• Korean journal of applied entomology
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• v.42 no.3
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• pp.241-248
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• 2003

The aphid-eating gall-midge, Aphidoletes aphidimyza (Rondani), as predator of aphids was wildly used as one of the biological control agents for control of several kinds of aphids. Their some kinds of biological characteristics were examined. The developmental periods of A. aphidimyza from egg to adult with the green peach aphid as prey were 40 and 12 days at 15$^{\circ}C$ and 30$^{\circ}C$, respectively. Supplying the cotton aphid as prey, their developmental periods were shorter than with the green peach aphid. In case of the preservation of pupa in the cold condition, emergence rates were over 90% for 1 and 2 weeks at 5$^{\circ}C$ and l0$^{\circ}C$, respectively. Adult females of A. aphidimyza began mating and laying eggs at 2-3 days after emergence, and they laid about 200 eggs for lo days of average life span. Most of adults were emerged from pupa at 6 to 8 pm during a day, and they mainly acted in the early night.

• Nuclear Engineering and Technology
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• v.11 no.1
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• pp.1-20
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• 1979

Neutron inelastic scattering studies on polycrystalline hydrates, NaBr-2$H_2O$ and BaCl$_2$-2$H_2O$ have been performed to observe librational modes. Assuming all observed peaks are from the $H_2O$ librational origin, the weighted frequency distribution functions are obtained by eliminating the contributions from the higher order processes. All of theoretical frequencies obtained using FG matrix method are dus to highly mixed modes, and therefore the modes identified as significant $H_2O$ librationat modes from their large potential energy distributions are assigned to the observed peaks. The H-bond interactions are estimated using a modified Lippincott Schroeder potential function, and the applicability of the potential function to the H-bond with highly bent or bifurcated configuration is examined on the basis of the shape of $H_2O$ librational potential energies. Some discussions are given on the usefulness of introducing O-H…Y bending terms in addition to the H…Y stretching in similar frequency calculation in order to obtain more information on the nature of H-bond. Also the purity and symmetry properties of the $H_2O$ librational modes are discussed using group theoretical analyses.

• Korean journal of applied entomology
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• v.32 no.2
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• pp.123-128
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• 1993

The comparative toxicities of selected acaricides against the twospotted spider mite, Tetranychus urticae, were investigated. The ovicidal and adulticidal activities of selected acaricides were examined under different developmental stages. Fenpyroximate showed high activity throughout all developmental stages of mites. The oviposition inhibition effect of fenpyroximate was more highly effective than that of cyhexatin. At 100 ppm concentration, the effect of fenpyroximate on the residual oviposition inhibition was persistant during 25 days with 85% level, while the effect of cyhexatin gradually decreased, and then decreased to 40% at 25 days after treatment. Fenpyroximate at 100 ppm showed 100% knockdown activity within 3 hour while cyhexatin showed only 91% knockdown activity within 24 hours after treatment. Most of selected acaricides had no systemic activity, but metasystox at 800 ppm had 100% of the systemic activity at 24 hours after treatment. For the influence of temperature on the activity, fenpyroximate showed stable activity and no temperature-dependent in comparison with other selected adaricides.

• Korean Journal of Poultry Science
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• v.44 no.4
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• pp.267-274
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• 2017

This study was conducted to investigate the effect of feeding with dietary silicate based complex mineral (SCM) on the performance of laying hens. SCM at five levels (0%, 0.2%, 0.4%, 0.6% and 0.8%) was added to commercial diets, and fed to four hundred fifty Hy-Line Brown from fifty four to sixty five weeks of age. Egg production increased as the addition of dietary SCM to basal diets increased up to 0.6% (P<0.05). Furthermore, Feed intake increased in a manner similar to that of egg production (P<0.05). However, there was no difference in feed efficiency among the treatments. Eggshell thickness and breaking strength were significantly higher for the chickens fed with SCM than control from sixty weeks old to the end of experiment (P<0.05). Similarly, albumen height and Haugh unit were significantly higher for the chickens fed with SCM compared to those of control group (P<0.05). AST of birds fed SCM showed significantly higher than control (P<0.05). However, blood neutral fat level tended to increase in SCM treatments. Moreover, bone mineral density increased with SCM addition up to 0.4% (P<0.05). IL-2 (Interleukin-2) and IL-6 (Interleukin-6) levels appeared to be improved in the chickens fed with SCM addition diets, although not statistically different from all treatments. The results of this study indicated that the optimum SCM for improving the performance, egg quality and immunological competence of laying hens from 54 to 65 weeks of age was 0.6%.

