Hideto Sasaki, Helen Negash Shiferaw, Toshiyuki Kanakubo
This study aims to verify the adaptability of a crack width evaluation method for fiber-reinforced cementitious composite (FRCC) proposed by the authors to various combinations of fiber-reinforced polymer (FRP) bars and FRCCs. As this evaluation method requires bond constitutive laws between FRP bars and FRCC, bond tests between FRP and FRCCs were conducted. The FRP and FRCC combinations used in the bond tests were spiral-type CFRP and GFRP bars with PVA-FRCC, as well as strand-type CFRP bars with aramid–FRCC. The maximum bond stress tended to increase as the rib–height ratio of the spiral-type bars increased. When the rib–height ratio increased by 50%, the maximum bond stress of the CFRP and GFRP bars increased by 11% and 33%, respectively. For aramid–FRCC, the average maximum bond stress in the FRCC with a 0.25% volume fraction was 1.67 times that in mortar, and that in 0.50% was 2.01 times that in mortar. The bond constitutive laws were modeled using the trilinear model. Verifications of the method’s adaptability were conducted using tension tests on prisms made of spiral-type CFRP and GFRP bars with PVA-FRCC. As a result of the tension tests, when the FRP strain reached approximately 0.3%, the crack width was about 0.2 mm for CFRP bars and about 0.1 mm for GFRP bars. Verifications were also conducted using four-point bending tests on strand-type CFRP bar beams with aramid–FRCC. The crack width at the same FRP strain tended to become smaller as the fiber volume fraction of FRCC increased. When the FRP strain reached approximately 0.2%, the average crack width of the mortar specimen was around 0.25 mm, whereas it was about 0.15 mm in FRCC with a 0.25% volume fraction and about 0.10 mm at 0.5%. The test results for FRP strain versus crack width relationships were compared with the calculations using the crack width prediction formula. The test results and calculation results were in good agreement.
Chemicals: Manufacture, use, etc., Textile bleaching, dyeing, printing, etc.
Emilija Zdraveva, Zenun Skenderi, Ivana Salopek Čubrić
et al.
Thermal insulating materials are of paramount importance in many application areas, including building construction, electronics, aerospace engineering, the automobile industry and the clothing industry. Electrospun materials are light weight with a well-controlled fibre diameter/morphology and a highly interconnected porous structure that facilitates the trapping of air and breathability. When combined with other conventional materials, they enhance the thermal insulating property of a composite structure. This study focused on electrospun single polyurethane (PU), polystyrene (PS) and layered composites thereof, in terms of heat resistance and its dependence on fibre diameter, pore area, number, thickness (solution volume) and the position of electrospun layers. It thus contributes to the field by addressing the effects of multiple parameters effect on a composite material’s heat resistance. The fibre diameter for both electrospun polymers increased significantly by increasing the concentration, while there was a generally opposite effect from increasing electrical voltage. The 10 wt% PU and 30 wt% PS used to produce the layered composites demonstrated the highest reduction of the fibre mean diameter, from (443 ± 224) nm to (328 ± 148) nm, and from (2711 ± 307) nm to (2098 ± 290) nm, respectively. Thicker PS fibres resulted in the greatest mean pore areas of (13 ± 9) µm2, while the PU mean pore areas were in the range of (2 ± 1) µm2 to (4 ± 2) µm2. Although all single and PS/PU composites demonstrated a porosity greater than 97%, their configuration in terms of number of layers, total thickness and PS and PU positioning (includes fibre diameter and pore area) affected the measured heat resistance. Single electrospun PS demonstrated a reduction in heat resistance of 0.0219 m2K/W (compared to electrospun PU) due to its thicker fibres and larger pore areas, and thus looser structure. Combining the two electrospun layers improved heat resistance up to 0.0341 m2K/W. The total heat resistance of the layered PU/PS composite was increased (up to 0.1063 m2K/W for the electrospun PS/PS/PU/PU) by increasing the number and volume of each electrospun layer solution, and by spinning the PU layer on top of the system, which resisted the heat flow due to its smaller pore areas and compact structure. These results prove that by optimizing process/structure parameters, a multi-layered material with good thermal performance can be designed to meet the requirements of a thermal insulating product.
