To understand effects of the compositions of marine macrobenthic communities on carbon storage in subtidal rocky habitat, a diving survey was conducted at Aewol and Biyangdo stations in the northwestern regions of Jeju Island in the summer of 2023. Cluster analysis revealed no significant differences in community composition between the two stations. The mean biomass of the dominant species was Cnidaria (2,047.4 gwwt m-2) of macroinvertebrate, followed by Rhodophyta (745.4 gwwt m-2) of seaweed in studied areas. According to similarity percentage analysis, Alveopora japonica and Ecklonia cava were major contributors to the communities in Aewol, whereas diverse marine organisms, including these two species, contributed to the community in Biyangdo. The estimated mean carbon storage by benthic communities derived from their carbon contents in surveyed areas was 202.7 gC m-2, with variations reflecting differences in community compositions. The biomass of Cnidaria, dominated by A. japonica, showed a positive correlation with carbon storage, whereas the biomass of Rhodophyta, primarily composed of coralline algae, showed a negative correlation. These variations in carbon storage among marine communities may result from species-specific carbon assimilation patterns, survival strategies, marine carbon cycling, and intra-community interactions such as competition and feeding.

Yam is an important tuber crop nutritionally, socio-culturally, and an income generator for many Nigerian. This explains its high demand both locally and internationally, causing increased production as Nigeria leads world production with about 45.41 million metric tons annually. The peculiarity of yam production in Nigeria entails lower yield, high cost of production, and post-harvest losses. Yam produced in Nigeria falls far below the potential crop yield, therefore, it is essential to close these yield gaps through the provision of solutions to the different constraints that hamper sustainable yam production. Despite the challenges, there is still insufficient information on the impact of policies, weeds, pests, and diseases which constitute major constraints. Nigerian farmers mostly utilize indigenous cultural approaches to manage yam production. Their goal of production is to produce yam cultivars that are suitable mainly for food products leading to the neglect of other cultivars. Few selected institutions with a yam mandate have been working on improving the production of D. rotundata and D. alata through breeding yam cultivars suitable for consumption and resilient against pests and diseases. However, more extensive studies should focus on breeding programs for yam resilient under drought and flooding, with peculiar physicochemical properties that give unique textual qualities considered in pounded yam and other yam food products. In this review paper, the significance and limitations of yam production in Nigeria and her efforts to achieve sustainable production are extensively studied.

Double slug interaction in downward-facing nucleate boiling was studied to investigate its effect on boiling performance. Two heating surfaces were individually controlled to apply heat flux while their boiling performance were measured. A slug generated from upper heater affect on lower heater to make convectional flow by suction following departure of slug. Moreover, it showed to reduce hovering time of slug bubble on lower heater because it could help bubble departure on lower heater. Meanwhile, a slug generated from lower heater affected on upper heater to make convectional flow by sweeping. However, it showed to increase hovering time of slug bubble on upper heater, because they collapsed to each other. So, the slugs from lower heater enhanced the boiling performance of upper heater with low heat flux condition, but reduced the performance of it with high heat flux condition.

한국은 2000년을 기점으로 국내 복지국가에 대한 논의와 연구가 활발히 진행 되고 있는 상황이다. 대부분의 연구 주제는 한국이 복지국가가 되기 위한 조건이 무엇이며 그 전략이 무엇인가에 대한 것이다. 그러나 많은 연구들이 한국은 이미 복지국가라는 것을 상정한 상태로 논의를 하고 있거나 한국의 목표가 유럽의 복지국가라는 전제하에서 논의되고 있는 상태다. 즉, 복지국가의 유형이나 성격 논쟁 등 대부분의 연구가 유럽 의 복지국가로 수렴 되어지는 결론을 보여주고 있다. 하지만 과연 한국의 여러 제한된 시스템 속에서 ‘유럽의 복지국가 모델이 합리적인 대안이 될 수 있는가’ 또, 한국의 복지 철학과 정치 시스템을 바탕으로 ‘유럽의 복 지국가 모델을 적용하는 것이 가능한가’ 라는 문제의식을 갖게 한다. 본 고는 거시적인 관점에서 복지국가론을 비판하고 한국이 나아가야 할 국가모델이 복지국가에만 있는 것이 아니라 다른 발전된 미래 모델에도 있다는 것을 제시함에 목적이 있다. 먼저 에스핑 앤더슨의 ‘복지국가 유형 분류’를 이용하여 유럽 복지국가의 모델을 설명하고 복지국가의 성공 요인을 다섯 가지로 논하였다. 그리고 한국과 유럽의 정치구조를 비교한 후 한국이 지향하는 복지국가 형태에 따른 저해 요소들에 대하여 설명하고, 새로운 국가모델로 공진 국가, 생태 국가, 혁신국가, 소강 국가, 지식 국가를 제시하였다. 결론적으로 본고는 한국의 프레임 속 복지가 과연 완벽한 복지 시스템인가를 생각해보고, 미래 한국의 발전을 위해 복지국가 이외의 새로운 국가모델을 제시해 본 시론적 성격의 논문이다.

