• Title/Summary/Keyword: Limiting temperature

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The Characteristics of Spatio-Temporal Distribution on Phytoplankton in the Nakdong River Estuary, during 2013-2015 (낙동강 하구역에서 2013-2015년 식물플랑크톤의 시·공간분포 특성)

  • Yoo, Man-Ho;Youn, Seok-Hyun;Park, Kyung-Woo;Kim, A-Ram;Yoon, Sang-Chol;Suh, Young-Sang
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.6
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    • pp.738-749
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    • 2016
  • To understand the characteristics of the spatio-temporal distribution of phytoplankton after barrage construction in the Nakdong River Estuary, this study investigated relevant environmental parameters and phytoplankton status based on bi-monthly samples collected from the Nakdong River Estuary itself from February 2013 to December 2015. Environmental parameters did not differ significantly across these years but did vary between zones and seasons. The results suggested that the upper zone was dominated by fresh-water diatoms, green algae, and blue-green algae, whereas the lower zone was mostly dominated by dinoflagellates. The presence of Stephanodiscus spp., Asterionellopsis formosa, and Microcystis spp. in the upper zone was related to the inflow of freshwater discharge by artificial control of dyke gates. The dominant phytoplankton species in this zone were dependent on temperature, wind speed, DIP, and DIN, while those in the lower zone were mostly dependent on nutrients and wind speed. In addition, at the lower zone, there were negative correlations between Prorocentrum donghaiense, DIN, and wind speed, with its abundance being higher during the summer than other seasons. Analysis of temporal variations did not indicate any significant differences in the upper zone but did reveal variations among seasons at the lower zone. Except in 2014, the lower zone could be divided into periods dominated by diatoms (October-April) and dinoflagellates (June-August). These results suggest that the characteristics of the phytoplankton community were influenced by changes in the inflow of freshwater species and nutrients given the difference in the range affected by freshwater discharge.

Determination of Optimal Conditions of Pressure Toasting on Legume Seeds for Dairy Deed Industry : I. Effects of Pressure Toasting on Nutritive Values of Lupinus albus in Lactating Dairy Cows

  • Yu, P.;Goelema, J.O.;Tamminga, S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.8
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    • pp.1205-1214
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    • 1999
  • Whole lupinus albus seeds were pressure toasted at temperatures of 100, 118 and $136^{\circ}C$ for 3, 7, 15 and 30 min to study rumen degradation and post-rumen digestion and to determine optimal heating conditions for the Dutch dairy feed industry. In sacco nylon bag and mobile bag techniques were employed for rumen and intestine incubations to determine ruminal degradation characteristics and intestinal digestion of crude protein (CP) in 4 lactation rumen cannulated and 4 lactating intestinal cannulated Dutch dairy cows fed 47% hay and 53% concentrate according to Dutch dairy requirements. Measured rumen degradation characteristics were soluble fraction (S), undegradable fraction (U), potentially degradable fraction (D), lag time (T0) and rate of degradation (Kd) of insoluble but degradable fraction. Percentage bypass feed protein (BCP), ruminal microbial protein synthesized based on available nitrogen (N_MP) and that based on available energy (E_MP), true protein supplied to the small intestine (TPSI), truly absorbed BCP (ABCP), absorbed microbial protein (AVP) in the small intestine, endogenous protein losses in the digestion (ENDP), true digested protein in the small intestine (TAP or DVE in Dutch) and degraded protein balance (PDB or OEB in Dutch) were totally evaluated using the new Dutch DVE/OEB System. Pressure toasting decreased (p<0.001) rumen degradability of CP. It reduced S (p<0.05) and Kd (p=0.06), increased D (p<0.05) and U (p<0.01) but did not alter T0 (p>0.05), thus resulting in dramatically increased BCP (p<0.001) with increasing time and temperature from 73.7 (raw) up to 182.5 g/kg DM ($136^{\circ}C/15min$). Although rumen microbial protein synthesized based on available energy (E_MP) was reduced, true protein (microbial and bypass feed protein) supplied to the small intestine (TPSI) was increased (p<0.001) from 153.1 (raw) to 247.6 g/kg DM ($136^{\circ}C/15min$). Due to digestibility of BCP in the intestine not changing (p>0.05) average 87.8%, the absorbed BCP increased (p<0.001) from 62.3 (raw) to 153.7 g/kg DM ($136^{\circ}C/15min$). Therefore DVE value of true digested protein in the small intestine was significantly increased (p<0.001) from 118.9 (raw) to 197.0 g/kg DM ($136^{\circ}C/15min$) and OEB value of degraded protein balance was significantly reduced (p<0.001) from 147.2 (raw) to 63.1 g/kg DM ($136^{\circ}C/15min$). It was concluded that pressure toasting was effective in shifting degradation of CP of lupinus albus from the rumen to small intestine without changing intestinal digestion. Further studies are required on the degradation and digestion of individual amino acids and on the damaging effects of processing on amino acids, especially the first limiting amino acids.

