• Title/Summary/Keyword: extension rate

Search Result 1,217, Processing Time 0.032 seconds

Effect of Medium Composition on in Vitro Shoot Regeneration from Leaves of Cassava (Manihot esculenta Crantz) Through Somatic Embryogenesis and Callus Induction (카사바 잎 절편 유래 체세포배 배양시 배지조성이 기내 식물체 재분화에 미치는 영향)

  • Young Hee Kwon;Joung Kwan Lee;Hee Kyu Kim;Kyung Ok Kim;Ju Hyoung Kim
    • Proceedings of the Plant Resources Society of Korea Conference
    • /
    • 2020.08a
    • /
    • pp.19-19
    • /
    • 2020
  • The Cassava(Manihot esculenta Crantz) is a tropical root crop, originally from Amazonia, that provides the staple food of an estimated 800 million people worldwide. It belongs to the family Euphorbiaceae which also includes rubber (Hevea brasiliensis) and castor bean (Ricinus communis). Among tropical crops, rice, sugarcane, maize and cassava are the most important sources of calories for human consumption. Problems in the propagation of cassava are virus diseases and low rates of seed germination. So we tried to optimize protocols for mass production of somatic embryo amenable to large-scale vegetative propagation of Cassava. After in vitro eight-week culture of leaves of Cassava, the medium which contained the 2,4-D, BAP and IBA showed the highest callus induction rate, embryogenesis callus formation rate and somatic embryo formation in Cassava culture. In the medium with GA3 and myo-inositol, shoots were most vigorously regenerated from somatic embryos of Cassava. Our experiments confirmed that in vitro growth and multiplication of plantlets could depend on its reaction to the different medium composition, and this micropropagation techniques could be a useful system for healthy and vigorous plant production.

  • PDF

The effect of sawdust fermentation period and storage period after sawdust fermentation on the development of Protaetia brevitarsis larvae

  • Ju-Rak Lim;Sang-sik Lee;Eun-Jin Lee;Woong Kim;Chang-hak Choi
    • International Journal of Industrial Entomology and Biomaterials
    • /
    • v.48 no.1
    • /
    • pp.33-41
    • /
    • 2024
  • To investigate the effect of sawdust fermentation period and storage period after fermentation on development as food for P. brevitarsis larvae, individual and group breeding were conducted on berry sawdust and oak sawdust. In individual breeding, the growth period of P. brevitarsis larvae was reduced by 12 days from the 60-day fermentation of berry sawdust to the 40-day fermentation of berry sawdust, 30 days from the 90-day fermentation of oak sawdust, and the weight of the larvae was the heaviest. In group breeding, the time it takes for P. brevitarsis larvae to change from 1st to 3rd instar is about 30 days after hatching from 60-day fermentation of berry sawdust, while 90-day fermentation of oak sawdust took more than 60 days, so the growth speed was fast and the survival rate was good. The results of the farmhouse demonstration test were the same trend, and it was judged that it would be possible to produce P. brevitarsis larvae with berries fermented sawdust, and it would be advantageous in terms of economy. In addition, for both individual and group breeding, the growth period of P. brevitarsis larvae was longer as the storage period was longer, the weight of the larvae decreased, and the survival rate was no different. The development period of P. brevitarsis larvae was the longest in the storage period of 18 months for berries fermented sawdust, and the storage period of oak fermented sawdust was longer in the storage period of 12 months and 18 months. Therefore, considering the results of individual breeding and group breeding, the fermentation period was appropriate for 60 days for berries sawdust, and the storage period for berries sawdust was stable from 0 to 12 months, and 0 to 6 months for oak sawdust.

