542 research outputs found
Conceptual aspects of line tensions
We analyze two representative systems containing a three-phase-contact line:
a liquid lens at a fluid--fluid interface and a liquid drop in contact with a
gas phase residing on a solid substrate. We discuss to which extent the
decomposition of the grand canonical free energy of such systems into volume,
surface, and line contributions is unique in spite of the freedom one has in
positioning the Gibbs dividing interfaces. In the case of a lens it is found
that the line tension is independent of arbitrary choices of the Gibbs dividing
interfaces. In the case of a drop, however, one arrives at two different
possible definitions of the line tension. One of them corresponds seamlessly to
that applicable to the lens. The line tension defined this way turns out to be
independent of choices of the Gibbs dividing interfaces. In the case of the
second definition,however, the line tension does depend on the choice of the
Gibbs dividing interfaces. We provide equations for the equilibrium contact
angles which are form-invariant with respect to notional shifts of dividing
interfaces which only change the description of the system. Conceptual
consistency requires to introduce additional stiffness constants attributed to
the line. We show how these constants transform as a function of the relative
displacements of the dividing interfaces. The dependences of the contact angles
on lens or drop volumes do not render the line tension alone but a combination
of the line tension, the Tolman length, and the stiffness constants of the
line.Comment: 34 pages, 9 figure
Contact angles on a soft solid: from Young's law to Neumann's law
The contact angle that a liquid drop makes on a soft substrate does not obey
the classical Young's relation, since the solid is deformed elastically by the
action of the capillary forces. The finite elasticity of the solid also renders
the contact angles different from that predicted by Neumann's law, which
applies when the drop is floating on another liquid. Here we derive an
elasto-capillary model for contact angles on a soft solid, by coupling a
mean-field model for the molecular interactions to elasticity. We demonstrate
that the limit of vanishing elastic modulus yields Neumann's law or a slight
variation thereof, depending on the force transmission in the solid surface
layer. The change in contact angle from the rigid limit (Young) to the soft
limit (Neumann) appears when the length scale defined by the ratio of surface
tension to elastic modulus reaches a few molecular sizes
M\"ossbauer, nuclear inelastic scattering and density functional studies on the second metastable state of Na2[Fe(CN)5NO]2H2O
The structure of the light-induced metastable state SII of
Na2[Fe(CN)5NO]2H2O 14 was investigated by transmission M\"ossbauer
spectroscopy (TMS) in the temperature range 15 between 85 and 135 K, nuclear
inelastic scattering (NIS) at 98 K using synchrotron 16 radiation and density
functional theory (DFT) calculations. The DFT and TMS results 17 strongly
support the view that the NO group in SII takes a side-on molecular orientation
18 and, further, is dynamically displaced from one eclipsed, via a staggered,
to a second 19 eclipsed orientation. The population conditions for generating
SII are optimal for 20 measurements by TMS, yet they are modest for
accumulating NIS spectra. Optimization 21 of population conditions for NIS
measurements is discussed and new NIS experiments on 22 SII are proposed
Observation of the magnetic domain structures in CuNi thin films at low temperatures
We report on the first experimental visualization of domain structure in
films of weakly ferromagnetic CuNi alloy with different
thickness at liquid helium temperatures. Improved high-resolution Bitter
decoration technique was used to map the magnetic contrast on the top of the
films well below the Curie temperature T ( 60 K). In contrast
to magnetic force microscopy, this technique allowed visualization of the
domain structure without its disturbance while the larger areas of the sample
were probed. Maze-like domain patterns, typical for perpendicular magnetic
anisotropy, were observed. The average domain width was found to be about 100
nm.Comment: 4 pages, 5 figures, will be published in JETP Let
A Large-Scale FPGA-Based Trigger and Dead-Time Free DAQ System for the Kaos Spectrometer at MAMI
The Kaos spectrometer is maintained by the A1 collaboration at the Mainz
Microtron MAMI with a focus on the study of (e,e'K^+) coincidence reactions.
