Investment Maintenance Research Articles

Effect of Visibility on Maintenance Investment and Consequent Performance of Urban Stormwater Control Measures

AbstractStudies on the performance of urban stormwater control measures (SCMs) mainly focus on hydrologic and biological factors. SCMs are located in an urban context and humans are part of this ec...

Early life adversity, reproductive history and breast cancer risk.

Background and objectivesIndividuals who experience early life adversity are at an increased risk for chronic disease later in life. Less is known about how early life factors are associated with cancer susceptibility. Here, we use a life history framework to test whether early life adversity increases the risk of breast cancer. We predict that early life adversity can shift investment in somatic maintenance and accelerate the timing of reproduction, which may mediate or interact with the risk of breast cancer.MethodologyWe use population-wide data from the Utah Population Database (UPDB) and Utah Cancer Registry, leading to 24 957 cases of women diagnosed with breast cancer spanning 20 years (1990–2010) and 124 785 age-matched controls. We generated a cumulative early life adversity summation score to evaluate the interaction (moderation) and mediation between early life adversity, reproductive history and their association with breast cancer risk.ResultsOur analyses led to three key findings: (i) more early life adversity, when considered as a main effect, accelerates the time to first birth and death, (ii) early age at first birth and high parity decreases the risk of breast cancer and (iii) we find no association between early adversity and breast cancer risk either as a main effect or in its interaction with reproductive history.Conclusion and implicationsEarly adversity elevates the risk of overall mortality through mechanisms other than breast cancer risk. This suggests early life factors can generate different effects on health. Future work should incorporate more complex view of life history patterns, including multiple life stages, when making predictions about cancer susceptibility.

Sperm Storage Costs Determine Survival and Immunocompetence in Newly Mated Queens of the Leaf-Cutting Ant Atta colombica

In the leaf-cutting ant Atta colombica, queens receive ejaculates from multiple males during one single mating event early in their lives. A queen’s fertility and fitness therefore depend on maximizing the number of sperm cells she can store and maintain inside her spermatheca. Previous studies implied significant physiological mating costs, either originating from energetic investments maximizing sperm survival, or from resolving sexual conflicts to terminate male-driven incapacitation of rival sperm via serine proteases found in seminal fluid. Here we conducted an artificial insemination experiment, which allowed us to distinguish between the effects of sperm and seminal fluid within the queen’s sexual tract on her survival and immunocompetence. We found significantly higher mortality in queens that we had inseminated with sperm, independently of whether seminal fluid was present or not. Additionally, after receiving sperm, heavier queens had a higher probability of survival compared to lightweight queens, and immunocompetence decreased disproportionally for queens that had lost weight during the experiment. These findings indicate that queens pay significant physiological costs for maintaining and storing sperm shortly after mating. On the other hand, the presence of seminal fluid within the queens’ sexual tract neither affected their survival nor their immunocompetence. This suggests that the energetic costs that queens incur shortly after mating are primarily due to investments in sperm maintenance and not costs of terminating conflicts between competing ejaculates. This outcome is consistent with the idea that sexually selected traits in social insects with permanent castes can evolve only when they do not affect survival or life-time fitness of queens in any significant way.

Experimental study on compressive strength of permeable concrete with shredded plastic fiber and plastic pellets

Water logging on highways and parking lots is a big concern in many projects, especially during the monsoon, because pavements and floors are generally impervious. This necessitates a significant investment in maintenance and storm water drainage systems, which may become clogged at peak overflow. Aside from that, there are a slew of other issues that occur as a result of the preceding. In such cases, it is critical to consider a cost-effective solution that aids in the resolution of all of the aforementioned issues. Permeable concrete is the best answer to the problem mentioned above. This paper outlines the many studies that have been conducted in order to meet the demand for permeable concrete by using plastic pellets and shredded plastics as additional materials in the production of permeable concrete.

Early adversity, adult lifestyle, and posttraumatic stress disorder in a military sample.

