• 제목/요약/키워드: Cold Reduction

검색결과 590건 처리시간 0.033초

경화촉진제를 사용한 콘크리트의 초기강도 발현 특성 검토 (Investigation of Early-Age Concrete Strength Development Using Hardening Accelerator)

  • 김규용;김용로;박종호
    • 콘크리트학회논문집
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    • 제28권3호
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    • pp.309-316
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    • 2016
  • 본 연구에서는 21~27 MPa 수준의 콘크리트를 대상으로 하여, 양생온도 및 단위결합재량에 따른 초기강도 발현 특성을 검토한 후, 초기강도를 개선하기 위한 방안으로 시멘트의 응결 및 경화를 촉진할 수 있는 경화촉진제의 종류에 따른 성능을 검토하였다. 검토 결과 본 연구의 범위에서는 수용성 무기염이 유기염에 비해 상대적으로 경화촉진 효과가 우수하였으며, 사용량이 낮은 범위에서는 수용성 무기염에 의한 $C_3S$의 수화 반응촉진효과가 초기강도 발현에 효과적인 것으로 나타났다. 또한, 경화촉진제 중에서는 Pt(Potassium thiocyanate)의 촉진효과가 가장 우수하였으며, 양생온도 $15^{\circ}C$ 조건에서도 약 25시간에 초기동해 제어 강도 확보가 가능하여 공기단축 효과를 기대할 수 있고, 양생온도 $5^{\circ}C$에서도 양생온도 $10^{\circ}C$ 조건의 Plain과 유사한 시간에 5MPa 확보가 가능하여, 동일한 공기를 고려할 경우 연료비용 및 $CO_2$ 가스 발생 저감 등의 효과를 기대할 수 있을 것으로 판단된다.

小型定置網資料에 의한 淺水灣 魚類의 水質에 따른 種組成 및 量的 變動 (Seasonal Fluctuations in Abundance and Species Composition of Fishes in Cheonsu Bay Using Trap Net Catches)

  • 이태완;석규진
    • 한국해양학회지
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    • 제19권2호
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    • pp.217-227
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    • 1984
  • 1981年에서 1982年 사이 淺水灣 入口에서 小型定置網으로 蒐集한 魚類 群集 의 種組成과 量的 變動을 季節別로 分析하였다. 總 64種의 魚類가 採集되었으며, 小數種이 魚類群集을 優占하였다. 이른 봄에는 漁獲量이 적었으며, 베로라치 (Enedias fangi)와 까나리(Ammodytes personatus)가 優占하였다. 魚類의 種數, 個體數 및 漁獲量은 늦봄에 年中最大값을 보였으며, 이는 魚類들이 産卵 혹은 攝餌를 위하여 灣으로 回族하여 들어오기 때문인 것으로 보인다. 이 시기에는 3種 의 乳泳生魚類, 밴댕이 (Harengula zunasi), 멸치(Engraulis japonica) 및 전어 (Konosirus punctatus)가 優占하였으며, 種類, 個體數 및 어획량이 낮에 비하여 밤에 훨씬 많았다. 여름에는 種數 및 漁獲量이 크게 감소하였으며, 이는 産卵후 成漁가 죽거나, 널리 퍼져 있기 때문인 것으로 보인다. 가을에는 그 해에 태어난 魚類가 再介入하여 어획량이 증가하였다. 이 시기에는 봄, 여름에 産卵한 밴댕이, 멸치 및 전어의 幼漁가 우점하였다. 또, 낮과 밤의 種組成도 큰 차를 보이지 않았다.

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생장점배양에 의한 우량마늘 체계적 증식 1.생장점배 양으로부터 기관형성 (Systematic Propagation of High Quality Garlic (Allium sativum L.) Through Shoot Apical Meristem Culture 1. Organogenesis from in Vitro Cultured Shoot-tips)

