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• Energy-efficient intensification is introduced for direct production of diethyl carbonate. • By eliminating MeOH-DMC azeotrope separation unit, two novel designs are proposed. • 1st design has two RD units for each transesterification while 2nd one combines three reactions in one RD unit. • Two designs show 12% and 24% of total energy savings compared to the conventional case. This study presents a novel process for producing diethyl carbonate and ethylene glycol directly from ethylene carbonate and ethanol through reactive distillation. Previous studies have mainly focused on investigating two reactive distillation systems with a pressure swing azeotropic separation for producing diethyl carbonate. By integrating the two separated reactive distillation systems into a single flowsheet, an energy-efficient process is enabled. Especially, the need for separating the azeotrope mixture is eliminated, and the primary feed of methanol is not required due to the reaction stoichiometry. Two design alternatives have been proposed based on the reactive distillation configuration and catalyst employed. The first design significantly reduces the amount of equipment needed by utilizing two reactive distillation columns, while the second design offers high energy savings, as all reactions occur in a single reactive distillation column. Compared to the conventional process of producing individual dimethyl and diethyl carbonate, both design alternatives result in total energy consumption reductions of 12% and 24%, respectively, as well as total annual cost reductions of 12% and 14%, respectively. Furthermore, both design alternatives demonstrate a reduction in CO 2 emissions by 15% and 11% respectively. Not only do these results demonstrate their economic viability, but they also indicate their effectiveness in CO 2 mitigation. From an industry perspective, the two proposed design alternatives can be effectively implemented for the direct production of diethyl carbonate and mono-ethylene glycol by intensifying the existing dimethyl carbonate production process. [Display omitted] [ABSTRACT FROM AUTHOR]

The port-injection-type hydrogen engine is advantaged in that hydrogen gas is injected into the intake pipe through a low-pressure fuel injector, and the mixing period with air is sufficient to produce uniform mixing, improving the thermal efficiency. A drawback is that the flame backfires in the intake manifold, reducing the engine output because the amount of intake air is reduced, owing to the large volume of hydrogen. Here, the backfire mechanism as a part of the development of full-load output capability is investigated, and a 2.4-liter reciprocating gasoline engine is modified to a hydrogen engine with a hydrogen supply system. To secure the stability and output performance of the hydrogen engine, the excess air ratio was controlled with a universal engine control unit. The torque, excess air ratio, hydrogen fuel, and intake air flow rate changes in time were compared under low- and high-engine speed conditions with a wide-open throttle. The excess air ratio depends on the change in the fuel amount when the throttle is completely opened, and excess air ratio increase leads to fuel/air-mixture dilution by the surplus air in the cylinder. As the engine speed increases, the maximum torque decreases because the excess air ratio continues to increase due to the occurrence of the backfire. The exhaust gas temperature also increases, except at an engine speed of 6000 rpm. Furthermore, the increase in exhaust gas temperature affects the backfire occurrence. At 2000 rpm, under low-speed and wide-open throttle conditions, backfire first occurs in the No. 4 cylinder because the mixture is heated by the relatively high port temperature. In contrast, at 6000 rpm, under high-speed and wide-open throttle conditions, the backfire starts at the No. 2 cylinder first because of a higher exhaust gas temperature, resulting in a lower excess air ratio in cylinders 2 and 3, located at the center of the engine. • The maximum torque decreases due to the backfire as the hydrogen engine speed increases. • The increase in the exhaust gas temperature affects the backfire with the increase in speed. • The backfire occurs in the No. 4 cylinder under low-speed conditions due to a higher port temperature. • The backfire starts in the cylinders located at the center of the engine under high-speed conditions. [ABSTRACT FROM AUTHOR]

We have measured the half-lives of 87mY and 87gY produced from the 89Y(γ, 2n) and 89Y(n, 3n) reactions with the bremsstrahlung end-point energy of 65 MeV and the average neutron energy of 37.2 MeV using an activation and an off-line γ-ray spectrometric technique, respectively. The bremsstrahlung photon was produced by using the 100 MeV electron linac of the Pohang Accelerator Laboratory (PAL), whereas the fast neutron was produced from the 9Be(p, n) reaction by using the 45 MeV proton of the MC-50 Cyclotron at the Korea Institute of Radiological and Medical Sciences (KIRAMS). We have also measured the half-lives of 194Au and 196m2,gAu produced from the 197Au(γ, xn; x = 1, 3) and 197Au(n, xn; x = 2, 4) reactions with the bremsstrahlung end-point energy of 60 MeV and the average neutron energy of 37.2 MeV using the same technique and the same facilities as mentioned above. The induced γ-ray activities of the irradiated samples were measured by using an energy- and efficiency calibrated high purity germanium (HPGe) detector. The spectrum analysis has been done by using the ROOT software to separate signals from background. The measured half-lives are compared with the literature values and are in general agreement with each other within the uncertainties. [ABSTRACT FROM AUTHOR]

A proton linac based boron neutron capture therapy system (A-BNCT, 10MeV, 4mA) was successfully developed in Korea. We performed in vitro experiments with U87 and SAS cells and revealed the efficacy of a binary therapy BNCT using epithermal neutrons and boronophenylalanine (BPA). The results revealed that BNCT showed cancer cell selectivity and caused cell death. Further in vitro studies can be a valuable method to characterize an A-BNCT system. We expect BNCT to become a treatment option for cancer patients. • Proton Linac based BNCT (A-BNCT) has been developed in Korea. • Cell death was confirmed in U87 and SAS cells using an A-BNCT system. • We are performing preclinical trials and clinical trials with an A-BNCT system. [ABSTRACT FROM AUTHOR]

