Supplementary material to "Effective coefficient of diffusion and permeability of firn at Dome C and Lock In, Antarctica – Estimates over the 100–850 kg m<sup>−3</sup> density range"

2021 ◽  
Author(s):  
Neige Calonne ◽  
Alexis Burr ◽  
Armelle Philip ◽  
Frédéric Flin ◽  
Christian Geindreau
Keyword(s):  
Density Range ◽  
Effective Coefficient ◽  
Supplementary Material ◽  
Lock In ◽  
Coefficient Of Diffusion

scholarly journals Effective coefficient of diffusion and permeability of firn at Dome C and Lock In, Antarctica – Estimates over the 100–850 kg m<sup>−3</sup> density range

2021 ◽  
Author(s):  
Neige Calonne ◽  
Alexis Burr ◽  
Armelle Philip ◽  
Frédéric Flin ◽  
Christian Geindreau
Keyword(s):  
Diffusion Coefficient ◽  
Analytical Models ◽  
Density Range ◽  
Effective Coefficient ◽  
Structural Anisotropy ◽  
Near Surface ◽  
Tomographic Images ◽  
Porosity Ratio ◽  
Lock In ◽  
Coefficient Of Diffusion

Abstract. Modeling air transport through the entire ice sheet column is needed to interpret climate archives. To this end, different regressions were proposed to estimate the effective coefficient of diffusion and permeability of firn. Such regressions are often valid for specific depth or porosity ranges and were little evaluated as data of these properties are scarce. To contribute with a new dataset, this study presents the effective coefficient of diffusion and the permeability at Dome C and Lock In, Antarctica, from the near-surface to the close-off (23 to 133 m depth). Also, microstructure is characterized based on density, specific surface area, closed porosity ratio, connectivity index and structural anisotropy through the correlation lengths. All properties were estimated based on pore-scale computations on 3D tomographic images of firn samples. Normalized diffusion coefficient ranges from 1.9 × 10−1 to 8.3 × 10−5 and permeability ranges from 1.2 × 10−9 to 1.1 × 10−12 m2, for densities between 565 and 888 kg m−3. No or little anisotropy is reported. Next, we investigate the relationship of the transport properties with density over the firn density range as well as over the entire density range encountered in ice sheets by including snow data. Classical analytical models and regressions from literature are evaluated. For firn (550–850 kg m−3), good agreements are found for permeability and diffusion coefficient with the regressions based on the open porosity of Freitag et al. (2002) and Adolph and Albert (2014), despite the rather different site conditions (Greenland). Over the entire 100–850 kg m−3 density range, permeability is accurately reproduced by the Carman-Kozeny and Self-Consistent (spherical bi-composite) model when expressed in terms of a rescaled porosity ϕres = (ϕ–ϕoff) / (1–ϕoff) to account for pore closure, with ϕoff the close-off porosity. For the normalized diffusion coefficient, none of the evaluated formulas were satisfactory so we propose a new regression based on the rescaled porosity that reads D/Dair = (ϕres)1.61.

scholarly journals Analysis of Sensitive Parameters Affecting Unlocking Force of Finger Lock in Landing Gear

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Yu Hou ◽  
Ming Zhang ◽  
Hong Nie
Keyword(s):  
Mechanical Characteristics ◽  
Landing Gear ◽  
Effective Coefficient ◽  
Wear Model ◽  
Obvious Effect ◽  
Working Cycle ◽  
Inner Surface ◽  
Surface Diameter ◽  
Lock In ◽  
Sensitive Parameters

The mechanical characteristics of the unlocking force of the landing gear finger lock were studied in this paper, the influence of its diameter, fingertip angle, wear, and other factors on the unlocking force in one complete working cycle was analyzed, and the sensitive parameters that affect the unlocking force were obtained. Firstly, the unlocking force and wear of finger lock were calculated theoretically, and the changing rule of the unlocking force and wear with each parameter was obtained. Then, the validity of the correlation coefficient and model was verified by experiment. Finally, combined with the effective coefficient obtained from the experiment, the Archard wear model was used to simulate the change rule of lock force. The results show that in one complete working cycle, the inner surface diameter is negatively related to the unlocking force, fingertip diameter has little effect on the unlocking force, fingertip angle is negatively related to the unlocking force, and wear is positively related to the unlocking force; friction coefficient and fingertip angle are high sensitive parameters that affect the unlocking force, which have obvious effect on the unlocking force. The inner surface diameter, fingertip diameter of finger lock, and wear are the low sensitive parameters that affect the unlocking force, and the influence on the unlocking force is weak.

