Search results for: ROOM ACOUSTIC EQUALIZATION
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A Wideband Channel Model for Body Area Networks in Circular Metallic Indoor Environments
PublicationIn this paper, the wideband characterization of the propagation channel in circular metallic indoor environments is addressed, regarding Body Area Networks and 5G small cells, an analytical model for the dependence of the mean delay and the average delay spread on the circle radius, the working frequency and the distance between the transmitter and the receiver being proposed. The derivation of the model is initially done analytically,...
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Synthesis, thermal, structural and electrical properties of vanadium-doped lithium-manganese-borate glass and nanocomposites
PublicationA glassy sample with a nominal formula LiMn1−3x/2VxBO3 (where x = 0.05) was synthesised using the melt-quenching method. Material was characterised by differential thermal analysis (DTA), X-ray diffactometry (XRD) at room temperature and as a function of temperature (HT-XRD), X-ray photoelectron spectroscopy (XPS), impedance spectroscopy (IS) and scanning electron microscopy (SEM). Dependences of glass transition and crystallisation...
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Properties of LiMnBO3 glasses and nanostructured glass-ceramics
PublicationPolycrystalline LiMnBO3 is a promising cathode material for Li-ion batteries. In this work, we investigated the thermal, structural and electrical properties of glassy and nanocrystallized materials having the same chemical composition. The original glass was obtained via a standard melt-quenching method. SEM and 7Li solid-state NMR indicate that it contains a mixture of two distinct glassy phases. The results suggest that the...
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Piezoresponse force microscopy and dielectric spectroscopy study of Ba0.6Sr0.4TiO3 thin films
PublicationResearch on synthesis, characterization and determination of processing – structure – property relationships of commercially important ferroelectric thin films has been performed. The sol-gel-type solution deposition technique was applied to produce good quality thin films of Ba0.6Sr0.4TiO3 (BST60/40) chemical composition on the stainless steel substrates. The thin films were characterized in terms of their microstructure, crystal...
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Małgorzata Warecka dr inż.
People -
Application of auto calibration and linearization algorithms to improve sound quality of computer devices
PublicationAn application of auto calibration and linearization algorithms designed for correcting acoustic characteristics of selected computer devices was presented in the paper. The functionality of the algorithms were presented for two kind of computer devices: ultrabook class computer and portable device of All-In-One type. The algorithms were adjusted for the given type of the device on the basis of series of measurements conducted...
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INVESTIGATION OF BOTTOM SEDIMENT STRATIFICATION
PublicationThe main goal of this paper is to find a method to assess remotely the type of sediments on the basis of the signal received using the parametric echosounder. The images of the sea bottom sediments taken by a parametric echosounder show the fine structure of the upper layer of the bottom sediments. The depth of penetration depends on the type of sediment, in fact on the attenuation of acoustic wave. In the paper the method of distinguishing...
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Reliable underwater communication system for shallow coastal waters
PublicationThis paper presents a reliable and robust low data rate spread spectrum approach which is implemented in the acoustic underwater communication system for shallow coastal waters. It shows operation assumptions of spread spectrum techniques based on the wellknown Shannon equation. It describes two methods of spread spectrum: frequency hopping spread spectrum and direct sequence spread spectrum; their block diagram and their characteristics...
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The Analysis of Cross-Polarisation Discrimination for Body Area Networks in Cylindrical Metallic Environment
PublicationThe analysis of cross-polarisation discrimination for Body Area Networks in an untypical environment of cylindrical metallic room has been performed in the paper. This analysis was done based on the measurements carried out for dynamic narrowband off-body channels operating at the frequency of 2.45 GHz. The results have shown that there is a strong dependence of the depolarisation effect on the existence of direct component in...
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Piotr Kasprzak dr
PeopleDr. Piotr Kasprzak - works at the Department of Finance at the Faculty of Management and Economics of the Gdańsk University of Technology. He specializes in aspects related to corporate taxation and accounting issues. His scientific and professional interests include issues related to corporate accounting, management accounting and the application of the provisions of the Polish Accounting Act in practice. Piotr Kasprzak is...
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TG-hydroxyl groups in TiO2-P25
Open Research DataTG analyses were performed for powdered TiO2 - commercial P25 sample, which was heat-treated from room temperature to 500 C in the nitrogen atmosphere. Mass loss at lower temperature such as 120 C was related to the physisorbed water, and that one occurring at 500 C to the chemisorbed hydroxyl groups.
