Search results for "oxygen"

Negligible effect of hypolimnetic oxygenation on the trophic state of Lake Jyväsjärvi, Finland

2016

Hypolimnetic oxygenation by pumping oxygen-rich surface water to the hypolimnion (HLO) is a commonly used tool for the restoration of nutrient-loaded dimictic lakes. However, in recent years its effectiveness has been questioned. In this case study we evaluated monitoring data covering a period of 23-years to show that, although experimental cessation of HLO drastically changed the lake's temperature and dissolved oxygen regimes, it did not significantly affect its trophic status. Thus, we recommend that the limited financial resources available are better directed towards further lowering the lake's external phosphorus load than continuing HLO. peerReviewed

Effect of Non-Surgical Periodontal Treatment on Oxidative Stress Markers in Leukocytes and Their Interaction with the Endothelium in Obese Subjects w…

2020

Aim: The primary objective of this pilot study was to evaluate the effect of non-surgical periodontal treatment. The secondary aim was to evaluate the effect of dietary therapy on both parameters of oxidative stress in leukocytes and leukocyte-endothelial cell interactions in an obese population. Methods: This was a pilot study with a before-and-after design. Forty-nine obese subjects with periodontitis were randomized by means of the minimization method and assigned to one of two groups, one of which underwent dietary therapy while the other did not. All the subjects underwent non-surgical periodontal treatment. We determined periodontal, inflammatory and oxidative stress parameters&mdash

Optical Absorption of Excimer Laser‐Induced Dichlorine Monoxide in Silica Glass and Excitation of Singlet Oxygen Luminescence by Energy Transfer from…

2021

An optical absorption (OA) band of interstitial dichlorine monoxide molecules with peak at 4.7 eV and halfwidth 0.94 eV is identified in F2 laser - irradiated (photon energy=7.9 eV) synthetic silica glass bearing both interstitial O2 and Cl2 molecules. Alongside with intrinsic defects, this OA band can contribute to solarization of silica glasses produced from SiCl4. While the formation of ClClO is confirmed by its Raman signature, its structural isomer ClOCl may also contribute to this induced OA band. Thermal destruction of this band between 300C and 400C almost completely restores the pre-irradiation concentration of interstitial Cl2. An additional weak OA band at 3.5 eV is tentatively a…

Photoluminescence time decay of surface oxygen deficient centers in un‐doped and Ge‐doped silica

2005

We report a study of the emission decay from the singlet excited state of two fold coordinated Si and Ge centers stabilized on the surface of silica and Ge-doped silica. The PL lifetimes are of the order of nanoseconds and increase on decreasing the temperature. The results suggest that, for the surface centers, the phonon assisted intersystem-crossing process linking the excited states affects the decay rates, is effective down to low temperatures and is distributed because of the inhomogeneity of the defects. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Carbon Dioxide Activation and Reaction Induced by Electron Transfer at an Oxide-Metal Interface

2015

A model system has been created to shuttle electrons through a metal-insulator-metal (MIM) structure to induce the formation of a CO2 anion radical from adsorbed gas-phase carbon dioxide that subsequently reacts to form an oxalate species. The process is completely reversible, and thus allows the elementary steps involved to be studied at the atomic level. The oxalate species at the MIM interface have been identified locally by scanning tunneling microscopy, chemically by IR spectroscopy, and their formation verified by density functional calculations.

DFT Prediction of Enhanced Reducibility of Monoclinic Zirconia upon Rhodium Deposition.

2018

Oxides are an important class of materials and are widely used, for example, as supports in heterogeneous catalysis. In a number of industrial catalytic processes, oxide supports actively participate in chemical transformations by releasing lattice oxygen anions. While this is intuitively understood for reducible oxides, the reducibility of irreducible oxides may be modified via nanoengineering or upon inclusion of foreign species. Our calculations predict that the ability of irreducible monoclinic zirconia to release oxygen improves substantially upon deposition of rhodium. Through a comprehensive screening of Rh/ZrO2 with different size of the rhodium species, we find that a Rh adatom and…

Lipid peroxidation and protein oxidation are related to the severity of OSAS

2014

Oxygen Vacancy Formation and Migration within the Antiphase Boundaries in Lanthanum Scandate-Based Oxides: Computational Study.

2022

The study was performed with the financial support from the Latvian Council of Science under the grant agreement LZP-2020/2-0009. Calculations were performed at the HLRS, University of Stuttgart, within the project 12939 DEFTD. The Institute of Solid State Physics, University of Latvia (Latvia), as the Centre of Excellence has received funding from the European Union’s Horizon 2020 Frame-work Programme H2020-WIDESPREAD-01-2016-2017-Teaming Phase2 under grant agreement No. 739508, project CAMART2.

Oxygen uptake, acid-base balance and hormonal responses in maximal 300 - 400 m running in child, adolescent and adult athletes

2013

Vilmi, Nikke (2013). Oxygen uptake, acid-base balance and hormonal responses in maximal 300 - 400 m running in child, adolescent and adult athletes. Department of Biology of Physical Activity, University of Jyväskylä, Master's thesis, Science of Sport Coaching and Fitness Testing, 55 pp. The 400 m sprint demands both aerobic and anaerobic energy systems. During the race the acid-base balance of the body is disturbed and that has effects on the oxygen uptake. The purpose of this study was to investigate the oxygen uptake and acid-base balance during and after the maximal anaerobic running test in child (300 m), adolescent (350 m) and adult (400 m) athletes. Furthermore, the aim was also to d…

Ski economy and physiological responses while double poling : curved vs. straight poles

2015

Christina Mishica (2015). Ski economy and physiological responses while double poling: curved vs. straight poles. Department of Biology of Physical Activity, University of Jyväskylä, Master’s Thesis in Exercise Physiology. 57 pp. Introduction. Double poling (DP) is commonly used in cross country skiing (XC). It is becoming more and more popular and in some competitions it is the exclusive technique. Ski poles allow a skier to apply power and force to the snow and their composition and design have a significant effect on performance. Different pole lengths and cross sections are some of the differences that have been tested. Advancements in equipment will continue to be introduced so it is i…