• Title/Summary/Keyword: heat transport

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Influence of Ga Content on the Ionic Conductivity of Li1+XGaXTi2-X(PO4)3 Solid-State Electrolyte Synthesized by the Sol-Gel Method

  • Seong-Jin Cho;Jeong-Hwan Song
    • Korean Journal of Materials Research
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    • v.34 no.4
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    • pp.185-193
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    • 2024
  • In this study, NASICON-type Li1+XGaXTi2-X(PO4)3 (x = 0.1, 0.3 and 0.4) solid-state electrolytes for all-solid-state batteries were synthesized through the sol-gel method. In addition, the influence on the ion conductivity of solid-state electrolytes when partially substituted for Ti4+ (0.61Å) site to Ga3+ (0.62Å) of trivalent cations was investigated. The obtained precursor was heat treated at 450 ℃, and a single crystalline phase of Li1+XGaXTi2-X(PO4)3 systems was obtained at a calcination temperature above 650 ℃. Additionally, the calcinated powders were pelletized and sintered at temperatures from 800 ℃ to 1,000 ℃ at 100 ℃ intervals. The synthesized powder and sintered bodies of Li1+XGaXTi2-X(PO4)3 were characterized using TG-DTA, XRD, XPS and FE-SEM. The ionic conduction properties as solid-state electrolytes were investigated by AC impedance. As a result, Li1+XGaXTi2-X(PO4)3 was successfully produced in all cases. However, a GaPO4 impurity was formed due to the high sintering temperatures and high Ga content. The crystallinity of Li1+XGaXTi2-X(PO4)3 increased with the sintering temperature as evidenced by FE-SEM observations, which demonstrated that the edges of the larger cube-shaped grains become sharper with increases in the sintering temperature. In samples with high sintering temperatures at 1,000 ℃ and high Ga content above 0.3, coarsening of grains occurred. This resulted in the formation of many grain boundaries, leading to low sinterability. These two factors, the impurity and grain boundary, have an enormous impact on the properties of Li1+XGaXTi2-X(PO4)3. The Li1.3Ga0.3Ti1.7(PO4)3 pellet sintered at 900 ℃ was denser than those sintered at other conditions, showing the highest total ion conductivity of 7.66 × 10-5 S/cm at room temperature. The total activation energy of Li-ion transport for the Li1.3Ga0.3Ti1.7(PO4)3 solid-state electrolyte was estimated to be as low as 0.36 eV. Although the Li1+XGaXTi2-X(PO4)3 sintered at 1,000 ℃ had a relatively high apparent density, it had less total ionic conductivity due to an increase in the grain-boundary resistance with coarse grains.

Effects of Dietary Buffer Material for Chicken Meat Grades and PSE Incidence in Broilers under Transport Heat Stress (고온기 육계의 수송 스트레스에 대한 버퍼제 급여에 따른 닭고기 품질 및 PSE 발생에 미치는 영향)

  • Chae, Hyun-Seok;Choi, Hee-Chul;Na, Jae-Cheon;Jang, Ae-Ra;Kim, Min-Ji;Bang, Han-Tae;Kang, Hwan-Ku;Kim, Dong-Wook;Seo, Ok-Suk;Park, Sung-Bok;Ham, Jun-Sang
    • Korean Journal of Poultry Science
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    • v.37 no.2
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    • pp.131-137
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    • 2010
  • The present study has been performed to suggest a method to decrease the adverse effects of transportation on chicken meat quality. The groups were prepared as follows; Control group and three groups of treatments (sodium phosphate, sodium bicarbonate and magnesium sulfate). The chicken fed magnesium sulfate showed higher chicken meat quality compared to control and other treatment groups. Also, minor and severe PSE incidence of chicken breast was found at 88% in sodium phosphate group, 24% in sodium bicarbonate group and 56% in magnesium sulfate group. Control group showed 92% higher minor and severe PSE incidence of chicken breast compared to other groups. In control group, the external bruise of chicken showed 32% but 22, 24 and 44% in other treatment groups, respectively. Lightness ($L^*$) of chicken containing sodium phosphate treatment, sodium bicarbonate treatment and magnesium sulfate were 67.05, 66.27 and 65.89, while Lightness ($L^*$) of chicken containing control group was decreased of 67.88. In conclusion, dietary buffer material (sodium phosphate, sodium bicarbonate, magnesium sulfate) under heat stress decreased adverse effects including death, wound or abnormality of chickens.

