An important mechanism for void air removal during oven vacuum bag processing for thermoplastic composites relies on void air flow to the part perimeters through the permeable pathways created by the rough surfaces of two adjacent prepreg layers. In this paper, the interlayer air permeability of AS4/APC2 carbon poly (ether ether ketone) thermoplastic prepreg was investigated before and after oven vacuum bag processing conditions. The permeability thickness product was measured with an experimental set-up and data reduced based on one-dimensional Darcy’s flow. The interlayer permeability exhibit directional dependency and are uniquely determined by the angle between two adjacent prepreg layers. Before oven vacuum bag processing, the principal permeability thickness products for lay-ups with included angle of 0°, 30°, 60°, and 90° were determined. Good agreement was achieved between the rotation matrix predicted permeability thickness products and the measured results. During processing, when temperature is above resin glass transition and below melting, the permeability of 0°/0° and 90°/90° interlayers reduces dramatically with increasing temperature and dwell time. For the 0°/90° interlayer, only a slight reduction compared to the room temperature baseline was obtained for temperature ramps up to 300℃ and dwell time up to 8 h at 240℃. The changes of the surfaces roughness were correlated to the reduction of measured permeability. The 0°/90° interlayer surface shows the evidence of fiber–fiber contact that limits the contact between layers and prevents significant drop of permeability during processing. Off-axis stacking sequences with fiber–fiber contact are advantageous for oven vacuum bag processing of large thermoplastic composite parts.

Metabolic regulatory mechanisms are designed to maintain stable myocardial function during extremes in physiological insult; they can now be studied in vivo and may provide insight into mechanisms of altered myocardial functional decompensation during disease processes. To determine mechanisms of myocardial stability during hypoxia and acute pressure loading, creatine kinase (CK) kinetics (forward rate constant, K_f, and flux of phosphocreatine, PCr, to adenosine triphosphate, ATP), and nicotinamide adenine dinucleotide (NADH) redox state were determined with ³¹P nuclear magnetic resonance (NMR) and NADH fluorometry, respectively, and correlated with heart work (heart rate × systolic blood pressure, HR × SBP), cardiac output (CO) and O₂ consumption (MVO₂) in 15 anesthetized open chest dogs. Hypoxia (Pa_o2 of 30-35 mm Hg) was produced in 6 dogs with an inspired O₂/N₂ of 200/3,000. Cardiac loading was produced in 9 dogs by administration of norepinephrine (NE, 1 µg/kg/min). Each dog acted as its own control. Baseline NADH fluorometry, ³¹P-NMR saturation transfer and cardiac function measurements were performed simultaneously in each dog, after which the experimental interventions were made. Similar increases in HR × SBP, CO, and MVO2 which occurred during both interventions were associated with different bioenergetic responses. During NE infusion, the K_f of CK increased from control; during hypoxia, the K_f decreased from control (p < 0.05). Flux of PCr → ATP was significantly lower during hypoxia than during NE infusion (p < 0.05). PCr was decreased significantly during NE infusion (p < 0.05). In addition, NADH redox state increased (from baseline of 100%) during hypoxia (140 ± 10%) and decreased during NE infusion (78 ± 6%). These data indicate that the myocardial response to demand is not universally regulated by adenosine diphosphate (ADP) or redox state. In addition, metabolic regulators can induce changes related to the type of intervention irrespective of similarity of workload.

Feline calicivirus, herpesvirus, and panleukopenia virus are major infectious viruses to cause serious diseases in cats, yet their current trivalent vaccines have limitations in immune efficacy and duration of protection. This study assessed the immune-enhancing effects of novel adjuvants (feline IL-15, IL-23, and metabolic modulators) on vaccine responses. Forty mice were randomly assigned to four groups: Group A (composite adjuvants), Group B (metabolic regulatory molecules and Mn adjuvant), Group C1 (Mn adjuvant), and Group C2 (blank commercial vaccine). Results showed that Group A had significantly higher neutralizing antibody titers against calicivirus post-booster immunization, while both Group A and B exhibited enhanced antibody responses against herpesvirus and parvovirus. Notably, Group A displayed increased proportions of memory T cells, follicular B cells, and activated B cells. These findings suggest that the combination of feline IL-15, IL-23, and metabolic modulators are safe and effective immunoadjuvants for the trivalent feline vaccines to promote immune cell differentiation and antibody production, thus representing a promising strategy to optimize vaccine efficacy.

In order to predict the key health parameters of complex equipment, this paper constructs an ensemble learning model based on LightGBM with a data-driven idea. Taking the hydraulic system as a typical research object, we have realized the prediction of its flow parameters. Under multiple working conditions, the R² reached 0.9988, and the prediction accuracy and time cost were excellent. Finally, using the relevant tool chain, we deploy the prediction model in the embedded environment to verify the effectiveness of the method.

Extreme weather events have left deep imprints in the long history of humankind, and these imprints have formed historical landmarks of great value. These landmarks are not only records of natural phenomena, but also witnesses to the social, cultural and economic development of humankind. The study of these historical landmarks can provide a better understanding of the relationship between human beings and the natural environment, and provide a useful reference for future sustainable development. This paper analyzes and learns that these historical landmarks are records and warnings of natural disasters. Extreme weather events, such as floods, hurricanes, droughts and extreme heat, have wreaked havoc and impact on human societies. Therefore, this paper determines the past temperature trends by fitting past weather data, temperature data, and terrain data. The occurrence of these events reminds people of the power and unpredictability of natural forces. Through in-depth study of these historical landmarks, people can better understand the formation mechanism and scope of impact of natural disasters, so as to take effective preventive measures and reduce disaster losses.