Search Results (38)

Vacuum-based packaging is less frequently applied to poultry at the retail level. Evaluating the impact of vacuum packaging on fresh poultry may elicit extensions to storage life and reduce spoilage for consumer products such as fresh chicken. Boneless–skinless chicken breasts (N = 315; 105/treatment) were packaged using polyvinyl chloride (PVC) overwrap, vacuum packaging (VP), or vacuum skin packaging (VSP) and stored in simulated retail conditions for 20 days. Packages of fresh chicken were measured for changes in surface color, odor, pH, microbial growth, lipid oxidation, and volatile compounds. Packaging treatment significantly influenced surface color, with VP samples appearing lighter (p < 0.0001) and less red (p < 0.0001) than chicken packaged using PVC. Odor scores increased as storage time increased (p < 0.0001), and VSP maintained the most favorable odor throughout the 20-day refrigerated display. Lipid oxidation was greatest in PVC (p = 0.0338) packages on day 5 and lowest for VSP chicken packages on day 15. Electronic nose (e-nose) analysis concluded that packaging can influence aldehydes (p = 0.0025), alkanes (p = 0.0143), and terpene (p = 0.0214), compounds which have been associated with off-odors. In addition, microbial counts increased during storage time across all packaging types (p < 0.0001) but did not exceed a spoilage threshold of 7-log CFU/g throughout the 20 days of storage. The results conclude that vacuum-based packaging methods, either VP or VSP, can improve storage duration meat quality characteristics during refrigerated storage, and volatile e-nose compounds may be linked to the development of off-odors. Full article

Composite overwrapped pressure vessels (COPVs) have become the core unit for high-pressure hydrogen storage and transportation. However, excessive autofrettage pressure could induce unilateral buckling damage of the metal liner because of large rebound compressive stress induced by large plastic deformation in the depressurization stage. When the liner contains initial defects, its critical unilateral buckling pressure would be further reduced. In this paper, a critical buckling pressure calculation formula was established by finite element analysis and theoretical derivation. Firstly, the classical theoretical calculation models and research methods were analyzed and discussed. Then, by discussing the key influencing parameters, a semi-empirical calculation formula of nonlinear confined buckling pressure of a metal liner with ovality defects was established. Finally, the proposed semi-empirical formula was used to predict the critical internal pressure of a Type-III COPV, and the predicted value was compared with the experimental result. The predicted result was higher than the experimental result and the error range was −2.8%~−23%. The proposed semi-empirical formula of nonlinear confined buckling could provide theoretical support for designing the autofrettage pressure of Type-III COPVs and help to reduce the uncertainty and repeated test cost in the design process. Full article

Hydrogen is one of the future green energy sources that could resolve issues related to fossil fuels. The widespread use of hydrogen can be enabled by composite-overwrapped pressure vessels for storage. It offers advantages due to its low weight and improved mechanical performance. However, the safe storage of hydrogen requires continuous monitoring. Combining ultrasonic guided waves with interpretable machine learning provides a powerful tool for structural health monitoring. In this study, we developed a feature extraction approach based on a similarity method that enables interpretability in the proposed machine learning model for damage detection and localization in pressure vessels. Furthermore, a systematic optimization was performed to explore and tune the model’s parameters. This resulting model provides accurate damage localization and is capable of detecting and localizing damage on hydrogen pressure vessels with an average localization error of 2 cm and a classification accuracy of 96.5% when using quantized classification. In contrast, binarized classification yields a higher accuracy of 99.5%, but with a larger localization error of 6 cm. Full article

