885 resultados para Monitoring methods


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Since the 1990s, regular comparisons of gamma-ray spectrometry in Switzerland were organized to improve laboratory abilities to measure the radioactivity in the environment and food stuffs at typical routine levels. The activity concentration of the test samples and the evaluation of the associated uncertainties remained each year the main required test result. Over the years, the comparisons used certified reference solutions as well as environmental samples. The aim of this study is to research the effect of the comparisons on measurement quality. An analysis of the seven last interlaboratory comparisons revealed that the Swiss measurement capability is up to date. In addition, the results showed that the participants now have an improved evaluation of the uncertainties associated with their measurement.

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Background and Objectives - Sevoflurane is an inhalational anesthetic drug with low blood/gas solubility providing fast anesthesia induction and emergence. Its ability to maintain cardiovascular stability makes it ideal for pediatric anesthesia. The aim of this study was to evaluate hemodynamic stability, consumption of inhalational anesthetics and emergence time in children with and without premedication (midazolam or clonidine) anesthetized with sevoflurane titrated according to BIS monitoring. Methods - Participated in this study 30 patients aged 2 to 12 years, physical status ASA I, undergoing elective surgeries who were divided into 3 groups: G1 - without premedication, G2 - 0.5 mg.kg-1 oral midazolam, G3 - 4 μg.kg-1 oral clonidine 60 minutes before surgery. All patients received 30 μg.kg-1 alfentanil, 3 mg.kg-1 propofol, 0.5 mg.kg-1 atracurium, sevoflurane in different concentrations monitored by BIS (values close to 60) and N2O in a non rebreathing system. Systolic and diastolic blood pressure, heart rate, expired sevoflurane concentration (EC), sevoflurane consumption (ml.min-1) and emergence time were evaluated. Emergence time was defined as time elapsed between the end of anesthesia and patients' spontaneous movements trying to extubate themselves, crying and opening eyes and mouth. Results - There were no differences among groups as to systolic and diastolic blood pressure, EC, sevoflurane consumption and emergence time. Heart rate was lower in G3 group. Conclusions - Sevoflurane has provided hemodynamic stability. Premedication with clonidine and midazolam did not influence emergence time, inhaled anesthetic consumption or maintenance of anesthesia with sevoflurane. Anesthesia duration has also not influenced emergence time. Hypnosis monitoring was important for balancing anesthetic levels and this might have been responsible for the similarity of emergence times for all studied groups.

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Redes Ópticas Passivas estão cada vez mais difundidas como rede de acesso de banda larga. Devido à sua importância, tais redes necessitam constantemente de supervisão. Diversas técnicas vêm sendo empregadas para supervisão de redes ópticas, dentre as quais se destacam as que utilizam reflectometria, pois agregam vantagens, tais como: baixo custo, em comparação com outros métodos de supervisão, e não exigência de intervenção na casa do usuário. Esta dissertação apresenta uma estratégia capaz de quantificar, por meio de simulações, o impacto que a técnica de reflectometria no domínio do tempo gera como interferência em transmissões típicas de uma rede WDM-PON.

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Pós-graduação em Ciências Cartográficas - FCT

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV

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Blooms of phytoplankton can be a risk to human health and aquatic biota, so the adoption of monitoring methods of phytoplankton and mechanisms for preventing its occurrence are needed. Thus, traditional monitoring methods could be more effective if complemented by approaches using the optical properties of phytoplankton pigments by means of Remote Sensing. In order to evaluate the potential of multi-scale remote sensing for detection of the phytoplankton activity, a study area was selected in Nova Avanhandava reservoir, located in the Tiete River, SP. For this analysis, hyperspectral field data and multispectral images of low and medium spatial resolution (Modis and RapidEye) were acquired and were related to indicator limnological variables of phytoplankton behavior; chlorophyll a and phycocyanin. The results show that a specific spectral band of RapidEye system (690-730 nm) allowed detect chlorophyll a and to evaluate the phytoplankton biomass, however hyperspectral data are needed to detect the phycocyanin pigment, indicative of cyanobacteria.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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OBJECTIVE: To analyze the competency of people with diabetes mellitus to perform the insulin administration process, before and after telephone monitoring. METHODS: A quantitative, observational, longitudinal, comparative study. Participants were 26 people enrolled in the at-home capillary glycemia self-monitoring program. Data collection occurred in three phases, in January and February of 2010, for a period of 30 days for each person, by means of interview guided by a data collection instrument and an intervention manual. RESULTS: Of the 38 (100%) questions referring to the insulin administration process, telephone monitoring was demonstrated to be efficient in 30 (78.9%), but in 19 (50%) the intervention was statistically significant (p<0.05), in 11 (28.9%) there were no errors in responses to the final competency evaluation, and seven (18.4%) were not amenable to intervention. CONCLUSION: Telephone mornitoring was effective, as a nursing intervention strategy for the insulin administration process in the home.