• Journal of the Korean Institute of Telematics and Electronics
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• v.13 no.5
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• pp.1-8
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• 1976

Microwave GaAs Metal Semiconductor Field effect Transistors (MESFET) with the gate-length of two micrometers are investigated. The scattering parameters of the transistors have been measured from 1GHz to 2GHz by Hp8545 Automatic network analyzer. From the measured data, an equivalent circuit is established which consists of an ntrinsic and. extrinsic transistor elements. In this paper, GaAb MESFET Amplifier is used in conjunction with conventional microstrip techniques to match into a 50 ohms high input/output impedances system. We found that Power gain is less than 8dB and VSWR is less than 1.5 in L-Band.

• The Korean Journal of Pesticide Science
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• v.3 no.2
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• pp.74-80
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• 1999

These studies were carried out to investigate the effects of nonsteroidal ecdysone agonist, tebufenozide on embryonic and postembryonic development of sycamore lace bug, Corythucha ciliata. Tebufenozide exhibited ovicidal activity($LC_{50}=4.0$ ppm). Susceptibility of each instar nymphs to tebufenozide was nearly same($LC_{50}=2.3{\sim}6.0$ ppm). The tebufenozide treatment in the final instar affected the emergence, longevity and fecundity of surving adults significantly. Tebufenozide applied at high concentration (10 ppm) to younger adults delayed prioviposition period, and decreased adult longevity, the number of eggs laid per female and hatchability. The treatment also inhibited the ovarian development of the female adults.

• Korean journal of applied entomology
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• v.26 no.1 s.70
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• pp.13-23
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• 1987

This study was conducted to know the effects of temperature conditions on the growth and oviposition of the brown planthopper(BPH), Nilaparvata lugens $St{\aa}l$. Results obtained were to predict the timing of the BPH control by measuring population dynamics of the BPH in response to temperature fluctuations upon migration of the insects in paddy fields. Developmental and ovipositional rates under constant and alternating temperature conditions were observed in a plant growth cabinet. Hatchabilities of eggs of the BPH were the highest at $25^{\circ}C$ and were decreased below or above the optimum temperature. Egg periods were the shortest at $27.5^{\circ}C$ and prolonged with decreasing temperature, but retarded at higher temperature above $30^{\circ}C$. Adult emergence rates were the highest at $27.5^{\circ}C$ and reduced with decreasing temperature, and no adult emerged at $32.5^{\circ}C$ and $35^{\circ}C$. Developmental period of nymph was the shortest at both $27.5^{\circ}C$ and $30^{\circ}C$, but extended with decreasing temperature. Female longevity was increased with decreasing temperature and the male longevity was the shortest at $27.5^{\circ}C$. Preoviposition period was the shortest at $32.5^{\circ}C$, but prolonged with decreasing temperature. It was about 6.5 times longer at $17.5^{\circ}C$ than that at $32.5^{\circ}C$. Number of eggs oviposited per female was the greatest at $25^{\circ}C$, but decreased at the temperature below or above the optimum. Under the same total effective day-degrees, hatchabilty at the alternating temperature was about 10% higher than that at the constant temperature but egg period at the alternating temperature was nearly identical as that at the constant. Under the $22^{\circ}C$ condition, emergence rate was about 8% higher at the alternating temperature than that at the constant, however, at the $28^{\circ}C$, the rate was about 8% higher at the constant than that at the alternating. Nymphal period was about $4{\sim}6$ days longer at the alternating temperature than that at the constant. Under the same total effective day-degrees in adult stage, both longevity and oviposition period were longer at alternating temperature than those at the constant. Number of eggs oviposited per female was also higher at the alternating. Longevities of females reared under $28^{\circ}C$ of constant temperature was the longest no matter what temperatures they were exposed after the emergence. This result seems to be indicating that female longevity is greatly influenced by the temperature to which they were exposed durings immature stages. Preoviposition period was affected by the temperature exposed during the nympal and adult stage whereas the number of eggs oviposited was affected by the temperature during the adult stage only. Based on the results from this study, the developmental threshold temperatures seem to be $14.12^{\circ}C$ for eggs, $14.76^{\circ}C$ for nymphs, $9.62^{\circ}C$ for adults, and $15.95^{\circ}C$ for preoviposition period. Estimated values of the total effective temperature for completing each stage were 141.25 day-degrees for eggs, 167.83 day-degrees for nymphs, 349.64 day-degrees for adults, and 58.60 day-degrees for preoviposition.

