scholarly journals Luster measurement of pearl by UV-Vis reflectance spectroscopy

2021 ◽  
Vol 2145 (1) ◽  
pp. 012063
Author(s):  
C Salyacheewin ◽  
N Monarumit ◽  
W Wongkokua
Keyword(s):  
Reflectance Spectroscopy ◽  
Integrating Sphere ◽  
Phase Structures ◽  
Unique Color ◽  
Surface Normal ◽  
Reflected Light ◽  
Relative Brightness ◽  
The Difference

Abstract Pearl is an organic gem with its unique color and luster. One of the factors determining the quality and price of pearl is the luster. The different luster of pearls could be related to the different phase structures such as aragonite, calcite and vaterite. Previously, a gloss meter has been developed to measure light specularly reflected at 45° to the surface normal. Six different visual criteria for measuring gloss have been determined. Luster, a type of gloss, was defined as the ratio of specularly reflected light and that diffusely reflected normal to the surface. In practice, luster may be interpreted as relative brightness of specularly and diffusely reflecting areas. Due to the roundness of pearl, we measured the luster of pearl samples by a portable UV-Vis spectrophotometer with an integrating sphere. The luster could be calculated from the difference of CIELAB lightness measured by SCI and SCE geometries.

scholarly journals Road lighting density and brightness linked with increased cycling rates after-dark

2020 ◽  
Author(s):  
Jim Uttley ◽  
Steve Fotios ◽  
Robin Lovelace
Keyword(s):  
Negative Impact ◽  
Time Of Day ◽  
Aerial Images ◽  
Minimal Amount ◽  
Night Time ◽  
Road Lighting ◽  
International Policies ◽  
Relative Brightness ◽  
Two Measures ◽  
The Difference

Cycling has a range of benefits as is recognised by national and international policies aiming to increase cycling rates. Darkness acts as a barrier to people cycling, with fewer people cycling after-dark when seasonal and time-of-day factors are accounted for. This paper explores whether road lighting can reduce the negative impact of darkness on cycling rates. Changes in cycling rates between daylight and after-dark were quantified for 48 locations in Birmingham, United Kingdom, by calculating an odds ratio. These odds ratios were compared against two measures of road lighting at each location: 1) Density of road lighting lanterns; 2) Relative brightness as estimated from night-time aerial images. Locations with no road lighting showed a significantly greater reduction in cycling after-dark compared with locations that had some lighting. A nonlinear relationship was found between relative brightness at a location at night and the reduction in cyclists after-dark. Small initial increases in brightness resulted in large reductions in the difference between cyclist numbers in daylight and after-dark, but this effect reached a plateau as brightness increased. These results suggest only a minimal amount of lighting may be sufficient to promote cycling after-dark.

scholarly journals Phase structures, loss, storage, damping, voice-absorption, and mechanical properties: NCB/BWZT/RTV

2021 ◽  
Author(s):  
juanjuan wang ◽  
Hua Jiao ◽  
Qijiu Deng ◽  
Yaning Feng ◽  
Yule Yang
Keyword(s):  
Loss Modulus ◽  
Wave Tube ◽  
Rubber Composites ◽  
Comprehensive Properties ◽  
Phase Structures ◽  
The Difference ◽  
Standing Wave Tube ◽  
Mechanical Performances ◽  
Roller Milling ◽  
And Storage

