background: premature ovarian failure (pof) is a common condition; its incidence is estimated to be as great as 1 in 100 by the age of 40 years. physiologic replacement of ovarian steroid hormones seems rational until the age of normal menopause. temporary return of ovarian function and pregnancy may occur rarely in women with pof. we report a case of pof who conceived during hormone replacemen...

Age replacement policy is concerned with finding an optional time to minimize the cost, at which time the unit is replaced even if it does not fail. So far, age replacement policy involving random age has been proposed. This paper will assume the age of the unit is an uncertain variable, and find the optimal time to replace the unit.

The early age shrinkage is responsible for the early age cracking of concrete. It is very critical for durability of concrete. The change in volume of concrete due to evaporation of water or dehydration process is known as shrinkage. To reduce the early age shrinkage utilized the supplementary cementitious material (SCM) in concrete. In present research industrial and agricultural waste byprodu...

An age replacement maintenance policy is considered here, in which a system is restored whenever it fails, or ages without failure up to a preventive maintenance epoch (whichever comes first). The duration of the restoration activity is random, and depends on whether it was precipitated by a failure or by a preventive maintenance action. The case where the preventive maintenance epoch is determ...

Condition-Based Maintenance (CBM) optimization using Proportional Hazards Model (PHM) is a kind of maintenance optimization problem in which inspections of a system relevant to its failure rate depending on the age and value of covariates are performed in time intervals. The general approach for constructing a CBM based on PHM for a system is to minimize a long run average cost per unit of time...

from may 1994 to december 1996 thirty patients received viable fresh aortic homografts. mean age was 55 years (13 to 70), male to female ratio was 2/1, 24 operations were elective whereas 6 were semiurgent. predominant lesions were aortic stenosis or regurgitation in lb patients, aortic valve endocarditis in 10, prosthetic valve dysfunction in 3, and aortic root pathology in one patient. from t...

Osteoarthritis is the leading cause of total hip replacement, accounting for more than 80% of all total hip replacements. Emerging evidence suggests that osteoarthritis has a chronic inflammatory component to its pathogenesis similar to age-related macular degeneration. We evaluated the association between age-related macular degeneration and total hip replacement as proxy for severe osteoarthr...