In this study, laser-induced graphene oxide (LIGO) was synthesized through a facile liquid-based process involving the introduction of deionized (DI) water onto polyimide (PI) film and subsequent direct laser irradiation using a CO2 laser (λ = 10.6 μm). The synthesized LIGO was then evaluated as a sensing material for monitoring changes in humidity levels. The synthesis conditions were optimized by precisely controlling the laser scribing speed, leading to the synthesis of LIGO with different structural characteristics and varying oxygen contents. The increased number of oxygen-containing functional groups contributed to the hydrophilic properties of LIGO, resulting in a superior humidity sensing capabilities compared with laser-induced graphene (LIG). The LIGO-based sensors outperformed LIG-based sensors, demonstrating approximately tenfold higher sensing responsivity when detecting changes at each humidity level, along with 1.25 to 1.75 times faster response/recovery times, making LIGO-based sensors more promising for humidity-monitoring applications. This study demonstrated laser ablation in a renewable and natural precursor as an eco-friendly and energy-efficient approach to directly synthesize LIGO with controllable oxidation levels.

Heavy metal ions pollution has become of worldwide critical concern, thus, it is particularly important to monitor it in the environment and food for ensuring human health. In this study, p-phenylenediamine and 2-mercaptothiazoline were used to prepare nitrogen (N) and sulfur (S) co-doped carbon dots (N/SCDs) for fluorescent and colorimetric detection of Cu2+. The fabricated N/SCDs with bright green fluorescence showed excellent optical characteristics and favorable water solubility. In an aqueous system, a significant fluorescence quenching of N/SCDs at 512 nm is obtained in the presence of Cu2+. It also caused a significant colorimetric response with the color of prepared N/SCDs solution changed from colorless to yellow. Under optimal conditions, the analytical results showed that the linear range spanning from 5 to 400 μM, with a detection limit of 0.215 μM in fluorescence and 0.225 μM in colorimetric detection. In addition, N/SCDs displayed high selectivity toward Cu2+. No obvious interference was observed over other metal ions. Furthermore, we have also used N/SCDs to monitor Cu2+ in tap and lake water. The recovery of Cu2+ ranged between 89.6% and 113.1%. Exhibiting remarkable sensitivity and selectivity, the designed sensor offers a promising detection method for Cu2+ detection in the real sample.

In this work, we have designed a novel gas inlet structure for efficient usage of growth and doping precursors. Our previous gas injection configuration is that the gas is mixed to one pipe first, then divided into two pipes, and finally entered the chamber symmetrically above the substrate without a jet nozzle. The distance between gas inlet and substrate is about 14.75 cm. Our new design is to add a new tube in the center of the susceptor, and the distance between the new tube and substrate is about 0.5 cm. In this new design, different gas injection configurations have been planned such that the gas flow in the reactor aids the transport of reaction species toward the sample surface, expecting the utilization efficiency of the precursors being improved in this method. Experiments have shown that a high doping efficiency and fast growth could be achieved concurrently in diamond growth when methane and diborane come from this new inlet, demonstrating a successful implementation of the design to a diamond microwave plasma chemical vapor deposition system. Compared to our previous gas injection configuration, the growth rate increases by 15-fold and the boron concentration increases by ~ 10 times. COMSOL simulation has shown that surface reaction and precursor supply both have a change in determining the growth rate and doping concentration. The current results could be further applied to other dopants for solving the low doping efficiency problems in ultra-wide-band-gap semiconductor materials.

This study prepares highly porous carbon (c-fPI) for lithium-ion battery anode that starts from the synthesis of fluorinated polyimide (fPI) via a step polymerization, followed by carbonization. During the carbonization of fPI, the decomposition of fPI releases gases which are particularly from fluorine-containing moiety (–CF3) of fPI, creating well-defined microporous structure with small graphitic regions and a high specific surface area of 934.35 m2 g− 1. In particular, the graphitic region of c-fPI enables lithiation–delithiation processes and the high surface area can accommodate charges at electrolyte/electrode interface during charge–discharge, both of which contribute electrochemical performances. As a result, c-fPI shows high specific capacity of 248 mAh g− 1 at 25 mA g− 1, good rate-retention performance, and considerable cycle stability for at least 300 charge–discharge cycles. The concept of using a polymeric precursor (fPI), capable of forming considerable pores during carbonization is suitable for the use in various applications, particularly in energy storage systems, advancing materials science and energy technologies.