Previous research on the self-containment of new towns has focused on access to employment and commute travel; little research has been documented regarding access to non-work facilities and its relation to non-work active travel, overlooking an important aspect to assessing the self-containment of new towns. Drawing on multiple sources of data in Hong Kong, we measure walking accessibility to three main types of non-work facilities (markets, restaurants and parks) as major destinations for non-work travel. Through a series of statistical analysis, we investigate in detail the effects of accessibility on the probability and duration of home-based walking trips. Our findings indicate that: (1) new towns were more disadvantaged and less equitable in terms of the accessibility to non-work facilities than urban areas; and (2) accessibility increased both the likelihood and duration of new town residents' walking trips particularly for grocery-shopping and dining-out purposes. The findings indicate that enhancing accessibility to non-work facilities in new towns can be beneficial in terms of both achieving self-containment and promoting more sustainable travel behaviour. Recommendations are proposed accordingly to help create more pedestrian-friendly environment, and balanced provision of non-work facilities in and around new towns and other suburban developments. • Accessibility to non-work facilities is vital to the self-containment of new towns • Walking accessibility to three main types of non-work facilities is measured. • The relationship between accessibility and walking trips is investigated. • Accessibility is lower and less equitable in new towns than urban areas. • Higher accessibility encourages longer walking trips for new-town residents. [ABSTRACT FROM AUTHOR]

• Effects of piston shape and multi-angle nozzle were evaluated for DF RCCI operation. • Enhanced air utilization w/multi-angle nozzle reduced combustion and HT losses. • The highest GIE of RCCI improved as 51.8 % by hardware modifications. • Intake air amount could be increased by lowering CR (from 17 to 15) at the maximum load. • The maximum load of RCCI could be extended from 81 (reference) to 101 kW of BP. In this study, the effects of modifications of both the piston shape and injector nozzle are experimentally investigated for high load extension of a natural gas–diesel dual-fuel reactivity-controlled compression ignition (RCCI) engine. First, a bathtub shape with a reduced compression ratio is applied to the modified piston which was reported to improve the flame propagation in squish volume, the cooling loss, and the air induction rate under the same limit of in-cylinder pressure from previous studies. In addition, a multiangle two-layer injector is used to extend the maximum load, which has been proven to be effective for unburned hydrocarbon emissions and gross indicated efficiency in part-load operation in our previous study. The experiments are conducted under both 1200 rpm part-load operation (approximately 1950 J/cylinder per cycle of fuel input energy) and 1800 rpm maximum load operation. The objectives are to comprehensively evaluate the effects of the modifications on natural gas–diesel RCCI operation and verify the effects of all load conditions. The experimental results reveal that the changes in the piston—reduction in the compression ratio and a bathtub piston shape—are effective for both NOx and smoke emissions as the diesel injection timing is advanced. Although the multi-hole double layer (combined narrow and wide injection) has less effect on emissions compared to that of the change in piston, it affects the mixing process inside the cylinder, thus retarding the combustion phasing, prolonging the combustion duration, and eventually reducing the cooling loss. Both modifications are highly effective for advanced diesel injection timing corresponding to RCCI operation, which extends high-load operation from 80.9 to 101 kW of brake power, relatively 24.8 % increase, by adopting both the piston and injector modifications. Based on the modifications, the mass fraction of natural gas is suggested to be approximately 80 %. A higher fraction causes the variation in the maximum in-cylinder pressure to be extremely sensitive to allow robust operation. In contrast, if it is lower, the amounts of both NOx and smoke emissions exceed the emission standard levels (0.4 g/kWh and 15 mg/kWh for NOx and smoke emissions, respectively, corresponding to Stage-V of non-road engine operation). [ABSTRACT FROM AUTHOR]

Threshold switching devices with Ag-doped amorphous chalcogenides show enhanced threshold switching characteristics of a high selectivity and a low current in the subthreshold region. However, the mechanism underlying the decrease in this subthreshold current caused by Ag doping is not well understood. In this study, the effects of Ag doping in amorphous Ga 2 Te 3 are investigated in terms of the change in bonding structure and localized states in conjunction with threshold switching characteristics. X-ray photoelectron and Raman spectroscopies reveal the formation of Ag–Te bonds with a reduction in the amount of Te–Te bonds in Ga 2 Te 3. In addition, the UV absorption shows an increase in the optical bandgap and a decrease of Urbach energy with Ag doping. The subthreshold current of the Ag-doped Ga 2 Te 3 device decreases by a factor of seven, and accordingly, the selectivity increases with respect to that of the undoped device. In addition, analyzing on the subthreshold conduction with a thermally assisted hopping model demonstrates a decrease in the density of localized states. Thus, the enhanced threshold switching characteristics of Ag-doped Ga 2 Te 3 are associated with the reduction of Te-induced localized states and the formation of Ag–Te bonds. • Excellent threshold switching characteristics of Ag-doped Ga 2 Te 3 thin films with various Ag doping concentrations. • The bonding structure was affected as Ag-Te bonding was formed with increasing Ag doping concentration. • The optical bandgap and localized states were significantly affected by Ag doping. • Extremely low off current of Ag-doped chalcogenide is correlated to the bonding structure, bandgap and localized states. [ABSTRACT FROM AUTHOR]

