132 research outputs found

    Evaluation of brick infill walls under in-plane and out-of-plane loading

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    In this paper, the in-plane (IP) and out-of-plane (OP) interaction of masonry infill walls with various length-to-height ratios and vertical forces from dead and live loads are studied. For this purpose, calibrated numerical simulation for IP and OP behaviors of infilled frames has been exploited. In this method, first, the vertical loads are applied, then increasing IP displacement is imposed at the top of the models and finally OP demands are applied to the walls up to their failure. Two different methods of applying OP loading are studied: increasing static uniform pressure on the wall, and increasing dynamic acceleration. Three levels of IP displacement demands are considered: at the first reduction of tangential stiffness for IP force-displacement response, at the maximum IP strength, and at the displacement related to 20 % reduction of IP strength. The results obviously show that up to the point of the maximum IP strength capacity, the OP behavior of the considered models slightly enhanced due to the effects of improved arching actions originated from the development of IP compressive diagonal struts. Moreover, slight differences exist between the static and dynamic loadings in OP direction, hence proving the accuracy of the equivalent static loading in determining OP capacity for the studied infilled frames. Comparing the results of masonry infilled frames with those of the corresponding masonry walls indicate that the IP displacements negatively affect the OP strength in the latter, even at small IP displacement demands; however, the rate of OP strength reduction in larger IP drift ratios is lower compared to that of the corresponding infilled frame

    Aircraft-based aerosol size and composition measurements during ACE-Asia using an Aerodyne aerosol mass spectrometer

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    An Aerodyne aerosol mass spectrometer (AMS) was deployed during the Aerosol Characterization Experiment-Asia (ACE-Asia) field campaign on board the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS) Twin Otter aircraft to measure the size-resolved chemical composition of submicron aerosols in the outflow from eastern Asia. Research flights were carried out from 31 March to 1 May 2001 in an area that covered 127°E–135°E and 32°N–38°N. Valid data from the AMS were obtained during 15 out of a total of 19 research flights. During the mission the AMS measured distinct layers (from the boundary layer to ∼3700 m) of submicron aerosols composed of sulfate, ammonium, and organics as the major nonrefractory components, separated by layers with much lower aerosol concentrations. Sulfate and organics mass concentrations of up to 10 μg m^(−3) and 13 μg m^(−3), respectively, were measured in some pollution layers. Back-trajectory analysis shows that the polluted layers originated in urban and industrial areas of China and Korea. The mass-weighed size distribution of the submicron sulfate was relatively constant from day to day and layer to layer, with an aerodynamic diameter mode of 400–500 nm and a width (full width half maximum) of about 450 nm in most of the layers. On the days with low influence of dust in the aerosol outflow, as indicated by other instruments aboard the Twin Otter, the total mass of nonrefractory aerosols estimated by the AMS correlated well with total volume of aerosols measured by a differential mobility analyzer

    Los Angeles Basin airborne organic aerosol characterization during CalNex

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    We report airborne organic aerosol (OA) measurements over Los Angeles carried out in May 2010 as part of the CalNex field campaign. The principal platform for the airborne data reported here was the CIRPAS Twin Otter (TO); airborne data from NOAA WP-3D aircraft and Pasadena CalNex ground-site data acquired during simultaneous TO flybys are also presented. Aerodyne aerosol mass spectrometer measurements constitute the main source of data analyzed. The increase in organic aerosol oxidation from west to east in the basin was sensitive to OA mass loading, with a greater spatial trend in O:C associated with lower mass concentration. Three positive matrix factorization (PMF) components (hydrocarbon-like organic aerosol (HOA), semi-volatile oxidized organic aerosol (SVOOA), and low volatility oxidized organic aerosol (LVOOA)) were resolved for the one flight that exhibited the largest variability in estimated O:C ratio. Comparison of the PMF factors with two optical modes of refractory black carbon (rBC)-containing aerosol revealed that the coating of thinly coated rBC-containing aerosol, dominant in the downtown region, is likely composed of HOA, whereas more thickly coated rBC-containing aerosol, dominant in the Banning pass outflow, is composed of SVOOA and LVOOA. The correlation of water-soluble organic mass to oxidized organic aerosol (OOA) is higher in the outflows than in the basin due to the higher mass fraction of OOA/OA in the outflows. By comparison, the average OA concentration over Mexico City MILAGRO (Megacity Initiative: Local and Global Research Observations) campaign was ∼7 times higher than the airborne average during CalNex

