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As manufacturers continue to provide new and unique products and services for their customers, we argue that warranty menus with differentiated options are an often-overlooked unique selling point. Meanwhile, there is a huge swathe of customers who own durable products which are still in use even after the expiration of a warranty. It is in this area that we develop a research perspective which urges customers to consider warranty plans and post-warranty maintenance strategies simultaneously when making a purchasing decision. In this paper, through the lens of a consumer, we propose an integrated model of warranty and post-warranty maintenance under a flexible renewable warranty. This model takes into account repair limits and multiple failure types with time-varying probabilities. As part of this, a new post-warranty maintenance strategy is designed, in which the repair time-based corrective replacement and the age-based preventive replacement are combined. The life cycle cost rate of the product is minimised by a synthetic decision-making about the consumer's warranty purchase and post-warranty maintenance strategy. Numerical studies show that there exists a joint optimal solution, which can help the customer to develop an optimal overall warranty-maintenance strategy under the warranty menu with minimised cost rate. An integrated model of warranty and post-warranty maintenance is developed. The warranty product has minor and catastrophic failures with time-varying probabilities. A flexible renewable warranty is considered for the consumer. A post-warranty maintenance strategy with the repair time limit is proposed. The optimal warranty-maintenance strategy is derived to minimise the Life cycle cost rate. [ABSTRACT FROM AUTHOR]

Hemp-based construction materials have increasingly captured attention in recent years as viable alternatives to carbon-intensive materials. A benefit of using hemp (Cannabis sativa L) in construction is its ability to sequester carbon dioxide during plant growth, thereby providing the potential to create carbon-negative materials. However, hemp production can contribute to other environmental impacts such as acidification and eutrophication. Additionally, hemp-based materials usually involve higher costs compared to traditional materials. This study presented an application of an eco-efficiency framework to explore options for improving the environmental and economic performance of non-load-bearing hemp-based construction boards at the production stage in Australia. The study integrated environmental life cycle assessment, multi-criteria analysis, environmental mitigation strategies, life cycle costing and eco-efficiency portfolio analysis in order to identify eco-efficiency improvement opportunities for non-structural hemp-based construction boards and to compare them with conventional alternatives. The analysis showed that the use of solar electricity during the post-farm stage of hemp-based board production can reduce their environmental impact by 26 per cent and production costs by 0.4 per cent. The proposed framework can assist hemp growers and hemp-based composite manufacturers in Australia in developing cost-effective environmental mitigation strategies to assist sustainability in the construction sector. [ABSTRACT FROM AUTHOR]

Conceptual pre-estimation of road tunnel costs is a vital yet challenging process during feasibility studies due to the prevailing underground uncertainties and risks. Most existing cost estimation approaches are deterministic, probabilistic methods are limited to a single cost examination. This paper introduces a probabilistic model for pre-estimating road tunnels life-cycle costs. It aims to capture their inherent uncertainty holistically, thus enabling more reliable decision-making at a project's early stages. The proposed model is developed in three steps: multiple regression analysis, fitting distribution, and Monte-Carlo simulation. The first step unveils the correlations between independent and dependent variables, while the other two steps return the probabilistic descriptions of cost drivers and life-cycle costs. Civil engineering, electromechanical works costs, energy consumption, and operation & maintenance costs are determined as the model's output variables. A real-world database of 32 dual-bore road tunnels with a total length of 55 km is used to develop probability distributions within reasonable confidence intervals and a sensitivity analysis was performed utilizing tornado charts. The results can assist public authorities and managers in estimating the probability of a specific life-cycle cost and making appropriate decisions in accordance with their risk tolerance. [ABSTRACT FROM AUTHOR]

This research investigates the decarbonization of India's electricity grid using ammonia in power plants. It focuses on ammonia produced in Western Australia and transported to India, co-fired with high rank coal, and compared with power plants utilizing carbon capture and sequestration (CCS). The study assesses the overall costs and the life cycle greenhouse gas (LC GHG) emissions for both new plants and retrofits. For 20% gray, blue, and green ammonia, the levelized cost of electricity is 86, 89, 125 $/MWh, with corresponding LC GHG emissions of 1,234, 1,079, and 1,062 kg CO2e/MWh. Co-firing with green ammonia, though more expensive than blue ammonia, yields lower CO2 emissions. Conversely, reducing the same amount of direct CO2 emission via CCS costs $84/MWh and a LC GHG emission of 1,227 kg CO2e/MWh. While CCS is cheaper, it results in higher LC GHG. There is a trade-off between cost and emissions across the strategies. Under scenarios with low capacity factors or reduced ammonia production costs, coal-ammonia co-firing could become more economical and greener than the CCS. This study provides quantitative insights for policymakers and project developers. However, it is crucial for decision-makers to consider several factors: (1) the potential impact of social resistance to CCS; (2) the time required for large-scale commercialization of CCS technology, which is expected to be significantly longer than the implementation time for a coal-ammonia co-firing decarbonization strategy; (3) the potential of either CCS or ammonia-coal co-firing strategy to enhance India's electricity mix, thus contributing to energy security. [ABSTRACT FROM AUTHOR]

Different approaches continue to be used to evaluate the environmental and financial impacts of road pavements throughout their life cycle. This paper aims to provide a methodological review of published studies of asphalt pavement Life Cycle Assessment (LCA) and Life Cycle Cost Analysis (LCCA) and make recommendations for future studies. The results indicate that LCA studies limitations are related to functional units (FUs), chosen life cycle phases, maintenance schedules decision, and uncertainty. In comparison, the use of LCCA is limited to assessing maintenance strategies, is largely focused on agency cost, and usually ignores the possibility of current or future uncertainty. Accordingly, it is recommended to incorporate both LCA and LCCA, define a standard set of FUs, include the complete life cycle (including for new materials), consider pavement performance predictions in determining realistic maintenance schedules, include both short- and long-term costs and environmental impacts, and emphasise on probabilistic analysis of uncertainty. [ABSTRACT FROM AUTHOR]

