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Catastrophic forgetting, which means a rapid forgetting of learned representations while learning new data/samples, is one of the main problems of deep neural networks. In this paper, we propose a novel incremental learning framework that can address the forgetting problem by learning new incoming data in an online manner. We develop a new incremental learning framework that can learn extra data or new classes with less catastrophic forgetting. We adopt the hippocampal memory process to the deep neural networks by defining the effective maximum of neural activation and its boundary to represent a feature distribution. In addition, we incorporate incremental QR factorization into the deep neural networks to learn new data with both existing labels and new labels with less forgetting. The QR factorization can provide the accurate subspace prior, and incremental QR factorization can reasonably express the collaboration between new data with both existing classes and new class with less forgetting. In our framework, a set of appropriate features (i.e., nodes) provides improved representation for each class. We apply our method to the convolutional neural network (CNN) for learning Cifar-100 and Cifar-10 datasets. The experimental results show that the proposed method efficiently alleviates the stability and plasticity dilemma in the deep neural networks by providing the performance stability of a trained network while effectively learning unseen data and additional new classes. [ABSTRACT FROM AUTHOR]

With the development of maritime technology and equipment, most ships are equipped with an automatic identification system (AIS) to store navigation information. Over time, the size of the data increases, rendering its storage and processing difficult. Hence, it is necessary to transform the AIS data into trajectories, and then simplify the AIS trajectories to remove unnecessary information that is not related to route shape. Moreover, topographic information must be considered because otherwise, the simplified trajectory can intersect obstacles. In this study, we propose an AIS trajectory simplification algorithm considering topographic information. The proposed algorithm simplifies the trajectories without the intersection of the trajectory and obstacle using the improved Douglas–Peucker algorithm. Polygon map random (PMR) quadtree was used to consider topographic information on the coast, and the intersection between topographic information and simplified trajectories was efficiently computed using the PMR quadtree. To verify the effectiveness of the proposed algorithm, experiments were conducted on real-world trajectories in the Korean sea. The proposed algorithm yielded simplified trajectories with no intersections of the trajectory and obstacle. In addition, the computational efficiency of the proposed algorithm with the PMR quadtree was superior to that without the PMR quadtree. [ABSTRACT FROM AUTHOR]

Various neurological and musculoskeletal disorders can induce pathologic toe walking and lead to changes in foot kinematics. In this study, we analyzed the differences in foot kinematics between toe walking and heel-toe walking (HW) in able-bodied individuals. Twenty young healthy adults performed three gaits: HW, comfortable-height toe walking (CTW), and maximum-height toe walking (MTW). Oxford Foot Model was used for gait analysis. Toe walking showed increase of forefoot plantarflexion and hindfoot internal rotation compared to HW. Thus, our results may help distinguish the pathologic mechanism of the equinus gait in various disorders from the kinematic change of toe walking itself. [ABSTRACT FROM AUTHOR]

Physical education teacher communities have been studied and implemented as a successful approach to teacher professional development. Despite a wealth of literature, less is known about three aspects: sustained nature of a community over time, power relations among community members, and a comprehensive case study. This study aimed to address these gaps in the literature by investigating the journey of a physical education community of practice (CoP) in South Korea. In this intrinsic case study, seven core members were interviewed using a timeline drawing method to elicit the stories behind the community's history. In addition, field notes from observations and documents from the official community website were used to corroborate the interview data. Inductive and collaborative data analysis organised the community's history into four phases: Beginning, Rise, Fall, and Comeback. Detailed explanations of each phase represent what happened and how the community evolved over time. Discussions suggested, first, that changing power relations facilitate different types of learning in CoPs. Initially, a strong leader drove learning as experiencing and doing, but as power shifted to members, the community changed to learning as belonging and becoming. Second, conflict can be a natural process to revisit the shared vision. Since the shared vision is not static but rather reflects contextual values, community members should revisit and discuss it as conflicts arise. Third, community engagement can be understood as an opportunity to gain recognition. This research underscores the significance of understanding long-term teacher motivation and the collective factors that drive it through community engagement. [ABSTRACT FROM AUTHOR]

Synchronous reluctance motors show nonlinear behavior in the high torque region due to core saturation, especially on the $d$ -axis. In this study, the maximum torque per ampere (MTPA) solution is sought in the mathematical frame. First, flux linkage data are obtained from finite element method, and fitted as the plane functions of currents by the least square method. Thereafter, the inductances are derived as binomials in $i_d$ and $i_q$. These analytic expressions of inductances are used in deriving a necessary condition for the MTPA, and constructing an on-line MTPA control method. The effectiveness is verified through simulation and experimental results. [ABSTRACT FROM AUTHOR]

Techniques such as direct sequencing and PCR-RFLP (restriction fragment length polymorphism) are widely used to analyze the genotypes of livestock. However, these conventional methods have the disadvantage of taking a lot of time and incurring considerable cost. The allele-specific PCR method performs PCR using two primers, and a single nucleotide polymorphism (SNP) genotype can be identified through electrophoresis, saving time and cost. Highly accurate results can be obtained by designing specific primers according to the allele of the SNP under study, utilizing primer binding to a complementary matching sequence. In this study, we established a genotyping system with the AS-PCR technique, using SNPs related to the improvement of the meat quality and meat mass of Korean cattle. Using the PRIMER1 program, we designed specific primers for SNPs located at the 3 ′ end, with one SNP marker in the HSPB1 gene related to meat quantity and two SNP markers in the ADH1C and FASN genes related to meat quality in cattle. AS-PCR was performed on 10 Korean cattle using the primers designed with this system, and the genotypes could be identified by the size of the PCR product amplified as a result of electrophoresis. In the case of the HSPB1 g.2352T > C SNP, the T allele was amplified to 148 bp, and the C allele was amplified to 222 bp. The ADH1C c.-64T > C SNP was amplified to 492 bp at the T allele and 330 bp at the C allele. The FASN g.17924G > A SNP A allele was amplified to 377 bp and the G allele to 507 bp. The results for each SNP genotype were verified using direct sequencing, which showed that the genotypes identified by direct sequencing and the genotypes identified by the AS-PCR method matched exactly. The AS-PCR method therefore appears to be valuable for use in a genotyping system. [ABSTRACT FROM AUTHOR]

Electrochemical CO2 reduction (ECO2R) is considered as one of the economically viable means to convert CO2 into useful products, for achieving carbon neutrality in the future. Many studies have been conducted on developing and evaluating electrochemical cells that provide high energy efficiency and conversion of CO2 for CO production via ECO2R. However, commercially feasible technologies are yet to be developed and demonstrated due to various technical limitations as well as the lack of a systematic evaluation framework. In this study, CO production performance is examined by catholyte-free electrochemical CO2 reduction (CF-ECO2R), which eliminates a large ohmic drop by removing the catholyte compartment, thus lowering the energy requirement. The CF-ECO2R shows 0.6 V lower cell voltage and 17.4% higher electrical energy conversion efficiency than a typical GDE-catholyte method using 1 M KOH as the catholyte at a current density of 240 mA cm−2. The obtained results are used to demonstrate its technical feasibility and to provide basic data for the evaluation of a scale-up process. A mathematical model is developed based on the obtained experimental data and the model is simulated along with three different options of downstream separation to provide basic mass and energy balance data. Then, techno-economic and CO2 life cycle analyses are conducted to suggest the best configuration of the overall CO production system in terms of the economics and net CO2 reduction. It is estimated that the best configuration provides a reduction in CO2 emission by 48% compared to the conventional CO production via steam methane reforming. This configuration is also assessed to be economically feasible, giving a production cost (584 USD per ton CO) that is competitive with the current market price of CO. It is also demonstrated that the operating voltage of the CF-ECO2R and regional influences such as CO2 emission intensity and cost of the mixed electricity strongly affect the cost and CO2 emission of the system. [ABSTRACT FROM AUTHOR]

