Economic Lifespan Research Articles

Life Cycle Cost versus Life Cycle Investment – A new Approach

The paper proposes a model for the life cycle of physical assets that includes the maintenance policy, because it has direct implications on the equipment’s Return On Investment (ROI) and Life Cycle Cost; the developed model can be applied to any type of physical asset. The model is called Life Cycle Investment (LCI) instead of the traditional Life Cycle Cost (LCC). The paper proposes a new methodology based on the modified economic life cycle and lifespan methods by including the maintenance policy using maintenance Key Performance Indicators (KPI), namely Availability, based on the Mean Time Between Failures (MTBF) and the Mean Time To Repair (MTTR). The benefits (profits) that result from the asset’s Availability must be balanced with the initial investment and the variable maintenance investment along its life, which has relation with the maintenance policy and the ROI.

Analysis of RC structures with different design mistakes under explosive based demolition

AbstractMost of the RC buildings in Turkey have reached the end of their economic lifespan, so urban transformation studies have been accelerated in recent years. Considering the fact that these buildings do not meet the construction regulations and have structural defects in terms of earthquake resistance is concluded the necessity of renewal of this building stock. For this reason, it is needed to study the explosive based demolition technique, which have been widely used in the future in Turkey. The aim of this study is to analyze the structural behavior of buildings planed for demolition by using explosive materials and demonstrating the effect of structural faults on the demolition process. In this context, the effect of structural defects on structural behavior is investigated under explosive based demolition for a typical RC framed building model. Within the scope of the study, it is aimed to investigate the effects of design errors frequently encountered in reinforced concrete structures during the demolition of the building using explosives. The main objective of the study is to determine the effects of design errors, which may be present in the building on important results such as demolition of reinforced concrete structures that are planned to be demolished in two different types using an explosive inside or towards a selected direction, distribution of the parts scattered after demolition and the demolition time. In this way, it is aimed to prevent accidents or unwanted demolition patterns that may occur in demolition works of reinforced concrete structures with design errors. A 12‐storey square building in plan with 6x6 axles (5 m axle opening) is selected as a structural system. The selected structure has been designed with Ide Static Structural Analysis Program. The same structure is also modeled with extreme loading for structures (ELS) program for low concrete strengths, reinforcement defects, and locally located structural defects considering inside and side demolition used explosives. All building models have been subjected to the same blast planning. It is observed that reduced the concrete strength and reinforcement faults shorten the time of destruction of buildings scheduled for demolition by using explosive materials and all the structural defects effect the debris affecting area. It is generally concluded that, all the structural defects are affective on the structural behavior of buildings under explosive based demolition.

ÇORUH NEHRİ HAVZASINA BAĞLI OLTU MİKROHAVZASINDA KANAL VE OYUNTU EROZYONUYLA GERÇEKLEŞEN TOPRAK KAYBININ “EROZYON ÇUBUK YÖNTEMİYLE” BELİRLENMESİ

Water erosion is an important erosion type that erodes and transports the most. With the effects of stream water, both streambank and gully erosions cause even more soil transport and debris accumulation resulting more flood events and associated loss of life and properties, as well as increasing the deposition of sediment in dam reservoirs that shorten the economic lifespan of these dams. This study was carried out in 14 different bank erosion sites (stream reach) in the Oltu Micro Catchment (OMC), one of the sub-watershed of the Coruh River Basin, to measure gully and streambank erosions over five-year long study period using “erosion pin method”. Oltu Micro Catchment has arid and semi-arid climate and has a 37% slope degree with a rugged structure. Over the five-year study period, the annual gully and streambank erosion rates were ranged from 1.25 to 8.79 cm/yr and the five-year average was measured as 4.43 cm/yr. The five-year soil losses were ranged from 30.5 to 190.8 tons/km/yr, and the five-year average was measured as 83.9 tons/km/yr. Compared to 1st and 2nd order streams, most of these measured soil losses were due to gully erosion (78%). In addition, it was determined that very large increase in bank erosion was occurred due to increase in rainfall in this semi-arid region showing that these types of watersheds are sensitive to bank erosions. As a conclusion, streambank and gully erosions are dynamic processes effected by the spatial and temporal scale differences under varying climate settings. Additionally, this study is a pioneer one in the region that identifies a need for the conservation practices (particularly for the gullies) to reduce the soil losses and deposited sediment in the whole channel system and eventually in dam reservoirs.

