213 research outputs found
Colour-Specific Microfluidic Droplet Detection for Molecular Communication
Droplet-based microfluidic systems are a promising platform forlab-on-a-chip
(LoC) applications. These systems can also be used toenhance LoC applications
with integrated droplet control information or for data transmission scenarios
in the context of molecular communication. For both use-cases the detection and
characterisation of droplets in small microfluidic channels is crucial. So far,
only complex lab setups with restricted capabilities have been presented as
detection devices. We present a new low-cost and portable droplet detector. The
device is used to confidently distinguish between individual droplets in a
droplet-based microfluidic system. Using on-off keying a 16-bit sequence is
successfully transmittedfor the first time with such a setup. Furthermore, the
devices capabilities to characterise droplets regarding colour and size are
demonstrated. Such an application of a spectral sensor in a microfluidic system
presents new possibilities, such as colour-coded data transmission or analysis
of droplet content
Dynamical adjustment of crystal reflectivity by large-amplitude ultrasonic excitation for synchrotron X-ray monochromatization
Rotation data collection for protein crystallography with time-variable incident intensity from synchrotron radiation sources
Accuracy and precision in protein structure analysis: restrained least-squares refinement of the structure of poplar plastocyanin at 1.33 Å resolution
Проблемы технической оснащённости России для работы в условиях Арктики
Cytochrome c oxidase is a respiratory enzyme catalysing the energy-conserving reduction of molecular oxygen to water. The crystal structure of the ba(3)-cytochrome c oxidase from Thermus thermophilus has been determined to 2.4 Å resolution using multiple anomalous dispersion (MAD) phasing and led to the discovery of a novel subunit IIa. A structure-based sequence alignment of this phylogenetically very distant oxidase with the other structurally known cytochrome oxidases leads to the identification of sequence motifs and residues that seem to be indispensable for the function of the haem copper oxidases, e.g. a new electron transfer pathway leading directly from Cu(A) to Cu(B). Specific features of the ba(3)-oxidase include an extended oxygen input channel, which leads directly to the active site, the presence of only one oxygen atom (O(2–), OH(–) or H(2)O) as bridging ligand at the active site and the mainly hydrophobic character of the interactions that stabilize the electron transfer complex between this oxidase and its substrate cytochrome c. New aspects of the proton pumping mechanism could be identified
Accuracy and precision in protein crystal structure analysis: two independent refinements of the structure of poplar plastocyanin at 173 K
Предельные метрологические характеристики генераторов сигналов на основе прямого цифрового синтеза
Выпускная квалификационная работа 75 страниц, 24 рисунка, 26 таблиц, 16 источников, 4 приложения.
Ключевые слова: генератор сигналов, метрологические характеристики, амплитуда, период, коэффициент гармоник.
Объектами исследования являются характеристики гармонических колебаний: амплитуда, период и коэффициент гармоник.
Цель работы – исследование метрологических характеристик генераторов сигналов на основе прямого цифрового синтеза.
В ходе работы проводилось определение нестабильности амплитуды, нестабильности периода и коэффициента гармоник путем моделирования с помощью программного обеспечения для инженерных вычислений – Mathcad.
В результате работы были получены зависимости, позволяющие оценить необходимый период дискретизации по заданной нестабильности амплитуды, нестабильности периодаFinal qualifying work is 75 pages, 24 figures, 26 tables, 16 sources, 4 of the annex. Keywords: signal generator, the metrological characteristics, amplitude, period, total harmonic distortion. The objects of study are the characteristics of harmonic vibrations: amplitude, period, and total harmonic distortion. The purpose is research of metrological characteristics signal generator based on direct digital synthesis. The work was carried out determining the amplitude of instability, instability period and harmonic distortion by simulation software for engineering calculations - Mathcad. As a result of the work were obtained according to assess the required sampling period for a given amplitude instability, instability period and harmonic distortion
Experimental procedure for the characterization of radiation damage in macromolecular crystals
A novel automatic procedure to determine the sensitivity of macromolecular crystals to radiation damage is presented. The information extracted from this procedure can be directly used for optimal planning of data collection or/and beamline calibration
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