Early adversity is considered a major risk factor for adult posttraumatic stress disorder (PTSD). Simultaneously, however, early adversity is also known to contribute to psychological resilience, and, indeed, some high-adversity groups do not display elevated PTSD risk. We explored correlates of PTSD in the Study to Assess Risk and Resilience in Servicemembers military dataset to evaluate contrasting accounts of the relationship between early adversity and PTSD. The standard deficit model depicts ontogeny as inherently vulnerable to insult, such that early adversity yields a less robust adult phenotype. A complementary life history theory account holds that adverse early experiences cue a fast life history orientation that reduces investment in maintenance, yielding an adult phenotype less able to recover from trauma. An opposing life history theory account holds that early adversity cues expectations of an adverse adult environment, adaptively reducing reactivity to adverse events. We use principal component analysis to extract a latent variable representing several childhood experiences and multiple lifestyle factors that plausibly proxy life history orientation. After correcting for covariates, we find a strong positive influence of such proxies on PTSD risk, suggesting that early adversity may indeed increase risk for PTSD, and thus that either the standard deficit model, the reduced maintenance account or a combination are correct.

Private Sector Investment in Infrastructure in Sub-Saharan Africa Post-COVID-19: The Role of Law.

Sub-Saharan Africa (SSA) is the lowest income region of the world with a considerable number of low-income countries. The region is challenged by a massive infrastructure deficit. In recent years, the governments of the countries in the region have expressed the desire to bridge the huge gap in infrastructure assets through a partnership with the private sector using the public-private partnership model. However, the advent of the Coronavirus (COVID-19) pandemic which has resulted in unplanned public sector expenditure poses a new kind of hurdle to climb for states in the region. As such, there is a need for governments in SSA to create and sustain efficient opportunities for private sector investment in infrastructure procurement and maintenance. This article adopted the doctrinal legal research method as well as review of literature in the examination of the role of law in creating a healthy and sustainable business environment for private sector participation in infrastructure financing and operation in a post-COVID-19 era in the SSA region. The article recommends among others, the enactment of legislation to create an enabling environment for raising domestic capital for the purposes of private sector–led public infrastructure procurement as well as the implementation of strategies suited for developing economies to attain successful outcomes in private sector backed infrastructure procurement.

Defect management of hospital buildings

Healthcare organisations are increasingly recognising the need to improve building performance in order to improve health care delivery, profits, and to reduce penalties. Hospital maintenance organisations are under constant pressure to plan maintenance work due to a shortage of funds on account of huge catalogues of defects in hospital buildings. While investments in hospital building maintenance are increasing, the requirement to increase building performance and user satisfaction is also increasing. The nature of building faults and the factors that influence hospital building maintenance management in Malaysia were explored. Primary data were collected through structured interview techniques involving six hospital maintenance organisations. According to the results of a survey interview involving six hospitals, water seepage, cracks, peeling paint, broken ironmongery, pipe leakage, damaged plasterboard, and discoloured paint are all widespread in hospital structures, according to the results of a survey interview involving six private and public hospitals. The key aspects that determine the maintenance management practise of hospital buildings are user attitudes, misuse/abuse, weather, and bad maintenance practice. The data revealed that hospital building users are demanding improved building performance through enhanced maintenance management service delivery. Implicit in the findings of this research is the lack of effective maintenance organisations. It is necessary to reorganise the hospital's maintenance organisations. From an ontological standpoint, the main findings of this study are generalizable to other hospitals and building typologies in and outside of Malaysia.

