261 research outputs found

    Aerodynamic aircraft design methods and their notable applications: Survey of the activity in Japan

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    An overview of aerodynamic aircraft design methods and their recent applications in Japan is presented. A design code which was developed at the National Aerospace Laboratory (NAL) and is in use now is discussed, hence, most of the examples are the result of the collaborative work between heavy industry and the National Aerospace Laboratory. A wide variety of applications in transonic to supersonic flow regimes are presented. Although design of aircraft elements for external flows are the main focus, some of the internal flow applications are also presented. Recent applications of the design code, using the Navier Stokes and Euler equations in the analysis mode, include the design of HOPE (a space vehicle) and Upper Surface Blowing (USB) aircraft configurations

    Use of high-resolution upwind scheme for vortical flow simulations

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    For vortical flow simulations at high Reynolds numbers, it is important to keep the artificial dissipation as small as possible since it induces unphysical decay of the vortex strength. One way to accomplish this is to decrease the grid spacing. Another way is to use computational schemes having little dissipation. Here, one of the high-resolution upwind schemes called MUSCL with Roe's average is applied to vortical flow fields. Two examples are considered. One is the leading-edge separation-vortex flow over a strake-delta wing. The other is a high-angle of attack supersonic flow over a spaceplane-like geometry. Comparison with the central difference solutions indicates that the present upwind scheme is less dissipative and thus has better resolution for the vortical flows

    Navier-Stokes simulation of wind-tunnel flow using LU-ADI factorization algorithm

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    The three dimensional Navier-Stokes solution code using the LU-ADI factorization algorithm was employed to simulate the workshop test cases of transonic flow past a wing model in a wind tunnel and in free air. The effect of the tunnel walls is well demonstrated by the present simulations. An Amdahl 1200 supercomputer having 128 Mbytes main memory was used for these computations

    Multiobjective Design Exploration in Space Engineering

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    温泉療法による気管支喘息に対する年間薬剤費の削減

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    Costs of drugs used for the treatment for 1 year were compared before and after spa therapy in 16 patients with asthma in relation to disease severity. Asthma severity was classified as : stage 1 (intermittent), 2 (mild persistent), 3(moderate persistent), and 4(severe persistent). 1. The total cost of drugs used for each pa-tient for 1 year clearty decreased in all groups. The % decrease of the costs of drugs in each group was 27.2% in patients with stage 1, 43.5% in those with stage 2 and 34.1% in those with stage 3-4 (mean 34.5% ). The reduction of the cost of bronchodilators was predominant in patients with stage 3-4, and the decrease in the cost of corticosteroids predominant in those with stage 2. The reduction of costs of antiallertgics, mucolytics, and antibiotics was predominant in patients with stage 2 and stage 3-4. The % reduction in the cost of corticostroids was remarkable in patients with stage 2. The % decrease in the costs of mucolytics and antibiotics was predomi-nant in patients with stage 2 and stage 3-4. The results obtained here suggest that the costs of drugs used for asthmatics could be reduced by long-term spa therapy, and the reduction of the costs was larger as asthma stage became more severe.気管支喘息16例を対象に,治療のために要した年間薬剤費が温泉療法により削減可能であるのかどうかについて,国際ガイドラインの重症度分類(stageト4)別に若干の検討を加えた。1.年間の総薬剤費は重症度別の全てのグループにおいて明らかに減少した.2.その削減率は,ステージ1で27.2%,ステージ2で43.5%,ステージ3-4で34.1%であり,その平均は34.5%であった。3.気管支拡張剤の薬剤費の減少はステージ3-4で高度であり,副腎皮質ホルモンの薬剤費の減少はステージ2で著明であった。また,抗アレルギー薬,去痩薬,抗生物質などの薬剤費の削減は,ステージ2および3-4で高度であった。4.削減率では,去壊薬,抗生物質の削減率が,2および3-4で著明であった。 以上の結果より,温泉療法により,気管支喘息の治療に必要な薬剤費は削減可能であること,そして,温泉療法による薬剤費の削減は職息の重症度が高い症例でより高度であることが示唆された

    長期間喫煙による気管支唱息,肺気腫の病態的変化

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    The influence of long-term cigarette smoking on the pathophysiology of chronic respiratory diseases with obstructive ventilatory dysfunction was discussed in patients with asthma and pulmonary emphysema (PE). 1. In patients with asthma, significant differences in the pathophysiology of the disease were observed between smokers and nonsmokers. A positive RAST score against inhalant allergens, bronchial hyperresponsiveness, and LTB4 generation by leucocytes were significantly more increased in smokers than in nonsmokers. The values of FEV1/FVC and OLco were significantly more decreased, and % RV was significantly more increased in smokers than in nonsmokers. 2. In comparison of asthma with PE, IgE-mediated allergy was significantly more increased in smokers with asthma than in nonsmokers with asthma and in smokers with PE. The values of % FEV1, FEVl %, and % OLco were significantly higher in nonsmokers with asthma than in smokers with PE, however, the % OLco and % RV were not significantly different between smokers with asthma and those with PE. The % LAA of the lungs on HRCT was larger in patients with PE than in smokers and nonsmokers with asthma. The results suggest that cigarette smoking influences the pathophysiology of asthma and PE.長期間喫煙による気管支喘息および肺気腫の病態的変化について若干の検討を加えた。1.気管支嘱喘息に関しては,喫煙例と非喫煙例との間に以下のような病態的特徴に差が見られた。吸入抗原に対する特異的IgE抗体の陽性率,気道過敏性,白血球のI:TB4産生能はいずれも,喫煙例で非喫煙例に比べ有意の亢進を示した。また,喫煙例では,非喫煙例に比べ,FEV1%や% DLcoは有意の低下,% RVは有意の増加傾向を示した。2.喘息と肺気腫の比較では,IgEにmediateされるア レルギー反応は,喘息の非喫煙例や肺気腫(全て喫煙例)に比べ,喘息の喫煙例で有意の亢進が見られた。% FEVl,FEV1,% DLco値はいずれも喘息の非喫煙例で,肺気腫と比べ有意に高い値を示したが,% DLcoと% RV値には,喘息の喫煙例と肺気腫の間に有意の差は見られなかった。また,肺のHRCT上の% I.AAは,肺気腫において,喘息の喫煙例,非喫煙例いずれよりも有意に高い値を示した。以上の結果より,長期間の喫煙が喘息や肺気腫の病態に影響を与えることが示された

