1,076 research outputs found
Multi-source data assimilation for physically based hydrological modeling of an experimental hillslope
Data assimilation has recently been the focus of much attention
for integrated surface–subsurface hydrological models, whereby joint
assimilation of water table, soil moisture, and river discharge measurements
with the ensemble Kalman filter (EnKF) has been extensively applied. Although
the EnKF has been specifically developed to deal with nonlinear models,
integrated hydrological models based on the Richards equation still represent
a challenge, due to strong nonlinearities that may significantly affect the
filter performance. Thus, more studies are needed to investigate the
capabilities of the EnKF to correct the system state and identify parameters
in cases where the unsaturated zone dynamics are dominant, as well as to
quantify possible tradeoffs associated with assimilation of multi-source
data. Here, the CATHY (CATchment HYdrology) model is applied to reproduce the hydrological dynamics
observed in an experimental two-layered hillslope, equipped with
tensiometers, water content reflectometer probes, and tipping bucket flow
gages to monitor the hillslope response to a series of artificial rainfall
events. Pressure head, soil moisture, and subsurface outflow are assimilated
with the EnKF in a number of scenarios and the challenges and issues arising
from the assimilation of multi-source data in this real-world test case are
discussed. Our results demonstrate that the EnKF is able to effectively
correct states and parameters even in a real application characterized by
strong nonlinearities. However, multi-source data assimilation may lead to
significant tradeoffs: the assimilation of additional variables can lead to
degradation of model predictions for other variables that are otherwise well
reproduced. Furthermore, we show that integrated observations such as outflow
discharge cannot compensate for the lack of well-distributed data in
heterogeneous hillslopes.</p
Reducing the Loss of Built Heritage in Seismic Areas
The presence of the largest part ofWorld Heritage sites in a seismically-prone area, like Italy,
demands always greater measures to protect the most important built heritage, as well as the minor
architecture. This requires a constant improvement of the current protocol from the damage survey
and the provisional safety measures to the final intervention. This procedure is summarized, briefly,
here and additional practical suggestions are given to improve the activities, based on the experience
of on-site volunteers during the damage survey after the earthquake that struck Italy in 2016. Basic
issues on the recurrent characteristics of historic masonry buildings, that make them often complex
constructions with unexpected behaviour, are fundamental in the preparation of the volunteers in
surveying damage. This helps in reducing evaluation mistakes and in designing the provisional
safety structures aimed at the preservation of built heritage to the extent possible. Some examples of
incorrect interpretation of the damage in historic buildings are reported here. In conclusion, only
the awareness that it is necessary that a correct understanding of the recurrent or, on the contrary,
peculiar, characteristics of a historic building plays a key role in the damage evaluation and in its
subsequent protection from further damage
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LiDAR mapping of tidal marshes for ecogeomorphological modelling in the TIDE project
The European research project TIDE (Tidal Inlets Dynamics and Environment) is developing and validating coupled models describing the morphological, biological and ecological evolution of tidal environments. The interactions between the physical and biological processes occurring in these regions requires that the system be studied as a whole rather than as separate parts. Extensive use of remote sensing including LiDAR is being made to provide validation data for the modelling.
This paper describes the different uses of LiDAR within the project and their relevance to the TIDE science objectives. LiDAR data have been acquired from three different environments, the Venice Lagoon in Italy, Morecambe Bay in England, and the Eden estuary in Scotland. LiDAR accuracy at each site has been evaluated using ground reference data acquired with differential GPS. A semi-automatic technique has been developed to extract tidal channel networks from LiDAR data either used alone or fused with aerial photography. While the resulting networks may require some correction, the procedure does allow network extraction over large areas using objective criteria and reduces fieldwork requirements. The networks extracted may subsequently be used in geomorphological analyses, for example to describe the drainage patterns induced by networks and to examine the rate of change of networks. Estimation of the heights of the low and sparse vegetation on marshes is being investigated by analysis of the statistical distribution of the measured LiDAR heights. Species having different mean heights may be separated using the first-order moments of the height distribution
Cinética de volatilização de componentes secundários da aguardente de cana-de-açúcar durante dupla destilação em alambique retificador