  • Lee, Eun-Mo;Lee, Young-Bok
    • 식물조직배양학회지
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    • 제21권3호
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    • pp.161-166
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    • 1994
  • 본 연구는 마늘 무병우량종구의 효율적인 생산, 증식 및 보급체계를 확립하기 위한 기초 자료를 얻기 위하여 한지형 서산종 마늘의 생장점 배양시 기관분화에 미치는 배양 온도, 배양시기, 생장조절물질 및 저온처리 영향을 검토하기 위하여 실시하였다. 동절기의 생장점 배양은 28/2$0^{\circ}C$의 변온 조건에서 배양하는 것보다 24$^{\circ}C$ 항온조건에서 배양하는 것이 생존율 및 shoot 형성과 생장이 양호하였다. 마늘인편 휴면기인 7, 8월에는 kinetin 2 mg/L와 NAA 0.1 mg/L을 첨가한 배지에서 생존율 및 shoot의 생장이 양호한 반면에, GA$_3$ 1 mg/L 첨가한 배지는 억제되었다. 또한 휴면기에는 생장점 배양 전 종구를 15-60일간 4$^{\circ}C$에서 저온처리 함으로서 shoot 생장 및 발근을 촉진시켰으며, 또한 구형성 배지에 계대배양시 저온처리기간이 증가할수록 기내인경구 형성 및 비대를 촉진하였다.

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Water relations of plants under environmental stresses: role of aquaporins

  • Kang, H.S.;Ahn, S.J.;Hong, S.W.;Chung, G.C.
    • 한국식물생명공학회:학술대회논문집
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    • 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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    • pp.71-80
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    • 2005
  • Effects of low temperature ($8^{\circ}C$) on the hydraulic conductivity of young roots of a chilling-sensitive (cucumber; Cucumis sativus L.) and a chilling-resistant (figleaf gourd; Cucurbita ficifolia Bouche) crop have been measured at the levels of whole root systems (root hydraulic conductivity, $Lp_r$) and of individual cortical cells (cell hydraulic conductivity, Lp). In figleaf gourd, there was a reduction only in hydrostatic $Lp_r$ but not in osmotic $Lp_r$ suggesting that the activity of water channels was not much affected by low root temperature (LRT)treatment in this species. Changes in cell Lp in response to chilling and recovery were similar asroot level, although they were more intense at the root level. Roots of figleaf gourd recovered better from LRT treatment than those of cucumber. In figleaf gourd, recovery (both at the root and cell level) often resulted in Lp and $Lp_r$ values which were even bigger than the original, i.e. there was an overshoot in hydraulic conductivity. These effects were larger forosmotic (representing the cell-to-cell passage of water) than for hydrostatic $Lp_r$. After a short term (1 d) exposure to $8\;^{\circ}C$ followed by 1 d at $20\;^{\circ}C$, hydrostatic $Lp_r$ of cucumber nearly recovered and that of figleaf gourd still remained higher due to the overshoot. On the contrary, osmotic $Lp_r$ and cell Lp in both species remained high by a factor of 3 as compared to the control, possibly due to an increased activity of water channels. After pre-conditioning of roots at LRT, increased hydraulic conductivitywas completely inhibited by $HgCl_2$ at both the root and cell levels. Different from figleaf gourd, recovery from chilling was not complete in cucumber after longer exposure to LRT. It is concluded that at LRT, both changes in the activity of aquaporins and alterations of root anatomy determine the water uptake in both species. To better understand the aquaporin function in plants under various stress conditions, we examined the transgenic Arabidopsisand tobacco plants that constitutively overexpress ArabidopsisPIP1;4 or PIP2;5 under various abiotic stress conditions. No significant differences in growth rates were found between the transgenic and wild-type plants under favorable growth conditions. By contrast, overexpression of PIP1;4 or PIP2;5 had a negative effect on seed germination and seedling growth under drought stress, whereas it had a positive effect under cold stress and no effect under salt stress. Measurement of water transport by cell pressure probe revealed that these observed phenotypes under different stress conditions were closely correlated with the ability of water transport by each aquaporin in the transgenic plants. Together, our results demonstrate that PIP-type aquaporins play roles in seed germination, seedling growth, and stress response of Arabidopsis and tobacco plants under various stress conditions, and emphasize the importance of a single aquaporin-mediated water transport in these cellular processes.

