Materials and Technology

STRESS ANALYSIS AND NUMERICAL SIMULATION STUDY OF COLD METAL TRANSFER WELD HEAD

Mei Li, Fu Yang, Xiaolong Wei, Zheng Jia — Thu, 04 Jun 2026 06:28:48 +0200

In order to study stress and deformation during welding, the macroscopic and microscopic morphologies of the welded joints were recorded to obtain the best welding parameters. Taking a Q235 steel plate as the specimen, six groups were welded under different welding parameters using the cold metal transfer method. The stress field and deformation field in the welding process were simulated using the finite element method. The simulation results were used to further explain the experimental findings and to compare them with the experimental data. The results show that an excessive welding current aggravates the stress concentration of the joint and reduces the fatigue strength of the joint. If the welding current is too small, the stress of the base metal after welding is small, and there are defects including incomplete penetration and undercut. By comparison, the optimal welding parameters are identified as a current of 180 A, a voltage of 14.0 V, a welding speed of 600 mm/min, and a wire feeding speed of 5.5 m/min, under which good weld formation is achieved, and both stress and deformation are relatively low. The experimental results are basically consistent with the numerical simulation results.

3D-PRINTED POLYLACTIC ACID REINFORCED CARBON FIBER IN BULK AND TRIPLY PERIODIC MINIMAL SURFACE (TPMS) LATTICE STRUCTURES: A MECHANICAL PROPERTIES COMPARATIVE STUDY

Nabilah Afiqah Mohd Radzuan — Thu, 04 Jun 2026 06:32:55 +0200

Focusing on lightweight design while maintaining mechanical integrity at the highest levels has made triply periodic minimal surface (TPMS) lattice structures one of the promising structural concepts.¹ Therefore, this study investigates the mechanical performance of polylactic acid (PLA) reinforced with 15 w/% carbon fiber (CF) in both bulk and TPMS lattice. Bulk PLA/CF (15 w/%) exhibited a 58.2 % increase in the tensile modulus over neat PLA, though stiffness decreased with the temperature due to matrix softening. Compression tests showed that the gyroid lattice structure achieved higher compressive strength (19.02 MPa) with stable energy absorption, while the honeycomb structure had greater stiffness (691.53 MPa) but lower strength (17.73 MPa). Finite element simulations confirmed these trends, highlighting stress localization in the honeycomb and a uniform stress distribution in the gyroid. Overall, gyroid lattices are preferable for energy absorption applications, whereas honeycomb structures are more suitable for stiffness-critical lightweight designs.

MECHANICAL PROPERTIES OF ZrO2-TOUGHENED Al2O3 CERAMICS: EFFECT OF ZrO2 CONTENT

Thu, 04 Jun 2026 06:43:53 +0200

Alumina ceramics are important high-temperature materials with exceptional properties; however, their applications are limited by their low flexural strength and brittle nature. Adding a secondary phase effectively improves the toughness of alumina without compromising its hardness. In this study, as a cost-effective solution for the production of high-performance alumina composites, zirconia-toughened alumina (ZTA) composites with different ZrO₂ contents (3–20 %) were prepared using the vacuum hot-pressing sintering of micron-scale ZrO₂ and Al₂O₃ powders. Furthermore, the influence of the ZrO₂ content on the mechanical properties and fracture morphology of the composites was investigated. The density, hardness, fracture toughness and flexural strength of the zirconia/alumina composite ceramic increased with an increase in the ZrO₂ content from 3 % to 15 %. The ceramic exhibited the best comprehensive mechanical properties –a density of 98.15 %, a hardness of 887.3 HV and a bending strength of 326.28 MPa – at a ZrO₂ content of 15 %. This was attributed to the uniform distribution of the secondary phase at the fracture surface and toughening mechanisms of phase transformation and crack deflection. At ZrO₂ contents of ≥18 %, the agglomeration of the ZrO₂ particles caused stress concentration and other phenomena, which weakened the toughening mechanism. This study provided a feasible approach for the industrial-scale production and application of high-performance ZTA multiphase ceramics.

