70 research outputs found
Raman spectroscopy as a tool for characterisation of liquid phase devices
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordIn this paper, we demonstrate how Raman spectroscopy can be an effective tool for the elucidation of the properties of liquid phase devices, looking at signal enhancement through to beam profiling
In-situ optical characterisation of the spatial dynamics of liquid crystalline nanocomposites
Liquid crystalline nanocomposites are a novel class of hybrid fluid materials, which are currently attracting significant interest from the photonics community. Such fluid nano-composites are based on low-dimensional nanoparticles (carbon nanotubes, graphene, transition metal dichalcogenides (TMDCs), metal nanoparticles etc.) dispersed in a fluidic host material. Liquid crystalline properties can either be provided by using a liquid crystal host fluid, or, through the solvent-induced self-assembly of particles. They possess a unique capability to interact with light, utilising many possibilities in plasmonics and quantum optics while they can also be integrated on Si chip by means of microfluidic technology. Integration of the nanocomposites on chip allows for dynamic control of the dispersed particle ordering through the application of various external stimuli. However, this dynamic control requires a suitable characterisation technique to fully understand the time evolution of metastructure formation. Integrated nanocomposites are characterised by the particle concentration at different points on chip, while the individual particles are defined by their sizes, xyz positions and orientation relative to the chip architecture. Here, we present a method by which all the required information for complete characterisation of the system can be obtained using a single spectroscopic technique- Raman spectroscopy- and how changes in the system can then be monitored during device operation. Liquid crystalline nanocomposites have been synthesised based on two-dimensional (2D) materials including graphene oxide (GO) and TMDCs dispersed in either commercially available liquid crystals or various organic solvents. We present both numerical analysis of the theoretical practicability of the use of Raman spectroscopy to extrapolate the desired nanocomposite properties and the experimental confirmation of the achievability of these measurements for the full range of synthesised nanocomposites
Ultra-sensitive label-free in-situ detection of dynamically driven self-assembly of 2D nanoplatelets on SOI chip
Fluid dispersed two-dimensional (2D) composite materials with dynamically tunable functional properties have recently emerged as a novel highly promising class of optoelectronic materials, opening up new routes not only for the emerging field of metamaterials but also to chip-scale multifunctional metadevices. However, in-situ monitoring and detection of the dynamic ordering of 2D nanoparticles on chip and during the device operation is still a huge challenge. Here we introduce a novel approach for on-chip, in-situ Raman characterisation of 2D-fluid composite materials incorporated into Si photonics chip. In this work the Raman signal for 2D nanoplatelets is selectively enhanced by Fabry-Perot resonator design of CMOS photonic-compatible microfluidic channels. This has then been extended to demonstrate the first in-situ Raman detection of the dynamics of individual 2D nanoplatelets, within a microfluidic channel. Our work paves the way for the first practicable realisation of 3D photonic microstructure shaping based on 2D-fluid composites and CMOS photonics platform.We acknowledge financial support from: the Engineering and Physical Sciences Research Council
(EPSRC) of the United Kingdom via the EPSRC Centre for Doctoral Training in Electromagnetic
Metamaterials (Grant No. EP/L015331/1) and also via Grants No. EP/G036101/1, EP/M002438/1,
and EP/M001024/1, Science Foundation Ireland Grant No. 12/IA/1300, the Ministry of Education
and Science of the Russian Federation (Grant No. 14.B25.31.0002) and the Royal Society
International Exchange Grant 2015/R3. The microfluidic structures were fabricated at Tyndall
National Institute under the Science Foundation Ireland NAP368 and NAP94 programmes
1-{3-[(4-Oxopiperidin-1-yl)carbonyl]benzoyl}piperidin-4-one
Two independent molecules comprise the asymmetric unit in the title compound, C18H20N2O4. One of the molecules exhibits disorder in one of its 4-piperidone rings, which is disposed over two orientations [site occupancy of the major component = 0.651 (5)]. The first independent molecule and the minor component of the second disordered molecule are virtually superimposable. The central four C atoms in the major component of the disordered molecule have an opposite orientation. All the 4-piperidone rings have a chair conformation. The carbonyl groups in each molecule have approximate anti conformations [O=C⋯C=O = 146.2 (2) and −159.9 (2)°]. The 4-piperidone rings lie to opposite sides of the central benzene ring in both molecules. In the crystal, molecules are linked by C—H⋯O interactions. The crystal studied was found to be a non-merohedral twin (twin law −1 0 0, 0 1 0, 0 − 1/2 − 1), the fractional contribution of the minor component being approximately 11%
ТРИГЕНЕРАЦИЯ КАК СПОСОБ ПОВЫШЕНИЯ ЭНЕРГЕТИЧЕСКОЙ ЭФФЕКТИВНОСТИ
