Application of different transient sorption methods to evaluate moisture diffusion coefficients of building materials on the hygroscopic range

2011 ◽  
Vol 35 (3) ◽  
pp. 251-266 ◽  
Author(s):  
JMPQ Delgado ◽  
NMM Ramos ◽  
VP de Freitas
Keyword(s):  
Building Materials ◽  
Transport Coefficients ◽  
Moisture Diffusion ◽  
Moisture Diffusivity ◽  
Time Saving ◽  
Adsorption Processes ◽  
Different Temperatures ◽  
Set Up ◽  
The Moment ◽  
End Stage

Typically, moisture transport coefficients are determined either by stationary measurements, as standard cup set-up and modified cup method, or by dynamic measurements, as the means of the type [Formula: see text] rule in the initial phase of adsorption processes, logarithmic procedure in the end stage of adsorption processes, the half-time method, the moment method, and the hybrid 1-term method. The aim of this work was to test the usability of the five dynamic calculation methods to define the moisture diffusivity in the hygroscopic range of different building materials. The results obtained were compared in order to evaluate the discrepancies between the different calculation techniques. Advantages in time saving using each experimental technique were compared with the feasibility of each process. Two commonly used building materials are considered in the study, gypsum board and gypsum plaster, for adsorptive measurement of the moisture diffusivity at three different temperatures in three different relative humidity ranges.

scholarly journals Study of the dependence of equilibrium sorption humidity of heat-insulating products on temperature

2021 ◽  
Vol 274 ◽  
pp. 04008
Author(s):  
Artem Petrov ◽  
Valerij Kupriyanov
Keyword(s):  
Moisture Content ◽  
Building Materials ◽  
Small Mass ◽  
Mineral Wool ◽  
Scientific Development ◽  
Relative Air Humidity ◽  
Different Temperatures ◽  
Sorption Moisture ◽  
The Moment ◽  
Modern Building

The desiccator method for products like mineral wool has a low accuracy, which is due to the small mass of the samples and the uneven content of the binder between the samples. The standard method does not involve testing materials at different temperatures. However, the value of sorption moisture depends not only on the nature and structure of the material, but also on the temperature conditions. At the moment, the regularities of changes in the sorption moisture content of materials depending on the air temperature have been studied only in separate scientific works and do not cover the entire spectrum of modern building materials. The paper presents the results of a study of the sorption moisture content of modern mineral wool products at various temperatures above 0 ºС. The results show an increase in sorption humidity with decreasing temperature from 22 ºС to 0 ºС. The greatest increase in humidity occurs at values of relative air humidity in the range of 90–97 %. It is shown that the standard desiccator method for studying sorption moisture requires scientific development and increased control of test conditions with decreasing temperature.

The Revolutionizing of the Revolution

2017 ◽  
Author(s):  
R. R. Palmer
Keyword(s):  
French Revolution ◽  
Point Of View ◽  
Strict Sense ◽  
French Government ◽  
Thing In Itself ◽  
Set Up ◽  
The Moment ◽  
The French Revolution ◽  
The Revolution

In 1792, the French Revolution became a thing in itself, an uncontrollable force that might eventually spend itself but which no one could direct or guide. The governments set up in Paris in the following years all faced the problem of holding together against forces more revolutionary than themselves. This chapter distinguishes two such forces for analytical purposes. There was a popular upheaval, an upsurge from below, sans-culottisme, which occurred only in France. Second, there was the “international” revolutionary agitation, which was not international in any strict sense, but only concurrent within the boundaries of various states as then organized. From the French point of view these were the “foreign” revolutionaries or sympathizers. The most radical of the “foreign” revolutionaries were seldom more than advanced political democrats. Repeatedly, however, from 1792 to 1799, these two forces tended to converge into one force in opposition to the French government of the moment.

scholarly journals Polythermal conditions in arctic glaciers

1991 ◽  
Vol 37 (126) ◽  
pp. 261-269 ◽  
Author(s):  
Heinz Blatter ◽  
Kolumban Hutter
Keyword(s):  
Steady State ◽  
Continuum Hypothesis ◽  
Basal Layer ◽  
Moisture Diffusion ◽  
Moisture Diffusivity ◽  
Climatic Conditions ◽  
Two Dimensions ◽  
Water Mixture ◽  
Plane Flow ◽  
Transition Surface