The comprehensive trade-off among reliability, maintainability, availability and life cycle cost should be solved in the overall design of warship equipment. Maintainability analysis and comprehensive trade-off of naval ships equipment based on the PROMETHEE method are proposed. In the method, the evaluation model of alternatives set is formed through the analysis of maintainability-related factors, the determination of target attribute and related attribute weight of alternatives, the selection of attribute priority function and threshold. And carry out calculation and analysis, form the ranking of alternatives. Combined with the calculation and analysis of specific examples, the evaluation results of six groups of alternatives are obtained, and the optimal scheme is determined. The research provides an effective theoretical basis for maintainability analysis and comprehensive trade-off of system overall design. It guides the implementation and decision of the project. It's suitable for the comprehensive trade-off problem of multi-objective relationships to find the optimal solution. [ABSTRACT FROM AUTHOR]

This study investigates the cooling, heating and power (CHP) systems integration with the carbon capture and storage (CCS) for different LNG carriers. Different integration levels of conventional waste heat recovery, boil-off natural gas (BO-NG) reliquefaction, CO2 capture and liquefaction, and ORC systems are modelled and simulated using Aspen HYSYS. Thermoeconomic optimisation is also carried out using Genetic algorithm method. Results demonstrate that using CCS system is more cost-effective than paying European Union carbon tax for LNG carriers. Integrating the BO-NG and CO2 liquefaction cycles could reduce the total life cycle cost of the CCS system up to 17%. Optimised results show that selecting working pressure is very critical for the liquefaction of BO-NG and CO2. CHP system using ORC reduces the energy penalty of the CCS system, however, it increases the total life cycle cost of the system due to its initial cost and relatively low exergy efficiency. [ABSTRACT FROM AUTHOR]

"Climate Resilient Urban Areas: Governance, Design, and Development in Coastal Delta Cities" edited by Rutger de Graaf-van Dinther is a comprehensive exploration of urban planning's response to climate change challenges, focusing on coastal delta cities. The book emphasizes the role of city planners and policymakers in developing global resilience strategies beyond traditional approaches. With contributions from 26 experts, the book offers innovative techniques and perspectives for creating resilient urban landscapes, reevaluating the concept of resilience in the face of global climate dynamics. The chapters provide practical insights and case studies, highlighting the importance of context-specific approaches and innovative governance in addressing climate change challenges in urban settings." [Extracted from the article]

Recent studies demonstrated that high-frequency earthquakes have the most effect on the economic losses during seismic events. However, code-based seismic design criteria mainly aim to provide the occupants' life safety. In this regard, code-compliant structures may result in significant economic losses during their life span. These damages contribute to the higher repair costs and lengthy functional disruptions of these structures. Improving the seismic behaviour of the structures by control devices could be one of the most efficient solutions. On this subject, applying fluid viscous dampers (FVDs) is an economical and reliable method. Optimizing the properties of these devices contributes to more efficient seismic behaviour of the structures. In this study, the key design parameters of viscous dampers, including damping coefficient and velocity exponent, are considered as optimization variables to achieve minimum life cycle cost (LCC) using the genetic algorithm (GA). To investigate the efficiency of the proposed approach, four-, eight- and twelve-story structures in high-seismic regions are investigated to consider different assumptions. The Endurance Time method (ETM) is adopted to conduct nonlinear analysis due to its high computational cost-efficiency and reliability. The results show that the nonlinear viscous dampers would decrease the total seismic loss of the structures by up to 40% in comparison with linear dampers. The optimal amount of velocity exponent is also obtained as a function of variation with the height and seismic region of the structures. [ABSTRACT FROM AUTHOR]

Increasing greenhouse gas emissions from the conventional fleet of diesel buses has made Canadian transit agencies explore low-emission alternative fuels. Despite electric buses showing great potential to reduce emissions during their operational phase, the transformation from diesel buses to electric buses would require in-depth analysis pertaining to their economic and social implications. Published literature highlights the importance of developing a comprehensive framework that considers multiple decision parameters over a life cycle perspective for analyzing different fuel options to replace the existing fleet of diesel buses. This paper assesses the triple-bottom-line sustainability of diesel and electric buses in different regions of Canada. Moreover, a framework is proposed to incorporate multiple decision criteria (life cycle environmental, economic, and social impacts) over different perspectives to make the best decisions for transitioning the diesel bus fleet. The results showed that the environmental performance of electric buses highly depended on the electricity grid mix. Despite diesel buses having a low cost of production compared to electric buses, most provinces showed a low life cycle operational cost for electric buses. Electric buses' life cycle social impacts are high during their production stage, whereas diesel buses have the highest social impacts during their operational phase. Overall, electric buses have a high sustainability performance in all provinces and territories in Canada except Nunavut. The proposed framework and findings can aid policymakers and planners in implementing electric buses for public transit systems in Canada and beyond. [ABSTRACT FROM AUTHOR]

Over the last decade, restructuring of railway systems has resulted in infrastructure management assets demanding increased performance and reliability while adopting budget limits and reduced time available for maintenance. In fact, the current routine and major programmed maintenances are such capital-intensive activities that transport operating companies always attempt to optimise the operational procedures and related assets' performances towards minimising the costs. Characteristically, the use of macro synthetic fibre reinforcement is proposed to improve the structural performances and service life of the sleeper component. Accordingly, this study addresses the economic feasibility of implementing macro synthetic fibre reinforced concrete (MSFRC) as an alternative material for railway sleeper applications. Through a life cycle costing (LCC) approach, the study evaluates the impact of different asset phases such as acquisition, operation and maintenance, and end-of-life towards a cost comparison of MSFRC with conventional sleeper materials. Hence, the most financially viable option is identified, although key economic parameters are varied to simulate future market values. [ABSTRACT FROM AUTHOR]

In this paper, the optimal maintenance strategy for the warranty product subject to multiple failure modes and repair time limit is studied from the customer's perspective. When the product fails, a minimal repair based on the failure type is conducted. If the product can not be repaired within a given time limit, it will be replaced with a new one by the manufacturer during the warranty period. Different from the traditional renewing warranty policy, a geometric warranty policy is adopted in this work, under which once the warranty product is replaced; the length of warranty period is geometrically renewed. After the warranty expires, the product undergoes preventive maintenance (PM) periodically and the PM effect is modeled by reducing the virtual age of different failure modes by different degree. The objective is to determine the optimal interval time for PM and the optimal number of PMs by minimizing the expected life cycle cost rate of product. The existence and uniqueness of the optimal PM policy are proved theoretically, and the optimal bivariate policy can be obtained by using a recursive seeking algorithm. Numerical examples illustrate the effectiveness of geometric warranty policy and the proposed PM model. [ABSTRACT FROM AUTHOR]