Lee, K. and Lee, W., 2023. Temperature accuracy analysis of land cover around urban rivers using thermal infrared sensor-mounted UAV. In: Lee, J.L.; Lee, H.; Min, B.I.; Chang, J.-I.; Cho, G.T.; Yoon, J.-S., and Lee, J. (eds.), Multidisciplinary Approaches to Coastal and Marine Management. Journal of Coastal Research, Special Issue No. 116, pp. 215-219. Charlotte (North Carolina), ISSN 0749-0208. With rapid industrialization and urbanization, city centres experience a higher temperature than the surrounding suburbs, a phenomenon known as the Urban Heat Island (UHI). Efficient management of the permeable surface of a city is necessary to reduce UHI. Rivers are the representative permeable surfaces of a city and require steady management. However, monitoring around rivers requires a higher spatial resolution of satellite images and aerial photographs. For a Thermal Infrared (TIR) sensor, obtaining high-accuracy information is difficult in a small area because of the low spatial resolution. As an alternative, high-resolution data can be obtained using an Unmanned Aerial Vehicle (UAV) mounted with a TIR sensor. However, none of the studies have assessed the accuracy according to the angle and shooting height. Therefore, it is necessary to study the method of acquisition of data according to the shooting height and sensor angle around the river area using the TIR sensor. In this study, TIR images were acquired for two rivers using UAV-mounted TIR sensors to evaluate the accurate shooting height and TIR sensor angle. Land Surface Temperature (LST) data were obtained by generating orthophotos using the acquired TIR images. Therefore, the most accurate LST data was obtained at a shooting height of 50 m and a sensor angle of 80°. Based on our analysis, an 80° sensor angle and a low shooting height was recommended for acquiring ground LST, depending on the shooting situation. [ABSTRACT FROM AUTHOR]

Dementia has become a profound public health problem due to the number of patients increasing every year. Previous studies have reported that environmental factors, including greenness, may influence the development and progression of dementia. Studies have found that exposure to green space is associated with a lower incidence of dementia. However, many definitions of green space exist, and the effects of its use may differ with the type of green space. Therefore, two types of green space measures were considered in this study to assess the differences in their impact on the prevalence of dementia among females and males. This study used five years of data (2017–2021) from 235 districts in South Korea. The two green space measures used were open space density and normalized difference vegetation index (NDVI), which were derived from satellite images. The analysis utilized a combination of traditional and spatial panel analyses to account for the spatial and temporal effects of independent variables on dementia prevalence. The spatial autocorrelation results revealed that both measures of greenness were spatially correlated with dementia prevalence. The spatial panel regression results revealed a significant positive association between NDVI and dementia prevalence, and open space had a negative association with dementia prevalence in both genders. The difference in the findings can serve as the basis for further research when choosing a greenspace measure, as it affects the analysis results, depending on the objective of the study. This study adds to the knowledge regarding improving dementia studies and the application of spatial panel analysis in epidemiological studies. [ABSTRACT FROM AUTHOR]

Abstract: Electrochemical reduction of carbon dioxide (CO2) into value‐added chemicals is a promising strategy to reduce CO2 emission and mitigate climate change. One of the most serious problems in electrocatalytic CO2 reduction (CO2R) is the low solubility of CO2 in an aqueous electrolyte, which significantly limits the cathodic reaction rate. This paper proposes a facile method of catholyte‐free electrocatalytic CO2 reduction to avoid the solubility limitation using commercial tin nanoparticles as a cathode catalyst. Interestingly, as the reaction temperature rises from 303 K to 363 K, the partial current density (PCD) of formate improves more than two times with 52.9 mA cm−2, despite the decrease in CO2 solubility. Furthermore, a significantly high formate concentration of 41.5 g L−1 is obtained as a one‐path product at 343 K with high PCD (51.7 mA cm−2) and high Faradaic efficiency (93.3 %) via continuous operation in a full flow cell at a low cell voltage of 2.2 V. [ABSTRACT FROM AUTHOR]

Abstract: Electrochemical reduction of carbon dioxide (CO2) into value‐added chemicals is a promising strategy to reduce CO2 emission and mitigate climate change. One of the most serious problems in electrocatalytic CO2 reduction (CO2R) is the low solubility of CO2 in an aqueous electrolyte, which significantly limits the cathodic reaction rate. This paper proposes a facile method of catholyte‐free electrocatalytic CO2 reduction to avoid the solubility limitation using commercial tin nanoparticles as a cathode catalyst. Interestingly, as the reaction temperature rises from 303 K to 363 K, the partial current density (PCD) of formate improves more than two times with 52.9 mA cm−2, despite the decrease in CO2 solubility. Furthermore, a significantly high formate concentration of 41.5 g L−1 is obtained as a one‐path product at 343 K with high PCD (51.7 mA cm−2) and high Faradaic efficiency (93.3 %) via continuous operation in a full flow cell at a low cell voltage of 2.2 V. [ABSTRACT FROM AUTHOR]

Pre-combustion CO 2 capture technology was investigated via a hydrate-based gas separation process. Semiclathrate phase equilibria were measured for the simulated fuel gas from the integrated gasification combined cycle (IGCC) consisting of 40 mol% CO 2 and balanced H 2 in the presence of tetra-n-butyl ammonium bromide (TBAB) and porous silica gel particles containing water inside. The basic idea is an extension of our previous work [34], that is, using a porous silica gel structure made it possible to get rid of stirring the content inside the hydrate reactor and ensure the rapid hydrate formation with relatively short induction. TBAB was introduced to confined aqueous solution in silica gel pore structure, having nominal pore diameter of 100 nm, as a thermodynamic promoter and formed semiclathrate with the gas mixture under milder temperature and pressure conditions. Compositional analysis of semiclathrate and coexisting gas phases was also performed at various temperatures and TBAB concentrations. The highest CO 2 concentration obtained from the dissociated semiclathrate was 94 mol% formed at 277.15 K and 3.0 MPa, with 20 wt% TBAB solution in 100 nm silica gel. To demonstrate the highly-concentrated CO 2 outlet stream from the single-stage semiclathrate reactor, the kinetic study of CO2 distribution through fixed-bed type reactor charged with silica gel particles containing aqueous TBAB solution was also investigated. Utilization of porous silica gel makes it possible to capture higher concentration of CO2 in the semiclathrate phase, but it also reduced the total amount of gas consumed for semiclathrate conversion. However, the use of silica gel particles with TBAB enabled formation of semiclathrate hydrate under milder conditions and unstirred continuous method to a high extent and a high rate. [ABSTRACT FROM AUTHOR]

The simultaneous process of NaOH production via electrolysis of NaCl and CO2 capture was investigated due to the expectation of reduction in capital cost. It was found that seawater concentration of NaCl solution was adaptable to be used as both anolyte and catholyte and that 90 °C was the most proper temperature for NaOH production among the test conditions in this work. Under these electrolyte and temperature conditions, the simultaneous NaOH production and CO2 capture processes were conducted and more than 98.83 % of OH− was reacted with CO2 to yield aqueous carbonate solutions. Additional electrochemical CO2 capture tests were carried out depending on the different CO2 concentration of mixed gases. [ABSTRACT FROM AUTHOR]

