Filler Material Research Articles

Biomedical Application of Enzymatically Crosslinked Injectable Hydrogels.

Hydrogels have garnered significant interest in the biomedical field owing to their tissue-like properties and capability to incorporate various fillers. Among these, injectable hydrogels have been highlighted for their unique advantages, especially their minimally invasive administration mode for implantable use. These injectable hydrogels can be utilized in their pristine forms or as composites by integrating them with therapeutic filler materials. Given their primary application in implantable platforms, enzymatically crosslinked injectable hydrogels have been actively explored due to their excellent biocompatibility and easily controllable mechanical properties for the desired use. This review introduces the crosslinking mechanisms of such hydrogels, focusing on those mediated by horseradish peroxidase (HRP), transglutaminase (TG), and tyrosinase. Furthermore, several parameters and their relationships with the intrinsic properties of hydrogels are investigated. Subsequently, the representative biomedical applications of enzymatically crosslinked-injectable hydrogels are presented, including those for wound healing, preventing post-operative adhesion (POA), and hemostasis. Furthermore, hydrogel composites containing filler materials, such as therapeutic cells, proteins, and drugs, are analyzed. In conclusion, we examine the scientific challenges and directions for future developments in the field of enzymatically crosslinked-injectable hydrogels, focusing on material selection, intrinsic properties, and filler integration.

Environmental sustainable treatment and disposal technologies for reservoir wastes: a review.

The process of dredging reservoirs serves the purpose of preserving water storage capacity and ensuring the functionality of navigational channels. Additionally, it has the potential to mitigate the presence of pollutants and chemicals that pose risks to both the environment and human well-being. This review article examines the many ways of disposal and treatment of dredged sediment, as well as the ecological and economic advantages associated with these approaches. Algae and reed-based treatment methods have the potential to effectively and economically remediate and sustainably manage dredged sediments. Landfills and ocean dumping are widely utilized methods for the disposal of excavated materials. However, other approaches such as land reclamation, the use of fill material, and the preservation of wetlands can offer cost-effective solutions while also contributing to environmental conservation. The implementation of sediment cleaning, stabilization, and solidification techniques has the potential to effectively mitigate waste and improve the quality of sediment, hence facilitating its reuse. Algae and reed-based treatment systems have been found to effectively mitigate disposal costs and contribute to environmental enhancement. Additionally, the practice of reusing dredged sediments has been recognized as a valuable strategy in promoting a circular economy.

Comparison of Biowaste Fillers Extracted from Fish Scales and Collagen on the Mechanical Properties of High-Density Polyurethane Foams

The utilization of biowaste fillers in the development of high-density polyurethane (PU) foams has gained significant attention due to environmental and economic benefits. This study investigates the mechanical properties of PU foams reinforced with biowaste fillers extracted from fish scales (FS) and fish scale-derived collagen (FSC). The fish scales and collagen were characterized for their composition and integrated into PU foams at various loadings. Mechanical properties such as tensile strength, hardness, and density were evaluated. ANOVA was used to analyze the mean values. Bonferroni tests were used to identify differences between the filler materials (α = 0.05). The tensile strength increases with an increase in filler content for both FS (59.48 Kpa) and FSC (65.43 Kpa). No differences were observed between FS and FSC in tensile strength. Significant differences were observed between the FS and FSC in both hardness and density (p < 0.001). The results demonstrated that both fillers enhanced the mechanical properties of PU foams, with collagen-reinforced foams showing superior performance. This suggests that collagen and fish scales can be effective biowaste fillers for developing environmentally friendly PU foams with enhanced mechanical properties.

Mechanical Properties of Iron Tailing Sand Grout Sleeve Joints and Force Analysis.

