Initial Fiber Research Articles

MiR96- and miR182-driven regulation of cytoskeleton results in inhibition of glioblastoma motility.

Glioblastoma multiforme (GBM) is one of the most common forms of brain tumor. As an excessively invasive tumor type, GBM cannot be fully cured due to its invasion ability into healthy brain tissues. Therefore, molecular mechanisms behind GBM migration and invasion need to be deeply investigated for the development of effective GBM treatments. Cellular motility and invasion are strictly associated with the cytoskeleton, especially with actins and tubulins. Palladin, an actin-binding protein, tightly bundles actins during initial invadopodia and contraction fiber formations, which are essential for cellular motility. Spastin, a microtubule-binding protein, cuts microtubules into small pieces and acts on invadopodia elongation and cellular trafficking of invadopodia-associated proteins. Regulation of proteins such as spastin and palladin involved in dynamic reorganization of the cytoskeleton, are rapidly carried out by microRNAs at the posttranscriptional level. Therefore, determining possible regulatory miRNAs of spastin and palladin is critical to elucidate GBM motility. miR96 and miR182 down-regulate SPAST and PALLD at both transcript and protein levels. Over-expression of miR96 and miR182 resulted in inhibition of the motility. However, over-expression of spastin and palladin induced the motility. Spastin and palladin rescue of miR96- or miR182-transfected U251 MG cells resulted in diminished effects of the miRNAs and rescued the motility. Our results demonstrate that miR96 and miR182 over-expressions inhibit GBM motility by regulating cytoskeleton through spastin and palladin. These findings suggest that miR96 and miR182 should be investigated in more detail for their potential use in GBM therapy.

Modification of the Tensile Performance of an Extruded ZK60 Magnesium Alloy with the Addition of Rare Earth Elements.

The influence of rare earth (RE) elements on the microstructure and mechanical performance of an extruded ZK60 Mg alloy was studied. Two types of RE elements were added to a ZK60 material and then extruded at a ratio of 18:1. The first new alloy contained 2 wt% Y while the second one was produced using 2 wt% Ce-rich mischmetal. The microstructure, the texture, and the dislocation density in a base ZK60 alloy and two materials with RE additives were studied by scanning electron microscopy, electron backscattered diffraction, and X-ray line profile analysis, respectively. It was found that the addition of RE elements caused a finer grain size, the formation of new precipitates, and changes in the initial fiber texture. As a consequence, Y and Ce-rich RE elements increased the strength and reduced the ductility. The addition of these two types of RE elements to the ZK60 alloy decreased the work hardening capacity and the hardening exponent mainly due to grain refinement.

Measurement of microfibril angle in plant fibres: Comparison between X-ray diffraction, second harmonic generation and transmission ellipsometry microscopies

The orientation of cellulose microfibrils within plant fibres is one of the main factors influencing their mechanical properties. As plant fibres are more and more used as reinforcement for agro-composites, their mechanical properties have a strong influence on the final composite properties. It is, therefore, of interest to obtain reliable information about the microfibril angle (MFA) to better support the choice of fibres depending on the product requirements. In the present study, the reliability and specificities of three non-destructive methods that allow analysis on the same fibre glued on a holder; X-ray diffraction (XRD), second harmonic generation (SHG) and transmission ellipsometry (TE) microscopy; are investigated. Three types of plant fibres, with both low (nettle), and high (cotton, sisal) MFA values, are compared and their geometry and biochemical composition are characterised. The results obtained on the same fibre confirm that MFA analysis remains tedious and that despite their limitations, the methods are complementary depending on the information requested. Indeed, SHG is recommended for direct, qualitative and plane-selective mapping of heterogeneities in macrofibril orientations at various depths. However, reliable quantitative results with SHG depend on the initial image quality and could benefit from further image processing refinement. On the contrary, XRD and TE measure MFAs over the entire fibre thickness and provide variations along the fibres if a sufficient optical/spatial resolution is reached. Regarding the characterization of intrinsic defects in plant fibres, both SHG and TE suffer from uncertainties induced by the disorganization of the microfibril network and the lack of symmetry between the front and back fibre walls. Finally, all techniques prove to be dependant on the initial fibre alignment and geometry (i.e. twisting, double fibre configuration or form factor) which vary along the fibre length and should be carefully taken into account.