AbstractEnglacial temperature measurements in Arctic valley glaciers suggest in the ablation zone the existence of a basal layer of temperate ice lying below the bulk of cold ice. For such a polythermal glacier, a mathematical model is presented that calculates the temperature in the cold part and the position of the cold-temperate transition surface (CTS). The model is based on the continuum hypothesis for ice and the ice-water mixture, and on the conservation laws for moisture and energy. Temperate ice is treated as a binary mixture of ice and water at the melting point of pure ice. Boundary and transition conditions are formulated for the free surface, the base and the intraglacial cold-temperate transition surface. The model is reduced to two dimensions (plane flow) and the shallow-ice approximation is invoked. The limit of very small moisture diffusivity is analysed by using a stationary model with further reduction to one dimension (parallel-sided slab), thus providing the means of a consistent formulation of the transition conditions for moisture and heat flux through the CTS at the limit of negligibly small moisture diffusion.The application of the model to the steady-state Laika Glacier, using present-day conditions, results in a wholly cold glacier with a cold sole, in sharp contrast to observations. The present polythermal state of this glacier is suspected to be a remnant of the varying climatic conditions and glacier geometry during the past few centuries. Steady-state solutions representing apolythermalstructure can indeed be found within a range of prescribed conditions which are judged to be realistic for Laika Glacier at the last maximum extent of the glacier.

scholarly journals Assessing biases, relaxing moralism: On ground-truthing practices in machine learning design and application

2021 ◽  
Vol 8 (1) ◽  
pp. 205395172110135
Author(s):  
Florian Jaton
Keyword(s):  
Machine Learning ◽  
William James ◽  
A Priori ◽  
Learning Algorithms ◽  
Three Dimensional ◽  
Ground Truth ◽  
Machine Learning Algorithms ◽  
Ground Truthing ◽  
Set Up ◽  
The Moment

This theoretical paper considers the morality of machine learning algorithms and systems in the light of the biases that ground their correctness. It begins by presenting biases not as a priori negative entities but as contingent external referents—often gathered in benchmarked repositories called ground-truth datasets—that define what needs to be learned and allow for performance measures. I then argue that ground-truth datasets and their concomitant practices—that fundamentally involve establishing biases to enable learning procedures—can be described by their respective morality, here defined as the more or less accounted experience of hesitation when faced with what pragmatist philosopher William James called “genuine options”—that is, choices to be made in the heat of the moment that engage different possible futures. I then stress three constitutive dimensions of this pragmatist morality, as far as ground-truthing practices are concerned: (I) the definition of the problem to be solved (problematization), (II) the identification of the data to be collected and set up (databasing), and (III) the qualification of the targets to be learned (labeling). I finally suggest that this three-dimensional conceptual space can be used to map machine learning algorithmic projects in terms of the morality of their respective and constitutive ground-truthing practices. Such techno-moral graphs may, in turn, serve as equipment for greater governance of machine learning algorithms and systems.

scholarly journals The estimation of electric moment in solution by the temperature coefficient method. Part I.—Experimental method and the electric moments of some benzyl compounds

1933 ◽  
Vol 142 (846) ◽  
pp. 173-197 ◽  
Keyword(s):  
Single Molecule ◽  
Polar Solvent ◽  
Fundamental Equation ◽  
Absolute Temperature ◽  
Electric Moment ◽  
Avogadro’S Number ◽  
Boltzmann Gas ◽  
Different Temperatures ◽  
The Moment ◽  
Coefficient Method

The theory of the estimation of the electric moment of molecules dissolved in a non-polar solvent is now well known. The fundamental equation is P 2∞ = 4 π /3 N (α 0 + μ 2 /3 k T) (1) in which the symbols have the following significance: P 2∞ the total polarizability of the solute per grain molecule at infinite dilution, N Avogadro’s number, α 0 the moment induced in a single molecule by unit electric field, k the Boltzmann gas constant, T the absolute temperature, and μ the permanent electric moment of the molecule. This equation is of the form P 2∞ = A + B/T, (2) where A = 4 π /3 Nα 0 and B = 4 π /9 . N μ 2 / k , from which it follows that if A and B are constant, i. e ., independent of temperature, then each may be evaluated from a series of measurements of P 2∞ at different temperatures or alternatively B (and hence μ ) may be obtained from one value of P 2∞ at one temperature, provided that A can be obtained by some independent method.

scholarly journals Cell-Based Regeneration and Treatment of Liver Diseases

2021 ◽  
Vol 22 (19) ◽  
pp. 10276
Author(s):  
Julia Hofmann ◽  
Verena Hackl ◽  
Hannah Esser ◽  
Andras T. Meszaros ◽  
Margot Fodor ◽  
...  
Keyword(s):  
Liver Diseases ◽  
Ex Vivo ◽  
Organ Shortage ◽  
Clinical Implementation ◽  
Organ Function ◽  
Novel Technologies ◽  
Recent Developments ◽  
Underlying Mechanisms ◽  
The Moment ◽  
End Stage

