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Carbon-based nanodots have garnered recent interest for their simple synthesis and versatile utility, ranging from biomedical to (opto) electronic applications, evolving into a tunable and biocompatible material. Here, for the first time, a biochar (lotus leaf) derived carbon nanodots was synthesized through hydrothermal carbonization. The synthesized hollow spherical biochar was engineered via functionalization by grafting –SO3H active sites. The attained catalyst was broadly analyzed by XRD, FTIR, TGA, BET, SEM–EDX, TEM, and XPS analysis after which it was applied for the acetalization reaction of crude glycerol (a biodiesel by-product) to form solketal, a potential fuel additive to valorize the large waste stream generated from biodiesel industry. Employing the RSM-CCD methodology, the experimental matrix was executed, and subsequent data were scrutinized through multiple regressions to model a quadratic equation. Under specific reaction parameters—a reaction duration of 14 min, a molar ratio of 7.5:1, and a catalyst loading of 5.7 wt.%, maximum solketal yield (95.7%) was attained through the ultrasonication method. Finally, to conclude, life cycle cost analysis (LCCA) for solketal production was studied here which determined the overall cost of solketal production per kilogram to be 0.719 USD ($), indicating high commercial applicability. [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]

Due to the high cost and complex challenges faced by offshore wind power transmission, economic research into offshore wind power transmission can provide a scientific basis for optimal decision-making on offshore wind power projects. Based on the analysis of the topology structure and characteristics of typical wind power transmission schemes, this paper compares the economic benefits of five different transmission schemes with a 3.6 GW sizeable onshore wind farm as the primary case. Research includes traditional high voltage alternating current (HVAC), voltage source converter high voltage direct current transmission (VSC-HVDC), a fractional frequency transmission system (FFTS), and two hybrid DC (MMC-LCC and DR-MMC) transmission scenarios. The entire life cycle cost analysis model (LCCA) is employed to thoroughly assess the cumulative impact of initial investment costs, operational expenses, and eventual scrap costs on top of the overall transmission scheme's total cost. This comprehensive evaluation ensures a nuanced understanding of the financial implications across the project's entire lifespan. In this example, HVAC has an economic advantage over VSC-HVDC in the transmission distance range of 78 km, and the financial range of a FFTS is 78–117 km. DR-MMC is better than the flexible DC delivery scheme in terms of transmission capacity, scalability, and offshore working platform construction costs in the DC delivery scheme. Therefore, the hybrid DC delivery scheme of offshore wind power composed of multi-type converters has excellent application prospects. [ABSTRACT FROM AUTHOR]

Line planning and timetabling play important roles in the design of urban rail transportation services. Due to the complexity of the integrated optimization of entire transportation plans, previous studies have generally considered line planning and timetabling design independently, which cannot ensure the global optimality of transportation services. In this study, the integrated design problem of line planning and timetabling was characterized as an equilibrium space–time network design problem and solved with a bi-objective nonlinear integer programming model. The model, in which train overtaking and passenger path choice behavior were considered, adjusted the network topology and link attributes (time and capacity) of the travel space–time network by optimizing the train service frequency, operation zone, stopping pattern, train formation, and train order to minimize the system life cycle cost and total passenger travel time perception. An algorithm was constructed using the non-dominated sorting genetic algorithm II combined with the self-adaptive gradient projection algorithm to solve the model. A real-world case was considered to evaluate the effectiveness of the proposed model and algorithm. The results showed that the model not only performed well in the trade-off between system cost and passenger travel efficiency, but it could also reduce the imbalance of train and station loads. Pareto front analysis of the model with different parameters showed that more types of trains did not correlate with a better performance, some line-planning strategies had a combination effect, and multi-strategy line planning was more suitable for scenarios with a high imbalance in the temporal and spatial distributions of passenger flow. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive Life Cycle Cost Assessment (LCCA) of geothermal-assisted hydrogen liquefaction, explicitly focusing on the Afyon Geothermal Power Plant (AGPP) as a case study. The study evaluates the economic viability and sustainability of integrating geothermal energy into hydrogen liquefaction. The results of the LCCA contribute to the ongoing discourse on sustainable energy solutions, offering a nuanced understanding of the economic considerations associated with geothermal-assisted hydrogen liquefaction. The study serves as a model for assessing the economic feasibility of similar systems, fostering informed decision-making in the pursuit of cleaner and more economically sustainable energy pathways. This study has conducted a technical and economic investigation of liquid hydrogen production using geothermal heat and electricity effects. Geothermal water pre-cools the hydrogen by providing heat to the absorption system. Then, the electricity generated in the geothermal plant is used to work in the liquefaction cycle. The generated electricity is used to liquefy hydrogen in the liquefaction cycle. The capacity of the electricity generated from the AGPP produced here is 2621 kW. The proposed system can be achieved by pre-cooling unit H 2 up to −30 °C at 120 °C and 150 kg/s geothermal source. In the liquefaction cycle, 0.84 kg/s H 2 can be liquefied. As a result, the total energy efficiency of the proposed system can be calculated as 32.4% and exergy efficiency as 15.4%. The system's net present value (NPV) was calculated as 65,320,000 $. When life cycle cost analysis was performed using the levelized annual cost (LAC) method, the project's levelized cost was calculated as 7,673,000 $/yr. The unit cost of the liquid hydrogen produced is 1.252 $/kg. This system's discounted payback period (N dpp) is calculated as 3.48. Configuration of geothermal assisted hydrogen generation system. [Display omitted] • A techno-economic evaluation of a hydrogen liquefaction system is introduced. • The Life Cycle Cost Assessment of liquefied hydrogen is conducted. • Using geothermal water in an absorption system, H 2 gas can be pre-cooled to −30 °C. • In the liquefaction cycle, using geothermal energy, 0.84 kg/h H 2 can be liquefied. • Liquefied hydrogen market cost and system payback period are calculated as 1.252 $/kg and 3.48 years, respectively. [ABSTRACT FROM AUTHOR]

Commercial Buildings release large volumes of greenhouse gases, expediting global warming. The commercial building industry accounts for 37% of global CO2 emissions. Geothermal energy technologies are an intriguing solution that provides a low-impact, emission-free, and cost-effective thermal fuel source for baseload energy production. Geothermal energy systems offer a potential solution to dramatically halt global warming and facilitate the transition to a carbon-neutral civilization. This study develops a framework for assessing the geothermal power capabilities of innovative house and district heating systems. The energy requirements are first assessed, and then the spatial evaluation of district heating infrastructure is carried out using a Python-based program. Economic comparisons between geothermal energy and fossil fuels are made using LCC analysis. Environmental impacts are measured by Life Cycle Analysis (LCA). This study compares geothermal energy to fossil fuels, and the LCA results show that geothermal energy has a low environmental impact. With a Net Present Value (NPV) of 34.81 USD, it displays economic viability as well as a satisfactory financial return. The study's findings show that geothermal energy has the ability to compete with fossil fuels in commercial heating applications while still being environmentally beneficial. [ABSTRACT FROM AUTHOR]

