2,694 research outputs found
Amplifying ribbon extensometer
A self-contained, nonelectrical strain gage capable of amplifying strain inputs and preserving the maximum strain measurement for later observance is presented
Reigning the River: Urban Ecologies and Political Transformation in Kathmandu by Anne M. Rademacher; Reviewed by Kelly D. Alley
Amplifying ribbon extensometer
Device provides accurate measurement of strain on flexible membranes and fabrics. It is compact and lightweight, has strain-amplification capability up to five, and has an accuracy better than one percent
Nozzle extraction process and handlemeter for measuring handle
Method and apparatus for quantitatively measuring the handle of fabrics and other flexible materials is presented. Handle is that term used to refer to the qualities of drapability, flexibility, compressibility, foldability, stretchability, pliability, etc., possessed by fabrics and other flexible materials. In the present invention the handle of a material sample is quantified by measuring the force required to draw the sample through an orifice and expressing the resultant extractive force as a function of test apparatus geometry and the amount of sample drawn through the orifice to arrive at quantitative measure of handle, to be defined as handle modulus, for the sample in question
Laser beam pointing tests
Laser beam pointing tests for lunar communication and rangefinding and tracking using Surveyor 7 vidicon camer
Conformational Preferences of 3-(Dimethylazinoyl)propanoic Acid as a Function of pH and Solvent; Intermolecular versus Intramolecular Hydrogen Bonding
The conformational equilibrium of 3-(dimethylazinoyl)propanoic acid (DMAPA, azinoyl = N^+(O^−) has a weak pH-dependence in D_2O, with a slight preference for trans in alkaline solutions. The acid ionization constants of the protonated amine oxide and carboxylic functional groups as determined by NMR spectroscopy were 7.9 × 10^(−4) and 6.3 × 10^(−6), respectively. The corresponding value of K_1/K_2 of 1.3 × 10^2 is not deemed large enough to provide experimental NMR evidence for a significant degree of intramolecular hydrogen bonding in D_2O. Conformational preferences of DMAPA are mostly close to statistical (gauche/trans = 2/1) in other protic solvents, e.g., alcohols. However, the un-ionized form of DMAPA appears to be strongly intramolecularly hydrogen-bonded and gauche in aprotic solvents
The far field diffraction pattern for corner reflectors with complex reflection coefficients
The far field diffraction pattern of a geometrically perfect corner reflector is examined analytically for normally incident monochromatic light. The states of polarization and the complex amplitudes of the emerging light are expressed through transformation matrices in terms of those of the original incident light for each sextant of the face in a single coordinate system. The analytic expression of the total diffraction pattern is obtained for a circular face. This expression consists of three component functions in addition to the basic Airy function. The coefficient of each function is expressed in terms of complex coefficients of reflectance of the reflecting surface. Some numerical results for different reflecting surfaces, including total internal reflection, are presented. The iso-intensity contours of the diffraction pattern evaluated from the analytical expressions for an uncoated solid corner reflector are also presented along with the photographs of the pattern
Does haste make waste? The human factors of overtaking land design
The aim of this research was to improve overtaking safety and efficiency through improvements in road signage, markings, geometry and speed control associated with the placement and layout of passing lanes. The approach of the research was to explore the effects of several types of overtaking lane treatments in the safety and controlled environment of a state-of-the-art driving simulator. It was found that under the most benign conditions there were no differential effects of the three treatments. With poorer visibility or more taxing road geometry, the drivers relied more heavily on the road markings and signage and the effects of the treatments become more pronounced. The sensitivity to the more "challenging" situations was borne out by the greater speed differential between merge area sections at these sites
Visualizing Hydropower Across the Himalayas: Mapping in a time of Regulatory Decline
This paper introduces the busy field of hydropower development in the Himalayan region of the GBM basin to press the urgency for greater information and data exchange. The paper provides an example of a mapping method and a database that will add to the existing online sources of information and analysis offered by nongovernmental agencies and some government departments. This project contributes to the general aim of many citizen groups to limit, monitor and regulate the practices of hydropower companies and the management of their infrastructure in the GBM. The monitoring pressure from citizen groups and science projects continues to serve as an important replacement to the weak functioning of the country environment ministries and corrects the corruptions of the license raj that plaque project deals and environmental clearances. These citizen motivated knowledge exchanges, especially through online portals and social media, can even push for better transnational instruments for formal governmental data sharing
Time transfer between the Goddard Optical Research Facility and the U.S. Naval Observatory using 100 picosecond laser pulses
A horizontal two-way time comparison link in air between the University of Maryland laser ranging and time transfer equipment at the Goddard Optical Research Facility (GORF) 1.2 m telescope and the Time Services Division of the U.S. Naval Observatory (USNO) was established. Flat mirrors of 25 cm and 30 cm diameter respectively were placed on top of the Washington Cathedral and on a water tower at the Beltsville Agricultural Research Center. Two optical corner reflectors at the USNO reflect the laser pulses back to the GORF. Light pulses of 100 ps duration and an energy of several hundred microjoules are sent at the rate of 10 pulses per second. The detection at the USNO is by means of an RCA C30902E avalanche photodiode and the timing is accomplished by an HP 5370A computing counter and an HP 1000 computer with respect to a 10 pps pulse train from the Master Clock
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