Study of the structure of the inflow/outflow region in the self-gravitating standard accretion disks

New Astronomy ◽  
2020 ◽  
Vol 81 ◽  
pp. 101426
Author(s):  
M. Eskandari Cherati ◽  
A. Khesali
Keyword(s):  
Accretion Disks ◽  
The Self ◽  
Outflow Region

Numerical study of toroidal magnetic field on the self-gravitating protoplanetary disks

2020 ◽  
Vol 29 (09) ◽  
pp. 2050067
Author(s):  
Hanifeh Ghanbarnejad ◽  
Maryam Ghasemnezhad
Keyword(s):  
Magnetic Field ◽  
Accretion Disks ◽  
Numerical Solutions ◽  
Numerical Study ◽  
Ohmic Heating ◽  
The Self ◽  
Toroidal Magnetic Field ◽  
Heating Process ◽  
Heating And Cooling ◽  
The Magnetic Field

In this paper, we study the self-gravitating accretion disks by considering the toroidal component of magnetic field, [Formula: see text] and wind/outflow in the flow and also investigate the effect of two parameters, [Formula: see text] and [Formula: see text] corresponding to magnetic field on the latitudinal structure of such accretion disks. The cooling of the disk is parameterized simply as, [Formula: see text] (where [Formula: see text] is the internal energy and [Formula: see text] is the cooling timescale and [Formula: see text] is a free constant) and the heating rate is decomposed into two components, magnetic field and viscosity dissipations. We have shown that when the toroidal magnetic field becomes stronger, the heating process (viscous and resistivity) and the radiative cooling rate increase. Ohmic heating is much bigger than viscous heating and cooling, so we must consider the role of the magnetic field in the energy equation. Our numerical solutions show that the thickness of the disk decreases with strong toroidal component of magnetic field. The magnetic field leads to production of the outflow in the low latitude. So, by increasing the toroidal component of the magnetic field, the regions which belong to inflow decrease and the disk is cooled.

scholarly journals Structure of Outer Regions of Accretion Disks in AGN: Non Irradiated, Vertically Averaged Accretion Disks

1994 ◽  
Vol 159 ◽  
pp. 483-483
Author(s):  
Jean Marc Huré ◽  
Suzy Collin ◽  
Guillaume Pineau Des Forêts
Keyword(s):  
Equation Of State ◽  
Accretion Disks ◽  
Radiative Flux ◽  
The Self ◽  
Disk Structure ◽  
Averaged Equations ◽  
Radial Structure

Radial structure of outer regions of α-disks (Shakura & Sunyaev 1973) is investigated in a more sophisticated way than in Collin-Souffrin & Dumont (1990). The vertically averaged equations for the disk structure hold but some of them are reconsidered : the equation of state (atoms, ions and molecules) with a the rigourous treatment of opacities is introduced. The radiative flux is treated as in Hubeny (1990), and finally a rigourous treatment of the self-gravitaty is included.

scholarly journals Outflows from Accretion Disks around Compact Objects

2012 ◽  
Vol 8 (S290) ◽  
pp. 82-85
Author(s):  
Cheng-Liang Jiao ◽  
Xue-Bing Wu
Keyword(s):  
Numerical Simulation ◽  
Accretion Disks ◽  
Compact Objects ◽  
Analytical Models ◽  
Hydrodynamic Equations ◽  
Spherical Coordinates ◽  
Accretion Flows ◽  
Outflow Region

AbstractWe solve the set of hydrodynamic equations for accretion disks in the spherical coordinates (rθφ) to obtain the explicit structure along the θ direction. The results display thinner, quasi-Keplerian disks for Shakura-Sunyaev Disks (SSDs) and thicker, sub-Keplerian disks for Advection Dominated Accretion Flows (ADAFs) and slim disks, which are consistent with previous popular analytical models, while an inflow region and an outflow region always exist, which supports the results of some recent numerical simulation works. Our results indicate that the outflows should be common in various accretion disks and stronger in slim disks and ADAFs.

scholarly journals Magnetized Accretion Disks Driving Jets

1994 ◽  
Vol 159 ◽  
pp. 249-252
Author(s):  
G. Pelletier ◽  
J. Ferreira ◽  
F. Rosso
Keyword(s):  
Magnetic Field ◽  
Angular Momentum ◽  
Accretion Disk ◽  
Accretion Disks ◽  
The Self ◽  
Mhd Equations ◽  
Back Reaction ◽  
Systematic Method ◽  
Field Lines

