Modulus Values Research Articles

DFT study of the binary intermetallic compound NdMn2 in different polytypic phases.

The structural stability, ground state magnetic order, electronic, elastic and thermoelectric properties of NdMn2 in the C15, C14 and C36 polytypic phases is investigated. The magnetic phase optimization and magnetic susceptibility reveal that NdMn2 is antiferromagnetic (AFM) in C36 phase; and paramagnetic (PM) in C14 and C15 phases respectively. The band profiles and electrical resistivity show the metallic nature in all these polytypic phases and reveal that the C36 phase possesses smaller resistivity. The presence of covalent bonds among Nd-Nd and Nd-Mn has been verified from the electron charge densities plots. The elastic constants calculated in different phases confirm the mechanical stability and are elastically anisotropic and incompressible in all phases. Due to large enough value of Young and Bulk moduli in C14 phase NdMn2 would be suitable candidate for applications that require high strength, stiffness and durability, as well as the ability to withstand extreme environments. The density functional theory (DFT) is used to investigate the physical properties of understudy binary intermetallic compounds NdMn2 in the C15, C14 and C36 polytypic phases. BoltzTraP code based on Boltzmann semi-classical transport theory is used to investigate magnetic susceptibility and electrical resistivities of the understudy compounds. The elastic constants are calculated with the help of IRELAST code embedded in WIEN2k software. Linux based xmgrace and origin software are used for plotting.

Thermal Insulating and Mechanically Strong Polyimide Aerogel Composites Reinforced by Polyhedral Oligomeric Silsesquioxane-Grafted Carbon Nanotubes

In the ship industry, developing thermal insulation materials with exceptional high-temperature resistance, structural stability and light weight is essential. Herein, polyimide (PI) composite aerogels were synthesized. Carbon nanotubes (CNTs) introduced cross-linking structures within the aerogel matrix, effectively reducing shrinkage and forming micrometer-scale pores. Furthermore, the rigid cage-like structure of polyhedral oligomeric silsesquioxane (POSS) generated additional nanoscale pores. This multiscale pore structure enhanced both compressive strength and thermal insulation properties. The PI-CNT-POSS composite aerogel with a 2 wt% CNT content (PI-CP2) demonstrated outstanding overall performance, with compressive strength, modulus and thermal conductivity values of 167.7 KPa, 360.3 Kpa and 40.6 mW/(m·K), respectively, possessing remarkable advantages over the neat PI aerogel. Consequently, this PI composite aerogel can be used as a promising material for heat management in complex environments.

Mechanical Wear of Degraded Articular Cartilage.

To evaluate the mechanical wear of cartilage with different types of degradation. Bovine osteochondral explants were treated with interleukin-1β (IL-1β) to mimic inflammatory conditions, with chondroitinase ABC (ChABC) to specifically remove glycosaminoglycans (GAGs), orwith collagenase to degrade the collagen network during 5 days of culture. Viscoelastic properties of cartilage were characterized via indentation. Biochemical assays were performed to quantify the cartilage matrix loss to the media during culture and from an accelerated, ex vivo wear test. The coefficient of friction during the wear test was measured. Distribution of GAGs in the tissue was assessed histologically. All three degradative treatments decreased the cartilage modulus values and depleted GAGs in histological sections. However, wear was not uniform among the different treatments. Collagen loss from the tissue due to mechanical wear was only higher with IL-1β and collagenase treatment, while collagen loss due to wear with ChABC treatment was similar to untreated controls. In addition, less GAG was released due to mechanical wear in all degraded groups than the controls, likely because GAGs had already been depleted from these tissues during culture. As no significant differences in the coefficient of friction were observed between groups, changes in wear were attributed to altered tissue composition and structure rather than to changes in frictional forces. Results suggest that cartilage with a degraded collagen network is more susceptible to mechanical wear, but that cartilage wear may be relatively unaffected by the loss of GAGs. Furthermore, exacerbated mechanical wear could be an additional mechanism by which inflammatory cytokines induce cartilage breakdown.

