Using off-site hydrogen can reduce CO2 emissions from urban buildings with limited renewable energy generation. We demonstrated the supply and usage of off-site green hydrogen using a pilot-scale ...hydrogen energy utilization system, Hydro Q-BiC®, for a commercial building. The off-site location supplied green hydrogen to the on-site system using high-pressure gas. By developing rapid-filling-type metal hydride tanks, we could safely fill 100 Nm3 of off-site hydrogen at <1 MPaG in approximately 1 h. The use of off-site green hydrogen in a 24 h operation of Hydro Q-BiC® can extend the operation time of fuel cells and significantly contribute to a reduction in CO2 emissions. Estimations indicate that gray hydrogen increases CO2 emissions, and CO2 emissions can be reduced to zero using a green-hydrogen supply of 300 Nm3. The results indicate that the type and quantity of supply of off-site hydrogen are important for reducing the CO2 emissions of buildings.
•Utilization of off-site hydrogen can help reduce CO2 emissions from urban buildings.•Hydrogen energy utilization system Hydro Q-BiC® developed for a commercial building.•Hydro Q-BiC® tested to demonstrate efficacy in reducing CO2 emissions of a building.•Type and quantity of off-site green hydrogen influence reduction in CO2 emissions.
•A method based on dose rate was proposed to estimate the expected contaminated people at each assemble point in nuclear accident scenarios, which is more rigorous compared with the other methods ...using average wind frequency and assembly point orientation.•Combined with public contaminated proportion, population structure and waiting psychology, a public decontamination model based on queuing theory and system dynamics method was proposed for offsite nuclear emergency to quantify the decontamination process and estimate overall time.•A configuration plan for adding devices was provided to meet the time requirement and control the number of waiting queues within the specified threshold efficiently.•The proposed method can help nuclear emergency decision-makers display the decontamination process, estimate the overall time and optimize site configuration plan.
Decontamination is an important means to reduce the personnel radioactive contamination under sever nuclear accidents. Public decontamination time estimation with the process simulation is helpful for emergency organizations to improve efficiency. To date, most studies focus on improving personal decontamination technology and decontamination strategies, while research on the overall decontamination process and time estimating is limited. Due to the complex population structure, the unknown contaminated proportion and the complicated psychological emotions, it is hard to quantify the decontamination process and calculate the decontamination time with numerous procedures and diverse facility configurations. Combined with public contaminated proportion, crowd structure and waiting psychology, a public decontamination model based on queuing theory and system dynamics method is established for offsite nuclear emergency to simulate the decontamination process and give an estimate of decontamination time. A hypothetical nuclear leakage accident of Changjiang Nuclear Power Plant in Hainan, China is conducted to simulate the established model. The results show the working status of different facilities at different stages and the changes in waiting queues at different times, which can effectively calculate the duration time of each link and the overall public decontamination progress. A plan for adding devices is provided to meet the decontamination time requirements and control the number of waiting queues within the specified threshold efficiently. The method proposed in this paper could help nuclear emergency decision-makers estimate the public decontamination time, optimize site configuration plans, give guidance on public decontamination procedures and prepare for the subsequent nuclear emergency evacuation.
There is currently a “mother-daughter” model for hydrogen refueling stations (HRS). On-site “mother” stations produce hydrogen from city natural gas or water electrolysis, and off-site “daughter” ...stations are supplied with hydrogen from nearby on-site stations. This HRS system is a micro hydrogen supply chain that includes hydrogen suppliers, retailers, and end consumers characterized via demand functions. The present paper designs an optimal business model for this distributed HRS system using a multi-level game model, given that on-site and off-site HRS can operate individually or as a coalition to supply hydrogen. Stackelberg game and Shapley value models are constructed to explore how cooperative operation is superior by generating more profits than separate operation. Accordingly, in order to promote cooperation between on-site and off-site operators of HRS, an evolutionary game model is developed to investigate the allocation of profits and coordinated costs on the equilibrium of cooperative operation. The authors conclude that boosting the initial probabilities of actors to choose cooperative strategies and decreasing the coordinated cost can lead the game system to the ideal consequence. The present paper offers recommendations including establishing regulation standards for HRS operation, and advancing the information technology to design a more effective cooperative mechanism.
