Author: M. Ogawa
Publisher:
ISBN:
Category : Absorption spectra
Languages : en
Pages : 26
Book Description
The vibrational isotope shift of the nitrogen absorption bands has been studied in the 830-1000 angstrom region. A 3-meter normalincidence vacuum spectrograph was used with the helium continuum as background. (Author).
Isotope Shift of the Nitrogen Absorption Bands in the Vacuum Ultraviolet Region
Author: M. Ogawa
Publisher:
ISBN:
Category : Absorption spectra
Languages : en
Pages : 26
Book Description
The vibrational isotope shift of the nitrogen absorption bands has been studied in the 830-1000 angstrom region. A 3-meter normalincidence vacuum spectrograph was used with the helium continuum as background. (Author).
Publisher:
ISBN:
Category : Absorption spectra
Languages : en
Pages : 26
Book Description
The vibrational isotope shift of the nitrogen absorption bands has been studied in the 830-1000 angstrom region. A 3-meter normalincidence vacuum spectrograph was used with the helium continuum as background. (Author).
Effects of Experimental Parameters on Thermoluminescence of a Type II-a Diamond
Author: Albert D. Johnson
Publisher:
ISBN:
Category : Crystals
Languages : en
Pages : 42
Book Description
Thermoluminescence provides a method for studying properties of those crystalline imperfections which behave as electron traps and recombination centers in wide bandgap materials. This approach, however, has been used relatively little, possibly due to the fact that the shapes and intensities of thermoluminescent glow curves are functions of several experimental parameters and are often complicated by the overlapping of a number of individual glow peaks. In the present work, experimental parameters were isolated and some of their effects on thermoluminescent glow curves were analyzed. This yielded information on activation energies associated with trapping levels, the nature of the kinetics involved in electron transitions, and electron retrapping. A Type II-a diamond, which has a wide distribution of thermoluminescent glow peaks, was used in this work. (Author).
Publisher:
ISBN:
Category : Crystals
Languages : en
Pages : 42
Book Description
Thermoluminescence provides a method for studying properties of those crystalline imperfections which behave as electron traps and recombination centers in wide bandgap materials. This approach, however, has been used relatively little, possibly due to the fact that the shapes and intensities of thermoluminescent glow curves are functions of several experimental parameters and are often complicated by the overlapping of a number of individual glow peaks. In the present work, experimental parameters were isolated and some of their effects on thermoluminescent glow curves were analyzed. This yielded information on activation energies associated with trapping levels, the nature of the kinetics involved in electron transitions, and electron retrapping. A Type II-a diamond, which has a wide distribution of thermoluminescent glow peaks, was used in this work. (Author).
State - Logic Relations in an Iterative Structure for Autonomous Sequential Machine
Author: William F. King (III)
Publisher:
ISBN:
Category : Cellular automata
Languages : en
Pages : 30
Book Description
The state-logic relations are determined in an iterative structure for any autonomous sequential machine. A model (unlike that of Mealy) is used in which delay is distributed throughout the machine. Theorems are presented which prescribe the interconnection of identical elements to realize any autonomous sequential behavior. Synthesis, as described here, yields a more costly machine in terms of delay elements than those of previous workers. In addition to the iterative structure, increased speed of operation is the advantage bought by the extra delay elements.
Publisher:
ISBN:
Category : Cellular automata
Languages : en
Pages : 30
Book Description
The state-logic relations are determined in an iterative structure for any autonomous sequential machine. A model (unlike that of Mealy) is used in which delay is distributed throughout the machine. Theorems are presented which prescribe the interconnection of identical elements to realize any autonomous sequential behavior. Synthesis, as described here, yields a more costly machine in terms of delay elements than those of previous workers. In addition to the iterative structure, increased speed of operation is the advantage bought by the extra delay elements.
On Measuring the Radar Cross Sections of Ducks and Chickens
Author: P. Blacksmith (Jr.)
