scholarly journals Φυσικές και χημικές επεξεργασίες οικολογικών κλωστοϋφαντουργικών υλών

2013 ◽  
Author(s):  
Γεώργιος Σαββίδης
Keyword(s):  
Physical Properties ◽  
Cotton Fabrics ◽  
Partial Replacement ◽  
Synthetic Dyes ◽  
Natural Pigments ◽  
Colour Measurements ◽  
Application Techniques ◽  
Digital Textile Printing ◽  
Jet Printing ◽  
The Stability

Various applications of natural pigments in cotton fabrics were studied.There was a research on the potentials of the plant colorant annatto on the cotton fabrics. Alumwas selected as a mordant. The study focused on the most important application techniques andconditions (temperature, pH, amount of alum) bearing in mind the new environmentalrequirements and the new technological possibilities.The aim was to standardize the whole procedure in order to form a regular protocol for the textiledyeing with natural dyes, thus achieving at least a partial replacement of synthetic dyes bynatural dyes. Quality control of all the dyeing performed was made using standard fastness testsand colour measurements.Another part of the study was the usage of 11 natural pigments for the preparation of printingpastes. The physical properties pH, conductivity, surface tension and viscosity of these pasteswere measured over a period of 16 days for the evaluation of the stability and suitability of themand they proved to be suitable and used for printing of cotton fabrics. The prints were subjectedto wash, light, rub, perspiration, dry clean, dry heat fixation, PVC migration, hypochlorite bleachand discharge fastness tests and colour measurements and they proved, to be satisfactory.The third section of the study involves four natural pigments, which were used as colorants forthe preparation of water-based ink jet inks for digital textile printing. The physical properties ofthe inks were estimated over a period of 90 days and were proved to be stable and suitable forink jet printing. The prints were subjected to wash, light and rub fastness tests and colourmeasurements. The results were promising and this paves the way for the production ofenvironmentally friendly cotton prints through the formulation of suitable printing techniques.

The tuning effect of the electric field on the physical properties of some typical wurtzite semiconductors

2017 ◽  
Vol 31 (33) ◽  
pp. 1750310 ◽  
Author(s):  
Jia-Ning Li ◽  
San-Lue Hu ◽  
Hao-Yu Dong ◽  
Xiao-Ying Xu ◽  
Jia-Fu Wang ◽  
...  
Keyword(s):  
Electric Field ◽  
Physical Properties ◽  
First Principles ◽  
Electronic Structures ◽  
Density Functional ◽  
Great Influence ◽  
Semiconductor Materials ◽  
Functional Theory ◽  
The Stability ◽  
Wurtzite Semiconductors

Under the tuning of an external electric field, the variation of the geometric structures and the band gaps of the wurtzite semiconductors ZnS, ZnO, BeO, AlN, SiC and GaN have been investigated by the first-principles method based on density functional theory. The stability, density of states, band structures and the charge distribution have been analyzed under the electric field along (001) and (00[Formula: see text]) directions. Furthermore, the corresponding results have been compared without the electric field. According to our calculation, we find that the magnitude and the direction of the electric field have a great influence on the electronic structures of the wurtzite materials we mentioned above, which induce a phase transition from semiconductor to metal under a certain electric field. Therefore, we can regulate their physical properties of this type of semiconductor materials by tuning the magnitude and the direction of the electric field.

scholarly journals Noninvasive and safe cell viability assay forEuglena gracilisusing natural food pigment

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6636 ◽  
Author(s):  
Kyohei Yamashita ◽  
Koji Yamada ◽  
Kengo Suzuki ◽  
Eiji Tokunaga
Keyword(s):  
Cell Viability ◽  
Euglena Gracilis ◽  
Food Culture ◽  
Live Cells ◽  
Natural Food ◽  
Synthetic Dyes ◽  
Cell Viability Assay ◽  
Natural Pigments ◽  
Viability Assay ◽  
Good Ability