The lithium-ion battery has been utilized in various fields including energy storage system, portable electronic devices and electric vehicles due to their high energy and power densities, low self-discharge, and long cycle-life performances. However, despite of various research on electrode materials, there is a lack of research on developing of binder to replace conventional polymer-based binding materials. In this work, petroleum pitch (MP-50)/polymer (polyurethane, PU) composite binder for lithium-ion battery has fabricated not only to use as a binding material, but also to re-place conventional polymer-based binder. The MP-50/PU composite binder has also prepared to various ratios between petroleum pitch and polymer to optimize the physical and electro-chemical performance of the lithium-ion battery based on the MP-50/PU composite binder. The physical and electrochemical performances of the MP-50/PU composite binder-based lithium-ion battery were evaluated using a universal testing machine (UTM), charge/discharge test. As a result, lithium-ion battery based on the MP-50/PU composite (5:5, mass ratio) binder showed optimized performances with 1.53 gf mm− 1 of adhesion strength, 341 mAh g− 1 of specific discharge capacity and 99.5% of ICE value.

The interlacing technique has a long history of use as a means of creative expression and persists in modern society to satisfy the individual pursuit of pastimes. This method has the developmental potential to create new trends in the future. Interlacing techniques (e.g., basketry, plaiting, braiding, and knotting) are closely related to plastic arts fields, architecture, art, and industrial design where the various interlacing practices are applied. This research uses case analysis to study the types of expression found in the formative art field wherein the interlacing technique is applied. Results reveal several expressions, including optical illusion visual type, relief surface type, porous perspective type, and object borrowing type, all of which appeared in fashion bags. The aesthetic formativeness, which appeared in the fashion bags that applied interlacing techniques, was then classified according to geometric formative beauty in a process based on rules and order. Nature-friendly formative beauty reflecting handicraft locality and omnidirectional formative beauty by disordered deconstruction and heterogeneous combination were determined. The use of interlacing techniques that show creative, unique combinations and variations is expected to inspire the development and application of bag design that suits individual and original modern fashion trends. One limitation of this thesis is that it only studied cases appearing in modern fashion bags.

This study investigates the negative perceptions (veganphobia) held by consumers toward vegan diets and fashion and aims to foster a genuine acceptance of ethical veganism in consumption. The textual data web-crawled Korean online posts, including news articles, blogs, forums, and tweets, containing keywords such as “contradiction,” “dilemma,” “conflict,” “issues,” “vegan food” and “vegan fashion” from 2013 to 2021. Data analysis was conducted through text mining, network analysis, and clustering analysis using Python and NodeXL programs. The analysis revealed distinct negative perceptions regarding vegan food. Key issues included the perception of hypocrisy among vegetarians, associations with specific political leanings, conflicts between environmental and animal rights, and contradictions between views on companion animals and livestock. Regarding the vegan fashion industry, the eco-friendliness of material selection and design processes were seen as the pivotal factors shaping negative attitudes. Furthermore, the study identified a shared negative perception regarding vegan food and vegan fashion. This negativity was characterized by confusion and conflicts between animal and environmental rights, biased perceptions linked to specific political affiliations, perceived self-righteousness among vegetarians, and general discomfort toward them. These factors collectively contributed to a broader negative perception of vegan consumption. In conclusion, this study is significant in understanding the complex perceptions and attitudes that consumers hold toward vegan food and fashion. The insights gained from this research can aid in the design of more effective campaign strategies aimed at promoting vegan consumerism, ultimately contributing to a more widespread acceptance of ethical veganism in society.

대한민국의 해양레저산업은 세일링을 비롯한 다양한 형태의 수상레저 활동이 증가하는 추세에 따라 세계적으로 신흥시장으로 주목받고 있어 세일링 요트에 대한 수요가 높아질 것으로 추정된다. 이에 따라 2022년 현재 우리나라 요트 문화의 부흥과 보급을 위해 해 양수산부의 지원을 받아 28피트 세일 요트의 설계 및 개발이 착수되었다. 개발 초기 단계에서의 성능을 확인하고 이를 통해 설계 인자를 결정하기 위하여 속도 예측 프로그램 VPP(Velocity Prediction Program) 분석이 수행되었다. 본 연구에서 사용된 소프트웨어는 University of Southampton의 Wolfson Unit社의 WinDesign으로, 속도 예측에 적용된 유체역학적 데이터 모델은 Wolfson Unit社자체적인 조선공학 및 요트 연구 분야에서 수십 년간의 예인 수조 시험 데이터를 회귀 분석한 방법으로 대부분의 현대식 요트에 대해 신뢰할 수 있는 추정치를 제공 하는 것으로 여겨진다. 하지만 예인 수조 시험이나 CFD 수치해석 등을 통한 실험 결과적인 유체역학적 정보가 없기 때문에 소프트웨어에 서 제공하는 유체역학적 데이터 회귀 모델의 저항 값은 다소 차이가 있을 것으로 예상된다. 또한, 아직 미완료된 무게 중심 추정에 의한 VCG 값은 속도 예측의 입력 변수 중 하나로, 성능 결과에 어느 정도 영향을 미칠 수 있을 것으로 예상된다. 개발 세일 요트에 대한 최적 화된 보트 속도는 풍속 4, 8, 12, 16 및 20노트의 집세일 조합(최대 120° TWA) 및 스피네커 세일 조합(80° TWA부터) 모두에서 확인되었으 며, VPP를 활용하여 얻어진 최적화된 속도는 국제적으로 유사한 등급의 요트와 견줄수 있는 수준으로 확인되었다.

