• 수산경영론집
• /
• 제52권2호
• /
• pp.55-67
• /
• 2021

Global warming affects critical natural resources, one of which is the oceans that occupy 70% of the total cover of the earth. In other words, ocean warming is a subset of global warming which needs to be addressed urgently. Purple laver (pyropia spp.) is one of the most vulnerable items to climate change although it is a major export product of Korean fisheries. The purpose of this study is to analyze the causality of how climate change caused by global warming affects the increase or decrease of PLP (purple laver production). The target area for analysis was set to Maro-hae between Jindo-gun and Haenam-gun. We selected marine environmental factors and meteorologic factors that could affect PLP as variables, as well as co-integration tests to determine long-term balance, and the Granger causticity tests. As a result, PLP and marine environmental factors WT (water temperature), pH, and DO confirmed that long-term equilibrium relationships were established, respectively. However, there is only causality with WT and it is confirmed that there is only a correlation between pH and DO (dissolved oxygen). There was no long-term equilibrium relationship between PLP and HDD (heating degree days) and there is a causal effect that HDD affects PLP; however, it was less clear than that of WT. The relationship between PLP and RF (rainfall), WS (wind speed), SS (percentage of sunshine), and FF (farm facilities) was all balanced in the long term, and causality exists. Based on the results of the analysis, policy proposals were made.

• 생태와환경
• /
• 제52권2호
• /
• pp.161-170
• /
• 2019

Invasive alien plants were identified and recorded in Ulsan city based on field surveys and related literatures. These plants consisted of 147 taxa in total, belonging to 30 families, 93 genera, 144 species, 2 subspecies and 1 variant. The family of Asteraceae was predominant with 42 taxa, followed by Gramineae with 27 taxa and Leguminosae with 15 taxa. According to the result of life-form based distribution analysis revealed that 62 taxa (42.2%) were annual plants, 48 taxa (33.6%) were perennial plants, 34 taxa (23.1%) were biennial plants, and 3 taxa (2%) were woody perennials. Compare to other administrative districts in Korea, prevalence of invasive alien plants in a certain city of Ulsan showed the seventh highest species number followed after Jeju, Gyeonggi, Jeonnam, Incheon, Seoul and Gangwon. On the basis of the results from the country origin analysis, two dominating taxa were introduced from Europe and America, 55 taxa and 51 taxa respectively. The spreading grade of alien plants was elucidated in order of 1 grade (PS) 67 grade (21.1%)>2 grade (MS) 31 taxa (21.1%)>5 grade (WS) 18 taxa (11.6%)>3 grade (CS) 17 taxa (11.6%)>4 grade (SS) 14 taxa (9.5%). Ulsan city is one of a pivotal conduit for the introduction of invasive alien plants. Thereby, reliable management plans are required to monitor these species.

• Asian-Australasian Journal of Animal Sciences
• /
• 제32권8호
• /
• pp.1195-1204
• /
• 2019

Objective: The purpose of this study was to investigate whether addition of konjac gel with three different vegetable powders can increase quality of low-fat frankfurter-type sausage. Methods: Low-fat frankfurter-type sausages were manufactured with formulations containing konjac gel and three vegetable powders (aloe vera, cactus pear, or wheat sprout) as pork fat replacers. The formulations of frankfurters were as follows: NF (normal-fat; 20% pork fat), LF (low-fat; 10% pork fat), KG (low-fat; 10% pork fat+10% konjac gel), and konjac gel with three vegetable powders (KV), such as KV-AV (10% pork fat+10% konjac gel with aloe vera), KV-CP (10% pork fat+10% konjac gel with cactus pear), and KV-WS (10% pork fat+10% konjac gel with wheat sprout). Proximate analysis, pH value, color evaluation, cooking loss, water-holding capacity, emulsion stability, apparent viscosity, texture profile analysis, and sensory evaluation were determined. Results: The konjac gel containing groups showed lower fat content (p<0.05) and higher moisture content than NF group (p<0.05). The pH value of frankfurters was decreased in three KV groups (p<0.05). The three KV groups had increased dark color (p<0.05) compared with KG, and KV-CP had the highest redness (p<0.05). The water-holding capacity and emulsion stability were higher in the three KV groups than KG and LF (p<0.05). Cooking loss was generally decreased in the three KV groups, compared with KG (p<0.05). The apparent viscosity of KV groups was similar with NF group and overall texture properties were improved in KV-CP. In the sensory evaluation, the highest overall acceptability was found in KV-CP groups (p<0.05). Conclusion: The four fat replacers improved physicochemical properties of low-fat frankfurters. Particularly, konjac gel with cactus pear powder seems more acceptable as a pork fat replacer.