Ganoderma infection of oil palm – a persistent problem in Papua New Guinea and Solomon Islands

Basal stem rot (BSR) disease caused by Ganoderma boninense Pat. is a major limiting factor to palm oil producing countries in South East Asia, which produce 90% of the world’s palm oil demand. BSR has been known for over 100 years and to date continues to be a disease of increasing economic importance. Once considered a disease of senescing palms, BSR has persisted through successive replants, infecting younger plantings and shortening the economic life span of each cropping cycle. Many approaches have been applied to control BSR of oil palm with varying levels of success. To date, there is still no single approach that has been demonstrated to be effective in BSR management. The long-term strategy would be to breed genotypes resistant or tolerant to BSR. However, this is dependent on a multi-disciplinary approach to understanding oil palm-Ganoderma interactions that can reveal the mechanisms involved with infectivity and pathogenicity of Ganoderma, and susceptibility, resistance or tolerance of oil palm. This review aims to highlight the knowledge gaps that need addressing to improve the control and management of BSR.

A Review on Possibilities of Intercropping with Immature Oil Palm

Oil palm (Elaeisguineensis) is identified as the world’s leading edible oil producing plant and well established as a perennial plantation crop in tropical countries. Economic life span of the plant is around 30-35 years and stand per hectare is around 120-135 plants. At the initial stage of the plantations (age up to 3-5 years) there are ample amount of free space available inside young plantations. During this period growers were not getting any income from oil palm and have to spend several other agricultural practices such as weeding. Intercropping with young oil palm is possible and practiced specially by small and medium scale farmers with suitable combinations of crop species. Early identification, proper management of short and medium term intercrops gives better returns for the farmers. Furthermore, in addition to the advantages there were some limitations for intercropping with young oil palm.

A practical genome-enabled legitimacy assay for oil palm breeding and seed production

BackgroundLegitimacy in breeding and commercial crop production depends on optimised protocols to ensure purity of crosses and correct field planting of material. In oil palm, the presence of three fruit forms permits these assumptions to be tested, although only after field planting. The presence of incorrect fruit forms in a cross is a clear sign of illegitimacy. Given that tenera forms produce 30% more oil for the same weight of fruit as dura, the presence of low levels of dura contamination can have major effect during the economic lifespan of an oil palm, which is around 25 years. We evaluated two methods for legitimacy test 1) The use of SHELL markers to the gene that determines the shell-thickness trait 2) The use of SNP markers, to determine the legitimacy of the cross.ResultsOur results indicate that the SHELL markers can theoretically reduce the major losses due to dura contamination of tenera planting material. However, these markers cannot distinguish illegitimate tenera, which reduces the value of having bred elite tenera for commercial planting and in the breeding programme, where fruit form is of limited utility, and incorrect identity could lead to significant problems. We propose an optimised approach using SNPs for routine quality control.ConclusionsBoth dura and tenera contamination can be identified and removed at or before the nursery stage. An optimised legitimacy assay using SNP markers coupled with a suitable sampling scheme is now ready to be deployed as a standard control for seed production and breeding in oil palm. The same approach will also be an effective solution for other perennial crops, such as coconut and date palm.

Food, Eating, and Happy Aging: The Perceptions of Older Chinese People.

