Low-Speed Wind-Tunnel Test of an Unpowered High-Speed Stoppable Rotor Concept in Fixed-Wing Mode

An experimental investigation of the M85, a High Speed Rotor Concept, was conducted at the NASA Langley 14 x 22 foot Subsonic Tunnel, assisted by NASA-Ames. An unpowered 1/5 scale model of the XH-59A helicopter fuselage with a large circular hub fairing, two rotor blades, and a shaft fairing was used as a baseline configuration. The M85 is a rotor wing hybrid aircraft design, and the model was tested with the rotor blade in the fixed wing mode. Assessments were made of the aerodynamic characteristics of various model rotor configurations. Variation in configurations were produced by changing the rotor blade sweep angle and the blade chord length. The most favorable M85 configuration tested included wide chord blades at 0 deg sweep, and it attained a system lift to drag ratio of 8.4

An Experimental Investigation of Helicopter Rotor Hub Fairing Drag Characteristics

A study was done in the NASA 14- by 22-Foot Wind Tunnel at Langley Research Center on the parasite drag of different helicopter rotor hub fairings and pylons. Parametric studies of hub-fairing camber and diameter were conducted. The effect of hub fairing/pylon clearance on hub fairing/pylon mutual interference drag was examined in detail. Force and moment data are presented in tabular and graphical forms. The results indicate that hub fairings with a circular-arc upper surface and a flat lower surface yield maximum hub drag reduction; and clearance between the hub fairing and pylon induces high mutual-interference drag and diminishes the drag-reduction benefit obtained using a hub fairing with a flat lower surface. Test data show that symmetrical hub fairings with circular-arc surfaces generate 74 percent more interference drag than do cambered hub fairings with flat lower surfaces, at moderate negative angle of attack

{BOAO Photometric Survey of Galactic Open Clusters. II. Physical Parameters of 12 Open Clusters

We have initiated a long-term project, the BOAO photometric survey of open clusters, to enlarge our understanding of galactic structure using UBVI CCD photometry of open clusters which have been little studied before. This is the second paper of the project in which we present the photometry of 12 open clusters. We have determined the cluster parameters by fitting the Padova isochrones to the color-magnitude diagrams of the clusters. All the clusters except for Be 0 and NGC 1348 are found to be intermediate-age to old (0.2 - 4.0 Gyrs) open clusters with a mean metallicity of [Fe/H] = 0.0.Comment: 11 page

Economic cost of tobacco use in India, 2004

ObjectiveTo estimate the tobacco-attributable costs of diseases separately for smoked and smokeless tobacco use in India.MethodsThe prevalence-based attributable-risk approach was used to estimate the economic cost of tobacco using healthcare expenditure data from the National Sample Survey, a nationally representative household sample survey conducted in India in 2004. Four major categories of tobacco-related disease-tuberculosis, respiratory diseases, cardiovascular diseases and neoplasms-were considered.ResultsDirect medical costs of treating tobacco related diseases in India amounted to $907 million for smoked tobacco and$285 million for smokeless tobacco. The indirect morbidity costs of tobacco use, which includes the cost of caregivers and value of work loss due to illness, amounted to $398 million for smoked tobacco and$104 million for smokeless tobacco. The total economic cost of tobacco use amounted to $1.7 billion. Tuberculosis accounted for 18$311 million) in India. Of the total cost of tobacco, 88% was attributed to men.ConclusionsThe cost of tobacco use was many times more than the expenditures on tobacco control by the government of India and about 16% more than the total tax revenue from tobacco. The tobacco-attributable cost of tuberculosis was three times higher than the expenditure on tuberculosis control in India. The economic costs estimated here do not include the costs of premature mortality from tobacco use, which is known to comprise roughly 50% to 80% of the total economic cost of tobacco in many countries

Assessment of Climate Events in Changma Season (Korean Monsoon) for Production Trend of Sorghum-Sudangrass Hybrid (\u3ci\u3eSorghum bicolor\u3c/i\u3e L.) in the Central Inland Regions of Korea Using Time Series Analysis

This study aimed to assess the impact of climate events in the Changma (Korean Monsoon) season on the production trend of sorghum-sudangrass hybrid (SSH) in central inland regions using time series analysis. The dataset in Suwon from 1988–2013 (n = 388) was generated by merging SSH data and climate data. The accumulated temperature (SHAT, ℃), rainfall amount (SHRA, mm) and sunshine duration (SHSD, hr) from seeding to harvesting were used to assess their impact on the trend of dry matter yield (DMY, kg/ha) for SSH. Furthermore, heavy rainfall (HRF) and typhoons (TPH) were considered as climate events. As a result, the impact of climate events did not affect DMY, even though the frequency and intensity of HRF increased. Conversely, SHAT and SHRA had positive and negative effects on the trend of DMY, respectively. Therefore, the DMY trend of SSH was forecasted to increase until 2045, unlike maize, which has shown a declining trend. The forecasted DMY in 2045 was 14,926 kg/ha. It is likely that the damage by heavy rainfall and typhoons was reduced due to multiple-harvesting and a deeper extension of the root system. Therefore, in an environment that is rapidly changing due to climate change and abnormal weather, such as the Changma season, the cultivation of SSH would be advantageous as it would ensure a stable and robust yield