    Aerosol–cloud drop concentration closure in warm cumulus

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    Our understanding of the activation of aerosol particles into cloud drops during the formation of warm cumulus clouds presently has a limited observational foundation. Detailed observations of aerosol size and composition, cloud microphysics and dynamics, and atmospheric thermodynamic state were collected in a systematic study of 21 cumulus clouds by the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter aircraft during NASA's Cirrus Regional Study of Tropical Anvils and Cirrus Layers–Florida Area Cirrus Experiment (CRYSTAL-FACE). An “aerosol-cloud” closure study was carried out in which a detailed cloud activation parcel model, which predicts cloud drop concentration using observed aerosol concentration, size distribution, cloud updraft velocity, and thermodynamic state, is evaluated against observations. On average, measured droplet concentration in adiabatic cloud regions is within 15% of the predictions. This agreement is corroborated by independent measurements of aerosol activation carried out by two cloud condensation nucleus (CCN) counters on the aircraft. Variations in aerosol concentration, which ranged from 300 to 3300 cm^(−3), drives large microphysical differences (250–2300 cm^(−3)) observed among continental and maritime clouds in the South Florida region. This is the first known study in which a cloud parcel model is evaluated in a closure study using a constraining set of data collected from a single platform. Likewise, this is the first known study in which relationships among aerosol size distribution, CCN spectrum, and cloud droplet concentration are all found to be consistent with theory within experimental uncertainties much less than 50%. Vertical profiles of cloud microphysical properties (effective radius, droplet concentration, dispersion) clearly demonstrate the boundary layer aerosol's effect on cloud microphysics throughout the lowest 1 km of cloud depth. Onboard measurements of aerosol hygroscopic growth and the organic to sulfate mass ratio are related to CCN properties. These chemical data are used to quantify the range of uncertainty associated with the simplified treatment of aerosol composition assumed in the closure study

    Aircraft-based aerosol size and composition measurements during ACE-Asia using an Aerodyne aerosol mass spectrometer

    Get PDF
    An Aerodyne aerosol mass spectrometer (AMS) was deployed during the Aerosol Characterization Experiment-Asia (ACE-Asia) field campaign on board the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS) Twin Otter aircraft to measure the size-resolved chemical composition of submicron aerosols in the outflow from eastern Asia. Research flights were carried out from 31 March to 1 May 2001 in an area that covered 127°E–135°E and 32°N–38°N. Valid data from the AMS were obtained during 15 out of a total of 19 research flights. During the mission the AMS measured distinct layers (from the boundary layer to ∼3700 m) of submicron aerosols composed of sulfate, ammonium, and organics as the major nonrefractory components, separated by layers with much lower aerosol concentrations. Sulfate and organics mass concentrations of up to 10 μg m^(−3) and 13 μg m^(−3), respectively, were measured in some pollution layers. Back-trajectory analysis shows that the polluted layers originated in urban and industrial areas of China and Korea. The mass-weighed size distribution of the submicron sulfate was relatively constant from day to day and layer to layer, with an aerodynamic diameter mode of 400–500 nm and a width (full width half maximum) of about 450 nm in most of the layers. On the days with low influence of dust in the aerosol outflow, as indicated by other instruments aboard the Twin Otter, the total mass of nonrefractory aerosols estimated by the AMS correlated well with total volume of aerosols measured by a differential mobility analyzer

