Absorption and index of refraction for the modeling of InGaAsP/InP photonic devices

1993 ◽  
Vol 71 (9-10) ◽  
pp. 410-416 ◽  
Author(s):  
B. Reid ◽  
R. Maciejko ◽  
A. Champagne
Keyword(s):  
Experimental Data ◽  
Optical Properties ◽  
Wavelength Range ◽  
Photonic Devices ◽  
Index Of Refraction ◽  
The Other ◽  
Other Hand ◽  
Lattice Matched

Methods for modeling, over an extended practical wavelength range, the index of refraction and the absorption in lattice-matched InGaAsP/InP-based photonic devices are reviewed, completed, and clarified. Carrier-induced effects on the optical properties are given special attention. For the index of refraction, the method gives results within 1% of the experimental ones. On the other hand, the results for absorption are more difficult to compare owing to the lack of experimental data.

OBSCURANT AND EMISSION CHARACTERISTICS OF THE SCREENING SMOKE COMPOSITIONS USED IN NAVAL SHIPS

2020 ◽  
pp. 108-117
Author(s):  
Toan
Keyword(s):  
Wavelength Range ◽  
Extinction Coefficient ◽  
Infrared Emission ◽  
The Other ◽  
Emission Characteristics ◽  
Red Phosphorus ◽  
Other Hand

Obscurant and optronic decoy compositions are the pyrotechnic formulations that are an effective way to protect naval ships from optical guided missile seekers. In this work, the obscurant characteristics (i.e. the transmittance and the extinction coefficient) and the infrared emission characteristics (i.e. the infrared emission distribution and the radiance) of the obscurant and optronic decoy compositions were described. The results showed that the obscurant cloud made from the mixture of red phosphorus, Ba(NO3)2 and Viton rubber has a low transmittance, high extinction coefficient with 1.06 µm laser and strong infrared emission in the wavelength range of 8.0 to 14.0 µm. On the other hand, the infrared emission radiance (in the wavelength range of 2.5 to 5.0 µm) of the optronic decoy composition based on Mg-Al, hexachloroethane and Viton rubber reaches maximum values (i.e. 17.77E-3 W.cm-2.Sr-1) at about 17 wt% Mg-Al. Finally, the above obscurant and optronic decoy compositions can be used combination in naval ships against the anti-ship missile.

About lung surgery

1903 ◽  
Vol 3 (9-10) ◽  
pp. 548-549
Author(s):  
E. Board
Keyword(s):  
Experimental Data ◽  
Lung Tissue ◽  
Lung Surgery ◽  
Operative Intervention ◽  
The Other ◽  
Pulmonary Diseases ◽  
Other Hand

Lung surgery is one of the youngest departments of surgical science. The basis for the development of methods of operative intervention in pulmonary diseases lies in the 1st possibility of preventing the danger of pneumothorax, which (danger) is currently so insignificant that some surgeons consider it even necessary to cause preliminary pneumothorax. On the other hand, the experimental data have shown the possibility of the loss of parts of the lung tissue and the conditions for the healing of its wounds.

Optical Propagation in Solids

2006 ◽  
Author(s):  
Michael E. Thomas
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Solid State ◽  
Optical Fibers ◽  
Optical Materials ◽  
Photonic Devices ◽  
Index Of Refraction ◽  
Optical Detectors ◽  
Optical Propagation ◽  
Valence Bands

This chapter emphasizes the linear optical properties of solids as a function of frequency and temperature. Such information is basic to understanding the performance of optical fibers, lenses, dielectric and metallic mirrors, window materials, thin films, and solid-state photonic devices in general. Optical properties are comprehensively covered in terms of mathematical models of the complex index of refraction based on those discussed in Chapters 4 and 5. Parameters for these models are listed in Appendix 4. A general review of solid-state properties precedes this development because the choice of an optical material requires consideration of thermal, mechanical, chemical, and physical properties as well. This section introduces the classification of optical materials and surveys other material properties that must be considered as part of total optical system design involving solidstate optics. Solid-state materials can be classified in several ways. The following are relevant to optical materials. Three general classes of solids are insulators, semiconductors, and metals. Insulators and semiconductors are used in a variety of ways, such as lenses, windows materials, fibers, and thin films. Semiconductors are used in electrooptic devices and optical detectors. Metals are used as reflectors and high-pass filters in the ultraviolet. This type of classification is a function of the material’s electronic bandgap. Materials with a large room-temperature bandgap (Eg > 3eV) are insulators. Materials with bandgaps between 0 and 3 eV are semiconductors. Metals have no observable bandgap because the conduction and valence bands overlap. Optical properties change drastically from below the bandgap, where the medium is transparent, to above the bandgap, where the medium is highly reflective and opaque. Thus, knowledge of its location is important. Appendix 4 lists the bandgaps of a wide variety of optical materials. To characterize a medium within the region of transparency requires an understanding of the mechanisms of low-level absorption and scattering. These mechanisms are classified as intrinsic or extrinsic. Intrinsic properties are the fundamental properties of a perfect material, caused by lattice vibrations, electronic transitions, and so on, of the atoms composing the material.