• Effects of multi-angle injector on DF combustion was evaluated. • Multi-angle injector helped to reduce NMHC emissions under RCCI. • Multi-angle injector showed better GIE due to lower HT loss. • GWI could be improved more by multi-angle injector under RCCI. In this study, natural gas and diesel dual-fuel combustion in a heavy-duty compression ignition engine is experimentally evaluated by adopting a modified multi-angle nozzle of a diesel injector to reduce the global warming impact (GWI) factor while maintaining high thermal efficiency. The original injector has a single layer with an umbrella angle of 150° and eight holes, whereas the modified injector has an additional layer below with an injection angle of 90° and four holes. The engine speed is 1,200 rpm under low load conditions (intake pressure of 0.11 MPa and overall equivalence ratio of 0.5, such that the torque is varied); meanwhile, the natural gas fraction is varied from 45% to 71% while considering the combustion stability. The diesel injection timing is varied from the top dead center to 70° before top dead center at intervals of 10° for the injector nozzle conditions. Results show that the modified injector improves combustion efficiency under the reactivity-controlled compression ignition (RCCI) regime. In addition, the GWI factor is reduced by 5.6% compared with that of the original injector. Hence, RCCI combustion by early diesel injection using a multi-angle nozzle affords low emissions while considering the GWI factor, as well as maintains a high gross indicated thermal efficiency of 48.6%. [ABSTRACT FROM AUTHOR]

[Display omitted] • Intensified processes for energy-efficient production of dimethyl carbonate are proposed. • Internal or external heat integration was conjugated with a vapor recompression heat pump. • CFD and process simulations are performed to validate heat transfer rates and energy savings. • Hybrid heat integration reduces energy, cost and CO 2 emissions by higher than 35%. This study presents energy-efficient design alternatives for dimethyl carbonate production by combining various heat integration routes of reactive and pressure-sensitive distillation columns. The design of the hybrid heat-integrated sequences was based on internal and external heat integration with a vapor recompression heat pump (VRHP). The conventional pressure-swing separation design and the proposed hybrid heat integration processes were compared subject to a constraint of high product purity of 99.5%. The combined sequence of internal and external heat integration resulted in a cost reduction of 30.28% by eliminating the low-pressure (LP) column reboiler. The VRHP combined with external heat integration fully eliminated the heat duty of the high-pressure (HP) column condenser and the LP column reboiler, resulting in 38.33% energy savings and a 37.5% reduction in CO 2 emissions. The two hybrid sequences with external heat integration showed better energy and economic efficiency and more reduced CO 2 emissions than the VRHP combined with internal heat integration, since the reflux flow rate of the HP column and the reboil flow rate of the LP column were dramatically reduced. [ABSTRACT FROM AUTHOR]

Compressed natural gas (CNG)/diesel reactivity-controlled compression ignition was investigated to understand the combustion and emission characteristics over wide ranges of intake pressure and exhaust gas recirculation (EGR) rate at high load condition. Reactivity-controlled compression ignition is a dual fuel engine combustion strategy that employs in-cylinder fuel blending with two different reactivity fuels, and multiple injections for the in-cylinder fuel reactivity control to optimize the combustion phasing, duration, and magnitude as well as NOx and soot reduction. High CNG substitution was of interest since it could lead to greater CO 2 and particulate matter reductions. The present 80% CNG substitution required substantial intake boosting due to the charge air displaced by CNG. The experimental engine is commissioned for the reactivity-controlled compression ignition regime using natural gas and diesel fuel with a two-stage turbocharging system. The intake boosting system achieved the intake pressure and EGR rate of 210 kPa and 25%, respectively, when the EGR valve was fully open. The intake pressure and EGR levels varied in the ranges of 150 to 210 kPa and 0 to 25%, respectively. The corresponding equivalence ratio ranged from 0.85 to 0.5. The intake system achieved the highest turbocharger efficiency of 56% at the maximum boosting operation. The highest CO 2 reduction was 23.4% at the maximum boosting condition. The improvements under the enhanced intake condition were significant from the standpoints of both efficiency and emissions, including in terms of the particle concentrations. • A two-stage intake boosting system for high-CNG dual-fuel diesel engine is proposed. • Intake system attained the highest turbocharger efficiency under maximum boosting. • Strong correlation between intake conditions and particle concentrations observed. • Significant reduction in CO 2 and NOx emissions and particulate number concentration. [ABSTRACT FROM AUTHOR]

Abstract: Long-term operation of the biomass-to-liquid (BTL) process was conducted with a focus on the production of bio-syngas that satisfies the purity standards for the Fischer–Tropsch (FT) process. The integrated BTL system consisted of a bubbling fluidized bed (BFB) gasifier (20kWth), gas cleaning unit, syngas compression unit, acid gas removing unit, and an FT reactor. Since the raw syngas from the gasifier contains different types of contaminants, such as particulates, condensable tars, and acid gases, which can cause various mechanical problems or deactivate the FT catalyst, the syngas was purified by passing through cyclones, a gravitational dust collector, a two-stage wet scrubber (packing-type), and a methanol absorption tower. The integrated system was operated for 500h over several runs, and stable operating conditions for each component were achieved. The cleaned syngas contained no sulfur compounds (under 1ppmV) and satisfied the requirements for the FT process. [Copyright &y& Elsevier]

