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During the spring of 2021, rapid surface cooling in the Arctic area expanded to most of the East Asian region, featuring surface-temperature dipole patterns of the colder west (Mongolia and northern-central China) and the warmer east (eastern-northeastern China, the Yellow Sea, and Korea). Despite the decreasing trend of dusty days within Korea, a notable rise in the occurrence of transboundary mineral dust-induced dusty days was observed in contributing to an increase in PM 10 levels in the spring of 2021. This study investigated the PM 10 source apportionment of anthropogenic dust, mineral dust, and biomass burning in the East Asian region and its transboundary impact on Korea, within the context of the surface-temperature dipole pattern observed in April of 2021. Source apportionment of PM 10 was determined through a comparative analysis between baseline and sensitivity experiments conducted by means of a WRF-Chem simulation. In these sensitivity simulations, emissions from each source were systematically excluded to assess their individual contributions. PM 10 Base refers to baseline simulations, PM 10 Anthro to anthropogenic emissions, PM 10 Dust to mineral dust, and PM 10 Biomass to biomass burning. The colder west pattern was linked to increased synoptic-scale cyclonic activity, marked by higher positive potential vorticity, causing a sudden surge in severe dust storms over Mongolia and northern China. PM 10 Base levels were most elevated in the higher terrain of Mongolia, comprising predominantly PM 10 Dust (95%). However, the dominance of atmospheric-warming-induced anticyclones, represented by enhanced negative potential vorticity, prevailed over the lower terrain in the warmer east regions, obstructing the transboundary dispersion of PM 10 Base to Korea. Nevertheless, Korea experienced a transboundary contribution of PM 10 Dust , reaching 35%. In addition, the source apportionments indicated a PM 10 Anthro ratio of 55% in eastern China and a PM 10 Biomass ratio of 35% in northeastern China, contributing 25% and 5% respectively to Korea. During April 14–30, 2021, the dipole pattern evolved further to the significantly colder west (Mongolia and China) and the moderately warmer east (the Yellow Sea and Korea). The transboundary contributions of PM 10 Anthro , PM 10 Dust , and PM 10 Biomass were intensified as a composite mixture within Korea, an outcome attributed to the intermittent cyclones and subsequent anticyclones. • Dusty days fell in Korea, but mineral dust surged, raising PM 10 in spring 2021. • Arctic spring cooling led to an East Asian cold-west, warm-east dipole pattern. • The colder west amplified cyclones, sparking dust storms in Mongolia and China. • Warming-induced anticyclones obstructed the transboundary dispersion of mineral dust. • Dust from eastern-northern China impacted Korea's PM 10 in a warm anticyclone. [ABSTRACT FROM AUTHOR]

Surgeons usually used short screws to avoid extensor tendon problems during volar locking plate fixation in distal radius fracture. However, the stability according to the length of distal locking screws have not been fully understood. We investigated this issue through finite element analysis and compression test using synthetic radius. Our results demonstrated that the bi-cortical full-length fixation does not contribute to the stiffness increase in the axial compression direction, and a reduction in length of up to more than 50% length can still provide similar stability to full-length screws. Our data can support that surgeon should undersize the distal screw. [ABSTRACT FROM AUTHOR]

The pandemic of highly infectious diseases like COVID-19 has highlighted the vulnerabilities of public transportation. In particular, railways are more vulnerable due to their dense environment, and the heating system used in winter is a major factor in increasing the transmission and risk of the virus. To improve the existing heating system, a study was conducted to develop a resistive heating composite capable of radiant heating. In this study, the applicability of heating elements, heating performance, and internal thermal deformation factors of laminated panels and sandwich panels used as rail vehicle components were analyzed in detail to consider the actual application of this technology in the railway industry. The experimental results confirmed that both types of panels effectively heated above the target temperature (120℃) in the heating element layer, demonstrating uniform heating characteristics. Additionally, sandwich panel is more affected by thermal deformation compared to the laminate panel. These experimental results are expected to serve as essential foundational data for the effective utilization, safety, and reliability considerations of resistive heating composite materials in real industrial environments. [ABSTRACT FROM AUTHOR]

Bcl-2 family proteins are critical switches to control cell death and survival, and Bcl-2 is a key regulator in pro-survival signaling, causing various diseases including cancers. Bcl-2 has drawn a considerable attention as a potential target for developing a pro-apoptotic agent for cancers. We here present the development of a specific protein binder against human Bcl-2 and its cytosolic delivery to effectively induce apoptosis of cancer cells. The protein binder composed of leucine-rich repeat modules was selected for human Bcl-2, and its binding affinity was increased up to 60 nM through a modular evolution-based approach. The protein binder was efficiently delivered into cancer cells by an intracellular delivery system using a translocation domain from a bacterial exotoxin, resulting in a strong suppression of anti-apoptotic signaling in cancer cells. Our results demonstrate that the human Bcl-2-specific protein binder can act as a potent therapeutic agent for cancers. • We developed a protein binder which specifically binds to human Bcl-2. • The protein binder was selected against human Bcl-2 through phage display, and its binding affinity was matured by a modular approach. • Efficient intracellular delivery of the protein binder led to a significant suppression of anti-apoptotic signaling in cancer cells. • The protein binder showed a strong cytotoxicity against cancer cells in EGFR-specific manner, implying its great therapeutic potential. [ABSTRACT FROM AUTHOR]

Abstract Chalcone (1,3-diphenyl-2-propen-1-one) derivatives exert anti-cancer activity by targeting key molecules that can lead to carcinogenesis. We synthesized the chalcone derivative 3-phenyl-1-(2,4,6-tris(methoxymethoxy)phenyl)prop-2-yn-1-one (KB-34) and previously reported its anti-inflammatory activity in macrophages. In this study, we examined the anti-metastatic activity of KB-34 against human colorectal cancer (CRC) cells and elucidated its underlying molecular mechanisms. KB-34 treatment significantly inhibited 12- O -tetradecanoylphorbol-13-acetate (TPA)-induced migration, as well as the invasion and proliferation of CRC cells (HT-29 and SW620). TPA-induced activation of NF-κB was also markedly suppressed by KB-34 in HT-29 cells. KB-34 suppressed the expression of matrix metalloproteinase-7 (MMP-7) at both the mRNA and protein levels in TPA-stimulated CRC cells (HT-29 and SW620). We also demonstrated that induced heme oxygenase-1 (HO-1) expression in CRC cells (HT-29 and SW620) and HO-1 is required for KB-34-mediated suppression of the expression of MMP-7 in TPA-stimulated HT-29 cells. Additionally, the cyclin-dependent kinase inhibitor p21 was significantly induced by treatment with KB-34 in CRC cells (HT-29 and SW620). Knockdown of HO-1 prevented the induction of p21 expression by KB-34 in HT-29 cells. Furthermore, we also demonstrated that 5-fluorouracil (5-FU) together with KB-34 produced a significantly greater inhibition of growth and stimulation of apoptosis of HT-29 cells than did 5-FU alone. In conclusion, KB-34 inhibits the TPA-stimulated metastatic potential of HT-29 cells by induction of HO-1 and may be a promising anti-cancer agent in chemotherapeutic strategies for CRC. [ABSTRACT FROM AUTHOR]

