Color Tone Research Articles

Effects of Post-Curing Time on the Mechanical and Color Properties of Three-Dimensional Printed Crown and Bridge Materials.

Three-dimensional (3D) printing is increasingly being utilized in the dental field. After fabricating a prosthesis using a 3D printed resin, a post-curing process is required to improve its mechanical properties, but there has been insufficient research on the optimal post-curing conditions. We used various 3D printed crown and bridge materials in this study, and evaluated the changes in their properties according to post-curing time by evaluating the flexural strength, Weibull modulus, Vickers hardness, color change, degree of conversion, and biocompatibility. The obtained results confirmed that the strength of the 3D printed resin increased when it was post-cured for 60–90 min. The Vickers hardness, the degree of conversion, and biocompatibility of the 3D printed resins increased significantly around the beginning of the post-curing time, and then increased more gradually as the post-curing time increased further. It was observed that the color tone also changed as the post-curing time increased, with some groups showing a ΔE00 value of ≥ 2.25, which can be recognized clinically. This study has confirmed that, after the printing process of a 3D printed resin was completed, a sufficient post-curing time of at least 60 min is required to improve the overall clinical performance of the produced material.

Iris thickness measurements in patients with diabetic retinopathy.

The aim of the study was to investigate iris alterations in diabetic retinopathy (DR). Sixty-nine eyes of 69 patients were recruited and three groups of patients were examined: proliferative DR (n = 25), non-proliferative DR (n = 21) and healthy controls (n = 23). Macular optical coherence tomography (OCT), anterior segment iris OCT, and slit lamp digital camera photographs were taken. The thicknesses of the iris at a distance of 1 mm, 2 mm, and 3 mm from pupil margin were measured via iris OCT. Iris crypt count, furrow extent, color tone and collarette/diameter ratio were measured by means of anterior segment photography. Visual acuity, refractive error, intraocular pressure, and numbers of intravitreal injections were also recorded. The iris thickness measurements at 1 mm from pupil margin were significantly correlated with the macular thickness measurements (r = 0.32, p = 0.016). In the proliferative DR group, total number of injections were significantly correlated with the iris thickness measurements at 1 mm (r = 0.25, p = 0.04). The iris thickness measurements at distances 1 mm, 2 mm, and 3 mm from the pupil margin were similar in all of the groups (p > 0.05). Iris thickness did not correlate with age, intra-ocular pressure and collarette iris ratio in all the participants (p > 0.05). Iris thickness is similar in diabetic patients and healthy controls. Meanwhile, iris thickness near the pupillary margin is positively correlated with macular thickness.

Role of chelating compounds towards thermal resistance property of industrial grade goethite

PurposeThe iron oxide-based goethite (FeOOH) is proven to be an alternative replacement for carcinogenic chrome-based pigments. Because of its low heat stability, it tends to lose water of hydration and turns red as temperature ascends beyond 240ºC. Thus, the purpose of this paper is to increase the heat stability temperature of industrial grade (IG) goethite pigment. For this, the IG goethite pigment was surface treated with sequestrant. The properties of untreated and treated IG goethite were compared.Design/methodology/approachThree different compounds (sodium hexametaphosphate, calcium disodium ethylene diamine tetra-acetate salt, sodium gluconate) were used into the IG goethite at different concentration level. The experiments were conducted by varying the temperature and exposure time of treated and untreated samples. The total colour difference value (DE) was compared for the treated and untreated samples.FindingsThe surface treatment of IG goethite showed significant enhancement in heat stability property. From X-ray diffraction results it was confirmed that with surface treatment, there was no phase change of IG goethite even at 300ºC. Fourier transform infrared analysis states that with surface treatment when there is gradual increase in temperature from 260ºC the % transmittance of the OH (hydroxyl) deformation region band is delayed due to sequestering effect. Also, based on the total colour DE, the colour tone of surface treated IG goethite was not perceptible by human eyes even at 280ºC.Research limitations/implicationsBy increasing the heat stability of IG goethite, it will have increased spectrum of end usage in the high temperature coating segment. Coil coating is one of the biggest potential markets for this pigment. The increased heat stability will provide manufacturers with the option of an economical and non-toxic pigment in coil coatings and also in other sectors such as plastics, powder coatings and high temperature coatings.Practical implicationsThe outcome of this study has been commercially implemented to produce heat stable goethite pigments in an industrial plant. The surface treated IG goethite pigments can be used in high-performance coil, powder and high temperature coatings.Originality/valueThe method for enhanced heat stability property of IG goethite by surface treatment with sequestrants is novel and could find numerous applications in high-performance coatings.

