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        검색결과 5,342

        1.
        2025.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the impact of various soil environmental factors on the growth and yield of Actinidia arguta (A. arguta) in Suwon, South Korea. By employing Pearson correlation analysis, we explored the relationships between soil properties such as pH, electrical conductivity (EC), organic matter content, available phosphorus, available silicon, soil moisture, and soil temperature with A. arguta growth and yield. The results revealed that soil temperature and EC had the strongest positive correlations with A. arguta growth, while organic matter content exhibited a strong negative correlation with fruit yield. The high levels of available phosphorus emerged as a potential adverse factor affecting yield. These findings suggest that managing soil temperature, EC, and phosphorus levels is crucial for optimizing A. arguta productivity. Future research should focus on fine-tuning phosphorus levels and further investigating the interactions between soil factors to enhance A. arguta yield and sustainability.
        4,300원
        2.
        2025.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 아민화 셀룰로오스 나노섬유(CNF)를 시멘트 복합체에 적용하여 기계적 및 미세구조적 성능 향상을 도모하고자 하였다. CNF는 (3-aminopropyl) triethoxysilane (APTES)를 활용해 화학적으로 개질하였으며, 이는 시멘트 수화 생성물과의 계면 결합력 및 분산성을 향상시키기 위한 목적이다. 표면 개질의 성공 여부는 주사전자현미경(SEM)과 X-선 회절 분석(XRD)을 통해 확인 하였다. 다양한 함량의 개질 및 비개질 CNF를 혼입한 모르타르를 제작하여 압축강도 및 휨강도를 평가하였다. 그 결과, 아민화 CNF는 0.2% 혼입 시 압축강도 향상 효과가 가장 두드러졌으며, 휨강도는 0.3%에서 가장 우수한 성능을 나타내었다. 미세구조 분석을 통해, 아민화 CNF가 시멘트 수화물과의 상호작용을 통해 내부 조직을 치밀하게 형성하고 공극률을 저감시키는 것으로 확인되었다. 본 연구는 화학적으로 개질된 CNF가 지속가능하고 고성능인 시멘트 복합재료 개발에 있어 유효한 기능성 첨가제로 활용될 수 있음을 시사한다.
        4,000원
        3.
        2025.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        전 세계 이산화탄소 배출량이 지속적으로 증가하면서, 환경 개선 및 탄소 격리를 위한 다양한 연구들이 진행되고 있 다. 건설 산업에서도 탄소를 줄이기 위한 연구로 바이오차를 건설 자재에 사용하여, 탄소 격리를 위한 방법으로 진행되고 있다. 바이오차는 바이오매스를 열분해하여 생성한 숯으로, 높은 탄소 함량과 다공성 구조가 특징이며, 탄소 격리를 위한 물질로 떠오 르고 있다. 본 연구에서는 시멘트 사용량을 줄이고 바이오차를 혼입한 콘크리트를 건설 자재로써 가능성을 확인하고자 하였다. 이를 위해 시멘트의 일부를 바이오차로 치환하여 혼입한 콘크리트의 역학적 특성(슬럼프, 공기량, 압축강도)과 질량 기반 특성 (흡수율, 밀도, 공극률)을 평가하였다. 바이오차의 시멘트 치환율은 0%, 5%, 10%로 설정하였다. 바이오차의 수분 흡수 및 보유 력에 따라 바이오차의 시멘트 치환율이 증가할수록 슬럼프는 감소하였다. 바이오차의 다공성 구조를 SEM 실험으로 확인하였으 며, 이에 따라 콘크리트에서의 공극 형성으로 바이오차의 시멘트 치환율이 증가할수록 공기량과 흡수율이 증가하였다. 바이오차 의 시멘트 치환율 5%에서 압축강도와 비강도가 가장 높은 값으로 나타났으며, 탄소 격리를 위한 방법으로 건설 자재 활용의 가능성을 확인하였다.
        4,000원
        4.
