Dust opacity variations in the pre-stellar core L1544

Context. The study of dust emission at millimeter wavelengths is important to shed light on the dust properties and physical structure of pre-stellar cores, the initial conditions in the process of star and planet formation. Aims. Using two new continuum facilities, AzTEC at the Large Millimeter Telescope Alfonso Serrano and MUSTANG-2 at the Green Bank Observatory, we aim to detect changes in the optical properties of dust grains as a function of radius for the well-known pre-stellar core L1544. Methods. We determined the emission profiles at 1.1 and 3.3 mm and examine whether they can be reproduced in terms of the current best physical models for L1544. We also made use of various tools to determine the radial distributions of the density, temperature, and dust opacity in a self-consistent manner. Results. We find that our observations cannot be reproduced without invoking opacity variations. New temperature and density profiles, as well as opacity variations across the core, have been derived with the new data. The opacity changes are consistent with the expected variations between uncoagulated bare grains, toward the outer regions of the core, and grains with thick ice mantles, toward the core center. A simple analytical grain growth model predicts the presence of grains of ~3–4 μm within the central 2000 au for the new density profile.

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Phenomenological Analysis of Melt Progression in LWRS: Proposal of an In-Vessel Corium Progression Scenario in the Unit 1 of Fukushima Dai-ichi Nuclear Power Plant

Journal of Nuclear Engineering and Radiation Science ◽

10.1115/1.4033397 ◽

2016 ◽

Vol 2 (4) ◽

Author(s):

Payot Frédéric ◽

Seiler Jean-Marie

Keyword(s):

Power Plant ◽

Nuclear Power Plant ◽

Nuclear Power ◽

Large Scale ◽

Initial Conditions ◽

Physical Models ◽

Severe Accident ◽

Fukushima Accident ◽

Support Plate ◽

The Core

In the field of severe accident, the description of corium progression events is mainly carried out using integral calculation codes. However, these tools are usually based on bounding assumptions because of the high complexity of phenomena. The limitations associated with bounding situations [1] (e.g., steady-state situations and instantaneous whole core relocation in the lower head) led CEA to develop an alternative approach to improve the phenomenological description of the melt progression. The methodology used to describe the corium progression was designed to cover the accidental situations from the core meltdown to the molten core–concrete interaction (MCCI). This phenomenological approach is based on the available data (including learnings from TMI-2) on physical models and knowledge about the corium behavior. It provides emerging trends and best-estimate intermediate situations. As different phenomena are unknown, but strongly coupled, uncertainties at large scale for the reactor application must be taken into account. Furthermore, the analysis is complicated by the fact that these configurations are most probably three-dimensional (3D), all the more so because 3D effects are expected to have significant consequences for the corium progression and the resulting vessel failure. Such an analysis of the in-vessel melt progression was carried out for the Unit 1 of the Fukushima Dai-ichi Nuclear Power Plant. The core uncovering kinetics governs the core degradation and impacts the appearance of the first molten corium inside the core. The initial conditions used to carry out this analysis are based on the available results derived from codes such as the MELCOR calculation code [2]. The core degradation could then follow different ways: (1) Axial progression of the debris and the molten fuel through the lower support plate, or (2) lateral progression of the molten fuel through the shroud. On the basis of the Bali program results [3] and the TMI-2 accident observations [4], this work is focused on the consequences of a lateral melt progression (not excluding an axial progression through the support plate). Analysis of the events and the associated time sequence will be detailed. Besides, this analysis identifies some number of issues. Random calculations and statistical analysis of the results could be performed with calculation codes such as LEONAR–PROCOR codes [5]. This work was presented in the frame of the OECD/NEA/CSNI Benchmark Study of the Accident at the Fukushima Dai-ichi Nuclear Power Station (BSAF) project [6]. During the years of 2012 and 2014, the purpose of this project was both to study, by means of severe accident codes, the Fukushima accident in the three crippled units, until 6 days from the reactor shutdown, and to give information about, in particular, the location and composition of core debris.

