Integrating CFD, CAA, and Experiments Towards Benchmark Datasets for Airframe Noise Problems

Airframe noise corresponds to the acoustic radiation due to turbulent flow in the vicinity of airframe components such as high-lift devices and landing gears. The combination of geometric complexity, high Reynolds number turbulence, multiple regions of separation, and a strong coupling with adjacent physical components makes the problem of airframe noise highly challenging. Since 2010, the American Institute of Aeronautics and Astronautics has organized an ongoing series of workshops devoted to Benchmark Problems for Airframe Noise Computations (BANC). The BANC workshops are aimed at enabling a systematic progress in the understanding and high-fidelity predictions of airframe noise via collaborative investigations that integrate state of the art computational fluid dynamics, computational aeroacoustics, and in depth, holistic, and multifacility measurements targeting a selected set of canonical yet realistic configurations. This paper provides a brief summary of the BANC effort, including its technical objectives, strategy, and selective outcomes thus far

Earthquake-Induced Potentiation of Acute Risk Factors in Hypertensive Elderly Patients: Possible Triggering of Cardiovascular Events After a Major Earthquake

AbstractObjectives. We sought to investigate the potentiation of acute risk factors after the Hanshin-Awaji earthquake (7.2 on the Richter scale).Background. The frequency of cardiovascular events increases just after a major earthquake, but the causative factors have not been fully investigated.Methods. We studied the changes in cardiovascular risk factors in 42 elderly outpatients with well-controlled hypertension living near the epicenter (Awaji-Hokudan districts) 7 to 14 days after the earthquake when the major felt-aftershocks persisted. They all experienced the highest stress grading of 6 (catastrophic stress) according to the DSM-III-R. To study the hemostatic profile and endothelial cell state, we measured the blood pressure (BP), hematocrit and lipid profiles as well as fibrinogen, a marker of fibrin turnover (d-dimer), fibrinolytic factors (plasmin-alpha2–plasmin inhibitor complex [PIC], tissue-type plasminogen activator [t-PA] antigen and t-PA inhibitor [PAI] activity) and an endothelial cell-derived marker (von Willebrand factor [vWF]).Results. Systolic and diastolic blood pressures and other variables increased after the earthquake. Before and after the earthquake, the median (25th to 75th percentiles) systolic BP was 152 (range 142 to 164) and 170 mm Hg (range 161 to 178), respectively (p < 0.0001), and the diastolic BP was 83 (range 79 to 88) and 91 mm Hg (range 84 to 96), respectively (p < 0.0001). Of blood viscosity determinants, hematocrit was 38.1% (range 40.7% to 35.9%) and 39.7% (range 42.9% to 38.3%), respectively (p < 0.001), and fibrinogen 316 (range 272 to 360) and 335 mg/dl (range 307 to 391), respectively (p < 0.05). Von Willebrand factor was 128% (range 74% to 148%) and 148% (range 100% to 178%), respectively (p < 0.01); d-dimer was 410 (range 285 to 633) and 560 ng/ml (range 391 to 888), respectively (p < 0.0001); and PIC was 0.74 (range 0.58 to 0.91) and 0.75 μg/ml (range 0.58 to 1.1), respectively (p < 0.05). In contrast, lipid profiles did not change after the quake. When the patients were classified into the high stress and moderate stress groups according to the degrees of damage to their house and injury to family members, the levels of fibrinogen, vWF, PIC and t-PA antigen were increased only in the former group, whereas BP, hematocrit and d-dimer levels were increased in both groups. These abnormalities of acute risk factors, except for vWF, were transient and decreased to prequake levels by 4 to 6 months after the quake.Conclusions. Earthquake-induced stress seems to induce transient increases in BP, blood viscosity determinants and fibrin turnover and to prolong endothelial cell stimulation. The potentiation of these acute risk factors might contribute to the occurrence of cardiovascular events just after a major earthquake in elderly subjects with hypertension.(J Am Coll Cardiol 1997;29:926–33)© 1997 by the American College of Cardiolog

Experimental Study of Slat Noise from 30P30N Three-Element High-Lift Airfoil in JAXA Hard-Wall Low-Speed Wind Tunnel

Aeroacoustic measurements associated with noise radiation from the leading edge slat of the canonical, unswept 30P30N three-element high-lift airfoil configuration have been obtained in a 2 m x 2 m hard-wall wind tunnel at the Japan Aerospace Exploration Agency (JAXA). Performed as part of a collaborative effort on airframe noise between JAXA and the National Aeronautics and Space Administration (NASA), the model geometry and majority of instrumentation details are identical to a NASA model with the exception of a larger span. For an angle of attack up to 10 degrees, the mean surface Cp distributions agree well with free-air computational fluid dynamics predictions corresponding to a corrected angle of attack. After employing suitable acoustic treatment for the brackets and end-wall effects, an approximately 2D noise source map is obtained from microphone array measurements, thus supporting the feasibility of generating a measurement database that can be used for comparison with free-air numerical simulations. Both surface pressure spectra obtained via KuliteTM transducers and the acoustic spectra derived from microphone array measurements display a mixture of a broad band component and narrow-band peaks (NBPs), both of which are most intense at the lower angles of attack and become progressively weaker as the angle of attack is increased. The NBPs exhibit a substantially higher spanwise coherence in comparison to the broadband portion of the spectrum and, hence, confirm the trends observed in previous numerical simulations. Somewhat surprisingly, measurements show that the presence of trip dots between the stagnation point and slat cusp enhances the NBP levels rather than mitigating them as found in a previous experiment