Application of Isocyanate and Modified Polyester Containing Phosphorous and Chlorine to Crosslinked PU Flame-Retardant Coatings (인과 염소 함유 변성폴리에스터/이소시아네이트 가교 폴리머의 PU 난연도료에의 적용)

  • Park, Hong-Soo;Kim, Song-Hyoung;Ahn, Sung-Hwan;Yoo, Gyu-Yeol;Hahm, Hyun-Sik
    • Journal of the Korean Applied Science and Technology
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    • v.24 no.2
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    • pp.124-139
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    • 2007
  • In order to obtain the maximum flame retardancy with the minimal deterioration of physical properties of PU flame-retardant coatings, chlorine and phosphorous functional groups were introduced into the pre-polymer of modified polyesters. In the first step, the tetramethylene bis(orthophosphate) (TBOP) and neohexanediol dichloroacetate (DCA-adduct) intermediates were synthesized. In the second step, 1,4-butanediol and adipic acid monomers were polymerized with the two kind of intermediates to obtain copolymer. The modified polyesters containing chlorine and phosphorous (ATBA-10C, -20C, and -30C) were synthesized by adjusting the contents of chlorine compound (dichloroacetic acid, 10, 20, 30 wt%) with fixed the content of phosphorous compound (2 wt%). The PU flame-retardant coatings (TTBAH -10C, -20C, and -30C) were prepared using the synthesized ATBAs and HDI-trimer as curing agent at room temperature. The physical properties of PU flame-retardant coatings with chlorine and phosphorous were inferior to those with phosphorous only and the properties were getting worse with increasing chlorine content. Flame retardancy was tested with three methods. With the vertical method, Complete combustion time of ATBAHs were $259^{\sim}347$ seconds, which means that the prepared coatings are good flame-retardant. With the $45^{\circ}$ Meckel burner method, char lengths of the three prepared coatings were less than 2.9 cm, which indicates that the prepared coatings are 1st grade flame retardancy. With the limiting oxygen index (LOI) method, the LOI values of the three prepared coatings were in the range of $30^{\sim}35%$, which proves good flame retardancy of the prepared coatings. From the results of flame retardancy tests of the specimens that contain the same amounts of flame retarding compounds, it was found that the coatings containing both phosphorous and chlorine show higher flame retardancy than the coatings containing phosphorous alone. This indicates that some synergy effect of flame retardancy exists between phosphorous and chlorine.

A Study for Development of Ratio Beale Measuring Pain Using Korean Pain Tersm (통증어휘를 이용한 통증비율척도의 개발연구)