This paper reports critical heat flux(CHF) performance on wire heater according to material, thickness, length, cross sectional shape. Water was employed as the working fluid, which was saturated at 1 atm. By comparison of CHF values with difference conditions of wire length, contact resistance inherent in the experimental apparatus could be analyzed, which had made the bias error in many research groups. So, exact value of CHF could be measured, which was consistent with the literatures. The CHF value showed decrease tendency, as the cross sectional area increased and reach to the capillary length of the working fluid. Meanwhile, the effect of thermal properties on CHF was not observed in the experimental cases. This data would be used as a reference data in research field of CHF using wire heater, i.e. reactivity initiative accident(RIA).

This paper reports slug bubble dynamics on modified surface with two-dimensional graphene film in downward-facing nucleate boiling. Behaviors of slug bubbles were observed with high speed camera, and post-processing was followed to measure departing speed, frequency, and diameter of slug bubbles, which were important to analyze boiling performance change. The graphene-modified surface showed enhanced boiling heat transfer coefficient (BHTC) and critical heat flux (CHF). The effect of surface modification on slug bubble dynamics was quantitatively analyzed; bigger slugs departed from the modified surface with faster speed but same frequency, compared with the bare. It seems that the BHTC enhancement is caused by increase of bubble diameter, resulting in increase of its departing speed. The higher speed of departing bubble could extend the hydrodynamic limit of vapor removal from downward-facing surface, so that CHF performance could be enhanced.

재생 불가능한 에너지 자원이 수년에 걸쳐 고갈됨에 따라, 재생 에너지 생산을 위한 보다 효과적인 방법에 대한 연구가 증가되었다. 연로전지 개발의 한 분야인 미생물 연료전지(MFC)는 이중 성능의 잠재력 덕분에 발전하였다. MFC는 박테리아와 같은 전극 감소 생물에서 전력을 모아서 전기 에너지를 생산한다. MFC는 폐수를 연료로 사용하여 에너지를 생산하고 폐수를 정화한다. 양성자 교환막(PEM)은 양극과 음극 챔버의 분리막으로, 양성자만 효과적으로 통과할 수 있게 하는 중요한 역할을 한다. Nafion은 MFC에 상업적으로 사용되는 PEM이지만 비용, 생산 시간, 양성자 전도성 차원에서 보완할 점들이 많다. 본 리뷰 논문에는 Nafion을 대체할 수 있는 새로 개발된 PEM 몇 가지를 논의하였다. 또한, PEM, 혼합 PEM 및 복합 PEM에 기반한 MFC를 요약하고자 한다.

This paper reports the pH effect of reduced graphene oxide (RGO) colloids on formation of three dimensional (3D) graphene network in nucleate boiling condition, so called boiling method. When nucleated bubbles grow on the hot surface, thin liquid film beneath the bubble is supposed to be dried, in which RGO flakes become close to each other and form a structure. Accordingly, what happened when they are in high particle density would be a key issue for the formation of 3D graphene network. Here, we changed pH and oxidation level of RGO colloids so that their effect was observed on extent of 3D graphene network after boiling method. As pH was lower, i.e. being acid, the RGO colloids become unstable, resulting in 3D structure rather than 2D structure. Similarly, As oxidation level was lower, i.e. being more reduced, it showed a tendency to form 3D structure.

