Optical methods for hydrogen degassing monitoring in urban conditions

2015 ◽  
Vol 119 (6) ◽  
pp. 948-954 ◽  
Author(s):  
E. V. Timchenko ◽  
P. E. Timchenko ◽  
L. A. Zherdeva ◽  
N. V. Tregub ◽  
E. A. Selezneva ◽  
...  
Keyword(s):  
Optical Methods ◽  
Urban Conditions

Preparation and characterisation of vanadium pentoxide supported rhodium catalyst

1988 ◽  
Vol 46 ◽  
pp. 946-947
Author(s):  
A. Legrouri
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Vanadium Pentoxide ◽  
High Purity ◽  
Gas Adsorption ◽  
Rhodium Catalyst ◽  
Optical Methods ◽  
Reducible Oxides

The industrial importance of metal catalysts supported on reducible oxides has stimulated considerable interest during the last few years. This presentation reports on the study of the physicochemical properties of metallic rhodium supported on vanadium pentoxide (Rh/V2O5). Electron optical methods, in conjunction with other techniques, were used to characterise the catalyst before its use in the hydrogenolysis of butane; a reaction for which Rh metal is known to be among the most active catalysts.V2O5 powder was prepared by thermal decomposition of high purity ammonium metavanadate in air at 400 °C for 2 hours. Previous studies of the microstructure of this compound, by HREM, SEM and gas adsorption, showed it to be non— porous with a very low surface area of 6m2/g3. The metal loading of the catalyst used was lwt%Rh on V2Q5. It was prepared by wet impregnating the support with an aqueous solution of RhCI3.3H2O.

Investigation of cluster layers of small netal particles by TEM, SEM, EELS and by photoacoustic spectroscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 250-251
Author(s):  
H. Seiler ◽  
U. Haas ◽  
K.H. Körtje
Keyword(s):  
Bulk Material ◽  
High Vacuum ◽  
Optical Methods ◽  
Metal Particles ◽  
Silver Particles ◽  
Low Loss ◽  
Plasmon Excitation ◽  
First Results ◽  
Diffraction Patterns ◽  
Small Metal Particles

The physical properties of small metal particles reveal an intermediate position between atomic and bulk material. Especially Ag has shown pronounced size effects. We compared silver layers evaporated in high vacuum with cluster layers of small silver particles, evaporated in N2 at a pressure of about 102 Pa. The investigations were performed by electron optical methods (TEM, SEM, EELS) and by Photoacoustic (PA) Spectroscopy (gas-microphone detection).The observation of cluster layers with TEM and high resolution SEM show small silver particles with diameters of about 50 nm (Fig. 1 and Figure 2, respectively). The electron diffraction patterns of homogeneous Ag layers and of cluster layers are similar, whereas the low loss EELS spectra due to plasmon excitation are quite different. Fig. 3 and Figure 4 show first results of EELS spectra of a cluster layer of small silver particles on carbon foil and of a homogeneous Ag layer, respectively.

Comparison of sensitivity of the refractometric methods of frustrated total internal reflection and surface plasmon resonance

2020 ◽  
pp. 44-49
Author(s):  
I. N. Pavlov
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Total Internal Reflection ◽  
Resonance Method ◽  
Internal Reflection ◽  
Optical Methods ◽  
Thin Boundary Layer ◽  
Experimental Conditions ◽  
Frustrated Total Internal Reflection

Two optical methods, namely surface plasmon resonance imaging and frustrated total internal reflection, are described in the paper in terms of comparing their sensitivity to change of refractive index of a thin boundary layer of an investigated medium. It is shown that, despite the fact that the theoretically calculated sensitivity is higher for the frustrated total internal reflection method, and the fact that usually in practice the surface plasmon resonance method, on the contrary, is considered more sensitive, under the same experimental conditions both methods show a similar result.

