• Title/Summary/Keyword: 혼합현상

Search Result 1,389, Processing Time 0.032 seconds

Studies on the Propagation of the Freshwater Prawn, Macrobrachium nipponense (De Haan) Reared in the Laboratory 2. Life History and Seedling Production (담수산 새우, Macrobrachium nipponense (De Haan)의 증${\cdot}$양식에 관한 생물학적 기초연구 2. 생활사 및 종묘생산에 관한 연구)

  • KWON Chin-Soo;LEE Bok-Kyu
    • Journal of Aquaculture
    • /
    • v.5 no.1
    • /
    • pp.29-67
    • /
    • 1992
  • Life cycle and seed production of the freshwater prawn, Macrobrachium nipponense, were studied and the results are as follows : 1. Larval development : Embryos hatched out as zoea larvae of 2.06 mm in mean body length. The larvae passed through 9 zoea stages in $15{\~}20$ days and then metamorphosed into postlarvae measuring 5.68 mm in mean body length. Each zoea stage can be identified based on the shapes of the first and second antennae, exo- and endopodites of the first and second pereiopods, telson and maxillae. 2. Environmental requirements of zoea larvae : Zoea larvae grew healthy when fed with Artemia nauplii. Metamorphosing rate was $65{\~}72{\%}$ at $26{\~}28\%$ and $7.85{\~}8.28\%_{\circ}Cl.$. The relationship between the zoeal period (Y in days) and water temperature (X in $^{\circ}C$) is expressed as Y=46.0900-0.9673X. Zoeas showed best survival in a water temperature range of $26{\~}32^{\circ}C$ (optimum temperature $28^{\circ}C$), at which the metamorphosing rate into postlarvae was $54{\~}72\%$ The zoeas survived more successfully in chlorinity range of $4.12{\~}14.08{\%_{\circ}}Cl.$, (optimum chlorinity $7.6{\~}11.6\;{\%_{\circ}}Cl.$.), at which the metamorphosing rate was $42{\~}76{\%}$. The whole zoeal stages tended to be longer in proportion as the chlorinity deviated from the optimum range and particularly toward high chlorinity. Zoeas at all stages could not tolerate in the freshwater. 3. Environmental requirements of postlarvae and juveniles : Postlarvae showed normal growth at water temperatures between $24{\~}32^{\circ}C$ (optimun temperature $26{\~}28^{\circ}$. The survival rate up to the juvenile stage was $41{\~}63{\%}$. Water temperatures below $24^{\circ}C$ and above $32^{\circ}$ resulted in lower growth, and postlarvae scarcely grew at below $17^{\circ}C$. Cannibalism tended to occur more frequently under optimum range of temperatures. The range of chlorinity for normal growth of postlarvae and juveniles was from 0.00 (freshwater) to $11.24{\%_{\circ}}Cl.$, at which the survival rate was $32{\~}35\%$. The postlarvae grew more successfully in low chlorinities, and the best growth was found at $0.00\~2.21{\%_{\circ}}Cl.$. The postlarvae and juveniles showed better growth in freshwater but did not survive in normal sea water. 4. Feeding effect of diet on zoea Ilarvae : Zoea larvae were successfully survived and metamorposed into postlarvae when fed commercial artificial plankton, rotifers, and Artemia nauplii in the aquaria. However, the zoea larvae that were fed Artemia nauplii and reared in Chlorella mixed green water showed better results. The rate of metamorphosis was $68\~{\%}75$. The larvae fed cow live powder, egg powder, and Chlorella alone did not survive. 5. Diets of postlarvae, juveniles and adults : Artemia nauplii and/or copepods were good food for postlarvae. Juveniles and adults were successfully fed fish or shellfish flesh, annelids, corn grain, pelleted feed along with viscera of domestic animals or fruits. 6. Growth of postlarvae, juveniles and adults : Under favorable conditions, postlarvae molted every five or six days and attained to the juvenile stage within two months and they reached 1.78 cm in body length and 0.17 g in body weight. The juveniles grew to 3.52 cm in body length and 1.07 g in body weight in about four months. Their sexes became determinable based on the appearance of male's rudimental processes (a secondary sex character) on the endopodites of second pereiopods of males. The males commonly reached sexual maturity in seven months after attaining the postlarvae stage and they grew to 5.65 cm in body length and 3.41 g in body weight. Whereas the females attained sexual maturity within six to seven months, when they measured 4.93 cm in body length and 2.43 g in body weight. Nine or ten months after hatching, the males grew $6.62{\~}7.14$ cm in body length and $6.68{\~}8.36$ g in body weight, while females became $5.58{\~}6.08$ cm and $4.04{\~}5.54$ g. 7. Stocking density : The maximum stocking density in aquaria for successful survival and growth was $60{\~}100$ individuals/$\ell$ for zoeas in 30-days rearing (survival rate to postlarvae, $73{\~}80{\%}$) ; $100{\~}300$ individuals/$m^2$ for postlarvae of 0.57 cm in body length (survival rate for 120 days, $78{\~}85{\%}$) ; $40{\~}60$ individuals/$m^2$ for juveniles of 2.72 cm in body length (survival rate for 120 days, $63{\~}90{\%}$) : $20{\~}40$ individuals/$m^2$ for young prawns of 5.2 cm in body length (survival rate for 120 days, $62\~90{\%}$) ; and $10\~30$ individuals/$m^2$ for adults of 6.1 cm in body length (survival rate for 60 days, $73\~100{\%}$). The stocking density of juveniles, youngs and adults could be increased up to twice by providing shelters.