Amplitude-Modulated Lock-In Vibrothermography for NDE of Polymers and Composites

1995 ◽  
Vol 7 (1) ◽  
pp. 215-228 ◽  
Author(s):  
J. Rantala ◽  
D. Wu ◽  
G. Busse
Keyword(s):  
Lock In

A Raman signature of the incommensurate-commensurate phase transition (lock-in) in a crystalline monomer diacetylene : pTS

1982 ◽  
Vol 43 (5) ◽  
pp. 755-759 ◽  
Author(s):  
M. Bertault ◽  
M. Krauzman ◽  
M. Le Postollec ◽  
R.M. Pick ◽  
M. Schott
Keyword(s):  
Phase Transition ◽  
Commensurate Phase ◽  
Lock In

Examination of Measurement Method for Magnetostriction of Electrical Steel Sheet with Lock-in Amplifier

2012 ◽  
Vol 132 (11) ◽  
pp. 1033-1038
Author(s):  
Yuichiro Kai ◽  
Yuji Tsuchida ◽  
Takashi Todaka ◽  
Masato Enokizono
Keyword(s):  
Measurement Method ◽  
Steel Sheet ◽  
Electrical Steel ◽  
Lock In ◽  
Electrical Steel Sheet

Designing Workbook for Teaching Writing Descriptive Text Based on Scientific Approach

2019 ◽  
Vol 1 (2) ◽  
pp. 59
Author(s):  
Indah Pratiwi ◽  
Yanti Sri Rezeki
Keyword(s):  
Teaching Writing ◽  
English Teacher ◽  
Design Development ◽  
Seventh Grade ◽  
Internal Evaluation ◽  
Writing Ability ◽  
Good Book ◽  
Scientific Approach ◽  
Supplementary Material ◽  
Analysis Design

This research aims to design workbook based on the scientific approach for teaching writing descriptive text. This research was conducted on the seventh-grade students of SMPN 24 Pontianak. The method of this research is ADDIE (Analysis, Design, Development, Implementation, and Evaluation) with the exclusion of Implementation and Evaluation phases. This material was designed as supplementary material to support the course book used especially in teaching writing of descriptive text. The respondents in this research were the seventh-grade students and an English teacher at SMPN 24 Pontianak. In this research, the researchers found that workbook based on scientific approach fulfilled the criteria of the good book to teach writing descriptive text. The researchers conducted an internal evaluation to see the usability and the feasibility of the workbook. The result of the evaluation is 89%. It showed that the workbook is feasible to be used by students as the supplementary material to support the main course book and help the students improve their writing ability in descriptive text.

Catalytic Fluorination of Boron Compounds at a Bismuth Redox Platform

2019 ◽  
Author(s):  
Oriol Planas ◽  
Feng Wang ◽  
Markus Leutzsch ◽  
Josep Cornella
Keyword(s):  
Transition Metal ◽  
Main Group ◽  
Group Element ◽  
Oxidation States ◽  
Boron Compounds ◽  
Main Text ◽  
Main Group Element ◽  
Rational Ligand Design ◽  
Supplementary Material

The ability of bismuth to maneuver between different oxidation states in a catalytic redox cycle, mimicking the canonical organometallic steps associated to a transition metal, is an elusive and unprecedented approach in the field of homogeneous catalysis. Herein we present a catalytic protocol based on bismuth, a benign and sustainable main-group element, capable of performing every organometallic step in the context of oxidative fluorination of boron compounds; a territory reserved to transition metals. A rational ligand design featuring hypervalent coordination together with a mechanistic understanding of the fundamental steps, permitted a catalytic fluorination protocol based on a Bi(III)/Bi(V) redox couple, which represents a unique example where a main-group element is capable of outperforming its transition metal counterparts.<br>A main text and supplementary material have been attached as pdf files containing all the methodology, techniques and characterization of the compounds reported.<br>

Scoping Social Entrepreneurship in India: Organisation, Technology, and Collaboration

GIS Business ◽  
2007 ◽  
Vol 2 (1) ◽  
pp. 39-47
Author(s):  
Sunita Kumari ◽  
Bino Paul G.D.
Keyword(s):  
Social Development ◽  
Human Development ◽  
Social Entrepreneurship ◽  
Social Stratification ◽  
Poverty Reduction ◽  
Social Protection ◽  
Secondary Data ◽  
Non Profit ◽  
The Core ◽  
Lock In

We explore emerging contexts of social entrepreneurship in India. Social entrepreneurship is emerging as an important option in poverty reduction and social change wherein organizing societal responses to scenarios like entrenched deprivation, cumulative disadvantages, long extant institutional lock-in, and vulnerabilities enmeshed in social stratification, hiatus emanating from segmentation of labour market and inadequate coverage of social protection form the core of strategies/collectives/organisation. In this paper, first, drawing cues from the literature, we outline basic typology of social entrepreneurship while delineating pivotal role technology and collaboration play in social entrepreneurship. Second, we provide a glimpse of not profit organisations in India, based on the secondary data. We juxtapose select patterns from the data on non profit organisations with human development. Third, we discuss select cases of social entrepreneurship that diverge in characteristics and contexts, in particular how these initiatives work towards poverty reduction and social development.

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