The overview of current scientific literature on one of the key aspects of the development of the energy sector is presented, it is the increase of the efficiency of energy systems. The ability of cogeneration and trigeneration systems to increase energy efficiency of power stations, supermarkets, shopping centers, airports, etc. was demonstrated. In addition, it was shown that these systems have a high potential for reducing greenhouse gas emissions. The examples of polygeneration systems and ways to optimize them by improving techno-economic parameters were also demonstrated.Представлен обзор актуальной научно-технической литературы по одному из ключевых направлений развития энергетики – повышению эффективности энергетических систем. Была продемонстрирована способность когенерационных и тригенерационных систем повышать энергоэффективность на электростанциях, в супермаркетах, торговых центрах, аэропортах и др. Кроме того, было показано, что эти системы обладают высоким потенциалом в области снижения выбросов парниковых газов. Также были продемонстрированы примеры полигенерационных систем и пути их оптимизации путем улучшения технико-экономических показателей
On Validating an Astrophysical Simulation Code
We present a case study of validating an astrophysical simulation code. Our
study focuses on validating FLASH, a parallel, adaptive-mesh hydrodynamics code
for studying the compressible, reactive flows found in many astrophysical
environments. We describe the astrophysics problems of interest and the
challenges associated with simulating these problems. We describe methodology
and discuss solutions to difficulties encountered in verification and
validation. We describe verification tests regularly administered to the code,
present the results of new verification tests, and outline a method for testing
general equations of state. We present the results of two validation tests in
which we compared simulations to experimental data. The first is of a
laser-driven shock propagating through a multi-layer target, a configuration
subject to both Rayleigh-Taylor and Richtmyer-Meshkov instabilities. The second
test is a classic Rayleigh-Taylor instability, where a heavy fluid is supported
against the force of gravity by a light fluid. Our simulations of the
multi-layer target experiments showed good agreement with the experimental
results, but our simulations of the Rayleigh-Taylor instability did not agree
well with the experimental results. We discuss our findings and present results
of additional simulations undertaken to further investigate the Rayleigh-Taylor
instability.Comment: 76 pages, 26 figures (3 color), Accepted for publication in the ApJ
Способ очистки технологических и природных вод от радионуклидов и устройство для его осуществления
Использование: электросорбционная очистка технологических и природных вод от радионуклидов в ионной форме. Сущность: способ очистки водных растворов заключается в адсорбции из очищаемого раствора примесных ионов сорбентом, расположенным между двумя электродами, при наложении на электроды разности потенциалов, достаточной для омического нагрева очищаемого раствора. В результате омического нагрева в прианодной полости создается конвективный поток раствора, направленный вдоль блока сорбента, при этом образуется ионный поток примесей из прианодной полости в направлении блока сорбента. Преимущественно разность потенциалов составляет 25-250 В. Устройство для очистки вод представляет собой цилиндрическую конструкцию с соосно установленными наружным катодом и внутренним анодом. В межэлектродном пространстве вблизи катода коаксиально электродам расположен блок сорбента. Между анодом и блоком сорбента находится полость для протекания очищаемого раствора. Устройство работает в погружном режиме без принудительной прокачки очищаемого раствора и применимо для очистки растворов в емкостях, резервуарах, колодцах, водохранилищах
The Size Ellect on the Infrared Spectra of Condensed Media Under Conditions of ID, 2D and 3D Dielectric Confinement
A general expression for the dielectric loss spectrum of an absorbing composite medium was obtained from a Maxwell-Garnett general equation. This expression was simplified for the cases of one, two and three dimensional dielectric confinement in both ordered and disordered thin layers, rods (wires) and spheres of absorbing medium which are considered as mesoparticles or mesoscopic molecules. This theoretical approach was verified experimentally using high purity organic liquids with strong absorption bands in the infrared range. Three organic liquids, namely benzene, chloroform and carbon disulphide, were measured in various dielectric confinement configurations using Fourier Transform Infrared (FTIR) spectroscopy with a Grazing Angle attachment GATRTM. A significant shift of the resonant absorption band of liquid mesoparticles was observed for various dielectric confinement geometries which is in good agreement with theoretical predictions. Possible applications of this work include investigations of industrial smoke, toxic aerosols and liquid droplets
Non-Standard Errors
In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty: Non-standard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for better reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants
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