Publisher:
ISBN:
Category : Chickens
Languages : en
Pages : 14
Book Description
Publisher:
ISBN:
Category : Chickens
Languages : en
Pages : 14
Book Description
Optimum Binary FSK for Transmitted Reference Systems Over Rayleigh Fading Channels
Author: Neil J. Bershad
Publisher:
ISBN:
Category : Decision theory
Languages : en
Pages : 32
Book Description
It is well known that in communicating over randomly time-varying channels, a receiver which performs a channel measurement can make a better decision than one that does not. It is shown that a channel-measuring system improves system performance even when the channel characteristics are fixed only during the present message interval. The randomly time-varying channel studied is that of a Rayleigh fading medium with independently fading mark and space channels whose fading is fixed over one baud interval but is independent from baud to baud. The transmission system is a modified frequency shift keying (FSK) system such that during a portion of a baud interval the mark and space frequencies are always transmitted so as to act as reference signals. For the above system, the following characteristics have been established: (a) Optimum receiver configuration, (b) Optimum ratio alpha of information energy to total signal energy as a function of total available signal-to-noise ratio for a single fading channel, (c) Asymptotic optimum alpha for an M-diversity channel, (d) Error probabilities for (b) and asymptotic error probabilities for (c) for alpha opt as a function of total signal-to-noise ratio. The asymptotic results show that by using reference techniques the order of diversity is effectively doubled. (Author).
Publisher:
ISBN:
Category : Decision theory
Languages : en
Pages : 32
Book Description
It is well known that in communicating over randomly time-varying channels, a receiver which performs a channel measurement can make a better decision than one that does not. It is shown that a channel-measuring system improves system performance even when the channel characteristics are fixed only during the present message interval. The randomly time-varying channel studied is that of a Rayleigh fading medium with independently fading mark and space channels whose fading is fixed over one baud interval but is independent from baud to baud. The transmission system is a modified frequency shift keying (FSK) system such that during a portion of a baud interval the mark and space frequencies are always transmitted so as to act as reference signals. For the above system, the following characteristics have been established: (a) Optimum receiver configuration, (b) Optimum ratio alpha of information energy to total signal energy as a function of total available signal-to-noise ratio for a single fading channel, (c) Asymptotic optimum alpha for an M-diversity channel, (d) Error probabilities for (b) and asymptotic error probabilities for (c) for alpha opt as a function of total signal-to-noise ratio. The asymptotic results show that by using reference techniques the order of diversity is effectively doubled. (Author).
The Control of Electromagnetic Scattering by Impedance Loading
Author: J. K. Schindler
Publisher:
ISBN:
Category : Electromagnetism
Languages : en
Pages : 24
Book Description
Publisher:
ISBN:
Category : Electromagnetism
Languages : en
Pages : 24
Book Description
Modified Phycoerythrin from Porphyridium Cruentum Treated with P-chloro-mercuribenzoate
Author: Eiji Fujimori
Publisher:
ISBN:
Category : Absorption spectra
Languages : en
Pages : 14
Book Description
Phycoerythrin, pigment-protein complex in photosynthetic organisms, plays a role in photosynthesis in transferring an energy abosrbed by itself to chlorophyll. Previous studies in this laboratory showed that the longest absorption band at 565 millimicrons responsible for fluorescence originates from the interaction between the pigment and SH-group of the protein in phycoerythrin. During the course of investigation on the effect of SH-blocking agent on energy transfer, it was found that modified phycoerythrin is released from cells treated with PCMB. This modified phycoerythrin possesses a single absorption band at 545 millimicrons, while native phycoerythrin shows three absorption bands at 500, 545, and 565 millimicrons. In the glutathione-treated modified phycoerythrin, the highly fluorescent 565 millimicrons chromophore was partially regenerated. This investigation indicates that native phycoerythrin is composed of two units and that modified phycoerythrin is one of them separated from the other containing the 500 millimicrons chromophore only. (Author).
Publisher:
ISBN:
Category : Absorption spectra
Languages : en
Pages : 14
Book Description
Phycoerythrin, pigment-protein complex in photosynthetic organisms, plays a role in photosynthesis in transferring an energy abosrbed by itself to chlorophyll. Previous studies in this laboratory showed that the longest absorption band at 565 millimicrons responsible for fluorescence originates from the interaction between the pigment and SH-group of the protein in phycoerythrin. During the course of investigation on the effect of SH-blocking agent on energy transfer, it was found that modified phycoerythrin is released from cells treated with PCMB. This modified phycoerythrin possesses a single absorption band at 545 millimicrons, while native phycoerythrin shows three absorption bands at 500, 545, and 565 millimicrons. In the glutathione-treated modified phycoerythrin, the highly fluorescent 565 millimicrons chromophore was partially regenerated. This investigation indicates that native phycoerythrin is composed of two units and that modified phycoerythrin is one of them separated from the other containing the 500 millimicrons chromophore only. (Author).