The extinction of unsteady counterflow diffusion flame without the retardation effect of a mixing layer (혼합층의 지연효과를 배제한 비정상 대향류 확산 화염의 소화)

  • Lee, Uen-Do;Oh, Kwang-Chul;Lee, Ki-Ho;Lee, Chun-Bum;Lee, Eui-Ju;Shin, Hyun-Dong
    • 한국연소학회:학술대회논문집
    • /
    • 2003.05a
    • /
    • pp.93-101
    • /
    • 2003
  • The extinction of unsteady diffusion flame was experimentally studied in an opposing jet counterflow burner using diluted methane. The stabilized flame was perturbed by linearly varying velocity change that was generated by pistons installed on both sides of the air and fuel stream. As the results, the extinction of unsteady flame is dependent not only on the history of unsteadiness, but also on the initial condition. We found that there are several unsteady effects on the flame extinction. First, the extinction strain rates of unsteady cases are extended well beyond steady state extinction limits. Second, as the slope of the strain rate change increases, the unsteady extinction strain rate becomes larger. Third, the extension of unsteady extinction strain rate becomes smaller as the initial strain rate increases. We also found that the extension of the extinction limit mainly results from the unsteady response of the reaction zone because there is no retardation effect of a mixing layer for our experimental condition.

  • PDF

Experimental Determination of Concrete Fracture Properties with Modified S-FPZ Model

  • Yon, Jung-Heum;Kim, Tai-Hoon
    • International Journal of Concrete Structures and Materials
    • /
    • v.18 no.3E
    • /
    • pp.213-219
    • /
    • 2006
  • Modified singular fracture process zone(S-FPZ) model is proposed in this paper to determine a fracture criterion for continuous crack propagation in concrete. The investigated fracture properties of the proposed fracture model are strain energy release rate at a micro-crack tip and the relationship between crack closure stress(CCS) and crack opening displacement(COD) in the FPZ. The proposed model can simulate the actual fracture energy of experimental results fairly well. The results of the experimental data analysis show that specimen geometry and loading condition did not affect the CCS-COD relation. However, the strain energy release rate is a function of not only specimen geometry but also crack extension. The strain energy release rate remained constantly at the minimum value up to the crack extension of 25 mm, and then it increased linearly to the maximum value. The maximum fracture criterion occurred at the peak load for specimens of large size. The fracture criterion remained at the maximum value after the peak load. The variation of the fracture criterion is caused by micro-cracking and micro-crack localization. The fracture criterion of strain energy release rate can simply be the size effect of concrete fracture, and it can be used to quantify the micro-cracking and micro-crack localizing behavior of concrete.

A Study on the Variation of the Body surface Area by the Arm movements to Somatotype -The Subject of the College Men- (체형별 상복동작에 따른 상체의 체표면 변화에 관한 연구 -남자대학생을 중심으로-)

  • 김진경
    • Journal of the Korean Home Economics Association
    • /
    • v.26 no.2
    • /
    • pp.1-13
    • /
    • 1988
  • The purpose of this study was to classify somatotype of males, to show changes of the body skin surface by the somatotype. The size of sample was 156 males between age 20 and 24. Somatotype classified into Bending somatotype, Standard somatotype, Turning over somatotype. And according to the somatotype, changing of the upper part of the body by the arm movements analyzed through gypsum experiment. The result obtained from this study were as follows; 1. the variation of the upper part of the body form by changing the am movements, by the increasing of movements, shoulder-point ws moved to be inside or upside, the anterior armpit point & armpit point were moved to the upside. 2. As a result of investigating into the rate of the expansion and contraction of the basic lines and body surface area by the arm movements, the rate of expansion and contraction of the basic lines by the arm movements, the side sea length showed the maximum rate of extension in 135 degrees, the shoulder length showed the maximum rate of contraction in 135 degrees. The rate of expansion and contraction on the body surface area by the arm movements showed the phenomenon of contraction, of items F1, F6, B1, B9 showed the phenomenon of extension, of items F3, F4, F8, F9, B8, B9. 3. According to somatotypes, items which show the significant difference were, of items f3, f8, b3, b8, F2, F7, F8, B3, B7, in all movements.

