Effect of Cu, Cr, S Doped TiO2 for Transparent Plastic Bar Reinforced Concrete

In this study, after firing and powdering Cu, Cr, and S with NP-400 TiO2, an NOx removal rate test was performed according to the ISO test method to analyze the photocatalytic reactivity in visible light. The distribution of the photocatalyst and visible light reactivity on the surface of the test specimen were confirmed through SEM (Scanning electron microscope), EDS (Energy dispersive spectroscopy), XRD (X-ray diffraction), UV-visible absorption spectrum and energy band gap tests. The flowability of UHPC (Ultra high performance concrete) slightly decreased due to the increase in the photocatalyst mixing rate, but both J-Ring and L-Box test results showed that there is no problem when concrete is placed. As a result of SEM and EDS tests, good microstructure and peak values were confirmed in the test specimens doped with Cu, and as a result of the XRD test, anatase and rutile peaks were confirmed in the Cu, Cr, and S specimens. In the UV-visible absorption spectrum analysis, it was confirmed that only the specimen doped with Cu maintains a high absorption power of 0.8 up to 700 nm, and the inherent band gaps are reduced to 2.9 eV, thereby increasing the possibility of reaction in visible light. Finally, as a result of the NOx removal test by the ISO test method, about 15.8% was removed for 5 h in the specimen doped with Cu, and the removal efficiency is estimated to be possible up to about 25% when applied with the TPBRC (transparent plastic bar reinforced concrete).

Synthesis of Novel Oxazolidines and Study of Its Naked Eye CO2 Detecting Properties

Herewith, we synthesized the new oxazolidines (SP-1, SP-2 and SP-3) by without using any withdrawing or donating substitution, and for these molecules we demonstrated CO2 sensing properties in naked eye condition with different colors (yellow and magenta). All the dyes showed different colors in the presence and absence of CO2 in ethanol solution with the concept of ring closing and opening. In UV-visible absorption spectrum all the compounds showed visible light absorptions after purging of CO2. To confirm this mechanism for SP-1 molecule case, we approached the 1H-NMR and 13C-NMR techniques deuterated methanol as a solvent and we clearly identified. The stability of the SP-1 molecule in ethanol for CO2 purging case, we studied repeatability test up to ten cycles and we confirmed that there is no any decrease in sensing ability.

Direct observation of o-benzyne formation in photochemical hexadehydro-Diels–Alder (hν-HDDA) reactions

We report the transient ultraviolet/visible absorption spectrum of an o-benzyne species in solution for the first time.

UV-visible absorption spectrum of FAD and its reduced forms embedded in a cryptochrome protein

Simulation of UV-vis absorption spectra of cryptochromes and flavoproteins requires an explicit account of vibrations of the flavin chromophore embedded in protein.

pH-Dependent absorption spectrum of oxyluciferin analogues in the active site of firefly luciferase

pH-Induced changes in the UV-visible absorption spectrum of oxyluciferin analogues in luciferase are experimentally and computationally investigated using three different oxyluciferin analogues.

Copper nanoparticles prepared by pulsed exploding wire

In this work copper nanopowder was created at different liquidmedias like DDDW, ethylene glycol and Polyvinylpyrrolidone(PVP). Copper nanopowder prepared using explosion wire processand investigated the effects of the exploding energy, wire diameter,the type of liquid on the particle size, and the particles sizedistribution. The nanoparticles are characterized by x-ray diffraction,UV-visible absorption spectroscopy and transmission electronmicroscopy (TEM). The x-ray diffraction results reveal that thenanoparticles continue to routine lattice periodicity at reducedparticle size. The UV-Visible absorption spectrum of liquid solutionfor copper nanoparticles shows sharp and single surface Plasmonresonance (SPR) peak centered at a wavelength of 590 nm inethylene glycol media, but don’t have peak in PVP fluid. This peakindicated the production of pure and spherical copper nanoparticle.

Can ozone be used to calibrate aerosol photoacoustic spectrometers?

Photoacoustic spectroscopy (PAS) has become a popular technique for measuring absorption of light by atmospheric aerosols in both the laboratory and field campaigns. It has low detection limits, measures suspended aerosols, and is insensitive to scattering. But PAS requires rigorous calibration to be applied quantitatively. Often, a PAS instrument is either filled with a gas of known concentration and absorption cross section, such that the absorption in the cell can be calculated from the product of the two, or the absorption is measured independently with a technique such as cavity ring-down spectroscopy. Then, the PAS signal can be regressed upon the known absorption to determine a calibration slope that reflects the sensitivity constant of the cell and microphone. Ozone has been used for calibrating PAS instruments due to its well-known UV–visible absorption spectrum and the ease with which it can be generated. However, it is known to photodissociate up to approximately 1120 nm via the O3 + hν(>1.1eV)→O2(3Σg-) + O(3P) pathway, which is likely to lead to inaccuracies in aerosol measurements. Two recent studies have investigated the use of O3 for PAS calibration but have reached seemingly contradictory conclusions with one finding that it results in a sensitivity that is a factor of 2 low and the other concluding that it is accurate. The present work is meant to add to this discussion by exploring the extent to which O3 photodissociates in the PAS cell and the role that the identity of the bath gas plays in determining the PAS sensitivity. We find a 5 % loss in PAS signal attributable to photodissociation at 532 nm in N2 but no loss in a 5 % mixture of O2 in N2. Furthermore, we discovered a dramatic increase of more than a factor of 2 in the PAS sensitivity as we increased the O2 fraction in the bath gas, which reached an asymptote near 100 % O2 that nearly matched the sensitivity measured with both NO2 and nigrosin particles. We interpret this dependence with a kinetic model that suggests the reason for the observed results is a more efficient transfer of energy from excited O3 to O2 than to N2 by a factor of 22–55 depending on excitation wavelength. Notably, the two prior studies on this topic used different bath gas compositions, and although the results presented here do not fully resolve the differences in their results, they may at least partially explain them.

Age Determination of Blood-Stained Fingerprints Using Visible Wavelength Reflectance Hyperspectral Imaging

The ability to establish the exact time a crime was committed is one of the fundamental aims of forensic science. The analysis of recovered evidence can provide information to assist in age determination, such as blood, which is one of the most commonly encountered types of biological evidence and the most common fingerprint contaminant. There are currently no accepted methods to establish the age of a blood-stained fingerprint, so progress in this area would be of considerable benefit for forensic investigations. A novel application of visible wavelength reflectance, hyperspectral imaging (HSI), is used for the detection and age determination of blood-stained fingerprints on white ceramic tiles. Both identification and age determination are based on the unique visible absorption spectrum of haemoglobin between 400 and 680 nm and the presence of the Soret peak at 415 nm. In this study, blood-stained fingerprints were aged over 30 days and analysed using HSI. False colour aging scales were produced from a 30-day scale and a 24 h scale, allowing for a clear visual method for age estimations for deposited blood-stained fingerprints. Nine blood-stained fingerprints of varying ages deposited on one white ceramic tile were easily distinguishable using the 30-day false colour scale.