ABSTRACT The printing and dyeing industry is one of the most polluting (∼20% of global clean water pollution), water-consuming and energy-wasting sectors in the manufacturing field, highlighting the need to find green catalysts to improve its sustainability. Herein, a novel artificial green catalyst was developed, known as a bifunctional chimeric peptide DNAzyme (bi-CPDzyme), comprising peptide, DNA and hemin moieties. This catalyst displays both catalase (CAT) and peroxidase (POD) activities. The turnover number (kcat) of the optimized bi-CPDzyme prototype (G-quadruplex-Hemin-HRRHKHRRH) surpasses the natural CAT/POD bifunctional enzyme KatG, and competes with individual CAT and POD enzymes. This remarkable performance is attributed to the strategic combination and incorporation of histidine (H) and arginine (R) residues, which effectively trap hydrogen peroxide (H2O2) near the catalytic center via hydrogen bond formation, thus facilitating the generation of the active intermediate compound I, as supported here by theoretical calculations. Significantly, bi-CPDzyme achieves efficient decomposition of bleaching-derived residual H2O2 in a water-/energy-saving manner, while degrading dyes from textile industry effluents even in complex real samples, in addition to being easily recyclable and implementable. These findings make bi-CPDzyme a cutting-edge and environmentally friendly catalyst, positioning it at the forefront of advancements towards creating a sustainable society.
In recent years, pollution stemming from pharmaceuticals has garnered widespread global concern, which exacerbates the ecological risk to both surface and groundwater. In the current study, Fe and O co-embedded biochar (Fe-O-BC) was synthesized through a one-step pyrolysis procedure with corncob serving as the feedstock. The fabricated Fe-O-BC catalysts were characterized by various techniques and were employed for the activation of peroxymonosulfate (PMS) to degrade tetracycline (TC). TC was rapidly degraded within 40 min, with a degradation rate of 0.1225 min−1, which was much higher than those for O-BC/PMS (0.0228 min−1) and Fe-BC/PMS (0.0271 min−1) under the same conditions. The effects of PMS dosage, Fe-O-BC dose, initial pH value and coexisting anions for TC degradation were investigated. Finally, the mechanism of TC oxidation in the catalytic system was implored through experiments of determining the active sites and radical scavenging experiments. The C-O-Fe bond in the catalyst was confirmed to be the dominant active sites accelerating TC degradation. Free diffused HO•, the surface-bound HO• and SO4•− and O2•−participated in the reaction and absorbed SO4•−, and HO• predominantly contributed to TC degradation. This study provides an efficient and green alternative for pharmaceutical wastewater treatment by Fe and O co-doped catalyst-induced heterogeneous process.
Today, a major concern associated with the environment is the water pollution occurred due to the introduction of variety of persistent organic pollutants and residual dyes from different sources (e.g., dye and dye intermediates industries, paper and pulp industries, textile industries, tannery and craft bleaching industries, pharmaceutical industries, etc.) into our natural water resources. Recently, advanced oxidation processes (AOPs) by photocatalyst have garnered great attention as a new frontier promising eco-friendly and sustainable wastewater treatment technology. Utilization of the photocatalytic technology efficiently is significant for cleaner environment. Bismuth based photocatalyst have aroused widespread attention as a visible light responsive photocatalyst for waste water treatment due to their non-toxicity, low cost, modifiable morphology, and outstanding optical and chemical properties. In this review, we have dealt with the research progress on bismuth-based photocatalysts for waste water treatment. However, it seems to give limitation over pristine photocatalysts such as slow migration of charge carriers, charge carrier recombination, low visible light absorption, etc., Various bismuth based photocatalyst and its modifications via doping, heterojunction, Z-scheme etc., are discussed in detail. Further, the strategies adopted to improve the photocatalytic activity of bismuth based photocatalyst to improve the waste water treatment (mostly drugs and dyes) are critically reviewed. Also, we have discussed the bacterial inactivation by bismuth based photocatalyst. Finally, the challenges and future aspects against bismuth based photocatalyst are explored for further research.
There is a significant trend towards the integration of natural substances with bio-polymers for fully bio-based functional composites. Polylactic acid is regarded as a promising biodegradable polymer for replacing synthetic polymers. Differing from the case of natural fiber, the incompatibility of polylactic acid with bio-based molecules prevents it from being used to fabricate high-quality sustainable composites. This work presents a simultaneous ultraviolet shielding and antibacterial finishing process of polylactic acid combined with bioactive baicalin and an eco-friendly ester, which is highlighted for (a) the lack of synthetic chemicals involved in such process, (b) adsorption enhancement achieved at a mild temperature, and (c) marginal color change on treated polylactic acid. A response surface methodology was adopted to analyze the impacts of various factors on the baicalin quantity in polylactic acid, and to optimize the treatment condition. The uptake ratio of baicalin in polylactic acid was drastically promoted from 8.5 mg/g to 21.1 mg/g using methyl cinnamate. The response surface methodology based on a central composite design experiment indicated that the usage of baicalin was the most significant factor followed by methyl cinnamate and temperature. After optimization, a very faint color depth of 1.2 was apparent, but UPF 50+ and 92% bacterial reduction could be achieved. In all, the success in strengthening of the functionalities of polylactic acid extends the applications of polylactic acid products.
