257 research outputs found
Cracking Control in Mezzanine Floor Slabs using Rice Husk Ash and Polypropylene Fibers
The continuous population increase in recent years requires a greater number of households to be built quickly, with good materials and produced under quality standards that guarantee their manufacturing process. The prefabricated concrete, produced and supplied by concrete plants, is poured into the different structural elements, the mezzanine slabs being the most careful surfaces in the appearance of fissures; because being horizontal and having larger dimensions, the dimensional changes in the concrete appear more frequently due to the rapid loss of water from the surface of the concrete before setting; which generates superior stresses to the resistant capacity of the concrete at early ages, which affect the durability and reduce the resistance of the structures, causing greater economic expenses in maintenance and repairs. In the present investigation, 5%, 10% and 15% of rice husk ash was used as a replacement for cement and 900g/m3 of polypropylene fiber; The results indicate that as the percentage of rice husk ash increases, there is a reduction in the slump and the crack fissures, and that the resistance to compression and flexion decreases, with respect to the concrete pattern
Wavelength calibration of the JWST-MIRI medium resolution spectrometer
We present the wavelength and spectral resolution characterisation of the
Integral Field Unit (IFU) Medium Resolution Spectrometer for the Mid-InfraRed
Instrument (MIRI), to fly onboard the James Webb Space Telescope in 2014. We
use data collected using the Verification Model of the instrument and develop
an empirical method to calibrate properties such as wavelength range and
resolving power in a portion of the spectrometer's full spectral range (5-28
microns). We test our results against optical models to verify the system
requirements and combine them with a study of the fringing pattern in the
instrument's detector to provide a more accurate calibration. We show that
MIRI's IFU spectrometer will be able to produce spectra with a resolving power
above R=2800 in the wavelength range 6.46-7.70 microns, and that the unresolved
spectral lines are well fitted by a Gaussian profile.Comment: 12 pages, submitted to SPIE Proceedings vol. 7731, Space Telescopes
and Instrumentation 2010: Optical, Infrared, and Millimeter Wav
Desenvolvimento de um método de caracterização de esquemas de controle químico em vinhedos por Análise Explanatória Multivariada.
Calendários de pulverização das safras de 2013/2014 foram utilizados para o desenvolvimento de um Método Explanatório Multivariado para caracterização da proteção de quatro vinhedos contra doenças, em vinícolas da Campanha Gaúcha
Dynamic risk control by human nucleus accumbens
Real-world decisions about reward often involve a complex counterbalance of risk and value. Although the nucleus accumbens has been implicated in the underlying neural substrate, its criticality to human behaviour remains an open question, best addressed with interventional methodology that probes the behavioural consequences of focal neural modulation. Combining a psychometric index of risky decision-making with transient electrical modulation of the nucleus accumbens, here we reveal profound, highly dynamic alteration of the relation between probability of reward and choice during therapeutic deep brain stimulation in four patients with treatment-resistant psychiatric disease. Short-lived phasic electrical stimulation of the region of the nucleus accumbens dynamically altered risk behaviour, transiently shifting the psychometric function towards more risky decisions only for the duration of stimulation. A critical, on-line role of human nucleus accumbens in dynamic risk control is thereby established
Recommendations for core critical care ultrasound competencies as a part of specialist training in multidisciplinary intensive care: a framework proposed by the European Society of Intensive Care Medicine (ESICM)
© 2020 The Author(s). Critical care ultrasound (CCUS) is an essential component of intensive care practice. Although existing international guidelines have focused on training principles and determining competency in CCUS, few countries have managed to operationalize this guidance into an accessible, well-structured programme for clinicians training in multidisciplinary intensive care. We seek to update and reaffirm appropriate CCUS scope so that it may be integrated into the international Competency-based Training in Intensive Care Medicine. The resulting recommendations offer the most contemporary and evolved set of core CCUS competencies for an intensive care clinician yet described. Importantly, we discuss the rationale for inclusion but also exclusion of competencies listed. Background/aim: Critical care ultrasound (CCUS) is an essential component of intensive care practice. The purpose of this consensus document is to determine those CCUS competencies that should be a mandatory part of training in multidisciplinary intensive care. Methods: A three-round Delphi method followed by face-to-face meeting among 32 CCUS experts nominated by the European Society of Intensive Care Medicine. Agreement of at least 90% of experts was needed in order to enlist a competency as mandatory. Results: The final list of competencies includes 15 echocardiographic, 5 thoracic, 4 abdominal, deep vein thrombosis diagnosis and central venous access aid. Conclusion: The resulting recommendations offer the most contemporary and evolved set of core CCUS competencies for an intensive care clinician yet described
Diferentes épocas de poda e aplicação de estimuladores de brotação em "Chardonnay" e "Cabernet Sauvignon" cultivados na Campanha Gaúcha.