        2025.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Sodium sulfate, as a commonly used early strengthening agent, has been widely used in different areas. Because of its sulfonic acid group, sodium sulfate is also used as a cement capillary crystal waterproof material. However, temperature has a significant effect on concrete mixed with sodium sulfate. The effect of sodium sulfate on the early hydration rate at different temperatures was studied by conducting a time and hydration thermal analysis. The effects of sodium sulfate on the mechanical properties of concrete at different temperatures were studied through compressive strength experiments. Impermeability at different temperatures was studied by testing resistance to chloride ion penetration and resistance to water penetration. The effect of resistance to sulfate attack was also experimentally. The hydration products were analyzed by electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The experimental results showed that at low temperature, sodium sulfate can accelerate the early hydration reaction rate, and the effect becomes weaker with increasing temperature. At low temperature, the addition of sodium sulfate can effectively improve the degree of hydration, and enhance the permeability resistance and ion erosion resistance of the matrix.
        4,300원
        5.
        2025.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Eu-doped SrAl2O4 is a promising thermoluminescent and mechanoluminescent material with high brightness and stability, making it suitable for various luminescent devices. In this study, SrAl2O4:Eu was synthesized using a solid-state reaction method, and the effects of reducing atmosphere and high-temperature synthesis conditions on its luminescence properties were systematically analyzed. The luminescence characteristics of SrAl2O4:Eu were found to be highly sensitive to synthesis temperature, atmosphere, and Eu doping concentration, and optimal conditions were determined. A comparison of SrAl2O4:Eu synthesized at 1,300 °C under air and reducing atmospheres revealed that the reducing atmosphere plays a critical role in stabilizing Eu2+ ions, forming a single-phase SrAl2O4, and establishing luminescence centers. Notably, SrAl2O4:Eu synthesized at 1,600 °C in a reducing atmosphere achieved a photoluminescence quantum yield (PLQY) of 43 % and a maximum luminance of 2,030 Cd/m2, showing significant improvement in luminescence efficiency compared to samples synthesized at 1,300 °C. When Eu doping concentrations were adjusted from 1 % to 20 %, the highest luminescence performance was observed at 10 % doping, while excessive doping (20 %) increased non-radiative recombination pathways, and no further improvement in luminescence efficiency was observed. X-ray Diffraction (XRD) and Photoluminescence (PL) analyses elucidated the effects of synthesis conditions on the structural stability and luminescence properties of SrAl2O4:Eu, and the optimal reducing atmosphere and high-temperature synthesis conditions are proposed. This study provides a synthesis strategy for enhancing the luminescence properties of Eu-doped SrAl2O4 and lays the groundwork for the development of highperformance thermoluminescent and mechanoluminescent materials.
        4,000원
        6.
        2025.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, the changes of the uniaxial tensile mechanical properties of the ETFE film after the uniaxial pre-stretching stress exceeds the first yield stress and the second yield stress was investigated. The ETFE film is first pre-stretched uniaxially along the MD direction or TD direction. After the pre-stretching loading stress exceeds the first yield stress and the second yield stress to cause the ETFE film to undergo plastic deformation, rectangular uniaxial tensile specimens are cut from the pre-stretched film along the MD direction and the TD direction for subsequent uniaxial tensile tests, thereby determining the uniaxial tensile mechanical property parameters of the ETFE film after uniaxial pre-stretching, including yield stress, tensile strength and elongation at break, and discussing the changes in its uniaxial tensile mechanical properties.
        4,000원
        7.