A hybrid artificial neural network–genetic algorithm back-analysis technique for local anomaly detection in railway track substructure

The UK’s ageing railway transportation network is increasingly at risk of substructure failure, often caused by malfunctioning buried drainage systems. These drainage issues lead to localised soil weaknesses in the substructure layers, which, if undetected, can result in costly maintenance interventions or, worse, catastrophic system failure. Regular non-destructive test (NDT) assessments are essential for monitoring the condition of the substructure, yet current interpretation techniques for NDT data provide limited insight into the size, location and even the presence of weakened zones. This results in an incomplete understanding of the substructure's condition, impeding effective maintenance planning. A novel hybrid back-analysis technique to detect weakened zones in railway substructures caused by drainage malfunctions is proposed, addressing a critical gap in existing solutions. The method employs an artificial neural network surrogate model, trained on virtual experimental data generated through finite-element simulations, and couples it with a genetic algorithm to optimise the match between modelled and measured deflections. This novel method is computationally efficient, independent of seed modulus values and thoroughly validated for accuracy. It delivers a precise understanding of soil weaknesses in railway substructures, transforming maintenance strategies by improving safety, reducing costs and promoting infrastructure sustainability.

Glass Fiber-Reinforced Polypropylene Composites with High Solar Reflectance for Thermal Insulation Applications

Reflective thermal insulation layers can offer an energy-efficient strategy for preventing temperature rises by reflecting sunlight on surfaces. Our previous study presented a novel solvent-based method to prepare porous polypropylene (PP) with high solar reflectivity. However, the stiffness and strength of the neat porous PP were insufficient for thermal insulation applications, as mechanical loads from installation and environmental factors limit the applicability of such products. This paper addresses this gap by applying our solvent-based surface modification technology to glass fiber (GF)-reinforced PP composite sheets, creating a previously unexplored system. While the enhanced modulus and strength aligned with expectations, the micro- and nano-structured porous outer layers situated below the skin layer of the sheets, the refractive index mismatch between the PP matrix and the GF, and the size of the GF delivered a notable advancement in reflective thermal insulation performance. The combined effect of 30 wt% GF, nucleating agents, and surface modification resulted in a highly porous surface layer featuring spherulite sizes of 0.5–2.0 μm. With these combined effects, we achieved a modulus value of ~4 GPa, a tensile strength of 60 MPa, and an average solar reflectance of up to 94%. Thermal insulation performance measurements demonstrated that the registered inner temperature was lower by 24.1 °C compared to neat PP sheets. These combined effects demonstrate the potential of our solvent-based surface modification technology to develop cost-effective, porous PP composite sheets for efficient reflective thermal insulation.

Bond Performance of GFRP Bars in Glass and Basalt Fiber-Reinforced Geopolymer Concrete Under Hinged Beam Tests

In recent years, researchers have focused on the usability of fiber-reinforced polymer (FRP) bars due to their lightweight, corrosion-resistant, and eco-friendly characteristics. Geopolymers, as low-carbon alternatives to traditional binders, aim to reduce CO2 emissions in concrete production. The bond strength between FRP bars and concrete is critical for the load-bearing capacity and deformation characteristics of reinforced elements. The objectives of this work are to investigate the bond performance of GFRP bars in chopped glass and basalt fiber-added geopolymer concrete using hinged beam tests. Since the hinged beam test accurately represents the behavior of real bending elements, this test method was selected as a main bonding test. Initially, three geopolymer mixtures with Ms modulus values of 1.2, 1.3, and 1.4 were prepared and tested. The mixture with a modulus of 1.2 Ms, achieving a compressive strength of 56.53 MPa, a flexural strength of 3.54 MPa, and a flow diameter of 57 cm, was chosen for beam production due to its optimal workability and strength. After mechanical and workability tests, SEM analysis was performed to evaluate its internal structure. For evaluating the bond performance of GFRP bars, 12 geopolymer beam specimens were prepared, incorporating varying fiber types (chopped glass fiber or basalt fiber) and embedment lengths (5 Ø or 20 Ø). Hinged beam tests revealed that the bond strengths of glass and basalt fiber-added mixtures were up to 49% and 37% higher than that of the control geopolymer concrete, respectively. It was concluded that incorporating fibers positively influenced the bond between geopolymer concrete and GFRP bars, with glass fibers proving more effective than basalt fibers. These findings enhance the understanding of bond mechanisms between GFRP bars and geopolymer concrete, emphasizing their potential for sustainable and durable construction in both industrial and scientific applications.