This study evaluated the impact of using different contents and sources of Reclaimed Asphalt Pavement (RAP) on the bottom-up fatigue cracking of asphalt mixtures and the return on investment (ROI). Two RAP sources were used that primarily provided a significant difference in RAP binder Performance Grade (PG): Source A was a PG 76-22 while Source B was a PG 94-10. Bottom-up fatigue cracking was predicted using Level 1 of the AASHTOWare Pavement Mechanistic-Empirical Design (PMED) software. The ROI was then evaluated using FHWA RealCost. To increase the accuracies of the predictions, volumetric properties and blended binder properties were calculated based on the amount of RAP binder that actively blended with the virgin binder. The accuracies were also increased by determining the AASHTOWare PMED fatigue strength coefficients, $k_{\,f1}$ k f 1 , $k_{\,f2}$ k f 2 , and $k_{\,f3}$ k f 3 , using flexural bending beam fatigue tests rather than using the global defaults provided by this software. In conclusion, the ROI of the six RAP mixtures based on bottom-up fatigue cracking was found to be affected by both RAP content and RAP source, and because of the effect of RAP source, it could not be generalised that using either a higher or lower RAP content will always provide a higher ROI. [ABSTRACT FROM AUTHOR]

In this research, a methodology was developed to optimize the design of Warm Mix Asphalt (WMA) with the inclusion of three recycled materials as partial replacement of natural aggregates (NAs), namely Crumb Rubber (CR), Reclaimed Asphalt Pavement (RAP), and Recycled Concrete Aggregate (RCA). The methodological proposal is composed of 4 sections denominated: (I) environmental module, (II) economic module, (III) decision-support module, and (IV) results report module. Initially, a Life Cycle Assessment (LCA) is carried out to quantify the environmental impacts associated with WMA production. Similarly, in the second module, a Life Cycle Costing (LCC) is performed to estimate the financial investment required by the process under evaluation. Meanwhile, a computational model based on genetic algorithms (GAs) is created in the decision-support module to execute multi-objective optimization (minimization of costs and contaminating potential). In the last module, the more accurate WMA designs are presented employing a Pareto front, ternary plot, composition pie chart, and statistical analysis of the influence of the CR, RAP, and RCA on the validation criteria. This study concludes that even under long hauling distances and huge prices, it is possible to design WMA with CR, RAP, and/or RCA additions that form sustainability benefits compared to conventional WMA. [ABSTRACT FROM AUTHOR]

As people put forward higher demand for the effect and quality of building interior decoration, the attention to building energy-saving materials has become higher and higher. In recent years, there have been many researches on green building energy-saving technology, green building evaluation and other aspects, but there are relatively few researches on applying the concept of full life cycle cost to the performance analysis of new materials for building energy conservation and environmental protection. Considering the economic performance of buildings will help to save resources in the construction industry and reduce energy consumption. The so-called full life cycle optimization of energy-saving design of green buildings is to take the concept of full life cycle optimization as the most reference, fully coordinate all elements in the portfolio project, and ensure that the full life cycle cost of the building can be greatly reduced. To realize the energy-saving optimization of green buildings, it is necessary to ensure that it runs through the whole life cycle of the building, fully combine the life cycle cost with the building function, and systematically do the optimization work. The performance analysis model of building decoration energy-saving and environmental protection new materials based on the whole life cycle proposed in this paper can be used to analyse the various properties of various new materials. The experimental results show that the maximum error of the test results is 9.6%, the minimum error is 1.3%, and the average error is only 6.43%. This shows that the model built in this paper is reliable, and the calculated results are in good agreement with the experimental results, which can be used to analyse the performance of new building decoration energy-saving and environmental protection materials. The ideas and methods of solving the model established in this paper have important guiding significance, and can be used as a powerful reference tool for studying other solving methods. [ABSTRACT FROM AUTHOR]

Aluminum dross (AD) has become a severe problem for the environment and public health due to the great prosperity of the aluminum industry because it contains Al, AlN, Al4C3, fluoride salts, and various metal cations. In this review, the source and characterization of AD are introduced, and the differences between primary aluminum dross (PAD) and secondary aluminum dross (SAD) are analyzed. Then, the harmless treatment and utilization of AD are studied. Relative to the mature PAD recycling industry, the treatment of SAD is still in the small-scale experimental stage. The pyrometallurgical and hydrometallurgical routes are discussed as SAD processing methods, and the removal rate of hazardous content of SAD can reach 90%. Based on the high removal rate, high-purity Al, Al2O3, and other products can be prepared from SAD. Certain products, such as foaming materials, refractory materials, admixtures, and aluminum hydroxide gel material can be prepared by SAD. Finally, the economic and environmental values of the treatment and utilization of SAD are discussed. The environmental and economic assessment of SAD treatment behaves well in both life cycle assessment and life cycle cost calculations. A comprehensive display of SAD lifecycle treatment may promote the sustainable development of the aluminum industry. [ABSTRACT FROM AUTHOR]

Recent studies showed that while code-compliant structures can generally protect the safety of the occupants, they may exhibit extensive damages during strong earthquake events. On the other hand, structures are generally designed to satisfy the seismic code requirements with the least initial cost regardless of their life cycle cost. In recent years, value-based design has been considered as an effective alternative for code-based design procedures. In this method, as well as the initial cost of the structure, a comprehensive consequence modeling is performed in the design process. In this paper, for the first time, a value-based design optimization method is developed for seismic enhancement of existing RBS steel frames using nonlinear viscous dampers. The efficiency of the method is demonstrated through 4-, 8-, and 12-story frames designed for low, medium, and high earthquake intensity levels, while the life cycle costs are evaluated using FEMA P-58. A time-based approach is carried out to consider different earthquake events and their corresponding probability of occurrence in a specific range of intensities. For dynamic analysis of the structures, the Endurance Time (ET) method is adopted to significantly reduce the computational costs while providing accurate results. The Genetic Algorithm (GA) is then used to optimize the damping coefficient of the viscous dampers for minimum life cycle cost. The results, in general, indicate the efficiency of the proposed method in increasing the total economic value of the studied structures with the least additional cost. It is shown that shorter structures and those designed in high-seismic risk regions benefit more from using optimized viscous dampers, leading to up to 42% lower life cycle costs. The results of this study should prove useful in more efficient strengthening design of existing steel frames. [ABSTRACT FROM AUTHOR]

