981 resultados para Humidity.


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Fatores que afetam a viabilidade das sementes; Umidade; Temperatura; Oxigenio; Especie; Armazenamento; Danos mecanicos; Condicoes ambientais antes da colheita; Pragas e doencas; Dormencia.

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BackgroundAsthma is a common condition characterised by airway inflammation and airway narrowing, which can result in intermittent symptoms of wheezing, coughing and chest tightness, possibly limiting activities of daily life. Water-based exercise is believed to offer benefits for people with asthma through pollen-free air, humidity and effects of exercise on physical function.ObjectivesTo evaluate the effectiveness and safety of water-based exercise for adults with asthma.Search methodsWe searched the Cochrane Airways Group Specialised Register of Trials (CAGR), the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Allied and Complementary Medicine Database (AMED), PsycINFO, the Latin American and Caribbean Health Science Information Database (LILACS), the Physiotherapy Evidence Database (PEDro), the System for Information on Grey Literature in Europe (SIGLE) and Google Scholar on 13 May 2014. We handsearched ongoing clinical trial registers and meeting abstracts of the American Thoracic Society (ATS), the European Respiratory Society (ERS) and the British Thoracic Society (BTS).Selection criteriaWe included all randomised controlled trials (RCTs) of adults with asthma comparing a water-based exercise group versus one or more of the following groups: usual care, land-based exercise, non-exercise.Data collection and analysisTwo review authors (AJG, VS) independently extracted data fromthe primary studies using a standard form developed for this purpose, which includes methods, participants, interventions and outcomes. We contacted trial authors to request additional data. Data were input by one review author and were double-checked by a second review author.Main resultsIn this systematic review, we provide a narrative synthesis of available evidence from three small studies including 136 adult participants. the studies were at high risk of bias. No meta-analysis was possible because of methodological and interventional heterogeneity between included studies. the primary outcomes of quality of life and exacerbations leading to use of steroids were not reported by these studies. for exacerbations leading to health centre/hospital visits, uncertainty was wide because a very small number of events was reported (in a single study). Secondary outcomes symptoms, lung function, changes in medication and adverse effects, where available, described for each included study. the overall quality of the studies was very low, and no clear differences were noted between water-based exercise and comparator treatments. Therefore, we remain very uncertain about the effects of water-based exercise for adults with asthma.Authors' conclusionsThe small number of participants in the three included studies, the clinical and methodological heterogeneity observed and the high risk of bias assessed mean that we are unable to assess the place of water-based exercise in asthma. Randomised controlled trials are needed to assess the efficacy and safety of water-based exercise for adults with asthma. for future research, we suggest greater methodological rigour (participant selection, blinding of outcome assessors, reporting of all outcomes analysed and registering of the study protocol).

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RESUMO: O objetivo do presente trabalho foi avaliar a reação de genótipos de girassol à podridão branca, causada por Sclerotinia sclerotiorum, no colo e no capítulo, em condições de campo. Dezoito cultivares de girassol foram avaliadas, em experimento implantado em maio de 2014, em Mauá da Serra, PR, em condições de infecção natural do fungo. A avaliação das plantas indicou que a doença foi favorecida pelas condições climáticas de baixa temperatura e alta umidade, ocorrida na região na época de condução do experimento. Todos os genótipos de girassol avaliados foram suscetíveis a S. sclerotiorum. ABSTRACT: The objective of the present work was to evaluate the reaction of sunflower genotypes to Sclerotinia stalk and head rot, caused by Sclerotinia esclerotiorum. Eighteen cultivars were evaluated in a field experiments sowed in May 2014, in Maua da Serra, PR, Brazil, under natural infection in the field. The evaluation of the plants indicated that the disease was favored by the climatic conditions of low temperature and high humidity, which occurred in the region during the time of conducting the experiment. All sunflower genotypes tested are susceptible to Sclerotinia stalk and/or head rot.

