341,259 research outputs found
Holographic photography of high velocity particles
Fourier transform hologram camera increases the velocity range for holography by a factor of 10 to 1000. Two different optical systems, using a triangular arrangement of beam splitters and a mirror to illuminate the object from two directions, are investigated
Feasibility Study of Velocity Synchronized Fourier Transform Hologram Camera System
Velocity synchronized Fourier transform hologram camera syste
Investigation of dyeing based on pandanus amaryllifolius for superhydrophobic coating in cotton-polyester blended in textile application
Natural dyes are derived from natural resources. Colouring materials obtained from natural resources of plant, animal, mineral, and microbial origins were used for colouration of various textile materials. Use of natural dyes started fall after the invention of synthetic dyes in the second half of the nineteenth century. The synthetic dyes were rapidly industrialization of textile production resulted in almost complete replacement of natural dyes by synthetic dyes because their easy availability simple application process, better fastness properties and consistency of shades [1]. Recent environmental awareness has again revived interest in natural dyes mainly among environmentally conscious people. Natural pigments are considered eco-friendly as these are renewable and biodegradable which is skin friendly and provide healthier benefits to the wearer [2]. Pandanus amaryllifolius also called as pandan leaf is a tropical plant that under screw pine genus and it can be easily found all around in Malaysia. It is a genus monocotyledon plants with over 750 accepted species. Extraction of green pigments from pandanus amaryllifolius to produce an organic pigment for fabric dyeing can become an alternative of synthetic pigments. Organic pigments also can be classified as a biochrome substance which is produced by living organisms. These biological pigments include flower and plant pigments [3]
The Relation between Packing Effects and Solid State Fluorescence of Dyes
The solid state fluorescence of diketopyrrolopyrrole dyes and perylene-3,4:9,10- tetracarboxylic bisimides with alkyl substituents are investigated and compared with noncovalent interactions. The latter are estimated by crystal structure analysis, heats and entropies of fusion and solubilities in organic solvents. Applications of the dyes are discussed
Molecular First Hyperpolarizabilities of a New Class of Asymmetric Squaraine Dyes
The molecular first hyperpolarizabilities (β) of a series of asymmetric squaraine dyes have been measured by electric-field-induced second harmonic generation; the dyes have negative β-values whose magnitudes are comparable to 4-N,N-dimethylamino-4′-nitrostilbene (DANS)
The Comparison Between Chemical and Natural Extraction In Textile Dyeing With Indigofera
Indigo is categorized as a vat dyes, which is needs to pass a fermentation phase in the extraction process before it could be used as a textile dye due to its lack of fastener substances. Vat dyes are known to be the most solid dye with high endurances compared to other textile dyes according to how the colour will fade caused by acid or alkaline substances. The fermentation process of Indigofera dye could be done using chemical or natural ingredients. Sodium Hydrosulphite could be used in chemical fermentation, while Javanese brown sugar is used in natural fermentation for Indigo dye. This study uses comparative method with material experimental approach. Comparison between the use of Indigofera dye with natrium hydrosulphite fermentations and Indigofera dye with Javanese brown sugar fermentations will be analyzed. this study is purposed to find the advantages and disadvantages in both Indigofera dye substances made of brown sugar fermentation in the vatting process and hydrosulfite fermentation in the vatting process. the results of this study can be used as references in dyeing textile using indigofera for business people, craftsmen, artists, and students in developing their product designs.
Keywords Indigofera dye, natural dyes, extraction, fermentatio
First examples of pyran based colorants as sensitizing agents of p-Type Dye-Sensitized solar cells
Three different pyran based dyes were synthesized and tested for the first time as photosensitizers of NiO based p-type dye-sensitized solar cells (p-DSSC). The molecules feature a similar molecular structure and are based on a pyran core that is functionalized with electron acceptor groups of different strength and is symmetrically coupled to phenothiazine donor branches. Optical properties of the dyes are deeply influenced by the nature of the electron-acceptor group, so that the overall absorption of the three dyes covers the most of the visible spectrum. The properties of devices based on the NiO electrodes sensitized with the investigated dyes were evaluated under simulated solar radiation: the larger short circuit current density exceeded 1mA/cm2 and power conversion efficiency as high as 0.04% could be recorded. The performances of the fabricated p-DSSC have been compared to a reference cell sensitized with P1, a high level benchmark, which afforded a photoelectrochemical activity similar to the best example of our pyran sensitized devices (1.19 mA/cm2 and 0.049%)
Dyes adsorption from aqueous solutions by Chitosan
In this study the ability of chitosan to remove acid, basic, reactive and direct dyestuffs by adsorption was studied. The effect of several factors influencing dye adsorption such as dye concentration, grain size, pH and temperature were investigated. Desorption of dyes at different pH was also examined. It was shown that the adsorption capacities of chitosan were comparatively high for acid and direct dyes and that the adsorption was controlled by the acidity of the solution. The kinetics of adsorption were found to be of pseudo second order. Batch isotherm studies showed that adsorption of dyes from aqueous solution by chitosan was described by the Langmuir equation
Environmental effects of natural dyes and syntetic dyes: a comparison
Dyes is important to add colorant on fabrics. The dyeing process makes a fabric colourful and attractive. However, the waste disposed by dyeing process was hazard to environment especially synthetic dyes. Most of the textile industry uses synthetic dyes compared to natural dyes. This happens because natural dyes are difficult to extract its colour. Four types of natural and synthetic dyes were reviewed in this study. It was understood that all types of dyes have its advantages and disadvantages. Natural dyes have poor colour fastness compared to synthetic dyes. Besides, natural dyes can combine with synthetic dyes for greater commercial dyeing. Dyeing is one of the method to beautify the appearance of fabrics. It is a process to add colour to textile products like yarn, fiber and fabrics. Dyeing can be divided into synthetic dyes and natural dyes whereas can be produced either chemically or by plants. Synthetic dyes are man-made and normally made from synthetic resources such as petroleum by-products and earth minerals while natural dyes are from plant and animal sources. Most of the textile industry is using synthetic dyes compared to natural dyes. Natural dyes are hardly to extract their colour and environmentally friendly. Synthetic dyes can be extracted easily but brings harmful effect to environment. Unfortunately, the exact amount of dyes produced in the world is still unknown. It is estimated that the production of dyes to be over 10,000 tons per year. Exact data on the quantity of dyes discharged in the environment are also not available (Forgacs and Cserhátia, 2004)
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