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ObjectiveThe open area of the superstructure of a luxury cruise ship has a complex spatial layout and appearance modeling. In this study, the wind load and flow field characteristics in this area are accurately simulated to guide cruise ship design. MethodsThe realizable k−ε turbulence model and substructure method in the Reynolds time-average method are used to numerically simulate the flow field characteristics of the whole cruise ship and the open area of the superstructure, and wind tunnel experiments are carried out for verification. ResultsThe appearance and spatial layout of the open area of the superstructure have an important impact on the flow field characteristics of the cruise ship, and the substructure simulation method can accurately simulate the flow field characteristics of the local area. ConclusionsWhen designing cruise ships, the overall shape of the superstructure should be streamlined and the height difference and spacing between adjacent structures in the open area should not be too large. The results of this study can provide guiding references for cruise ship design.

ObjectiveThis paper aims to reveal the influence of the afterburning effect of explosive materials in confined space explosion. MethodsA series of TNT blast tests are performed in a confined cabin filled with two different atmospheres, air and nitrogen. The temperature, pressure-time histories and deflection of the blast-loaded steel plate are recorded. The relationship between the deformation of the target plate and the energy released by the explosive is established. On this basis, a TNT equivalent method is proposed which takes into account the afterburning effect in a confined cabin. ResultsThe pressure, temperature and dynamic response of the target plate are significantly lower in the nitrogen environment than in the air environment due to the difference in the amount of energy released by the combustion of the explosive material. Thus, the energy released by the burning of TNT explosive materials and their enhancement effects should be considered in blast load analysis. ConclusionThe validity and applicability of the method are illustrated through a comparison with the existing TNT equivalent method based on quasi-static pressure.

The traditional processing method of peanuts has drawbacks such as high energy consumption, slow flavor absorption, and long processing cycles, to get better flavor of pepper-flavored peanut kernel snack food, this study used the vacuum technology combining with traditional technology to optimize by examining the effect of negative pressure time, negative pressure times and vacuum degree on the content of zanthoxylamide and sensory score using a combination of single factor method and response surface design. The results showed that the order of influence of various factors on pepper-flavored peanut kernels was negative pressure time>negative pressure frequency>vacuum degree. The optimal process parameters were negative pressure time of 100 seconds, negative pressure frequency of 6 times, and vacuum parameter of 0.80 MPa. The protein and fat content of pepper-flavored peanut kernels produced by this optimal process were 27% and 57%, respectively. The peroxide value and acid value meet national standards, and the sensory score was 93.1 points. This study would provide a reference for promoting the standardized processing of the entire nut snack food industry chain, and promoted the sustainable development of the nut snack food industry.

The fat, protein and other compounds in konjac powder limit the application of konjac glucomannan. Konjac glucomannan with relatively high purity could be applied in food, medicine and other sectors. This research aimed to optimize the ultrasonic assisted purification process of glucomannan from konjac powder with ethanol. The significance effects of five relevant factors including the ratio of konjac powder to ethanol, ethanol concentration, ultrasonic time, power and temperature were analyzed based on single factor analysis of variance. The first three aforementioned factors were selected for further analysis their significant effects on the purity of glucomannan. Moreover, the relevant factors were optimized via response surface model fitting. The final optimized parameters were as follows: 1:102 (g/mL) for the ratio of konjac powder to ethanol, 73% ethanol, 55 min ultrasonic time, 175 W ultrasonic power, 50 ℃ ultrasonic temperature. The content of konjac glucomannan under the process condition was 88.1%, which was close to the predicted value, and the purification process of glucomannan from konjac powder was feasible. The structure of the samples before and after optimization were measured by infrared spectroscopy and X-ray diffraction with no significant difference. The content of konjac glucomannan in the purified konjac powder by this process was significantly higher than that in the unpurified one, and the structure was less affected. Results from this study could provide theoretical support for efficient utilization of konjac glucomannan and development of relevant functional products.