China's government and its people have for a long time focused on food security for its population as one of the most important issues in economic and social development. Many older people in China have lived in times when food security was not stable. Thus, while food has a central position in Chinese culture for all Chinese people, it is of particular pertinence to older people. In this paper we explore the meaning of food and eating in the lives of older Chinese people in China and how it contributes to healthy, thus happy aging. Focus groups and qualitative interviews were used in this study. Participants were recruited from the rural Yongfu Province of Southwest China, and the urban Fangzhuang and Haidan districts in Beijing. Forty-two participants were recruited aged 62–83 years of age. All focus groups and interviews were conducted in Mandarin and audiotaped with the participants' permission. Audio-tapes were transcribed by a Chinese speaking researcher and then were translated into English. Data were analyzed continuously and comparatively, transcripts were coded, and themes and sub-themes were identified. The initial analysis and interpretation were then presented and discussed at a workshop with all the authors. Two major themes emerged—the quantity of food and the quality of food required to have a happy old age. Participants discussed the desire to eat “until you are full” because of their experiences of famine during childhood. However, they also believed that as an older person they should eat less for their health, particularly less high fat foods. The importance of the food quality and food affordability was also discussed. Grain and meat were characterized as “good” foods and important in their diets for a happy old age. The participants, especially those from urban areas, were concerned with food safety. The high cultural importance of food for older Chinese in China was confirmed in this study. Social and economic lifespan experiences continue to impact on the food and eating attitudes and practices of older Chinese. The food related life experiences of older Chinese in China are quite different from younger Chinese and health promotion messaging needs to be informed by these unique perspectives in order to maximize its effectiveness.

Efficacy of Fungicide Treatments for Control of Anthracnose Canker in Young Cider Apple Trees in Western Washington

Anthracnose canker, caused by Neofabraea malicorticis, threatens the sustainability of cider apple (Malus ×domestica) production in the maritime climate of western Washington. In the short-term, the disease reduces overall orchard productivity and in the long-term it reduces an orchard’s economic life span. The disease is difficult to manage using cultural practices, and information on fungicide efficacy is limited and contradictory. To address this situation, a 2-year study was conducted to evaluate efficacy of zinc (4.49 lb/acre), basic copper sulfate (2.49 lb/acre), captan (2.94 lb/acre), thiophanate-methyl (0.69 lb/acre), pyraclostrobin plus boscalid (0.38 lb/acre), and combinations of these fungicides to manage anthracnose canker infection in young cider apple trees cultivated in a maritime climate. Trees used in the first year of the study (2016) were found to be infected by anthracnose canker on receipt, so the first year was a measure of disease control and the second year (2017) was a measure of disease prevention. In 2016, when fungicide treatments were applied every 3 weeks from March through October, none of the treatments evaluated inhibited the development of new infections or the expansion of existing cankers (77% increase in canker size on average for all treatments). In 2017, when fungicide treatments were applied every 3 weeks from February through April, two to three new cankers were observed 3 weeks after final treatment application for all treatments. Results from this study demonstrate that the current fungicides recommended for control of anthracnose canker are not reliably effective in the orchard environment of northwest Washington. Future studies should assess the fungicides evaluated in this study applied in rotation with additional systemic fungicides.

Experimental investigation of a vertical earth-to-air heat exchanger system

A vertical earth-to-air heat exchanger system (VEAHE) system was proposed in this study. Compared to conventional EAHE systems, it has smaller land use and higher geothermal energy utilization efficiency. To validate its thermal and economic feasibility, an experimental setup was established to examine the variation of its outlet air temperature, air temperature along the tube and soil temperature. Also, the energy metrics of the proposed system were calculated for its economic assessment. Results showed that the outlet air temperature of this system ranged from 22.4 °C to 24.4 °C in summer and from 16.0 °C to 18.0 °C in winter. A detailed air temperature profile along the whole tube revealed that, the air temperature difference under 5 m in deep soil was more than twice as many as that from the inlet to 5 m. For the soil temperature at different depths, its recovery rate approximately equaled to the corresponding changing rate at the same depth during operation. For the proposed system, its energy payback time was calculated as 8.2 years, and its CO2 emission mitigation potential and total carbon credits were calculated as 7170.42 kg and $203.43 respectively, given an economic lifespan of 20 years. In addition, its monetary payback period was calculated as 17.5 years. The above results demonstrate the feasibility and effectiveness of the proposed system in exploiting deep ground soil as a natural heat sink/source in summer/winter. Meanwhile, the energy metrics analysis indicates that the proposed system is economically viable.