ADDITIVE MANUFACTURING OF ARCHITECTED INCONEL 718 STRUCTURES: EXPLORING THE STRENGTH AND FAILURE OF LATTICE STRUCTURES

Thu, 04 Jun 2026 08:06:43 +0200

This study investigates the mechanical performance and failure behaviour of additively manufactured Inconel 718 (IN718) lattice structures fabricated via laser powder bed fusion (PBF-LB). Five distinct unit-cell topologies were evaluated: three triply periodic minimal surfaces (TPMSs), namely Schoen gyroid (SG), Schwarz diamond (SD), and Schwarz primitive (SP), and two beam-based strut lattices with body-centred cubic (BCC) and beam diamond (BD) unit cells. All specimens were fabricated on an EOS M290 system with a controlled infill density of approximately 18–20 % and subjected to the manufacturer-recommended solution and ageing heat treatment for IN718. Monotonic tensile tests were performed to quantify the ultimate tensile strength (UTS) and to evaluate topology-dependent failure mechanisms. The results reveal a pronounced architectural influence on tensile performance, with TPMS lattices consistently outperforming beam-based designs. Among all configurations, the SD lattice achieved the highest UTS, reaching approximately 817 MPa, whereas the BCC lattice exhibited the lowest UTS, 315 MPa. Fractographic analysis showed that beam-based structures failed predominantly at strut–node intersections, while TPMS lattices displayed micro-void coalescence with local shear facets, indicative of distributed ductile tearing. Overall, the results indicate that TPMS geometries exhibit superior tensile performance compared with conventional beam lattices in static load-bearing applications.

PREPARATION AND VULCANIZATION CHARACTERISTICS OF EXTREMELY COLD-RESISTANT CARBOXYL-BASED ACRYLIC RUBBER WITH BUTYL FUMARATE AS A VULCANIZING MONOMER

Thu, 04 Jun 2026 08:11:26 +0200

In this article, ethyl acrylate, butyl acrylate, and 2-methoxyethyl acrylate are used as reaction monomers; butyl fumarate (BFM) is used as a vulcanization crosslinking point monomer; ammonium persulfate and sodium bisulfite are used as initiators; and sodium dodecyl sulfonate is used as an emulsifier to prepare extremely cold-resistant acrylic rubber (ACM). The synthesized raw rubber is mixed and vulcanized, and the vulcanization characteristics are tested to characterize and analyze the structure of the raw rubber. Moreover, the influence of the BFM amount on the mechanical properties, air-aging resistance, and oil resistance is studied. The structure and design of the acrylic rubber are consistent with expectations, with a glass transition temperature of –34.62 °C. As the BFM amount increases, the vulcanization rate and the tensile strength increase, while the elongation at break decreases. Furthermore, the ACM with BFM as a vulcanizing monomer exhibits excellent hot-air aging performance and good oil resistance. Therefore, this product can be widely used in oil and high-temperature environments and is particularly recommended for automotive oil seals and pipes.

EXPERIMENTAL INVESTIGATION ON TRIBOLOGY AND MECHANICAL CHARACTERISTICS OF FUNCTIONALIZED GRAPHENE AND MWCNTs REINFORCED EPOXY HYBRID NANOCOMPOSITES

Alagar S, Sabarinathan C, Arivazhagan R, Sundaravadivel T A — Thu, 04 Jun 2026 08:16:57 +0200