[Display omitted] • Indium-doped tin oxide nanowires (In-SnO 2 NWs) were synthesized by the facile polyol technique, followed by wet-impregnation and calcination. • Enhanced formate selectivity up to ∼82 % at −1.04 V (vs RHE) is mainly driven by the In-SnO 2 synergistic interaction. • A defective SnO 2 surface induced by the In dopant provides more active sites; concurrently, the regulating electronic structure tailors the reaction intermediates to be stably adsorbed to produce more formate ions. Electrochemical reduction of CO 2 to various chemicals is a promising approach to dealing with excessive CO 2 accumulation in the atmosphere. Even though numerous electrocatalysts have been extensively utilized for the reaction, several challenges remain such as high overpotential, poor stability, and low selectivity followed by the domination of hydrogen formation. To overcome these problems, multi-component materials have been proposed due to their advanced catalytic activity compared to single-component materials. Herein, we present preparation of the indium-doped tin oxide nanowires (In-SnO 2 NWs) as an efficient electrocatalyst to promote CO 2 reduction into formate. The unique 1D structure of SnO 2 NWs with simultaneously doped-In (5.4at% In) can enhance the selectivity toward formate by up to ∼82 % compared to bare SnO 2 NWs (∼58.9 %) at −1.04 V (vs RHE). The modified SnO 2 surface driven by In-doping induces electron delocalization in between, and the surface defects provide more active sites. Thus, the intermediate could be stably adsorbed to produce more formate ions. [ABSTRACT FROM AUTHOR]

This study investigates the effect of boron/nitrogen (B/N) dual doping on the electrocatalytic activity for oxygen reduction reaction (ORR) of carbon materials that are derived from gaseous carbon dioxide (CO 2 ) at 1 atm. In the presence of NaBH 4 , CO 2 was converted to a B-doped carbon material which was further treated with urea at 850 °C for N-doping. Through RDE and RRDE measurements, the enhanced ORR activity of the B/N dual-doped carbon was confirmed in terms of both early onset potentials and large current densities. This arose from the existence of B-N related bond and pyridinic N in the carbon network. As the amount of N content increased, the carbon material became more crystalline and the B/N dual doping led to an increase in the electron transfer number of the carbon materials, implying that the ORR occurred through a dominant four-electron transfer pathway. By utilizing the abundant greenhouse gas as a carbon source, this study provides a facile means by which to synthesize B/N dual-doped carbon for enhanced electrocatalysis. [ABSTRACT FROM AUTHOR]

High sensitivity, on-chip calorimeter platform using V 2 O 5 thin film thermistor was developed. Integration of a V 2 O 5 thermistor with a high temperature sensitivity of −2.2%/K with a vacuum insulated, suspended SiN membrane structure enabled a low thermal conductance of 12 μW/K and a direct detection of 10 nW of heat with an estimated detection limit of 570 pW. We also investigated the feasibility of integrating the platform with a microfluidic system, and, suggest that, based on numerical simulations, a further 5-fold lowering of detection limit may be possible. [ABSTRACT FROM AUTHOR]

Purpose: We determined the relationship between apnea severity and depressive symptoms in a large sample of the newly diagnosed male patients with severe obstructive sleep apnea (OSA). Methods: Data were collected from patients who received polysomnography due to suspected OSA. The questionnaires included the Beck Depression Inventory (BDI), Epworth Sleepiness Scale (ESS), and Medical Outcomes Study (MOS)-Sleep Scale, for which Sleep Problems Index-1 (SPI-1) was calculated. The apnea-hypopnea index (AHI) and respiratory distress index (RDI) were used to measure apnea severity. The mediational model, which states that OSA severity affects depression through a mediator, was tested here. Results: In total, 302 male patients with severe OSA participated. The mean patient age was 48.4 years (SD = 11.3 years). The BDI was ≥10 in 118 patients (39 %) and was significantly associated with body mass index ( r = 0.114; p = 0.048), ESS ( r = 0.164; p = 0.004), SPI-1 ( r = 0.453; p < 0.001), and RDI ( r = 0.126; p = 0.029). According to the linear regression analyses, the RDI is not independently associated with the BDI. The strongest predictor of BDI was sleep quality (SPI-1; β = 0.425; p < 0.001). The bootstrap method confirmed that the depressive effects of RDI are significantly mediated by poor sleep quality (bootstrapped 95 % CI 0.0113-0.0632). Conclusions: There is evidence of a mediational role of subjective sleep quality on the relationship between apnea severity and depressive symptoms in male patients with severe OSA. [ABSTRACT FROM AUTHOR]

Microfluidics has experienced massive growth in the past two decades, and especially with advances in rapid prototyping researchers have explored a multitude of channel structures, fluid and particle mixtures, and integration with electrical and optical systems towards solving problems in healthcare, biological and chemical analysis, materials synthesis, and other emerging areas that can benefit from the scale, automation, or the unique physics of these systems. Inertial microfluidics, which relies on the unconventional use of fluid inertia in microfluidic platforms, is one of the emerging fields that make use of unique physical phenomena that are accessible in microscale patterned channels. Channel shapes that focus, concentrate, order, separate, transfer, and mix particles and fluids have been demonstrated, however physical underpinnings guiding these channel designs have been limited and much of the development has been based on experimentally-derived intuition. Here we aim to provide a deeper understanding of mechanisms and underlying physics in these systems which can lead to more effective and reliable designs with less iteration. To place the inertial effects into context we also discuss related fluid-induced forces present in particulate flows including forces due to non-Newtonian fluids, particle asymmetry, and particle deformability. We then highlight the inverse situation and describe the effect of the suspended particles acting on the fluid in a channel flow. Finally, we discuss the importance of structured channels, i.e. channels with boundary conditions that vary in the streamwise direction, and their potential as a means to achieve unprecedented three-dimensional control over fluid and particles in microchannels. Ultimately, we hope that an improved fundamental and quantitative understanding of inertial fluid dynamic effects can lead to unprecedented capabilities to program fluid and particle flow towards automation of biomedicine, materials synthesis, and chemical process control. [ABSTRACT FROM AUTHOR]

Abstract: Although electrochemical stability is an essential factor in relation to the potential applications of ionic clathrate hydrates to solid electrolytes, most studies regarding the proton conductors have focused on their ionic conductivity and thermal stability. Solid electrolytes in various electrochemical devices have to endure the applied potentials; thus, we examined the linear sweep voltammograms of various tetraalkylammonium hydroxide hydrates in order to shed light on the trend of electrochemical stability depending on the hydrate structure. We revealed that the electrochemical stability of Me4NOH hydrates is mainly affected by both their ionic concentration and cage occupancy. In particular, the true clathrate structures of β-Me4NOH hydrates are more electrochemically stable than their α-forms that possess partially broken hydrogen bonds. We also observed that the binary THF–Pr4NOH and pure Bu4NOH clathrate hydrates exhibit greater electrochemical stability than those of pure Me4NOH hydrates having lower or similar ionic concentrations. These results are considered to arise from the fact that each of the Pr4N+ and Bu4N+ ions occupies an extended space comprising four cages, which leads to stabilization of the larger unit, whereas a Me4N+ ion is completely included only in one cage. [Copyright &y& Elsevier]