Biorefinery Based on Weeds and Agricultural Residues (잡초 및 농림부산물을 이용한 Biorefinery 기술개발)

  • Hwang, In-Taek;Hwang, Jin-Soo;Lim, Hee-Kyung;Park, No-Joong
    • Korean Journal of Weed Science
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    • v.30 no.4
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    • pp.340-360
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    • 2010
  • The depletion of fossil fuels, ecological problems associated with $CO_2$ emissions climate change, growing world population, and future energy supplies are forcing the development of alternative resources for energy (heat and electricity), transport fuels and chemicals: the replacement of fossil resources with $CO_2$ neutral biomass. Several options exist to cover energy supplies of the future, including solar, wind, and water power; however, chemical carbon source can get from biomass only. When used in combination with environmental friend production and processing technology, the use of biomass can be seen as a sustainable alternative to conventional chemical feedstocks. The biorefinery concept is analogous to today's petroleum refinery, which produce multiple fuels and chemical products from petroleum. A biorefinery is a facility that integrates biomass conversion processes and equipment to produce fuels, power, and value-added chemicals from biomass. Biorefinery is the co-production of a spectrum of bio-based products (food, feed, materials, and chemicals) and energy (fuels, power, and heat) from biomass [definition IEA Bioenergy Task 42]. By producing multiple products, a biorefinery takes advantage of the various components in biomass and their intermediates therefore maximizing the value derived from the biomass feedstocks. A biorefinery could, for example, produce one or several low-volume, but high-value, chemical or nutraceutical products and a low-value, but high-volume liquid transportation fuel such as biodiesel or bioethanol. Future biorefinery may play a major role in producing chemicals and materials as a bridge between agriculture and chemistry that are traditionally produced from petroleum. Industrial biotechnology is expected to significantly complement or replace the current petroleum-based industry and to play an important role.

A Study on the documentary characteristics of acupuncture and moxibustion recorded in Dusagyeong(杜思敬)'s "Jesaengbalsu(濟生拔粹)" (두사경(杜思敬)의 "제생발수(濟生拔粹)"에 수록된 침구의적(鍼灸醫籍)에 관한 문헌)