BackgroundPostoperative delirium (POD) is a common anesthetic side effect in cardiac surgery. However, the role of oxygen saturation monitoring in reducing postoperative delirium has been controversial. Therefore, this meta-analysis aimed to analyze whether NIRS monitoring during cardiac surgery under cardiopulmonary bypass could reduce the incidence of postoperative delirium.MethodsPubMed, Web of Science, Cochrane Library, Embase and China National Knowledge Infrastructure (CNKI) databases were systematically searched using the related keywords for randomized-controlled trials (RCTs) published from their inception to March 16, 2024. This review was conducted by the Preferred Reporting Project and Meta-Analysis Statement (PRISMA) guidelines for systematic review. The primary outcome was postoperative delirium, and the second outcomes included the length of ICU stay, the incidence of kidney-related adverse outcomes, and the incidence of cardiac-related adverse outcomes.ResultsThe incidence of postoperative delirium could be reduced under the guidance of near-infrared spectroscopy monitoring (OR, 0.657; 95% CI, 0.447–0.965; P = 0.032; I2 = 0%). However, there were no significant differences in the length of ICU stay (SMD, 0.005 days; 95% CI, −0.135–0.146; P = 0.940; I2 = 39.3%), the incidence of kidney-related adverse outcomes (OR, 0.761; 95% CI, 0.386–1.500; P = 0.430; I2 = 0%), and the incidence of the cardiac-related adverse outcomes (OR, 1.165; 95% CI, 0.556–2.442; P = 0.686; I2 = 0%) between the two groups.ConclusionNear-infrared spectroscopy monitoring in cardiac surgery with cardiopulmonary bypass helps reduce postoperative delirium in patients.Systematic Review RegistrationPROSPERO, identifier, CRD42023482675

ObjectivesAlthough the fluid-structure interaction calculation method can better simulate the ship collision process, it requires a longer calculation time. To address this problem, a simplified numerical calculation method is proposed. MethodsThe local cabin section of a ship is taken as the object to carry out water collision experiments under various operating conditions. Force sensors and non-contact measurement based on high-speed photography technology are used to obtain the collision force and motion time history data of the ship. The collision contact force and acceleration response data are then analyzed, and arbitrary Lagrange−Euler (ALE) coupled fluid-solid numerical computational analysis is carried out on the experimental process. The effect of the water on the impacting ship in the collision process is then simplified to the equivalent mass, and the effect on the impacted ship is simplified to the equivalent resistance, which acts on the non-impacting side of the impacted ship in the form of surface force to hinder the movement of the impacted ship. Numerical calculations that do not involve the water-structure coupling process are then carried out on the basis of the simplified method. ResultsThe results show that the errors between the peak collision force and the experimental values for each condition obtained by the simplified calculation method are within 5%, and the calculation time required by this method is much smaller than that of the ALE fluid-structure interaction algorithm ConclusionsThe proposed simplified numerical calculation method can provide useful references for realizing the efficient calculation of ship structure collision response.

ObjectiveIn order to improve the safety of ship navigation, this study focuses on virtually aided ship navigation strategies.MethodsTwo different inland river routes are chosen for the simulation of virtually aided ship navigation models based on the fluid-structure interaction mechanism, while taking the navigation rules and flow details of the rivers into consideration. The simulation of the ship sailing process on a typical inland river route under specific current conditions provides the corresponding virtually aided navigation plan in which the ship's velocity, location and course are obtained in a timely manner. ResultsIt is found that the simulation method established on the basis of Fluent can be used to solve the problems of multi-degree-of-freedom motion and fluid-structure interaction. When sailing through bends or branches, steering with a small rudder angle over long distances ensures safe navigation and prevents speed reduction and significant lateral displacement.ConclusionThe proposed method can be effectively combined with the flow field information of digital channels to simulate the ship sailing process, thereby providing data support for the decision-making of intelligent navigation on inland river routes.

ObjectiveThis paper investigates the coupling effect of ship nonlinear wave load and transient high-amplitude slamming load in view of the whipping response of ships under extreme sea conditions. MethodsA two-way computational fluid dynamics-finite element method (CFD-FEM) fluid-structure interaction method is used to carry out the numerical simulation of an S175 container ship, and the results are compared with the test results and 2D linear strip theory. The testing of a segmented ship model with a variable cross-section elastic backbone is carried out, and the analysis of the bow's slamming load and high-frequency nonlinear whipping characteristics is undertaken based on the two-way CFD-FEM fluid-structure interaction method. The results are then verified through comparison with the model test. ResultsThe influence of wave slamming load on the whipping response of the bow cannot be ignored. The second order high-frequency component induced by whipping accounts for 59.86% of the low-frequency wave bending moment in sea state 6. ConclusionsThe proposed two-way CFD-FEM fluid-structure interaction method can calculate the whipping response accurately. The nonlinear wave-induced load and dynamic structural response of the ship under extreme sea conditions are affected by the transient slamming load of the bow. In conclusion, the high-frequency whipping response should be taken into consideration in the safety design and assessment stages of ship structures.