In this study, a hydrogen-fueled spark ignition engine was investigated for UAV operation, with a focus on its combustion region and idle condition. A 2.4l, four-cylinder spark ignition engine was used for experiments, with modification for hydrogen usage instead of gasoline. In experiments, the feasible combustion region and limitations of the combustion phenomena for the hydrogen-fueled spark ignition engine at specific load and speed conditions of 50 Nm and 2000 RPM were examined. It was found that owing to the wide flammability range of hydrogen, the air–fuel ratio could be varied from 1.0 to 2.4. However, misfire and backfire occurred because of the mixing issue and highly ignitable characteristics of the hydrogen–air mixture, respectively, under relatively rich conditions (excess air ratio between 1.0 and 1.5). Unstable combustion occurred under a relatively lean condition (excess air ratio>2.0). Considering important parameters such as the nitrogen oxide emissions, unburned hydrogen, and brake thermal efficiency, an excess air ratio between 1.8 and 2.0 with maximum brake torque timing (MBT) operation was appropriate for this condition. Extremely lean conditions with zero load can be achieved with stable combustion with the excess air ratio up to 3.0, which can almost eliminate nitrogen oxide emissions. • Unstable ignition causes misfire with advanced ignition timing at part load. • Backfire by undesirable ignition occurs with retarded ignition timing under λ > 1.6. • λ is limited to 1.8–2.0 at MBT due to NO x and unburned H 2. • NO x can be eliminated under stable idle operation. • Unburned H 2 is converted with commercial TWC of gasoline engine. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel CD-BVO/rGH photocatalyst was constructed by coupling Carbon dot-coupled BiVO 4 with rGH. • CD-BVO/rGH display enhanced photocatalytic activity for TCH degradation and CO 2 reduction. • The synergetic effects of CD-BVO and rGH can enhanced the separation of carriers. • Possible photocatalytic reaction mechanism of TCH degradation and CO 2 reduction was presented. In this study, we fabricated a novel hybrid photocatalyst (CD-BVO/rGH) by coupling carbon dot (CD)-decorated BiVO 4 (BVO) with a reduced graphene hydrogel (rGH). The CD-BVO/rGH photocatalyst significantly enhanced the photocatalytic efficiency for tetracycline hydrochloride (TCH) degradation compared with pure BVO and BVO/rGH under simulated solar irradiation. CD-BVO/rGH also showed a substantial performance in the photocatalytic reduction of CO 2. The enhanced photocatalytic activity of CD-BVO/rGH is attributed to synergistic effects, such as better light energy utilization via the upconversion effects of the CDs and the enhanced migration and separation of photoexcited carriers by the three-dimensional (3D) network structure of the rGH. The systematic analysis of the band structure, electron spin resonance, and free radical trapping revealed that h+ and O 2 – mediate the final photocatalytic degradation of pollutants. Our results provide insight into the design and construction of highly efficient hybrid photocatalysts combined with functional carbon nanostructures to enhance the photocatalytic activity for the photodegradation of environmental pollutants and CO 2 reduction. [ABSTRACT FROM AUTHOR]

[Display omitted] • N-GNDs/Ag/BiVO 4 is constructed by co-deposition N-GNDs and Ag-NPs on the BiVO 4 surface. • N-GNDs/Ag/BiVO 4 display enhanced photocatalytic activity than that of BiVO 4. • The synergistic effects of Ag-NPs and N-GNDs enable a full-spectrum response to light. • Schottky energy barrier and electron trap restrain the recombination of carries. • Possible photocatalytic mechanism and intermediates for TC•HCl degradation is proposed. The efficient removal of antibiotics in water is essential to protect aquatic environment as antibiotics are some of the most hazardous pollutants in water. Herein, we report the synthesis of a novel N-GNDs/Ag/BiVO 4 ternary photocatalyst consisting of BiVO 4 coupled with Ag nanoparticles (Ag-NPs) and nitrogen-doped graphene nanodots (N-GNDs) to degrade and mineralize tetracycline hydrochloride (TC•HCl) in water. The ternary photocatalyst shows higher photocatalytic degradation of TC•HCl under full spectrum light than pure BiVO 4. Based on the morphology, crystalline structure, physicochemical properties, and photoelectrochemical behavior of the ternary photocatalyst, the enhanced photocatalytic performance is attributed to the upconversion effect of N-GNDs and the localized surface plasmon resonance (LSPR) effect of Ag-NPs. Thus, the synergetic effects expand the absorption range of light and significantly promotes the separation of photoexcited carriers. Further, a possible photocatalytic reaction mechanism of TC•HCl degradation over N-GNDs/Ag/BiVO 4 is discussed via through investigation of the charge carrier migration, active species, and intermediates in the degradation processes. [ABSTRACT FROM AUTHOR]

• Effects of fuel fractions and diesel SOI on THC are discussed. • Methane is related with crevice effect and bulk quenching. • NMHC is related with wall-wetting of diesel spray. • MFB50 position has strong influence on heat transfer loss. • RCCI improved the BTE with reduction of THC emissions. In dual-fuel combustion, the levels of total hydrocarbon (THC) emissions have increased, unlike the neat diesel compression ignition (CI) combustion. Intuitively, it can be inferred that most THC emissions are produced by the crevice effect of low-reactivity fuels (high-volatility fuels) under dual-fuel combustion. Additionally, it is possible that high levels of THC emissions are produced by dual-fuel combustion. If reactivity-controlled compression ignition (RCCI) combustion is applied by advancing the diesel injection timing to improve the premixing conditions, the occurrence of the wall-wetting effect may induce the production of high levels of THC emissions owing to incomplete combustion. Thus, in this study, the characteristics of non-methane hydrocarbons (NMHC) and methane emissions under general dual-fuel combustion conditions (diesel injection timings before top dead center (BTDC) 0 and 30 crank angle degree (CAD)) and RCCI conditions (diesel injection timings at 60 and 84 CAD BTDC) were investigated under a low-load in a 6-L heavy-duty engine. The natural gas fraction varied from 50% to the maximum level considering the combustion stability (coefficient of variance of indicated mean effective pressure). The results revealed that the overall THC emissions from the general dual-fuel combustion were higher compared with those of RCCI combustion, owing to the methane emissions from the squish area and the lower average in-cylinder temperature. Notably, methane emissions were dominant in the THC emissions (52–87%) under the general dual-fuel combustion condition, while NMHC emissions were a major part of the in THC emissions (61–87%) under the RCCI regimes. Hence, combustion inefficiency is a major concern in dual-fuel combustion. In this study, this problem was resolved by advancing the diesel injection timings. The findings in this study can be useful in the design of oxidation catalysts, regardless of whether the combustion regime is a general dual-fuel combustion or RCCI combustion considering the portion of methane emissions in the exhaust gas. Additionally, it is known that the RCCI combustion is superior to the general dual-fuel combustion with respect to higher thermal efficiency and low harmful THC emissions. [ABSTRACT FROM AUTHOR]