  • Kim, Jung-Ho;Kim, Ki-Wook;Park, Hyun-Guk
    • Journal of Korean Medical classics
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    • v.22 no.2
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    • pp.71-83
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    • 2009
  • The documentary characteristics of acupuncture and moxibustion recorded in Dusagyeong(杜思敬)'s".Jesaengbalsu(濟生拔粹)" can be summarized into 3 major parts: 1. "Gyeolgo-ungichimbeop(潔古雲岐鍼法)" and "Dutaesachimbeop(竇太師鍼法)" 1) "Gyeolgo-ungichimbeop" was edited by Dusagyeong of the Won dynasty, and was recorded in "Jesaengbalsu". Du was influenced by his teacher Heohyeong(許衡) and followed Janggyeolgo(張潔古) and his son Jangbyeok(張璧), and collected his work "Chimgu-pyeon(鍼灸篇)" for Jang and named it "Gyeolgo-ungichimbeop", and took the content from the medical book of Jang and his student Wang-haejang(王海藏). (2) "Jesaengbalsu"'s original edition exists today. The "Gyeolgo-ungichimbeop" listed in "Jesaengbalsu"'s index contain two collections, the first collection being "Gyeolgo-ungichimbeop" and the second collection being "Dutaesachimbeop(竇太師鍼法)" (3) Gyeolgo(潔古)、Un-gija(雲岐子)'s acupuncture methods can be seen in Un-gija "Bomyeongjipryuyo(保命集類要)" and Wanghaejang "Chasananji(此事難知)". (4) The related acupuncture methods are 'Non-gyeong-rak-yeongsubosabeop(論經絡迎隨補瀉法)', 'Gyeong-rakchwiwonbeop(經絡取原法)', 'Jeopgyeongbeop(接經法)', and 'Sang-hanyeolbyeongjabeop(傷寒熱病刺法)' (5) Du's edition of the entire text of 'Gyeolgojajetongbeop(潔古刺諸痛法)' 'Jasimtongjehyeol(刺心痛諸穴)' and the first half of 'Jeopgyeongbeop(接經法)' is all recorded in "Somunbyeonggigi-uibomyeongjip(素問病機氣宜保命集)". The existing "Somunbyeonggigi-uibomyeongjip" is a combination of the unfinished posthumous work of Yuwanso(劉完素), "Gi-ui(氣宜)" and "Byeonggi(病機)" with works such as Jangwonso(張元素)'s '"Bomyeongseo(保命書)"'. (6) Of the titles "Gyeolgo-ungichimbeop" and "Dutaesachimbeop", the 14$\sim$19th chapters "Dutaesachimbeop" should be concentrated at the end of the chapter, and the 16th chapter that Du added was put after chapter 14 "Yujujiyobu(流注指要賦)", and chapters 20, 21 should be put in "Gyeolgoungichimbeop" after chapter 13. 2. "Chimgyeongjeok-yeongjip(鍼經摘英集)" (1) "Chimgyeongjeok-yeongjip" is a collection of the acupuncture and moxibustion contents of medical books from the Geum and Won dynasties that Dusagyeong collected and organized during the Won dynasty, which is consisted of 5 chapters : "Guchimshik(九鍼式)", "Jeolyangchwisuhyeolbeop(折量取腧穴法)", "Bosabeop(補瀉法)", "Yongchimhoheupbeop(用鍼呼吸法)", "Chibyeongjik-ralgyeol(治病直剌訣)". (2) First, the contents. The nine acupuncture needles[九鍼] listed in "Guchimshik(九鍼式)" is the first existing document recording to systematically illustrate the 'nine classical needles' in drawing and text form which reflects the forms of the needles of the era. Second, "Jeolyangchwisuhyeolbeop(折量取腧穴法)" has the same basic way of measuring points [量穴法] as Wang-yuil's "Dong-insuhyeolchimgudo-gyeong(銅人腧穴鍼灸圖經)" and the same point selection rules as "Jeonyeongbang(全嬰方)". Third, in "Bosabeop(補瀉法)", "Somun(素問)" and Janggyeolgo's "Yeongsubosabeop(迎隨補瀉法)" is put together. Fourth, in "Yongchimhoheupbeop(用鍼呼吸法)", the cold and heat supplementation and draining [寒熱補瀉] method that combines breathing with inner and outer rotation[外 內撚] is recorded. Fifth, "Chi-byeongjik-ralgyeol(治病直剌訣)" is the main part of "Chimgyeongjeok-yeongjip(鍼經摘英集)" listing 69 acupuncture treatments reflecting Du's scholastic ideas on aspects such as syndrome differentiation[辨證], needling method and type of needle[鍼具]. (3) The content of this book was quoted by "Bojebang Chimgumun(普濟方 鍼灸門)" and when Gomu compiled "Chimguchwiyeong", he put the acupuncture treatments for the main indications of the disease patterns[鍼方主治病證] of this book in the related main indications of acupuncture points[腧穴主治證], which influenced books on acupuncture points there after. 3. "Chimgyeongjeolyo(鍼經節要)" (1) Consists of 1 volume. The original title of this book is "Dong-insuhyeolchimgudo-gyeong (銅人腧穴鍼灸圖經)" and the author is Wang-yuil of the Northern Song dynasty, written in the 4th year of the Cheonseong(天聖) era of the Song dynasty(1026). (2) Dusagyeong selected the contents on pathology of the 12 meridians in volume one and two, the introduction and five transport points[五輸穴] in volume 5 of "Dong-indo-gyeong(銅人圖經)" and named it "Chimgyeongjeolyo." During the Won dynasty it was recorded in "Jesaengbalsu".