A Review on Experimental Investigations and Geotechnical Characteristic of Peat Soil Stabilization

Peat soil is an organic soil which consist more of that 70% of organic matters and can be recognize from their color and texture. Peat bogs are an important ecosystem that contributes significantly to global climate stability. Peat from Malaysia is tropical peat. This peat has distinct features that distinguish it from other types of peat. This soil is normally dark reddish-brown to black and made up of partially decomposed leaves, branches, twigs, and tree trunks with a low mineral content in its natural state. Various of experimental and study has been conducted to improve and stabilize of peat soil due to compressibility and geotechnical characteristics of peat. Peat also is an inadequate soil for sustaining foundations in its natural condition due to its high moisture content (>100%), high compressibility (0.9-1.5), and poor shear strength (5-20 kPa). Thus, injection method of Eco-Processed Pozzolan (EPP) will be used to increase the stabilization of peat soil. The study of index properties such as von Post scale, natural moisture content, liquid limit, bulk unit weight, specific gravity, initial void ratio, pH value, linear shrinkage, plastic limit, fiber content, ash content and organic content and composition compressibility of peat soil will be conducted; present of compressibility of peat soil with Eco-Processed Pozzolan (EPP). A comprehensive laboratory work will be carried out to study the compressive parameters of hemic peat stabilized with various quantities of Eco-Processed Pozzolan (EPP) which they were subjected to Rowe Cell Consolidation test between disturbed and undisturbed samples. From this research, the relationship between peat soil and Eco-Processed Pozzolan (EPP) will be determined whether usage of EPP may can increase a stabilization of peat soil and be a ‘binder’ element in peat soil.

Experimental Study on the Mechanical Behaviors of Aeolian Sand Treated by Microbially Induced Calcite Precipitation (MICP) and Basalt Fiber Reinforcement (BFR).

Aeolian sand flow is a major cause of land desertification, and it is prone to developing into a dust storm coupled with strong wind and thermal instability. The microbially induced calcite precipitation (MICP) technique can significantly improve the strength and integrity of sandy soils, whereas it easily leads to brittle destruction. To effectively inhibit land desertification, a method coupled with MICP and basalt fiberreinforcement (BFR) was put forward to enhance the strength and toughness of aeolian sand. Based on a permeability test and an unconfined compressive strength (UCS) test, the effects of initial dry density (ρd), fiber length (FL), and fiber content (FC) on the characteristics of permeability, strength, and CaCO3 production were analyzed, and the consolidation mechanism of the MICP-BFR method was explored. The experiments indicated that the permeability coefficient of aeolian sand increased first, then decreased, and subsequently increased with the increase in FC, whereas it exhibited a tendency to decrease first and then increase with the increase in FL. The UCS increased with the increase in the initial dry density, while it increased first and then decreased with the increase in FL and FC. Furthermore, the UCS increased linearly with the increase in CaCO3 generation, and the maximum correlation coefficient reached 0.852. The CaCO3 crystals played the roles of providing bonding, filling, and anchoring effects, and the spatial mesh structure formed by the fibers acted as a bridge effect to enhance the strength and brittle damage of aeolian sand. The findings could supply a guideline for sand solidification in desert areas.