Impact of tapping quality and harvesting practices on the sustainability of the rubber industry in Sri Lanka

Maintaining the tapping quality in rubber fields is the key requirement to obtain potential yield with minimum harm to the tree. It also determines productivity and the economical lifespan of 30 years and sustainable rubber industry. The length of the tapping cut, the depth, the thickness of the bark shaving, and the slope of the tapping cut are the main factors determining the tapping quality. Use of a stencil according to the intended tapping frequency, i.e. d2, d3, d4, etc., to mark the guidelines to maintain the proper tapping angle of 30 degrees to the horizontal, and the bark consumption allowed for one year, are all equally contribute to maintaining the tapping quality. About 5000 ha. was surveyed to assert the tapping quality and to make recommendations. The average bark consumption rate per panel was four years deviating from recommended six years under d2 tapping. The monitory loss per hectare under this bark consumption rate is Rs.2.5 million at a productivity level of 1000 kg/ha/y and Rs.350.00 per kg of rubber. Trees affected by tapping panel dryness varied and was over 70% in some extreme cases. Introducing a quarter cut on the upper opposite panel of the tree ceased the situation to a greater extent.

Analytical Study of Fleet Management and Vehicle Replacement Model: Evidence from the Nigerian National Petroleum Cooperation Headquarter Abuja

This study focuses on improving the operational performance of transport services in Nigeria by examining the economic life cycle of the vehicles in Nigerian National Petroleum Cooperation (NNPC). Data were collected on vehicle numbers, make, price, year of purchase and maintenance costs. Using Vehicle Replacement and Maintenance Model (VRMM) for the analysis. The study found that Toyota Hilux (T/Hilux) has economic life span of six years, while both Corolla T/Coaster and Skoda Superb have economic life span of eight years. Lastly, T/Camry and Honda Pilot should be replaced after nine years. Also, it is discovered that the NNPC vehicles were used to the end of their life spans. In the asset management principle, this practice is an economic wastage i.e. waste of resources and this issue need to be addressed. In view of the findings in this research work, the following recommendations are explained; the land transport department of NNPC should derive a policy of using their vehicles to its economic life span thereby preventing economic wastage, and NNPC fleet managers should be able to set apart a certain amount every year to make replacement easy. For example, 15% of inflation rate can be set apart every year for each vehicle.

What Affects the Secondhand Value of Smartphones: Evidence from eBay

SummaryReuse via secondhand markets can extend the use phase of products, thereby reducing environmental impacts. Analyzing 500,000 listings of used Apple and Samsung smartphones sold in 2015 and 2016 via eBay, we examine which product properties affect how long smartphones retain market value and facilitate market‐based reuse. Our results suggest that although repairability and large memory size are typically thought to be “life extending,” in practice they have limited impact on the current economic life span of smartphones and their market‐based reuse. In contrast, we show that brand, an intangible product property, can extend smartphones’ economic life span by 12.5 months. Because longer economic life spans imply extended use phases and longer life spans overall, these results illustrate the potential of harnessing the intangible properties of products to promote sustainable consumption.

The impact of human behaviour and restoration on the economic lifespan of the proposed Ntabelanga and Laleni dams, South Africa: A system dynamics approach

Abstract The South African government intends to develop the Mzimvubu Water Project (MWP) which includes the construction of two dams (the Ntabelanga and Laleni dams) in the Tsitsa River, Eastern Cape province, South Africa. This investment is believed to be important to unlock the economic potential of this rural, poor and underdeveloped area. We consider a range of variables to ascertain what the realistic economic lifespan of each of the dams are, subject to uncertainty and complexity, as the benefits from the development of the dams are closely linked to such lifespans. The selected sites are prone to soil erosion thereby potentially jeopardising the derived benefits from the investment. We therefore develop a catchment-wide system dynamics model, incorporating both technical and behavioural dimensions, in an effort to determine which factors influence the economic lifespan of the dams and to what extent. The results suggest that, without taking any restorative or behavioural effects into consideration, the lifespan of the Ntabelanga and Laleni dams are 55–68 years and 26–33 years, respectively. Introducing business-as-usual type behavioural patterns could reduce the dams’ lifespans by between 35% and 44% due to the increased erosion. The increased soil erosion and resulting sedimentation is the direct result of increased human and animal movements due to the economic investment and associated land use change. Restorative and desirable behavioural action that will mitigate these impacts have the potential to reduce this loss to only 4%–9%. This would imply investing heavily both in restoration and in capacity-building and community development programmes to facilitate desirable behavioural change. In sum, this suggests that investment in social and natural capital has to coincide with the investment of financial capital in manufactured capital to make economic development last. Investment in social and natural capital could therefore be viewed as a type of insurance policy, and thus an insurance investment, against the risk of very plausible losses of the benefits derived from the manufactured capital (the dams). Alternatively, the opportunity cost of not investing in social and natural capital, is the much reduced lifespans of the dams and all associated economic benefits.