The fatigue safety assessment of critical details in steel bridges is dominated by several uncertainties mainly related to load modelling. The use of integrated weigh-in-motion (WIM) systems in roadway bridges allows to collect all the necessary information for tracking actual traffic conditions. Based on WIM data, the uncertainty associated to the evaluation of the probability of fatigue failure is reduced, allowing the optimal scheduling of repair and maintenance activities and thus improving safety and economic savings. The paper presents a methodology for estimating fatigue life cycle cost (LCC) of roadway bridges equipped with a WIM system that considers uncertainties in measurement and modelling errors. The procedure allows the quantification of the economic gain enabled by WIM systems, useful in assessing the cost/accuracy trade-off for a given WIM system. It is found that the continuous use of a WIM system may improve the rate of decrease of the structural reliability index, compared with temporally limited use of WIM data. The periodic update of the reliability index and of the probability of failure based on WIM measurements results in a rather accurate estimation of the fatigue life cycle cost, which is crucial in identifying the payback time of the WIM system. [ABSTRACT FROM AUTHOR]

The International Maritime Organization proposes several strategies to eliminate the adverse effects of ship emissions. The most important is finding alternative fuels, such as hydrogen. The current paper aims to compare diesel and renewable hydrogen-powered ships using Life Cycle Assessment (LCA) and Life Cycle Cost Assessment (LCCA). As a case study, three different ships sailing in the Red Sea area are investigated. The environmental outcomes are presented in terms of global warming potential (GWP), photochemical potential, eutrophication potential, particulate matter and acidification potential. Producing hydrogen fuel onboard ships will increase the total carbon footprint by 10%–28% higher than the currently used diesel fuels. Economically, the cost-effective target will be achieved at the cost of hydrogen production by electrolysis below 5.15$/kg. [ABSTRACT FROM AUTHOR]

Insulation performance and buried depth of heating pipelines are the vital factors affecting the energy loss of directly buried heating pipelines. This study considers the thermo-economic assessment of insulation of directly buried heating pipelines for district heating. The optimal insulation thickness, energy-saving effect, and payback period of district heating pipelines with five nominal pipe diameters, four fuel types, four kinds of insulation materials, and four buried depths are calculated. A numerical code is developed based on Life Cycle Cost Analysis and is validated via comparing with results in the open literature. Three representative cities of Xi'an, Shenyang, and Harbin subjected to three different climatic zones in China are explored. The highest values of optimum insulation thickness are 176, 153, and 121 mm in Harbin, Shenyang, and Xi'an, respectively, which are reached using oil as fuel, rock wool as insulation material, nominal pipe diameter 500 mm, and buried depth 1 m. A sensitivity analysis is performed to indicate how much the optimum insulation thickness and payback period are sensitive to the changes of insulation, fuel, and buried depth. The results show that insulation and fuel have a greater influence on the optimum insulation and payback period than the buried depth. [ABSTRACT FROM AUTHOR]

Extreme precipitation from climate change may strain many existing stormwater systems. While studies have evaluated such effects on stormwater infrastructure, other sources of uncertainty not yet explored should also be considered. This paper presents an analysis of adaptation costs for new stormwater infrastructure to mitigate increases in design storm precipitation depth with climate change, including how economic and managerial uncertainty related to life cycle unit costs and knowledge of existing infrastructure affect costs. For case study areas in California, we quantify adaptation costs for new green infrastructure capacity by evaluating future design storms. Results indicate that design storm depths increase by an average of 28%, but lack of knowledge of the condition of existing infrastructure and life cycle unit costs result in wide cost ranges. The findings illustrate how climate change planning for stormwater should also consider economic and managerial uncertainty when estimating long-term adaptation costs. [ABSTRACT FROM AUTHOR]

The life cycle cost (LCC) design method tries to improve conventional design practices with different costs, such as risk costs, over the life cycle of the structure in the design procedure. The present study introduces a modified life cycle cost (MLCC) approach for the design of excavations. Some modifications proposed in the typical LCC design method include considering the effect of risk aversion/seeking of decision-makers in the main LCC formula by a risk-seeking factor and taking in the effect of risk exposure time on risk cost by a risk duration as an impact factor. The risk-seeking factor is obtained by identifying the risky behaviour of decision-makers based on the expected utility theory. The risk duration impact factor is evaluated by analysing statistical information about high-risk excavations versus their lifetime. The novel MLCC design method is evaluated in real deep urban excavation projects and the method is applicable for design and yields sensible outputs. [ABSTRACT FROM AUTHOR]

The maritime transport sector is nowadays an object of interest for the scientific community and shipping companies due to its embodied environmental and economic impacts. In this context, the Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) methods can provide support in obtaining useful information through a detailed analysis of both the environmental and economic performances related to the whole life cycle of maritime means of transport. Based on this, the scope of this study is to provide a comprehensive literature review focused on the analysis of scientific articles in which the environmental and economic impacts of maritime means of transport have been assessed using the LCA and LCC methods. In particular, this study analyses 77 scientific articles in which the above-mentioned methods, as well as integrated approaches, have been applied. The analysis is performed using three review methods: bibliometric, network, and systematic analysis. The results outline the state of the art connected to the research area, as well as identifying the main scientific evidence and the availability of life cycle inventory data. Furthermore, methodological and practical issues are discussed through a critical analysis. This article is a revised and expanded version of a paper entitled "Assessing maritime transport through LCA and LCC: a literature review" presented at "IX Convegno dell'Associazione Rete Italiana di LCA", Cortina d'Ampezzo (Italy), 9-11th December 2020. [ABSTRACT FROM AUTHOR]

This study investigated the use of soil to create a substitute textile material in Thailand. It aims to maximise the utilisation of natural resources in response to climate change, thus promoting the concept of living in harmony with nature. A bio-fibre was synthesised from soil bacteria, ensuring that the whole production cycle generated no waste. To highlight the idea of the connection to life cycles, the design incorporated amplituhedrons, patterns of scattered quantum particles, representing the dynamics of cells, which often symbolise the smallest units of life. The final material contained melanin pigments similar to human skin tones, with hues comparable to those of people from Thailand. The proposed technology has applications in fashion design, where it can enhance the aesthetics and self-esteem of individuals. Further, this research can help advance Thailand's national sustainable development, driving creativity through scientific innovation. [ABSTRACT FROM AUTHOR]