        2025.03 구독 인증기관·개인회원 무료
        아스팔트는 아스팔텐(Asphaltene)과 레진(Resin), 포화분(Saturates), 방향족화합물(Aromatics)로 구성되어 있고, 레 진, 포화분, 방향족화합물의 혼합물을 말텐(Malten)이라 하며, 아스팔텐이 말텐에 분산되어 있는 형태를 가진 콜로이 드 상태의 혼합물이다. 아스팔트를 조성하고 있는 조성물의 조성비, 온도 변화에 따라 결합 상태 및 내부 구조가 변 화하고, 아스팔트의 물성과 상태 등에 영향을 주어, 아스팔트 혼합물이 고온에서 소성변형(Rutting), 저온에서의 균열 (Crack)등의 파손에 영향을 미친다. 이러한 아스팔트 혼합물의 파손을 방지하기 위하여 SBS(Styrene-Butadiene- Styrene Block Copolymer)와 같은 폴리머를 혼합하여 아스팔트의 점탄성을 향상시키고, 오일류와 같은 첨가제를 활 용하여 저온에서 탄성과 유연성을 증가시킨다. 이와 같이 고온과 저온의 성능을 용도에 맞게 개선한 아스팔트를 개질 아스팔트(Polymer Modified Asphalt)라고 하며, 도로의 품질 및 내구성 향상을 위해 개질아스팔트 포장의 수요가 점 차 증가하는 추세로 아스팔트혼합물의 성능 향상을 위해 오일류를 활용한 폴리머 아스팔트의 물성 변화에 대한 연구 가 필요하다고 판단된다.
        8.
        2025.03 구독 인증기관·개인회원 무료
        지표면의 불투수층 증가는 빗물의 토양침투를 감소시키고 우수 침투를 제한하여 표면 유출에 의한 피해를 야기하였으며, 홍수 도달시간이 단축됨에 따라 첨두 유출량이 증가하므로 배수 시스템의 용량 부족 및 침수 피해를 초래하였다. 이에, 환 경부에서는 생태면적률 제도를 도입하여 저영향 개발(Low Impact Development, LID) 기술 도입의 활성화를 도모하고 있 으며, 이 중 투수블록포장이 약 40%를 차지하고 있다. 그러나, 주로 표층 콘크리트 블록의 품질기준 마련 및 성능 개선 연 구가 수행되었으며, 하부구조의 우수 침투 능력을 평가한 연구는 미흡한 실정이다. 특히, 투수성능이 증가할수록 구조적 지 지력이 감소하므로 내구성을 만족하는 범위에서 투수계수를 충족하는 입도분포를 실험적 연구를 통해 제시할 필요가 있다. 따라서, 시험체 내 수두를 일정하게 유지시켜 일정 시간동안 유입되는 하부 유출량을 측정하였으며, 같은 입도분포일 때 잔 골재 함량이 증가할수록 투수계수가 감소하는 것으로 나타났다. 이처럼 골재 입도분포 특성에 의해 물이 하부로 침투되는 유출량이 상이하므로 정량적인 평가를 통해 투수계수를 만족하는 적정 입도 기준의 제시가 가능할 것으로 판단된다.
        9.
        2025.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As global greenhouse gas reduction regulations are strengthened and the demand for eco-friendly energy increases, renewable energies, including offshore wind power, are growing rapidly. Unlike onshore wind power generation, offshore wind power is located in the ocean. As a result, the offshore wind power substructure is exposed to low temperatures, corrosion, and continuous fatigue loads. Therefore, selecting appropriate materials and welding techniques is crucial for durability. In this study, FCAW welding was performed on S355ML steel (EN10025) for offshore wind power applications. After the welding process, the mechanical properties of the welded joint were evaluated through tensile, low-temperature impact, and hardness tests to assess the welding condition. The study revealed that the tensile and yield strength of the welded joint were superior to those of the base material. Additionally, the impact strength at low temperatures was confirmed to exceed the standard.
        4,000원
        10.