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Remote sensing (RS) techniques have evolved into an important instrument to investigate forest function. New methods based on the remote detection of leaf biochemistry and photosynthesis are being developed and applied in pilot studies from airborne and satellite platforms (PRI, solar-induced fluorescence; N and chlorophyll content). Non-destructive monitoring methods, a direct application of RS studies, are also proving increasingly attractive for the determination of stress conditions or nutrient deficiencies not only in research but also in agronomy, horticulture and urban forestry (proximal RS). In this work I will focus on some novel techniques recently developed for the estimation of photochemistry and photosynthetic rates based (i) on the proximal measurement of steady-state chlorophyll fluorescence yield, or (ii) the remote sensing of changes in hyperspectral leaf reflectance, associated to xanthophyll de-epoxydation and energy partitioning, which is closely coupled to leaf photochemistry and photosynthesis. I will also present and describe a mathematical model of leaf steady-state fluorescence and photosynthesis recently developed in our group. Two different species were used in the experiments: Arbutus unedo, a schlerophyllous Mediterranean species, and Populus euroamericana, a broad leaf deciduous tree widely used in plantation forestry. Results show that ambient fluorescence could provide a useful tool for testing photosynthetic processes from a distance. These results confirm also the photosynthetic reflectance index (PRI) as an efficient remote sensing reflectance index estimating short-term changes in photochemical efficiency as well as long-term changes in leaf biochemistry. The study also demonstrated that RS techniques could provide a fast and reliable method to estimate photosynthetic pigment content and total nitrogen, beside assessing the state of photochemical process in our plants’ leaves in the field. This could have important practical applications for the management of plant cultivation systems, for the estimation of the nutrient requirements of our plants for optimal growth.

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Spannungsumlagerungen in Mineralen und Gesteinen induzieren in geologisch aktiven Bereichen mikromechanische und seismische Prozesse, wodurch eine schwache natürliche elektromagnetische Strahlung im Niederfrequenzbereich emittiert wird. Die elektromagnetischen Emissionen von nichtleitenden Mineralen sind auf dielektrische Polarisation durch mehrere physikalische Effekte zurückzuführen. Eine gerichtete mechanische Spannung führt zu einer ebenso gerichteten elektromagnetischen Emission. Die Quellen der elektromagnetischen Emissionen sind bekannt, jedoch können sie noch nicht eindeutig den verschiedenen Prozessen in der Natur zugeordnet werden, weshalb im Folgenden von einem seismo-elektromagnetischen Phänomen (SEM) gesprochen wird. Mit der neuentwickelten NPEMFE-Methode (Natural Pulsed Electromagnetic Field of Earth) können die elektromagnetischen Impulse ohne Bodenkontakt registriert werden. Bereiche der Erdkruste mit Spannungsumlagerungen (z.B. tektonisch aktive Störungen, potenzielle Hangrutschungen, Erdfälle, Bergsenkungen, Firstschläge) können als Anomalie erkannt und abgegrenzt werden. Basierend auf dem heutigen Kenntnisstand dieser Prozesse wurden Hangrutschungen und Locker- und Festgesteine, in denen Spannungsumlagerungen stattfinden, mit einem neuentwickelten Messgerät, dem "Cereskop", im Mittelgebirgsraum (Rheinland-Pfalz, Deutschland) und im alpinen Raum (Vorarlberg, Österreich, und Fürstentum Liechtenstein) erkundet und die gewonnenen Messergebnisse mit klassischen Verfahren aus Ingenieurgeologie, Geotechnik und Geophysik in Bezug gesetzt. Unter Feldbedingungen zeigte sich großenteils eine gute Übereinstimmung zwischen den mit dem "Cereskop" erkundeten Anomalien und den mit den konventionellen Verfahren erkundeten Spannungszonen. Auf Grundlage der bisherigen Kenntnis und unter Einbeziehung von Mehrdeutigkeiten werden die Messergebnisse analysiert und kritisch beurteilt.