The development of epoxy-based hybrid nanocomposites reinforced with functionalized graphene and multi-walled carbon nanotubes (MWCNTs) has emerged as a promising strategy to enhance structural performance under combined mechanical and tribological characteristics. In this study, the tribological and mechanical characteristics of epoxy and its hybrid nanocomposites (EGpCn1–EGpCn5) was systematically evaluated under different loads, obtaining results that indicated a significant improvement in the wear resistance of the optimized formulations. Among all compositions, EGpCn3 demonstrated superior wear performance, exhibiting considerably lower material loss, smoother worn surfaces as well as evidence of nanofiller bridging and thin-film formation, which acted as protective layers against severe abrasive damage. Conversely, EGpCn5 revealed deep grooves, nanofiller bundles and pull-out regions, indicating poor dispersion and leading to accelerated wear degradation. Beyond tribological performance, the tensile properties of the hybrid nanocomposites also exhibited noteworthy enhancements, with EGpCn3 achieving the highest tensile strength of 69.12 MPa, corresponding to an almost 88 % increase over epoxy (36.71 MPa). This remarkable improvement can be attributed to strong interfacial adhesion, effective stress transfer and restricted crack propagation facilitated by the uniform graphene–MWCNT network. However, EGpCn5 again showed considerably lower tensile strength (27.12 MPa), where large voids, agglomeration and stepped fracture morphology confirmed the detrimental effect of poor nanofiller dispersion. Morphological examinations, using SEM, further demonstrated that the synergistic interaction of graphene and MWCNTs provided superior reinforcement by bridging microcracks, dissipating energy and enhancing load bearing capacity under both static and dynamic conditions.

OPTIMIZED TRIBOLOGICAL BEHAVIOUR OF MUSA–BASALT–SiC HYBRID COMPOSITES USING RSM

Thu, 04 Jun 2026 08:35:18 +0200

The study examines the influence of SiC additions on tribological properties of basalt–Musa fiber-reinforced hybrid composites with a phenol-formaldehyde matrix. The composite with 60 % of Musa, 26 % of basalt and 4 % of SiC (S5) had the highest mechanical properties, such as tensile, flexural and compressive strength of 38.8 MPa, 186.8 Mpa and 70.8 MPa, respectively, and was selected for wear testing. Experiments on tribological behaviors at different sliding velocities (2–6 m/s), contact pressures (0.25–0.75 MPa) and durations (60–180 s) indicated wear rates between 4.2 × 10^–5 and 34 × 10^–5 mm³/m and a COF of 0.08–0.205. These results were well modelled using response surface methodology with R² values of 0.995 and 0.922, for wear rate and COF, respectively. It was found that the effect of the wear rate was governed by contact pressure and duration, while the COF was affected by all the factors together. The article emphasizes the wear properties of the Musa–basalt–SiC hybrid composite and determines the most favorable conditions in terms of improved tribological quality.

HYBRID NATURAL GEOTEXTILES FOR SUSTAINABLE GROUND IMPROVEMENT: INSIGHTS FROM UCC, CBR, AND DIC ANALYSES

Saranya Nithiyanandan, Ganesh Kumar Shanmugam, Sivapriya Vijayasimhan — Thu, 04 Jun 2026 08:42:19 +0200

The growing need for environmentally sustainable ground improvement has accelerated the use of natural fiber geotextiles as alternatives to synthetic reinforcements. This study investigates the mechanical and deformation characteristics of clayey soil reinforced with coir and jute geotextiles, used individually and in hybrid configurations. Reinforcement layers were positioned at mid-height (H/2), one-third height (H/3), and as dual hybrid systems. Improved soil specimens compacted at dry-of-optimum (DOP), optimum-moisture-content (OMC), and wet-of-optimum (WOP) conditions were evaluated using Unconfined Compression (UCC), California Bearing Ratio (CBR), and Digital Image Correlation (DIC) techniques. Results indicate that specimens prepared at OMC consistently achieved the highest strength. Hybrid reinforcement with jute at the bottom and coir at the top (J-B, C-T) delivered the best overall performance, producing up to 45–55 % improvement in the UCC strength and more than two-fold enhancement in CBR compared with unreinforced soil under soaked conditions. DIC analysis confirmed a substantial reduction in strain localization and bulging in reinforced samples, with the lowest vertical strain (≈1.27 %) recorded for the hybrid system against 2.24 % for unreinforced soil. The findings demonstrate that hybrid coir–jute geotextile systems placed near the critical shear zone provide an effective, economical, and sustainable solution for improving the performance of pavement subgrades.