In this paper, the mechanical properties and internal stress condition of the reinforcing bar sleeve connectors with ferro-tailed mineral sand cementitious grout as filler material were analyzed as research objects. Firstly, an experimental study was carried out on the reinforcing bar sleeve connectors of iron tailing sand grout with a 40% substitution rate of mechanism sand to analyze the mechanical properties of different grout types, age, and reinforcement diameters under unidirectional tensile, high stress, and large deformation of repeated tensile and compressive stresses. Next, five groups of sleeve joints with different anchorage lengths were set up for unidirectional tensile tests. The results show that, with the decrease of the diameter of the reinforcement, the grip force and bond strength of the iron tailing sand grout on the internal reinforcement gradually increase. Under conditions of large deformation and high stress due to repeated tensile loading, the residual deformation and total elongation of iron tailing sand grout sleeve joints are satisfactory. Additionally, the restraining anchorage effect of iron tailing sand grout in the end section is small. The utilization rate and integrity of iron tailing sand grout in the initial anchorage section are better.

A study on road noise reduction using recycled material

Recently, there has been a shift in the paradigm of the automobile industry from internal combustion engines to electric vehicles. An NVH research has also evolved rapidly from studying noise and vibration in conventional internal combustion engines to exploring methods for reducing road noise. A road noise during vehicle operation can be amplified by the resonance of the cavity inside chassis. As a countermeasure, so, filler materials have been applied inside the chassis to reduce resonance, However, fillers applied to existing cavities, such as pads and polyurethane foam, generally focus on blocking resonance inside the cavity rather than reducing vehicle road noise. In this study, a filler has been developed to fill the cavities of vehicles; Filler resources are from residual scrap gathered in manufacturing shop floor of automobile interior and exterior parts. As a result, fillers introduced in the study offer not only excellent acoustic performance but also are recyclable. The effect in terms of acoustic performance of recycled fillers was confirmed by conducting tests, sound transmission loss in reverberation and anechoic chambers. Also, actual vehicle driving tests were conducted on a proving ground.

Investigation of the particle crushing characteristics of stacked stone materials under different stress path conditions

Stone fill materials are widely used in engineering projects such as earth-rock dams, railways, and highway embankments. Nevertheless, they are susceptible to particle breakage, which can lead to a decline in engineering performance. A complete set of studies on crushed stone aggregates was carried out to investigate particle crushing characteristics under various stress path conditions. To quantify the amount of particle crushing, the relative particle crushing rate was utilized as an indicator. The plastic work performed during the trials was compared across different stress routes, and the relationships between particle crushing and average stress p and generalized shear stress q were investigated. In triaxial testing, the differences in particle crushing behavior under different stress routes were thoroughly examined. The results show that particle crushing is substantially lower in the modelling of a rockfill dam constructed with a core wall and subjected to reservoir water pressure pathways than in conventional triaxial tests. A clear relationship was discovered. Across several stress routes, a clear link between plastic work and the relative particle crushing rate was detected, which was successfully characterized by a power function. Notably, the contributions of different stress components to the overall plastic work varied significantly. The plastic work exerted by the generalized shear stress q accounted for a large percentage of traditional triaxial testing, although the proportion of plastic work given by p and q changed significantly in complex stress path tests. This research enhances the understanding of the particle breakage characteristics of stone fill materials under complex stress paths.

Wire arc direct energy deposited multiphase steel through in situ micropowder alloying: mechanical and metallurgical studies

Purpose This study aims to investigate the effect of copper and titanium micropowder addition on the mechanical and metallurgical properties of additively manufactured low-carbon steel, aiming to produce a modified (multiphase) steel with ferritic low-carbon steel using in situ micropowder addition during wire arc direct energy deposition (WA-DED). Design/methodology/approach A robotic arm equipped with a GMA welding source deposited ER70S6 filler wire on AISI S235 substrate steel using WA-DED. Cu and Ti micropowders were interspersed between layers for microstructural modifications. Microscopy, spectroscopy, diffraction and mechanical testing were used to evaluate the properties of the deposited samples. Findings Incorporating Cu and Ti micropowders significantly enhanced the yield and tensile strength of the deposited material, showing an 83% increase in yield strength and a 33% increase in tensile strength. Microstructural analysis identified key phases such as ferrite, pearlite, bainite, retained austenite and martensite/austenite, with Cu and Ti acting as grain refiners. Nanoscaled Cu precipitates contribute to enhanced low-temperature toughness and a 150% improvement in impact strength at −30°C. Originality/value This study presents a novel approach to overcome the limitations of the available alloys (filler materials). This can be achieved by introducing in situ micropowder alloying during the WA-DED process. The micropowder addition allows altering the properties of the deposited material without changing the parent filler material itself, achieving the desired composition. With this approach, there is no need to manufacture the filler material with the preferred alloy composition separately and then carry out the deposition process.

