101,909 research outputs found
A Search for CO in the Local Group Dwarf Irregular Galaxy WLM
We present 12CO J = 1-0 and J = 2-1 observations of the low metallicity (12 +
log(O/H) = 7.74) Local Group dwarf irregular galaxy WLM made with the 15 m SEST
and 14 m FCRAO telescopes. Despite the presence a number of HII regions, we
find no CO emission. We obtain low upper limits on the integrated intensity
(I(CO) >= 0.18 K km/s for CO (1-0)). The non-detection is consistent with the
result of Taylor, Kobulnicky and Skillman (1998), that dwarf galaxies below a
metallicity of ~ 7.9 are not detected in CO emission. WLM shows that this trend
continues for low metallicity galaxies even as their metallicities approach
7.9. These results are consistent with the models of the metal poor ISM by
Norman and Spaans (1997). By comparing our CO data with observations of star
formation in WLM, we find evidence for a high CO to H conversion factor.Comment: 11 pages, 3 figures, accepted by A&
Some transition metal complexes of 8-amino- quinoline
Transition metal complexes of 8-aminoquinolin
LOGSIM programmer's manual
A programmer's manual is reported for a Logic Simulator (LOGSIM) computer program that is a large capacity event simulator with the capability to accurately simulate the effects of certain unknown states, rise and fall times, and floating nodes in large scale metal oxide semiconductor logic circuits. A detailed description of the software with flow charts is included within the report
LOGSIM user's manual
The user's manual for the LOGSIM Program is presented. All program options are explained and a detailed definition of the format of each input card is given. LOGSIM Program operations, and the preparation of LOGSIM input data are discused along with data card formats, postprocessor data cards, and output interpretation
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Gorlin syndrome in a patient with skin type VI
Gorlin syndrome, also known as nevoid basal cell carcinoma syndrome, is a rare autosomal dominant disorder that is characterized by multiple basal cell carcinomas developing at a young age, keratocystic odontogenic tumors of the jaw, palmar or plantar pits, calcification of the falx cerebri, and skeletal abnormalities. Nevoid basal cell carcinoma syndrome is caused by mutations in the PTCH1 or SUFU genes. Our patient with Fitzpatrick skin type VI was diagnosed with Gorlin syndrome based on the presentation of multiple major diagnostic characteristics. Although he is 33 years old, he has not developed any multiple basal cell carcinomas to date
Use of active control technology to improve ride qualities of large transport aircraft
Analyses, construction and flight testing of two systems: Beta-vane and Modal Suppression Augmentation System (MSAS), which were developed to suppress gust induced lateral accelerations of large aircraft, are described. The 747 transport was used as the test vehicle. The purpose of the Beta-vane system is to reduce acceleration levels at the dutch roll frequency whereas the function of the MSAS system is to reduce accelerations due to flexible body motions caused by turbulence. Data from flight test, with both systems engaged shows a 50 to 70 percent reduction in lateral aft body acceleration levels. Furthermore, it is suggested that present day techniques used for developing dynamic equations of motion in the flexible mode region are limited
Nonlinear static and dynamic analysis of mixed cable elements
This paper presents a family of finite elements for the nonlinear static and dynamic analysis of cables based on a mixed variational formulation in curvilinear coordinates and finite deformations. This formulation identifies stress measures, in the form of axial forces, and conjugate deformation measures for the nonlinear catenary problem. The continuity requirements lead to two distinct implementations: one with a continuous axial force distribution and one with a discontinuous. Two examples from the literature on nonlinear cable analysis are used to validate the proposed formulation for St VenantKirchhoff elastic materials. These studies show that displacements and axial forces are captured with high accuracy for both the static and the dynamic case
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