MECHANICAL AND MICROSTRUCTURAL BEHAVIOUR OF STIR-CAST AA7065–B4C–GRAPHITE HYBRID COMPOSITES WITH OPTIMIZED REINFORCEMENT CONTENT

Madhan Baladhandapani, Parthiban Alagesan — Thu, 04 Jun 2026 10:01:13 +0200

High-strength aluminium hybrids reinforced with ceramics and solid lubricants are used in structural and tribological parts. AA7065 supports precipitation hardening and the incorporation of B₄C and graphite. Quantitative links between reinforcement content and mechanical behaviour remain limited for AA7065. This study quantifies the effect of B₄C content at a near-constant graphite level on hardness, tensile metrics, and Izod impact energy. Hybrids containing 0–7 w/% B₄C with 3 w/% graphite were produced by vortex-assisted stir casting, T6-treated, machined into ASTM E8 and ASTM D256 specimens, tested, and characterized using optical/SEM microscopy, followed by ANOVA response-surface analysis. Strengthening is evident, with hardness increasing from about 100 HV to about 130 HV (30 %), and tensile strength increasing from about 300 MPa to about 360 MPa (20 %) at 7 w/% B₄C. Damage tolerance declined, with elongation decreasing from about 12 % to about 5 %, and Izod impact energy decreasing from about 20 J to about 12 J. The pattern is consistent with load transfer and dislocation blocking combined with particle-assisted void nucleation. These data guide reinforcement selection for AA7065–B₄C–graphite composites used in high-strength parts with controlled deformability. Future work will target fatigue and wear response under service loading and evaluate graphite fraction and particle size as design variables.

CHARACTERIZATION OF ABACA-E-GLASS/EPOXY POLYMER COMPOSITES REINFORCED WITH BAMBOO-ACTIVATED CARBON NANOFILLERS

Lies Banowati, N. Chitraningrum, B. Mulyati — Thu, 04 Jun 2026 10:12:38 +0200

This study aims to investigate the effect of fiber volume fraction and NaOH treatment on the mechanical and physicochemical properties of hybrid abaca–E-glass/epoxy composites reinforced with bamboo-activated carbon nanofiller. Composites were fabricated using hand lay-up and vacuum bagging, with fiber volume fractions (V_f) of (40, 50 and 60) % and fiber orientations of 0° and (0/90)°. Meanwhile, the weight percentage of bamboo-derived activated carbon filler was 2 w/%. Tensile tests were conducted according to ASTM D3039, while morphological, elemental, and chemical characterizations were performed using SEM-EDS and FTIR analyses. The results show that the composite with a V_f of 50 % and 0° fiber orientation treated with NaOH exhibited the highest tensile strength of 56.62 MPa, compared to 46.08 MPa for untreated fibers, indicating improved interfacial adhesion due to alkali treatment and hybridization with E-glass fibers. SEM observations revealed relatively uniform nanofiller dispersion and predominant fiber fracture, whereas a higher V_f of 60 % led to void formation and reduced tensile strength. SEM-EDS confirmed dominant carbon content in the nanofiller (90.90 %), while FTIR spectra identified characteristic O–H, C=O, C–O–C, and Si–O–Si groups, demonstrating successful curing and good compatibility among fibers, nanofiller, and epoxy matrix. Overall, the optimized composite at a V_f of 50 % exhibits enhanced mechanical performance and interfacial interaction, highlighting its potential for lightweight structural and radar-absorbing applications.

QUANTITATIVE CORRELATION BETWEEN AGGREGATE WATER ABSORPTION AND CONCRETE STRENGTH IN MULTI-CYCLE RECYCLING

Hongseok Yang, Jeonghyun Kim, Ganza Jean Francois Regis, Namho Kim — Thu, 04 Jun 2026 10:22:56 +0200