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WPŁYW KAUSTYKI NA AKUSTYKĘ GROT SZEPTÓW W PARKU OLIWSKIM W GDAŃSKU
PublicationW pracy omówiono kaustykę jako uporządkowaną formę rozmycia ogniska, tworzonego przez zwierciadło wklęsłe. Zaprezentowano przykład kaustyki powstającej przy odbiciu światła od zwierciadła wklęsłego. Na tym tle wskazano na możliwość powstawania kaustyk w pomieszczeniach. Szczególną uwagę zwrócono na duże pomieszczenia o charakterze historycznym, ze względu na częstą obecność w nich zwierciadeł akustycznych w postaci sklepień i...
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The Innovative Faculty for Innovative Technologies
PublicationA leaflet describing Faculty of Electronics, Telecommunications and Informatics, Gdańsk University of Technology. Multimedia Systems Department described laboratories and prototypes of: Auditory-visual attention stimulator, Automatic video event detection, Object re-identification application for multi-camera surveillance systems, Object Tracking and Automatic Master-Slave PTZ Camera Positioning System, Passive Acoustic Radar,...
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Adaptive Personal Tuning of Sound in Mobile Computers
PublicationAn integrated methodology for enhancing audio quality in mobile computers is presented. The key features are adaptation of the characteristics of their acoustic track to changing acoustic conditions of the environment and to users’ individual preferences. Signal processing algorithms are introduced that concern: linearization of frequency response, dialogue intelligibility enhancement, and dynamics processing tuned up to the users’...
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Adaptive system for recognition of sounds indicating threats to security of people and property employing parallel processing of audio data streams
PublicationA system for recognition of threatening acoustic events employing parallel processing on a supercomputing cluster is featured. The methods for detection, parameterization and classication of acoustic events are introduced. The recognition engine is based onthreshold-based detection with adaptive threshold and Support Vector Machine classifcation. Spectral, temporal and mel-frequency descriptors are used as signal features. The...
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X-ray diffractometry results of the Sr0.86Ti0.65Fe0.35O3 powder
Open Research DataThis dataset contains results of X-ray diffractometry mesurement (XRD) of the Sr0.86Ti0.65Fe0.35O3-d (STF35) powder. The phase composition of the investigated STF35 powder was analyzed by XRD at room temperature. It confirms the formation of the cubic perovskite oxide phase. Calculated average lattice constant is a 3.90882(1) Å, with Goodness of Fit...
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Wisłoujście Fortress. Architectural investigation and analysis (2013)
PublicationIn 2013, as part of archaeological and architectural reserch conducted in the Area of Wisłoujście Fortress, an inventory and architectural studies of the rooms of tenement houses in the Ring, serving as kitchen, were performed. Work consisting in preparing measurement documentation, drawings and descriptive documentation was the first such study conducted inside buildings at Fort Carre. The article presents preliminary results...
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Krystian Zawadzki dr hab. inż.
PeopleKrystian Zawadzki is associate professor in the Department of Finance at the Faculty of Management and Economics of the Gdańsk University of Technology; member of the Polish Olympic Academy at the Polish Olympic Committee; coordinator of the Stock Exchange School (Warsaw Stock Exchange) in Gdańsk; Head of postgraduate studies "Capital Investments and Personal Finance Management"; member of the audit committee of the sports club...
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Fabrication and Study of BiNbO4 Ceramics
PublicationAim of the present research was to fabricate and study crystalline structure as well as dielectric properties of BiNbO4 ceramics. In the present study BiNbO4 ceramics was fabricated by solid state reaction from the mixture of simple oxides viz. Bi2O3, and Nb2O5. Stoichiometric mixture of the powders was thermally analyzed so parameters of the thermal treatment were determined. The EDS measurements proved conservation of the chemical...
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Highly effective degradation of selected groups of organic compounds by cavitation based AOPs under basic pH conditions
PublicationCavitation has become on the most often applied methods in a number of industrial technologies. In the case of oxidation of organic pollutants occurring in the aqueous medium, cavitation forms the basis of numerous advanced oxidation processes (AOPs). This paper presents the results of investigations on the efficiency of oxidation of the following groups of organic compounds: organosulfur, nitro derivatives of benzene, BTEX, and...
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XRD patterns of nickel-modified V2CTx
Open Research DataThe set includes data for XRD pattern preparation of nickel-modified V2CTx samples.