Effect of ethephon stimulation on natural rubber latex properties; new insight into ethephon stimulation

Stimulation based low intensity harvesting (LIH) systems are accepted all over the world as an agronomic tool to overcome issues such as high cost of production, worker scarcity and low economic lifespan of trees in rubber plantation industries. When developing a protocol for ethephon stimulation, yield levels were concerned regardless of the effect on associated latex quality parameters. Therefore, this study elucidated the effect of ethephon on dry rubber yield and associated latex quality parameters together with latex rheological behaviour and physiological parameters. Five stimulation levels of ethephon (1 − 5 %) were investigated with RRIC 121 genotype under S/2 d3 (tapping half of the spiral once in three days frequency) harvesting system with unstimulated latex as the control. The results revealed that all the properties studied were significantly affected by the ethephon concentration and maximum yield with optimum properties could be achieved with the application of 3 % ethephon under S/2 d3 harvesting system.

A study on the time-dependent changes of the intensities of factors determining patent lifespan from a biological perspective

The lifespan of a human is determined by inborn factors including genetic factors and acquired factors, such as social-environmental factors and individual-behavior. From this point of view, this study classified factors determining the economic lifespan of patents into inborn “genetic factors,” acquired “social-environmental factors,” as well as “individual-behavioral factors,” and analyzed the change in the influence intensity of factors with patent age along with application year. The results showed that the intensities of factors determining patent lifespan differed by industry and changed with the maintenance period and application year. Moreover, while “social-environmental factors” (such as a patent litigation), together with “individual-behavioral factors” (such as the number of patent family) had a stronger influence on patent lifespan than “genetic factors” (such as the number of claim), patents maintained longer period had stronger influence of behavioral and environmental factors rather than genetic factors. Furthermore, recently applied patents had a stronger influence due to the external environments than patents applied a relatively long time ago.

Improved recovery from fractured oil reservoirs

Fluid loss through natural fractures in oil reservoirs can be overcome using flow induced viscoelastic surfactant (FIVES) solutions. Single phase tests show higher flow resistance in fractures compared to matrix. This reduces the fluid lost through the fracture. During decane displacement, the amount of fluid lost through the fracture is lowered due to this increased local flow resistance. Improved recovery is obtained and the pore volume injected at break-through is reduced from 2.5 PV to ca. 1.0 PV. These results translate to a prolonged economic lifespan of a fractured heterogeneous reservoir and a significant reduction in post-processing costs.

Adaptation to climate change in perennial cropping systems: Options, barriers and policy implications

Plantation crops are likely to be highly vulnerable to climate change because of their long economic life span, their typically non-irrigated cropping pattern and the inability to easily switch crops due to high upfront capital costs. Hence the sector requires appropriately designed adaptation options to cope with on-going climate change. Studies on climate adaptation in perennial cropping systems are rare relative to those on annual crops. Based on a cross-sectional survey of 50 tea estate managers representing all tea growing areas in Sri Lanka, this study analyses factors affecting choice of preferred adaptation options, barriers to adaptation and associated policy implications for tea production as an example of a perennial tree crop system. Current adaptation options identified are crop diversification, soil conservation, and shade tree establishment and management. All of these options are adopted in some situations and locations. All estate managers interviewed believe that climate change is happening and almost all are experiencing the negative impacts of climate change on tea production. Results from a multinomial logit analysis show that information on climate change, company size, tea growing elevation, and increases in temperature and rainfall are key factors influencing the preferred choice of adaptation option. Furthermore, results reveal that barriers such as a lack capital, inadequate access to near-term and medium-term climate knowledge, and poor governmental and institutional support may prevent estate managers from experimenting with new adaptation options. Policies should, therefore, be aimed at promoting new adaptation options through information exchange between a wide range of stakeholders, and integrating climate change adaptation with Sri Lanka’s sustainable developmental goals. Governmental and institutional support and involvement would be instrumental in facilitating adoption of adaptation options such as joint-production of tea with valuable timber crops.