ObjectiveThis paper aims to study the wind-induced noise of typical rods in the open areas of cruise ships. MethodsThe numerical simulation of aerodynamic noise and wind-induced vibration noise is carried out using computational fluid dynamics (CFD) combined with the acoustic analogy method and vibro-acoustic coupling method in order to explore the generation mechanisms and characteristics of the two kinds of noise. Results Under different wind speeds, the maximum frequency of aerodynamic noise is dominated by the vortex shedding frequency, while the maximum frequency of wind-induced vibration noise is dominated by the natural frequency of the structure. The aerodynamic noise of three different cross-section rods is generally greater than that of wind-induced vibration noise, and the aerodynamic noise of square rods is the greatest. Under large flexibility, when the fluctuating pressure frequency of the rod is close to the natural frequency, the wind-induced vibration noise will be close to or even exceed the aerodynamic noise. ConclusionsIn the design of typical rods to be applied in the open areas of cruise ships, in order to reduce wind-induced noise, circular rods should be selected, square rods should be avoided, reasonable rod sizes should be selected and the vortex shedding frequency of the rods should not be close to the natural frequency.

In scale-down tests of ship structures subjected to a blast load, the accuracy of the predicted response of a prototype is affected by the material substitution and geometric distortion between a scaled model and a full-size structure; this is known as incomplete similarity. To obtain a more accurate response from a prototype during small-size tests, a corrected method for scaling the response of thin plates and stiffened plates under a blast load was derived. In addition, based on numerical simulations of explosion responses by employing the elastic–plastic model and the Johnson–Cook constitutive model, it was found that using the average yield stress derived from the equivalent plastic strain energy in the ideal elastic–plastic model can obtain consistent structural responses. Moreover, a method for calculating the distortion factor caused by the yield stress of different materials was proposed. Furthermore, it was demonstrated that the average effective plastic strain between the prototype and the corrected model is equal, and based on this, a similarity prediction method was established to correct the distortions caused by yield stress and the thickness of blast loaded plates. The results indicate that the proposed correction method can compensate for the differences caused by distorted factors of yield stress and thickness, with the maximum error in the structure’s peak displacement being less than 3%.

Remote-sensing technology has gradually become one of the most important ways to extract sea–land boundaries due to its large scale, high efficiency, and low cost. However, sea–land segmentation (SLS) is still a challenging problem because of data diversity and inconsistency, “different objects with the same spectrum” or “the same object with different spectra”, and noise and interference problems, etc. In this paper, a new sea–land segmentation method (PMFormer) for remote-sensing images is proposed. The contributions are mainly two points. First, based on Mask2Former architecture, we introduce the prompt mask by normalized difference water index (NDWI) of the target image and prompt encoder architecture. The prompt mask provides more reasonable constraints for attention so that the segmentation errors are alleviated in small region boundaries and small branches, which are caused by insufficiency of prior information by large data diversity or inconsistency. Second, for the large intra-class difference problem in the foreground–background segmentation in sea–land scenes, we use deep clustering to simplify the query vectors and make them more suitable for binary segmentation. Then, traditional NDWI and eight other deep-learning methods are thoroughly compared with the proposed PMFormer on three open sea–land datasets. The efficiency of the proposed method is confirmed, after the quantitative analysis, qualitative analysis, time consumption, error distribution, etc. are presented by detailed contrast experiments.

This study investigates the dynamic response and failure mechanisms of carbon fiber honeycomb sandwich structures under underwater impact loads using finite element numerical simulation. The geometric modeling was performed using HyperMesh, and the dynamic response simulations were carried out in ABAQUS, focusing on honeycomb core configurations with varying edge lengths, heights, and gradient forms. The Hashin damage model was employed to describe the damage evolution of the composite materials. The simulation results revealed that the dynamic response was significantly influenced by the initial shock wave pressure and the geometrical parameters of the honeycomb cells. Larger cell-edge lengths and heights generally resulted in improved energy absorption and reduced rear panel displacement. Among the different configurations, interlayer gradient honeycomb structures demonstrated superior impact resistance compared to homogeneous and in-plane gradient structures, particularly under higher initial shock wave pressures. These findings contribute to optimizing the design of carbon fiber honeycomb sandwich structures for enhanced impact resistance in relevant applications.

