The present facusos on the performance of mesmeric indices in relation to visual,, assessments. T... more The present facusos on the performance of mesmeric indices in relation to visual,, assessments. To this end, 98 real pairs of metameric samples were prepared using computer colour match predictions and the differences between the pairs were assessed ...
Principal component analysis (PCA) has been used in color technology over 50 years. Along these y... more Principal component analysis (PCA) has been used in color technology over 50 years. Along these years many researches have been done to find out new usages or improve its shortcomings in different applications in color technology. One of the most difficult tasks is ...
Artificial intelligence is an advanced technology which is recently taking into account by resear... more Artificial intelligence is an advanced technology which is recently taking into account by researchers. In fact, Artificial intelligence is a method that provides required base to do intelligent processes by computer. A branch of artificial intelligence is Expert systems. ...
In addition to medical recognition applications, X-ray CT-scan images are increasingly found to h... more In addition to medical recognition applications, X-ray CT-scan images are increasingly found to have more innovative and widespread applications. Due to the ability of producing high resolution and high contrast images from soft tissues with low attenuation coefficients, the ...
In different fields, including military industries, for whether military forces' or ... more In different fields, including military industries, for whether military forces' or military armament, Camouflage is of high importance. Which camouflage pattern, therefore, in what size, with which color composition is more suitable for soldier's camouflage, in a specific ...
SUMMARY Statement of the Problem: The color stability of resin cements plays a major role in the ... more SUMMARY Statement of the Problem: The color stability of resin cements plays a major role in the esthetic performance of porcelain laminate veneers. Some dual-polymerizable resin cements used to bond porcelain laminates were shown to undergo color changes during service. Some recently produced cements are described as being color stable, but scientific data are not available. Purpose: The current study evaluated the effect of accelerated aging on the color and opacity of resin cements. The hypothesis was that the auto-polymerizing cements would show less color and opacity stability. Materials and Methods: Forty (0.7 x 18 mm) feldspathic porcelain disks were prepared and divided into four equal groups. The resin cements were bonded to the disks by application of an identical load of 2.5 kilograms, and they were polymerized according to the manufactur-er's instructions. The groups were: Variolink Veneer (light-polymerizing), Variolink II (light-polymerizing), Variolink II (dual-polymerizing) and Multilink (auto-polymerizing). A spectro-photometer was used to measure the following color parameters in the CIE L*a*b* color space on a black and white background: ∆ ∆a*, ∆ ∆b*, ∆ ∆L*, ∆ ∆C, ∆ ∆H, ∆ ∆E and ∆ ∆CR (contrast ratio). The measurements were performed before and after aging. Paired t-and one-way ANOVA tests were used to analyze the data (α α=.05). Results: None of the groups showed significant differences in ∆ ∆E before and after aging (p>.05); ∆ ∆E remained in the range of clinical acceptance (∆ ∆E<3.3). All of the cements became more opaque, while ∆ ∆CR (difference in contrast ratio) Clinical Relevance While the studied cements behaved acceptably according to the color change index (∆E), they functioned differently in regards to opacity, especially the self-cure ones.
Color constancy and metamerism are two phenomena that take place when the spectral power distribu... more Color constancy and metamerism are two phenomena that take place when the spectral power distribution of illuminant is changed. The difference between the color inconstancies of the metameric pairs is the source of metamerism.
To print a colour image on a fabric, colour image clustering is an important step to reduce the n... more To print a colour image on a fabric, colour image clustering is an important step to reduce the number of colours and separate the coloured pattern. Therefore, the performance of colour-clustering algorithm can strongly affect the quality of printing process. Fuzzy c-...
Nano fibers produced by electrospinning are of industrial and scientific attention due to their s... more Nano fibers produced by electrospinning are of industrial and scientific attention due to their special characteristics such as long length, small diameter and high surface area. Applications of electrospun structures in nanotechnology are included tissue scaffolds, fibers for drug delivery, composite reinforcement, chemical sensing, enzyme immobilization, membrane-based filtration, protective clothing, catalysis, solar cells, electronic devices and others. Many polymer and ceramic precursor nano fibers have been successfully electrospun with diameters in the range from 1 nm to several microns.