Environmental Friendly Polymer Based Recycled Nitrile Gloves Incorporated With Poly(Lactic Acid)/Graphene Nanoplatelets Binary Blends

ABSTRACTThe waste issue from the widespread use of nitrile gloves emphasize the environmental and health risks associated with improper disposal. This study introduces an innovative approach by incorporating recycled nitrile gloves made from acrylonitrile butadiene (rNBR) into a composite with poly(lactic acid) (PLA) and graphene nanoplatelets (GNPs) (1, 2, and 3 phr). The results showed a maximum improvement in mechanical properties at a PLA/rNBR blend ratio of 60:40 wt%, demonstrating a balance between stiffness and toughness compared to other binary blend ratios. The incorporation of GNP enhanced the values of Young's modulus, tensile strength, and elongation, respectively. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) recorded that the thermal stability of PLA/rNBR tends to increase with the loaded GNP. The morphological properties observed through scanning electron microscopy (SEM) revealed that the PLA/rNBR surface exhibited a nonhomogeneous distribution, leading to the formation of numerous voids and low adhesion. However, the good distribution of GNP within the matrix contributed to greater homogeneity, thereby reducing defects caused by rubber crumbs and voids in the PLA/rNBR fracture. Based on this research, this strategy offers a promising solution to address the environmental challenges posed by personal protective equipment waste.

Monitoring of Strength Development in Portland Cement Concrete With High Fly-Ash Content at the FAA’s National Airport Pavement Test Facility

Construction Cycle 2 (CC2) at the FAA’s National Airport Pavement Test Facility (NAPTF) included construction of three concrete test items MRC, MRG, and MRS on three different support conditions (crushed-stone subbase, slab on grade, and econocrete stabilized subbase). All three test items were constructed on a CBR 7-8 subgrade. The existing econocrete subbase (P-306) from CC1 test item MRS was used for CC2 MRS. Concrete was placed in the test items using a concrete pump into fully formed 15 ft. (4.57 m) by 15 ft. (4.57 m) slabs. Test results are presented and discussed in this paper. Test results include concrete placement details (slump, air content, concrete temperature), compressive strengths, flexural strengths, elastic modulus from free-free resonance tests on concrete beams and cylinders, portable seismic pavement analyzer (PSPA) tests, and strength results from sawed beams and cored cylinders taken from untrafficked test slabs. Concrete specimens included both laboratory cured and field cured specimens. PSPA tests were performed on the test item slabs at the age of one day and on regular intervals after that, coinciding with the laboratory testing of beams and cylinders. The test results showed good correlation between elastic modulus (from free-free resonance and PSPA tests) and strength values (compressive and flexural strengths) and demonstrated the application potential of a testing device such as PSPA for assessing the early-age strength of concrete.

From Waste to Innovation: A Circular Economy Approach for Tissue Engineering by Transforming Human Bone Waste into Novel Collagen Membranes.

The aim of the circular economy is to treat waste as a valuable raw material, reintegrating it into the industrial economy and extending the lifecycle of subsequent products. Efforts to reduce the production of hard-to-recycle waste are becoming increasingly important to manufacturers, not only of consumer goods but also of specialized items that are difficult to manufacture, such as medical supplies, which have now become a priority for the European Union. The purpose of the study is to manufacture a novel human-purified type I collagen membrane from bone remnants typically discarded during the processing of cortico-cancellous bones in tissue banks and to evaluate its mechanical properties and effectiveness in regenerating bone-critical mandibular defects in rabbits. To prepare the novel membrane, cortico-cancellous bone chip samples from a local tissue bank were processed to isolate collagen by demineralization under agitation in HCl, cast into a silicone mold, and air-dried at room temperature and UV irradiation. The average thickness of the four batches analyzed by SEM was 37.3 μm. The average value of Young's modulus and tensile strength obtained from the specimens was 2.56 GPa and 65.43 Mpa, respectively. The membrane's efficacy was tested by creating a critical bicortical and bilateral osteoperiosteal defect in rabbit mandibles. The right-side defects were covered with the collagen membrane, while the left-side defects were left untreated as a control. Nine weeks post-surgery, clinical, radiological, and histological analyses demonstrated new bone formation in the treated areas, whereas the control sites showed no bone regeneration. This innovative approach not only contributes to sustainability in healthcare by optimizing biological waste but also exemplifies efficient resource use in line with the circular economy, offering a cost-effective, biocompatible option that could benefit national health systems.