• Fe-doped Bi 4 O 5 Br 2 nanosheets coupled with Au nanoparticles is prepared. • Enhanced photodegradation of bisphenol A and NO removal has been observed. • Au nanoparticles showed surface plasmon resonance effect. • •O 2 – radical species play a key role in the photocatalytic process. The two key factors such as light adsorption and separation of charge carriers in photocatalysts play crucial roles in determining the overall photocatalytic efficiency. Herein, we report synergetic effects of Fe-doping and Au nanoparticles (Au-NPs) deposition on the photocatalytic activity of the modified Bi 4 O 5 Br 2 (BOB) nanosheets photocatalyst for Bisphenol A degradation and gaseous NO oxidative removal. Fe-doped BOB nanosheets decorated with Au-NPs are synthesized by a two-step chemical method. It was found that the Fe-doped BOB sample decorated with Au-NPs (Au-Fe-BOB) exhibits higher photocatalytic activity than the BOB, Fe-doped BOB, and Au-NPs-loaded BOB samples. Internal Fe-doping in the BOB enhanced the visible light absorption and the separation efficiency of photogenerated charge carriers acting as a scavenger. Moreover, the decorated Au-NPs in the composite photocatalyst extended the light adsorption in the range of visible and near- infrared light due to surface plasmon resonance effect of Au-NPs. The spin trapping measurements of Au-Fe-BOB composite photocatalyst show that the •O 2 − is a main reactive species during the photocatalytic reaction under visible-light irradiation. The excellent photocatalytic efficiency and stability of Au-Fe-BOB with visible-light response allow to be readily constructed and applied for practical removal of various pollutants using solar light in the future. [ABSTRACT FROM AUTHOR]

• Nanofiber-structured catalyst layer was created by adjusting polarity of dispersion. • Electrochemical active surface area was improved by the nanofibers structure. • Distinction between polar/non-polar regions promotes order mass-transfer in cathode. • Novel catalyst layer exhibits a 41.5% improvement in fuel cell power density. Due to eco-friendly production and running processes, direct methanol fuel cell has been considered as a clean and green energy generation technology. However, the dissatisfactory discharge performance of fuel cell, mainly caused by low-efficient catalyst layers, has limited its commercialization. To improve the electrochemical active surface area, herein, the novel cathode catalyst layer with nanofiber microstructure has been prepared by adding water additive into the catalyst slurry, during the heat-spray process, for enhancing electrochemical performance of direct methanol fuel cells. In the catalyst slurry, owing to its high molecular polarity, the water phase collects polar parts of Nafion molecules, i.e. sulfonic acid group, together to form the polar region. Simultaneously, the nonpolar fluorocarbon chain spreads into an isopropanol phase to form the low-polar region. The distinction between polar and non-polar regions provides a structural basis for orderly mass transfer inside the catalyst layer. Finally, the novel catalyst layer exhibits a 34.7% increase in electrochemical active surface area and signally enhanced mass transport properties, leading to a 41.5% improvement in the power density of the fuel cell. This design to concurrently enhance electroactive surface area and build order mass transfer provides a new strategy for developing high-performance catalyst layers. [ABSTRACT FROM AUTHOR]

Many previous studies have attempted to substitute diesel fuel with compressed natural gas (CNG) in compression-ignition engines, which can substantially reduce CO 2 and soot emissions. However, the CNG substitution rate cannot be maximized due to several restrictions, most prominently the amount of diesel injection. The minimum injection quantity becomes more significant under conditions of lower torque or higher CNG substitution rate. In this study, engine experiments were performed at 0, 70, and 80% CNG substitution rates under various EGR (exhaust gas recirculation) levels in a six-cylinder, 5899-cm3 diesel engine to determine the combustion and emission characteristics at various CNG substitution rates. The 80% CNG case exhibited the highest thermal efficiency and largest CO 2 reduction with an elevated combustion noise level of 92.3 dB. The thermal efficiency increase and CO 2 reduction with 80% substitution were 2.7% and 18.7%, respectively. A three-dimensional engine combustion simulation was performed to optimize the diesel injector nozzle hole size and rate-of-injection (ROI) for 80% CNG substitution, whereby the mass of diesel injection quantity was reduced to 20% that of the conventional diesel case. The computational result demonstrated that a 25% smaller diameter nozzle (150 μm) with an advanced ROI exhibited a 3.4% increase in the gross indicated mean effective pressure. [ABSTRACT FROM AUTHOR]