Abstract The objective of this work is to characterize the effect of NCB(Nano-carbon black)on the comprehensive performances and micro, chemical and phase structures of NCB/BWZT/RTV composite [BWZT is Ba (W1/2Cu1/2)O3-Pb0.98Sr0.02 (Mg1/3Nb2/3) 0.275(Ni1/3 Nb2/3)0.10(Zr0.25Ti0.375) O3 and, RTV is Room Temperature Vulcanizing silicone rubber.]. Composites with damping-absorption performances and storage-loss behaviors based on RTV, BWZT and, NCB as conductive agent were fabricated employing three steps methods of ball-milling, three-roller milling and pressing. The effects of NCB and its amount on storage, loss and damping properties were investigated by the method of DMTA and, absorption and mechanical performances are measured by the methods of standing wave tube and TG separately. The micro, chemical and phase structures of composites are characterized by SEM, XRD and IR. The results indicated that both doping of NCB and the combination of BWZT and RTV can be proposed to improve greatly the comprehensive performance of RTV matrixes and, there would be more excellent comprehensive properties in NCB/BWZT/RTV composites with amount of 4 wt. %.-6wt. % for NCB as d33 of 81 pC/N, storage modulus of 25003MPa, loss modulus of 398MPa, damping coefficient of 0.07–0.12, and absorption coefficients of 0.45–0.55 with the difference of frequency in the range of 400-1600Hz. Also, the lattice growth of BWZT is found showing strong dependences on the contents of NCB and, the absorption and damping performance of composites on frequency and temperature separately.

Spectroscopy of Matrices and Thin Films with an Integrating Sphere

1989 ◽  
Vol 43 (2) ◽  
pp. 320-324 ◽  
Author(s):  
E. Berger ◽  
D. W. T. Griffith ◽  
G. Schuster ◽  
S. R. Wilson
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Experimental Approach ◽  
Matrix Isolation ◽  
Standard Theory ◽  
Integrating Sphere ◽  
Weak Absorption ◽  
Matrix Isolation Spectroscopy ◽  
Reflected Light ◽  
The Matrix

The paper describes a novel experimental approach to improving sensitivity to weak absorption in matrix isolation and thin film spectroscopy. The matrix or film is grown on the surface of an integrating sphere, in which the multiply reflected light correspondingly multipasses the sample film. The quantitative photometric behavior of the sphere is satisfactorily described by extending standard theory. Enhancement of absorption by a factor of at least 20 is possible and is demonstrated. The sphere has a number of useful advantages over other multipass techniques, particularly in matrix isolation spectroscopy.

Method for Testing and Analyzing the Printing Performance of Fluorescent Inks

2014 ◽  
Vol 556-562 ◽  
pp. 2779-2782
Author(s):  
Pan Pan Yang ◽  
Yan Fang Xu ◽  
Na Gao ◽  
Ya Yuan Zhang
Keyword(s):  
Light Source ◽  
Ultraviolet Light ◽  
Vertical Direction ◽  
Luminescent Properties ◽  
Radiation Energy ◽  
Energy Data ◽  
Unique Color ◽  
Reflected Light ◽  
Dot Gain ◽  
To Receive

In recent years, fluorescent ink, with a unique color performance and the advantages of green non-toxic, fast drying, thin ink, etc., is widely used in packaging printing, security printing, and other fields. What’s more, the luminescent properties and the interaction with paper of fluorescent ink are pained more and more attention. In this experiment, an ultraviolet light source is used to motivate the samples to emit, the fiber spectrophotometer is used to receive the reflected light of the samples in the vertical direction of the samples. The tone rendering curve and dot gain curve are obtained according to the radiation energy data of the sample, the printing indicators of fluorescent ink are obtained by analyzing the reproducing image tone scale and dot expansion characteristics of ink on the paper.

scholarly journals Comparative study of accuracy of differential global positioning system (DGPS) and total station instruments

2021 ◽  
pp. 49-58
Author(s):  
Didigwu Augustus Ugonna Sunday ◽  
Ogbe David .O
Keyword(s):  
Global Positioning System ◽  
Positioning System ◽  
Total Station ◽  
The Earth ◽  
Optical Distance ◽  
Reflected Light ◽  
Global Positioning ◽  
Similar Survey ◽  
The Difference ◽  
Land Using

