Optical Data of Rough-Surfaced Ceramics: Infrared Specular and Diffuse Reflectance versus Spectra Simulation

1993 ◽  
Vol 47 (4) ◽  
pp. 423-429 ◽  
Author(s):  
V. Hopfe ◽  
E. H. Korte ◽  
P. Klobes ◽  
W. Grählert
Keyword(s):  
Phase Shift ◽  
Smooth Surface ◽  
Diffuse Reflectance ◽  
Optical Data ◽  
Evaluation Procedure ◽  
Alumina Ceramics ◽  
Specular Reflectance ◽  
Optical Functions ◽  
Infrared Reflection ◽  
Simple Evaluation

Infrared reflection of strongly absorbing as well as scattering samples was studied. The optical functions of sintered alumina ceramics were derived with the use of the Kramers-Kronig transformation to reconstruct the phase shift under the assumption of a semi-infinite sample with an ideal plane and, in any scale, a smooth surface. In order to validate this procedure and to optimize measuring parameters, the results were compared to their simulated counterparts. Starting from the dielectric functions of monocrystalline Al2O3, the optical response of the sample was calculated by taking into account the polycrystallinity of the bulk and the roughness of the surface; eventually the spectra of specular reflectance were simulated on this basis for different angles of incidence. It turned out that the comparably simple evaluation procedure is well suited in spite of the rough surface and is particularly reliable in the case of large angles of incidence whereby scattering is minimized. Some characteristics of this diffusely reflected component are discussed.

scholarly journals Characterization and Application of a Grazing Angle Objective for Quantitative Infrared Reflection Microspectroscopy

1995 ◽  
Vol 49 (3) ◽  
pp. 354-360 ◽  
Author(s):  
Stephen V. Pepper
Keyword(s):  
Angular Dependence ◽  
Grazing Angle ◽  
Fresnel Reflection ◽  
Angular Aperture ◽  
Incident Intensity ◽  
Specular Reflectance ◽  
Fresnel Reflection Coefficient ◽  
Infrared Reflection ◽  
Good Agreement

A grazing angle objective on an infrared microspectrometer is studied for quantitative spectroscopy by considering the angular dependence of the incident intensity within the objective's angular aperture. The assumption that there is no angular dependence is tested by comparing the experimental reflectance of Si and KBr surfaces with the reflectance calculated by integrating the Fresnel reflection coefficient over the angular aperture under this assumption. Good agreement was found, indicating that the specular reflectance of surfaces can straightforwardly be quantitatively integrated over the angular aperture without considering nonuniform incident intensity. This quantitative approach is applied to the thickness determination of dipcoated Krytox on gold. The infrared optical constants of both materials are known, allowing the integration to be carried out. The thickness obtained is in fair agreement with the value determined by ellipsometry in the visible. Therefore, this paper illustrates a method for more quantitative use of a grazing angle objective for infrared reflectance microspectroscopy.

scholarly journals Design and Verification of a Simple Approach to Brownfields Categorization

2021 ◽  
Vol 13 (20) ◽  
pp. 11206
Author(s):  
Barbara Vojvodíková ◽  
Radim Fojtík ◽  
Iva Tichá
Keyword(s):  
Assessment Tool ◽  
Research Evaluation ◽  
Assessment Method ◽  
Simple Approach ◽  
Evaluation Procedure ◽  
Concerted Action ◽  
Different Types ◽  
The Subject ◽  
Simple Evaluation ◽  
D Model

Brownfields have been the subject of research, evaluation, categorization and, of course, redevelopment for many years. The ABC(D) model (an assessment tool to identify different types of sites in terms of their potential) by the Concerted Action on Brownfield and Economic Regeneration Network (CABERNET) has been mentioned in many publications. The aim of the assessment method presented in this article is to use the basic essence of the categories in the ABC(D) model and to use our own very simple criteria. Our criteria are the result of many years of experience in the creation and management of the brownfield database. In 2017, the development potential of selected brownfields in the database of the Moravian-Silesian region (Czech Republic) was evaluated using our proposed procedure (three objective and one subjective criterion). In 2020, verification of the categories in regard to how correctly or incorrectly they were proposed was carried out. The results from this verification, including reasons for the accompanying inaccuracies, are a part of this article. We verified that the very simple evaluation procedure we proposed is functional and can be applied by database administrators continuously without the need to create complex datasets and statistical evaluations.

scholarly journals Diffuse Reflectance Spectroscopy reveals heat stress-induced changes in hemoglobin profile in chicken breast

2019 ◽  
Author(s):  
Sina Dadgar ◽  
Liz Greene ◽  
Ahmed Dhamad ◽  
Barbara Mallmann ◽  
Sami Dridi ◽  
...  
Keyword(s):  
Heat Stress ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Hemoglobin Concentration ◽  
Reflectance Spectroscopy ◽  
Optical Data ◽  
Chicken Breast ◽  
Poultry Industry ◽  
Short Period ◽  
Induced Changes

