2,570 research outputs found
Um Sistema de Informação Geográfica para a prevenção e combate aos incêndios florestais (SIGPF)
Comunicação apresentada no Congresso Ibérico de Fogos Florestais que decorreu de 17 a 19 de Dezembro de 2000, em Castelo Branco, na Escola Superior Agrária do Instituto Politécnico.Para uma maior eficácia na prevenção e combate aos fogos florestais é fundamental um conhecimento adequado e actualizado da área de intervenção. No âmbito da protecção civil, compete à s Câmaras Municipais, em conjugação com outras instituições, a elaboração de Planos Municipais de Intervenção Florestal, no sentido de minimizar o risco da ocorrência de incêndios e optimizar os meios envolvidos no combate. Os sistemas de informação geográfica ao relacionarem informação espacial e alfanumérica, possibilitando a manipulação, análise e visualização dos dados, apresentam-se como um recurso informático de extrema importância no planeamento de medidas de prevenção e combate aos fogos florestais. A metodologia utilizada passou por uma sequência de fases usuais na construção deste tipo de aplicações, tendo como objectivo a caracterização da área de estudo quanto à ocupação do solo, rede viária, superfÃcies com água e postos de vigia. Os resultados obtidos são (1) cartografia temática de ocupação de solo e infra-estrutura (2) carta de risco de incêndio florestal
High temperature tribological characterization of TiAl laser cladding coating on Ti6Al4V alloy
Ti6Al4V alloy has proven to be an important engineering material due to the excellent
strength, weight ratio, high corrosion resistance and biocompatibility. However, the
alloy is susceptible to mechanical degradation in applications involving sliding wear
or abrasion. In order to improve wear resistance, coatings by laser cladding of
intermetallic Ti48Al2Cr2Nb on Ti6Al4V have been developed. Different process
parameters: laser power (W), scanning speed (mm/min), powder feeding rate (g/min)
and preheating temperature of substrate (°C) were optimized, resulting in a
microstructure of the coatings considered appropriate, with good metallurgical bond,
though cracks and pores were observed [1]. The composition and microstructure of
the coatings were evaluated using optical microscopy (OM), scanning electron
microscopy (SEM) and X-ray diffraction (XRD) analysis, further the tribological
properties were evaluated using a ball on disk tribometer, with Al2O3 ball, constant
speed of 0.1 m/s, 10 N load at room temperature and 500 °C. We measure the 3D
surface topography obtained from the wear scar and calculated the wear rate. The
coatings microstructure consists of -TiAl phase and 2-Ti3Al. The wear test results at
room temperature show a lower wear rate for the coating compared to the substrate.
At high temperature the coating have a higher friction coefficient and a higher rate of
wear is obtained when compared with the substrate, obtaining differences between
the coatings depending on the wear mechanism observed in the worn surface.The authors acknowledge the economical support from the Ministry of Science and
Innovation of the Government of Spain through research project MAT2011-28492-03
and the Generalitat Valenciana through support ACOMP/2014/151. Thanks also to
Dr. José Luis Jorda by X-ray diffraction analysis performed
Development of laser cladding MCrAlY coatings: high temperature friction and wear behaviour
Temperature can have a significant effect on the extent of wear damage of metallic
components. Thermal barrier coatings with MCrAlY (where M=Ni, Co, Fe or
combinations) alloys can improve the high temperature tribological and friction wear
behaviour. In this work the dry friction and wear behaviour at room temperature and
high temperature of new developed NiCoCrAlY and CoNiCrAlY laser cladding
coatings were evaluated. Dense coatings, with good metallurgical bonding to the AISI
304 substrate was obtained by coaxial laser cladding tracks (40% overlapping), with
previously optimized laser parameters. Tribological tests were performed by sliding
wear at room temperature and 500 ºC, with an Al2O3 counterpart in ball on disk
configuration tribometer. The wear scar surface was evaluated by scanning electron
microscopy (SEM) and energy dispersive spectroscopy (EDS) microanalysis. The 3D
wear track topography was measured by inductive contact profilometer which
enabled the wear rate calculation. The microstructure of the coatings consists of -
Ni/-NiAl or -Co/-(Co,Ni)Al phases depending on the chemical composition of the
alloy, as confirmed by X-ray diffraction (XRD) analysis. The wear test results show a
reduction in wear rate at high temperature for all materials tested. For the NiCoCrAlY
coating, the high temperature also reduces the friction coefficient, while it significantly
increases the friction coefficient of CoNiCrAlY coating. The main damage mode is
abrasion and adhesion, caused by oxides and partially-oxidized particles in the
contact surface. The coatings and substrate results were compared, resulting in
improved wear behaviour.The authors acknowledge the financial support of the Ministry of Science and
Innovation of the Government of Spain through research project MAT2011-28492-
C03 and the Generalitat Valenciana through ACOMP/2013/114 support. Professor Juan Carlos Pereira Falcón thanks the University of Carabobo for the financial
support to pursue his doctoral studies at the UPV
Multi-monitorização de estufa agrÃcola
A agricultura tem recorrido, tradicionalmente, a métodos empÃricos que não rentabilizavam a produção e estava fortemente dependente das condições meteorológicas.