This study investigated the influence of quality enhancement of multi-recycled aggregates on the performance of concrete. First-generation (RA1) and second-generation (RA2) recycled aggregates were subjected to three conditions – untreated, mechanically treated, and chemically treated – and the corresponding concretes incorporating these aggregates as coarse aggregate were evaluated in terms of workability and compressive strength. For untreated RAs, water absorption sharply increased with increasing recycling cycles, accompanied by a marked decrease in density. These changes resulted in a slump loss of 47 % and a compressive strength reduction of up to 13 %. Mechanical treatment slightly reduced the water absorption, but the improvement was marginal for RA2. In contrast, chemical treatment improved the physical properties of both RA1 and RA2, bringing them close to those of natural aggregate, and the corresponding concretes achieved strengths equivalent to those of natural aggregate concrete. According to regression analysis, a strong negative linear correlation was observed, indicating that a 1 % reduction in water absorption of RAs leads to an approximate 1.9 % increase in compressive strength of concretes. The findings of this study indicate that improving the properties of RAs can effectively enhance the performance of concrete and demonstrate the feasibility of repeated recycling, regardless of the number of recycling cycles.

PREPARATION OF NANO MANGANESE OXIDE AND ITS APPLICATION IN THE WET OXIDATION OF PHENOL

Weitao Huo, Hongjing Yuan, Yongchao Hao, Cuige Lu, Lixia Wang, Mengdi Cao — Thu, 04 Jun 2026 10:41:53 +0200

Manganese oxide nanoparticles have application prospects in catalysis due to their high specific surface area, abundant active sites, and excellent chemical stability. In this study, nano α-Mn₂O₃ catalysts were synthesized via microwave-assisted carbonization in a glucose-urea system. Characterization results revealed that the amount of urea added influences the structure of the prepared manganese oxide, the optimized sample, Mn-3 possessed the smallest crystallite size, the highest specific surface area, and a mesoporous structure. In the catalytic wet oxidation of phenol, Mn-3 demonstrated a remarkable conversion rate of 97.8 %, significantly outperforming α-Mn₂O₃ prepared by conventional precipitation methods of 58.8 %. Recycling tests indicated that Mn-3 retained a 60 % conversion efficiency after five cycles, demonstrating good stability. This superior performance was attributed to its abundant surface defects, high specific surface area, and mesoporous structure.

GREEN AND CONVENTIONAL SYNTHESIS OF NiO NANOPARTICLES: IMPACT OF ERUCA SATIVA ON PHOTOCATALYSIS

Samia Remli, Djanette Meriem Blizak, Salah Blizak — Fri, 05 Jun 2026 11:56:42 +0200

In this study, we report a hybrid synthesis route to nickel oxide (NiO) nanoparticles that combines conventional sol–gel and Pechini methods with a green, bio-mediated approach using Eruca sativa (rocket) extract for the first time in NiO synthesis. This plant-based approach offers a genuinely sustainable alternative to purely chemical synthesis, while a factorial design helps us identify the specific contributions of each component. Four distinct samples were prepared from nickel acetate and calcined at 450 °C for two hours, then characterized by XRD, FTIR and UV–Vis spectroscopy to probe their structure and optical properties; their photocatalytic ability was evaluated by degrading methylene blue under UV light. Interestingly, the Pechini route produced markedly larger crystallites (41.3 nm) than the sol–gel co-precipitation method (15.5 nm), pointing to the decisive role of citric acid and ethylene glycol in steering crystal growth. More strikingly, incorporating rocket extract significantly narrowed the optical band gap – from 3.46 eV down to 3.22 eV in Pechini samples, and from 3.52 eV to 3.31 eV in the sol–gel batch. The best-performing catalyst was the bio-assisted Pechini sample, which degraded 65.6 % of the dye in 180 min, a clear improvement over the 43 % achieved by its conventional counterpart. Our findings suggest that blending optimized chemical routes with botanical extracts is a viable, powerful strategy for engineering high-efficiency NiO photocatalysts suited to sustainable water treatment.

