Geometric imperfect preventive maintenance and replacement (GIPMAR) model for aging repairable systems

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nse Udoh ◽  
Effanga Effanga
Keyword(s):  
Developing Countries ◽  
Life Span ◽  
Preventive Maintenance ◽  
Hazard Function ◽  
Repairable Systems ◽  
Average Life ◽  
Average Life Span ◽  
Content Type ◽  
Replacement Model ◽  
Three Phases

PurposeThis work seeks to develop a geometric imperfect preventive maintenance (PM) and replacement model (GIPMAR) for aging repairable systems due to age and prolong usage that would meet users need in three phases: within average life span, beyond average life span and beyond initial replacement age of system.Design/methodology/approachThe authors utilized the geometric process (GP) as the hazard function to characterize the increasing failure rate (IFR) of the system. The GP hazard function was incorporated into the hybridized preventive and replacement model of Lin et al. (2000). The resultant expected cost rate function was optimized to obtain optimum intervals for PM/replacement and required numbers of PM per cycle. The proposed GIPMAR model was applied to repairable systems characterized by Weibull life function and the results yielded PM/replacement schedules for three different phases of system operation.FindingsThe proposed GIPMAR model is a generalization of Lin et al. (2000) PM model that were comparable with results of earlier models and is adaptive to situations in developing countries where systems are used across the three phases of operation depicted in this work. This may be due to economic hardship and operating environment.Practical implicationsThe proposed model has provided PM/Replacement schedules for different phases of operation which was never considered. This would provide a useful guide to maintenance engineers and end-users in developing countries with a view to minimizing the average cost of maintenance as well as reducing the number of down times of systems.Social implicationsA duly implemented GIPMAR model would ensure efficient operation of systems, optimum man-hour need in the organization and guarantee customer's goodwill in a competitive environment.Originality/valueIn this work, the authors have extended Lin et al. (2000) PM model to provide PM/replacement schedules for aging repairable systems which was not provided for in earlier existing models and literature.

Amalaki as a Rasayan in Geriatric Diseases

2018 ◽  
Vol 6 (06) ◽  
Author(s):  
Naina Vishwakarma
Keyword(s):  
Quality Of Life ◽  
Life Span ◽  
Old Age ◽  
Natural Process ◽  
Healthy Ageing ◽  
Average Life ◽  
Average Life Span ◽  
Medical Facilities

Geriatric problems are arising much and more in the present Era. With the increase in average life-span due to medical facilities it resulted in large number of people with old age Worldwide. To overcome this Ayurved advocates healthy ageing through Rasayan Chikitsa. By proper administration of Rasayan Therapy as a preventive tool one can prevent Jarajanit(Geriatic) vyadhis. Many herbs and techniques which provide solution to ageing and their complications are described in Ayurved. The Herbs with their properties slows down the natural process of aging and help in managing geriatric problem and improving the quality of life. Here   Amalaki an Rasayan Dravya in Geriatric diseases is brought in focus.

Longevity of exercising obese hypertensive rats

1980 ◽  
Vol 49 (4) ◽  
pp. 634-637
Author(s):  
F. W. Booth ◽  
W. F. MacKenzie ◽  
M. J. Seider ◽  
E. W. Gould
Keyword(s):  
Life Span ◽  
Myocardial Necrosis ◽  
Early Death ◽  
Early Age ◽  
Hypertensive Rats ◽  
Average Life ◽  
Average Life Span ◽  
Daily Food ◽  
Body Weights ◽  
Genetically Hypertensive

The purpose of this study was to determine whether daily running lengthens the life-span of animals dying prematurely due to cardiovascular disease. We used a strain of rat that is genetically hypertensive and obese and is reported to develop atherosclerosis (Exp. Mol. Pathol. 19: 53--60, 1973). These animals were divided into three groups consisting of runners exercised daily on treadmills from an early age life, food-restricted sedentary rats, and libitum eaters that were sedentary. This latter group had significantly higher average daily food intakes and body weights than either of the other two groups. The average life-span of both sedentary groups was significantly longer than the running group. Runners had a greater frequency of focal myocardial necrosis, but atherosclerosis was absent in all three groups. We speculate that daily running may have accentuated the development of factor s that may have contributed to the early death of runners.

