15,451 research outputs found
High-speed pulse camera
Miniaturized, 16 mm high speed pulse camera takes spectral photometric photographs upon instantaneous command. The design includes a low-friction, low-inertia film transport, a very thin beryllium shutter driven by a low-inertia stepper motor for minimum actuation time after a pulse command, and a binary encoder
Improved gas ring laser
Minimizing mode coupling improves sensing resolution of a gas ring laser in a gimballess gyroscope system or inertial rotation sensor. The piezoelectric-driven corner mirrors of the ring laser are oscillated in a direction parallel to their surfaces and the plane of rotation
Carbon and titanium diboride (TiB2) multilayer coatings.
Titanium Diboride, (TiB2) is a metal-based refractory ceramic material that has
been investigated in industrial applications ranging from, cutting tools to wear
parts and for use in the aerospace industry. The unique properties which make
this material so fascinating are, its high hardness, high melting point and its
corrosion resistance. TiB2 is prevented from wider mainstream use because of its
inherent brittle nature. With a view to overcome this in coating form and with
the aim of providing in addition inherent lubricity, in this study 50 layer
TiB2/C multilayer stacks have been fabricated, with varying volume fractions of
ceramic, whereby the interfaces of the layers limit crack propagation in the
TiB2 ceramic. TiB2 has been multilayered with carbon, to make use of the unique
and hybrid nature of the bonding in carbon coatings. DC magnetron sputtering
with substrate bias was the preferred route for the fabrication of these
coatings. AISI tool steel has been used as the substrate material. By varying
the amount of TiB2 ceramic from 50% to 95%, the Hardness of the coating is seen
to increase from 5 GPa to 17GPa. The Hardness is observed to decrease as a
function of increasing carbon content, agreeing with other studies that the
carbon layers are not load-bearing. The graphitic nature of the sp2 bond,
however, acts as a lubricant layer
The platinum nuclei: concealed configuration mixing and shape coexistence
The role of configuration mixing in the Pt region is investigated. For this
chain of isotopes, the nature of the ground state changes smoothly, being
spherical around mass and and deformed around the
mid-shell N=104 region. This has a dramatic effect on the systematics of the
energy spectra as compared to the systematics in the Pb and Hg nuclei.
Interacting Boson Model with configuration mixing calculations are presented
for gyromagnetic factors, -decay hindrance factors, and isotope shifts.
The necessity of incorporating intruder configurations to obtain an accurate
description of the latter properties becomes evident.Comment: Accepted in Physical Review
Bangor -- The Queen City: Industrial, Commercial, and Social Interests
Opening
As a commercial centre, there is no city in Maine that rivals Bangor. To thousands of people, north, east, west, and even south of it, it is the Mecca of tradesmen, on the one hand coming to town, laden with produce or stock; on the other hand, returning to their household carrying all sorts of necessities or luxuries; or having left an order that demands freight transportation. Commercially then, Bangor ranks first in inportance in the Pine Tree State and has such advantages in location, water power, shipping facilities and abundant profitable surrounding acreage, that should she ever assert herself in these lines, she would become a leader in industrial and manufacturing centres.https://digicom.bpl.lib.me.us/books_pubs/1207/thumbnail.jp
Ring laser angle encoder
Ring laser angle encoder with a scanning photometer autocollimator and an isolation axis, provides continuous digital readout. It measures the angular difference in inertial attitudes of target /any phenomena generating or reflecting a light beam/ two at a time relative to target one at a time
Protein adsorption on heterogeneous surfaces
The adsorption of the protein bovine serum albumin from an aqueous solution onto substrata made from pure silica, pure zirconia, and a mixture of the two has revealed that the adsorption behavior of the protein onto the mixture very significantly diverges from the corresponding mean of the behaviors with the pure substrata. A tentative explanation in terms of matching substratum heterogeneity with protein surface heterogeneity is offered
Application of digital particle image velocimetry to insect aerodynamics: measurement of the leading-edge vortex and near wake of a Hawkmoth.
Some insects use leading-edge vortices to generate high lift forces, as has been inferred from qualitative smoke visualisations of the flow around their wings. Here we present the first Digital Particle Image Velocimetry (DPIV) data and quantitative analysis of an insect’s leading-edge vortex and near wake at two flight speeds. This allows us to describe objectively 2D slices through the flow field of a tethered Tobacco Hawkmoth (Manduca sexta). The near-field vortex wake appears to braodly resemble elliptical vortex loops. The presence of a leading-edge vortex towards the end of the downstroke is found to coincide with peak upward force production measured by a six-component force–moment balance. The topology of Manduca’s leading-edge vortex differs from that previously described because late in the downstroke, the structure extends continuously from wingtip across the thorax to the other wingtip
Basic linear algebra subprograms for FORTRAN usage
A package of 38 low level subprograms for many of the basic operations of numerical linear algebra is presented. The package is intended to be used with FORTRAN. The operations in the package are dot products, elementary vector operations, Givens transformations, vector copy and swap, vector norms, vector scaling, and the indices of components of largest magnitude. The subprograms and a test driver are available in portable FORTRAN. Versions of the subprograms are also provided in assembly language for the IBM 360/67, the CDC 6600 and CDC 7600, and the Univac 1108
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