This document discusses the challenges and advancements in the design, control, and application of unmanned surface and underwater vehicles (USVs and UUVs). These vehicles are used for tasks in hazardous environments, such as underwater missions. The challenges include uncertain models, nonlinear dynamics, navigation, control, communication, energy efficiency, and power management. The document also provides summaries of six research papers that explore topics such as microgrid systems, underwater target tracking, object detection for search and rescue operations, logic gates in digital circuits, and maintainability analysis of naval ships equipment. The authors express gratitude to the contributors and reviewers for their valuable contributions. [Extracted from the article]

Today, energy management systems are usually assessed as key to sustainable development goals. One of the best criteria for energy management systems in construction projects is Life Cycle Energy Analysis (LCEA). This research is a quantitative-qualitative study based on a Multi-Criteria Decision-Making (MCDM) model. This research involves four stages: library study, statistical survey, descriptive study, and case study. The review of previous studies showed that the LCEA and MCDM alone could not provide a comprehensive energy consumption management assessment model, due to inherent uncertainty and the existence of various analysis parameters; however, when are used in an integrated framework; the LCEA & MCDM hybrid approach serves as the best instruments to assess energy management systems. This research has proposed a newly developed hybrid multi-objective mathematical decision-making model to select appropriate and optimum options for all building shell components to optimize and manage the Cost and Energy of the Building Life Cycle. The life cycle energy analysis of an educational building in a case study showed that optimization using the proposed model saves about 16% of energy during the lifetime of the building. In addition, the investment payback period for this optimization is less than seven months in the first year of operation. [ABSTRACT FROM AUTHOR]

Investigating the economic consequences of the natural hazards on the infrastructures is a crucial task in any risk-based decision-making process. Life-cycle cost (LCC) analysis is an important tool in both design (to choose the most economic configuration) and analysis (to estimate the future cost of ownership) stages. The pile-supported wharves, as one of the main parts in a marine harbor system, may experience significant deterioration (i.e. strength reduction) and seismic shaking during their life time. In this paper, damage cost in multiple limit states of a deteriorated pile-supported wharf due to chloride corrosion is calculated. A precise finite element model is developed to account for structural aging and the simultaneous seismic shaking. Aging-dependent seismic fragility functions are first developed using incremental dynamic analysis. Next, the LCC analysis is conducted considering the crane damage, as well as, inspection and maintenance costs. The results are calculated for three seismic hazard levels. The findings confirm significance of corrosion on LCC of pile-supported wharf. It is observed that corrosion may increase the LCC of the structure and system (i.e. structure and cranes) by 15% and 8%, respectively. Finally, a set of analytical formulations are proposed for performance index as a function of age, damage state, and seismic hazard level. [ABSTRACT FROM AUTHOR]

High-performance systems are a prerequisite for profitable borehole thermal-energy storage. This paper presents performance measures for a system operating at a seasonal performance factor of 4.5 and evaluates the life-cycle costs of the actual and alternative system configurations. Compared to systems using dry cooling and electric or district heating the as-built system represents a profitable investment with internal rates of return of respectively 4.9% and 5.9% over a 50-year life cycle. Consequently, ambient-temperature borehole thermal-energy storage is economically competitive in North-European climates at current prices. [ABSTRACT FROM AUTHOR]

The current need to diversify the global energy matrix implies introducing renewable energy sources and evaluating commercially available solutions. This study assesses a trigeneration system from thermoeconomic and environmental viewpoints, employing the Theory of Exergy Cost and Life Cycle Assessment. The location of the theoretical study case is the state of Pernambuco, Northeast Brazil. The trigeneration system operates on biogas and is comprised of four subsystems: biogas purification, molted carbon fuel cell, combined cycle, and absorption refrigeration system. The energy services produced are electricity, heat (hot water), and cooling. The results of the thermoeconomic analysis revealed that the energy system requires an electricity tariff of at least US$ 106.76/MWh to generate revenue due to the high costs associated with the purchase of biogas and capital costs of the equipment for biogas purification and fuel cell. The life cycle assessment identified that the biogas purification step presented the highest environmental impacts due to the material composition of the absorption and regeneration columns, which is interesting as this is the most critical step of the process. LCA results indicate that although methane is a vital energy vector for energy transition, further studies are required on the technical and environmental aspects of its use in energy systems. [ABSTRACT FROM AUTHOR]

Water distribution systems (WDSs) are designed to supply water to consumers. Previously, the performance of WDSs was assessed based on the hydraulics, i.e., delivering water with sufficent quantity and good quality under the desired pressure. However, the recent sustainability paradigm has been widely recognized in engineering projects, leading water stakeholders to evaluate WDSs' performance not only in terms of hydraulics but also considering the environmental and economic impacts. This research proposes an approach to evaluating the sustainability of WDSs at the design stage by applying a life cycle thinking approach. The proposed approach was demonstrated by selecting a small WDS located in the City of Kelowna, Canada as a case study. Twelve alternative designs were created by varying WDS design variables such as pipe diameters, pipe materials, etc. The selected design scenario has 2.5% less CO2 emissions and 12.6% lower cost compared to the baseline design. The developed approach can be applied to WDS having different characteristics to identify conditions, design parameters, and infrastructure components having less environmental and economic impacts. [ABSTRACT FROM AUTHOR]

Flooded streets and homes, polluted surface waters, degraded aquatic habitats, stressed aquifers, and expensive drainage infrastructures are evidence that Canada's current approach to stormwater management requires rethinking. To address these challenges, the authors developed an integrated community-level urban stormwater decision support framework. The framework assesses low impact development infrastructure, traditional stormwater infrastructure, and community-level stormwater reuse schemes to better understand the interactions between various water resources in the context of various stormwater management strategies. The framework also incorporates stochastic variation in natural processes to predict a community's water footprint using the One Water Approach. A climate change sensitivity analysis is also incorporated to test proposed stormwater systems for resiliency to climate change. Fuzzy clustering analysis was then performed to identify the most appropriate stormwater management strategy. A case study demonstration of the framework was performed for a hypothetical 80-hectare mixed-use urban community in Kelowna, British Columbia. [ABSTRACT FROM AUTHOR]

