Titania nanofibers were fabricated using the industrial Nanospider(TM) technology. The preparative protocol was optimized by screening various precursor materials to get pure anatase nanofibers. Composite films were prepared by mixing a commercial paste of nanocrystalline anatase particles with the electrospun nanofibers, which were shortened by milling. The composite films were sensitized by Ru-bipyridine dye (coded C106) and the solar conversion efficiency was tested in a dye-sensitized solar cell filled with iodide-based electrolyte solution (coded Z960). The solar conversion efficiency of a solar cell with the optimized composite electrode (η = 7.53% at AM 1.5 irradiation) outperforms that of a solar cell with pure nanoparticle film (η = 5.44%). Still larger improvement was found for lower light intensities. At 10% sun illumination, the best composite electrode showed η = 7.04%, referenced to that of pure nanoparticle film (η = 4.69%). There are non-monotonic relations between the film's surface area, dye sorption capacity and solar performance of nanofiber-containing composite films, but the beneficial effect of the nanofiber morphology for enhancement of the solar efficiency has been demonstrated.

• MeSH
• 2,2'-dipyridyl analogy a deriváty   chemie   MeSH
• barvicí látky chemie   MeSH
• elektrody MeSH
• elektrolyty chemie   MeSH
• nanočástice chemie   MeSH
• nanovlákna chemie   ultrastruktura   MeSH
• organokovové sloučeniny chemie   MeSH
• polymery chemie   MeSH
• sluneční energie * MeSH
• titan chemie   MeSH
• zdroje elektrické energie * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The potential of solar cells have not been fully tapped due to the lack of energy conversion efficiency. There are three important mechanisms in producing high efficiency cells to harvest solar energy; reduction of light reflectance, enhancement of light trapping in the cell and increment of light absorption. The current work represent studies conducted in surface modification of single-crystalline silicon solar cells using wet chemical etching techniques. Two etching types are applied; alkaline etching (KOH:IPA:DI) and acidic etching (HF:HNO3:DI). The alkaline solution resulted in anisotropic profile that leads to the formation of inverted pyramids. While acidic solution formed circular craters along the front surface of silicon wafer. This surface modification will leads to the reduction of light reflectance via texturizing the surface and thereby increases the short circuit current and conversion rate of the solar cells.

• MeSH
• analýza selhání vybavení MeSH
• design vybavení MeSH
• hydroxidy chemie   MeSH
• křemík chemie   MeSH
• kyseliny chemie   MeSH
• nanočástice chemie   ultrastruktura   MeSH
• povrchové vlastnosti MeSH
• sloučeniny draslíku chemie   MeSH
• sluneční energie * MeSH
• smáčivost MeSH
• zdroje elektrické energie * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

A large-scale, double-stream gas puff target has been illuminated by sub-kJ, near-infrared (NIR) focused laser pulses at the PALS facility (Prague Asterix Laser System) to produce high-energy pulses of soft X rays from hot, dense plasma. The double-puff arrangement ensures high gas density and conversion efficiency from NIR to X rays approaching that typical for solid targets. In addition, its major advantage over solid targets is that it is free of debris and has substantially suppressed charged-particle emission. The X-ray emission characteristics of the source were determined for a range of gases that included krypton, xenon, N(2), CO and N(2)-CO. A demonstrated application of the xenon-based source is a single-shot damage induction to plasmid DNA. The yields of single-strand breaks (SSBs) and double-strand breaks (DSBs) were determined as a function of energy fluence adjusted by varying distance of sample from the source and thickness of aluminum filters.

• MeSH
• analýza selhání vybavení MeSH
• dávka záření MeSH
• design vybavení MeSH
• lasery MeSH
• nanotechnologie metody   přístrojové vybavení   MeSH
• odběr biologického vzorku metody   přístrojové vybavení   MeSH
• plazmidy chemie   účinky léků   MeSH
• poškození DNA účinky záření   MeSH
• radiobiologie metody   přístrojové vybavení   MeSH
• rentgenové záření MeSH
• výzkum přístrojové vybavení   MeSH
• výzkumný projekt MeSH
• Publikační typ
• hodnotící studie MeSH

• MeSH
• diagnostické zobrazování MeSH
• fyzika přístrojové vybavení   MeSH
• nukleární lékařství přístrojové vybavení   MeSH
• radiologie metody   přístrojové vybavení   MeSH

• NLK Obory
• fyzika, biofyzika
• radiologie, nukleární medicína a zobrazovací metody

The microbial fuel cells (MFCs) are recognized to be highly effective for the biodegradation of phenol. For isolating the phenol-degrading bacteria, the sample containing 500 mg/L phenol was collected from the MFCs. The strain (WL027) was identified basing on the 16S rRNA gene analysis and phylogenetic analysis as Bacillus cereus. The effects of pH, temperature, concentrations of phenol, heavy metal ions, and salt on the growth of strain as well as the degradation of phenol have been carefully studied. The WL027-strain exhibited favorable tolerance for the metal cations including Cr2+, Co2+, Pb2+, and Cu2+ with the concentration of 0.2 mg/L and NaCl solution with a high concentration of 30 g/L. In 41 h, 86.44% of 500 mg/L phenol has been degraded at the initial pH at 6 and the temperature of 30 °C. The strain was highly active electrogenesis bacteria and the coulombic efficiency reached 64.25%, which showed significant advantage on the efficient energy conversion. Therefore, due to the highly efficient degradation of phenol, WL027-strain could be used in the treatment of phenol-containing wastewater.