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Contextualization of the Bioeconomy Concept through Its Links with Related Concepts and the Challenges Facing Humanity

Sustainability ◽

10.3390/su13147746 ◽

2021 ◽

Vol 13 (14) ◽

pp. 7746

Author(s):

Leire Barañano ◽

Naroa Garbisu ◽

Itziar Alkorta ◽

Andrés Araujo ◽

Carlos Garbisu

Keyword(s):

Environmental Economics ◽

Green Economy ◽

Added Value ◽

Economic Activities ◽

Biological Resources ◽

Beneficial Effects ◽

The Core ◽

Points Of View ◽

Broad Interpretation ◽

Shed Light

The concept of bioeconomy is a topic of debate, confusion, skepticism, and criticism. Paradoxically, this is not necessarily a negative thing as it is encouraging a fruitful exchange of information, ideas, knowledge, and values, with concomitant beneficial effects on the definition and evolution of the bioeconomy paradigm. At the core of the debate, three points of view coexist: (i) those who support a broad interpretation of the term bioeconomy, through the incorporation of all economic activities based on the production and conversion of renewable biological resources (and organic wastes) into products, including agriculture, livestock, fishing, forestry and similar economic activities that have accompanied humankind for millennia; (ii) those who embrace a much narrower interpretation, reserving the use of the term bioeconomy for new, innovative, and technologically-advanced economic initiatives that result in the generation of high-added-value products and services from the conversion of biological resources; and (iii) those who stand between these two viewpoints. Here, to shed light on this debate, a contextualization of the bioeconomy concept through its links with related concepts (biotechnology, bio-based economy, circular economy, green economy, ecological economics, environmental economics, etc.) and challenges facing humanity today is presented.

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Dynamical Evolution of Globular Clusters After Core Collapse

Symposium - International Astronomical Union ◽

10.1017/s0074180900147357 ◽

1985 ◽

Vol 113 ◽

pp. 139-160 ◽

Cited By ~ 4

Author(s):

Douglas C. Heggie

Keyword(s):

Surface Density ◽

Globular Clusters ◽

Stellar System ◽

Dynamical Evolution ◽

Theoretical Models ◽

Numerical Calculations ◽

Core Collapse ◽

Density Profiles ◽

The Core ◽

Fokker Planck

This review describes work on the evolution of a stellar system during the phase which starts at the end of core collapse. It begins with an account of the models of Hénon, Goodman, and Inagaki and Lynden-Bell, as well as evaporative models, and modifications to these models which are needed in the core. Next, these models are related to more detailed numerical calculations of gaseous models, Fokker-Planck models, N-body calculations, etc., and some problems for further work in these directions are outlined. The review concludes with a discussion of the relation between theoretical models and observations of the surface density profiles and statistics of actual globular clusters.

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On New Aspects of Nested Carbon Nanotubes as Gigahertz Oscillators

Journal of Vibration and Acoustics ◽

10.1115/1.4003933 ◽

2011 ◽

Vol 133 (5) ◽

Cited By ~ 28

Author(s):

R. Ansari ◽

B. Motevalli

Keyword(s):

Carbon Nanotubes ◽

Initial Velocity ◽

Initial Conditions ◽

Strong Dependence ◽

Interaction Force ◽

Arbitrary Length ◽

Oscillatory Frequency ◽

Analytical Expression ◽

System Parameters ◽

The Core

Nested carbon nanotubes exhibit telescopic oscillatory motion with frequencies in the gigahertz range. In this paper, our previously proposed semi-analytical expression for the interaction force between two concentric carbon nanotubes is used to solve the equation of motion. That expression also enables a new semi-analytical expression for the precise evaluation of oscillation frequency to be introduced. Alternatively, an algebraic frequency formula derived based on the simplifying assumption of constant van der Waals force is also given. Based on the given formulas, a thorough study on different aspects of operating frequencies under various system parameters is conducted, which permits fresh insight into the problem. Some notable improvements over the previously drawn conclusions are made. The strong dependence of oscillatory frequency on system parameters including the extrusion distance and initial velocity of the core as initial conditions for the motion is shown. Interestingly, our results indicate that there is a special initial velocity at which oscillatory frequency is unique for any arbitrary length of the core. A particular relationship between the escape velocity (the minimum initial velocity beyond which the core will leave the outer nanotube) and this specific initial velocity is also revealed.