  • 이은옥;윤순녕;송미순
    • Journal of Korean Academy of Nursing
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    • v.14 no.2
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    • pp.93-111
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    • 1984
  • The main purpose of this study is to develop a ratio scale measuring level of pain using Korean pain terms. The specific purposes of this study are to identify the degree of pain of each pain term in each subclass: to classify each subclass in terms of dimensions of pain; and to analyze factors of the Korean pain ratio scale clustering together. One hundred an4 fifty eight pain terms which were originally identified as representative terms and their synonyms were used for data collection. Fifty eight nursing professors ana sixty one medical doctors who have contacted with patients having pain were asked to rate the weight of each pain term on a visual analogue scale. Subclasses in which ranks of pain terms were same f s findings in two previous studies were 1) thermal 3 am 2) cavity pressure, 3) single stimulating pain, 4) radiation pain. and 5) chemical pain. Subclasses in which ranks of pain terms were confused were 1) incisive pressure, and 2) cold pain. Subclasses in which one new pain term was added were 1) inflammatory-repeated pain, 2) punctuate pressure, 3) constrictive pressure, 4) fatigue-related pressure, and 5) suffering-relate4 pain. Subclasses in which two new pain terms were added were 1) traction pressure, 2) peripheral nerve pain, 3) dull pain, 4) pulsation-related pain, 5) digestion-related pain, 6) tract pain, and 7) punishment-related pain. Subclass in which 3 new pain terms were included was fear-related pain. Rating scores of 5 words in 4 subclasses were significantly different between the normal group and the extreme group of subjects in terms of subjective rating. Only one word among 6 words was that newly added to the scale. Rating scores of 12 words in 9 subclasses were significantly different between doctor group and nursing professor group. Among these 12 words, only 3 were those newly added to the scale. In comparison of these 12 words, mean scores of the nursing professors were always 7 to 16 points higher than those of the medical doctors. In the analysis of judgement of subjects in terms of dimensions of pain terms, subclasses of dull pain, cavity pressure, tract pain and cold pain were suggested to be included in the miscellaneous dimension. As a result of factor analysis of the ratings given to 96 pain words using principal components analysis without iteration and with varimax rotation limiting the number of factors to 4, factors of severe pain (factor I) mild-moderate pain (factor II) , causative pain (factor III) and temperature-related pain(factor IV) were extracted with the factor loading above 0.388. When the pain words were re-arranged on the bases of factor loading above 0.368, number of factors decreased to only first two factors. Maximum score of pain word in factor II was 46.17 and the minimum score of the factor I was 45.36. Further studies are needed to identify the validity, reliability, sensitivity and practicability of this ratio scale using patients having various sources of pain.

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Effect of Environmental Factors on the Growth of Microcystis aeruginosa (Cyanobacteria) in Agricultural Reservoirs (농업용 저수지에서 환경 요인이 Microcystis aeruginosa (cyanobacteria) 성장에 미치는 영향)

  • Kwon, O-Chang;Park, Jung-Won;Chung, Gyu-Young;Lee, Jong-Eun;Seo, Eul-Won
    • Journal of Life Science
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    • v.21 no.8
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    • pp.1183-1189
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    • 2011
  • The present study is aimed at examining the effects of the physico-chemical environmental factors of water systems on water bloom at Homin and Gagok reservoirs in Pungcheon-Myeon, Andong, Gyeongsangbuk-do. The mean water temperature and the contents of chlorophyll-a, total-nitrogen, total-phosphorus and phosphate-phosphorus were higher at the Gagok reservoir. On the other hand, the pH mean value was higher at the Homin reservoir. The mean value of microelements (Na, K, Mg, Fe, Si) was higher at the Gagok reservoir. The cyanobacteria which was considered to be the cause of water bloom at the two reservoirs was Microcystis aeruginosa. It started to grow in May and showed the highest standing crop in August. Between the increase of standing crop of M. aeruginosa and the water quality, correlation values of $Na^+$ (r=-0.910, p<0.05), $Fe^{2+}$ (r=-0.855, p<0.05) and $Si^{4+}$ (r=0.989, p<0.01) at the Homin reservoir increased amount of standing crop. Meanwhile, at the Gagok reservoir, the contents of $Na^+$ (r=-0.776, p<0.05), $Si^{4+}$ (r=0.899, p<0.05) were highly related to the increase of standing crop. Interestingly, Si, which is the limiting factor for diatoms, has a high correlation with standing crop of cyanobacteria. In conclusion, the water blooming is caused not by a simple factor but a synergistic effect due to complex actions including high concentrations of nitrogen and phosphorus ions and many other environmental factors.

Ecological Studies on the Culture Bed and Production of Young Top Shell, Batillus cornutus in Cheju Island (제주도산 소라의 치패생산 및 서식생태에 관한 연구)

  • Pyen Choong Kyu;Youn Jeong Su
    • Journal of Aquaculture
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    • v.3 no.1
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    • pp.89-125
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    • 1990
  • In order to improve top shell seed production techniques spawning and larvae rearing were done in rearing tanks. Growth of young top shell in the nursing ground were also investigated. For induced spawning, top shells were maintained in still water during night time. Then they were treated with ultra violet iradiated sea water after dried up in air for 60 minutes. Spawning rate were 10 to $39.77\%$. It was found that young top shells moved in the growing grounds from nursing grounds when they reached approximately 30-40mm in shell heignt. Among main food algae for top shell in the natural growing grounds, sea mustard were melted away during June. Therefore, presence of another food algae such as Ecklonia cava or Sargassum spp. seems to be the main limiting factor for survival of top shell during summer. The tolerance of top shells ranging from 30mm to 60mm to low density of seawater for were tested at the temperature between 29.5 and $31.4^{\circ}C$. Hundred percent mortality occoured in 20, 55 and 90 hours after first stocking at the specific gravity of 1.010, 1.015, and 1.020, respectively.

