668 research outputs found
Microscale 3-D capacitance tomography with a CMOS sensor array
Electrical capacitance tomography (ECT) is a non-optical imaging technique in which a map of the interior permittivity of a volume is estimated by making capacitance measurements at its boundary and solving an inverse problem. While previous ECT demonstrations have often been at centimeter scales, ECT is not limited to macroscopic systems. In this paper, we demonstrate ECT imaging of polymer microspheres and bacterial biofilms using a CMOS microelectrode array, achieving spatial resolution of 10 microns. Additionally, we propose a deep learning architecture and an improved multi-objective training scheme for reconstructing out-of-plane permittivity maps from the sensor measurements. Experimental results show that the proposed approach is able to resolve microscopic 3-D structures, achieving 91.5% prediction accuracy on the microsphere dataset and 82.7% on the biofilm dataset, including an average of 4.6% improvement over baseline computational methods.1019304.01 - Burroughs Wellcome Fund; 000000000000000000000000000000000000000000000000000000001612 - Brown UniversityFirst author draf
Microscale 3-D Capacitance Tomography with a CMOS Sensor Array
Electrical capacitance tomography (ECT) is a nonoptical imaging technique in
which a map of the interior permittivity of a volume is estimated by making
capacitance measurements at its boundary and solving an inverse problem. While
previous ECT demonstrations have often been at centimeter scales, ECT is not
limited to macroscopic systems. In this paper, we demonstrate ECT imaging of
polymer microspheres and bacterial biofilms using a CMOS microelectrode array,
achieving spatial resolution of 10 microns. Additionally, we propose a deep
learning architecture and an improved multi-objective training scheme for
reconstructing out-of-plane permittivity maps from the sensor measurements.
Experimental results show that the proposed approach is able to resolve
microscopic 3-D structures, achieving 91.5% prediction accuracy on the
microsphere dataset and 82.7% on the biofilm dataset, including an average of
4.6% improvement over baseline computational methods
Advanced Spectroscopic and Thermal Imaging Instrumentation for Shock Tube and Ballistic Range Facilities
The Electric Arc Shock Tube (EAST) facility and Hypervelocity Free Flight Aerodynamic Facility (HFFAF, an aeroballistic range) at NASA Ames support basic research in aerothermodynamic phenomena of atmospheric entry, specifically shock layer radiation spectroscopy, convective and radiative heat transfer, and transition to turbulence. Innovative optical instrumentation has been developed and implemented to meet the challenges posed from obtaining such data in these impulse facilities. Spatially and spectrally resolved measurements of absolute radiance of a travelling shock wave in EAST are acquired using multiplexed, time-gated imaging spectrographs. Nearly complete spectral coverage from the vacuum ultraviolet to the near infrared is possible in a single experiment. Time-gated thermal imaging of ballistic range models in flight enables quantitative, global measurements of surface temperature. These images can be interpreted to determine convective heat transfer rates and reveal transition to turbulence due to isolated and distributed surface roughness at hypersonic velocities. The focus of this paper is a detailed description of the optical instrumentation currently in use in the EAST and HFFAF
A Proposal of Standardised Data Model for Cloud Manufacturing Collaborative Networks
[EN] The growing amount of data to be handled by collaborative networks raises the need of introducing innovative solutions to fulfil the lack of affordable tools, especially for Small and Medium-Sized Enterprises, to manage and exchange data. The European H2020 Project Cloud Collaborative Manufacturing Networks develops and offers a structured data model, called Standardised Tables, as an organised framework to jointly work with existing databases to manage big data collected from different industries belonging to the CNs. The information of the Standardised Tables will be mainly used with optimisation and collaboration purposes. The paper describes an application of the Standardised Tables in one of the pilots of the aforementioned project, the automotive industry pilot, for solving the collaborative problem of a Materials Requirement Plan.The research leading to these results is in the frame of the “Cloud Collaborative Manufacturing Networks” (C2NET) project, which has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement
