Amount Of Fibers Research Articles

Investigation of Dielectric, Mechanical, and Thermal Properties of Epoxy Composites Embedded with Quartz Fibers.

Polymer matrix wave transparent composites are used in a variety of high-speed communication applications. One of the applications of these involves making protective enclosures for antennas of microwave towers, air vehicles, weather radars, and underwater communication devices. Material performance, structural, thermal, and mechanical degradation are matters of concern as advanced wireless communication needs robust materials for radomes that can withstand mechanical and thermal stresses. These polymer composite radomes are installed externally on antennas and are exposed directly to ambient as well as severe conditions. In this research, epoxy resin was reinforced with a small amount of quartz fibers to yield an improved composite radome material compared to a pure epoxy composite with better thermal and mechanical properties. FTIR spectra, SEM morphology, dielectric constant (Ɛr) and dielectric loss (δ), thermal degradation (weight loss), and mechanical properties were determined. Compared to pure epoxy, the lowest values of Ɛr and δ were 3.26 and 0.021 with 30 wt.% quartz fibers in the composite, while 40% less weight loss was observed which shows its better thermal stability. The mechanical characteristics encompassing tensile and bending strength were improved by 42.8% and 48.3%. In high-speed communication applications, compared to a pure epoxy composite, adding only a small quantity of quartz fiber can improve the composite material's dielectric performance, durability, and thermal and mechanical strength.

Flexural Performance Study of Basalt-Fiber-Reinforced Polymer Bar Basalt-Fiber-Reinforced Concrete Beams

The utilization of Fiber-Reinforced Polymer (FRP) rods to strengthen concrete beam structures can enhance their ultimate load-carrying capacity and mitigate steel reinforcement corrosion damage. However, a prominent issue with BFRP (Basalt FRP) rod reinforcement in flexural members is its lack of yielding behavior, which can lead to catastrophic brittle failure without any preventive measures. Therefore, this study aims to enhance the ductility of concrete by introducing a specific quantity of basalt fiber, thereby reducing the hazards associated with the brittle failure of this composite structure. This experiment focuses on two main variables: the inclusion rate of basalt fiber and the type of longitudinal reinforcement and conducts four-point static bending tests on four BFRP bar BFRC (Basalt-Fiber-Reinforced Concrete) beams. Results showed that the inclusion of fibers resulted in a delayed initiation of vertical cracks and a reduction in the severity of beam failure, thereby enhancing structural safety and reliability. When the basalt fiber inclusion rate was 0.2%, the cracking load and ultimate load of the beam increased by 18.42% and 8.27%, respectively. Furthermore, compared to traditional RC beams, BFRP bar BFRC beams showed a 58.27% increase in ultimate load capacity. A cracking moment calculation model for BFRP beams is proposed and subsequently validated through the utilization of existing experimental data.

Implications of Particle Size in the Extraction of Cellulose from the Calamagrostis Intermedia Species

This research aimed to elucidate the implications of particle size on cellulose extraction from the species Calamagrostis intermedia, endemic to Ecuador. Within the versatile cellulose extraction and trade industry, using timber sources results in a relentless environmental impact, mainly when no resource rationing occurs during the washing or bleaching phases. The investigation incorporated a sample pretreatment encompassing a drying, grinding, and sieving study, followed by an alkaline extraction. The study found that particle size significantly affected the quantity of fiber and cellulose pulp extracted from samples previously dried at 65°C with particle sizes of 300 and 106 μm. Characterization tests revealed variations in the color and texture of the extracted cellulose, attributable to an ineffective delignification stage within the fiber bleaching process. Variations in molecular weight corresponding to 126.32 x 103 g/mol were identified among samples, and FTIR analysis presented a syringyl ring and lignin stretching. Optical microscopy exposed the absence of well-defined regions in the fibers and a readily observable crystalline network. In conclusion, particle size critically influences cellulose extraction from Calamagrostis intermedia, impacting the yield and properties of the resultant product, indicating that further optimization of the extraction and delignification process is required to enhance the quality of the extracted cellulose. Keywords: Calamagrostis intermedia; Particle Size; Cellulose Extraction

Chopped Areca Nut Fibers as Filler in Epoxy Matrix: Mechanical and Tribological Studies

