Search Results (192)

For meeting the growing demand for lightweight impact-resistant materials, this study designed and fabricated a carbon hollow microsphere (CHM)-reinforced polydimethylsiloxane (PDMS) composite and systematically investigated the influence of CHM packing structure on its energy absorption performance. Through optimizing the controllable preparation processes of the CHMs, CHMs with low breaking rates and novel structural stability were successfully prepared. A vacuum-assisted mixing–casting method was employed to synthesize the CHM/PDMS composites with varying CHM contents (0~10 wt.%). The results demonstrated that the incorporation of CHMs significantly enhanced the compressive strength, compressive modulus, and energy absorption efficiency of the PDMS matrix. Under quasi-static loading, the composite with 4 wt.% CHM exhibited optimal comprehensive performance, achieving a 124.68% increase in compressive strength compared to pure PDMS. In dynamic impact tests, the compressive strength and energy absorption at a strain rate of 4500 s⁻¹ increased by 1245.09% and 1218.32%, respectively. The improvement of mechanical properties can be mainly attributed to the introduction of CHMs with an appropriate percentage, which can form a dense stacking structure so that the interaction force between the CHMs and PDMS matrix can be improved through the dense stacking effect, and the external force can be effectively dissipated through interface interaction, in addition to the energy dissipated by the deformation of the matrix deformation and crush of the CHMs. Additionally, the introduction of CHMs elevated the onset thermal decomposition temperature of the materials, leading to an enhanced thermal stability of the CHM/PDMS composite compared to that of the pure PDMS. Overall, this study provides theoretical and experimental foundations for designing lightweight impact-resistant materials and demonstrates the potential of CHM/PDMS composites for multifunctional safety protection. Full article

The objective of this work was to produce and characterize active gelatin–acerola packaging films based on gelatin incorporated with different concentrations of acerola pulp and applied to evaluate the stability of meat products in packaging. The active films were produced by casting using gelatin (5%), sorbitol (0,1%), and acerola pulp (60, 70, 80, and 90%). The characterization of the acerola pulp was carried out. Visual aspects, thickness, pH, water vapor permeability, and total phenolic compounds were characterized in the films. The commercial acerola pulp presented the characteristics within the identity and quality standards. A good film formation capacity was obtained in all formulations, presenting the color parameters tending to red coloration, characteristic of the acerola pulp. The total phenolic compounds content ranged from 2.88 ± 70.24 to 3.94 ± 96.05 mg GAE/100 g, with 90 g of acerola pulp per 100 g of filmogenic solution. This film formulation was selected to apply in a vacuum pack of beef and chicken samples, analyzing the weight loss, color parameters, pH, water holding capacity, shear strength after 9 days of refrigeration storage, and soil biodegradability. Additionally, beef and chicken (in nature) were stored under the same conditions without using the wrapping film. The beef and chicken samples showed greater water retention capacity and color maintenance over the storage period compared to the control (without film addition). This way, active gelatin–acerola films can be considered a sustainable packaging alternative to preserve meat products. Full article

The eutectic PbLi (15.7 at.% Li) alloy appears promising for producing tritium from fertile materials. Currently, in nuclear fusion design, the technologies being explored for tritium extraction in molten phases primarily focus on (i) established processes based on Gas–Liquid Contactor (GLC), such as bubble, packed, or spray columns, or on (ii) exploiting hydrogen permeation phenomena using dense metallic membranes, i.e., Permeation Against Vacuum (PAV). This work introduces a new concept, a Membrane Gas–Liquid Contactor, to address several open issues related to mass transport phenomena within the previously mentioned technologies. The MGLC concept merges the advantages of Permeation Against Vacuum (PAV) and Gas–Liquid Contactor (GLC), which have been extensively applied to extract hydrogen and its isotopes from liquid metals. A comprehensive description of the MGLC’s operation is then provided, suggesting a mass transfer model suitable for the practical application of this new concept. Finally, the results of the experimental campaign conducted on a lab-scale test facility are presented and critically analyzed. Full article

