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1.
Non-singular method of fundamental solutions for biomedical stokes flow problems
Božidar Šarler, Eva Sincich, 2013, published scientific conference contribution

Found in: ključnih besedah
Summary of found: ...non-singular method of fundamental solutions, Stokes decomposition, blood flow, ...
Keywords: non-singular method of fundamental solutions, Stokes decomposition, blood flow
Published: 05.08.2014; Views: 3875; Downloads: 22
URL Fulltext (0,00 KB)

2.
Real-time motor unit identification from high-density surface EMG
Vojko Glaser, Aleš Holobar, Damjan Zazula, 2013, original scientific article

Abstract: This study addresses online decomposition of high-density surface electromyograms (EMG) in real-time. The proposed method is based on previouslypublished Convolution Kernel Compensation (CKC) technique and sharesthe same decomposition paradigm, i.e. compensation of motor unit action potentials and direct identification of motor unit (MU) discharges. In contrast to previously published version of CKC, which operates in batch mode and requires ~ 10 s of EMG signal, the real-time implementation begins with batch processing of ~ 3 s of the EMG signal in the initialization stage and continues on with iterative updating of the estimators of MU discharges as blocks of new EMG samples become available. Its detailed comparison to previously validated batch version of CKC and asymptotically Bayesian optimal Linear Minimum Mean Square Error (LMMSE) estimator demonstrates high agreementin identified MU discharges among all three techniques. In the case of synthetic surface EMG with 20 dB signal-to-noise ratio, MU discharges were identified with average sensitivity of 98 %. In the case of experimental EMG, real-time CKC fully converged after initial 5 s of EMG recordings and real-time and batch CKC agreed on 90 % of MU discharges, on average. The real-time CKC identified slightly fewer MUs than its batch version (experimental EMG, 4 MUs versus 5 MUs identified by batch CKC, on average), but required only 0.6 s of processing time on regular personal computer for each second of multichannel surface EMG.
Found in: ključnih besedah
Summary of found: ...This study addresses online decomposition of high-density surface electromyograms (EMG) in real-time....
Keywords: discharge pattern, high-density EMG, surface EMG, motor unit, real time decomposition
Published: 05.01.2016; Views: 3409; Downloads: 0

3.
In-situ XAS analysis of nanoshaped CuO/CeO2 catalysts used for N2O decomposition
Albin Pintar, Petar Djinović, Maxim Zabilsky, Iztok Arčon, 2018, published scientific conference contribution abstract

Abstract: The goal of this research is to establish the working state and correlations between atomic structure and catalytic activity of nanoshaped CuO/CeO2 catalysts used in N2O decomposition reaction. The catalysts contained CuO nanoclusters dispersed over different CeO2 morphologies: nano-rods and nano-cubes. N2O is a side product of nitric and adipic acid production and a very potent greenhouse gas that is formed in amounts estimated at about 400 Mt/a of CO2 equivalent. Consequently, the development of robust, active and selective catalysts for N2O decomposition is of a great environmental and economical interest. CeO2-based materials promoted by CuO represent a new class of catalysts that exhibit considerable activity in N2O decomposition reaction between 300 and 500 °C [1-3], and are significantly cheaper and more efficient than Pt, Pd or Rh based catalysts. In order to maximize the efficiency of the catalyst, the active site in this reaction needs to be identified and the mechanism clarified. In-situ Cu K-edge and Ce L3-edge XANES and EXAFS analysis was done on a set of CuO/CeO2 catalysts with different ceria morphology (nano-cubes, nano-rods) and Cu loadings between 2 to 8 wt. %, during N2O decomposition reaction, under controlled reaction conditions at 400 °C. The XAS spectra were measured in-situ, in a tubular reactor, filled with protective He atmosphere at 1 bar, first at RT, then during heating, and at final temperature of 400 °C, during catalytic reaction, when the catalyst was exposed to a small amount (0.2 vol%) of N2O mixed with He. The Cu K-edge and Ce L3-edge XANES and EXAFS analysis reveals changes in valence and local structure of Cu and Ce in the CuO/CeO2 catalysts. In the initial state (in He at RT), copper is present in the form of CuO nanoparticles attached to the CeO2 surface. After heating in He to 400 °C, partial (10%) reduction of Ce [Ce(IV)→Ce(III)] is detected, significant part of Cu(II) is reduced to Cu(I) and Cu(0) species, and direct Cu-Cu bonds are formed. During catalytic N2O decomposition at 400°C, all Ce(III) is oxidized back to Ce(VI), and a major part of Cu is oxidized back to Cu(II), with about 5% of Cu(I) remaining in equilibrium state. Observed structural and valence changes of copper strongly depend on its loading and CeO2 morphology. With systematic In-situ XAS analysis of different nanoshaped CuO/CeO2 catalysts, we identified the structural characteristics and changes of Cu and Ce phases during catalytic N2O decomposition reaction, which could lead to identification of the active catalytic site during the reaction and further improve the performance of these promising catalytic materials.
Found in: ključnih besedah
Keywords: EXAFS, CuO/CeO2 catalyst, N2O decomposition
Published: 12.09.2018; Views: 2090; Downloads: 0
.pdf Fulltext (281,07 KB)