The process of hydrate dissociation and production induced by depressurization incorporates intricate hydraulic, thermal, and mechanical phenomena. Thus, coupled thermal-hydraulic-mechanical (T-H-M) simulation is critically necessary to evaluate the geomechanical stability of hydrate production in hydrate-bearing sediments (HBS). However, methods of estimating the input model parameters and properties of the target reservoir, in particular in unconsolidated marine sediments, have received limited attention compared to studies on production simulators. The T-H-M properties of the marine sediments change considerably with depth, geological strata, and soil type of each layer. Therefore, it is important that representative layers and their corresponding T-H-M properties should be properly estimated to analyze the stability and productivity of methane gas recovery in the field. This study provides a comprehensive estimation for the model parameters and properties of unconsolidated marine sediments, based on vast data from field seismic surveys and laboratory experimental results with core samples, investigates empirical correlations between model parameters and methane hydrate saturation, and finally summarizes the estimated model parameters and properties, which can possibly be applied to on-going numerical research into stability assessment of the pilot gas hydrate (GH) production test, which is soon to be performed in the Ulleung basin. [ABSTRACT FROM AUTHOR]

This study analyzed the PM 10 aerosol enhancement caused by East Asian atmospheric warming during transboundary transport in March of 2021. It was found to be cooled near the north polar area and to have shifted the polar vortices northward over the East Asian region in the mid-troposphere. The Siberian high was weakened and the East Asian region was characterized by a positive air temperature anomaly and negative zonal wind speeds. The increasing rate of air temperature anomalies at 2 m was higher in the high latitude areas over 40°N in Mongolia and northeastern China, causing a decrease in zonal wind speeds at 10 m over eastern China and Korea. The anomalous variations of the MODIS-induced aerosol optical depth (AOD) were found to be positive with the highest value of +0.93 in the area ranging from northeastern China to Korea, despite the recent decreasing trends. The positive anomalous region of the MODIS-induced AOD was correlated with positive air temperatures and negative zonal wind speeds, causing enhanced formations of secondary aerosols in the atmosphere. As cold northerly winds were suppressed in the East Asian region, anomalous high pressures (anticyclonic anomalies) developed frequently in eastern China and moved to Korea. The Weather Research and Forecasting model to which meteorological and climate data were applied coupled with Chemistry (WRF-Chem) simulations on increases in the PM 10 enhancement ratio, indicating enhanced formation amounts, during transboundary transport for the period of March 13–15, 2021. An air mass near the high terrain surface over eastern China under the backward side of an anticyclone warmed and moved toward the relatively low terrain of the Yellow Sea and Korea in keeping with the height. Air temperature inversion developed in the anomalous warmer center in the mid-troposphere, reaching the surface of the Yellow Sea and Korea. High PM 10 concentrations were constrained near the shallow inversion layer. Furthermore, the PM 10 enhancement ratio showed a positive level over the Yellow Sea with nearly zero anthropogenic emissions on the surface, gradually increasing at a rate of approximately 60% in Korea. The hourly contribution by the warming-induced PM 10 enhancement (PM 10 CbWIE) was calculated and found to be at the highest level of 70% in Seoul, Korea. Among PM 10 secondary inorganic aerosols, nitrate formations were enhanced during transboundary transport in the warming-induced anticyclone with reactions rich in ammonium. While the sulfate enhancement ratio reached a positive level over the Yellow Sea, the gradual decrease during transboundary transport may be reflected by the decreased emissions of sulfur dioxide in eastern China. • PM10 aerosol enhancement caused by atmospheric warming during transboundary transport. • Anomalous variations of the aerosol optical depth from northeastern China to Korea. • Meteorological and climate data-applied WRF-Chem simulations in the East Asian region. • Enhanced formations of PM10 secondary aerosols in the warming-induced anticyclone. [ABSTRACT FROM AUTHOR]

The particulate matter (PM 10) trend has decreased at a growing rate in South Korea, which is on the downwind side in the East Asian region over the last five-year period of 2014–2018. Nevertheless, nationwide, days of high PM 10 levels and haze frequently occurred over the period of February–March in 2019. During the period of February–March 2019, two major atmospheric blockings were identified over the Alaskan region in the northeast Pacific over the periods of February 21-March 1 and March 18–29. Warm and stagnant synoptic meteorological conditions favorable for high-PM 10 haze days in the East Asian region were accompanied 4–5 days later by the remote Alaskan atmospheric blockings. The Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) was used, applying zero-out emission to analyze the regional PM 10 contribution on severe haze days exceeding a daily average of 100 μg m−3 over South Korea during March 3–6, 2019. The daily average regional PM 10 contribution indicated a rate of 57% compared to rates of 23% before and 29% after severe haze days. Furthermore, the major regional PM 10 components were nitrates (49%), other inorganics (28%), and sulphates (9%) during the severe haze days. Among inorganic PM 10 aerosols, other inorganics mainly composed of anthropogenic fine dust were not a major contribution component in the South Korean case due to fuel consumption changes in China. However, higher nitrate flux from sources in eastern China remained in South Korea, though in slightly reduced amounts. The contribution rate of NO X discharged from automobiles has gradually increased in China, and the level of SO 2 remained on a low level through emission control technologies and regulatory options. The warm and stagnant atmosphere in the East Asian region caused the flux of relatively more nitrates were likely transported, with ammonium nitrate in the atmosphere and with lower sulphate levels. • Warm and stagnant conditions favorable for haze were accompanied by blocking 4–5 days later. • WRF-Chem was used, applying zero-out emission to analyze regional PM10 contribution. • Regional PM10 contribution indicated 57% compared to 23% before and 29% after haze. • The warm and stagnant atmosphere caused the flux of more nitrates likely transported. [ABSTRACT FROM AUTHOR]

