Characterisation of an n-type segmented BEGe detector

A four-fold segmented n-type point-contact "Broad Energy" high-purity germanium detector, SegBEGe, has been characterised at the Max-Planck-Institut f\"ur Physik in Munich. The main characteristics of the detector are described and first measurements concerning the detector properties are presented. The possibility to use mirror pulses to determine source positions is discussed as well as charge losses observed close to the core contact

Sirfídeos (Diptera: Syrphidae) predadores de pulgões (Hemiptera: Aphididae) em Prunus persica nas regiões Nordeste e Sul do Rio Grande do Sul.

Este estudo teve por objetivo realizar um levantamento dos sirfídeos predadores de afídeos em pomares na região Sul e da Serra Gaúcha, no período da safra 2012/2013

Componentes não-integrantes da carcaça de bovinos de três grupos genéticos terminados em confinamento ou pastejo rotacionado com suplementação.

Foram avaliados os componentes não-integrantes da carcaça de bovinos castrados (novilhos) Brahman, Brangus e Hereford terminados em confinamento ou pastejo com suplementação (capim-mombaça). Os animais foram abatidos com espessura de gordura subcutânea superior a 4mm. A dieta do confinamento foi formulada com 60% de volumoso e 40% de concentrado, com 13% PB e 62% NDT. O capim mombaça apresentou 7% de PB e 56%NDT e o suplemento apresentou 24% PB e 76% NDT. O delineamento experimental foi inteiramente casualizado, com arranjo fatorial 3x2 (três grupos genéticos e dois sistemas de terminação) e as médias foram comparadas pelo teste de Tukey ajustado. Foram observadas diferenças significativas para o peso de abate (PA) e peso do corpo vazio (PCV) favorável aos animais mantidos em pastejo com suplementação (444,03 vs 416,50kg para PA e 409,68 vs 375,24kg para PCV), entretanto não houve diferença significativa entre os sistemas de terminação para o rendimento de corpo vazio (RCV). O menor percentual de órgãos vitais foi apresentado pela raça Brahman independente do sistema de terminação utilizado (2,19%). A mesma tendência foi observada para o trato digestivo com um percentual de participação de 3,77% PCV do Brahman vs 4,87% e 4,48% PCV do Hereford e Brangus, respectivamente. Os novilhos Brahman apresentaram menores pesos de coração, pulmão e baço que os Hereford e Brangus. Os animais terminados em pastejo apresentaram maiores pesos de abomaso, pulmão e rins que os terminados em confinamento, 0,47 vs 0,35% PCV; 0,77 vs 0,71% PCV e 0,77 vs 0,71% PCV, respectivamente

The trion: two electrons plus one hole versus one electron plus one exciton

We first show that, for problems dealing with trions, it is totally hopeless to use the standard many-body description in terms of electrons and holes and its associated Feynman diagrams. We then show how, by using the description of a trion as an electron interacting with an exciton, we can obtain the trion absorption through far simpler diagrams, written with electrons and \emph{excitons}. These diagrams are quite novel because, for excitons being not exact bosons, we cannot use standard procedures designed to deal with interacting true fermions or true bosons. A new many-body formalism is necessary to establish the validity of these electron-exciton diagrams and to derive their specific rules. It relies on the ``commutation technique'' we recently developed to treat interacting close-to-bosons. This technique generates a scattering associated to direct Coulomb processes between electrons and excitons and a dimensionless ``scattering'' associated to electron exchange inside the electron-exciton pairs -- this ``scattering'' being the original part of our many-body theory. It turns out that, although exchange is crucial to differentiate singlet from triplet trions, this ``scattering'' enters the absorption explicitly when the photocreated electron and the initial electron have the same spin -- \emph{i}. \emph{e}., when triplet trions are the only ones created -- \emph{but not} when the two spins are different, although triplet trions are also created in this case. The physical reason for this rather surprising result will be given

Carbon footprint in different beef production systems on a southern Brazilian farm: a case study.

