2,181 research outputs found
Maturation sexuelle et fonctionnement ovarien de Rhammatocerus schistocercoides (Rehn, 1906) (Orthoptères, Acrididae, Gomphocerinae), acridien ravageur de l´état du Mato Grosso (Brésil).
bitstream/item/116976/1/1417.pd
Dismantling the bacterial glycocalyx: Chemical tools to probe, perturb, and image bacterial glycans
The bacterial glycocalyx is a quintessential drug target comprised of structurally distinct glycans. Bacterial glycans bear unusual monosaccharide building blocks whose proper construction is critical for bacterial fitness, survival, and colonization in the human host. Despite their appeal as therapeutic targets, bacterial glycans are difficult to study due to the presence of rare bacterial monosaccharides that are linked and modified in atypical manners. Their structural complexity ultimately hampers their analytical characterization. This review highlights recent advances in bacterial chemical glycobiology and focuses on the development of chemical tools to probe, perturb, and image bacterial glycans and their biosynthesis. Current technologies have enabled the study of bacterial glycosylation machinery even in the absence of detailed structural information
NtGCM User's Manual: 1.1 (High Pressure High Temperature Laser based) Nanotube Growth Chamber Monitor
This manual describes the installation and use of NtGCM software. NtGCM is software designed for monitoring the growth of nanotubes in a high temperature and high pressure chamber using a laser*. NtGCM software monitors a dozen dierent parameters that are important to understanding the growth of the nanomaterials including the laser input power, the temperature at eight separate locations inside and outside the growth chamber, as well as the pressure and ow rate of the gaseous media that control the environment in the chamber. The measurements are all made in real time. The program features a robust user account management layer and a rich data display manager that allows plotted data, displayed units and other parameters to be changed on the y for the operator's convenience
Spacecraft Reed-Solomon downlink module
Apparatus and method for providing downlink frames to be transmitted from a spacecraft to a ground station. Each downlink frame includes a synchronization pattern and a transfer frame. The apparatus may comprise a monolithic Reed-Solomon downlink (RSDL) encoding chip coupled to data buffers for storing transfer frames. The RSKL chip includes a timing device, a bus interface, a timing and control unit, a synchronization pattern unit, and a Reed-Solomon encoding unit, and a bus arbiter
A very High Gradient Test of a 30 GHz Single-Cell Cavity
In order to extend the available range of data on achievable accelerating gradients and pulse lengths at the CLIC (Compact Linear Collider) frequency of 30 GHz, a single-cell resonant cavity has been high-gradient tested in the CLIC Test Facility, CTFII. The cavity was excited by a 4 ns long bunched electron beam, resulting in a field pulse with a steep rise, followed by an exponential decay with a 1/e time of 25 ns (corresponding to a loaded Q of 3800). The cavity operated without breakdown at a peak accelerating gradient of 290 MV/m, with operation progressively less stable with increasing gradient. At about 400 MV/m the cavity broke down on every pulse. For this condition the cavity surface was subject to a surface electric field in excess of 750 MV/m
Adaptive EAGLE dynamic solution adaptation and grid quality enhancement
In the effort described here, the elliptic grid generation procedure in the EAGLE grid code was separated from the main code into a subroutine, and a new subroutine which evaluates several grid quality measures at each grid point was added. The elliptic grid routine can now be called, either by a computational fluid dynamics (CFD) code to generate a new adaptive grid based on flow variables and quality measures through multiple adaptation, or by the EAGLE main code to generate a grid based on quality measure variables through static adaptation. Arrays of flow variables can be read into the EAGLE grid code for use in static adaptation as well. These major changes in the EAGLE adaptive grid system make it easier to convert any CFD code that operates on a block-structured grid (or single-block grid) into a multiple adaptive code
Giant Spin Seebeck Effect through an Interface Organic Semiconductor
Interfacing an organic semiconductor C60 with a non-magnetic metallic thin
film (Cu or Pt) has created a novel heterostructure that is ferromagnetic at
ambient temperature, while its interface with a magnetic metal (Fe or Co) can
tune the anisotropic magnetic surface property of the material. Here, we
demonstrate that sandwiching C60 in between a magnetic insulator (Y3Fe5O12:
YIG) and a non-magnetic, strong spin-orbit metal (Pt) promotes highly efficient
spin current transport via the thermally driven spin Seebeck effect (SSE).
Experiments and first principles calculations consistently show that the
presence of C60 reduces significantly the conductivity mismatch between YIG and
Pt and the surface perpendicular magnetic anisotropy of YIG, giving rise to
enhanced spin mixing conductance across YIG/C60/Pt interfaces. As a result, a
600% increase in the SSE voltage (VLSSE) has been realized in YIG/C60/Pt
relative to YIG/Pt. Temperature-dependent SSE voltage measurements on
YIG/C60/Pt with varying C60 layer thicknesses also show an exponential increase
in VLSSE at low temperatures below 200 K, resembling the temperature evolution
of spin diffusion length of C60. Our study emphasizes the important roles of
the magnetic anisotropy and the spin diffusion length of the intermediate layer
in the SSE in YIG/C60/Pt structures, providing a new pathway for developing
novel spin-caloric materials
When is a firm's information asymmetry priced? The role of institutional investors
This study reexamines the competing claims that probability of informed trading (PIN) is priced in the cross-section of stock returns while adjusted PIN (AdjPIN), the component of PIN related to information asymmetry, is not. We find that behind these seemingly contradicting conclusions is the role of institutional investors, and the pricing of PIN and AdjPIN depends on institutional ownership. Only for those stocks with low institutional ownership are both PIN and AdjPIN priced. Our findings imply that investors require compensation for information risk only from stocks with low institutional ownership
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