In recent years, unmanned surface vehicles (USVs) have been widely used in various applications. To fulfill target missions, USVs must be able to plan their path to the destination. Although many path-planning methods have been developed, most are inappropriate for application in complex marine environments. In this study, we propose a novel path-planning algorithm, which combines the merits of quadtree representation and visibility graphs, for efficient path planning of USVs in complex marine environments. Quadtree representation reduced the computation time and memory consumption. Additionally, the wind and wave data were considered to shorten the voyage time from the departure to destination points. Furthermore, the Dijkstra algorithm was applied to the quadtree to determine the suboptimal path. We then constructed a visibility graph with path waypoints using an improved line-of-sight algorithm to perform path planning on the visibility graph. The proposed algorithm not only facilitates path planning with minimum voyage time but also maintains the USV clearance distance from the coastline. To verify the performance, the proposed algorithm was compared with other methods for South Korean case studies. Overall, the proposed algorithm was able to generate a high-quality suboptimal path for the USV within a short time span. [ABSTRACT FROM AUTHOR]

Herein, we suggest a new approach to an electric double-layer capacitor (EDLC) that is based on a proton-conducting ionic clathrate hydrate (ICH). The ice-like structures of clathrate hydrates, which are comprised of host water molecules and guest ions, make them suitable for applications in EDLC electrolytes, owing to their high proton conductivities and thermal stabilities. The carbon materials in the ICH Me4NOH ⋅5 H2O show a high specific capacitance, reversible charge-discharge behavior, and a long cycle life. The ionic-hydrate complex provides the following advantages in comparison with conventional aqueous and polymer electrolytes: 1) The ICH does not cause leakage problems under normal EDLC operating conditions. 2) The hydrate material can be utilized itself, without requiring any pre-treatments or activation for proton conduction, thus shortening the preparation procedure of the EDLC. 3) The crystallization of the ICH makes it possible to tailor practical EDLC dimensions because of its fluidity as a liquid hydrate. 4) The hydrate solid electrolyte exhibits more-favorable electrochemical stability than aqueous and polymer electrolytes. Therefore, ICH materials are expected to find practical applications in versatile energy devices that incorporate electrochemical systems. [ABSTRACT FROM AUTHOR]

Extensive intraplate volcanism in the East Asia regions, including Dokdo and Ulleungdo (DU), occurred due to the extensional stress field during the Cenozoic era. However, the origin of magmatism is still controversial. Here we report new results of helium isotopes in olivine and clinopyroxene phenocrysts as well as major and trace element compositions from the DU basalts in order to determine the origin of the DU magmas and provide insights into Cenozoic mantle dynamics in East Asia. The DU volcanic islands were formed by magmatism after opening of the East Sea (Sea of Japan), a back-arc basin behind the Japanese arc, and are currently located in the Ulleung basin, one of sub-basins of the East Sea. The 3He/4He ratios range from 5.7 to 5.9 Ra for Dokdo and 4.5 to 6.0 Ra for Ulleungdo, respectively, similar to the sub-continental lithospheric mantle (SCLM) range of East Asia (4.6 to 7.7 Ra). Helium isotope compositions indicate that the depleted asthenosphere or the lower mantle plume might not be the direct source of the DU magmas. Also, there is no geochemical evidence that the DU magmas were influenced by subduction-derived components or the HIMU mantle source. Hence, we argue that SCLM provided enriched geochemical features in the DU basalts, contrary to basalts from other back-arc basins composed of the oceanic crust. In this respect, it is likely that the extended SCLM may still remain beneath the Ulleung basin. Our helium isotope and trace element mixing model shows the mixing trend between the metasomatized lithospheric melts and the asthenospheric melts. In addition, the presence of the low-velocity zone beneath the surface of the DU volcanoes in seismic tomography implies that the magmas were formed through the lithospheric melting due to the hot asthenospheric upwelling. Therefore, our study shows that the DU volcanism was mainly contributed by SCLM and that the lithosphere-asthenosphere interaction was the main mechanism that led to the Cenozoic magmatism in East Asia. • Dokdo and Ulleungdo are Cenozoic intraplate volcanoes in East Asia. • The Dokdo-Ulleungdo magmas were significantly contributed by SCLM. • Lithosphere-asthenosphere interaction played a pivotal role in the Cenozoic magmatism. [ABSTRACT FROM AUTHOR]

This study utilizes Thermal Infrared (TIR) imaging technology to detect hotspots in photovoltaic (PV) modules of solar power plants. Unmanned aerial vehicle (UAV)-based TIR imagery is crucial for efficiently analyzing fault detection in solar power plants. This research explores optimal operational parameters for generating high-quality TIR images using UAV technology. In addition to existing variables such as humidity, emissivity, height, wind speed, irradiance, and ambient temperature, newly considered variables including the angle of incidence between the target object and the thermal infrared camera are analyzed for their impact on TIR images. Based on the solar power plant's tilt (20°) and the location coordinate data of the hotspot modules, the inner and outer products of the vectors were used to obtain the normal vector and angle of incidence of the solar power plant. It was discovered that the difference between measured TIR temperature data and Land Surface Temperature (LST) data varies with changes in the angle of incidence. The analysis presented in this study was conducted using multiple regression analysis to explore the relationships between dependent and independent variables. The Ordinary Least Squares (OLS) regression model employed was able to explain 63.6% of the variability in the dependent variable. Further, the use of the Condition Number (Cond. No.) and the Variance Inflation Factor (VIF) revealed that the multicollinearity among all variables was below 10, ensuring that the independence among variables was well-preserved while maintaining statistically significant correlations. Furthermore, a positive correlation was observed with the actual measured temperature values, while a negative correlation was observed between the TIR image data values and the angle of incidence. Moreover, it was found that an angle of incidence between 15° and 20° yields the closest similarity to LST temperature data. In conclusion, our research emphasizes the importance of adjusting the angle of incidence to 15–20° to enhance the accuracy of TIR imaging by mitigating overestimated TIR temperature values. [ABSTRACT FROM AUTHOR]

In practice, road management data are typically managed in two-dimensional (2D) geospatial forms. However, 2D geographic information system (GIS)-based road infrastructure management data have limitations in their representation of complex roads, such as interchanges, bridges, and tunnels. As such, complex and large road network management data cannot be adequately managed in a 2D GIS-based form. This study discusses the use of the LandInfra standard for road infrastructure management in Korea, considering its focus on land and civil engineering infrastructure facilities. To facilitate the transition from 2D to 3D GIS, we analyzed existing road management models of road pavement and road register information and created Unified Modeling Language (UML) class diagrams depicting these models. Then, existing road management classes and LandInfra classes were mapped. Based on the results, we propose a road management model based on the Facility, Alignment, and Road parts of LandInfra. For its implementation, several classes of the proposed data model were encoded into InfraGML using real-world data input. Taken together, this study shows how the LandInfra standard can be extended and applied to the field of road infrastructure management in Korea, supporting the transition from a 2D to a 3D GIS-based model. [ABSTRACT FROM AUTHOR]