  • PDF

Epidemiology and Control of Rice Blast in Korea (한국(韓國)에서의 도열병(病) 발생(發生), 만연(蔓延)과 그 방제(防除))

  • Park, Jong Seong
    • Korean Journal of Agricultural Science
    • /
    • v.12 no.2
    • /
    • pp.356-369
    • /
    • 1985
  • In Korea, inevitable researches for the blast control exactly started from 1927 by the organization of Office of Rural Development with the local extensive outbreak of panicle blast at Jeonlla Buk-Do Province in 1926. At present, the rice blast is still one of the most destructive and widespread diseases in spite of considerable contributions by rice scientists, particularly plant pathologists during last 55 years in Korea. Rice blast control and management are very difficult because of the marked variability in pathogenicity of the blast fungus. From the results obtained through the disease surveys during last 70 years, different 3 prevalence type of blast such as bimodal leaf-blast type, bimodal panicle-blast type and bimodal continual blast type were recognized. In generally speaking, pattern of blast outbreak is said to be characterized by severe outbreak of panicle blast after slight outbreak of leaf blast with discontinuity between leaf and panicle blast. So we have to pay much attention for successful management of panicle blast giving direct influence to rice yield. Main factors induce blast epidemic were pointed out to be breakdown of the disease resistance, nutritional unbalance such as excess application of nitrogen, delay of transplantation and longspell of rain fall by extensive surveys and researches on blast during last 70 years in Korea. The fact some of Japonica varieties such as Kokuryomiyako, Tamanishiki, Ginbozu and Pungok belong to varietal group A had been cultivated with extensive acrage over 30 years in this country should be mentioned by Korean rice scientists. Differences in field resistance between varieties in the same group are detectable and apparently small but sometimes epidemiologically significant differential effects may be found out in case of blast. Much more attention should be payed to accumulate the knowledges on field resistance for successful management of blast. Excess application of nitrogen is more effective to outbreak of panicle blast than that of leaf blast of IR varieties. In comparatively low level application of nitrogen infection rate of panicle blast of IR varieties is considerably high. Low temperature effects on outbreak of blast is very great. It results in remarkable increase of the inoculum potential on the leaf lesions and infection of panicle blast in leaf sheathes of IR varieties during the booting stage. In economic point of view, it is concluded that 5 times sprays of effective fungicides including 3 times before and 2 times after heading is good enough to control blast. We have experienced no one of control measures for blast is superior to all others. The integrated control measures was established as guideline of blast control around 1950 in Korea. This guideline must be helpful for rice growers as long as rice growing continue.

