• Title/Summary/Keyword: Water quality changes

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Establishment of Thermal Infrared Observation System on Ieodo Ocean Research Station for Time-series Sea Surface Temperature Extraction (시계열 해수면온도 산출을 위한 이어도 종합해양과학기지 열적외선 관측 시스템 구축)

  • KANG, KI-MOOK;KIM, DUK-JIN;HWANG, JI-HWAN;CHOI, CHANGHYUN;NAM, SUNGHYUN;KIM, SEONGJUNG;CHO, YANG-KI;BYUN, DO-SEONG;LEE, JOOYOUNG
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.22 no.3
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    • pp.57-68
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    • 2017
  • Continuous monitoring of spatial and temporal changes in key marine environmental parameters such as SST (sea surface temperature) near IORS (Ieodo Ocean Research Station) is demanded to investigate the ocean ecosystem, climate change, and sea-air interaction processes. In this study, we aimed to develop the system for continuously measuring SST using a TIR (thermal infrared) sensor mounted at the IORS. New SST algorithm is developed to provide SST of better quality that includes automatic atmospheric correction and emissivity calculation for different oceanic conditions. Then, the TIR-based SST products were validated against in-situ water temperature measurements during May 17-26, 2015 and July 15-18, 2015 at the IORS, yielding the accuracy of 0.72-0.85 R-square, and $0.37-0.90^{\circ}C$ RMSE. This TIR-based SST observing system can be installed easily at similar Ocean Research Stations such as Sinan Gageocho and Ongjin Socheongcho, which provide a vision to be utilized as calibration site for SST remotely sensed from satellites to be launched in future.

Changes in physicochemical characteristics of sorghum among different varieties and at different harvest stages after heading (품종 및 수확시기를 달리한 수수의 이화학 특성 변화)

  • Kim, Sung Kook;Jung, Gun Ho;Lee, Jae Eun;Lee, Byoung Kyu;Woo, Koan Sik
    • Korean Journal of Food Science and Technology
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    • v.50 no.3
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    • pp.260-266
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    • 2018
  • The change in physicochemical characteristics of sorghum among different varieties and at different harvest stages after heading were evaluated. The proximate compositions and chromaticity of sorghum were significantly different, depending on their varieties and harvesting times. Water solubility was high in sorghum harvested on the $50^{th}$ day after heading; however, the swelling power was reversed. Total polyphenol content of Hwanggeumchal, Nampungchal, and Sodamchal was 17.60-24.62, 17.88-24.67, and 17.37-22.37 mg GAE/g, respectively, and the flavonoid content was 10.43-13.50, 9.68-13.85, and 9.52-12.46 mg CE/g, respectively. The DPPH radical-scavenging activities were 9.94-16.21, 11.42-16.54, and 10.12-15.16 mg TE/g, respectively, and the ABTS radical-scavenging activities were 8.85-19.99, 10.51-20.24, and 9.71-17.93 mg TE/g, respectively. Total polyphenol and flavonoid contents, and radical scavenging activities were high in sorghum harvested on the $40-50^{th}$ day after heading. As a result, it is considered that sorghum varieties such as Hwanggeumchal, Nampungchal, and Sodamchal should be harvested on the $40^{th}$ day after heading.

Effects of Cattail Pollen Powders on the Rheology of Dough and Processing Adaptability of White Pan Bread (부들화분을 첨가한 밀가루 반죽의 물성과 제빵 적성)