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RESUMO: Este trabalho teve como objetivo comparar a severidade da mancha de Alternaria de genótipos de girassol em ambientes do Cerrado do Distrito Federal. Três experimentos foram avaliados, dois na Embrapa Cerrados (Planaltina, DF) e um localizado na Embrapa Produtos e Mercado (Recanto das Emas, DF). Foram feitas análises ao longo do ciclo da cultura com um intervalo de 15 dias, sendo a primeira aos 35 dias após emergência. Cada planta foi analisada em três partes: terço inferior, terço médio e terço superior. Ao final de cada experimento, a área abaixo da curva de progresso da doença (AACPD) foi calculada para cada genótipo. De acordo com os resultados observados, o ambiente de sequeiro na Embrapa Cerrados, que deteve a maior média da severidade da doença, entre os ambientes avaliados. Dentre os genótipos avaliados, MG 360 mostrou menor severidade da doença no sequeiro e AGUARA 06 no irrigado da Embrapa Cerrados. O genótipo BSG 42 na Embrapa Produtos e Mercado, se destacou pela menor severidade do fungo. Houve influência significativa do ambiente nos resultados de severidade da doença, que está estreitamente relacionada com os fatores climáticos como temperatura e umidade relativa do ar. A compreensão dessas condições favoráveis ao desenvolvimento do fungo é essencial quando se avalia a resistência em genótipos de girassol. ABSTRACT: This study had the purpose of comparing the severity of Alternaria leaf spot on genotypes of sunflower in the Brazilian Cerrado. Three field trials were established, two at Embrapa Cerrados (Planaltina, DF) and one at Embrapa Produtos e Mercados (Recanto das Emas, DF). Evaluations were made during the crop cycle every 15 days, the first one happening 35 days after crop emergency. Each plant was analyzed in three parts: lower, middle and upper thirds. At the end of each trial the average area under the disease progress curve (AUDPC), for each third, was calculated for all genotypes. According to the observed results, the dryland environment at Embrapa Cerrados had the highest mean disease severity, among the studied environments. Between the evaluated genotypes, MG360 showed less severity in dryland and AGUARA 06 in the irrigated environment at Embrapa Cerrados. At Embrapa Produtos e Mercado the genotype that presented the best performance was BRS G42. Environmental conditions deeply affected the trials, mainly temperature and relative humidity. Their influence on Alternaria leaf spot epidemics in the Cerrado region must be studied in more detail, to avoid misinterpreting data when evaluating sunflower genotypes for resistance to this important fungal disease.

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Two different kinds of sensors have been developed by using the same kind of vapochromic complexes. The vapochromic materials [Au2Ag2(C6F5)(4)L-2](n) have different colours depending on the ligand L. These materials change, reversibly, their optical properties, colour and fluorescence, in the presence of the vapours of volatile organic compounds (VOCs). For practical applications, two different ways of fixing the vapochromic material to the optical fibre have been used: the sol-gel technique and the electrostatic self-assembly method (ESA). With the first technique the sensors can even be used to detect VOCs in aqueous solutions, and using the second method it has been possible to develop nanosensors.

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The Meteorological Section at the scientific camp 2009–2010 conducted a series of meteorological measurements in the region of Biała Góra. The exploration area is located about 2 km east of Międzyzdroje, at the research station of the AMU Faculty of Geographical and Geological Sciences. Members of the section made measurements in the six selected points. The location of points had to reflect the specifics of the area (from the beach to the car park at the research station). The section focused on three basic measurements: air temperature (2009–2010), relative humidity (2009–2010) and atmospheric pressure (2009). This article aims to analyse a topoclimate section of cliff coast in the Wolin National Park. The compilation recognised the impact of various land surfaces, sea and altitude on the variability of air temperature and relative humidity. It notes the varied course of the daily meteorological elements analysed, which is directly related to the value of radiation balance dependent upon the intensity of direct solar radiation. In this article, particular emphasis is applied to the analysis of temperature amplitudes and humidity at different measuring points.