α-tocopherol (α-T), β-sitosterol (β-S), canolol (CA), and sinapic acid (SA) are the four main endogenous lipid phytochemicals (LP) found in Brassica napus L. seed oil, which possess the bioactivity to prevent the risk of several chronic diseases via antioxidant-associated mechanisms. Discovering the enhancer effects or synergies between LP is valuable for resisting oxidative stress and improving health benefits. The objectives of this study were to identify a potentially efficacious LP combination by central composite design (CCD) and cellular antioxidant activity (CAA) and to investigate its protective effect and potential mechanisms against H2O2-induced oxidative damage in HepG2 cells. Our results indicated that the optimal concentration of LP combination was α-T 10 μM, β-S 20 μM, SA 125 μM, and CA 125 μM, respectively, and its CAA value at the optimal condition was 10.782 μmol QE/100 g. At this concentration, LP combination exerted a greater amelioration effect on H2O2-induced HepG2 cell injury than either antioxidant (tea polyphenols or magnolol) alone. LP combination could reduce the cell apoptosis rate induced by H2O2, lowered to 10.06%, and could alleviate the degree of oxidative damage to cells (ROS↓), lipids (MDA↓), proteins (PC↓), and DNA (8-OHdG↓). Additionally, LP combination enhanced the antioxidant enzyme activities (SOD, CAT, GPX, and HO-1), as well as the T-AOC, and increased the GSH level in HepG2 cells. Furthermore, LP combination markedly upregulated the expression of Nrf2 and its associated antioxidant proteins. It also increased the expression levels of Nrf2 downstream antioxidant target gene (HO-1, SOD-1, MnSOD, CAT, GPX-1, and GPX-4) and downregulated the mRNA expression levels of Keap1. The oxidative-stress-induced formation of the Keap1/Nrf2 complex in the cytoplasm was significantly blocked by LP treatment. These results indicate that LP combination protected HepG2 cells from oxidative stress through a mechanism involving the activation of the Keap1/Nrf2/ARE signaling pathways.

The concept of “all cores are created equal” has been popular for several decades due to its simplicity and effectiveness in CPU (Central Processing Unit) design. The more cores the CPU has, the higher performance the host owns and the higher the power consumption. However, power-saving is also one of the key goals for servers in data centers and embedded devices (e.g., mobile phones). The big.LITTLE multicore architecture, which contains high-performance cores (namely big core) and power-saved cores (namely little core), has been developed by ARM (Advanced RISC Machine) and Intel to trade off performance and power efficiency. Facing the new heterogeneous computing architecture, the traditional lock algorithms, which are designed to run on homogeneous computing architecture, cannot work optimally as usual and drop into the performance issue for the difference between big core and little core. In our preliminary experiment, we observed that, in the big.LITTLE multicore architecture, all these lock algorithms exhibit sub-optimal performance. The FIFO-based (First In First Out) locks experience throughput degradation, while the performance of competition-based locks can be divided into two categories. One of them is big-core-friendly, so their tail latency increases significantly; the other is little-core-friendly. Not only does the tail latency increase, but the throughput is also degraded. Motivated by this observation, we propose a Core-Aware Lock for the big.LITTLE multicore architecture named CAL, which keeps each core having an equal opportunity to access the critical section in the program. The core idea of the CAL is to take the slowdown ratio as the matric to reorder lock requests of these big and little cores. By evaluating benchmarks and a real-world application named LevelDB, CAL is confirmed to achieve fairness goals in heterogeneous computing architecture without sacrificing the performance of the big core. Compared to several traditional lock algorithms, the CAL’s fairness has increased by up to 67%; and Its throughput is 26% higher than FIFO-based locks and 53% higher than competition-based locks, respectively. In addition, the tail latency of CAL is always kept at a low level.

With rapid urbanization, retrieving information about residential complexes in a timely manner is essential for urban planning. To develop efficiency and accuracy of building extraction in residential complexes, a Segment Anything Model-based residential building instance segmentation method with an automated prompt generator was proposed combining LiDAR data and VHR remote sensing images in this study. Three key steps are included in this method: approximate footprint detection using LiDAR data, automatic prompt generation for the SAM, and residential building footprint extraction. By applying this method, residential building footprints were extracted in Pukou District, Nanjing, Jiangsu Province. Based on this, a comprehensive assessment model was constructed to systematically evaluate the spatial layout of urban complexes using six dimensions of assessment indicators. The results showed the following: (1) The proposed method was used to effectively extract residential building footprints. (2) The residential complexes in the study area were classified into four levels. The numbers of complexes classified as Excellent, Good, Average, and Poor were 10, 29, 16, and 1, respectively. Residential complexes of different levels exhibited varying spatial layouts and building distributions. The results provide a visual representation of the spatial distribution of residential complexes that belong to different levels within the study area, aiding in urban planning.