A vitivinicultura na campanha gaúcha tem se destacado no cenário enológico pelas condições edafoclimáticas que proporcionam a produção de uvas de ótima qualidade. No entanto, a região apresenta oscilação nas temperaturas de inverno em diferentes anos, sendo o baixo acúmulo de horas de frio um grande limitador na brotação e consequente produção da cultura
Implementation of Signal Processing Methods in a Structural Health Monitoring (SHM) System based on Ultrasonic Guided Waves for Defect Detection in Different Materials and Structures
The local defect inspection in longitudinal structures such as plates or pipelines implies high
economical costs and it is time consuming mainly in underground infrastructures, energy or
water, and aerospace sectors. Moreover, if these structures are non-accessible, their local
inspection is not possible. Ultrasonic (US) inspection technique based on guided waves is
one of the potential alternatives to address this issue. The US inspection based on these type
of waves could be applied in many scenarios to monitor the damage state of structures; i.e.,
in water underground pipelines to identify the wall thickness losses or impact damage
detection on Carbon Fiber Reinforced Composites (CFRC).
A SHM system based on guided waves requires a special signal processing in order to
identify possible damage in the structure. The signal emitted and received is a combination of
different propagation modes which are difficult to identify and analyse. However, if the
signals are compared to each other (signal related to non-damaged components compared to
damaged signal) it is possible to measure their difference as a distance that can be used to
estimate the damage level.
In this work, signals corresponding to non-damaged samples have been captured and then
different types of damage have been applied for different cases. After the data acquisition
phase, the comparison between signals has been carried out by applying different
mathematical methods and distance metrics (SDC, DTW, Euclidean, Manhattan and
Chebyshev), with the aim of detecting defects in different structures and materials. For this
purpose, two cases have been analysed: 1) In CFRC plates subjected to impact damage and
deformations and 2) In a pipe coated by cement-mortar in order to quantify the wall
thickness losses.
In both cases ultrasonic PZT sensors, an ultrasonic multichannel pulser/receiver and a
software developed ad-hoc have been used. Although the SHM system components were
similar, it must be noted that the type of ultrasonic guided waves used were different; in the
case of CFRC plates, Lamb waves were excited whereas in the case of the pipeline, Love
waves have been used. A comparison between the above mentioned methods is provided. The
results show the validity of the approach for damage characterization.Authors would like to acknowledge the Basque Government funding within the ELKARTEK Programme (AIRHEM)
Manejo da poda e de indutores de brotação em diferentes cultivares Vitis vinifera na região da Campanha Gaúcha.
A vitivinicultura no Rio Grande do Sul tem reconhecimento no cenário enológico nacional e a Campanha Gaúcha tem sua participação neste processo. Com vinhedos implantados na década de 70, no município de Santana do Livramento- RS, para produção de uvas finas, a região tem apresentado crescente desenvolvimento com instalação de novas vinícolas. Apesar dos benefícios climáticos, a Campanha apresenta invernos irregulares, tanto na distribuição como na qualidade do frio, provocando brotações irregulares, baixa produtividade e desuniformidade na produção dos vinhedos. Buscando novas tecnologias para melhorar a qualidade de brotação e consequente qualidade produtiva, o presente trabalho objetivou avaliar o comportamento de brotação de diferentes cultivares de Vitis vinifera em relação às diferentes épocas de poda com a interação de indutores químicos de brotação.(Embrapa Uva e Vinho. Documentos, 99
Épocas de poda e uso de cianamida hidrogenada na brotação de videiras "Merlot" (Vitis vinifera L.) na Região da Campanha Gaúcha.
A Campanha Gaúcha vem sendo classificada entre as regiões vitivinícolas mais promissoras no Rio Grande do Sul, especialmente pelas suas condições edafoclimáticas com maior restrição hídrica e drenagem do solo. Apesar do início da vitivinicultura nesta região datar da década de 70, a maior intensificação dos plantios e produção ocorreu nos últimos dez anos, porém sem muitos subsídios técnicos. Os objetivos deste trabalho foram avaliar os efeitos da antecipação da poda hibernal e concentrações de cianamida hidrogenada (CH) sobre o potencial produtivo da uva ?Merlot?/SO4 conduzida nos sistemas de poda Guyot Duplo (DG) e Cordão Esporonado (CE).(Embrapa Uva e Vinho. Documentos 99
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