5,945 research outputs found
Use of color-coded sleeve shutters accelerates oscillograph channel selection
Sleeve-type shutters mechanically adjust individual galvanometer light beams onto or away from selected channels on oscillograph papers. In complex test setups, the sleeve-type shutters are color coded to separately identify each oscillograph channel. This technique could be used on any equipment using tubular galvanometer light sources
Advanced study of video signal processing in low signal to noise environments Semiannual progress report, Jun. - Nov. 1970
Video signal processing in low signal to noise environments - bandpass filter in multi-filter phase lock loo
Evaluating the Baluti Formation at Sararu village, Ora Anticline, Iraqi Kurdistan : a stratigraphic and geochemical approach
Open access through Springer Compact Agreement Acknowledgements The authors would like to thank Colin Taylor and Walter Ritchie from University of Aberdeen for their technical support and assistance with laboratory work. We would also like to thank Mr. Omer Kamil Ali, the Head of the Qumri village, for providing accommodation during fieldwork.Peer reviewedPublisher PD
Stiffness of Contacts Between Rough Surfaces
The effect of self-affine roughness on solid contact is examined with
molecular dynamics and continuum calculations. The contact area and normal and
lateral stiffnesses rise linearly with the applied load, and the load rises
exponentially with decreasing separation between surfaces. Results for a wide
range of roughnesses, system sizes and Poisson ratios can be collapsed using
Persson's contact theory for continuous elastic media. The atomic scale
response at the interface between solids has little affect on the area or
normal stiffness, but can greatly reduce the lateral stiffness. The scaling of
this effect with system size and roughness is discussed.Comment: 4 pages, 3 figure
Experiments to investigate particulate materials in reduced gravity fields
Study investigates agglomeration and macroscopic behavior in reduced gravity fields of particles of known properties by measuring and correlating thermal and acoustical properties of particulate materials. Experiment evaluations provide a basis for a particle behavior theory and measure bulk properties of particulate materials in reduced gravity
Vibrational Stability of NLC Linac accelerating structure
The vibration of components of the NLC linac, such as accelerating structures
and girders, is being studied both experimentally and analytically. Various
effects are being considered including structural resonances and vibration
caused by cooling water in the accelerating structure. This paper reports the
status of ongoing work.Comment: 3 pages 8 figures Presented at EPAC 2002 Paris Franc
Theory of adhesion: role of surface roughness
We discuss how surface roughness influence the adhesion between elastic
solids. We introduce a Tabor number which depends on the length scale or
magnification, and which gives information about the nature of the adhesion at
different length scales. We consider two limiting cases relevant for (a)
elastically hard solids with weak adhesive interaction (DMT-limit) and (b)
elastically soft solids or strong adhesive interaction (JKR-limit). For the
former cases we study the nature of the adhesion using different adhesive force
laws (, , where is the wall-wall separation). In
general, adhesion may switch from DMT-like at short length scales to JKR-like
at large (macroscopic) length scale. We compare the theory predictions to the
results of exact numerical simulations and find good agreement between theory
and the simulation results
On the noise immunity and legibility of Lucida fonts
Modern digital typography often has to contend with output devices such as workstation screens and laser-printers which have a much lower resolution than metal type or phototypesetter machines. In this paper we present results of some legibility investigations in which volunteers were asked to read laser-printed and photocopied material produced in three different typefaces. Two of these faces were not designed with adverse imaging conditions in mind but the third, Lucida, had as one of its design aims that it should be robust and readable at low resolutions. Evidence is presented for Lucida’s enhanced legibility in noisy conditions when compared to the other two faces. However, the difficulties of devising suitable tests and the subjective nature of much of the evidence are also discussed
On the noise immunity and legibility of Lucida fonts
Modern digital typography often has to contend with output devices such as workstation screens and laser-printers which have a much lower resolution than metal type or phototypesetter machines. In this paper we present results of some legibility investigations in which volunteers were asked to read laser-printed and photocopied material produced in three different typefaces. Two of these faces were not designed with adverse imaging conditions in mind but the third, Lucida, had as one of its design aims that it should be robust and readable at low resolutions. Evidence is presented for Lucida’s enhanced legibility in noisy conditions when compared to the other two faces. However, the difficulties of devising suitable tests and the subjective nature of much of the evidence are also discussed
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