The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Thermo-vision is the fastest identification method of the possible defects and energy losses, being an important instrument in the forecast maintenance. In this study, it is proposed a task notebook model for the thermo-vision equipment acquisition that can be utilized in different laboratories for the energetic efficiency study, electrical equipment and mechanics and lasers physics diagnosis. By...
We demonstrate a novel real-time steam quality measurement system relying on NIR absorption. A simple two-phase flow model is used where the vapor phase absorbance is assumed constant for high steam quality for a given pipe pressure. Two NIR light sources of different peak wavelengths are used to compensate for reflection and scattering. A sensor prototype was designed using high temperature resistant...
Because of excellent electrical properties, epoxy resin is widely used in packaging and casting power equipment. Moisture and temperature in the environment are inclined to seriously affect the insulation tolerance of epoxy resin. This work focuses on the aging characteristics of epoxy resin in hygrothermal environment. The effect of hygrothermal aging on the properties of epoxy resin was deeply studied...
The crystallinity of sheets of poly(ether ether ketone) (PEEK) was changed by thermal treatments conducted at 295 °C for various periods and their terahertz (THz) and Fourier-transform infrared absorption (FT-IR) spectra were obtained. As a result, it has been confirmed that an absorption peak appears at around 3.5 THz in the sheet samples that exhibit clear X-ray diffraction patterns at 2Θ = 18.8,...
In this work, the terahertz (THz) absorption spectra of a typical protein BSA (Bovine Serum Albumin) in aqueous solution were measured under different pH conditions. The temporal changes in the absorption spectra were analyzed using the two-dimensional correlation spectroscopy (2DCOS). By comparing the cross peaks corresponding to the different pH values, it can be obtained that the conformation is...
The so called protein dynamical transition has long been associated with thermally activated excitations of the solvent adjacent to the polypeptide surface. Recently we reported the somewhat surprising result that the low temperature (<270K) terahertz absorption measurements of a series of red fluorescent protein showed an increase in the dynamical transition temperature with photobleaching, and...
The photo-thermal effects of plasmonic nanoparticles are promising for cancer therapies. These treatments would greatly benefit from real time, multi-scale temperature mapping by non-invasive means. Here we show that intense terahertz time domain spectroscopy can be used as a non-contact and high resolution thermometer of water solutions. Using this technique we measure the temperature change, triggered...
We present Terahertz (THz) measurements of dl-norvaline (dl-Nva) organic molecular crystals. This material undergoes a solid-state phase transition when the temperature is reduced to less than 180 K. The low temperature and room temperature phases have different THz absorption spectra, which allows them to be distinguished. A better understanding of the mechanism of the phase transition is gained...
We present angle-resolved terahertz time-domain spectroscopy (THz TDS) measurements of poly(butylene) terephthalate (PBT) and compare the results to x-ray scattering measurements. This comparison confirms that the THz TDS measurements can be correlated to the crystal structure. Further, the THz TDS measurements give insights into the binding energies of the crystal bounds.
A 0.14 THz wireless communication system that can transmit data with bit rate of 5 Gbps in real time over more than 21 km is developed. Solid-state power amplifier and vacuum electronic amplifier are cascaded to achieve nearly watts output power. An all solid-state receiver running in room temperature with equivalent noise temperature of 1100 K is used. An experiment over 21 km is carried out with...
We design a reflective photonic limiter for the W-band. The design is based on a Bragg reflector cavity filled with the Mott insulator, VO2. At low intensity, the cavity displays strong resonant transmission via the localized cavity mode. As the input wave intensity increases, the heat-induced transition from insulating to metallic phase in VO2 occurs, suppressing the cavity mode and the resonant...
Quantum dots have excellent optical properties such as broad excitation spectra, tunable emission spectra, large Stokes shift, quantum-enhanced luminescence efficiency and so on. In this work, CuInS2 quantum dots were prepared successfully by utilizing the non-thermal injection method. They had diameters in the range of 2∼4 nm. The average diameter of the dots was about 2.4 nm. The dominant wavelength...
The temperature dependencies of the characteristics of a bismuth-doped fiber amplifier (BDFA) for a 1725-nm band have been studied. The amplifier was backward-pumped with an Er-Yb-codoped fiber laser at 1568 nm. A peak gain of 24 dB, a 3-dB gain bandwidth of 55 nm, a noise figure of 5 dB and slope gain efficiency of 0.17 dB/mW at room temperature have been obtained. It has been shown that peak gain...
In this contribution, we present a physically motivated dynamic model for a plasmonic hydrogen sensor based on a multilayer sample design with palladium nanodisks, which exhibits near-perfect absorption at visible wavelengths. This plasmonic gas sensor enables detection of low hydrogen concentrations providing the advantages of optical measurement principles and may be produced cost-effectively as...
Temperature dependence of polymer solar cell with a poly (3-hexylthiophene) : indene-C60 bisadduct (P3HT:ICBA) active layer were investigated from 15°C to 50°C to evaluate their application in standard working conditions. A standard drift-diffusion model including the temperature dependent hole mobility was used as a starting point to simulate measured I-V curves. Temperature induced solar cell parameters...
The transition cross sections on the pump and laser wavelength of rare-earth-doped materials are of crucial importance for their performance as amplifiers and lasers and for the understanding of their performance in a rate-equation model. Since typically part of the absorbed pump power is converted to heat, the temperature of the host material increases with increasing pumping. This implies a temperature-dependent...
When a photosensitive (PS) fiber is exposed to UV-irradiation, a permanent refractive index change is induced in the core. As a result, according to Kramers-Kronig relations, the absorption coefficient (α) is also increased. This increment of the absorption can lead to a significant heating of the fiber when it is illuminated by a moderate optical power. Thermal effects may produce spectral changes...
High power laser systems suffer from optical materials overheating by laser radiation. For optical absorptance testing laser calorimetry is widely used [1]. Its main part is temperature kinetics measurement of the sample exposed to laser radiation. Temperature is measured mostly by indirect methods with sensors adjusted to the sample surface. However, absorption of scattered radiation can induce additional...
Absorption spectroscopy is attractive for combustion diagnostics because it allows in-situ and calibration-free quantification of reactants/products and thermometry. However, spectra measured at atmospheric pressure in the near-infrared telecom range, where laser sources and optical components are readily available, suffer from strong water interference. Cavity-enhanced optical frequency comb spectroscopy...
The mid-infrared (MIR) part of the optical spectrum (3–12 μm) houses the fundamental absorption bands of a multitude of environmentally important molecules, but the abundance of water absorption often causes interference with the target species and makes concentration measurement inaccurate. The broad spectral coverage of optical frequency comb spectroscopy (OFCS) provides access to entire ro-vibrational...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.