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Monografia apresentada à Universidade Fernando Pessoa para obtenção do grau de Licenciado em Medicina Dentária

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Complex systems, from environmental behaviour to electronics reliability, can now be monitored with Wireless Sensor Networks (WSN), where multiple environmental sensors are deployed in remote locations. This ensures aggregation and reading of data, at lower cost and lower power consumption. Because miniaturisation of the sensing system is hampered by the fact that discrete sensors and electronics consume board area, the development of MEMS sensors offers a promising solution. At Tyndall, the fabrication flow of multiple sensors has been made compatible with CMOS circuitry to further reduce size and cost. An ideal platform on which to host these MEMS environmental sensors is the Tyndall modular wireless mote. This paper describes the development and test of the latest sensors incorporating temperature, humidity, corrosion, and gas. It demonstrates their deployment on the Tyndall platform, allowing real-time readings, data aggregation and cross-correlation capabilities. It also presents the design of the next generation sensing platform using the novel 10mm wireless cube developed by Tyndall.

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Existing Building/Energy Management Systems (BMS/EMS) fail to convey holistic performance to the building manager. A 20% reduction in energy consumption can be achieved by efficiently operated buildings compared with current practice. However, in the majority of buildings, occupant comfort and energy consumption analysis is primarily restricted by available sensor and meter data. Installation of a continuous monitoring process can significantly improve the building systems’ performance. We present WSN-BMDS, an IP-based wireless sensor network building monitoring and diagnostic system. The main focus of WSN-BMDS is to obtain much higher degree of information about the building operation then current BMSs are able to provide. Our system integrates a heterogeneous set of wireless sensor nodes with IEEE 802.11 backbone routers and the Global Sensor Network (GSN) web server. Sensing data is stored in a database at the back office via UDP protocol and can be access over the Internet using GSN. Through this demonstration, we show that WSN-BMDS provides accurate measurements of air-temperature, air-humidity, light, and energy consumption for particular rooms in our target building. Our interactive graphical user interface provides a user-friendly environment showing live network topology, monitor network statistics, and run-time management actions on the network. We also demonstrate actuation by changing the artificial light level in one of the rooms.

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In this paper, The radio Frequency (RF) Monitoring and Measurement of the Environmental Research Institute (ERI) located in Cork city will be monitored and analyzed in both the Zigbee (2.44 GHz) and the industrial, scientific and medical (ISM 433 MHz). The main objective of this survey is to confirm what the noise and interferences threat signals exist in these bands. It was agreed that the surveys would be carried out in 5 different rooms and areas that are candidates for the Wireless Sensors deployments. Based on the carried on study, A Zigbee standard Wireless Sensor Network (WSN) will be developed employing a number of motes for sensing number of signals like temperature, light and humidity beside the RSSI and battery voltage monitoring. Such system will be used later on to control and improve indoor building climate at reduced costs, remove the need for cabling and both installation and operational costs are significantly reduced.

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This thesis describes a broad range of experiments based on an aerosol flow-tube system to probe the interactions between atmospherically relevant aerosols with trace gases. This apparatus was used to obtain simultaneous optical and size distribution measurements using FTIR and SMPS measurements respectively as a function of relative humidity and aerosol chemical composition. Heterogeneous reactions between various ratios of ammonia gas and acidic aerosols were studied in aerosol form as opposed to bulk solutions. The apparatus is unique, in that it employed two aerosol generation methods to follow the size evolution of the aerosol while allowing detailed spectroscopic investigation of its chemical content. A novel chemiluminescence apparatus was also used to measure [NH4+]. SO2.H2O is an important species as it represents the first intermediate in the overall atmospheric oxidation process of sulfur dioxide to sulfuric acid. This complex was produced within gaseous, aqueous and aerosol SO2 systems. The addition of ammonia, gave mainly hydrogen sulfite tautomers and disulfite ions. These species were prevalent at high humidities enhancing the aqueous nature of sulfur (IV) species. Their weak acidity is evident due to the low [NH4+] produced. An increasing recognition that dicarboxylic acids may contribute significantly to the total acid burden in polluted urban environments is evident in the literature. It was observed that speciation within the oxalic, malonic and succinic systems shifted towards the most ionised form as the relative humidity was increased due to complete protonisation. The addition of ammonia produced ammonium dicarboxylate ions. Less reaction for ammonia with the malonic and succinic species were observed in comparison to the oxalic acid system. This observation coincides with the decrease in acidity of these organic species. The interaction between dicarboxylic acids and ‘sulfurous’/sulfuric acid has not been previously investigated. Therefore the results presented here are original to the field of tropospheric chemistry. SHO3-; S2O52-; HSO4-; SO42- and H1,3,5C2,3,4O4-;C2,3,4O4 2- were the main components found in the complex inorganic-organic systems investigated here. The introduction of ammonia produced ammonium dicarboxylate as well as ammonium disulfite/sulfate ions and increasing the acid concentrations increased the total amount of [NH4+].

