227 research outputs found

    An introduction to neighborhood sustainability assessment tool (NSAT) study for China from comprehensive analysis of eight Asian tools

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    In comparison to city-level and building-level sustainability research, neighborhood-level sustainable urban development is less studied. One of the ways of achieving sustainability at this level is the use of the Neighborhood Sustainability Assessment Tool (NSAT), which focuses on the sustainable urban development of districts, communities, and neighborhoods. NSAT is comprised of urban sustainable indicators and associated points ascribed towards achieving specific urban agendas, called headline sustainability indicators (HSIs) and themes. In China, neighborhood-level sustainability agenda has just been recently established in 2017. Hence, there is an immediate need for NSAT development of multiple cities responding to specific regions of different climate zones in China. As an example, this study utilizes the case of Ningbo City, located in east China, for such NSAT development. This paper provides a comprehensive analytical and comparison study of eight Asian NSATs to highlight compatibilities and extract specific indicators for a new NSAT development for China. The results from this comparative and analytical study, developed through a multidimensional approach of sustainable pathway model (SPM) inform a new NSAT development in a new context. This novel contribution is significant in a context where neighborhood sustainability measures are recently developed. This study serves as the starting point for future research of NSATs in China and other countries

    Effect of dynamic threshold pressure gradient on production performance in water-bearing tight gas reservoir

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    AbstractWater content and distribution have important impacts on gas production in water-bearing tight gas reservoirs. However, due to the structural and chemical heterogeneity of tight reservoirs, the water phase exists in various states, which has complicated the analyses of the effects of water characteristics on tight gas production performance. In this work, the water phase is distinguished from immobile to mobile states and the term of constrained water saturation is proposed. It is established that water can flow when the driving pressure difference is larger than the critical driving pressure difference. A new theoretical model of threshold pressure gradient is derived to incorporate the influences of constrained water saturation and permeability. On this basis, a new prediction model considering the varied threshold pressure gradient is obtained, and the result indicates that when threshold pressure gradient is constant, the real gas production capacity of the reservoir will be weakened. Meanwhile, a dynamic supply boundary model is presented, which indicates that the permeability has a strong influence on the dynamic supply boundary, whereas the impact of initial water saturation is negligible. These findings provide insights into the understanding of the effects of water state and saturation on the threshold pressure gradient and gas production rate in tight gas reservoirs. Furthermore, this study provides useful guidance on the prediction of field-scale gas production.Cited as: Zhu, W., Liu, Y., Shi, Y., Zou, G., Zhang, Q., Kong, D. Effect of dynamic threshold pressure gradient on production performance in water-bearing tight gas reservoir. Advances in Geo-Energy Research, 2022, 6(4): 286-295. https://doi.org/10.46690/ager.2022.04.0

    Magnetic Manganese Oxide Sweetgum-Ball Nanospheres with Large Mesopores Regulate Tumor Microenvironments for Enhanced Tumor Nanotheranostics.

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    An important objective of cancer nanomedicine is to improve the delivery efficacy of functional agents to solid tumors for effective cancer imaging and therapy. Stimulus-responsive nanoplatforms can target and regulate the tumor microenvironment (TME) for the optimization of cancer theranostics. Here, we developed magnetic manganese oxide sweetgum-ball nanospheres (MMOSs) with large mesopores as tools for improved cancer theranostics. MMOSs contain magnetic iron oxide nanoparticles and mesoporous manganese oxide (MnO2) nanosheets, which are assembled into gumball-like structures on magnetic iron oxides. The large mesopores of MMOSs are suited for cargo loading with chlorin e6 (Ce6) and doxorubicin (DOX), thus producing so-called CD@MMOSs. The core of magnetic iron oxides could achieve magnetic targeting of tumors under a magnetic field (0.25 mT), and the targeted CD@MMOSs may decompose under TME conditions, thereby releasing loaded cargo molecules and reacting with endogenous hydrogen peroxide (H2O2) to generate oxygen (O2) and manganese (II) ions (Mn2+). Investigation in vivo in tumor-bearing mice models showed that the CD@MMOS nanoplatforms achieved TME-responsive cargo release, which might be applied in chemotherapy and photodynamic therapy. A remarkable in vivo synergy of diagnostic and therapeutic functionalities was achieved by the decomposition of CD@MMOSs and coadministration with chemo-photodynamic therapy of tumors using the magnetic targeting mechanism. Thus, the result of this study demonstrates the feasibility of smart nanotheranostics to achieve tumor-specific enhanced combination therapy

    Highly sensitive temperature sensing based on all-solid cladding dual-core photonic crystal fiber filled with the toluene and ethanol

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    An all-solid cladding dual-core photonic crystal fiber (DC-PCF) filled with toluene and ethanol is proposed for the temperature sensing. The all-solid cladding is formed by using the fluorine-doped silica glass instead of the air holes in the cladding region. By selectively filling the toluene and ethanol into the three air holes near the core region, the characteristic of the temperature sensing is numerically investigated. The simulation results show that the average sensitivity of the temperature sensing can achieve −11.64 and −7.41 nm/°C in the temperature ranges from 0 to 70 °C and −80 to 0 °C, respectively, when the length of the DC-PCF is as short as 1.6 mm. The maximum sensitivity in the considered temperature ranges can be up to −15 and −9 nm/°C, respectively. Moreover, the proposed temperature sensor is insensitive to the hydrostatic pressure

    A Surface Plasmon Resonance-Based Photonic Crystal Fiber Sensor for Simultaneously Measuring the Refractive Index and Temperature

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    In this paper, a surface plasmon resonance (SPR)-based photonic crystal fiber (PCF) sensor is proposed for simultaneously measuring the refractive index (RI) and temperature. In the design, the central air hole and external surface of the proposed PCF are coated with gold films, and an air hole is filled with the temperature-sensitive material (TSM). By introducing the inner and outer gold films and TSM, the RI and temperature can be measured simultaneously at different wavelength regions. The simulation results show that the average wavelength sensitivities of the proposed SPR-based PCF sensor can reach 4520 nm/RIU and 4.83 nm/°C in the RI range of 1.35~1.40 and a temperature range of 20~60 °C, respectively. Moreover, because of using the different wavelength regions for sensing, the RI and temperature detections of the proposed SPR-based PCF sensor can be achieved independently. It is believed that the proposed SPR-based PCF RI and temperature sensor has important applications in biomedicine and in environmental science
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