scholarly journals On the Kármán momentum-integral approach and the Pohlhausen paradox

2020 ◽  
Vol 32 (12) ◽  
pp. 123605
Author(s):  
Joseph Majdalani ◽  
Li-Jun Xuan
Keyword(s):  
Integral Approach ◽  
Momentum Integral

Developing Film Flow on an Inclined Plane With a Critical Point

2001 ◽  
Vol 123 (3) ◽  
pp. 698-702 ◽  
Author(s):  
Kenneth J. Ruschak ◽  
Steven J. Weinstein ◽  
Kam Ng
Keyword(s):  
Velocity Profile ◽  
Critical Point ◽  
Film Flow ◽  
Boundary Layer Equation ◽  
Critical Conditions ◽  
Integral Approach ◽  
Inclined Plane ◽  
Navier Stokes Equation ◽  
Moderate Reynolds Number ◽  
Momentum Integral

Viscous, laminar, gravitationally-driven flow of a thin film on an inclined plane is analyzed for moderate Reynolds number under critical conditions. A previous analysis of film flow utilized a momentum integral approach with a semiparabolic velocity profile to obtain an ordinary differential equation for the film thickness for flow over a round-crested weir, and the singularity associated with the critical point for a subcritical-to-supercritical transition was removable. For developing flow on a plane with a supercritical-to-subcritical transition, however, the same approach leads to a nonremovable singularity. To eliminate the singularity, the film equations are modified for a velocity profile of changing shape. The resulting predictions compare favorably with those from the two-dimensional boundary-layer equation obtained by finite differences and with those from the Navier-Stokes equation obtained by finite elements.

A Simple Method for Estimating Velocity Distributions in Swirling Flows

1994 ◽  
Vol 116 (4) ◽  
pp. 694-701
Author(s):  
D. Kinnear ◽  
P. A. Davidson
Keyword(s):  
Scaling Laws ◽  
Numerical Approach ◽  
Structural Features ◽  
Integral Approach ◽  
Simple Method ◽  
Numerical Solution Methods ◽  
Wide Range ◽  
Solution Methods ◽  
High Reynolds ◽  
Momentum Integral

We describe the important structural features of swirling recirculating flows induced by a rotating boundary. A knowledge of this structure has allowed us to match the core flow to the boundary layer using a momentum-integral technique. In particular, we derive a single integral-differential equation, valid for any shape of container, which predicts the distribution of swirl, secondary recirculation, and wall shear stress. This momentum-integral approach has been applied to three cases: flow between parallel disks; flow in a cone; and flow in a hemisphere. The results compare favorably with published experimental data, and with computed numerical results. Our momentum-integral approach complements numerical solution methods. For simple geometries all the important information can, in principle, be derived using the momentum-integral approach, and this is particularly useful for establishing the scaling laws. In more complex geometries a numerical approach may be more appropriate. However, even in such cases, the scaling laws derived using the momentum-integral analysis are still useful as they allow extrapolation of a single computation to a wide range of high Reynolds number flows.

Gandhian Method of Conflict Resolution: Perception of Educated Youths

2017 ◽  
Vol 1 (6) ◽  
pp. 1 ◽  
Author(s):  
Dr. P. K. Kar
Keyword(s):  
Conflict Resolution ◽  
Image Of God ◽  
Integral Approach ◽  
Human Beings ◽  
Life Itself ◽  
The Image Of God ◽  
Negative Concept

Gandhiji’s method of conflict resolution was based on truth and non-violence. Truth was for him the image of God. He did not believe in personal God. For Gandhi truth is God and God is truth. Life is a laboratory where experiments are carried on. That is why he named his autobiography “My Experiment with Truth”, without these experiments truth cannot be achieved. According to Gandhi, the sayings of a pure soul which possesses nonviolence, non-stealing, true speech, celibacy and non-possession is truth. The truth of Gandhiji was not confined to any country or community. In other words , his religion had no geographical limits. His patriotism was not different from the service of human beings but was its part and parcel(Mishra:102). Gandhiji developed an integral approach and perspective to the concept of life itself on the basis of experience and experiments. His ideas ,which came to be known to be his philosophy, were a part of his relentless search for truth(Iyer:270). The realization of this truth is possible only with the help of non-violence The negative concept of Ahimsa presupposes the absence of selfishness, jealousy and anger, but the positive conception of ahimsa demands the qualities of love ,liberalism, patience, resistance of injustice, and brutal force.

The Departure from Equilibrium of Turbulent Boundary Layers

1968 ◽  
Vol 19 (1) ◽  
pp. 1-19 ◽  
Author(s):  
H. McDonald
Keyword(s):  
Boundary Layer ◽  
Shear Stress ◽  
Kinetic Energy ◽  
Stress Distribution ◽  
Boundary Layers ◽  
Turbulent Boundary Layers ◽  
Two Dimensional ◽  
Pressure Distributions ◽  
Momentum Integral ◽  
State Examination

SummaryRecently two authors, Nash and Goldberg, have suggested, intuitively, that the rate at which the shear stress distribution in an incompressible, two-dimensional, turbulent boundary layer would return to its equilibrium value is directly proportional to the extent of the departure from the equilibrium state. Examination of the behaviour of the integral properties of the boundary layer supports this hypothesis. In the present paper a relationship similar to the suggestion of Nash and Goldberg is derived from the local balance of the kinetic energy of the turbulence. Coupling this simple derived relationship to the boundary layer momentum and moment-of-momentum integral equations results in quite accurate predictions of the behaviour of non-equilibrium turbulent boundary layers in arbitrary adverse (given) pressure distributions.