Highways, while vital for transportation, often lead to heightened air and noise pollution, adversely affecting nearby communities. This study delves into the effectiveness of highway capping, a sustainable urban development strategy, in addressing these environmental challenges, with a specific focus on the Bundang-Suseo Highway in South Korea. This study employed a multifaceted approach, incorporating on-road monitoring, in situ measurements, and vertical assessments using UAVs. Following the cap's installation, the area experienced more stable pollutant levels, marking a notable shift from the previously fluctuating conditions heavily influenced by the highway. In-depth in situ monitoring near the cap revealed significant reductions in noise and pollutants like UFP and BC. Furthermore, UAV monitoring captured these changes in pollutant levels at different altitudes. Notably, the installation of the highway cap led to increased PM 2.5 , PM 10 , and NO 2 levels at ground level, but a decrease above the cap, emphasizing the critical importance of intentional highway cap design in enhancing urban air quality and reducing exposure to harmful pollutants. This research yields invaluable insights for urban planners, health authorities, and policymakers, aiding the precise identification of pollution-prone areas and advocating for improved highway cap design to enhance urban environments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Airway management is a fundamental and intricate process that involves a sequence of integrated tasks. Situations requiring emergency airway management may occur in emergency department, intensive care units, and various other spaces. Emergency airway management can face a variety of challenges during preparation, intubation, and post-intubation, and may result in significant complications for the patients. Therefore, many countries are establishing step-by-step systemization and detailed guidelines, and updating the content based on the latest research. This clinical review introduces the current trends in emergency airway management, such as emergency airway management algorithms, comparison of video and direct laryngoscopy, rapid sequence intubation, pediatric airway management, pre-hospital airway management, surgical airway management, and airway management education.

Quercetin is a flavonol belonging to the flavonoid group of polyphenols. Quercetin is reported to have a variety of biological functions, including antioxidant, pigment, auxin transport inhibitor and root nodulation factor. Additionally, quercetin is known to be involved in bacterial pathogen resistance in Arabidopsis through the transcriptional increase of pathogenesis-related ( PR ) genes. However, the molecular mechanisms underlying how quercetin promotes pathogen resistance remain elusive. In this study, we showed that the transcriptional increases of PR genes were achieved by the monomerization and nuclear translocation of nonexpressor of pathogenesis-related proteins 1 (NPR1). Interestingly, salicylic acid (SA) was approximately 2-fold accumulated by the treatment with quercetin. Furthermore, we showed that the increase of SA biosynthesis by quercetin was induced by the transcriptional increases of typical SA biosynthesis-related genes. In conclusion, this study strongly suggests that quercetin induces bacterial pathogen resistance through the increase of SA biosynthesis in Arabidopsis .

Reactive distillation (RD) provides notable advantages over conventional processes, regarding reduced energy requirements and CO 2 emissions. However, as the benefits of RD may not be universally applicable, a comprehensive feasibility assessment is necessary. This study introduced an automated feasibility evaluation procedure for an RD column using an AI-based region recognition approach, reducing the reliance on expert knowledge and heuristics in graphical methods. Through k -means clustering-based image segmentation, topological information on the reaction and separation reachable region was extracted from ternary diagram landscapes. Subsequently, the extracted information was integrated into tray-by-tray calculations to automate the evaluation. This geometric calculation procedure was applied to assess the feasibility of RD columns with different types of reactions. The feasibility results were obtained within seconds, demonstrating the efficiency of the proposed approach. Furthermore, case studies validated the feasibility of the evaluation results for three practical examples using rigorous simulations, confirming its reliability and applicability., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Rationally engineered porous structures enable lightweight broadband electromagnetic (EM) wave absorbers for countering radar signals or mitigating EM interference between multiple components. However, the scalability of such structures has been hindered by their limited mechanical properties resulting from low density. Herein, an additively manufactured Kelvin foam-based EM wave absorber (KF-EMA) is reported that exhibits multifunctionality, namely EM wave absorption and light-weighted load-bearing structures with constant relative stiffness made possible using bending-dominated lattice structures. Based on tuning design parameters, such as the backbone structures and constituent materials, the proposed KF-EMA features a multilayered 3D-printed design with geometrically optimized KF structures made of carbon black-based backbone composites. The developed KF-EMA demonstrated an absorbance greater than 90% at frequencies ranging from 5.8 to 18 GHz (average EM wave absorption rates of 95.89% and maximum of 99.1% at 15.8 GHz), while the low-density structures of the absorber (≈200 kg m -3 ) still maintained a compression index between the stiffness and relative density (n = 2) under compression. The design strategy paves the way for using metamaterials as mechanically reinforced EM wave absorbers that enable multifunctionality by optimizing unit-cell parameters through a single and low-density structure., (© 2023 Wiley-VCH GmbH.)

The resistive random-access memory (RRAM) with multi-level storage capability has been considered one of the most promising emerging devices to mimic synaptic behavior and accelerate analog computations. In this study, we investigated the reset-first bipolar resistive switching (RS) and multi-level characteristics of a LaNiO 3-x thin film deposited using a reactive magnetron co-sputtering method. Polycrystalline phases of LaNiO 3 (LNO), without La 2 O 3 and NiO phases, were observed at similar fractions of Ni and La at a constant partial pressure of oxygen. The relative chemical proportions of Ni 3+ and Ni 2+ ions in LaNiO 3-x indicated that it was an oxygen-deficient LaNiO 3-x thin film, exhibiting RS behavior, compared to LNO without Ni 2+ ions. The TiN/LaNiO 3-x /Pt devices exhibited gradual resistance changes under various DC/AC voltage sweeps and consecutive pulse modes. The nonlinearity values of the conductance, measured via constant-pulse programming, were 0.15 for potentiation and 0.35 for depression, indicating the potential of the as-fabricated devices as analog computing devices. The LaNiO 3-x -based device could reach multi-level states without an electroforming step and is a promising candidate for state-of-the-art RS memory and synaptic devices for neuromorphic computing.

