Tumor hypoxia severely limits the efficacy of traditional photodynamic therapy (PDT). Here, a liposome‐based nanoparticle (designated as LipoMB/CaO2) with O2 self‐sufficient property for dual‐stage ...light‐driven PDT is demonstrated to address this problem. Through a short time irradiation, 1O2 activated by the photosensitizer methylene blue (MB) can induce lipid peroxidation to break the liposome, and enlarge the contact area of CaO2 with H2O, resulting in accelerated O2 production. Accelerated O2 level further regulates hypoxic tumor microenvironment and in turn improves 1O2 generation by MB under another long time irradiation. In vitro and in vivo experiments also demonstrate the superior competence of LipoMB/CaO2 to alleviate tumor hypoxia, suppress tumor growth and antitumor metastasis with low side‐effect. The O2 self‐sufficient LipoMB/CaO2 nanoplatform with dual‐stage light manipulation is a successful attempt for PDT against hypoxic tumor.
A liposome‐based nanoparticle (desig‐nated as LipoMB/CaO2) with O2 self‐sufficient property is developed to combat hypoxic tumor. Through dual‐stage irradiation, O2 self‐sufficient LipoMB/CaO2 can alleviate tumor hypoxia and strongly suppress tumor growth with low side‐effect.
This article revisits the Moving to Opportunity housing mobility experiment, which heretofore has not provided strong evidence to support the hypothesis of neighborhood effects on economic ...self-sufficiency among adults. The authors undertake a conceptual and empirical analysis of the study's design and implementation to gain a better understanding of the selection processes that occur within the study. The article shows that the study is potentially affected by selectivity at several junctures: in determining who complied with the program's requirements, who entered integrated versus segregated neighborhoods, and who left neighborhoods after initial relocation. Furthermore, previous researchers have not found an experimental treatment effect on adult economic self-sufficiency, relative to controls. The authors propose an alternative approach that involves measuring the cumulative amount of time spent in different neighborhood environments. With this method, they find evidence that neighborhood is associated with outcomes such as employment, earnings, TANF receipt, and use of food stamps. PUBLICATION ABSTRACT
Achieving food and feed self‐sufficiency is important for both China and the world. While China's food self‐sufficiency has been examined at the national and provincial levels, few studies consider ...lower administrative levels or different food and feed items. This study quantifies self‐sufficiency in the eastern regions of China and examines correlations with agronomic (arable area, yield, fertilizer input, and machinery power) and socioeconomic (population density, gross domestic product GDP) variables at the local level, which are related to the interactions of the Sustainable Development Goals. We calculated food and feed balances, and checked correlations across and within regions grouped by population density levels between production, balance indices, and other agronomic and socioeconomic variables. The results showed that most regions can achieve self‐sufficiency in cereals, vegetables, and meat. Regarding eggs and maize, there was self‐sufficiency in the north but deficiency in the south. Nearly all regions demonstrated extreme shortages of milk and soybeans. The results also showed a positive correlation between the production of some food commodities and the population in eastern regions of China, demonstrating that the aim of achieving food self‐sufficiency at the local level is pursued. For cereals, vegetables, and maize, the yield and arable land per capita were positive factors for self‐sufficiency, while GDP per capita was a negative factor for cereals, meat, and maize. Various factors have different impacts on the food and feed self‐sufficiency of regions based on population density. Protecting arable land by rural revitalization and mitigating urban sprawl can retain food and feed self‐sufficiency in large cities. This study outlines important implications for policymakers seeking to achieve food and feed self‐sufficiency in China.
Food and feed self‐sufficiency was quantified at the local level in the eastern regions of China. For cereals, vegetables, and maize, the yield and arable land per capita were positive factors for self‐sufficiency, while GDP per capita was a negative factor for cereals, meat, and maize. Food and feed self‐sufficiency are driven by different factors in different population density regions.
Nano-grid (NG) clusters (NGCs) have the potential to serve as as an essential configuration for future low-voltage distribution networks. To address the comprehensive energy efficiency (CEE) problem ...over a longer time horizon, this paper proposes an energy optimization management strategy. First of all, three typical models are developed, namely equivalent circuit model, cluster loss model and energy sharing model. In the modelling, influences of port characteristics and power transmission losses of interconnecting converters are considered to more accurately describe the cluster power flow. Then, an optimal energy scheduling mechanism with high CEE is proposed based on the three established models. The strategy decomposes the complex CEE problem into three interdependent sub-problems, corresponding to the three established models. First, ensuring the bus power quality and battery requirements are satisfied based on the proposed equivalent circuit model. Second, improving cluster self-sufficiency based on cluster energy sharing model. Third, achieving high energy transfer efficiency based on cluster loss model. Extensive simulation results demonstrate that the CEE under the proposed strategy achieves significant performance improvements, with increases of 8% and 32% in energy transfer efficiency and energy self-sufficiency respectively.