4.
Guaranteed and robust error bounds for nonconforming approximations of elliptic problems
Sergey Repin, Satyendra Tomar, 2011, original scientific article

Found in: ključnih besedah
Summary of found: ...a posteriori error estimates, nonconforming approximation, Helmholtz decomposition, Trefftz method...
Keywords: a posteriori error estimates, nonconforming approximation, Helmholtz decomposition, Trefftz method
Published: 13.11.2018; Views: 1777; Downloads: 0
.pdf Fulltext (253,92 KB)

5.
IETI, Isogeometric Tearing and Interconnecting
Stefan K. Kleiss, Clemens Pechstein, Bert Jüttler, Satyendra Tomar, 2012, original scientific article

Found in: ključnih besedah
Summary of found: ...isogeometric analysis, NURBS, domain decomposition, FETI, IETI...
Keywords: isogeometric analysis, NURBS, domain decomposition, FETI, IETI
Published: 13.11.2018; Views: 1647; Downloads: 0
.pdf Fulltext (1,58 MB)

6.
Primeness of Relative Annihilators in BCK-Algebra
Hashem Bordbar, 2020, original scientific article

Abstract: Conditions that are necessary for the relative annihilator in lower BCK-semilattices to be a prime ideal are discussed. Given the minimal prime decomposition of an ideal A, a condition for any prime ideal to be one of the minimal prime factors of A is provided. Homomorphic image and pre-image of the minimal prime decomposition of an ideal are considered. Using a semi-prime closure operation “cl”, we show that every minimal prime factor of a cl-closed ideal A is also cl-closed.
Found in: ključnih besedah
Summary of found: ...ideal are discussed. Given the minimal prime decomposition of an ideal A, a condition for...
Keywords: lower BCK-semilattice, relative annihilator, semi-prime closure operation, minimal prime decomposition, minimal prime factor
Published: 24.02.2020; Views: 1249; Downloads: 0
.pdf Fulltext (267,96 KB)

7.
Mediterranean Coastal Lagoons: The Importance of Monitoring in Sediments the Biochemical Composition of Organic Matter
Monia Renzi, Francesca Provenza, Sara Pignattelli, Lucrezia Cilenti, Antonietta Specchiulli, Milva Pepi, 2019, original scientific article

Abstract: Transitional water ecosystems are targeted by the European Union (EU) Water Framework Directive (WFD, CE 2000/60) monitoring programs in coastal zones. Concerning sediments, activities performed for the WFD focus on a few variables concerning the biochemical composition of organic matter. Our research reports the effects of oxygen availability on the biochemical composition of organic matter in sediments to highlight levels of targeted variables in time and, according to the depth of sediment layer, both under oxygenated and anoxic conditions in a mesocosm study on sediment cores. Results provide evidence that tested factors of interest (i.e., disturbance type, oxygenic versus anoxic conditions; persistence time of disturbance, 0–14 days; penetration through sedimentary layers, 0–10 cm depth) are able to significantly affect the biochemical composition of organic matter in sediments. Large part of the variables considered in this study (total organic carbon (TOC), total phosphorous (TP), total sulphur (TS), Fe, carbohydrates (CHO), total proteins (PRT), biopolymeric carbon (BPC), chlorophyll-a (Chl-a) are significantly affected and correlated to the oxygenation levels and could be good early indicators of important changes of environmental conditions. Monitoring activities performed under WFD guidelines and management strategies of Mediterranean coastal lagoon ecosystems shall include the biochemical composition of organic matter in sediment to provide an exhaustive picture of such dynamic ecosystems.
Found in: ključnih besedah
Summary of found: ... decomposition, transitional water ecosystems, organic loads, mesocosm, monitoring...
Keywords: decomposition, transitional water ecosystems, organic loads, mesocosm, monitoring programs
Published: 20.04.2020; Views: 1226; Downloads: 0
.pdf Fulltext (2,22 MB)

8.
In-situ XAS study of catalytic N[sub]2O decomposition over CuO/CeO[sub]2 catalysts
Elena Tchernychova, Petar Djinović, Iztok Arčon, Maxim Zabilsky, Albin Pintar, 2021, original scientific article

Abstract: We performed in‐situ XAS study of N 2 O decomposition over CuO/CeO 2 catalysts. The Cu K‐edge and Ce L 3 ‐edge XANES and EXAFS analyses revealed the dynamic and crucial role of Cu 2+ /Cu + and Ce 4+ /Ce 3+ ionic pairs during the catalytic reaction. We observed the initial formation of reduced Cu + and Ce 3+ species during activation in helium atmosphere at 400 °C, while concentration of these species decreased significantly during steady‐state nitrous oxide degradation reaction (2500 ppm N 2 O in He at 400 °C). In‐situ EXAFS analysis further revealed a crucial role of copper‐ceria interface in this catalytic reaction. We observed dynamic changes in average number of Cu‐Ce scatters under reaction conditions, indicating an enlarging the interface between both copper and ceria phases, where electron and oxygen transfer occurs.
Found in: ključnih besedah
Keywords: in-situ XAS, Cu EXAFS, CuO/CeO2 nanorod catalys, N2O decomposition
Published: 29.01.2021; Views: 808; Downloads: 0
.pdf Fulltext (1,31 MB)

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