Noninvasive and safe cell viability assay is required in many fields such as regenerative medicine, genetic engineering, single-cell analysis, and microbial food culture. In this case, a safe and inexpensive method which is a small load on cells and the environment is preferable without requiring expensive and space-consuming equipment and a technician to operate. We examined eight typical natural food pigments to findMonascuspigment (MP) or anthocyanin pigment (AP) works as a good viability indicator of dye exclusion test (DET) forEuglena graciliswhich is an edible photosynthetic green microalga. This is the first report using natural food pigments as cell viability assay.Euglena gracilisstained by MP or AP can be visually judged with a bright field microscope. This was spectrally confirmed by scan-free, non-invasive absorbance spectral imagingA(x, y,λ) microscopy of single live cells and principal component analysis (PCA). To confirm the ability of staining dead cells and examine the load on the cells, these two natural pigments were compared with trypan blue (TB) and methylene blue (MP), which are synthetic dyes conventionally used for DET. As a result, MP and AP had as good ability of staining dead cells treated with microwave as TB and MB and showed faster and more uniform staining for dead cells in benzalkonium chloride than them. The growth curve and the ratio of dead cells in the culture showed that the synthetic dyes inhibit the growth ofE. gracilis, but the natural pigments do not. As the cell density increased, however, AP increased the ratio of stained cells, which was prevented by the addition of glucose. MP can stain dead cells in a shorter time than AP, while AP is more stable in color against long-term irradiation of intense light than MP. Due to the low toxicity of these pigments, viability of cells in culture can be monitored with them over a long period.

scholarly journals Effect of Lactic Acid Content into on during Miconazole Eye Drops to be Used for Infection Preventive

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yoshimura K ◽  
Inoue Y ◽  
Koizumi A ◽  
Suzuki M ◽  
Itakura S ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Physical Properties ◽  
Acid Content ◽  
Eye Drops ◽  
Lactic Acid Content ◽  
The Stability

Purpose: The aims of this study were to prepare a 0.1% Miconazole (MCZ) eye-drop solution and to evaluate the stability and physical properties of the preparation.

Layer-by-layer Assembly Polyethylenimine/phytic Acid Coating With Gradient Structure for High-Efficiency and Durable Flame Retardant Cotton Fabric With Good Physical and Mechanical Properties

2021 ◽  
Author(s):  
Xinhua Liu ◽  
Hailong Liu ◽  
Yinchun Fang
Keyword(s):  
Physical Properties ◽  
Flame Retardant ◽  
Cotton Fabric ◽  
High Efficiency ◽  
Cotton Fabrics ◽  
Gradient Structure ◽  
Layer By Layer ◽  
Assembly Method ◽  
Lbl Assembly ◽  
Coated Cotton

Abstract In this study, intumescent flame retardant coating of polyethylenimine/phytic acid (PEI/PA) with gradient structure was constructed on cotton fabric through facile layer-by-layer (LBL) assembly method. The LOI value of coated cotton fabric reached over 40% indicating excellent flame retardancy. Reasonable controlling the LBL assembly process of PEI/PA coating brought less influence to the physical properties of cotton fabrics. And the coated cotton fabric revealed good flame retardant washing durability. Thermogravimetric analysis results of coated cotton fabrics showed that PEI/PA flame retardant coating changed the thermal decomposition process and promoted char formation revealing the obviously condensed phase flame retardant action. SEM images of char residues revealed that PEI/PA flame retardant coating promoted to form the intumescent flame retardant (IFR) char layer showing obvious IFR action. This research provides novel strategy for the development of high-efficiency flame retardant cotton fabric with good durability and physical properties using simple LBL assembly method.

Sinusoidal AC-induced electrohydrodynamic direct-writing nanofibers on insulating collector

2021 ◽  
pp. 2140009
Author(s):  
Huatan Chen ◽  
Guoyi Kang ◽  
Jiaxin Jiang ◽  
Juan Liu ◽  
Xiang Wang ◽  
...  
Keyword(s):  
Electric Field ◽  
Flexible Electronics ◽  
Direct Writing ◽  
Printing Process ◽  
Ac Electric Field ◽  
Jet Printing ◽  
Voltage Frequency ◽  
Fiber Deposition ◽  
The Stability ◽  
Application Fields

Printing orderly patterns on the insulating collector is the key for the development and application of flexible electronics. However, electrospinning on the insulating collector still has the problem of unstable jet due to the charge accumulation. The alternating current (AC)-induced electrohydrodynamic direct-writing (EDW) technology is a good way to decrease the interferences of charge repulsion, which is beneficial to printing orderly micro/nanostructures on the insulating collector. In this work, the sinusoidal AC-induced EDW is used to enhance the stability of charged jet and the deposition behaviors under AC electric field are also studied. The reciprocation transferring of charges induced by the AC electric field decreased the density of the accumulating charges on the insulating collector. The effect of AC electric field parameters on the direct-written micro/nanostructures are investigated to optimize the printing process. As the voltage peak increases, the fiber deposition bandwidth shows a trend of decreasing first and then increasing. Increasing the voltage frequency appropriately is beneficial to decrease the bandwidth of fiber deposition and to increase the stability of the jet. By improving the stability and controllability of the jet printing process, precise micro/nanopatterns can be direct-written on the insulating collector. This research provides a good foundation for expanding the application fields of EDW.

