser cooled Rb atoms from a magneto-optical trap were optically excited to 32d Rydberg states. The two-atom process 32d(j=5/2) + 32d(j=5/2) -> 34p(j=3/2) + 30g is resonant at an electric field of approximately 0.3 V/cm. This process is driven by the electric dipole-dipole interaction, which is allowed due to the partial f character that the g state acquires in an electric field. The experimentally observed resonant field, together with the Stark map calculation is used to make a determination of the Rb ng-series quantum defect: delta_g (n=30) = 0.00405(6)

Nutritional Support for Small Ruminant Development Based on Oil Palm By-products

Biomass by-products or plant residues from the plantation system would play a crucial role in animal production since the utilization of forages from the underneath tree crops would be less or minimal when the palm oil crop mature. By-products generated from the palm oil system vary, but in relation to the animal production they could be generally categorized into the fibrous by-products and the non-fibrous (concentrate) by-products. Palm oil mill effluent (POME) and palm kernel cake (PKC) are concentrate by-products produced during the processing of palm oil extraction which have great potency to support sheep and goat production, although limiting factors such as contamination of shell and high copper level in PKC need to be considered in their utilization as feed. The fibrous palm oil by-products include oil palm fronds (OPF) and oil palm trunk (OPT) generated from the palm crop trees and oil palm empty fruit bunch (OPEFB) and palm pressed fiber (PPF) generated from processing of fresh fruits to yield crude oil. These fibrous by-products cannot meet the metabolisable energy required for high growth rate and for lactation of sheep and goats due to low DM digestibility, low crude protein content, low fermentable carbohydrate and low level of intake. Limited inclusion level in ration should be applied for those by-products to yield an acceptable production level of sheep and goats. Pretreatments (physical, chemical, and biological) gave some improvement in their nutritional qualities, however additional cost of pretreatments need to be considered. In the future, there would be a great challenge for the utilization of those fibrous by-products as animal feed since bioconversion of lignocellulosic materials to products such as chemicals (bioethanol, sugar, and bioplastic), fuels, and organic fertilizers are receiving greater interest. Some comparative advantages of these natural wastes are their relatively low cost, renewable and widespread in nature for used in an industrial operation

Evidence of kaon nuclear and Coulomb potential effects on soft K+ production from nuclei

The ratio of forward K+ production on copper, silver and gold targets to that on carbon has been measured at proton beam energies between 1.5 and 2.3 GeV as a function of the kaon momentum p_K using the ANKE spectrometer at COSY-Juelich. The strong suppression in the ratios observed for p_K<200-250 MeV/c can be ascribed to a combination of Coulomb and nuclear repulsion in the K+A system. This opens a new way to investigate the interaction of K+-mesons in the nuclear medium. Our data are consistent with a K+A nuclear potential of V_K~20 MeV at low kaon momenta and normal nuclear density. Given the sensitivity of the data to the kaon potential, the current experimental precision might allow one to determine V_K to better than 3 MeV.Comment: 9 pages, 3 figures; changed conten

a0+(980)-resonance production in pp->dK+Kbar0 reactions close to threshold

The reaction pp->d K+ Kbar0 has been investigated at an excess energy of Q=46 MeV above the (K+ Kbar0) threshold with ANKE at COSY-Juelich. From the detected coincident dK+ pairs about 1000 events with a missing Kbar0 were identified, corresponding to a total cross section of sigma(pp->d K+ Kbar0)=(38 +/- 2(stat) +/- 14(syst)) nb. Invariant-mass and angular distributions have been jointly analyzed and reveal s-wave dominance between the two kaons, accompanied by a p-wave between the deuteron and the kaon system. This is interpreted in terms of a0+(980)-resonance production.Comment: 4 pages, 4 figures; accepted by Phys. Rev. Let

Utilização do processo de nanofiltração para concentração de compostos de soja.