Although partial meniscectomy is a common treatment for the tears in the avascular region of the meniscus, mechanical alterations following meniscectomy are known to initiate mechanically-induced osteoarthritis. We aimed to measure the articular cartilage contact pressure distributions in the knees with surgically repaired and partially resected menisci in the avascular region. A pneumatic loading device was developed to apply a 1000 N compressive load on the cadaveric porcine knee samples at the flexion angles of 20, 35, 50, and 65°. We simulated longitudinal meniscal tears in the avascular inner 1/3 portion and the well-vascularized middle 1/3 portion of the meniscus. Articular cartilage contact pressures for the knees with intact, torn, repaired, and resected menisci were compared. For the tears in well-vascularized regions, meniscal repairs restored articular cartilage contact pressures to the levels in intact joints. However, partial meniscectomy significantly increases the maximum contact pressures and the average contact pressures in highly compressed areas. However, partial meniscectomy in the avascular region did not alter the maximum articular cartilage contact pressures and the average contact pressures in highly compressed areas. Stabilities in knee samples were not significantly altered following partial meniscectomy in both inner and middle regions. Although repair surgeries are beneficial for the tears in well-vascularized areas because the articular cartilage contact mechanics are reconstructed, partial meniscectomy may be a viable alternative treatment for the tears in avascular regions without introducing significant mechanical alterations. • Meniscal repair effectively restored articular cartilage contact pressures. • Meniscectomy in avascular regions did not altered cartilage contact pressures. • Meniscectomy could be a viable treatment for the tears in avascular regions. [ABSTRACT FROM AUTHOR]

In this paper, we report an improved luminous efficiency of a direct-current-driven electroluminescent (EL) device using ZnS powder by controlling electron and hole injection barriers. The emission layer was fabricated by screen-printing of an EL paste using Cu-coated ZnS particles on a transparent conductive indium–tin-oxide electrode. The device was completed by stacking an Al thin film on the emission layer by thermal evaporation. We applied various forming voltages to investigate the current–voltage–luminescence characteristics of the device. An abrupt change in current during the forming process was caused by variation of the electron-blocking barrier toward the anode. The hole-injection barrier from the anode to the emission layer increased with the forming voltage. The obtained results indicated that the hole-injection barrier to the emission layer can be lowered by inserting materials with a low highest-occupied-molecular-orbital (HOMO) energy level between the anode and emission layer. We achieved a brightness enhancement of 29% by employing a thin film of poly-N-vinyl carbazole with a HOMO level of −5.6 eV as a hole-injection layer on the anode. We believe that the presented results will guide further studies for efficiency improvement of EL devices using powder particles applicable to next-generation lighting and displays. • The electron blocking layer induces abnormal current drop during forming process. • Stoichiometry changes the band structure of Cu-coated ZnS powder-based EL devices. • Tunneling of holes through the hole injection layer improves luminous efficiency. [ABSTRACT FROM AUTHOR]

In the present study, the hydrate anti-agglomerant (AA) performance of three biodegradable emulsifiers (Span 80, lecithin, and lanolin) was evaluated in oil-dominated systems using high-pressure rheological tests. The viscosity variations of the fluid systems were examined depending on the concentration of the emulsifiers and water cut during the entire hydrate formation process. The biodegradable emulsifying AAs prevented the drastic increase in the viscosity of the CH 4 hydrate slurry in mineral oil and significant hydrate agglomeration. The AA performance decreased in the following order: Span 80, lecithin, and lanolin. These biodegradable AAs create W/O (water-in-oil) emulsions, namely, small water droplets in mineral oil, by which more water is converted to hydrate that is well dispersed in the oil phase than in the cases without the AAs. The hydrate aggregates formed in the absence of the AAs contain more unconverted water that acts as a capillary bridge for hydrate aggregation or that is confined at the core of the hydrate particles by the partial conversion of water. The density of the dispersed hydrate particles in the AA tests is lower than that of the hydrate aggregates formed in the absence of the AAs. This is due to the unconverted water confined in the aggregates. Therefore, the AAs not only prevent hydrate agglomeration but also reduce the hydrate bedding risk by increasing the conversion of water to hydrate. Image 1 • Performance of a biodegradable emulsifier was evaluated for gas hydrate inhibition. • Viscosity and pressure variations of oil-dominated fluid systems were examined. • Emulsifier makes hydrates dispersed well in oil phase. • Hydrate agglomeration was prevented and reduce hydrate bedding risk reduced. [ABSTRACT FROM AUTHOR]

Using radio frequency magnetron sputtering, we fabricated spinel-phase LiMn2O4 films with different thicknesses. The stress state of the 200 nm-thick films maintained the compressive stress and that of the 400 nm-thick films changed from compressive to tensile stress during annealing. During the cycle test, the amount of volume change in the 400 nm-thick films was larger than that in the 200 nm-thick films. In the case of the 400 nm-thick, micro-cracks on the surface were generated during the cycle test and this phenomenon caused the stress transition and also a harmful effect on the cycle retention of the cathode thin films. [Copyright &y& Elsevier]

Inertial microfluidic systems have been widely used for particle or cell separation applications, especially for rare-cell enrichment and separation from blood due to the high throughput and simplicity of the systems. However, most of the separation techniques using inertial microfluidic systems require dilution of blood samples or RBC lysis to achieve a high separation efficiency, which can adversely affect the throughput and/or analysis of the collected sample. We developed a cell separation technique compatible with untreated whole blood by inflection point focusing, that is, an inertial focusing phenomenon toward inflection points of the velocity profile. We generated a strong shear-gradient lift force by varying the velocity profile in a channel cross-section with the combined effect of the channel geometry and the co-flows of two liquids with different viscosities. The natural viscosity of blood leads to a lagging flow region in the middle of the channel where larger particles and cells can be extracted to the side flow region, which enables a highly efficient separation scheme with an unprecedented high throughput. [ABSTRACT FROM AUTHOR]

Background: Conventional fat quantification methods for rotator cuff muscles have various limitations, such as inconsistent reliabilities of the Goutallier grades and need for advanced techniques in quantitative MRI sequences. We aimed to examine a threshold-based fat quantification method in the supraspinatus muscle on standard T1-weighted MR images and compare the threshold-based method with Goutallier grades and MR spectroscopy.Methods: We retrospectively examined 38 symptomatic patients, who underwent T1 and T2-weighted fast spin-echo MR imaging and a single voxel spin-echo MR spectroscopy. The supraspinatus muscle and fossa were manually segmented in T1-weighted sagittal images and clustering-based thresholding was applied to quantify the fat fractions in the segmented areas using custom MATLAB software. Threshold-based fat fractions were compared with the Goutallier grades and MR spectroscopy fat/water ratios. A one-way analysis of variance and Pearson correlation were tested in the MATLAB software.Results: Inter-observer reliability of threshold-based fat fractions for the supraspinatus muscle and fossa were 0.977 and 0.990 respectively, whereas the reliability of the Goutallier grading was 0.798. Threshold-based fat fractions in the supraspinatus fossa were significantly different between various Goutallier grades (one-way ANOVA, p < 0.001). Threshold-based fat fractions in the supraspinatus muscle strongly correlated with the MR spectroscopy fat/water ratio (Pearson correlation R-square = 0.83).Conclusions: Threshold-based fat quantification on standard T1-weighted MR images was highly reliable and produced comparable results to conventional Goutallier grades and MR spectroscopy fat/water ratios and could serve as an alternative method for accurate fat quantification in rotator cuff muscles. [ABSTRACT FROM AUTHOR]