In this brief communication, we present some progress in the investigation of a most promising model that was designed to combine ejection with accretion. In this model, a bipolar configuration of opened magnetic field lines that thread the accretion disk, allows the extraction of angular momentum, the acceleration of matter up to super Alfvénic velocities and the self collimation of the jet. However, important issues have remained unsolved. First, a systematic method for solving the jet MHD equations with their critical surfaces was lacking. Second, the capability of accretion disks to generate super Alfvénic jets was unknown. Third, the back-reaction of the ejection on the accretion disk dynamics and its energetics remained to be done. Solving these three points led us to draw some noteworthy consequences for the understanding of AGNs.

Problem behavior in autism spectrum disorders: A paradigmatic self-organized perspective of network structures

2019 ◽  
Vol 42 ◽  
Author(s):  
Lucio Tonello ◽  
Luca Giacobbi ◽  
Alberto Pettenon ◽  
Alessandro Scuotto ◽  
Massimo Cocchi ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Problem Behaviors ◽  
Autism Spectrum ◽  
The Self ◽  
Network Structures ◽  
Self Organized ◽  
Critical Equilibrium ◽  
Self Organized Criticality ◽  
Acute Agitation ◽  
Spectrum Disorders

AbstractAutism spectrum disorder (ASD) subjects can present temporary behaviors of acute agitation and aggressiveness, named problem behaviors. They have been shown to be consistent with the self-organized criticality (SOC), a model wherein occasionally occurring “catastrophic events” are necessary in order to maintain a self-organized “critical equilibrium.” The SOC can represent the psychopathology network structures and additionally suggests that they can be considered as self-organized systems.

The Nature of Rapidly Extracted Phycocyanin from the Blue-Green Alga Plectonema Boryanum

1971 ◽  
Vol 29 ◽  
pp. 366-367
Author(s):  
M. Kessel ◽  
R. MacColl
Keyword(s):  
Self Assembly ◽  
Analytical Ultracentrifugation ◽  
Uranyl Acetate ◽  
The Self ◽  
Major Protein ◽  
Subunit Structure ◽  
Blue Green Alga ◽  
Thin Sections ◽  
Blue Green Algae ◽  
Cacodylate Buffer

The major protein of the blue-green algae is the biliprotein, C-phycocyanin (Amax = 620 nm), which is presumed to exist in the cell in the form of distinct aggregates called phycobilisomes. The self-assembly of C-phycocyanin from monomer to hexamer has been extensively studied, but the proposed next step in the assembly of a phycobilisome, the formation of 19s subunits, is completely unknown. We have used electron microscopy and analytical ultracentrifugation in combination with a method for rapid and gentle extraction of phycocyanin to study its subunit structure and assembly.To establish the existence of phycobilisomes, cells of P. boryanum in the log phase of growth, growing at a light intensity of 200 foot candles, were fixed in 2% glutaraldehyde in 0.1M cacodylate buffer, pH 7.0, for 3 hours at 4°C. The cells were post-fixed in 1% OsO4 in the same buffer overnight. Material was stained for 1 hour in uranyl acetate (1%), dehydrated and embedded in araldite and examined in thin sections.

Interrelationship of the cellular distribution and secretion of regular structure (RS) protein in Bacillus licheniformis nm 105

1992 ◽  
Vol 50 (1) ◽  
pp. 712-713
Author(s):  
Xiaorong Zhu ◽  
Richard McVeigh ◽  
Bijan K. Ghosh
Keyword(s):  
Alkaline Phosphatase ◽  
Bacillus Licheniformis ◽  
Self Assembly ◽  
Gel Electrophoresis ◽  
Culture Supernatant ◽  
Regular Structure ◽  
The Self ◽  
Cellular Distribution ◽  
Structural Protein ◽  
Laboratory Cultures

A mutant of Bacillus licheniformis 749/C, NM 105 exhibits some notable properties, e.g., arrest of alkaline phosphatase secretion and overexpression and hypersecretion of RS protein. Although RS is known to be widely distributed in many microbes, it is rarely found, with a few exceptions, in laboratory cultures of microorganisms. RS protein is a structural protein and has the unusual properties to form aggregate. This characteristic may have been responsible for the self assembly of RS into regular tetragonal structures. Another uncommon characteristic of RS is that enhanced synthesis and secretion which occurs when the cells cease to grow. Assembled RS protein with a tetragonal structure is not seen inside cells at any stage of cell growth including cells in the stationary phase of growth. Gel electrophoresis of the culture supernatant shows a very large amount of RS protein in the stationary culture of the B. licheniformis. It seems, Therefore, that the RS protein is cotranslationally secreted and self assembled on the envelope surface.

