228 research outputs found
Effect of the anisotropy of monocrystalline silicon mechanical properties on the dynamic characteristics of a micromechanical gyroscope
The aim of the research was to determine the effect of temperature on mechanical properties of a micromechanical gyroscope with the sensing element mounted on a silicon wafer, with the crystallographic orientation of (100) (110) (111). The research is of current relevancy since the metrological characteristics that depend on the eigenfrequencies over the full temperature range are to be controlled. The temperature-modal analysis of the micromechanical gyroscope model was performed with ANSYS program. The temperature dependence for eigenfrequencies was obtained. The dependence of the scale factor on temperature for the most temperature-independent variant of sensor positioning on the wafer was determined. The developed mathematical model was used to find the forms of the output oscillations of the gyroscope
Structure of the 1,N2-Ethenodeoxyguanosine Adduct Opposite Cytosine in Duplex DNA: Hoogsteen Base Pairing at pH 5.2†
Wind-induced variability in the Northern Current (northwestern Mediterranean Sea) as depicted by a multi-platform observing system
The variability and evolution of the Northern Current (NC) in the area off
Toulon is studied for 2 weeks in December 2011 using data from a glider, a
high-frequency (HF) radar network, vessel surveys, a weather station, and an atmospheric model.
The NC variability is dominated by a synoptic response to wind events, even
though the dataset also evidences early stages of transition from late summer
to fall–winter conditions. With weak winds, the current is mostly zonal and
in geostrophic balance even at the surface, with a zonal transport associated
with the NC of ≈ 1 Sv. Strong westerly wind events (longer than
2–3 days) induce an interplay between the direct-wind-induced ageostrophic
response and the geostrophic component: upwelling is observed, with offshore
surface transport, surface cooling, flattening of the isopycnals, and reduced
zonal geostrophic transport (0.5–0.7 Sv). The sea surface response to wind
events, as observed by the HF radar, shows total currents rotated at ≈ −55 to −90° to the right of the wind. Performing a
decomposition between geostrophic and ageostrophic components of the surface
currents, the wind-driven ageostrophic component is found to rotate by
≈ −25 to −30° to the right of the wind. The ageostrophic
component magnitude corresponds to ≈ 2 % of the wind speed.</p
Structure of the 1,N2-Etheno-2′-deoxyguanosine Lesion in the 3′-G(εdG)T-5′ Sequence Opposite a One-Base Deletion†
Safety and Quality in the Agricultural Product Chain in Brazil
An agriculture-intensive country should be aware of natural toxins, including both mycotoxins and cyanotoxins, which are closely associated with the quality of raw materials, for food safety and industry. The major production chains – corn, wheat, beef, and broiler chicken – are the top components of agribusiness, and they should be tracked by reliable and practical tools. The corn chain is of particular concern in food production; intensive controls, multi-year mycotoxin monitoring, and improved harmless/sustainable management methods for uninterrupted farming in the tropic-subtropics are needed to achieve a long-lasting trend. The rapid control of natural toxins (mycotoxin and cyanotoxin) has focused on immunochemical methods developed with highly specific monoclonal antibodies (mAb) matched with chromatographic methods. In parallel, the promising widespread application of non-destructive analytical methods based on NIR (Near Infrared Reflectance) spectroscopy, computer vision and hyperspectral imaging coupled with multivariate analyses have been introduced as an alternative for the prediction of quality and compositional parameters. Rapid quality control and product traceability are discussed, as well as accurate monitoring, which is essential for potentially launching an innovative system for food production in Brazil
Epigenetic control of nuclear architecture
The cell nucleus is a highly structured compartment where nuclear components are thought to localize in non-random positions. Correct positioning of large chromatin domains may have a direct impact on the localization of other nuclear components, and can therefore influence the global functionality of the nuclear compartment. DNA methylation of cytosine residues in CpG dinucleotides is a prominent epigenetic modification of the chromatin fiber. DNA methylation, in conjunction with the biochemical modification pattern of histone tails, is known to lock chromatin in a close and transcriptionally inactive conformation. The relationship between DNA methylation and large-scale organization of nuclear architecture, however, is poorly understood. Here we briefly summarize present concepts of nuclear architecture and current data supporting a link between DNA methylation and the maintenance of large-scale nuclear organization
Impact of volatile phenols and their precursors on wine quality and control measures of Brettanomyces/Dekkera yeasts
Volatile phenols are aromatic compounds and one of the key molecules responsible for olfactory defects in wine. The yeast genus Brettanomyces is the only major microorganism that has the ability to covert hydroxycinnamic acids into important levels of these compounds, especially 4-ethylphenol and 4-ethylguaiacol, in red wine. When 4-ethylphenols reach concentrations greater than the sensory threshold, all wine’s organoleptic characteristics might be influenced or damaged. The aim of this literature review is to provide a better understanding of the physicochemical, biochemical, and metabolic factors that are related to the levels of p-coumaric acid and volatile phenols in wine. Then, this work summarizes the different methods used for controlling the presence of Brettanomyces in wine and the production of ethylphenols
Plant growth-promoting bacteria associated with nitrogen fertilization at topdressing in popcorn agronomic performance
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