179 research outputs found
Equation of state SAHA-S meets stellar evolution code CESAM2k
We present an example of an interpolation code of the SAHA-S equation of
state that has been adapted for use in the stellar evolution code CESAM2k. The
aim is to provide the necessary data and numerical procedures for its
implementation in a stellar code. A technical problem is the discrepancy
between the sets of thermodynamic quantities provided by the SAHA-S equation of
state and those necessary in the CESAM2k computations. Moreover, the
independent variables in a practical equation of state (like SAHA-S) are
temperature and density, whereas for modelling calculations the variables
temperature and pressure are preferable. Specifically for the CESAM2k code,
some additional quantities and their derivatives must be provided. To provide
the bridge between the equation of state and stellar modelling, we prepare
auxiliary tables of the quantities that are demanded in CESAM2k. Then we use
cubic spline interpolation to provide both smoothness and a good approximation
of the necessary derivatives. Using the B-form of spline representation
provides us with an efficient algorithm for three-dimensional interpolation.
The table of B-spline coefficients provided can be directly used during stellar
model calculations together with the module of cubic spline interpolation. This
implementation of the SAHA-S equation of state in the CESAM2k stellar structure
and evolution code has been tested on a solar model evolved to the present. A
comparison with other equations of state is briefly discussed. The choice of a
regular net of mesh points for specific primary quantities in the SAHA-S
equation of state, together with accurate and consistently smooth tabulated
values, provides an effective algorithm of interpolation in modelling
calculations. The proposed module of interpolation procedures can be easily
adopted in other evolution codes.Comment: 8 pages, 5 figure
Identity of electrons and ionization equilibrium
It is perhaps appropriate that, in a year marking the 90th anniversary of
Meghnad Saha seminal paper (1920), new developments should call fresh attention
to the problem of ionization equilibrium in gases. Ionization equilibrium is
considered in the simplest "physical" model for an electronic subsystem of
matter in a rarefied state, consisting of one localized electronic state in
each nucleus and delocalized electronic states considered as free ones. It is
shown that, despite the qualitative agreement, there is a significant
quantitative difference from the results of applying the Saha formula to the
degree of ionization. This is caused by the fact that the Saha formula
corresponds to the "chemical" model of matter.Comment: 9 pages, 2 figure
Болезнь Помпе с поздним началом: предварительные результаты ферментозаместительной терапии
Pompe disease is an orphan hereditary accumulation disease associated with a deficiency of the lysosomal enzyme alglucosidase alpha. Manifestations of the disease are associated with pathological deposition of glycogen in body tissues as a result of GAA gene mutation and subsequent reduction in the activity of the enzyme alglucosidase alpha or acid maltase. The variety of phenotypic forms and varying degrees of damage to the skeletal and respiratory muscles, cardiomyocytes and internal organs greatly complicates the diagnosis and treatment of patients with Pompe»s disease. This article describes the clinical case of late-onset Pompe disease, which was followed by a course of enzyme replacement therapy, as well as an assessment of the condition before and after treatment and preliminary results.Болезнь Помпе – орфанная наследственная болезнь накопления, связанная с дефицитом лизосомного фермента алглюкозидазы альфа. Проявления заболевания связаны с патологическим отложением гликогена в тканях организма в результате мутации гена GAA и последующего снижения активности фермента алглюкозидазы альфа или кислой мальтазы. Разнообразие фенотипических форм и разная степень поражения скелетных и дыхательных мышц, кардиомиоцитов и внутренних органов в значительной степени затрудняет постановку диагноза и начало лечения пациентов с болезнью Помпе. Представлен доказанный клинический случай болезни Помпе с поздним началом с оценкой состояния до лечения и предварительные результаты после 4 курсов ферментозаместительной терапии
Telomerase inhibition improves tumor response to radiotherapy in a murine orthotopic model of human glioblastoma
Non-destructive detection of cross-sectional strain and defect structure in an individual Ag five-fold twinned nanowire by 3D electron diffraction mapping
Coherent x-ray diffraction investigations on Ag five-fold twinned nanowires (FTNWs) have drawn controversial conclusions concerning whether the intrinsic 7.35° angular gap could be compensated homogeneously through phase transformation or inhomogeneously by forming disclination strain field. In those studies, the x-ray techniques only provided an ensemble average of the structural information from all the Ag nanowires. Here, using three-dimensional (3D) electron diffraction mapping approach, we non-destructively explore the cross-sectional strain and the related strain-relief defect structures of an individual Ag FTNW with diameter about 30 nm. The quantitative analysis of the fine structure of intensity distribution combining with kinematic electron diffraction simulation confirms that for such a Ag FTNW, the intrinsic 7.35° angular deficiency results in an inhomogeneous strain field within each single crystalline segment consistent with the disclination model of stress-relief. Moreover, the five crystalline segments are found to be strained differently. Modeling analysis in combination with system energy calculation further indicates that the elastic strain energy within some crystalline segments, could be partially relieved by the creation of stacking fault layers near the twin boundaries. Our study demonstrates that 3D electron diffraction mapping is a powerful tool for the cross-sectional strain analysis of complex 1D nanostructures
Investigation of the conversions of 1,3-cyclohexadiene and 1, 4-cyclohexadiene in the presence of skeletal catalysts of cobalt and nickel
Influence of heat-treating conditions on formation of pore structure of surface layer of palladium-ruthenium alloy foil
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