Research of eyesight contrast sensitivity for the work with displays

The article is devoted to determining the adaptation level of the visual system to illumination in condition of changing the surrounding field brightness arising from the dynamic control of artificial lighting in industrial premises, as well as when controlling the brightness of modern displays’ illumination. There is given a general idea of the visual system structure and retina properties and considered two consecutive mechanisms of adaptation to illumination. In the article an experimental calculation of determining the contrast threshold under conditions of complete adaptation is presented, the results of which allow us to conclude that there is no dependence of the color tone perception on brightness in a wide range of its measurements. The research materials can be used to create lighting control systems and select appropriate displays for operators of automated control systems in order to minimize the load on the organs of vision.

Person Tracking and Reidentification for Multicamera Indoor Video Surveillance Systems

For practical use, the relevance of indoor surveillance from multiple cameras to track the movement of people and reidentify them in video sequences is constantly increasing. This is a complex task due to the effect of uneven illumination, background inhomogeneity, overlap, uncertainty of the trajectories of people, and the similarity of their visual features. The article presents an approach to track people by video sequences and reidentify them in multicamera video surveillance systems that are used indoors. At the first step, people are detected using a YOLO v4 convolution neural network (CNN) and described by a rectangular area. Further, the search for the face area and the calculation of its features are carried out, which in the developed method are used when accompanying a person in a video sequence and during his intercamera reidentification. This approach improves the accuracy of tracking with a complex movement trajectory and multiple intersections of people with similar characteristics. The search for faces is carried out on the detected areas based on the multitasking MTCNN, and the MobileFaceNetwork model is used to form the vector of the features of the face. Human features are generated using a modified CNN based on ResNet34 and an HSV color tone channel histogram. The correspondence between people on different frames is established based on the analysis of the spatial coordinates of faces and people, as well as their CNN features, using the Hungarian algorithm. To ensure the accuracy of intercamera tracking, reidentification is performed based on the facial features. Five test video sequences of different numbers of people captured indoors with a fixed video camera were used to test and compare different approaches. The obtained experimental results confirmed the strength of the characteristics of the proposed approach.

How Was the World's First Single-Tube Color Video Camera for Home Use, Born?

It was Toshiba IK-12 who overcame such a common sense that the shooting of a TV camera was a job of expert engineers. TV cameras using image pickup tubes were already put into practical use in the 1970s. It had many functions to adjust the size, light intensity, color tone, etc., and it could only be operated by an experienced professional engineers. Under such circumstances, the world's first home-use color video camera IK12 released in 1974 was the small and light weight. It included various innovations. The number of adjustment points has been reduced as much as possible so that anyone can use it, and a compact and lightweight design has been devised so that even women can use it. The IK12 opened up a new market for home video cameras and created an era where everyone could shoot. The basic technologies and ideas of digital cameras and mobile phones were built at this time. How was the groundbreaking single-tube color video camera for home born? I would like to verify these from a technical point of view. I think these will often be helpful for young researchers and engineers who will lead the next generation.