Hybrid Radial‐Axial Flow for Enhanced Thermal Performance in Packed Bed Energy Storage

ABSTRACTIn this work, a hybrid radial‐axial (HRA) system is used to store thermal energy in a packed bed. The heat transfer fluid (HTF) is delivered via a perforated radial pipe placed at the center of the packed bed along the axial length. Hot fluid flows from the center toward the wall through the holes (like other radial systems), but then leaves via the traditional axial flow exit, creating the HRA flow configuration. A computational fluid dynamics (CFD) model is used to analyze the thermal performance of the packed bed during the charging process utilizing the new HRA system. Alumina beads of 6 mm were filler materials and air was HTF with inlet temperature of 75°C for proof of concept. The present paper focuses on two aims: (1) utilizing CFD models to analyze flow and temperature profiles in the packed bed; (2) comparing the model results to experimental results published in a previous HRA flow study and to traditional axial flow. Two HRA configurations were considered based on previous experimental designs, one with uniform holes in the central pipe (R1) and one with gradients in the hole sizes to promote even flow from the central pipe into the bed (R2). The numerical results agree with the experimental results in both cases. The HRA system performance depends on the flow profile created by the hole designs, and it can perform better than the axial flow depending on the design of the radial pipe. Design R2, which promotes even flow from the central pipe into the bed, has higher charging efficiency than standard axial flow methods. For HRA design R2 at 0.0048 m3/s (7 SCFM, standard cubic feet per minute), numerical results for charging efficiency were 75.5% versus 73.8% for traditional axial flow. For HRA design R2 at 0.0061 m3/s (9 SCFM), numerical charging efficiency was 80.5% versus 78.1% for traditional axial flow. These results are consistent with experimental data.

High-strength WC-Co/Low carbon steel connected by Ni–Cr–Fe alloy through brazing for roller sleeves

Enhancing the bond strength between WC-Co and steel is crucial for broadening its applications. In this study, WC-Co was bonded to low-carbon steel (LCS) using a Ni–Fe–Cr alloy at 1180 °C in an argon atmosphere furnace. The WC-Co/LCS (WL) interface was characterized by XRD, SEM, and EPMA, revealing no cracks or pores and confirming robust metallurgical bonding. The bonded material's shear strength reached approximately 321–328 MPa, significantly exceeding that achieved with Ag–Cu–Zn–Cd, Cu–Zn, Cu–Ni–Al, Ag–Cu–Zn + Ni/Mn, and Ag–Cu–In–Ti filler materials in the welding process. EPMA analysis showed that Fe, Cr, and Ni from the Ni–Fe–Cr alloy diffused into the WC-Co over distances of approximately 802–815 μm, 803–817 μm, and 632–641 μm, respectively. Initially, WC decomposed at sharp corners to form W₂C, which subsequently reacted with Fe and Cr to form M₆C and M₇C₃. This methodology was also applied to producing roller sleeves for vertical mills, increasing their lifespan by 1.9 times.

Effect of filler morphology on mechanical behaviour of Mg/HA nanocomposites for degradable implant applications

Abstract Magnesium (Mg) alloys exhibit promising potential for biodegradable orthopaedic applications, with the incorporation of hydroxyapatite (HA), which offers a means to tailor their bioactivity and biodegradation behavior. In this study, the effect of filler morphology on mechanical behaviour and biocorrosion of the Mg/HA composites is analysed. Two distinct morphologies of nano-hydroxyapatite (nHA), needle-like and flake-shaped, were incorporated into Mg using a stir-casting technique. The incorporation of nHA led to a notable increase in hardness, with enhancements of 15% for needle-like nHA and 29% for flake-like nHA. Moreover, the ultimate compressive strength exhibited a significant improvement of 29% for the flake-shaped nHA and 12% for the needle-like nHA. Interestingly, the morphological variation did not impact the degradation behaviour of the composites. Based on these findings, it is proposed that Mg metal matrix composites utilizing bioactive flake-shaped nHA as a filler material hold promise for enhancing the mechanical properties of Mg/HA nanocomposites, particularly for load-bearing implant applications.

