72 research outputs found
New approaches to ultrasensitive magnetic resonance
Spectroscopic methods tend to exhibit an inverse correlation between sensitivity and the ability to discriminate between similar structures. Were they obtainable with adequate sensitivity, magnetic resonance spectra could resolve structural controversies involving the nature of clusters, ions, semiconductor defects and catalytic intermediates. This paper describes several novel approaches to magnetic resonance, which have in common that the spins are coupled to other degrees of freedom in order to obtain nonequilibrium polarization and/or greater detection sensitivity. The methods under development include single-ion electron spin resonance (ESR) detected by ion trapping frequencies, catalyst NMR detected by the branching ratio to different spin symmetry species, and semiconductor nuclear magnetic resonance (NMR) detected via the circular polarization of luminescence
New approaches to ultrasensitive magnetic resonance
Spectroscopic methods tend to exhibit an inverse correlation between sensitivity and the ability to discriminate between similar structures. Were they obtainable with adequate sensitivity, magnetic resonance spectra could resolve structural controversies involving the nature of clusters, ions, semiconductor defects and catalytic intermediates. This paper describes several novel approaches to magnetic resonance, which have in common that the spins are coupled to other degrees of freedom in order to obtain nonequilibrium polarization and/or greater detection sensitivity. The methods under development include single-ion electron spin resonance (ESR) detected by ion trapping frequencies, catalyst NMR detected by the branching ratio to different spin symmetry species, and semiconductor nuclear magnetic resonance (NMR) detected via the circular polarization of luminescence
LICSTER -- A Low-cost ICS Security Testbed for Education and Research
Unnoticed by most people, Industrial Control Systems (ICSs) control entire
productions and critical infrastructures such as water distribution, smart grid
and automotive manufacturing. Due to the ongoing digitalization, these systems
are becoming more and more connected in order to enable remote control and
monitoring. However, this shift bears significant risks, namely a larger attack
surface, which can be exploited by attackers. In order to make these systems
more secure, it takes research, which is, however, difficult to conduct on
productive systems, since these often have to operate twenty-four-seven.
Testbeds are mostly very expensive or based on simulation with no real-world
physical process. In this paper, we introduce LICSTER, an open-source low-cost
ICS testbed, which enables researchers and students to get hands-on experience
with industrial security for about 500 Euro. We provide all necessary material
to quickly start ICS hacking, with the focus on low-cost and open-source for
education and research
Effectiveness of breeding selection for grain quality in common bean.
he aims of this study were to investigate the genetic variability and the genotype × environment interaction for quality and yield traits in common bean (Phaseolus vulgaris L.), to evaluate the degree of informativeness of the evaluations of grain quality in only one environment, to estimate genetic parameters for grain quality traits, and to select lines with superior grain quality. We evaluated 81 carioca common bean lines in preliminary line trials in several environments for nutritional, technological, and commercial quality and selected the 20 superior lines, which were evaluated in validation trials in nine environments. Individual and combined ANOVAs were performed for all the traits. Correlations were estimated between Fe and Zn concentrations and yield; adaptability and phenotypic stability were analyzed; and superior genotypes were selected based on the Mulamba & Mock index. It is possible to increase the Fe, Zn, and crude protein concentrations and reduce cooking time; however, increasing crude fiber is a challenge. Preliminary evaluation of the quality traits in only one environment was effective and sufficient for selection of genotypes superior in Fe concentration, crude fiber, crude protein, and cooking time; and genetic gains can be obtained from selection for these traits. Genetic and phenotypic correlations were observed between Fe and Zn concentrations. The lines CNFC 16627, CNFC 16518, CNFC 16602, CNFC 16615, and CNFC 16520 are superior based on the selection index and are recommended for breeding for grain quality in carioca common bean
Factors That Drive Peptide Assembly and Fibril Formation: Experimental and Theoretical Analysis of Sup35 NNQQNY Mutants
Residue mutations have substantial effects on aggregation kinetics and propensities of amyloid peptides and their aggregate morphologies. Such effects are attributed to conformational transitions accessed by various types of oligomers such as steric zipper or single β-sheet. We have studied the aggregation propensities of six NNQQNY mutants: NVVVVY, NNVVNV, NNVVNY, VIQVVY, NVVQIY, and NVQVVY in water using a combination of ion-mobility mass spectrometry, transmission electron microscopy, atomic force microscopy, and all-atom molecular dynamics simulations. Our data show a strong correlation between the tendency to form early β-sheet oligomers and the subsequent aggregation propensity. Our molecular dynamics simulations indicate that the stability of a steric zipper structure can enhance the propensity for fibril formation. Such stability can be attained by either hydrophobic interactions in the mutant peptide or polar side-chain interdigitations in the wild-type peptide. The overall results display only modest agreement with the aggregation propensity prediction methods such as PASTA, Zyggregator, and RosettaProfile, suggesting the need for better parametrization and model peptides for these algorithms
Investigation of pole fire on a 22kV wooden power pole structure
Wooden pole fires caused by leakage current flow are a major problem faced by various power distribution utilities in Australia and many other parts of the world. The excessive leakage current activity in wooden structures caused by contamination of insulators over a period of time starts to deteriorate the insulation characteristics leading to pole fires and subsequently power cut-off. This paper reports an investigation of a fire at the bolt mounting a transformer to a 22kV wooden structure experienced by one of the electricity distribution utilities in Australia. A comparative analysis is undertaken between a undamaged and damaged poles of similar ages and species. The effect of surface conductivity and varying moisture content on leakage current flowing through the wooden structure is also studied. An Infrared camera study is also undertaken to study the heat mechanism caused by leakage current flow. A relatively low leakage current magnitude is observed to be enough current flow to create sufficient heat, causing smoldering. A combination of environmental factors and pole configuration created the right circumstances for the resulting pole fire
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