    Characteristics of the elderly in high - resolution computed tomography lung densitometry

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    To determine the characteristics of the elderly in high - resolution computed tomography (HRCT) lung densitometry, mean lung density (MLD) and relative area of the lungs showing attenuation values less than -950 HU (RA(950)) on HRCT were evaluated in nonsmoking control subjects (n = 80) and patients with asthma (n = 80) in relation to their age and pulmonary function. MLD was significantly decreased, and RAW was significantly increased with increasing age in both asthmatics and controls. The MLD values were significantly lower in asthmatics compared with controls in subjects aged between 60 and 69 years and over age 70. RAgsov alues were significantly higher in asthmatics compared with controls in subjects aged between 50 and 59 years, between 60 and 69, and over 70. % FEV(1) and FEV(1) / FVC were significantly decreased in elderly asthmatic patients over 70 years of age compared with the values in those under 49. Percent residual volume (% RV) was significantly larger in patients over 70 years of age than in those between 50 and 59, and under 49 years. RAW was significantly larger in patients with steroid-dependent intractable asthma (SDIA) between 50 and 59 years of age, and between 60 and 69 compared with RA 950 in those without SDIA. However, RAW did not differ significantly between SDIA and non-SDIA in patients over age 70. The results suggested that in % LAA of the lungs on HRCT was significantly increased in the elderly subjects with and without asthma, and it was significantly higher in the elderly asthmatics than the elderly controls.高齢者の病態的特徴を明らかにするために,健常者80例および非喫煙喘息患者80例を対象として,平均肺CT値(MLD)ならびに高分解能CT(HRCT)による-950HU以下の肺low attenuation area(RA950)を評価し,年齢及び肺機能との関連を検討した。  1.健常者,喘息患者いずれにおいても年齢とともにMLDは有意に減少し,RA(950)は有意に増加した。MLDは,60-69歳と70歳以上の年 齢層において,健常者に比して喘息患者で有意に低値を示した。RA(950)。は,50-59歳・60-69歳・70歳以上の年齢層において,健常者に比して喘息患者で有意に高値を示した。  2.喘息患者において,1秒量(% FEV(1))および1秒(FEV(1)/ FVC)は,49歳以下の年齢層に比して70歳以上の年齢層で有意に低値を示した。一方,残気量(% RV)は,50-59歳ならびに49歳以下の年齢層に比して70歳以上の年齢層で有意に高値を示した。 3.50-59歳および60-69歳の年齢層では,RA(950)は,ステロイド依存性重症難治性喘息(SDIA)患者において非SDIA患者に比して有意に高値を示した。しかし,70歳以上の年齢層では両者に有意の差は認められなかった。これらの結果より,HRCT上の肺low attenuation areaは高齢者において有意に増加すること,さらに嘱息患者の方が健常者に比してより高値を示すことが示唆された

    Age-dependent vulnerability to ischemia-reperfusion injury of cyanotic myocardium in a chronic hypoxic rat model

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    This study evaluated the effects of chronic hypoxia from birth on the resistance of rat hearts to global ischemia, with special emphasis on the duration of hypoxia. Male Wistar rats were housed from birth for 4 weeks or 8 weeks either in a hypoxic environment (FiO20.12) or in ambient air (8 animals for each group). Isolated rat hearts were perfused for 40 min with oxygenated Krebs-Henseleit buffer, subjected to 20 min global no-flow ischemia at 37, and then underwent 40 min of reperfusion. A non-elastic balloon was inserted into the left ventricle and inflated until the pre-ischemic LVEDP rose to 8mmHg. Cardiac function was measured before and after ischemia. The post-ischemic percent recovery of LVDP in hypoxic hearts was worse than in normoxic hearts (4 weeks:55+/-7 vs. 96+/-3%, p0.01;8 weeks:40+/-5 vs. 92+/-4%, p0.01), and was worst in the 8-week-hypoxic hearts. Similarly, the percent recovery of dP/dt in the hypoxic hearts was lower than in the normoxic hearts (4 weeks:51+/-5 vs. 96+/-7%, p0.01;8 weeks:31+/-6 vs. 92+/-7%, p0.01), and was lowest in the 8-week-hypoxic hearts. In conclusion, cyanotic myocardium revealed an age-dependent vulnerability to ischemia-reperfusion injury in a chronic hypoxic rat model.</p

    Successful intra-postoperative extracorporeal circulatory support with atrial communication for treatment of anomalous left coronary artery from the pulmonary artery : a case report

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    We describe a successful case of surgical treatment for anomalous left coronary artery from the pulmonary artery (ALCAPA) syndrome with severe left ventricular dysfunction. Because of the severe left ventricular dysfunction, we planned to use an extracorporeal membrane oxygenation for heart support until a satisfactory recovery had been established. The left ventricular function signifi cantly recovered in a few days, and the patient could be discharged without any complications.</p
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