        2025.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 일반홍삼(70 °Brix)과 발효홍삼(45 °Brix)에 대한 항산화 성분 분석 및 항산화 효능 측정을 위한 적정 분석시료 함량을 설정하고, 홍삼의 발효에 따른 항산화성의 변화를 조사하였다. 홍삼의 flavonoid 및 phenolics 함량 측정은 일반홍삼과 발효홍삼 각각 농축액 시료 3 g을 증류수로 100배 희석하여 측정용 시료 1 mL 당 홍삼농축액 20-30 mg을 사용하는 것이 시료 채취와 낮은 흡광도에 의한 오차도 줄일 수 있었다. 홍삼의 항산화성 측정으로 홍삼 시료 mg 당 DPPH에 대한 전자공여능 및 ABTS radical 소거능은 일반홍삼과 발효홍삼 모두 농축액 분석시료 20-30 mg/mL에서 가장 안정적이었다. 세포에서의 항산화 효능으 로 ROS의 소거능은 일반홍삼과 발효홍삼 모두 농축액 분석시료 20 mg/mL 전후에서 ROS radical 소거능의 차이가 가장 컸으며 분석에 적합한 농도였다. Flavonoid 함량과 ROS radical 소거능은 발효홍삼 농축액이 일반홍삼 농축액보다 더 높았으나, radical 소거능은 유사하였다. 같은 농도의 일반홍삼과 발효홍삼을 비교할 경우 발효홍삼이 일반홍삼보다 항산화 효과가 더 높았다. 일반홍삼 및 발효홍삼의 항산화성 물질의 정량 및 그 항산화 효능을 측정하기 위해서는 농축액의 농도 차이에도 불구하고 일반홍삼과 발효홍삼 각각 농축액 2-3 g을 채취하여 100배 희석하여 분석 시료로 사용하는 것이 적합하였다.
        4,200원
        11.
        2025.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Galaxy evolution studies require the measurement of the physical properties of galaxies at different redshifts. In this work, we build supervised machine learning models to predict the redshift and physical properties (gas-phase metallicity, stellar mass, and star formation rate) of star-forming galaxies from the broad-band and medium-band photometry covering optical to near-infrared wavelengths, and present an evaluation of the model performance. Using 55 magnitudes and colors as input features, the optimized model can predict the galaxy redshift with an accuracy of σ(Δz/1+z) = 0.008 for a redshift range of z < 0.4. The gas-phase metallicity [12 + log(O/H)], stellar mass [log(Mstar)], and star formation rate [log(SFR)] can be predicted with the accuracies of σNMAD = 0.081, 0.068, and 0.19 dex, respectively. When magnitude errors are included, the scatter in the predicted values increases, and the range of predicted values decreases, leading to biased predictions. Near-infrared magnitudes and colors (H, K, and H −K), along with optical colors in the blue wavelengths (m425–m450), are found to play important roles in the parameter prediction. Additionally, the number of input features is critical for ensuring good performance of the machine learning model. These results align with the underlying scaling relations between physical parameters for star-forming galaxies, demonstrating the potential of using medium-band surveys to study galaxy scaling relations with large sample of galaxies.
        4,200원
        12.
        2025.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A cold roll-bonding (CRB) process is applied to fabricate an AA1050/AA5052 layered sheet. In the process, commercial AA1050 and AA5052 sheets of 1 mm thickness, 40 mm width and 300 mm length are stacked onto each other, and then reduced to a thickness of 0.5 mm through a 2-pass cold rolling process without lubricant. The roll-bonded AA1050/AA5052 layered sheet is then annealed for 1 h at various temperatures from 200 to 400 °C. The specimens annealed at temperatures below 250 °C showed a typical deformation structure in which the grains were elongated along the rolling direction. However, the specimens annealed at temperatures higher than 300 °C exhibited recrystallization structures in both the AA1050 and AA5052 regions. All the roll-bonded and subsequently annealed specimens showed an inhomogeneous distribution of hardness in the thickness direction, in which the hardness in the AA5052 regions was higher than that in the AA1050 regions. As the annealing temperature increased, the tensile and yield strengths decreased and the elongation increased gradually. The mechanical properties were compared to those of commercial AA1050 and AA5052 materials and CRBed AA5052-2L materials from a previous study.
