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Ana Diana Ancas, M. Profire, I. L. Cirstolovean, M. Hornet and G. Cojocaru

Abstract

The lifetime of glass reinforced plastic pipes is 50 years. Extensive use of this type of pipe in its various applications, led to investigate their behavior in land that anthropogenic or natural causes, shows the different values of pH to neutral. The paper presents experimental results conducted on three samples of a PN SN10000 DN150 PN10 pipe buried in three different types of terrain: neutral, acidic, basic. They were subjected to axial load, measuring the force applied deformation force function. On the basis of the calculation formulas determined rigidity of the pipeline, the deformation speed of 50 mm / min. This concludes the type of land affects the rigidity of the pipe so its length of life decreases to that provided by suppliers in order to be taken compensatory measures in this regard such as choosing a higher class of pressure and stiffness pipeline than those arising discounted. This will allow for long-term value (50 years) in the mechanical characteristics sufficient for safe operation.

Open access

Mareike Trauerstein, Sally E. Lowick, Frank Preusser and Heinz Veit

) using continuous wave OSL (CW-OSL) were conducted to identify the lifetime of the signal at varying temperatures for sample ABH09 and STH01. A set of 8 small aliquots (2 mm) per sample was first used for D e determination and then given a dose of ~100 Gy, followed by a preheat of 250°C for 10 s (as for D e determination). Similar to the approach of Buechi et al . (2017) , the aliquot was then held for various times, between 0 and 5000 s, at elevated temperatures of between 220 and 280°C, after which the remaining signal was measured, followed by a 20 Gy test dose

Open access

Vasilis Pagonis and Reuven Chen

Simulation of OSL Pulse-Annealing at Different Heating Rates: Conclusions Concerning the Evaluated Trapping Parameters and Lifetimes

Pulse annealing has been the subject of several studies in recent years. In its basic form, it consists of relatively short-time optically stimulated luminescence (OSL) measurements of a given sample after annealing at successively higher temperatures in, say, 10°C increments. The result is a decreasing function with a maximum OSL at low temperatures and gradually decreasing to zero at high temperature. Another presentation is that of the percentage OSL signal lost per annealing phase, associated with minus the derivative of the former curve, which yields a thermoluminescence (TL)-like peak. When the heating is performed at different heating rates, the TL various heating rates (VHR) method can be utilized to evaluate the trapping parameters. Further research yielded more complex pulse-annealing results in quartz, explained to be associated with the hole reservoir. In the present work, we simulate numerically the effect, following the experimental steps, in the simpler form when no reservoir is involved, and in the more complex case where the reservoir plays an important role. The shapes of the reduction-rate curves resemble the experimental ones. The activation energies found by the VHR method are very close to the inserted ones when the retrapping probability is small, and deviate from them when retrapping is strong. The theoretical reasons for this deviation are discussed.

Open access

Shreya Sarkar and Anindya Bose

–693. Sarkar S. and Bose A. (2016a), “Studies on Solution Accuracy of GLONASS from India”, Gyroscopy and Navigation , Vol 7, No 1, 39-49. Sarkar S. and Bose A. (2016b), “Lifetime of Revitalized GLONASS satellites: a Review”, in Proc. National Conference on Materials, Devices and Circuits for Communication Technology (MDCCT 2016) , Burdwan, India, pp 173 – 176. Ta T. H., Truong D. M., Nguyen T. T., Hieu T. T., Nguyen T. D. and Belforte G. (2013), “Multi-GNSS positioning campaign in South-East Asia”, Coordinates , Vol IX, Issue 11, 11-20 University of New

Open access

Mohammed Chessab Mahdi

Abstract

The probability of KufaSat collisions with different sizes of orbital debris and with other satellites which operating in the same orbit during orbital lifetime was determined. Apogee/Perigee Altitude History was used to graph apogee and perigee altitudes over KufaSat lifetime. The required change in velocity for maneuvers necessary to reentry atmospheric within 25 years was calculated. The prediction of orbital lifetime of KufaSat using orbital parameters and engineering specifications as inputs to the Debris Assessment Software (DAS) was done, it has been verified that the orbital lifetime will not be more than 25 years after end of mission which is compatible with recommendation of Inter-Agency Space Debris Coordination Committee (IADC).

Open access

Lihua Ma

The Benefits of Inclined-Orbit Operations for Geostationary Orbit Communication Satellites

Geostationary orbit (GEO) communication satellites can be extended in lifetime by switching to inclined-orbit operations. In this mode, a small amount of propellant is reserved to maintain the assigned orbit longitude. Inclination is allowed to build up at a rate of approximately 0.8○ per year. Developing these space resources can bring out a number of benefits. Besides communication application, these satellites can be used to construct navigation constellation of the Chinese Area Positioning System (CAPS). In this present paper, the realization way of communication and navigation applications is studied and the benefits and problems are explained.