  • PDF

Depositional Environment and Formation Ages of Eurimji Lake Sediments in Jaechon City, Korea (제천 의림지 호저퇴적물 퇴적환경과 형성시기 고찰)

  • 김주용;양동윤;이진영;김정호;이상헌
    • The Korean Journal of Quaternary Research
    • /
    • v.14 no.1
    • /
    • pp.7-31
    • /
    • 2000
  • Quaternary Geological and geophysical investigation was performed at the Eurimji reservoir of Jaechon City in order to interprete depositional environment and genesis of lake sediments. For this purpose, echo sounding, bottom sampling and columnar sampling by drilling on board and GPR survey were employed for a proper field investigation. Laboratory tests cover grain size population analysis, pollen analysis and $^{14}C$ datings for the lake sediments. The some parts of lake bottom sediments anthropogenically tubated and filled several times to date, indicating several mounds on the bottom surface which is difficult to explain by bottom current. Majority of natural sediments were accumulated both as rolling and suspended loads during seasonal flooding regime, when flash flow and current flow are relatively strong not only at bridge area of the western part of Eurimji, connected to stream valley, but at the several conduit or sewage system surrounding the lake. Most of uniform suspend sediments are accumulated at the lake center and lower bank area. Some parts of bottom sediments indicate the existence of turbid flow and mudflow probably due to piezometric overflowing from the lake bottom, the existence of which are proved by CM patterns of the lake bottom sediments. The columnar samples of the lake sediments in ER-1 and ER-3-1 boreholes indicate good condition without any human tubation. The grain size character of borehole samples shows poorly sorted population, predominantly composed of fine sand and muds, varying skewness and kurtosis, which indicate multi-processed lake deposits, very similar to lake bottom sediments. Borehole columnar section, echo sounding and GPR survey profilings, as well as processed data, indicate that organic mud layers of Eurimji lake deposits are deeper and thicker towards lower bank area, especially west of profile line-9. In addition the columnar sediments indicate plant coverage of the Eurimji area were divided into two pollen zones. Arboreal pollen ( AP) is predominant in the lower pollen zone, whreas non-aboreal pollen(NAP) is rich in the upper pollen zone. Both of the pollen zones are related to the vegetation coverage frequently found in coniferous and deciduous broad-leaved trees(mixed forest) surrounded by mountains and hilly areas and prevailing by aquatic or aquatic margin under the wet temperate climate. The $^{14}C$ age of the dark gray organic muds, ER1-12 sample, is 950$\pm$40 years B.P. As the sediments are anthropogenetically undisturbed, it is assumed that the reliability of age is high. Three $^{14}C$ ages of the dark gray organic muds, including ER3-1-8, ER3-1-10, ER3-1-11 samples, are 600$\pm$30 years B.P., 650$\pm$30 years B.P., 800$\pm$40 years B.P. in the descending order of stratigraphic columnar section. Based on the interpretation of depositional environments and formation ages, it is proved that Eurimji reservoir were constructed at least 950$\pm$40 years B.P., the calibrated ages of which ranges from 827 years, B.P. to 866 years B.P. Ancient people utilize the natural environment of the stream valley to meet the need of water irrigation for agriculture in the local valley center and old alluvium fan area.

  • PDF

Studies on the Anther Culture of Some Woody Species (목본식물(木本植物)의 약배양(葯培養)에 관(關)한 연구(硏究))

  • Kim, Jai Saing
    • Journal of Korean Society of Forest Science
    • /
    • v.13 no.1
    • /
    • pp.25-39
    • /
    • 1971
  • Recently successful induction of haploid plant by means of anther culture method has become a big topic among geneticists and plant breeders. The haploid plant can be used as a precious material for such basic researches as mutation or genetics. Once the haploid is obtained, production of homozygous plant is not a difficult problem. The method of producing homozygous plant can, also, be applied to the practical breeding works. When applied to the hybridization of self-fertilizing breeding period would be greatly shortened and in cross-fertilizing vegetables production of uniform hybrid seed would be very easily obtained. Last few years many scientists attempted anther cultures using various plant species, but it was successful only in several species. Unlike the other tissue cultures which use somatic organs or tissues as explants, anther culture seems to be very difficult because the plants or calli have to be induced from the haploid microspores or pollen grains. In the present experiment anther culture of fruit trees and ornamental shrubs of four genera and seven species was attemped. Anthers of Various stages ranging from tetrad and late microspore were cultured on the modified Murashige and Skoog's medium supplemented with various concentrations of auxins and kinetin as growth regulators. Handling of materials, sterilization, and other operations of culture were done by routine methods. The results were summarized as follows: 1. Calli were induced in the anthers of Forsythia Koreana Nak., Rhododendron mucronuratum Turcz., R. yedoense Max. var. Poukhanense Nak., and Prunus armeniaca L. var. ansu Max. No signs of callus were observed in Prunus persica Sieb. et Zucc. var. vurgaris Max., Pyrus ussuriensis var. macrostipes (Nak.), and Prunus salcina Lindley. 2. Calli were easily formed in any of the media with differing concentrations of auxins and kinetin. 3. In F. Koreana calli developed from anther surface and connective. Callus emerging out of anther locule was not observed. 4. Somatic calli arose from filament, connective, and inside of anther wall in R. mucronulatum. Many of the microspores accumulated starch grains. 5. The anther lobes located opposite the filament of R. yedoense turned easily to calli. This phenomenon was not observed in R. mucronulatum. Microspore embedded for a period in the medium became starch pollen. No callus was observed arising from microspore. 6. In P. armeniaca calli were not induced from somatic anther tissues. Instead, callus emerged out of anther locule rupturing the anther slit. Starch was not formed in the microspore. 7. In P. persica, Pyrus ussuriensis, and P. salcina, calli were not observed in the anthers examined more than 60 days after culture. Microspores of these species, however, were free of starch grains even after long period of subculture. 8. It was learned that somatic calli of the species examined arose usually from endothelium of anther wall, septum of two neighboring anther locules, parenchyma tissues of connectives, or anther lobes. 9. In the anther locule of P. armeniaca cultured long in medium, swollen microspores, polynucleate microspores, multicellular pollen grains, or callus mass were frequently observed, this indicating that the callus of this species was microspore-origin. 10. It was clarified that in P. armeniaca production of haploid plant by anther culture might be possible.