Total Station and Global Positioning System (GPS) are two instruments used to fix position on the earth. The total station employs electro-optical distance meter method, emitting laser beams to a target and detecting light reflected off it by measuring the deviation of the wavelength of the reflected light. Global Positioning System (GPS) is a space-based satellite for rapid position determination, its’ receiver calculates its position by precisely turning the signal sent by GPS satellite high above the earth. The study aims at the assessment of the two instruments: GPS and Total Station. To achieve this aim, two surveys were performed on the same parcel of land using the two instruments. In the first part of the survey, a closed-loop traverse was performed around a chosen parcel of land using a calibrated total station. The station determined only coordinates of points from where bearings and distances were extracted. Thereafter, DGPS equipment was then used to perform a similar survey as the total station. In this case, visible satellites were used to determine the coordinates of all the stations. The results of the two methods present the distances, bearings, and coordinates. The difference between each of the results was also analyzed. Thus the maximum average difference in distance of 5mm occurred throughout the chainage and maximum differences in the coordinate of 12mm Easting and 9mm Northing were found where there are tree covers. However, the study shows that even though the two instruments are good tools for positioning, each exhibited it’s own accuracy, efficiency, advantages and disadvantage.

scholarly journals DEVELOPMENT OF OPTICAL TRANSDUCER ON FABRICS FOR THE APPLICATION OF LIQUID CLUSTERING USING REFLECTANCE SPECTROSCOPY

2021 ◽  
Vol 5 (2) ◽  
Author(s):  
Viona Hazar Briliana ◽  
Totok Mujiono
Keyword(s):  
Light Source ◽  
Monochromatic Light ◽  
Reflectance Spectroscopy ◽  
Wearable Device ◽  
Light Scatter ◽  
Optic System ◽  
Pca Method ◽  
The Difference ◽  
Scatter Intensity ◽  
Optical Transducer

Recently, usage of fabrics as wearable device, along with their applications are increasing, one example being the detection of bio-analyzes such as blood or sweat. One method used to observe the properties of the material of a fabric is to use the Refcletance Spectroscopy, in which excitation of monochromatic light with a specific wavelength is given to a fabrics. Intensity value is then processed using the PCA method in order to obtain the pattern of the difference between each substrate. The proposed transducer optic system consists of 405nm blueviolet laser as the light source, biconvex lens, Adafruit AS7262 light detector, and Arduino. This system can only detect the difference in substrate content from the occurring light scatter. This system can be applied to various kinds of fabric wearable material with differing scatter intensity values depending on the kind of fabrics. Softer kind of fabric is proposed as material for the wearable device because it gives a high scatter intensity value and constant values in every repetation which results in better data reading.Keywords: clustering, optical, reflectance, spectroscopy, transducer, wearable.

Medical applications of reflectance spectroscopy in the diffusive and sub-diffusive regimes

2018 ◽  
Vol 26 (6) ◽  
pp. 337-350 ◽  
Author(s):  
Sharmin Akter ◽  
Md. Golzar Hossain ◽  
Izumi Nishidate ◽  
Hisanao Hazama ◽  
Kunio Awazu
Keyword(s):  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Biological Tissues ◽  
Disease Diagnosis ◽  
Structural Features ◽  
Reflectance Spectroscopy ◽  
Medical Applications ◽  
Light Spectrum ◽  
Tissue Morphology ◽  
Reflected Light

Diffuse reflectance spectroscopy is a widely used technique for medical applications that may analyze the optical characteristics of biological tissues. By using diffuse reflectance spectroscopy, different tissue types can be distinguished based on specific changes on reflected light spectrum that are a result of differences on a molecular level between compared tissues. Identification of the structural features of tissue can be performed by applying diffuse reflectance spectroscopy, and the spectra obtained from this technique could provide important diagnostic information about the tissue morphology and physiology. Moreover, different tissue types can be classified using diffuse reflectance spectroscopy, during surgery on the basis of their optical properties that are related to the tissue morphology and constituents. In recent years, several research groups have been shown the feasibility of diffuse reflectance spectroscopy in discriminating benign and malignant tissue, and thus making it a good competitor for margin assessment. Therefore, the diffuse reflectance spectroscopy has the possibility to become an important optical means for disease diagnosis, treatment and prognosis monitoring. This review represents a summary of the literature on diffuse reflectance spectroscopy and its important clinical applications.