No. 636909.Andres, B.; Sanchis, R.; Poler, R.; Saari, L. (2017). A Proposal of Standardised Data Model for Cloud Manufacturing Collaborative Networks. IFIP Advances in Information and Communication Technology. 560:77-85. https://doi.org/10.1007/978-3-319-65151-4_7S7785560Andres, B., Poler, R.: Models, guidelines and tools for the integration of collaborative processes in non-hierarchical manufacturing networks: a review. Int. J. Comput. Integr. Manuf. 2(29), 166–201 (2016)Zikopoulos, P., Eaton, C.: Understanding Big Data: Analytics for Enterprise Class Hadoop and Streaming Data. McGraw-Hill Osborne Media, New York (2011)Zhou, B., Wang, S., Xi, L.: Data model design for manufacturing execution system. J. Manuf. Technol. Manag. 16(8), 909–935 (2005)Steven, W.: Getting the MES model – methods for system analysis. ISA Trans. 35(2), 95–103 (1996)Reda, A.: Extracting the extended entity-relationship model from a legacy relational database. Inf. Syst. 28(6), 597–618 (2003)Teorey, T.J., Yang, D., Fry, J.P.: A logical design methodology for relational database using the extended entity-relationship model. ACM Comput. Surv. 18(2), 197–222 (1986)Victor, M., Arie, S.: Representing extended entity-relationship structures in relational databases: a modular approach. ACM Trans. Database Syst. 17(3), 423–464 (1992)CORDIS Europa, Factories of the Future, H2020-EU.2.1.5.1. - Technologies for Factories of the Future (2014)H2020 Project C2NET (2015). http://cordis.europa.eu/project/rcn/193440_en.htmlAndres, B., Sanchis, R., Poler, R.: A cloud platform to support collaboration in supply networks. Int. J. Prod. Manag. Eng. 4(1), 5–13 (2016)APICS, “SCOR Framework,” Supply Chain Operations Reference model (SCOR) (2017)Orbegozo, A., Andres, B., Mula, J., Lauras, M., Monteiro, C., Malheiro, M.: An overview of optimization models for integrated replenishment and producction planning decisions. In: Building Bridges Between Researchers and Practitioners. Book of Abstracts of the International Joint Conference CIO-ICIEOM-IISE-AIM (IJC2016), p. 68 (2016)Andres, B., Poler, R., Saari, L., Arana, J., Benaches, J.V., Salazar, J.: Optimization models to support decision-making in collaborative networks: a review. In: Building Bridges Between Researchers and Practitioners. Book of Abstracts of the International Joint Conference CIO-ICIEOM-IISE-AIM (IJC2016), p. 70 (2016)Andres, B., Sanchis, R., Lamothe, J., Saari, L., Hauser, F.: Combined models for production and distribution planning in a supply chain. In: Building Bridges Between Researchers and Practitioners. Book of Abstracts of the International Joint Conference CIO-ICIEOM-IISE-AIM (IJC2016), p. 71 (2016
Shock Tube and Ballistic Range Facilities at NASA Ames Research Center
The Electric Arc Shock Tube (EAST) facility and the Hypervelocity Free Flight Aerodynamic Facility (HFFAF) at NASA Ames Research Center are described. These facilities have been in operation since the 1960s and have supported many NASA missions and technology development initiatives. The facilities have world-unique capabilities that enable experimental studies of real-gas aerothermal, gas dynamic, and kinetic phenomena of atmospheric entry
Importance of obesity, race and age to the cardiac structural and functional effects of hypertension
AbstractObjectives. The purpose of this study was to determine the effects of obesity and its interaction with age, race and the magnitude of blood pressure elevation in a large cohort of patients with mild to moderate hypertension and a high prevalence of left ventricular hypertrophy.Background. Obesity, race and age each have important effects on the incidence and severity of hypertension and may contribute to the effects of blood pressure elevation on the cardiac manifestations of hypertension.Methods. Left ventricular structure and function were assessed with two-dimensional targeted M-mode echocardiography in 692 men with mild to moderate hypertension (average blood pressure 153/100 mm Hg), and the data were compared in relation to obesity (determined from body mass index), age, race, blood pressure, physical activity, plasma renin activity, urinary sodium excretion, hematocrit, heart rate and serum lipids.Results. Left ventricular hypertrophy was common (630% with increased left ventricular mass, 22% with left ventricular hypertrophy on the electrocardiogram [ECG]). On multivariable regression analysis, body mass index was the strongest predictor of left ventricular mass and magnified the slope relation of blood pressure to left ventricular mass. Despite a greater prevalence of ECG left ventricular hypertrophy in blacks (31%) than in whites (10%), left ventricular mass and echocardiographic prevalence of left ventricular hypertrophy did not differ by race. However, septal, posterior left ventricular and relative wall thickness were greater in black than in white men.Conclusions. Obesity is the strongest clinical predictor of left ventricular mass and left ventricular hypertrophy la men, even in those with mild to moderate hypertension of sufficient severity to be associated with a high prevalence of left ventricular hypertrophy. Moreover, independent effects of systolic blood pressure on left ventricular mass an amplified by obesity. Although race does not affect left ventricular mass or the prevalence of left ventricular hypertrophy, black race is associated with greater relative wall thickness, itself a predictor of unfavorable cardiovascular outcome
Accumbens D2-MSN hyperactivity drives antipsychotic-induced behavioral supersensitivity
