نشریه مطالعات در دنیای رنگ
سال دهم شماره 4 (پیاپی 39، زمستان 1399)

General familiarity with the early and ancient fundamentals of making paint and ink of the early centuries results in reconstruction and renewal of the identity of ancient sciences, islamic art and industry.Unlike simple and today's methods of combining of the elements in different industries, in the past, the way of merging the elements with the quadruple methods of construction, in relation to Aristotle’s natural and each element's temperament quality in merging with the other element has been a fundamental principle of  paint-making and ink manufacturing. "Fusion" unlike "combination” is a special type of combining with effect and affect under a special circumstance.This research aims to general familiarization with fundamentals of historical methods of making an ink called Golden ink. This research is a general revision of the methods of paint and ink making in the early centuries.

The religion of Islam since its formation has caused changes and alterations in various fields of architecture. These changes included various topics, including building decorations. With the passage of time and the formation of various Girih designs in different parts of the building and various materials, the color factor also found its place and finally color became an integral element in the art of Girih. In the present study, an attempt has been made to study the Girih from a close angle through its constituent geometric elements, and to analyze the color in Girih. The study of color is based on both psychology and archetype. The main research questions are what color characteristics of the Girih are placed next to each other and can a color combination pattern be provided for it? To achieve this question, library studies and architectural and historical documents along with the use of AutoCAD and Photoshop software have been used to determine the color pattern of Girih. The present study has been done with an exploratory approach and a descriptive-analytical research method. Findings indicate that the three main categories of Iranian Girih, namely Kond, Tond and Shol, each have a specific geometric pattern in color combination, and the background and routine of each instrument, depending on the type of Girih, has been determined as the main finding of the research.

At present, a higher demand is put towards the use of natural dyes due to increased awareness of the environmental and health hazards associated with the synthesis and use of synthetic dyes. Natural dyes are non-carcinogenic, produce soothing and exclusive color to the textiles, and have better biodegradability and higher compatibility with the environment. However, with the increased interest in natural plant dyes a greater importance was given to using mordant in dyeing processes. The mordants classified into two main groups: natural and metal mordant. The action of the mordant is purely chemical bonding, which is fixed on the fibers in combination with any given colorants. This paper presents the latest research on metal mordant and the development of natural mordant for use in the fiber dyeing process. For this end, an attempt structure properties to improve dyeing properties and to test landscape perspective.

Currently, 3D bioprinting as an additive manufacturing technique for building 3D constructs with desired geometries is broadly employed in tissue engineering and drug screening applications. Bioprinting enables the fabrication of living tissues using cell aggregates or cells encapsulated in biomaterials—all of which can be referred to as bioink. Research on novel bioinks with appropriate printability, biocompatibility, and mechanical properties akin to the target tissue is an essential prerequisite toward advancing 3D bioprinting applications in regenerative medicine. The only class of materials capable of providing an environment similar to the human body and maintaining cell viability during encapsulation is hydrogels. Among the two categories of natural and synthetic hydrogels employed as bioinks, natural materials are much more widely used than synthetic ones due to their better biocompatibility, lower risk of immune rejection, more similarity to native tissues, and the possibility of laboratory modification and combination with other materials to obtain optimal properties. In this article, first, a review of 3D bioprinting technology and its defined modalities is presented. Next, bioink biomaterials and their cross-linking mechanism are discussed. Finally, a summary of studies on some of the most widely used natural bioinks (including collagen, gelatin, silk, alginate, hyaluronic acid, chitosan and extracellular matrix) is reported. Research results indicate that recreating organs using 3D bioprinting necessitates precise placement of specific cells, materials, and bioactive factors to induce functional tissue formation. Attempting to meet these requirements for more complex tissues highlights the need for more tissue-specific, biologically and mechanically tunable bioinks.

Optical sensors and biosensors have the great potential to detect metal cations, anions, organic dyes, drugs, pesticides and other contaminants. These sensors are considered for their easy preparation, fast sensing, high sensitivity and selectivity, as well as naked eye detection. Optical sensors are divided into two categories of colorimetric and fluorescent sensors. In this regard, molecularly imprinted polymers, indicators, nanomaterials (metal nanoparticles, metal oxides, quantum dots) and etc. are used for the designation of optical sensors. The fabrication of MIP-based optical sensors is one of the considerable methods for the preparation of optical sensors. This method, known as the molecular lock-key method, for creating molecularly imprinted polymers (MIPs) which are complement to template molecules in shape, size, and functional groups. These materials are similar to biological systems in structure and application that result from the copolymerization of functional monomers and crosslinkers in the presence of the target molecule. These polymers are used for the detection, separation and removal of trace amount of various contaminants in complex substrates. For the preparation of MIP-based sensors, fluorescent functional monomers and dyes including coumarins, xanthenes, naphthalimides, carbazoles, boron dipyrromethenes, azo dyes, schiff bases and etc. are used. Therefore, in this study, various applications of MIPs including environmental, pharmaceutical and medical usage through separation, biomimetic assays, sustained delivery and release, new application areas and specially, optical sensors (synthesis process and its mechanism), will be expressed. In addition, recent developments and commercialization of MIPs and MIP based sensors, will be discussed as well as the introduction of some active companies in this field.

In recent years, with the expansion of the diagnostic range of many medical facilities, the likelihood of exposure to X-rays and gamma rays has increased. For this reason, lead aprons have been used to provide X-ray protection and are still widely used for this purpose. Current lead aprons have many problems, such as reduced protection efficiency, increased discomfort, and high weight. Defects in lead aprons, such as cracks and holes, can leak the beam and cause physical injury. In this paper, we investigate why lead is used and find alternative materials for lead in different composites and compare these materials in terms of particle size, radiation intensity, thickness and physical properties. The researchers showed that substituting lead for minerals could lead to lower weight, better biocompatibility and more flexibility. The particle size of the minerals used and the thickness of the protective layer consisting of these materials play an important role in attenuating ionizing radiation.