소형 선박(<499 GT)이 전체 선박의 46%를 지배하고 있어 상대적으로 많은 CO2 배출가스를 가지고 있다고 결론지을 수 있다. 최 적의 Trim 조건에서 운전하면 선박의 저항을 감소시킬 수 있어 온실가스가 적게 발생할 수 있다. Trim을 최적화하는 가장 저렴한 방법 중 하 나는 최적의 Longitudal Center of Gravity(LCG)를 얻기 위해 무게 분포를 조정하는 것이다. 따라서 본 연구에서는 소형 선박의 저항에 대한 LCG 변화의 영향을 경험적 및 수치적 해석을 통해 연구하고자 한다. 선체를 설계하는 Savitsky 경험식은 Maxsurf Resistance의 방법으로 사용 된다. 수치해석에는 STAR-CCM+ 상용 CFD(Computational Fluid Dynamics) 소프트웨어가 사용되지만 최종적으로 선박 설계 과정 이후 최적의 LCG를 얻기 위해 전체 저항을 비교한다. 결론적으로 Froude Number 0.56에서는 수치해석에 의해 전체 길이(LoA) 46.2%에서 최적의 LCG를 달성하고 Froude Number 0.63에서는 43.4% LoA를 달성하여 29.2% LoA에서 기준점에 비해 최대 41.12% - 45.16%의 상당한 저항 감소를 얻을 수 있다.

Henricia specimens were collected using a dual approach of trimix scuba diving and fishing nets. This inclusive collection encompasses the discovery of two species highlighted in this study and introduces and provides comprehensive descriptions for Henricia kinkasana and Henricia longispina aleutica. The descriptions offered in this study were derived from the thorough examinations of external morphological characteristics. The documentation provides detailed insight into key traits related to the abactinal and actinal skeletons and spines of these newly recorded species in Korea. This comprehensive examination contributes to our understanding of the distinct morphological characteristics defining each species within the genus Henricia.

Two newly recorded sea stars, Henricia densispina (Sladen, 1879) and H. reniossa asiatica Djakonov, 1958, collected from the East Sea of Korea using fishing nets, were described in this study. Morphologically, H. densispina is characterized by the shape (sub-triangular) similarity of the intermarginal plates to the superomarginal plates. Henricia reniossa asiatica Djakonov, 1958, has long and slender arms (R/r=7.2- 9.1); clustered abactinal paxillae with 3-13 abactinal spinelets; a denuded abactinal skeleton made up of crescentic, elongated cross-shaped, the presence of small ossicles that divided the papular areas; and an adambulacral armature comprised of 14-17 spinelets. This study provides the first occurrence of H. densispina and H. reniossa asiatica in the Korean fauna and a detailed morphological description of these species’ key characteristics is provided.

선박의 설계과정에 있어, 선박의 중량은 유체역학적 성능에 큰 영향을 미치는 가장 중요한 요소 중 하나이다. 선박은 일반적으 로 최적의 흘수와 배수량을 갖는 하나의 조건으로 설계되지만, 실제로는 연료의 소비, 선박 평형수의 충전과 적재 조건과 같은 운항 활동 으로 인해 선박의 중량 및 흘수가 일정 범위 내에서 바뀐다. 본 연구에서는 소형선박을 대상으로 3가지 하중조건에 따른 선박의 저항성능 변화를 모형실험과 수치해석을 통해 연구하였다. 마지막으로 2050년까지 CO2 배출 가스를 50% 감축한다는 국제해사기구(IMO) 목표를 따 라 선박의 저항 성능을 개선하여 동력 요구 사항을 줄이기 위해 선박의 중량 변화에 따른 저항성능의 민감도를 연구하였다. 연구 결과, 선박의 중량변화에 따른 효과는 낮은 프루드 수에서 크게 나타나는 것으로 확인되며, 저항성능에 대한 연구 결과, 설계 흘수의 적재조건 을 기준으로 배수량이 11.1% 증가하고, 흘수가 5% 증가한 Over load의 적재조건에서 운항 시 선체의 총 저항이 모형시험과 CFD 시뮬레이 션에서 각각 15.97%, 14.31%까지 증가하는 것을 볼 수 있다.