The increasing demand for sustainable air mobility has led to the development of innovative aircraft designs, necessitating a balance between environmental responsibility and profitability. However, despite technological advancements, there is still limited understanding of the maintenance implications for hydrogen systems in aviation. The aim of this study is to estimate the maintenance costs of replacing the hydrogen storage system in an aircraft as part of its life cycle costs. To achieve this, we compared conventional and hydrogen-powered aircraft. As there is insufficient data for new aircraft concepts, typical probabilistic methods are not applicable. However, by combining global sensitivity analysis with Dempster–Shafer Theory of Evidence and discrete event simulation, it is possible to identify key uncertainties that impact maintenance costs and economic efficiency. This innovative framework offers an early estimate of maintenance costs under uncertainty, enhancing understanding and assisting in decision-making when integrating hydrogen storage systems and new aviation technologies. • Examining hydrogen storage exchange necessity in an aircraft's life cycle. • Pioneering use of evidence theory and global sensitivity analysis amid data scarcity. • Identifying maintenance impact on hydrogen aircraft life cycle costs. • Uncertainties in maintenance events have a high economic impact. [ABSTRACT FROM AUTHOR]

A Life Cycle Assessment (LCA) quantifies the environmental impacts during the life of a product from cradle to grave. It evaluates energy use, material flow, and emissions at each stage of life. This report addresses the challenges and potential solutions related to the surge in electric vehicle (EV) batteries in the United States amidst the EV market's exponential growth. It focuses on the environmental and economic implications of disposal as well as the recycling of lithium-ion batteries (LIBs). With millions of EVs sold in the past decade, this research highlights the necessity of efficient recycling methods to mitigate environmental damage from battery production and disposal. Utilizing a Life Cycle Assessment (LCA) and Life Cycle Cost Assessment (LCCA), this research compares emissions and costs between new and recycled batteries by employing software tools such as SimaPro V7 and GREET V2. The findings indicate that recycling batteries produces a significantly lower environmental impact than manufacturing new units from new materials and is economically viable as well. This research also emphasizes the importance of preparing for the upcoming influx of used EV batteries and provides suggestions for future research to optimize the disposal and recycling of EV batteries. [ABSTRACT FROM AUTHOR]

This study examines the strategic use of life cycle cost analyses (LCCAs) in the management and conservation of heritage sites, emphasizing the need for comprehensive financial planning. With an increasing number of heritage sites showing signs of deterioration, our aim was to improve the sustainability and effectiveness of restoration practices. We used dynamic life cycle costing methods and developed the MONUREV software V2 to simulate different restoration scenarios, providing accurate, data-driven projections for maintaining structural, functional and aesthetic integrity. The field research involved testing these methods through case studies of heritage buildings in the Czech Republic, focusing on holistic cost management from initial analysis to practical application. The results showed that LCC analysis can significantly assist in making informed decisions, balancing economic and cultural values, and ensuring long-term conservation outcomes. This study concludes that the integration of a detailed LCC analysis into heritage conservation strategies represents a methodological advance that can significantly improve the economic and operational planning of the maintenance of heritage buildings, thereby ensuring their preservation for future generations. [ABSTRACT FROM AUTHOR]

This study conducts a comprehensive life cycle cost analysis (LCC) of green retrofitting in mosque buildings, assessing its financial feasibility and performance. The research involves a risk assessment of three crucial stages: pre-, construction, and post-construction. A Likert scale is employed for the validation process based on responses from 51 experts involved in green building retrofit projects. Results indicate that the highest risk occurs during construction, impacting investment performance. Sensitivity analysis reveals the potential longevity of investments, with pre-construction risks affecting the Net Present Value (NPV) in the 18th year and post-construction risks proving feasible by the 17th year. The study introduces benchmarks such as NPV, Internal Rate of Return (IRR), Benefit-Cost Ratio (BCR), and Break Even Point (BEP) for investment evaluation. The financial feasibility of green retrofit items, including solar panels and energy-efficient utilities, is confirmed with an NPV of IDR 140,797,698, IRR of 10.26%, and BCR of 2.21, with feasibility realized in the 17th year. Risk visualization through a Tornado Chart emphasizes the significance of each risk stage on NPV values. In conclusion, the study recommends broader case studies involving multiple certified green mosques for more accurate risk identification. This research provides valuable insights for informed investment decisions in mosque building green items, emphasizing the importance of risk management for long-term sustainability. [ABSTRACT FROM AUTHOR]

Bridge components are subject to both structural loads and environmental stressors, rendering them susceptible to accelerated deterioration and potential collapse in the absence of effective maintenance and rehabilitation strategies. Moreover, the phenomenon of wet-dry cycling, coupled with elevated chloride concentrations prevalent in coastal regions, further expedites the degradation process of bridges, thereby escalating maintenance frequency and repair costs. In response to this challenge, the integration of innovative materials such as Ultra High-Performance Concrete (UHPC) is being explored for the development and implementation of maintenance and rehabilitation strategies. This study presents a comparative analysis between conventional methods and UHPC applications for bridge repairs, utilizing Life Cycle Cost Analysis (LCCA) to encompass both agency and user costs, and applies Monte Carlo simulation to account for the variability of the modeling factors. A practical case study illustrates the applicability of the LCCA methodology, revealing that the utilization of UHPC contributes to a reduction in the total life cycle cost for bridge maintenance and rehabilitation. Life expectancy, Average Daily Traffic (ADT), and the duration of construction activities during rehabilitation emerge as the most influential factors affecting life cycle costs. The main contributions of the study are the development of the life-expectancy model and step-by-step Life-Cycle Cost Analysis (LCCA) methodology. Findings from this study aim to identify cost-effective retrofitting techniques for maintaining bridges in a "State of Good Repair." [ABSTRACT FROM AUTHOR]

This paper aims to investigate potential strategies to reduce energy consumption and environmental impacts of a recently converted rural complex into an agri-spa in a high environmental value area within the province of Viterbo (Italy). Actual operational data on appliances, climate, and energy consumption are employed for the energy audit. While this analysis generally provides energy-saving solutions, such options are not examined for their life cycle environmental impacts. The current article is based on the experimentation of a consolidated methodological approach in the scientific literature, integrating the energy audit, life cycle assessment (LCA), and economic analysis (Life Cycle Cost) to assess a series of energy-efficiency measures designed for the new wellness centre function. The combined use of these well-established procedures provides a comprehensive assessment of intervention scenarios for a particularly energy-intensive type of case study, not yet widely documented in the literature. The results reveal that energy consumption related to heating/cooling is marginal compared to the actual electrical consumption in the specific case study. Therefore, the most efficient scenarios involve installing photovoltaic systems and replacing gas boilers with high-efficiency heat pumps, especially with economically advantageous insulation. This leads to a 51% reduction in energy consumption and an 81% decrease in heating, DHW, and electricity costs. [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]