This research study uses a computer simulation based on real input data to examine the impact of a supercapacitor module working as a fast response energy storage unit in renewable energy systems to ...increase energy self-consumption and self-sufficiency. The evaluated system includes a photovoltaic system with a capacity of 3.0 kWp and between 0 and 5 supercapacitor units with a capacity of 500 F per module. The study was carried out using experimental data for electrical load, solar irradiance, and ambient temperature for the year 2020, with a 1 min temporal resolution. The daily average ambient temperature was 10.7 °C, and the daily average solar irradiance was 3.1 kWh/m2/day. It is assumed that the supercapacitor could only be charged from a photovoltaic system using renewable energy and not from the grid. The simulation results showed that using the supercapacitors to feed the short and large peaks of the electrical load significantly increases energy self-consumption and self-sufficiency. With only five supercapacitor modules, yearly energy self-sufficiency increases from 28.09% to 40.77%.
One of the main energy consumptions in wastewater treatment plants (WWTPs) is due to the oxygenation of aerobic biological processes. In order to approach to an energy self-sufficient scenario in ...WWTPs, Membrane Aerated Biofilm Reactors (MABRs) provide a good opportunity to reduce the impact of aeration on the global energy balance. However, mass transfer limitations derived from poor flow distribution must be tackled to take advantage of this technology. In this work, in order to improve mass transfer between biofilm and bulk water, a specific configuration was developed and studied at laboratory scale, aimed at compactness, energy efficiency and high nitrification rates. Nitrification rates were higher in the innovative configuration than in the conventional one, achieving a Volumetric Nitrification Rate (VNR) as high as 575.84 g NH4-N m−3 d−1, which is comparable with confirmed technologies. Regarding energy consumption due to aeration, a reduction of 83.7% was reached in comparison with aeration through diffusers with the same Oxygen Transfer Efficiency (OTE). These results highlight the importance of hydrodynamic conditions and the membranes configuration on treatment performance.
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•A high packing MABR configuration enhances flow pattern and mass transfer.•Volumetric nitrification rates comparable to confirmed technologies are achieved.•A reduction of 83.7% in energy consumption is reached in comparison with diffusers.•Membranes configuration and recycling velocity influence biological performance.
•Study of hydrogen energy storage for microgrid using a reversible solid oxide cell.•Optimisation is used to choose and size components for simulated microgrid.•Case studies are considered for ...England and Texas.•Economics for such a system are challenging: payback generally at least 20 years.•Hybrid storage (hydrogen + battery) preferred to battery for high self sufficiency.
Reversible solid oxide cells (rSOCs) offer the prospect of long term bulk energy storage using hydrogen or methane fuel. Solid oxide technology, whilst less mature than alkaline and PEM technology, offers superior conversion efficiency - especially for electrolysis. Furthermore, the possibility of using the cells reversibly means that separate ‘power-to-gas’ and ‘gas-to-power’ components are not needed, potentially reducing costs. In this work, we consider the suitability of energy storage using rSOCs and/or battery storage for a microgrid consisting of houses equipped with solar PV generation. An agent-based simulation model is developed to assess the performance of such a microgrid. The model enables the microgrid’s self-sufficiency to be quantified, and hence the possible cost savings through avoided imports of grid power. Sizing of microgrid components is optimised to determine the most cost-effective design capable of achieving given self-sufficiency ratio. Case studies are considered for England and Texas. Initially, designs are considered with hydrogen energy storage only; subsequently, hybrid energy storage is considered, with a community scale battery working alongside the rSOC. Results suggest that payback periods for pure rSOC systems tend to be unfavourable. However, if prices fall to levels foreseen in the literature, a system designed to achieve 50% grid-independence could pay back its investment costs within 20 years. Systems designed for Texas need relatively less storage, owing to the good year-round solar resource; as such, payback time in Texas is superior to the UK. Hybrid storage with battery + rSOC is found to be preferable to battery only systems when (i) high SSR is required and (ii) large over-capacity of PV generation is not possible.