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MOŻLIWOŚCI IDENTYFIKACJI STANU TECHNICZNEGO WARSTW ŚLIZGOWYCH ŁOżYSK SILNIKÓW SPALINOWYCH O ZAPŁONIE SAMOCZYNNYM W PRZYPADKU WYKORZYSTANIA EMISji AKUSTYCZNEJ JAKO SYGNAŁU DIAGNOSTYCZNEGO
PublicationW artykule zaprezentowano wyniki badań wielowarstwowych panwi łożysk ślizgowych silników tłokowych. Scharakteryzowano własności obciążeń tego rodzaju panwi oraz ich zużycia szczególnie zmęczeniowego i ściernego. Wykazano przydatność emisji akustycznej jako sygnału diagnostycznego do ujawniania zużycia powłok ślizgowych i zaporowych. Przedstawiono wyniki pomiarów parametrów emisji akustycznej, wykonanych za pomocą 12- kanałowej...
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Introduction to the special issue on machine learning in acoustics
PublicationWhen we started our Call for Papers for a Special Issue on “Machine Learning in Acoustics” in the Journal of the Acoustical Society of America, our ambition was to invite papers in which machine learning was applied to all acoustics areas. They were listed, but not limited to, as follows: • Music and synthesis analysis • Music sentiment analysis • Music perception • Intelligent music recognition • Musical source separation • Singing...
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Excitation of Non-Wave Modes by Sound of Arbitrary Frequency in a Chemically Reacting Gas
PublicationThe nonlinear phenomena in the field of high intensity sound propagating in a gas with a chemical reaction, are considered. A chemical reaction of A → B type is followed by dispersion and attenuation of sound which may be atypical during irreversible thermodynamic processes under some conditions. The first and second order derivatives of heat produced in the chemical reaction evaluated at the equilibrium temperature, density and...
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A Comparison of STI Measured by Direct and Indirect Methods for Interiors Coupled with Sound Reinforcement Systems
PublicationThis paper presents a comparison of STI (Speech Transmission Index) coefficient measurement results carried out by direct and indirect methods. First, acoustic parameters important in the context of public address and sound reinforcement systems are recalled. A measurement methodology is presented that employs various test signals to determine impulse responses. The process of evaluating sound system performance, signals enabling...
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Measurements of the chemical composition of LTO:Cu powders
Open Research DataLithium titanate doped by copper was measured by X-ray photoemission spectroscopy (XPS). For sol-gel synthesis lithium acetate dehydrate and titanium (IV) butoxide 97% and copper (II) nitrate from Alfa Aesar were used as a reagents. Cu precursor was added in the proper weight to get an x index equal 0, 0.1 and 0.2. In the first step lithium acetate...
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Wastewater treatment by means of advanced oxidation processes based on cavitation – A review
PublicationHydrodynamic and acoustic cavitation combined with advanced oxidation processes (AOPs), including, among others, the Fenton process, is a promising alternative to the technologies of wastewater treatment technologies in use today. The present review discusses processes based on cavitation combined with AOPs and evaluates their effectiveness in oxidation of organic contaminants. Complete degradation of, among others, p-nitrotoluene,...
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Tailoring structural properties of lanthanum orthoniobates through an isovalent substitution on the Nb-site
PublicationTetragonal polymorph of lanthanum orthoniobate can be stabilized to room temperature by the substitution of Nb with an isovalent element. LaNb1-xAsxO4 (0 < x ≤ 0.3), where As is an element stabilizing tetragonal structure, were successfully synthesized with combined co-precipitation and solid-state reaction method. The phase transition temperature, above which the material has tetragonal structure, decreases linearly with increasing...
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Detection of Objects Buried in the Sea Bottom with the Use of Parametric Echosounder
PublicationThe paper contains results of a in situ research main task of which was to detect objects buried, partially or completely, in the sea bottom. Object detecting technologies employing acoustic wave sources based on nonlinear interaction of elastic waves require application of parametric sound sources. Detection of objects buried in the sea bottom with the use of classic hydroacoustic devices such as the sidescan sonar or multibeam...
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Influence of the Widespread Use of Corten Plate on the Acoustics of the European Solidarity Centre Building in Gdansk
PublicationThis paper describes the relationship between a strong architectural vision that is difficult to balance, and user expectations in terms of acoustics. The focus is on the use of corten steel as the dominant finishing material on façades and interiors to achieve an expressive, symbolic message through program-based design. The architectural premises justifying the adopted solutions are presented, especially the universality and...