Boron neutron capture therapy (BNCT) is a radiation therapy that selectively kills cancer cells and is being actively researched and developed around the world. In Korea, development of the proton linear accelerator-based BNCT system has completed development, and its anti-cancer effect in the U-87 MG subcutaneous xenograft model has been evaluated. To evaluate the efficacy of BNCT, we measured 10 B-enriched boronophenylalanine (BPA) uptake in U-87 MG, FaDu, and SAS cells and evaluated cell viability by clonogenic assays. In addition, the boron concentration in the tumor, blood, and skin on the U-87 MG xenograft model was measured, and the tumor volume was measured for 4 weeks after BNCT. In vitro, the intracellular boron concentration was highest in the order of SAS, FaDu, and U-87 MG, and cell survival fractions decreased depending on the BPA treatment concentration and neutron irradiation dose. In vivo, the tumor volume was significantly decreased in the BNCT group compared to the control group. This study confirmed the anti-cancer effect of BNCT in the U-87 MG subcutaneous xenograft model. It is expected that the proton linear accelerator-based BNCT system developed in Korea will be a new option for radiation therapy for cancer treatment.

We recently reported a lack of interference between inactivated rotavirus vaccine (IRV) and inactivated poliovirus vaccine (IPV) and their potential dose sparing when the two vaccines were administered intramuscularly either in combination or standalone in rats and guinea pigs. In the present study, we optimized the formulations of both vaccines and investigated the feasibility of manufacturing a combined IRV-IPV dissolving microneedle patch (dMNP), assessing its compatibility and immunogenicity in rats. Our results showed that IRV delivered by dMNP alone or in combination with IPV induced similar levels of RV-specific IgG and neutralizing antibody. Likewise, IPV delivered by dMNP alone or in combination with IRV induced comparable levels of neutralizing antibody of poliovirus types 1, 2, and 3. We further demonstrated high stability of IRV-dMNP at 5, 25, and 40 °C and IPV-dMNP at 5 and 25 °C, and found that three doses of IRV or IPV when co-administered at a quarter dose was as potent as a full target dose in inducing neutralizing antibodies against corresponding rotavirus or poliovirus. We conclude that IRV-IPV dMNP did not interfere with each other in triggering an immunologic response and were highly immunogenic in rats. Our findings support the further development of this innovative approach to deliver a novel combination vaccine against rotavirus and poliovirus in children throughout the world., (© 2022. This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.)

Competing Interests: Conflict of Interest: Park MH has no financial conflicts of interest. Hanmi Pharmaceutical Company provided support in the form of salaries for the other authors (Lee J, Nam H, Kyoung DS), but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Background: Dipeptidyl peptidase-4 inhibitor (DPP-4i) and renin-angiotensin system (RAS) blockade are reported to affect the clinical course of coronavirus disease 2019 (COVID-19) in patients with diabetes mellitus (DM)., Methods: As of May 2020, analysis was conducted on all subjects who could confirm their history of claims related to COVID-19 in the National Health Insurance Review and Assessment Service (HIRA) database in Korea. Using this dataset, we compared the short-term prognosis of COVID-19 infection according to the use of DPP-4i and RAS blockade. Additionally, we validated the results using the National Health Insurance Service (NHIS) of Korea dataset., Results: Totally, data of 67,850 subjects were accessible in the HIRA dataset. Of these, 5,080 were confirmed COVID-19. Among these, 832 subjects with DM were selected for analysis in this study. Among the subjects, 263 (31.6%) and 327 (39.3%) were DPP4i and RAS blockade users, respectively. Thirty-four subjects (4.09%) received intensive care or died. The adjusted odds ratio for severe treatment among DPP-4i users was 0.362 (95% confidence interval [CI], 0.135 to 0.971), and that for RAS blockade users was 0.599 (95% CI, 0.251 to 1.431). These findings were consistent with the analysis based on the NHIS data using 704 final subjects. The adjusted odds ratio for severe treatment among DPP-4i users was 0.303 (95% CI, 0.135 to 0.682), and that for RAS blockade users was 0.811 (95% CI, 0.391 to 1.682)., Conclusion: This study suggests that DPP-4i is significantly associated with a better clinical outcome of patients with COVID-19.

The Z-scheme BiVO 4 /α-Fe 2 O 3 photocatalyst was synthesized by a simple hydrothermal method. The photocatalyst is composed of α-Fe 2 O 3 nanocubes with a regular cubic structure and the BiVO 4 particles distributed on the surface of the α-Fe 2 O 3 nanocubes. The photocatalytic performance of Z-scheme BiVO 4 /α-Fe 2 O 3 photocatalyst was investigated in terms of its capacity for photodegradation of tetracycline hydrochloride. Improved photocatalytic activity was observed for Z-scheme BiVO 4 /α-Fe 2 O 3 photocatalyst compared with pure BiVO 4 and α-Fe 2 O 3 nanocubes under visible light irradiation. Studies of its morphology, physicochemical properties and photoelectrochemical behaviors demonstrated that BiVO 4 loading on the surface of α-Fe 2 O 3 nanocubes forms a Z-scheme heterojunction, which increases the specific surface area and significantly promotes the separation of photoinduced carriers. The main active species were determined to be OH and h + by ESR technique and trapping experiments. We propose a possible photocatalytic mechanism of Z-scheme BiVO 4 /α-Fe 2 O 3 photocatalyst system. This study may also provide a novel and eco-friendly demonstration of a useful strategy for the design and preparation of special structure photocatalytic materials., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Advances in single-cell isolation and barcoding technologies offer unprecedented opportunities to profile DNA, mRNA, and proteins at a single-cell resolution. Recently, bulk multiomics analyses, such as multidimensional genomic and proteogenomic analyses, have proven beneficial for obtaining a comprehensive understanding of cellular events. This benefit has facilitated the development of single-cell multiomics analysis, which enables cell type-specific gene regulation to be examined. The cardinal features of single-cell multiomics analysis include (1) technologies for single-cell isolation, barcoding, and sequencing to measure multiple types of molecules from individual cells and (2) the integrative analysis of molecules to characterize cell types and their functions regarding pathophysiological processes based on molecular signatures. Here, we summarize the technologies for single-cell multiomics analyses (mRNA-genome, mRNA-DNA methylation, mRNA-chromatin accessibility, and mRNA-protein) as well as the methods for the integrative analysis of single-cell multiomics data.