  • Lee, Bung-Chan;Joung, Yong-Myeon;Hwang, Seong-Yun;Lee, Jong-Hwa;Oh, Man-Jin
    • Food Science and Preservation
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    • v.16 no.4
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    • pp.525-533
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    • 2009
  • To explore cattail pollen powder as a functional food ingredient, we analyzed the general components of pollen powder, tested changes in the physical properties of dough containing the powder, and investigated the process ability of powder-containing dough in bread making by adding 3%, 6%, or 9% by weight of pollen powder to wheat flour. Cattail pollen powder consisted of (all w/w) 12.7-13.2% water, 15.7-17.8% crude protein, 1.3% crude fat, 7.5-7.7% free sugar, 14.7-18.6% crude fiber, 3.4-4.9% pollen, and 49.7-55.9% soluble nitrogen-free extract (NFE). Analysis of the physical properties of dough mixed with pollen powder showed that as more pollen powder was added, the absorption rate increased, but dough stability decreased. With increasing levels of cattail pollen powder, the falling number decreased, and amylase activity increased. Fermentability was highest in dough made with 3% by weight of pollen powder, and the bread product made from such dough had the greatest volume. As more cattail pollen powder was added, the moisture activity in dough tended to decrease to a greater extent than seen in control dough, and this tendency increased with time. We found that longer storage periods were associated with greater hardness and springiness, which indicated degradation in product quality. Therefore, it is suggested that bread products containing cattail pollen powder should be consumed within 3 days of preparation. In a taste survey, bread baked with 3% (w/w) cattail pollen powder scored highest in all questionnaire items.

Changes in the Physicochemical Properties of Ground Pork Meat Containing Persimmon Peel during Refrigerated Storage (감 껍질을 함유한 분쇄 돈육의 냉장 저장 중 이화학적 특성 변화)

  • Choi, Gang-Won
    • Journal of Life Science
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    • v.29 no.7
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    • pp.792-799
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    • 2019
  • This study was carried out to investigate the effect of persimmon peel on the physicochemical properties of ground pork stored at $4^{\circ}C$ for 10 days. Four types of ground pork were evaluated: T0 without dried persimmon peel powder, and T1 with 0.3%, T2 with 0.7%, and T3 with 1.0% dried persimmon peel powder. The pH increased during storage, with the pH of T3 being the lowest (p<0.01). The L-value and b-value were not significantly changed, but the a-value decreased during storage. On the 10th day of storage, the a-values were significantly higher for T2 and T3 than for T0 and T1 (p<0.001). TBARS significantly increased during storage, with lower values for T2 and T3 than for T0 and T1 (p<0.001). DPPH free radical scavenging activity decreased during storage, with T0 having the lowest value (p<0.001). The VBN content increased during storage, and the VBN content of T0 was the highest at the 10th day (p<0.05). The water-holding capacity decreased and cooking loss increased during storage. Hardness and chewiness increased, while springiness and gumminess decreased during storage. The results of this study showed that the addition of persimmon peel during the process of making ground pork had antioxidant effects that maintained redness and physical quality. A 0.7% addition was the most appropriate.

Comparative Analysis of Radiative Flux Based on Satellite over Arctic (북극해 지역의 위성 기반 복사 에너지 산출물의 비교 분석)

  • Seo, Minji;Lee, Eunkyung;Lee, Kyeong-sang;Choi, Sungwon;Jin, Donghyun;Seong, Noh-hun;Han, Hyeon-gyeong;Kim, Hyun-Cheol;Han, Kyung-soo
    • Korean Journal of Remote Sensing
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    • v.34 no.6_2
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    • pp.1193-1202
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    • 2018
  • It is important to quantitatively analyze the energy budget for understanding of long-term climate change in Arctic. High-quality and long-term radiative parameters are needed to understand the energy budget. Since most of radiative flux components based on satellite are provide for a short period, several data must be used together. It is important to acquaint differences between data to link for conjunction with several data. In this study, we investigated the comparative analysis of Arctic radiative flux product such as CERES and GEWEX to provide basic information for data linkage and analysis of changes in Arctic climate. As a result, GEWEX was underestimated the radiative variables, and it difference between the two data was about $3{\sim}25W/m^2$. In addition, the difference in high-latitude and sea ice regions have increased. In case of comparing with monthly means, the other variables except for longwave downward flux represent high difference of $9.26{\sim}26.71W/m^2$ in spring-summer season. The results of this study can be used standard data for blending and selecting GEWEX and CERES radiative flux data due to recognition of characteristics according to ice-ocean area, season, and regions.