In the current investigation, fibers extracted from the areca nut tree husk were either used unprocessed or processed with an alkaline treatment by being submerged in a 5 % sodium hydroxide solution. The average length of the areca fibers used in this work is 30 mm. Compression molding is used to create the composite out of an epoxy matrix with fibers added at 10, 15, 20 and 25 weight percent. The composites were tested for tensile strength, flexural modulus, Charpy impact, and shore D hardness, all of which showed the significant advantage acquired with quantity of fibers and fiber treatment. Pin on disc tribometer was used to conduct tribological tests on the treated fiber composites to analyse how the fiber-matrix bonding improved with an increase in fiber content. The primary shortcoming of the fibers is their relatively low elongation, which, even after treatment, hardly approaches 4 %. This indicates that the fibers are not uniform in length and prevents direct comparison to comparable composites containing a similar volume and length of natural fibers. The mechanical qualities of materials made with alkali treated chopped areca fibers where found to be enhanced when it was at 20 % volume fraction. A linear increment in values where observed in samples till 20 % volume fraction and a decrement with further increase in volume fraction. In the case of tribological evaluations, lesser values or wears were obtained at combination III for all the 3 loads, 10N, 15N and 20N. HIGHLIGHTS Three different amounts of fibers, namely 10, 15, 20 and 25 wt%, have been introduced in an epoxy matrix, fabricating the composite by compression molding. The composites were subjected to tensile, flexural, Charpy impact and Shore D hardness testing, which all demonstrated the considerable advantage obtained with quantity of fibers and fiber treatment, except in the case of hardness, where limited advantages were encountered. Also wear tests were carried out on treated fiber composites and surface morphology of the worn-out samples was studies, which demonstrated the improvement in fiber-matrix bonding obtained with the growing amounts of fibers. From the results on composites testing, it is evident that the areca nut husk fiber/epoxy polymer composites with an amount of short (30 mm length) random reinforcement introduced of 20 wt%, exhibits the highest peak mechanical properties among all the calculated properties. GRAPHICAL ABSTRACT

Influence of Fiber Orientation on the Shear Properties of Steel Fiber-Reinforced Reactive Powder Concrete Beams

Steel fiber-reinforced reactive powder concrete (SFRPC) has good mechanical properties and is thus useful for engineering applications. Generally, the fibers in SFRPC are randomly distributed. To study the effects of the amount, length, and orientation of steel fibers on the shear strength of SFRPC beams, nonreinforced aligned steel fiber-reinforced reactive powder concrete (ASFRPC) beams were prepared using a large-scale electromagnetic field orientation device. Shear tests of specimens with a shear span ratio of 1.5 were performed under two fiber contents (1.0% and 2.0%) and three fiber lengths (20, 30, and 40 mm). The full-field strain during the loading process was obtained via the digital image correlation method, and the effects of fiber quantity and orientation on the shear strength of the beams were analyzed. The ASFRPC beams exhibited higher ductility but lower shear capacity than the SFRPC beams under the same conditions. The shear capacity increased with the quantity of steel fibers. According to the test results, the calculation formulas of the shear-bearing capacities of ASFRPC and SFRPC beams were established.

Influence of nano-coated micro steel fibers on mechanical and self-healing properties of 3D printable concrete using graphene oxide and polyvinyl alcohol

High ductility cementitious composite is one of the proposed new generations of concrete for use in 3D concrete printing with a large dosage of microfibers. This large volume of fibers negatively affects printed layers’ fresh properties and durability. It also increases the porosity of concrete and is not cost-effective. Accordingly, through an experimental program, this article introduces a novel coating technique to reduce the required quantity of fibers for 3D concrete printing. Polyvinyl alcohol (PVA) is used in the present study to help in coating graphene oxide (GO) nanomaterials on the surface of micro steel fibers. Compressive, direct tensile, and bending tests are considered for the mechanical properties. The self-healing property of the proposed mixture is also checked by applying pre-loading on direct tension and bending samples and followingly putting for the healing period. The results show that the nano-coating method improves the compressive and direct tensile strength of cement mortar so that this technique can be used to reduce the volume percentage of steel fibers to achieve the same mechanical characteristics. Also, promising findings were obtained for the self-healing properties of cementitious composites containing nano-coated fibers.