The liver, in combination with a functional biliary system, is responsible for maintaining a great number of vital body functions. However, acute and chronic liver diseases may lead to irreversible liver damage and, ultimately, liver failure. At the moment, the best curative option for patients suffering from end-stage liver disease is liver transplantation. However, the number of donor livers required by far surpasses the supply, leading to a significant organ shortage. Cellular therapies play an increasing role in the restoration of organ function and can be integrated into organ transplantation protocols. Different types and sources of stem cells are considered for this purpose, but highly specific immune cells are also the focus of attention when developing individualized therapies. In-depth knowledge of the underlying mechanisms governing cell differentiation and engraftment is crucial for clinical implementation. Additionally, novel technologies such as ex vivo machine perfusion and recent developments in tissue engineering may hold promising potential for the implementation of cell-based therapies to restore proper organ function.

scholarly journals Comprehensive Studies of the Processes of the Molecular Transfer of the Momentum, Thermal Energy and Mass in the Nutrient Media of Biotechnological Industries

2022 ◽  
Vol 9 (1) ◽  
pp. 18
Author(s):  
Aleksandr G. Novoselov ◽  
Sergei A. Sorokin ◽  
Igor V. Baranov ◽  
Nikita V. Martyushev ◽  
Olga N. Rumiantceva ◽  
...  
Keyword(s):  
Thermal Diffusivity ◽  
Dynamic Viscosity ◽  
Empirical Equation ◽  
Molecular Diffusion ◽  
Transport Coefficients ◽  
Molecular Transport ◽  
Rolling Ball ◽  
Molecular Transfer ◽  
Exchange Processes ◽  
Different Temperatures

This article puts forward arguments in favor of the necessity of conducting complex measurements of molecular transport coefficients that quantitatively determine the coefficients of dynamic viscosity, thermal diffusivity and molecular diffusion. The rheological studies have been carried out on the viscometers of two types: those with a rolling ball (HÖPPLER® KF 3.2.), and those with a rotary one (Rheotest RN 4.1.). The thermophysical studies have been performed using the analyzer Hot Disk TPS 2500S. The measurements have been taken in the temperature range of 283 to 363 K. The concentration of dry substances has varied from 16.2 to 77.7% dry wt. An empirical equation for calculating the density of aqueous solutions of beet molasses has been obtained. The diagrams of the dependence of the dynamic viscosity on the shear rate in the range of 1 s−1 to 500 s−1 at different temperatures have been provided. The diagrams of the dependence of the coefficients of thermal conductivity and thermal diffusivity on the temperature and the concentration of dry substances have been presented, and empirical equations for their calculation have been obtained. The findings can be used for engineering calculations of hydrodynamic and heat-exchange processes in biotechnological equipment.

scholarly journals Five-Year Experience of Liver Transplant at Kerman University of Medical Sciences: Afzalipoor Hospital

2020 ◽  
Author(s):  
Masood Dehghani
Keyword(s):  
Liver Transplantation ◽  
Liver Transplant ◽  
Cross Sectional Study ◽  
Outcome Data ◽  
Time Interval ◽  
Cross Sectional ◽  
The Past ◽  
Transplantation Center ◽  
Set Up ◽  
End Stage

Introduction: The only option for treatment of end stage liver diseases is liver transplantation. Afzalipour Hospital in Kerman, Iran is the third largest liver transplantation center in Iran. In this study, the outcomes of this center have been studied during the past 5 years. Methods: In this cross-sectional study, the pre and post transplantation’s clinical, demographic and outcome data of all patients who received liver transplant at Afzalipour Hospital during the past 5 years have been collected and reviewed. SPSS software ver. 16 was used to analyze the data. Results: Forty-three patients have received liver transplantation during this time interval. The 3-year survival rate of patients was 77%. The most common cause of death was primary nonfunction graft after transplantation. The most common complication was acute rejection (15%), all of which were successfully treated with corticosteroids. Conclusion:  Due to increment of cases of acute and chronic liver failure in the community and since the final treatment of these cases is liver transplantation, so there is need to develop liver transplant centers in the future. Quantitative and qualitative study of the activity of centers based liver transplant in Iran is necessary to set up successful centers.

Sign in / Sign up

Export Citation Format

Share Document