This study investigated the meat quality, sensory properties and microbiology of Angus beef after a short dry or wet aging. For that, a total of 16 Biceps femoris muscles from female Aberdeen Angus x Charoles calves were used. Half of these underwent a technological aging process in the carcass (dry aging) for 7 days, whilst the remaining were filleted, vacuum-packed and stored at refrigerated conditions (wet aging) for 7 days at 4 ± 2 °C. The type of aging affected the ratio of the myoglobin forms but did not translate into differences in the instrumental colour measurements. Dry aging led to minor water release after the application of a force (17.58 dry-aged vs. 31.09 wet-aged) or after cooking and yielded higher hardness and lower shear force in the Warner–Braztler shear force test compared to wet aging. Nevertheless, these differences were not appreciated at the sensory level. Higher counts of mesophilic aerobic bacteria (11.66%) and enterobacteria (3.68%) were found in samples subjected to dry aging. Full article

Particles ejected during thermal runaway (TR) of lithium-ion batteries carry a significant fraction of the total TR energy and can cause danger to other components in the battery system. The associated safety hazards should be addressed in the battery pack development process, which requires a deep understanding of TR particle characteristics. In this study, these characteristics are determined by applying several measurement techniques. Among them, dynamic image analysis and large particle image processing are applied to battery abuse particles for the first time, allowing their size and shape to be quantified in detail. Particles are collected from three overheating tests on a prismatic 51 Ah NMC622 cell under vacuum conditions in an autoclave environment. Battery abuse particles cover a wide size range, from micrometers to millimeters, with the largest particle reaching 51.4 mm. They are non-spherical, whereby sphericity, symmetry, and aspect ratio decrease for larger particles. Re-solidified copper droplets and intact separator pieces indicate particle temperatures of ~200–1100 °C at the time of cell ejection. Particles are partially combustible, with an exothermic onset at ~500 °C associated with graphite oxidation. Reactivity is non-linearly size dependent. Implications of these findings for battery system development are discussed. Full article

Biosecurity is vital to Australia’s efforts to prevent and respond to pests and diseases. Here, we report on testing suspected illegal goods (SIGs) as part of an active Australian biosecurity response in Sydney. The Australian Government, Department of Agriculture, Fisheries and Forestry detected and secured consignments containing tuber products of unknown biosecurity risk and origin. Swab samples were collected from vacuum-sealed yam products, organic packing material (background negative controls), and field negative controls to assess possible cross-contamination from the storage facility. DNA from all samples was analysed using high-throughput metabarcoding targeting the Internal Transcribed Spacer 2 (ITS2) and the chloroplast trnL (UAA) P6 Loop gene regions by two independent teams in Australia. A plant community profile comprising Australian native species and other non-native established species would support the notion of produce being harvested and/or packaged domestically, while their absence would suggest foreign production. Of the 5,764,942 total reads produced, the bioinformatic analysis generated 5,181,530 amplicon sequencing variants employed for species identification. Twenty plant taxa were identified via ITS2 and 15 via trnL, corresponding to worldwide distributed plants, non-native species established in Australia, or species not recorded in Australia. No Australian endemic species were detected. The absence of common Australian native plants, combined with the presence of species not known to occur in Australia, provided strong evidence that the suspect tuber products were illegally imported. Full article