The effects of Mediterranean diets with low or high glycemic index on plasma glucose and insulin profiles are different in adult men and women: Data from MEDGI-Carb randomized clinical trial

Recent evidence suggests that the ability to regulate glucose and insulin homeostasis is different in men and women. Against this background, it has been hypothesized that the impact on daily plasma glucose and insulin profiles of the glycemic index (GI) of the habitual diet may differ according to sex. The aim of this study is to evaluate whether 8-h average plasma glucose and insulin profiles during a low- or a high-GI diet in individuals at high risk of developing type 2 diabetes are influenced by sex. We conducted a randomized, controlled, parallel group dietary intervention, comparing high-versus low-GI diets in a multi-national (Italy, Sweden, and the United States) sample of 156 adults at risk for type 2 diabetes. For 12 weeks, 82 vs 74 participants consumed either a low-GI or high-GI Mediterranean diet, respectively. The two experimental diets contained the same quantity of available carbohydrate (270g/d) and fiber (35g/d) and the same foods and beverages, except for the major sources of starch that was specific to the low-GI and high-GI groups (pasta, brown rice, flatbread, all bran, and wheat bread plus rye and seeds, vs jasmine rice, potato, couscous, wholegrain bread, and rusks). At baseline and after the intervention plasma glucose and insulin profiles were evaluated for 8h in the two intervention groups - separately for men and women - with both breakfast and lunch resembling food choices of the assigned diet. One hundred fifty-six adults (82 women, 74 men) with at least two traits of the metabolic syndrome completed the intervention. In women, the high-GI induced significantly higher (23%, p<0.05) 8-h average plasma glucose concentrations in comparison to the low-GI dietalready on the first day of the intervention; the difference increased up to 37% (p<0.05) after 12 weeks of diet. Conversely, there were no significant differences between the two diets in men. These results were confirmed by the two-way analysis of variance showing a statistically significant interaction between the effects of sex and diet on the glucose profile after breakfast and lunch (F=7.887, p=0.006). The results of our intervention show that women, compared to men, are more sensitive to the metabolic effects of the dietary GI. This has a strong clinical and scientific relevance and, if confirmed in further studies, it might have important implications for dietary strategies for diabetes and cardiovascular disease prevention in the context of personalized nutrition. Clinicaltrials.gov n. NCT03410719.

Comprehensive characteristics of rectal morphology in chickens with different types of autonomous regulation

The influence of typological features of autonomous regulation on the dimensions, structure, and blood supply of the rectum in chickens has been studied. The experimental group consisted of clinically healthy adult chickens of the Isa-Brown breed, divided into two groups using electrocardiography and variation pulsometry methods: chickens with sympathetic-tonic regulation and chickens with sympathetic-normotonic regulation. In each group, the length and diameter of the rectum, the branching of its arterial vessels, and the microscopic structure of the intestinal wall were examined. The corresponding artery provides the blood supply to the rectum, the branching of which showed no significant differences between the poultry groups. The peculiarities of autonomous regulation significantly influence the morphological structure of the intestinal wall’s mucous and muscular membranes. The serous membrane does not respond to these features. Chickens with sympathetic-tonic regulation (ST chickens) are characterized by a greater thickness of all indicated membranes and, consequently, the entire intestinal wall. Chickens with sympathetic-normotonic regulation (ST-NT chickens) have a greater thickness only in the muscular plate of the mucous membrane and its longitudinal layer. Regarding the quantity of collagen and elastic fibers, ST chickens dominate the mucous membrane’s crypt area, while ST-NT chickens dominate the muscular membrane. However, the density of connective tissue fibers in the mucous membrane is much lower than in the muscular one. The quantity and distribution of plasma cells have similar patterns in both groups. Specific morphometric compensation between two functionally related indicators is also an important aspect. In this case, larger values of one indicator are combined with smaller values of another. For example, a smaller diameter of the rectum in ST chickens is associated with its greater length; a smaller number of goblet cells on one villus corresponds to a larger area of their secretory section; a larger area of the nerve node of the intramuscular nerve plexus is combined with a smaller number of these nodes per 1 cm² of the intestinal wall. Thus, the structure of the rectum in chickens, adapting to the corresponding type of autonomous regulation, maintains the balance at the level of individual membranes and the entire intestinal wall.