This study investigates the hydrogen permeability of injection-molded polyamide 6 (PA6) nanocomposites reinforced with organo-modified montmorillonite (OMMT) at varying concentrations (1, 2.5, 5, and 10 wt. %) for potential use as Type IV composite-overwrapped pressure vessel (COPV) liners. While previous work examined their mechanical properties, this study focuses on their crystallinity, morphology, and gas barrier performance. The precise inorganic content was determined using thermal gravimetry analysis (TGA), while differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and scanning electron microscopy (SEM) were used to characterize the structural and morphological changes induced by varying filler content. The results showed that generally higher OMMT concentrations promoted γ-phase formation but also led to increased agglomeration and reduced crystallinity. The PA6/OMMT-1 wt. % sample stood out with higher crystallinity, well-dispersed clay, and low hydrogen permeability. In contrast, the PA6/OMMT-2.5 and -5 wt. % samples showed increased permeability, which corresponded to WAXD and SEM evidence of agglomeration and DSC results indicating a lower degree of crystallinity. PA6/OMMT-10 wt. % showed the most-reduced hydrogen permeability compared to all other samples. This improvement, however, is attributed to a tortuous path effect created by the high filler loading rather than optimal crystallinity or dispersion. SEM images revealed significant OMMT agglomeration, and DSC analysis confirmed reduced crystallinity, indicating that despite the excellent barrier performance, the compromised microstructure may negatively impact mechanical reliability, showing PA6/OMMT-1 wt. % to be the most balanced candidate combining both mechanical integrity and hydrogen impermeability for Type IV COPV liners. Full article

Type IV composite overwrapped pressure vessels (COPVs) store hydrogen at pressures up to 70 MPa and must meet stringent safety standards through physical testing. However, full-scale burst, plug torque, axial compression, impact, and drop tests are time-consuming and costly. This study proposes a unified finite element analysis (FEA) workflow that replicates these mandatory tests and predicts failure behavior without physical prototypes. Axisymmetric and three-dimensional solid models with reduced-integration elements were constructed for the polyamide liner, aluminum boss, and carbon/epoxy composite. Burst simulations showed that increasing the hoop-to-axial stiffness ratio shifts peak stress to the cylindrical region, promoting a longitudinal rupture—considered structurally safer. Plug torque and axial load simulations revealed critical stresses at the boss–composite interface, which can be reduced through neck boss shaping and layup optimization. A localized impact with a 25 mm sphere generated significantly higher stress than a larger 180 mm impactor under equal energy. Drop tests confirmed that 45° oblique drops cause the most severe dome stresses due to thin walls and the lack of hoop support. The proposed workflow enables early-stage structural validation, supports cost-effective design optimization, and accelerates the development of safe hydrogen storage systems for automotive and aerospace applications. Full article

The objective of the present work was to examine the effect of incorporating spirulina powder (SP) in merguez-type sausages made exclusively with camel meat, as well as to evaluate its physicochemical, microbiological, and sensory quality attributes and its prebiotic potential. The final purpose was to offer an innovative meat product to increase camel meat consumption. Several innovative fresh sausage formulations were developed using SP (00, 100, 250, and 500 mg/kg) and stored under vacuum conditions with refrigeration at 1 ± 1 °C for 35 days. A control group of camel sausage without SP was also stored overwrapped (OW) under aerobic conditions, to serve as the negative control. The addition of SP to the vacuum-packed camel sausages extended their shelf life by 20 to 35 days compared to the control group, which was completely spoiled by the fifth day of storage. These results were more pronounced the higher the percentage of SP incorporated into the camel sausage formulation, as indicated by the following parameters: 2-thiobarbituric acid-reactive substances TBARS (1.46 vs. 2.89 mg MDA/kg), CIE a* (14.65 vs. 10.12), total volatile basic nitrogen TVB-N (13.02 vs. 15.09 mg/kg), total psychrotrophic bacteria TPB (5.71 vs. 6.34 log CFU/g), and overall acceptability score (3.17 vs. 2.5). The study of prebiotic potential suggested that the addition of SP to camel sausages promoted the growth of probiotic strains, which in turn were able to inhibit the growth of pathogenic microorganisms such as S. aureus and E. coli O157:H7. In conclusion, this study highlighted how SP, as a clean label ingredient, based on its rich composition and its antioxidant, antibacterial, and prebiotic effects, may represent a source of beneficial substances for human health and offer an alternative approach to producing a new traditional merguez-type sausage with improved acceptance. Full article