  • PDF

Effects of Mixed Organic Fertilizer Application with Rice Cultivation on Yield and Nitrogen Use Efficiency in Paddy Field (벼 재배시 혼합유기질비료 시용이 질소이용율과 수량에 미치는 영향)

  • Cho, Kwang-Rae;Won, Tae-Jin;Kang, Chang-Sung;Lim, Jae-Wook;Park, Kyeong-Yeol
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.42 no.3
    • /
    • pp.152-159
    • /
    • 2009
  • This study was carried out to investigate optimum application rate with mixed organic fertilizer for chemical fertilizer alternative where the paddy rice (Chucheong) was cultivated in clay loam of paddy field. The mixed organic fertilizer were applied at 0, 50, 100 and 150% levels of recommended nitrogen by soil testing plot compared with plot of chemical fertilizer (nitrogen, phosphate and potash), respectively. The ammonium nitrogen content in paddy soil and surface water of mixed organic fertilizer 100% plot were higher than chemical fertilizer plot. The absorbed amount of nitrogen and nitrogen use efficiency by rice plant in mixed organic fertilizer 100% plot were higher than chemical fertilizer plot. The number of tillers on rice at 30 days and 60 days after transplanting mixed organic fertilizer 100% plot were many more than chemical fertilizer plot. The milled rice yield of mixed organic fertilizer 100% plot was increased by 4% than chemical fertilizer plot. The optimum application rate of mixed organic fertilizer was as follows ; $OAR_{MOF}(Mg\;ha^{-1})=[(NAR_{ST}{\div}NC_{MOF}/1,000{\times}0.93)/1,000]$ ($OAR_{MOF}$ : Optimum application rate of mixed organic fertilizer, NARST : Nitrogen application rate($kg\;ha^{-1}$) by soil testing, $NC_{MOF}$ : Nitrogen content($g\;kg^{-1}$) of mixed organic fertilizer, and $0.93:124.3kg\;ha^{-1}/133.0kg\;ha^{-1}$, respectively).

A Study of the Physical Properties of Weft Knit Fabrics (위편조직(緯編組織)의 물성(物性)에 관한 연구(硏究))

  • Kim, In-Suk;Lee, Soon-Hong
    • Journal of Fashion Business
    • /
    • v.2 no.4
    • /
    • pp.93-101
    • /
    • 1998
  • Knit products which had been limited only to underwear, recently became popularized, fashionized and highly classified covering even outer garments such as sportswear like golfwear, woman's dress, and man' s suit. As fashion cycle is getting shorter and the more a nation advanced prefers knit to woven fabrics knit industry has a very bright prospect, particularly woman's knit which is sensitive to fashion can be said as a fashion product with high value added. This study is to grasp the physical properties of stitch which are fundamental to the development of knit products. For this purpose, 2/20s of 100% wool were woven by the author of this study to basic plain stitch, rib stitch, varied transfer stitch, and float stitch on a SEMASEIKI cross knitter 7G to test the physical properties, and the result was as follows; 1. As for the relation between knit stitch and rate of extension recovery, rate of extension recovery was higher in the course direction than in the wale direction of three stitches except transfer stitch; rib stitch showed the highest rate of extension recovery in the course direction while float stitch showed the highest rate of extension recovery in the wale direction. 2. As for the relation between knit stitch and bursting strength elastic rib stitch showed higher bursting strength to indicate elasticity is an important factor of bursting strength and float stitch showed higher bursting strength too to indicate that the floating yarn on the surface plays a role of support. 3. As for the relation between knit stitch and air permeability perforated transfer stitch showed the lowest air permeability to prove that the size of perforation affects on the air permeability a great deal. 4. As for the relation between knit stitch and warmth retaining rib stitch through two lined needle bar showed the highest degree. The reason the warmth of perforated transfer stitch didn't decrease much was because the perforation wasn't big enough and content of air increased from the unevenness of the perforated parts through stitch variation. Based upon this result, each stitch can be characteristically summarized as follows; plain stitch showed a stable condition of knit cloth in four kinds of physical property test. And rib stitch is proper to tighten the edge of sleeve or clothe making use of its excellent extension recovery and to make socks for the highest bursting strength and warmth retaining. In the case of transfer stitch, seasonable designs can be taken by controlling the size of loop. Considering the pleasantness, underwear should be made of stitches with good air permeability float stitch was revealed to have color and pattern effects and a great bursting strength. This study has limitations in the aspect that it dealed with a small part of various knit stitches and the items of physical property test were not enough. The author of this study hopes that further studies would make deeper understandings about knit stitch based on more varied stitches and physical property tests ultimately to contribute to the development of fashionable designs proper to maximize the usage, function and originality.