E72 Distribution of cells and extracellular matrix in the marginal synovium during the postnatal period

Abstract Introduction The marginal transitional zone of the joint is of fundamental importance in joint pathology. The normal marginal synovium takes part in articular cartilage repair (Adachi et al. 2012). The inflamed marginal synovium, in turn, promotes irreversible damage to the adjacent cartilage and bone (Hitchon &amp; El-Gabalawy, 2011). Early erosive damage in rheumatoid arthritis and osteophyte formation in osteoarthritis occurs primarily here (Allard et al. 1990). Objectives The morphology of the marginal synovium from birth till the 90th day was studied using the hip joints of Wistar rats. Methods The collection of joints was carried out on the first, seventh, 14th, 30th, 45th, 60th and 90th day (six rats in each group, 42 in total). Joints were fixed, decalcified and dehydrated. Histologic paraffine sections were stained with Mallory's trichrome and Hart's elastin staining, analyzed at the acetabular labrum by light microscopy (χ100), morphometrical and statistical (P &amp;lt; 0.05) methods with extrapolation to humans (Sengupta, 2013). The obtained data were presented as percentages. Results In the marginal synovium, cells and components of the extracellular matrix, which are typical for fibrous connective tissue, could be seen. The synovial lining cells are embedded in the modified basement membrane which includes collagen and elastic fibers. They form a three-dimensional reticulum in it and adjacent synovial subintima. Vessels of the microcirculatory bed are also widely represented in the marginal synovium. The overall quantity of collagen fibers increased gradually, exceeding on the 90th day (approximately corresponds to 18–19 human years) that of newborns by one and a half times (48.92 ± 3.39 vs 72.17 ± 7.77; P = 0.023). The number of arranged collagen fibers increased gradually, exceeding on the 90th day that of newborns almost twofold (37.25 ± 3.21 vs 60.08 ± 5.99; P = 0.008). The area of distribution of disarranged collagen fibers in newborns was almost four and a half times less than the overall quantity of collagen fibers (11.67 ± 1.03 vs 48.92 ± 3.39; P &amp;lt; 0.001) and did not change substantially throughout the experiment. The number of elastic fibers increased till the 30th day (0.63 ± 0.11 vs 18.3 ± 1.25; P &amp;lt; 0.001) and did not undergo significant changes later. In newborns, the area of distribution of ground substance was not considerably higher than the ratio of disarranged collagen fibers (10.42 ± 1.8 vs 11.67 ± 1.03; P = 0.562) and did not undergo substantial changes later. The distribution density of vessels increased till the 30th-45th day (4.5 ± 0.67 vs 7.5 ± 0.82 and 7.7 ± 0.54; P &amp;lt; 0.001; approximately corresponds to the 9th and 14th human years respectively), followed by a gradual decrease from the 60th day (7.05 ± 0.72; roughly corresponds to the 16th human years). The maximum number of cells was in newborns. Subsequently, it gradually decreased and was almost three times less on the 90th day than that of newborns (38.01 ± 3.06 vs 12.58 ± 1.53; P &amp;lt; 0.001). Conclusion The morphogenesis of the marginal synovium during the postnatal period is accompanied by a gradual decrease in the number of cells, an increase in the area occupied by elastic and arranged collagen fibers with a relatively constant distribution density of disarranged collagen fibers and ground substance together with an undulatory pattern in the distribution of vessels. These peculiarities emphasize the morphological uniqueness of the marginal transitional zone, which forms the innate nonspecific barrier between the joint capsule and the articular cartilage, and thereby provides the necessary anatomical and physiological integrity of the joint as a whole organ. Knowledge about the patterns of morphogenesis of the marginal synovium will help in the future to analyze the modeled pathological or boundary states in it. Ethics The study was approved by the ethics committee of the Zaporizhzhia State Medical University.