Жизненное состояние древесных насаждений в условиях города Актобе (Казахстан)

2017 ◽  
Vol 7 (4) ◽  
pp. 51-55
Author(s):  
S. A. Abiev ◽  
S. A. Aipeisova ◽  
N. A. Utarbaeva
Keyword(s):  
Urban Area ◽  
Woody Plants ◽  
Health State ◽  
Urban Habitats ◽  
Resistant Species ◽  
Vital State ◽  
Ulmus Laevis ◽  
Urban Conditions ◽  
The City ◽  
Trees And Shrubs

<p>The purpose of our work is to assess the health state of woody plants growing in different habitats of the city of Aktobe. We have studied the health state of arboreal and shrubby plants growing in various urban habitats; the survey was conducted during 2016-2017 by route-visual method. We performed the analysis of species diversity, abundance and density in urban area. The assessment of health state of the trees was made according to V.A. Alekseev. From your data and literature review we established that such species as Ulmus pinnato-ramosa, Acer negundo, Populus tremula, Populus nigra, and Syringa vulgaris have strong winter resistnce in the territory of Aktobe; we registered that only their apex buds and emds of the shoots were frozen in severe winters. The medium-resistant speices include Ulmus laevis and Acer platonoides. They are less plastic and suffer from late spring and early autumn frosts. The Amorpha fruticosa, Vitis vinifera, and Parthenocissus guinguefolia could be considered as the non-resistant species, since they usually freeze up to the snow cover line. The analysis of the vital state made it possible to assess the resistance to urban conditions of the majority of trees and shrubs registered in urban habitats of Aktobe. According to the preliminary data, the origin of the plant and its winter resistance are of main importance when introducing new species to urban area.</p>

APPLICATION OF PHYSICAL AND OPTICAL METHODS FOR SOOT EVALUATION IN A FULL-SCALE POWER PLANT

1995 ◽  
Author(s):  
Loretta Bonfanti ◽  
Leonardo Castellano ◽  
Sauro Pasini ◽  
Nice Pintus ◽  
Christine Mounaim-Rousselle
Keyword(s):  
Power Plant ◽  
Full Scale ◽  
Optical Methods

scholarly journals Dynamic Manipulation of THz Waves Enabled by Phase-Transition VO2 Thin Film

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 114
Author(s):  
Chang Lu ◽  
Qingjian Lu ◽  
Min Gao ◽  
Yuan Lin
Keyword(s):  
Optical Methods ◽  
Stimuli Responsive ◽  
Device Structure ◽  
Current State ◽  
Insulator Metal Transition ◽  
Potential Applications ◽  
Fs Laser ◽  
External Stimuli ◽  
Thz Applications ◽  
Thz Waves

The reversible and multi-stimuli responsive insulator-metal transition of VO2, which enables dynamic modulation over the terahertz (THz) regime, has attracted plenty of attention for its potential applications in versatile active THz devices. Moreover, the investigation into the growth mechanism of VO2 films has led to improved film processing, more capable modulation and enhanced device compatibility into diverse THz applications. THz devices with VO2 as the key components exhibit remarkable response to external stimuli, which is not only applicable in THz modulators but also in rewritable optical memories by virtue of the intrinsic hysteresis behaviour of VO2. Depending on the predesigned device structure, the insulator-metal transition (IMT) of VO2 component can be controlled through thermal, electrical or optical methods. Recent research has paid special attention to the ultrafast modulation phenomenon observed in the photoinduced IMT, enabled by an intense femtosecond laser (fs laser) which supports “quasi-simultaneous” IMT within 1 ps. This progress report reviews the current state of the field, focusing on the material nature that gives rise to the modulation-allowed IMT for THz applications. An overview is presented of numerous IMT stimuli approaches with special emphasis on the underlying physical mechanisms. Subsequently, active manipulation of THz waves through pure VO2 film and VO2 hybrid metamaterials is surveyed, highlighting that VO2 can provide active modulation for a wide variety of applications. Finally, the common characteristics and future development directions of VO2-based tuneable THz devices are discussed.

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