  • PDF

Effect of tannin content in sorghum on digestive enzymes (수수의 탄닌 함량이 소화효소에 미치는 영향)

  • Bae, Jeong-Suk;Ko, Hee-Sun;Choi, Hong-Jib;Lee, Ji-Yun;Kim, Se-Jong
    • Food Science and Preservation
    • /
    • v.23 no.5
    • /
    • pp.738-745
    • /
    • 2016
  • We evaluated the distribution pattern of tannin in 164 sorghum breeding lines and the inhibition rates of amylase, protease, and lipase in sorghum lines with different tannin concentrations. Tannin was existed in the testa of sorghum grain. The tannin content in whole grain of Nampungchal sorghum was 11.54 mg/g, and that in grain (milling rate 73%) and bran fractions was 4.57 mg/g and 28.71 mg/g, respectively. The inhibition rate of ${\alpha}$-amylase, ${\alpha}$-glucosidase, and ${\beta}$-glucosidase in sorghum lines with tannin was higher than that in sorghum lines without tannin. The inhibition rate of ${\alpha}$-glucosidase was greater than 97% in sorghum lines with tannin. The inhibition rate of protease ranged from 20% to 70% in the sorghum lines, showing no discernable trends in tannin content. Lipase inhibition was either very low or not observed and did not seem to correlate with tannin concentration.

Shoot Development thorough Cytokinin Treatments in Ovary Culture of Three Interspecific Hybrid Lilies (세 가지 나리 종간교잡의 자방배양에서 사이토키닌 농도별 신초형성 효과)

  • Kim, Seung Deok;Kim, Ju Hyung;Lee, Jong Won;Lee, Ki Yeol;Kim, Tae Jung;Paek, Kee Yoeup
    • Korean Journal of Plant Resources
    • /
    • v.28 no.2
    • /
    • pp.259-262
    • /
    • 2015
  • We performed the following experiment to increase the development of shoots in the in vitro culture of hybrid progeny. MS medium was used as the base medium; cytokinins BA at a concentration of 2.0, 3.0, or 5.0 ㎎/L and TDZ at a concentration of 0.2, 0.3, or 0.5 ㎎/L were added to the in vitro cultures. For the FO progeny, the shoot development rate was highest of 18% with 2.0 ㎎/L BA, at 18%, and 3.0 ㎎/L and 5.0 ㎎/L BA resulted in a lower rate of 12%. TDZ addition tended to identical or similar results to that of the control media. For the FA progeny, addition of TDZ tended to lead to a higher shoot development rate and was superior with 0.3 ㎎/L treatment. However, the addition of BA to the media resulted in a shoot development rate between 14.3% and 15.7%, similar to that of the control.

Evaluation of Four Plant Species as Potential Banker Plants to Support Predatory Orius laevigatus (Fieber) (Hemiptera: Anthocoridae) in Cucumber Plant Systems (시설오이에서 미끌애꽃노린재의 천적유지식물로서 4종 식물의 평가)

  • YongSeok Choi;Gun-Woo Lee;Gyung-Ju Lee;Han-Jung Na;InSu Hwang
    • Korean journal of applied entomology
    • /
    • v.63 no.1
    • /
    • pp.25-32
    • /
    • 2024
  • Frankliniella occidentalis and Thrips palmi are economically important pests of cucumber. The chemicals used to control them can be effective; however, they should not be used frequently on cucumbers that are consumed raw. Banker plants were selected to increase the control efficiency of Orius laevigatus, a natural enemy that can replace the chemicals. The hatching rate, emergence rate, nymph developmental period, survival rate, and reproductive capacity (fecundity and oviposition period) of O. laevigatus for four plants (moss rose, basil, broad bean, and cucumber) were investigated. The density of O. laevigatus on two selected banker plants was investigated in a cucumber greenhouse. The hatching rate of O. laevigatus eggs was highest at 92% in moss rose; however, there was no significant difference in survival rates between moss rose and basil. The fecundity and oviposition period of O. laevigatus were better in moss rose than in basil, with no significant difference between them. The flowering period of basil was longer than that of moss rose, from April to September. Therefore, basil has potential value as a banker plant for O. laevigatus and is expected to increase the biological control effect of O. laevigatus.