This paper reports an uncertainty analysis of quantitative visualization methodology for slug bubble dynamics in downward-facing nucleate boiling condition. Measurement of dynamics of slug bubble, i.e. departing speed, frequency, and diameter, is very important to predict safety margin of thermal systems in moving vehicle. By employing high speed visualization and post-processing, we quantitatively measured the volume and location of slug bubble, so that vapor generation rate and departing speed data were derived from their time differentiation. As a visualization methodology, its reliability was evaluated via uncertainty analysis. For 95% confidence interval, uncertainty of vapor generation rate and departing speed were 3% and 2%, respectively, and which were one order lower than standard deviation of those data.

Microbubble is a part of advanced water treatment technologies, and there are several ways for microbubble generation. A strategy using Venturi (convergent-divergent) nozzle with air-suction holes has advantage of energy and time saving compared with the others. Here, we used 3D printer to make the various nozzle geometries in order to understand two-phase flow in the Venturi nozzle and air-breaking mechanism. It was evaluated the effects of convergent and divergent angles independently on air-suction rate and pressure drop, and the two-phase flow (air bubbles and liquid water) were observed. The convergent angle strongly affect the air-suction rate corresponding with increase of pressure drop. Meanwhile, as the divergent angle increased, it became dominant the minor loss by sudden enlargement of flow area, so that the air-suction rate and pressure drop showed decreased.

목 적：간 MRI 검사 시 호흡 정지 기법으로 검사를 진행하게 되는데 긴 검사시간으로 인해 호흡에 의한 움직임이나 불수의 적 움직임으로 영상의 질이 저하되는 경우가 빈번하다. 이런 이유로 영상의 질을 저하시키지 않으면서 검사시간을 단축시키기 위해 영상 획득 속도를 향상시키는 방법인 CS기법을 사용하고 있다. 본 연구에서는 CS기법의 extra reduction과 denoising level 조합의 변화에 따른 검사시간과 영상 변화를 기존의 conventional 3D-FFE THRIVE와 비교분석을 통하여 최적화된 parameter설정에 관하여 알아보고자 한다. 대상 및 방법：2018년 12월 1일부터 2019년 2월 3일까지 본원에서 간 MRI 검사를 시행한 환자 30명을 대상(남자 15명 여자 15명±6.73세)으로 extra reduction 1, denoising level 0% 가 적용된 3D-FFE THRIVE 시퀀스를 기존의 conventional 3D-FFE THRIVE로 간주하였으며, extra reduction level 1, 1.5, 2, 2.5, 3 값에 각각 denoising level을 0%, 20%, 40%, 60%, 80% 로 변화를 주고 다른 매개변수들은 모두 동일하게 하여 실험을 진행하였다. 획득한 각 영상들의 SNR, CNR, SSIM 을 측정하고, 정성적 영상 평가와 검사시간의 변화를 비교하였다. 정성적 평가에서 3점 이하로 평가받은 영상을 제외한 총 11개의 조합영상에 대하여 각 조합별로 순위를 매긴 후 1위는 1점, 11위는 11점으로 점수를 부여한 후, 합산 한 최종 점수가 가장 낮은 영상을 최적의 영상으로 선택하였다. 결 과：Extra reduction의 증가에 따라 SNR, CNR은 유의한 변화가 없었고, SSIM과 정성적 영상 평가 점수, 검사시간은 extra reduction증가에 따라 유의하게 감소하였다. Denoising level의 증가에 의해 SNR, CNR은 유의하게 증가하였고 SSIM과 검사시간은 유의한 변화가 없었으며, 정성적 영상 평가점수는 denoising level의 증가에 따라 유의하게 감소하였다. 결 론：본 연구의 실험결과를 종합해봤을 때 extra reduction 3, denoising level 20% 로 설정 시, 기존 영상 대비 정량적 평가인 SNR의 경우 12%, CNR의 경우 13% 향상되었으며, SSIM과 정성적 평가에서는 동일한 평가를 얻었고, 검사 시간은 50% 단축시키는 효과를 얻을 수 있었다. CS기법을 이용하여 간 검사 시, 시각적으로 용인되는 영상의 질 변화를 고려하여 extra reduction, denoising level을 조절한다면 화질의 유지와 함께 획기적인 검사 시간 단축을 이룰 수 있을 것으로 사료된다.