Open for All: How Are Federal and Municipal Land Management Agencies Adapting to the COVID-19 Pandemic Alongside Increased Societal Recognition of Racial Injustice

In addition to impacts on human health and the economy, COVID-19 is changing the way humans interact with open space. Across urban to rural settings, public lands–including forests and parks – experienced increases and shifts in recreational use. At the same time, certain public lands have become protest spaces as part of the public uprisings around racial injustice throughout the country. Land managers are adapting in real-time to compound disturbances. In this study, we explore the role of the public land manager during this time across municipal and federal lands and an urban-rural gradient. We ask: How adaptable are public land managers and agencies in their recreation management, collaborative partnerships, and public engagement to social disturbances such as COVID-19 and the co-occurring crisis of systemic racial injustice brought to light by the BLM uprisings and protests? This paper applies qualitative data drawn from a sample of land managers across the northeastern United States. We explore management in terms of partnership arrangements, recreational and educational programs, and stakeholder engagement practices and refine an existing model of organizational resilience. The study finds abiding: reports of increased public lands usership; calls for investment in maintenance; and need for diversity, equity, and inclusion in both organizational settings and landscapes themselves; and the need for workforce capacity. We discover effective ways to respond to compound disturbances that include open and reflective communication, transforming organizational cultures, and transboundary partnerships that are valued as critical assets.

Integrating Scalable Genome Sequencing Into Microbiology Laboratories for Routine Antimicrobial Resistance Surveillance.

Antimicrobial resistance (AMR) is considered a global threat, and novel drug discovery needs to be complemented with systematic and standardized epidemiological surveillance. Surveillance data are currently generated using phenotypic characterization. However, due to poor scalability, this approach does little for true epidemiological investigations. There is a strong case for whole-genome sequencing (WGS) to enhance the phenotypic data. To establish global AMR surveillance using WGS, we developed a laboratory implementation approach that we applied within the NIHR Global Health Research Unit (GHRU) on Genomic Surveillance of Antimicrobial Resistance. In this paper, we outline the laboratory implementation at 4 units: Colombia, India, Nigeria, and the Philippines. The journey to embedding WGS capacity was split into 4 phases: Assessment, Assembly, Optimization, and Reassessment. We show that on-boarding WGS capabilities can greatly enhance the real-time processing power within regional and national AMR surveillance initiatives, despite the high initial investment in laboratory infrastructure and maintenance. Countries looking to introduce WGS as a surveillance tool could begin by sequencing select Global Antimicrobial Resistance Surveillance System (GLASS) priority pathogens that can demonstrate the standardization and impact genome sequencing has in tackling AMR.

Environmental perturbations and transitions between ecological and evolutionary equilibria: an eco-evolutionary feedback framework

I provide a general framework for linking ecology and evolution. I start from the fact that individuals require energy, trace molecules, water, and mates to survive and reproduce, and that phenotypic resource accrual traits determine an individual9s ability to detect and acquire these resources. Optimum resource accrual traits, and their values, are determined by the dynamics of resources, aspects of the environment that hinder resource detection and acquisition by imposing risks of mortality and reproductive failure, and the energetic costs of developing and maintaining the traits -- part of an individual9s energy budget. These budgets also describe how individuals utilize energy by partitioning it into maintenance, development and/or reproduction at each age and size, age and size at sexual maturity, and the size and number of offspring produced at each reproductive event. The optimum energy budget is consequently determined by the optimum life history strategy that describes how resources are utilized to maximize fitness by trading off investments in maintenance, development, and reproductive output at each age and size. The optimum life history in turn determines body size. An eco-evolutionary feedback loop occurs when resource accrual traits evolve to impact the quality and quantity of resources that individuals accrue, resulting in a new optimum life history strategy and energy budget required to deliver it, a change in body size, and altered population dynamics that, in turn, impact the resource base. These feedback loops can be complex, but can be studied by examining the eco-evolutionary journey of communities from one equilibrium state to another following a perturbation to the environment.

Telomerase activity in ecological studies: What are its consequences for individual physiology and is there evidence for effects and trade-offs in wild populations.