Study on Synergistically Improving Corrosion Resistance of Microarc Oxidation Coating on Magnesium Alloy by Loading of Sodium Tungstate and Silane Treatment.

Sodium tungstate (Na2WO4) was filled into the micropores and onto the surface of a magnesium alloy microarc oxidation (MAO) coating by means of vacuum impregnation. Subsequently, the coating was sealed through silane treatment to synergistically boost its corrosion resistance. The phase composition of the coating was inspected using XRD. FTIR was utilized to analyze the functional groups in the coating. XPS was employed to study the chemical composition and valence state of the coating. The surface and cross-sectional morphology of the coating, along with its elemental composition and distribution, were investigated by SEM and EDS. Meanwhile, the thickness of the coating was analyzed using Image J software. Electrochemical impedance spectroscopy (EIS) was employed to determine the corrosion resistance of the coating. The results show that compared with an MAO coating, M-0.125W composite coating (only filled with sodium tungstate on the surface of the MAO coating), and M-SG composite coating (only receiving silanization treatment applied to the surface of the MAO coating), the corrosion resistance of the M-nW-SG composite coating (loaded with sodium tungstate on the surface of the MAO coating and then treated with silane) is significantly improved. This is mainly attributed to the fact that sodium tungstate can be combined with Mg2+ to form insoluble magnesium tungstate protective film, which blocks corrosion media. At the same time, silanization treatment further seals the MAO coating and increases the compactness of the coating. In addition, with the increase in the impregnation concentration of sodium tungstate, the content of sodium tungstate in the M-nW-SG composite coating improves, and the sealing effect of silanization treatment is better. When the impregnation concentration of sodium tungstate is 0.1 mol/L or above, the MAO coating with sodium tungstate can be completely sealed. When the impregnation concentration of sodium tungstate is 0.125 mol/L, M-0.125W-SG composite coating has the best corrosion resistance, and its impedance modulus value can be maintained at 8.06 × 106 Ω·cm2 after soaking in 3.5 wt.% NaCl solution for 144 h, which is about three orders of magnitude higher than those of MAO coating and M-0.125W and M-SG composite coatings.

LOCATIONAL AND ORIENTATION VARIATION IN VISCOELASTIC PROPERTIES OF A CORTICAL BONE UNDER DYNAMIC LOADING

Bone behaves as a complex composite material, and is highly heterogenous and anisotropic in nature due to its hierarchical structure. The effect of the location and orientation of bone specimens on the viscoelastic properties of bovine femoral cortical bone was examined in this study. The bone samples were extracted from different locations i.e., proximal, central and distal along the direction of longitudinal and transverse and underwent sinusoidal loading. The longitudinal orientation shows more values of loss tangent and loss modulus in comparison to transverse orientation bone samples. Across locations reveal no significant difference in the storage modulus, loss tangent, loss modulus and complex modulus. The trends in the complex and storage moduli remain consistent within both types of orientations. Significant differences were observed across the locations for both storage and recovered energy, with no variance in the hysteresis loss. The findings from the study shall help in a deep understanding of the bone biomechanics, offering insights for material design and orthopedic interventions in biomechanical engineering.

