scholarly journals The stability relation of kyanite, sillimanite, and andalusite, and the physical conditions of the metamorphic processes.,

1950 ◽  
Vol 55 (650-651) ◽  
pp. 218-223 ◽  
Author(s):  
Akiho Miyashiro
Keyword(s):  
Physical Conditions ◽  
Stability Relation ◽  
The Stability

scholarly journals General Discussion of Accretion Disks

1999 ◽  
Vol 194 ◽  
pp. 321-322
Author(s):  
Vahagn G. Gurzadyan
Keyword(s):  
Magnetic Field ◽  
Accretion Disks ◽  
Galactic Nuclei ◽  
The Other ◽  
Seminal Paper ◽  
Physical Conditions ◽  
Electron Positron ◽  
Free Parameters ◽  
The Stability ◽  
Electron Positron Pair

Even 25 years after the Shakura-Sunyaev seminal paper on the α-disk, we cannot claim that we have a reliable theory of accretion disks in galactic nuclei. Why? Because the problem is extremely complicated, it is essentially nonlinear and contains a number of parameters (i.e. is many-dimensional). The key point is whether it is possible to determine the magneto-hydrodynamical viscosity self-consistently, i.e. as a function of parameters of the disk - the temperature, matter and radiation densities, magnetic field, radius, etc., both in the radiation dominated and matter dominated regions. Another class of fundamental problems concerns the stability of the disk; Krolik mentioned only one instability - in the radiation dominated region, but there are many other types of instabilities which are quite sensitive to the physical conditions in the disk, for example, to the anisotropy of the ion pressure in the outer regions and possible electron-positron pair production near the inner edge of the disk. The other problems include those of the radiative transfer within the disk in various conditions, Comptonization of the outgoing radiation, radiation reflections by the desk, etc. Therefore it is not suprising that one can ‘explain' almost whatever he wants - spectra, variability, jets, wind, etc., by proper fit of the ‘free’ (which are never free) parameters and ignoring the instabilities and so on.

Improvements of physical properties of degraded shallow organic soils by admixing organic overlays and mineral sublayers

1991 ◽  
Vol 71 (1) ◽  
pp. 101-117 ◽  
Author(s):  
H. Dinel ◽  
S. P. Mathur ◽  
M. Lévesque
Keyword(s):  
Soil Structure ◽  
Crop Yields ◽  
Organic Amendments ◽  
Aggregate Size ◽  
Organic Soils ◽  
Structure Stability ◽  
Size Fractionation ◽  
Physical Conditions ◽  
Soil Media ◽  
The Stability

Twenty-five soil media representing 13 subsoils and organic overlays, and their mixtures, that had been used in pot culture fallow, or for growing root, leafy vegetable and grass crops, were studied to determine if the benefits of organic amendments to crop yields in optimally watered and fertilized soils were due to improvements in soil physical conditions. The soils were subjected to particle and aggregate size fractionation; and the stability of the aggregates was determined. The results suggested that admixing of residual organic overlays improved the structure of all mineral subsoils, except perhaps an alluvial sand. Aggregation and stability of aggregates > 2 mm were improved, thus leading to improved aeration, root proliferation and to increases in crop yields. In addition, grass crops were shown to be more effective than root and leafy crops for improvement of the structure of the various soils. Key words: Organic soils, soil aggregation, soil structure stability

scholarly journals Effect of Slam Waves Battle rope Exercise and Up down Waves Battle rope Exercise to Arm Strength And Arm Endurance (Study of boxing exstracurriculer at senior high school 3 Kediri)

2020 ◽  
Vol 3 (2) ◽  
pp. 828-836
Author(s):  
Dhayu Briyan Wijaya ◽  
Wijono Wijono ◽  
Acmad Widodo
Keyword(s):  
High School ◽  
Muscle Strength ◽  
Male And Female ◽  
Physical Conditions ◽  
The Face ◽  
Improve Student Achievement ◽  
Arm Muscles ◽  
Conducting Research ◽  
The Stability ◽  
Arm Strength