Effect of rootstocks and soil management on growth and physiological parameters in new plantations of apple under replant conditions

Apple orchards planted in late sixties in Himanchal Pradesh and North Western Himalayan region have shown symptoms of declining productivity as these plants have completed their economic life span. Due to limited land and choice of crops for smaller micro climatic niches and incomparable economic equivalence of other fruits with apple, orchardists are compelled to replant at old apple orchard sites. Standardization of suitable agro-techniques to combat replant problem in apple for better field survival rate and productivity is required to sustain apple industry in the state. In the present study, there were 20 treatments comprising of four apple rootstocks i.e. seedling, M793, MM111 and M7 and five different soil management treatments i.e. control, soil fumigation, Plant growth promoting rhizobacteria (PGPR), biocontrol and combined soil fumigation + PGPR + Biocontrol with three replications. The pooled data over the years 2015 and 2016 revealed that M793 rootstock had the maximum growth, vigour, chlorophyll content and photosynthetic efficiency. Among the soil management treatments, the highest growth and vigour parameters, chlorophyll content and photosynthetic efficiency were recorded maximum in combined treatment. The interaction between rootstocks and treatments revealed that combinations of M793 and combined treatment resulted the maximum growth and vigour traits, chlorophyll content, rate of photosynthesis, transpiration rate, stomatal conductance, water use efficiency and minimum stomatal resistance compared to other rootstocks and treatment combinations under replant situations, which can be exploited for the management of replant problem in apple.

PREDICTION OF E-WASTE GENERATION BASED ON GREY MODEL (1,1) AND MANAGEMENT IN BOTSWANA

This paper seeks to evaluate the quantities of e-waste in Botswana from 2000-2019, with a view towards formulating an effective and sound e-waste management system. Due to a lack of complete historical records on e-waste quantity and quality, this was achieved by the Grey Model GM(1,1) forecasting method. Our estimations indicate that an average weight of about 293.18 tons of e-waste will be generated in 2019 in the country. Considering an economic lifespan of between 3 and 10 years, more e-waste is expected to be produced annually in the country. This paper also highlights key societal factors influencing successful implementation of a sound e-waste management system. These include the introduction of legislation dealing specifically with e-waste, establishment of formal take-back systems, integration of the informal recycling sector into the formal recycling sector, innovative technologies and investment on e-waste management activities. An effective management system of waste from this sector should involve consideration of the toxicity and value of some of the components and materials of electrical and electronic equipment (EEE) and the prevailing inappropriate disposal practices for such potentially toxic materials.

승강기 리모델링을 위한 최적 시기에 관한 연구

In 2016, there are 600,000 elevators installed in Korea. Of these, more than 30,000 elevators are newly installed or completely replaced each year because the percentage of old elevators exceeds 30%. However, the owner of the elevator often misses the optimal time due to the lack of expertise and data on how to replace or replace the old elevator. Also, the risk of safety accidents due to the aging of elevators is increased. Although the maintenance of the elevator is carried out monthly, the risk of a safety accident is increasing because the lowest cost is paid for troubleshooting and maintenance. For this reason, it is important to predict the life expectancy and replacement timing of the elevator, and to provide information so that the elevator can be replaced at the optimum time, in order to prevent accidents. Through the fault data of the elevator, Cumulative failure probability can be estimated by 'Kaplan-Meier' estimation method, 'Weibull' distribution analysis can be used to predict life expectancy. Age Replacement Method can determine the optimal time of economic life. The greater the preventive replacement rate, the less the risk of accidents and the longer the economic life span.