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A detailed series of simulation chamber experiments has been performed on the atmospheric degradation pathways of the primary air pollutant naphthalene and two of its photooxidation products, phthaldialdehyde and 1-nitronaphthalene. The measured yields of secondary organic aerosol (SOA) arising from the photooxidation of naphthalene varied from 6-20%, depending on the concentrations of naphthalene and nitrogen oxides as well as relative humidity. A range of carbonyls, nitro-compounds, phenols and carboxylic acids were identified among the gas- and particle-phase products. On-line analysis of the chemical composition of naphthalene SOA was performed using aerosol time-of-flight mass spectrometry (ATOFMS) for the first time. The results indicate that enhanced formation of carboxylic acids may contribute to the observed increase in SOA yields at higher relative humidity. The photolysis of phthaldialdehyde and 1-nitronaphthalene was investigated using natural light at the European Photoreactor (EUPHORE) in Valencia, Spain. The photolysis rate coefficients were measured directly and used to confirm that photolysis is the major atmospheric loss process for these compounds. For phthaldialdehyde, the main gas-phase products were phthalide and phthalic anhydride. SOA yields in the range 2-11% were observed, with phthalic acid and dihydroxyphthalic acid identified among the particle phase products. The photolysis of 1-nitronaphthalene yielded nitric oxide and a naphthoxy radical which reacted to form several products. SOA yields in the range 57-71% were observed, with 1,4-naphthoquinone, 1-naphthol and 1,4-naphthalenediol identified in the particle phase. On-line analysis of the SOA generated in an indoor chamber using ATOFMS provided evidence for the formation of high-molecular-weight products. Further investigations revealed that these products are oxygenated polycyclic compounds most likely produced from the dimerization of naphthoxy radicals. These results of this work indicate that naphthalene is a potentially large source of SOA in urban areas and should be included in atmospheric models. The kinetic and mechanistic information could be combined with existing literature data to produce an overall degradation mechanism for naphthalene suitable for inclusion in photochemical models that are used to predict the effect of emissions on air quality.

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Sinapic acid (SA) is a nutraceutical with known anti-oxidant, anti-microbial, anti-inflammatory, anti-cancer, and anti-anxiety properties. Novel co-crystals of SA were prepared with co-formers belonging to the category of GRAS [isonicotinic acid (INC), nicotinamide (NIA)], non-GRAS [4-pyridinecarbonitrile (PYC)], and active pharmaceutical ingredients (APIs) [6-propyl-2-thiouracil (PTU)] list of compounds. Structural study based on the X-ray crystal structures revealed the intermolecular hydrogen-bonded interactions and molecular packing. The crystal structure of sinapic acid shows the anticipated acid-acid homodimer along with discrete hydrogen bonds between the acid carbonyl and the phenolic moiety. The robust acid-acid homodimer appears to be very stable and is retained in the structures of two co-crystals (SA[middle dot]NIA and SA[middle dot]PYC). In these cases, co-crystallization occurs via intermolecular phenol O-H[three dots, centered]Naromatic hydrogen bonds between the co-formers. In the SA[middle dot]PTU[middle dot]2MeCN co-crystal the acid-acid homodimer gives way to the anticipated acid-amide heterodimer, with the phenolic moiety of SA hydrogen-bonded to acetonitrile. Attempts at obtaining the desolvated co-crystal led to lattice breakdown, thus highlighting the importance of acetonitrile in the formation of the co-crystal. Among the co-crystals examined, SA[middle dot]INC (5 weeks), SA[middle dot]NIA (8 weeks) and SA[middle dot]PYC (5 weeks) were found to be stable under accelerated humidity conditions (40 [degree]C, 75% RH), whereas SA[middle dot]PTU[middle dot]2MeCN decomposed after one week into individual components due to solvent loss.