The shift from conventional buildings to the so-called Nearly Zero Energy Buildings (NZEBs) is becoming one of the major contemporary challenges in the world. In this work, a multi-objective ...optimization approach, based on a smart surrogate model, has been developed to minimize the energy consumption, improve the thermal comfort of the occupants and increase the energy self-sufficiency of residential buildings. For this purpose, two main phases have been considered: the first one is related to the development of the surrogate model, based on machine learning utilities, in particular Artificial Neural Networks (ANNs), and the second is related to the optimization process, performed by means of the Multi-Objective Particle Swarm Optimization algorithm (MOPSO). This approach has been applied to a typical Moroccan building, Ground Floor + First Floor (GFFF), in different regulatory climate zones. The results show that the approach was successfully implemented using TRNSYS, Matlab and other numerical simulation tools, leading to different solutions in terms of building envelope design. The best-fit solution achieved a huge improvement potential in most climate zones, averaging about 75%, 50% and 85% respectively for energy consumption, thermal comfort and energy self-sufficiency of the studied building. Finally, we strongly recommend this approach to the various stakeholders in this field, including designers, engineers, architects, consulting firms, etc., since the results have proven its effectiveness as a very promising step towards designing Comfortable and Nearly Zero Energy Buildings. Future work will focus on the implementation of a hardware device that is able to perform all the steps of the proposed framework for possible pre-project optimizations.
•A mathematical model to initiate the metamodeling process has been developed.•A hybrid local energy supply system has been considered.•The computation time of the whole solving process has been significantly reduced.•The building envelope has been optimized to achieve the best possible performance.
China produces 28% of global rice supply and is currently self-sufficient despite a massive rural-to-urban demographic transition that drives intense competition for land and water resources. At ...issue is whether it will remain self-sufficient, which depends on the potential to raise yields on existing rice land. Here we report a detailed spatial analysis of rice production potential in China and evaluate scenarios to 2030. We find that China is likely to remain self-sufficient in rice assuming current yield and consumption trajectories and no reduction in production area. A focus on increasing yields of double-rice systems on general, and in three single-rice provinces where yield gaps are relatively large, would provide greatest return on investments in research and development to remain self-sufficient. Discrepancies between results from our detailed bottom-up yield-gap analysis and those derived following a top-down methodology show that the two approaches would result in very different research and development priorities.
•Power management algorithm (PMA) prioritizes PV&hybrid storage use instead of grid.•Novel PMA for increased PV self-consumption and self-sufficiency of the building.•Twelve different cases depending ...on PV and load power, and availability of storage.•Supercapacitor handles rapid changes within 0.2 s, hence battery is relieved.•Results show effective power sharing and fast response for different scenarios.
The increasing penetration of renewable energy technologies causes major problems in the power network, as their generation cannot be totally predicted. Along with fluctuations in the generation of renewables due to weather uncertainties, storage is very important for mitigating several problems that may arise, affecting the stability and reliability of the grid. In particular, in recent years there has been an emphasis on residential storage applications (behind-the-meter storage), with the aim of increasing the energy self-consumption and therefore reducing electricity bills. The proposed model consists of a 3 kWp rooftop solar photovoltaic (PV) system connected to the grid through converters and a battery-supercapacitor hybrid energy storage system. The model is developed and simulated in the MATLAB/Simulink software environment, based on mathematical analysis and average modeling. The supercapacitor handles rapid changes that occur within 0.2 s, and this can relieve the battery stress and extend the battery lifetime. The building’s electricity demand is satisfied through the PV, hybrid energy storage and/or grid. A new filtration-based power management algorithm (PMA) is proposed here, prioritizing the utilization of the PV and battery-supercapacitor instead of the grid, thus achieving a reduced power exchange between the building and the grid and increasing the PV self-consumption and self-sufficiency of the building. The dynamic performance of the proposed model is verified through several simulations over short time periods (10–30 s) for different scenarios that could occur. The obtained results show that the model works properly and responds extremely fast during the different mode transitions, exhibiting a very fast DC-bus voltage regulation with a very small ripple voltage of up to 5 V (a maximum of ± 0.625%). Additionally, both battery and supercapacitor remain between their minimum and maximum limits. Finally, an effective power sharing is achieved between the PV, the battery-supercapacitor storage, the building load and the grid.
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