In this study, the moisture related hygroscopic characteristics and mechanical properties of polymer–clay nanocomposites (PCNs) were investigated using molecular dynamics (MD) simulations and experiments as a function of the weight fraction of nanoclay. The hygroscopic and mechanical properties including the moisture saturation amount, moisture diffusivity, work of adhesion, and elastic modulus of the PCNs were studied using MD simulations and compared to experimental results as a function of the nanoclay content. It was demonstrated that the proposed MD simulation technique can be successfully used for the prediction of the effects of the nanoclay on the moisture diffusion characteristics as well as mechanical improvements of PCNs. It is expected that the simulation technique applied in this work can be widely used to evaluate the performances of nanocomposite materials. [ABSTRACT FROM AUTHOR]

In this study, we developed a new way to increase the efficiency of dye-sensitized solar cells by using TiO2/silver/carbon nanotube composites as the working electrode. Silver nanoparticles and multi-walled carbon nanotubes were mixed with TiO2 nanoparticles and used as working electrodes in a dye-sensitized solar cell. The effect of the silver nanoparticles and multi-walled carbon nanotubes on the efficiency of the dye-sensitized solar cell was studied as function of their volume fractions using several microscopic and spectroscopic characterization techniques such as scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, ultra-violet-vis and electrochemical impedance spectroscopy. It was found that the silver nanoparticles could induce surface plasmonic phenomena, where the light absorption was enhanced in the ultra-violet wavelength range. Additionally, the carbon nanotubes could increase the electron mobility in the working electrode due to their high surface-to-volume ratio and superior electrical conductivity. The efficiency of the silver/carbon nanotube/TiO2 nanocomposite working electrode was compared with that of a conventional TiO2 working electrode under one-sun illumination (100 mWcm–2, AM 1.5 G). The TiO2/Ag/carbon nanotube nanocomposite working electrode had a two-fold higher efficiency (3.76%) than the conventional pure TiO2 working electrode (1.88%). [ABSTRACT FROM PUBLISHER]

Abstract: In this paper, a sintering process for nickel nanoparticles using flash light irradiation was investigated for multilayer ceramic capacitors, magnetic devices and printed electronics. The existence of a small amount of 10nm size nanoparticles in the ink significantly improved the flash light absorption and induced the melting and sintering of the nanoparticles. Due to this phenomenon, uniform diameter nickel nanoparticles (50nm) could not be sintered, while the nickel nanoparticles with varying diameters (5–500nm) were sintered by flash light irradiation. In order to acquire high electrical conductivity in the sintered nickel nanoparticles, several flash light sintering parameters such as light energy and pulsed light patterns were optimized. Also, the nickel nano-ink was optimized by changing the weight fractions of organic binder in the ink. [Copyright &y& Elsevier]

Abstract: When adhesively bonded joints are exposed to a moist environment, the tensile load capability of the joint is significantly decreased because moisture absorption weakens the mechanical properties of epoxy adhesive. In this paper, a nanoclay with excellent penetration resistance properties was used as a filler in epoxy adhesive in order to enhance adhesive strength in moist environments. The water absorption of the epoxy adhesive and the adhesive strength of the adhesively bonded joints were measured in water absorption experiments with respect to the weight fraction of the nanoclay and the moisture exposure time. These results showed that the tensile load capability of the nanoclay-filled adhesively bonded joint was greatly enhanced, even in a moist environment, because the nanoclay reduced water absorption into the epoxy adhesive as well as into the interface between the epoxy adhesive and the steel adherend and increased the strength of the epoxy adhesive itself. [Copyright &y& Elsevier]

Abstract: This study investigates the geotechnical and geophysical properties of minimally disturbed fine-grained marine sediments recovered during the second Ulleung Basin Gas Hydrate expedition (UBGH2), East Sea, Korea. Conventional laboratory geotechnical engineering test methods were used to characterize the sediments from a geotechnical engineering perspective. The sediments were mostly uncompacted and classified as highly plastic silty soils according to the Unified Soil Classification System (USCS); they exhibited high compressibility when subjected to an increase in effective stress (or a decrease in pore water pressure), low hydraulic conductivities, and low coefficient of consolidation (or pressure diffusion). It is expected that the application of a depressurization method for gas hydrate production at the investigated sites would cause a significant amount of settlement and compaction around the production hole. Because the shear wave velocity of gas hydrate-bearing sediments is much less sensitive to the stress state and is much higher than that of sediments without gas hydrates, it is possible to estimate the degree of hydrate saturation from shear wave velocity data measured in gas hydrate-bearing sediments. In addition, the prior presence of gas hydrates in the sediments was verified through a comparison of water content, compressibility, and electrical resistivity of the sediments. [Copyright &y& Elsevier]

Generally, the thermal residual stress which is generated during the curing process of an adhesive significantly decreases the tensile load capability of adhesively bonded joints. In this work, a smart cure cycle with abrupt cooling and postcuring at room temperature was devised to eliminate thermal residual stress and to produce sufficient interfacial wetting. For monitoring and controlling the curing reaction, dielectrometry was used, where the dissipation factor of the adhesive joint was measured. These results showed that the tensile load capability of the adhesively bonded joint fabricated by the smart cure cycle was greatly enhanced because the thermal residual stress was reduced, and sufficient interfacial wetting between the adhesive and adherend was achieved. [ABSTRACT FROM AUTHOR]

Abstract: Generally, a large, thermal residual stress is generated during the curing process for composite laminates due to differences in the coefficients of thermal expansion of the respective layers. The thermal residual stress during fabrication greatly decreases the fatigue life and dimensional accuracy of the composite structures. In the present study, through a fiber bragg grating (FBG) sensor and dielectrometry in an autoclave, the strain evolution and curing reaction in composite laminates with a stacking sequence of [05/905]S were monitored simultaneously during a conventional cure cycle and a modified cure cycle to reduce the thermal residual stress. From the study, it was verified that about 50% of the thermal residual stress during fabrication could be reduced in a composite laminate by adjusting the cure cycle; this improved the static strength and fatigue life by 16% and up to 614%, respectively, for a peak ratio of 0.9. [Copyright &y& Elsevier]