        4,000원
        13.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Iron oxide (ε-Fe2O3) is emerging as a promising electromagnetic material due to its unique magnetic and electronic properties. This review focuses on the intrinsic properties of ε-Fe2O3, particularly its high coercivity, comparable to that of rare-earth magnets, which is attributed to its significant magnetic anisotropy. These properties render it highly suitable for applications in millimeter wave absorption and high-density magnetic storage media. Furthermore, its semiconducting behavior offers potential applications in photocatalytic hydrogen production. The review also explores various synthesis methods for fabricating ε-Fe2O3 as nanoparticles or thin films, emphasizing the optimization of purity and stability. By exploring and harnessing the properties of ε-Fe2O3, this study aims to contribute to the advancement of next-generation electromagnetic materials with potential applications in 6G wireless telecommunications, spintronics, high-density data storage, and energy technologies.
        4,800원
        14.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 본 연구의 목적은 근적외선 차단 안경렌즈의 광학적 특성을 분석하고, 근적외선 차단 안경렌즈를 이해하는 데 도움이 되는 자료를 제시하는 것이다. 방법 : 근적외선 차단 안경렌즈(소재 방법 및 코팅 방법)와 일반 렌즈를 시감투과율 0, 2, 3등급( 10종)으로 구 분하여, 250∼1,400 nm의 분광 투과율을 측정하였고, 청색광 및 근적외선 차단율을 산출하였다. 또한, 주행 중 교통 신호등 감지에 대한 적합도를 확인하기 위해 상대 시각 감쇄 계수(Q)를 분석하였다. 결과 : 시감투과율 분류 0, 2, 3등급에서 투과율은 일반렌즈가 근적외선 차단 안경렌즈보다 높았다(p<0.05). 410∼470 nm 영역에서 근적외선 차단 안경렌즈와 일반렌즈의 청색광 차단율은 차이가 없었고(p>0.05), 470 nm ∼500 nm 영역의 0, 2, 3등급은 차이가 있었다(p<0.05). 근적외선(780 nm∼1,400 nm) 영역의 차단율은 0, 2, 3등급에서 근적외선 차단 안경렌즈가 일반 렌즈에 비해 높았고(p<0.05), 근적외선 차단 성능이 더 우수함을 입증 하였다. 근적외선의 침투로 인해 영향을 받는 눈과 피부 영역에서 근적외선 차단 안경렌즈는 일반 렌즈보다 차단율 이 높았고(p<0.05), 일반렌즈 보다 근적외선의 침투를 감소시킬 수 있을 것이다. 동일한 차단율의 0등급 근적외선 차단 안경렌즈는 소재 방식보다 코팅방식 차단 렌즈의 차단 성능이 좋았다(p<0.05). 시감투과율 0, 2, 3등급에서 근적외선 차단 안경렌즈는 주행 중 교통 신호등 감지를 위한 색 구별에 적합했다. 결론 : 시감투과율 분류 0, 2, 3등급에서 근적외선 차단 안경렌즈는 일반 렌즈에 비해 높은 차단율을 나타내어 그 성능을 입증하였고, 근적외선의 영향을 받는 눈과 피부의 파장 영역에서도 근적외선의 침투를 감소시킬 수 있을 것이다. 결과적으로, 근적외선 차단 안경렌즈의 광학적 특성에 대해 이해하는데 도움이 되는 자료를 제공하였다.