  • PDF

Experimental Investigation of Stannite-Sphalerite System In Relation to Ores (황석석일섬아연석계(黃錫石一閃亞鉛石系)의 실험연구(實驗硏究)와 천연건물(天然鍵物)에의 활용(活用))

  • Lee, Jae Yeong
    • Economic and Environmental Geology
    • /
    • v.8 no.1
    • /
    • pp.1-23
    • /
    • 1975
  • The subject of this study deals with phase relations between stannite ($Cu_2FeSnS_4$) and sphalerite (${\beta}-ZnS$)/wurtzite (${\alpha}-ZnS$). The phase relations were systematically investigated from liquidus temperature to $400^{\circ}C$ under controlled conditions. ${\beta}-stannite$ (tetragonal) is stable up to $706{\pm}5^{\circ}C$, where it inverts to a high-temperature polymorph ${\alpha}-stannite$ (cubic) melting congruently at $867{\pm}5^{\circ}C$. Sphalerite (cubic, ${\beta}-ZnS$) inverts at $1013{\pm}3^{\circ}C$ to wurtzite, which is the hexagonal hightemperature polymorph of ZnS. Between ${\alpha}-stannite$ and sphalerite a complete solid solution series exists above approximately $870^{\circ}C$ up to solidus temperature. The melting temperature of ${\alpha}-stannite$ rises towards sphalerite and reaches a maximum at $1074{\pm}3^{\circ}C$, which is the peritectic with the composition of 91 wt. % sphalerite and 9 wt. % ${\alpha}-stannite$. At this temperature, wurtzite takes only 5wt. % ${\alpha}-stannite$ in solid solution which decreases with increasing temperature. The inverson temperature of ${\alpha}/{\beta}-stannite$ is lowered with increasing amounts of sphalerite in solid solution down to $614{\pm}7^{\circ}C$, which is the eutectoid with the composition of 13 wt. % sphalerite and 87 wt. % ${\alpha}-stannite$. Here, ${\beta}-stannite$ contains only 10wt. % sphalerite in solid solution. With decreasing temperature, the ranges of the solid solution on both sides of the system narrow. The phase relations in the above pure system changed due to the FeS impurities in the sphalerite solid solution. The eutectoid increased from $614{\pm}7^{\circ}C$ up to $695{\pm}5^{\circ}C$ (5 wt. % FeS) and $700{\pm}5^{\circ}C$ (10wt. % FeS), while the peritectic decreased from $1074{\pm}3^{\circ}C$ down to $1036{\pm}3^{\circ}C$ (wt. %FeS) and $987{\pm}3^{\circ}C$ (10wt. %FeS). A most notable change is the appearance of non-binary regions. An important feature is the combination of this study system with the experimental results reported by Sprinfer (1972). If a stannite-kesterite solid solution is used in the place of stannite as a bulk composition, the inversion temperature is lowered to less than $400^{\circ}C$ which belongs to temperatures of the hydrothermal region.

