• Title/Summary/Keyword: Dry processes

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A Study of Arctic Microbial Community Structure Response to Increased Temperature and Precipitation by Phospholipid Fatty Acid Analysis

  • Sungjin Nam;Ji Young Jung
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.4 no.2
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    • pp.86-94
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    • 2023
  • Climate change is more rapid in the Arctic than elsewhere in the world, and increased precipitation and warming are expected cause changes in biogeochemical processes due to altered microbial communities and activities. It is crucial to investigate microbial responses to climate change to understand changes in carbon and nitrogen dynamics. We investigated the effects of increased temperature and precipitation on microbial biomass and community structure in dry tundra using two depths of soil samples (organic and mineral layers) under four treatments (control, warming, increased precipitation, and warming with increased precipitation) during the growing season (June-September) in Cambridge Bay, Canada (69°N, 105°W). A phospholipid fatty acid (PLFA) analysis method was applied to detect active microorganisms and distinguish major functional groups (e.g., fungi and bacteria) with different roles in organic matter decomposition. The soil layers featured different biomass and community structure; ratios of fungal/bacterial and gram-positive/-negative bacteria were higher in the mineral layer, possibly connected to low substrate quality. Increased temperature and precipitation had no effect in either layer, possibly due to the relatively short treatment period (seven years) or the ecosystem type. Mostly, sampling times did not affect PLFAs in the organic layer, but June mineral soil samples showed higher contents of total PLFAs and PLFA biomarkers for bacteria and fungi than those in other months. Despite the lack of response found in this investigation, long-term monitoring of these communities should be maintained because of the slow response times of vegetation and other parameters in high-Arctic ecosystems.

Exploring the Impact of Appetite Alteration on Self-Management and Malnutrition in Maintenance Hemodialysis Patients: A Mixed Methods Research Using the International Classification of Functioning, Disability and Health (ICF) Framework

  • Wonsun Hwang;Ji-hyun Lee;Se Eun Ahn;Jiewon Guak;Jieun Oh;Inwhee Park;Mi Sook Cho
    • Clinical Nutrition Research
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    • v.12 no.2
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    • pp.126-137
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    • 2023
  • Hemodialysis (HD) patients face a common problem of malnutrition due to poor appetite. This study aims to verify the appetite alteration model for malnutrition in HD patients through quantitative data and the International Classification of Functioning, Disability, and Health (ICF) framework. This study uses the Mixed Method-Grounded Theory (MMGT) method to explore various factors and processes affecting malnutrition in HD patients, create a suitable treatment model, and validate it systematically by combining qualitative and quantitative data and procedures. The demographics and medical histories of 14 patients were collected. Based on the theory, the research design is based on expansion and confirmation sequence. The usefulness and cut-off points of the creatinine index (CI) guidelines for malnutrition in HD patients were linked to significant categories of GT and the domain of ICF. The retrospective CIs for 3 months revealed patients with 3 different levels of appetite status at nutrition assessment and 2 levels of uremic removal. In the same way, different levels of dry mouth, functional support, self-efficacy, and self-management were analyzed. Poor appetite, degree of dryness, and degree of taste change negatively affected CI, while self-management, uremic removal, functional support, and self-efficacy positively affected CI. This study identified and validated the essential components of appetite alteration in HD patients. These MM-GT methods can guide the selection of outcome measurements and facilitate the perspective of a holistic approach to self-management and intervention.

Effects of Increasing Ambient Temperatures on the Static Load Performance and Surface Coating of a Gas Foil Thrust Bearing (외기 온도 증가가 가스 포일 스러스트 베어링의 하중지지 성능과 표면 코팅에 미치는 영향)

  • Hyunwoo Cho;Youngwoo Kim;Yongbum Kwon;Tae Ho Kim
    • Tribology and Lubricants
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    • v.40 no.3
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    • pp.103-110
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    • 2024
  • Gas foil thrust bearings (GFTBs) are oil-free self-acting hydrodynamic bearings that support axial loads with a low friction during airborne operation. They need solid lubricants to reduce dry-friction between the runner and top foil and minimize local wears on their surfaces during start-up and shutdown processes. In this study, we evaluate the lift-off speeds and load capacity performance of a GFTB with Polytetrafluoroethylene (PTFE) surface coating by measuring drag torques during a series of experimental tests at increasing ambient temperatures of 25, 75 and 110℃. An electric heat gun provides hot air to the test GFTB operating in the closed booth to increase the ambient temperature. Test results show that the increasing ambient temperature delays the lift-off speed and decreases the load capacity of the test GFTB. An early developed prediction tool well predicts the measured drag torques at 60 krpm. After all tests, post inspections of the surface coating of the top foil are conducted. Scanning electron microscope (SEM) images imply that abrasive wear and oxidation wear are dominant during the tests at 25℃ and 110℃, respectively. A quantitative energy dispersive spectroscopy (EDS) microanalysis reveals that the weight percentages of carbon, oxygen, and nitrogen decrease, while that of fluorine increases significantly during the highest-temperature tests. The study demonstrates that the increasing ambient temperature noticeably deteriorates the static performances and degrades the surface coating of the test GFTB.