        5,400원
        15.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        For centuries, humans have leveraged the health-promoting properties of plants for our well-being. While research has been conducted on numerous medicinal plants, the specific benefits of many species remain underexplored. Eupatorium Japonicum (EJ), a member of the Asteraceae family, has historically been consumed in Japan, South Korea, China, and Vietnam for its traditional use in soothing digestive issues. This study aimed to explore the radical scavenging and antiinflammatory efficacy of EJ extract using RAW 264.7 cells. The radical-scavenging effects were assessed using the DPPH and ABTS assays, where an anti-oxidative molecule in the test sample will react with a stable free radical in DPPH and ABTS causing discoloration. The anti-inflammatory efficacy was assessed using the nitric oxide (NO) assay in LPS-induced RAW 264.7 cells, where the amount of NO produced in response to infection was measured using Griess reagent. Reversetranscriptase polymerase chain reaction (RT-PCR) and real-time PCR were executed to confirm the anti-inflammatory activity by measuring the RNA levels of pro-inflammatory cytokines. The DPPH and ABTS assays revealed that EJ extract decreased oxidation in a concentration-dependent manner (7.8-1,000 μg/mL) compared to ascorbic acid and Trolox respectively. EJ extract significantly reduced NO production concentration independently. Furthermore, EJ extract showed no cytotoxic effects as determined through the MTT assay. RT-PCR and real-time PCR analyses revealed inhibition of mRNA expression of pro-inflammatory cytokines (iNOS, COX-2, TNF-α, and IL-6). Western blotting demonstrated EJ’s anti-inflammatory activity by reducing protein levels of iNOS, COX-2, TNF-α, and IL-6. These findings suggest that EJ extract exhibits anti-inflammatory activities and can be further evaluated in the future.
        4,200원
        16.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Following the previous study, which investigated the pharmacological properties of the Technekitty injection (Tc-99m), the toxicity of a single intravenous administration of the Technekitty injection (Tc-99m) and the side effects that may occur at the diagnostic dose were confirmed. The Technekitty injection (Tc-99m) was administered intravenously once at a dose of 0, 0.67, 2.0, and 6.0 mCi/kg to 5 male and female rats per group. Mortality, general symptom observation, and weight measurement were performed for 2 weeks, followed by observation of autopsy findings. There were no deaths, and no statistically significant weight change was observed. No abnormal systemic signs related to the Technekitty injection (Tc-99m) were observed. These results confirmed that Technekitty injection (Tc-99m) can be safely administered intravenously at doses up to 6.0 mCi/kg. Additionally, technetium-99m at an average dose of 2 mCi (74 MBq) has been verified as a diagnostic dose without adverse effects, allowing the Technekitty injection (Tc-99m) to be used safely without side effects at this dosage. This study demonstrates that the Technekitty injection (Tc-99m) has a wide safety margin, supporting its potential for clinical application. Moreover, these findings align with the nonclinical safety standards for radiopharmaceuticals, reinforcing its utility in veterinary medicine. The Technekitty injection (Tc-99m) is expected to be applicable for clinical diagnosis as a veterinary drug in Korea.
        4,000원
        17.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Thyroid scanning using technetium-99m (99mTc) is the gold standard for diagnosing feline hyperthyroidism. In cats with an overactive thyroid, a thyroid scan is the most appropriate imaging technique to detect and localize any hyperfunctional adenomatous thyroid tissue. In this study, the pharmacological properties of the Technekitty injection (Tc-99m), developed as a diagnostic agent for feline hyperthyroidism using 99mTc as an active ingredient, were tested in FRTL-5 thyroid follicular cell line and ICR mice. The percentage of cell uptake of the Tc-99m in FRTL-5 thyroid cells was 0.182 ± 0.018%, which was about 6 times higher compared to Clone 9 hepatocytes. This uptake decreased by 38.2% due to competitive inhibition by iodine (sodium iodide). In tissue distribution tests by using ICR mice, the highest distribution was observed in the liver, kidneys, spleen, lungs, and femur at 0.083 hours after administration, and this distribution decreased as the compound was excreted through the kidneys, the primary excretory organ. Maximum distribution was confirmed at 1 hour in the small intestine, 6 hours in the large intestine, and 2 hours in the thyroid gland. Additionally, the total amount excreted through urine and feces over 48 hours (2 days) was 78.80% of the injected dose, with 37.70% (47.84% of the total excretion) excreted through urine and 41.10% (52.16% of the total excretion) through feces. In conclusion, the Tc-99m has the same mechanism of action, potency, absorption, distribution, metabolism, and excretion characteristics as 99mTc used for feline hyperthyroidism in the United States, Europe, and other countries, because the Technekitty injection (Tc-99m) contains 99mTc as its sole active ingredient. Based on these results, the Technekitty injection (Tc-99m) is expected to be safely used in the clinical diagnosis of feline hyperthyroidism.