scholarly journals Preparation and Thermal and Anti-UV Properties of Chitosan/Mica Copolymer

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Yih-Sheng Huang ◽  
Sheng-Haur Yu ◽  
Yea-Ru Sheu ◽  
Kuo-Shien Huang
Keyword(s):  
Experimental Data ◽  
Thermal Stability ◽  
Free Radical ◽  
Physical Properties ◽  
Ammonium Persulfate ◽  
Sodium Bisulfite ◽  
The Other ◽  
Other Hand

This experiment aims to produce a free radical while annoying the oxidizing-reducing reagent of the ammonium persulfate and the sodium bisulfite under nitrogen, then trigger copolymerization between modified-mica and chitosan to prepare a variety of copolymers. This experiment also aims to study the related properties of these copolymer materials. The experimental data shows that the copolymer has more thermal stability and better absorption of UV than chitosan. But the above physical properties will be less if the mica ratio in copolymer is more than 8%. On the other hand, the SEM photo of the microstructure also shows that the modified mica distributes homogeneously on the surface of the film of the copolymer.

scholarly journals Understanding the Interaction Modes and Reactivity of Trimedoxime toward MmAChE Inhibited by Nerve Agents: Theoretical and Experimental Aspects

2020 ◽  
Vol 21 (18) ◽  
pp. 6510
Author(s):  
Alexandre A. de Castro ◽  
Daniel A. Polisel ◽  
Bruna T. L. Pereira ◽  
Elaine F. F. da Cunha ◽  
Kamil Kuca ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mus Musculus ◽  
Active Site ◽  
Theoretical Calculations ◽  
Nerve Agents ◽  
The Other ◽  
Chemical Weapons ◽  
Reactivation Process ◽  
Other Hand

Organophosphorus (OP) compounds are used as both chemical weapons and pesticides. However, these agents are very dangerous and toxic to humans, animals, and the environment. Thus, investigations with reactivators have been deeply developed in order to design new antidotes with better efficiency, as well as a greater spectrum of action in the acetylcholinesterase (AChE) reactivation process. With that in mind, in this work, we investigated the behavior of trimedoxime toward the Mus musculus acetylcholinesterase (MmAChE) inhibited by a range of nerve agents, such as chemical weapons. From experimental assays, reactivation percentages were obtained for the reactivation of different AChE–OP complexes. On the other hand, theoretical calculations were performed to assess the differences in interaction modes and the reactivity of trimedoxime within the AChE active site. Comparing theoretical and experimental data, it is possible to notice that the oxime, in most cases, showed better reactivation percentages at higher concentrations, with the best result for the reactivation of the AChE–VX adduct. From this work, it was revealed that the mechanistic process contributes most to the oxime efficiency than the interaction in the site. In this way, this study is important to better understand the reactivation process through trimedoxime, contributing to the proposal of novel antidotes.

The Interaction of Carbon Black with Sulfur, MBT and TMTD in Vulcanization

1961 ◽  
Vol 34 (2) ◽  
pp. 588-599 ◽  
Author(s):  
G. A. Blokh ◽  
Ch. L. Melamed
Keyword(s):  
Experimental Data ◽  
Carbon Black ◽  
Chemical Reactions ◽  
The Other ◽  
Considerable Importance ◽  
Physical Aspect ◽  
Active Centers ◽  
Other Hand ◽  
The One

Abstract The experimental data collected on the interaction of active centers of carbon black with the rubber on the one hand and of the active centers of carbon black with the sulfur and accelerators, and also with the antioxidants, on the other hand, provide a sound basis for belief that the problem of reinforcement of rubber by active fillers in the process of vulcanization cannot be explained from the physical aspect alone. The facts indicate the considerable importance of the chemical reactions between the active groups of carbon black and the compounding ingredients in the course of vulcanization.