Organomorphic Silicon Carbide Reinforcing Preform Formation Mechanism

Development of the organomorphic ceramic-matrix composites (CMCs), where the reinforcing preform is built using polymer fibers subject essentially to hot pressing, was motivated by a desire to obtain much higher structural uniformity as well as to reduce the number of the process steps involved in the production of CMCs. This paper addresses the peculiarities of the organomorphic silicon carbide preform formation process. Using X-ray phase analysis, tomography, mass and IR spectroscopy, and thermomechanical and X-ray microanalysis, both the properties of the initial fibers of polycarbosilane (PCS)—the silicon carbide fiber precursor—and their transformation in the preform while heated to 1250 °C under constant pressing at 10–100 kPa were studied. Analysis of the data obtained showed the organomorphic SiC preform relative density at a level of 0.3–0.4 to be ensured by self-bonding of the silicon carbide preform, resulting from the fact that during the low-temperature part of pyrolysis, easily polymerizing substances are released leaving a high coke residue, thus cementing the preform. Another possible factor of SiC framework self-bonding is the destruction of the polymer fibers during pyrolysis of various PCS preforms differing in their methylsilane composition (for example, dimethylsilane), where deposition of silicon carbide on the contacting fibers starts as early as at 450–500 °C.

Antitumor activity of triazine mimic antibiotics for DNA-binding implications (impressive activity in vitro against a variety of tumor types in the NCI-60 screen): NSC 710607 to fight HCT-116 human colon carcinoma cell lines in vivo using the hollow fiber assay and xenograft mouse models.

Successful clinical applications of DNA-directed selective cytotoxic agents disrupt the vital replication/transcription processes and ultimately lead to cancer cell death. This study aimed to examine the growth screen of two lead triazine compounds in a number of cell lines and xenografts and to develop anticancer agents with noncovalent binding affinity bringing fewer side effects. The NCI initial hollow fiber test was performed using an established procedure. The cytostatic and cytocidal capacities of the test compounds were assessed by evaluating cytotoxicity by simply performing a standard cellular viability assay. The nude mouse human tumor xenograft system was used as an in vivo model. More sensitive drug with sub-micromolar activity met the interdisciplinary criteria for testing and was referred to evaluations in subcutaneous colorectal carcinoma HCT-116 human tumor xenografted into nude mice. Principal findings of the study: total cytostasis, almost nontoxic schedules, specific working hypotheses, strong rationale for the potential use, and important general implications (relevance to human biology). NSC 710607 displayed in vivo better than Cisplatin and 5-fluorouracil abilities to significantly decrease tumor growth. Cell proliferation can be reduced or stopped in vivo in view of the xenograft results. The mimic molecule behaves as DNA-binding antitumor antibiotics with great potential as general anticancer agents and deserves further trials. NSC 710607 represents the result of a design strategy with outstanding potential. This study also identifies the prognostic significance and is likely to translate to other species or systems.

Preparation of biomorphic porous La0.8Ce0.2Fe0.3Co0.7O3 perovskite‐type catalysts for automobile exhaust purification

AbstractBiomorphic porous La0.8Ce0.2Fe0.3Co0.7O3 perovskite‐type catalysts are synthesized through a facile bio‐templating method taking wood fiber as template for achieving the four‐way purification of PM, NOx, CO, and HC emitted by automobile exhausts. The catalyst samples were characterized by X‐ray diffractometer, Fourier‐transform infrared spectroscopy, scanning electron microscope and Brunauer–Emmett–Teller analysis. The results showed that catalyst sample calcined at 700°C obtained high purity, high surface area (4.01 m2/g), wide pore size distribution and retained the initial wood fiber structure, which was suitable for purifying automobile exhausts. In addition, the performances for four‐way purification under the simulated exhaust were analyzed by simulation test bench. The highest purification efficiency of PM, NOx, HC, and CO can reach 92%, 92%, 98%, and 76%, separately. Moreover, four‐way purification mechanism was deduced according to the theoretical research of Mars‐van krevelen on the redox reaction mechanism and experimental result.