Conjugate Simulation of Flow and Heat Conduction with a New Method for Faster Calculation

ABSTRACT

Modification of single-nucleotide polymorphism in a fully humanized CYP3A mouse by genome editing technology

Abe, S., Kobayashi, K., Oji, A. et al. Modification of single-nucleotide polymorphism in a fully humanized CYP3A mouse by genome editing technology. Sci Rep 7, 15189 (2017). https://doi.org/10.1038/s41598-017-15033-

Sorafenib plus low-dose cisplatin and fluorouracil hepatic arterial infusion chemotherapy versus sorafenib alone in patients with advanced hepatocellular carcinoma (SILIUS): a randomised, open label, phase 3 trial

Background Hepatic arterial infusion chemotherapy plus sorafenib in phase 2 trials has shown favourable tumour control and a manageable safety profile in patients with advanced, unresectable hepatocellular carcinoma. However, no randomised phase 3 trial has tested the combination of sorafenib with continuous arterial infusion chemotherapy. We aimed to compare continuous hepatic arterial infusion chemotherapy plus sorafenib with sorafenib alone in patients with advanced, unresectable hepatocellular carcinoma. Methods We did an open-label, randomised, phase 3 trial (SILIUS) at 31 sites in Japan. Eligible patients were aged 20 years or older, with advanced hepatocellular carcinoma not suitable for resection, local ablation, or transarterial chemoembolisation; Eastern Cooperative Oncology Group (ECOG) performance status 0–1; Child-Pugh score 7 or lower; and adequate bone marrow, liver, and renal function. Patients were randomly assigned (1:1) via an interactive web response system with a computer-generated sequence to receive 400 mg sorafenib orally twice daily or 400 mg sorafenib orally twice daily plus hepatic arterial infusion chemotherapy (cisplatin 20 mg/m 2 on days 1 and 8 and fluorouracil 330 mg/m 2 continuously on days 1–5 and 8–12 of every 28-day cycle via an implanted catheter system). The primary endpoint was overall survival. The primary efficacy analysis comprised all randomised patients (the intention-to-treat population), and the safety analysis comprised all randomised patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, number NCT01214343. Findings Between Nov 4, 2010, and June 10, 2014, 206 patients were randomly assigned (103 to the sorafenib group, 103 to the sorafenib plus hepatic arterial infusion chemotherapy group). One patient in the sorafenib plus hepatic arterial infusion chemotherapy group withdrew after randomisation. Median overall survival was similar in the sorafenib plus hepatic arterial infusion chemotherapy (n=102) and sorafenib monotherapy (n=103) groups (11·8 months [95% CI 9·1–14·5] vs 11·5 months [8·2–14·8]; hazard ratio 1·009 [95% CI 0·743–1·371]; p=0·955). Grade 3–4 adverse events that were more frequent in the sorafenib plus hepatic arterial infusion chemotherapy group than in the sorafenib monotherapy group included anaemia (15 [17%] of 88 vs six [6%] of 102), neutropenia (15 [17%] vs one [1%]), thrombocytopenia (30 [34%] vs 12 [12%]), and anorexia (12 [14%] vs six [6%]). Interpretation Addition of hepatic arterial infusion chemotherapy to sorafenib did not significantly improve overall survival in patients with advanced hepatocellular carcinoma. Funding Japanese Ministry of Health, Labour and Welfare

Difference of health-care associated pneumonia between large hospitals and small hospitals in Japan

Objective : Health-care associated pneumonia (HCAP) is a new category of pneumonia. We investigated differences of epidemiology, pathogens, and outcomes between HCAP patients in large hospitals and those in small hospitals. Methods : This was a retrospective observational study of patients hospitalized with HCAP from December 2009 to March 2010. HCAP was defined according to ATS/IDSA criteria. A large hospital was defined as 200 beds and a small hospital was 200 beds. Results : Of 117 patients, 61 patients were admitted to large hospitals and 56 patients were admitted to small hospitals. There was a significant difference of HCAP diagnostic criteria between the two groups. The A-DROP severity class was worse in the large hospital group than the small hospital group (P 0.05). Respiratory failure and disturbance of consciousness were more frequent in the large hospital group (P 0.05). The mortality rate was 8.2% in the large hospital group versus 1.8% in the small hospital group. Patients in the very severe A-DROP class had a high mortality rate of 33% in both groups. Conclusion : Patients with severe HCAP were more likely to be admitted to large hospitals. Patients in the very severe A-DROP class should receive intensive antibiotic therapy, but not all patients need broad-spectrum therapy

Self-Excited Oscillation of Transonic Flow Around an Airfoil in Two-Dimensional Channel

ABSTRACT A self-excited oscillation of transonic flow in a simplified cascade model was investigated experimentally, theoretically and numerically. The measurements of the shock wave and wake motions, and unsteady static pressure field predict a closed loop mechanism, in which the pressure disturbance, that is generated by the oscillation of boundary layer separation, propagates upstream in the main flow and forces the shock wave to oscillate, and then the shock oscillation disturbs the boundary layer separation again. A one-dimensional analysis confirms that the self-excited oscillation occurs in the proposed mechanism. Finally, a numerical simulation of the Navier-Stokes equations reveals the unsteady flow structure of the reversed flow region around the trailing edge, which induces the large flow separation to bring about the anti-phase oscillation