E71 Distribution of cells and extracellular matrix in the normal marginal synovium of the hip joint capsule during the postnatal period

Abstract Introduction The marginal transitional zone is of fundamental importance in joint pathology. It includes the marginal cartilage and marginal synovium. The normal marginal synovium takes part in articular cartilage repair (Adachi et al. 2012). The inflamed marginal synovium, in turn, promotes irreversible damage to the adjacent cartilage and bone (Hitchon &amp; El-Gabalawy, 2011). Objectives The morphology of the normal marginal synovium from birth till the 90th day was studied using the hip joints of Wistar rats. Methods The collection of joints was carried out on the first, seventh, 14th, 30th, 45th, 60th and 90th day (six rats in each group, 42 in total). Joints were fixed, decalcified and dehydrated. Histologic paraffine sections were stained with Mallory's trichrome and Hart's elastin staining, analyzed at the acetabular labrum by light microscopy (χ100), morphometrical and statistical (P &amp;lt; 0.05) methods with extrapolation to humans (Sengupta, 2013). The obtained data were presented as percentages. Results In the marginal synovium, cells and components of the extracellular matrix, which are typical for fibrous connective tissue, could be distinguished. The synovial lining cells are embedded in the modified basement membrane which is a meshwork of collagen and elastic fibers. They form a three-dimensional reticulum in it and adjacent synovial subintima. Vessels of the microcirculatory bed are also widely represented in the marginal synovium. The overall quantity of collagen fibers increased gradually, exceeding on the 90th day (∼18–19 human years) that of newborns by one and a half times (48.92 ± 3.39 vs 72.17 ± 7.77; P = 0.023). The number of arranged collagen fibers increased gradually, exceeding on the 90th day that of newborns almost twofold (37.25 ± 3.21 vs 60.08 ± 5.99; P = 0.008). The area of distribution of disarranged collagen fibers in newborns was almost four and a half times less than the overall quantity of collagen fibers (11.67 ± 1.03 vs 48.92 ± 3.39; P &amp;lt; 0.001) and did not change substantially throughout the experiment. The number of elastic fibers increased till the 30th day (0.63 ± 0.11 vs 18.3 ± 1.25; P &amp;lt; 0.001) and did not undergo significant changes later. In newborns, the area of distribution of ground substance was not considerably higher than the ratio of disarranged collagen fibers (10.42 ± 1.8 vs 11.67 ± 1.03; P = 0.562) and did not undergo substantial changes later. The distribution density of vessels increased till the 30th-45th day (4.5 ± 0.67 vs 7.5 ± 0.82 and 7.7 ± 0.54; P &amp;lt; 0.001; ∼9-14th human years), followed by a gradual decrease from the 60th day (7.05 ± 0.72; ∼16 human years). The maximum number of cells was in newborns. Subsequently, it gradually decreased and was almost three times less on the 90th day than that of newborns (38.01 ± 3.06 vs 12.58 ± 1.53; P &amp;lt; 0.001). Conclusion The morphogenesis of the marginal synovium during the postnatal period is accompanied by a gradual decrease in the number of cells, an increase in the area occupied by elastic and arranged collagen fibers with a relatively constant distribution density of disarranged collagen fibers and ground substance together with an undulatory pattern in the distribution of vessels. These peculiarities emphasize the morphological uniqueness of the marginal transitional zone, which forms the innate nonspecific barrier between the joint capsule and the articular cartilage, and thereby provides the necessary anatomical and physiological integrity of the joint as a whole organ. Knowledge about the patterns of morphogenesis of the normal marginal synovium will help to understand joint pathology. Ethics The study was approved by the ethics committee of the Zaporizhzhia State Medical University.

Effect of fresh concrete compression technique on pre- and post-heating compressive behavior of steel fiber-reinforced concrete: Experiments and RSM-based optimization

