Search Results

You are looking at 1 - 10 of 12 items for :

  • Technical and Applied Physics x
Clear All
Open access

R. Grunvalds, A. Ciekurs, J. Porins and A. Supe

Abstract

In the research, measurements of polarisation mode dispersion of two OPGWs (optical ground wire transmission lines), in total four fibres, have been carried out, and the expected lifetime of the infrastructure has been assessed on the basis of these measurements. The cables under consideration were installed in 1995 and 2011, respectively. Measurements have shown that polarisation mode dispersion values for cable installed in 1995 are four times higher than that for cable installed in 2011, which could mainly be explained by technological differences in fibre production and lower fibre polarisation mode dispersion requirements in 1995 due to lack of high-speed (over 10 Gbit/s) optical transmission systems. The calculation methodology of non-refusal work and refusal probabilities, using the measured polarisation mode dispersion parameters, is proposed in the paper. Based on reliability calculations, the expected lifetime is then predicted, showing that all measured fibres most likely will be operational within minimum theoretical service life of 25 years accepted by the industry.

Open access

E. Elsts, U. Rogulis, J. Jansons and A. Sharakovskis

Cathodoluminescence of Terbium- and Ytterbium-Activated Oxyfluoride Glasses and Glass Ceramics

Cathodoluminescence (CL) spectra and decay times have been studied for oxyfluoride glasses and glass ceramics of the system: SiO2 - Al203 - Na2O - LaF3 - NaF, activated by terbium and ytterbium.

The CL spectra of the glasses and glass ceramics show characteristic Tb3+ luminescence bands: blue (5D37FJ) and green (5D47FJ) groups. With increasing terbium concentration the blue- to green-group ratio decreases.

The CL decay curves can be sufficiently well approximated by two exponents - fast and slow. Decay times for the blue-group CL bands are faster than for those of green group.

As the terbium concentration increases, the lifetimes for the lines of the blue group shorten, while for the green group they remain unchanged. This could be explained by the cross-relaxation between the transitions 5D35D4 and 7F67F0 of two terbium ions.

Open access

V. Bobinaite and I. Konstantinaviciute

Abstract

The paper aims at demonstrating the relevance of financing instruments, their terms and financing strategies in relation to the cost of wind power production and the ability of wind power plant (PP) to participate in the electricity market in Lithuania. The extended approach to the Levelized Cost of Energy (LCOE) is applied. The feature of the extended approach lies in considering the lifetime cost and revenue received from the support measures. The research results have substantiated the relevance of financing instruments, their terms and strategies in relation to their impact on the LCOE and competitiveness of wind PP. It has been found that financing of wind PP through the traditional financing instruments (simple shares and bank loans) makes use of venture capital and bonds coming even in the absence of any support. It has been estimated that strategies consisting of different proportions of hard and soft loans, bonds, own and venture capital result in the average LCOE of 5.1–5.7 EURct/kWh (2000 kW), when the expected electricity selling price is 5.4 EURct/kWh. The financing strategies with higher shares of equity could impact by around 6 % higher LCOE compared to the strategies encompassing higher shares of debt. However, seeking to motivate venture capitalists, bond holders or other new financiers entering the wind power sector, support measures (feed-in tariff or investment subsidy) are relevant in case of 250 kW wind PP. It has been estimated that under the unsupported financing strategies, the average LCOE of 250 kW wind PP will be 7.8–8.8 EURct/kWh, but it will reduce by around 50 % if feed-in tariff or 50 % investment subsidy is applied.

Open access

L. Latkovskis, U. Sirmelis, L. Grigans, J. Cernovs and K. Kroics

, D., Buller, S., Karden, E., & De Doncker, R.W. (2005). Analysis and evaluation of charge-balancing circuits on performance, reliability, and lifetime of supercapacitor systems. IEEE Transactions on Industry Applications , 41 (5), 1135- 1141. 5. Schneuwly, A., Bärtschi, M., Hermann, V., Sartorelli, G., Gallay, R., & Kötz, R. (2002). BOOSTCAP - Double-Layer Capacitors for Peak Power Automotive Applications. In: Proceedings on Advanced Automotive Battery and EC Capacitor , Las Vegas (Nevada, USA). 6. Barrade, P. (Aug. 2002). Series