A Hybrid Semi-empirical Model for Lean Blow-Out Limit Predictions of Aero-engine Combustors

2014 ◽  
Vol 137 (3) ◽  
Author(s):  
Bin Hu ◽  
Yong Huang ◽  
Jianzhong Xu
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Empirical Model ◽  
The Other ◽  
Model Parameters ◽  
Model Parameter ◽  
Other Hand ◽  
Aero Engine ◽  
Semi Empirical

According to the Lefebvre's model and flame volume (FV) concept, an FV model about lean blow-out (LBO) was proposed by authors in early study. On the other hand, due to the model parameter (FV) contained in FV model is obtained based on the experimental data, FV model could only be used in LBO analysis instead of prediction. In view of this, a hybrid FV model is proposed that combines the FV model with numerical simulation in the present study. The model parameters contained in the FV model are all estimated from the simulated nonreacting flows. Comparing with the experimental data for 11 combustors, the maximum and average uncertainties of hybrid FV model are ±16% and ±10%.

scholarly journals A note on dynamical compensation and its relation to parameter identifiability

2017 ◽  
Author(s):  
Omer Karin ◽  
Uri Alon ◽  
Eduardo Sontag
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
The Other ◽  
Apparent Discrepancy ◽  
Parameter Identifiability ◽  
Other Hand ◽  
The Face ◽  
System Variables

AbstractWe recently identified a motif for dynamical compensation (DC) – a property where a system maintains the dynamics and steady-state of a regulated variable robust in the face of fluctuations in key parameters. Such parameters are therefore unidentifiable from measurements of the regulated variable at steady-state. On the other hand, since the models showing dynamical compensation are typically non-redundant, their parameters are identifiable from experimental data. We clarify this apparent discrepancy by requiring that the parameters of DC circuits be identifiable both away from steady-state and when measuring other system variables. We use this observation to provide a definition for DC in terms of parameter identifiability and discuss its relevance for the examples provided in Karin et al.

scholarly journals General approach to the sensitivity of the optics of an eye to change in elementary parameters with application to the Gaussian optics of a reduced eye

2009 ◽  
Vol 68 (4) ◽  
Author(s):  
W. F. Harris
Keyword(s):  
Optical Properties ◽  
Index Of Refraction ◽  
The Other ◽  
Radius Of Curvature ◽  
Corneal Curvature ◽  
Independent Variables ◽  
Gaussian Optics ◽  
Clear Statement ◽  
Two Independent Variables ◽  
General Method

Optical properties of the eye, including the refractive compensation, for example, may change if there are changes in any of the components that make up the eye.  The sensitivity to such changes isquantified via the derivative.  This paper employs the reduced eye and Gaussian optics to illustrate a general method for the analysis of sensitivity in eyes.  The method requires a clear statement of the dependent variable as a function of independent variables.  A symbolism is offered that makes the function unambiguous.  Sensitivities are determined for the fundamental optical properties,the transference and the corneal-plane refractivecompensation of a reduced eye to change in corneal power, curvature and radius of curvature and to change in axial length and index of refraction.  Emsley’s reduced eye is examined in particular.  Its corneal-plane refractive compensation has a sensitivity of  135 −135 D to change in refractive index,  1 −2.7 D/mm to change in length and  135 −1/3 to change in corneal curvature when the other two independent variables are held fixed.  The method has the potential to develop guidelines that are useful clini-cally.

Skin Friction

1911 ◽  
Vol 15 (59) ◽  
pp. 115-118
Author(s):  
W. Ellis Williams
Keyword(s):  
Experimental Data ◽  
Skin Friction ◽  
Laboratory Experiments ◽  
Surface Friction ◽  
Normal Pressure ◽  
The Other ◽  
Other Hand

Among the various experimental data which are required in the discussion of the theory and design of the aeroplane, there are none of greater importance than those relating to surface friction, while at the same time there are none about which greater uncertainty prevails.Owing to the difficulty of separating skin friction from head resistance, very little can be learnt from observations on actual machines in flight, while on the other hand, if we turn to laboratory experiments on the resistance of planes, we are met with the most bewildering variations in the values obtained for it. Many of the most careful experimenters make out that it is quite inappreciable while others maintain that it is from 1—4 per cent. of the normal pressure, and therefore forms an important part of the drift at small angles of attack.

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