Abstract: Moisture-induced package failures such as interfacial delamination and pop-corn cracking are common failure phenomena that occur during the solder reflow process in the semiconductor industry. Therefore, the hygroscopic properties of the package materials are crucial factors in the reliability of electronic packaging products. In this work, molecular dynamics (MD) simulation was performed to study the hygroscopic properties, including diffusivity and swelling strain, of epoxy materials with respect to temperature and moisture concentration. Hygroscopic material properties predicted by MD are discussed and compared with the experimental data. [Copyright &y& Elsevier]

In this work, moisture-induced interfacial delamination in a semiconductor package was investigated by experiment and multi-scale numerical analysis. The interfacial adhesion strength between a silicon wafer and an epoxy adhesive layer was characterized by a die-shear test with respect to moisture concentration and temperature. Molecular dynamics simulation was performed to study the effect of moisture and temperature on the interfacial adhesion energy and strength at the Si/epoxy adhesive interface. Based on the molecular dynamics predicted interfacial adhesion strength, a numerical stress analysis was performed considering hygro-swelling stress and the thermo-mechanical stress during a solder reflow process to predict the moisture-induced delamination failure of the semiconductor package. The multi-scale simulation result was compared with the actual reliability test result. From this study, it was concluded that the proposed multi-scale simulation technique can be used successfully for the prediction of moisture-induced package failure. [ABSTRACT FROM AUTHOR]

In this work, moisture-induced interfacial delamination in a semiconductor package was investigated by experiment and multi-scale numerical analysis. The interfacial adhesion strength between a silicon wafer and an epoxy adhesive layer was characterized by a die-shear test with respect to moisture concentration and temperature. Molecular dynamics simulation was performed to study the effect of moisture and temperature on the interfacial adhesion energy and strength at the Si/epoxy adhesive interface. Based on the molecular dynamics predicted interfacial adhesion strength, a numerical stress analysis was performed considering hygro-swelling stress and the thermo-mechanical stress during a solder reflow process to predict the moisture-induced delamination failure of the semiconductor package. The multi-scale simulation result was compared with the actual reliability test result. From this study, it was concluded that the proposed multi-scale simulation technique can be used successfully for the prediction of moisture-induced package failure. [ABSTRACT FROM AUTHOR]

Hybrid or aluminum tube structure requires reliable joining of the shaft to other components such as steel yoke and universal joint, which is often the most difficult task. Therefore, a reliable joining method between the aluminum tube and the steel yoke of a hybrid composite propeller shaft for automobile is required. In this work a press fitting method for joining of an aluminum tube to an aluminum yoke is devised by a steel ring with many small teeth to increase reliability as well as to reduce manufacturing cost of the hybrid propeller shaft rather than using other joining methods such as adhesively bonded or welded joints. The optimal shape and number of teeth of the steel ring were obtained experimentally for the maximum static torque capabilities and fatigue characteristics of the press fit joint, and was compared to the finite element analysis results. Finally, a design guideline for the press fit joint using a steel ring with many small teeth for joining the aluminum shaft to the steel ring was suggested. With the developed press fit joint, the static average shear strength of 70 MPa and fatigue strength of 21 MPa between the aluminum tube and the steel ring were realized, which were almost three times higher than that of the adhesively bonded joint. [ABSTRACT FROM AUTHOR]

Abstract: A novel method using intense pulsed light (IPL) for the metal nano-island formation on carbon nanotube (CNT) was introduced. The IPL-induced photothermal dewetting process improved platinum (Pt) catalyst utilization by transforming nano-islands from Pt film on CNT and increasing the surface area for the subsequent sputtering. The irradiation of high intensity of light on the Pt film causes surface-energy-driven diffusion of Pt atoms and forms the array of nano-islands on CNT. The thickness of Pt film can change the size of nano-islands. Cyclic voltammetry showed a dramatically improved glucose oxidation at the IPL morphology modified Pt–CNT electrode compared to the Pt sputtered CNT electrode without IPL irradiation. The power densities of glucose/air biofuel cell based on the morphology modified Pt–CNT electrode and the as-sputtered Pt–CNT electrode were 0.768μW/cm2 and 0.178μW/cm2, respectively. The biofuel cell based on morphology modified Pt–CNT electrode showed highly stable output in long-term performance. The power density dropped 14.1% in 30 days. Efforts are underway to improve the interface transfer to achieve higher potential and current output. [Copyright &y& Elsevier]

Abstract: Copper nano-ink with a drop-on-demand (DOD) piezoelectric inkjet printing method was introduced. The printed electrodes were thermally sintered to ensure high-quality electrical and mechanical performances. To check the reliability of the printed electrodes on a polymer layer, resistance changes were measured under static loading. The electrodes with various widths and thicknesses were used to find the optimal dimensions. A multifunctional composite laminate which can harvest and store a solar energy was fabricated using printed electrodes. An amorphous silicon solar cell and a thin film solid state lithium-ion battery were adhesively joined and electrically connected to a thin flexible printed circuit board (PCB). Then, the passive components such as resistor and diode were electrically connected to the printed circuit board by silver pasting. The integrated PCB was co-cured with a carbon/epoxy composite laminate by the vacuum bag molding process in an autoclave. The structural and functional performance of the final energy harvesting/storage composite laminate was tested under mechanical loading. [Copyright &y& Elsevier]

Abstract: The cure kinetics of a thermally mendable polymer based on Diels-Alder (DA) and retro-Diels-Alder (rDA) reactions, mendomer 401, was investigated using dynamic differential scanning calorimetry (DSC). The resulting behavior was modeled using a conventional cure kinetic model for thermosetting polymers. A composite panel with two layers of carbon fabric and mendomer 401 was fabricated following the cure cycle suggested by the cure kinetics model. Micro-indentation tests were performed to investigate mechanical properties and dynamic mechanical thermal analysis (DMTA) was conducted to study thermal behavior and to find the trigger temperature for healing. Self-healing behavior of the carbon fiber/mendomer composite was demonstrated using electrical resistive heating over the glass transition temperature. [Copyright &y& Elsevier]