Microstructure and Mechanical Behavior of Magnetron Co-Sputtering MoTaN Coatings

In recent years, there have been important developments in the refractory metal nitride coatings used for versatile applications, such as MoN, TaN, NbN, etc. Engineered approaches, including the deposition method, microstructure control, structural design, and the addition of functional elements, are put into practice for the promotion of coating characteristics. This study focuses on the microstructure and mechanical properties of ternary molybdenum tantalum nitride, MoTaN, coatings. MoTaN was deposited using a reactive radio frequency (r.f.) magnetron co-sputtering system with Mo/Ta target input power modulation control. The effects of composition and microstructure variations on its mechanical properties, including its hardness, elastic modulus, and wear behavior, were investigated. In general, the MoTaN coatings exhibited a columnar polycrystalline microstructure with MoN(111), Mo2N(111), Mo2N(200), TaN(200), and TaN(220) phases and orientations based on X-ray diffraction analysis. The addition of Ta triggered the transition of the primary orientation of Mo2N(111) into Mo2N(200). Transmission electron microscopy was utilized to analyze the transformation of the multiphase structure and changes in the grain size in terms of the Ta addition. According to nanoindentation and wear resistance analyses, superior hardness, elastic modulus, H/E, H3/E2, and wear-resistance values were identified for the MoTaN coatings with 6.8 to 10.4 at.% Ta, and a maximum hardness of 18.0 GPa was found for the MoTaN coating deposited at an input power of Mo/Ta = 150/100 W/W. An optimized hardness of 18.0 GPa and an elastic modulus of 220.7 GPa were obtained. The adjustment of the input power during deposition played a critical role in determining the overall performance of the MoTaN co-sputtering coatings. The MoTaN coating with optimized mechanical properties is attributed to its multiphase microstructure and fine columnar grain size of less than 30 nm.

An Investigation of the Influence of Paste's Rheological Characteristics on the Tensile Creep of HVFAC at Early Ages.

The rheological properties of concrete paste significantly influence its tensile creep behavior. In this study, the tensile creep behavior of high-volume fly ash concrete (HVFAC) employing the same cementitious pastes was experimentally investigated, and the rheological properties of the paste containing a high volume of fly ash using the nanoindentation (NI) technique was investigated in order to explore the influence of the paste's rheological properties (such as micro-mechanical properties and microscopic creep) on the early-age tensile creep of HVFAC. The results demonstrated that the micro-strain of paste containing a high volume of fly ash (HVFA) showed a larger value than that without fly ash. As the test age extends, a decreasing trend in microscopic creep was observed which could be attributed to the growth of the content of HD C-S-H (high density C-S-H) gel. Moreover, within the same age period, the experimental data revealed that the incorporation of fly ash resulted in the reduction of the values of the creep modulus C and characteristic time τ. The effects of fly ash dosages and loading age on the creep properties of concrete was consistent with the micro-creep properties of the cementitious paste. The tensile specific creep values derived from the ZC ("ZC" are initials for the word ''self-developed" in Chinese) model based on nanoindentation data closely match those obtained from experiments.

New Intestinal Ultrasound Score for Assessing Inflammatory Bowel Disease Activity and Identifying Severity.

The purpose of this study is to propose new ultrasound scores to assess inflammatory bowel disease (IBD) activity and to analyze their accuracy in assessing disease severity. In addition to this, to validate that intestinal ultrasound can be used as a follow-up tool for the assessment of IBD. One hundred and thirty-six adult IBD patients who underwent intestinal ultrasound. Patients were divided into two groups based on colonoscopic findings: 93 patients with UC, 43 patients with CD. UC patients and CD patients were divided into active and inactive groups based on colonoscopic findings, respectively. After forming scores, cut-off values, sensitivity, and specificity were calculated using receiver operating characteristic (ROC) analysis, respectively. Both in UC patients and in CD patients, bowel wall thickness (BWT) and vascular index (VI) were much higher in the active group compared with the inactive group, CEUS mode III, IV, CDFI grades 3-4, fat wrapping, and lost stratification were more likely to imply active disease. In UC patients only, Young's modulus value was much higher in the active group compared with the inactive group. The new intestinal ultrasound scores can be used to assess UC and CD activity and may be useful in identifying severe endoscopic activity in IBD.