• Animal Bioscience
• /
• 제35권7호
• /
• pp.1080-1090
• /
• 2022

Objective: This study aimed to characterize the effect of pre-treated black garlic (BG) extracts addition into retorted Korean ginseng chicken soup (Samgyetang) on the fatty acid composition and flavour-related indexes. Methods: Four different treatments; Samgyetang made with a 5% (w/w) addition of garlic (G), fresh BG (FBG), oven-dried BG (DBG), or encapsulated BG (EBG) extracts were developed and compared to negative control (NC) without any extract addition. Prepared samples were cooked via retorting at 121.1℃, 1.5 kgf/cm² for 1 h. Results: The BG treated samples were higher in C18:3n3 and C18:2n6 fatty acids, with thrombogenic index was 18% to 20% lower than the NC. EBG yielded the highest umami-related nucleotides (5'-guanosine monophosphate and 5'-inosine monophosphate) and modified some free amino acid (alyne, phenylalanine and leucine) thus possessed the highest equivalent umami concentration among samples. Some individual aldehydes (pentanal, hexanal, and heptanal) were lower, while furans and volatile sulfur compounds were higher than the NC and G treatment group, indicating a potential suppression of unpleasant flavour alongwith the intensificiation of favourable flavour from the addition of BG extracts into retorted Samgyetang. Conclusion: Taken together, the synergistic results of this study indicate that incorportating suitable pre-treatment of BG extract could be of critical importance for the development of the retorted Samgyetang with improved flavour and functionalities.

• 대기
• /
• 제32권2호
• /
• pp.119-133
• /
• 2022

From 2015 to 2021, high-concentration fine dust episodes with a daily average PM_2.5 concentration of 50 ㎍ m^-3 or higher were selected and classified into 3 types [long range transport (LRT), mixed (MIX) and Local emission and stagnant (LES)] using synoptic chart and backward trajectory analysis. And relationships between the fine particle data (PM_2.5 and PM₁₀ concentration and PM_2.5/PM₁₀ ratio) and meteorological data (PBLH, Ta, WS, U-wind, and Rainfall) were analyzed using hourly observation for the classification episodes on the Korean Peninsula and the Seoul metropolitan area (SMA). In LRT, relatively large particles such as dust are usually included, and in LES, fine particle is abundant. In the Korean peninsula, the rainfall was relatively increased centered on the middle and western coasts in MIX and LES. In the SMA, wind speed was rather strong in LRT and weak in LES. In LRT, rainfall was centered in Seoul, and in MIX and LES, rainfall appeared around Seoul. However, when the dust cases were excluded, the difference between the LRT and other types of air quality was decreased, but the meteorological variables (Ta, RH, Pa, PBLH, etc.) were further strengthened. In the case of the Korean Peninsula, it is difficult to find a clear relationship because regional influences (topographical elevation, cities and coasts, etc.) are complexly included in a rather wide area. In the SMA, it is analyzed that the effects of urbanization such as the urban heat island centered on Seoul coincide with the sea and land winds, resulting in a combination of high concentrations and meteorological phenomena.

• 한국결정성장학회:학술대회논문집
• /
• 한국결정성장학회 1999년도 PROCEEDINGS OF 99 INTERNATIONAL CONFERENCE OF THE KACG AND 6TH KOREA·JAPAN EMG SYMPOSIUM (ELECTRONIC MATERIALS GROWTH SYMPOSIUM), HANYANG UNIVERSITY, SEOUL, 06월 09일 JUNE 1999
• /
• pp.419-431
• /
• 1999

InP, III-V binary compound semiconductor, single crystal was grown by VGF (vertical gradient freeze) method using quartz ampoule and its electrical optical properties were investigated. Phosphorous powders were put in the bottom of quartz ampoule and Indium metal changed in conical quartz crucible hat was attached at the upper side position inside the quartz ampoule. It was vacuous under the pressure of 10-5 Torr and sealed up. In metal in the quartz crucible was melted at 1070$^{\circ}C$ and phophorous sublimated at 450$^{\circ}C$, there after it was diffused in In melt and so InP composition was formed. By cooling the InP composition melt (2$^{\circ}C$∼5$^{\circ}C$/hr of cooling rate) in range of 1070$^{\circ}C$∼900$^{\circ}C$, InP crystal was grown. the grown InP single crystals were investigated by X-ray analysis and polarized optical microscopy. Electrical properties of them were measured by Van der Pauw method. At the cooling rate of 2$^{\circ}C$/hr, its direction was (111), quality of the ingot ws better upper side of the ingot than lower. It was found that the InP crystals were n-type semiconductor and the carrier concentration, electron mobility and relative resistivity were 1015∼1016/㎤, 2x103∼3x104$\textrm{cm}^2$/Vsec and 2x10-1∼2x10-3Ωcm in the range of 150K∼300K, respectively.