This study aims to assess the comprehensive energy, environmental and economic performance of a retrofit zero energy building (ZEB). Three life cycle assessments were conducted: life cycle energy (LCE), life cycle carbon emissions (LCCE) and life cycle cost (LCC). Actual building construction cost data and energy use data were used in the assessments. The analysis results indicated that during the whole building life span, the operational life stage (B6) was a major contributor to LCE (82%) and LCCE (77%), but not to LCC (18%). Within the life cycle embodied carbon (LCEC), A3 was the life stage with the highest contribution (56%), which is mainly related to the manufacturing of building assemblies. This case study provides new empirical evidence of ZEB performance in the United States. The findings suggest that to achieve the carbon neutrality goal, current ZEB certifications or designations are not adequate to measure actual building performance. A further reduction of operational energy, in addition to reducing the embodied carbon released during manufacturing, should be the focus. [ABSTRACT FROM AUTHOR]

The overall performance of the composite insulation external walls (CIEW) may not be optimal as the current methods calculate the optimal insulation thickness (OIT) considering only the cost due to an increase in the insulation layer. The influence of base wall costs on optimum construction form is worthy of further investigated. This study is to close the knowledge gap to improve the overall performance of a CIEW. For this, an optimization model was established using a life-cycle cost analysis (LCCA) method considering the structural and insulation layers to determinate the optimal structural layer thickness (OSLT), optimal insulation thickness (OIT), and overall U-value of a CIEW. A case study of a masonry wall in a cold area in Beijing was conducted. Coal-fired boiler (CFB), gas-fired boiler (GFB), and air source heat pump (ASHP) were used as heat sources, and extruded polystyrene panel (XPS), rock wool (RW), and glass wool (GW) were used as insulation materials. The OSLT, OIT, optimal overall U-value, life-cycle cost (LCC), life-cycle saving (LCS) and payback period were calculated and compared between scenarios determined by this model and traditional model when the structural layer was known. The results indicate that the scenario determined by this model could achieve better energy-saving benefits. The payback period ranged from 2.25 to 5.07 years. The LCC saving rates and the growth ratio of life-cycle savings varied with these materials and heat sources from 0.55% to 3.70% and 0.19% to 1.40%, respectively. When same heat source being used, the total thicknesses of the structure and insulation layer (TTSIL) equals 300 mm, the order of achieved energy-saving benefits is XPS>GW>RW. The optimal overall U-value of the CIEW was independent of the required thickness of the structural and insulation layers and decreases with increasing unit heat consumption of heat sources. However, the energy efficiency revenue decreases with an increase in the TTSIL. The proposed method provides different proportions of thicknesses for construction walls and insulation layers, the variation of heat accumulation potential, influence on peak cooling/heating demand and environmental impact of the optimal CIEW will be studied in the future. [ABSTRACT FROM AUTHOR]

The edge beams of reinforced concrete bridges with de-icing salts sprayed experience extensive corrosion damage. The average service life of edge beams needing replacement in Sweden has been reported as only 45 years, causing great economic loss to both owners and users. Hence, finding a durable solution for edge beams would benefit society. Hybrid reinforced concrete structures, produced by adding a low-to-moderate fibre content into traditional reinforced concrete, can effectively limit the service crack width and improve resistance to chloride-induced corrosion damage. In this paper, different alternatives of hybrid and traditional reinforced edge beams were designed for a case study. The service life of the alternatives was compared by conducting chloride diffusion calculations and by applying a corrosion-induced cracking model. The economic and environmental (indicated by greenhouse gas emissions) benefits of using hybrid reinforced edge beams were assessed by life-cycle cost analysis and life-cycle assessment. The results showed that the service life of edge beams made of hybrid reinforced concrete can be prolonged by over 58%, thereby enabling a significant reduction in the total life-cycle costs and annual total greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

Viscoelastic (VE) dampers are powerful tools for mitigating structural response when exposed to an earthquake. The fractional models for these dampers are adequately capable of taking the effects of ambient temperature and excitation frequencies into account. In this paper, the effect of these dampers on reducing the life-cycle cost of steel structures and the exceedance probability of different damage states is evaluated during the lifetime of the structures. Modal pushover analysis has been employed for nonlinear dynamic analysis of the steel frames with viscoelastic dampers. The effect of the random parameters, such as ambient temperature, excitation frequency, and accelerogram type, were also considered. The results from the analysis of six presented scenarios demonstrate a significant improvement in structural performance, especially in reducing the maximum inter-story drifts and ductility demands. Incorporating VE dampers into different design scenarios has decreased the expected damage cost and total life-cycle cost of the structure by at least 58% and 31%, respectively. Also, it was observed that due to the nonlinearity of the equations and uncertainties associated with seismic loading and ambient temperature, the best design scenario is not easily predictable. [ABSTRACT FROM AUTHOR]

In the aircraft industry, the ultimate goal in any component's design is to minimize its weight, maximize its durability, and increasing its life while keeping its overall life cycle costs low. As technology is progressing, UCAVs are gaining more and more prominence as jet powered UCAVs are already taking to skies presenting a myriad of challenges. This is especially true in the case of Landing gears as greater crashworthiness is required in high-speed high payload UCAVs. As jet powered UCAVs have a higher touchdown velocity and thus a higher chance of failure. In this research, a category of unmanned combat aerial vehicles was picked. In that category, a number of reference unmanned combat aerial vehicles were selected to extract the required parameters and dimensions of their main landing gears from literature review and analysis. The main landing gear was then modeled in CAD. Simultaneously loading conditions were defined and loads were determined. The equivalent von mises and maximum principal stresses were obtained from finite element analysis for multiple materials using the finite element package ANSYS. These results were then in turn used to calculate the factor of safety. Furthermore, an impact analysis was carried out in this crashworthiness study using Explicit Dynamics in LS DYNA for the same material. The stress formulations and deformations in impact were highly non-linear and more realistic and accurate than in static structural. The results were then validated. [ABSTRACT FROM AUTHOR]

Concurrent design is a systematic approach that aims to help developers consider all elements related to the product life cycle, including quality, cost, schedule and user requirement. This approach is challenging because designers conduct these elements manually in the design process. In addition, studies on the formation mechanism of design defects are limited. To minimise the difficulties of product designers and prevent design defects, a structural relationship model is presented for the concurrent design process. The structural relationship model, which incorporates design defects, design process and influencing factors, is marked through polychromatic sets. The interval analytic hierarchy process is used to determine the weight of each influencing factor. Furthermore, a brief model instruction for concurrent design is proposed to guarantee the model application's validity. The proposed method enables designers to concentrate on functionality and performance design, and the findings are expected to be theoretically and practically useful for preventing and controlling defects in concurrent design. [ABSTRACT FROM AUTHOR]

