1,546 research outputs found
THERMODYNAMIC AND ECONOMIC ANALYSIS OF A BIOGAS -FUELED MICRO GAS TURBINE WITH COMPRESSOR PHOTOVOLTAIC DRIVE
The increase in global and Brazilian energy demand plus environmental concern due to pollutant emissions are motivating investigation and development of sustainable energy sources and the interaction between them. In this context, electricity generation through solar and solid urban waste energy harnessing has become an effective option for Brazilian energy matrix diversification. Therefore, in order to ratify this trend, a thermodynamic analysis of a 200 kWe micro gas turbine using biogas as fuel and photovoltaic panels to drive compressor shaft is presented in this paper. In terms of methodology, Engineering Equation Solver (EES) Demo was used to run a classic steady state thermodynamic model and a parametric analysis to evaluate MGT performance with a PV system integrated in order to assess specific fuel consumption reduction (SFC) at Belo Horizonte, Minas Gerais, Brazil, operation. Radiasol 2 was the software used to acquire solar insolation data over the year. The fuel economy occurs since power produced in turbine does not need to be discounted to drive compressor shaft during periods when solar insolation is present or when energy generation during the day is sufficient to be credited as Brazilian legislation allows grid integrated systems. In cases that solar energy is not enough or absent, a transmission mechanism similar to a clutch should be considered as well as proposed in other studies to guarantee uninterrupted system operation. Futhermore, an economic analysis was performed to evaluate kWh cost for conventional and hybrid systems. Interest rate, inflation, construction period and amortization period are important parameters taken into account to calculated annuity factor that must be evaluated to predict energy cost. The thermodynamic results showed that SFC=0,718 kg/kWh for conventional operation and SFC=0,266 kg/kWh for hybrid operation for the best operating compressor pressures ratio. The economic results showed that payback time for MGT and MGT with compressor photovoltaic drive are lower than lifetime systems, and hybrid MGT electricity cost is lower when compared to paid ones nowadays
Predictive models for managing financial incentives oriented to companies: Application to Portugal 2020
Since Portugal joined the European Union (EU) that it has been receiving incentives/funds to reduce disparities with other EU countries. Despite this goal, disparities between European regions still exist and the impact of such funds is questionable. What if it is possible to predict the success of such incentives when the funds are awarded to the beneficiaries? Using data from the database of The Agency for Competitiveness and Innovation (IAPMEI), for the programs National Strategic Reference Framework (QREN), and Portugal 2020, two predictive models are developed to estimate the number of applications to be received and the schedule of expected payments to beneficiaries for a four-month period. The results allow for a better prediction, on one hand, of the resources to be allocated to the evaluation process of the applications, and on the other hand, of the financial execution plan for the upcoming period, in order to prepare the financial execution.info:eu-repo/semantics/acceptedVersio
Protocolo de amostragem para determinação de atributos de raízes de plantas de campo nativo.
bitstream/item/58209/1/CO82.pd
EUS assessment for intermediate risk of choledocholithiasis after a negative magnetic resonance cholangiopancreatography
© 2020 SPRING MEDIA PUBLISHING CO. LTD | PUBLISHED BY WOLTERS KLUWER - MEDKNOW 291. Background and Aims: Guidelines recommend either EUS or magnetic resonance cholangiopancreatography (MRCP) for intermediate risk of choledocholithiasis. There is a lack of evidence that supports proceeding with EUS if the MRCP is negative and if clinical suspicion still exists. Methods: This is a retrospective study of all patients who underwent EUS to assess for choledocholithiasis at a tertiary care referral center from July 2013 to October 2019. Results: A total of 593 patients underwent EUS for evaluation for choledocholithiasis. Of the 593 patients, 35.2% (209/593) had an MRCP. 73.2% (153/209) had a negative MRCP while 26.8% (56/209) had a positive MRCP. Of the group of patients who underwent EUS with a negative MRCP, 15% (23/153) were positive for choledocholithiasis on EUS. Of these, 91% (21/23) were also positive for sludge or stones on endoscopic retrograde cholangiopancreatography and thus 14% (21/153) of the EUS were \u27true positives.\u27 There were no clinical or laboratory factors predictive of choledocholithiasis on univariate analysis in the EUS plus negative MRCP group. When further analyzing the MRCP negative group into MRCP-/EUS+ and MRCP-/EUS-subgroups, a total bilirubin \u3e3 mg/dL predicted a bile duct stone (55% vs. 32%, P = 0.05). Conclusion: The diagnostic yield of EUS for suspected choledocholithiasis in the setting of a negative MRCP is 14% in our cohort. EUS should be considered in patients with intermediate risk of choledocholithiasis with a negative MRCP if the clinical suspicion is still present, and especially if the total bilirubin is above 3 mg/dL
Umidade do solo estimada por TDR em vertissolo e luvissolo na região da Campanha do RS.
CONGREGA URCAMP 2012
Piezoresistive silicon thin film sensor array for biomedical applications
N-type hydrogenated nanocrystalline silicon thin film piezoresistors, with gauge factor −28, were deposited
on rugged and flexible polyimide foils by Hot-wire chemical vapor deposition using a tantalum filament
heated to 1750 °C. The piezoresistive response under cyclic quasi-static and dynamical (up to 100 Hz) load
conditions is reported. Test structures, consisting of microresistors having lateral dimensions in the range
from 50 to 100 μm and thickness of 120 nm were defined in an array by reactive ion etching. Metallic pads,
forming ohmic contacts to the sensing elements, were defined by a lift-off process. A readout circuit for the
array consisting in a mutiplexer on each row and column of the matrix is proposed. The digital data will be
processed, interpreted and stored internally by an ultra low-power micro controller, also responsible for the
communication of two-way wireless data, e.g. from inside to outside the human body.© 2011 Elsevier B.V. All rights reservedFundação para a Ciência e a Tecnologia (FCT
Qualidade e compostos bioativos na uva Syrah influenciados pelas práticas culturais de desfolha e desponte: avaliação preliminar.
Em parreiral irrigado da cultivar Syrah, enxertada sobre IAC 766, avaliou-se a qualidade e o teor de compostos bioativos nas bagas sob influência das práticas de desfolha e desponte em diferentes fases fenológicas
Comparação de métodos de estimativa de evapotranspiração de referência para a região da Campanha.
SIEPE
Adsorption of 2,2 '-dithiodipyridine as a tool for the assembly of silver nanoparticles
Silver nanostructured thin films stabilized by 2,2’-dithiodipyridine (2dtpy) were prepared. The Ag nanoparticles
were obtained by treating the complex [Ag(2dtpy)]NO3 with NaBH4 in a methanol–toluene mixture. The films
were transferred to borosilicate glass slips by a dip-coating method and were found to consist of Ag
nanoparticles possibly linked via 2dtpy molecules. Surface-enhanced Raman scattering (SERS) studies have
offered the possibility of investigating the adsorption modes of 2dtpy at the Ag nanoparticle surfaces in the
fil
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