  • PDF

Phase Equilibria of the System Pd-Sb-Te and Its Geological Implications (팔라듐-안티몬-테루르 계(系)의 상평형(相平衡)과 지질학적(地質學的) 의의(意義))

  • Kim, Won-Sa;Chao, George Y.
    • Economic and Environmental Geology
    • /
    • v.26 no.3
    • /
    • pp.327-335
    • /
    • 1993
  • Phase relations in the system Pd-Sb-Te were investigated at $1000^{\circ}$, $800^{\circ}$, and $600^{\circ}C$, using the sealed-capsule technique; the quenched products were studied by reflected light microscopy, X-ray diffraction, and electron microprobe analysis. At $1000^{\circ}C$, the solid phases Pd, $Pd_{20}Sb_7$, $Pd_8Sb_3$, $Pd_{31}Sb_{12}$, and $Pd_5Sb_2$ are stable with a liquid phase that occupies most of the isothermal diagram. Additional solid phases at $800^{\circ}C$ are $Pd_5Sb_3$, PdSb, $Pd_8Te_3$, $Pd_7Te_3$, and a continuous $Pd_{20}Te_7-Pd_{20}Sb_7$ solid solution becomes stable. At $600^{\circ}$, $PdSb_2$, $Pd_{17}Te_4$, $Pd_9Te_4$, PdTe, $PdTe_2$, $Sb_2Te_3$, and Sb and continuous PdSb-PdTe and $PdTe-PdTe_2$ solid solutions are stable. All the solid phases exhibit solid solution, mainly by substitution between Sb and Te to an extent that varies with temperature of formation. The maximum substitution (at.%) of Te for Sb in the Pd-Sb phases is: 44.3 in $Pd_8Sb_3$, 52.0 in $Pd_{31}Sb_{12}$, 46.2 in $Pd_5Sb_2$ at $800^{\circ}C$; 15.3 in $Pd_5Sb_3$, 68.3 in $PdSb_2$ at $600^{\circ}C$. The maximum substitution (at.%) of Sb for Te in the Pd-Te phases is 34.5 in $Pd_5Sb_3$ at $800^{\circ}C$, and 41.6 in $Pd_7Te_3$, 5.2 in $Pd_{17}T_4$, 12.4 in $Pd_9Te_4$, and 19.1 in $PdTe_2$ at $600^{\circ}C$. Physical properties and X-ray data of the synthetic $Pd_9Te_4$, PdTe, $PdTe_2$, $Pd_8Sb_3$, PdSb, and $Sb_2Te_3$ correspond very well with those of telluropalladinite, kotulskite, merenskyite, mertieite II, sudburyite, and tellurantimony, respectively. Because X-ray powder diffraction data consistently reveal a 310 peak ($2.035{\AA}$), the $PdSb_2$ phase is most probably of cubic structure with space group $P2_13$. The X-ray powder pattern of a phase with PdSbTe composition, synthesized at $600^{\circ}C$, compares well with that of testibipalladite. Therefore, testibiopalladite may be a member of the $PdSb_2-Pd(Sb_{0.32}Te_{0.68})$ solid solution series which is cubic and $P2_13$ in symmetry. Thus the ideal fonnula for testibiopalladite, presently PdSbTe, must be revised to PdTe(Sb, Te). Borovskite($pd_3SbTe_4$) has not been found in the synthetic system in the temperature range $1000^{\circ}-600^{\circ}C$.

  • PDF

A study of the difference of Dongeui-Suse-Bowon and past Oriental-Medicine appeared in the argument of Interior-overheating-sympton of the Tae-Eum-In caused by liver's receiving heat (태음인(太陰人) 간수열(肝受熱) 이열병론(裡熱病論)을 통해 살펴본 과거의학(過去醫學)과 동의수세보원(東醫壽世保元)의 음양관(陰陽觀)의 차이(差異))

