Dual-functioning displays, which can simultaneously transmit and receive information and energy through visible light, would enable enhanced user interfaces and device-to-device interactivity. We ...demonstrate that double heterojunctions designed into colloidal semiconductor nanorods allow both efficient photocurrent generation through a photovoltaic response and electroluminescence within a single device. These dual-functioning, all-solution-processed double-heterojunction nanorod light-responsive light-emitting diodes open feasible routes to a variety of advanced applications, from touchless interactive screens to energy harvesting and scavenging displays and massively parallel display-to-display data communication.
This study was conducted to explore the effectiveness of participatory training for promoting farmer's health and reducing agricultural work-related injuries. Candidates for this study included 595 ...farmers in 8 rural villages of South Korea. The one-day course participatory training was administered to 217 (36.5%) farmers and included an action-checklist, a good example presentation, and group discussion. The follow-up visit to participants' houses and farms was performed after 1 to 3 months. A direct interview survey was administered pre- and post-trainings. The total number of proposed action plans for the improvement of working condition was 620. It was observed that 61.5% of action plans (72.2% of short term and 41.3% of long term plans) were completely implemented. In regards to health and safety indices, the proportion of current smokers was reduced from 29.8% to 25.3% in the group that underwent training. The pesticide intoxication was reduced from 16.1% to 4.8% in participants that underwent training. However, the agricultural injury rate was unchanged in both groups. This study reports significant beneficial effects of participatory training in the agriculture sector in Korea.
Dendritic cell-based cancer immunotherapy requires tumour antigens to be delivered efficiently into dendritic cells and their migration to be monitored in vivo. Nanoparticles have been explored as ...carriers for antigen delivery, but applications have been limited by the toxicity of the solvents used to make nanoparticles, and by the need to use transfection agents to deliver nanoparticles into cells. Here we show that an iron oxide-zinc oxide core-shell nanoparticle can deliver carcinoembryonic antigen into dendritic cells while simultaneously acting as an imaging agent. The nanoparticle-antigen complex is efficiently taken up by dendritic cells within one hour and can be detected in vitro by confocal microscopy and in vivo by magnetic resonance imaging. Mice immunized with dendritic cells containing the nanoparticle-antigen complex showed enhanced tumour antigen specific T-cell responses, delayed tumour growth and better survival than controls.
Here, we report multilayer stacking of films of quantum dots (QDs) for the purpose of tailoring the energy band alignment between charge transport layers and light emitting layers of different color ...in quantum dot light-emitting diodes (QD LED) for maximum efficiency in full color operation. The performance of QD LEDs formed by transfer printing compares favorably to that of conventional devices fabricated by spin-casting. Results indicate that zinc oxide (ZnO) and titanium dioxide (TiO2) can serve effectively as electron transport layers (ETLs) for red and green/blue QD LEDs, respectively. Optimized selections for each QD layer can be assembled at high yields by transfer printing with sacrificial fluoropolymer thin films to provide low energy surfaces for release, thereby allowing shared common layers for hole injection (HIL) and hole transport (HTL), along with customized ETLs. This strategy allows cointegration of devices with heterogeneous energy band diagrams, in a parallelized scheme that offers potential for high throughput and practical use.
High-resolution patterning of quantum dot (QD) films is one of the preconditions for the practical use of QD-based emissive display platforms. Recently, inkjet printing and transfer printing have ...been actively developed; however, high-resolution patterning is still limited owing to nozzle-clogging issues and coffee ring effects during the inkjet printing and kinetic parameters such as pickup and peeling speed during the transfer process. Consequently, employing direct optical lithography would be highly beneficial owing to its well-established process in the semiconductor industry; however, exposing the photoresist (PR) on top of the QD film deteriorates the QD film underneath. This is because a majority of the solvents for PR easily dissolve the pre-existing QD films. In this study, we present a conventional optical lithography process to obtain solvent resistance by reacting the QD film surface with diethylzinc (DEZ) precursors using atomic layer deposition. It was confirmed that, by reacting the QD surface with DEZ and coating PR directly on top of the QD film, a typical photolithography process can be performed to generate a red/green/blue pixel of 3000 ppi or more. QD electroluminescence devices were fabricated with all primary colors of QDs; moreover, compared to reference QD-LED devices, the patterned QD-LED devices exhibited enhanced brightness and efficiency.