The composite stiffened plate has garnered significant attention in the lightweight design of ship structures due to its superior mechanical properties. Although it reduces the structural weight, it also increases vibration sensitivity. Thus, investigating the vibration characteristics of the composite stiffened plate is crucial. This paper proposed a theoretical model based on the energy principle and the improved Fourier series method (IFSM) to analyze the composite stiffened plate vibration characteristics. The model demonstrates high reliability and accuracy, as confirmed through convergence analysis and comparison with experimental results from the published literature. Results indicate that geometry and material parameters significantly impact the natural frequency and can mitigate vibration responses by increasing thickness and stiffness. Additionally, ply design parameters markedly influence the vibration of composite stiffened plates, enhancing low-frequency vibration performance through optimal ply design. The structural parameters of the stiffeners, particularly the height and number of stiffeners, play a crucial role, enhancing stiffness and reducing the vibration responses of the composite stiffened plates.

Research has established that the incorporation of 3D-printed lattice structures in cement substrates enhances the mechanical properties of cementitious materials. However, given that 3D-printing materials, notably polymers, exhibit varying degrees of mechanical performance under high-temperature conditions, their efficacy is compromised. Notably, at temperatures reaching 150 °C, these materials soften and lose their load-bearing capacity, necessitating further investigation into their compressive mechanical behavior in such environments. This study evaluates the compressibility of cement materials reinforced with lattice structures made from polyamide 6 (PA6) across different structural configurations and ambient temperatures, employing ABAQUS for simulation. Six distinct 3D-printed lattice designs with equivalent volume but varying configurations were tested under ambient temperatures of 20 °C, 50 °C, and 100 °C to assess their impact on compressive properties. The findings indicate that heightened ambient temperatures significantly diminish the reinforcing effect of 3D-printed materials on the properties of cement-based composites.

The explosive growth of massive data makes shingled magnetic recording (SMR) disks a promising candidate for balancing capacity and cost. SMR disks are typically configured with a persistent buffer to reduce the read–modify–write (RMW) overhead introduced by non-sequential writes. Traditional SMR zones-based persistent buffers are subject to sequential-write constraints, and frequent cleanups cause disk performance degradation. Conventional magnetic recording (CMR) zones with in-place update capabilities enable less frequent cleanups and are gradually being used to construct persistent buffers in certain SMR disks. However, existing CMR zones-based persistent buffer designs fail to accurately capture hot blocks with long update periods and are limited by an inflexible data layout, resulting in inefficient cleanups. To address the above issues, we propose a strategy called Amphisbaena. First, a two-phase data block classification method is proposed to capture frequently updated blocks. Then, a locality-aware buffer space management scheme is developed to dynamically manage blocks with different update frequencies. Finally, a latency-sensitive garbage collection policy based on the above is designed to mitigate the impact of cleanup on user requests. Experimental results show that Amphisbaena reduces latency by an average of 29.9% and the number of RMWs by an average of 37% compared to current state-of-the-art strategies.

The effect of ultraviolet C (UV-C) radiation on the physicochemical properties and the bacterial diversity of fresh-cut cabbage was investigated over 12 days of storage at 5 °C. The color index (L*, a* and b*), decrease in weight, and content of soluble sugar, chlorophyll, ascorbic acid, total phenol, and malondialdehyde were measured. The structure of the bacterial community was also clarified by high-throughput sequencing analysis. After irradiation, the weight loss of fresh-cut cabbage during storage was reduced, and the content of antioxidant-related components, such as total phenols, ascorbic acid, and malondialdehyde, was increased. The results showed that the dominant phylum of bacteria in fresh-cut cabbage was Proteobacteria, and the dominant genus was Pseudomonas. A β-diversity analysis showed that the composition of the bacterial community of the irradiated and control treatments was different. [ABSTRACT FROM AUTHOR]

Task scheduling based on temperature perception is beneficial for avoiding hotspots and optimizing the internal temperature distribution of data centers. However, the accuracy of task scheduling largely depends on the accuracy of temperature prediction. There are many features that affect the accuracy of temperature prediction in data centers, and the variation periods of these features vary greatly. Traditional machine learning models are difficult to accurately fit them. Therefore, this article proposes a step-by-step temperature prediction algorithm based on Gated Recurrent Unit (GRU). This algorithm establishes prediction models for important parameters such as CPU utilization and air conditioning temperature that affect temperature prediction, and uses the outputs of these two models as inputs for the server temperature prediction model to better fit the changes of feature values. The model combines the principle of thermal locality and integrates the temperature of upper and lower servers for joint modeling. Experiments show that our prediction model can accurately predict the inlet temperature evolution of the server with dynamic workload. RSME reaches 0.278 and the average prediction temperature difference is 0.633, which is much higher than the traditional model. In addition, this article also propose a minimum temperature difference scheduling algorithm based on temperature prediction model, which can effectively reduce the number of servers running at high temperature and low temperature in the data center, make the temperature of the data center more balanced and achieve better energy-saving compared with other baseline algorithms. [ABSTRACT FROM AUTHOR]