Vacant space detection is critical in modern parking lots. However, deploying a detection model as a service is not an easy task. As the camera in a new parking is set up at different heights or ...viewing angles from the original parking lot where the training data are collected, the performance of the vacant space detector could be degraded. Therefore, in this paper, we proposed a method to learn generalized features so that the detector can work better in different environments. In detail, the features are suitable for a vacant detection task and robust to environmental change. We use a reparameterization process to model the variance from the environment. In addition, a variational information bottleneck is used to ensure the learned feature focus on only the appearance of a car in a specific parking space. Experimental results show that performances on a new parking lot increase significantly when only data from source parking are used in the training phase.
We estimate the impact of temperature extremes on mortality in Vietnam, using daily data on temperatures and monthly data on mortality during the 2000–2018 period. We find that both cold and heat ...waves cause higher mortality, particularly among older people and those living in the hot regions in Southern Vietnam. This effect on mortality tends to be smaller in provinces with higher rates of air‐conditioning and emigration, and provinces with higher public spending on health. Finally, we estimate economic cost of cold and heat waves using a framework of willingness to pay to avoid deaths, then project the cost to the year 2100 under different Representative Concentration Pathway scenarios.
Biomass, one of the renewable resources, is expected to play an important role in the world's energy future. In Asia, rice straw is an abundant agricultural surplus because rice is one of the leading ...staple food crops in the region. Often, rice straw is burned directly in the field via uncontrolled combustion methods that emit large amounts of short-lived air pollutants, greenhouse gases, and other pollutants. In Vietnam, the energy and environment protection sectors are facing great challenges because of rapid urbanisation and industrialisation. A national strategic choice is to exploit renewable energy, including biomass-derived energy, to achieve energy security and CO
emission reduction. This study investigates the potential of rice straw as an energy source for power plants at a local scale in Vietnam using data derived from satellite Sentinel-1 images. The results show that Vietnam can produce 2,565 MW from rice straw, for which 24 out of 63 provinces have a potential capacity higher than 30 MW, and the Kien Giang province has the highest capacity (245 MW). The study also analyses limitations and obstacles overcoming which can promote the biomass energy sector in the country.
Ni-doped TiO
2
nanoparticles have been synthesized by a modified sol–gel method. The crystal phase composition, particle size, and magnetic and optical properties of the samples were comprehensively ...examined using x-ray diffraction analysis, transmission electron microscopy, Brunauer–Emmett–Teller surface area analysis, Raman spectroscopy, magnetization measurements, and ultraviolet–visible (UV–Vis) absorption techniques. The results showed that the prepared Ni-doped TiO
2
samples sintered at 400°C crystallized completely in anatase phase with average particle size in the range from 8 nm to 10 nm and presented broad visible absorption. The bactericidal efficiency of TiO
2
was effectively enhanced by Ni doping, with an optimum Ni doping concentration of 6% (
x
= 0.06), at which 95% of
Escherichia coli
were killed after just 90 min of irradiation. Density functional theory (DFT) calculations revealed good agreement with the experimental data. Moreover, the Ni dopant induced magnetic properties in TiO
2
, facilitating its retrieval using a magnetic field after use, which is an important feature for photocatalytic applications.
This paper studies continuing optimal lockdowns (can also be interpreted as quarantines or self-isolation) in the long run if a disease (Covid-19) is endemic and immunity can fail, that is, the ...disease has SIRS dynamics. We model how disease related mortality affects the optimal choices in a dynamic general equilibrium neoclassical growth framework. An extended welfare function that incorporates loss from mortality is used. In a disease endemic steady state, without this welfare loss even if there is continuing mortality, it is not optimal to impose even a partial lockdown. We characterize how the optimal restriction and equilibrium outcomes vary with the effectiveness of the lockdown, the productivity of working from home, the rate of mortality from the disease, and failure of immunity. We provide the sufficiency conditions for economic models with
SIRS
dynamics with disease related mortality–a class of models which are non-convex and have endogenous discounting so that no existing results are applicable.
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•The networked SnO2 nanowire sensors can detect NO2 gas under UV-radiation at room temperature.•Pulsed UV-radiation significantly enhanced NO2 gas response of networked SnO2 nanowire ...sensors.•Enhanced response under UV-radiation attributed to photo-adsorption and -desorption gas molecules.
A unique combination of high response and fast response-recovery is still a challenge in the development of room-temperature gas sensors. Herein, we demonstrated the on-chip growth of nanojunction-networked SnO2 NW sensors to work under UV-radiation at room temperature. The morphological, compositional, and structural properties of synthesized SnO2 nanowires were examined using field emission electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and high-resolution transmission electron microscopy, respectively. The results presented the SnO2 NWs with smooth surfaces were entangled between the Pt electrode. Besides, the internal properties showed the SnO2 NWs were crystallized as the tetragonal rutile structure of SnO2. The use of UV-radiation with the optimum intensity of 50 μW/cm2 increased the gas response to 5 ppm NO2 up to 7-fold, while response and recovery times decreased about 8- and 4-fold, respectively. Moreover, alternative use of pulsed UV-radiation (provided only during the air recovery phase) can enhance significant gas response as compared with continuous UV-radiation. The enhancement of gas response could be attributed to the photo-adsorption and -desorption of NO2 molecule due to the photogeneration of electron-hole pairs. The combination of NW-NW nanojunctions and pulsed UV-radiation is expected to be a novel strategy for high-performance room temperature gas sensors.