Performance-based design and manufacturing of filament wound Type-4 cylinders for compressed gas storage

Filament wound type-4 cylinders are widely used in automotive applications for the storage of compressed gases. The performance of the storage cylinders critically depends on their manufacturing parameters. These paramters include the material properties of the reinforcement and matrix material, the number of fiber spools used during winding, the fiber bandwidth, the initial fiber band volume fraction, the mandrel geometry, the winding sequence, and the composite layer thickness distribution. An interim link between the critical parameters, the composite thickness distribution and the amount of fiber and resin consumed for winding a type-4 composite vessel has been established using an analytical model in this study. The developed model is validated by manufacturing the cylinder and comparing the theoretical and experimental results. The composite layer distribution across the entire geometry of the vessel is included into an FEA model to predict the burst pressure and weight of the obtained type-4 cylinder with greater precision. The given study can be used to design low-cost high burst performing type-4 composite structures with significant weight reduction.

Fibrin fiber deformation mechanisms: insights from phenomenological modeling to molecular details.

The deformation mechanism of fibrin fibers has been a long-standing challenge to uncover due to the fiber's complex structure and mechanical behaviors. In this paper, a phenomenological, bilinear, force-strain model is derived to accurately reproduce the fibrin fiber force-strain curve, and then, the phenomenological model is converted to a mechanistic model using empirical relationships developed from particle simulation data. The mechanistic model assumes that the initial linear fibrin fiber force-strain response is due to entropic extension of polypeptide chains, and the final linear response is due to enthalpic extension of protofibrils. This model is the first fibrin fiber tensile force-strain equation to simultaneously (1) reproduce the bilinear force-strain curve of fibrin fibers in tension; (2) explicitly include the number of protofibrils through the fibrin fiber cross section, persistence length of [Formula: see text]-regions, and stiffness of fibrin protofibrils; and (3) make demonstrably reasonable/accurate predictions of fibrin fiber mechanics when tempered against experimental results. The model predicted that the count of protofibrils through the cross section for the analyzed fibrin fibers is between 207 and 421, the persistence length of [Formula: see text]-regions is [Formula: see text], and the stiffness of protofibrils in a deforming fiber is [Formula: see text]. The predicted [Formula: see text]-region persistence length is within the range typical of amino acid residue lengths [Formula: see text] and the predicted protofibril stiffness is shown to correspond to half-staggered protofibrils of unfolded fibrin monomers. Our analysis supports the proposition that entropic extension of [Formula: see text]-regions could be responsible for fibrin fiber's initial force-strain stiffness and suggests a structural change in fibrin protofibrils during fibrin fiber deformation. The results from the model are compared to those from five candidate deformation mechanisms reported in the literature. Our work provides (1) strong quantitative support to a deformation mechanism that was previously supported by anecdote and qualitative argument, and (2) a model for rigorously analyzing fibrin fiber force-strain data and simulating fibrin fibers in tension.

Waste wool/polycaprolactone filament towards sustainable use in 3D printing

3D printing is a popular technique for numerous applications from households to industrial purposes. Commercially available filaments for 3D printing are not eco-friendly, yet energy intensive due to their high extrusion temperature (200–220°C). Polycaprolactone (PCL) is increasingly proposed for 3D printing due to its biocompatibility and lower extrusion temperature, which is more sustainable, though is slow in actual biodegradation. Although PCL-blends are often proposed to promote the degradation, strong hydrophobicity of PCL leads to poor compatibility. This study, for the first time proposes waste wool/PCL filaments for 3D printing using a clean production method, to utilise the hydrophobicity of wool as an advantage with PCL interfaces. Micro-sized wool powders from waste wool fabrics of two fibre fineness (16 and 24 μm) were prepared with minimal in-process waste and then extruded completely with PCL using different ratios (10/90, 20/80 and 25/75 combination of wool/PCL) to produce the composite filaments. A uniform mixing in the composite structure was observed particularly with 10% of wool loading, also the biodegradation rate significantly increased, i.e., from 0.8% to 6.8–10.5% in 3 months. Filaments prepared with 10% and 20% wool showed an increased yield strength, while a finer diameter of initial fibre was found more influential in changing tensile, thermal, and crystalline properties. The reduction in crystallinity was found correlated to the increasing amount of wool, though interlayer spacing of PCL was unaltered and overall thermal stability improved. The filaments were found printable through a 0.4 mm nozzle using a desktop 3D printer at 80 mm/min speed. The findings suggested the possible use of the produced filaments for fabrication of varied products, such as containers for holding or packing, toys, and other common household objects or industrial tools.