Carnosine, the Protective, Anti-aging Peptide

1999 ◽  
Vol 19 (6) ◽  
pp. 581-587 ◽  
Author(s):  
Alexander A. Boldyrev ◽  
Steven Ch. Gallant ◽  
Gennady T. Sukhich
Keyword(s):  
Life Span ◽  
Standard Diet ◽  
Control Strain ◽  
Average Life ◽  
Average Life Span ◽  
Behavioral Parameters ◽  
Senescence Accelerated Mice

Carnosine attenuates the development of senile features when used as a supplement to a standard diet of senescence accelerated mice (SAM). Its effect is apparent on physical and behavioral parameters and on average life span. Carnosine has a similar effect on mice of the control strain, but this is less pronounced due to the non-accelerated character of their senescence processes.

scholarly journals Cross-fostering as a conservation tool to augment endangered carnivore populations

2018 ◽  
Vol 99 (5) ◽  
pp. 1033-1041
Author(s):  
Eric M Gese ◽  
William T Waddell ◽  
Patricia A Terletzky ◽  
Chris F Lucash ◽  
Scott R McLellan ◽  
...  
Keyword(s):  
Life Span ◽  
Litter Size ◽  
Average Life ◽  
Canis Rufus ◽  
Average Life Span ◽  
Red Wolf ◽  
In The Wild ◽  
Red Wolves ◽  
Cross Fostering

Abstract Cross-fostering offspring with nonbiological parents could prove useful to augment populations of endangered carnivores. We used cross-fostering to augment captive-born and wild-born litters for the endangered red wolf (Canis rufus). Between 1987 and 2016, 23 cross-fostering events occurred involving captive-born pups fostered into captive litters (n = 8 events) and captive-born pups fostered into wild recipient litters (n = 15 events). Percentage of pups surviving 3 and 12 months was 91.7% for captive-born pups fostered into captive recipient litters. For pups fostered into wild litters, percentage of pups surviving 5 months was > 94% among fostered pups (pups fostered into a wild red wolf litter or replaced a hybrid litter), pups in recipient litters (wild-born litters receiving fostered pups), and pups in control litters (wild-born litters not in a fostering event) when using pups with known fates. Including pups with unknown fates as deaths, percentage of pups surviving 5 months was > 54% among fostered pups, pups in recipient litters, and pups in control litters. Among wild litters, percentage of pups surviving 12 months was > 82% among fostered pups, pups in recipient litters, and pups in control litters when using pups with known fates. Including pups with unknown fates as deaths, percentage of pups surviving 12 months was > 48% among fostered pups, pups in recipient litters, and pups in control litters. Although survival to 12 months was similar among the groups, average life span was different with pups in control litters living 3.3 years, pups in recipient litters living 4.6 years, and fostered pups living 5.6 years. Of fostered pups surviving > 12 months in the wild, 9 animals whelped or sired 26 litters. Cross-fostering was successful at augmenting litter size for red wolves without any deleterious effects on recipient litters, illustrating fostering as a tool for increasing populations of endangered carnivores.

Women in the Shari῾a court records of Ottoman Damascus

2012 ◽  
Vol 3 (2) ◽  
pp. 119-142 ◽  
Author(s):  
Abdul-Karim Rafeq
Keyword(s):  
Life Span ◽  
Average Life ◽  
Christian Women ◽  
Average Life Span ◽  
Female Ratio ◽  
Court Records ◽  
Marriage Patterns ◽  
Number Of Children ◽  
Male Female Ratio ◽  
Deceased People

Qassam registers give detailed information about the estates of deceased people, the size of their households, the number of times they were married, the number of children, and the male-female ratio of minors and adults. The estates of deceased Christians in Damascus are reported more frequently in nineteenth-century qassam registers due to the application of the Tanzimat which advocated equality among all subjects and the tolerance shown towards the Christians by Egyptian rule in Syria in the 1830s. The registers indicate that monogamy was dominant in Damascus due to a low-to-average life-span. Marriage patterns and the composition of the estates of deceased women and men are examined in six qassam registers spanning a period of over a century (1750-1861). The establishment of religious endowments (vakıf) by Muslim and Christian women, and the varying titles given to these women in the court records are also discussed.

scholarly journals Maximum intrinsic rate of population increase in sharks, rays, and chimaeras: the importance of survival to maturity

2016 ◽  
Vol 73 (8) ◽  
pp. 1159-1163 ◽  
Author(s):  
Sebastián A. Pardo ◽  
Holly K. Kindsvater ◽  
John D. Reynolds ◽  
Nicholas K. Dulvy
Keyword(s):  
Life Span ◽  
Reproductive Output ◽  
Extinction Risk ◽  
Intrinsic Rate ◽  
Population Increase ◽  
Age At Maturity ◽  
Average Life ◽  
Demographic Parameter ◽  
Average Life Span

The maximum intrinsic rate of population increase (rmax) is a commonly estimated demographic parameter used in assessments of extinction risk. In teleosts, rmax can be calculated using an estimate of spawners per spawner, but for chondrichthyans, most studies have used annual reproductive output (b) instead. This is problematic as it effectively assumes all juveniles survive to maturity. Here, we propose an updated rmax equation that uses a simple mortality estimator that also accounts for survival to maturity: the reciprocal of average life-span. For 94 chondrichthyans, we now estimate that rmax values are on average 10% lower than previously published. Our updated rmax estimates are lower than previously published for species that mature later relative to maximum age and those with high annual fecundity. The most extreme discrepancies in rmax values occur in species with low age at maturity and low annual reproductive output. Our results indicate that chondrichthyans that mature relatively later in life, and to a lesser extent those that are highly fecund, are less resilient to fishing than previously thought.

scholarly journals Ziziphus spina-christi (Christ's thorn jujube).