scholarly journals Bacterial Pigments: The Bioactivities and as an Alternative for Therapeutic Applications

2018 ◽  
Vol 13 (12) ◽  
pp. 1934578X1801301 ◽  
Author(s):  
Adzzie-Shazleen Azman ◽  
Christina-Injan Mawang ◽  
Sazaly Abubakar
Keyword(s):  
Food Industry ◽  
Good Alternative ◽  
Biological Properties ◽  
Review Article ◽  
Synthetic Dyes ◽  
Anticancer Activities ◽  
Natural Pigments ◽  
Synthetic Pigments ◽  
Coloring Agents ◽  
Bacterial Pigments

Synthetic pigments have been widely used in various applications since the 1980s. However, the hyperallergenicity or carcinogenicity effects of synthetic dyes have led to the increased research on natural pigments. Among the natural resources, bacterial pigments are a good alternative to synthetic pigments because of their significant properties. Bacterial pigments are also one of the emerging fields of research since it offers promising opportunities for different applications. Besides its use as safe coloring agents in the cosmetic and food industry, bacterial pigments also possess biological properties such as antimicrobial, antiviral, antioxidant and anticancer activities. This review article highlights the various types of bacterial pigments, the latest studies on the discovery of bacterial pigments and the therapeutic insights of these bacterial pigments which hopefully provides useful information, guidance and improvement in future study.

scholarly journals Use of Phycobiliproteins from Atacama Cyanobacteria as Food Colorants in a Dairy Beverage Prototype

Foods ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 244 ◽  
Author(s):  
Alexandra Galetović ◽  
Francisca Seura ◽  
Valeska Gallardo ◽  
Rocío Graves ◽  
Juan Cortés ◽  
...  
Keyword(s):  
Food Industry ◽  
Skim Milk ◽  
Antioxidant Property ◽  
Exchange Chromatography ◽  
Water Soluble ◽  
Antioxidant Power ◽  
Natural Pigments ◽  
Freeze Dried ◽  
The Stability ◽  
Sensory Tests

The interest of the food industry in replacing artificial dyes with natural pigments has grown recently. Cyanobacterial phycobiliproteins (PBPs), phycoerythrin (PE) and phycocyanin (PC), are colored water-soluble proteins that are used as natural pigments. Additionally, red PE and blue PC have antioxidant capabilities. We have formulated a new food prototype based on PBP-fortified skim milk. PBPs from Andean cyanobacteria were purified by ammonium sulfate precipitation, ion-exchange chromatography, and freeze-drying. The stability of PE and PC was evaluated by changes in their absorption spectra at various pH (1–14) and temperature (0–80 °C) values. Purified PBPs showed chemical stability under pH values of 5 to 8 and at temperatures between 0 and 50 °C. The antioxidant property of PBP was confirmed by ABTS (2,2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical ion scavenging, and FRAP (Ferric Antioxidant Power) assays. The absence of PBP toxicity against Caenorhabditis elegans was confirmed up to 1 mg PBP/mL. Skim milk fortified with PE obtained a higher score after sensory tests. Thus, a functional food based on skim milk-containing cyanobacterial PBPs can be considered an innovative beverage for the food industry. PBPs were stable at an ultra-high temperature (138 °C and 4 s). PBP stability improvements by changes at its primary structure and the incorporation of freeze-dried PBPs into sachets should be considered as alternatives for their future commercialization.

Effect of the Surfactant Concentration on Sinking Electric Discharge Machining Performance with Water-in-Oil Emulsion as Dielectric

2011 ◽  
Vol 189-193 ◽  
pp. 3153-3157
Author(s):  
Yan Zhen Zhang ◽  
Yong Hong Liu ◽  
Ren Jie Ji ◽  
Bao Ping Cai
Keyword(s):  
Physical Properties ◽  
Electric Discharge ◽  
Surfactant Concentration ◽  
Emulsion Stability ◽  
Experimental Results ◽  
Machining Performance ◽  
Electric Discharge Machining ◽  
Oil Emulsion ◽  
The Stability ◽  
Water In Oil Emulsion

In this paper, the EDM performance of water-in-oil (W/O) emulsions dielectric with different surfactant concentration is investigated by correlated to its physical properties, such as viscosity and droplets size, which is predominantly determined by the surfactant concentration. Experimental results show that the stability of the W/O emulsions increases with increasing surfactant concentration, whereas the EDM performance deteriorates with increasing surfactant concentration. So, taking a comprehensively consideration of the emulsion stability and EDM performance, the concentration of surfactant must be appropriately selected.

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