The aggressive scaling of dynamic random-access memory capacitors has increased the need to maintain high capacitance despite the limited physical thickness of electrodes and dielectrics. This makes it essential to use high-k dielectric materials. TiO2 has a large dielectric constant, ranging from 30~75 in the anatase phase to 90~170 in rutile phase. However, it has significant leakage current due to low energy barriers for electron conduction, which is a critical drawback. Suppressing the leakage current while scaling to achieve an equivalent oxide thickness (EOT) below 0.5 nm is necessary to control the influence of interlayers on capacitor performance. For this, Pt and Ru, with their high work function, can be used instead of a conventional TiN substrate to increase the Schottky barrier height. Additionally, forming rutile-TiO2 on RuO2 with excellent lattice compatibility by epitaxial growth can minimize leakage current. Furthermore, plasma-enhanced atomic layer deposition (PEALD) can be used to deposit a uniform thin film with high density and low defects at low temperatures, to reduce the impact of interfacial reactions on electrical properties at high temperatures. In this study, TiO2 was deposited using PEALD, using substrates of Pt and Ru treated with rapid thermal annealing at 500 and 600 °C, to compare structural, chemical, and electrical characteristics with reference to a TiN substrate. As a result, leakage current was suppressed to around 10-6 A/cm2 at 1 V, and an EOT at the 0.5 nm level was achieved.

In this work, we investigated the photo-degradation performance of MnO2-SiC fiber-TiO2 (MnO2-SiC-TiO2) ternary nanocomposite according to visible light excitation utilizing methylene blue (MB) and methyl orange (MO) as standard dyes. The photocatalytic physicochemical characteristics of this ternary nanocomposite were described by X-ray diffraction (XRD), scanning electron microscopy (SEM), tunneling electron microscopy (TEM), ultraviolet-visible (UV-vis), diffuse reflectance spectroscopy (DRS), electrochemical impedance spectroscopy (EIS), photocurrent and cyclic voltammogram (CV) test. Photolysis studies of the synthesized MnO2-SiC-TiO2 composite were conducted using standard dyes of MB and MO under UV light irradiation. The experiments revealed that the MnO2-SiC-TiO2 exhibits the greatest photocatalytic dye degradation performance of around 20 % with MB, and of around 10 % with MO, respectively, within 120 min. Furthermore, MnO2-SiC-TiO2 showed good stability against photocatalytic degradation. The photocatalytic efficiency of the nanocomposite was indicated by the adequate photocatalytic reaction process. These research results show the practical application potential of SiC fibers and the performance of a photocatalyst composite that combines these fibers with metal oxides.

High-entropy alloys (HEAs) have been reported to have better properties than conventional materials; however, they are more expensive due to the high cost of their main components. Therefore, research is needed to reduce manufacturing costs. In this study, CoCrFeMnNi HEAs were prepared using metal injection molding (MIM), which is a powder metallurgy process that involves less material waste than machining process. Although the MIM-processed samples were in the face-centered cubic (FCC) phase, porosity remained after sintering at 1200°C, 1250°C, and 1275°C. In this study, the hot isostatic pressing (HIP) process, which considers both temperature (1150°C) and pressure (150 MPa), was adopted to improve the quality of the MIM samples. Although the hardness of the HIP-treated samples decreased slightly and the Mn composition was significantly reduced, the process effectively eliminated many pores that remained after the 1275°C MIM process. The HIP process can improve the quality of the alloy.

InP quantum dots (QDs) have attracted researchers’ interest due to their applicability in quantum dot light-emitting displays (QLED) or biomarkers for detecting cancers or viruses. The surface or interface control of InP QD core/ shell has substantially increased quantum efficiency, with a quantum yield of 100% reached by introducing HF to inhibit oxide generation. In this study, we focused on the control of bandgap energy of quantum dots by changing the Zn/(In+Zn) ratio in the In(Zn)P core. Zinc incorporation can change the photoluminescent light colors of green, yellow, orange, and red. Diluting a solution of as-synthesized QDs by more than 100 times did not show any quenching effects by the Förster resonance energy transfer phenomenon between neighboring QDs.