Orientation effect and locational variation in elastic-plastic compressive properties of bovine cortical bone.

Bone is a highly heterogeneous and anisotropic material with a hierarchical structure. The effect of diaphysis locations and directions of loading on elastic-plastic compressive properties of bovine femoral cortical bone was examined in this study. The impact of location and loading directions on elastic-plastic compressive properties of cortical bone was found to be statistically insignificant in this study. The variances of most of the compressive properties were also observed to be location and directionality independent except for the locational differences in modulus of resilience (distal to central for longitudinal loading) and plastic work (central to distal for transverse loading) as well as differences in variances of the modulus of resilience and elastic modulus values for two directions of loading. The micro-mechanisms of cortical bone failure for longitudinal and transverse directions of loading were considered to be responsible for the difference in variances in the later properties values as well as for the maximum and minimum coefficient of variation (CV) obtained for compressive properties in two directions of loading. The representative cubical volume at the tested hierarchical level contained all unique microstructural features of the plexiform bone and therefore produced the homogeneous and isotropic elastic-plastic compressive properties of cortical bone. It is expected that the outcome of this study may be helpful in the area of bone tissue engineering and finite element simulation of cortical bone.

Rheological Behavior of Oil Well Cement Slurries with Addition of Core/Shell TiO2@SiO2 Nanoparticles-Effect of Superplasticizer and Temperature.

This study investigates the rheological behavior of oil well cement pastes (OWCPs) modified with core/shell TiO2@SiO2 (nTS) nanoparticles and polycarboxylate-ether (PCE) superplasticizers at different temperatures (25, 45, and 60 °C). Results show that nTS particles increased static and dynamic yield stresses and the apparent viscosity of the cement slurries due to an increased solid volume fraction and reduced free water availability. The increase in the slurry dispersion by adding PCE superplasticizers enhanced the effect of the nanoparticles on the rheological parameters. Oscillation rheometry demonstrated that nTS nanoparticles enhanced the structural buildup, while PCE retarded hydration. Furthermore, slurries hydrated at 60 °C experienced higher initial values of the elastic modulus and a faster exponential increase in this rheological parameter due to the acceleration of the cement hydration.

Effect of waterproofing treatment on mechanical properties of bamboo

Longitudinal tensile, longitudinal compressive, and flexural tests of bamboo from different regions were carried out, and the values of strength and elastic modulus were obtained. The probability distribution models of mechanical properties of bamboo in different regions were studied based on the data. The effects of no waterproofing treatment, tung oil treatment, and wood wax oil treatment on mechanical property degradation of bamboo were studied in response to 7 days of soaking. The main conclusions include: the mechanical properties of bamboo produced in Yunnan Province were the highest, followed by Jiangxi Province, and the lowest in Zhejiang Province. The Weibull distribution model achieved a good fit for all mechanical properties. With the increase of soaking time, the mechanical properties of bamboo were degraded. Degradation in the control group was the highest, followed by the wood wax oil group, and tung oil group was the lowest. On the 7th day, the average mechanical properties of the control group had decreased by 32.0%, the tung oil group by 14.5%, and the wood wax oil group by 25.6%. Through comprehensive comparison, it was evident that tung oil treatment provided the best waterproofing effect for bamboo.

Yellow fluorescent UV-curable epoxy acrylate/VTMS-modified GQDs coatings: study of UV-blocking and viscoelastic properties

Polymer coatings decompose in the presence of UV radiation from sunlight and beget economic and environmental losses. Hence, it is necessary to reinforce the polymer coatings with UV-blocking nanoparticles and to convert the UV light into visible light. In this research work, the surface of graphene quantum dots (GQDs) was modified by vinyltrimethoxysilane (VTMS). VTMS-modified GQDs (VmGQDs) including 0, 0.3 and 0.6 wt% were taken into account to synthesize UV-curable epoxy acrylate/VmGQDs (Ep/VmGQDs) nanocomposite coatings. Surface modification, UV-blockage, fluorescence features and viscoelastic properties of Ep/VmGQDs coatings were analyzed by various spectrometry tests. The existence of VmGQDs (0.3 wt% and 0.6 wt%) in the polymer matrix led to absorption of UV rays in UV regions and fluorescence emission in the visible area with 578 nm wavelength (yellow fluorescence). Appearance of strong absorption bands at 250, 285 and 365 nm by the coatings with VmGQDs confirmed that a large portion of UV rays was absorbed and blocked. The intensity of UV-blockage by Ep/VmGQDs 0.6 wt% was recorded >99%. Furthermore, reinforcement of the coatings with VmGQDs resulted in increase in storage modulus, cross-linking density and Tg value.

