The Doppler effect of spectral lines and shift of the frequency of light in space
The Doppler effect of spectral lines in space is the change in the frequency of light emitted by an illuminated celestial body, which moves closer or farther away from the Earth in vacuum. A description of the change in light frequency is realized with the assumption that an illuminated celestial body in vacuum moves closer or farther away from the observer in vacuum. In this case, the propagation of light of the moving celestial body toward an observer also occurs in vacuum. Everywhere on Earth and in the surrounding space there is matter, so the choice of vacuum for the Doppler effect and the propagation of light from the moving celestial body toward the observer is not correct. From the observation of space as we know it, such as galaxies and stars, the area between the celestial bodies consists of a vacuum, but in some restricted spaces of the universe there is a transparent mass – gas, that moves at high speed against Earth. These spaces in universe filled by gas were called “intergalactic bubbles of gas” by astronomers. The propagation of light on the trajectory from an illuminated celestial body toward the observer takes place not only in a vacuum, but alternately also in the gases of intergalactic bubbles, respecting the laws of optics. The topic of the propagation of light in the universe is a very broad topic. For further information, please see reference [1], [2] and [3].
Simulation of the Dendritic Growth Velocity for Binary Alloy Al-Cu in the Undercooled System
The phase-field model was applied to simulate the solidification kinetics to undercooled Al-Cu alloy. The relationships between material properties and model parameters are presented. The diffusivity of solute in the solid region and liquid and liquidus temperature are calculated during the simulation of solidification process. As an example, the two-dimensional computations for the dendritic growth in Al–Cu binary alloy have been performed. The dendritic morphology calculated by phase-field model showed features that are commonly found in experiments on the solidification. The concentration profiles of solute calculated in the solid region and liquid are not completely horizontal, showing evidence of microsegregation. The velocity of the dendrite tip and solute concentration at the interface front are calculated. It is found that the tip velocity is greatly concentration dependent around interface. In order to validate the growth kinetics predicted by this model tests have been performed for comparison with Stefanescu’s model. The present work based results show good agreement with those obtained by Stefanescu. The dependence of growth velocity on the initial concentration and super-cooling are also demonstrated.
Enhancing the liquid phase exfoliation of graphite in both aqueous and organic mixtures
Two different solvent mixtures, aqueous and organic, were used in the graphite liquid phase exfoliation. These solvent mixtures were selected through a detailed study of Hansen Solubility Parameters. Different operational sonication parameters (sonication temperature, cycle, amplitude and time) were studied in order to analyze their influence over the exfoliation process. Exfoliated graphite obtained after different sonication conditions were further characterized by RAMAN spectroscopy and thermogravimetric techniques. Obtained results showed that, among all the studied sonication parameters, time is the most important one due to its influence over characteristics of the final exfoliated product. Thus, it was evidenced the defect formation at higher sonication times, being dominant the growth of bulk defects in the structure of exfoliated samples at sonication times superior to 5 hours. As consequence, a careful tuning of the sonication parameters is necessary in order to obtain exfoliated samples with low disorder.
Treatment for Homeopathy in Andropause (Male Menopause)
In this review article the author argues that complete presentation of various homeopathy remedies can reduce the Andropause and related all mental and physical illnesses Life is neither Possible to overcome safely.
Bioassay guided fractionation-an emerging technique influence the isolation, identification and characterization of lead phytomolecules
Natural products have thus played an important role in drug discovery in the past and promise to provide still more drugs in the future. The search for a new drug from nature is based on a biological and ecological rationale. Natural products have provided many effective drugs. These include older drugs such as quinine and morphine and newer drugs such as paclitaxel, camptothecin, etoposide, mevastatin, and artemisinin. The discovery of novel drugs from nature is also important because many isolated molecules are quite complex, and would not be obtained by a simple synthetic approach. Most bioactive compounds of natural origin are secondary metabolites, i.e. species-specific chemical agents that can be grouped into various categories. A typical protocol to isolate a pure chemical agent from natural origin is bioassay-guided fractionation, meaning step-by-step separation of extracted components based on differences in their physicochemical properties, and assessing the biological activity, followed by next round of separation and assaying.