• Korean Journal of Poultry Science
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• v.32 no.2
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• pp.101-106
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• 2005

This study was designed to estimate effect of wood vinegar on meat quality in old Layer which was low production and low economic value. The old layer chickens were used to resource for income increase of layer farm and protein supply. Two hundred forty Isa Brown chickens were assigned with control(Broiler feed), Treatment 1 (Broiler feed with addition of domestic wood vinegar $0.8\%$) and Treatment 2(Broiler feed with addition of foreign wood vinegar $0.4\%$). Feed intake of control group was lower 3g than other treatments. This is the reason of result that what organic acid in wood vinegar of treatment groups affect to feed digestibility, The different of chicken production was depended on ingredient and included value of wood vinegar in domestic and foreign. Foreign wood vinegar have organic acids which that functionally act sexual Pheromone so that promote endocrine matter. This is reason that old Layer chicken increase to egg production rate. Treatment 2 group effect to thigh meat rather than breast meat and improve to value of crude fat and meat color. The Meat quality and sensory test of thigh meat of foreign wood vinegar was better appraise rather than that of domestic wood vinegar. Because foreign wood vinegar make to fine of meat tissue and to decline cooking loss and also to increase juiciness and tenderness on sensory test.

• Korean journal of applied entomology
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• v.27 no.2
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• pp.87-93
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• 1988

Some attempts were made to investigate the biological characteristics of the brown planthopper(BPH), Nilaparvata lugens St${\aa}$l, biotypes in terms of perference in feeding oviposition on rice field, egg and nymphal periods, egg hatchability, emergemce ratio, growth index, adult lingevity and gecundity fed on 60-day-old rece cultivaes with different resistance genes. Feeding and oviposition perference of the three BPH biotypes on Dongjinbyeo with no resistance gene were shown very higher than on rice cultivars with resistance genes. Those of biotype-2 on Cheongcheongbyeo with bph 1 gene and bitype-3 on Milyang 63 with bph 2 gene were relatively high, however, they were still remarkably lower than those of Dongjibyeo. The egg and nymphal periods of the three BPH biotyes on Milyang 23 were shorter than on the other rice cultivars. The periods of biotype-2 on Cheongcheongbyeo and biotype-3 on Milyang 63 were as short as those of the three BPH biotypes on Milyang 23. The egg hachability, emergence ratio, and growth index of the three BPH bioyoes on Milyang 23 were higher than on the other rice cultivars and those of biotype-2 on Cheongcheongbyeo and biotyoe-3 on Milyang 63 were as high as on Milyang 23. The female adult longevity of the BPH biotype-1 on Milyang 23 was longer than on the other cultivaes, and that of biotype-2 on Cheongcheongbyeo and bioty-3 an Milyang 63 were as ling as on Milyang 23. The number of egg laid by a female of the three BPH biotypes were greatly increased on Milyang 23. Those of biotype-2 on Cheongcheongbyeo and biotype-3 an Milyang 63 were also greatly increased.

• Korean journal of applied entomology
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• v.58 no.2
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• pp.151-157
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• 2019

It was available to store both nymphs and adults of Geocoris pallidipennis at $5^{\circ}C$ for 3 weeks without negative effects on their survival, fecundity, and Bemisia tabaci predation. Fecundities of G. pallidipennis showed the tendency to be decreased with increasing cold storage duration, but up to 4 weeks, storage at $5^{\circ}C$ didn't affect their fecundity. When Micromus angulatus adults were stored at $5^{\circ}C$ with honey solution as preys, it was possible to store up to 140 days showing approximately 50% of cumulative survival, but over 2 week cold storage was not suitable for their fecundity. With the increase of cold storage duration, the aphid predation by M. angulatus decreased, but it could be possible to cold store until 5 weeks without any significant effect on their aphid predation. Thus, short term cold storage of G. pallidipennis and M. angulatus could be useful for inundative biological strategies.