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Isolation and Characterization of Dextrans Produced by Leuconostoc sp. strain JYY4 from Fermented Kimchi

  • Gu, Ji-Joong;Ha, Yoo-Jin;Yoo, Sun-Kyun
    • Journal of the Korean Applied Science and Technology
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    • v.32 no.4
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    • pp.758-766
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    • 2015
  • Dextran is a generic term for a bacterial exopolysaccharide synthesized from sucrose and composed of chains of D-glucose units connected by ${\alpha}$-1,6-linkages by using dextransucrases. Dextran could be used as vicosifying, stabilizing, emulsifying, gelling, bulking, dietary fiber, prebiotics, and water holding agents. We isolated new strain capable of producing dextran from Korean traditional kimchi and identified as Leuconostoc sp. strain JYY4. Batch fermentation was conducted in bioreactor with a working volume of 3 L. The media was MMY and 15% (w/v) sucrose. Mineral medium consisted of $3.0g\;KH_2PO_4$, $0.01g\;FeSO_4$, $H_2O$, $0.01g\;MnSO_4$, $4H_2O$, $0.2g\;MgSO_4\;7H_2O$, 0.01 g NaCl, $0.05g\;CaCl_2$ per 1 liter deionized water. The pH of media was initially adjusted to 6.0. The inoculation rate was 1.0% (v/v) of the working volume. Temperature was maintained at $28^{\circ}C$. The agitation rate was 100 rpm. The production pattern of dextran was associated with the cell growth. After 24 hr dextran reached its highest concentration of 59.4 g/L. The sucrose was consumed completely after 40 hr. Growth reached stationery phase when sucrose became limiting, regardless of the presence of fructose or mannitol. When the specific growth rate was 0.54 hr-1, utilization averaged 5.8 g/L-hr. The yield and productivity of dextran were 80% and 2.0 g/L-hr, respectively. Dextrans produced by were separated to two different size by an alcohol fraction method. The size of high molecular weight dextran (45% alcohol, v/v), less soluble dextran, was between MW 500,000 and 2,000,000. Soluble dextran (55% alcohol, v/v) was between 70,000 and 150,000. The molecular weight average of total dextran (70% alcohol, v/v) was between 150,000 to 500,000. The enzymatic hydrolyzates of total dextran of ATCC 13146 showed branched dextrans by Penicillium dextranase contained of glucose, isomaltose, isomaltotriose, and isomaltooligosaccharides greater than DP4 (degree of polymerization) that had branch points. Compounds greater than DP4 were branched isomaltooligosaacharides. Hydrolysates by the Lipomyces dextranase produced the same composition of oligosaccharides as those by Penicillin dextranase.

Effects of Rumen Undegradable Protein and Minerals Proteinate on Early Lactation Performance and Ovarian Functions of Dairy Cows in the Tropics

