627 research outputs found
FEATURE-BASED GEOMETRIC MODELLING AND ANALYSIS OF MULTIBODY MECHANICAL SYSTEM BEHAVIOUR
The aim of this paper is to present a modelling system and an application to analyse
the mechanical behaviour of a gear-box. Designing a new type of gear-box, there is a
real need for the concurrent engineering activities of the designers of geometric modelling,
mesh generation and mechanical analysis. In this system own developed contact types of
finite elements (FEM) have been used.
The new system contains some programs of the earlier system ASSYM (CASM
Lab.) for modelling the casing as the superstructure of a gear-box and its bearings as
FEM contact-macroelements. In the proposed system the designers can use the modeller
CAEDS (IBM Corp.) for feature-based geometric modelling and for generating the global
mesh model of casing, the FEM analysis processor Mac/NASTRAN (MacNeal-Schwendler
Corp.) and the new version of the N_SIM program (CASM Lab.) for modelling the pairs
of gears and the bearings, furthermore the New Grid (N.G.) preprocessor (CASM Lab.).
The N.G. can introduce the local mesh models of macroelements to the global mesh of
gear-box casing
Study of a high spatial resolution 10B-based thermal neutron detector for application in neutron reflectometry: the Multi-Blade prototype
Although for large area detectors it is crucial to find an alternative to
detect thermal neutrons because of the 3He shortage, this is not the case for
small area detectors. Neutron scattering science is still growing its
instruments' power and the neutron flux a detector must tolerate is increasing.
For small area detectors the main effort is to expand the detectors'
performances. At Institut Laue-Langevin (ILL) we developed the Multi-Blade
detector which wants to increase the spatial resolution of 3He-based detectors
for high flux applications. We developed a high spatial resolution prototype
suitable for neutron reflectometry instruments. It exploits solid 10B-films
employed in a proportional gas chamber. Two prototypes have been constructed at
ILL and the results obtained on our monochromatic test beam line are presented
here
Measurement of the complex Faraday angle in thin-film metals and high temperature superconductors
A sensitive polarization modulation technique uses photoelastic modulation
and hetrodyne detection to simultaneously measure the Faraday rotation and
induced ellipticity in light transmitted by semiconducting and metallic
samples. The frequencies measured are in the mid-infrared and correspond to the
spectral lines of a CO2 laser. The measured temperature range is continuous and
extends from 35 to 330K. Measured samples include GaAs and Si substrates, gold
and copper films, and YBCO and BSCCO high temperature superconductors.Comment: 12 pages of text, 6 figures, fixed typos in formulas, added figur
Insectivorous bats in Indian rice fields respond to moonlight, temperature, and insect activity
ABSTRACT: Context - Rice, India’s most widely grown crop, suffers substantial and increasing yield loss to insect pests. Insectivorous bats are known suppressors of insect pests, providing significant economic value to agricultural systems worldwide, yet their ecology in Indian agricultural landscapes is poorly understood.
Objectives - We assess the influence of key biotic and abiotic factors on the activity of insectivorous bats over the growing season and within a night in a rice cultivation landscape.
Methods - Passive acoustic recorders were used to track bat activity in a rice field in the Sonitpur district of Assam, India. We used generalised linear mixed models to analyse the effect of temperature, insect activity, and moonlight intensity on the activity of six bat sonotypes. We also used a multimodal analysis to describe the within-night activity patterns of these sonotypes.
Results - Minimum nightly temperature and moonlight intensity had a positive and negative influence, respectively, on the activity of six bat sonotypes, while the activity of four bat sonotypes increased with insect activity. Within-night activity showed one of two patterns: three sonotypes displayed a dusk peak in activity, while the three other sonotypes were active through the night.
Conclusion - The potential to maximise natural pest control in agricultural landscapes can only be realised through understanding the ecology of natural enemies in these landscapes. Our findings suggest that bats in rice fields are tracking insects over a season and within a night, pointing to a valuable ecosystem service in Indian agriculture that is yet to be quantified.info:eu-repo/semantics/publishedVersio
Power-law scaling in intratumoral microbiota of colorectal cancer
It has recently been proposed that the study of microbial dynamics in humans may gain insights from island biogeographical theory. Here, we test whether the diversity of the intratumoral microbiota of colorectal cancer tumors (CRC) follows a power law with tumor size akin to the island species-area relationship. We confirm a direct correlation between the quantity of Amplicon Sequence Variants (ASVs) within CRC tumors and tumor sizes, following a (log)power model, explaining 47% of the variation. Understanding the processes involved, potentially through the analogy of tumors and islands, may ultimately contribute to future clinical and therapeutic strategies
Power-law scaling in intratumoral microbiota of colorectal cancer
It has recently been proposed that the study of microbial dynamics in humans may gain insights from island biogeographical theory. Here, we test whether the diversity of the intratumoral microbiota of colorectal cancer tumors (CRC) follows a power law with tumor size akin to the island species-area relationship. We confirm a direct correlation between the quantity of Amplicon Sequence Variants (ASVs) within CRC tumors and tumor sizes, following a (log)power model, explaining 47% of the variation. Understanding the processes involved, potentially through the analogy of tumors and islands, may ultimately contribute to future clinical and therapeutic strategies
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