1,497 research outputs found

    Heat transfer characteristics of hydrid microjet-microchannel cooling module

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    This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.The paper presents the experimental investigation of heat transfer intensification in a microjetmicrochannel cooling module. Applied technology takes benefits from two very attractive heat removal techniques. When jets are impinging on the surface, they have a very high kinetic energy at the stagnation point, also in microchannels boundary layer is very thin allowing to obtain very high heat fluxes. Main objective of this paper was to experimentally investigate the performance of a microjet-microchannel cooling module. Intense heat transfer in the test section has been examined and described with precise measurements of thermal and flow conditions. Reported tests were conducted under steady state conditions for single phase liquid cooling. Obtained database of experimental data were compared to standard cooling techniques, and compared with superposed semi-empirical models for minichannels and microjet cooling, Mikielewicz and Muszynski (2009). Gathered data with analytical solutions and numerical computer simulation allows the rational design and calculation of hybrid modules and optimum performance of these modules for various industrial applications

    Comparison of heat transfer characteristics in surface cooling with boiling microjets of water, ethanol and HFE7100

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    This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.The basis of microjet technology is to produce laminar jets which when impinging the surface have a very high kinetic energy at the stagnation point. Boundary layer is not formed in those conditions, while the area of film cooling has a very high turbulence resulting from a very high heat transfer coefficient. Applied technology of jet production can result with the size of jets ranging from 20 to 500μm in breadth and 20 to 100μm in width. Presented data are used in order to validate authors own semi-empirical model of surface cooling by evaporating microjet impingement in the stagnation point. Main objective of this paper was to investigate the physical phenomena occurring on solid surfaces upon impingement of the single microjet in case of three fluids. Intense heat transfer in the impact zone of microjet has been examined and described with precise measurements of thermal and flow conditions of microjets. Reported tests were conducted under steady state conditions for surface cooling by single microjet producing an evaporating film. Obtained database of experimental data with analytical solutions and numerical computer simulation allows the rational design and calculation of microjet modules and optimum performance of these modules for various industrial applications

    Blood manufacturing methods affect red blood cell product characteristics and immunomodulatory activity

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    Transfusion of red cell concentrates (RCCs) is associated with increased risk of adverse outcomes that may be affected by different blood manufacturing methods and the presence of extracellular vesicles (EVs). We investigated the effect of different manufacturing methods on hemolysis, residual cells, cell-derived EVs, and immunomodulatory effects on monocyte activity. Thirty-two RCC units produced using whole blood filtration (WBF), red cell filtration (RCF), apheresis-derived (AD), and whole blood-derived (WBD) methods were examined (n = 8 per method). Residual platelet and white blood cells (WBCs) and the concentration, cell of origin, and characterization of EVs in RCC supernatants were assessed in fresh and stored supernatants. Immunomodulatory activity of RCC supernatants was assessed by quantifying monocyte cytokine production capacity in an in vitro transfusion model. RCF units yielded the lowest number of platelet and WBC-derived EVs, whereas the highest number of platelet EVs was in AD (day 5) and in WBD (day 42). The number of small EVs (<200 nm) was greater than large EVs (≥200 nm) in all tested supernatants, and the highest level of small EVs were in AD units. Immunomodulatory activity was mixed, with evidence of both inflammatory and immunosuppressive effects. Monocytes produced more inflammatory interleukin-8 after exposure to fresh WBF or expired WBD supernatants. Exposure to supernatants from AD and WBD RCC suppressed monocyte lipopolysaccharide-induced cytokine production. Manufacturing methods significantly affect RCC unit EV characteristics and are associated with an immunomodulatory effect of RCC supernatants, which may affect the quality and safety of RCCs

    Dynamic changes in ANGUSTIFOLIA3 complex composition reveal a growth regulatory mechanism in the maize leaf

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    Most molecular processes during plant development occur with a particular spatio-temporal specificity. Thus far, it has remained technically challenging to capture dynamic protein-protein interactions within a growing organ, where the interplay between cell division and cell expansion is instrumental. Here, we combined high-resolution sampling of the growing maize (Zea mays) leaf with tandem affinity purification followed by mass spectrometry. Our results indicate that the growth-regulating SWI/SNF chromatin remodeling complex associated with ANGUSTIFOLIA3 (AN3) was conserved within growing organs and between dicots and monocots. Moreover, we were able to demonstrate the dynamics of the AN3-interacting proteins within the growing leaf, since copurified GROWTH-REGULATING FACTORs (GRFs) varied throughout the growing leaf. Indeed, GRF1, GRF6, GRF7, GRF12, GRF15, and GRF17 were significantly enriched in the division zone of the growing leaf, while GRF4 and GRF10 levels were comparable between division zone and expansion zone in the growing leaf. These dynamics were also reflected at the mRNA and protein levels, indicating tight developmental regulation of the AN3-associated chromatin remodeling complex. In addition, the phenotypes of maize plants overexpressing miRNA396a-resistant GRF1 support a model proposing that distinct associations of the chromatin remodeling complex with specific GRFs tightly regulate the transition between cell division and cell expansion. Together, our data demonstrate that advancing from static to dynamic protein-protein interaction analysis in a growing organ adds insights in how developmental switches are regulated

    Aesthetic Highlight Detection in Movies Based on Synchronization of Spectators’ Reactions.