Edward Wantahe, Cosmas Fednand Kindole, Pendo Bigambo
Natural fibers are gaining significant attention in minimizing the usage of non-ecofriendly fibers in various industrial applications. In the present study, fibers extracted from the leaves of the Sansevieria ehrenbergii (SE) plant were investigated as potential sources of cellulosic fibers for textile applications. The water-extracted fibers were alkali-treated using varying treatment parameters, and their properties were then characterized using X-ray diffractometry, Fourier Transform Infrared spectroscopy, and Thermogravimetric analyzer. The optimal treatment parameters were found to be 15 g/L NaOH, 90°C temperature, and 60 min. The obtained average length (980 mm), fineness (31.3 Tex), moisture regain (10.6%), and moisture content (9.6%) values were comparable to other fibers. Tensile strength values for untreated and treated fibers were 470.7 MPa and 582 MPa, respectively, while the elongations at break were 5.8% and 6.3%, respectively. The treated SE fibers contained 75.3%, 8.6%, and 5.8% of cellulose, hemicelluloses, and lignin, respectively. In addition, the crystallinity index and crystal size of the treated SE fiber were 74.6% and 0.79 nm, respectively. Moreover, alkali treatment was found to enhance the thermal stabilities of the fibers. These findings suggest that the SE plant is a potential source of cellulosic fibers for various textile products.
Science, Textile bleaching, dyeing, printing, etc.
Fiber-reinforced mycelium (FRM) composites offer an innovative and sustainable approach to construction materials for architectural structures. Mycelium, the root structure of fungi, can be combined with various natural fibers (NF) to create a strong and lightweight material with environmental benefits. Incorporating NF like hemp, jute, or bamboo into the mycelium matrix enhances mechanical properties. This combination results in a composite that boasts enhanced strength, flexibility, and durability. Natural FRM composites offer sustainability through the utilization of agricultural waste, reducing the carbon footprint compared to conventional construction materials. Additionally, the lightweight yet strong nature of the resulting material makes it versatile for various construction applications, while its inherent insulation properties contribute to improved energy efficiency in buildings. Developing and adopting natural FRM composites showcases a promising step towards sustainable and eco-friendly construction materials. Ongoing research and collaboration between scientists, engineers, and the construction industry will likely lead to further improvements and expanded applications. This article provides a comprehensive analysis of the current research and applications of natural FRM composites for innovative and sustainable construction materials. Additionally, the paper reviews the mechanical properties and potential impacts of these natural FRM composites in the context of sustainable architectural construction practices. Recently, the applicability of mycelium-based materials has extended beyond their original domains of biology and mycology to architecture.
Chemicals: Manufacture, use, etc., Textile bleaching, dyeing, printing, etc.
The geometric structure of the surface of textile materials is of significant functional, operational and aesthetic importance. The basic parameters of the woven fabrics’ structure are the following: weave, warp and weft density as well as warp and weft linear density. Roughness is one of the surface quality features most often assessed by quantitative indicators called surface roughness parameters. The aim of the presented research was to analyze the parameters characterizing the geometric structure of the surface of cotton woven fabrics with different weaves. Surface topography measurements were performed using the MicroSpy® Profile profilometer by FRT the art of metrology™. Using the Mark III software cooperating with the profilometer, a number of indices characterizing the geometric structure of the fabric surface and histograms illustrating the frequency of occurrence of points of a certain height on the tested surface were determined. The research confirmed that, on the basis of the results obtained with the profilometer, it is possible to analyze comprehensively the topography of the fabric surface.
Textile bleaching, dyeing, printing, etc., Engineering machinery, tools, and implements
A.V. Pavlov, E.A. Porokhovinova, L Novikova
et al.
Market demand for flax fiber continues to grow. Partially, it can be replaced with linseed fiber. In 2015–2017, 40 linseed accessions were evaluated in North-West of Russia. Warm-water retted fiber was tested with the technique used for fiber flax. Contrasting weather conditions in 2015–2017 made it possible to compare accessions characters. Since plant height and yield of long fibers are determined mainly by genotype, it is possible to select promising genotypes directly during the breeding process under unusual conditions. A significant contribution of genotypes to the formation of fiber quality characters and duration of the growing season facilitates the breeding process. A stable close relationship between plant height with straw yield and a weaker one with long fiber content can simplify the selection of productive plants according to their height in the initial stages of breeding. The absence of close links between fiber quality and other characteristics makes feasible independent selection to improve product quality. A three-year-long evaluation of linseed accessions has shown the possibility of such cultivar cultivation in the North arias in order to produce both fiber and seeds. On the basis of these results, promising accessions suitable for dual utilization have been identified.
Science, Textile bleaching, dyeing, printing, etc.