Performance Study on Odor Reduction of Indole/Skatole by Composite

  • Young-Do Kim
    • Journal of Wellbeing Management and Applied Psychology
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    • v.7 no.3
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    • pp.67-72
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    • 2024
  • This study developed a dry composite module-type deodorization facility with Twisting airflow changes and two forms (catalyst, adsorbent) within one module. Experiments were conducted to evaluate the reduction efficiency of odor substances C8H7N and C9H9N. The device combines UV oxidation using TiO2, catalytic oxidation using MnO2, and adsorption using A/C in five different methods. Data analysis of experimental results utilized the statistical package program Python 3.12. The program applied frequency analysis of odor removal efficiency, one-way ANOVA, and post-hoc tests, with statistical significance determined by p-value to ensure reliability and validity of the measurements. Results indicated that the highest removal efficiency of C8H7N and C9H9N was achieved by the UV+A/C method, suggesting the superior effectiveness and efficiency of the developed device. Combining multiple processes and technologies within one module enhanced odor treatment efficiency compared to using a single method. The device's modularity allows for flexibility in adapting to various sewage treatment scenarios, offering easy maintenance and cost-effective deodorization. This composite reaction module device can apply multiple technologies, such as biofilters, plasma, activated carbon filters, UV-photocatalysis, and electromagnetic-chemical systems. However, this study focused on UV-photocatalysis, catalysts, and activated carbon filters. Ultimately, the research demonstrates the practical applicability of this innovative device in real sewage treatment operations, showing excellent reduction efficiency and effectiveness by integrating UV oxidation, TiO2 photocatalysis, MnO2 catalytic oxidation, and A/C adsorption within a modular system.

Study on sink-mark reduction and gas venting of injection molded parts using compressed air (압축공기를 사용한 사출성형품의 싱크마크 저감 및 가스 벤팅에 관한 연구)

  • Se-Ho Lee;Ho-Sang Lee
    • Design & Manufacturing
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    • v.18 no.3
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    • pp.71-80
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    • 2024
  • Sink marks are a common defect that occurs due to differences in shrinkage in areas with significant thickness variations in injection-molded parts. In this paper, we investigated the reduction of sink marks and the improvement of gas venting in injection molding processes using External Gas Injection (EGI). A mold was designed with considerations for EGI core pins, O-ring grooves to prevent gas leakage, and ejector-pin sealing. The sink marks were then examined through a series of experiments. When the delay time for injecting compressed air was set to 2.2 seconds, the depth of the sink marks was minimized. However, when the delay time was either too short or too long, the depth of the sink marks increased. There was almost no difference in the depth of the sink marks at discharge pressures of 30 and 50 bar of compressed air, but the sink marks were significantly reduced at a discharge pressure of 70 bar. Under the conditions of a 2.2-second delay time and a supply pressure of 70 bar, the smallest depth, 0.594 ㎛, was observed when the supply time was between 6 and 7 seconds. This represents a reduction of approximately 94% compared to the sink mark depth of 10.078 ㎛ observed with conventional injection molding. To verify the gas venting effect of compressed air injection, an experiment was conducted using non-dried PC. The silver streaks that appeared on the exterior of the molded part were completely eliminated when the air supply pressure was set to 20 bar. This indicates that by injecting compressed air into the mold cavity before injecting the resin, the appearance quality of the injection-molded part can be improved without the need to dry the resin in advance.

A Study on the Cooking in 'The Kosa-sibi Jip' (2) ("고사십이집(攷事十二集)"의 조리가공에 관한 분석적 연구(2))