Collective effect of reduced graphene oxide and Zn2U hexaferrite filler based epoxy composites on microwave absorption with improved mechanical properties

Herein, we have synthesized Ba4Zn2Fe36O60 (Zn2U) and have produced reduced graphene oxide (rGO) wrapped filler material for the preparation of epoxy composites of different weight percentages (40, 50 and 60 wt %). These rGO wrapped Zn2U hexaferrite filler was analyzed by XRD and SEM to examine the crystal structure and distribution of Zn2U hexaferrite in between/on the surface of rGO respectively. The magnetic and mechanical properties of prepared rGO@Zn2U@epoxy composites were evaluated by employing vibrating sample magnetometer and universal testing machine respectively. The investigation involved analyzing the complex permittivity and permeability, and based on this information, an assessment of the reflection loss was conducted. The results obtained indicate that epoxy composites with a filler content of 60 % rGO@Zn2U have significant promise as an advantageous choice for EMI shielding and microwave absorption applications.

Ion transport properties and performance of gellan gum based composite polymer membrane electrolytes in proton battery and PEMFC applications

Biopolymer Gellan gum (GG) incorporated with ammonium iodide (NH₄I) salts and inorganic filler nano-TiO2 improved the ion transport facility in the salt-polymer matrix. The crystalline/amorphous nature of the membranes and the presence of n-TiO2 are evident from XRD analysis. The vibration modes corresponding to the characteristic functional groups and bonding interactions within the polymer matrix and incorporated filler materials present in the as-prepared membranes were analyzed using FTIR technique respectively. The ion transport parameters such as ionic conductivity (σ), diffusion coefficient (D), and mobility (μ), were studied using Ac impedance, transference number measurement, and FTIR deconvolution. The biopolymer membrane with the composition, 1 g GG: 0.3 M.wt% of NH4I (GGAI-3) shows the highest ionic conductivity of 2.65 ± 0.03×10−3 S/cm and on addition of 0.1 M.wt% of n-TiO2 (GGAIT-1) the increase in ionic conductivity of 4.07 ± 0.02×10−2 S/cm was observed. The H¹NMR studies help in understanding the mobility of charge carriers upon their chemical shifts. The glass transition temperature values of the as-prepared membranes were determined using DSC studies. The morphological change on the surface of the GG polymer membrane due to the addition of NH4I and n-TiO2 were analyzed using the SEM technique. The thermal, mechanical, and chemical stability of the highest ion-conducting biopolymer and composite polymer membranes were assessed using TGA, mechanical stability tests, and chemical stability tests. The IEC test exhibits the number of exchangeable ions in the polymer matrix. Utilizing the GGAI-3 and GGAIT-1 membranes as electrolytes, proton batteries were constructed and observed to have the pseudocapacitive behaviour; as the electrodes experience surface limited redox reaction at the electrode-electrolyte interface. The PEMFC cell using the GGAI- 3 and GGAIT-1 as proton exchange membrane exhibits the OCV of 646 mV and 682 mV respectively. Their performances were analyzed using the I-V polarization curve resulted with the power density of 0.14 mW/cm2and 0.34 mW/cm2 respectively.

The Effect of Different Oral Root Canal Filling Materials on the Expression of Inflammatory Factors and Protease Related Molecules in Gingival Crevicular Fluid in Patient with Posterior Tooth Anatomy Defects

The Effect of Different Oral Root Canal Filling Materials on the Expression of Inflammatory Factors and Protease Related Molecules in Gingival Crevicular Fluid in Patient with Posterior Tooth Anatomy Defects

Performance of steel fibers reinforced self compacting concrete subjected to high temperature