Open access

Neil H. Landman, Joshua S. Slattery and Peter J. Harries

Abstract

The inarticulate brachiopod Discinisca is a rare faunal element in the Upper Cretaceous of the U.S. Western Interior. We report two occurrences of encrustation of Discinisca on a scaphitid ammonite (scaphite) and several inoceramids from the lower Maastrichtian Baculites baculus/Endocostea typica Biozones of the Pierre Shale at two localities. Six specimens of Discinisca are present on a single specimen of Hoploscaphites crassus from east-central Montana. They occur along the furrow at the mature apertural margin. Because the brachiopods are restricted to the margin and do not occur on the rest of the shell, it is likely that they encrusted the ammonite during its lifetime. If so, this implies that the soft body of the scaphite did not cover the outside surface of the aperture, leaving this area vulnerable to epizoan attachment. A total of 13 specimens of Discinisca are also present on four specimens of Cataceramus? barabini from east-central Wyoming. The brachiopods occur in crevices on the outside of the shells and may have encrusted the inoceramids after their death as the shells began to break down and delaminate, resulting from the decomposition of the organic matrix holding them together. Based on the faunal assemblages at both localities, the presence of Discinisca may indicate environments with either low oxygen levels and/or few predators or competitors.

Open access

Jana Magnusková, Zdeněk Pavelek and Lucie Krčmarská

Abstract

The present article focuses on the importance of making investment decisions and its long-term effect on the economy of companies. It presents a specific investment in the recovery of rescue equipment used for interventions in the irrespirable or deleterious environment on an example of the company HBZS, a.s. The objective is to evaluate the effectiveness of the investment project using static methods in relation to setting an optimal price level for leasing the equipment. The optimization of such setting is examined in terms of the economic lifetime of relevant tangible fixed assets

Open access

Zhongping Lai and Anchuan Fan

Abstract

When using quartz OSL to date loess samples from the Chinese Loess Plateau, it has been reported that the agreement between OSL ages and the independent ages is limited to the samples younger than ∼70 ka with a corresponding De of ∼230 Gy, and a sample with an expected age of 780 ka was dated to 107 ka, corresponding to 403 Gy. The growth curves of these samples do not saturate at doses of 700 Gy, and a linear growth part was observed for doses higher than 200 Gy. However, the maximum measured age of ∼100 ka imply that the De determined using this linear part of a growth curve could be problematic, or that the quartz OSL signal is not as stable as previously thought and has a barrier age of ∼100 ka. In the current study, we examine the reasons for the age underestimation. We examined the shape of growth curves, anomalous fading, thermal stability, etc. The results show that, for the loess samples examined, quartz OSL does not fade anomalously, and the barrier age of ∼100 ka is due to the fact that the OSL signals are less thermally stable, the lifetime of 0.311 Ma at 20°C obtained is much smaller than those for quartz samples from other regions such as Australia (∼100 Ma).

Open access

Kuzin Sergey, Mitrikas Vladimir, Revnivykh Sergey and Tatevyan Suriya

On the Role of Glonass for the Development of the Russian Geodetic Reference Network

The combined use of GPS and GLONASS satellite systems is a main technology for the development of the fundamental geodetic network in Russia and for crust movement studies along the North Eurasian tectonic plate. All permanent stations of the state fundamental geodetic network will be provided with the two frequency GPS and GLONASS receivers. A collocation of these stations with the existing Russian sites of the international GNSS (Global Navigation Satellite System) network is foreseen. The GLONASS state program foresees to come to 18 satellites in constellation in 2007-2008, and full operation capability (24 satellites) will be reached by 2009. The second generation of satellites: GLONASS-M have the L2 civil signal, extended lifetime and improved clock stability. GLONASS-K satellites are expected by 2009 with the L3 civil signal and Synthetic Aperture Radar function. A combination of GPS and GLONASS will benefit the scientific geodynamic research and practical users, especially in the urban, mountain and near polar areas. Results of the experimental GLONASS data analysis performed. Comparison of mean values of coordinates from only GLONASS solution, obtained at the Institute of Astronomy (Moscow) with the use of GIPSY-OASIS2 software, with the mean values from the GPS PPP solution for the IGS sites showed that differences are mainly within a few cm, provided that incomplete configuration of GLONASS satellites have been observed.