  • 김성미
    • Journal of the East Asian Society of Dietary Life
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    • v.4 no.3
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    • pp.1-19
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    • 1994
  • In this paper, twenty-five kinds of food presented in Sooljip(戌集) 5 and 6 of Food collections of 'Kosa-sibi Jip(攷事十二集)' have been classified into four : Staple food, subsidiary food, Tuck(rice cake) and Han-gwa(Korean confectionery), and Tang-jng and tea. Cooking processes have been examined and scientifically analyzed in terms of cooking, Fourteen kinds of Jook (thick gruel with cereal) as well as Urak-Jook were presented among the methods of making Jook, one of staple foods. Milk and ground rice were boiled together into Urak-Jook, which was nutritious because of carbohydrate, added to milk. Hong-sa Myun was mode of ground shrimps, ground bean, ground rice and flour which were kneaded together. It was a nutritiously balanced food. Nineteen kinds of Kimchi presented in this book were classified by the recipes. The five of Jook-soon Ja, U-so Ja, Tam-bok Ja and Jo-gang were made by adding red malt and cereals(boiled rice or candies). Jo-gang, Jo-ga and Jo-gwa-chae were made by adding salt and rice wine. With salt and fermenters added, eight were made. Chim-jup-jeo-ga was made by adding Jang(soy-bean sauce) and the inner chaff of wheat instead of salt. The four of Ka-za-san, Hwang-gwa-san, Tong-gwa-san and Jo-gang were made by adding salt and vinegar. Jo-gang was made by adding salt, rice wine, residue of rice wine and candies. The four of Kae-mal-ga, Ku-cho-chim-chae, Un-gu-hwa and Suk-hwa-chim-chim-chae were made by adding salt and spices. San-got-Kimchi was made without salt. San-got-Kimchi and Suk-hwa-chim-chae were made originally in Korea. Suk-hwa-chim-chae, in particular, was first classified as a kind of Kimchi in this book and oysters were added, which is notable. Pork could be preserved longer when smoked oven the weak fire of thatch ten days and nights. Dog meat was sauced and placed on the bones in a pot. A porcelain was put on the top of the pot. Flour paste sealed the gap between the porcelain and the pot. Some water was poured into the porcelain, and the meat was steamed, with two or three thatched sacks burned, which was a distilled dry steaming. This process has been in use up to now. Various cooking methods of chicken were presented from in Umsik-dimi-bang to in Chosun Musang Sinsik Yori Jebup. These methods were ever present regardless of ages. Such measuring units as Guin(斤) and Nyang(兩) were most frequently used in cooking processes of this book, except in case of Jang(soy bean sauce), vinegar and liquor. Twenty eight kinds of kitchenware and cookers were used, of which porcelains wee most used and pans and sieves followed. The scientific eight cooking methods were as follows. First, salt was refined through saturated solution. Next, it was recommended Hong-sa Myun containing shrimps should not be taken along with pork, which is thought to be a proper diet in terms of cholesterol contained by shrimps and pork. Third, meat was coated with thin gruel and quickly roasted and cleared of the dried gruel membrane, which prevented nutrients from exuding and helped to make the meat well-done. Fourth, The fruit of paper mulberry trees has the protease which can soften meat. Therefore when meat was boiled with th fruit of paper mulberry trees, it can be softened easily. Fifth, pork was smoked over the weak fire of thatch. Sixth, in cooking dog meat, distilled dry steaming raised the boiling point and made it possible to preserve meat longer. Seventh, in boiling the sole of a bear, lime was added, which made meat tender by making the pH lower or higher than that of raw meat. Finally, in boiling down rice gluten, a porcelain in the pot prevented boiling over the brim, which is applied to pots in which to boil medical herbs.

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Geochemistry of Stream Water around the Abandoned Boeun Coal Mine, Hoenam Area (보은제일폐탄광 주변 하천수의 지구화학적 특징)

  • Jeon, Seo-Ryeong;Shin, Ik-Jong;Lee, Kyu-Seung
    • Korean Journal of Environmental Agriculture
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    • v.20 no.1
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    • pp.20-27
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    • 2001
  • Stream water chemistry in the abandoned Boeun Jeil coal mine area was studied for a period of 3 months, including rainy and dry season. The stream waters were a nearly neutral and slightly alkali condition, and $Mg-SO_4$ type with Mg>Ca>Na>K and $SO_4>HCO_3>Cl>NO_3$. Chemical composition of the stream water was quite irregular during the experimental period. Concentrations of Na, K, $HCO_3$, U, Sr, and Cr decreased by $10{\sim}30%$ during rainy season, caused by dilution effects with rain. The concentration of Ca, Mg, $NO_3$, Cd, and Co increased during the rainy season, caused by more easily dissolved from bedrocks or mine drainage with slightly acidic condition than dry season. The stream water was enriched in Mg, Ca, $HCO_3$, $SO_4$, Al, Fe, Zn, Ni, Co, Cr, Cd, Sr and U. Concentrations of Na, Mg, Ca, $SO_4$, $HCO_3$, Fe, Zn, Ni, Sr, and U decreased linearly with distance from the mine adit. These elements were strongly controlled by dilution of unpolluted water influx and/or adsorption on the clay minerals and iron oxyhydroxide precipitates. This mine area exhibited two main weathering processes ; 1) oxidation with acidification derived from Fe sulphides, and 2) pH buffering due to Ca and Mg carbonate dissolution. This weathering processes were followed by adsorption of metals on iron oxyhydroxides and precipitation.