Currently, due to the insufficient resources of renewable natural gas, the development of renewable pathways to integrate into the natural gas-industry portfolio can reduce many concerns about the reserves depletion and the environmental crises. In the present article a structure-oriented framework for gas networks is developed to compare and prioritize different investment scenarios for renewable natural gas production projects. In this regard, different pathways to produce renewable natural gas through the waste-to-natural gas process were discussed and compared based on different waste feedstocks. To discuss and compare different pathways, a decision-making structure and framework under life cycle cost analysis (LCCA) and life cycle environmental analysis (LCEA) is employed to choose the appropriate pathway for the waste-to-natural gas process. The optimal pathway is identified through different multi-variable decision-making scenarios (under different geographical conditions, access to different feedstocks, and different interests of stakeholders). From the outcomes, under the neutral and Pro-economic scenarios, the renewable natural gas production pathway driven by landfill gas integrated with the pressure swing adsorption- biogas upgrading unit is the optimal and desirable option. While under an Eco-friendly scenario, the pathway driven by animal manure integrated with the pressure swing adsorption-upgrading unit is an optimal and desirable pathway. [Display omitted] [ABSTRACT FROM AUTHOR]

Climate change and urbanization have led to an increase in the amount of water flowing into traditional drainage systems, which results in frequent urban flooding. Low–Impact Development (LID) facilities, with their distributed feature, are one of the important means to mitigate flooding and have been widely used. In this paper, based on integrated catchment management (ICM), we compare the abatement of runoff, flooding, and ponding under two durations of rainfall and eight different return periods with runoff as the control objective (RACO) and flooding as the control objective (FACO) for the deployment of LID facilities. The waterlogged area of FACO is higher by a range of 92.462 m2 to 24,124.39 m2 compared to RACO. Both percentage reduction of overflow volume and runoff volume tend to decrease gradually with the increase in the return period. For the percentage reduction of runoff volume per unit area, sometimes RACO is greater than FACO, and sometimes vice versa, while for the percentage reduction of overflow volume per unit area, the range where FACO exceeds RACO is between 0.29 to 10.95 (%/ha). The cost of FACO has decreased by 4.94% to 46.20% compared to RACO. This shows that FACO's LID deployment method can fully utilize the capacity of LID facilities to mitigate inundation, reducing the cost of LID facilities to a certain extent. [ABSTRACT FROM AUTHOR]

Optimizing the multilayer thermal insulation of pipelines transporting liquids and gases at higher than ambient temperatures is crucial for heat energy conservation and cost optimization. This study utilizes a multi-objective genetic algorithm to optimize the multilayer thermal insulation thickness around a pipe carrying fluid to minimize heat loss and associated costs. The model adopted mathematical associations between design variables and the overall installation cost of layers over a pipe from the available literature. The proposed model considered one or more insulation layers of rock wool and calcium silicate to oil pipelines containing steam, furfural, reduced crude or 300-distillate oil. All calculations considered fixed-charge rates as a fraction of 1 or 0.15. The results were compared with standard values and those predicted by other researchers in the literature. For the steam line, the standard insulation thickness was 50 mm, jumping to 327 mm for rock wool and 232 mm for calcium silicate. However, it decreased to 38 mm for double-layer calcium silicate and 138 mm for double-layer rock wool. For furfural, the insulation thickness was 40 mm, which rose to 159 mm for rock wool and 112 mm for calcium silicate. In general, for all four cases, the results show that using normal insulation thickness is inadequate and not economical. For example, for 300-distillate oil, the present practice puts the cost function at 54 USD/m, which drops to 20 USD/m for rock wool and 24 USD/m each for single-layer silicate and double-layer insulation. This amounts to almost 60% cost savings. Similar trends are observed for the other three cases. This model can provide up to 60% savings in cost and a 92% reduction in heat loss at optimum insulation thickness compared to other models. [ABSTRACT FROM AUTHOR]

This study verified the technological and economic feasibility of converting urban air mobility (UAM) to a fuel cell–battery hybrid propulsion system from an existing battery–only propulsion system. The battery–fuel cell hybrid propulsion UAM was conceptually designed through reverse engineering and redesigned of the existing battery–only propulsion UAM. Under various design conditions, the economic feasibility of the hybrid propulsion system was verified through life cycle cost (LCC) analysis. Hybrid propulsion UAMs designed with appropriate hybridization ratios had 10% lower life cycle costs than battery-only propulsion UAMs. In particular, this cost–saving effect was more noticeable when UAM's flight distance became longer. The life cycle cost increased proportionally as the number of UAM passengers increased, but was relatively unrelated to energy storage technology improvements. Considering the current electricity and hydrogen price changes, the economic feasibility of fuel cell–battery hybrid UAM is expected to continue to improve in the future compared to batteries alone. • The technical and economic feasibility of the fuel cell-battery hybrid propulsion UAM was verified. • The fuel cell-battery hybrid propulsion UAM was conceptually designed through reverse engineering technology. • A properly designed hybrid propulsion UAM had a 10% lower life cycle cost than a battery-only propulsion UAM. • Considering energy price trends, the economics of hybrid UAM are expected to continue to improve. [ABSTRACT FROM AUTHOR]

1960s Europe saw a large number of residential neighborhoods built to house those migrating from the countryside. Today, more than 50 years later, these neighborhoods suffer high levels of functional, social, and technical obsolescence. In response to this, the University of Seville developed the Aura Strategy as an intervention methodology to find global solutions to issues in outdated neighborhoods. To provide visibility to this aspect of the Aura Strategy, the retrofit proposal presented in this article provides a solution to improve the roofing of buildings in a case study neighborhood (Polígono de San Pablo, Seville) and an analysis of the results in terms of energy and financial savings for local residents. The results show that for a population of roughly 18,000 (in 2018), net savings, including energy and retrofitting costs, ranging from nearly € 6.5 to over € 8.6 million can be made over the 20-year life-cycle span. Likewise, the results obtained on the reduction of thermal loads indicate a 72% decrease in energy consumption, equivalent to a saving of close to 4500 tons of greenhouse gas emissions for the district and the entire life-cycle time period, with the consequent benefits on the impact on air quality and the fight against climate change. [ABSTRACT FROM AUTHOR]

This study investigated the applicability of a tracking photovoltaic (PV) system installed in the roof area of a commercial building. Because PVWatts is the only PV module with a tracking feature in EnergyPlus, its electricity generation was validated through comparisons with detailed PV modules in EnergyPlus. The tracking PV system generated 26.8–35.5% more electricity annually than a fixed system in the climate of Incheon (S. Korea). The load coverage analysis of the tracking PV system was conducted with the reference commercial building model in EnergyPlus. Approximately 14% of the total building electric demand, including heating, ventilation, and air-conditioning; lighting; and equipment, was met by one PV array. Finally, the life cycle cost analysis of the tracking PV system was conducted by considering the net present value, which includes the initial installation and operation costs. The initial investment was returned after approximately 8 years, assuming between two and six tracking PV arrays were installed. Moreover, up to 26.8% cost savings were achieved in 15 years compared to the case without any PV arrays. [ABSTRACT FROM AUTHOR]