Multi-analytical investigation of panel, pigments and varnish of The Martyirdom of St. Catherine by Gaudenzio Ferrari (16th century)

The recent conservative project of the imposing panel painting The Martyrdom of St. Catherine painted by Gaudenzio Ferrari (c.1477–1546) has been a precious opportunity to deepen the scientific knowledge about the execution technique—hitherto scarcely investigated—of one of the prominent exponents of the Lombard and Piemontese Renaissance. The conservative intervention had become necessary because of serious problems of the wooden support: cracks and deformations had caused lifts and color gaps. In addition, over time, many overpaints and varnishes had been altered, obscuring the brilliant original color tones of the painting. A diagnostic survey was planned based on a multidisciplinary approach consisting of a well-established protocol of non-invasive imaging (UVF, IRR, IRFC, RX) and point techniques (XRF, Vis-NIR FORS). The diagnostic analyses were performed in situ and carried out in the restoration laboratory of the Pinacoteca di Brera, an ad hoc space that allows visitors to see in real time restorers and scientists at work during the different stages of the conservation treatments. Analyses on micro-samples were further performed in laboratory by means of FTIR, Raman, SEM-EDX and GC-MS techniques. The research group together with restorers and art historians were able to deepen the understanding of the artwork from a technical, material and conservative point of view, making it possible a specific conservative intervention. Furthermore, the results of this research allowed shedding light on the mounting system of the wooden support and on the reconstruction of the original color palette used by the artist. An interesting point was the presence of pararealgar as an intentional use or as a result of the realgar alteration in some yellow areas. The huge dimensions of the painting (331 × 210 cm) forced the researchers to find unconventional technical solutions for a complete overview of the conservative condition. The results obtained from the precise recognition of the state of preservation of the varnish, the painting layers, the preparatory layers and the wooden support are here presented.

Effect of the Polydopamine Composite Method on Structural Coloration: Comparison of Binary and Unary Assembly of Colloidal Particles.

Melanin influences light reflection and absorption and is known to be one of the elements producing structural color, such as that in the feathers of birds. In this study, we used polydopamine (PDA), an artificial melanin, as a light-absorbing material and examined in detail the effect of its composite method on the structural color. The following two composite methods were investigated using cerium(IV) oxide (CeO2) particles as a core particle: binary coassembly of CeO2 and PDA particles and unary assembly of CeO2@PDA core-shell particles. Although both methods dramatically improved the visibility of the structural color by suppressing the scattered light owing to the light absorption capability of the PDA, there was a difference in the particle arrangement, angle dependence of the structural color, and color tone change. By selecting the PDA composite method, the guidelines for providing high visibility and the desired structural color were presented.

Guided filter based image enhancement for focal error compensation in low cost automated histopathology microscopic system.

Low-cost automated histopathology microscopy systems usually suffer from optical imperfections, producing images that are slightly Out of Focus (OoF). In this work, a guided filter (GF) based image preprocessing is proposed for compensating focal errors and its efficacy is demonstrated on images of healthy and malaria infected red blood cells (h-RBCs and i-RBCs), and PAP smears. Since contrast enhancement has been widely used as an image preprocessing step for the analysis of histopathology images, a systematic comparison is made with six such prominently used methods, namely Contrast Limited Adaptive Histogram Equalization (CLAHE), RIQMC-based optimal histogram matching (ROHIM), modified L0, Morphological Varying(MV)-Bitonic filter, unsharp mask filter and joint bilateral filter. The images enhanced using GF approach lead to better segmentation accuracy (upto 50% improvement over native images) and visual quality compared to other approaches, without any change in the color tones. Thus, the proposed GF approach is a viable solution for rectifying the OoF microscopy images without the loss of the valuable diagnostic information presented by the color tone.

Tone Curve Compensation of Multiple Color Halftoning Screen Printing for Heterogeneous Fabrics

Abstract For mass production, multiple color halftoning screen printing (MCHSP) can be considered as the alternative textile printing technology when vivid color gradation is needed and the cost of digital printing is a concern. Essentially, MCHSP utilizes the same equipment as traditional screen printing to print overlapping multiple color gradation under halftoning patterns by applying dedicated treatments on color separation and calibration. To ensure color quality, equipment calibration and tone curve compensation are required to compensate for the variables arising from equipment setup and heterogeneous fabrics. In this research, the authors present a procedure of tone curve compensation to eliminate the discrepancy from heterogeneous fabrics. The experimental results based on 55 samples of 44 different fabrics show the effectiveness of compensation and reveal the distribution of average compensation percentage across fabrics.