AbstractGlobal rise in incidence of woody breast (WB) syndrome imposes a significant economic burden on the poultry industry. The increase in WB is due to the large increase in the weight of chickens these days within a very short period. An early determination of WB can significantly reduce losses to the poultry industry. Diffuse reflectance spectroscopy provides a noninvasive and rapid method to interrogate tissue function. The sensitivity of DRS to the distinct absorption spectra of oxygenated and deoxygenated hemoglobin allows accurate quantification of average hemoglobin concentration and vascular oxygenation within the sampled tissue. In this study, we used diffuse reflectance spectroscopy to monitor breast hemoglobin concentration (THb) and vascular oxygen saturation (sO2) of 16 chickens that were exposed to heat stress (HS). HS is an important cause of WB myopathy in chickens. Animals were exposed to heat-stress (HS) and optical data were acquired at three time points: at baseline prior to heat stress, 2 days, and 21 days after initiation of HS. Our results show that animals from control and HS groups had a steady decay in optically derived breast hemoglobin concentration consistent with independent i-STAT measurements made on blood sampled from the femoral artery and could provide a noninvasive technology for monitoring tissue function in the poultry industry.

Phase-transparent optical data exchange of 40 Gbit/s differential phase-shift keying signals

2010 ◽  
Vol 35 (17) ◽  
pp. 2979 ◽  
Author(s):  
Jian Wang ◽  
Zahra Bakhtiari ◽  
Scott R. Nuccio ◽  
Omer F. Yilmaz ◽  
Xiaoxia Wu ◽  
...  
Keyword(s):  
Phase Shift ◽  
Data Exchange ◽  
Optical Data ◽  
Phase Shift Keying ◽  
Differential Phase Shift ◽  
Differential Phase ◽  
Differential Phase Shift Keying ◽  
Shift Keying

Evaluation of the National Acoustic Laboratories' New Hearing Aid Selection Procedure

1988 ◽  
Vol 31 (2) ◽  
pp. 178-186 ◽  
Author(s):  
Denis Byrne ◽  
Sue Cotton
Keyword(s):  
Frequency Response ◽  
High Frequency ◽  
Paired Comparison ◽  
Hearing Aid ◽  
Low Frequency ◽  
Selection Procedure ◽  
Evaluation Procedure ◽  
Speech In Noise ◽  
Simple Evaluation ◽  
New Formula

This study evaluated the National Acoustic Laboratories' (NAL) new formula for prescribing the gain and frequency response of a hearing aid. The frequency response prescribed for 44 clients (67 fitted ears) was compared with a series of variations having increased or decreased low-frequency and/or high-frequency emphasis. The evaluations consisted of paired-comparison judgments of the intelligibility of speech in quiet and the pleasantness of speech in noise. There were only 4 ears (6%) where a comparison response was more intelligible than the NAL response, but there were 16 ears (24%) where one of the comparison responses was more pleasant. On the average, hearing aid gain that was used by each subject agreed closely with prescribed gain. These trends were not affected by audiogram configuration, experience in aid usage, or type of aid limiting. The formula was found to be highly effective, but there were some cases where a change in aid prescription was indicated. A simple evaluation procedure using paired-comparison judgments is proposed for detecting such cases.

Facile Synthesis of Conical Arrays with Broadband Antireflective Property

2014 ◽  
Vol 614 ◽  
pp. 79-83
Author(s):  
Wen Yan Zhang ◽  
Ling Yun Hao ◽  
Chun Hua Lu ◽  
Chun Hua Feng ◽  
Qin Lin ◽  
...  
Keyword(s):  
Mass Production ◽  
Smooth Surface ◽  
Near Infrared ◽  
Low Cost ◽  
Infrared Region ◽  
Polydimethyl Siloxane ◽  
Facile Synthesis ◽  
Specular Reflectance ◽  
Regular Shape ◽  
Reflective Property

Conical arrays of polydimethyl siloxane were fabricated by duplicating the morphology of needle tips. The prepared cones have periodic order and regular shape, with the bottom diameter of about 80 μm and height of about 250 μm. Due to their special structure, the conical arrays of polydimethyl siloxane exhibited broadband anti-reflective property. Compared with smooth surface, they could reduce the reflection of incident electromagnetic wave at ultraviolet, visible and near-infrared region. The specular reflectance was lower than 0.75% in the range of 250-2600 nm. The prepared PDMS cones have potential to be applied for antireflective devices. The method was simple for mass production of PDMS cones at low cost.

scholarly journals A simple evaluation procedure of the TAN calibration and the influence of non-ideal calibration elements on VNA S-parameter measurements

2007 ◽  
Vol 5 ◽  
pp. 5-12 ◽  
Author(s):  
U. Stumper
Keyword(s):  
Calibration Method ◽  
Evaluation Procedure ◽  
S Parameter ◽  
Calibration Methods ◽  
S Parameters ◽  
Error Terms ◽  
Network Analyser ◽  
Simple Evaluation ◽  
True Values ◽  
Test Objects

Abstract. For the 7-term general TAN (Through-Attenuator-Network) self-calibration method of a four-sampler vector network analyser (VNA), and for all derived calibration methods like TLN, TRL, TRM, TAR, or TMN, it is shown that a very simple evaluation procedure of the seven error terms is possible, even if the Through connection is replaced by a reflectionless network with known transmission. Expressions for the deviations of the measured S-parameters of two-port test objects (d.u.t.s) from the true values, which are caused by deviations of the modeled S-parameters of non-ideal calibration elements ("standards") from their true values, are also presented. Additionally, it is shown that a TAN calibration is also possible in case of unequal reflections of the Network.

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