All the modern gadgets and space conditioning in buildings consume lots of energy. Energy consumption can be optimized using Composite Insulation External Walls (CIEW) built from mortar plaster and structural and insulation layers. This study aimed to improve the overall performance of CIEW by optimizing the structural and insulation layer thickness. The objective was to minimize the Life Cycle Cost (LCC) and maximize the Life Cycle Savings (LCS) of CIEW. The nonlinear Least Squares Estimation (LSE) optimization technique for optimizing LCC and LCS of CIEW was used in the study. The study considered three insulation materials—Extruded Polystyrene (XPS), Rock Wool (RW), and Glass Wool (GW)—across three heat sources, including Circulating Fluidized Bed (CFB), Grate-Fired Boiler (GFB), and Air-Source Heat Pump (ASHP). The Life Cycle Cost Analysis (LCCA) methodology suggested by Huang using a traditional optimization technique was used as a basis for mathematical formulations and result comparison. The payback period of CIEW with optimal structural and insulation layer thickness was computed. The findings revealed that applying the LSE method enabled greater economic efficiency than the LCCA method, with an up to 9.12% increase in LCS value and an up to 7.41% decrease in LCC value. The research also revealed significant correlations between insulation and structural layer thicknesses and economic parameters. [ABSTRACT FROM AUTHOR]

Construction industry projects play a significant role in the sustainable economic growth of all other industries. To achieve a sustainable economy, the future associated costs act as a barrier that must be addressed in the initial stages of a construction project. To evaluate the future costs, Life Cycle Cost Analysis (LCCA) is found to be an effective technique that determines the present worth of future costs. This study focuses on reviewing the conducted research in the field of optimising cost during the project life cycle via LCCA to sustain economic sustainability and associating the environmental and social cost factors to enhance sustainability. A systematic literature review strategy is developed to extract relevant literature from Scopus, Web of Science, Science Direct, Emerald and American Society of Civil Engineering from the year 2009 to 2020. Adopting the PRISMA statement, a total of 83 articles are reviewed systematically in detail. Many construction sections are explored with the impact of LCCA on them. The LCCA impact the performance of construction projects during certain practices such as structural designing, energy cost optimisation, building envelope efficiency in energy demand and utilisation optimisation and earthquake engineering. Moreover, this study highlights the influence of LCCA in optimising the environmental impact of a new or existing construction project to avail economic sustainability along with the social and environmental. A conceptual framework has been proposed that shows the influence of LCCA on the construction industry, which directly impacts economic sustainability and indirectly environmental sustainability. [ABSTRACT FROM AUTHOR]

This study aims to present the life cycle cost (LCC) for 1 kg of pear produced using organic technology in Southern Romania. Two principal stages were depicted: production stage costs (PC) and Transport costs (TC). For each stage, investment and operational costs were determined. Pear orchard establishment (POE), the first I-III years of orchard management (without harvest) (OM.I-III), and IV-XX years of orchard management (OM.IV-XX) were analyzed considering the elemental activities included. Three scenarios were applied for fertilization: (S1) compost produced at the farm level using a composter Oklin GG-50S combined with the one produced on outdoor platform in the farm, mainly from vegetable sources. (S2) compost from the outdoor platform for organic residues, and (S3) acquisition of a commercial organic fertilizer. The total LCC for 1 kg of pear ranged between 0.400 € (S2), 0.481 € (S3), and 0.496 € (S1). Details regarding the LCC components and optimization were presented. [ABSTRACT FROM AUTHOR]

This paper focuses on quantifying the economic and financial viability of NB-IoT and LoRaWAN technologies, two low-power wide-area network (LPWAN) technologies with unique characteristics that make them suitable for IoT applications. The purpose of this study is to propose a "pragmatic" artifact for performing life cycle cost analysis and demonstrate its application to these technologies. The methodology uses pragmatic computational tools to facilitate the analysis and considers all relevant economic and financial factors, such as operating costs, equipment costs, and revenue potential. The main finding of this study is that Narrow Band-Internet of Things (NB-IoT) and Long Range Wide Area Network (LoRaWAN) technologies have different cost structures and revenue potentials, which may affect their economic and financial viability for different IoT applications. Ultimately, the study concludes that a comprehensive life cycle cost analysis is critical to making informed decisions about technology adoption, and that the proposed methodology can be applied to other IoT technologies to gain insight into their economic and financial viability. [ABSTRACT FROM AUTHOR]

Significant amounts of waste heat are deposited in greywater, which can be utilized, among other things, for heating domestic hot water in residential buildings. The manuscript presents an economic analysis of a greywater heat recovery system using a vertical heat exchanger of the "tube-in-tube" type in a single-family building. The analysis is based on the results of experimental research on the energy efficiency of three domestic hot water preparation systems equipped with a vertical heat exchange unit. The analyzed systems had different concepts for the flow of preheated water and cold water. The research showed that the implementation of a vertical "tube-in-tube" heat exchanger can reduce the energy consumption for domestic hot water preparation by approximately 45.7% to 60.8%, depending on the system variant. Furthermore, it was determined that the energy savings associated with reducing domestic hot water consumption can cover the investment costs related to the purchase and system of the heat exchanger within a period of 2 to 5 years of system operation, depending on the design variant and the unit price of electricity. [ABSTRACT FROM AUTHOR]

Owing to the unavailability of electricity in many remote areas in Peninsular and East Malaysia, these areas do not have access to telephone signals. In remote areas, a diesel generator is used as the power source for the telecommunications base station. Hence, the continuous supply of diesel (which is a fossil fuel) is necessary in these remote areas. In this study, an attempt is made to assess the potential of replacing diesel-generated electricity with wind energy, which is renewable energy. Life cycle cost analysis is carried out, and the payback period of a wind energy system is determined for a remote telecommunications base station in Malaysia. The load characteristics and wind data are obtained from the Mersing Meteorological Station, Malaysia, and it was found that the annual load and base load are 12 kW. Hence, a 12-kW wind turbine is selected for the life cycle cost analysis at the site. The results show that the total specific cost of the 12-kW wind turbine is MYR 0.27/kWh based on a discount rate of 5% and electricity tariff in Malaysia of MYR 0.28/kWh. The payback period and discounted payback period of the 12-kW wind turbine are estimated to be 11.8 and 18.2 yr, respectively. Based on the load characteristics in Mersing, Malaysia, the 12-kW wind turbine is economically viable for the remote telecommunications base station. Nonetheless, the 12-kW wind turbine is not economically viable because the simple payback period is greater than 1/3 of the wind turbine's lifetime, which is 20 years. The 12-kW wind turbine, on the other hand, is suitable for use as a remote telecommunications base station. [ABSTRACT FROM AUTHOR]