M\xf6ssbauer and Raman characterization of ash produced by burning ancient buried Japanese cedar and investigation for its unusual color tone

Mössbauer and Raman spectroscopic characterization of colored ash samples made by combustion of ancient buried Japanese cedar (Cryptomeria japonica) was carried out, and the factors governing the color tones were investigated mainly in terms of the chemical species of Fe. The ash samples displayed various unusual colors, depending clearly on the individual ancient tree and the part of it. Some of Mössbauer spectra of the ash samples showed magnetic hyperfine splittings due to internal magnetic fields. The Mössbauer and Raman spectra suggested that the primary Fe-containing species in all the ash samples was calcium ferrite, Ca2Fe2O5.

Efficacy of Ultrasonic-Assisted Curing Is Dependent on Muscle Size and Ultrasonication System

Ultrasound-assisted marinade is a promising technology for reducing the time of traditional immersion marination. This study evaluated the effect of the ultrasonic system (bath or probe, amplitude 50 or 100%) and muscle sample size (3 or 5 cm3) on physicochemical quality, yield (salt content, fresh weight, and relative fresh weight), and bacteria counts associated with pork. The results showed a significantly high salt (p < 0.0001) content in 3 cm3 (11.54%) and 5 cm3 (8.88%) samples after 24 h marination by immersion. The 3 cm3 cubes marinated in a 100% probe system for 20 min presented an amount of salt (9.55%) that was quite close to the controls. The 3 cm3 samples treated by immersion and in a 50% probe system gained more relative weight (in relation to the initial weight, 7.45 and 6.64%, respectively) after 7 d at 4 °C. Meanwhile the 5 cm3 cubes marinated by immersion gained 8.1%. The other treatments showed a weight loss after treatment. Although significant differences were found in the fresh weight and in water holding capacity (WHC) in the 3 and 5 cm3 meat samples, the relative fresh weight is a real measure of weight gain, more relevant for the industry. Thus, the samples with the highest salt transfer experienced a phenomenon of “dehydration”, retaining less water. The 3 and 5 cm3 cubes marinated by immersion presented orange color tones due to the long processing time, while the probe system produced redder and brighter tones. Ultrasound as a technology to assist in marinades is not efficient for bacteria control of mesophilic, psychrophilic, or coliform. However, a significant increase in lactic acid bacteria (LAB) counts may bring benefits for meat preservation during refrigerated storage.

High-Quality Inorganic Red Pigment Prepared by Aluminum Deposition on Biogenous Iron Oxide Sheaths.

Naturally occurring tubular iron oxides produced by aquatic bacteria in Leptothrix spp. are promising raw materials for hematite-based red pigments because of the higher heat resistance as compared with chemically synthesized hematite compounds. Here, we report iron oxide red pigments prepared through an additive deposition of aluminum on culture-based biogenous iron oxide (cBIOX) sheaths using an artificial culture system of L. cholodnii strain OUMS1. The heat-treated Al-containing cBIOXs exhibited elevated chroma and lightness along with increasing Al contents and enhanced thermal stability of color tones to repetitive heat treatments. XRD analysis showed a monophasic pattern of hematite in the Al-rich cBIOX after heating at a wide range of high temperatures. Micromorphology analyses revealed that putative Al oxide regions present among hematite particles plausibly prevented the grain growth of hematite during heat treatments. The results therefore demonstrate that the bioderived Al-rich iron oxide sheaths can serve as innovative inorganic red pigments feasible for industrial applications.