The objective of the present study was to determine the effect of mixed plant extracts on chemical (pH, total volatile base nitrogen (TVB-N), trimethylamine nitrogen (TMA), thiobarbituric acid reactive substances (TBARS), biogenic amines, relative fatty acid composition) and microbiological quality indicators of vacuum-packed fish burgers stored at 0 ± 2 °C over 13 days. Three mixtures of common juniper by-product and blackberry leaves extracts (JB), Padina pavonica and prickly juniper needles extracts (PCJ), and blackberry leaves extract with catechin and vanillic (BCV) were tested. At the end of storage, TVB-N (15.38–20.03 mg/100 g) and TMA (10.64–15.63 mg/100 g) of burgers with extracts were significantly lower than those of the control group (22.77 mg TVB-N/100 g, 18.37 mg TMA/100 g). The TBARS values in the control burger reached 2.62 ± 0.02 µmol malondialdehyde (MDA)/100 g, while in burgers with extracts, final values were in the range of 0.62 ± 0.01 to 0.80 ± 0.02 µmol MDA/100 g. The extracts showed no effect on biogenic amine formation (tryptamine, putrescine, and cadaverine levels increased during the storage, being the lowest in BCV) or microbial counts, with the exception of the Pseudomonas sp. counts that were significantly lower in JB and PCJ in comparison to the control, reaching 4.1, 4.1, and 5.0 log CFU/g in JB, PCJ, and control, respectively. Full article

Sweet potatoes play an important role in the global food supply, as they are rich in bioactive components and have numerous health benefits. Their minimally processed, ready-to-eat form is increasingly popular among consumers; however, discoloration and microbiological problems threaten the safety of these products. The aim of this study is to investigate the shelf life of cleaned, cut, ready-to-eat, vacuum-packed, and refrigerated Bonita (white) and Covington (orange) varieties of sweet potatoes after soaking in apple and chokeberry pomace extracts and treatment with citric and ascorbic acids. A series of microbiological and analytical tests was conducted during the storage period. The microbiological tests included the enumeration of cells of mesophilic aerobic and facultative anaerobic microbes, as well as lactobacilli, lactococci, Enterobacteriaceae, yeasts, and moulds. The analytical tests encompassed the determination of the total phenolic content, antioxidant capacity, water-soluble solid content, and pH value. The prevalent microbial groups detected in the examined sweet potato varieties were lactic acid bacteria, which were present in both fresh samples and following storage. This study established that low-temperature refrigeration (5 °C), vacuum packaging, and organic acid treatment can effectively control lactic acid bacteria, which are pivotal to spoilage. The combination of preservation steps is of particular significance for ready-to-cook sweet potatoes, as this approach effectively extends the shelf life of these products. Full article

The study was conducted on 100 unsalted goat cheeses produced on a certified organic farm. From the 100 cheeses, 10 were selected, which constituted the so-called sample day 0 (before the start of cold storage) and were divided into three groups of 30 pieces each: A—unpackaged group; B—vacuum packed group; and C—vacuum packed group with MEGA CO₂ absorbing insert. The cheeses were stored in a cold store at a temperature of 4 ± 1 °C and relative humidity of 85% for 5, 10, and 15 days. The greatest weight loss of the cheese was shown in group C (4.63%) and on the 10th day of storage (6.09%). The lowest pH value was recorded in groups B (6.31) and C (6.32) and on the 15th day of storage (5.48). The lowest titratable acidity was recorded in group C (14.90°SH) and in sample 0 (12.40 °SH). The highest value of shear force was in group B (3.89 N) and on the 10th day of storage (3.56 N). An analysis of the color parameters of the cheeses showed that the L* value on the surface and after cutting was the highest at p ≤ 0.01 and p ≤ 0.05 in group C and sample 0 and was, respectively: 94.30 and 94.97 and 95.31 and 96.17. The lowest values of the sensory evaluation were obtained in the case of cheeses from group A and on the 15th day of storage, where these values (points) were, respectively: 3.32 and 3.76—color; 2.79 and 3.32—aroma; 3.27 and 3.64—appearance; 4.07 and 4.18—structure and 2.80 and 2.91—taste. Full article