scholarly journals Challenges of health services related to the population displaced by violence in Mexico

2018 ◽  
Vol 52 ◽  
pp. 77 ◽  
Author(s):  
María Beatriz Duarte-Gómez ◽  
Silvia Magali Cuadra-Hernández ◽  
Myriam Ruiz-Rodríguez ◽  
Armando Arredondo ◽  
Jesús David Cortés-GilI
Keyword(s):  
Health Services ◽  
Sexual And Reproductive Health ◽  
Public Health Problem ◽  
Internal Displacement ◽  
Integral Approach ◽  
International Literature ◽  
Inclusion Criteria ◽  
Political Will ◽  
Persons With Disabilities ◽  
The Subject

OBJECTIVE: To analyze the impacts of the care to the population displaced by violence on the health system and the challenges that this entails. METHODS: This is a narrative review of the national and international literature in PubMed, SciELO, WHO/PAHO, and Bireme. Inclusion criteria were date of publication ( from 2000), relation with the subject, and language (Spanish or English). We found 292 documents, of which 91 met the inclusion criteria. RESULTS: The main challenges are the intersectoral, participatory, and integral approach (with emphasis on mental health and sexual and reproductive health), ensured accessibility to health services, the need for a reliable registration and information system of the population displaced by violence and its characteristics, and the addressing of the biopsychosocial problems of the different groups, especially women, persons with disabilities or infectious diseases, adolescents, children, ethnic minorities, older adults and the lesbian, gay, bisexual, transsexual, and intersexual population. CONCLUSIONS: The lack of political will to accept and see the internal displacement by violence and its importance as a humanitarian and public health problem is an obstacle to the adequate and timely care of the population displaced by violence in Mexico.

Evaluation of the combined differential-integral approach for limb viewing geometry

2002 ◽  
Vol 29 (11) ◽  
pp. 1843-1848 ◽  
Author(s):  
A. Rozanov ◽  
V. Rozanov ◽  
J.P. Burrows
Keyword(s):  
Integral Approach

Path Integral Calculations of Particle Self-Energy and Effective Mass in Coulomb Systems

1997 ◽  
Vol 11 (04) ◽  
pp. 129-138 ◽  
Author(s):  
V. Sa-Yakanit ◽  
V. D. Lakhno ◽  
Klaus Haß
Keyword(s):  
Effective Mass ◽  
Path Integral ◽  
State Energy ◽  
Coulomb Systems ◽  
Integral Approach ◽  
Coupling Region ◽  
Self Energy ◽  
Consistent Approximation ◽  
A Value ◽  
Wide Range

The generalized path integral approach is applied to calculate the ground state energy and the effective mass of an electron-plasmon interacting system for a wide range of densities. It is shown that in the self-consistent approximation an abrupt transition between the weak coupling and the strong coupling region of interaction exists. The transition occurs at low electron densities according to a value of 418 for rs, when Wigner crystallization is possible. For densities of real metals, the electron bandwidth is calculated and a comparison with experimental results is given.

scholarly journals Evaluation of olive mill waste as substrate for carotenoid production by Rhodotorula mucilaginosa

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Carolina Ghilardi ◽  
Paola Sanmartin Negrete ◽  
Amalia Antonia Carelli ◽  
Virginia Borroni
Keyword(s):  
Liquid Fraction ◽  
Added Value ◽  
Organic Load ◽  
Integral Approach ◽  
Rhodotorula Mucilaginosa ◽  
Total Sugars ◽  
Carotenoid Production ◽  
Total Sugar Concentration ◽  
Valuable Compounds ◽  
Olive Mill

Abstract The “alperujo” is a waste from the olive oil industry with great potential for valorization. It has a high organic load, with the presence of valuable compounds such as biophenols and sugars. The use of this waste can be thought of as a biorefinery from which different compounds of high added value can be obtained, whether they are present in the “alperujo” such as biophenols or can be generated from the “alperujo”. Therefore, the production of carotenoids by Rhodotorula mucilaginosa was evaluated using the liquid fraction of ‘alperujo’ (Alperujo Water, AW) or an aqueous extract (AE) of “alperujo” at different concentrations (5, 10, 20 and 30% w/V) as substrates. The AEs had an acidic pH, a total sugar concentration ranging from 1.6 to 7.6 g/L, a polyphenols content from 0.4 to 2.9 g/L and a significant amount of proteins (0.5–3 g/L). AW is similar in composition as 30% AE, but with a higher amount of total sugars. Rh. mucilaginosa was able to grow at the different mediums with consumption of glucose and fructose, a reduction in protein content and alkalinization of the medium. Maximum total carotenoid production (7.3 ± 0.6 mg/L) was achieved at AW, while the specific production was higher when the yeast grew at AW or at 30% AE (0.78 ± 0.06 and 0.73 ± 0.10 mg/g of biomass, respectively). Torulene and torularhodin were the main carotenoids produced. Polyphenol content did not change; thus, it is still possible to recover these compounds after producing carotenoids. These results demonstrate the feasibility of using alperujo-based mediums as cheap substrates to produce torularhodin and torulene and to include this bioprocess as a step in an integral approach for alperujo valorization.

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