DEVELOPMENT OF THE PRINCIPLES OF BASALT FIBER MODIFICATION WITH THE PURPOSE OF INCREASING THE EFFICIENCY OF ITS APPLICATION IN TRANSPORT CONSTRUCTION

The article examines the experimental and theoretical justification of the use of basalt fiber, as a promising material, with the help of which it is possible to obtain a new class of building materials. As a result, it was established that an increase in temperature contributes to an increase in alkali resistance of the fiber. The mass loss during aging in an alkaline solution after 28 days is about 5%, while the initial fiber loses more than 30% of the fiber mass during this time. A further increase in the temperature of isothermal aging is not effective due to a decrease in alkali resistance of the fibers and economic impracticability. To explain the processes occurring in the structure of the fiber during its heat treatment, X-ray images and spectra of the original and heat-treated fiber were obtained. In the process of heat treatment from 300 to 500 0С, the processes of defect healing, changes in the chemical composition and surface structure of the fibers occur as a result of Fe+2 → Fe+3 oxidation and the formation of iron oxide tetrahedra [FeO4]Na with the attraction of alkaline cations to the surface of the fibers. The expediency of thermal treatment of basalt fiber at a temperature of 500 0C is substantiated, which leads to compaction of the fiber structure and contributes to increasing its alkali resistance, which is confirmed by the morphostructural features of the surface of heat-treated basalt fiber aged in cement mortar.

Normalization of impact energy by different layer arrangement for kenaf-glass hybrid composite laminates

An increase of interest to mesh up two or more fillers in the matrix is increasing. The main objective is to improve the performance of a single filler reinforced matrix with other fillers that have higher strength as compared to the initial fibre. Thus, in this study, kenaf fibre plies have been hybridised with woven glass fibre mats in order to improve its post impact tensile properties. These hybrid composite materials were fabricated by hand lay-up and cold press techniques. Two different systems were fabricated based on specific fibre layer arrangements of kenaf-glass fibre reinforced polymer (KGFRP) hybrid composites. The results revealed that the woven glass fibre at the outer layer arrangement produced better strength than having kenaf fibre at the outer layer as shown in Normalized Stress curve. This arrangement helps to sustain more impact, as a consequence, exhibits more resistance to crack growth.

Open Hole Tension of 3D Printed Aligned Discontinuous Composites

This paper explores the use of Discontinuous Aligned Fibre Filament (DcAFF), a novel discontinuous fibre reinforced thermoplastic filament for 3D printing, to produce structural complex parts. Compared to conventional composite manufacturing, 3D printing has great potential in steering fibres around small structural features. In this current study, the initial thin carbon fibre (CF)-poly(L-lactic acid) (PLA) tape, produced with the High Performance Discontinuous Fibre (HiPerDiF) technology, is now reshaped into a circular cross-section filament, the DcAFF, using a bespoke machine designed to be scalable to high production rates rather than using a labour-intensive manual moulding method as in previous work. The filaments are then fed to a general-purpose 3D printer. Tensile and open-hole tensile tests were considered in this paper for mechanical and processability of DcAFF. The 3D printed specimens fabricated with the DcAFF show superior tensile properties compared to other PLA-based 3D printed composites, even those containing continuous fibres. Curvilinear open-hole tensile test samples were fabricated to explore the processability and performances of such material in complex shapes. The mechanical performance of the produced specimens was benchmarked against conventionally laid-up specimens with a cut hole. Although the steered specimens produced have lower strength than the fully consolidated samples, the raster generated by the printing path has turned the failure mechanism of the composite from brittle to ductile.