The most popular extraculiler in kediri High School 3 is boxing, because it can be done and studied by both male and female students. Boxing extraction itself is in demand because it is a well-known sport with weight loss and also for self-defense. Boxing itself requires a hard punch produced from a strong arm and also requires the stability of the hand to be beside the face to support the punch technique that is in boxing.When observing at State High School 3 Kediri, many students had not yet mastered the physical condition of the arm muscle strength or arm muscle endurance. Extraculiler trainers and teachers also said that physical conditions and non-boring forms of training are important to improve student achievement in school and outside school performance. Based on the background description above, the researcher wants to provide alternative exercises to improve physical conditions specifically in increasing arm muscle strength and endurance of arm muscles in male and female extracurricular students of SMAN 3 Kediri. So that researchers are interested in conducting research "Effect of slam waves batlle rope exercise, updown battle rope on arm muscle strength and muscular endurance of students and extracurricular students of SMAN 3 Kediri Boxing"

Hydromagnetic Instability Conditions for Viscoelastic Non-Newtonian Fluids

2000 ◽  
Vol 55 (3-4) ◽  
pp. 460-466
Keyword(s):  
Magnetic Field ◽  
Growth Rates ◽  
Stable Configuration ◽  
Horizontal Magnetic Field ◽  
Physical Conditions ◽  
Unstable Configuration ◽  
The Stability ◽  
Parameter Values ◽  
The Magnetic Field ◽  
Second Order Fluids

Abstract The effect of a horizontal magnetic field and a non-Newtonian stress tensor, as described by the Wal-ters B’ model, on the instability of two second order fluids of high kinematic viscosities and viscoelas-ticities is investigated. For the potentially stable configuration, it is found that the system is stable or unstable for a wavenumber range depending on the kinematic viscoelasticity. For the potentially un-stable configuration, it is found that the stability criterion is dependent on orientation and magnitude of the magnetic field which is found to stabilize a certain range of the unstable configuration related to the viscoelasticity values. The behaviour of growth rates with respect to Alfvén velocities are examined analytically, and it is found that the magnetic field has a dual role on the instability problem. For the exponentially varying stratifications, the system is found to be stable or unstable for the stable and un-stable stratifications under certain physical conditions, and the growth rates are found to increase or de-crease with increasing the stratification parameter values, according to some restrictions satisfied by the chosen wavenumbers range

scholarly journals Cholera: possible infection from aircraft effluent

1978 ◽  
Vol 81 (3) ◽  
pp. 361-372 ◽  
Author(s):  
C. J. M. Rondle ◽  
B. Ramesh ◽  
J. B. Krahn ◽  
R. Sherriff
Keyword(s):  
Vibrio Cholerae ◽  
Ultra Violet ◽  
Ground Level ◽  
Human Infection ◽  
High Altitudes ◽  
Important Conclusion ◽  
Physical Conditions ◽  
Chloramine T ◽  
The Stability ◽  
Slight Contamination

SummaryThis paper presents the hypothesis that some cases of cholera might be due to effluent discharge from aircraft. The theoretical case is borne out by inspection of data on the physical conditions pertaining between high altitudes and ground level. A study of the distribution of isolated outbreaks and single cases of disease and their relation to major airline routes showed a reasonable correspondence. Sporadic outbreaks of cholera in Europe between 1970 and 1975 were found to lie within the flight paths of regular airline services from Calcutta, where cholera is endemic, to the Northern Hemisphere. Laboratory studies on the stability of Vibrio cholerae to conditions likely to be encountered in droplets falling from high altitude to the ground suggested that significant numbers of organisms might survive. It should be noted that in this study no account was taken of the effect of ultra-violet light on viability and it is known that at high altitudes the ultraviolet light component of solar radiation is much higher than at ground level. Results of experiments where small numbers of organisms were inoculated into relatively poor media showed that rapid growth ensued and that sufficient organisms were produced to give an infective dose of Vibrio cholerae in 1–10 ml/fluid. It could be concluded that human infection could easily occur by ingestion of fluids such as milk or soup which had some time earlier received a fortuitous but slight contamination from the air. Investigation of one disinfectant (chloramine T) showed that it reacted rapidly and in a complex manner with peptone. One effect of this reaction was the elimination of bactericidal activity and it seems likely that, as at present employed, chloramine T is of doubtful value in aeroplanehygiene. One important conclusion that arises from this work is that if cholera can be spread, even only occasionally, by effluent from aircraft then close investigation should be made of the possibility of other bacteria and viruses being spread in a similar way.