In this research the morphology and mechanical properties of PAN/MWNTs nano bers are studied. The... more In this research the morphology and mechanical properties of PAN/MWNTs nano bers are studied. The electrospinning process is used to produce ber at micro and nano scale. The dispersion of MWNTs in polymer solution is the key factor to obtain desirable properties in the nal product. Thus, the dispersion condition is investigated using SEM images. The morphological study of ber mats show that by increasing the amount of MWNTs in the polymer from 0 to 1 wt%, the surface roughness of bers is increased. Increasing the percentage of MWNTs in ber improves the tensile stress at maximum load for about 114% and modulus for about 40%.
Layered fabric systems with an electrospun nanofiber web layered onto a sandwich of woven fabric ... more Layered fabric systems with an electrospun nanofiber web layered onto a sandwich of woven fabric were developed to examine the feasibility of developing breathable barrier textile materials. Some parameters of nanofiber mats, including the time of electrospinning and the polymer solution concentration, were designed to change and barrier properties of specimens were compared. Air permeability, water vapor transmission, and water repellency (Bundesmann and hydrostatic pressure tests) were assessed as indications of comfort and barrier performance of different samples. These performances of layered nanofiber fabrics were compared with a well-known water repellent breathable multi-layered fabric (Gortex). Multi-layered electrospun nanofiber mats equipped fabric (MENMEF) showed better performance in windproof property than Gortex fabric. Also, water vapor permeability of MENMEF was in a range of normal woven sport and work clothing. Comparisons of barrier properties of MENMEF and the currently available PTFE coated materials showed that, those properties could be achieved by layered fabric systems with electrospun nanofiber mats.
In the conventional subjective method, wrinkled fabric specimens are visually compared with the s... more In the conventional subjective method, wrinkled fabric specimens are visually compared with the standard replicas under a specific light source in order to be evaluated and classified. In the present work, the rank ordering method is incipiently applied for grading a wide range of wrinkled fabrics. The five standard replicas are orderly placed among the ranked specimens and their grades are extracted. Results show that the specimens ranked by the ordering method are reliable and can be used for grading of wrinkled fabric to overcome the problems associated with the standard method such as the limited grading range and high and non uniform intervals between each pair of replicas. Conventional image processing methods used for grading fabric wrinkle are also applied on images taken from the ranked specimens. Among the methods studied in the literature Radon transform, wrinkle paths length and fractal dimension show a good correlation with the wrinkle grades derived from the rank ordering method.
The present investigation entails a procedure by which the surface tension and viscosity of liqui... more The present investigation entails a procedure by which the surface tension and viscosity of liquids could be predicted. To this end, capillary experiments were performed for porous media by utilizing fifteen different liquids and powders. The time of capillary rise to a certain known height of each liquid in a particular powder was recorded. Two artificial neural networks (ANNs) were designed and used to separately predict the surface tension and the viscosity of each liquid respectively. The surface tension predictor network had six inputs, namely: particle size, bulk density, packing density and surface free energy of the powders as well as the density of the probe liquids together with the capillary rise time of the liquids in the corresponding powders. The viscosity predictor network had surface tension as an extra input. In order to correlate the surface tension and viscosity as predicted by the corresponding artificial neural network to their experimentally determined equivalents, two different statistical parameters namely the product moment correlation coefficient (r 2 ) and the performance factor (PF/3) were used. It must be noted that for a perfect correlation r 2 = 1 and PF/3 = 0. The results of the present work clearly showed that the artificial neural network approach is able to predict the surface tension (i.e. r 2 = 0.95, PF/3 = 16) and viscosity (i.e. r 2 = 0.998 , PF/3 = 13) of the probe liquids with unsurpassed accuracy.
In this paper, the perceptual and instrumental effects of texture on colour is investigated, usin... more In this paper, the perceptual and instrumental effects of texture on colour is investigated, using 63 textile samples, in nine colour centres and seven texture structures. The effectiveness of texture is evaluated by assessing colour differences between six texture samples and a standard ...