A utilização da soja para a produção de alimentos aumentou nas últimas décadas devido ao forte apelo das pesquisas na área da saúde, destacando seus efeitos benéficos, quando consumidos regularmente. Com isso, os derivados da soja passaram a ganhar um destaque comercial, principalmente devido às suas características funcionais, contribuindo para a geração de novos produtos com essas mesmas propriedades. Dessa forma, esse trabalho teve como objetivo utilizar o processo de nanofiltração (NF) até o Fator de Redução Volumétrico (FRV) igual a 3, para concentrar os compostos funcionais de um extrato etanólico de soja (10% etanol) e verificar a eficiência do processo por meio da quantificação de isoflavonas presentes nos concentrados. Os resultados obtidos mostraram que o fluxo permeado médio obtido na nanofiltração foi de 9,2 L.m-2.h-1. Com relação ao processo de concentração, observou-se um fator de concentração de 3 vezes para os conjugados glicosil, de 2,4 vezes para os conjugados malonil e 1,3 vezes para as agliconas, significando que parte desses últimos compostos permeiam a membrana. Com relação às isoflavonas totais verificou-se um aumento de 60% no concentrado obtido a partir da nanofiltração. Conclui-se que a nanofiltração pode ser utilizada para a concentração de compostos bioativos presentes na soja com possibilidades utilizá-los nas indústrias alimentícia e farmacêutica

Proton--induced deuteron breakup at GeV energies with forward emission of a fast proton pair

A study of the deuteron breakup reaction $pd \to (pp)n$ with forward emission of a fast proton pair with small excitation energy $E_{pp}<$ 3 MeV has been performed at the ANKE spectrometer at COSY--J\"ulich. An exclusive measurement was carried out at six proton--beam energies $T_p=$~0.6,~0.7,~0.8,~0.95,~1.35, and 1.9 GeV by reconstructing the momenta of the two protons. The differential cross section of the breakup reaction, averaged up to $8^{\circ}$ over the cm polar angle of the total momentum of the $pp$ pairs, has been obtained. Since the kinematics of this process is quite similar to that of backward elastic $pd \to dp$ scattering, the results are compared to calculations based on a theoretical model previously applied to the $pd \to dp$ process.Comment: 17 pages including 6 figures and 1 table v2: minor changes; v3: minor change of author list; v4: changes in accordance with referee remark

Forward K+ production in subthreshold pA collisions at 1.0 GeV

K+ meson production in pA (A = C, Cu, Au) collisions has been studied using the ANKE spectrometer at an internal target position of the COSY-Juelich accelerator. The complete momentum spectrum of kaons emitted at forward angles, theta < 12 degrees, has been measured for a beam energy of T(p)=1.0 GeV, far below the free NN threshold of 1.58 GeV. The spectrum does not follow a thermal distribution at low kaon momenta and the larger momenta reflect a high degree of collectivity in the target nucleus.Comment: 4 pages, 3 figure

Biosafety standards for working with Crimean-Congo haemorrhagic fever virus

In countries from which Crimean-Congo haemorrhagic fever (CCHF) is absent, the causative virus CCHF virus (CCHFV) is classified as a hazard group 4 agent and handled in containment level 4. In contrast, most endemic countries out of necessity have had to perform diagnostic tests under biosafety level (BSL) -2 or -3 conditions. In particular, Turkey and several of the Balkan countries have safely processed more than 100000 samples over many years in BSL-2 laboratories. It is therefore advocated that biosafety requirements for CCHF diagnostic procedures should be revised, to allow the required tests to be performed under enhanced BSL-2 conditions with appropriate biosafety laboratory equipment and personal protective equipment used according to standardized protocols in the affected countries. Downgrading of CCHFV research work from Cl-4, BSL-4 to Cl-3, BSL-3 should also be considered.Additional co-authors: Gülay Korukluoglu, Pieter Lyssen, Ali Mirazimi, Johan Neyts, Matthias Niedrig, Aykut Ozkul, Anna Papa, Janusz Paweska, Amadou A Sall, Connie S Schmaljohn, Robert Swanepoel, Yavuz Uyar, Friedemann Weber, Herve Zelle