Abstract: Chalcones, a subclass of the flavonoid family, are widely known for their anti-inflammatory and anti-oxidative properties. In the present study, we synthesized the chalcone derivative, KB-34 (3-Phenyl-1-(2,4,6-tris (methoxymethoxy)phenyl)prop-2-yn-1-one), and examined its effect on nitric oxide (NO) production. KB-34 potently inhibited nitrite production in RAW 264.7 macrophages stimulated by lipopolysaccharide (LPS). KB-34 treatment also markedly inhibited inducible nitric oxide synthase (iNOS) expression, as assessed by Western blot and quantitative RT-PCR analyses. Treatment of cells with KB-34 significantly inhibited LPS-induced transcriptional activation by activator protein-1 (AP-1) as determined by luciferase reporter gene assay, whereas nuclear factor-κB (NF-κB) activity was not affected by KB-34, indicating that down-regulation of iNOS gene expression by KB-34 is mainly attributed by blockade of AP-1 activation. We also demonstrated that KB-34 treatment led to an increase in heme oxygenase-1 (HO-1) mRNA and protein expression, mediated by stimulating the expression of nuclear factor-erythroid 2-related factor 2 (Nrf2). Treatment with SnPP, a selective inhibitor of HO-1, reversed the KB-34-mediated inhibition of nitrite production, suggesting that HO-1 plays an important role in the suppression of NO production by KB-34. In contrast, SnPP treatment did not counteract the KB-34-mediated suppression of AP-1 activity, suggesting that inhibition of AP-1 activation by KB-34 is independent of HO-1 induction. Taken together, these results indicate that KB-34 suppresses NO production in LPS-stimulated RAW 264.7 macrophages via simultaneous induction of HO-1 expression and blockade of AP-1 activation. This study reveals that KB-34 would be a promising agent for the treatment of inflammation-associated disease. [Copyright &y& Elsevier]

Abstract: Long brush shafts are used to clean large glass panels of liquid crystal display (LCD). Since the surface quality of glass panels is most important for LCD products, reliable cleaning of the glass panels is indispensable during the manufacturing process of LCD product. Generally, stainless steel tubes covered with outside soft brush have been used for cleaning LCD glass panels. Although the stainless steel tube rotates at the low rotating speed of 700rpm, support bearings fail frequently earlier than the design period due to whirling vibration and shaft tilting. In this work, a hybrid composite shaft composed of outside stainless steel tube and inside carbon/epoxy composite layer was designed to increase the specific stiffness of the shaft. The composite layers were stacked inside the stainless steel tube to protect the composite material from acid liquid for cleaning, and co-cured using a flexible pressure tube to decrease manufacturing cost. The deflection and tilting angle due to gravity and the fundamental natural frequency of the hybrid shaft were calculated and compared to those from experimental results. [Copyright &y& Elsevier]

Abstract: The present work studies the moisture induced failures of a stacked-die package. The study includes various experimental tests to find the characteristics of constituent packaging materials such as interfacial strength, hygro-swelling property and vapor pressure, and a comprehensive finite element analysis integrating the effects of the hygro-swelling stress, the thermo-mechanical stress and the vapor pressure. Specifically, the vapor pressures with respect to the moisture concentration and the temperature in epoxy molding compound were characterized experimentally by combined TMA/TGA technique. In the numerical stress analysis, the interfacial delamination was newly simulated by applying a cohesive element modeling technique, in which a quadratic traction damage initiation law and an exponential displacement separation law were used. [Copyright &y& Elsevier]

Abstract: In this work, cure control system using dielectrometry for co-cured metal/composite hybrid structures was devised to reduce the fabricational thermal residual stress of the bonding layer between metal and composite material. The cure kinetic model of carbon fiber epoxy composite materials was developed by curve fitting the differential scanning calorimetry (DSC) data. The relationship between start of cure and gelation points of epoxy resin and the dissipation factor were investigated. The degree of cure was obtained by comparing the dissipation factor from the dielectric properties to the degree of cure from the DSC. Also, the curvature experiment of co-cured steel/composite strip and the static lap shear tests of the co-cured steel/composite lap joints were measured to investigate the effect of cure cycle on the thermal residual stress of the co-cured hybrid structures. From these results, the cure control algorithm using the dielectrometry for reduction of thermal residual stress was devised and verified under various temperature profiles. [Copyright &y& Elsevier]

Abstract: The micro-multi-functional actuator (MFA) of a cellular phone is a mass-spring system which is resonated by electrical force at the fundamental natural frequency to generate and transmit the vibration signal to the customers. The MFA has two design requirements such as high vibration force transmission and long fatigue life. Generally, conventional multi-functional actuators have been manufactured using stamped metal plate springs using precision dies. Since cracks are often generated in the cut area of metal plate during stamping operation, fatigue failures of conventional MFA’s are inevitable. In this study, a new micro-multi-functional actuator was designed using a spring (music) wire which has a high fatigue endurance limit because the surface of music wire is finely surface-finished. After the static and dynamic characteristics of MFA were analyzed using finite element analysis with respect to the diameter and shape of the spring wire, its dynamic performance such as fundamental natural frequency, vibration force transmission and fatigue life, and adhesion characteristics between the wire and the composite molding were experimentally investigated with respect to manufacturing parameters such as surface treatment method of spring wire, injection molding temperature and pressure of polymer mold. [Copyright &y& Elsevier]

Abstract: In this work, a smart curing method for the co-cured aluminum/composite hybrid shaft which can reduce the thermal residual stresses generated during co-curing bonding operation between the composite layer and the aluminum tube was applied. In order to reduce the thermal residual stresses generated during co-cure bonding stages due to the difference of coefficients of thermal expansions (CTE) of the composite and the aluminum tube, a smart cure cycle composed of cooling and reheating cycles was applied. The heating and cooling operations were realized using a pan type heater and water cooling system. The thermo-mechanical properties of the high modulus carbon epoxy composite were measured by a DSC (differential scanning calorimetry) and rheometer to obtain an optimal time to apply the cooling operation. Curvature experiment of the co-cure bonded steel/composite strip was performed to investigate the effect of cure cycle on generation of the thermal residual stress. Also, the thermal residual stresses of the aluminum/composite hybrid shaft were measured using strain gauges with respect to cure cycles. Finally, torsional fatigue test and vibration test of the aluminum/composite hybrid shaft were performed, and it has been found that this method might be used effectively in manufacturing of the co-cured aluminum/composite hybrid propeller shaft to improve the dynamic torque characteristics. [Copyright &y& Elsevier]