•A business model of the hydrogen distribution is designed by multi-level games.•The centralized cooperation mode is better than the decentralized separation mode.•Reduction in the communication cost can help to achieve the cooperative mode.•Regulation and information technology related to the hydrogen should be enhanced.
Recently, more attention has been devoted to Prefabricated Buildings (PBs) as an alternative technique for developing building sustainability. Due to a great deal of discussion about the link between ...environmental and economic performance and a lack of critical review relating the PBs to these two aspects, the main focus of this research is on the environmental and economic performance of PBs. Using a systematic search and critical literature review, this paper reviews the significant studies in this area and discusses corresponding assessment methods, systems boundaries, recommended methods, and research gaps. It is concluded that, on average, environmental dimensions of PBs have been studied more than economic ones and with more certainty. It was also recommended to assess the economic profitability of PBs in a long-term period utilizing various measurements. The contribution of this study can be summarized by 1) providing a deeper insight into both the environmental and economic performance of PBs, and 2) identifying the research gaps and future research directions.
•Exploring environmental and economic assessment methods of PBs in the literature.•Discussing GHG emission and thermal and energy performance of PBs.•Investigating cost and time related results in PBs.•Highlighting future research agenda for environmental and economic aspects of PBs.
The members within organizations have various types of job duties to put into operation. These are to be paid attention towards in both personal and professional lives. Some job duties are less time ...consuming, whereas, some arc more time consuming. Time is necessary which needs to be taken out for all job duties. From the stage of early childhood, the individuals arc trained in terms of putting into operation these skills in an effective manner. In order to complete all job duties on time, the members need to recognise the meaning and significance of time management skills. The implementation of these skills in an effective manner will facilitate in completing all job duties on time. Furthermore, they will create a balance between personal and professional lives. The time management skills will enable the individuals to incur the feelings of pleasure and contentment. When the individuals arc able to take out sufficient amount of time for all job duties in their personal and professional lives, they will feel satisfied. Hence, throughout the lives of the individuals in both personal and professional spheres, they need to put emphasis on reinforcement of these skills. Therefore, it can be stated, time management skills arc essential in implementing all job duties on time. The main concepts that arc taken into account in this research paper arc, understanding the four Ds of time management skills, factors highlighting the meaning and significance of time management skills and measures of bringing about improvements in time management skills.
As the development of hydrogen refueling stations (HRS) is key to the hydrogen industry, it is necessary to study the investment feasibility for potential investors in order to stimulate its ...investment. We view the HRS investment as a two-stage decision-making process, distinguishing characteristics of off-site HRS from those of on-site HRS. Investors can first decide whether or when to invest in an off-site HRS, and then can accordingly decide whether or when to upgrade from an existing off-site HRS to an on-site HRS, by retrofitting off-site HRS with on-site hydrogen production device. We select natural gas reforming as the technology of on-site hydrogen production device, not only because natural gas reforming is cheaper and maturer, but also because this type of retrofit has been applied in a real case. Since the investment in HRS entails multiple uncertainties, we use a compound real options approach for conducting an appraisal of HRS investment. Accordingly, we use the Chinese case to present a new perspective to the sequential analysis of HRS investment decision-making. Four various scenarios are set for a case study, including one benchmark scenario reflecting the current Chinese hydrogen policies, and three comparative scenarios reflecting potentially improved policies, such as increasing operational subsidy, implementing preferential taxation and stimulating demand. The results show the current scenario is not beneficial to invest in HRS building on the proposed analytical framework and the data collected from the case of China. Furthermore, the increase in demand plays the leading role in improving the probability of HRS investment, followed by the implementation of preferential taxation and increasing operational subsidies. Additionally, the on-site HRS shows its superiority over off-site HRS, because all scenarios suggest upgrading to on-site HRS should be executed immediately once the initial off-site HRS is constructed. Therefore, in the context of Chinese hydrogen market and the selected on-site technology of natural gas reforming, it is necessary to create a more favorable business environment for the layout of on-site HRS.