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Measurement of Impulse Response of Shallow Water Communication Channel by Correlation Method
PublicationPerformances of underwater acoustic communication (UAC) systems are strongly related to specific propagation conditions of the underwater channel; conditions that can additionally change in time due to the movement of the acoustic system transmitter and receiver or to reflection by underwater objects of the transmitted signal. The time-varying impulse response is a comprehensive description of dynamically changing transmission...
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Analysis of a caustic formed by a spherical reflector: Impact of a caustic on architectural acoustics
PublicationFocusing sound in rooms intended for listening to music or speech is an acoustic defect. Design recommendations provide remedial steps to effectively prevent this. However, there is a category of objects of high historical or architectural value in which the sound focus correction is limited or even abandoned. This also applies to indoor or outdoor concert shells, installations for teaching and acoustic presentations, etc. The...
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Sol-gel derived lithium titanate powders measured by XPS method
Open Research DataFor sol-gel synthesis lithium acetate dehydrate from Alfa Aesar GmbH &Co and titanium (IV) butoxide 97% from Aldrich were used as reagents. Copper (II) nitrate from Alfa Aesar was used as a source of Cu dopant. It was added in the proper weight to get an x index equal 0, 0.1 and 0.2. In the first step lithium acetate and copper nitrate were dissolved...
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Thermographic images during testing measuring instrument boards
Open Research DataThe dataset presents thermografic images acquired during testing the prototype of measuring instrument for resistiometric corrosion monitoring. The testing was performed in the room temperature. VIGOcam v50 thermal imaging camera (VIGO System S.A., Ozarow Mazowiecki, Poland) was used for taking the pictures. These pictures were used as preliminary tests...
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Low temperature electrical conductivity of the SrFeO3-d pellet
Open Research DataThis dataset contains results of low temperature electrical conductivity measurements of dense SrFeO3-d (SFO) pellet. DC electrical conductivity measurements of SFO were performed by the Van der Pauw method between 400 °C and room temperature with 20 °C step. Studies were performed at Synthetic Air flow under humidified (~4 vol%) gas flow rate of 40...
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Low temperature electrical conductivity of the SrTi0.65Fe0.35O3-d pellet
Open Research DataThis dataset contains results of low temperature electrical conductivity measurements of dense SrTi0.65Fe0.35O3-d (STF35) pellet. DC electrical conductivity measurements of STF35 were performed by the Van der Pauw method between 400 °C and room temperature with 20 °C step. Studies were performed at Synthetic Air flow under humidified (~4 vol%) gas...
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Low temperature electrical conductivity of the SrTi0.30Fe0.70O3-d pellet
Open Research DataThis dataset contains results of low temperature electrical conductivity measurements of dense SrTi0.30Fe0.70O3-d (STF70) pellet. DC electrical conductivity measurements of STF70 were performed by the Van der Pauw method between 400 °C and room temperature with 20 °C step. Studies were performed at Synthetic Air flow under humidified (~4 vol%) gas...
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Low temperature electrical conductivity of the SrTi0.50Fe0.50O3-d pellet
Open Research DataThis dataset contains results of low temperature electrical conductivity measurements of dense SrTi0.50Fe0.50O3-d (STF50) pellet. DC electrical conductivity measurements of STF50 were performed by the Van der Pauw method between 400 °C and room temperature with 20 °C step. Studies were performed at Synthetic Air flow under humidified (~4 vol%) gas...
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Low temperature electrical conductivity of the SrTi0.10Fe0.90O3-d pellet
Open Research DataThis dataset contains results of low temperature electrical conductivity measurements of dense SrTi0.10Fe0.90O3-d (STF90) pellet. DC electrical conductivity measurements of STF90 were performed by the Van der Pauw method between 400 °C and room temperature with 20 °C step. Studies were performed at Synthetic Air flow under humidified (~4 vol%) gas...
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Developing assumptions for the tram noise attenuation passive system using the noise maps analysis method
PublicationThe paper presents experimental research carried out to determine the possible actions to reduce thenoise generated by trams in a highly urbanised area. A few design strategies affecting tram ride qualityhave been presented – especially in the aspect of the acoustic phenomena. Main sources of the noisein trams were characterised. The paper includes selected results of comprehensive...