Abstract: Since the co-cured joint composed of composite and metallic structures has been widely used in joining process due to its simple and easy manufacturing process, the optimum design of the co-cured joint is important because the joint is usually the weakest part among the components of assembled structures. In this work, the effect of design parameters for co-cured joint, such as fiber stacking sequence, stiffness ratio of composite to aluminum on the static tensile load capabilities and dynamic fatigue characteristics of the co-cured double lap joint composed of aluminum and carbon epoxy composite were experimentally investigated. Also, the stress distribution and energy release rate of the co-cured joint were calculated using finite element analysis with respect to design parameters. From the experimental and finite element analysis results, the optimum values for each design parameters were obtained. Also, the optimum stiffness ratio for each stacking sequence of the carbon epoxy composite was obtained. [Copyright &y& Elsevier]

Abstract: Substituting composite structures for conventional metallic structures has many advantages because composite materials have both high specific stiffness and damping characteristics compared to conventional metallic materials. In this study, circular plate cutting tools which are used for rough machining of bearing sites in crankshafts or camshafts were designed with the fiber reinforced composite material to reduce tool mass and to improve the dynamic stiffness of circular plate cutting tools. The hybrid steel/composite circular plate cutting tool was analyzed by finite element method with respect to material types such as composite and foam, stacking angles of the composite, adhesive bonding thickness, and dimensions of the cutting tool. Also, the constrained damping characteristics of the tools were experimentally investigated with respect to the adhesive bonding thickness and material type such as composite and PVC foam. From the finite element analysis and experimental results, optimal design parameters for the hybrid steel/composite circular plate cutting tool were suggested. [Copyright &y& Elsevier]

Abstract: In this work, a one-piece hybrid drive shaft composed of aluminum and carbon/epoxy composite was designed for a rear wheel drive automobile. The aluminum yoke was joined to the hybrid shaft by the press fit joining method using a steel ring which has many small teeth to increase reliability and to reduce manufacturing cost. To obtain high strength of the press fit joint, an optimal design method for the teeth was devised with respect to number and shape of the steel teeth. The developed optimal design method predicted well the static torque capability and failure mode of the press fit joint. Then, the prototype one-piece automotive hybrid aluminum/composite drive shaft was manufactured and tested. The one-piece automotive hybrid aluminum/composite drive shaft allowed 50% mass reduction compared with the conventional two-piece steel drive shaft. [Copyright &y& Elsevier]

In this work, the low velocity impact damage characteristics of aluminum/composite hybrid drive shaft were investigated. The hybrid drive shaft was manufactured by stacking carbon epoxy composite prepregs and insulating layer for galvanic corrosion on the inner surface of an aluminum tube, and co-curing them in an autoclave under recommended cure cycle. After impacting the co-cured hybrid drive shafts using a drop-weight impact tester, the damage and delamination of the composite layers were observed with an ultrasonic C-scan, from which the damage modes of aluminum/composite hybrid shaft were found with respect to the stacking sequence of composite materials, the thickness of the aluminum tube and the impact energy. Finally, optimal stacking sequence of the composite material and optimal thickness of the aluminum tube for the drive shaft for low velocity impact were suggested. [Copyright &y& Elsevier]

Continuous monitoring of sand and duststorms (SD) and associated heavy dustfall (HD) is made in Korea. In particular, accurate measurements of atmospheric dust loadings have been carried out with the tapered element oscillating microbalance method, and satellite detection of dust clouds is included in the analysis. In 2002, we found three gigantic dust clouds that moved over the Korean Peninsula, and associated HD occurred with PM10 values of 1106–3006 μg m−3. In Beijing, China much higher concentrations were recorded, while in SW Japan measured values were up to 986 μg m−3. Two SD occurred in March and April, while the third one occurred unusually in November. During the year, there were nine cases of reddish-brown sand with 18 dusty days. The intensity of HD was extraordinary for the recent decade. It was observed that with invading SD, the higher the PM10 values the lower the PM2.5 loadings. Also, variations of visibility were more depending on PM2.5 variations than PM10 values. It is shown that satellite detection is a useful technique in monitoring SD and HD. [Copyright &y& Elsevier]

Although an adhesive joint can distribute the load over a larger area than a mechanical joint, requires no holes, adds very little weight to the structure and has superior fatigue resistance, but it not only requires a careful surface preparation of the adherends but also is affected by service environments. In this paper, suitable conditions for surface treatments such as plasma surface treatment, mechanical abrasion, and sandblast treatment were investigated to enhance the mechanical load capabilities of carbon/epoxy composite adhesive joints. A capacitively coupled radiofrequency plasma system was used for the plasma surface treatment of carbon/epoxy composites and suitable surface treatment conditions were experimentally investigated with respect to gas flow rate, chamber pressure, power intensity, and surface treatment time by measuring the surface free energies of treated specimens. The optimal mechanical abrasion conditions with sandpapers were investigated with respect to the mesh number of sandpaper, and optimal sandblast conditions were investigated with respect to sandblast pressure and particle size by observing geometric shape changes of adherends during sandblast process. Also the failure modes of composite adhesive joints were investigated with respect to surface treatment. From the peel tests on plasma treated composite adhesive joints, it was found that all composite adhesive joints failed cohesively in the adhesive layer when the surface free energy was higher than about 40 mJ/m[sup 2], because of high adhesion strength between the plasma treated surface and the adhesive. From the peel tests on mechanically abraded composite adhesive joints, it was also found that the optimal surface roughness and adhesive thickness increased as the failure load increased. [ABSTRACT FROM AUTHOR]

Investigates the crystal structure of hydantoinase from bacillus stearothermophilus. Industrial production of antibiotics; Chemical structures; Side-chain precursors.