The qualitative variation of secondary components plays a key role in the aroma and taste of the sugarcane spirit. The objective of this work was to study the volatilization kinetics of secondary components of sugarcane spirits during double distillation process in a rectifying still to verify the cutoff point in ethanol between "head" and "tail" fractions. Fermented sugarcane juice was distilled in rectifying still according to the methodology used for whisky production. Both distillates from first and second distillations were collected in fractions of 500 mL and analyzed for the concentrations of ethanol, copper, volatile acidity, furfural and hydroxymethylfurfural, aldehydes, esters, methanol and higher alcohols. In the first distillation, aldehydes and esters were distilled at the beginning of the distillation, while acetic acid was distilled at the end of the distillation. Methanol was found in the fractions up to almost half of the first distillation. Higher alcohols were distilled during the whole first distillation, but with greater intensity up to the alcoholic degree of 40% v v-1 of the distillate. During the second distillation, aldehydes, esters and methanol were distilled in the first distillate fractions, being collected mainly at alcohol concentrations above 80% v v-1. Acetic acid was distilled in the final distillate fractions, with concentrations in alcohol content below 20% v v-1. Higher alcohols followed a distillation kinetics pattern similar to ethanol, being collected mainly at alcoholic concentrations above 60% v v-1 of the distillate. The presence of copper, furfural and hydroxymethylfurfural was not detected in any fraction of the distillates of the first and second distillation.A variação qualitativa dos componentes secundários é função chave no aroma e sabor da aguardente de cana-de-açúcar. Avaliou-se a cinética de volatilização de componentes secundários da aguardente de cana-de-açúcar ao longo do processo de dupla destilação em alambique retificador para verificar tempo de corte em etanol entre a fração cabeça e calda. Mosto fermentado de caldo de cana-de-açúcar foi destilado em alambique retificador seguindo a metodologia utilizada para a produção de whisky. Os destilados, tanto da primeira como da segunda destilação, foram recolhidos em frações de 500 mL e analisados quimicamente quanto às concentrações de etanol, cobre, acidez volátil, furfural e hidroximetilfurfural, aldeídos, ésteres, metanol e álcoois superiores. Na primeira destilação, os aldeídos e os ésteres foram arrastados no início da destilação, enquanto que o ácido acético se destilou no final da destilação. O destilado apresentou concentração de metanol até praticamente metade da primeira destilação. Os álcoois superiores se destilaram durante toda a primeira destilação, porém com maior concentração até a graduação alcoólica de 40% v v-1 no destilado. Durante a segunda destilação os aldeídos, os ésteres e o metanol se destilaram nas primeiras frações do destilado, sendo recolhidos principalmente em concentrações alcoólicas acima de 80% v v-1. O ácido acético se destilou nas frações finais do destilado, tendo se concentrado em teores alcoólicos abaixo de 20% v v-1. Os álcoois superiores apresentaram a cinética de destilação semelhante à do etanol, sendo recolhidos principalmente em concentrações alcoólicas superiores a 60% v v-1 do destilado. Não foi detectada presença de cobre, de furfural e hidroximetilfurfural nos destilados da primeira e da segunda destilação
Abertura do capital como o mercado favorece a abertura de capital das empresas
A economia brasileira está mais receptiva à entrada de novas empresas no mercado de
capitais. Seja pela elaboração de leis que facilitem o processo de entrada no mercado,
pela maior entrada de capital entrada de capital estrangeiro ou pela aplicação de novos
conceitos como governança corporativa, o mercado de capitais no Brasil está em
constante crescimento, possibilitando que novas empresas ingressem no mercado de
capitais. O presente trabalho visa mostrar quais os motivos que motivou o crescimento
do número de empresas que abriram seu capital nos anos de 2002 a 2007. O trabalho
tem como objetivo geral identificar quais foram os motivos que levaram as empresas
estudadas a abrirem seu capital no período analisado. Foi utilizada como método de
análise a pesquisa bibliográfica em torno do assunto, bem como o levantamento de
dados econômicos sobre o assunto. No embasamento teórico, a abordagem foi feita
sobre a evolução da legislação que rege o mercado de capitais, foi abordado o conceito
de governança corporativa e do Novo Mercado bem como alguns motivos que possam
levar empresas a abrirem seu capital. A apresentação dos dados consiste na análise de
dados econômicos que possam ter influenciado a economia brasileira a ser mais
atrativa à entrada de novas empresas no mercado como a evolução do PIB, entrada de
capital estrangeiro e a taxa de juros (SELIC). Na conclusão, é feita uma retomada ao
embasamento teórico e à análise dos dados econômicos para que uma conclusão geral
do trabalho possa ser obtida, bem como possa ser sugerido novas pesquisas e análises
do tema
New Results on Classifying EMG Signals for Interfacing Patients and Mechanical Devices