This study assessed the potential for natural anti-microbials to control Listeria monocytogenes in vacuum packed beef burgers. Minimum inhibitory and bactericidal concentration (MIC and MBC) results for natural anti-microbials (carvacrol; essential oils of thyme, rosemary, clove and cinnamon; hop extract; cranberry extract; cranberry pomace; propolis extract; and chitosan sourced from both shrimp and mushroom) were used to select agents (n = 6) showing the most promise against L. monocytogenes. These agents, including chitosan from shrimp and mushroom (a novel source), and cranberry extract, were then tested against L. monocytogenes in vacuum packed beef burgers during chilled storage (3 ± 1 °C, 16 days). Following storage (16 d), the number of L. monocytogenes in beef burgers treated with chitosan (2.5%), regardless of source, was significantly lower (p < 0.05) (1.2 to 1.6 log₁₀CFU g⁻¹) than in the control samples, while smaller reductions (0.5 log₁₀ CFU g⁻¹; p < 0.05) were noted in samples with cranberry extract (0.625%). While chitosan had no significant impact on HunterLab colour measurements during chilled storage, cranberry extract significantly impacted the colour (p < 0.05), resulting in lower L*, a*, and b* values. Observational assessment of colour, odour and the overall quality of the raw meat on opening the pack found that beef burgers with added chitosan (both sources) were acceptable, while those with added cranberry extract received an overall quality score of approximately 5.4, which is above the acceptability threshold (5/10). Overall, the study showed the potential of chitosan to control L. monocytogenes in beef burgers, and the advantage of this agent sourced from mushrooms is discussed. Full article

Nanocomposite laminates containing carbon fibers, epoxy, and multiwalled carbon nanotubes were fabricated using a vacuum bag process. Ecofriendly ionic liquid (5 wt%)-treated multiwalled carbon nanotubes (pristine and nickel-coated) were added to the epoxy independently, in amounts ranging from 1 wt% to 3 wt%, in order to tailor the mechanical, electrical, and thermal performance of manufactured carbon fiber epoxy composite laminates. These nanocomposite laminates were later characterized through flexural testing, dynamic mechanical analysis, impedance spectroscopy, thermal conductivity tests, and FTIR spectroscopy to evaluate their suitability for battery pack applications. The findings showed that both types of multiwalled carbon nanotubes exhibited multifaceted effects on the properties of bulk hybrid carbon fiber epoxy nanocomposite laminates. For instance, the flexural strength of the composites containing 3.0 wt% of ionic liquid-treated pristine multiwalled carbon nanotubes reached 802.8 MPa, the flexural modulus was 88.21 GPa, and the storage modulus was 18.2 GPa, while the loss modulus peaked at 1.76 GPa. The thermal conductivity of the composites ranged from 0.38869 W/(m · K) to 0.69772 W/(m · K), and the electrical resistance decreased significantly with the addition of MWCNTs, reaching a minimum of 29.89 Ω for CFRPIP-1.5 wt%. The structural performance of hybrid nanocomposites containing ionic liquid-treated pristine multiwalled carbon nanotubes was higher than that of the hybrid nanocomposite of ionic liquid-treated Ni-coated multiwalled carbon nanotubes, although the latter was found to possess better functional performance. Full article

In order to explore the effects of different silage inoculants on the silage quality of alfalfa (Medicago sativa L.), this study utilized six groups of experimental treatments and five kinds of additive treatments: Xinlaiwang I straw silage (group A), Xinlaiwang I alfalfa silage (group B), Zhuanglemei silage starter culture (group C), Baoshiqing (group D), Kangfuqing S lactic acid bacteria silage (group E), and another blank control group (CK group, distilled water). The effect of silage on fermentation characteristics and nutritional value of Adina alfalfa silage was studied by membership function analysis. The main study variable was inoculant strains. Alfalfa silage was packed into polyethylene plastic vacuum bags in the laboratory and sealed for 60 days. The silage was divided into six treatment groups with three replicates per group. The fermentation performance and nutrient composition of the silage were determined. The results showed that compared with the control group, adding Xinlaiwang I alfalfa silage (group B) could significantly increase the contents of crude protein (CP) and lactic acid (LA) in alfalfa silage (p < 0.05), decrease the contents of neutral detergent fiber (NDF) and acid detergent fiber (ADF), and decrease the pH and ammoniacal nitrogen/total nitrogen (AN/TN). The results showed that different inoculants could improve the silage quality of alfalfa to different extent, and Xinlaiwang I alfalfa silage had the best effect. Full article