Henricia specimen was collected from the East Sea of Korea using fishing nets. The specimen was identified as Henricia hayashii (Djakonov 1961), belonging to the family Echinasteridae of the order Spinulosida. This species can be distinguished from other Henricia species by slender arms (R/r=7.4), constricted arm base, six to thirtyfive slender spinelets, open-meshed, reticulated abactinal skeleton comprising semitriangular, rod-like form, and small ossicles present inside the papular areas. This species superficially resembles H. reniossa in terms of its body size but differs in the shape and arrangement of the abactinal and actinal plates. To date, two genera of Echinasteridae, Aleutihenricia and Henricia, including a total of 14 species, have been reported in Korea. Herein, the morphological characteristics of H. hayashii are described, and photographs are provided.

Engineering the microstructure of the carbonaceous materials is a promising strategy to enhance the capacitive performance of supercapacitors. In this work, nanostructured Black Pearl (1500 BP) carbon which is a conductive carbon being commercially used in printing rolls, conductive packaging, conductive paints, etc. is analyzed for its feasibility as an electrode material for Electric Double-Layer Capacitors (EDLCs). To achieve that commercial Black Pearl (BP), carbon is treated with mild acid H3PO4 to remove the impurities and enhance the active sites by regulating the growth of agglomerates and creating micropores in the nano-pigments. Generally, the coalescence of nanoparticles owing to their intrinsic surface energy has tendency to create voids of different sizes that act like meso/micropores facilitating the diffusion of ions. The electrochemical performance of BP carbon before and after chemical activation is investigated in aqueous ( H2SO4, KOH and KCl) and a non-aqueous electrolyte (1 M TEMABF4 in acetonitrile) environment employing different electrochemical techniques such as Cyclic Voltammetry (CV), Galvanostatic charge/discharge (GCD) and Electrochemical Impendence Spectroscopy (EIS). The chemically activated BP carbon delivers the highest specific capacitance of ∼156 F g−1 in an aqueous electrolyte, 6 M KOH. The highest specific power, ~ 15.3 kW kg−1 and specific energy, 14.6 Wh kg−1 are obtained with a symmetric capacitor employing non-aqueous electrolyte because of its high working potential, 2.5 V.

Henricia specimens were collected using fishing nets from the East Sea of Korea. The specimens were identified as Henricia oculata Pennant, 1777, belonging to the family Echinasteridae of the order Spinulosida. This species can be distinguished from other Henricia species by broad arms (R/r=4-4.1), rough skin, a thick arm base, three to nine minute delicate abactinal spines, and inferomarginal plates reniform in shape. This species superficially resembles H. pachyderma in its body size and wide papular areas but differs mainly in the number of papulae and abactinal spines, and the shape and arrangement of the inferomarginal plates. To date, two genera of Echinasteridae, Aleutihenricia and Henricia, with a total of 13 species, have been reported in Korea. The morphological characteristics of H. oculata are described, and photographs are provided.

This study provides an assessment on a proposed method for separation of cesium, strontium, and barium using electrochemical reduction at a liquid bismuth cathode in LiCl-KCl eutectic salt, investigated via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDS). CV studies were performed at temperatures of 723-823 K and concentrations of the target species up to 4.0wt%. Redox reactions occurring during potential sweeps were observed. Concentration of BaCl2 in the salt did not seem to influence the diffusivity in the studied concentration range up to 4.0wt%. The presence of strontium in the system affected the redox reaction of lithium; however, there were no distinguishable redox peaks that could be measured. Impedance spectra obtained from EIS methods were used to calculate the exchange current densities of the electroactive active redox couple at the bismuth cathode. Results show the rate-controlling step in deposition to be the mass transport of Cs+ ions from the bulk salt to the cathode surface layer. Results from SEM-EDS suggest that Cs-Bi and Sr-Bi intermetallics from LiCl-KCl salt are not thermodynamically favorable.