• 한국항행학회논문지
• /
• 제27권1호
• /
• pp.63-70
• /
• 2023

본 연구는 선박 추진 축계의 무선 센서 시스템(WSS) 응용을 위한 용량성 무선 전력 전송(C-WPT) 시스템을 제시한다. 커플링 커패시터 양쪽의 단일 Q 팩터 및 회로에서 무효 전력제거를 위해 양면 LCLC 컨버터 및 변압기 토폴로지가샤프트에서 WSS용 회전식 C-WPT 시스템을 구동하도록 설계되었습니다. 170pF의 용량을 갖는 병렬 연결된 평행판 회전 커패시터가 설회전축의 C-WPT 시스템용으로 설계 및 구현된다. 실험 결과 C-WPT 시스템은 3mm 거리 및 1 MHz 작동 주파수에서 7.8 W 출력 전력으로 66.67 %의 전송 효율을 달성했다. 따라서 제작된 C-WPT 시스템은 회전축의 WSS에 전원을 공급할 수 있음을 증명하였다.

• 한국분무공학회지
• /
• 제28권1호
• /
• pp.43-48
• /
• 2023

The waste-heat-recovery boiler with water spray (HR-B/WS) applies the heat exchange between the inlet air and exhaust gas with the water spray into the inlet air. The evaporation of water in the inlet air promotes heat recovery from the exhaust gas so that thermal efficiency can be improved by the enhanced condensing effect. The NOx emission can also be reduced by lowering the flame temperature due to the dilution effect of the water. In this study, the validity of this concept is examined by the practical boiler test performed with a 24 kW condensing boiler under the full load condition according to the water injection amount. The theoretical amount of water injection is calculated under the assumption of full evaporation of the sprayed water, which is calculated as 50 g/min. Since the injected water cannot evaporate fully in the actual system, the maximum water spray amount is set as 100 g/min. The results showed that the water injection can increase the thermal efficiency up to 95.59% and reduce NOx and CO emissions simultaneously to 8.9 ppm and 35 ppm at 0% of O₂. Although the heat energy loss increased due to the unevaporated water, the increase in water injection amount caused higher thermal efficiency due to the increased amount of the evaporated water.

• 한국수산과학회지
• /
• 제56권5호
• /
• pp.701-707
• /
• 2023

We investigated Euphausia pacifica population in Korean waters in 2016 By samplings for genetic structur at five stations. Three sampling stations were located in the middle of the water masses which were clustered by temperature and salinity whereas the other stations were at the boundaries of the water masses. We amplified a 566 bp region and compared it with sequences of E. pacifica distributed in other waters. Sequences were classified two clades, and a clade was formed in the station E. Genetic distance of station E was close to E. pacifica present in Bering Sea, while it was distant to E. pacifica present in Yellow Sea near China. In genetic analysis, seven haplotypes were formed. Hap-1 and Hap-2 were shared in all five stations, while Hap-3 was shared in station W and WS. Four independent haplotypes were present in station E. Haplotype and nucleotide diversity were the highest in station E and the lowest in station S. The F_ST distances between station E and other stations were the highest, but distances among other stations were low. As a result, we concluded that E. pacifica, which is distributed in Korean waters, has a genetic population differentiation in the East Sea (station E).

• 한국식품영양학회지
• /
• 제36권6호
• /
• pp.462-470
• /
• 2023

The aim of this study was to investigate the hypoglycemic effects of saengshik in Sprague-Dawley (SD) rats and to explore the potential of three commercially available saengshik products (BS, LS, WS) as an alternative diabetic meal. Blood glucose levels were measured at 30, 60, 90, 120, and 150 minutes after the ingestion of experimental materials. In experiment 1, the amount of experimental materials remained the same. We measured blood glucose-related biomarkers as the area under the blood glucose response curve (AUC), glycemic index (GI), maximum concentration (Cmax), and time to reach maximum concentration (Tmax). AUC and Cmax of the experimental group showed significant differences compared to the control group, while GI and Tmax did not show significant differences among the groups but were lower in the experimental group compared to the control group. In experiment 2, carbohydrates were adjusted to the same amount. We measured blood glucose-related biomarkers in the same manner as Experiment 1 and obtained similar results. These hypoglycemic effects appear to be attributed to phytochemicals and dietary fiber found in whole, unrefined grains. These results suggest that saengshik exerts hypoglycemic effects by modulation of glucose-related biomarkers.