Mining discharge, namely acid mine drainage (AMD), is a significant environmental issue due to mining activities and site-specific factors. These pose challenges in choosing and executing suitable treatment procedures that are both sustainable and effective. Ceramic membranes, with their durability, long lifespan, and ease of maintenance, are increasingly used in industrial wastewater treatment due to their superior features. This review provides an overview of current remediation techniques for mining effluents, focusing on the use of ceramic membrane technology. It examines pressure-driven ceramic membrane systems like microfiltration, ultrafiltration, and nanofiltration, as well as the potential of vacuum membrane distillation for mine drainage treatment. Research on ceramic membranes in the mining sector is limited due to challenges such as complex effluent composition, low membrane packing density, and poor ion separation efficiency. To assess their effectiveness, this review also considers studies conducted on simulated water. Future research should focus on enhancing capital costs, developing more effective membrane configurations, modifying membrane outer layers, evaluating the long-term stability of the membrane performance, and exploring water recycling during mineral processing. Full article

This study investigates the effects of different preservation methods—tray packing (control), vacuum packing (T1), and tray packing with 2 mg/mL pepper essential oil (T2)—on the quality of sauced beef during 4 °C storage for 1, 5, 9, and 13 days. The results revealed that T2 significantly inhibited microbial growth, as reflected by reduced total aerobic counts (TACs), minimized lipid oxidation (indicated by lower thiobarbituric acid reactive substances (TBARSs)), and reduced protein degradation (evidenced by decreased total volatile basic nitrogen (TVB-N)). Additionally, T2 delayed the reduction in inosine-5′-monophosphate (IMP) and accumulation of hypoxanthine (Hx), effectively extending shelf life and preserving sensory quality. T1 also showed beneficial effects in limiting oxygen-related spoilage, as demonstrated by lower TAC and TBARS levels. In contrast, the control group showed limited effectiveness in preserving the quality of sauced beef, as indicated by higher microbial counts and more pronounced lipid and protein degradation. These findings provide a theoretical basis for improving sauced beef preservation by highlighting the effectiveness of different packaging methods and the potential of pepper essential oil as a natural preservative. Full article

The preservation of fermented stinky sea bass (FSSB) has always been a major challenge. In this study, four preservation methods, including partial freezing (PF), freezing (F), irradiation + partial freezing (IPF), and irradiation + freezing (IF), were employed, and their effects on the storage quality of vacuum-packed fermented stinky sea bass were investigated. The results revealed that histamines and coliforms were not detected in any of the four preservation methods. Meanwhile, the TVB-N, peroxide value, pH, and cooking loss showed an increasing trend, while the hardness, springiness, and chewiness showed a decreasing trend, following FSSB vacuum packaging during the 30-day preservation period. Compared with PF or F only, irradiation significantly reduced the total plate number, TVB-N, pH, L*, and whiteness of the FSSB samples but increased the peroxide value content while maintaining the cohesiveness, gumminess, and chewiness. Furthermore, the of 1-butanol, propanal, and (E)-2-pentenal contents increased. In contrast, IPF preservation showed a better ability to maintain the texture quality of the FSSB. The safety index of the FSSB samples complied with the Chinese Standard GB10136-2015 National Food Safety Standards Animal Aquatic Products, following the 30-day preservation period under the four preservation methods. Overall, the experimental results suggest that the IPF preservation method is the most preferable approach to preserving FSSB, which can significantly maintain the product quality and save energy. Full article