The carbon footprint (CF) of beef production is one of the most widely discussed environmental issues within the current agricultural community due to its association with climate change. Because of these relevant and serious concerns, the beef cattle industry is under increasing pressure to reduce production or implement technological changes with significant consequences in terms of beef marketing. The goals of this study were to evaluate the CF per 1 kg of live weight gain (LWG) at the farm gate for different beef production systems in the southern part of Brazil. Aberdeen Angus beef-bred cattle were assigned to one of seven categories: natural grass; improved natural grass; natural grass plus ryegrass; improved natural grass plus sorghum; cultivated ryegrass and sorghum; natural grass supplemented with protein mineralised salt; and natural grass supplemented with protein-energetic mineralised salt. Monte Carlo analysis was employed to analyse the effect of variations of dry matter intake digestibility (DMID), total digestible nutrients (TDN) and crude protein (CP) parameters in methane (CH4) enteric, CH4 manure, nitrous oxide (N2O) manure and N2O N-fertiliser. The method used was a comparative life cycle assessment (LCA) centred on the CF. The CF varied from 18.3 kg CO2 equivalent/kg LWG for the ryegrass and sorghum pasture system to 42.6 kg CO2 equivalent/kg LWG for the natural grass system, including the contributions of cows, calves and steers. Among all grassland-based cattle farms, production systems with DMID from 52 to 59% achieved the lowest CO2 emissions and the highest feed conversion rate, thereby generating lower CH4 and N2O emissions per production system. Because the feed intake and feed conversion rate are one of the most important production parameters in beef cattle production with an obvious risk of data uncertainty, accurate feed data, which include quantity and quality, are important in estimates of CF for LWG. The choice of adequate feeding strategies to mitigate greenhouse gas (GHG) emissions may result in better environmental advantages

Nova planilha de sistematização da produção (Nova PSP): ferramenta de apoio no diagnóstico e intervenção em unidades de produção familiar com atividade leiteira.

Definição do problema; Proposta de um novo instrumento de análise de sistemas de produção com atividade leiteira; Método de construção participativa da planilha; Características e funcionalidades da nova PSPbitstream/item/177970/1/DT-156-impresso.pdf; bitstream/item/223509/1/PSP-Leite-versao-7.2.xls

Competitiveness levels in cattle herd farms.

The aim of this experiment was to identify improvement demands for farms with different levels of competitiveness in the west of Rio Grande do Sul state, Brazil. A total of 63 owners of large farms were interviewed (farms with an area greater than 900ha) by applying a semi-structured questionnaire, guided by four drivers: technology (TEC), management (MAN), market relations (MR) and the institutional environment (IE).It was used the Statistical Analysis System 9.2 software to perform the cluster analysis and identify farmers' characteristics. Three random clusters with different levels of competitiveness were observed: low competitiveness level (LCL), middle competitiveness level (MCL) and high competitiveness level (HCL). The 29 variables (sub factors) were evaluated in the cluster analysis according to level of impact on competitiveness, being classified into variables of high, medium or low impact. Stratification was carried out, ranking demands for improvements from aspects attributed by experts in relation to sub factors. The farmers with low competitiveness level (LTL) had an unfavorable status for MAN, while the farmers belonging to clusters MCL and HCL have, respectively, favorable and neutral status for the same driver. The management characteristics determined the level of competitiveness of the farms surveye

Field dynamics and kink-antikink production in rapidly expanding systems

Field dynamics in a rapidly expanding system is investigated by transforming from space-time to the rapidity - proper-time frame. The proper-time dependence of different contributions to the total energy is established. For systems characterized by a finite momentum cut-off, a freeze-out time can be defined after which the field propagation in rapidity space ends and the system decays into decoupled solitons, antisolitons and local vacuum fluctuations. Numerical simulations of field evolutions on a lattice for the (1+1)-dimensional $\Phi^4$ model illustrate the general results and show that the freeze-out time and average multiplicities of kinks (plus antikinks) produced in this 'phase transition' can be obtained from simple averages over the initial ensemble of field configurations. An extension to explicitly include additional dissipation is discussed. The validity of an adiabatic approximation for the case of an overdamped system is investigated. The (3+1)-dimensional generalization may serve as model for baryon-antibaryon production after heavy-ion collisions.Comment: 18 pages, 7 figures. Two references added. New subsection III.E added. Final version accepted for publication in PR

Previsão de indicadores econômicos individuais na pecuária leiteira.

O presente trabalho objetivou a obtenção de um modelo preditivo e didático capaz de representar a influência dos indicadores de desempenho da produção leiteira nos aspectos econômicos da atividade.SBIAGRO