Guide to the Interpretation of Space Group Symbols
Author: Stanley K. Dickinson
Publisher:
ISBN:
Category : Crystal lattices
Languages : en
Pages : 46
Book Description
Publisher:
ISBN:
Category : Crystal lattices
Languages : en
Pages : 46
Book Description
On the Resolving Power of Ground Mapping Radar Antennas
Author: J. F. McIlvenna
Publisher:
ISBN:
Category : Aerial photography
Languages : en
Pages : 66
Book Description
The mapping of extended, cultural ground targets by an airborne radar is examined using communication theory concepts including those of the antenna transfer function and the target spatial frequency spectrum. Use of the set of transfer functions that correspond to Taylor aperture distributions and specification of the targets directly in terms of their spatial frequency spectra, permits one to examine the antenna images for quality and resolution. The results obtained indicate that resolution for a class of ground targets can be much better than is predicted by the two-point Rayleigh resolution criterion. It is also true that there can be situations in which the shape of the antenna images are quite independent of the radiation pattern. Several types of spatial noise were also included in the input spectrum to investigate noise effects on image quality and resolution. (Author).
Publisher:
ISBN:
Category : Aerial photography
Languages : en
Pages : 66
Book Description
The mapping of extended, cultural ground targets by an airborne radar is examined using communication theory concepts including those of the antenna transfer function and the target spatial frequency spectrum. Use of the set of transfer functions that correspond to Taylor aperture distributions and specification of the targets directly in terms of their spatial frequency spectra, permits one to examine the antenna images for quality and resolution. The results obtained indicate that resolution for a class of ground targets can be much better than is predicted by the two-point Rayleigh resolution criterion. It is also true that there can be situations in which the shape of the antenna images are quite independent of the radiation pattern. Several types of spatial noise were also included in the input spectrum to investigate noise effects on image quality and resolution. (Author).
Waveforms and Relative Phase Stability of Transients Radiated from a Helicopter-supported Antenna Wire
Author: E. A. Lewis
Publisher:
ISBN:
Category : Hanscom AFB (Mass.)
Languages : en
Pages : 18
Book Description
A nearly vertical antenna wire varying in length from 3000 to 8000 ft was shock-excited by a high-voltage source. The resulting radiation fields were received at distances of about 600 km by two stations separated laterally so as to subtend an angle of about 15© at the source. The difference in wavefront arrival times at the two stations, observed for 101 transmissions, showed an average absolute deviation from the mean of about only 1/2 [mu]s. This figure includes the effects of possible source asymmetries, sferics noise, instrumental errors, and wave propagation. Typical oscillograms of antenna currents and radiation fields are given. It is shown that the amplitudes and durations of the pulse envelopes, the amplitudes and durations of the first half-cycles, and the quasi-frequencies of the pulses are in good agreement with a theory that takes energy losses into account.
Publisher:
ISBN:
Category : Hanscom AFB (Mass.)
Languages : en
Pages : 18
Book Description
A nearly vertical antenna wire varying in length from 3000 to 8000 ft was shock-excited by a high-voltage source. The resulting radiation fields were received at distances of about 600 km by two stations separated laterally so as to subtend an angle of about 15© at the source. The difference in wavefront arrival times at the two stations, observed for 101 transmissions, showed an average absolute deviation from the mean of about only 1/2 [mu]s. This figure includes the effects of possible source asymmetries, sferics noise, instrumental errors, and wave propagation. Typical oscillograms of antenna currents and radiation fields are given. It is shown that the amplitudes and durations of the pulse envelopes, the amplitudes and durations of the first half-cycles, and the quasi-frequencies of the pulses are in good agreement with a theory that takes energy losses into account.