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Conformation Study of Dual Stimuli-Responsive Core-Shell Diblock Polymer Brushes

Polymers ◽

10.3390/polym10101084 ◽

2018 ◽

Vol 10 (10) ◽

pp. 1084

Author(s):

Kaimin Chen ◽

Lan Cao ◽

Ying Zhang ◽

Kai Li ◽

Xue Qin ◽

...

Keyword(s):

Polymer Brushes ◽

Core Shell ◽

Stimuli Responsive ◽

Research Topics ◽

Design And Synthesis ◽

Mild Conditions ◽

The Core ◽

Responsive Polymer ◽

Stimuli Responsive Polymer ◽

Shed Light

Stimuli-responsive nanoparticles are among the most popular research topics. In this study, two types of core-shell (polystyrene with a photoiniferter (PSV) as the core and diblock as the shell) polymer brushes (PSV@PNIPA-b-PAA and PSV@PAA-b-PNIPA) were designed and prepared using surface-initiated photoiniferter-mediated polymerization (SI-PIMP). Moreover, their pH- and temperature-stimuli responses were explored by dynamic light scattering (DLS) and turbidimeter under various conditions. The results showed that the conformational change was determined on the basis of the competition among electrostatic repulsion, hydrophobic interaction, hydrogen bonding, and steric hindrance, which was also confirmed by protein adsorption experiments. These results are not only helpful for the design and synthesis of stimuli-responsive polymer brushes but also shed light on controlled protein immobilization under mild conditions.

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Can evolutionary thinking shed light on gender diversity?

BJPsych Advances ◽

10.1192/bja.2019.35 ◽

2019 ◽

Vol 25 (6) ◽

pp. 351-362 ◽

Cited By ~ 1

Author(s):

Bernadette Wren ◽

John Launer ◽

Michael J. Reiss ◽

Annie Swanepoel ◽

Graham Music

Keyword(s):

Gender Identity ◽

Gender Diversity ◽

Medical Intervention ◽

List Type ◽

Sex And Gender ◽

Medical Interventions ◽

The Core ◽

Causal Pathways ◽

And Gender ◽

Shed Light

SUMMARYIssues of sexual reproduction lie at the core of evolutionary thinking, which often places an emphasis on how individuals attempt to maximise the number of successful offspring that they can produce. At first sight, it may therefore appear that individuals who opt for gender-affirming medical interventions are acting in ways that are evolutionarily disadvantageous. However, there are persuasive hypotheses that might make sense of such choices in evolutionary terms and we explore these here. It is premature to claim knowledge of the extent to which evolutionary arguments can usefully be applied to issues of gender identity, although worth reflecting on the extent to which nature tends towards diversity in matters of sex and gender. The importance of acknowledging and respecting different views in this domain, as well as recognising both the uncertainty and likely multiplicity of causal pathways, has implications for clinicians. We make some suggestions about how clinicians might best respond when faced with requests from patients in this area.LEARNING OBJECTIVESAfter reading this article you will be able to:•understand evolutionary arguments about diversity in human gender identity•identify strengths and weaknesses in evolutionary arguments applied to transgender issues•appreciate the range and diversity of gender experience and gender expression among people who present to specialist gender services, as well as the likely complexities of their reasons for requesting medical intervention.

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فکر اقبال کی تشکیل میں ملائکہ مقربین کے کرداروں کی معنویت (اردو نظموں کی روشنی میں)

University of Chitral, Journal of Urdu Language & Literature ◽

10.33195/uochjull-v1ii132017 ◽

2017 ◽

pp. 21-31

Author(s):

Dr. Anwar ul Haq

Keyword(s):

Full Detail ◽

The Core ◽

Islamic Thought ◽

Core Subjects ◽

Islamic Values ◽

Shed Light

The characters of angels(Jibrael, Izrael ,Israfeel and Rizwan) in the poetry of Iqbal are capable of great virtual importance. Through these supernatural characters, Iqbal has successfully conveyed his thoughts in a very impressive and artistic way. He was against the slavery and used these characters in his poetry to motivate Muslims to obtain the virtual goal of freedom. These characters are also the symbols of Islamic values and thoughts. They successfully convey the core subjects of Islamic thought. The researcher has shed light on this specific angle of Iqbal’s poetry in full detail.