Self-Compassion and Quality of Life in Adults Who Stutter

2020 ◽  
Vol 29 (4) ◽  
pp. 2097-2108
Author(s):  
Robyn L. Croft ◽  
Courtney T. Byrd
Keyword(s):  
Quality Of Life ◽  
Social Connectedness ◽  
The Self ◽  
Future Research ◽  
Self Compassion ◽  
Adults Who Stutter ◽  
And Gender ◽  
Relationship Of ◽  
The Impact

Purpose The purpose of this study was to identify levels of self-compassion in adults who do and do not stutter and to determine whether self-compassion predicts the impact of stuttering on quality of life in adults who stutter. Method Participants included 140 adults who do and do not stutter matched for age and gender. All participants completed the Self-Compassion Scale. Adults who stutter also completed the Overall Assessment of the Speaker's Experience of Stuttering. Data were analyzed for self-compassion differences between and within adults who do and do not stutter and to predict self-compassion on quality of life in adults who stutter. Results Adults who do and do not stutter exhibited no significant differences in total self-compassion, regardless of participant gender. A simple linear regression of the total self-compassion score and total Overall Assessment of the Speaker's Experience of Stuttering score showed a significant, negative linear relationship of self-compassion predicting the impact of stuttering on quality of life. Conclusions Data suggest that higher levels of self-kindness, mindfulness, and social connectedness (i.e., self-compassion) are related to reduced negative reactions to stuttering, an increased participation in daily communication situations, and an improved overall quality of life. Future research should replicate current findings and identify moderators of the self-compassion–quality of life relationship.

AAC Collaboration Using the Self-Anchored Rating Scales (SARS): An Aphasia Case Study

2012 ◽  
Vol 21 (4) ◽  
pp. 136-143
Author(s):  
Lynn E. Fox
Keyword(s):  
Augmentative And Alternative Communication ◽  
Rating Scales ◽  
Rating Scale ◽  
Therapeutic Process ◽  
Family Counseling ◽  
The Self ◽  
Alternative Communication ◽  
Her Family ◽  
Solution Focused

Abstract The self-anchored rating scale (SARS) is a technique that augments collaboration between Augmentative and Alternative Communication (AAC) interventionists, their clients, and their clients' support networks. SARS is a technique used in Solution-Focused Brief Therapy, a branch of systemic family counseling. It has been applied to treating speech and language disorders across the life span, and recent case studies show it has promise for promoting adoption and long-term use of high and low tech AAC. I will describe 2 key principles of solution-focused therapy and present 7 steps in the SARS process that illustrate how clinicians can use the SARS to involve a person with aphasia and his or her family in all aspects of the therapeutic process. I will use a case study to illustrate the SARS process and present outcomes for one individual living with aphasia.

Practioner Reflection That Enhances Interprofessional Collaborative Practices for Serving Children Who Are Deaf/Hard-of-Hearing

2017 ◽  
Vol 2 (9) ◽  
pp. 3-9 ◽  
Author(s):  
Kristina M. Blaiser ◽  
Mary Ellen Nevins
Keyword(s):  
Young Children ◽  
Professional Practice ◽  
Hard Of Hearing ◽  
Service Providers ◽  
Interprofessional Collaboration ◽  
The Self ◽  
Self Awareness ◽  
Collaborative Practices ◽  
Interprofessional Teams ◽  
Client Care

Interprofessional collaboration is essential to maximize outcomes of young children who are Deaf or Hard-of-Hearing (DHH). Speech-language pathologists, audiologists, educators, developmental therapists, and parents need to work together to ensure the child's hearing technology is fit appropriately to maximize performance in the various communication settings the child encounters. However, although interprofessional collaboration is a key concept in communication sciences and disorders, there is often a disconnect between what is regarded as best professional practice and the self-work needed to put true collaboration into practice. This paper offers practical tools, processes, and suggestions for service providers related to the self-awareness that is often required (yet seldom acknowledged) to create interprofessional teams with the dispositions and behaviors that enhance patient/client care.

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