Increasing evidence at the cellular level is helping to provide proximate explanations for the balance between investment in growth, reproduction and somatic maintenance in wild populations. Studies of telomere dynamics have informed researchers about the loss and gain of telomere length both on a seasonal scale and across the lifespan of individuals. In addition, telomere length and telomere rate of loss seems to have evolved differently among taxonomic groups, and relate differently to organismal diversity of lifespan. So far, the mechanisms behind telomere maintenance remain elusive, although many studies have inferred a role for telomerase, an enzyme/RNA complex known to induce telomere elongation from laboratory studies. Exciting further work is also emerging that suggests telomerase (and/or its individual component parts) has a role in fitness that goes beyond the maintenance of telomere length. Here, we review the literature on telomerase biology and examine the evidence from ecological studies for the timing and extent of telomerase activation in relation to life history events associated with telomere maintenance. We suggest that the underlying mechanism is more complicated than originally anticipated, possibly involves several complimentary pathways, and is probably associated with high energetic costs. Potential pathways for future research are numerous and we outline what we see as the most promising prospects to expand our understanding of individual differences in immunity or reproduction efficiency.

Stochastic Economic Analysis of Investment Projects in Forest Restoration Involving Containerized Tree Seedlings in Brazil

Background: Experts in ecological restoration have discussed the cost reduction to make forest restoration financially feasible. This is very important in developing countries, such as Brazil, and for smallholder farmers; however, economic studies do not usually consider the uncertainties in their analysis. Therefore, this study aimed to analyze, under conditions of uncertainty, how tropical tree seedlings produced in polyethylene bags, polyethylene tubes, and biodegradable containers (Ellepot®) interfere with the costs of implementation and post-planting maintenance investment projects in a deforested tropical seasonal forest area in southern Brazil. Methods: We evaluated total costs, production costs, and equivalent annual uniform costs, and the probability distributions and estimated ranges of stochastic values were adjusted through Monte Carlo method simulation. Furthermore, the seedling survival rate was recorded over 12 months post-planting. Results: The costs with tree seedling acquisition and direct labor were the components that most impacted total costs in the three investment projects. The forest restoration investment project with tree seedlings produced in polyethylene bags was economically unfeasible in relation to other projects. Conclusions: The best economic alternative was observed in the investment project with tree seedlings produced in Ellepot®, which showed a survival rate >80% after one year and the lowest total cost, production cost, and equivalent uniform annual cost.

Three-dimensional modelling of slab-track systems based on dynamic experimental tests

The accurate computational modelling of railway systems is crucial for analysis and design, which allows for excellent and enduring performance of such systems. It is capable of providing the industry with data for improving speed, comfort, load capacity and reliability. Further, as accurate solutions serve as an aid to improve railway systems, they contribute to quality services, social welfare, cost effectiveness and sustainability. An important component of a railway system is the track, which, in general, requires high investments for construction and maintenance. This work develops calibrated three-dimensional (3D) Finite Element (FE) models for slab track systems which can be employed for analysis and design with great level of reliability. These models are developed based on full-scale dynamic tests performed under the application of loads which simulate the passage of high-speed trains. The components considered are the rails, rail pads, slab track, grout, Hydraulicaly Bonded Layer (HBL), Frost Protection Layer (FPL) and subgrade. The FE models are built and calibrated in order to reproduce the measured displacement and acceleration test results. Due to the uncertainties in some material properties, a parametric analysis is also performed to establish to which material characteristics of the system the model is more sensitive to. It has been found that the Young’s moduli for the FPL layer and subgrade are the most important parameters. Further, the stiffness properties of rail pads play a paramount role in the accuracy of the model.

Optimizing the Life Cycle of Physical Assets through an Integrated Life Cycle Assessment Method