Evaluation of the use of pequi pulp flour in breaded meat

Processed meat foods may be associated with poor eating habits, but the aggregation of vegetable ingredients, such as pequi (Caryocar brasiliense), makes the formulations of these products healthier and more nutritious. Thus this study aimed to characterize the chemical composition of breaded chicken prepared with pequi pulp flour in breading, as well as to evaluate the technological and sensorial properties of the breaded chicken. The pequis pulp from the region of Montes Claros - MG was dehydrated to obtain flour used in predust, with substitutions of 0%, 25%, 50% and 100% of the breadcrumbs flour. Meat products were chemically evaluated for moisture, lipids, proteins, carbohydrates, and ashes, technologically with measures of specific volume, yield, color difference, chromaticity, and tone of the breaded chicken, and sensorially by the evaluation of the intention of consumption and acceptance. As a result, pequi flour added lipid and protein content, improved yield, allowed higher specific volumes, and more intense color tones to the breaded. In addition, these presented good sensorial results and without significant differences among the studied formulations. It was concluded that the use of pequi flour in the production of breaded chicken can provide nutritional and technological enrichment to these products, without adversely affecting their sensorial characteristics.

Measurements of temperature and optical power caused by an IPL therapy device on an artificial tissue

In recent years, due to the effective achievements of IPL therapies such as treatment of spots, freckles, birthmarks, sunburn damage, vascular lesions, skin photorejuvenation, and hair and tattoo removal, IPL technology is of great interest especially in dermatology and aesthetic research. In this study, the temperature and optical power effects of an IPL therapy device on an artificial tissue were searched. Artificial tissues made of agar material were prepared to represent skins of two different color tones. The temperature measurement was performed via a thermocouple placed at a certain distance in the artificial tissue phantom. Optical power measurements were also taken from two different distances within the phantom. As a result of this study, it can be said that the IPL therapy device is safe and harmless for human use.

Peculiarities of nomination and usage of color tones in the French language

This article is dedicated to studying the methods of designation of color tones in the French language using adjectivized nouns. The research material consists of 90 nominations of color tones, acquired by means of continuous sampling from dictionaries and Internet sources. Nominations of such specific color tones are given on the basis of associations with the color of various objects, phenomena, and substances that have similar tone. Classification is conducted on the units under consideration, depending on the type of metaphorical transfer underlying the nomination. Special attention is turned to examination of grammatical peculiarities of application of the indicated units in the French language. The obtained results allowed determining the following types of associations in color designation: with the plant life (names of vegetables, fruit, nuts, flowers, plants, trees); with the animal world (names of fish, birds, mammals); with the natural resources, stones, and minerals; with the natural phenomena (force of sky and sea); with the gastronomy (food, sweets, seasonings, drinks); with various materials, substances and objects. The results of quantitative analysis of color tones in the French language, which was conducted for the first time, allowed revealing most productive associations in formation of color neologisms, among which are plant life, natural resources, stones and minerals. The authors’ special contribution consists in studying the grammatical peculiarities of usage the units in question in the French language. In these constructs consisting of two elements — two nouns without a preposition (main + adherent), the second element is an adjectivized noun that exercise function of an adjective. Due to adjectivization, such constructs significantly expand the capabilities of conveying color tones in the French language.

Malaysia Textile Craft Industry: Innovation Inspired by Bamboo for Batik Block Contemporary Design

Block Batik in batik industry has been practised in Malaysia since 1920s. It also known as “Batik Cop” or “Batik Terap”. The block for stamping or “Sarang Batik” normally made from steel with variety design on the surface of it. The beauty of the block batik pattern designs depend on the fineness and creativity of the motifs designed that engraved on the surface of the block by the expertise of the engraver. Therefore the objective of the study is to produce new design for block batik used from natural sources which is bamboo as a block to stamp the design for batik. The study emphasized on the uses of bamboo sticks cutted from bamboo tree sections as a block to create new geometric and spontaneous design for block batik design. Bamboo is one of the tropical resources in Malaysia. The light weight of the bamboo sticks alternatively can reduce the consequences towards the practitioners rather than using block made from steel which is more heavy than bamboo. The structure on the bamboo vascular cross sections scattered around the trunk create circular motif, dots and dotted lines. The uniqueness of the motif and pattern using bamboo as a block depends on the creativity in manipulating the structure of the bamboo with stamping techniques and the application of wax and the color techniques. A variety of designs such as overall repetition, vertical stripes and horizontal stripes as well as color overlays and tones highlight the creativity of the batik design. Such designs can be featured in the market especially for production of handicraft products, interior decoration and clothing design. Therefore, this study significantly gives an ideas and inspiration for batik entrepreneurs in producing block batik by using bamboo as new natural based batik design at a lower-cost.

