49,624 research outputs found
Ginzburg-Landau theory of dirty two band superconductors
In this paper we study the effect of non-magnetic impurities on two-band
superconductors by deriving the corresponding Ginzburg-Landau (GL)
equation. Depending on the strength of (impurity-induced) inter-band scattering
we find that there are two distinctive regions where the superconductors behave
very differently. In the strong impurity induced inter-band scattering regime
, where mean-life time an electron stays in one
band the two-band superconductor behaves as an effective one-band dirty
superconductor. In the other limit , the dirty two-band
superconductor is described by a network of frustrated two-band superconductor
grains connected by Josepshon tunnelling junctions. We argue that most pnictide
superconductors are in the later regime.Comment: 4 pages, 1 figur
Data catalog series for space science and applications flight missions. Volume 4B: Descriptions of data sets from meteorological and terrestrial applications spacecraft and investigations
The main purpose of the data catalog series is to provide descriptive references to data generated by space science flight missions. The data sets described include all of the actual holdings of the Space Science Data Center (NSSDC), all data sets for which direct contact information is available, and some data collections held and serviced by foreign investigators, NASA and other U.S. government agencies. This volume contains narrative descriptions of data sets from meteorological and terrestrial applications spacecraft and investigations. The following spacecraft series are included: Mariner, Pioneer, Pioneer Venus, Venera, Viking, Voyager, and Helios. Separate indexes to the planetary and interplanetary missions are also provided
Fabrication of Embedded Microvalve on PMMA Microfluidic Devices through Surface Functionalization
The integration of a PDMS membrane within orthogonally placed PMMA
microfluidic channels enables the pneumatic actuation of valves within bonded
PMMA-PDMS-PMMA multilayer devices. Here, surface functionalization of PMMA
substrates via acid catalyzed hydrolysis and air plasma corona treatment were
investigated as possible techniques to permanently bond PMMA microfluidic
channels to PDMS surfaces. FTIR and water contact angle analysis of
functionalized PMMA substrates showed that air plasma corona treatment was most
effective in inducing PMMA hydrophilicity. Subsequent fluidic tests showed that
air plasma modified and bonded PMMA multilayer devices could withstand fluid
pressure at an operational flow rate of 9 mircoliters/min. The pneumatic
actuation of the embedded PDMS membrane was observed through optical microscopy
and an electrical resistance based technique. PDMS membrane actuation occurred
at pneumatic pressures of as low as 10kPa and complete valving occurred at
14kPa for 100 micrometers x 100 micrometers channel cross-sections.Comment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/handle/2042/16838
NEW PARTICLES AND INTERACTIONS
We analyze the manifestations of new matter particles predicted by models of
new physics beyond the Standard Model, at present and future high--energy
colliders. We consider both the production of these new particles and some of
their indirect signatures at and colliders as well as TeV \ee
colliders with their \ee, e \gamma, \gamma \gamma and modes. The
report is arranged into four main sections plus an overview. These sections
will deal separately with exotic and excited fermions, difermions, and new
interactions.Comment: 64 pages, latex, 30 figures (not included). The full *.ps file
including the figures can be obtained via anonymous ftp at
ftp://lpsvsh.lps.umontreal.ca/hep_th/dpf.ps . To appear as a chapter in
"Electroweak Symmetry Breaking and Beyond the Standard Model", edited by T.
Barklow, S. Dawson, H.E. Haber and S. Siegrist, World Scientifi
Lower body design of the ‘iCub’ a human-baby like crawling robot
The development of robotic cognition and a greater understanding of human cognition form two of the current greatest challenges of science. Within the RobotCub project the goal is the development of an embodied robotic child (iCub) with the physical and ultimately cognitive abilities of a 2frac12 year old human baby. The ultimate goal of this project is to provide the cognition research community with an open human like platform for understanding of cognitive systems through the study of cognitive development. In this paper the design of the mechanisms adopted for lower body and particularly for the leg and the waist are outlined. This is accompanied by discussion on the actuator group realisation in order to meet the torque requirements while achieving the dimensional and weight specifications. Estimated performance measures of the iCub are presented
- …