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Current Status of the Research on the Postharvest Technology of Melon(Cucumis melo L.) (멜론(Cucumis melo L.) 수확 후 관리기술 최근 연구 동향)

  • Oh, Su-Hwan;Bae, Ro-Na;Lee, Seung-Koo
    • Food Science and Preservation
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    • v.18 no.4
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    • pp.442-458
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    • 2011
  • Among Cucubitaceae, melon (Cucumis melo) is one of the most diversified fruits, with various forms, sizes, pulps, and peel colors, In addition, it is a commercially important crop because of its high sweetness, deep flavor, and abundant juice. In the species, there are both climacteric and non-climacteric melons depending on the respiration and ethylene production patterns after harvest. Ethylene is also considered a crucial hormone for determining sex expression, Phytohormones other than ethylene interact and regulate ripening, There are some indices that can be used to evaluate the optimum harvest maturity. The harvest time can be estimated after the pollination time, which is the most commonly used method of determining the harvest maturity of the fruit. Besides the physiological aspects, the biochemical alterations, including those of sweetness, firmness, flavor, color, and rind, contribute to the overall fruit quality. These changes can be categorized based on the ethylene-dependent and ethylene-independent phenomena due to the ethylene-suppressed transgenic melon. After harvest, the fruits are precooled to $10^{\circ}C$ to reduce the field heat, after which they are sized and packed. The fruits can be treated with hot water ($60^{\circ}C$ for 60 min) to prevent the softening of the enzyme activity and microorganisms, and with calcium to maintain their firmness. 1-methylenecyclopropene (1-MCP) treatment also maintains their storability by inhibiting respiration and ethylene production. The shelf life of melon is very short even under cold storage, like other cucurbits, and it is prone to obtaining chilling injury under $10^{\circ}C$. In South Korea, low-temperature ($10^{\circ}C$) storage is known to be the best storage condition for the fruit. For long-time transport, CA storage is a good method of maintaining the quality of the fruit by reducing the respiration and ethylene. For fresh-cut processing, washing with a sanitizing agent and packing with plastic-film processing are needed, and low-temperature storage is necessary. The consumer need and demand for fresh-cut melon are growing, but preserving the quality of fresh-cut melon is more challenging than preserving the quality of the whole fruit.

Studies on Changes in the Hydrography and Circulation of the Deep East Sea (Japan Sea) in a Changing Climate: Status and Prospectus (기후변화에 따른 동해 심층 해수의 물리적 특성 및 순환 변화 연구 : 현황과 전망)

  • HOJUN LEE;SUNGHYUN NAM
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.28 no.1
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    • pp.1-18
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    • 2023
  • The East Sea, one of the regions where the most rapid warming is occurring, is known to have important implications for the response of the ocean to future climate changes because it not only reacts sensitively to climate change but also has a much shorter turnover time (hundreds of years) than the ocean (thousands of years). However, the processes underlying changes in seawater characteristics at the sea's deep and abyssal layers, and meridional overturning circulation have recently been examined only after international cooperative observation programs for the entire sea allowed in-situ data in a necessary resolution and accuracy along with recent improvement in numerical modeling. In this review, previous studies on the physical characteristics of seawater at deeper parts of the East Sea, and meridional overturning circulation are summarized to identify any remaining issues. The seawater below a depth of several hundreds of meters in the East Sea has been identified as the Japan Sea Proper Water (East Sea Proper Water) due to its homogeneous physical properties of a water temperature below 1℃ and practical salinity values ranging from 34.0 to 34.1. However, vertically high-resolution salinity and dissolved oxygen observations since the 1990s enabled us to separate the water into at least three different water masses (central water, CW; deep water, DW; bottom water, BW). Recent studies have shown that the physical characteristics and boundaries between the three water masses are not constant over time, but have significantly varied over the last few decades in association with time-varying water formation processes, such as convection processes (deep slope convection and open-ocean deep convection) that are linked to the re-circulation of the Tsushima Warm Current, ocean-atmosphere heat and freshwater exchanges, and sea-ice formation in the northern part of the East Sea. The CW, DW, and BW were found to be transported horizontally from the Japan Basin to the Ulleung Basin, from the Ulleung Basin to the Yamato Basin, and from the Yamato Basin to the Japan Basin, respectively, rotating counterclockwise with a shallow depth on the right of its path (consistent with the bottom topographic control of fluid in a rotating Earth). This horizontal deep circulation is a part of the sea's meridional overturning circulation that has undergone changes in the path and intensity. Yet, the linkages between upper and deeper circulation and between the horizontal and meridional overturning circulation are not well understood. Through this review, the remaining issues to be addressed in the future were identified. These issues included a connection between the changing properties of CW, DW, and BW, and their horizontal and overturning circulations; the linkage of deep and abyssal circulations to the upper circulation, including upper water transport from and into the Western Pacific Ocean; and processes underlying the temporal variability in the path and intensity of CW, DW, and BW.