    FILTWAM and Voice Emotion Recognition

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    This paper introduces the voice emotion recognition part of our framework for improving learning through webcams and microphones (FILTWAM). This framework enables multimodal emotion recognition of learners during game-based learning. The main goal of this study is to validate the use of microphone data for a real-time and adequate interpretation of vocal expressions into emotional states were the software is calibrated with end users. FILTWAM already incorporates a valid face emotion recognition module and is extended with a voice emotion recognition module. This extension aims to provide relevant and timely feedback based upon learner's vocal intonations. The feedback is expected to enhance learner’s awareness of his or her own behavior. Six test persons received the same computer-based tasks in which they were requested to mimic specific vocal expressions. Each test person mimicked 82 emotions, which led to a dataset of 492 emotions. All sessions were recorded on video. An overall accuracy of our software based on the requested emotions and the recognized emotions is a pretty good 74.6% for the emotions happy and neutral emotions; but will be improved for the lower values of an extended set of emotions. In contrast with existing software our solution allows to continuously and unobtrusively monitor learners’ intonations and convert these intonations into emotional states. This paves the way for enhancing the quality and efficacy of game-based learning by including the learner's emotional states, and links these to pedagogical scaffolding.The Netherlands Laboratory for Lifelong Learning (NELLL) of the Open University of the Netherlands

    Biallelic loss of LDB3 leads to a lethal pediatric dilated cardiomyopathy

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    Autosomal dominant variants in LDB3 (also known as ZASP), encoding the PDZ-LIM domain-binding factor, have been linked to a late onset phenotype of cardiomyopathy and myofibrillar myopathy in humans. However, despite knockout mice displaying a much more severe phenotype with premature death, bi-allelic variants in LDB3 have not yet been reported. Here we identify biallelic loss-of-function variants in five unrelated cardiomyopathy families by next-generation sequencing. In the first family, we identified compound heterozygous LOF variants in LDB3 in a fetus with bilateral talipes and mild left cardiac ventricular enlargement. Ultra-structural examination revealed highly irregular Z-disc formation, and RNA analysis demonstrated little/no expression of LDB3 protein with a functional C-terminal LIM domain in muscle tissue from the affected fetus. In a second family, a homozygous LDB3 nonsense variant was identified in a young girl with severe early-onset dilated cardiomyopathy with left ventricular non-compaction; the same homozygous nonsense variant was identified in a third unrelated female infant with dilated cardiomyopathy. We further identified homozygous LDB3 frameshift variants in two unrelated probands diagnosed with cardiomegaly and severely reduced left ventricular ejection fraction. Our findings demonstrate that recessive LDB3 variants can lead to an early-onset severe human phenotype of cardiomyopathy and myopathy, reminiscent of the knockout mouse phenotype, and supporting a loss of function mechanism

    Characteristics, sources, and transport of aerosols measured in spring 2008 during the aerosol, radiation, and cloud processes affecting Arctic Climate (ARCPAC) Project

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    We present an overview of the background, scientific goals, and execution of the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC) project of April 2008. We then summarize airborne measurements, made in the troposphere of the Alaskan Arctic, of aerosol particle size distributions, composition, and optical properties and discuss the sources and transport of the aerosols. The aerosol data were grouped into four categories based on gas-phase composition. First, the background troposphere contained a relatively diffuse, sulfate-rich aerosol extending from the top of the sea-ice inversion layer to 7.4 km altitude. Second, a region of depleted (relative to the background) aerosol was present within the surface inversion layer over sea-ice. Third, layers of dense, organic-rich smoke from open biomass fires in southern Russia and southeastern Siberia were frequently encountered at all altitudes from the top of the inversion layer to 7.1 km. Finally, some aerosol layers were dominated by components originating from fossil fuel combustion. <br></br> Of these four categories measured during ARCPAC, the diffuse background aerosol was most similar to the average springtime aerosol properties observed at a long-term monitoring site at Barrow, Alaska. The biomass burning (BB) and fossil fuel layers were present above the sea-ice inversion layer and did not reach the sea-ice surface during the course of the ARCPAC measurements. The BB aerosol layers were highly scattering and were moderately hygroscopic. On average, the layers produced a noontime net heating of ~0.1 K day<sup>−1</sup> between 3 and 7 km and a slight cooling at the surface. The ratios of particle mass to carbon monoxide (CO) in the BB plumes, which had been transported over distances >5000 km, were comparable to the high end of literature values derived from previous measurements in wildfire smoke. These ratios suggest minimal precipitation scavenging and removal of the BB particles between the time they were emitted and the time they were observed in dense layers above the sea-ice inversion layer
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