The Integrated Energy System fulfilled coordinated planning, optimized operation, coordinated management, which can improve energy efficiency and reduce energy costs. A multi-level planning optimization model with integrated energy system scenario reasoning, equipment selection, and capacity optimization is proposed. The minimum life cycle cost of integrated energy system is taken as the objective function, and the constraints of scenario reasoning, equipment selection and capacity optimization are also taken into account, including the similarity between planning scenarios and historical scenarios, equipment model matching and mutual exclusion, and operational constraints. In addition, an improved particle colony-ant colony optimization algorithm is used to solve the model. The K-proximity reasoning method is constructed based on multiple data types for reasoning of the equipment scenario in the park. The optimized results are transferred to the case library to further enrich the planning scenario case library. Finally, a park is taken as an example to analyze the impact of equipment-type changes on the planning results and provides important suggestions for the park construction. [ABSTRACT FROM AUTHOR]

As a cost-saving and environmental-friendly product strategy, modular design is an effective approach to shorten lead-time and reduce cost for development of products. However, the modular design of products with complex structure might be plagued by the difficulty of product structure modeling and unreasonable structural modular schemes. In this study, a core components-oriented modularisation method is presented to solve the problem of module division of complex products. The structural model of complex products is reasonably simplified by screening core components, which further reduces the modeling difficulty and improves the solution efficiency of module division scheme. Firstly, a hybrid structure decomposition method is proposed to obtain all components of complex products according to the different structure characteristics of each subsystem of complex products. Secondly, the core components of complex products are screened by calculating the whole life cycle cost (WLCC) of each component, and the design structure matrix (DSM) model of complex products is established according to the relationship between the core components. Finally, the module division scheme of complex products is obtained via hierarchical clustering and modularity evaluation. Effectiveness and robustness of the method are demonstrated through comparison experiments for the modular design of a hydraulic excavator case. [ABSTRACT FROM AUTHOR]

Optimizing the business environment is a new competitive edge to global economies in international competition and cooperation. Export variety is an important basis for the implementation of a country's foreign trade diversification strategy. However, the impact of the business environment on export diversity remains unclear. Using World Bank Doing Business data and detailed product data of 145 countries from 2010 to 2018, we investigate the effects of the business environment on the export variety of home countries. We separate regulatory variables based on different stages of a firm's life cycle and examine which regulatory factors of doing business influence export variety. The results show that business environment improvement promotes export variety through an increase in foreign direct investment (FDI). The improvement of the business environment promotes the export variety mainly in non-high-income countries but not in high-income countries. Dealing with construction permit negatively affect export variety, while trading across borders and resolving insolvency improve export variety. [ABSTRACT FROM AUTHOR]

Electric Centrifugal Chillers (ECC) are mostly incorporated into District Cooling (DC) systems for charging the Thermal Energy Storage (TES) tank or/and to supply Chilled Water (CW) directly to the DC network for Air Conditioning (AC). ECC accounts for the highest percentage of the total electrical energy consumption, making it the most energy-intensive system in the DC setup. The high positive correlation between energy consumption and cost, and its influence on the decision-making process, necessitate the requirement to conduct an economic performance evaluation of the ECC plants. To achieve this objective, a Life Cycle Cost (LCC) analysis is performed to quantify the economic implication resulting from the ECC system's acquisition, operation, and maintenance. In this analysis, four (4) ECC systems installed in a large DC plant in Malaysia are considered the case study. The result obtained from the analysis of the study year revealed that April and June accounted for the maximum and minimum cost implication per outcome, respectively. It is also observed from the results that the climatic temperature conditions had a significant influence on the monthly cooling demand, energy consumed, and cost incurred. The operational phase of the system's life cycle accounted for the highest cost implication from the overall LCC result. A significant reduction in the operating cost is recorded as the indirect energy source used for driving the chiller plant is switched from the electricity supplied from the National Electricity Grid (NEG) and supplied from the Natural Gas Plant (NGP). The LCC per refrigeration ton of the ECC system is estimated to be MYR 1.44/RTh. The impact of system degradation (i.e. decrease in Coefficient of Performance (COP) value) over time on the overall cost per output refrigeration was also investigated. The study also revealed that operating an actual ECC system on electricity from NGP led to a 31% cost savings compared to an ideal system running on electricity from NEG. A sensitivity analysis is also conducted at the end of the study to determine the influence of the input variable on the output result. [ABSTRACT FROM AUTHOR]

This paper investigates the total life-cycle cost of designed structures with different increasing seismic response coefficient from the aspects of the structural and social life-cycle damage costs combined with environmental impacts. The environmental impacts are converted to the equivalent costs as much as possible, to be integrated with other social and economic factors. The proposed framework is applied to reinforced concrete frames of 4, 8, and 12 stories. The results indicate that the importance of the environmental aspects regarding the significant contribution to the total life-cycle costs is even more than that of the social aspect. [ABSTRACT FROM AUTHOR]

Numerous bridges are exposed to increasingly frequent and intense extreme events due to climate change, while serving more traffic than originally designed due to population growth. Thus, predictive maintenance of bridges is of paramount importance for securing structural safety and bridge network reliability. However, the application of predictive maintenance for networks of bridges, considering condition and criticality of bridges within the network, has not seen much attention in practice and literature. Presented herein is a maintenance prioritisation method for networks of bridges, based on: a deterioration model for individual components considering uncertainty; life-cycle cost analysis; grouping of components maintenance to reduce traffic interruption and setup cost; and criticality evaluation of bridges using a specifically tailored version of closeness vitality and traffic simulation. This method has been applied to a network of 21 bridges in Portugal, composed of several heterogeneous elements. It showed a substantial decrease in maintenance cost, compared to the Structures Investment Toolkit, and significant differences between criticality of bridges within a network. The proposed methodology can be applied to any networks of bridges or serve as the basis for updated maintenance decision support systems for infrastructure asset networks. [ABSTRACT FROM AUTHOR]