Despite the many advantages of fresh concrete compression technique for improving the performance of hardened concrete under compression, no study has so far addressed various behavioral aspects of this type of concrete in different conditions and scenarios such as fire, which may occur during the service life for a structure made up of this concrete type. Here, the compressive performance of compressed concrete with steel fibers was addressed before and after experiencing elevated temperatures considering key variables including the volume quantity of steel fibers, diameter-to-thickness ratio of steel tube (mold), capacity of the reference concrete, and exposure temperature. To reach this goal, 60 concrete cylinders were tested under axial compression, and the results including the compressive strength, elastic modulus, strain at peak stress, toughness, axial stress–strain graph, and weight loss were assessed together with the results of a visual inspection, failure mode, and microstructure of concrete. The results demonstrated that although the fresh concrete compression technique notably improved the mechanical features of concrete, especially the compressive strength by up to 100 % at the ambient temperature, adding steel fibers, lowering the water-to-cement ratio (w/c), and using a tube with a thinner wall as the mold lowered the efficiency of this technique in improving the compressive performance. In addition, the amount of increase in concrete strength due to compressing the fresh concrete had a linear relationship with the amount of excess water removed from it. The positive impact of the fresh concrete compression technique on the concrete strength at high temperatures was significant. In this regard, the compressive strength reduction of the compressed concrete was 20 % lower than that of the uncompressed concrete. However, the fresh concrete compression technique was not very effective against the deterioration of the modulus of elasticity caused by high temperatures. Ultimately, the response surface method (RSM) was used to reach an optimum solution for the design variables that could maximize the compressive capacity of fibrous compressed concrete per different target temperatures.

Efek hipoglikemik cookies campuran tepung suweg dengan tepung garut

From 7.0% in 2007, to 6.9% in 2013, to 8.5% in 2018, and even to 21.3 million in 2030, the frequency of people with diabetes mellitus increases by 5.7% annually. In order to create mixed cookies with a low glycemic index that panelists prefer, this research mixes suweg flour and arrowroot flour. In this procedure, prepared and unprepared treatments are both used. Chemical properties (moisture content, protein content, total sugar content, and starch content), resistant starch (RS) flour, the amount of fiber in mixed cookies, the level of cookie choice among panelists, and volunteer blood glucose levels were all examined. to calculate the glycemic index of the biscuits. Based on a study of blood glucose levels in connection to the glycemic index, the sample cookies were rated as having a low GI (55) and had a glycemic index between 54.68 and 31.40. These cookies are a suitable diabetic diet food because they have a low glycemic index (55), resistant starch, and an adequate quantity of dietary fiber

Edible insect powder for enrichment of bakery products– A review of nutritional, physical characteristics and acceptability of bakery products to consumers

Bakery products including bread are traditionally good sources of carbohydrate but not nutrient-dense. Enrichment with edible insect powder could improve the quantity and quality of protein, fat and dietary fibers to bakery products. A systematic search carried out on the databases PubMed, Scopus and ScienceDirect identified 44 articles that would answer the question: what is known about the effect of enrichment of bakery products with various edible insect powders on the physical, nutritional composition and sensory properties of bakery products. The search strategy and terms applied were (Insect* OR Edible insect* OR Entomophagy*) AND (Bakery product* OR Bake* product*). Bread was the most common bakery product that was insect-enriched, yet muffins/biscuits/crackers/cookies were also reported. Commonly reported edible insects and their larvae were crickets, mealworms, palm weevil larvae, grasshoppers and African emperor moth caterpillars. Before milling into powders, insects and larvae were pre-treated by freeze-drying, oven/tray and microwave drying, blanching and roasting but was not reported for all studies. Generally, bread with up to 10% and muffins/biscuits/crackers/cookies with 5% of insect powder were acceptable to consumers. New areas of research should focus on comparing the water activity, shelf-life and cost of pre-treatment processing methods alongside the nutritional properties of edible insect powders.

Development of a cotton fiber quality simulation module and its incorporation into cotton crop growth and development model: GOSSYM

GOSSYM is a mechanistic, process-level cotton crop simulation model. It can simulate the growth and development of cotton under different environmental and management conditions and provide information on crop growth and development, various stresses, and yield. The current model version does not have the capability of simulating cotton fiber quality. Cotton fiber quality is as significant as fiber quantity. In this study, a cotton fiber quality simulation module is developed and integrated into GOSSYM. The functional relationships between the fiber quality and the major factors influencing fiber quality (temperature, water, and nutrient status) are established based on the temperature, water, and nutrient-controlled sunlit soil plant atmospheric research (SPAR) chamber experiments. In the developed model, the potential fiber quality in terms of four major fiber quality indices (fiber length, fiber strength, micronaire, and uniformity) is estimated based on the temperature function, and actual fiber quality indices are determined by reducing potential quality as a function of water and nutrient status in the crop. The newly developed model's fiber quality modeling capabilities are demonstrated using illustrative examples from a case study. Illustrated examples analyze the effect of different temperatures, nitrogen fertilizer application rates, irrigation, planting date, and atmospheric carbon dioxide concentrations on fiber quality indices. Simulation results are discussed by correlating them with underlying processes (growth and development, water, and nitrogen status), literature data, and functional relationships incorporated into the fiber quality module in GOSSYM. The model has demonstrated a reasonable simulation of fiber quality. The developed model can be a valuable tool for accurate cotton fiber quality simulations, lint yield production, fiber quality optimization, and making policy decisions under varying environmental and management conditions.

