scholarly journals THE ABSORPTION SPECTRA OF INDICATOR YELLOW IN THE NEAR-ULTRAVIOLET AND THE VISIBLE REGION OF THE SPECTRUM

1951 ◽  
Vol 2 ◽  
pp. 39-43
Author(s):  
MING-TSUNG PENG ◽  
HSI-MOU CHIAN

In a paper recently communicated to the Royal Society, experiments dealing with the absorption spectra of several metals were described, in which it was found that bismuth vapour shows both lines and bands in absorption. The banded spectrum consists of three groups of bands, each group consisting of a number of bands degraded towards the red, the group of bands in the visible region appearing at high temperatures. In the above experiments it was hoped that by raising the temperature of the absorption chamber sufficiently high, and raising the absorption in the lines of the several bands, it might be possible to detect a fine structure in some of these bands. Accordingly, the author modified the furnace previously used so as to blow through it a larger quantity of compressed air, and succeeded finally by using coke and this furnace to obtain a temperature of about 1500°C. to 1600°C. At this temperature the vapour emitted a fluorescent radiation orange yellow in colour.


1964 ◽  
Vol 42 (4) ◽  
pp. 856-860 ◽  
Author(s):  
P. Rama Murthy ◽  
C. C. Patel

Pyridine N-oxide complexes having the composition ZrO(Py•O)6(ClO4)2, Th(Py•O)8(ClO4)4, and UO2(Py•O)5(ClO4)2 have been prepared. The infrared and electronic absorption spectra show that the bonding between the metal and pyridine N-oxide in the complexes has occurred by donation of the lone pair of p-electrons on oxygen to the metal, and that the π-bond character of NO group increases in the complexes as uranyl < thorium < zirconyl. The decrease in the vibrational structure of the UO22+ spectrum in the visible region indicates strong coordination of pyridine N-oxide to the uranyl group. The decomposition temperatures of zirconyl, thorium, and uranyl complexes are 307, 350, and 319 °C respectively.


2019 ◽  
Vol 233 (9) ◽  
pp. 1247-1259
Author(s):  
Madhu Prakasam

Abstract In this work, we systematically investigate the impacts of electron-donor based on Triphenylamine (TPA). The Geometry structure, energy levels, light-harvesting ability and ultraviolet-visible absorption spectra were calculated by using Density Functional Theory (DFT) and Time-Dependent-DFT. The electron injection rate of the TPA-N(CH3)2 based dyes has 0.71 eV for high among the dye sensitizer. The First and Second order Hyperpolarizability of the 11.95 × 10−30 e.s.u and 12195.54 a.u, respectively for TPA-N(CH3)2 based dye. The calculated absorption spectra were showed in the ultra-violet visible region for power conversion region. The study reveals that the electron transfer character of TPA-N(CH3)2 based dyes can be made suitable for applications in Dye-Sensitized Solar Cells.


2011 ◽  
Vol 4 (3) ◽  
pp. 425-436 ◽  
Author(s):  
J. Chen ◽  
D. S. Venables

Abstract. Accurate absorption spectra of gases in the near–ultraviolet (300 to 400 nm) are essential in atmospheric observations and laboratory studies. This paper describes a novel incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS) instrument for measuring very weak absorption spectra from 335 to 375 nm. The instrument performance was validated against the 3B1-X1A1 transition of SO2. The measured absorption varied linearly with SO2 column density and the resulting spectrum agrees well with published spectra. Using the instrument, we report new absorption cross-sections of O3, acetone, 2-butanone, and 2-pentanone in this spectral region, where literature data diverge considerably. In the absorption minimum between the Huggins and Chappuis bands, our absorption spectra fall at the lower range of reported ozone absorption cross-sections. The spectra of the ketones agree with prior spectra at moderate absorptions, but differ significantly at the limits of other instruments' sensitivity. The collision-induced absorption of the O4 dimer at 360.5 nm was also measured and found to have a maximum cross-section of ca. 4.0×10−46 cm5 molecule−2. We demonstrate the application of the instrument to quantifying low concentrations of the short-lived radical, BrO, in the presence of stronger absorptions from Br2 and O3.


Physics Today ◽  
1964 ◽  
Vol 17 (1) ◽  
pp. 82-82
Author(s):  
L. Láng ◽  
Stuart A. Rice

Blood ◽  
1960 ◽  
Vol 16 (3) ◽  
pp. 1285-1297 ◽  
Author(s):  
C. A. SONDHAUS ◽  
BO THORELL

Abstract The strong near-UV absorption of inorganic iron makes possible the microspectrophotometric determination of nonheme intracellular iron as distinct from hemoglobin-bound iron. Erythroid cells of Salamandra Maculosa were therefore studied microspectrophotometrically in the near ultraviolet and visible region. Absorption curves from cytoplasmic areas in living and dried cells were obtained from 310 to 700 mµ., and two component analyses were made to determine the presence and amount of hemoglobin and nonhemoglobin absorption. Under the experimental conditions, intracellular hemoglobin was present largely as the carbon monoxide derivative, a stable form which provided a well defined standard to correct for nonspecific absorption and other spectral distortion due to the optical properties of single cells. Absorption curves from the youngest cells measured were found to differ from those of mature cells, the difference curve agreeing most closely with that of inorganic iron or ferritin in solution. In the youngest cells, nonheme iron appeared to exceed 6 per cent by weight of hemoglobin, or over 20 times molar hemoglobin concentration, dropping and remaining at about twice the hemoglobin molarity from the time hemoglobin synthesis was one-third complete until maturity. Allowing for the increase of total cell mass with growth, the data suggest that although young erythroblasts may already have enough Fe for subsequent Hb synthesis, they continue to incorporate excess Fe throughout maturation and may thus contain a reserve pool of nonheme iron.


1977 ◽  
Vol 31 (10) ◽  
pp. 672-674 ◽  
Author(s):  
Willard R. Wadt ◽  
David C. Cartwright ◽  
James S. Cohen

2020 ◽  
Vol 5 (1) ◽  
pp. 26-35
Author(s):  
Spyros Papantzikos ◽  
Alexandos G. Chronis ◽  
Fotios I. Michos ◽  
Mihail M. Sigalas

Background: ZnS nanoparticles (NPs) are attractive for quantum dots applications because they consist of abundant and non-toxic elements. Their major drawback is that they absorb in the UV region, ultimately limiting their applications. Objective: In the present study, 1D and 2D ZnS NPs have been found. The goal of this study is to find NPs that have absorption in the visible spectrum. Methods: Calculations based on the Density Functional Theory (DFT) have been used to find the optimized geometries. Their absorption spectra have been calculated with the Time-Dependent DFT. Results: Several shapes were examined, such as nanorod, and it is observed that these shapes move the absorption spectra in lower energies, into the visible spectrum, while the 3D NPs have absorption edges in the UV region. Conclusion: NPs with the shape of nanorod in different directions showed that their absorption spectra moved to lower energies well inside the visible spectrum with significantly high oscillator strength. In contrast with the mostly used CdSe NPs, the ZnS NPs are made from more abundant and less toxic elements. Therefore, by making them absorb in the visible region, they may find significant applications in solar cells and other photonic applications.


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