Continuous research efforts have been developed in the literature to raise the sustainability components of the road infrastructure industry, i.e., reduce potential contaminants and augment financial profitability. In this regard, this investigation aims to explore the feasibility of producing Hot Mix Asphalt (HMA) with the inclusion of Recycled Concrete Aggregate (RCA) as a partial substitute for coarse Natural Aggregates (NAs). Thus, four different HMAs were considered, namely HMAs with coarse RCA contents of 0, 15, 30, and 45%. Specifically, the mechanical and sustainability properties of the asphalt mixtures were determined. On the one hand, the Marshall design parameters, resilient modulus, moisture susceptibility, rutting resistance, and fatigue life were addressed as mechanical properties. Meanwhile, regarding the sustainability properties, the environmental impacts and production costs were estimated using the Life Cycle Assessment (LCA) and the Life Cycle Cost Analysis (LCCA) methodologies, respectively. Consequently, the following conclusions were obtained: (i) as the coarse RCA content increases, the mechanical behavior of the HMA progressively deteriorates; (ii) this decrease in mechanical performance is acceptable up to a 15% RCA of coarse RCA, whereas for higher dosages this alteration is abrupt; and (iii) the RCA only generates sustainability benefits at a 15% replacement amount. [ABSTRACT FROM AUTHOR]

The design process influences the resulting environmental impacts and life cycle costs. Life cycle assessment can assist the construction industry in selecting more sustainable technological alternatives. In this context, wall systems play a significant role in the environmental and economic performance of a building. This paper compares the potential energy, costs, and environmental impacts of three structural wall construction systems (ceramic, concrete, and soil-cement blocks) for standard residential housing in Southern Brazil, considering a 50-year lifespan. The highest environmental impacts are related to the use stage of all three systems. The ceramic brick system presents the highest impact in the product stage, the concrete block system in the use stage, and the soil cement brick system in the construction stage. The concrete block system presents the highest relative net present value, followed by soil cement and ceramic brick systems. The impacts for the soil-cement block system are similar to those for ceramic block, while the concrete block system is the most expensive, energy demanding, and CO2 releasing. The results demonstrate the importance of producing criteria for architectural decision-making based on scientific evidence when choosing wall systems. [ABSTRACT FROM AUTHOR]

In this study, the performance of different cooling technologies from energy and economic perspectives were evaluated for six different prototype residential Nearly Zero Energy Buildings (NZEBs) within a planned future city district in central Sweden. This was carried out by assessing the primary energy number and life cycle cost analysis (LCCA) for each building model and cooling technology. Projected future climate file representing the 2050s (mid-term future) was employed. Three cooling technologies (district cooling, compression chillers coupled/uncoupled with photovoltaic (PV) systems, and absorption chillers) were evaluated. Based on the results obtained from primary energy number and LCCA, compression chillers with PV systems appeared to be favorable as this technology depicted the least value for primary energy use and LCCA. Compared to compression chillers alone, the primary energy number and the life cycle cost were reduced by 13%, on average. Moreover, the district cooling system was found to be an agreeable choice for buildings with large floor areas from an economic perspective. Apart from these, absorption chillers, utilizing environmentally sustainable district heating, displayed the highest primary energy use and life cycle cost which made them the least favorable choice. However, the reoccurring operational cost from the LCCA was about 60 and 50% of the total life cycle cost for district cooling and absorption chillers, respectively, while this value corresponds to 80% for the compression chillers, showing the high net present value for this technology but sensitive to future electricity prices. [ABSTRACT FROM AUTHOR]

Hydrogen has gained significant attention in recent years as a clean and sustainable energy source, with the potential to revolutionize the energy industry. However, one of the challenges associated with hydrogen as an energy source is its storage and transportation. Hydrogen is a highly compressible gas, making it difficult to store and transport in its natural state. The study presents different varieties of hydrogen tanks that are used for the storage and transportation of hydrogen gas. The methods for compressing hydrogen are described, with a focus on their advantages and disadvantages. The study concludes by comparing different methods for compressing hydrogen and discussing the factors that influence the choice of method for a specific application. The importance of continued research and development in this area is emphasised, as the efficient compression of hydrogen is crucial for the widespread adoption of hydrogen as a clean and renewable energy source. Life cycle cost analysis can evaluate the economic feasibility of using different hydrogen compressor technologies by estimating the total cost of owning and operating the compressors over their entire lifespan. [ABSTRACT FROM AUTHOR]

In this study, we aimed to provide a practical method to estimate the economic and environmental impact of vehicle and work activities throughout the entire service life of a pavement area to support pavement management strategies and decisions. To achieve this, we integrated two key life cycle analysis methods, life cycle assessment (LCA)) and life cycle cost analysis (LCCA). The integrated model not only considers CO2 emissions associated with the four main modules—the materials module, the work activities module, the work zone module and the usage module—mentioned in LCA, it also considers agency costs and user costs related to highway usage, work activities, work zone traffic delays and detours in the LCCA process. We used detailed and integrated methods to compute CO2 emissions and costs based on the four modules and two components of agency and users mentioned above. A case study based on a real freeway project in China was used to verify the applicability of the integrated model. The results of the application of the integrated LCA-LCCA model indicate that maintaining the typical activity profile could be beneficial in terms of both CO2 emissions and cost, with savings of 36.8 ton/lane/km of CO2 emissions and 10,530 USD/lane/km (in 2007 dollars) representing the total benefits during the pavement's service life. This means that timely maintenance could help to achieve savings in terms of financial costs and CO2 emissions simultaneously. [ABSTRACT FROM AUTHOR]

The pathway to zero carbon emissions passing through carbon emissions reduction is mandatory in the shipping industry. Regarding the various methodologies and technologies reviewed for this purpose, Life Cycle Cost Analysis (LCCA) has been used as an excellent tool to determine economic feasibility and sustainability and to present directions. However, insufficient commercial applications cause a conflict of opinion on which fuel is the key to decarbonisation. Many LCCA comparison studies about eco-friendly ship propulsion claim different results. In order to overcome this and discover the key factors that affect the overall comparative analysis and results in the maritime field, it is necessary to conduct the comparative analysis considering more diverse case ships, case routes, and various types that combine each system. This study aims to analyse which greener fuels are most economically beneficial for the shipping sector and prove the factors influencing different results in LCCA. This study was conducted on hydrogen, ammonia, and electric energy, which are carbon-free fuels among various alternative fuels that are currently in the limelight. As the power source, a PEMFC and battery were used as the main power source, and a solar PV system was installed as an auxiliary power source to compare economic feasibility. Several cost data for LCCA were selected from various feasible case studies. As the difficulty caused by the storage and transportation of hydrogen and ammonia should not be underestimated, in this study, the LCCA considers not only the CapEx and OpEx but also fuel transport costs. As a result, fuel cell propulsion systems with hydrogen as fuel proved financial effectiveness for short-distance ferries as they are more inexpensive than ammonia-fuelled PEMFCs and batteries. The fuel cost takes around half of the total life-cycle cost during the life span. [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]

