Expiremental determination of the optical density of states for phthalocyanines and porphyrins

This paper deals with expanded polystyrene (EPS) as a potential source of smoke. We compared specific optical density of smoke from EPS and EPS strengthened by glass fibre mash and plaster which is used in external thermal insulation composite systems (ETICS). There was used testing method by ISO 5659 Plastics Smoke generation Part 2: Determination of optical density by a single-chamber test. The samples were exposed to a constant 50 kW.m-2 of thermal radiation. There was not used a pilot burner. During flame combustion samples evolved high amount of smoke. Samples from EPS released more smoke like samples with ETICS cover.

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Measurement of hemoglobin oxygen saturation in capillaries

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1987.252.5.h1031 ◽

1987 ◽

Vol 252 (5) ◽

pp. H1031-H1040 ◽

Cited By ~ 8

Author(s):

M. L. Ellsworth ◽

R. N. Pittman ◽

C. G. Ellis

Keyword(s):

Light Intensity ◽

Oxygen Saturation ◽

Red Blood Cells ◽

Optical Density ◽

Blood Cells ◽

Striated Muscle ◽

Cheek Pouch ◽

Retractor Muscle ◽

Hamster Cheek Pouch

We present a computer-aided videodensitometric method for the determination of oxygen saturation in red blood cells flowing through capillaries of the hamster cheek pouch retractor muscle. The optical density (OD) of red blood cells is determined at two wavelengths. At the first, 431 nm, there is a maximum difference between absorption by oxygen deoxyhemoglobin. At the second, 420 nm, absorption is equal for the two absorbing species (isosbestic wavelength). In capillaries of the retractor muscle a relationship between oxygen saturation (S) and the following OD ratio was obtained as S = -1.71 (OD431/OD420) + 2.20. The error (95% confidence interval) in oxygen saturation associated with a determination of the OD ratio is estimated to be +/- 4.8%. The computerization of the method employs a frame-by-frame analysis of the light intensity over a selected capillary segment. The light intensity waveform along the segment is digitized and the minimum (I) and maximum (I0) light intensities are used to compute an optical density (OD = log10 [I0/I]). These minimum and maximum intensities correspond to the presence and absence of a red blood cell, respectively. The method permits the off-line analysis of videotaped scenes and provides a means of assessing the extent of temporal and spatial heterogeneity of oxygen saturation in selected capillary networks. The method has been developed for use in capillaries in transilluminated striated muscle but should be generally applicable to the measurement of capillary oxygen saturation in other tissues.

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Determination of the phonon density of states from the thermodynamic functions of a crystal: Nickel, palladium, and platinum

Soviet Physics Journal ◽

10.1007/bf00889684 ◽

1979 ◽

Vol 22 (8) ◽

pp. 903-905

Author(s):

V. A. Korshunov

Keyword(s):

Density Of States ◽

Thermodynamic Functions ◽

Phonon Density ◽

Phonon Density Of States

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A spectrophotometric method for determination of fluorophore-to-protein ratios in conjugates of the blue fluorophore 7-amino-4-methylcoumarin-3-acetic acid (AMCA)

Journal of Histochemistry & Cytochemistry ◽

10.1177/38.1.1688452 ◽

1990 ◽

Vol 38 (1) ◽

pp. 87-94 ◽

Cited By ~ 11

Author(s):

M W Wessendorf ◽

S J Tallaksen-Greene ◽

R M Wohlhueter

Keyword(s):

Acetic Acid ◽

Optical Density ◽

Extinction Coefficient ◽

Spectrophotometric Method ◽

Extinction Coefficients ◽

Beer's Law ◽

Beer’S Law ◽

The Given

7-Amino-4-methylcoumarin-3-acetic acid (AMCA) has been found to be a useful fluorophore for immunofluorescence. The present study describes a spectrophotometric method for determining the ratio of moles AMCA to moles protein (or the f/p ratio) in an AMCA-conjugated IgG. The concentration of a substance absorbing light can be determined spectrophotometrically using Beer's Law: Absorbance = Concentration x Extinction coefficient. From Beer's law, one can derive the following formula for determining the f/p ratio of AMCA-IgG conjugates: f/p = (epsilon 280IgG).A350 - (epsilon 350IgG).A280/(epsilon 350AMCA).A280 - (epsilon 280AMCA).A350 where A is the optical density of the conjugate at the given wavelength and epsilon is the extinction coefficient of a substance at the wavelength specified. Using conjugates of model proteins, it was found that the extinction coefficients of the AMCA moiety of AMCA-conjugated protein were 1.90 x 10(4) at 350 nm and 8.29 x 10(3) at 280 nm. Similarly, it was found that the extinction coefficients of swine IgG were 1.56 x 10(3) at 350 nm and 1.26 x 10(5) at 280 nm. Thus, for AMCA-conjugated swine IgG: f/p = (1.26 x 10(5)).A350 - (1.56 x 10(3)).A280/(1.47 x 10(4)).A280 - (6.42 x 10(3)).A350 [corrected]. Based on this formula, the f/p ratios of some AMCA-IgG conjugates useful for immunohistochemistry have been found to range between 6 and 24.

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Determination of the Electronic Density of States of N-Type Hydrogenated Amorphous Silicon from Transient Sweep-Out Experiments

Disordered Semiconductors ◽

10.1007/978-1-4613-1841-5_44 ◽

1987 ◽

pp. 401-406 ◽

Cited By ~ 2

Author(s):

Marvin Silver ◽

David Adler ◽

Howard M. Branz

Keyword(s):

Amorphous Silicon ◽

Density Of States ◽

Hydrogenated Amorphous Silicon ◽

Electronic Density ◽

Electronic Density Of States ◽

Hydrogenated Amorphous

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Determination of Hydrogen Density of States in Amorphous Silicon Using Fractional Evolution Experiments

MRS Proceedings ◽

10.1557/proc-467-147 ◽

1997 ◽

Vol 467 ◽

Author(s):

A. J. Franz ◽

W. B. Jackson ◽

J. L. Gland

Keyword(s):

Amorphous Silicon ◽

Density Of States ◽

Silicon Film ◽

Mean Field ◽

Frequency Factor ◽

Silicon Films ◽

Hydrogen Density ◽

Heating And Cooling ◽

Novel Method

ABSTRACTHydrogen plays an important role in the electronic behavior, structure and stability of amorphous silicon films. Therefore, determination of the hydrogen density of states (DOS) and correlation of the hydrogen DOS with the electronic film properties are important research goals. We have developed a novel method for determination of hydrogen DOS in silicon films, based on fractional evolution experiments. Fractional evolution experiments are performed by subjecting a silicon film to a series of linear, alternating heating and cooling ramps, while monitoring the hydrogen evolution rate. The fractional evolution data can be analyzed using two complementary memods, the fixed frequency factor approach and Arrhenius analysis. Using a rigorous, mean-field evolution model, we demonstrate the applicability of the two approaches to obtaining the hydrogen DOS in silicon films. We further validate both methods by analyzing experimental fractional evolution data foran amorphous silicon carbide film. Both types of analysis yield a similar double peaked density of states for the a-Si:C:H:D film.

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