2021 ◽  
Author(s):  
Julissa Rojas-Sandoval
Keyword(s):  
Middle East ◽  
Life Span ◽  
Average Life ◽  
Average Life Span ◽  
Tropical Regions ◽  
Northwestern India ◽  
Drought Tolerant

Abstract Z. spina-christi is a widespread drought-tolerant tree of the Middle East, northeastern Africa and northwestern India. More formally, its distribution is sub-Sudano-Decanian, with penetrations into the Saharo-Sindian and adjacent Afro-tropical regions. When fully grown, it is a stately tree with an oval, intricately branched crown providing shade, but under the effects of ill-management and excessive browsing, it often occurs as a shrub. Average life span is reported to be 50-75 years (Vashishtha, 1997).

scholarly journals Radioprotective Properties of Cumaside, a Complex of Triterpene Glycosides from the Sea Cucumber Cucumaria Japonica and Cholesterol

2011 ◽  
Vol 6 (5) ◽  
pp. 1934578X1100600
Author(s):  
Dmitry L. Aminin ◽  
Tatiana S. Zaporozhets ◽  
Pelageya V. Adryjashchenko ◽  
Sergey A. Avilov ◽  
Vladimir I. Kalinin ◽  
...  
Keyword(s):  
Life Span ◽  
Sea Cucumber ◽  
Cell Number ◽  
Exposure Dose ◽  
Peripheral Blood Cell ◽  
Triterpene Glycosides ◽  
Average Life ◽  
Average Life Span ◽  
Radioprotective Properties ◽  
Cucumaria Japonica

The radioprotective activity has been studied of a new immunomodulatory lead material, Cumaside, which is a complex of monosulfated triterpene glycosides from the edible sea cucumber Cucumaria japonica and cholesterol. Female CD-1 strain mice administered with prophylactic doses of Cumaside were irradiated using a Gamma-therapeutic device with a 60Co source (exposure dose 6.5 Gy, dose rate 1.14 Gy /min) and the average life span of the mice was determined. The animals administrated with Cumaside and irradiated were killed by pervisceral dislocation on days 4 and 9. Peripheral blood cell composition indexes, blood forming function and cell number in blood-forming organs and the number of pluripotent blood-forming stem cells were determined using standard procedures and the results compared with those of non-treated irradiated mice. The survivability percentage and average life span of the irradiated mice that were not treated with Cumaside were decreased in comparison with the Cumaside-treated groups. Especially, the leukocyte and neutrophil numbers in the blood (bone marrow from hip), and the weight and cell number of lymphoid organs were higher in the Cumaside-treated groups compared with the non-treated irradiated mice. It was concluded that at low prophylactic doses Cumaside possesses moderate radioprotective properties.

Aspetti epidemiologici e demografici dell'invecchiamento della popolazione: Epidemiological and demographic aspects of an ageing population

1998 ◽  
Vol 65 (2) ◽  
pp. 203-208
Author(s):  
D. Schiavone ◽  
A. D'Amico ◽  
V. Ficarra ◽  
S. Cicuto
Keyword(s):  
Quality Of Life ◽  
Life Expectancy ◽  
Life Span ◽  
The Elderly ◽  
Ageing Population ◽  
Average Life ◽  
Average Life Span ◽  
Urinary Infections ◽  
Co Morbidity

An ageing population is mainly due to the reduction of births and the increase in life expectation. In Italy the percentage of people aged at least 65 years increased from 11.3% in 1971 to 15.3% in 1991. This increase mostly involved those aged 75 years and over. In the last four decades the average life span has extended by more than 11 years (from 65.5 to 76.9 years). The average life span in women is currently 80.2 years, almost 7 years longer than that of men. As age increases so does the incidence of various urological diseases requiring surgery, such as prostatic diseases (hyperplasia and carcinoma), urological tumours, urinary infections and incontinence. At the same time the probability of associated pathologies increases and consequently the risk of peri-operative complications, thus negatively influencing the prognosis. Surgery is only indicated in the elderly when it may increase life expectancy and/or improve the quality of life. A careful pre-operative evaluation of all the factors that may influence both life expectancy and quality of life is therefore indispensable, with particular reference to the actual disease and co-morbidity.

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