Search results for "TEMPERATURE"
showing 10 items of 3798 documents
Hydrothermally Synthesized Strontium Peroxyapatite
2015
The current research focuses on peroxide ion incorporation in the structure of strontium hydroxyapatite (SrHAp) by exposure to H2O2 ina closed hydrothermal vessel under mild conditions at 130 to 170 °C. Peroxide enriched strontium apatite (SrPerAp) was characterized for structure by X-Ray diffraction, for peroxide content- by permanganometric titration and then viewed by SEM. This study continued from previous work that used 30%H2O2 and showed a higher included peroxide content after processing with 50% H2O2 at 130 °C 70% of the theoretical peroxide content in apatitic channels of strontium apatite. This is the highest peroxide content incorporated to date and employs a lower temperature th…
Local Structure Studies of Ti for SrTi16O3 and SrTi18O3 by Advanced X-ray Absorption Spectroscopy Data Analysis
2015
Strontium titanate is a model quantum paraelectric in which in the region of dominating quantum statistics the ferroelectric instability is inhibited due to nearly complete compensation of the harmonic contribution into ferroelectric soft mode frequency by the zero-point motion contribution. The enhancement of atomic masses by the substitution of 18O for 16O decreases the zero-point atomic motion and low-T ferroelectricity in SrTi18O3 is realized. In this study we report on the local structure of Ti in SrTi16O3 and SrTi18O3 by Ti K-edge extended x-ray absorption fine structure measurements in temperature range 6 – 300 K.
Mazā Baltezera ķīmiskās un fizikālās stratifikācijas raksturojums
2019
Maģistra darba mērķis ir analizēt Mazā Baltezera stratifikācijas raksturu un to ietekmējošos faktorus. Zināšanas par stratifikācijas procesiem ir noderīgas, lai pilnveidotu ezera apsaimniekošanu. Literatūras apskatā aprakstīta stratifikācijas loma ezeros, to ietekmējošie faktori, kā arī ezeru klasifikācija pēc to termiskā režīma. Izvirzīto uzdevumi izpildes vajadzībām veikti lauka un laboratorijas pētījumi, pielietotas grafiskās, t. sk. kartogrāfiskās, un matemātiskās datu apstrādes metodes. Stratifikācijas analīze veikta, atsevišķi apskatot ezera termisko, ķīmisko un izšķīdušā skābekļa stratifikāciju. Secinājums: Mazajā Baltezerā pastāv termiskā stratifikācija, kuras ietekmē pastāv arī ķīm…
Sensitivity of jet quenching to enhancement of the medium opacity near TC
2014
[Introduction] One of the main goals of the study of high transverse momentum ( P T ) observables in the context of ultrarelativistic heavy-ion collisions is the determination of properties of QCD matter. In particular, the transport coefficients ˆ q and ˆ e characterizing the interaction of the medium with a high p T parton are accessible via hard probes. However, a precision extraction of their temperature dependence from current data faces the problem that neither the space-time geometry of the evolving matter nor the link between thermodynamics and transport coefficients is unambiguously known. Thus, various conjectured scenarios exist for how thermodynamics and transport coefficients b…
Under-ice temperature and oxygen conditions in boreal lakes
2013
Effects of temperature and feeding regime on compensatory growth of rainbow trout, Oncorhynchus mykiss
2006
Automated water quality monitoring of humic lakes by using the optical properties of water
2016
Automated water quality monitoring (AWQM) is becoming increasingly common in lakes worldwide. The history of AWQM is relatively short and standard calibration procedures for the measured variables are largely yet to be established. The use of optical AWQM sensors, developed in oceanic environments, raises new questions on the diverse effects which humic compounds may have on the automated optical measurements in inlands waters. The focus of this thesis was to characterize the effects of coloured dissolved organic matter (CDOM) on optical in situ measurements of organic matter (OM) and chlorophyll (Chl) in lakes with varying humic content, and to use AWQM data as a part of traditional monito…
Al2O3 ALD films grown using TMA + rare isotope 2H216O and 1H218O precursors
2021
In this work hydrogen and oxygen migration and exchange reactions in the atomic layer deposited (ALD) Al2O3 thin films were studied together with hydrogen incorporation by varying deposition parameters. Al2O3 films deposited at low temperatures can contain more than 20 at. % of hydrogen. Both higher temperature and longer purge length decrease the hydrogen and carbon concentrations significantly. In order to track the hydrogen and oxygen movement in the films, heavy water (2H216O) and oxygen-18 enriched water (1H218O) were used as precursors in combination with trimethylaluminium (TMA). Different isotopes of the same element were quantified by means of time-of-flight elastic recoil detectio…
Fabrication, Electrical Characterization and 1/f Noise Study of Submicron-sized Superconducting Tunnel Junctions
2016
Analysis of the performance of the TES algorithm over urban areas
2014
International audience; The temperature and emissivity separation (TES) algorithm is used to retrieve the land surface emissivity (LSE) and land surface temperature (LST) values from multispectral thermal infrared sensors. In this paper, we analyze the performance of this methodology over urban areas, which are characterized by a large number of different surface materials, a variability in the lowest layer of the atmospheric profiles, and a 3-D structure. These specificities induce errors in the LSE and LST retrieval, which should be quantified. With this aim, the efficiency of the TES algorithm over urban materials, the atmospheric correction, and the impact of the 3-D architecture of urb…