The purpose of this study was to apply new methods of econometric models to the Life Cycle Assessment (LCA) of physical assets, by integrating investments such as maintenance, technology, sustainability, and technological upgrades, and to propose a means to evaluate the Life Cycle Investment (LCI), with emphasis on sustainability. Sustainability is a recurrent theme of existing studies and will be a concern in coming decades. As a result, equipment with a smaller environmental footprint is being continually developed. This paper presents a method to evaluate asset depreciation with an emphasis on the maintenance investment, technology depreciation, sustainability depreciation, and technological upgrade investment. To demonstrate the value added of the proposed model, it was compared with existing models that do not take the previously mentioned aspects into consideration. The econometric model is consistent with asset life cycle plans as part of the Strategic Asset Management Plan of the Asset Management System. It is clearly demonstrated that the proposed approach is new and the results are conclusive, as demonstrated by the presented models and their results. This research aims to introduce new methods that integrate the factors of technology upgrades and sustainability for the evaluation of assets’ LCA and replacement time. Despite the increase in investment in technology upgrades and sustainability, the results of the Integrated Life Cycle Assessment First Method (ILCAM1), which represents an improved approach for the analyzed data, show that the asset life is extended, thus increasing sustainability and promoting the circular economy. By comparison, the Integrated Life Cycle Investment Assessment Method (ILCIAM) shows improved results due to the investment in technology upgrades and sustainability. Therefore, this study presents an integrated approach that may offer a valid tool for decision makers.

Exposure to food insecurity increases energy storage and reduces somatic maintenance in European starlings (Sturnus vulgaris).

Birds exposed to food insecurity—defined as temporally variable access to food—respond adaptively by storing more energy. To do this, they may reduce energy allocation to other functions such as somatic maintenance and repair. To investigate this trade-off, we exposed juvenile European starlings (Sturnus vulgaris, n = 69) to 19 weeks of either uninterrupted food availability or a regime where food was unpredictably unavailable for a 5-h period on 5 days each week. Our measures of energy storage were mass and fat scores. Our measures of somatic maintenance were the growth rate of a plucked feather, and erythrocyte telomere length (TL), measured by analysis of the terminal restriction fragment. The insecure birds were heavier than the controls, by an amount that varied over time. They also had higher fat scores. We found no evidence that they consumed more food overall, though our food consumption data were incomplete. Plucked feathers regrew more slowly in the insecure birds. TL was reduced in the insecure birds, specifically, in the longer percentiles of the within-individual TL distribution. We conclude that increased energy storage in response to food insecurity is achieved at the expense of investment in somatic maintenance and repair.

Probabilities of mission success and system survival in multi-state systems with arbitrary structure

Many critical systems are designed with the rescue function to possibly survive the system in the event of the defined mission not being able to continue. Existing models have focused on binary-state systems with certain structures. Going beyond the state of the art in modeling the rescue possibility, this paper considers multi-state systems with arbitrary system structures and arbitrary element time-to-failure distributions. System elements have dynamic reliability and performance characteristics during the primary mission and the rescue procedure. A probabilistic approach is suggested for evaluating the mission success probability and system survival probability. The proposed approach is further extended for the element sensitivity analysis and optimal maintenance investment. The sensitivity analysis provides importance ranking of system elements with respect to their influence on the mission success or system survival, facilitating the determination of effective strategies to improve the mission success and system survival probabilities. The optimal maintenance investment problem is aimed at identifying the system element and its reliability improvement factor that minimize the expected losses cost. Two examples of wireless sensor networks and chemical reactor supply systems are analyzed to demonstrate the applications of the proposed method.

The Dynamics of Ports Reforms in Nigeria: Implications for Sustainable Ports Operations

Over the time Nigeria economy is largely public sector driven, in which the seaports were not left out: managed by Nigerian Port Authority (NP A). With the seaports under the autonomous of NPA were faced with strangulating problems ranging from inefficiency of it services rendered, insecurity of ships and cargo, lack of modern infrastructures, inefficiency of the NPA staff and excess bureaucracy and sharp practice (corporate) these factors make port tariff on import and export higher than they need to be, couple with the technology trend in maritime transport which required huge capital fund. The government call for ports reforms; a reform that will liberalized and deregulate the seaport by the use of concession contract, this mandate the NPA to transfer terminals operators while NPA concentrates to play the role of landlord oversight functions. The government went further to reform the import guidelines procedures and documentation requirement, changing it form Pre-shipment Inspection (PSI) to Destination Inspection (DI). The Seaport reforms which government introduced in 1996 eliminated the crippling delays in the clearance of import goods in the ports. This research study will examine the dynamics of port operations, the contribution of private operator in seaport operations, and services; technological development: considering the variable attached to seaport operations. Furthermore, this research analyze private sector capital investment in port and maintenance of infrastructures, superstructures and the contract of concession with other practicing nations, while from drawn questionnaire and secondary data the research will examine how and if Nigeria will benefit in the area of capacity building, physical development and if at all there is competition among the terminal operators considering there role in the concession regime. Finally, emphasis and comparison will be laid on cargo throughout, ship tum around, clearing procedures and port charges with the involvement of private participation. DOI: 10.7176/PPAR/11-7-01 Publication date: August 31 st 2021