Antipsychotic-induced dopamine supersensitivity, or behavioral supersensitivity, is a problematic consequence of long-term antipsychotic treatment characterized by the emergence of motor abnormalities, refractory symptoms, and rebound psychosis. The underlying mechanisms are unclear and no approaches exist to prevent or reverse these unwanted effects of antipsychotic treatment. Here we demonstrate that behavioral supersensitivity stems from long-lasting pre, post and perisynaptic plasticity, including insertion of Ca2+-permeable AMPA receptors and loss of D2 receptor-dependent inhibitory postsynaptic currents (IPSCs) in D2 receptor-expressing medium spiny neurons (D2-MSNs) in the nucleus accumbens core (NAcore). The resulting hyperexcitability, prominent in a subpopulation of D2-MSNs (21%), caused locomotor sensitization to cocaine and was associated with behavioral endophenotypes of antipsychotic treatment resistance and substance use disorder, including disrupted extinction learning and augmented cue-induced cocaine-seeking behavior. Chemogenetic restoration of IPSCs in D2-MSNs in the NAcore was sufficient to prevent antipsychotic-induced supersensitivity, pointing to an entirely novel therapeutic direction for overcoming this condition
Computational fluid dynamics simulation on the heat sink performance of a graphics processing unit thermal management
The article focuses on the numerical investigation of temperature distribution in a central processing units (CPU) case with
different time interval such as t = 100 s, 200 s, 300 s, 400 s, 500 s. Heat sink performance of a graphics processing unit
(GPU) thermal management and impacts of different shape and velocity on the thermal performance are considered. In this
study, three heat sink models are designed (A, B, and C) based on the volume area of heat sink. This study emphasizes the
heat transfer phenomena caused by a GPU in a computer case in both steady state and transient state. A CFD software STAR
– CCM + is used to carry out to study the fluid flow and heat transfer simulation of graphics card heat sink in a computer
case and the same time an enhanced method of reducing the temperature of GPU is proposed. The results show that heat sink
B with the least volume area, has the fastest rate of heat exchange followed by heat sink C and heat sink A. Likewise, the
result indicates an inverse relationship between the volume and the total surface of the heat sink and the final temperature
of the graphics card chip. As the total volume and surface of the heat sink increases, the rate of heat transfer increases via
faster rate of conduction between graphics card chip to heat sink meanwhile the cooling of the heat sink is aided by wind
inlet via convection
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Current Issues in Terrestrial Solar Radiation Instrumentation for Energy, Climate and Space Applications Preprint prepared for New RAD '99
Reductions of uncertainty in terrestrial solar radiation measurements are needed to validate the Earth's radiation balance derived from satellite data. Characterization of solar energy resources for renewable technologies requires greater time and spatial resolution for economical technology deployment. Solar radiation measurement research at the National Renewable Energy Laboratory addresses calibrations, operational characteristics, and corrections for terrestrial solar radiation measurements. We describe progress in measurements of broadband diffuse-sky radiation, and characterization of field instrument thermal offsets and spectral irradiance. The need and prospects for absolute references for diffuse and long-wave terrestrial solar radiation measurements are discussed. Reductions in uncertainty of broadband irradiance measurements from tens of watts per square meter to a few (one to two) watts per square meter are reported, which reduce time and labor to quantify and identify trends in artificial optical radiation sources, terrestrial solar radiation, and the Earth's radiation budget
Developing highly nanoporous titanate structures via wet chemical conversion of DC magnetron sputtered titanium thin films
© 2020 The Authors Titanate structures have been widely investigated as biomedical component surfaces due to their bioactive, osteoinductive and antibacterial properties. However, these surfaces are limited to Ti and its alloys, due to the nature of the chemical conversion employed. The authors present a new method for generating nanoporous titanate structures on alternative biomaterial surfaces, such as other metals/alloys, ceramics and polymers, to produce bioactive and/or antibacterial properties in a simple yet effective way. Wet chemical (NaOH; 5 M; 60 °C; 24 h) conversion of DC magnetron sputtered Ti surfaces on 316L stainless steel were investigated to explore effects of microstructure on sodium titanate conversion. It was found that the more equiaxed thin films (B/300) generated the thickest titanate structures (ca. 1.6 μm), which disagreed with the proposed hypothesis of columnar structures allowing greater NaOH ingress. All film parameters tested ultimately generated titanate structures, as confirmed via EDX, SEM, XPS, XRD, FTIR and Raman analyses. Additionally, the more columnar structures (NB/NH & B/NH) had a greater quantity of Na (ca. 26 at.%) in the top portion of the films, as confirmed via XPS, however, on average the Na content was consistent across the films (ca. 5–9 at.%). Film adhesion for the more columnar structures (ca. 42 MPa), even on polished substrates, were close to that of the FDA requirement for plasma-sprayed HA coatings (ca. 50 MPa). This study demonstrates the potential of these surfaces to be applied onto a wide variety of material types, even polymeric materials, due to the lower processing temperatures utilised, with the vision to generate bioactive and/or antibacterial properties on a plethora of bioinert materials
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