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Cavitation based cleaner technologies for biodiesel production and processing of hydrocarbon streams: A perspective on key fundamentals, missing process data and economic feasibility – A review
PublicationThe present review emphasizes the role of hydrodynamic cavitation (HC) and acoustic cavitation in clean and green technologies for selected fuels (of hydrocarbon origins such as gasoline, naphtha, diesel, heavy oil, and crude oil) processing applications including biodiesel production. Herein, the role of cavitation reactors, their geometrical parameters, physicochemical properties of liquid media, liquid oxidants, catalyst loading,...
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Detection of the Incoming Sound Direction Employing MEMS Microphones and the DSP
PublicationA 3D acoustic vector sensor based on MEMS microphones and its application to road traffic monitoring is presented in the paper. The sensor is constructed from three pairs of digital MEMS microphones, mounted on the orthogonal axes. Signals obtained from the microphones are used to compute sound intensity vectors in each direction. With this data, it is possible to compute the horizontal and vertical angle of an incoming sound....
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Distributed System For Noise Threat Evaluation Based On Psychoacoustic Measurements
PublicationAn innovative system designed for the continuous monitoring of acoustic climate of urban areas was presentedin the paper. The assessment of environmental threats is performed using online data, acquired through a grid ofengineered monitoring stations collecting comprehensive information about the acoustic climate of urban areas.The grid of proposed devices provides valuable data for the purpose of long and short time acoustic climateanalysis....
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XPS study of the lithium titanate doped by copper
Open Research DataLithium titanate doped by copper was measured by X-ray photoemission spectroscopy. For sol-gel synthesis lithium acetate dehydrate from Alfa Aesar GmbH &Co and titanium (IV) butoxide 97% from Aldrich were used as reagents. Copper (II) nitrate from Alfa Aesar was used as a source of Cu dopant. It was added in the proper weight to get an x index equal...
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On Some Aspects of Fish Target Strength Estimation in Shallow Waters
PublicationThe theory of acoustic surveys for determining fish abundance are well established in fishery acoustics. The origins of the estimation are related to overcoming the problem of unknown position of target in the beam using statistical inversion. Although recently researchers use more sophisticated echosounders that provides more informative data allowing for direct solution it is known that the results are biased due to not ideally...
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Multimodal Surveillance Based Personal Protection System
PublicationA novel, multimodal approach for automatic detection of abduction of a protected individual, employing dedicated personal protection device and a city monitoring system is proposed and overviewed. The solution is based on combining four modalities (signals coming from: Bluetooth, fixed and PTZ cameras, thermal camera, acoustic sensors). The Bluetooth signal is used continuously to monitor the protected person presence, and in case...
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Investigation of the vertical distribution of the sound speed of the Gulf of Gdansk in the years 2000-2010
PublicationThe conditions of the acoustic wave propagation in the southern Baltic are much more complex than in other shallow waters. In the typical shallow water, seasonal changes in acoustical conditions in the upper layer, of the depth of about 60-70 m, are observed. They are caused by variation of the annual meteorological conditions. Most often, in the deep water layer, acoustical conditions are stable throughout the year. However, in...
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A Study of Cross-Linguistic Speech Emotion Recognition Based on 2D Feature Spaces
PublicationIn this research, a study of cross-linguistic speech emotion recognition is performed. For this purpose, emotional data of different languages (English, Lithuanian, German, Spanish, Serbian, and Polish) are collected, resulting in a cross-linguistic speech emotion dataset with the size of more than 10.000 emotional utterances. Despite the bi-modal character of the databases gathered, our focus is on the acoustic representation...
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The homometallic warwickite V 2 OBO 3
PublicationThe synthesis, structure and elementary magnetic characterization of the homometallic warwickite V2OBO3 are reported. The material adopts the orthorhombic warwickite structure type at room temperature, space group Pnma (No. 62) with lattice parameters a = 9.2317(1) Å, b = 3.1172(1) Å, and c = 9.5313(1) Å. Temperature-dependent magnetic susceptibility, electrical resistivity, and specific heat measurements show anomalies near 35 K,...
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Active dynamic thermography method for TRAM flap blood perfusion mapping in breast reconstruction
PublicationThis paper presents the new method of the transverse rectus abdominis musculocutaneous flap blood perfusion mapping based on the active dynamic thermography. The method is aimed at aiding a surgeon during breast reconstruction procedure. A pair of dTnorm and t90_10 parameters were used as parametric image descriptors of the flap blood perfusion. The method was tested on 38 patients that were subjected to breast reconstruction procedure....