Experimental Study on Mechanical Performance of Single-Side Bonded Carbon Fibre-Reinforced Plywood for Wood-Based Structures.

In addition to the traditional uses of plywood, such as furniture and construction, it is also widely used in areas that benefit from its special combination of strength and lightness, particularly as a construction material for the production of finishing elements of campervans and yachts. In light of the current need to reduce emissions of climate-damaging gases such as CO2, the use of lightweight construction materials is very important. In recent years, hybrid structures made of carbon fibre-reinforced plastics (CFRPs) and metals have attracted much attention in many industries. In contrast to hybrid metal/carbon fibre composites, research relating to laminates consisting of CFRPs and wood-based materials shows less interest. This article analyses the hybrid laminate resulting from bonding a CFRP panel to plywood in terms of strength and performance using a three-point bending test, a static tensile test and a dynamic analysis. Knowledge of the dynamic characteristics of carbon fibre-reinforced plywood allows for the adoption of such cutting parameters that will help prevent the occurrence of self-excited vibrations in the cutting process. Therefore, in this work, it was decided to determine the effect of using CFRP laminate on both the static and dynamic stiffness of the structure. Most studies in this field concern improving the strength of the structure without analysing the dynamic properties. This article proposes a simple and user-friendly methodology for determining the damping of a sandwich-type system. The results of strength tests were used to determine the modulus of elasticity, modulus of rupture, the position of the neutral axis and the frequency domain characteristics of the laminate obtained. The results show that the use of a CFRP-reinforced plywood panel not only improves the visual aspect but also improves the strength properties of such a hybrid material. In the case of a CFRP-reinforced plywood panel, the value of tensile stresses decreased by sixteen-fold (from 1.95 N/mm2 to 0.12 N/mm2), and the value of compressive stresses decreased by more than seven-fold (from 1.95 N/mm2 to 0.27 N/mm2) compared to unreinforced plywood. Based on the stress occurring at the tensile and compressive sides of the CFRP-reinforced plywood sample surface during a cantilever bending text, it was found that the value of modulus of rupture decreased by three-fold and the value of the modulus of elasticity decreased by more than five-fold compared to the unreinforced plywood sample. A dynamic analysis allowed us to determine that the frequency of natural vibrations of the CFRP-reinforced plywood panel increased by about 33% (from 30 Hz to 40 Hz) compared to the beam made only of plywood.

Supramolecular Ni(II)-Selective Gel Assembly toward Construction of a Schottky Barrier Diode.

A mechanically stable and thermo-irreversible supramolecular Ni(II)-selective gel (MG) has been developed by utilizing the N,O-donor Schiff base (E)-1-((4-(diethylamino)phenylimino)-methyl)naphthalen-2-ol (HL) gelator and Et3N in binary THF:CH3OH (1:1) solutions at room temperature (rt). Metallogel MG has been characterized by spectral and analytical techniques, i.e., ESI-MS, FT-IR, NMR (1H & 13C), powder-XRD, FE-SEM, and rheological analysis. Further, noncovalent interactions responsible for the gelation mechanism have been illustrated with the aid of powder-XRD and FE-SEM analysis. The toughness, viscoelasticity, and flow behavior of MG were explored through rheological studies. Rheological and compressive measurements showed higher values of storage modulus and rigidity of MG; however, the flow property along with enrichment of toughness in MG can be an analytical metric for various engineering and industrial applications. Eventually, a Schottky barrier diode (SBD) was successfully constructed to mimic the functionality of MG-based metal-semiconductor (MS) junction devices for possible application in electrical engineering.