TRIBOLOGICAL PERFORMANCE OF HEAT-TREATED Al6061 HYBRID METAL-MATRIX COMPOSITES

Pradeep A D, Kannakumar K, Vignesh Kumar S, Manojkumar S, Tamilarasan V D — Mon, 08 Jun 2026 11:49:30 +0200

We investigate the tribological performance of a heat-treated Al6061 alloy and its hybrid composites under dry-sliding conditions. Hybrid aluminium metal-matrix composites reinforced with graphite, nano-tungsten carbide and red mud were fabricated using the stir-casting technique. The as-cast alloy and composites were subjected to a T6 age-hardening treatment to examine the effect of microstructural modification on the wear behaviour. Dry-sliding wear tests were carried out using a pin-on-disc tribometer under varying loads, sliding velocities and sliding distances based on a Taguchi L9 design. The specific wear rate and coefficient of friction were measured, and worn surfaces were analysed using FESEM and EDS. The results show that hybrid composites exhibit superior wear resistance compared to the base alloy after heat treatment. Tungsten carbide improved the hardness and load-bearing capacity, reducing material removal, while graphite contributed to the friction reduction through tribo-layer formation. The combined addition of tungsten carbide and graphite resulted in the lowest wear rate and stable friction behaviour. Red mud enhanced the wear resistance under moderate conditions by promoting oxide-layer formation but caused brittleness under severe sliding. Heat treatment further improved the performance by refining the microstructure and strengthening matrix–reinforcement bonding. Overall, hybrid reinforcement combined with heat treatment enhances the tribological performance.

MICRO VICKERS HARDNESS AND SURFACE ROUGHNESS OF Al-Cu UNS A92124/T851 ALLOY IN RELATION TO TURNING PARAMETERS: AN EXPERIMENTAL STUDY

Vellingiri Sakthivel, Sundara Vadivel G., Arunkumar A., Sivamani S. — Mon, 08 Jun 2026 11:56:50 +0200

This study examines the effect of cutting speed and feed rate on the surface roughness and microhardness of UNS A92124-785 during CNC turning. The machined surfaces were evaluated in terms of surface roughness, microhardness, and corrosion behavior, while surface morphology and elemental characteristics were analyzed using SEM coupled with EDX. The results indicated that surface roughness (Rz) increased mainly with feed rate and showed moderate dependence on cutting velocity, with further deterioration observed after corrosion due to increased surface irregularities. Microhardness measurements revealed minimal variation with machining parameters before corrosion. However, a noticeable reduction in Vickers microhardness (VH) was observed after corrosion, suggesting surface softening. Overall, the findings highlight feed rate as the dominant factor influencing surface quality and demonstrate that corrosion adversely affects both surface integrity and hardness of the machined material.

HETEROGENOUS EQUILIBRIA IN Al-Mn QUASICRYSTALLINE ALLOY DURING HIGH-PRESSURE DIE CASTING

Borut Dremelj, Adam Zaky, Iztok Naglič, Matej Zupančič, Boštjan Markoli — Mon, 08 Jun 2026 12:05:41 +0200

Using advanced characterization techniques, including optical microscopy, scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS), and differential scanning calorimetry (DSC) combined with Thermo-Calc calculations, the study demonstrated the relationship between casting conditions, microstructure, and phase formation during high-pressure die casting (HPDC) and comparative gravity casting in steel and copper molds. We demonstrated how both casting conditions and changes in the alloy’s chemical composition instigate different heterogeneous equilibria and thus influence the constitution of the alloys. After equilibrium solidification, the microstructures of the synthesized alloys consist of α_Al matrix, Al₆Mn, and traces of Al₂CuMg, Al₁₂Mn, and Mg₂Si, while nonequilibrium solidification led to the formation of different phases, such as icosahedral quasicrystalline (IQC) phases, such as icosahedral quasicrystalline (IQC) phases their approximant α-AlMnSi and β-AlMnSi phase. Finally, we confirmed the presence of different heterogeneous equilibria that existed simultaneously during the solidification of the investigated alloys.

