Generation of three-dimensional body-fitted coordinates using hyperbolic partial differential equations

An efficient numerical mesh generation scheme capable of creating orthogonal or nearly orthogonal grids about moderately complex three dimensional configurations is described. The mesh is obtained by marching outward from a user specified grid on the body surface. Using spherical grid topology, grids have been generated about full span rectangular wings and a simplified space shuttle orbiter

Use of a hyperbolic grid generation scheme in simulating supersonic viscous flow about three-dimensional winged configuration

The present paper describes a numerical mesh generation technique to be used with an implicit finite difference method for simulating visous supersonic flow about low-aspect-ratio wing body configurations using a single grid strategy. The computational domain is segmented into multiple regions, with borders located in supersonic areas to avoid the otherwise costly interfacing procedure between adjacent segments. The numerical procedure is applied to calculate the turbulent flow around the shuttle orbiter and a canard projectile at supersonic free stream Mach number

Viscous computation of a space shuttle flow field

A procedure is presented, as well as some results, to calculate the flow over the winged orbiter. This necessitates the use of two computer codes. A parabolized marching Navier-Stokes code is used to obtain the solution up to the bow shock-wing shock interaction region and for the region after the interaction. An unsteady Navier-Stokes code is to be used in the region of the shock interaction. Only resuls for the marching code are presented. For the flow conditions calculated, M infinity = 7.9, alpha = 25 deg, T(wall) = 540 R, Re(L) = 60728 per inch, laminar or turbulent, the PNS code was marched up to an X/L = 0.7 which is where the bow shock-wing shock interaction region occurs

Variations in certain biological aspects of the cotton aphid, Aphis gossypii Glover (Homoptera: Aphididae) in relation to color of its forms

The stock populations of two groups of Aphis gossypii Glover (Homoptera: Aphididae) were collected from cucurbitaceous plant leaves cultivated in Assiut and the New Valley Governorates, Egypt. Both aphid groups were brought into the laboratory and used as base line of pirimicarb resistance. Pirimicarb LC50 base line was determined by the dipping technique in successive concentrations of the trade form of pirimicarb mixed in water. The LC25 was determined monthly throughout two years and used in the selection.. This procedure resulted four aphid forms at each location (i.e., base line, mixed, light color, and dark color).  It was found that the total nymphal duration of dark forms collected from both locations did not vary significantly from the base line forms. Data of the reproductive biology of aphids from both locations showed that the fecundity period, longevity and productivity of the dark morphs were significantly higher than those of the base line ones

Relationships between selectivity of Aphis gossypii Glover and Aphis craccivora Koch to sucrose and maltose and their resistance to pirimicarb

Pirimicarb LC50 base line was determined by the dipping technique in successive concentrations of the trade form of pirimicarb in water. The LC25 was used for the selection every month through a year. In case of 10 sucrose solutions versus water, 8 counts indicated that aphids did not prefer the sucrose solution. After 6 hours the cotton aphid could not discriminate between the sugar solution and water. The discrimination between sugars was enhanced by adding 10% maltose. It was observed that the dark forms of the cotton aphid, A. gossypii and light forms of the cowpea aphid, A. craccivora attracted to the higher sucrose solution than the other forms. The cotton aphid, A. gossypii has a light color as the basic color, transforming under reversible condition to dark green, whereas, the basic color of cowpea aphid, A. craccivora usually black in color, transforming under stress to light brownish. This reversed evidence explained the differences in response towards sugar of the two aphid species.It may be concluded that the dark morphs of A. gossypii, and light morphs of A. craccivora which are considered pirimicarb resistant preferred high sugar levels. In other meaning, the present study proved that dark morphs of the cotton aphid and light forms of the cowpea aphid were resistant to pirimicarb and this resistance was positively correlated with the levels of sugars in the plants. Therefore, plant breeders are requested to pay efforts in screening process of resistant plants to produce plants with low sugar contents to increase the effectiveness of pirimicarb against both species of aphids. 

A prospective antibiotic point prevalence survey in two primary referral hospitals during and after pilgrims stay in Madinah, Saudi Arabia

Purpose: To assess current patterns of antibiotic use by carrying out two point-prevalence surveys (PPS) in Madinah after the return of hajj pilgrims from Makkah and when Madinah is free from pilgrims. Methods: In September 2016 and November 2016, a prospective PPS was conducted on two separate dates (during the hajj pilgrims stay in Madinah and after they leave). Data on antibiotics use were generated during these two periods. This involved an audit from all the departments of two referral hospitals (King Fahad Hospital (KFH) - 425 beds, and Al Ansar Hospital - 100 beds) of inpatients records. Data were collected using standard forms adapted from the European Centre for Disease Control (ECDC). Results: A total of 675 inpatients were included in PPS; among them, 332 (49.18 %) patients were receiving antibiotic therapy. In September 2016, 168 patients were treated with antibiotics, with a prevalence rate of 50.60 %, whereas, in November 2016, the prevalence rate was 49.40 %. Overall, 198 patients were identified in surgical wards, of which 132 patients (66.6 %) were receiving antibiotic therapy; 121 patients in ICU of which 70 patients (57.8 %) received antibiotics; 13 patients in other wards of which 6 (46.1 %) received antibiotic treatment; and 343 patients in medical wards of which 126 patients (36.7 %) were treated with antibiotics. There was no significant difference in prevalence of antibiotic prescribing between the two surveys (Pearson Chi-square test, p = 0.56) and with regards to patient age between the two surveys (Mann-Whitney U-test, p = 0.32). Conclusion: The results demonstrate that antibiotic use with adherence to hospital guidelines and PPS helps in identifying targets for quality improvement. Moreover, to escalate the prudent use of antibiotics in hospitals, PPS provides a useful tool. Furthermore, this survey provides a background to evaluate antibiotic use by a standardized methodology. Keywords: Point prevalence survey, Antibiotic use, Prescribing practices, Antibiotic resistance, Quality improvement, Antibiotic stewardship, Hajj, Pilgrim

Cross calibration between Hayabusa2/ONC-T and OSIRIS-REx/MapCam for comparative analyses between asteroids Ryugu and Bennu

Proximity observations of (162173) Ryugu by the telescopic Optical Navigation Camera onboard Hayabusa2 and (101955) Bennu by MapCam onboard Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer found opposite spectral trends of space weathering on these carbonaceous asteroids. Whether the space weathering trends on these asteroids evolved from the same starting spectra would place an important constraint for understanding their relation. However, systematic error between data obtained by the two imagers needed to be reduced for accurate comparison. To resolve this problem, we cross calibrated albedo and color data using the Moon as the common standard. We show that the cross-calibrated reflectance can be obtained by upscaling the pre-cross-calibrated reflectance of Bennu by 12 +/- 2% at v-band, reducing the systematic errors down to 2%. The cross-calibrated data show that Bennu is brighter by 16 +/- 2% at v-band and bluer in spectral slope by 0.19 +/- 0.05 (/um) than Ryugu. The spectra of fresh craters on Ryugu and Bennu before cross calibration appeared to follow two parallel trend lines with offset, but they converged to a single trend after cross calibration. Such a post-cross-calibration perspective raise the possibility that Ryugu and Bennu evolved from materials with similar visible spectra but evolved in diverging directions by space weathering. The divergent evolution can be caused by the difference in space weathering dose/process and/or composition of the starting material. Thus, comparing the composition of samples returned from Ryugu and Bennu may change the way we interpret the spectral variation of C-complex asteroids