•Dehumidification performances of the cross and the counter-flow liquid desiccant dehumidifiers were compared.•Empirical models of both liquid desiccant dehumidifiers were also derived.•The inlet air ...humidity ratio and the inlet solution temperature affect highly the counter-flow dehumidifier performance.•The counter-flow type showed better performance than the cross-flow type.
In a liquid desiccant dehumidifier, the air-to-solution flow direction plays an important role in the dehumidification performance and the physical size of the dehumidifier tower. In this research, the dehumidification performance of counter-flow and cross-flow liquid desiccant dehumidifiers were compared via a series of experiments carried out in the environmental test chamber. To predict the dehumidification performance of both flow type dehumidifiers in various operating conditions, empirical models returning the dehumidification effectiveness and the enthalpy effectiveness, which were adopted as performance indices, were also derived based on the experimental data. From the sensitivity analysis conducted by using the proposed empirical correlations, it was observed that when the inlet air humidity ratio increased from 10.1 g/kg to 22.7 g/kg, the dehumidification effectiveness and enthalpy effectiveness of the counter-flow liquid desiccant dehumidifier increased from 51.2% to 82.4% and 40.2% to 72.5%, respectively. Meanwhile, both effectiveness values of the cross-flow dehumidifier increased from 62.3% to 63.4% and 46.3% to 55.0%, respectively. Likewise, when inlet solution temperature varied from 15.2 to 31.1 °C, the dehumidification effectiveness and enthalpy effectiveness of the counter-flow type dehumidifier decreased from 71.7 to 45.4% and 64.4 to 47.3%, respectively, while those of a cross-flow type dehumidifier decreased from 65.3 to 54.8% and 55.8 to 45.2%. Consequently, one may conclude that the cross-flow liquid desiccant dehumidifier would provide relatively stable dehumidification performance regardless of the changes in operating parameter, but the cross-flow dehumidifier may have limited dehumidification performance, especially at the lower desiccant solution temperature and in highly humid process air conditions.
Current‐induced control of magnetization in ferromagnets using spin–orbit torque (SOT) has drawn attention as a new mechanism for fast and energy efficient magnetic memory devices. Energy‐efficient ...spintronic devices require a spin‐current source with a large SOT efficiency (ξ) and electrical conductivity (σ), and an efficient spin injection across a transparent interface. Herein, single crystals of the van der Waals (vdW) topological semimetal WTe2 and vdW ferromagnet Fe3GeTe2 are used to satisfy the requirements in their all‐vdW‐heterostructure with an atomically sharp interface. The results exhibit values of ξ ≈ 4.6 and σ ≈ 2.25 × 105 Ω‐1 m‐1 for WTe2. Moreover, the significantly reduced switching current density of 3.90 × 106 A cm−2 at 150 K is obtained, which is an order of magnitude smaller than those of conventional heavy‐metal/ferromagnet thin films. These findings highlight that engineering vdW‐type topological materials and magnets offers a promising route to energy‐efficient magnetization control in SOT‐based spintronics.
All‐van der Waals (vdW) heterostructure with an atomically sharp interface based on topological semimetal shows spin–orbit torque (SOT)‐driven magnetization switching. These findings highlight that engineering vdW‐type topological materials and magnets offers a promising route to energy‐efficient magnetization control in SOT‐based spintronics.
•The performance of a vacuum membrane dehumidification-based air-conditioning system were evaluated.•There described the method to decide vacuum pump working conditions and membrane module ...design.•The proposed system consumed 8.2% less energy than conventional system.•To achieve energy benefit, optimal membrane module design and vacuum pump operation are necessary.