Rubberized concrete is widely used in construction by utilizing the advantages of partially replacing fine or coarse aggregate with rubber to enhance several properties of concrete and provide an environmentally friendly solution. This paper experimentally explores the influence of utilizing crumb rubber (CR) as an alternate coarse aggregate in concrete. Concrete specimens were prepared with different percentages of rubber (0%, 5%, 10%, 15%, and 20%). Additionally, other parameters, such as freezing–thawing cycles, temperature, and stainless steel fibers (SSFs), were investigated. The workability of fresh concrete and the compression properties of hardened concrete were examined. Reductions in the mechanical properties of rubberized concrete were obtained. The compressive strength reductions ranged between 13% and 50%, based on the percentage of CR in the concrete mix. However, a lesser unit weight and higher toughness were obtained relative to conventional concrete. The average unit weight decreased by 1.3%, 2.5%, 3.4%, and 5.7% of the control mixture when 5%, 10%, 15%, and 20% of the CR were incorporated into the concrete mixtures, respectively. Regression models to predict the compressive strength and unit weight of concrete with CR were developed. In addition, a life cycle cost analysis (LCCA) to identify and quantify the possible benefits of using CR in concrete mixes was carried out. Using rubberized concrete mixtures for thin whitetopping offered a slightly lower net present value compared to the ordinary concrete mix. [ABSTRACT FROM AUTHOR]

The circular economy concept resonates as a new approach to optimize limited resource usage and reduce waste generation. However, the most solar PV power plant analyses do not consider the sustainable disposal of used systems at the end of life (EoL) or at the time for potential refurbishment. The 50 MWp Burnoye‐1 solar power plant in the Jambyl region in Kazakhstan was modeled using the RETScreen Expert platform to determine how the circular economy concept may increase its environmental benefits and impact the levelized cost of produced electricity. Results proved that recycling Burnoye‐1's photovoltaic panels at EoL would increase the project's Net Present profit by almost 0.373 million USD, marginally raising its Benefit–cost and internal rate of return (IRR) on equity by much less than 1% each, with respect to the non‐recycling baseline. However, a significant impact on the 25‐year lifetime GHG emissions is achieved when PV recycling is considered. Recycling the PV panels in Burnoye‐1 at the EoL would add an extra 76.5 ktCO2e emissions reduction, representing an increase of 8.7% in its avoided lifetime GHG emissions. Furthermore, PV recycling may generate local jobs benefitting the neighboring communities. Thus, this study demonstrates that the circular economy approach is viable in Kazakhstan and will help the country meet its goal of becoming carbon neutral by 2060. [ABSTRACT FROM AUTHOR]

Biowaste-to-biogas processes have been introduced to design a valuable and green renewable plant to achieve a sustainable society and environment. The biomethane production process through biogas upgrading instead of designing a combined heat and power (CHP) system can be more attractive. This study presents a life cycle analysis (LCA) from both cost and environmental standpoints for four biowaste-to-biogas/biomethane process scenarios. Biogas production is achieved through anaerobic co-digestion of the organic fraction of municipal solid waste (OF-MSW) and secondary sewage sludge (S-SS), incorporating a pre-treatment process based on the dark co-fermentation process (DCFP). Each scenario offers distinct methods for utilizing the hydrogen-rich gas and biogas, with varying degrees of energy recovery and efficiency. Two sensitivity studies were conducted under various utilizations of the recovered biomethane and the anticipated electricity mix. Scenario SC-1 (CHP-from-biogas) was found to be the most co-friendly favorable in eight out of eleven impact categories (under the CML/IA technique). Further, biogas upgrading-integrated options exhibited lower impacts. Replacing biomethane instead of petrol in scenarios with upgraded biogas was identified as the most effective approach against climate change. Financial analysis indicated that all layouts are economically viable, each demonstrating a positive NPV over a 20-year period (up to $11.57 million). • Life cycle analysis for different biowaste-to-biogas/biomethane scenarios. • Anaerobic co-digestion process of MSW organic fraction and secondary sewage sludge. • Different method for utilizing the hydrogen-rich gas stream and biogas. • Biogas upgrading-integrated options exhibited less impact in the respective items. • Economically viable, all option demonstrating a positive NPV over a 20-year period. [ABSTRACT FROM AUTHOR]

In recent years, due to the advent of several additives and innovations, asphalt mix design has become more complex. The mixes meeting the volumetric mix design requirements may still fail prematurely in the field. Thus, a transition from a simplistic volumetric-based mix design to a performance-based mix design is required, which was also envisioned in the Strategic Highway Research Program (SHRP) and Superpave mix design. In addition to performance verification, asphalt mix designs should also be evaluated for the life-cycle costs and environmental impact to encourage durable as well as sustainable and cost-effective alternatives. In this study, three asphalt mixtures with different reclaimed asphalt pavement (RAP) contents and additives were evaluated for cracking and rutting performance by using different performance thresholds for asphalt mixtures that are generally used in the construction of high-volume roads in Oregon. A balanced mix design process was followed to determine the required binder content for the three mixtures. Based on the life cycle cost and environmental impact analyses, the mixture with warm mix additive (WMA) was selected as the most economically and environmentally viable asphalt mixture to be used for construction in Oregon. [ABSTRACT FROM AUTHOR]

In this study, the life cycle costs of railway projects involving hybrid diesel-electric vehicles are analysed. Specifically, the analysis focuses on the comparison of 3 lithium-ion battery technologies (NMC, LTO and LFP) and 8 energy management strategies (including rule-based and optimization-based strategies). In order to develop this analysis, a methodology that returns the life cycle cost of each proposed case is presented. The methodology includes the optimization of the diesel generator and lithium-ion battery sizing. A scenario based on a real railway line is introduced, and the obtained results are compared to a traditional diesel-electric railway vehicle to develop a techno-economical discussion. The best lithium-ion battery technologies are found to be LTO and NMC, and the most appropriated strategy a state-machine controller optimised by a genetic algorithm approach. The best case obtains a life cycle cost reduction of the 4.0% and diesel savings of the 13.7% compared to a traditional diesel-electric railway vehicle. The proposed analysis is claimed to be potentially helpful for the cost-optimal design and operation definition of powertrains for hybrid railway vehicles. [ABSTRACT FROM AUTHOR]