Luster for a fiber/fabric system is a phenomenon to the reflectance of incident light to the surface, addressed as its shine or gloss. Presently, objective evaluation of the shine for straight hair (human hair) can be quantified through Goniophotometer, and for a smooth plane and curved surfaces, the Gloss meter was used. Due to non-availability of suitable instrumental assistance, the wool luster is subjectively evaluated to determine wool quality. In the present study, the estimation of surface shines of multiple curved surfaces of crimped wool fibers has been explored in terms of gloss 60° values on gloss meter. The methodology for the wool sample preparation and its mounting on newly designed and developed platform was standardized for luster measurement using gloss meter. Wool samples of different grades/sheep breed viz. Carpet- Magra, Chokla and New Zealand, Apparel- Bharat Merino and Coarse -Malpura breed were selected for the present study. Thirty samples of wool from each breed were used for evaluating the luster. The average Gloss 60° values for Malpura, Magra, Chokla, Bharat Merino, and New Zealand wool was 2.30, 2.71, 2.43, 2.76, and 2.88, respectively. The differences in Gloss 60° values of different wool was found significantly (P < .01) different. The measured Gloss values had shown a good relation (R = .78) with subjectively assessed luster rank.
Science, Textile bleaching, dyeing, printing, etc.
Muhammad Mohsin, Shaheen Sardar, Khurram Shehzad
et al.
Digital textile printing has emerged as a sustainable alternative to the conventional screen printing. Similar to other forms of coloration, digitally printed cotton fabric also needs finishing to overcome the inherent drawbacks of the cotton fabric. However, research on the finishing of the digital printed fabric is very limited and focused on non-sustainable finishes. In the first instance, this paper optimizes the recipe of the pre-printing process. Then, this paper investigates the performance of the digitally printed cotton fabric using three sustainable and formaldehyde free cross-linkers, three different softeners, C8-free oil and water repellent, and halogen free flame-retardant. This study applies these finishes on the steamed and non-steamed digitally printed fabric samples. The paper tests the performance of the finished digitally printed fabric in terms of key finishing properties. The results show that the proposed sustainable finishes have significantly improved the performance of the digitally printed fabric as compared to the reference non-finished digitally printed sample.
Science, Textile bleaching, dyeing, printing, etc.
Citric acid (CA)-crosslinked cotton fabrics show a yellowish appearance because CA forms C=C bonds during the heating process. The whiteness was improved by sodium hydrosulfite (Na2S2O4), which was confirmed by the Fourier transform infrared spectra. The computational calculations showed that Na2S2O4 is more effective than H2O2 when the system of CA-treated cotton is bleached. Based on the reaction mechanism of Na2S2O4 bleaching, the influences of Na2S2O4 concentration, bleaching temperature, bleaching time, bleaching pH on whiteness, and wrinkle recovery angle were investigated. The optional bleaching condition was 14% Na2S2O4 and sodium pyrophosphate (Na4P2O7), 70°C, and 40 minutes. The effect on the performance of fabrics bleached with Na2S2O4 was similar to the effect of non-formaldehyde crosslinker 1,2,3,4-butane tetracarboxylic acid (BTCA) and the widely used crosslinker dimethyloldihydroxyethyleneurea-treated cotton. CA-treated cotton bleached by Na2S2O4 showed a good persistence of bleaching effect.
Science, Textile bleaching, dyeing, printing, etc.
In this paper, aiming at the problems of difficult positioning, slow speed and low precision of digital printing, a detection system suitable for textile printing positioning is proposed and designed. This detection system innovatively combines a neural network and field programmable gate array (FPGA) to realize rapid and accurate positioning of printing. In the neural network part, this paper selects the backbone network Darknet19 of YOLOv2 as the backbone network, and under the premise of ensuring a certain detection accuracy, the network model is pruned and quantified to make it suitable for deployment on the embedded device FPGA. In addition, before the network training, this paper optimizes the candidate boxes by introducing k-means clustering to customize the analysis of the fabric print dataset to improve the detection accuracy. In the FPGA part, this paper optimizes the architecture on the FPGA side in two parts: data computation and data transmission. In terms of computational optimization, parallel optimization of the neural network is performed by combining FPGA optimization methods, such as pipeline and unroll. In terms of transmission optimization, we use a double-buffered design to ping-pong in the input and output modules to overlap the latency, and then use multi-port transmission to improve the overall bandwidth utilization and reduce the transmission latency caused by on-chip and off-chip interactions. The experimental results show that the detection system combining the neural network and FPGA can effectively position fabric prints and meet the needs of real-time. The design scheme has lower power compared to the graphics processing unit and is faster compared to the central processing unit.
The study involved laminated nylon and viscose nonwovens, both perforated and non-perforated, with a view to using them for packaging of powders in mineral warmers. The nonwovens were examined in terms of morphology as well as tensile strength in dry and wet states. Thermal properties were determined by differential scanning calorimetry. Dynamic mechanical analysis was carried out in a broad range of temperatures. Surface wettability and water vapor permeability were assessed. The findings were analyzed to determine the utility of the studied materials as mineral warmer packaging materials in cold work or living environments.