Pengaruh pH Asam Terhadap Kekuatan Mekanik Fiber E-Glass: Systematic Review

Background: Dental fibers were first introduced by Smith (1960) which are used in various fields of dentistry. Dental fibers are classified into two categories, natural and synthetic. Glass fiber that is often used in dentistry is E-glass fiber because of its resistance to chemical reactions, has good aesthetic properties, has almost the same mechanical properties as dentin and is biocompatible. In the oral cavity, acidic conditions occur due to consumption of food and beverages containing acid. Acidic conditions in the oral cavity can affect the mechanical properties of the composite resin. Factors that affect the mechanical properties of fiber reinforced composite are the properties of the composite material and fiber used, fiber quantity, fiber position, fiber direction, fiber adhesion to the composite matrix. To determine and study the effect of acidic pH on the mechanical strength of e-glass fibers. Method: This type of research is a literature review using a systematic review approach.Result: The decrease in compressive strength and resistance was influenced by structural disturbances and loss of most components due to acid exposure. The decrease in the tensile strength of the glass fiber increases the time associated with immersion of the fiber surface which can interfere with the continuity of the e-glass network. Acidic drinks, carbonated drinks, and alcohol can produce erosion on the surface of the composite resin. The longer the immersion, the more solution particles that enter the resin microporosity space and reduce the strength of the composite resin.Conclusion: The mechanical strength of e-glass fiber will decrease with the length of exposure to acid. Types of acids that can affect the decline in mechanical strength are strong acids such as hydrochloric acid (HCl), sulfuric acid (H2SO4), nitric acid (HNO3), and phosphoric acid (H3PO4).

Experimental analysis of localized hybridization by means of adding woven polyester strip

Abstract Natural fiber-reinforced composites must be hybridized with synthetic fibers to enhance their mechanical strength. They are appropriate for structural applications after hybridizing with more than 40 % of synthetic fibers. The hybrid composite becomes a partly biodegradable material due to the blend of natural fibers. The localized hybridization approach has been used to minimize the quantity of synthetic fiber used in hybridization. The region around the drilled hole of a composite has been identified as stress concentrated region. In that stress-concentrated region, a polyester strip of different widths is deployed to reinforce it to reduce the delamination occurrence. The present work deals with Jute Fiber reinforced unsaturated polyester resin with local hybridization of woven polyester made up of Perma Core T-18 polyester fiber strands. The interfacial shear and tensile strengths are evaluated for the proposed composite. The results revealed that the yield strength of the proposed composite increased from 18.32 MPa to 29.62 MPa due to local hybridization. The increment of 69.24 % in yield strength is more significant for structural applications.

Ultralight and efficient microwave absorption of SiC/SiO2 ceramic aerogels derived from biomass

Rational multicomponent regulation and microstructure design have proven to be effective strategies for achieving high performance electromagnetic wave (EMW) absorbers. Herein, the ultralight hierarchically porous SiC/SiO2 aerogels (HPSA) were successfully synthesized by an ingenious one-step method to achieve carbonization and carbothermal reduction. The composition of the HPSA and the quantity of SiC/SiO2 fibers grown by in situ reaction can be controlled by adjusting the amount of silicon source introduced. The results indicate that the composition of HPSA and the quantity of fibers have a significant effect on the EMW absorption properties. When the introduced silicon source concentration was 0.7 mol/L, the HPSA exhibited excellent EMW absorption performance, with a minimum reflection loss (RLmin) of -55.01 dB at 6.00 GHz and a maximum effective absorption bandwidth (EABmax) of 6.16 GHz. The highly interconnected porous SiC/SiO2 skeleton structure significantly contributes to the multiple reflection-absorption effect of EMW and provides available pathways for electron conduction losses. The in situ reaction generates SiC/SiO2 fibers with a large number of stacking faults and heterojunctions, which further promote the dissipation of EMW. In addition, the maximum radar cross section of HPSA under far-field conditions is reduced to 20.21 dB m2 compared to the PEC conductive layer, which implies a much lower probability of detection by radar. In brief, this work provides a reference for the use of highly efficient EMW absorbers and electromagnetic stealth materials.