        4,800원
        18.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Hallux valgus (HV) is a common foot deformity in which the great toe deviates laterally and the first metatarsal deviates medially, leading to pain, discomfort, and reduced mobility. HV severity is typically assessed using the hallux valgus angle (HVA) and intermetatarsal angle (IMA). Objects: This study aimed to explore how changes in skeletal, muscular, and functional variables correlate with HV severity and to provide evidence for more integrated treatment approaches. Methods: Sixty volunteers with mild to moderate bilateral HV (HVA 15–40 degrees) participated. The measurements included HVA and IMA via radiography, abductor hallucis muscle (AbdH) cross-sectional area (CSA) and tone using ultrasound and Myoton PRO, range of motion (ROM) of the ankle and great toe metatarsophalangeal (MTP) joint with a goniometer, and plantar pressure during gait with a Zebris FDM system. Pearson’s correlation coefficient was used for the statistical analysis. Results: An Increased HVA was associated with a higher IMA (r = 0.858, p < 0.05). The HVA was inversely related to the AbdH CSA (r = –0.337, p < 0.05) and muscle tone (r = –0.889, p < 0.01). With increasing HVA, dorsiflexion ROM of the ankle (r = –0.307, p < 0.01) and both flexion (r = –0.197, p < 0.05) and extension (r=-0.182, p<0.05) ROM of the great toe MTP joint decreased. Conversely, ankle plantar flexion ROM increased with the HVA (r = 0.312, p < 0.01). Additionally, plantar pressure increased in the second metatarsal areas (r = 0.457, p < 0.05) a with higher HVA. Conclusion: This study demonstrates significant correlations between HV severity and various biomechanical factors, highlighting the need for comprehensive treatment strategies. While stretching the adductor hallucis muscle and strengthening the AbdH have been widely recognized interventions for HV, our findings provide evidence that ROM exercises for the ankle and the MTP joint of the great toe are also critical components of a physical therapy program for managing HV. Longitudinal studies are required to assess the effectiveness of these approaches.
        4,000원
        19.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Battery electrodes, essential for energy storage, possess pores that heavily influence their mechanical properties based on the level of porosity and the nature of the pores. The irregularities in pore shape, size, and distribution complicate the accurate determination of these properties. While stress-strain measurements can shed light on a material’s mechanical behavior and predict compression limits, the complex structure of the pores poses significant challenges for accurate measurements. In this research, we introduce a simulation-driven approach to derive stress-strain data that considers porosity. By calculating relative density and the rate of volume change under compression based on porosity, and applying pressure, we conducted a parametric study to identify the elastic modulus (E) in relation to the rate of volume change. This information was utilized within a material modeling equation, generating stress-strain (S-S) curves that were further analyzed to replicate the compression behavior of the electrode material. The outcomes of this study are expected to improve the prediction accuracy of mechanical properties for porous electrode materials, potentially enhancing battery performance and refining manufacturing processes.
        4,000원
        20.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Magnesium alloys, among various non-ferrous metals, are utilized in diverse fields from the automotive industry to aerospace due to their light weight and excellent specific strength. In the previous Part I study, fiber laser BOP experiments were conducted to derive basic welding characteristics and appropriate bu竹 welding conditions. Subsequently, in the Part II experiment, butt welding was performed, and through tensile tests, hardness tests, and cross-sectional observations, it was found that at laser power of 2.0 kW and welding speed of 50 mm/s, 93% of the base metafs tensile strength and 63.4% of its elongation could be achieved. In this Part III experiment, the microstructures of the base metal and the center of the weld were observed in butt-welded specimens. Through this, laser power and welding speed, on the mechanical behavior and microstructure of magnesium alloys were analyzed
        4,000원
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