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METODOLOGI PROGRAM RISET IMRE LAKATOS

JURNAL PENDIDIKAN ISLAM AL-ILMI ◽

10.32529/al-ilmi.v4i1.934 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Ahmad Saka Falwa Guna ◽

Fitria Ramadhani

Keyword(s):

Research Program ◽

Initial Conditions ◽

Human Mind ◽

Theory Theory ◽

Previous Theory ◽

Imre Lakatos ◽

The Core ◽

Library Research ◽

Hardcore Functions ◽

Protective Belt

This research was based on the limitations of the human mind itself in providing and obtaining reasonable explanations, because at that time the desire to know something was obstructed from various myths which existedin that society so that myths were embedded in human mind. The focus of this research was on the methodology of the Imre Lakatos research program. The purpose of this study was to determine the process of research program methodology from Imre Lakatos. The method used in this research was library research, where the researchers looked for and read sources that match the title to be studied, such as books, articles, writings and journals that were relevant.The results of this study in the Imre Lakatos research program methodology included: First, the core (hardcore) functions as a negative heuristic. Second, the protective-belt which consisted of auxiliary hypotheses in the initial conditions. Third, a series of theories (a series theory), theory linkages where the next theory was the result of the auxiliary clauses added from the previous theory.

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Tree crowns grow into self-similar shapes controlled by gravity and light sensing

Journal of The Royal Society Interface ◽

10.1098/rsif.2017.0976 ◽

2018 ◽

Vol 15 (142) ◽

pp. 20170976 ◽

Cited By ~ 5

Author(s):

Laurent Duchemin ◽

Christophe Eloy ◽

Eric Badel ◽

Bruno Moulia

Keyword(s):

Tree Growth ◽

Initial Conditions ◽

Tree Crown ◽

Tree Crowns ◽

Light Sensing ◽

The Core ◽

Long Period ◽

Self Similar ◽

On the apparent power law in CDM halo pseudo-phase space density profiles

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stx1245 ◽

2017 ◽

Vol 470 (1) ◽

pp. 500-511 ◽

Cited By ~ 1

Author(s):

Ethan O. Nadler ◽

S. Peng Oh ◽

Suoqing Ji

Keyword(s):

Phase Space ◽

Power Law ◽

Cold Dark Matter ◽

Initial Conditions ◽

Phase Space Density ◽

Fluid Approximation ◽

Density Profiles ◽

Space Density ◽

Scale Free ◽

Hydrodynamic Calculations

Abstract We investigate the apparent power-law scaling of the pseudo-phase space density (PPSD) in cold dark matter (CDM) haloes. We study fluid collapse, using the close analogy between the gas entropy and the PPSD in the fluid approximation. Our hydrodynamic calculations allow for a precise evaluation of logarithmic derivatives. For scale-free initial conditions, entropy is a power law in Lagrangian (mass) coordinates, but not in Eulerian (radial) coordinates. The deviation from a radial power law arises from incomplete hydrostatic equilibrium (HSE), linked to bulk inflow and mass accretion, and the convergence to the asymptotic central power-law slope is very slow. For more realistic collapse, entropy is not a power law with either radius or mass due to deviations from HSE and scale-dependent initial conditions. Instead, it is a slowly rolling power law that appears approximately linear on a log–log plot. Our fluid calculations recover PPSD power-law slopes and residual amplitudes similar to N-body simulations, indicating that deviations from a power law are not numerical artefacts. In addition, we find that realistic collapse is not self-similar; scalelengths such as the shock radius and the turnaround radius are not power-law functions of time. We therefore argue that the apparent power-law PPSD cannot be used to make detailed dynamical inferences or extrapolate halo profiles inwards, and that it does not indicate any hidden integrals of motion. We also suggest that the apparent agreement between the PPSD and the asymptotic Bertschinger slope is purely coincidental.

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