Towards a bioeconomy: How sugarcane fibre price structure stimulates farm-level decisions and sugarcane biorefinery feedstock supply

Biorefineries are fundamental to support the development of bio-based economies. Further development of sugarcane biorefineries in South Africa is likely to involve the use of sugarcane fibre as a feedstock. The current cane payment system incentivises growers to supply sugarcane with high sucrose yield per hectare; consequently, they are unlikely to produce energy cane cultivars that have high yields of fibre per hectare and lower sucrose yields. Because economies of scale are central to the economic viability of biorefinery investments, sugarcane biorefinery businesses may be willing to use price mechanisms to increase their supply of sugarcane fibre. This research is a case study for the Eston milling area in KwaZulu-Natal, South Africa. It demonstrates the potential impact of changes in the price paid for fibre on the farm-level decisions pertaining to the area planted with cane, the optimal choice of cultivars, and its implication for the quantities of sugar and fibre supplied. Optimisation mathematical models representing a “typical sugarcane farm” were constructed for three agricultural areas using a representative farm level linear programming approach. Each farm model provides a baseline scenario with supply from conventional cane varieties and an alternative scenario including a hypothetical cultivar, energy cane. It was found that the introduction of a composite fibre price results in expansion of the area under cane, modifies enterprise and cultivar selection and increases biomass availability, hence revitalising the sector. This informs policy makers and stakeholders to carefully consider the impact of introducing certain strategies and policies on biorefinery biomass suppliers.

Review on the influencing factors towards improving properties of composite insulation panel made of natural waste fibers for building application

The low performance of insulation panels has received great attention from many researchers and engineers to improve their properties as it has become a limiting factor that minimize their usage specifically as insulation building material. Recently, there has been an increase in interest in the development of composite insulation panels made from natural waste fiber. Due to the abundance of natural waste fiber generated by the agricultural industry, it has made them suitable to be utilized as raw material for composite insulation panels. Having improper waste disposal management might result in these massive quantities of valuable natural waste fiber having a detrimental effect on our ecosystem and contributing to various environmental pollution. A composite insulation panel made from natural waste fibers has unique and versatile features in terms of thermal, physical, and mechanical properties. Seeing such potential, this paper presents a review on the influencing factors towards improving comprehensive properties of composite insulation panels. Factors that influence the properties of the panel, such as the physico-chemical properties of fiber, fiber geometrical structure, and fiber treatment were discussed. Previous and recent research efforts related to factors influencing the properties of composite insulation panels were also compiled. Last but not least, the suitable criteria, limiting factors, and condition of the fiber used in composite insulation panels were also all highlighted.

Valorization and characterization of corn by-product polyphenols through green extraction technologies.

The amount of food waste throughout the world has become quite alarming and is contributing to lower food resources. The study aimed to extract and characterize the polyphenols from corn silks at immature and mature stages through conventional and green extraction techniques. Purposely, corn silks, which are some of the by-products of corn, (Zea mays L.) were collected and subjected to proximate analysis including moisture, ash, protein, fiber, and minerals. Secondly, the antioxidants from both immature and mature corn silks were extracted by techniques involving supercritical and ultrasound extraction alongside conventional extraction. The results displayed a promising quantity of protein and fiber along with calcium, magnesium, sodium potassium, and copper. Among the extraction techniques, supercritical extraction at 3,000 Pa acquired the highest total phenolic contents (TPC), total flavonoids (TF), 2, 2-diphenylpicrylhydrazyl (DPPH), ferric-reducing antioxidant power (FRAP) activities as 128.08 ± 3.74 mg GAE/100 g, 86.73 ± 2.75 mg CE/100 g, 106.73 ± 5.10%, and 73.52 ± 2.33 μM Fe + 2/g, respectively, followed by the ultrasound and conventional extraction techniques. Between the immature and mature corn silks, the highest antioxidant activity was displayed by immature corn silks.