Electrochemical CO2 reduction (CO2RR) has received much attention for its ability to generate value-added chemicals from a molecule that would otherwise be a waste end-product. Numerous studies have emerged in the past decades, but the renewable and sustainable carbon-neutral CO2 reduction process is yet to be industrialized. Here, we review the progress and bottlenecks of the electrochemical CO2 reduction technologies over the past 15 years (2004–2018) to examine whether CO2RR process is to be applicable in a large-scale. Although the techno-economic analysis and pilot plants based on liquid-phase electrolysis have shown some positive results, current densities of the liquid-phase electrochemical CO2 reduction are well below what techno-economic analyzes have projected due to its intrinsic limitations of solubility. On the other hand, the gas-phase electrolysis of CO2 has shown superior performance parameters compared to the liquid-phase electrolysis, especially in the current densities, showing commercial viability although its techno-economic analysis is yet to be performed. Herein, we offer some perspectives and guidelines where future research in CO2 electrolysis should aim. Based on the performance parameters obtained from the lab-scale gas-phase reactions, we believe that the current negative outlooks towards the industrial feasibility of the CO2 electrolysis system could turn to positive views. [ABSTRACT FROM AUTHOR]

• Faults take topographical control to form sedimentary basins. • Mature basins yield a variety of soil. • Faults, basins, and soil affect CO 2 emissions. Carbon dioxide (CO 2) is one of the main components of greenhouse gases, and there is a great concern about emissions mainly from human activities. However, long term CO 2 emissions during the Earth's history are largely related to natural emissions by geological factors. Natural CO 2 emissions are mainly at highly permeable passages below the surface (e.g., volcanoes or faults). Unlike volcanoes, which actively release mantle-derived volatiles, faults can be affected by CO 2 of more diverse origins and are relatively lacking in research. Here, we note that it is important for CO 2 emissions that faults as channels with high permeability take topographical control to form sedimentary basins and produce mature soils. To this end, we performed CO 2 flux measurements in the Yangsan Fault System (YFS), Republic of Korea. As this fault is an active fault, topographical variations are clear and accessible. In the YFS, high spring CO 2 fluxes (119.5 g m−2 d-1 to 77,699.5 g m−2 d-1) were observed in Sector 1, and high soil CO 2 fluxes (0.5 g m−2 d-1to 1,240 g m−2 d-1) were observed along the Hyeongsan River in Sector 2. The carbon isotope composition indicates that the mantle contributes to fault-related spring CO 2 (δ13C = -14.03 ‰ to −7.44 ‰), and soil CO 2 comes from shallow biogenic sources (δ13C = –22.82 ‰ to −13.53 ‰) deposited in fault-forming basins. In addition, the helium isotope ratios indicative of the mantle contribution (3He/4He = 1.86 to 6.02 Ra) are shown in the gas samples of the springs. Furthermore, in a post-earthquake survey, we found temporal changes in soil CO 2 flux values near the epicenter, which may be related to the earthquake. A simple calculation of overall CO 2 emissions suggests that significant amounts of CO 2 (6.2 Mt yr−1) are being emitted along the YFS. Therefore, this study reports both large-scale structural degassing and biological CO 2 emissions from fault zones, providing implications for the role of sedimentary basins and soil types formed in fault zones. [ABSTRACT FROM AUTHOR]

This study investigated the determination of detailed microstructure modeling of the trochlea of the superior oblique muscle (SOM) using micro-computed tomography (micro-CT) and modeling of a potential prototype for a trochlea implant using three-dimensional (3D) printing. We dissected 15 intact orbits of 15 embalmed cadavers. The trochleae of the SOM were detached from the periosteum. The specimens were stained by immersion in a 15% Lugol's solution. Images were reconstructed using conventional scanner software. Measurement points were determined for the middle cross section. Points P1 and P2 were selected where the SOM adjoined the curvature of the inner trochlea. They defined the inner contact points of the SOM in the inner part of the trochlea curvature. On the back of the trochlea, points P3 and P4 were selected at the uppermost and lowest points in the inner parts of the straight trochlea, respectively. Origin O was defined on the arcuate line of P 1 P 2 ^ to generate the smallest-diameter circle consisting of P1, O, and P2. We then measured the angle from O P 1 ¯ t o O P 2 ¯ , and from O P 3 ¯ t o O P 4 ¯. We also measured the distances O P 1 ¯ , O P 2 ¯ , O P 3 ¯ , a n d O P 4 ¯ for the design of a potential trochlea implant prototype using 3D-printing and micro-CT-based modeling. The distances O P 1 ¯ , O P 2 ¯ , O P 3 ¯ , a n d O P 4 ¯ were 2.2 ± 0.7, 1.4 ± 0.5, 2.7 ± 0.9, and 2.5 ± 0.4 mm (mean ± SD), respectively. The angles from O P 1 ¯ t o O P 2 ¯ , from O P 2 ¯ t o O P 4 , - and from O P 3 ¯ t o O P 4 ¯ were 100.7 ± 14.4, 66.3 ± 18.0, and 98.9 ± 24.9 degrees, respectively. The present investigation demonstrates that the high-resolution CT is a powerful imaging technique for defining the true 3D geometry of a specimen and can potentially be used to create a 3D-printed trochlea implant. [ABSTRACT FROM AUTHOR]

One fundamental challenge of technology and innovation management is for firms to decide which future technologies to develop in-house versus buying them outside. This challenge is particularly pertinent when industries emerge, typically a time of high levels of technological uncertainty. It has been long understood that technological uncertainty functions as important stimulus for firms to manage their boundaries. However, two to some extent competing strategy perspectives—governance and competence—predict that firms faced with uncertainty would either increase or decrease their scope of activities, respectively. To reconcile these conflicting positions, we propose a model in which knowledge modularity moderates the effect of technological uncertainty on firms’ research and development (R&D) scope decisions. We develop new measures for R&D scope, knowledge modularity, and technological uncertainty, drawing on population ecology, network theory, and technology management. We test our model empirically using data on patenting activity and firm boundary location in the emerging automotive air bag industry. Our results generally support our model and show that in case of knowledge-generating activities such as R&D, scope decisions under technological uncertainty are more driven by concerns about the risk of obsolescence than the risk of opportunistic behavior. We discuss implications for managerial practice and future research. [ABSTRACT FROM AUTHOR]

An index on the gas market commonly refers to the average price of a certain trading product, e.g., over the period of one month. Index-based sourcing is a widely-used habit in modern gas business. Risks are reduced by averaging prices over the purchasing period. Due to the significant volume, there have been many attempts to "beat the index", i.e., to design a strategy that, over time, offers cheaper prices than the index. Here, we use neural networks to identify n, n ∈ N , optimal shopping points. Both classification- and forecasting-based strategies are tested to decide on each trading day if gas should be purchased or not. Thereby, we use the Front Month index based on prices from the Dutch Title Transfer Facility as an example. Regarding cumulative performance, all but a very simple myopic algorithm are able to outperform the index. However, each strategy has its flaws and some positive results are due to the price increase during 2021. If one opts for an active sourcing strategy, then a forecasting-based approach is the best choice. [ABSTRACT FROM AUTHOR]