The energy and operating performances of a vacuum membrane dehumidification system were theoretically investigated for building air conditioning applications. The dehumidification effectiveness and coefficient of performance (COP) were adopted as performance indices. A one-dimensional mass-transfer model was derived to analyze the effect of each operating parameter on dehumidification performance. The data predicted by the model agreed well with measured results, with an error bound of 20%. Parametric analysis results indicated that the vacuum side pressure had the most significant impact on the energy and dehumidification performances. It was also observed that the membrane module length plays an important role in the module design. Based on the analysis results, a configuration and operating strategy of a vacuum membrane dehumidifier-assisted variable air volume air conditioning system were suggested. Subsequently, the proposed system was evaluated by comparing its energy and operating performances with those of the conventional variable air volume air system via energy simulations. The results indicated that the total primary energy consumption from the proposed system was 8.2% lower than that of the conventional system. However, the fan energy consumption in the proposed system was 2.5 times higher than that of the conventional system owing to the high pressure drop of membrane module. In addition, the proposed system consumed 7.7% more primary energy for dehumidification and sensible cooling process because of its lower COP. To achieve comparable energy performance, further research on the optimized design of a membrane module and optimized operation of a vacuum pump in the proposed system are necessary.
•Energy performance of a dual-core energy recovery ventilator combining high-efficient latent heat exchanger was evaluated.•Proposed system: a dual-core energy recovery ventilator integrated with ...parallel cooling and heating systems.•Proposed system reduces 15.9% of space cooling loads in summer, 14.1% space heating loads in winter.•10.1% of primary energy consumption savings was achieved by reclaiming latent heat from proposed ventilation unit.
High-efficiency energy recovery ventilators (ERVs) have a significant impact on the conservation of building energy. In particular, the importance of the latent cooling performance of ERV which used in hot, humid climates has been growing. To enhance the latent heat recovery performance of the existing ERVs and attain satisfactory sensible heat recovery performance as well, a dual-core energy recovery ventilation unit combining a hollow fiber membrane-based latent heat exchanger (M-LHX) and a sensible heat exchanger (SHX) was proposed in a previous work. This study evaluated the energy saving potential of the proposed ventilation unit integrated air-conditioning system via a series of building energy simulation. As the reference system, a conventional ERV with a flat-plate membrane enthalpy exchanger was chosen. The M-LHX and SHX in the proposed ventilation unit enable decoupled sensible and latent heat recovery of outdoor air. Energy simulations were conducted for a single-story office building located in South Korea, which is one of the humid regions during the summer. The simulation results showed that the proposed ventilation unit could reduce 15.9, 14.4, and 14.1% of building air-conditioning loads in summer, intermediate season, and winter, respectively, compared with the reference ERV. This is because the proposed ventilation unit provided energy benefits by recovering more latent heat from the M-LHX and comparable amount of sensible heat from the SHX than the reference system. Accordingly, the proposed system presented the annual primary energy savings of 10.6% over the reference system, although the proposed system consumed more fan energy.
•A prototype of hollow fiber membrane-based energy recovery ventilation unit was developed.•Seasonal operation sequences of the proposed system were established.•Sensible effectiveness: 53.6–80.1%, ...latent effectiveness: 68.1–73.1%, enthalpy effectiveness: 76.1–89.6%•Operating performance and energy efficiency satisfied minimum requirements from the local test standard.•Proposed system could have a 16.8–29.8% higher ventilation load reduction potential than existing ERVs.
A novel energy recovery ventilation unit with a hollow fiber membrane-based latent heat exchanger is proposed and built to experimentally evaluate its operational performance and energy efficiency. The proposed system consists of a latent heat exchanger fabricated by hollow fiber membrane to accommodate the latent load of introduced outdoor air and a flat-plate sensible heat exchanger to eliminate the sensible load. Annual operating strategies are established based on outdoor air conditions, and experiments are conducted under each operation mode. Further, the thermal behaviors of air (including temperature and humidity) under each operation mode are described according to the measured data. The proposed system exhibits a sensible, latent, and enthalpy effectiveness of 53.6–80.1%, 68.1–73.1%, and 76.1–89.6%, respectively. As for the energy efficiency of the proposed ventilation unit, the coefficients of energy are 29.63 and 15.29 under the summer and winter operation modes, respectively, which meet the minimum energy performance requirements of the local test standard. Finally, the potential reduction in the ventilation load for each operation mode is estimated using the measured data. The proposed unit could reduce the ventilation load by 75.4%and 77.3% in summer and winter operation modes, respectively. These results reveal that the proposed ventilation unit demonstrates significant application potential in improving the operating and energy performance of buildings.
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