[Display omitted] • The study is conducted to supply a multi-zone complex via a renewable energy cycle. • A hybrid PV/T–GSHP system has been opted as the source. • Overall COP of the system for the main scenario of the cycle is 2.866. • Winter holidays raise the COP by 16.85% and reduce the LCC by 3.67%. This paper introduces a novel cycle to supply the demands of a huge case study incorporating eight thermal zones with sports and administrative applications for space heating, space cooling, domestic hot water, and electricity. Choosing this complex is one of the most important innovations of the current study. A combination of photovoltaic/thermals and ground-source heat pumps are connected to the storage tanks, heaters, heat exchangers, and some other elements to provide energy for the mentioned buildings. This cycle is simulated numerically using TRNSYS 16, and the amounts of heating and cooling loads of the buildings are estimated via TRNBuild 3.0. The cycle is then discussed to investigate its capability of supplying the demands over the period of 20 years; reaching the coefficient of performance and life cycle cost of 2.866 and 164,451 €, respectively, with less than 0.03 °C drop in ground temperature at the end of the given period. In addition, as an important novelty, defining a number of scenarios provides a thorough examination of the important parameters of the cycle, including environmental, operational, and economic features under different conditions. This comprehensive analysis shows that adding winter holidays or insulating the walls of the buildings are the best ways of improving the system's performance. Lastly, the operation of the system in Iran is also compared with some other countries; showing that installing this system is not economically suitable in Iran. Portugal with a payback time of 3.84 years is the best country to install the designed cycle. [ABSTRACT FROM AUTHOR]

This paper aims to make recommendations about the convenience of using low-noise pavements to mitigate traffic noise under different traffic and population scenarios. To do so, a life cycle approach has been applied by performing a Life-cycle Assessment (LCA) and Life-cycle Cost Analysis (LCCA). To account for the noise mitigation achieved by the road surfaces, which is the main benefit compared to conventional road surfaces, the damage effect of traffic noise has been incorporated in both analyses. Thus, open source noise emission and propagation modelling and Geographical Information System (GIS) tools have been used to determine the noise level at which residents are exposed. The impact of noise emissions on human health is estimated and expressed in disability-adjusted life years (DALYs) and the related external cost have been calculated by monetarizing the environmental impacts and by integrating them within the cost assessment. The methodology followed allowed the comparison of different scenarios and the results show a huge potential for reducing environmental impacts and costs when using low-noise road surfaces although accurate information about the acoustic aging of the materials is key in order to ensure that benefits are obtained. [Display omitted] • The feasibility of low-noise road surfaces has been evaluated combining LCA and LCCA. • Noise exposure is assessed using open-source GIS and noise modelling tools. • Population and traffic density influence low-noise surfaces viability. • Traffic noise impacts significantly outweigh other LCA/LCCA categories. • Acoustic ageing estimates of low-noise surfaces affect low-noise surfaces viability. [ABSTRACT FROM AUTHOR]

• Climate change accelerates pavement deterioration, increasing maintenance and fuel use. • Significant pavement deterioration is expected to occur in Southeast China. • Preventative maintenance strategies can reduce fuel use, GHG emissions, and costs. Pavements are susceptible to accelerated deterioration due to changing climate conditions, leading to increased maintenance and excess fuel consumption through pavement-vehicle interaction. China's diverse climates raise concerns about the environmental and economic sustainability of flexible pavements amid climate change and the effectiveness of preventative maintenance strategies. This study examines climate change's potential impacts on long-term pavement performance, greenhouse gas (GHG) emissions, and costs, employing the Mechanistic-Empirical Pavement Design Guide method. The calibrated World Bank's Highway Development and Management Model 4 assesses the impacts of surface characteristics on vehicle fuel consumption. Life cycle assessment and life cycle cost analysis quantify GHG emissions and costs. Results reveal significant pavement deterioration in Southeast and Central China. Preventative maintenance strategies reduce fuel consumption, with GHG emissions and cost savings from smoother driving conditions outweighing those from maintenance. These insights stress the importance of proactive maintenance strategies for mitigating climate-induced deterioration and enhancing sustainability. [ABSTRACT FROM AUTHOR]

Oil-Based Drill Cuttings (OBDC) are one of the hazardous wastes of the oil and gas industry. In this study, Reclaimed Asphalt Pavement (RAP), OBDC and Fly Ash (FA) geopolymer were used in Cold Central Plant Recycling (CCPR) mixtures. The dynamic modulus test was used to appraise the viscoelastic properties of CCPR mixtures. The Toxicity Characteristic Leaching Procedure (TCLP) test was also utilized to investigate the long-term contaminants leaching. In addition, a cradle-to-grave Life Cycle Assessment (LCA) and Life Cycle Cost Analysis (LCCA) were conducted to evaluate the potential environmental burdens and economic costs of pavement structures containing CCPR mixtures. Moreover, Multi-Criteria Decision-Making (MCDM) analysis using four different methods was performed to determine the optimal sample. The results revealed that the recycling of OBDC and RAP in stabilized CCPR mixtures with FA geopolymer can improve the viscoelastic properties and prevent the leaching of contaminants from these waste materials. Furthermore, recycling of the mentioned waste materials in CCPR mixtures has caused a significant reduction in global warming, acidification, eutrophication, smog, respiratory effects, Human toxicity, ecotoxicity, and cumulative energy demand up to 41%, 36.6%, 73%, 43%, 47%, 34%, 73%, and 13%, respectively. Additionally, using CCPR mixtures containing the OBCD, RAP, and FA geopolymer in the pavement structure has led to economic benefits of up to 31% compared to the conventional pavement system. [Display omitted] • OBDC and RAP were recycled as alternative aggregates in CCPR mixtures. • Replacing RAP with OBDC enhanced the viscoelastic performance of CCPR mixtures. • Recycling OBDC and RAP in CCPR-stabilized mixtures with geopolymer lowers leaching. • LCA and LCCA reveal benefits from recycling OBDC and RAP compared to landfilling. • MCDM analysis was performed in order to determine the optimal mixture. [ABSTRACT FROM AUTHOR]

This research quantified the impact that truck mix, distress severity, and climate have on pavement damage and maintenance costs based on Long-Term Pavement Performance (LTPP) sections. Cost analysis was conducted using in-situ records of maintenance and rehabilitation data from 1988 to 2016. The paper quantified damage cost per VMT and ESAL-mile for each FHWA truck class. Economies of scale are evident in the cost per ESAL-mile relative to total pavement loading as segments carrying higher traffic loads require additional maintenance and rehabilitation, however additional cost for these procedures is outpaced by the increase in traffic resulting in a reduction in the pavement damage cost per ESAL-mile. The cost per ESAL-mile varied from $0.01 to $0.37 per ESAL-mile depending on total loading, a relationship that is accurately modeled (R2 = 0.97) using the developed power function. Results also show that vehicle class, and thereby the number and distribution of ESALs, significantly impacts the pavement damage cost. The research developed an accurate and robust model correlating pavement damage cost per ESAL-mile to the accumulated number of ESALs during the pavement service life. Transportation agencies can utilize this model to determine a fair variable compensation for the pavement damage imposed by individual trucks. [ABSTRACT FROM AUTHOR]