  • Kim, Jong-Weon
    • Journal of Sasang Constitutional Medicine
    • /
    • v.9 no.1
    • /
    • pp.127-153
    • /
    • 1997
  • Sasang-Medicine can classify all sympton with more simple classifying system than past Oriental-Medicine, because Sasang Byeon-Zeung(=classifying system of the sympton) separate by four clearly. The merit of this Sasang Byeon-Zeung can be seen more clearly on the part of the pathology of the expiratory-scattering and inspiratory-gathering of the Tae-Eum and Tae-Yang. On this view point, this thesis discussed the following subjects. 1. Investigate the theory of raising-falling and scattering-gathering developed in the Dongeui-Suse-Bowon. 2. Investigate the changes of the recognition of the Yang-Dog sympton and Jo-Yeol sympton argued as Interior-overheating-sympton of the Tae-Eum-In caused by liver's receiving heat. 3. Investigate the Yi-Je-Ma's view on the Eum-Yang in the argument of interior-overheating-sympton of the Tae-Eum-In caused by liver's receiving heat. As a result, the following conclusions were led to. 1. Dongeui-Suse-Bowon considers Spleen-Kidney has the couple motion of the raising Yang and falling Eum, and Liver-Lung has the couple motion of the expiratory-scattering and inspiratory-gathering. This theory of raising-falling and scattering-gathering is same as in the concept with the gathering. This theory of raising-falling and scattering-gathering is same as in the concept with the theory of raising-falling and floating-sinking of past Oriental-Medicine, but more consistently systematized in the pathology and prescription. 2. Dongeui-Suse-Bowon considers the Yang-Dog sympton and Jo-Yeol sympton as the interior-overheating-sympton of the Tae-Eum-In. As following the book, the fire of desire weeken the expiratory-scattering power of the lung, and deepen the shortage of the expiratory-scattering power comparison to the inspiratory-gathering power. Therfore the sympton can be treated by releasing ourselves from the desire and taking medicine strengthening the expiratory-scattering power. 3. In the early stage of the orintal medicine, they used prescriptions composed of So-Yang medicine and Tae-Eum medicine which can cool heat. Galgeun, Mawhang and Seungma were used in the age of Sanghanron, thereafter Jugoing's Jojung-Tang and Gongsin's Galgeunhaegi-Tang were developed as prescriptions of the interior-overheating-sympton of the Tae-Eum-In, and finally Tea-Uem-In Galgeunhaegi-Tang was settled by Yi-Je-Ma.

  • PDF

The Ripening of Camembert Cheese Made with Mucor Miehei Rennet (Mucor Miehei 응유효소(凝乳酵素)로 제조(製造)한 Camembert Cheese의 숙성(熟成)에 관(關)한 연구(硏究))

  • Park, Mooh Il;Kim, Jong Woo
    • Korean Journal of Agricultural Science
    • /
    • v.16 no.2
    • /
    • pp.179-200
    • /
    • 1989
  • Mucor miehei rennet(MR) was added as calf rennet(CR) substitutes in the fixed amounts of mixed rennets in making Camembert cheese. The conditions in the variations of chemical composition: water-soluble nitrogen, non-caseinic nitrogen, non-proteinic nitrogen, amino nitrogen, ammoniacal nitorgen, electrophoresis, molecular fractionation, mineral distribution, texture characterisitics, free amino acids and free fatty acids, were checked up with the sensory test and the chesse yields at each ripening period. The results obtained by investigating the utility of Mucor rennet were summarized as follows: 1. CR chesse, MR cheese and the mixed-rennet chesse failed to show any significant difference in their yields of 15%. 2. The contents of protein, fat and ash in MR cheese gave lower value than CR cheese did and with progress of ripening lactose decreased rapidly after 14 days of ripening. The difference among the rate of addition of mucor rennet was not recognized. 3. The WSN contents of 5 fresh sample chesse were from 14.7% to 17.3% and WSN increased from 39.7% to 41.0% with progress of ripening. After 21 days of ripening MR chesse had more WSN than CR cheese did. In NCN and ammoniacal nitrogen MR cheese showed higher value. 4. As the ripening progressed, MR chesse showed more cystein, phenylalanine and proline than CR chesse did but it failed to show any increase in aspartic acid, threonine and glutamic acid etc. 5. In the content of free fatty acid MR chesse showed higher value than CR cheese did and with the progress of ripening fatty acids increased from 8.36 mEq to 26.36 mEq but did not show any significant difference in the cheese types by the coagulant ratio. 6. Ca contents in the sample chesse were 0.238-0.27%, Mg 0.019-0.022%, Na 0.910-1.047%, and K 0.175-0.200%. The important non-sedimentable Ca in casein remained from 61 % to 77% without regard the ripening periods and added-rennets and Mg remained from 59.1% to 92.5% in non-sedimentable and water-soluble conditions. 7. In the fractionation of protein by ultrafilteration, MW> $5{\times}10^4$ decresed from 95% at the beginning period of ripening to 45% and MW< $10^4$ increased from 0.2% to 38% and definite caseinolysis was shown in all samples. 8. All the cheese showed to different electrophoretic patterns for the added-amounts of mucor rennet in the 14 days of ripenig. In the 28 days or ripening, MR cheese kept some bands on the patterns compared with CR cheese. 9. In vitro digestibility increased from 81.48-94.81 % to 94.47-98.61% but failed to show any significant difference in the cheese types by the coagulant ratio. 10. In hardness, MR cheese showed lower value compared with CR cheese as the ripening progressed. 11. The results of the sensory test failed to show any difference in flora rind, feelings in mouth and hands, deep structure, flavor and bitterness between CR Camembert cheese and MR Camembert chesse.