QUANTITATIVE MEASUREMENT OF MAGNETIC FORCE IN BASIC AND PRECIOUS DENTAL ALLOYS FOR PORCELAIN TECHNIQUE

Mon, 08 Jun 2026 12:16:28 +0200

Precious dental alloys based on gold, platinum, palladium or silver exhibit excellent corrosion resistance, high biocompatibility and optimal mechanical properties for use in prosthetic dentistry. In comparison, base dental alloys based on chromium, cobalt or nickel are cheaper, have excellent mechanical properties but poorer corrosion resistance and biocompatibility. This research examined the magnetic properties of dental alloys in a magnetic field, which vary with composition and electronic structure. Materials can be classified as diamagnetic, paramagnetic or ferromagnetic, depending on how they respond to an external magnetic field, with noble metals usually showing weak or negligible magnetic behaviour. Experimental results of magnetic force measurements in precious dental alloys have shown that most exhibit diamagnetic properties, being weakly repelled by a magnetic field, and do not retain any magnetization when the magnetic field is removed. One of the tested precious-metal alloys exhibited paramagnetic behaviour, indicating a weak attraction in a magnetic field. In contrast, all studied dental base-metal alloys exhibited stronger paramagnetic interactions with magnetic fields. Diamagnetic properties of precious-metal dental alloys present a significant advantage in the medical environment, especially in magnetic resonance imaging (MRI) as diamagnetic materials do not interfere with magnetic fields and thus reduce image distortion and patient risk during MRI. However, paramagnetic base-metal dental alloys can cause local heating or imaging artefacts under MRI conditions. Therefore, precious-metal dental alloys are more suitable for patients who may require MRI, as they combine functional durability with greater safety in medical diagnostics.

BIOPOLYMER COMPOSITE FILMS BASED ON HYDROXYPROPYL METHYLCELLULOSE (HPMC) AND PECTIN REINFORCED WITH MgO AND ZnO NANOPARTICLES FOR STRAWBERRY (Fragaria vesca) PRESERVATION

Nourdjihane Mazouzi, Boutemak Khalida, Haddad Ahmad — Mon, 08 Jun 2026 12:24:51 +0200

Biopolymers have been widely investigated as an alternative to synthetic plastics. Perishable foods such as fruits and vegetable products have a short shelf life and cause significant postharvest losses, posing a major challenge to the food supply chain. In this research, hydroxypropyl methylcellulose (HPMC)/pectin composite reinforced with 0.5 % magnesium oxide nanoparticles (MgO NPs) and 0.5 % zinc oxide nanoparticles (ZnO NPs) was investigated. The purpose of developing these materials is to improve the mechanical and barrier properties of biopolymer composite films and consider them as an alternative to synthetic plastics of fossil origin. The aim of this study was to create and characterize novel eco-friendly biopolymer composite films for the preservation of strawberries. However, strawberries are highly perishable and susceptible to physical and microbial deterioration after harvest. Their shelf life was extended using a nanocomposite coating based on an HPMC/pectin biopolymer matrix reinforced with MgO and ZnO nanoparticles. Coated and uncoated strawberries were monitored for 10 days at 20 °C. The HPMC/pectin/NPs coating acted as a physical barrier, reducing respiration rate, weight loss, and preserving the good shape of strawberries (Fragaria vesca) compared to uncoated fruits during storage. In addition, the results showed that nanocomposite films prepared from HPMC/pectin/NPs provided excellent bacterial inhibition against Escherichia coli and Staphylococcus aureus, making them suitable for food packaging. Moreover, the addition of MgO and ZnO NPs significantly increased the flexibility and plasticity of the nanocomposite films compared to HPMC/pectin films alone. In short, the use of an active nanocomposite coating of HPMC/pectin/MgO NPs and/or ZnO NPs can be considered an effective method to protect strawberries from physical and biological damage during storage and transportation.

INITIATION OF STRESS CORROSION CRACKING IN BRASS COMPONENTS FOR DRINKING WATER SYSTEMS: SELECTED CASE STUDIES

Mirjam Bajt Leban, Tadeja Kosec — Mon, 08 Jun 2026 12:32:43 +0200

Failure of various components in internal drinking water systems leads to water leakage and high economic costs. Brass is a promising material for machining such components; however, it is sensitive to special forms of corrosion. Dezincification of duplex (α+β') brass can cause dealloying and cracking of components and also lead to the release of lead into drinking water, which is one of the greatest health concerns in these systems. In the present study, the microstructure and fractures of three brass components that cracked a short or moderate time after the start of operation were investigated. The investigation showed their sensitivity to cracking regardless of the presence of a corrosive environment.