1,043 research outputs found
Energy and technological refurbishment of the School of Architecture Valle Giulia, Rome
Modern architecture built in historical urban contexts represents a demanding issue when its energy efficiency should be improved. Indeed, the strongest efforts have to be made to maintain the architectural identity and its harmony with the surrounding cultural heritage. This study deals with the main building of the School of Architecture Valle Giulia in Rome, designed by Enrico Del Debbio in the 30’s. Further constraints are related to several interventions of airspace expansion starting from 1958 which involved the building starting from 1958. So, preservation would mean highlighting its historic change but, adapting the built environment to the contemporary users’ needs. As above-mentioned, the building belongs to the Valle delle Accademie, within the historic park of Villa Borghese, so that to acquire landscaping values. Those latter ones call for ulterior requirements when any new design process is conceived. The study provides a global renewal of the building accounting for the current low Indoor Environmental Quality in both summer and winter seasons and the lack of suitability to the contemporary University student’s needs. The interaction between building performance and HVAC systems was studied by collecting data and architectural surveys conducted by all the architects who modified the building. This procedure was chosen since thermo-physical investigations are considered destructive due to required perforations to identify the actual wall layers. Moreover, thermographic surveys were carried out to validate the modelled building response. The result of the study is the identification of viable interventions to improve the accessibility and fruition of the building as well as its energy performance. A specific cost-benefit analysis was done to prioritize the design options along with considering the measures needed to preserve all the architectural features and values
Hydrogen turbine power conversion system assessment
A three part technical study was conducted whereby parametric technical and economic feasibility data were developed on several power conversion systems suitable for the generation of central station electric power through the combustion of hydrogen and the use of the resulting heat energy in turbogenerator equipment. The study assessed potential applications of hydrogen-fueled power conversion systems and identified the three most promising candidates: (1) Ericsson Cycle, (2) gas turbine, and (3) direct steam injection system for fossil fuel as well as nuclear powerplants. A technical and economic evaluation was performed on the three systems from which the direct injection system (fossil fuel only) was selected for a preliminary conceptual design of an integrated hydrogen-fired power conversion system
Cryopreservation of swine ovarian tissue : effect of different cryoprotectants on the structural preservation of preantral follicle oocytes
The present study aimed to test different cryoprotectants on cryopreservation of pig ovarian tissue. Pig ovaries (n = 3) were collected at a local slaughterhouse. From each ovary, ten cortex samples were taken. One was immediately fixed (control) and another placed in short-term tissue incubation (STTI control). The other 8 samples were cryopreserved, in pairs, using 4 different cryoprotectants: dimethyl sulphoxide (Me2SO – 1.5 M), ethylene glycol (EG – 1.5 M), propanediol (PROH – 1.5 M) and glycerol (GLY – 10%), all with 0.4% sucrose. Samples were slow cooled and stored in liquid nitrogen for 7 days. After thawing and cryoprotectant removal, one sample from each treatment was immediately fixed and the other was placed in short-term tissue incubation (STTI) for 2 h and then fixed. Samples were processed for histology and transmission electron microscopy. The percentages of morphologically normal follicles (MNF) in cryopreserved tissue using Me2SO (67.0 ± 4.9), EG (81.8 ± 1.4) and PROH (55.9 ± 9.9) were significantly lower (P < 0.05) than observed in fresh control tissue (97.7 ± 1.2). When ovarian tissue was cryopreserved with GLY, no morphologically normal follicles could be found (0%). After STTI, PROH showed a significantly lower percentage of MNF when compared with all other treatments and the control. After ultrastructural analysis, follicles cryopreserved with Me2SO and EG showed some small alterations, but no signs of advanced degeneration. Overall, these were similar to follicles from the control group. In conclusion, it is possible to cryopreserve preantral follicles from pig ovarian tissue using Me2SO or EG
Code for Multiblock CFD and Heat-Transfer Computations
The NASA Glenn Research Center General Multi-Block Navier-Stokes Convective Heat Transfer Code, Glenn-HT, has been used extensively to predict heat transfer and fluid flow for a variety of steady gas turbine engine problems. Recently, the Glenn-HT code has been completely rewritten in Fortran 90/95, a more object-oriented language that allows programmers to create code that is more modular and makes more efficient use of data structures. The new implementation takes full advantage of the capabilities of the Fortran 90/95 programming language. As a result, the Glenn-HT code now provides dynamic memory allocation, modular design, and unsteady flow capability. This allows for the heat-transfer analysis of a full turbine stage. The code has been demonstrated for an unsteady inflow condition, and gridding efforts have been initiated for a full turbine stage unsteady calculation. This analysis will be the first to simultaneously include the effects of rotation, blade interaction, film cooling, and tip clearance with recessed tip on turbine heat transfer and cooling performance. Future plans call for the application of the new Glenn-HT code to a range of gas turbine engine problems of current interest to the heat-transfer community. The new unsteady flow capability will allow researchers to predict the effect of unsteady flow phenomena upon the convective heat transfer of turbine blades and vanes. Work will also continue on the development of conjugate heat-transfer capability in the code, where simultaneous solution of convective and conductive heat-transfer domains is accomplished. Finally, advanced turbulence and fluid flow models and automatic gridding techniques are being developed that will be applied to the Glenn-HT code and solution process
Efeito da somatotropina bovina recombinante (RBST) no desempenho reprodutivo de vacas holandesas em lactação.