For its electron-arm two vertical planes of fiber arrays, each comprising
approximately 10 000 fibers, are operated close to zero degree scattering angle
and in close proximity to the electron beam. A nearly dead-time free DAQ system
to acquire timing and tracking information has been installed for this
spectrometer arm. The signals of 144 multi-anode photomultipliers are collected
by 96-channel front-end boards, digitized by double-threshold discriminators
and the signal time is picked up by state-of-the-art F1 time-to-digital
converter chips. In order to minimize background rates a sophisticated trigger
logic was implemented in newly developed Vuprom modules. The trigger performs
noise suppression, signal cluster finding, particle tracking, and coincidence
timing, and can be expanded for kinematical matching (e'K^+) coincidences. The
full system was designed to process more than 4 000 read-out channels and to
cope with the high electron flux in the spectrometer and the high count rate
requirement of the detectors. It was successfully in-beam tested at MAMI in
2009.Comment: Contributed to 17th IEEE Real Time Conference (RT10), Lisbon, 24-28
May 201
ΠΠ΅Ρ Π°Π½ΠΈΠ·ΠΌΡ ΡΠΎΡΠΎΠ΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΡ ΠΏΡΠΈ Π»Π΅ΡΠ΅Π½ΠΈΠΈ ΠΎΠ½ΠΊΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ Π±ΠΎΠ»ΡΠ½ΡΡ
Current views on mechanisms of therapeutic effect of photodynamic therapy for treating of cancer patients are represented. The history of formation and development of the method is described. The main requirements for agents used as photosensitizers are listed. Detailed review of main photosensitizers used in clinical practice in Russia and in foreign countries with their chemical structure, main spectral characteristics was performed. Methods of its application, therapeutic dose ranges, indications, specifi c pharmacokinetic properties and side-effects are briefl y outlined. Advantages and disadvantages of the most popular modern photosensitizers, main mechanisms of entry of photosensitizers of different chemical structure into cancer cells are observed. Three main possible component of anti-tumor effect: direct damage of cancer cells, impairment of vascular stroma of tumor and elimination of tumor due to immune cells are shown and closely discussed. Necrosis and apotosis of neovascular net which are main development trends of anti-tumor action for photodynamic therapy are noticed.Β ΠΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½Ρ ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΡΠ΅ Π²Π·Π³Π»ΡΠ΄Ρ Π½Π° ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΌΡ ΡΠ΅ΡΠ°ΠΏΠ΅Π²ΡΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΡΡΠ΅ΠΊΡΠ° ΡΠΎΡΠΎΠ΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠ΅ΡΠ°ΠΏΠΈΠΈ ΠΏΡΠΈ Π»Π΅ΡΠ΅Π½ΠΈΠΈ ΠΎΠ½ΠΊΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