  • Kanjanapruthipong, J.;Buatong, N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.6
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    • pp.806-811
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    • 2002
  • A 90 d study was designed to investigate the effects of rumen undegradable protein (RUP) and a mixture of Cu, Zn and Mn proteinate (CZMP) on milk yield and composition and ovarian functions during rainy months. Twenty four Holstein${\times}$ indigenous cows in their 2nd and 3rd lactation were randomly allocated to total mixed rations (TMR) containing soy bean meal (SBM) as a source of rumen degradable protein (RDP), SBM plus CZMP, and formalin treated SBM (FSBM) as a source of RUP. Maximum and minimum temperature humidity index during the experimental period were 83.6-84.7 and 75.4-76.1. There were no differences (p>0.05) in intakes of dry matter, crude protein and net energy and in contents of butterfat, lactose and minerals. Cows on TMR containing FSBM not only lost less weight (-278, -467 and -433 g/d) with more intake of RUP (0.92, 0.58 and 0.59 kg/d) but also produced more milk (19.27, 18.23 and 18.13 kg/d) and 4% fat corrected milk (18.57, 17.57 and 17.51 kg/d) with more protein (3.06, 2.81 and 2.80%), solids-not-fat (8.69, 8.38 and 8.38%) and less milk urea N (9.3, 15.4 and 15.0 mg/dl) compared with those on TMR containing SBM and SBM+CZMP, respectively (p<0.01). However, cows on TMR containing SBM and SBM+CZMP did not differ in these respects (p>0.05). Whereas incidence of cystic ovaries at 20 and 90 d pospartum was less (p<0.01) in cows on TMR containing SBM+CZMP (37.3 and 12.5%) than those on TMR containing SBM (62.5 and 25%), it was nil for cows on TMR containing FSBM. Cows in all three group differed (p<0.01) from each other for the recurrence of first observed estrus with those on TMR containing FSBM having least days (22, 36 and 47 d) compared with their counterpart on TMR containing SBM+CZMP and SBM, repectively. The results suggest that RUP is one of the limiting factors affecting milk yield and its composition and ovarian functions during early lactation of dairy cows in the tropics.

Phytohydrography and the Vertical Pattern of Nitracline in the Southern Waters of the Korean East Sea in Early Spring (춘계 한국 동해 남부해역에서의 식물 수문학적 수역과 질산염약층의 수직양상)

  • Shim, Jae Hyung;Yang, Sung Ryull;Lee, Won Ho
    • 한국해양학회지
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    • v.24 no.1
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    • pp.15-28
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    • 1989
  • A study on quantitative phytoplankton samples, hydrographic conditions (temperature, salinity, dissolved oxygen), and nutrients has been performed in the southern waters of the Korean East Sea in early spring. Phytoplankton community showed close correlation with hydrographic conditions. This study area could be divided into three phytohydrographic regions; 1) East Korean Warm Water Region (a branch of Tsushima Current), 2) North Korean Cold Water Region, and 3) offshore water region not affected by other two water regions. Vertical distribution of phytoplankton is dependent upon stability of water column and nutrient concentration. Nutrient concentration shows characteristic distribution according to water masses. N/P ratio of ca. 3 in surface layer indicates that nitrogen is the major limiting nutrient in this area. N/P removal ratio was 12.54 ($r^2$ = 0.96), consistent with the Redified ratio. Primary nitrite maxima at the nitracline depths are thought to be formed by phytoplankton exudation. Secondary nitrite maximum was observed in coastal area with dissolved oxygen content of >5.2 ml/l much higher than <0.25 ml/l in other areas. The mechanism of secondary maximum is different from that of other regions, and whether it may be due to in situ degradation of organic matter by bacterial activity is still open to discuss.

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Effects of Growth Regulator for Promoting Lateral Shooting in White-Spine Cucumber(Cucumis sativus L.) (백침계 모이 측지발생 촉진을 위한 생장조정제 이용 효과)

  • Lee Jae Han;Kwon Joon Kook;Kang Nam Jun;Jung Ho Jung;Park Jin Myeon;Kang Kyung Hee;Choi Young Hah
    • Journal of Bio-Environment Control
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    • v.14 no.4
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    • pp.275-279
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    • 2005
  • The fruiting habit pattern of white-spine cucumber, whose fruits are usually borne on the lateral branches, is different from domestic ones. The cucumber production far export has been focused on how to promote lateral shooting and how to increase the number of lateral branches. As the growing season of the exporting cucumber is confined to winter season, low temperature and weak light are limiting factors to lateral shooting. This study was conducted to investigate the effect of foliar application of growth regulator for induction of lateral shoot in white-spine cucumber. foliar application of growth regulator were focused on concentration and application time based on number of leaves. The visible damages were observed in applied leaves by $30mg{\cdot}L^{-1}$ BA(benzyladenine) in retarding culture, but no significant by $10mg{\cdot}L^{-1}$ BA in case of semi-forcing culture. The number of available lateral shoots were greater in applied plant with $10mg{\cdot}L^{-1}$ BA than that of $30mg{\cdot}L^{-1}$ BA, in applied plants at 10th and 15th loaves than that of applied plants at 5th leaves.