Índice de Confiança do Empresário de Pequenos e Médios Negócios no Brasil (IC-PMN): Metodologia e Resultados Preliminares
Efeito da somatotropina bovina recombinante (RBST) sobre a produção de leite e gordura em vacas da raça Holandesas.
Este estudo foi conduzido com o objetivo de avaliar os efeitos da aplicação de somatotropina bovina recombinante (rBST) sobre a produção de leite e gordura de vacas da raça Holandesa, durante os 60 aos 150 dias de lactação. O experimento foi desenvolvido no sistema de produção de leite do Centro de Pesquisa de Pecuária do Sudeste (Embrapa Pecuária Sudeste), em São Carlos, durante o período de abril a dezembro de 1999. Foram utilizadas 41 vacas distribuídas em um delineamento inteiramente casualizado, em três tratamentos: sem aplicação de rBST (controle) ? 15 vacas; aplicação de rBST 60 dias após o parto (rBST-60) ? 15 vacas; e aplicação de rBST 100 dias após o parto (rBST-100) ? 11 vacas. Foram realizadas análises de variância para as variáveis produção de leite; produção de leite corrigida a 4% de gordura e produção de gordura, tanto em porcentagem como em kg/dia. A suplementação com rBST aos 60 dias apresentou significativo aumento na produção de leite e na produção de leite corrigida em relação ao tratamento controle, entretanto esse fato não foi verificado para o tratamento com rBST aos 100 dias. Não ocorreram efeitos significativos da aplicação de rBST sobre a produção de gordura no leite, em % e em kg/dia. A suplementação com rBST aumentou a produção de leite e a produção de leite corrigida a 4% de gordura quando administrada aos 60 dias pós -parto. Não foram observados efeitos da suplementação de rBST sobre a porcentagem e produção de gordura do leite
Transport mechanism in granular Ni deposited on carbon nanotubes fibers
We investigate the transport properties of granular nickel electrodeposited on carbon nanotube fibers by
measuring the electrical resistance and the current voltage characteristics as a function of the temperature.
The bare fiber is governed by a three-dimensional variable range hopping transport mechanism, however, a
semiconducting to metallic transition is observed after the Ni deposition as a consequence of the evolution from
weak to strong coupling between the deposited nickel grains. The experimental results indicate that the charge
transport in the Ni-coated fiber develops from hopping governed by the Coulomb blockade in the case of small
grains dimensions to a metallic electron phonon interaction mechanism for large grains dimensions. Tunneling
enhanced by thermal fluctuation is responsible for the transport in the intermediate conductivity range. The role
of the fiber and the effects due to the magnetic nature of the nickel grains are also discussed
Efeito da somatotropina bovina recombinante (RBST) sobre a curva de lactação de vacas da raça holandesas.
Foi conduzido um estudo com o objetivo de avaliar os efeitos da aplicaç ão de rBST sobre a curva de lactação de vacas da raça Holandesa. O experimento foi desenvolvido no sistema de produção de leite do Centro de Pesquisa de Pecuária do Sudeste (Embrapa Pecuária Sudeste), em São Carlos, durante o período de abril a dezembro de 1999. Foram avaliadas 41 vacas, dos 60 aos 150 dias de lactação, distribuídas em um delineamento inteiramente casualizado, em três tratamentos: sem aplicação de rBST (controle) ? 15 vacas; aplicação de rBST 60 dias após o parto (rBST-60) ? 15 vacas; e aplicação de rBST 100 dias após o parto (rBST- 100) ? 11 vacas. Foram realizadas análises de regressão da produção de leite em função dos dias de lactação. A aplicação de rBST aos 60 dias de lactação apresentou maior resposta no aumento da produção de leite e menor queda na produção. Com relação ao tratamento rBST-100, foi verificada uma estabilização seguida da diminuição menos acentuada na curva de lactação quando comparado com o tratamento controle. Todos os tratamentos apresentaram diminuição na produção de leite em função dos dias de lactação. No tratamento com rBST-60 durante o período de 75 a 120 dias de lactação, a cada dia da lactação, a produção de leite diminuiu 25,7 g, enquanto que para o mesmo período no tratamento controle, a produção decresceu 80,9 g/dia. A suplementação com rBST aumentou a persistência de lactação e a produção de leite quando administrada aos 60 dias pós -parto
Migration of polypropylene oligomers into ready-to-eat vegetable soups
Polyolefin oligomeric hydrocarbons (POH) are non-intentionally added substances (NIAS) which mainly reside in the polymer (PE, PP) as a consequence of the polymerization process, and that under favorable conditions (high fat content, high temperature, and long contact time) may migrate at high amount from the packaging into the food. The food industry offers a wide range of ready-to-eat products, among these, vegetable soups designed to be stored at refrigeration temperature (for times around 6 weeks), and in most cases to be heated for a few minutes in a microwave oven (into the original container, mostly of PP) before consumption. The present work aimed to study for the first-time migration of POH during the shelf life of these products, including storage at refrigeration temperature and after microwave heating. On-line high-performance liquid chromatography (HPLC)-gas chromatography (GC), followed by flame ionization detection (FID), was applied for POH analysis in a number of ready-to-eat products purchased from the Italian market. Microwave heating determined a variable POH increase ranging from 0.1 to 6.2 mg/kg. Parameters possibly affecting migration such as fat content and heating time were also studied
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