Additive Manufacturing (AM) is a process that fabricates products by manufacturing materials according to a three-dimensional model. It has recently gained attention due to its environmental advantages, including reduced energy consumption and high material utilization rates. However, controlling defects such as melting issues and residual stress, which can occur during metal additive manufacturing, poses a challenge. The trial-and-error verification of these defects is both time-consuming and costly. Consequently, efforts have been made to develop phenomenological models that understand the influence of process variables on defects, and mechanical/ electrical/thermal properties of geometrically complex products. This paper introduces modeling techniques that can simulate the powder additive manufacturing process. The focus is on representative metal additive manufacturing processes such as Powder Bed Fusion (PBF), Direct Energy Deposition (DED), and Binder Jetting (BJ) method. To calculate thermal-stress history and the resulting deformations, modeling techniques based on Finite Element Method (FEM) are generally utilized. For simulating the movements and packing behavior of powders during powder classification, modeling techniques based on Discrete Element Method (DEM) are employed. Additionally, to simulate sintering and microstructural changes, techniques such as Monte Carlo (MC), Molecular Dynamics (MD), and Phase Field Modeling (PFM) are predominantly used.

Because most spent nuclear fuel storage casks have been designed for low burnup fuel, a safety-significant high burnup dry storage cask must be developed for nuclear facilities in Korea to store the increasing high burnup and damaged fuels. More than 20% of fuels generated by PWRs comprise high burnup fuels. This study conducted a structural safety evaluation of the preliminary designs for a high burnup storage cask with 21 spent nuclear fuels and evaluated feasible loading conditions under normal, off-normal, and accident conditions. Two types of metal and concrete storage casks were used in the evaluation. Structural integrity was assessed by comparing load combinations and stress intensity limits under each condition. Evaluation results showed that the storage cask had secured structural integrity as it satisfied the stress intensity limit under normal, off-normal, and accident conditions. These results can be used as baseline data for the detailed design of high burnup storage casks.

Pseudolithoderma subextensum is a crustose brown algal species in the family Lithodermataceae and order Sphacelariales. This species is distributed in several regions across the world including, Europe, Western Atlantic, Middle East and Asia (Hong Kong and Japan). Recent floristic surveys along the Korean coastal shores have revealed new records of encrusting brown algae. In this study, we report P. subextensum as a new record from Korea. Morpho-anatomical and molecular studies on Ralfsia-like specimens from Korea identified some of them as P. subextensum. Pseudolithoderma subextensum is characterized by dark chestnut brown crust with a hypothallial basal layer and erect perithallial filaments, tufts of hairs occasionally arising from the basal layer, several discoid shaped chloroplasts per cell, plurangia arising terminally on erect filaments and without sterile cells, and unangia arising terminally on erect filaments, elongated cylindrical and without paraphyses. Phylogenetic analyses based on COI-5P (545bp) reveal that P. subextensum are nested within Lithodermataceae and forms the same clade with P. roscoffense. The genetic divergences for COI-5P between them is 24.5%.

소 유방염 관련 대장균(BMEC)은 생산되는 우유의 양과 품질을 변화시키고 도태율을 높임으로써 전 세계 낙농 산 업에 심각한 재정적 손실을 초래할 수 있는 주요 원인 물 질로 간주된다. 연구자, 수의사, 농부가 가장 효과적인 치 료법과 진단 기술을 이해하고 결정하는 것은 젖소 유방염 을 극복하는데 중요하다. 특히 무증상 혹은 준임상형 유 방염의 경우, 소는 뚜렷한 증상을 보이지 않고, 장기간에 걸쳐 겉보기에 정상적인 우유를 계속 분비하여 원인 병원 체인 대장균이 무리 내에서 감염을 퍼뜨릴 수 있다. 유방 염 예방을 위해서는, 병원균의 유방 내 침입, 감염 확립, 유방의 염증의 3단계 병인 과정에 대한 이해가 필수적이 다. 지금까지 대장균 유방염의 임상적 중증도에 기여하는 독성 인자와 병원성 사이에 명확한 상관관계가 발견되지 않았다. 다제내성 대장균과 새로운 내성 기전의 진화는 유 방염 치료에 항생제를 광범위하게 사용하고 있기 때문에 문제시 되고 있는 실정이다. 따라서 BMEC 치료의 효능 을 향상시키기 위해서는 대체제 발굴이 중요하다. 지난 30 년 동안 소 유방염의 역학 조사를 위해 다양한 유전자형 분석 기술이 사용되었다. 이러한 연구는 BMEC 계통 간 의 진화 관련성 뿐 아니라 기원, 전염 경로, 개체군 구조 에 대한 이해를 크게 향상시켰다. 따라서 본 리뷰에서는 BMEC의 전반적 개요를 제공하여 병인, 유전적 관계, 발 병 기전, 관리 및 질병 통제를 위한 새로운 치료 옵션에 대한 통찰력을 제공하고자 한다.