Graphene oxide (GO) laminate is a new promising material for water purification system, which has extraordinary permeability only for water molecule. It consists of numerous nano-channels, in which water molecules could be nano-confined, resulting in slip of the molecules for very fast transportation speed. In this study, water penetration rate via different thickness of GO membrane according to driven pressures are measured experimentally, so that speed of water molecules and permeability are evaluated. Generally, water penetration rate via a membrane with macroscopic-sized channel increases linearly with pressure difference between up and bottom side of the membrane, but that via GO membrane approaches asymptotic value (i.e. saturation) as like a log function. Moreover, the permeability of GO membrane was observed in inverse proportion to its thickness. Based on the experimental observations, a correlation for volume flux via GO membrane was suggested with respect to its thickness and external pressure difference.

가금에서의 스트레스 지표는 혈중 corticosterone의 농도, heterohphil/lymphocyte 비율 뿐만 아니라 사료 및 물의 섭취량, 체중, 산란율, 이상행동 등도 포함된다. 사육온도, 바닥형태, 사육밀도, 수송, 부리자르기, 제한급이, 질병 등이 사육현장에서 가금이 경험할 수 있는 스트레스 요인이 될 수 있다. 다양한 스트레스 지표 중에서 특정 지표만으로 스트레스의 여부를 평가하는 것은 오류를 범할 수 있으므로 동시에 여러 지표를 이용하여 평가하는 것이 스트레스에 대한 평가의 신뢰도를 향상시킬 수 있다.

본 연구의 목적은 경상남도 하동에서 생산된 녹차의 사료적인 가치를 평가하는 것이다. 먼저, 하동에서 생산되는 녹차의 특성을 이해하기 위하여 일반성분, 항산화 활성 및 항균성활성 분석을 행하였으며, 녹차는 조단백질을 20%이상, 조섬유를 약 19% 함유하고 있으며, 높은 항산화 및 항균활성을 보였다. 68주령 하이라인브라운 레그혼 96수를 개체별 케이지에 수용하여 8주간의 사양실험을 수행하였을 때, 사료에 첨가된 녹차(1% 까지)는 산란계의 사료섭취량, 사료요구율 및 헨데이 난생산성(%)에 대한 영향이 없었다. 녹차는 급여 3-4주에 일시적으로 정상란의 산란율을 감소시켰고, 5-6주에 난중을 증가시켰다. 급여후기에 계란의 신선도(Haugh unit)의 감소를 지연시켰다(P<0.05). 녹차 급여는 난각강도와 무게에 영향을 미치지 않았다. 사료 중 녹차의 함량이 증가함에 따라 혈중 creatinine 과 amylase의 농도와 칼슘의 함량이 유의적으로 감소하였다(P<0.05). 따라서 이상의 결과는 하동녹차는 산란계의 사료에 충분히 이용 가능한 것으로 사료된다.

A simple thermal oxidation of Cu thin films deposited on planar substrates established a growth of vertically aligned copper oxide (CuO) nanorods. DC sputter-deposited Cu thin films with various thicknesses were oxidized in environments of various oxygen partial pressures to control the kinetics of oxidation. This is a method to synthesize vertically aligned CuO nanorods in a relatively shorter time and at a lower cost than those of other methods such as the popular hydrothermal synthesis. Also, this is a method that does not require a catalyst to synthesize CuO nanorods. The grown CuO nanorods had diameters of ~100 nm and lengths of 1~25μm. We examined the morphology of the synthesized CuO nanorods as a function of the thickness of the Cu films, the gas environment, the oxidation time, the oxidation temperature, the oxygen gas flow rate, etc. The parameters all influence the kinetics of the oxidation, and consequently, the volume expansion in the films. Patterned growth was also carried out to confirm the hypothesis of the CuO nanorod protrusion and growth mechanism. It was found that the compressive stress built up in the Cu film while oxygen molecules incorporated into the film drove CuO nanorods out of the film.