Para melhorar a produção agrÃcola, surgiram as estufas agrÃcolas que permitem culturas de elevado valor acrescentado. Estas permitem também a elaboração de estudos de conceitos de causa-efeito, que possibilitam a construção de modelos e sistemas para melhorar a produção e a qualidade de determinada colheita.
Com base nesta realidade, este artigo apresenta e descreve um trabalho que se encontra em fase de desenvolvimento por investigadores de duas escolas do Instituto Politécnico de Castelo Branco (IPCB) e que visa o desenvolvimento de um sistema para monitorização de uma estufa agrÃcola situada na Escola Superior Agrária (ESA) daquele Instituto
Boundary versus bulk behavior of time-dependent correlation functions in one-dimensional quantum systems
Greenhouse watching system using multi-technologies
Traditional agriculture uses empiric methods and is very exposed to meteorological conditions. To increase the agriculture production, greenhouses had appeared to allow crops with higher quality. Greenhouses also permit the study of cause-effect concepts that by them allow building models that improve the crop’s production and quality.
Based on this reality, this paper presents a system developed by researchers of two schools of the Instituto Politécnico of Castelo Branco(IPCB) to monitor a greenhouse located in the campus of Escola Superior Agrária (ESA). This proposed system uses several different technologies
PCV111 Stroke Prevention in Non-Valvular Atrial Fibrillation: Systematic Review of Cost-Effectiveness Studies
Genotypic differences in cyanogenic glycosides levels of compatible Prunus persica P. Persica and incompatible P. persica P. mume combinations
Graft incompatibility is a phenomenon associated with complex physiological, biochemical, and genetic interactions between scion and rootstock. The main objective of this work was to assess the role of cyanogenic glycosides (CGs), amygdalin and prunasin, in the graft incompatibility of Prunus and possible biochemical effects in compounds of the phenylpropanoid pathway. Graft compatibility, amygdalin and prunasin content, phenylalanine ammonia-lyase activity, total phenolic compounds content and antioxidant activity, were studied in different graft combinations (Chimarrita/Capdeboscq; Chimarrita/Tsukuba 1; Chimarrita/Umezeiro; Maciel/Capdeboscq; Maciel/’Tsukuba 1; Maciel/Umezeiro) and ungrafted genotypes. The results indicate that there was graft incompatibility of Chimarrita and Maciel cultivars grafted into Umezeiro rootstock. Combinations identified as incompatible showed higher prunasin concentration and phenylalanine ammonia-lyase (PAL) activity in rootstock and greater concentration of total phenolics compounds and antioxidant activity in scion and rootstock. The results indicate that large differences in CGs concentration, especially prunasin, can be the graft incompatibility cause between Prunus persica and P. mume. The prunasin concentration may be considered a promising marker to predict graft compatibility between P. persica and P. mume
Development of ternary diagrams for estimating water retention properties using geostatistical approaches
Most pedotransfer functions (PTFs) have adopted soil texture information as the main predictor to estimate
soil hydraulic properties, whether inputs are defined in terms of the relative proportion of different grain size
particles or texture-based classifications. The objective of this studywas to develop ternary diagrams for estimating
soil water retention (θ) at−33 and−1500 kPa matric potentials, corresponding to the field capacity and wilting
point, respectively, from particle size distribution using two geostatistical approaches. The texture triangle was
divided into a 1% grid of soil texture composition resulting in 4332 different soil textures. Measured soil water
retention values determined in 742 soil horizons/layers located in Portugal were then used to develop and
validate the hydraulic ternary diagrams. The development subset included two-thirds of the data, and the
validation subset the remaining samples. The measured soil water content values were displayed in the ternary
diagram according to the coordinates given by the particles size distribution determined in the same soil
samples. The volumetric water content values were then predicted for the entire ternary diagram using two
different geostatistical interpolation algorithms (ordinary kriging and the empirical best linear unbiased
predictor). Uncertainty analysis resulted in a root mean square error below 0.040 and 0.034 cm3 cm−3 when
comparing the interpolated water contents at −33 and −1500 kPa matric potential values, respectively, with
the measured ones included in the validation dataset. The estimation variance calculated with both methods
was also considered to access the uncertainty of the predictions. The available water content of Portuguese
soils was then derived from θ−33 kPa and θ−1500 kPa ternary diagrams developed with both approaches. The
hydraulic ternary diagrams may thus serve as simplified tools for estimating water retention properties from
particle size distribution and eventually serve as an alternative to the traditional statistical regression and data
mining techniques used to derive PTFsinfo:eu-repo/semantics/publishedVersio
Factores Biomecânicos no Desenvolvimento de Patologias nos Membros Pélvicos em Avicultura Industrial
O crescente aparecimento de patologias nos membros pélvicos nos efectivos de frangos de carne e de perus, especialmente nas estirpes de crescimento rápido e de peso adulto elevado, que se traduzem em perdas económicas significativas, faz do estudo da biologia do osso, em particular das questões relacionadas com aspectos biomecânicos, uma área de primordial importância na indústria avÃcola. Pretende-se com a presente revisão evidenciar a associação que existe, em avicultura industrial, muito particularmente no sector da produção de carne, entre factores biomecânicos e o desenvolvimento de algumas patologias nos membros pélvicos
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