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Effects of Chlorella Culture Solution Using As Midium of Anaerobic Digestate on Early Growth of Italian Ryegrass (Lolium multiflorum L.) (혐기소화처리액을 배지로 이용한 클로렐라 배양액 시용이 이탈리안 라이그라스의 초기생육에 미치는 영향)

  • Seo, Un Kab;Lee, Jin Woong;Ryoo, Jong Won
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.36 no.4
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    • pp.393-401
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    • 2016
  • Anaerobic digestion is a collection of naturally occurring processes that convert organic matter and liquid residue, so-called digestate. The use of digestate biofertilizers is one of the important components of integrated nutrient management, as they are renewable sources of plant nutrients for sustainable agriculture. Seeds of Italian ryegrass (Lolium multiflorum L.) were germinated in different concentration of Chlorella in order to investigate it's the effect of Chlorella on growth parameters, seed germination and early growth. The experiment using plug tray was conducted at the green house placed in the Sangji University. The experiment consisted of nine treatments including different concentrations of Chlorella sp. culture solution and non-treated control. The germination percentage at the treatment with 25% Chlorella sp. culture solution was greater than that of control. The 50% concentration of Chlorella sp. culture solution was found to promote a better seedling growth in terms of shoot length, fresh weight and dry weight compared to the anaerobic digestate. Results showed that the best concentration of Chlorella culture solution was achieved by the 50% concentration of Chlorella culture solution treatment. As a conclusion, the application of Chlorella culture solution was found to be able to promote the germination and shoots growth of Italian ryegrass.

Short-term Change in Channel Morphology of the Naeseong Stream before the Operation of Yeongju Dam, Korea (영주댐 운영 전 내성천에서 하도 형태의 단기 변화)

  • Lee, Chanjoo;Kim, Donggu
    • Ecology and Resilient Infrastructure
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    • v.4 no.1
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    • pp.12-23
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    • 2017
  • The Naeseong Stream is a meandering sand-bed stream flowing through mountains and has so long maintained its geomorphological uniqueness characterized by extensive braided bare bars. Recently, its long-lasting landscape has been changed due to encroachment of vegetation. In this study being a part of long-term monitoring research morphological changes of the 56.8 km long study reach of the Naeseong Stream, which occurred during the period of 2012 - 2016 were analyzed. Airborne LiDAR and terrestrial cross-section surveys were carried out. Hydrological and on-site investigation data were also collected. Among the main four sites, two bend reaches showed point bars enlarged, while along the other two straight reaches mid-channel bars were either newly formed or increased in area and height. At the highest deposition point of each bar, vertical changes which were caused by one or two times of sediment deposition amounted to 0.6 - 1.4 m. On the contrary channel bed degradation was not obvious. Overall morphological changes in the study reach were attributed to deposition of sediment which occurred during the flood in July 2016 on the bar surfaces vegetated during the precedent dry seasons. These kind of geomorphological processes are thought to be the same as those related to the existing mid-channel islands along the mid- and downstream reach of the Naeseong Stream.

Earth Hummocks on the Crater Floor of Baegnokdam at Mt. Halla (한라산 백록담 화구저의 유상구조토)

  • 김태호
    • Journal of the Korean Geographical Society
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    • v.36 no.3
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    • pp.233-246
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    • 2001
  • Topography and soil characteristics of earth hummocks are examined in the summit crater of Mt. Halla in order to evaluate their morphoclimatic significance as an indicator of a periglacial environment. The hummocks are generally oval in outline, and they have a diameter of 42 to 200 cm and a height of 9 to 27 cm Seventeen hummocks are distributed In a 5$\times$5 m quadrat at an interval of 20 to 40 cm Excavation reveals the cryoturbated soil profiles which consist of upper dark brown layer and lower brown layer. The dark brown layer has 61.8% total clay and silt content, implying Its high frost susceptibility Earth hummocks have the dry density of 0.761 to 1.009 g/㎤ the void ratio of 1420 to 2.008, and the moisture content of 24.2 to 68.8% by weight, respectively. The hummocky soils become compacted and desiccated downward. Earth hummocks are frozen as a hard solid mass during winter and early spring, and freezing fronts reach about 45 cm below their apices. The layer with high lute content appears in the upper horizon of dark brown soil. but Ice lenses are not so much segregated The moisture content of hummocky soils generally increases up to 73.9 to 118.80% for dark brown layer and 49.9 to 82.8% for brown layer during thins period Because the cohesive soil of earth hummocks indicates 72.8% of the moisture content as a liquid limit, the dark brown layer is highly fluid and consequently subject to cryoturbation processes.

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