Self-compacting concrete (SCC) has recently become more popular in high-rise structures and industrial units subject to fire explosions. Evaluating SCC performance at high temperatures is necessary to decrease the deterioration of these structures. In this study, SCC properties were investigated at elevated temperatures. Furthermore, the differential expansion between the aggregates and the cementitious matrix can induce internal stresses, which may result in cracking. Therefore, Steel fibers (SF) 0%,0.5%,1.0%,1.5%, and 2.0% were added to SCC to prevent crack formation under high temperatures. Also, marble waste (10%) was added as filler materials, which improved the interfacial transition zone. The performance of SCC at elevated temperatures was evaluated through visual inspection (cracking and spalling), mass loss (ML),compressive strength (CS), and tensile strength (TS). Furthermore, the microstructure of SCC was analyzed through scan electronic microscopy. Results indicate that the SF addition improved the performance of SCC at elevated temperatures. Considerable degradation was observed in the reference sample at 500 °C. However, SF reinforced is stable and has a better strength at 500 °C. Therefore, the study recommends that SF-reinforced SCC be used up to 500 °C without any harmful impact.

조선용 B Gr. 강의 용접부 미세조직과 기계적 성질에 미치는 용접기법의 영향

The microstructurale and mechanical properties of B Gr. steel were evaluated for shipbuilding according to a welding process. The following conclusions were drawn. In tandem submerged arc welding(TSAW), compared to single submerged arc welding(SAW), the grain boundary ferrite was coarsened, and the fraction was higher owing to the high heat input and low flux basicity ; conversely, the volume fraction of acicular ferrite was lower. Fine intragranular acicular ferrite and polygonal ferrite were observed in the weld metal of the electrogas welding (EGW), which had the highest heat input. In the microstructure near the fusion line, as the amount of heat input increased, the prior austenite grain boundary became coarse. Further, both the intergranular grainboundaryferrite and intragranular bainite became coarse, and the heat-affected zone became wider. The hardness of weld metal was independent of the amount of heat input and was demonstrated to be high in the order of EGW, single SAW, and TSAW owing to the microstructure difference caused by the chemical composition of the filler material and the dilution rate of the base metal. Furthermore, the tensile strength of all three welding processes resulted in stable satisfaction with the class society rules.

Composite Sand–Clay Infrastructural Soil Fills: Characteristic Consolidation and Hydraulic Properties

In the design construction of infrastructural projects comprised of geotechnical applications, including composite soil fill layers, compacted sand-clay soil fills are widely preferred as barrier layers, particularly in solid waste landfills, to minimize leakage, to prevent leachate from entering into groundwater. When bentonite clay with high water absorption capacity and low hydraulic conductivity is mixed with sand possessing relatively enhanced frictional properties, greater shear strength capacity, an effective fill material exhibiting low sensitivity to frost, and low volume change in case of wetting, drying can be obtained. On the other hand, when montmorillonite clay is loaded, due to highly critical volumetric contraction or dilation characteristics (high compressibility nature of clay), the soil fill composed of sand-clay will significantly consolidate. This situation may cause differential settlement problems of infrastructural fills employed in geotechnical applications. In this regard, the load conditions (mechanical effects) and the environmental conditions (physicochemical effects) in the field control compressibility characteristics and consolidation properties of sand-bentonite clay mixtures. This will ultimately impact the desired stability conditions of sand-clay soil layers built for constructed infrastructural fill, resulting in a deviation from anticipated performance conditions. To this end, in this study, the specimens of sand-bentonite clay mixtures prepared with different contents of sand-bentonite clay were subjected to one-dimensional consolidation tests to investigate the effect of bentonite content used in the mixture on consolidation behavior, hydraulic properties, and effect of sand amount on rate of consolidation and on resulting compressive strength behavior.

Assessment of the Activity of Galvanic Couples Involving Amalgam Filling Materials

Assessment of the Activity of Galvanic Couples Involving Amalgam Filling Materials

Mechanical properties of epoxy composites filled with multi-walled carbon nanotube, Nanoaluminum particles and glass fibers at elevated temperatures