The industrial and technological sectors are pushing the boundaries to develop a new class of high-pressure vessels for hydrogen storage that aim to improve durability and and endure harsh operating conditions. This review serves as a strategic foundation for the integration of hydrogen tanks into transport applications while also proposing innovative approaches to designing high-performance composite tanks. The goal is to offer optimized, safe, and cost-effective solutions for the next generation of high-pressure vessels, contributing significantly to energy security through technological advancements. Additionally, the review deepens our understanding of the relationship between microscopic failure mechanisms and the initial failure of reinforced composites. The investigation will focus on the behavior and damaging processes of composite overwrapped pressure vessels (COPVs). Moreover, the review summarizes relevant simulation models in conjunction with experimental work to predict the burst pressure and to continuously monitor the degree of structural weakening and fatigue lifetime of COPVs. Simultaneously, understanding the adverse effects of in-service applications is vital for maintaining structural health during the operational life cycle. Full article

The storage duration of fresh meat products is a contributing factor leading to increased waste and loss at the retail counter. Losses of fresh pork can be linked to packaging methods that do not protect the attributes of color, taste, and odors consumers use in determining wholesome meat. Boneless pork loins (N = 63) were fabricated into 2.54-cm-thick chops and assigned to one of three vacuum treatments (VacA, VacB, VacC) or a fourth polyvinyl chloride overwrap (PVC) treatment to assess objective fresh color, cook loss, Warner–Bratzler shear force (WBSF), and lipid oxidation. Pork chops (n = 882) were evaluated at 5-day intervals (D 0, 5, 10, 15) in a randomized complete block design. Pork chop surface color was lighter (L*; p < 0.0001) when stored in a vacuum compared to PVC-packaged loin chops, regardless of storage duration. Redness (a*) values were greater (p < 0.0001) for loin chops stored in PVC than all other vacuum packaging treatments throughout the entire 15-day display period. Relative values for chroma on PVC-packaged loin chops were greater (p < 0.0001) throughout the simulated retail display period. An interaction of day and packaging treatment (p < 0.0343) occurred for WBSF. Lipid oxidation for pork chops packaged using PVC was significantly greater (p < 0.0001) from Day 10 through the completion of the storage period. Results indicate that vacuum packaging limits the deterioration of fresh pork loin chops, whereas traditional overwrapping expedites the color and lipid oxidation during refrigerated storage. Full article

This study focuses on polyamide 6/organo-modified montmorillonite (PA6/OMMT) nanocomposites as potential liner materials, given the growing interest in enhancing the performance of type IV composite overwrapped hydrogen storage pressure vessels. The mechanical properties of PA6/OMMT composites with varying filler concentrations were investigated across a temperature range relevant to hydrogen storage conditions (−40 °C to +85 °C). Liner collapse, a critical issue caused by rapid gas discharge, was analyzed using an Ishikawa diagram to identify external and internal factors. Mechanical testing revealed that higher OMMT content generally increased stiffness, especially at elevated temperatures. The Young’s modulus and first yield strength exhibited non-linear temperature dependencies, with 1 wt. per cent OMMT content enhancing yield strength at all tested temperatures. Dynamic mechanical analysis (DMA) indicated that OMMT improves the storage modulus, suggesting effective filler dispersion, but it also reduces the toughness and heat resistance, as evidenced by lower glass transition temperatures. This study underscores the importance of optimizing OMMT content to balance mechanical performance and thermal stability for the practical application of PA6/OMMT nanocomposites in hydrogen storage pressure vessels. Full article

A multidisciplinary design optimisation (MDO) study of a hybrid rocket launcher is presented, with a focus on quantifying the impact of using composite overwrapped pressure vessels (COPVs) as the oxidiser tank. The rocket hybrid propulsion system (RHPS) consists of a combination of solid fuel (paraffin) and liquid oxidiser (NOx). The oxidiser is conventionally stored in metallic vessels. Alternative design concepts involving composite-based pressure vessels are explored that could lead to significant improvements in the overall performance of the rocket. This design choice may potentially affect parameters such as total weight, thrust curve, and maximum altitude achieved. With this eventual impact in mind, structural considerations such as wall thickness for the COPV are integrated into an in-house MDO framework to conceptually optimise a hybrid rocket launcher. Full article

