A study of heat and mass transfer in porous material under equilibrium conditions

Abstract

This paper surveys the heat and moisture transfer characteristics of fabric systems under equilibrium conditions. Results are given for absorptive and nonabsorptive systems measured under conditions in which no excess moisture secretion or recondensation takes place. It is shown that, with an absorptive textile, the after-exercise chill is large and persists for a few hours, but with a nonabsorptive type it is negligible.

Designing breathable superhydrophobic cotton fabrics

“…While water vapour permeability takes place in condition of free convection, which is governed not only by porosity and pore diameter, but also by its base bre moisture properties and the molecular mechanism (Fick's law), and is also depending on the capillary action. 27,[35][36][37] The pristine cotton fabric exhibits excellent water vapour absorption ability but a poor water diffusion rate because of a large number of hydrophilic hydroxyl groups on the cellulose molecules which can form strong hydrogen bonds with the water molecules that act as "stumbling blocks". Aer being subjected to gra polymerization, the hydrophilic surface of cotton fabric turns hydrophobic, meaning a frictionless interface has been formed on the fabric surface 38 at the same time, water molecules preferentially form strong hydrogen bonds.…”

Efeitos cognitivos do teste de esforço progressivo em eletricistas com equipamentos de proteção individual

“…Qualquer situação que dificulte a termorregulação contribui para o aumento da temperatura interna. A vestimenta, por exemplo, pode ter influência direta na termorregulação, dificultando a troca de calor do corpo com o ambiente pela: a) criação de uma barreira de isolamento 8 ; b) redução da evaporação do suor produzido 9 ; e c) redução da convecção de ar 10 .…”