The present facusos on the performance of mesmeric indices in relation to visual,, assessments. T... more The present facusos on the performance of mesmeric indices in relation to visual,, assessments. To this end, 98 real pairs of metameric samples were prepared using computer colour match predictions and the differences between the pairs were assessed ...
Principal component analysis (PCA) has been used in color technology over 50 years. Along these y... more Principal component analysis (PCA) has been used in color technology over 50 years. Along these years many researches have been done to find out new usages or improve its shortcomings in different applications in color technology. One of the most difficult tasks is ...
Artificial intelligence is an advanced technology which is recently taking into account by resear... more Artificial intelligence is an advanced technology which is recently taking into account by researchers. In fact, Artificial intelligence is a method that provides required base to do intelligent processes by computer. A branch of artificial intelligence is Expert systems. ...
In addition to medical recognition applications, X-ray CT-scan images are increasingly found to h... more In addition to medical recognition applications, X-ray CT-scan images are increasingly found to have more innovative and widespread applications. Due to the ability of producing high resolution and high contrast images from soft tissues with low attenuation coefficients, the ...
In different fields, including military industries, for whether military forces' or ... more In different fields, including military industries, for whether military forces' or military armament, Camouflage is of high importance. Which camouflage pattern, therefore, in what size, with which color composition is more suitable for soldier's camouflage, in a specific ...
SUMMARY Statement of the Problem: The color stability of resin cements plays a major role in the ... more SUMMARY Statement of the Problem: The color stability of resin cements plays a major role in the esthetic performance of porcelain laminate veneers. Some dual-polymerizable resin cements used to bond porcelain laminates were shown to undergo color changes during service. Some recently produced cements are described as being color stable, but scientific data are not available. Purpose: The current study evaluated the effect of accelerated aging on the color and opacity of resin cements. The hypothesis was that the auto-polymerizing cements would show less color and opacity stability. Materials and Methods: Forty (0.7 x 18 mm) feldspathic porcelain disks were prepared and divided into four equal groups. The resin cements were bonded to the disks by application of an identical load of 2.5 kilograms, and they were polymerized according to the manufactur-er's instructions. The groups were: Variolink Veneer (light-polymerizing), Variolink II (light-polymerizing), Variolink II (dual-polymerizing) and Multilink (auto-polymerizing). A spectro-photometer was used to measure the following color parameters in the CIE L*a*b* color space on a black and white background: ∆ ∆a*, ∆ ∆b*, ∆ ∆L*, ∆ ∆C, ∆ ∆H, ∆ ∆E and ∆ ∆CR (contrast ratio). The measurements were performed before and after aging. Paired t-and one-way ANOVA tests were used to analyze the data (α α=.05). Results: None of the groups showed significant differences in ∆ ∆E before and after aging (p>.05); ∆ ∆E remained in the range of clinical acceptance (∆ ∆E<3.3). All of the cements became more opaque, while ∆ ∆CR (difference in contrast ratio) Clinical Relevance While the studied cements behaved acceptably according to the color change index (∆E), they functioned differently in regards to opacity, especially the self-cure ones.
Color constancy and metamerism are two phenomena that take place when the spectral power distribu... more Color constancy and metamerism are two phenomena that take place when the spectral power distribution of illuminant is changed. The difference between the color inconstancies of the metameric pairs is the source of metamerism.
To print a colour image on a fabric, colour image clustering is an important step to reduce the n... more To print a colour image on a fabric, colour image clustering is an important step to reduce the number of colours and separate the coloured pattern. Therefore, the performance of colour-clustering algorithm can strongly affect the quality of printing process. Fuzzy c-...
Nano fibers produced by electrospinning are of industrial and scientific attention due to their s... more Nano fibers produced by electrospinning are of industrial and scientific attention due to their special characteristics such as long length, small diameter and high surface area. Applications of electrospun structures in nanotechnology are included tissue scaffolds, fibers for drug delivery, composite reinforcement, chemical sensing, enzyme immobilization, membrane-based filtration, protective clothing, catalysis, solar cells, electronic devices and others. Many polymer and ceramic precursor nano fibers have been successfully electrospun with diameters in the range from 1 nm to several microns.
