Experimental Research on Aircraft Landing Gear Drop Test Based on MRF Damper

AbstractIn this paper, the aircraft landing gear drop test based on MRF damper was conducted on the test platform. The parameter configuration of the buffer system and the parameters of the test platform were analyzed to study their influences on the performance of the landing gear. First, the initial pressure of the accumulator was calculated; next, a test plan was designed, then parameters such as drop height, drop mass, the initial pressure of the accumulator, and active current were selected to establish different conditions. Reasonable parameters of the landing gear were obtained through two drop tests and the analytical comparison of the performances. This research serves as a reference for in-depth researches on MRF damper performances and the application in practice

Oxidation behavior of two-phase (γ’+β) Ni-Al coatings doped with Dy and Hf

Dy/Hf co-doped two-phase (γ’+β) Ni-Al coatings were prepared by electron beam physical vapour deposition (EB-PVD). Cyclic oxidation behaviour of the coatings were investigated at 1100℃. The addition of 0.1at% Dy or 0.05at% Dy +0.3at% Hf to two-phase (γ’+β) Ni-Al coating significantly improved cyclic oxidation resistance, while addition of 0.5at% Hf to (γ’+β) Ni-Al coating no obvious effect on scale adhesion. The 0.1at% Dy doped and 0.05at% Dy +0.3at% Hf co-doped two-phase (γ’+β) Ni-Al coatings yielded mass gain of 1.24 mg/cm2 and 1.04 mg/cm2 after 100h cyclic oxidation. The Dy/Hf co-doped coating showed even further lower oxidation rate as compared to the corresponding Dy doped. In order to sufficiently exert reactive element effect (REE), extremely low solubility of the reactive element in each phase of the coatings should be guaranteed

Viremia Associated with Fatal Outcomes in Ferrets Infected with Avian H5N1 Influenza Virus

Avian H5N1 influenza viruses cause severe disease and high mortality in infected humans. However, tissue tropism and underlying pathogenesis of H5N1 virus infection in humans needs further investigation. The objective of this work was to study viremia, tissue tropism and disease pathogenesis of H5N1 virus infection in the susceptible ferret animal model. To evaluate the relationship of morbidity and mortality with virus loads, we performed studies in ferrets infected with the H5N1 strain A/VN/1203/04 to assess clinical signs after infection and virus load in lung, brain, ileum, nasal turbinate, nasal wash, and blood. We observed that H5N1 infection in ferrets is characterized by high virus load in the brain and and low levels in the ileum using real-time PCR. In addition, viral RNA was frequently detected in blood one or two days before death and associated with symptoms of diarrhea. Our observations further substantiate pathogenicity of H5N1 and further indicate that viremia may be a bio-marker for fatal outcomes in H5N1 infection

Organization Learning Oriented Approach with Application to Discrete Flight Control

In nature and society, there exist many learning modes; thus, in this paper the goal is to incorporate features from the social organizations to improve the learning of intelligent systems. Inspired by future prediction, in the high level, the discrete dynamics is further written into the equivalent prediction model which can provide the bridge from now to the future. In the low level, the efficiency could be improved in way of group learning. The philosophy is integrated into discrete neural flight control where the cascade dynamics is written into the prediction form and the minimal-learning-parameter technique is designed for parameter learning. The effectiveness of the proposed method is verified with simulation

Electrochemistry of myoglobin on graphene–SnO2 nanocomposite modified electrode and its electrocatalysis

AbstractIn this paper direct electrochemistry and electrocatalysis of myoglobin (Mb) immobilized on a graphene (GR)–SnO2 nanocomposite modified carbon ionic liquid electrode was reported. GR–SnO2 nanocomposite was synthesized by a simple solution method and further characterized by TEM and SEM, which exhibited large surface area beneficial for Mb immobilization. Spectroscopic results indicated Mb retained its native structure without denaturation after mixed with nanocomposite. Electrochemical investigation showed that a pair of well-defined redox peaks appeared on cyclic voltammogram, indicating that direct electron transfer of Mb with the underlying electrode was realized. The results could be attributed to the presence of GR–SnO2 nanocomposite that could enhance the electron transfer between the protein and the electrode. The Mb modified electrode exhibited good stability and catalytic activity to the electroreduction of NaNO2 in the concentration range from 0.2 to 350.0μmolL−1 with wider dynamic range and lower detection limit. Therefore the fabricated electrode has the potential application in the third-generation electrochemical biosensor

Evaluation of the learning curve for robotic single-anastomosis duodenal–ileal bypass with sleeve gastrectomy

BackgroundThe robotic surgical system is being used in various bariatric procedures. However, only a few studies with very small sample size are present on robotic single-anastomosis duodenal–ileal bypass with sleeve gastrectomy (SADI-S). Moreover, to date, the learning curve of robotic SADI-S has been poorly evaluated yet.ObjectiveThis retrospective study aimed to estimate the learning curve of robotic SADI-S.Methods102 consecutive patients who underwent robotic SADI-S between March 2020 and December 2021 were included. Textbook outcome standard was performed to comprehensively evaluate clinical outcome of robotic SADI-S. Based on the textbook outcome, we evaluated the learning curve of robotic SADI-S by the cumulative sum (CUSUM) method.ResultsThe mean operative time was 186.13 ± 36.91 min. No conversion to laparotomy or deaths occurred during the study period. The rate of complications was 6.9% (n = 7), of which major complications were identified in 2.9% (n = 3), including 2 gastric leakages and 1 respiratory failure. A total of 60 patients reached the textbook outcome standard. The rate of textbook outcome was positive and was steadily increasing after the number of surgical cases accumulated to the 58th case. Taking the 58th case as the boundary, all the patients were divided into the learning stage group (the first 58 patients) and mastery stage group (the last 44 patients). The rate of complications, proportion of abdominal drainage tubes and postoperative hospital stay were significantly higher in the learning stage group compared with the mastery stage group (P < 0.05). No significant difference was observed between the two groups in terms of patient demographic data, operative times, reoperations and readmission.ConclusionRobotic SADI-S is a feasible and reproducible surgical technique with a learning curve of 58 cases

A Fluorescent Sensor for Zinc Detection and Removal Based on Core-Shell Functionalized Fe 3

The magnetic Fe3O4@SiO2 nanoparticles (NPs) functionalized with 8-chloroacetylaminoquinoline as a fluorescent sensor for detection and removal of Zn2+ have been synthesized. The core-shell structures of the nanoparticles and chemical composition have been confirmed by TEM, XRD, FTIR, and XPS techniques. The addition of functionalized Fe3O4@SiO2 NPs into the acetonitrile solution of Zn2+ had an effect of visual color change as well as significant fluorescent enhancement. High-saturated magnetizations (24.7 emu/g) of functionalized Fe3O4@SiO2 NPs could help to separate the metal ions from the aqueous solution. The magnetic sensor exhibited high removal efficiency towards Zn2+ (92.37%). In this work, we provided an easy and efficient route to detect Zn2+ and simultaneously remove Zn2+