Built environment stocks (buildings and infrastructures) play multiple roles in our socio-economic metabolism: they serve as the backbone of modern societies and human well-being, drive the material cycles throughout the economy, entail temporal and spatial lock-ins on energy use and emissions, and represent an extensive reservoir of secondary materials. This review aims at providing a comprehensive and critical review of the state of the art, progress, and prospects of built environment stocks research which has boomed in the past decades. We included 249 publications published from 1985 to 2018, conducted a bibliometric analysis, and assessed the studies by key characteristics including typology of stocks (status of stock and end-use category), type of measurement (object and unit), spatial boundary and level of resolution, and temporal scope. We also highlighted the strengths and weaknesses of different estimation approaches. A comparability analysis of existing studies shows a clearly higher level of ...

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Taking Stock of Built Environment Stock Studies: Progress and Prospects.

勤務医の現職からの離職の傾向－就業構造基本調査から－ ; Trend of Medical Doctors Leaving Current Employment in Japan: Analysis of Data of Employment Status Survey Conducted by Ministry of Internal Affairs and Communications

Quantifying the changing patterns and determinants of material stocks (MS) is important for understanding the interplay between socioeconomic development and environment conservation, and for addressing the challenges in sustainable development. This paper conducts a MS accounting for 10 materials in 6 major infrastructures in Beijing, Tianjin and Shanghai, and probes into the driving factors behind the change within the 1978–2013 period through a logarithmic mean divisia index decomposition method. The results suggest that MS changes through a rapid enhancement in the 1980s, a steadily growth in the 1990s, and an acceleration after the 2000s. A relative decoupling phenomenon was detected in the development of economy and MS, which was largely caused by the decline of MS intensity. The policy implications include paying more attentions to the improvement of MS efficiency especially in buildings, substituting for less energy-intensive construction materials, controlling the extensive urban sprawl, and raising the population density.

Changing patterns and determinants of infrastructures’ material stocks in Chinese cities

Modern cities and societies are built fundamentally based on cement and concrete. The global cement production has risen sharply in the past decades due largely to urbanization and construction. Here we deployed a top-down dynamic material flow analysis (MFA) model to quantify the historical development of cement in-use stocks in residential, nonresidential, and civil engineering sectors of all world countries. We found that global cement production spreads unevenly among 184 countries, with China dominating the global production and consumption after the 1990s. Nearly all countries have shown an increasing trend of per capita cement in-use stock in the past century. The present per capita cement in-use stocks vary from 10 to 40 tonnes in major industrialized and transiting countries and are below 10 tonnes in developing countries. Evolutionary modes identified from historical patterns suggest that per capita in-use cement stock growth generally complies with an S-shape curve and relates closely to afflue...

Elaborating the History of Our Cementing Societies: An in-Use Stock Perspective

Understanding the complexity and sustainability of infrastructure development is crucial for reconciling economic growth, human well-being, and environmental conservation. However, previous studies on infrastructure's material metabolism were mainly conducted on a global or national scale, due largely to lack of more spatially refined data, and thus could not reveal the spatial patterns and dynamics on a city scale. Here, we integrated material flow analysis (MFA) and geographical information system (GIS) data to uncover the spatiotemporal patterns of the material stocks and flows accompanying the infrastructure development at a high spatial resolution for the case of Shanghai, China. From 1980 to 2010, material stocks and waste output flows of Shanghai's infrastructure system exhibited a significant increase from 83 to 561 million metric tons (Mt) and from 2 to 17 Mt, respectively. Input flows peaked in 2005 because of the economic slowdown and stepped-up policies to cool the housing market. Spatially, the center and peri-urban areas were the largest container of material stocks and biggest generator of demolition waste, while suburban areas absorbed 58%-76% of material inputs. Plans to make the city more compact will enhance the service capacity of stocks but may also increase the use of more energy and emissions-intensive construction materials (e.g., steel). Prolonging the service lifetime of infrastructure through proper management and increasing the recycling and reuse rate of demolition waste are also identified as highly efficient strategies.

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Uncovering the Spatiotemporal Dynamics of Urban Infrastructure Development: A High Spatial Resolution Material Stock and Flow Analysis.

