Una lettera di esortazione alla "viva fede" in Gesù Cristo nell'Istria di metà Cinquecento

La lettera è oggi conservata nella busta 4, nella quale sono raccolti in modo un po' caotico documenti e fascicoli processuali, che vanno dal gennaio del 1545 al 1568, collegati in certo modo alle vicende di Pier Paolo Vergerio, vescovo di Capodistria, processato dal nunzio apostolico Giovanni Della Casa per eresia dal 2 gennaio 1545 all'agosto del 1547, condannato definitivamente dal papa come eretico formale alla privazione del vescovato nel giugno del 1549, e a quelle di molti istriani che furono processati contemporaneamente e dopo di lui. L'ordinamento del fondo Inquisizione li considerò un blocco unico riguardante il Vergerio, ma in realtà si tratta di cause giuridicamente distinte e cronologicamente distanti. La lettera indirizzata da Ioseph da Faenza "Al pr.te (?) ser Zuane de Bertuci de ser Nicolò, suo in Christo fratello", a Pirano, si trova nel fascicolo archivistico "Pier Paolo Vergerio. Taidino Giovanni prete, Zanoni Giorgio, Greco Giorgio, Mercanzutti Giorgio, Tessaro Biagio, Castagna Marco, De Vittori Bono, Da Paderno Giuseppe, De Zanotti Giovanni, Valtollina Veronesa, Da Lesina Giovanni", secondo quanto sta scritto sulla camicia

Flow boiling heat transfer of a non-azeotropic mixture inside a single microchannel

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.This study moves from the need to study flow boiling of zeotropic mixture in microchannels. In the recent years much attention has been paid to the possible use of fluorinated propene isomers for the substitution of high-GWP refrigerants. The available HFOs (hydrofluoroolefins) cannot cover all the air-conditioning, heat pump, and refrigeration systems when used as pure fluids because their thermodynamic properties are not suitable for all operating conditions and therefore some solutions may be found using blends of refrigerants, to satisfy the demand for a wide range of working conditions. In the present paper a mixture of R1234ze(E) and R32 (0.5/0.5 by mass) has been studied. The local heat transfer coefficient during flow boiling of this mixture in a single microchannel with 0.96 mm diameter is measured at a pressure of 14 bar, which corresponds to a bubble temperature of 26.3°C. The flow boiling data taken in the present test section are discussed, with particular regard to the effect of heat flux, mass velocity and vapor quality. The heat transfer coefficients are compared against some predicting models available in the literature. Furthermore, the new experimental data are compared to flow boiling data of pure R1234ze(E) and pure R32 to analyze the heat transfer penalization due to the mass transfer resistance of this zeotropic mixture

Condensation in a square minichannel: application of the VOF method

This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute.A number of steady-state simulations of condensation of R134a at mass fluxes G=100 kg m-2s-1 and G=800 kg m-2s-1 inside a square cross section minichannel (Dh=1mm) are here proposed and compared against similar simulations in a circular cross section channel with same diameter. The VOF (Volume Of Fluid) method is used to track the vapour-liquid interface and the effects of interfacial shear stress and surface tension are both taken into account. A uniform wall temperature is fixed as boundary condition. At G=100 kg m-2s-1 the liquid film is assumed laminar and the vapour flow is turbulent; turbulence is handled by a low-Reynolds number form of the standard k-w model (Wilcox, 1998), which was modified in order to suppress the turbulent viscosity inside the liquid phase. At G=800 kg m-2s-1 a low Re form of the SST k-w model (Menter, 1994) has been used for turbulence modeling through both the liquid and vapour phases. Numerical simulations are validated against experimental data. The present paper looks at the effect of surface tension. Its influence on the shape of the vapour-liquid interface provides some heat transfer enhancement in non-circular minichannels. In circular minichannels, the overall effect of surface tension is shown to be not significant. On the contrary, the effect of surface tension in square channels provides a large enhancement at low mass flux

Two-Phase Flow and Heat Transfer of a Non-Azeotropic Mixture inside a Single Microchannel

In the recent years much attention has been paid to the use of fluorinated propene isomers for the substitution of high-GWP refrigerants. However, the HFOs (hydrofluoroolefins) cannot cover all the air-conditioning, heat pump, and refrigeration applications. In a recent study, it was found that the coefficient of performance (COP) and the capacity of heat pump cycles using HFO-1234ze(E) are significantly lower than those of R410A (Koyama et al., 2010). The main causes are the small latent heat and vapor density of R1234ze(E). To improve the COP and capacity, in the latest literature it was attempted to blend R1234ze(E) into another refrigerant, R32 Although R32 is one of the HFCs, it has relatively low GWP and excellent thermodynamic characteristics. Therefore, a zeotropic mixture of R1234ze(E) and R32 can be used in the field of air-conditioning due to its mild impact on environment. In this paper, a mixture of R1234ze(E) and R32 (0.5/0.5 by mass) is under study. In particular the frictional pressure gradient and the local heat transfer coefficients during flow boiling and condensation of this mixture in a single minichannel with 0.96 mm diameter are measured. Tests are carried out in the experimental apparatus available at the Two Phase Heat Transfer Lab of the University of Padova. As a peculiar characteristic of the present technique, the flow boiling heat transfer coefficient is not measured by imposing the heat flux; instead, the boiling process is governed by controlling the inlet temperature of the heating secondary fluid. For the determination of the local heat transfer coefficient, three parameters are measured: the local heat flux, the saturation temperature and the wall temperature. The heat flux is determined from the temperature profile of the secondary fluid in the test section. The wall temperature is directly measured along the test section and the saturation temperature is obtained from the pressure measurements at the inlet and outlet of the test tube. During condensation tests, the heat is subtracted from the fluid by using cold water. As in flow boiling, the heat transfer coefficient is obtained through the measurement of the local heat flux and the saturation-to-wall temperature difference. The heat transfer coefficients are compared against predicting models available in the literature. The new experimental data are also compared to heat transfer data of pure R1234ze(E) and R32. This allows to analyze the heat transfer penalization due to the mass transfer resistance of this zeotropic mixture and to assess available predicting models for condensation and evaporation of zeotropic mixtures in minichannels. Pressure drop data are also used to assess predicting pressure gradient correlations