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Environmental decay in porous masonry materials, such as brick and mortar, is a widespread problem concerning both new and historic masonry structures. The decay mechanisms are quite complex dependng upon several interconnected parameters and from the interaction with the specific micro-climate. Materials undergo aesthetical and substantial changes in character but while many studies have been carried out, the mechanical aspect has been largely understudied while it bears true importance from the structural viewpoint. A quantitative assessment of the masonry material degradation and how it affects the load-bearing capacity of masonry structures appears missing. The research work carried out, limiting the attention to brick masonry addresses this issue through an experimental laboratory approach via different integrated testing procedures, both non-destructive and mechanical, together with monitoring methods. Attention was focused on transport of moisture and salts and on the damaging effects caused by the crystallization of two different salts, sodium chloride and sodium sulphate. Many series of masonry specimens, very different in size and purposes were used to track the damage process since its beginning and to monitor its evolution over a number of years Athe same time suitable testing techniques, non-destructive, mini-invasive, analytical, of monitoring, were validated for these purposes. The specimens were exposed to different aggressive agents (in terms of type of salt, of brine concentration, of artificial vs. open-air natural ageing, …), tested by different means (qualitative vs. quantitative, non destructive vs. mechanical testing, punctual vs. wide areas, …), and had different size (1-, 2-, 3-header thick walls, full-scale walls vs. small size specimens, brick columns and triplets vs. small walls, masonry specimens vs. single units of brick and mortar prisms, …). Different advanced testing methods and novel monitoring techniques were applied in an integrated holistic approach, for quantitative assessment of masonry health state.

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CO2 leakage from subsurface storage sites is one of the main concerns connected with the CCS technology. As CO2 leakages into near surface formations appear to be very unlikely within pilot CCS projects, the aim of this work is to emulate a leakage by injecting CO2 into a near surface aquifer. The two main questions pursued by the injection test are (1) to investigate the impact of CO2 on the hydrogeochemistry of the groundwater as a base for groundwater risk assessment and (2) to develop and apply monitoring methods and monitoring concepts for detecting CO2 leakages in shallow aquifers. The presented injection test is planned within the second half of 2010, as a joint project of the University of Kiel (Germany), the Helmholtz-Centre for Environmental Research (Leipzig, Germany) and the Engineering Company GICON (Dresden, Germany). The test site has been investigated in detail using geophysical methods as well as direct-push soundings, groundwater well installation and soil and groundwater analyses. The present paper presents briefly the geological and hydrogeological conditions at the test site as well as the planned injection test design and monitoring concept.

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In recent years, remote sensing imaging systems for the measurement of oceanic sea states have attracted renovated attention. Imaging technology is economical, non-invasive and enables a better understanding of the space-time dynamics of ocean waves over an area rather than at selected point locations of previous monitoring methods (buoys, wave gauges, etc.). We present recent progress in space-time measurement of ocean waves using stereo vision systems on offshore platforms, which focus on sea states with wavelengths in the range of 0.01 m to 10 m. Classical epipolar techniques and modern variational methods are reviewed to reconstruct the sea surface from the stereo pairs sequentially in time. The statistical and spectral properties of the resulting observed waves are analyzed. Current improvements of the variational methods are discussed as future lines of research.

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In recent years, remote sensing imaging systems for the measurement of oceanic sea states have attracted renovated attention. Imaging technology is economical, non-invasive and enables a better understanding of the space-time dynamics of ocean waves over an area rather than at selected point locations of previous monitoring methods (buoys, wave gauges, etc.). We present recent progress in space-time measurement of ocean waves using stereo vision systems on offshore platforms, which focus on sea states with wavelengths in the range of 0.01 m to 1 m. Both traditional disparity-based systems and modern elevation-based ones are presented in a variational optimization framework: the main idea is to pose the stereoscopic reconstruction problem of the surface of the ocean in a variational setting and design an energy functional whose minimizer is the desired temporal sequence of wave heights. The functional combines photometric observations as well as spatial and temporal smoothness priors. Disparity methods estimate the disparity between images as an intermediate step toward retrieving the depth of the waves with respect to the cameras, whereas elevation methods estimate the ocean surface displacements directly in 3-D space. Both techniques are used to measure ocean waves from real data collected at offshore platforms in the Black Sea (Crimean Peninsula, Ukraine) and the Northern Adriatic Sea (Venice coast, Italy). Then, the statistical and spectral properties of the resulting observed waves are analyzed. We show the advantages and disadvantages of the presented stereo vision systems and discuss future lines of research to improve their performance in critical issues such as the robustness of the camera calibration in spite of undesired variations of the camera parameters or the processing time that it takes to retrieve ocean wave measurements from the stereo videos, which are very large datasets that need to be processed efficiently to be of practical usage. Multiresolution and short-time approaches would improve efficiency and scalability of the techniques so that wave displacements are obtained in feasible times.