  • PDF

An Analysis of the Research Trends in Safety Education for Home Economics Education (가정과 안전교육의 연구 동향 분석)

  • Kim, Nam Eun
    • Journal of Korean Home Economics Education Association
    • /
    • v.28 no.3
    • /
    • pp.47-63
    • /
    • 2016
  • The purpose of this study is to suggest the basic information for diverse and balanced research and development in this field with understanding research trends related to safety education in home economics. In order to so, this study makes population and sampling by targeting cases which refer to 'safety' on 15 papers of academic journals related to home economics registered in the National Research Foundation from 2001 to 2015, 244 papers related to safety education area and 179 master doctorate thesis by searching keyword as 'safety'. Analysis contents are research trends of papers related to safety education by year and by subject and research trends of safety education by area and by research method. As a result of the study, first, the number of research papers related to safety education by year on home economics curriculum repeated increase and decrease and there have been consistent studies conducted on safety education with 14-52 papers per every year and yearly average 28.2 papers. On the other hand, the most number of studies conducted in 2015 with 52 papers which are twice as much of 26 papers in 2014. This seems to be affected by the announcement of safety comprehensive countermeasures from government and the emphasis of safety subject on 2015 curriculum revision of the Ministry of Education. Second, with regards to research trends by topic, 137 papers are related to safety education (29%), 336 papers are related to safety actual condition (71%). Accidents and recognition had a greater percentage in a paper before 2009 (74.4%) and studies are increased after 2009 (from 21 papers to 53 papers) in terms of development or evaluation of safety education program, development of education materials, development of education method etc. Subject area dealt with the most on the research of safety actual condition is regarding safety accidents or effective variables (23.2%). Subject regarding the variables are researches related to factors influencing family violence, internet addiction, spouse violence, willingness to purchase unsafe food, age harassment, or suicidal attempt etc. Next, researches related to safety recognition (13.9%), safety knowledge and attitude (7.4%), safety behaviors (6.3%), safety consciousness (2.3%) show in sequence. Subject area dealt with the most on the researches regarding safety education is development and evaluation of safety education program (11%) and this appears the most in 2015 by year (21.5%). Third, with regards to eight areas of safety education, there are 143 papers regarding public safety (33.8%), 106 papers regarding violence and personal safety (25.1%), 93 papers regarding general subject on safety or whole safety area (22%) and 58 papers regarding drug and internet addiction (13.7%) in sequence. And there is no paper related to first aid and 1 paper is related to occupational safety (0.2%). Occupational safety area is less researched nevertheless its included in home economic curriculum as relative chapter. First aid does not directly correlate with home economics curriculum but should be studied in preparation for accident which could happen in practical class. Forth, with regards to research trends by research method, quantitative research (89.1%) is mostly used and both research study (70.4%) and experimental research (18.7%) are used the most frequently. In particular, researches on the actual condition of safety education and experimental studies for effectiveness verification take most of research method. As qualitative studies, there are phenomenological study (3.1%) and case study (3.1%) related to actual conditions of safety accidents. 10 papers (2.4%) are mixture of quantitative and qualitative research and some research conducted research study and experimental research at the same time (0.9%). With regards to subject of study, human environments (87.5%) are more than physical environments (12.5) and students (48.4%) are more than teachers and school parents (20.6%). As the subject of physical environments, school (6.5%) is the most but home environment is none. As a result of the study, research for the development of evaluation tool for evaluating safety education, occupational safety and lifelong education should be conducted from this time forward. In addition, the object of study shall be expanded to both human environments in terms of entire life and physical environments for home. An in-depth qualitative research should be needed by observing and meeting with each student.