In recent years, increased sales of fuel cell electric vehicles (FCEVs) have required composite overwrapped pressure vessel (COPV) designs to be lightweight and allow safe high-pressure hydrogen storage. In this study, we propose the weight minimization of Type 2 COPVs for FCEVs considering mechanical safety. Steel liner thickness, ply thickness, ply orientation, and the number of plies were set as design variables, and weight minimization was performed. For the constraints of optimization, the Tsai–Wu failure index of the composite layer and von Mises stress of the steel liner are considered. The design of experiments (DoE) was conducted to generate kriging model and perform sensitivity analysis. The optimized design of Type 2 COPVs was determined by satisfying all constraints, with significant weight reduction and preserved mechanical safety of the structure. Full article

Compressed gas storage of hydrogen has emerged as the preferred choice for fuel cell vehicle manufacturers, as well as for various applications, like road transport and aviation. However, designers face increasing challenges in designing safe and efficient composite overwrapped pressure vessels (COPVs) for hydrogen storage. One challenge lies in the development of precise software programs that consider a multitude of factors associated with the filament winding process. These factors include layer thickness, stacking sequence, and the development of particularly robust models for the dome region. Another challenge is the formulation of predictive behavior and failure models to ensure that COPVs have optimal structural integrity. The present study offers an exploration of numerical methods used in modeling COPVs, aiming to enhance our understanding of their performance characteristics. The methods examined include finite element analysis in Abaqus, involving conventional shell element, continuum shell element, three-dimensional solid element, and homogenization techniques for multilayered composite pressure vessels. Through rigorous comparisons with type-III pressure vessels from the literature, the research highlights the most suitable choice for simulating COPVs and their practicality. Finally, we propose a new design for type-IV hydrogen composite pressure vessels using one explored method, paving the way for future developments in this critical field. Full article

The present study aimed to investigate the effects of adding cinnamon bark oil (CBO) on the quality of ground lamb meat, considering different packaging conditions, including modified atmospheric packaging (MAP) using Hengxian HX-300H and overwrapped packaging. The CBO was incorporated into lamb meat samples at three different levels: 0% (control), 0.025% and 0.05% (v/w). The samples were then subjected to three packaging methods: MAP1 (80% O₂ + 20% CO₂), MAP2 (40% O₂ + 30% CO₂ + 30% N₂) and overwrapped packaging and stored at 4 °C for 0, 4, 8, 12 and 16 days. The findings of the present study revealed that the addition of 0.025% and 0.05% CBO under MAP1 condition significantly improved the color of the meat samples after 12 days of storage at 4 °C (p < 0.05). The overwrapped samples exhibited higher levels of thiobarbituric acid reactive substances (TBARS) compared to all other treatments, starting from day 4 of storage (p < 0.05). Furthermore, microbial counts were notably higher in the overwrapped samples than in all other samples after day 8 of storage (p < 0.05). In conclusion, the combination of 0.05% CBO with MAP proved to be an effective strategy for enhancing the color stability and oxidative stability of ground lamb meat. These results suggest that CBO can be utilized as a beneficial protective agent in meat packaging processes. Full article

The most practical way of storing hydrogen gas for fuel cell vehicles is to use a composite overwrapped pressure vessel. Depending on the driving distance range and power requirement of the vehicles, there can be various operational pressure and volume capacity of the tanks, ranging from passenger vehicles to heavy-duty trucks. The current commercial hydrogen storage method for vehicles involves storing compressed hydrogen gas in high-pressure tanks at pressures of 700 bar for passenger vehicles and 350 bar to 700 bar for heavy-duty trucks. In particular, hydrogen is stored in rapidly refillable onboard tanks, meeting the driving range needs of heavy-duty applications, such as regional and line-haul trucking. One of the most important factors for fuel cell vehicles to be successful is their cost-effectiveness. So, in this review, the cost analysis including the process analysis, raw materials, and manufacturing processes is reviewed. It aims to contribute to the optimization of both the cost and performance of compressed hydrogen storage tanks for various applications. Full article

The large thickness COPV is designed by netting theory and the finite element simulation method, but the actual performance is low and the cylinder performance still cannot be improved after increasing the thickness of the composite winding layer. This paper analyzes the reasons for this and puts forward a feasible solution: without changing the thickness of the winding layer, the performance of COPV can be effectively increased by increasing the proportion of annular winding fiber. This method has been verified by tests and is supported by theory. Full article