Compression of Fibrous Assemblies: Revisiting the Stress–Density Relation

Abstract Many engineering materials are made from fibers, and fibrous assemblies are often compacted during the fabrication process. Compression leads to the formation of contacts between fibers, and this causes stiffening. The relation between the uniaxial stress, S, and the volume fraction of fibers, φ, is of power law form. The derivation of this relation based on micromechanics considerations takes as input the structural evolution represented by the dependence of the mean segment length of the network, lc, on the current density, ρ (ρ is defined as the total length of fiber per unit volume of the network). In this work, we revisit this problem while considering that the mean segment length should be defined exclusively by fiber contacts that transmit load. We use numerical simulations of the compression of crimped fiber assemblies to show that, when using this definition, ρ∼1/lc2 at large enough strains. Purely geometric considerations require that ρ∼1/lc, and we observe that this applies in the early stages of compaction. In pre-stressed networks, the density–mean segment length scaling is of the form ρ∼1/lc2 at all strains. This has implications for the relation between stress and the fiber volume fraction. For both ρ versus lc scalings, S∼(φn−φ0n), where φ0 is the initial or reference fiber volume fraction; however, n = 3 when ρ∼1/lc and n = 2 for ρ∼1/lc2. These predictions are compared with experimental data from the literature.

Study of bearing strength for injection molded GFRPP composites under dry and wet conditions

Thermoplastics and fiber-reinforced thermoplastics represent great deals in nowadays industries and applications where some of these applications are projected to wet environment. The present study investigates the effect of water moisture on the bearing strength (BS) of Polypropylene (PP) and glass fiber (GF) reinforced Polypropylene (GFRPP) composites. PP and GFRPP are produced by injection molding using different GF weight fractions (wt%), 10, 20, and 30 wt%, and two different initial fiber lengths 12 and 24 mm. A burnout test indicated that produced specimens with 12 mm long fibers have higher final fiber lengths than those made of 24 mm long fibers. More water was absorbed for higher GF weight fractions. The results of the dry bearing test showed higher bearing strengths for specimens with higher GF wt% and longer fibers. The same observation was obtained from wet tests, while, wet-tested specimens of all compositions have higher strengths than their dry counterparts. Strain-at-break seemed to be significantly reduced by water absorption for all specimens. Specimens tested in wet conditions have different fracture morphology than dry ones due to the change in the mechanical behavior of the materials after water immersion.

Influence of Viscose Fibre Geometry on the Structure-Property Relationships of High-Density Polyethylene Composites.

This study investigated the influence of viscose fibre (VF) geometry on the microstructures and resulting properties of high-density polyethylene (HDPE) composites. Seven types of viscose fibres varying in cross-section shape, linear density, and length were pelletised, compounded into HDPE with a twin-screw extruder, and injection moulded. The microstructures of the composites were characterised by investigating their cross-sections and by extracting the fibres and measuring their lengths using optical microscopy (OM). The mechanical and thermal properties of the composites were characterised using differential scanning calorimetry (DSC), tensile tests, Charpy impact tests, and dynamic mechanical analysis (DMA). The composites prepared using cylindrical fibres with a linear density of 1.7 dtex exhibited the best fibre dispersion, highest orientation, and lowest fibre–fibre contact area. The decrease in the linear density of the cylindrical fibres resulted in increasingly worse dispersion and orientation, while composites containing non-cylindrical fibres exhibited a comparably larger fibre–fibre contact area. The initial fibre length of about 3 to 10 mm decreased to the mean values of 0.29 mm to 0.41 mm during processing, depending on the initial geometry. In general, cylindrical fibres exhibited a superior reinforcing effect in comparison to non-cylindrical fibres. The composites containing cylindrical fibres with a linear density of 1.7 dtex and a length of 5 mm exhibited the best reinforcing effect with an increase in tensile modulus and strength of 323% and 141%, respectively.

Non-linear elastic longitudinal behaviour of continuous carbon fibres/epoxy matrix composite laminae: Material or geometrical feature?