In this work, damage sensing of carbon fiber reinforced polymer composite (CFRP) was conducted based on an addressable conducting network (ACN). To improve the accuracy of damage detection, a deep learning-based damage sensing system was developed. The data for deep learning were generated using a resist network model based on Kirchhoff's law. The generated data was verified through finite element analysis. Then, the Artificial Neural Network (ANN) deep learning algorithm was used for damage detection and evaluation. The accuracy of damage sensing was improved by applying the resist network model that considered not only delamination but also the damage of the carbon fiber. As a result, damage detection of CFRP was performed with a high accuracy rate of about 95%. [ABSTRACT FROM AUTHOR]

CO2 hydrates are ice-like solid lattice compounds composed of hydrogen-bonded cages of water molecules that encapsulate guest CO2 molecules. The formation of CO2 hydrates in unconsolidated sediments significantly decreases their permeability and increases their stiffness. CO2 hydrate-bearing sediments can, therefore, act as cap-rocks and prevent CO2 leakage from a CO2-stored layer. In this study, we conducted an experimental simulation of CO2 geological storage into marine unconsolidated sediments. CO2 hydrates formed during the CO2 liquid injection process and prevented any upward flow of CO2. Temperature, pressure, P-wave velocity, and electrical resistance were measured during the experiment, and their measurement results verified the occurrence of the self-trapping effect induced by CO2 hydrate formation. Several analyses using the experimental results revealed that CO2 hydrate bearing-sediments have a considerable sealing capacity. Minimum breakthrough pressure and maximum absolute permeability are estimated to be 0.71 MPa and 5.55 × 10−4 darcys, respectively. [ABSTRACT FROM AUTHOR]

Power storage and conversion technologies are increasingly in demand for their energy efficiency and eco-friendliness, with capacitors being key in stabilizing and filtering voltage in these devices. However, during this process, thermal degradation phenomena often occur due to over-voltage and over-current. This degradation can lead to decreased performance, capacitor failure, and in severe cases, explosions. Thus, the precise monitoring and prediction of capacitor lifetime is paramount. In this study, we use accelerated life test data to create images using reference plots and compare the accuracy of deep neural network training through image fusion. This introduces a new methodology for monitoring the lifetime of capacitors. This approach involves collecting aging data through accelerated life tests and then generating images from time-series data composed of capacitor voltage, current, and resistance. These images are used to train the deep learning algorithm, extracting relevant features and predicting the remaining life of the capacitors. Our method demonstrates remarkable effectiveness, showing an impressive accuracy rate of 80% in the real-time monitoring of capacitors under various operating conditions. Ultimately, this deep neural network-based lifetime monitoring algorithm holds potential to be scaled and applied to diverse electronic systems, enhancing their reliability and safety. • New method for capacitor life prediction using deep neural networks. • Created images from time-series data for algorithm training. • Lifespan classification of capacitors with image-based training. • Achieved 90% accuracy in real-time lifespan prediction. [ABSTRACT FROM AUTHOR]

Additively printed circuits provide advantages in reduced waste, rapid prototyping, and versatile flexible substrate choices relative to conventional circuit printing. Copper (Cu) based inks along with intense pulsed light (IPL) sintering can be used in additive circuit printing. However, IPL sintered Cu typically suffer from poor solderability due to high roughness and porosity. To address this, hybrid Cu ink which consists of Cu precursor/nanoparticle was formulated to seed Cu species and fill voids in the sintered structure. Nickel (Ni) electroplating was utilized to further improve surface solderability. Simulations were performed at various electroplating conditions and Cu cathode surface roughness using the multi-physics finite element method. By utilizing a mask during IPL sintering, conductivity was induced in exposed regions; this was utilized to achieve selective Ni-electroplating. Surface morphology and cross section analysis of the electrodes were observed through scanning electron microscopy and a 3D optical profilometer. Energy dispersive X-ray spectroscopy analysis was conducted to investigate changes in surface compositions. ASTM D3359 adhesion testing was performed to examine the adhesion between the electrode and substrate. Solder-electrode shear tests were investigated with a tensile tester to observe the shear strength between solder and electrodes. By utilizing Cu precursors and novel multifaceted approach of IPL sintering, a robust and solderable Ni electroplated conductive Cu printed electrode was achieved. [ABSTRACT FROM AUTHOR]

In this study, an intense pulsed light (IPL) annealing process for a printed multi-layered indium–gallium–zinc–oxide (IGZO) and silver (Ag) electrode structure was developed for a high performance all-printed inorganic thin film transistor (TFT). Through a solution process using IGZO precursor and Ag ink, the bottom gate structure TFT was fabricated. The spin coating method was used to form the IGZO semiconductor layer on a heavily-doped silicon wafer covered with thermally grown silicon dioxide. The annealing process of the IGZO layer utilized an optimized IPL irradiation process. The Ag inks were printed on the IGZO layer by screen printing to form the source and drain (S/D) pattern. This S/D pattern was dried by near infrared radiation (NIR) and the dried S/D pattern was sintered with intense pulsed light by varying the irradiation energy. The performances of the all-printed TFT such as the field effect mobility and on–off ratio electrical transfer properties were measured by a parameter analyzer. The interfacial analysis including the contact resistance and cross-sectional microstructure analysis is essential because diffusion phenomenon can occur during the annealing and sintering process. Consequently, this TFT device showed noteworthy performance (field effect mobility: 7.96 cm2/V s, on/off ratio: 107). This is similar performance compared to a conventional TFT, which is expected to open a new path in the printed metal oxide-based TFT field. [ABSTRACT FROM AUTHOR]

In this work, the printing and sintering characteristics of pattern area and via-hole section were investigated. To analyze the printing characteristics depending on the rheology of ink, Cu micro/Ag nano-hybrid inks (Cu/Ag hybrid inks) were prepared by varying the amount of epoxy, and the fabricated inks were printed on via-hole formed substrates. The printed Cu/Ag hybrid ink films were subsequently sintered by an intense pulsed light (IPL) sintering method. Various IPL sintering parameters including irradiation energy and pulse number were employed to enhance the sintering characteristics of pattern area and via-hole section. The sintered Cu/Ag hybrid ink films were characterized using scanning electron microscopy and X-ray photoelectron spectroscopy. The detailed sintering mechanism of Cu/Ag hybrid ink inside the via-hole section was monitored in real-time by in situ resistance monitoring. As a result, the Cu/Ag hybrid ink with the optimal ratio of epoxy content (0.56 wt%) showed good printability of pattern area and via-hole section. In addition, the proposed multi-pulse IPL sintering conditions (irradiation energy: 7 J/cm2, pulse duration: 1 ms, off-time: 9 ms, pulse number: 20) exhibited low resistivity (pattern area: 5.12 μΩ cm, via-hole section: 7.79 μΩ cm) and a 5B adhesion strength level. • Cu micro/Ag nano-hybrid inks were printed and intense pulsed light (IPL) sintered. • Ink contents were optimized for printing of pattern area and via-hole section. • Multi-pulse IPL sintering was introduced to improve sintering characteristics. • Optimally IPL sintered case exhibited superior sintering characteristics. [ABSTRACT FROM AUTHOR]

