84 research outputs found

    Monitoramento da Produção Enxuta com Inteligência Artificial / Lean Production Monitoring with Artificial intelligence

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     The liquefied petroleum gas (LPG) production industry, commercially known as residential gas, presents challenges such as continuous production, the need to control the production process in real time and the variability of product quality due to the behavior of parameters thermodynamics of production. In this scenario, this work presents two distinct algorithms and proposes methods to monitor the quality of LPG in real time. At the end, an analysis tool and the control measures that must be implemented will be presented to guarantee the reduction of variability according to the principles of lean production

    Influence of grinding on the pozzolanic activity of granite residue.

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    This study explores the potential of the granite residue to be applied as a supplementary cementitious material. Furthermore, the efficiency of grinding methods in the improvement of the residue reactivity was also evaluated. The granite residue was collected in a facility located in Brazil and used as a Portland cement replacement with a substitution rate of 25% in mass. The residue was submitted to wet, dry and additive dry grinding methods, with several different times. The cement-based composites were characterized by quantitative X-Ray diffraction using the Rietveld's method, thermogravimetric analysis, and compressive strength. In conclusion, there was observed a higher efficiency of the wet grinding method, followed by an increase in compressive strength results as grinding time increased. Furthermore, the portlandite content was lower in the cement-based composite with granite residue, especially in the samples ground for 60, 120, and 180 minutes; a fact that summed up with other results for the pozzolanic potential of the granite residue

    DYNAMICS OF VEGETATION IN AN ATLANTIC FOREST FRAGMENT IN NORTHEASTERN BRAZIL

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    Para testar a hip\uf3tese que a fisionomia, estrutura e din\ue2mica de esp\ue9cies lenhosas s\ue3o influenciadas pelo gradiente espacial borda-interior, foram coletados dados desses par\ue2metros em 2004, 2007 e 2010 em um fragmento de Floresta Atl\ue2ntica. Foram amostradas para o Dossel (DS), plantas com circunfer\ueancia do caule a altura do peito (CAP) > 15 cm e do sub-bosque (SB) com circunfer\ueancia ao n\uedvel do solo entre > 3 cm e CAP < 15 cm em um gradiente borda-interior formado h\ue1 35 anos. Em 2004, foram avaliadas tr\ueas posi\ue7\uf5es no fragmento: borda, intermedi\ue1ria e interior (> 150 m do limite florestal), sendo analisados 1000 m\ub2 por local, divididos em parcelas de 10 m\ub2, para medir os indiv\uedduos de maior classe. Em cada parcela foi instalada uma subparcela de 5 m\ub2 para amostragem do sub-bosque. Foram recolhidos ramos de tr\ueas indiv\uedduos adultos das esp\ue9cies, para obten\ue7\ue3o da densidade da madeira. O n\ufamero de indiv\uedduos (NI), \ue1rea basal (AB), taxa de mortalidade (TM), taxa de recrutamento (TR), incremento peri\uf3dico anual em di\ue2metro (IPA), taxa de perda (P) e ganho (G) de \ue1rea basal e as taxas de rotatividade em n\ufamero de indiv\uedduos (TN) e em \ue1rea basal (TA) da classe do componente arb\uf3reo nos tr\ueas locais evidenciaram n\ue3o haver efeito de borda significativo. Na borda, o sub-bosque teve menores valores de NI e AB e maiores TM, que no interior do fragmento. Diferen\ue7as entre os estratos acontecem, independentemente do selamento da borda, j\ue1 que plantas jovens na maior classe amostral apresentam indiv\uedduos no SB, que s\ue3o mais sens\uedveis que as \ue1rvores adultas \ue0s mudan\ue7as causadas pela cria\ue7\ue3o da borda. Taxas de perda e ganho de AB e de rotatividade em NI e AB, no SB, apresentaram valores maiores que no DS, o que aponta para um estrato com maiores mudan\ue7as. No DS n\ue3o ocorreram diferen\ue7as de riqueza de esp\ue9cies entre os ambientes, distinto do observado no SB. A composi\ue7\ue3o flor\uedstica no DS nos ambientes mais pr\uf3ximos ao limite florestal foi bastante distinta que a do interior, indicando que ainda n\ue3o houve recupera\ue7\ue3o da composi\ue7\ue3o flor\uedstica. Todos os ambientes do SB tiveram baixa similaridade. As bordas do DS e SB apresentaram maior concentra\ue7\ue3o de indiv\uedduos em intervalos de classe de menores valores de densidade de madeira. O DS j\ue1 recuperou a biomassa, embora os ambientes de borda e intermedi\ue1rio n\ue3o tenham recuperado a composi\ue7\ue3o de esp\ue9cies tardias. O SB ainda sofre efeito de borda. Possivelmente, a maior concentra\ue7\ue3o de indiv\uedduos em classe de menor densidade da madeira sendo resultado na borda.To test the hypothesis that the physiognomy, structure and dynamics of woody species are influenced by the spatial gradient edge-interior, data were collected from these parameters in 2004, 2007 and 2010 in an Atlantic forest fragment. Species were sampled for the Canopy (DS), with circumference > 15 cm to 1.3 m soil and understory (SB) in circumference between ground level> 3 cm and CAP <15 cm on edge-gradient formed within 35 years. In 2004, we assessed three positions in the fragment: edge, intermediate and inner (> 150 m from the forest boundary), and analyzed 1,000 m\ub2 per site, divided into plots of 10 m\ub2, to measure individuals of higher class. In each plot a sub-plot of 5 m\ub2 for sampling understory was installed. Branches were collected from three adult individuals from the species to obtain the density of the wood. The number of individuals (NI), basal area (BA), mortality (TM), recruitment rate (TR), periodic annual diameter increment (IPA), loss rate (P) and gain rate (G) Area and basal turnover rates in number of individuals (TN) and basal area (TA) class tree component in the three locations showed no significant edge effect. At the edge, the understory had lower values of NI and AB and higher TM than in the forest interior. Differences between the strata occur regardless of edge sealing, since young plants present in most individuals in the sample class SB, which are more sensitive than adult trees to changes caused by the creation of the edge. Rates of loss and gain of AB and AB turnover in NI and in SB presented higher values than on the DS, which points to a stratum with larger changes. In DS there were no differences in species richness among environments differs from that observed in SB. The floristic composition of the DS in environments closer to the forest limit was quite distinct from that of the interior, indicating that there has been no recovery of floristic composition. All environments SB had low similarity. The edges of the DS and SB had a higher concentration of individuals in class intervals smaller density values timber. The DS has already recovered biomass, although the edge and intermediate environments have not recovered species composition late. The SB still suffers the edge effect. Possibly, the highest concentration of individuals is in class with lower density wood result on edge