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Widespread adoption of lead-free materials and processing for printed circuit board (PCB) assembly has raised reliability concerns regarding surface insulation resistance (SIR) degradation and electrochemical migration (ECM). As PCB conductor spacings decrease, electronic products become more susceptible to these failures mechanisms, especially in the presence of surface contamination and flux residues which might remain after no-clean processing. Moreover, the probability of failure due to SIR degradation and ECM is affected by the interaction between physical factors (such as temperature, relative humidity, electric field) and chemical factors (such as solder alloy, substrate material, no-clean processing). Current industry standards for assessing SIR reliability are designed to serve as short-term qualification tests, typically lasting 72 to 168 hours, and do not provide a prediction of reliability in long-term applications. The risk of electrochemical migration with lead-free assemblies has not been adequately investigated. Furthermore, the mechanism of electrochemical migration is not completely understood. For example, the role of path formation has not been discussed in previous studies. Another issue is that there are very few studies on development of rapid assessment methodologies for characterizing materials such as solder flux with respect to their potential for promoting ECM. In this dissertation, the following research accomplishments are described: 1). Long-term temp-humidity-bias (THB) testing over 8,000 hours assessing the reliability of printed circuit boards processed with a variety of lead-free solder pastes, solder pad finishes, and substrates. 2). Identification of silver migration from Sn3.5Ag and Sn3.0Ag0.5Cu lead-free solder, which is a completely new finding compared with previous research. 3). Established the role of path formation as a step in the ECM process, and provided clarification of the sequence of individual steps in the mechanism of ECM: path formation, electrodeposition, ion transport, electrodeposition, and filament formation. 4). Developed appropriate accelerated testing conditions for assessing the no-clean processed PCBs' susceptibility to ECM: a). Conductor spacings in test structures should be reduced in order to reflect the trend of higher density electronics and the effect of path formation, independent of electric field, on the time-to-failure. b). THB testing temperatures should be modified according to the material present on the PCB, since testing at 85oC can cause the evaporation of weak organic acids (WOAs) in the flux residues, leading one to underestimate the risk of ECM. 5). Correlated temp-humidity-bias testing with ion chromatography analysis and potentiostat measurement to develop an efficient and effective assessment methodology to characterize the effect of no-clean processing on ECM.

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Twelve months of aerosol size distributions from 3 to 560nm, measured using scanning mobility particle sizers are presented with an emphasis on average number, surface, and volume distributions, and seasonal and diurnal variation. The measurements were made at the main sampling site of the Pittsburgh Air Quality Study from July 2001 to June 2002. These are supplemented with 5 months of size distribution data from 0.5 to 2.5μm measured with a TSI aerosol particle sizer and 2 months of size distributions measured at an upwind rural sampling site. Measurements at the main site were made continuously under both low and ambient relative humidity. The average Pittsburgh number concentration (3-500nm) is 22,000cm-3 with an average mode size of 40nm. Strong diurnal patterns in number concentrations are evident as a direct effect of the sources of particles (atmospheric nucleation, traffic, and other combustion sources). New particle formation from homogeneous nucleation is significant on 30-50% of study days and over a wide area (at least a hundred kilometers). Rural number concentrations are a factor of 2-3 lower (on average) than the urban values. Average measured distributions are different from model literature urban and rural size distributions. © 2004 Elsevier Ltd. All rights reserved.