Wastewater treatment infrastructure (WWTI) construction in China has entered an accelerated stage of development in recent years as a result of rapid economic growth, urbanization, and the demand for improving water quality. As a result, a large amount of resources and materials will be allocated for the WWTI, and it is particularly important to find ways to reduce resource consumption effectively so that social dematerialization and sustainable development can be achieved. In this study, we employed the dynamic material flow model to estimate the material flows and stocks of WWTIs and the associated carbon dioxide (CO2) emissions through 2050, considering effects of a rise in water consumption, a longer lifetime, and an increased material recycling rate. Our results indicate that material consumption in WWTIs will increase rapidly through 2025 to meet the needs of the increased volume of discharged wastewater as well as to overcome the shortage of existing wastewater treatment plants. In contrast with the moderate effects of rise in water consumption, prolonging the lifetime will greatly reduce material consumption in WWTI construction during the period 2030–2050, and approximately 60% of the total material input will be saved in the medium-lifetime scenario, compared with the short-lifetime scenario. Material output and CO2 emissions associated with WWTIs will be reduced by 87% and 37%, respectively, in the medium-lifetime scenario, compared with the short-lifetime scenario, under high-water-consumption growth. Our results highlight the great importance of pipeline construction and cement consumption in resource consumption associated with WWTI construction in China. Moreover, this study also examined the potential ways to reduce material consumption in WWTI construction in the context of the demand chain, the design, construction, operation and management, and demolition.

https://papers.ssrn.com/sol3/Delivery.cfm/JIEC_JIEC12186.pdf?abstractid=2569430&mirid=1&type=2

Greening China's Wastewater Treatment Infrastructure in the Face of Rapid Development: Analysis Based on Material Stock and Flow through 2050

SUMO-specific proteases (SENPs) play pivotal roles in maintaining the balance of SUMOylation/de-SUMOylation and in SUMO recycling. Deregulation of SENPs leads to cellular dysfunction and corresponding diseases. As a key member of the SENP family, SENP1 is highly correlated with various cancers. However, the potential role of SENP1 in leukemia, especially in acute lymphoblastic leukemia (ALL), is not clear. This study shows that ALL cells knocking down SENP1 display compromised growth rather than significant alterations in chemosensitivity, although ALL relapse samples have a relatively higher expression of SENP1 than the paired diagnosis samples. Camptothecin derivatives 7-ethylcamptothecin (7E-CPT, a monomer compound) and topotecan (TPT, an approved clinical drug) induce specific SENP1 reduction and severe apoptosis of ALL cells, showing strong anticancer effects against ALL. Conversely, SENP1 could attenuate this inhibitory effect by targeting DNA topoisomerase I (TOP1) for de-SUMOylation, indicating that specific reduction in SENP1 induced by 7E-CPT and/or topotecan inhibits the proliferation of ALL cells. 

Anti-leukemic effects of topoisomerase I inhibitors mediated by the De-SUMOylase SENP1.

W-band traveling-wave tube (TWT) is a good choice for high-data-rate wireless communication systems that can improve linearity, spectral efficiency, and channel bandwidth. In this paper, A novel low-voltage TWT for high-data-rate communications is presented. The proposed slow-wave structure (SWS) is capable of generating a coupling impedance of about 10 ohms at 94 GHz and with a synchronous voltage of only 10.6 $\text{kV}$, Particle-in-cell (PIC) study is performed to evaluate the output power of the low-voltage TWT, and the proposed W-band TWT can reach an output power of 403.3 $\mathrm{W}$ with an electronic efficiency of 8.6% at the frequency of 94 GHz.

Preliminary study of a low-voltage W-band traveling-wave tube for high-data-rate wireless communication

Hospital overcrowding is becoming a major concern in the modern era due to the increasing demand for hospital services. This study seeks to identify effective and efficient ways to resolve the serious problem of congestion in hospitals by testing a range of decongestion strategies with simulated scenarios. In order to determine more efficient solutions, interventions with smaller changes were consistently tested at the beginning through a simulation platform. In addition, the implementation patterns were investigated, which are important to hospital managers with respect to the decisions made to control hospital congestion. The results indicated that diverting a small number of ambulances seems to be more effective and efficient in congestion reduction compared to other approaches. Furthermore, instead of implementing an isolated approach continuously, combining one approach with other strategies is recommended as a method for dealing with hospital overcrowding.

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Effective Response to Hospital Congestion Scenarios: Simulation-Based Evaluation of Decongestion Interventions

In this study, we analyze domestic material consumption (DMC) in building sector and employed an index decomposition analysis method to find out the driving force of material consumption during 1996-2009. We also conducted semi-parametric analysis to estimate the relationship between urban area change and DMC change. The results reveled several findings: (1) the contribution rate of per capita GDP growth was arrived at 102.54%, it was the main driver of growth in material consumption of building construction. (2) the increase in the DMC is one of the reasons that lead to the increase of farmland transformation into urban area, but the transformations from water, grassland and wetland to urban areas decreased .

Wanxin Hou

Papers

Greening China's Wastewater Treatment Infrastructure in the Face of Rapid Development: Analysis Based on Material Stock and Flow through 2050

Anti-leukemic effects of topoisomerase I inhibitors mediated by the De-SUMOylase SENP1.

Preliminary study of a low-voltage W-band traveling-wave tube for high-data-rate wireless communication

Effective Response to Hospital Congestion Scenarios: Simulation-Based Evaluation of Decongestion Interventions

Material Consumption of Building Construction with Land Use Change in China