• Curing depth prediction model of CNT reinforced photo-curable resins. • Curing depth theoretical modeling based on CNT degree of dispersion and concentration. • Significant experiment reduction for composite photocurable resin characterization. • Applicable to various photo-curable composites for stereolithographic processing. Carbon nanotubes (CNTs) have been often implemented as an additive in photopolymer resins for photo-reactive manufacturing processes such as vat photopolymerization (VP) 3D printing to endow various functionalities and improve properties of components. However, CNTs are known for their effective UV absorption and strong agglomeration tendency, which reduce the 3D-printability of the resin composites. Moreover, since varying dispersion qualities and concentrations of CNTs significantly influence curing depth photo-curing characteristics, it remains a challenge to determine the appropriate curing parameters. Consequently, many time-consuming and tedious experiments are required to find the proper curing parameters for adequate manufacturing. To overcome the need for extensive experimentation, a theoretical model that considers both the dispersion and concentration of CNTs needs to be established to provide appropriate curing parameters. This work introduces a simple model applying a modified Beer-Lambert's law that integrates both the degree of dispersion and concentration of CNTs, aiming to predict curing depth and subsequent printability of CNT reinforced photo-curable resins. Through this model, the curing depth can be predicted depending on the degree of dispersion and concentration via only two spectroscopic experiments and one curing experiment, thus significantly reducing time-consuming and material extensive experimental works for VP 3D printed CNT/resin composites. Results show that the curing depth decreases with improved dispersion and increasing concentration of CNTs as a result of higher degrees of light path obstruction. More significantly, the methodology used to construct our model is also applicable to the development of other photo-curable resin composites used in various stereolithographic manufacturing methods. [ABSTRACT FROM AUTHOR]

Abstract: We used the electrostatic deposition (ESD) method to prepare the protein microarray for observation of the stem cell responses to pattern size, space and shapes. The ESD method allows a reduction in spot size, high efficiency of substance transfer, and high rate in fabrication as a result of ability to simultaneously deposit thousands of identical spots. Typical electrospraying conditions for the deposition of proteins were a voltage of 3.5–4.5keV and the humidity under 40%. The patterns of masks have a variety of shapes, spaces, and hole sizes from 10 to 300μm. Collagen is deposited on conducting polymer in a dry state, preserving the functional activity of proteins. The surface morphology of deposited spots was observed using an atomic force microscope and a scanning electron microscope. Human mesenchymal stem cells were cultured on each extracelluar protein patterned sample and cellular morphology was observed by light microscopy. Cell attachment and spreading on the surface are dependent on the deposition conditions by ESD. Protein deposition with short time is effective on the cell culture. However, collagen pattern size, space and shapes in micrometer size seemed to have little effect on cellular response in our design. [Copyright &y& Elsevier]

[Display omitted] • CO 2 to syngas with controllable H 2 /CO ratio was investigated using Ag/TiO 2 catalysts. • The H 2 /CO ratio was controlled by oxygen vacancies and phase difference of TiO 2. • The H 2 /CO ratio was increased by the oxygen vacancy defects of TiO 2 anatase. The direct conversion of CO 2 to syngas with controllable H 2 /CO ratio has been investigated using electrochemical reduction of CO 2 in aqueous media. Despite considerable progress on electrocatalytic syngas production, it remains challenging to generate a stable H 2 /CO ratio over a wide range of applied potentials. In this study, we investigated Ag/TiO 2 catalysts, by which we achieved a stable H 2 /CO ratio with high Faradaic efficiency (93–100%) and partial current densities (~164 mA·cm−2) for syngas production in a flow cell. The H 2 /CO ratio was controlled by changing the catalyst properties resulting from oxygen vacancies and phase difference of TiO 2. The H 2 /CO ratio of Ag/TiO 2 catalysts was increased by introducing oxygen vacancy defects in the bulk and on the surface of TiO 2 anatase. Furthermore, the H 2 /CO ratio was also increased by changing the TiO 2 phases from anatase to rutile, even if the rutile phase possessed fewer oxygen vacancies. The 40 wt% Ag/TiO 2 catalysts calcined in different gases (Ag/TiO 2 anatase-air, Ag/TiO 2 anatase-H 2 /Ar, and Ag/TiO 2 rutile-air) exhibited H 2 /CO ratios of 0.1–0.3, 0.5–1.1, and 0.5–1.5, respectively, within the range of potential from −0.35 to −0.65 V (vs. RHE). [ABSTRACT FROM AUTHOR]

Jeju Island, South Korea, is a Cenozoic intraplate volcano located in East Asia. The Jeju basalts display ocean island basalt (OIB)-like trace element patterns and enriched mantle type 2 (EM2) radiogenic isotope compositions, but the source that enriched the mantle remains unclear. Here we report new geochemical compositions of basalts and xenoliths, including the first helium isotope and element analysis of olivine phenocrysts to constrain the source of basalt. Olivines in the Jeju basalts have 3He/4He ratios of 3.5 to 7.3 R a while olivines in the mantle xenoliths are 2.9 to 6.3 R a. They provide no evidence of a lower mantle plume but overlap the range of the regional subcontinental lithospheric mantle (SCLM) and OIBs with low 3He/4He values. Olivine phenocrysts included in the basalts show variations in Mn, Ni, and Ca concentrations with forsterite (Fo) contents, similar to the trend for olivines crystallized from the pyroxenite-derived melts. Elemental ratios of Ca-Fe-Ni-Mg-Mn for the olivines also indicate the pyroxenite contribution. Considering our results, it is suggested that the main source of the Jeju basalts is the SCLM containing pyroxenite. In addition, the tomography image shows the low-velocity zone extending to the asthenosphere mantle beneath the central Jeju Island. This implies that the localized asthenospheric upwelling is caused by edge-driven convection, and the high-velocity zones exist around Jeju island indicating a thick cratonic lithosphere. Therefore, we propose that the interaction between the SCLM component containing pyroxenite and the rising asthenosphere is the main mechanism to generate enriched basaltic magmas for the Cenozoic intraplate volcanism in East Asia, including Jeju Island. • Jeju Island is one of the Cenozoic intraplate volcanoes in East Asia. • Helium isotope ratios of the Jeju basalts and xenoliths are similar. • SCLM played an important role in the formation of the enriched Jeju magma. [ABSTRACT FROM AUTHOR]

Surface modification offers an efficient and economical route to installing functional groups on a polymer surface. This work demonstrates that primary amine groups can be introduced onto a polymer surface via Buchwald–Hartwig amination, and the functionalized substrates can be chemically bonded to produce functional microfluidic devices. By activating the CCl bond in commercially used poly(chloro‐p‐xylylene) (parylene C) by Pd catalyst and substituting Cl with the amine source, the amine groups are successfully installed in a facile and recyclable manner. The substrates can be covalently bonded with each other via amine‐isocyanate chemistry, providing much higher bonding strength compared to previous methods based on noncovalent adhesive coatings. As a result, transparent and flexible microfluidic channels can be fabricated that are compatible with organic solvents and high pressure. Retention of amine group reactivity in the channel suggests the potential of this methodology for the surface immobilization of functional molecules for microfluidic reactors and biosensors. [ABSTRACT FROM AUTHOR]

• Expression of AFPs on E. coli using cell surface display strategy was investigated. • Kinetic inhibition performance of AFPs was tested. • Monomer to hexamers of AFPs were displayed on surface of bacterial cells. • AFPs exhibited higher KHI effectiveness with increasing number of attached peptides. • KHI performance of AFPs is achieved with higher dosages of the cultures. The expression of anti-freeze proteins (AFPs) on the Escherichia coli using the cell surface display (CSD) strategy was investigated to determine the feasibility of the method as a potential application of kinetic hydrate inhibitors. Monomers to hexamers of type II and III AFPs were displayed on the surfaces of bacterial cells. The kinetic inhibition performance of the AFPs on the synthetic natural gas hydrate formation was tested. The displayed AFPs exhibited higher KHI effectiveness with the increase in the number of peptides attached to the cells. In addition, best KHI performance of the AFPs could be achieved with higher dosages of the cultures when the concentration of the inducer is optimized, regardless of AFP type. Only a small portion of AFPs in the cell cultures exhibited considerable KHI performance, which implies that the CSD could be an effective strategy, reducing the cost for the production and purification of the AFPs. [ABSTRACT FROM AUTHOR]