ANALYSIS OF MEASURES TO REDUCE DEFECTS IN HOSPITAL BUILDINGS

Buildings are major components of hospital assets and substantial resources are invested in their design, construction, and maintenance. Although investments in hospital maintenance are increasing, instances have been recorded of dissatisfaction among the hospital building users with respect to extent of defects in the buildings. Defects in the building have tremendous impacts on user’s performance and satisfaction and on the hospitals’ profit margins. This research investigated the remedial actions to reduce the defects in the hospital buildings. Through a survey interview involving 6 hospitals, the results revealed that educating building users, providing training to maintenance operatives, conducting preventive maintenance, and creating awareness on the importance of building are the measures remedies to prevent defects. Furthermore, it is important to blend design and construction with the functional value of the buildings. This research provides fresh information on the maintenance of hospital buildings. Even though the data are collected in Malaysia, the results can be applied to hospital buildings outside of Malaysia.

Anticipating Future Behavior of an Industrial Press Using LSTM Networks

Predictive maintenance is very important in industrial plants to support decisions aiming to maximize maintenance investments and equipment’s availability. This paper presents predictive models based on long short-term memory neural networks, applied to a dataset of sensor readings. The aim is to forecast future equipment statuses based on data from an industrial paper press. The datasets contain data from a three-year period. Data are pre-processed and the neural networks are optimized to minimize prediction errors. The results show that it is possible to predict future behavior up to one month in advance with reasonable confidence. Based on these results, it is possible to anticipate and optimize maintenance decisions, as well as continue research to improve the reliability of the model.

Powder bed coating of bitumen with asphaltenes to obtain solid prills for midstream transportation

A continuous increase in the global demand for liquid fuels has led to increased reliance on unconventional sources of fossil fuels such as bitumen. The extraction, midstream transportation, and ultimate processing of heavy oils presents a distinctive set of challenges. For example, the high viscosity of bitumen poses a challenge to its transportation through conventional transportation systems such as pipelines. Conventional approaches to address the challenging rheological properties of bitumen involve dilution of bitumen with natural gas condensates, addition of surfactants, ultrasonic heating, thermal jacketing of pipelines, and high pump pressures. These solutions require considerable investments in infrastructure, frequent inspection and maintenance, and pose a risk of spillage to vulnerable environments. As such, much interest has focused on the design of solid-state transportation methodologies. In this article, we propose a viable and safe transportation alternative wherein bitumen is reconfigured such that the droplets of lighter fractions of bitumen (saturates, aromatics, resins) are encapsulated within conformal shells of asphaltenes. The tendency of asphaltenes to aggregate has been exploited to obtain cross-linked shells without requiring the use of extraneous chemical additives. Thermally mediated crosslinking of the asphaltenes shells allow the microcapsules to hold their form and result in the emergence of mechanical strength. The stress-withstanding abilities and velocity impact resistance of these microcapsules have been studied to establish their viability for industrial use, and demonstrate that microcapsules with diameters of ca. 1.25 mm can withstand stresses as high as 576 kN/m2. Since the bitumen microcapsules have been formulated by simply reconfiguring the intrinsic components of bitumen, they can be readily fluidized by mechanical means to recover the encapsulated lighter fractions. The solid microcapsules demonstrate the viability of solid-state transportation of bitumen via roadways or marine tankers, thereby mitigating a primary impediment to the utilization of viscous oils.