Experimental Determination of Spectral Transmittance of Porous Cerium Dioxide in the Range 900–1700 nm

2011 ◽  
Vol 133 (10) ◽  
Author(s):  
Krithiga Ganesan ◽  
Wojciech Lipiński

Abstract Overall transmittance of porous cerium dioxide is measured in the spectral range of 900–1700 nm using dispersive spectroscopy. Dense and porous samples of cerium dioxide with average porosities of 0.08 and 0.72, respectively, are investigated. The transmittance of both sample types increases with decreasing thickness, and this trend is more pronounced for the dense samples. The on-average spectrally increasing transmittance of the dense samples is attributed to the decreasing absorption by bulk cerium dioxide with radiation wavelength. The transmittance of the porous samples, on the other hand, remains approximately constant over the spectrum. Porous samples attenuate radiation stronger than the dense samples at any wavelength in the considered range, and it is hypothesized that this effect is due to more intense scattering. Sharp local variations of the transmittance are observed for both sample types.

Author(s):  
Krithiga Ganesan ◽  
Wojciech Lipin´ski

Overall transmittance of porous cerium dioxide is measured in the spectral range of 900–1700 nm using dispersive spectroscopy. Dense and porous samples of cerium dioxide with average porosities of 0.08 and 0.72, respectively, are investigated. The transmittance of both sample types increases with decreasing thickness, and this trend is more pronounced for the dense samples. The on-average spectrally increasing transmittance of the dense samples is attributed to the decreasing absorption by bulk cerium dioxide with radiation wavelength. The transmittance of the porous samples, on the other hand, remains a constant over the spectrum. Porous samples attenuate radiation stronger than the dense samples at any wavelength in the considered range, and it is hypothesized that this effect is due to more intense scattering. Sharp local variations of the transmittance are observed for both sample types.


2014 ◽  
Vol 659 ◽  
pp. 262-267
Author(s):  
Marian Truta ◽  
Marin Marinescu ◽  
Octavian Alexa ◽  
Radu Vilau ◽  
Valentin Vinturis

Present paper aims at revealing a way to determine the cinematic misfit within a 4x4 vehicle’s inter-axle driveline, which is eventually the reason of the self-generated torque occurrence. We used experimental methods to determine the magnitude of the cinematic misfit. Within this frame, we used a vehicle that has a longitudinal (inter-axle) differential and we locked it, actually forcing the longitudinal transmission to work without differentiating the angular speeds on its output shafts. On the other hand, the tire radii were different, inducing the above-mentioned cinematic misfit that we were looking for. We also present the way we fit the transducers on the vehicle’s driveline components to measure the needed parameters. The paper also presents some theoretical considerations regarding the occurrence of the cinematic misfit and its way of generating closed power loops within the vehicle’s transmission.


2011 ◽  
Vol 24 (4) ◽  
pp. 285-299 ◽  
Author(s):  
Z. Liang ◽  
W. C. Chueh ◽  
K. Ganesan ◽  
S. M. Haile ◽  
W. Lipiński

Geophysics ◽  
1976 ◽  
Vol 41 (4) ◽  
pp. 774-775
Author(s):  
Sven‐Erik Hjelt

The authors have introduced the concept of effective demagnetizing factor to be used when measuring susceptibilities of highly magnetized samples. They have used one experiment to show that the factor thus defined differs considerably from factors computed theoretically. From its definition, it seems obvious that the numerical value of the effective demagnetizing factor will depend on the measuring geometry and, more so, on the shape of the sample. Furthermore, the relation between the new demagnetizing factor and susceptibilities calculated using it on the one hand, and true magnetization on the other hand, is far from trivial.


1872 ◽  
Vol 20 (130-138) ◽  
pp. 34-35

A galvanic current passes from the batteries at the Royal Observatory, Cape Town, at 1 o’clock, and discharges a gun at the Castle, and through relays drops a time-ball at Port Elizabeth. It appeared to the author that a valuable determination of the velocity of sound might be obtained by measuring upon the chronograph of the Observatory the interval between the time of the sound reaching some point near the gun and that of its arrival at the Observatory. As there is only a single wire between the Observatory and Cape Town, some little difficulty was experienced in making the necessary arrangements, without any interference with the 1 o’clock current to Port Elizabeth; but this difficulty was overcome by a plan which the author describes, and which was brought into successful operation on Feb. 27, 1871. The experiments could not have been carried out, on account of the encroachment they would have made on the time of the Observatory staff, had it not been for the assistance of J. Den, Esq., the acting manager of the Cape Telegraph Company, to whom the author is indebted for the preparation of a good earth-connexion near the gun, for permission to Mr. Kirby, a gentleman attached to the telegraph office, to assist in the experiments, and for a general superintendence of the arrangements at Cape Town. The observed times of hearing the sound were recorded on the chronograph by two observers, situated one (Mr. Kirby) at a distance of 641 feet from the gun, the other (Mr. Mann) at the Observatory, at a distance of 15,449 feet from the gun. The former distance was sufficient to allow the connexion of the main wire to be broken at the telegraph office after the gun had been fired, but before the sound reached the first observer.