• MeSH
• Bacteria klasifikace   genetika   izolace a purifikace   metabolismus   MeSH
• biodegradace MeSH
• fenol metabolismus   MeSH
• fylogeneze MeSH
• koncentrace vodíkových iontů MeSH
• teplota MeSH
• těžké kovy analýza   metabolismus   MeSH
• zdroje bioelektrické energie mikrobiologie   MeSH
• Publikační typ
• časopisecké články MeSH

Biogas produced from organic wastes contains energetically usable methane and unavoidable amount of carbon dioxide. The exploitation of whole biogas energy is locally limited and utilization of the natural gas transport system requires CO2 removal or its conversion to methane. The biological conversion of CO2 and hydrogen to methane is well known reaction without the demand of high pressure and temperature and is carried out by hydrogenotrophic methanogens. Reducing equivalents to the biotransformation of carbon dioxide from biogas or other resources to biomethane can be supplied by external hydrogen. Discontinuous electricity production from wind and solar energy combined with fluctuating utilization cause serious storage problems that can be solved by power-to-gas strategy representing the production of storable hydrogen via the electrolysis of water. The possibility of subsequent repowering of the energy of hydrogen to the easily utilizable and transportable form is a biological conversion with CO2 to biomethane. Biomethanization of CO2 can take place directly in anaerobic digesters fed with organic substrates or in separate bioreactors. The major bottleneck in the process is gas-liquid mass transfer of H2 and the method of the effective input of hydrogen into the system. There are many studies with different bioreactors arrangements and a way of enrichment of hydrogenotrophic methanogens, but the system still has to be optimized for a higher efficiency. The aim of the paper is to gather and critically assess the state of a research and experience from laboratory, pilot and operational applications of carbon dioxide bioconversion and highlight further perspective fields of research.

• MeSH
• anaerobióza MeSH
• Archaea metabolismus   fyziologie   MeSH
• biopaliva MeSH
• bioreaktory mikrobiologie   MeSH
• biotechnologie přístrojové vybavení   metody   MeSH
• fermentace MeSH
• methan metabolismus   MeSH
• oxid uhličitý metabolismus   MeSH
• průmyslová mikrobiologie metody   MeSH
• vodík metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

• MeSH
• diagnostické zobrazování MeSH
• radiografie * přístrojové vybavení   MeSH
• radiologická technologie MeSH
• Publikační typ
• monografie MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• radiologie, nukleární medicína a zobrazovací metody

Objective.This work presents a method for enhanced detection, imaging, and measurement of the thermal neutron flux.Approach. Measurements were performed in a water tank, while the detector is positioned out-of-field of a 20 MeV ultra-high pulse dose rate electron beam. A semiconductor pixel detector Timepix3 with a silicon sensor partially covered by a6LiF neutron converter was used to measure the flux, spatial, and time characteristics of the neutron field. To provide absolute measurements of thermal neutron flux, the detection efficiency calibration of the detectors was performed in a reference thermal neutron field. Neutron signals are recognized and discriminated against other particles such as gamma rays and x-rays. This is achieved by the resolving power of the pixel detector using machine learning algorithms and high-resolution pattern recognition analysis of the high-energy tracks created by thermal neutron interactions in the converter.Main results. The resulting thermal neutrons equivalent dose was obtained using conversion factor (2.13(10) pSv·cm2) from thermal neutron fluence to thermal neutron equivalent dose obtained by Monte Carlo simulations. The calibrated detectors were used to characterize scattered radiation created by electron beams. The results at 12.0 cm depth in the beam axis inside of the water for a delivered dose per pulse of 1.85 Gy (pulse length of 2.4μs) at the reference depth, showed a contribution of flux of 4.07(8) × 103particles·cm-2·s-1and equivalent dose of 1.73(3) nSv per pulse, which is lower by ∼9 orders of magnitude than the delivered dose.Significance. The presented methodology for in-water measurements and identification of characteristic thermal neutrons tracks serves for the selective quantification of equivalent dose made by thermal neutrons in out-of-field particle therapy.

• MeSH
• algoritmy * MeSH
• elektrony * MeSH
• kalibrace MeSH
• neutrony MeSH
• záření gama MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• infekce dýchací soustavy prevence a kontrola   MeSH
• prostředky na ochranu dýchání normy   MeSH
• Publikační typ
• směrnice MeSH
• Geografické názvy
• Austrálie MeSH
• Nový Zéland MeSH

• Konspekt
• Metrologie. Standardizace
• NLK Obory
• technika lékařská, zdravotnický materiál a protetika
• pneumologie a ftizeologie

• MeSH
• biochemie MeSH

• Konspekt
• Biochemie. Molekulární biologie. Biofyzika
• NLK Obory
• biochemie