•Building hydrogen refueling station (HRS) is a two-stage decision-making process.•The appraisal of two-stage HRS investment is studied by compound real options.•Off-site HRS construction is the prerequisite to the subsequent on-site retrofit.•On-site HRS show its superiority over off-site HRS based on the case study.•Growth in demand is a better policy for increasing investment probabilities of HRS.
Wuhan Leishenshan/Leishenshan (“Leishenshan” for short) hospital is a makeshift emergency hospital for treating patients diagnosed with the novel coronavirus-infected pneumonia (NCIP). Engineering ...construction uses modular composite building finished products to the greatest extent, which reduces the workload of field operations and saves a lot of time. The building information model (BIM) technology assists in design and construction work to meet rapid construction requirements. Besides, based on the unmanned aerial vehicles (UAVs) data analysis and application platform, digitization and intelligence in engineering construction are improved. Simultaneously, on-site construction and overall hoisting were carried out to achieve maximum efficiency. This article aims to take the construction of Leishenshan Hospital as an example to illustrate how to adopt BIM technology and other high-tech technology such as big data, artificial intelligence, drones, and 5G for the fast construction of the fabricated steel structure systems in emergency engineering projects.
•Assembled design, clean and dirty partition, total impermeability;•Modular sealing and anti-diffusion air pressure management unit;•Optimal architecture, development, logistics and process alignment;•BIM, 5G, AI, IoT, among other IT applications;•Cloud supervisors and civic engagement
While conventional wisdom suggests that financial supervision is costly for bank shareholders, agency theory suggests that supervisors’ audits can reduce shareholder monitoring costs. I study this ...trade-off in the context of an unexpected decrease in off-site surveillance intensity by the U.S. Federal Reserve. Banks subject to reduced surveillance experience a 1% loss in bank Tobin’s q and a 7% loss in equity market-to-book. These banks engage in more earnings management, and appear to compensate lower regulatory surveillance with costly internal audits. My results document a novel substitution effect between public monitoring by regulators and private monitoring by shareholders. This paper was accepted by Victoria Ivashina, finance. Supplemental Material: The online appendix and data files are available at https://doi.org/10.1287/mnsc.2021.03083 .
Modular construction (MC) has been regarded as a feasible solution to significantly improve productivity, shorten building times, and reduce the enormous environmental burden the construction ...industry has to shoulder. Although there has been considerable uptake of this construction method in several countries worldwide, widespread adoption is still held back by various interlinked barriers. In Germany – one example of a well-established off-site construction (OSC) market – the adoption of MC by housing corporations is still relatively low. This is surprising when considering their key role in quickly creating living spaces in areas with increasing housing shortages. Therefore, this study explores the interconnectedness of MC barriers from a developer's perspective. Based on a literature review, critical barriers (B1–B8) were identified; these barriers were evaluated by industry experts regarding their influence on each other by applying the fuzzy decision-making trial and evaluation laboratory (DEMATEL) approach. The results provide in-depth insights into the relationships of barriers that impede further uptake of MC and highlight the factors that should be given the most attention by practitioners and researchers to promote this cleaner production method. Based on these analyses, the barriers supply (B4), demand (B5), and process (B8) can be regarded as strongly interconnected and highly relevant, while the industry's attitude (B7) is the most critical barrier. In contrast, regulatory (B1) and knowledge (B6) factors are fundamental prerequisites but are largely detached from the network of barriers; therefore, they do not constitute crucial barriers in the context of this study. The technical barrier (B2) has neither strong interconnections in the network nor strong influences on other factors. The financial hurdle (B3) was found to be highly relevant for promoting MC while also being highly influenceable, indicating that there are several possible ways to raise the economic attractiveness of this construction method.
•Barriers towards further adoption of modular construction (MC) are identified.•Complex interrelationships of barriers in a well-established market are analyzed.•Effects between individual barriers reveal various potentials for promoting MC.•The industry's attitude is the most critical barrier to further adoption of MC.•Process and market-related factors are strongly interconnected and highly relevant.
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