Search results for "RAV"

Turning lipophilic phthalocyanines/TiO2 composites into efficient photocatalysts for the conversion of CO2 into formic acid under UV–vis light irradi…

2014

Metal-free, Cu(II)- or Zn(II) tetrakis [4-(2,4-bis-(1,1-dimethylpropyl)phenoxy)]phthalocyanines loaded over TiO2 (anatase) proved to be active in the photoreduction of CO2 to formic acid (HCO2H) in water under UV-vis light. CuPc/TiO2 is catalyst of choice, allowing to reach a maximum yield of HCO2H, unequalled by any other similar catalytic systems. Because of their low environmental impact, low potential cost, and efficient power conversion, these multipurpose materials show promise in the setup of sustainable methods for CO2 valorization. (C) 2014 Elsevier B.V. All rights reserved.

Study of phase composition, photocatalytic activity, and photoluminescence of TiO2 with Eu additive produced by the extraction-pyrolytic method

2021

The Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2. The work was also partially supported by the LZP grant 2020/2-0074. R. Burve has been supported by the project “Synthesis of nanostructured materials based on titanium dioxide and tin dioxide and investigation of their physicochemical properties” Nr. MP-2019/7, for strengthening scientific personnel capacity 2019/2020 at the Riga Technical University. Authors are grateful to Dr. K. Šmits for the microscopic measurements and SEM images.

Sol-gel derived anatase TiO2: morphology and photoactivity

1994

Abstract High-surface area TiO 2 (anatase) was prepared by the sol-gel method and characterized by various instrumental and analytical methods, including X-ray diffraction, thermogravimetric analysis, infrared spectroscopy, porosimetry, specific surface area measurements, scanning electron microscopy, and titration of surface hydroxyl groups. The specimen was tested for photodegradation of phenol and nitrophenols carried out in aqueous suspension at pH = 3; photoactivity was compared with that of commercially available anatase TiO 2 . Results are discussed in terms of porosity, surface area, and availability and population of surface OH groups, consequent upon the particular method used for…

Pēc 5 mirkļiem 100 gadi: bibliotēku dārgumi : izstādes buklets

2014

Reto izdevumu un manuskriptu izstāde BIBLIOTĒKU DĀRGUMI ir Latvijas Universitātes Bibliotēkas un Latvijas Universitātes Akadēmiskās bibliotēkas veltījums Latvijas Universitātei 95. gadadienā

Akadēmiskā Dzīve, Nr. 50

2014

Background Infusion during Intravenous Patient-Controlled Analgesia: The New Routine Analgesia?

2002

Aggressive Angiomyxoma: unusual pelvic mass

2016

Learning objectives Background Findings and procedure details Conclusion Personal information References

Focus on clinical practice: angiotensin-converting enzyme 2 and corona virus disease 2019: pathophysiology and clinical implications.

2020

: ACE2 receptor has a broad expression pattern in the cellular membrane and provides a protective action against the development of cardiovascular diseases. Recently, this enzyme has become of extreme interest during the pandemic infection of COVID-19 (coronavirus disease 2019). This virus invades alveolar epithelium and cardiomyocytes using ACE2 as a transmembrane receptor. ACE2 is a counter-regulatory peptide that degrades Ang II into Ang 1-7, thereby attenuating the biological effects of the AT1 receptor. The binding between the spike protein of COVID-19 and the enzyme is crucial for the virus to enter the target cells, but whether an increase in ACE2 activity could facilitate the infect…

Dynamics of thick discs around Schwarzschild-de Sitter black holes

2003

We consider the effects of a cosmological constant on the dynamics of constant angular momentum discs orbiting Schwarzschild-de Sitter black holes. The motivation behind this study is to investigate whether the presence of a radial force contrasting the black hole's gravitational attraction can influence the occurrence of the runaway instability, a robust feature of the dynamics of constant angular momentum tori in Schwarzschild and Kerr spacetimes. In addition to the inner cusp near the black hole horizon through which matter can accrete onto the black hole, in fact, a positive cosmological constant introduces also an outer cusp through which matter can leave the torus without accreting on…

On the timing properties of SAX J1808.4-3658 during its 2015 outburst

2017

We present a timing analysis of the 2015 outburst of the accreting millisecond X-ray pulsar SAX J1808.4-3658, using non-simultaneous XMM-Newton and NuStar observations. We estimate the pulsar spin frequency and update the system orbital solution. Combining the average spin frequency from the previous observed, we confirm the long-term spin down at an average rate $\dot{\nu}_{\text{SD}}=1.5(2)\times 10^{-15}$ Hz s$^{-1}$. We also discuss possible corrections to the spin down rate accounting for mass accretion onto the compact object when the system is X-ray active. Finally, combining the updated ephemerides with those of the previous outbursts, we find a long-term orbital evolution compatibl…