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소양인 형방패독산(荊防敗毒散)의 마우스 T 세포 활성에 대한 실험적 연구 (Effect of Soyangin-Hyeongbangpaedok-san on Anti-CD3 Stimulated Mouse T Cells In Vivo and In Vitro)

  • 김중배;강희;안광석;심범상;김성훈;최승훈;안규석
    • 동의생리병리학회지
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    • 제23권3호
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    • pp.554-561
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    • 2009
  • Soyangin-Hyeongbangpaedok-san(SHBPDS) is a herbal formula used for the common cold or upper respiratory illness. In order to investigate the effect of SHBPDS, mice were orally administered with SHBPDS alcohol extract for 7 days followed by intravenous anti-CD3 injection. In addition, splenocytes and CD4 T cells were cultured with SHBPDS in response to anti-CD3 in vitro and cytokines and transcription factors were evaluated. In vivo treatment with SHBPDS significantly augmented the expressions of the percentage of CD4 T cells and CD 69, an indicator of early T cell activation. Serum levels of IL-4 were significantly increased but those of IFN-${\gamma}$ and IL-2 did not reach statistical significance. The expressions of IFN-${\gamma}$ and T-bet mRNA were significantly downregulated in SHBPDS treated mice while those of IL-4 and C-Maf were significantly upregulated. In vitro stimulation of splenocytes and CD4 T cells by SHBPDS resulted in a reduction in IFN-${\gamma}$ secretion and STAT4 activity. The IL-4 releases from both cells were slightly reduced, but STAT6 activity was rather increased. In conclusion, SHBPDS exerted an inhibition in the expression of IFN-${\gamma}$, T-bet and STAT4 while IL-4, C-Maf and STAT6 were increased. Further studies are required to examine its pharmacological effects using more appropriate animal experiments.

다양한 스트레스에 유도되는 들잔디 ZjWRKY3, ZjWRKY7의 분석 (Analysis of ZjWRKY3, ZjWRKY7 induced by multiple stress in Zoysia japonica)

  • 김우남;송인자;강홍규;선현진;양대화;이용억;권용익;이효연
    • Journal of Plant Biotechnology
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    • 제44권3호
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    • pp.220-228
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    • 2017
  • 식용작물, 사료, 잔디를 포함하는 모든 작물은 건조, 염, 저온, 고온 등의 여러 가지 환경스트레스의 영향을 빈번히 받기 때문에 작물의 생산성이 떨어지게 된다. 식물은 환경스트레스 상황에서 스스로 벗어날 수 없다. 따라서 식물은 환경 스트레스를 극복하는 방향으로 진화하였다. ARF, ABI3, NAC, HSF, WRKY 같은 환경 스트레스에 반응하는 유전자들이 식물에서 보고되었다. 이 유전자들은 환경스트레스에 반응하는 전사인자로, 식물의 스트레스반응 경로에 연관되어 있다. OsWRKY76의 경우에는 저온 및 병원균에 대한 내성을 증가시켰고, AtWRKY28 의 경우 여러 가지 환경스트레스에 관련이 있는 것으로 보고되었다. 들잔디는 정원이나 골프코스에서 가장 흔하게 사용되는 잔디이다. 하지만 들잔디에서는 아직 WRKY 유전자가 알려지지 않았다. 본 연구에서는 들잔디로부터 1개의 WRKY domain을 포함하는 ZjWRKY3, ZjWRKY7 를 분리하였다. ZjWRKY3과 ZjWRKY7은 저온, 건조, 염 스트레스에 발현이 증가하였다. 들잔디의 갈색퍼짐병을 일으키는 R. solani의 감염이 ZjWRKY3과 ZjWRKY7의 발현을 증가시켰다. 또한 ZjWRKY3, ZjWRKY7이 Zjchi 유전자 promoter의 W-box에 결합하여 전사를 조절한다는 사실을 확인 하였다. 따라서 ZjWRKY3, ZjWRKY7 유전자는 전사인자로서 환경스트레스 및 병원균 관련 하위 유전자들을 조절할 것으로 예상된다.

늑간 신경 냉동요법에 의한 개흉술후 흉부 동통 관리 (Cryoanalgesia for the Post-thoracotomy Pain)