The present study aims to determine and model CO2 emissions based on the energy savings through the thermal insulation applied to the external walls of the buildings for eighty-one different zones using four diverse thermal insulation materials. Depending on the by life cycle cost analysis (LCCA) and the number of degree-days, optimum insulation thicknesses were determined in the present study, in which the heating and cooling needs of the buildings were considered separately. The net savings associated with insulated buildings were also calculated, including the optimum insulation thickness and the payback period for the insulation applied. In buildings with thermal insulation, it has been determined that CO2 emissions will be reduced by approximately 66–76% during the heating season and by 46–69% during the cooling season. Moreover, the amount of CO2 emissions released into the atmosphere from uninsulated and insulated buildings was modeled with ten polynomial-type functions derived from the MATLAB R2019a program. The model results controlled by regression analyses revealed statistical suitability. These models demonstrate a more advantageous approach than prior studies for determining the annual total CO2 emissions per unit area of the exterior walls of buildings. This study is intended to assist housing authorities and designers in making informed decisions about energy savings in buildings. [ABSTRACT FROM AUTHOR]

Subsidy incentive programs for accelerating the replacement of construction equipment are widely considered effective for reducing emissions from construction equipment. However, there are no known effective models for determining the optimal subsidy levels for voluntary early replacement of in-use high-emission construction equipment. In this study, a novel quantitative model is developed to address this problem by integrating emission reduction targets and life cycle cost of construction equipment to calculate the reduced service life of an item of construction for early replacement. The economic life of construction equipment and its corresponding equivalent uniform annual cost (EUAC) can be determined by using a traditional life cycle cost analysis model. Optimal subsidy levels are obtained on the basis that the subsidized EUAC of a piece of construction equipment over its shortened service life is not more than that over its normal economic life. The applicability of the proposed model is demonstrated through a case study of a crawler crane used in Hong Kong, whereby the subsidy levels for accelerating its replacement are determined. An interview with the contractor's equipment manager responsible for the crawler crane is conducted to validate the findings of the model. It is found that the optimal subsidy levels determined by the model can accelerate the replacement of construction equipment and achieve the goal of reducing emissions from construction equipment. Replacing construction equipment earlier than its economic life is a plausible strategy for emissions reduction but places a heavy financial burden on contractors if there is no financial compensation. This study shows that the subsidy levels determined by the proposed model can adequately compensate for the extra costs incurred from early replacement and would therefore not financially discourage contractors. This model also shows that the cost-effectiveness of subsidies increases as emission reduction targets are set at higher levels. [ABSTRACT FROM AUTHOR]

Transferability between input variables of life cycle cost analyses for concrete bridges Life cycle cost analyses are a method for prioritizing structures and measures in the context of building maintenance management. Life cycle cost analyses take into account a large number of different input variables, which in turn are themselves based on different parameters, because often infrastructure and real estate operators do not have all input variables available. This paper deals with the transferability of the different input variables and parameters in order to be able to perform a homogeneous life cycle cost analysis. For this purpose, a literature review and a subjective estimation of cross‐correlations were performed. [ABSTRACT FROM AUTHOR]

Civil infrastructure systems transform over the long-term due to complex interactions among socio-environmental stressors, degradation of physical networks, and decision-making processes of infrastructure agencies. To incorporate such complex transformation mechanisms into infrastructure cost management, this study integrates simulation modeling and life-cycle cost analysis (LCCA) to create a framework for dynamic network-level LCCA in infrastructure systems. The proposed framework was implemented using a multi-agent simulation model in a numerical case study related to a road network affected by sea-level rise, population growth, and uncertain maintenance funding. The results include identification of several state transition, and tipping point behaviors at which small changes in service demand, maintenance budget, and adaptation investment may result in significant improvement in network cost and performance conditions. The results show the capability of the proposed framework in modeling the long-term trajectories of life-cycle costs at the network level under different stressors and decision scenarios. [ABSTRACT FROM AUTHOR]

Because of their significant energy consumption and its economic and environmental impacts, existing buildings offer decision makers opportunities and challenges at the same time. In fact, there is a worldwide effort to improve the energy performance of the existing buildings as well as the new ones to achieve zero-energy buildings. In this paper, a framework for retrofitting existing buildings to help achieve the goal of zero-energy buildings is presented. The framework details the different steps required to develop and implement a successful retrofitting plan for both residential and commercial buildings. This includes data collection, life cycle cost calculation, building simulation, and multi-criteria decision making using the analytic hierarchy process (AHP). At the end of the paper, a case study is detailed to show the different steps necessary to select a successful retrofitting plan that reflects the decision maker's objectives. The case study resulted in a retrofitting plan that offers a yearly energy savings of 30% and a payback period of 2.2 years. [ABSTRACT FROM AUTHOR]

Communication towers are vital assets in our daily lives as they transfer signals between cell phones facilitating communication and commerce among people and businesses all around the world. Wind loads are crucial in the communication towers design since they are tall and slender. With climate change bringing more storms and higher wind speeds, it is more crucial to research the finest tower structure that withstands such conditions with the least life cycle cost. Therefore, in this paper, a comparative case study is performed between 45 m height lattice tower and monopole tower in Egypt. Two locations were considered, the first is inside the city and the second is an open terrain. In addition, two load scenarios were investigated. The comparison parameters are the behavior under critical wind loads taking into account three wind speeds which are 100 km/hr, 130 km/hr and 140 km/hr, and life cycle cost analysis. It was found that the lattice tower behaves better under critical wind loads with a maximum tilting equal to 0.4784 degrees at location 1, load 2, and a wind speed of 140 km/hr compared to 0.5806 in the case of the monopole tower. Similarly, the lattice tower behaves better at the second location as well. However, the monopole tower has less life cycle cost with a total life cycle cost of 3,201,846.80 EGP compared to 4,380,419.91EGP in case of lattice tower. Therefore, based on the location, wind speed, and available land area, and life cycle cost assessment, the optimum tower structure could be selected. [ABSTRACT FROM AUTHOR]

Recent United Nations high-level dialogue on energy, which had emphasized on energy usage and environmental protection, has renewed commitments by different countries on the adoption of electric vehicle (EVs). This paper aims to analyze the economic feasibility of establishing electrical charging stations, which is an important factor for the wide adoption of EVs, using life cycle cost analysis. Although local data have been used, the method can be easily adopted to analyze economic feasibility at different markets. The findings have revealed that an electrical charging station is only feasible when the acquisition cost is kept to a minimum to return 1.47 times the initial investment in terms of life cycle cost. An acquisition cost of BND 29,725 on the electrical charging station represents the threshold below which an electrical charging station is more attractive. In order to promote these charging stations, the government needs to provide multiple incentives, including a subsidy to reduce the acquisition cost, relaxing control on the electric selling price, taxing the establishment of conventional filling stations, and minimally reducing the profit margin on the selling price of fossil fuel. It has been shown that a 40% initial subsidy on the purchase of electrical charging stations, coupled with a slight subsidy of BND 0.018/kWh on electricity, would make electrical charging stations economically competitive. To reach its target of 60% electrification of the transportation sector, Brunei would need to implement a structure program to establish between 646 and 3300 electrical charging stations by the year 2035, to cater for its expected number of EVs. [ABSTRACT FROM AUTHOR]