    Microstructure and mechanical properties of a microalloyed steel after thermal treatments.

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    The properties of a microalloyed steel, with Nb and V in its composition, were studied, after different intercritical thermal treatments and at different austenitizing and tempering temperatures. The mechanical properties of the specimens were measured in a Vickers hardness tester, and their microstructures were analyzed by optical microscopy, with the aid of a digital image processor. After austenitizing at 1100 ?C and tempering at 625 ?C, the samples showed significantly higher tempering resistance, reflected by their retention of high hardness, which may be associated with a secondary hardening precipitation of Nb carbon nitrides. In the sample with dualphase microstructure, the martensite volume fraction varied from 18.2 to 26.3% and the ferrite grain size remained unchanged, upon the variation of the time length of the intercritical treatments. Tempered samples showed Vickers hardness (HVN) varying from 327 to 399, and dualphase samples showed HVN from 362 to 429

    The ALMA Survey of 70 μm Dark High-mass Clumps in Early Stages (ASHES). I. Pilot Survey: Clump Fragmentation

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    \ua9 2019. The American Astronomical Society. All rights reserved. The ALMA Survey of 70 μm dark High-mass clumps in Early Stages (ASHES) is designed to systematically characterize the earliest stages and constrain theories of high-mass star formation. Twelve massive (>500 M⊙ ), cold (≤15 K), 3.6-70 μm dark prestellar clump candidates, embedded in infrared dark clouds, were carefully selected in the pilot survey to be observed with the Atacama Large Millimeter/submillimeter Array (ALMA). We have mosaicked each clump (∼1 arcmin2) in continuum and line emission with the 12 m, 7 m, and Total Power (TP) arrays at 224 GHz (1.34 mm), resulting in ∼1.″2 resolution (∼4800 au, at the average source distance). As the first paper in the series, we concentrate on the continuum emission to reveal clump fragmentation. We detect 294 cores, from which 84 (29%) are categorized as protostellar based on outflow activity or "warm core" line emission. The remaining 210 (71%) are considered prestellar core candidates. The number of detected cores is independent of the mass sensitivity range of the observations and, on average, more massive clumps tend to form more cores. We find a large population of low-mass (30 M⊙) prestellar cores (maximum mass 11 M⊙). From the prestellar core mass function, we derive a power-law index of 1.17 \ub1 0.10, which is slightly shallower than Salpeter. We used the minimum spanning tree (MST) technique to characterize the separation between cores and their spatial distribution, and to derive mass segregation ratios. While there is a range of core masses and separations detected in the sample, the mean separation and mass per clump are well explained by thermal Jeans fragmentation and are inconsistent with turbulent Jeans fragmentation. Core spatial distribution is well described by hierarchical subclustering rather than centrally peaked clustering. There is no conclusive evidence of mass segregation. We test several theoretical conditions and conclude that overall, competitive accretion and global hierarchical collapse scenarios are favored over the turbulent core accretion scenario

    Interaction of climate change with effects of conspecific and heterospecific density on reproduction

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    We studied the relationship between temperature and the coexistence of great titParus majorand blue titCyanistes caeruleus, breeding in 75 study plots across Europe and North Africa. We expected an advance in laying date and a reduction in clutch size during warmer springs as a general response to climate warming and a delay in laying date and a reduction in clutch size during warmer winters due to density-dependent effects. As expected, as spring temperature increases laying date advances and as winter temperature increases clutch size is reduced in both species. Density of great tit affected the relationship between winter temperature and laying date in great and blue tit. Specifically, as density of great tit increased and temperature in winter increased both species started to reproduce later. Density of blue tit affected the relationship between spring temperature and blue and great tit laying date. Thus, both species start to reproduce earlier with increasing spring temperature as density of blue tit increases, which was not an expected outcome, since we expected that increasing spring temperature should advance laying date, while increasing density should delay it cancelling each other out. Climate warming and its interaction with density affects clutch size of great tits but not of blue tits. As predicted, great tit clutch size is reduced more with density of blue tits as temperature in winter increases. The relationship between spring temperature and density on clutch size of great tits depends on whether the increase is in density of great tit or blue tit. Therefore, an increase in temperature negatively affected the coexistence of blue and great tits differently in both species. Thus, blue tit clutch size was unaffected by the interaction effect of density with temperature, while great tit clutch size was affected in multiple ways by these interactions terms.Peer reviewe
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