Temporal and Spatial Distribution of Microbial Community and Odor Compounds in the Bukhan River System (북한강 수계 미소생물 군집 및 이취미 물질의 시공간적 분포 특성)

  • Byun, Jeong-Hwan;Yu, Mina;Lee, Eunjeong;Yoo, Soon-Ju;Kim, Baik-Ho;Byun, Myeong-Seop
    • Korean Journal of Ecology and Environment
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    • v.51 no.4
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    • pp.299-310
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    • 2018
  • Odor compounds (geosmin, 2-MIB) have been causing problems in the Bukhan River system, but the causative organisms have not been clearly identified. To evaluate the relationship between dynamics of microbial community and odor compounds, two times monthly monitoring of water quality and microbial community from the three serial lakes (Lake Uiam, Lake Cheongpyeong and Lake Paldang) in the Bukhan River system were conducted from April to October 2017. The odor compounds were analyzed by HS-SPME analysis method using GC/MS. Bacteria communities were identified at the class level by NGS analysis. Actinobacteria and Betaproteobacteria were dominant taxon in bacteria community of three serial lakes. In the case of phytoplankton communities showed that seasonal changes by Bacillariophyceae and Cryptophyceae in spring, Cyanobacteria in summer, and Bacillariophyceae and Cryptophyceae in autumn. Dominant species was Dolichospermum (=Anabaena), Microcystis and Pseudanabaena in Bukhan River system in all study period. At the same time the odors geosmin and 2-MIB were also detected at high concentration. There is a significant positive correlation between proportion of Actinobaceria and 2-MIB concentration (r=0.491, p<0.01). In addition, proportion of cyanobacteria showed a significant correlation of geosmin (r=0.381, p<0.05) and 2-MIB (r=0.386, p<0.05) concentration. In this study, odor compounds in the Bukhan River system are considered to be a direct relationship between with Actinobacteria and cyanobacteria.

Changes in CT Number and Noise Level according to Pitch in Spiral Image Acquisition (나선형영상획득에서 Pitch에 따른 CT 감약계수와 잡음의 변화)

  • Kang, SungJin
    • Journal of the Korean Society of Radiology
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    • v.14 no.7
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    • pp.981-989
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    • 2020
  • In this study, a self-made customized phantom was used to quantitatively measure the change in CT number and noise according to the change of pitch. In order to acquire an image using the phantom, the inside of the phantom was filled with sterile distilled water. Inside the glass tube, a solution obtained by diluting the ratio of normal saline and contrast medium to 100%(NS), 400:1, 200:1, 100:1, 50:1, respectively, was placed and imaged. At this time, the pitch was divided into steps of 0, 0.35, 0.7, 1.05, and 1.4 for each dilution ratio of the solution and imaged, respectively. One-way ANOVA analysis were performed to verify whether the mean of the CT number and noise values measured in all ROIs by dilution ratio showed a significant difference according to the change in pitch. As a result of the experiment, there was no statistically significant difference in the change of the CT number according to the change in the pitch for each dilution ratio, but the noise value tended to increase with the increase of the pitch, and showed a statistically significant difference. In the spiral image acquisition of CT, noise can be changed to a significant level depending on the pitch. Therefore, it will be necessary to set the quality evaluation items and criteria for CT images using the spiral image acquisition method.

Identifying Degradation Causes of Endangered Freshwater Fish, Microphysogobio rapidus Using Habitat-Environmental Characteristics (멸종위기 야생생물 I급 여울마자 서식지 환경 특성 파악을 통한 훼손 원인 분석)