Experiments on the stability of viscous flow between rotating cylinders II. Visual observations

1960 ◽  
Vol 258 (1292) ◽  
pp. 101-123 ◽  
Keyword(s):  
Experimental Data ◽  
Viscous Flow ◽  
Hydrodynamic Stability ◽  
Experimental Error ◽  
Asymptotic Form ◽  
Theoretical Calculations ◽  
Rotating Cylinders ◽  
Stability Relation ◽  
The Stability ◽  
Visual Observations

Measurements of the hydrodynamic stability of viscous flow between rotating cylinders have been made with an apparatus similar to that used by Taylor in his original experiments. The ratio of the radii of the cylinders was 1:2. The results confirm Chandrasekhar’s theoretical calculations within experimental error. The asymptotic form of the stability relation when the cylinders rotate in opposite directions is derived and found to agree with experimental data at hand.

Signatures of the Artist

2018 ◽  
Author(s):  
Steven E. Vigdor
Keyword(s):  
Particle Physics ◽  
Nuclear Physics ◽  
Biological Evolution ◽  
Vacuum State ◽  
Fine Tuning ◽  
Physical Conditions ◽  
Past Half Century ◽  
Perfect Symmetry ◽  
The Stability

This book provides a nonmathematical survey of the past half-century of research in particle physics, nuclear physics, and cosmology bearing on the physical conditions that allow our universe to support the development of structure and the origins of life. These conditions rely on a surprising number of tiny imperfections—deviations from perfect symmetry (i.e., symmetry violations), homogeneity, or predictability—that seem mysteriously fine-tuned. The emphasis here is on the intricate tapestry of elegant experiments that have revealed and quantified these imperfections, as well as on theoretical efforts to understand how the imperfections arose in the infant universe. Among the topics covered are: the dominance of matter over antimatter (i.e., matter–antimatter asymmetry); the existence and intermixing of three generations of quarks and leptons; the stability of hydrogen and synthesis of other elements essential for life; the longevity and energy budget of the universe; the remaining mysteries surrounding dark matter, dark energy, and the postulated inflationary expansion of space in the infant universe; the fundamental role of randomness in quantum mechanics, in generating the first biomolecules and in biological evolution; the apparent perching of the vacuum state in our universe on the edge between stability and meta-stability; and philosophical questions, including the possibility of a multiverse, surrounding the interpretation of a universe that exhibits such fine-tuning. On all of these issues, the book clarifies what we know and how we know it, as distinct from what we speculate and how we might test it.

scholarly journals Recent Progress in Fighting Ghosts in Quantum Gravity

Universe ◽  
2018 ◽  
Vol 4 (9) ◽  
pp. 91 ◽  
Author(s):  
Filipe Salles ◽  
Ilya Shapiro
Keyword(s):  
Quantum Gravity ◽  
High Energy ◽  
Effective Theory ◽  
Classical Solutions ◽  
Fundamental Theory ◽  
Physical Conditions ◽  
Higher Derivative ◽  
Low Energies ◽  
Gravitational Vacuum ◽  
The Stability

We review some of the recent results which can be useful for better understanding of the problem of stability of vacuum and in general classical solutions in higher derivative quantum gravity. The fourth derivative terms in the purely gravitational vacuum sector are requested by renormalizability already in both semiclassical and complete quantum gravity theories. However, because of these terms, the spectrum of the theory has unphysical ghost states which jeopardize the stability of classical solutions. At the quantum level, ghosts violate unitarity, and thus ghosts look incompatible with the consistency of the theory. The “dominating” or “standard” approach is to treat higher derivative terms as small perturbations at low energies. Such an effective theory is supposed to glue with an unknown fundamental theory in the high energy limit. We argue that the perspectives for such a scenario are not clear, to say the least. On the other hand, recently, there was certain progress in understanding physical conditions which can make ghosts not offensive. We survey these results and discuss the properties of the unknown fundamental theory which can provide these conditions satisfied.

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