The present work investigates the mechanical properties of a composite material composed of multi-walled carbon nanotubes (MWCNTs), nano-aluminum powder (NAP), and glass fibers (GF) for five different compositions. The study further investigated how MWCNTs contribute to maintaining the mechanical properties of nanocomposites when exposed to elevated temperatures, up to 180 °C. The evaluation of impact strength revealed that the nanocomposite, composed of 2 % MWCNTs, 15 % NAP, and 10 % GF, demonstrated the greatest impact strength. At room temperature, the composite containing 2 % MWCNTs, 5 % NAP, and 20 % GF exhibited the highest ultimate tensile strength (UTS). Conversely, at elevated temperatures reaching up to 180 °C, the highest UTS was observed in the composition with 2 % MWCNTs, 10 % NAP, and 15 % GF. The hardness of the nanocomposite was influenced by its composition; at room temperature, the maximum hardness was observed in the mixture containing 2 % MWCNTs, 20 % NAP, and 5 % GF. In contrast, at elevated temperatures, the composition with 2 % MWCNTs, 5 % NAP, and 20 % GF exhibited the highest hardness. Overall, the study found that incorporating GF and NAP improved the mechanical properties of the composite. These results indicate that the composite's performance could be further optimized for specific applications through the addition of filler materials.

A novel test set up to study three-dimensional electrokinetic dewatering of dredged soil

The dredged soil obtained from maintenance activities of water bodies has emerged as a potential alternate fill material for infrastructure development. However, dredged soil requires stabilization due to high initial water content, low shear strength and high compressibility. Among several methods, stabilization of dredged soil by using electrokinetics is one of the effective ground improvement techniques that uses electric field to dewater and strengthen the soil. In this context, a series of experiments were conducted on dredged soil by using a combination of electrokinetic treatment with and without 6 kPa seating pressure (viz., low surcharge). A customized and patented electrokinetic dewatering (EKD) test set up was used for the three-dimensional electrokinetic treatment of soil. The potential difference (in the range of 6 V–48 V) within the soil was achieved by inserting stainless steel pipes of 21.4 mm outer diameter, 1.2 mm thickness, and 170 mm length. Two control tests (with and without seating pressure of 6 kPa) also were performed to understand the effectiveness of EKD. From the study, up to 1057% and 427% increase in dewatering was noted in EKD tests due to application of 24 V (optimum voltage noted in EKD tests) as compared to control tests, without and with seating pressure, respectively. Further, seating pressure with EKD resulted in effective control of crack formation in the dredged soil and uniform improvement in shear strength along the depth (up to 95 kPa). The combination of low surcharge with EKD, adopted in the study, is also expected to yield lower differential settlement, and hence better performance of geotechnical structures built on improved dredged soil. The novel 3-dimensional patented EKD test setup with Arduino-programmed automatic water pumping enables collecting and accurately measuring dewatered effluent volume, performing cone penetration tests on undisturbed soil, and collecting soil samples for determination of water content/physiochemical properties from different locations. Overall, the developed EKD setup can be utilized for evaluating the effectiveness and adopting real-time progress management for EKD or other ground improvement methods, and remediation of sludge, mine tailings, dredged sediments, and contaminated soils.

Titanium Dioxide (TiO2): A Versatile Excipient in Pharmaceuticals

Titanium dioxide (TiO2) is a commonly used excipient in pharmaceutical formulations, offering several benefits to pharmaceutical products. As a highly insoluble and thermally stable oxide, TiO2 is utilized as an opacifying agent and suspending agent to improve the appearance, stability, and bioavailability of pharmaceutical products. Its high refractive index and high surface area make it an excellent adsorbent and filler material, while its non-toxic and odorless nature ensures its safe use in pharmaceutical applications. Here, the authors deliberate the properties and major applications of TiO2 as a versatile excipient in pharmaceuticals. The mesmerizing physic-chemical features of TiO2 depend on the size and shape of particles. At present, TiO2 has added countless considerations as an auspicious photocatalyst due to its extraordinary features such as excellent photocatalytic, electronic, and optical features, high stability, and economical and non-toxic nature. Moreover, the benefits of using TiO2 as an excipient are discussed, including its ability to improve product appearance, stability, and bioavailability. The review also reports the challenges associated with TiO2, including environmental concerns and biocompatibility issues. However, the benefits of TiO2 far outweigh its drawbacks, making it an extensively accepted excipient in pharmaceuticals. Inclusively, this article aims to provide a comprehensive overview of TiO2 as an excipient in pharmaceuticals, highlighting its unique properties, several applications, and benefits.