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CHANGES IN THE PHYSICAL PROPERTIES OF HUMAN HAIR WITH AGE
Author(s) -
NARUSE NOBUKO,
FUJITA TAKUO
Publication year - 1971
Publication title -
journal of the american geriatrics society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.992
H-Index - 232
eISSN - 1532-5415
pISSN - 0002-8614
DOI - 10.1111/j.1532-5415.1971.tb05371.x
Subject(s) - medicine , ultimate tensile strength , breaking strength , age groups , modulus , zoology , demography , composite material , materials science , sociology , biology
A bstract : With the use of Tensilon III apparatus for the measurement of tensile strength, stress‐strain curves were drawn on human capital hair samples obtained from 81 healthy Japanese male subjects whose ages ranged from 2 to 91 years. The diameter of the hair showed a peak at 15 years of age, followed by a gradual decrease with advancing age. The breaking strength rose up to the age of 20 years; then it diminished with advancing age. The per cent extension at breaking and the amount of energy required until breaking also rose up to age 15 and then gradually declined. Young's modulus followed a second‐power function of a gradual fall up to age 15, followed by a gradual rise with advancing age.