Industrial sector consumes a substantial portion of electrical energy. Building owners persistently believe that combining on-site renewable energy systems to buildings is not cost-effective in Sri Lanka. Therefore, this research aimed to evaluate the use of on-site renewable energy sources for industrial buildings in Sri Lanka. This research carried out 10 expert interviews and 6 case studies. Experts determined that solar and biomass as viable on-site energy generating sources in Sri Lanka. Life-cycle cost was calculated for six case studies representing three case studies for each viable option followed by a sensitivity analysis. Based on the research findings, biomass can effectively manage waste while eliminating the risk of the emission of harmful biomethane. Based on the calculations, the payback period for a solar system varies between 4 and 6 years and biomass system varies between 6 and 7 years. This research explored the potential of generating on-site renewable energy for industrial building. Although the 'on-site' energy generation is not widely discussed in industrial buildings, this research study strengthened the possibility of adopting solar and biomass as on-site renewable energy generation sources. [ABSTRACT FROM AUTHOR]

Sustainability in the construction and renovation of buildings is a requirement that in recent years is becoming particularly important in decision-making processes, in order to promote sustainable development in the construction sector, through methodologies and design approaches aimed at decarbonising building processes. This paper investigates the criteria and approaches adopted in a series of case studies in order to develop a useful tool to identify the 'sustainable compromise'. This study proposes, through the comparison of the application of two methods (TOPSIS and COMPROMISE), the analysis of the materials used in the design of the opaque building envelope, considering a series of performance and environmental characteristics (including the minimisation of the embedded carbon content). The results obtained make it possible to define, among 6 stratigraphic solutions identified in the same climatic area, the one that best meets the requirements underlying sustainable development (social, environmental and economic). [ABSTRACT FROM AUTHOR]

Clean cooking fuel is currently a prime need of human beings. Solar cooking is said to be one and thus needed to be tested and compared with other cooking options. This study deals with the multi-criteria assessment analysis of a double mirror reflector box-type solar cooker for the north-eastern Himalayan region of Sikkim. Multi-criteria assessment analysis was comprised of life cycle assessment, life cycle costing, and embodied energy analysis. Liquid Petroleum Gas (LPG) was considered as a reference system for the comparative assessment. The solar cooker was tested for its performance using standard testing methodologies. Life cycle assessment analysis for predicting environmental impacts was conducted using software tool SimaPro 9.0 with a functional unit of use of a device for cooking per year. The impact 2002+ method showed that LPG cooking option had impacted more than solar cooker on human health, climate change, ecosystem quality, and resource depletion predicted that for determining the impacts. The embodied energy and outputs of both systems showed that cooking with a solar cooker can replace around 5 cylinders of LPG annually. The Energy payback period for the solar cooker was found to be 4.13 years. Life cycle assessment results of solar cooker fabrication showed that the largest contributor within impact categories was aluminum, glass, and steel sheet. Economic analysis for substitution of LPG by solar cooker has a positive internal rate of return and payback period of 1.89 years. Thus, this study projected sustainability of double reflector box-type solar cooker over LPG cooking option. [ABSTRACT FROM AUTHOR]

This study examines the applicability to developing countries of a pavement management system (PMS) with less data (two-point) requirement to complement current practice. Due to limited capacity, many developing countries like Uganda have adopted a PMS after specified intervals regardless of deterioration rate (i.e. time-dependent policy). Maintenance planning based on deterioration rate (i.e. condition-dependent policy), as proposed, would be more ideal because pavement deterioration is stochastic. A PMS was developed using the Markov hazard model and then an empirical study was conducted for surveyed Ugandan national road network comparing both policies considering a basic plan and a fixed budget. A greedy algorithm was used to select sections for repair based on worst condition first (for time-dependent) or fastest deterioration first (for condition-dependent). A shift to the condition-dependent policy increased percentages of network in good and fair condition by 8.6% and 2.5%, respectively, and reduced percentages in poor and bad condition by 8.5% and 2.6%, respectively. Additionally, maintenance plans with and without preventive maintenance were compared considering a fixed budget. Preventive maintenance further increased percentage in good condition by 27.4% and reduced percentages in poor and bad condition by 11.6% and 4.2%, respectively, with a 53.5% reduction in life cycle costs. [ABSTRACT FROM AUTHOR]

Configuration systems are increasingly used as a means for efficient design of customised product service systems (PSS) to satisfy diverse customer needs. Cost evaluation is thereby important to assist the configuration engineers in making decisions on feasible configuration solutions. However, little research attention has been received until recently. To fill this gap, this paper contributes in developing a framework for cost evaluation in PSS configuration. A holistic view of PSS configuration, the three-dimensional PSS cost element, and a life cycle-oriented cost evaluation approach are successively proposed. The framework is thereby established with a number of parts, including the preparatory stage, the evaluation stage and the configuration stage. A pump PSS is illustrated to validate the developed framework. Four feasible configuration solutions in one configuration activity are evaluated and compared. The configuration engineers are thus assisted with the decision on selecting the one with the least cost. [ABSTRACT FROM PUBLISHER]

There are different approaches to modelling the products at the End of Life (EOL), including closed loop approach, the ladder of lansink and material flow. The sustainability principles and the complexity of the products may affect the choice of modelling type. The life cycle costs, several subsystems and the interaction between design features, construction, technology, suppliers and legislation affect the degree of complexity of the products. Hence, developing appropriate strategies are required for modelling EOL phase of the complex products. This article presents strategies for modelling EOL phase of complex products considering sustainability tools, EOL phase models and the characteristics of these products. An ingenerated approach is proposed to address the four essential aspects of the complex product at the EOL: operational, tactical, strategic and sustainability. The case of aircraft at the EOL is presented to highlight the application of the proposed approach. [ABSTRACT FROM AUTHOR]

Special purpose machine tools (SPMs) have been widely used to perform drilling-related operations in high volume production including within automotive component industries. The first step in designing and manufacturing a SPM is a feasibility analysis. Since SPMs have relatively higher investment cost than other machine tools, this task must be performed before any investment on the preparation of detailed design. The present paper explores an economic feasibility analysis strategy which aims to make logical decision by assessing the strengths and limitations of an SPM in comparison with other machine tools. The mathematical product cost model for SPMs is proposed for estimating important economic factors and then financial indicators are calculated to evaluate the SPM’s economic performance. A case study is used to examine the proposed model and results are compared with other machine tools. The proposed model provides a decision support approach for selecting an SPM for manufacturing a given part from an economic perspective. [ABSTRACT FROM AUTHOR]