2004 ◽  
Vol 1 (1) ◽  
pp. 110-115
Author(s):  
Baghdad Science Journal

We found that 4,5- diphenyl- 3(2- propynyl) thio- 1??-triazole [1? forms a complex with Pd (11) ion of ratio 1:1 which absorbs light in CH2CI2 at 400 nm, and 4,5- diphenyl- 3(2- propenyl) thio- 1,2,4- triazole [II] forms complexes with Pd (II) ion of ratio 1:1 which absorbs light at 390 nm, and of ratio 2:1 which absorbs light at 435 nm. On the other hand, we found that the new derivative 4- phenyl- 5( p- amino phenyl) -3- mercapto- 1,2,4- triazole ?111? forms complexes with Cu (II) ion of the ratio 1:1 which absorbs light at 380 nm, with Ni (II) ion of the ratio 3:1 which absorbs light at 358 nm; and with Co (11) ion of the ratio 3.2:1 which absorbs light at 588 nm. The ratio of the complexes were determined by measuring the electronic spectra of the complexes in CH2G2 and (CH^NCHO at different concentrations ofthe ligands and f?xed ' •' of the metal ion in every case, then applying the molar ratio plots on the data. Our results were confirmed by precipitating most ofthe above complexes in solid state, and then each complex was analyzed elementally.


Author(s):  
Vladimír Gryc ◽  
Petr Horáček

The paper was aimed at the determination of variability of horizontal resin canal dimension in spruce wood in relation to the position in a spruce stem. Significant changes of dimensions in horizontal resin canal along the stem length and radius were found. On the basis obtained of results 3D models (for CW, OW, SWL and SWP zones) describing changes in resin canal dimensions in spruce in relation to the position in a stem were created. In the models, the resin canal dimension decreases with the height of a stem and on the other hand, with an increasing distance from the stem pith the dimension of resin canal increases. The importance of the paper consists in the enlargement of findings about the structure of spruce with compression wood.


2021 ◽  
Author(s):  
Jelena Lukić ◽  

The aim of this paperis to determine the quality of TV classes World around us and Nature and Social Science,which were broadcasted on Radio Television of Serbia during the pandemic in the school year 2019/20. Although the work was indirect, so the immediate interaction between the teacher and student is missed. Therefore, teacher's questions were the way of establishing some kind of interaction in such classes organized in this manner. For this reason, we wanted to establish the types of questions that teachers were asking to students through small screens. Considering that the achievements of learning are based on Bloom's Taxonomy, we were analyzing sixteen TV classes and classified the questions the teachers asked according to cognitive area, on six educational levels. The results indicate that the most common were question within lower cognitive levels were (knowledge, understanding and application), and that there are no statistically significant differences in cognitive levels on questions asked between lower (1st and 2nd grade) and higher grades (3rd and 4th grade), on the other hand, on the classes of determination of educational content teachers were asking statistically significant quality questions compared to the classes of interpretation.


1967 ◽  
Vol 4 (3) ◽  
pp. 265-268 ◽  
Author(s):  
Stefan Vajda

The relationships between actuarial and pure mathematics are curious. Actuaries have contributed to the development of mathematical theory: it is sufficient to mention, as examples, Fredholm of an earlier, and Cramér of a more recent generation. Scandinavian mathematicians, in particular, have been concerned with a very special type of stochastic process, reflected in the collective theory of risk, and the work of Philipson, Ammeter and others in this field is well known to readers of this Bulletin. However, the main stream of the theory of stochastic processes has little contact with actuarial applications.On the other hand, many actuaries have studied and assimilated pure mathematics and have thrown light on actuarial matters by describing their own preoccupations in the terminology of modern, often abstract, mathematics. E. Franckx is one of their number.The Instituto di Matematica Finanziaria of the University of Trieste (Faculty of Economics and Commerce) has published a booklet entitledEssai d'une théorie opérationnelle des risques Markoviens which contains three lectures delivered by Professor Franckx in Trieste and a contribution which he presented to the 17th Congress of Actuaries, held in London in 1964.


1973 ◽  
Vol 22 (1) ◽  
pp. 91-98 ◽  
Author(s):  
Heloisa F. Peña ◽  
F.M. Salzano ◽  
Sidia M. Callegari

SummaryThe degree of genetic determination of 4 digital and 16 palmar characteristics was investigated in an unselected series of 49 MZ and 51 DZ adult twins. Low indications of heritability were obtained for the qualitative traits, but 6 of the 8 h2 estimates calculated for the quantitative measurements gave values above 0.70. In general, the results reported here are in agreement with those presented by other authors; however, the correlation coefficients observed for the A′d ridge count were lower than those of two other series. All palmar ridge counts seemed to be intercorrelated in a given individual; other expected relationships, however, were not observed. The fingerprints of MZ and DZ twins on the other hand, showed an unexplained difference.


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