  • Ju-Duk Yoon;Keun-Sik Kim;Chang-Deuk Park;Dong-Won Kang;Heung-Heon Lee;Chi-Hong Lim;Nam-Shin Kim
    • Korean Journal of Ecology and Environment
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    • v.56 no.3
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    • pp.229-241
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    • 2023
  • Microphysogobio rapidus is designated as endangered species class I by Ministry of Environment, and its distribution and population have been gradually declining, and it is now limited to the Nam River and some tributary streams of the Nakdong River Watershed. For the restoration of this highly endangered species, it is important to identify the causes of the decline and establish appropriate restoration plans. However, due to lack of basic data and ecological research, most steps are stagnant. Therefore, in this study, we identified the differences in the physical, biological, and sociological habitats between current and past distributed sites through field surveys and literature reviews. As a result of the field survey, there were differences in conductivity between the current and past distributed sites, and fish communities were also showed differences. The literature data also showed that the physico-chemical values of the past distributed sites were generally unfavorable, which generated negative consequences on biological factors. In particular, the effects of urbanization were found to be a major factor affecting the habitat of M. rapidus. Habitat stabilization is crucial for the recovery of this endangered species. However, in the past distributed sites, disturbances such as stream development and weir construction have altered streams physico-chemically and result in changes of M. rapidus. Therefore, a comprehensive plan that considers both stream connectivity and water quality is needed to manage and restore the habitat of M. rapidus.

Changes of Physicochemical Properties and Rheology during the Thawing Period of Frozen Condensed Milk (냉동농축유의 해동기간에 따른 이화학적 특성과 물성 변화)

  • Sang-Woo Kim;Woo Jin Ki;Myoung Soo Nam
    • Journal of Dairy Science and Biotechnology
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    • v.42 no.2
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    • pp.64-76
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    • 2024
  • This study analyzed the physicochemical properties and rheology of frozen condensed skim milk during thawing at 5 room temperature (20℃). The viscosity of the condensed milk was 80 cps (21.5℃) immediately after manufacture, and this value was decreased to 0 cps (21. 5℃) during storage at day 7. The particle sizes of the condensed skim milk were 0.128 mm just after manufacture, and 0.522 and 0.818 mm at days 3 and 5 of thawing at 20℃, respectively. Condensed skim milk with no temperature abuse had lower acidity than those stored at room temperature on the 3rd and 7th days. Additionally, a sandy texture was observed as the thawing period increased. Based on the comprehensive results of this study, when frozen condensed skim milk is added to a product as a raw material, the longer the thawing period at room temperature, the longer the ice crystals inside melt and become water drips. Quality defects, such as weight loss, decreased pH, protein denaturation, and texture deterioration, are expected to occur.

The effect of continuous application of the food waste composts on the paddy field environment (음식물류폐기물 활용 퇴비의 장기시용이 논 농업환경에 미치는 영향)

  • Kwon, Soon-Ik;So, Kyu-Ho;Hong, Seung-Gil;Kim, Gun-Yeob;Lee, Jeong-Taek;Seong, Ki-Seog;Kim, Kwon-Rae;Lee, Deog-Bae;Jung, Kwang-Yong
    • Journal of the Korea Organic Resources Recycling Association
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    • v.17 no.3
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    • pp.55-70
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    • 2009
  • The long-term effects and the soil environmental changes were examined to ensure the safety of food waste compost in agricultural use. Based on conventional nitrogen application rate of chemical fertilizer, Pig manure compost with $24g\;N\;kg^{-1}$, $8g\;P_2O_5\;kg^{-1}$, and $10.4g\;K_2O\;kg^{-1}$ and food waste compost with $20g\;N\;kg^{-1}$, $20.1g\;P_2O_5\;kg^{-1}$, and $6.5g\;K_2O\;kg^{-1}$ were applied to the paddy soil in $2{\times}2{\times}2m$ lysimeter in which paddy rice (Oryza sativa L. var Chucheong) were grown. The rice grown where food waste compost applied showed better growth responses than control, whereas less yield rate than chemical fertilizer applied. The contents of organic matter, nitrogen, and phosphorus after experiment were increased with compost applied. In addition, it improved soil aeration by the application of food waste compost, while little difference was observed in the quality of surface, infiltrated, and ground water compared to chemical fertilizer applied or control.