COVID-19 and a Green Recovery? Goenka, Aditya; Liu, Lin; Nguyen, Manh-Hung
Economic modelling,
11/2021, Volume:
104
Journal Article
Peer reviewed
Open access
Preliminary evidence indicates that pollution increases the severity and likelihood of COVID-19 infections similar to many other infectious diseases. This paper models the interaction of pollution ...and disease preventive actions, either pharmaceutical or non-pharmaceutical interventions, on transmission of infectious diseases in a neoclassical growth framework. There are two externalities - households do not take into account how their actions affect disease transmission, and productive activity results in pollution which increases the likelihood of infections. The disease dynamics are modeled to be of
type. We study the difference in health and economic outcomes between the decentralized economy, where households do not internalize externalities, and socially optimal outcomes, and characterize the taxes and subsidies that decentralize the latter. Thus, we examine the question whether there are sufficient incentives to reduce pollution, at both private and public levels, once its effects on disease transmission is considered. In competitive outcomes, pollution increases with increased productivity. The socially efficient outcome has higher pollution than a competitive outcome, despite increase in abatement, as the effect of higher productivity and larger labor supply dominates. The results question the hopes of a Green Recovery.
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•ZnCo2O4 nanoparticles designed to decorate BiVO4 nanoworms to form n-p heterojunction.•Impressive 4.4 fold increase in the photocurrent density was achieved for ...composite.•Incorporation of ZnCo2O4 accelerates the interfacial kinetics of BiVO4.•Establish correlation between PEC and band structure analysis of the photoelectrodes.•Understanding the surface kinetics of different photoelectrodes was developed.
During the past few decades, photoelectrochemical (PEC) water splitting has attracted significant attention because of the reduced production cost of hydrogen obtained by utilizing solar energy. Significant efforts have been invested by the scientific community to produce stable ternary metal oxide semiconductors, which can enhance the stability and increase the overall production of oxygen. Herein, we present the ternary metal oxide deposition of ZnCo2O4 as a route to obtain a novel photocatalyst layer on BiVO4 to form BiVO4/ZnCo2O4 a novel composite photoanode for PEC water splitting. The structural, topographical, and optical analyses were performed using field emission scanning electron microscopy, X-ray diffraction, high-resolution transmission electron microscopy, and UV–Vis spectroscopy to confirm the structure of the ZnCo2O4 grafted over BiVO4. A remarkable 4.4-fold enhancement of the photocurrent was observed for the BiVO4/ZnCo2O4 composite compared with bare BiVO4 under visible illumination. The optimum loading of ZnCo2O4 over BiVO4 yields unprecedented stable photocurrent density with an apparent cathodic shift of 0.46 V under 1.5 AM simulated light illumination. This is also evidenced by the flat-band potential change through Mott–Schottky analysis, which reveals the formation of p-ZnCo2O4 on n-BiVO4. The improvement in the PEC performance of the composite with respect to bare BiVO4 is ascribed to the formation of thin passivating layer of p-ZnCo2O4 on n-BiVO4 which improves the kinetics of interfacial charge transfer. Based on our study, we have gained an in-depth understanding of the BiVO4/ZnCo2O4 composite as high potential in efficient PEC water splitting devices.
•Systematic variation of the hybrid Co3O4/SWCNT nanohybrid structures for methanol sensing.•The sensing principle and mechanism in the composite sensor structures is explained.•Synergistic gas ...sensing effect derived from the high hole concentration in SWCNT and high oxygen adsorption site density of Co3O4.•Feasibility to high performance methanol sensing is proven.
Co3O4/single-walled carbon nanotube (Co3O4/SWCNT) hybrid structures are fabricated, and their methanol sensing properties and related sensing principles are systematically investigated. A series of Co/SWCNT nanohybrid structures are deposited on silicon dioxide substrates by a co-arc discharge process and converted to Co3O4/SWCNT nanohybrid structures by subsequent methanol treatment and oxidation processes. The morphologies and structures of the nanohybrid composites are investigated by scanning electron microscopy, transmittance electron microscopy, X-ray diffraction, and Raman spectroscopy. The effect of the nanohybrid film thickness and the Co3O4: SWCNT ratio in the films on their physical and gas sensing properties are systematically examined. The best methanol-sensing performance is observed upon measurement at 300 °C for the material fabricated by deposition for 15 min and oxidized at 500 °C. The enhanced gas-sensing performance of the hybrid nanostructures is analyzed to prove that the high carrier supply rate from the transducer determines the reaction rate on the receptor surface (providing the receptor can accommodate the oxygen ionosorption). The hybrid sensor structures also exhibit low detection limit of 50 ppb, good selectivity, repeatability, and long-term stability, demonstrating their potential for practical application to methanol sensing.
This paper studies an optimal growth model where there is an infectious disease with SIR dynamics which can lead to mortality. Health expenditures (alternatively intensity of lockdowns) can be made ...to reduce infectivity of the disease. We study implications of two different ways to model the disease related mortality – early and late in infection mortality – on the equilibrium health and economic outcomes. In the former, increasing mortality reduces infections by decreasing the fraction of infectives in the population, while in the latter the fraction of infectives increases. We characterize the steady states and the outcomes depend in the way mortality is modeled. With early mortality, increasing mortality leads to higher equilibrium per capita output and consumption while in the late mortality model these decrease. We establish sufficiency conditions and provide the first results in economic models with SIR dynamics with and without disease related mortality — a class of models which are non-convex and have endogenous discounting so that no existing results are applicable.
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