Background: Errors in counting spinal segments are common during interventional procedures when there are transitional vertebrae. In this study, we investigated the prevalence of the transitional vertebrae including thoracolumbar transitional vertebra (TLTV) and lumbosacral transitional vertebrae (LSTV). The relationship between the existence of TLTV and abnormal rib count or the existence of LSTV were also evaluated., Methods: The vertebral levels were counted craniocaudally, starting from C1, based on the assumption of 7 cervical, 12 thoracic, and 5 lumbar vertebrae, using whole spine spiral three-dimensional computed tomographic images. The 20th and 25th vertebrae were defined as L1 and S1, respectively., Results: In total, 150 patients had TLTV, with a prevalence of 11.2% (150/1,340). LSTV was observed in 111 of 1,340 cases (8.3%). Sacralization was observed in 68 of 1,340 cases (5.1%) and lumbarization in 43 of 1,340 cases (3.2%). There was a significant relationship between the existence of TLTV and the abnormal rib count (odds ratio [OR]: 117.26, 95% confidence interval [95% CI]: 60.77-226.27; P < 0.001) and LSTV (OR: 7.38, 95% CI: 3.99-13.63; P < 0.001)., Conclusions: Our study results suggest that patients with TLTV are more likely to have an abnormal rib count or LSTV. If a TLTV or LSTV is seen on the fluoroscopic image, a whole spine image is necessary to permit accurate numbering of the lumbar vertebra., Competing Interests: CONFLICTS OF INTEREST No potential conflict of interest relevant to this article was reported., (Copyright © the Korean Society of Anesthesiologists, 2020.)

Background: Retropharyngeal hematoma following cervical spine trauma may lead to life-threatening upper airway obstruction and difficult airway management. This retrospective study was performed to investigate whether the extension of retropharyngeal space (RPS) was associated with difficult intubation by direct laryngoscopy in traumatic cervical spine injury., Patients and Methods: Sixty-two patients who had undergone direct endotracheal intubation under general anesthesia for cervical spine surgery were retrospectively identified. Laryngoscopic grade by Cormack-Lehane (C-L) classification was collected; grade 1 or 2 was categorized as easy laryngoscopy, whereas grade 3 or 4 was categorized as difficult laryngoscopy. In these patients, RPS thickness and the proportions of RPS to the vertebral bodies were measured at the 2nd, 5th and 7th cervical spine levels using magnetic resonance imaging (MRI) of the cervical spine. Measures of RPS were compared between easy and difficult laryngoscopy. Relationships between measures of RPS and difficult laryngoscopy were analyzed with logistic regression analysis., Results: RPS thickness at C2 was significantly greater in difficult laryngoscopy (median 14.29 mm, IQR: 9.75-18.04) than easy laryngoscopy (median 5.10, IQR: 4.33-5.94, p <0.001). Proportion of RPS to the C2 vertebral body were significantly higher in difficult laryngoscopy than in easy laryngoscopy ( p <0.001). RPS thickness and the proportion of RPS to the vertebral body were significantly associated with difficult laryngoscopy (OR=2.13, 95% CI: 1.38-3.30; p <0.001 and OR=1.13, 95% CI: 1.05-1.21; p <0.001, respectively)., Conclusion: RPS extension at the upper cervical spine level is associated with difficult direct laryngoscopy in traumatic cervical spine injury., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

In order to tackle climate change effectively, the greenhouse gas emissions produced in Korea should be assessed precisely. To do so, the nation needs to accumulate country-specific data reflecting the specific circumstances surrounding Korea's emissions. This paper analyzed element contents of domestic anthracite, calorific value, and concentration of methane (CH₄) and nitrous oxide (N₂O) in the exhaust gases from circulating fluidized bed plant. The findings showed the concentration of CH₄ and N₂O in the flue gas to be 1.85 and 3.25 ppm, respectively, and emission factors were 0.486 and 2.198 kg/TJ, respectively. The CH₄ emission factor in this paper was 52% lower than default emission factor presented by the IPCC. The N₂O emission factor was estimated to be 46% higher than default emission factor presented by the IPCC. This discrepancy can be attributable to the different methods and conditions of combustion because the default emission factors suggested by IPCC take only fuel characteristics into consideration without combustion technologies. Therefore, Korea needs to facilitate research on a legion of fuel and energy consumption facilities to develop country-specific emission factors so that the nation can have a competitive edge in the international climate change convention in the years to come.

Introduction: Korea has been making efforts to reduce greenhouse gas (GHG) emissions, including a voluntary commitment to the target of a 30% reduction, based on business-as-usual of the total GHG emission volume, by 2020; 2006 IPCC Guidelines provided default values, applying country-specific emission factors was recommended when estimating national greenhouse gas emissions., Results and Discussion: This study focused on anthracite produced in Korea in order to provide basic data for developing country-specific emission factor. This study has estimated CO(2) emission factors to use worksheet of which five steps consisted according to the fuel analysis method., Conclusion: As a result, the average of net colorific value for 3 years (2007∼2009) was 4,519 kcal/kg, and the CO(2) emission factor was calculated to be 111,446 kg/TJ, which is about 11.8% lower than the 2006 IPCC guidelines default value, and about 7.9% higher than the US EPA emission factor.