Balanço social : estudo em uma indústria de rolamentos automotivos francesa

Orientador : Romualdo Douglas Colauto.Monografia (especialização) - Universidade Federal do Paraná, Setor de Ciências Sociais Aplicadas. Curso de Especialização em Controladoria.Inclui referênciasResumo : Este estudo de caso tem por objetivo mapear os indicadores sociais internos, externos, ambientais e funcionais de uma indústria francesa de rolamentos automotivos. Foram analisados os balanços e informações pertinentes para a aplicação do estudo nos anos de 2013 e 2014 utilizando o modelo IBASE de contabilidade social para buscar resultados que expressem o nível de comprometimento com a responsabilidade social e se existe impactos internos que refletem nos resultados. Os resultados mostram aumento do faturamento principalmente devido à conquista de novos projetos não alavancou o resultado operacional como o comitê executivo esperava, principalmente devido aos fatores externos (aumento do custo devido o aumento do câmbio), quando comparado ao ano de 2013 apresentou um crescimento significativo de 11,9%, mas se comparado ao ano de 2012 a perda de resultado operacional fica próxima dos 70%

Investigation of Evaporator Performance with and without Liquid Overfeeding

In the present work, the performance of a segmentally baffled shell-and-tube evaporator working with liquid overfeeding is investigated. The refrigerant is R134a that flows inside the tubes, while water flows on the shell side. A single shell pass has been adopted for the water with one tube pass for the evaporating fluid. The test rig used for the experimental measurements consists of a primary refrigerant loop plus the condenser and the evaporator water auxiliary loops. The evaporator can be fed with two-phase mixture from the expansion valve or with saturated liquid coming from the liquid-vapor separator (in this case a variable speed recirculation pump is used). Inlet and outlet temperatures have been measured for both fluids together with the flow rate allowing the determination of the overall heat transfer coefficient. In addition, pressure drop have been measured on the refrigerant side. Tests have been performed both without overfeeding and with overfeeding at different values of recirculation ratio. The recirculation ratio is defined as the ratio between refrigerant flow rate at the evaporator and the vaporized refrigerant flow rate. Furthermore, measurements have been taken at fixed water outlet temperature and varying the heat duty. In order to study the evaporator behavior, a computational procedure has been developed. Finally, the numerical model of the heat exchanger has been validated against experimental data

experimental and numerical study of a parabolic trough linear cpvt system

Abstract The electric and thermal performance of a parabolic trough linear concentrating photovoltaic-thermal (CPVT) system operating in Padova (northern Italy) is experimentally investigated. The system moves about two axes and exhibits a geometrical concentration ratio around 130. The receiving module placed on the focus line displays a secondary optics made of two flat mirrors to gather some reflected radiation and to contribute to the concentrated flux on two lines of triple junction photovoltaic cells soldered on a ceramic substrate. The substrate is in thermal contact with a aluminium heat exchanger with water flow channels to cool the PV cells. During the test runs, the inlet water temperature ranges from 20 °C to 80 °C and the heat yield is obtained from mass flow rate and temperature measurements while a rheostat and a power analyzer are connected to the electric terminals of the module to assess the electrical production. The direct normal irradiation (DNI) is measured by a pyrherliometer mounted on a solar tracker. Experimental results are used to assess a numerical model of the solar receiver and the whole concentrator

Effect Of The Refrigerant Charge On The System Performance And Mass Distribution In Air-To-Water Heat Pumps

Recent regulations in the matter of climate change and environmental protection are pushing to reduce the release of greenhouse gases into the atmosphere. The overall environmental impact of a refrigeration system can be reduced by optimizing and possibly minimizing the amount of refrigerant charge in the system. Even in the case of natural and low-GWP synthetic refrigerants, due to the well-known problems with toxicity and flammability, it is required to minimize the amount of refrigerant charged into the system to reduce the associated risks. The charge minimization process requires to know the refrigerant distribution to identify and redesign the critical components in terms of charge retention. This paper analyses numerically the influence of the refrigerant charge on the system performance and on the mass distribution in an air-to-water reversible heat pump working with R32. A mathematical model has been developed to simulate the unit during the cooling mode operation. The model uses the finite volume method to predict the refrigerant charge within the heat exchangers; the amount of refrigerant dissolved in the compressor oil is also accounted for. The results show that most of the charge is stored into the condenser and highlight the existence of an optimum charge that maximizes the system COP. The same model allows to compare various refrigerants in terms of direct and indirect impact on the greenhouse effect

DNI Estimation Procedures for the Assessment of Solar Radiation Availability in Concentrating Systems

Abstract DNI (Direct Normal Irradiance) is the resource utilized by solar concentrators. Besides, the determination of DNI is needed in the models for the estimation of global irradiance on tilted planes, which is the input to flat-plate systems. This paper describes a study of different estimation procedures for the assessment of the DNI , using experimental data with a time scale of 1 min, taken at two different latitudes. The analyzed approaches include measuring techniques and models. The results show that the different estimation methods can lead to quite different conclusions when comparing the solar radiation availability in concentrating and flat-plate systems and this can affect the energy and economic evaluations. Based on the experimental analysis, indications for reducing the uncertainty in the estimation of DNI are discussed