  • 김욱진;최영호;김형묵
    • Journal of Chest Surgery
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    • 제24권1호
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    • pp.54-63
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    • 1991
  • Post-thoracotomy pain is so severe that lead to postoperative complications, such as sputum retention, segmental or lobar atelectasis, pneumonia, hypoxia, respiratory failure due to the patient`s inability to cough, deep breathing and movement. Many authors have been trying to reduce the post-thoracotomy pain, but there is no method of complete satisfaction. In 1974, Nelson and associates introduced the intercostal nerve block using the cryoprobe. The application of cold directly to the nerves causes localized destruction of the axons while preserving the endoneurium and connective tissue, thereby introducing a temporary pain block and able to complete regeneration of intercostal nerves. One hundred and two patients, who undergoing axillary or posterolateral thoracotomy at the Department of Thoracic and Cardiovascular Surgery in Korea University Medical Center between April 1990 and August 1990, were evaluated the effects of cryoanalgesia for the post-thoracotomy pain reduction. The patients were divided into two groups: Group A, control, the patients without the cryoanalgesia[No.=50], Group B, trial, the patients with cryoanalgesia[No.=52]. Before the thorax closed, in the group A, local anesthetics, 2% lidocaine 3cc, were injected to the intercostal nerves[one level with the thoracotomy, one cranial and caudal intercostal level and level of drainage tube insertion]. In the group B, cryoprobe was directly applied for 1 minute at the same level. Postoperative analgesic effects were evaluated by the scoring system which made arbitrary by author: The pain score 0 to 4, The limitation of motion score 0 to 3, The analgesics consumption score 0 to 3, The total score, the sum of above score, 0 to 10. For the evaluation of immediate analgesic effects, the score were evaluated at the operative day, the first postoperative day, the second postoperative day, and the seventh postoperative day. The effects of incision type, and rib cut to the post-thoracotomy pain were also evaluated. The results were as follows; 1. The intercostal block with cryoanalgesia reduced the immediate postoperative pain significantly compare with control group. 2. The intercostal block with cryoanalgesia improved the motion of the operation side significantly compare with control group. 3. The intercostal block with cryoanalgesia reduced the analgesics requirements at the immediate postoperative periods significantly. 4. The intercostal block with cryoanalgesia lowered the total score significantly compare with control group. 5. The intercostal block with cryoanalgesia were more effective to the mid-axillary incision than to the posterolateral incision 6. The intercostal block with cryoanalgesia were more effective to the patients without rib cut than to the patients with rib cut. 7. No specific complication need to be treated were not occurred during follow-up.

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품종 및 도정도별 백미와 미강의 특성 및 페놀산 함량 (Various Properties and Phenolic Acid Contents of Rices and Rice Brans with Different Milling Fractions)

  • 김성란;안지윤;이현유;하태열
    • 한국식품과학회지
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    • 제36권6호
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    • pp.930-936
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    • 2004
  • 본 연구에서는 오대, 남평, 추청, 일미 4품종으로부터 각각 현미와 7분도, 10분도 및 12분도의 백미와 미강을 제조하고 품종과 도정도에 따른 특성을 비교하였으며 총 폴리페놀과 페놀산의 함량을 분석하였다. 현미의 성분 중 지방과 회분 함량이 도정도가 증가할수록 크게 감소하였으며 단백질 함량은 변화가 크지 않았다. 미강의 지방과 회분 함량은 품종에 따른 차이가 매우 큰 것으로 나타났으며 도정도에 따른 차이는 적었다. 도정도가 증가할수록 쌀가루의 호화개시온도가 낮아지고 피크점도(P)와 $95^{\circ}C$ 15분간 유지 후 점도(H)가 증가하였으나 반면 냉각점도, 최종점도, setback 등은 도정도에 따라 일정한 경향을 보이기보다는 품종에 따른 차이가 더 큰 것으로 나타났다. 현미에 함유된 총 폴리페놀의 함량은 93.9-88.8 mg catechin eq/100 g이고 도정한 백미 중에는 30.3-71.9 mg catechin eq/100g 범위였으며, 미강에는 310.0-541.6 mg catechin eq/100g이었다. Phenolic acid는 ferulic acid, p-coumaric acid가 주요 성분이었으며 현미의 총 phenolic acid 함량은 65.9-27.9 mg%였으나 도정도가 증가할수록 감소되고 ferulic acid 조성비가 증가하는 것으로 나타났다. 품종 중에서는 추청과 일미에서 도정으로 인한 phenolic acid 함량 감소가 컸다. 미강의 경우 ferulic acid는 157.8-240.2 mg%, p-coumaric acid는 31.8-90.4 mg% 범위로 나타났고 현미와 백미와는 달리 sinapinic acid, benzoic acid, m-hydroxybenzoic acid의 함량도 높았다.