Π±ΠΎΠ»ΡΠ½ΡΡ
. ΠΠΏΠΈΡΠ°Π½Π° ΠΈΡΡΠΎΡΠΈΡ Π²ΠΎΠ·Π½ΠΈΠΊΠ½ΠΎΠ²Π΅Π½ΠΈΡ ΠΈ ΡΠ°Π·Π²ΠΈΡΠΈΡ ΠΌΠ΅ΡΠΎΠ΄Π°. ΠΠ΅ΡΠ΅ΡΠΈΡΠ»Π΅Π½Ρ ΠΎΡΠ½ΠΎΠ²Π½ΡΠ΅ ΡΡΠ΅Π±ΠΎΠ²Π°Π½ΠΈΡ, ΠΏΡΠ΅Π΄ΡΡΠ²Π»ΡΠ΅ΠΌΡΠ΅ ΠΊ Π²Π΅ΡΠ΅ΡΡΠ²Π°ΠΌ, ΠΈΡΠΏΠΎΠ»ΡΠ·ΡΠ΅ΠΌΡΠΌ Π² ΠΊΠ°ΡΠ΅ΡΡΠ²Π΅ ΡΠΎΡΠΎΡΠ΅Π½ΡΠΈΠ±ΠΈΠ»ΠΈΠ·Π°ΡΠΎΡΠΎΠ². ΠΡΠΎΠ²Π΅Π΄Π΅Π½ Π΄Π΅ΡΠ°Π»ΡΠ½ΡΠΉ ΠΎΠ±Π·ΠΎΡ ΠΎΡΠ½ΠΎΠ²Π½ΡΡ
, ΠΏΡΠΈΠΌΠ΅Π½ΡΠ΅ΠΌΡΡ
Π² ΠΊΠ»ΠΈΠ½ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΏΡΠ°ΠΊΡΠΈΠΊΠ΅ Π² Π ΠΎΡΡΠΈΠΈ ΠΈ Π·Π° ΡΡΠ±Π΅ΠΆΠΎΠΌ, ΡΠΎΡΠΎΡΠ΅Π½ΡΠΈΠ±ΠΈΠ»ΠΈΠ·Π°ΡΠΎΡΠΎΠ², ΠΈΡ
Ρ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠ°Ρ ΡΡΡΡΠΊΡΡΡΠ°, ΠΎΡΠ½ΠΎΠ²Π½ΡΠ΅ ΡΠΏΠ΅ΠΊΡΡΠ°Π»ΡΠ½ΡΠ΅ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠΈ. ΠΡΠ°ΡΠΊΠΎ ΠΎΠΏΠΈΡΠ°Π½Ρ ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠΈ ΠΈΡ
ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΡ, Π΄ΠΈΠ°ΠΏΠ°Π·ΠΎΠ½Ρ ΡΠ΅ΡΠ°ΠΏΠ΅Π²ΡΠΈΡΠ΅ΡΠΊΠΈΡ
Π΄ΠΎΠ·, ΠΏΠΎΠΊΠ°Π·Π°Π½ΠΈΡ ΠΊ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΡ, ΡΠ°ΡΠΌΠ°ΠΊΠΎΠΊΠΈΠ½Π΅ΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΎΡΠΎΠ±Π΅Π½Π½ΠΎΡΡΠΈ ΠΈ ΠΏΠΎΠ±ΠΎΡΠ½ΡΠ΅ ΡΡΡΠ΅ΠΊΡΡ. Π Π°ΡΡΠΌΠΎΡΡΠ΅Π½Ρ ΠΏΡΠ΅ΠΈΠΌΡΡΠ΅ΡΡΠ²Π° ΠΈ Π½Π΅Π΄ΠΎΡΡΠ°ΡΠΊΠΈ Π½Π°ΠΈΠ±ΠΎΠ»Π΅Π΅ ΠΏΠΎΠΏΡΠ»ΡΡΠ½ΡΡ
ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΡΡ
ΡΠΎΡΠΎΡΠ΅Π½ΡΠΈΠ±ΠΈΠ»ΠΈΠ·Π°ΡΠΎΡΠΎΠ², ΠΎΡΠ½ΠΎΠ²Π½ΡΠ΅ ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΌΡ ΠΏΡΠΎΠ½ΠΈΠΊΠ½ΠΎΠ²Π΅Π½ΠΈΡ ΡΠΎΡΠΎΡΠ΅Π½ΡΠΈΠ±ΠΈΠ»ΠΈΠ·Π°ΡΠΎΡΠΎΠ² ΡΠ°Π·Π½ΠΎΠΉ Ρ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΡΡΡΠΊΡΡΡΡ Π² ΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΡΠ΅ ΠΊΠ»Π΅ΡΠΊΠΈ. ΠΠΎΠΊΠ°Π·Π°Π½Ρ ΠΈ ΠΏΠΎΠ΄ΡΠΎΠ±Π½ΠΎ ΠΎΠ±ΡΡΠΆΠ΄Π΅Π½Ρ ΡΡΠΈ ΠΎΡΠ½ΠΎΠ²Π½ΡΡ
Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΡΡ
Π·Π²Π΅Π½Π° ΠΏΡΠΎΡΠΈΠ²ΠΎΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΠΎΠ³ΠΎ ΡΡΡΠ΅ΠΊΡΠ°: ΠΏΡΡΠΌΠΎΠ΅ ΠΏΠΎΠ²ΡΠ΅ΠΆΠ΄Π΅Π½ΠΈΠ΅ ΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΡΡ
ΠΊΠ»Π΅ΡΠΎΠΊ, Π½Π°ΡΡΡΠ΅Π½ΠΈΠ΅ ΡΠΎΡΡΠ΄ΠΈΡΡΠΎΠΉ ΡΡΡΠΎΠΌΡ ΠΎΠΏΡΡ
ΠΎΠ»Π΅ΠΉ ΠΈ ΡΠ»ΠΈΠΌΠΈΠ½Π°ΡΠΈΡ ΠΎΠΏΡΡ
ΠΎΠ»ΠΈ ΠΏΠΎΠ΄ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΠ΅ΠΌ ΠΈΠΌΠΌΡΠ½Π½ΡΡ
ΠΊΠ»Π΅ΡΠΎΠΊ. Π£Π΄Π΅Π»Π΅Π½ΠΎ Π²Π½ΠΈΠΌΠ°Π½ΠΈΠ΅ Π½Π΅ΠΊΡΠΎΠ·Ρ ΠΈ Π°ΠΏΠΎΠΏΡΠΎΠ·Ρ Π½Π΅ΠΎΠ²Π°ΡΠΊΡΠ»ΡΡΠ½ΠΎΠΉ ΡΠ΅ΡΠΈ β ΠΎΡΠ½ΠΎΠ²Π½ΡΠΌ ΠΏΡΡΡΠΌ ΡΠ°Π·Π²ΠΈΡΠΈΡ ΠΏΡΠΎΡΠΈΠ²ΠΎΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΠΎΠ³ΠΎ Π΄Π΅ΠΉΡΡΠ²ΠΈΡ ΠΏΡΠΈ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ΠΈΠΈ ΡΠΎΡΠΎΠ΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠ΅ΡΠ°ΠΏΠΈΠΈ.
Correlation between proteome changes and synchrony of cardiac electrical excitation under 3-day Β«dry immersionΒ» conditions
MOLECULAR THERMODYNAMICS OF MICELLIZATION: MICELLE SIZE DISTRIBUTIONS AND GEOMETRY TRANSITIONS
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