pigment layer
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2021 ◽  
Vol 5 (1) ◽  
pp. 7-13
Author(s):  
Delianis Pringgenies ◽  
Dafit Ariyanto

The light organ is an electronic device that can emit light. However, there are light organs in animals that can produce light naturally. Loligo duvaucelii is a species whose biolumenesence comes from fluorescent bacteria that live in symbiosis in its ink sacs. This study aims to determine in detail the construction of the squid light organ using the transmission electron microscopy (TEM) method. The results showed that this type of squid has a pair of light organs attached to the dorso-lateral ink sac. The light organ is spherical, some are found on the surface and some are embedded on the wall of the ink sac. It consists of a lens that is located on the outer surface of the ink sac, and a sac of light organs (embedded on the wall of the ink sac) with channels connecting the pocket to the mantle cavity. The wall of the sac of the light organ consists of three layers, namely the innermost layer which is multi-fold with microvilli on the cell surface and between the folds of the sac populated with bacteria, the dense layer that acts as a reflector, and the pigment layer. Cilia are observed on the surface of the duct connecting the sac with the mantle cavity. This study concluded that the construction of the squid light organ has a convex-shaped lens structure and is muscular. In the pockets of light organs, a dense population of bacteria is found. The reflector consists of many layers, and the pigment layer contains many granules.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Seon Hee Kim ◽  
Jihye Lee ◽  
Yun Jung Jang ◽  
Kang-Bong Lee ◽  
Yeonhee Lee

Over the years, soft contact lenses for vision correction and cosmetic and therapeutic purposes have been greatly improved. For cosmetic contact lenses, the pigments need to be nontoxic, and the position of the pigment layer is particularly important because of the risks posed by pigment elution and the roughness of the lens surface. In this paper, we characterized the properties of brown cosmetic contact lenses made by three different manufacturers using surface analytical techniques. The surface topographies of the noncolored and colored parts were obtained by atomic force microscopy (AFM), and the position and composition of the pigment layer were determined by analyzing the cross section of the contact lenses using scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). The influence of pigment location on surface roughness was also examined. In addition, to find the method of the evaluation for the risk of surface elution of the pigments in the colored parts, the mass spectra and ion images of the surfaces were obtained by time-of-flight secondary ion mass spectrometry (ToF-SIMS) with a new sample preparation. From the ToF-SIMS spectra, we observed specific fragment ions of the poly(hydroxyethyl methacrylate) (PHEMA) polymer and found differences in the composition of the pigment layer depending on the manufacturers. The cross-sectioned image and 3D chemical characterizations of metallic and specific ions in the brown cosmetic contact lenses clearly indicated the spatial distribution and location of the pigment layer that can be used for the evaluation of pigment elution.


2017 ◽  
Vol 17 (1) ◽  
pp. 193-200
Author(s):  
Anding Shao ◽  
Qianli Fu ◽  
Zhouyong Sun ◽  
Jing Shao

AbstractThis paper presents preliminary scientific analytical results and discussion on the murals unearthed at the Shimao Site in Shenmu County, Shaanxi Province. The murals were composed of pigment layer, plaster base layer and daub layer. The pigments used include hematite, goethite, glauconite and carbon black. Same with the floor plaster layer of the house foundations in the site, the plaster layer of murals is made of calcium carbonate. For the painting procedure, a draft had firstly been designed by engraved lines, and then the murals were painted with various pigments. A tentative comparative study shows that the manufacturing technology and painting techniques of the Shimao mural are similar to that of the murals of the Han and Tang Dynasties. It indicates that the fundamental manufacturing technology of mural had probably been established in the Erlitou Period at latest, which was just followed and enriched over the Han and Tang Dynasties.


2016 ◽  
Vol 45 (3) ◽  
pp. 141-148 ◽  
Author(s):  
Baolian Zhang ◽  
Zhenzhen Zhang ◽  
Xuening Fei ◽  
Yingchun Gu ◽  
Lu Yu

Purpose The purpose of the study reported in this paper was to prepare modified C.I. Pigment Red (PR) 170 to reduce production cost and improve application performance. The structure of the modified pigment was characterised. The colour strength, thermal stability, mobility, aqueous dispersability and ultraviolet (UV) resistance of modified pigments were studied. Design/methodology/approach Silica fume was added into the diazonium salt solution under acidic condition, followed by the activation to generate new surface. Subsequently, coupling component was dropwise added to the system to form the modified pigments evenly on the surface of silica fume in situ. The structure and properties of the modified pigment were studied by fourier transform infrared spectoscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermal gravity analysis (TG-DTA), UV-visible diffuse reflectance spectra (UV-Vis DRS), and commission internationale de L‘Eclairage (CIE L*a*b*) colour measurements. Findings The morphology and particle size of the modified pigment were controlled by the modification of the silica fume, and the organic pigment and silica fume formed a core–shell structure. The properties of the modified pigment including colour strength, thermal stability, mobility, aqueous dispensability and UV resistance were improved significantly. Research limitations/implications The effect of the amount of silica fume on the thickness of the organic pigment layer and the effect of the thickness of the organic pigment layer on the properties of the modified pigment need to be studied further. Practical implications This paper shows a feasible method of the modification of the PR170 with the silica fume, and the modification can improve the properties of the PR170. The use of silica fume to modify organic pigment can realise the reuse of solid waste and reduce the production cost of the organic pigment. Social implications This modification method of the organic pigment is adaptive and it can be adjusted to the modification of other species of the organic pigment. Originality/value The modification of the PR170 with the silica fume was carried out in its preparation process, which synchronised the preparation and modification of the organic pigment. The properties of the modified pigment were improved, which were beneficial for their application in inks and coatings.


2016 ◽  
Vol 73 (10) ◽  
pp. 973-975
Author(s):  
Vesna Jovanovic ◽  
Ljubisa Nikolic

Introduction. Urrets-Zavalia syndrome is an uncommon complication of the deep anterior lamellar keratoplasty in keratoconus. The manifestations of this syndrome are an irreversible mydriasis, iris atrophy and secondary glaucoma. Case report. Deep anterior lamellar keratoplasty was done for keratoconus with a presumably healed corneal hydrops in a 21-year-old Caucasian man. The graft remained clear, but the surgery was complicated by a fixed, dilated pupil, patches of iris atrophy, ectropium of the iris pigment layer and glaukomflecken in the lens. Conclusion. Although safer than penetrating keratoplasty, the deep anterior lamellar by not trying to secure an unhealed Descemet?s membrane with air. Instead, a new Descemet?s membrane transplanted within a penetrating graft is a safer choice.


Author(s):  
Andrea Pataki-Hundt ◽  
Eva Hummert

AbstractTwo aspects of consolidation of powdery paint layers are discussed in this paper: First, the colour stability of different consolidation media including cellulose and protein based materials was evaluated. Film sheet samples of the adhesives were exposed to a Xenontester for 276 hours to reach Blue Wool Standard 7. Light exposure caused loss of colour rather than yellowing in most adhesives which correlates to microfading tests. Secondly, colour changes of the pigment layer during application of consolidation media with an aerosol generator were examined. Any shift of colour results in a change of surface structure rather than a detectable shift seen in the ΔE*


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