We consider inertial focusing of particles in channels with triangular cross sections. The number and the location of inertial focusing positions in isosceles triangular channels can change with varying blockage ratios (a/H) and Reynolds numbers (Re). In triangular channels, asymmetric velocity gradient induced by the sloped sidewalls leads to changes in the direction and the strength of the inertial lift forces. Therefore, varying the configuration (specifically, angle) of the triangular cross section is expected to lead to a better understanding of the nature of the inertial lift forces. We fabricated triangular microchannels with various apex angles using channel molds that were shaped by a planing process, which provides precise apex angles and sharp corners. The focusing position shift was found to be affected by the channel cross section, as expected. It was determined that the direction of the focusing position shift can be reversed depending on whether the vertex is acute or obtuse. More interestingly, corner focusing modes and splitting of the corner focusing were observed with increasing Re, which could explain the origin of the inertial focusing position changes in triangular channels. We conducted fluid dynamic simulations to create force maps under various conditions. These force maps were analyzed to identify the basins of attraction of various attractors and pinpoint focusing locations using linear stability analysis. Calculating the relative sizes of the basins of attractions and exhaustively identifying the focusing positions, which are very difficult to investigate experimentally, provided us a better understanding of trends in the focusing mechanism. [ABSTRACT FROM AUTHOR]

Radiotherapy for cancer patients requires accurate measurement of the absorbed dose of radiation in a treatment planning step. Various types of radiation detectors are currently utilized for dose measurement. Among them, calorimeters are known to be the most precise detector for measuring absorbed dose, but their on-site application is limited by the large size of the equipment. We developed a miniaturized chip calorimeter for application as a radiation detector. The calorimetric radiation detector was built using micro/nano fabrication techniques, and consists of an SU-8 photoresist absorber and high-sensitivity vanadium oxide (VO x) thermistors. The thermistors had a temperature resolution of 135 μK, and the calorimeter showed a thermal conductance of 11 μW/K. The detector was irradiated with various X-ray dose rates from a linear accelerator, and the absorbed dose to SU-8 was measured. The detector responses showed high linearity with dose rates, demonstrating the feasibility of the radiation detector for practical uses. • For the first time, the feasibility of a chip calorimeter as a radiation detector was demonstrated. • Microscale radiation absorber of SU-8 was constructed on top of high-sensitivity VO x thermistors. • The calorimetric detector enabled precise measurements of X-ray dose rate. [ABSTRACT FROM AUTHOR]

Heterogeneity in a tumor allows a small portion of cancer cells to survive and regrow upon targeted cancer therapy, eventually leading to cancer relapse. Such drug-resistant cells often exhibit dynamic adaptation of their signaling pathways at the level of protein–protein interactions (PPIs). To probe the rewiring of signaling pathways and the heterogeneity across individual cancer cells, we developed a single-cell version of the co-immunoprecipitation (co-IP) analysis that examines the amount and PPIs of target proteins immunoprecipitated from individual cells. The method captures cancer cells at predefined locations using a microfluidic chip, pulls down target proteins on the surface using antibodies, and lyses the captured cells in situ. Then, subsequent addition of eGFP-labeled downstream proteins enables the determination of the corresponding PPIs for the minimal amount of target proteins sampled from a single cell. We applied the technique to probe epidermal growth factor receptors (EGFRs) in PC9 lung adenocarcinoma cells. The results reveal that the strength of EGFR PPIs can be largely uncorrelated with the expression level of EGFRs in single cells. In addition, the individual PC9 cells showed markedly different patterns of PPIs, indicating a high heterogeneity in EGFR signaling within a genetically homogeneous population. [ABSTRACT FROM AUTHOR]

Optical diffraction tomography (ODT) enables the reconstruction of the three-dimensional (3D) refractive-index (RI) distribution of a biological cell, which provides invaluable information for cellular and subcellular structures in a non-invasive manner. However, ODT suffers from an inferior axial resolution, due to the limited accessible angles imposed by the numerical aperture of the objective lens. In this study, we propose and experimentally demonstrate an approach to enhance the 3D reconstruction performance in ODT. By employing trapezoidal micromirrors, side scattered signals from the sample are measured for various side plane-wave-illumination angles. By combining the side scattered fields with the forward scattered fields, the axial resolution and 3D image quality of ODT are improved, without changing optical instruments. The feasibility and applicability of the proposed method are demonstrated by reconstructing the 3D RI distribution of a red blood cell and HeLa cells in hydrogel. We also present systematic analyses of the improved 3D imaging performance using numerical simulations and experimental measurements for the 3D transfer function, a point object, and a microsphere. The analyses demonstrate an improved axial resolution of 0.31 μm, 4.8 times smaller than that of the conventional method. The proposed method enables the non-invasive and accurate 3D imaging of 3D cultured cells, which is crucial for cell biology studies. [ABSTRACT FROM AUTHOR]

[Display omitted] • A systematic study for the effect of porous structures on CO production was performed. • Different performance trends between H-cell and full cell analyses were observed. • A thin catalyst layer possessing mesopores promoted CO production in MEA condition. • The optimized catalyst exhibited the highest energy efficiency (55 %) at 265 mA cm−1. The introduction of a porous structure is a promising approach to promote the electrochemical reaction of catalysts, which can maximize the utilization of catalytic active sites and enhance mass transport. To fully understand the role of the porous structure, parallel studies on both half-cell and full-cell environments must be performed; however, few studies have reported electrochemical CO 2 conversion in a full-cell operation. In this work, we fabricated four types of porous Ni N C model catalysts designed to systematically investigate the relationship between porous structures and catalytic performances in a membrane electrode assembly (MEA) based catholyte-free CO 2 electrolyzer. The performance degradation of the microporous catalyst in the MEA resulted from low CO 2 accessibility due to small openings (<2 nm), and the absence of meso- or macropores that can facilitate mass transport in the catalyst layer. A thick catalyst layer developed a region in which H 2 evolution was dominant; the formation of this region degraded the CO 2 reduction efficiency in the MEA based on the macroporous catalyst. Consequently, mesoporous Ni-N x catalysts with small, uniform particles exhibited the highest efficiency in MEAs, because their appropriate pore size and catalyst layer thickness facilitated mass transport. The optimized catalyst achieved industry-relevant performance for CO production (265 mA cm−2 at 2.3 V) with a state-of-the-art energy efficiency of 55 % and excellent long-term stability in a full cell. [ABSTRACT FROM AUTHOR]

To avoid the main disadvantage of the carbon dioxide (CO 2 ) capture process, namely the large amount of energy consumed to regenerate the amine absorbent using current thermal methods, chemical regeneration has been introduced as a novel method to regenerate the amine. Chemical regeneration deploys a swing in the pH of the amine absorbent rather than the swing in temperature of typical thermal regeneration procedures, and hence reduces the regeneration energy. Here we tested calcium chloride (CaCl 2 ) and calcium hydroxide (Ca(OH) 2 ) as a calcium source for CO 2 desorption and a pH swing agent for amine regeneration. After desorbing from the amine, CO 2 in our procedures reacted with Ca 2+ to form calcium carbonate (CaCO 3 ). Forming precipitated CaCO 3 is a permanent way to sequester CO 2 . Since carbonates have a low energy level compared to CO 2 , we expect the developed method to be an economical and energy-efficient process. [ABSTRACT FROM AUTHOR]