A Volumetric Difference-based Adaptive Slicing and Deposition Method for Layered Manufacturing

2003 ◽  
Vol 125 (3) ◽  
pp. 586-594 ◽  
Author(s):  
Y. Yang ◽  
J. Y. H. Fuh ◽  
H. T. Loh ◽  
Y. S. Wong
Keyword(s):  
Local Features ◽  
Layered Manufacturing ◽  
Deposition Method ◽  
Adaptive Slicing ◽  
Surface Normal ◽  
Staircase Effect ◽  
Slicing Method ◽  
Cusp Height ◽  
The Difference ◽  
New Criterion

Adaptive slicing capable of producing variable thickness is a useful means to improve the fabrication efficiency in layered manufacturing (LM) or Rapid Prototyping (RP) processes. Many approaches have been reported in this field; however, most of them are based on the cusp height criteria, which is not an effective representation of the staircase effect when the surface normal is near vertical. Furthermore, most of the existing methods slice the model without considering the local features in the plane of the sliced layer. This paper introduces a novel difference-based adaptive slicing and deposition method. The advantage of this slicing method is that the slicing error is independent of the surface normal. A new criterion for adaptive slicing is evaluated and compared with that based on cusp-height. An adaptive slicing algorithm, which uses the volumetric difference between two adjacent layers as the criterion for slicing, has been developed in this work. Different deposition strategies for the common area and the difference area are applied to layer fabrication while considering the local features of the sliced layer. The algorithm has been tested with a sample part, and the results indicate that a better surface finish can be achieved for both surfaces whose normals are nearly in the slicing plane and surfaces whose normals are nearly perpendicular to the slicing plane. It is found that the building time can be reduced by 40% compared with the traditional adaptive slicing. The proposed method has minimized the volumetric error between the built LM part and the original CAD model while achieving a higher efficiency. It is suitable for most commercialized LM systems due to its simplicity in implementation.

Quantitative reflectance spectroscopy as an alternative to traditional wet lab analysis of foliar chemistry: near-infrared and mid-infrared calibrations compared

2005 ◽  
Vol 35 (5) ◽  
pp. 1122-1130 ◽  
Author(s):  
Andrew D Richardson ◽  
James B Reeves III
Keyword(s):  
Chemical Composition ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Predictive Ability ◽  
Reflectance Spectroscopy ◽  
Mid Infrared ◽  
Mir Spectroscopy ◽  
Wet Lab ◽  
The Difference ◽  
Primitive State

Quantitative reflectance spectroscopy offers an alternative to traditional analytical methods for the determination of the chemical composition of a sample. The objective of this study was to develop a set of spectroscopic calibrations to determine the chemical composition (nutrients, carbon, and fiber constituents, determined using standard wet lab methods) of dried conifer foliage samples (N = 72), and to compare the predictive ability of calibrations based on three different spectral regions: visible and shortwave near infrared (VIS–sNIR, 400- to 1100-nm wavelengths), near infrared (NIR, 1100- to 2500-nm wavelengths), and mid infrared (MIR, 2500- to 25 000-nm wavelengths). To date, most quantitative reflectance spectroscopy has been based on the VIS–sNIR–NIR, and the ability of MIR calibrations to predict the composition of tree foliage has not been tested. VIS–sNIR calibrations were clearly inferior to those based on longer wavelengths. For 8 of 11 analytes, the MIR calibrations had the lowest standard error of cross-validation, but in most cases the difference in accuracy between NIR and MIR calibrations was small, and against an independent validation set, there was no clear evidence that either spectral region was superior. Although quantitative MIR spectroscopy is at a more primitive state of development than NIR spectroscopy, these results demonstrate that the mid infrared has considerable promise for quantitative analytical work.

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