In this research the morphology and mechanical properties of PAN/MWNTs nano bers are studied. The... more In this research the morphology and mechanical properties of PAN/MWNTs nano bers are studied. The electrospinning process is used to produce ber at micro and nano scale. The dispersion of MWNTs in polymer solution is the key factor to obtain desirable properties in the nal product. Thus, the dispersion condition is investigated using SEM images. The morphological study of ber mats show that by increasing the amount of MWNTs in the polymer from 0 to 1 wt%, the surface roughness of bers is increased. Increasing the percentage of MWNTs in ber improves the tensile stress at maximum load for about 114% and modulus for about 40%.
Layered fabric systems with an electrospun nanofiber web layered onto a sandwich of woven fabric ... more Layered fabric systems with an electrospun nanofiber web layered onto a sandwich of woven fabric were developed to examine the feasibility of developing breathable barrier textile materials. Some parameters of nanofiber mats, including the time of electrospinning and the polymer solution concentration, were designed to change and barrier properties of specimens were compared. Air permeability, water vapor transmission, and water repellency (Bundesmann and hydrostatic pressure tests) were assessed as indications of comfort and barrier performance of different samples. These performances of layered nanofiber fabrics were compared with a well-known water repellent breathable multi-layered fabric (Gortex). Multi-layered electrospun nanofiber mats equipped fabric (MENMEF) showed better performance in windproof property than Gortex fabric. Also, water vapor permeability of MENMEF was in a range of normal woven sport and work clothing. Comparisons of barrier properties of MENMEF and the currently available PTFE coated materials showed that, those properties could be achieved by layered fabric systems with electrospun nanofiber mats.
In the conventional subjective method, wrinkled fabric specimens are visually compared with the s... more In the conventional subjective method, wrinkled fabric specimens are visually compared with the standard replicas under a specific light source in order to be evaluated and classified. In the present work, the rank ordering method is incipiently applied for grading a wide range of wrinkled fabrics. The five standard replicas are orderly placed among the ranked specimens and their grades are extracted. Results show that the specimens ranked by the ordering method are reliable and can be used for grading of wrinkled fabric to overcome the problems associated with the standard method such as the limited grading range and high and non uniform intervals between each pair of replicas. Conventional image processing methods used for grading fabric wrinkle are also applied on images taken from the ranked specimens. Among the methods studied in the literature Radon transform, wrinkle paths length and fractal dimension show a good correlation with the wrinkle grades derived from the rank ordering method.
The present investigation entails a procedure by which the surface tension and viscosity of liqui... more The present investigation entails a procedure by which the surface tension and viscosity of liquids could be predicted. To this end, capillary experiments were performed for porous media by utilizing fifteen different liquids and powders. The time of capillary rise to a certain known height of each liquid in a particular powder was recorded. Two artificial neural networks (ANNs) were designed and used to separately predict the surface tension and the viscosity of each liquid respectively. The surface tension predictor network had six inputs, namely: particle size, bulk density, packing density and surface free energy of the powders as well as the density of the probe liquids together with the capillary rise time of the liquids in the corresponding powders. The viscosity predictor network had surface tension as an extra input. In order to correlate the surface tension and viscosity as predicted by the corresponding artificial neural network to their experimentally determined equivalents, two different statistical parameters namely the product moment correlation coefficient (r 2 ) and the performance factor (PF/3) were used. It must be noted that for a perfect correlation r 2 = 1 and PF/3 = 0. The results of the present work clearly showed that the artificial neural network approach is able to predict the surface tension (i.e. r 2 = 0.95, PF/3 = 16) and viscosity (i.e. r 2 = 0.998 , PF/3 = 13) of the probe liquids with unsurpassed accuracy.
In this paper, the perceptual and instrumental effects of texture on colour is investigated, usin... more In this paper, the perceptual and instrumental effects of texture on colour is investigated, using 63 textile samples, in nine colour centres and seven texture structures. The effectiveness of texture is evaluated by assessing colour differences between six texture samples and a standard ...
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