Abstract In modern days the goal of rehabilitative robotics is to take advantage of robotics-inspired solutions in order to assist people affected by disabilities using physical training assisted by robots. In this way the rehabilitative exercises could be autonomously performed by the patients, with a reduced involvement of the therapist, making high-intensity rehabilitative therapy an affordable reality. Moreover high-precision sensors integrated in rehabilitation devices would allow a quantitative evaluation of the progresses obtained, effectively comparing different training strategies. That would represent a huge scientific achievement in a field where evaluations up to this day are performed only by means of subjective observations. Important results were obtained in rehabilitative robotics, but results in the field of the hand rehabilitation are poorer, due to the high complexity and dexterity of the organ. This chapter proposes to integrate the detection of the muscular activity in the rehabilitation loop. A new EMG analysis tool was developed to achieve a reliable early recognition of the movement. Experimental results confirmed that our system is able to recognize the performed movement and generate the first control variable after 200 ms, below the commonly accepted delay of 300 ms for interactive applications. This shows that it is possible to effectively use an EMG classifier to obtain a reliable controller for a flexible device, able to assist the patient only after having detected his effort
Long‐Term Monitoring of Coupled Vegetation and Elevation Changes in Response to Sea Level Rise in a Microtidal Salt Marsh
Tight interplays between physical and biotic processes in tidal salt marshes lead to self-organization of halophytic vegetation into recurrent zonation patterns developed across elevation gradients. Despite its importance for marsh ecomorphodynamics, however, the response of vegetation zonation to changing environmental forcings remains difficult to predict, mostly because of lacking long-term field observations of vegetation evolution in the face of changing rates of sea level rise and marsh vertical accretion. Here we present novel data of coupled marsh elevation-vegetation distribution collected in the microtidal Venice Lagoon (Italy) over nearly two decades. Our results suggest that: (a) despite increasing absolute marsh elevations (i.e., above a fixed datum), vertical accretion rates across most of the studied marsh were not high enough to compensate for relative sea-level rise (RSLR), thus leading to a progressive marsh drowning; (b) accretion rates ranging 1.7–4.3 mm/year are overall lower than the measured RSLR rate (4.4 mm/year) and strongly site-specific. Accretion rates vary largely at sites within distances of a few tens of meters, being controlled by local elevation and sediment availability from eroding marsh edges; (c) vegetation responds species-specifically to changes in environmental forcings by modifying species-preferential elevation ranges. For the first time, we observe the consistency of a sequential vegetation-species zonation with increasing marsh elevations over 20 years. We suggest this is the signature of vegetation resilience to changes in external forcings. Our results highlight a strong coupling between geomorphological and ecological dynamics and call for spatially distributed marsh monitoring and spatially explicit biomorphodynamic models of marsh evolution
TUMORES FILÓIDES GIGANTES (VARIANTES BENIGNA E MALIGNA): ALTERAÇÕES CLÍNICAS, TRATAMENTO CIRÚRGICO E SEGUIMENTO AMBULATORIAL – RELATOS DE CASOS
Phyloid Tumors are rare fibroepithelial tumors of the breast, representing less than 1% of all breast neoplasms, affecting women in the age group with the highest incidence between 40 and 50 years. With a variable biological behavior, the spectrum of benign presentation is confused with cellular fibroadenoma and, not the other extreme, the malignant presents similarities with other malignant neoplasms of the breast. Indicate, appear as a palpable, smooth, multinodular, firm, mobile and painless tumor, with abnormal mammographic and ultrasound findings. Tumor growth is usually rapid, with no correlation with increased risk of malignancy. The diagnosis is confirmed by histopathological evaluation. The treatment is eminently surgical, with excision with free margins and even mastectomy, a tumor-dependent extension being indicated. The presence of margins is important, since this contributes to the reduction of local recurrences, very common in this type of tumor. Adjuvant radiotherapy is controversial in the literature, but it appears to reduce recurrence without changing mortality. This article requires 02 cases of Phyloid Tumor, a benign and malignant variant, with which we aim to emphasize the importance of differential diagnosis and adequate surgical treatment, especially less postoperative morbidity.Os Tumores Filoides são tumores fibroepiteliais raros da mama, representando menos de 1% de todas as neoplasias mamárias, acometendo mulheres na faixa etária de maior incidência entre 40 e 50 anos. Com comportamento biológico variável, o espectro de apresentação benigna se confunde com o fibroadenoma celular e, no outro extremo, o maligno apresenta semelhanças com outras neoplasias malignas da mama. Geralmente, aparecem na forma de tumoração palpável, lisa, multinodular, firme, móvel e indolor, com achados mamográficos e ultrassonográficos anormais. O crescimento tumoral costuma ser rápido, sem correlação com maior risco de malignidade. O diagnóstico é confirmado por avaliação histopatológica. O tratamento é eminentemente cirúrgico, sendo indicada excisão com margens livres e, até mesmo, mastectomia, a depender da extensão tumoral. É importante a presença de margens livres, visto que isso contribui para a redução das recidivas locais, muito comuns nesse tipo de tumor. Radioterapia adjuvante é controversa na literatura, mas parece reduzir a recorrência, sem alterar a mortalidade. Esse artigo descreve 02 casos de Tumor Filoides, variante benigna e maligna, com os quais objetivamos ressaltar a importância do diagnóstico diferencial e adequado tratamento cirúrgico, visando menor morbidade pós-operatória
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