Open access

L. Kalvans and L. Kalvāns

.826 Kitching, J., Hollberg, L., Knapp S., & Wynands, R. (2001). Compact atomic clock based on coherent population trapping. Electron. Lett., 37 (24), 1449-1551. Hau, L. V., Harris, S. E., Dutton, Z., & Behroozi, C. H. (1999) Light speed reduction to 17 metres per second in an ultracold atomic gas. Nature, 397 , 594-598; DOI: 10.1038/17561 Schmieder, R. W., Lurio, A., Happer, W., & Khadjavi, A. (1970). Level-crossing measurement of lifetime and hfs constants of the 2 P 3/2 states of the stable alkali atoms Phys. Rev

Open access

M. Maltisovs, K. Krumins, A. Ozols and D. Pikulins

://doi.org/10.1016/j.solmat.2017.10.026 5. Coates, D., Crossland, W. A., Morrisy, J. H., & Needham, B. (1978). Electrically induced scattering textures in smectic a phases and their electrical reversal. Journal of Physics D: Applied Physics , 11 (14), 2025–2034. https://doi.org/10.1088/0022-3727/11/14/012 6. Gardiner, D. J., & Coles, H. J. (2007). Enhancing lifetime in a bistable smectic A liquid crystal device. Journal of Physics D: Applied Physics , 40 (4), 977–981. https://doi.org/10.1088/0022-3727/40/4/009 7. Lueder, E. (2010). Liquid crystal

Open access

A. Ogurcovs, V. Gerbreders, E. Tamanis, E. Sledevskis and A. Gerbreders

References 1. Wyatt, K. Metzger, Ingrid, L. Repins, & Miguel, A. Contreras (2008). Long lifetimes in high efficiency Cu(In,Ga)Se2 solar cells. Appl. Phys. Lett., 93, 022110. 2. Rega, N., Siebentritt, S., Albert, J., Nishiwaki, S., Zajogin, A., Lux-Steiner, M. C., Kniese, R., & Romero, M. J. (2005). Excitonic luminescence of Cu(In,Ga) Se-2. Thin Solid Films, 480, 286-290. 3. Green, M. A., Emery, K., Hishikawa, Y., Warta, W., & Dunlop, E. D. (2012). Solar cell efficiency tables (version 39) Prog. Photovolt

Open access

A. Ivanova, A. Tokmakov, K. Lebedeva, M. Roze and I. Kaulachs

., Lo, M.-F., & Lee, C.-S. (2015). Chlorine incorporation for enhanced performance of planar perovskite solar cell based on lead acetate precursor. ACS Appl. Mater. Interfaces , 7(41), 23110–23116. DOI: 10.1021/acsami.5b06819. 16. Quilettes, D. W., Vorpahl, S. M., Stranks, S. D., Nagaoka, H., Eperon, G. E., Ziffer, M. E., Snaith, H. J., & Ginger, D. S. (2015). Impact of microstructure on local carrier lifetime in perovskite solar cells. Science , 348(6235), 683–686. DOI: 10.1126/science.aaa5333 17. Fan, L., Ding, Y., Luo, J., Shi, B., Yao, X., Wei, C

Open access

Tejwant Singh Brar and Navneet Munoth

Abstract

There are, presently, two schools of thought when it comes to designing buildings that promote sustainable development. One school emphasizes materials use and ‘‘green’’ buildings, while the other emphasizes energy use and energy efficient buildings. The promoters of ‘‘green’’ buildings often claim that the reduced energy use during operation of the low energy and solar buildings is counteracted by the increased embodied energy in these buildings. This paper gives categorical analysis of the technologies available for Low energy and green architecture and emphasizes the need to integrate both in residential buildings to of lower the energy use in operation during the lifetime in a residential building in hot arid climate. The results also show that there should be little difference between the approaches of the two schools of thought. The best buildings will generally be those that are both low energy, and ‘‘green’’. This paper also gives policy guidelines to integrate them in the building bye-laws for hot arid climate

Open access

Vladyslav Kyrychok and Vasyl Torop

Performance of the Assembly of the Joints of Header to Steam Generator PGV-1000M, Technical Diagnostics and Non-destructive Control, No. 4 , 2014, 36-51 (in Russian). [4] DSTU-N B V.2.3-21:2008. Assessment of the Residual Strength of Magistral Pipelines with Defects (In Ukrainian). [5] Guidelines for Integrity and Lifetime Assessment of Components and Piping in WWER Nuclear Power Plants (VERLIFE), 2013. [6] ASME Boiler and Pressure Vessel Code, Section XI: Rules for In-service Inspection of Nuclear Power Plant Components. [7] Abaqus Scripting