초등학교 급식의 수산물 이용실태 및 소비촉진 방안에 관한 연구 (A Study on Utilization and Consumption Promotion of Seafood in Elementary School Lunch Program)

  • 조미연;이민준;이영미
    • 한국식생활문화학회지
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    • 제18권2호
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    • pp.139-150
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    • 2003
  • The objective of this study consists in promoting seafood consumption by increasing its intake opportunities for children through analysis of seafood using frequency in the elementary school lunch program. For that purpose, randomly sampled out from elementary schools through the county were 155 dietitians and 5th grade 3581 children, on whom a mail survey was conducted to analyse their seafood using frequency, and preference, and lunch menu by seasons. Results of this study are as follows : The seafood using frequency of the respondents represented the highest value in one or two times a week, while obstacles in seafood use presented high values in the safety of food by 71.6% and children preference by 68.4%. The seafood intake frequency of the respondents showed the highest value in three or four times a week by 34.5% and the places of seafood intake indicated the highest response in the home by 43.5% and then school lunch and dining out. The dietitians responded that children for the most part had not a preference for seafood, whereas the children pointed out average by 46.2%. As for reasons for avoidance of seafood, the dietitians expressed the highest response in it depends cooking methods by 45.8%, while the children because of its peculiar taste and smell by 42.1%. Their required improvement showed the highest response in the taste improvement by 51.8%. The children most preference for seafood that dietitians thought included fried Alaska pollack and shrimp cutlet, while dislikes braised mackerels and seasoned cold jelly fish. Cooking methods frequently used were represented in order of soup, hot soup, and stew, and the children's preferred cooking method was from fried food. Above results suggested that the intention to increase seafood using frequency is needed to at the time of planning the menus so that more seafood-providing opportunities can be given. The development of cooking methods is urgently needed that can change the taste or the smell of seafood, and concurrently with this conveniences be taken into account in eating such as elimination of bones, etc. as early as the states of purchase or checking of seafood. The reflection of the preferred cooking methods is thought to contribute to the enhancement of satisfaction with the seafood as well as to the reduction of food remnants. The recommendation of intake of low preference but nutritionally good seafood is required to be expanded in nutrition education.

Analyses of Inter-cultivar Variation for Salinity Tolerance in Six Korean Rapeseed Cultivars

  • Lee, Yong-Hwa;Lee, Tae-Sung;Kim, Kwang-Soo;Jang, Young-Seok;Nam, Sang-Sik;Park, Kwang-Geun
    • 원예과학기술지
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    • 제30권4호
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    • pp.417-425
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    • 2012
  • Salinity stress is one of the most serious factors limiting the productivity of agricultural crops. The aim of this study was to assess inter-cultivar (intraspecific) variation for salinity tolerance in six Korean rapeseed (Brassica napus L.) cultivars at the seedling stage. The effect of three different salinity stress levels (EC 4, 8, and 16 $dS{\cdot}m^{-1}$) on seedlings of six cultivars was investigated through leaf size, leaf dry weight, and leaf chlorosis. At the highest salinity level (16 $dS{\cdot}m^{-1}$), the mean decrease of leaf dry weight in 'Sunmang', 'Tammi', 'Tamla', 'Naehan', 'Youngsan', and 'Halla' was about 56.2, 56.9, 78.4, 79.3, 77.4, and 80.9%, respectively. 'Tammi' and 'Sunmang' showed much less reduction in leaf dry weight than all the other cultivars. In addition, diluted seawater treatments increased the occurrence of leaf chlorosis in six cultivars. At EC 8 and 16 $dS{\cdot}m^{-1}$, 'Naehan', 'Youngsan', and 'Halla' showed a higher level of leaf chlorosis than 'Tammi' 'Sunmang', and 'Tamla'. On the basis of these results, six cultivars were placed into salinity-tolerant and sensitive groups. 'Tammi' and 'Sunmang' were the salinity-tolerant cultivars, while 'Naehan', 'Halla', 'Youngsan', and 'Tamla' were the salinity-sensitive cultivars. 'Tammi' and 'Naehan' rated as the most tolerant and most sensitive cultivar, respectively. To further analyze protein expression profiles in 'Tammi' and 'Naehan', 2-D proteomic analysis was performed using the plants grown under diluted seawater treatments. We identified eight differentially displayed proteins that participate in photosynthesis, carbon assimilation, starch and sucrose metabolism, amino acid metabolism, cold and oxidative stress, and calcium signaling. The differential protein expressions in 'Tammi' and 'Naehan' are likely to correlate with the differential growth responses of both cultivars to salinity stress. These data suggest that 'Tammi' is better adapted to salinity stressed environments than 'Naehan'.