Browsing by Subject "Surfaces"

Article

Adaptive VN/Ag nanocomposite coatings with lubricious behavior from 25 to 1000 °c

Aouadi, S. M.; Singh, D. P.; Stone, D. S.; Polychronopoulou, K.; Nahif, F.; Rebholz, Claus; Muratore, C.; Voevodin, A. A. (2010)

A two-phase nanocomposite coating that consists of inclusions of silver in a vanadium nitride matrix (VN/Ag) was investigated as a potential adaptive coating with a reduced friction coefficient from 25 to 1000 °C. This ...

Article

Comparative study of La-Sr-Fe-O perovskite-type oxides prepared by ceramic and surfactant methods over the CH4 and H2 lean-deNOx

Stathopoulos, Vassilis N.; Belessi, Vassiliki C.; Bakas, Thomas V.; Neophytides, Stylianos G.; Costa, Costas N.; Pomonis, Phillippos J.; Efstathiou, Angelos M. (2009)

Mixed oxides of the general formula La0.8Sr0.2FeO3-x were prepared by ceramic and surfactant methods and tested towards the NO/H2/O2 and NO/CH4/O2 lean-deNOx reactions in the 200-450 °C range. The materials were characterized ...

Article

Effect of thermal aging on the transient kinetics of oxygen storage and release of commercial Cex Zr1-x O2-based solids

Christou, Stavroula Y.; Bradshaw, H.; Butler, C.; Darab, J.; Efstathiou, Angelos M. (2009)

The use of powerful analytical methodologies for the evaluation of the performance of commercial oxygen storage materials based on oxygen transient isothermal isotopic exchange experiments is illustrated in this study. Ce ...

Article

The influence of reaction temperature on the chemical structure and surface concentration of active NOx in H2-SCR over Pt/MgO{single bond}CeO2: SSITKA-DRIFTS and transient mass spectrometry studies

Savva, Petros G.; Efstathiou, Angelos M. (2008)

Steady-state isotopic transient kinetic analysis (SSITKA), transient isothermal, and temperature-programmed surface reaction in H2 (H2-TPSR) techniques coupled with online mass spectroscopy (MS) and in situ diffuse reflectance ...

Article

The phenol steam reforming reaction towards H2 production on natural calcite

Constantinou, D. A.; Fierro, José Luis García; Efstathiou, Angelos M. (2009)

The steam reforming of phenol towards H2 production was studied in the 650-800 °C range over a natural pre-calcined (air, 850 °C) calcite material. The effects of reaction temperature, water, hydrogen, and carbon dioxide ...

Conference Object

Processing of semi-solid materials using a shear-thickening Bingham fluid model

Ahmed, Alauddin; Alexandrou, Andreas N. (Publ by ASME, 1994)

Recently the importance of processing metals and metal matrix composites in semi-solid state is growing rapidly. Performing the shape making operations in the semi-solid state provides a better opportunity to control the ...

Article

Raman spectroscopy using a fiber optic probe with subwavelength aperture

Tsai, D. P.; Othonos, Andreas S.; Moskovits, M.; Uttamchandani, D. (1994)

Raman spectroscopy with subwavelength spatial resolution of a diamond sample was recorded using a tapered fiber optical probe in conjunction with a conventional Raman spectrometer. The experiment demonstrates the potential ...

Article

Recent advances in vacuum sciences and applications

Stana-Kleinschek, K.; Mozetič, M.; Ostrikov, K.; Ruzic, D. N.; Curreli, D.; Cvelbar, U.; Vesel, A.; Primc, G.; Leisch, M.; Jousten, K.; Malyshev, O. B.; Hendricks, J. H.; Kövér, L.; Tagliaferro, A.; Conde, O.; Silvestre, A. J.; Giapintzakis, John; Buljan, M.; Radić, N.; Dražić, G.; Bernstorff, S.; Biederman, H.; Kylián, O.; Hanuš, J.; Miloševič, S.; Galtayries, A.; Dietrich, P.; Unger, W.; Lehocky, M.; Sedlarik, V.; Drmota-Petrič, A.; Pireaux, J. J.; Rogers, J. W.; Anderle, M. (2014)

Recent advances in vacuum sciences and applications are reviewed. Novel optical interferometer cavity devices enable pressure measurements with ppm accuracy. The innovative dynamic vacuum standard allows for pressure ...

Article

The steam reforming of phenol over natural calcite materials

Constantinou, D. A.; Efstathiou, Angelos M. (2009)

Five natural calcite materials of different geographical origin were studied towards the steam reforming of phenol reaction and the activity results obtained were correlated with some of their physico-chemical properties. ...

Conference Object

Surface failure detection for an F/A-18 aircraft using neural networks and fuzzy logic

Raza, H.; Ioannou, Petros A.; Youssef, H. M. (IEEE, 1994)

In this paper we consider the problem of detecting control surface failures of a high performance aircraft. The detection model is developed using a linear, six degree of freedom dynamic model of an F/A-18 aircraft. The ...

Article

Time-dependent compressible extrudate-swell problem with slip at the wall

Georgiou, Georgios C. (1994)

We solve the time-dependent compressible Newtonian extrudate-swell problem with slip at the wall, in an attempt to simulate the stick-slip extrusion instability. An arbitrary nonlinear slip model relating the shear stress ...