About quantifying small color differences in digital images

We discuss aspects of the use and possibilities provided by three-color colorimeters or digital cameras in problems of detecting small color differences by computer vision methods. The spectral dependence of the total color differences between pairs of visually indiscernible monochromatic stimuli is experimentally revealed. An experimental setup based on the UM-2 monochromator is created for producing a digital atlas of monochromatic stimuli at 1-nm increments. The atlas serves to test the color gamut and color differentiation of cameras. It is experimentally shown that in the visible spectral range a color difference of 3 units is detected by pairs of stimuli that are unevenly distributed across the spectrum and differ in wavelengths from 1 to 6 nm. The capabilities of computer vision are tested on the examples of identifying additional texts during a technical and forensic examination of documents. A new algorithm is developed for finding and quantitatively characterizing color difference of inserts based on a digital image of the inscription. In the algorithm, the objective analysis of the image is divided into a block of color segmentation and that of color tone and color difference assessment. With such an approach, the color segmentation block performs preprocessing functions, making a border map for the classes with different colors for the subsequent calculations. The Otsu method of optimal global threshold transformation is for the first time applied to a problem of image segmentation by color saturation. The trial of the algorithm confirms its efficiency in the solution of expert tasks.

A ratiometric fluorescence nanoprobe using CdTe QDs for fast detection of carbaryl insecticide in apple

In this study, a novel, simple and sensitive ratiometric fluorescence method is presented for the detection of very low quantities of the carbaryl in Iranian apple using cadmium telluride quantum dots (CdTe QDs) nanoprobe. The principle of the proposed strategy relies on the rapid hydrolysis of the carbaryl under an alkaline condition and production of the 1-naphthol with a blue emission at 470 nm. Besides, using the CdTe QDs with a yellow emission at 580 nm, as a reference, improves the visual tracking of carbaryl through changes in color tonality. The herein described methodology is applied for enzyme-free visual detection of carbaryl with satisfactory results in the presence of other common pesticides in Iranian apple sample. Additionally, the calculated limit of detection (LOD) of 0.12 ng mL−1 for carbaryl is much lower than the maximum residue limits of carbaryl warned value reported by the European Union and United States pesticides database, which is so promising for carbaryl sensing in the monitoring of fruits. Furthermore, the ability of the proposed method for the detection of carbaryl residues in Iranian apple was confirmed by the high-performance liquid chromatography (HPLC) method as a standard method through statistical analysis. This fast and highly sensitive naked-eye ratiometric sensor may hold great promise to provide the technical support for the rapid and valid detection of other targets in food safety fields.

Aceptación sensorial de carne de carnero y cordero: análisis químico, instrumental y de panel de consumidores

The objective of this study was to evaluate the sensory acceptance of loin meat of ram and lambs. Chemical (moisture, ether extract, protein, intramuscular fat and ash) and instrumental (color, pH, cooking loss, shear force and water retention capacity) were analyzed. Samples of this meat were supplied to a consumer panel (n = 46) and evaluated for sensory attributes of aroma, tenderness, taste and overall appreciation. Differences were found for protein concentration, ash, red intensity (a*) and color tone (h*) (P < 0.01). No differences were found between the sensory attributes tested (P > 0.05). Ram meat analyzed showed a sensory appreciation close to lamb meat.