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    Detection of aesthetic highlights is a challenge for understanding the affective processes taking place during movie watching. In this paper we study spectators’ responses to movie aesthetic stimuli in a social context. Moreover, we look for uncovering the emotional component of aesthetic highlights in movies. Our assumption is that synchronized spectators’ physiological and behavioral reactions occur during these highlights because: (i) aesthetic choices of filmmakers are made to elicit specific emotional reactions (e.g. special effects, empathy and compassion toward a character, etc.) and (ii) watching a movie together causes spectators’ affective reactions to be synchronized through emotional contagion. We compare different approaches to estimation of synchronization among multiple spectators’ signals, such as pairwise, group and overall synchronization measures to detect aesthetic highlights in movies. The results show that the unsupervised architecture relying on synchronization measures is able to capture different properties of spectators’ synchronization and detect aesthetic highlights based on both spectators’ electrodermal and acceleration signals. We discover that pairwise synchronization measures perform the most accurately independently of the category of the highlights and movie genres. Moreover, we observe that electrodermal signals have more discriminative power than acceleration signals for highlight detection

    Ground Autonomy for an Aging Spacecraft

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    As it approaches the sixteenth of a 5 year prime mission, NASA's Solar Radiation and Climate Experiment (SORCE) mission continues to meet and exceed all science requirements while operating with severely degraded batteries. By 2013, the batteries had degraded such that the On Board Computer (OBC) could not be powered through eclipse. This prevents science data collection in eclipse and erases over 99% of all stored science and engineering telemetry. To mitigate these problems, the Flight Operations Team (FOT) at the Laboratory for Atmospheric and Space Physics (LASP) adopted a new operations scheme. "Daylight Only Operations" (DO-OP) transitions the spacecraft from safemode to science mode every orbit. This involved heavily automating the transition process using ground autonomy to improve spacecraft recovery time to 6 minutes - down from 3 orbits of manual commanding. While highly successful, this method of operations poses daily challenges that must be overcome using increasingly complex ground software

    Films, Affective Computing and Aesthetic Experience: Identifying Emotional and Aesthetic Highlights from Multimodal Signals in a Social Setting.

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    Over the last years, affective computing has been strengthening its ties with the humanities, exploring and building understanding of people’s responses to specific artistic multimedia stimuli. “Aesthetic experience” is acknowledged to be the subjective part of some artistic exposure, namely, the inner affective state of a person exposed to some artistic object. In this work, we describe ongoing research activities for studying the aesthetic experience of people when exposed to movie artistic stimuli. To do so, this work is focused on the definition of emotional and aesthetic highlights in movies and studies the people responses to them using physiological and behavioral signals, in a social setting. In order to examine the suitability of multimodal signals for detecting highlights, we initially evaluate a supervised highlight detection system. Further, in order to provide an insight on the reactions of people, in a social setting, during emotional and aesthetic highlights, we study two unsupervised systems. Those systems are able to (a) measure the distance among the captured signals of multiple people using the dynamic time warping algorithm and (b) create a reaction profile for a group of people that would be indicative of whether that group reacts or not at a given time. The results indicate that the proposed systems are suitable for detecting highlights in movies and capturing some form of social interactions across different movie genres. Moreover, similar social interactions during exposure to emotional and some types of aesthetic highlights, such as those corresponding to technical or lightening choices of the director, can be observed. The utilization of electrodermal activity measurements yields in better performances than those achieved when using acceleration measurements, whereas fusion of the modalities does not appear to be beneficial for the majority of the cases

    Recognizing Induced Emotions of Movie Audiences: Are Induced and Perceived Emotions the Same?

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    Predicting the emotional response of movie audi- ences to affective movie content is a challenging task in affective computing. Previous work has focused on using audiovisual movie content to predict movie induced emotions. However, the relationship between the audience’s perceptions of the affective movie content (perceived emotions) and the emotions evoked in the audience (induced emotions) remains unexplored. In this work, we address the relationship between perceived and in- duced emotions in movies, and identify features and modelling approaches effective for predicting movie induced emotions. First, we extend the LIRIS-ACCEDE database by annotating perceived emotions in a crowd-sourced manner, and find that perceived and induced emotions are not always consistent. Second, we show that dialogue events and aesthetic highlights are effective predictors of movie induced emotions. In addition to movie based features, we also study physiological and be- havioural measurements of audiences. Our experiments show that induced emotion recognition can benefit from including temporal context and from including multimodal information. Our study bridges the gap between affective content analysis and induced emotion prediction

    Thin crust and exposed mantle control sulfide differentiation in slow-spreading ridge magmas

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    Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Geology 45 (2017): 935-938, doi:10.1130/G39287.1.Gabbroic veins enclosed in mantle peridotite from ocean core complexes next to oceanic transform faults demonstrate sub-crustal crystallization of silicate minerals from a MORB-like melt. Cooler lithosphere there may also affect sulfide crystallization and the metal budget of the lower and upper crust but the related sulfide behavior is poorly understood. Here, we use chalcophile elements to trace sulfide crystallization in a suite of MORB's erupted at the Kane Megamullion south of the Kane Fracture Zone along the Mid-Atlantic Ridge. Cool lithosphere there is inferred from a low magma supply, and lithostratigraphic evidence for thin crust with abundant mantle rock exposed to the seafloor (Dick et al., 2008). We show that the concentrations of Cu, Zn, As, Ga, Pb, Sb and Tl in the Kane Megamullion MORB's rise linearly with melt differentiation expressed by decreasing MgO and Ni content. The low-pressure fractional crystallization within the crust thus occurs at sulfur-undersaturated conditions. Sulfur-undersaturated MORB's are unusual. At the Kane Megamullion, however, the thin crust allows melt to more extensively interact with the shallow and serpentinized mantle. We argue that sulfur and chalcophile elements have been lost from the melt due to sulfide crystallization during melt-rock reaction in the shallow mantle.This research was funded by a Diamond Grant of the Polish Ministry of Science and Higher Education (DI2012 2057 42 to Ciazela), and partially supported by the European Association of Geochemistry (Early Career Science Ambassador grant to Ciazela) and the National Science Foundation (grant #’s OCE1434452 and OCE1637130 to Dick)
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