Vertical takeoff and landing (VTOL) is a core feature of unmanned aerial vehicles (UAVs), which are commonly referred to as drones. In emerging smart logistics, drones are expected to play an increasingly important role as mobile platforms. Therefore, research on last-mile delivery using drones is on the rise. There is a growing trend toward providing drone delivery services, particularly among retailers that handle small and lightweight items. However, there is still a lack of research on a structural definition of the VTOL drone flight model for multi-point delivery service. This paper describes a VTOL drone flight route structure for a multi-drone delivery service using rotary-wing type VTOL drones. First, we briefly explore the factors to be considered when providing drone delivery services. Second, a VTOL drone flight route model is introduced using the idea of the nested graph. Based on the proposed model, we describe various time-related attributes for delivery services using drones and present corresponding calculation methods. Additionally, as an application of the drone route model and the time attributes, we comprehensively describe a simple example of the multi-drone delivery for first-come-first-served (FCFS) services.

Teaching is often regarded as a profession with a high probability of job burnout. Research has shown a close relationship between teachers’ motivation and their burnout, but it has not been closely explored among EFL (English as a foreign language) teachers in Chinese contexts. Considering the large number of college English teachers in Chinese universities and recent changes in their role, the study explores the relationship between their motivation and burnout, as well as the factors that affect teacher burnout among Chinese college English teachers. For this purpose, a total of 261 college English teachers from ten Chinese universities participated in the survey. Among them, 68 teachers submitted their narratives on teacher burnout using the narrative frame. The results showed that high mastery and relational goals and a low level of work avoidance goals contributed to higher motivation and less teacher burnout. The demand for research, lack of autonomy, and guanxi-based practices influenced Chinese teachers’ burnout. The results show that teacher burnout is highly context-dependent and affected by the organizational structure and cultural practices. An organizational support needs to be provided for teachers to maintain their mastery goal orientations and increase their autonomy as professional teachers.

Inflammatory bowel disease (IBD) is a chronic condition characterized by continuous inflammation of the gastrointestinal tract that varies in intensity over time. IBD is caused by several factors including aberrant gut flora, immunological dysregulation, altered environmental conditions, and genetic variations. However, the pathogenesis of IBD remains unclear. Studies have indicated that an imbalance between T helper 17 (Th17) and regulatory T (Treg) cells contributes significantly to the development of IBD. Intestinal Tregs suppress inflammation and are critical for maintaining tissue homeostasis. Th17 cells are known to play an important role in the development and pathogenesis of IBD and provide non-inflammatory support for the integrity of the intestinal barrier against bacterial and fungal infections. Therefore, the Th17/Treg cell balance is crucial in the pathogenesis of IBD and gut integrity. The microenvironment of the intestinal mucosal immunity is regulated by the secretion of cytokines associated with Th17 cells and Tregs. Several studies have indicated that the gut bacteria contribute to the control of the immune milieu and play a key role in the regulation of Th17 cell development. Intestinal bacteria and cytokines control Th17 cell development. Th17 cells secrete cytokines that regulate the immune microenvironment in the gut mucosa. This review provides an overview of Th17 cells and examines the strategies for treating patients with IBD using Th17 cell-targeted drugs.

Diatoms, which are reported to have over 18,000 species worldwide and approximately 2,400 species in Korea, can be found in various environments including freshwater, seawater, and wetlands. They are particularly valuable for understanding global environmental changes throughout history due to their ability to maintain their shape for extended periods of time. Instead of collecting floating diatoms using nets, low-layer substrates such as gravel and leaves, as well as sedimentary surface layers, were gathered in order to identify attached diatom species. This is because attached diatoms demonstrate higher species diversity compared to floating diatoms. In this study, seven previously unrecorded diatoms were discovered in various domestic freshwater environments. Two species were found in reservoirs (Eunotia yanomami, Gomphonella pseudookunoi), two in parasitic cones (Eunotia carverenensis, Luticola minor), two in rivers (Cavinula maculata and Prestauroneis integra), and one (Surirella brebissonii var. kuetzingii) in a lagoon. The shapes, structures, and morphological characteristics of each diatom were identified using electron microscopy.