Carbon fibres and unidirectional continuous carbon fibre composites exhibit a non-linear elastic behaviour. There has long been a debate on the physical origins of such a behaviour for these materials. Indeed, two main mechanisms have been proposed: either the reorientation of graphene sheets in the carbon fibre or that of the fibre itself due to initial fibre waviness arising from composite manufacturing. This paper addresses this issue by performing, on the one hand, specific mechanical tests to extract the non-linear elastic coefficients in a reliable way, and, on the other hand, using specific finite element analyses with a non-local model. It is shown first that the proposed experimental method is adequate. Besides, the simulations allow us to show that, while both contributions for non-linear elasticity indeed come into play for the non-linear elasticity of carbon fibres, the intrinsic behaviour of fibres can be considered as the main contributory factor. Composites with glass fibres stay fully linearly elastic, due to the limited stiffness of these fibres.

Influence of cellulose-containing sorbent preparation method based on linen fiber on its functional properties

The creation of biosorbents based on modified flax fiber is aimed at solving the problem of water pollution from heavy metal ions. A method for obtaining a sorbent on the basis of linen fiber including sequential treatment of polysaccharide material with sodium metaperiodate and sodium bisulfite has been developed. Modification conditions for obtaining an effective sorbent have been selected. Equilibrium and kinetics of copper ions sorption with the use of native and modified linen fiber in comparison with Lewatit S100 cationic exchange resin have been studied. It is established that the time of achieving sorption equilibrium in the heterophase system 'aqueous solution of copper sulfate - a modified sorbent' is reduced by 1.5-2 times while the degree of extraction of copper ions is increased by about 1.5 times as compared to the initial fiber. The influence of solution pH on the sorption of copper ions by native flax fiber has been studied. It has been found that in the pH range of the medium 1-7, along with the sorption of Cu ions, the sorption of H ions is observed, which indicates a competitive mechanism of sorption of heavy metal cations and protons with the participation of the cellulose-containing sorbent. Experimental isotherms of copper ions sorption have been processed in linear coordinates of Langmuir's equation that made it possible to determine the values of maximum sorption capacity of sorbents under study which increase in a series: native flax fiber (0.86 mol/kg) < flax fiber, oxidized and treated with sodium bisulfite (1.69 mol/kg) < Lewatit S100 cationite (1.89 mol/kg). Data from infrared spectroscopy and elemental analysis indicate the appearance of new sorption-active groups in the sorbent structure. The sorbent has been tested for purification of aqueous solutions and beverages from heavy metal ions under laboratory conditions. Peculiarities of the sorption of copper (II) ions from juice and white wine have been revealed. It has been found that the obtained modified sorbent on the basis of flax fiber in the purification of beverages is not inferior to the industrial cationic exchange resins in its sorption properties.

Evaluation of the Physical Properties of Unbleached Kraft Pulp Produced from Persimmon Byproducts

This study examined the features of unbleached kraft pulp produced from persimmon byproducts (PB-UKP), which can be used to replace commercial kraft pulp. PB-UKPs prepared through the kraft pulping laboratory process were beaten to 500 and 400 mL CSF. Their fiber properties were subsequently analyzed and compared with those of commercial hardwood bleached kraft pulp (Hw-BKP). The physical properties of handsheets made from PB-UKP and Hw-BKP with a grammage of 60 g/m² were also evaluated.BRPB-UKP and Hw-BKP exhibited similar initial fiber properties. However, after beating, the fiber length of PB-UKP was longer than that of Hw-BKP, and the fines content of Hw-BKP increased considerably. Moreover, no noticeable difference was observed in the fiber width of the pulp. As the beating time increased, sheet bulk decreased, and the sheet strengths increased. The tensile and burst strengths of the handsheet made from PB-UKP were higher than those made from Hw-BKP at a similar sheet bulk because PB-UKP had a higher long fiber content. Thus, PB-UKP could be used as a colored raw material to manufacture paper products.