Despite increasing consumer engagement with social commerce, conditions influencing user intention to utilize m-payment services on social media platforms remain unclear. This study employs fsQCA to ascertain configurations of conditions for behavioral intention, identifying solutions to assist theory and practice regarding the adoption of this form of commerce.

Sea stars were collected from the adjacent waters of Jukbyeon and Jumunjin, Korea, using fishing nets at depths of 70-100 m. The specimens were identified as Henricia perforata (O.F. Müller, 1776) in the family Echinasteridae and order Spinulosida, with worldwide species distribution. H. perforata can be distinguished from some morphologically related Henricia species by its long, slender, and pointed adambulacral spines. The abactinal skeleton of H. perforata has wide papular areas resembling those of H. pachyderma, but the former has more papulae (two to seven). Previously, two genera of Echinasteridae, Aleutihenricia and Henricia, with a total of 12 echinasterid species, have been reported in Korea. The morphological characteristics of H. perforata are described and photographs are provided.

Introduction: Age-related co-morbidities are common among persons living with chronic Human Immunodeficiency Virus (HIV). However, data are largely absent on the relationship between frailty and incontinence as related to falls—common age-related co-morbidities—among people living with chronic HIV (PLWH). Methods: To inform hospital-based Occupational Therapy (OT) services for PLWH, we performed a case-control study using extracted data from the electronic medical records of PLWH who had received OT at a large academic hospital. Two-hundred-and-four subjects were included in the final dataset; sixty-eight were cases that reported a fall within the last 12 months, while 136 were controls which were PLWH who had not sustained a fall. Results: The association between falls and frailty indicated that persons categorized as ‘pre-frail’ with balance deficits were more likely to fall (OR=2.77 [1.18-6.52]). Women who lacked insurance were less likely to fall (OR=0.38 [0.18-0.82]) and (OR=0.29 [0.09-0.88]) respectively. The association between incontinence and falls among PLWH were not statistically significant in a multivariate adjusted regression model (OR=1.38 [.59-3.22]). Conclusion: Our findings suggest further examination of the person factors of PLWH who are categorized clinically as ‘pre-frail’ or ‘frail’ may improve health outcomes and reduce falls when paired with occupation-based interventions.

Molten salt solutions consisting of eutectic LiCl-KCl and concentrations of samarium chloride (0.5 to 3.0 wt%) at 500℃ were analyzed using both cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The CV technique gave the average diffusion coefficient for Sm3+ over the concentration range. Equipped with Sm3+ diffusion coefficient, the Randles-Sevcik equation predicted Sm3+ concentration values that agree with the given experimental values. From CV measurements; the anodic, cathodic, and half-peak potentials were identified and subsequently used as a parameter to acquire EIS spectra. A six-element Voigt model was used to model the EIS data in terms of resistance-time constant pairs. The lowest resistances were observed at the half-peak potential with the associated resistance-time constant pairs characterizing the reversible reaction between Sm3+ and Sm2+. By extrapolation, the Voigt model estimated the polarization resistance and established a polarization resistance-concentration relationship.

Asteroid specimens were collected using fishing nets from the East Sea, Korea. The specimens were identified as Solaster paxillatus Sladen, 1889, belonging to the family Solasteridae of the order Valvatida. This species can be distinguished from three other Korean Solaster species by having 10 arms; subambulacral spines comprising four or five near base of arm, six or seven in middle part, and five or six in distal part of arm; furrow spines comprising four or five near basal part and three or four in distal part of arm; and suboral spines comprising more than ten spinules. The morphological characteristics of this species were described with illustrations. Solaster paxillatus is first reported in marine fauna of Korea.