Abstract In this work, intense pulsed light (IPL) sintering process was investigated with vacuum stretching and heating of the polymer substrate for warpage free printed electronics circuit. The IPL irradiation energy and substrate heating temperature were optimized to obtain high electrical conductivity, high adhesion strength, and little warpage of printed Cu electrodes pattern on the polyimide (PI) substrate. Scanning electron microscopy and x-ray diffraction were conducted to characterize microstructure and transformation crystal phase of the IPL sintered Cu nanoparticle (NP)/microparticle (MP)-ink film. The resistivity of IPL sintered Cu NP/MP-ink films was measured using the four-point probe method and profilometer. In order to monitor IPL sintering process, in-situ resistance and temperature monitoring of Cu NP/MP-ink were conducted. Also, a transient heat transfer analysis was performed using finite-element analysis software to predict temperature gradients of Cu NP/MP-ink and polymer substrate during IPL light sintering process. As a result, the optimal IPL light sintered Cu NP/MP-ink film (vacuum applied, 150 °C heating, and irradiation energy: 3.5 J/cm2) had a low resistivity 6.94 μΩ·cm and 5 B level of adhesion strength with almost no warpage of PI substrate. Highlights • Cu nano/micro particle (NP/MP)-ink was intense pulsed light (IPL) sintered. • We employed the substrate vacuum holding and heating during IPL sintering. • 3.5 J/cm2 with 150 °C heating was determined as optimum conditions. • The sintered Cu NP/MP-ink showed the lowest resistivity with 5B adhesion level. • The Cu NP/MP-ink was sintered with almost no warpage of polymer substrate. [ABSTRACT FROM AUTHOR]

Abstract In this study, the effect of rheological properties of Cu nano/micro (NP/MP)-inks with various amounts of dispersant on the print-ability and sinter-ability for flash light sintering was investigated. The rheological properties such as viscosity, viscoelasticity and thixotropic index of Cu NP/MP-inks were measured using a rheometer. The fabricated Cu NP/MP-inks were printed on polyimide substrate using a screen printing method. The 3D profile of printed Cu NP/MP-ink pattern was measured using surface profiler. In order to sinter the printed Cu NP/MP-inks, flash light sintering technique was employed. The flash light irradiation conditions (pulse power, pulse number, on-time, and off-time) were optimized to obtain the high sintering characteristic of Cu NP/MP-inks. In order to characterize the microstructures and transformation crystal phase of the sintered Cu NP/MP-inks, scanning electron microscopy, focused ion-beam and X-ray diffraction analysis were performed. From the results, the optimal sintered Cu NP/MP-ink film had a 6.16 μΩ·cm resistivity and 5B level of adhesion strength. Highlights • We investigated the effect of dispersant on print-ability and sinter-ability. • 2.6 wt% of dispersant enhanced the printing uniformity and aspect ratio. • Enhanced print-ability improved the flash light sinter-ability. • The sintered Cu film showed the low resistivity and high adhesion strength. [ABSTRACT FROM AUTHOR]

Review: [55 refs. [ABSTRACT FROM AUTHOR]

Accurate and non-destructive measurement of thin layer thickness is critical for ensuring the quality and performance of microelectronic devices. In this study, terahertz time-domain spectroscopy (THz-TDS) was used to measure the combined thickness of a silicon wafer and its deposited thin layer without requiring prior knowledge of the individual material properties. The multi-reflected THz signals from the Si wafer were utilized to accurately calculate the actual thickness and optical properties with a 0.19% error. In the reflection measurement, the variation of optical properties was measured according to the thickness of the deposition through the quartz chamber window. To overcome the intrinsic overlapping of the pulse signal through the quartz chamber window, the detection time of unwanted signals was calculated theoretically, and the inspection conditions such as quartz window thickness and distances between the wafer and window were optimized for accurate measurement with THz-TDS. Based on these results, the accuracy of thickness prediction in the thin layer was confirmed with 4.2% of an error. [ABSTRACT FROM AUTHOR]

Motivation: The identification of T-cell epitopes has many profound translational applications in the areas of transplantation, disease diagnosis, vaccine/therapeutic protein development and personalized immunotherapy. While data-driven methods have been widely used for the prediction of peptide binders with notable successes, the structural modeling of peptide binding to MHC molecules is crucial for understanding the underlying molecular mechanism of the immunological processes. Results: We developed GradDock, a structure-based method for the rapid and accurate modeling of peptide binding to MHC Class I (pMHC-I). GradDock explicitly models diverse unbound peptides in vacuo and inserts them into the MHC-I groove through a steered gradient descent with a topological correction process. The simulation process yields diverse structural conformations including native-like peptides. We completely revised the Rosetta score terms and developed a new ranking function specifically for pMHC-I. Using the diverse peptides, a linear programming approach is applied to find the optimal weights for the individual Rosetta score terms. Our examination revealed that a refinement of the dihedral angles and a modification of the repulsion can dramatically improve the modeling quality. GradDock is five-times faster than a Rosetta-based docking approach for pMHC-I. We also demonstrate that the predictive capability of GradDock with the reweighted Rosetta ranking function is consistently more accurate than the Rosetta-based method with the standard Rosetta score (approximately three-times better for a cross-docking set). [ABSTRACT FROM AUTHOR]

Small GTPases are key signaling nodes that regulate the cellular processes and subcellular events, and their abnormal activities and dysregulations are closely linked with diverse cancers. Here, we report the development of conformation-selective protein binders for a KRAS mutant. The conformation-specific protein binders were selected from a repebody scaffold composed of LRR (Leucine-rich repeat) modules through phage display and modular engineering against constitute active conformation of KRAS. Epitope of the selected binders was mapped to be located close to switch I of KRAS. The conformation-selective protein binders were shown to effectively block the interaction between active KRAS and RAS-binding domain of BRAF, suppressing the KRAS-mediated downstream signaling. • We developed a conformation-selective protein binder against KRAS mutant. • The protein binder effectively inhibits the interaction of KRAS and BRAF. • The protein binder suppresses the KRAS-mediated downstream signaling. [ABSTRACT FROM AUTHOR]