• The Plant Pathology Journal
• /
• v.38 no.4
• /
• pp.287-295
• /
• 2022

Citrus tristeza virus (CTV) is efficiently transmitted in a semi-persistent manner by the brown citrus aphid (Toxoptera citricida (Kirkaldy)). Currently, the most sensitive method for detecting plant viruses in insect vectors is reverse-transcription quantitative polymerase chain reaction (RT-qPCR). In this study, the elongation factor-1 alpha (EF-1α) gene and acidic p0 ribosomal protein (RPAP0) gene were confirmed to be suitable reference genes for RT-qPCR normalization in viruliferous T. citricida aphids using the geNorm, NormFinder, and BestKeeper tools. Then the relative CTV titer in aphids (T. citricida) at different post-acquisition feeding times on healthy plants was quantified by RT-qPCR using EF-1α and RPAP0 as reference genes. The relative CTV titer retained in the aphids gradually decreased with increasing feeding time. During the first 0.5 h of feeding time on healthy plants, the remaining CTV titer in aphids showed about 80% rapid loss for the highly transmissible isolate CT11A and 40% loss for the poorly transmissible isolate CTLJ. The relative CTV titer in aphids during more than 12 h post-acquisition times for CT11A was significantly lower than at the other feeding times, which is similar to the trend found for CTLJ. To our knowledge, this is the first report about the relative titer variation of CTV remaining in T. citricida at different post-acquisition feeding times on healthy plants.

• Journal of the East Asian Society of Dietary Life
• /
• v.7 no.1
• /
• pp.87-95
• /
• 1997

One- to three-month-old infants (n=232) were compared their upper arm cumference and skinfold thickness(triceps, subscapular) by feeding methods in cross-sectional study. There were two groups : breast-fed(BF) and formula-fed groups(FF). As reported previously, weight, length, head and chest circumferences of these infants were good, and overall growth status was not significantly different by feeding methods, but weight, weight velocity and chest circumference of formula-fed infants were higher than breast-feds at 3month, significantly. Hear, the triceps skinfold thickness of infants at 1, 2, and 3 postpartum months were 7.4, 9.5 and 10.5 mm, respectively. The triceps skinfold thickness of breast-fed infants were higher than formula-feds at 1 and 2 postpartum month, but at 3 month that of formula-fed infants was greater than breast-fed infants, insignificantly. The subscapular skinfold thickness of infants were 6.4, 9.2 and 10.6 mm at 1 to 3 postpartum months, respectively. The upper arm circumference of infants were 11.7, 13.4, 14.3cm, and the arm muscle diameter were 34.5,39.3 and 41.7cm at one to three postpartum months, respectively. The upper arm circumference of male infants was higher than females at 2, 3 postpartum months. Overall, there were no signifiant differences between feeding methods in triceps and subscapular skinfold thickness, upper arm circumference and arm muscle diameter. But 3-month-old formula-fed male infant showed bigger significantly in arm circumference than the breast-feds. From this survey, long-term survey on growth and body composition of large scales might be necessary to determine the effect of feeding methods of infants after 3 months and to set proper body composition standard for infant.

• Child Health Nursing Research
• /
• v.9 no.3
• /
• pp.272-284
• /
• 2003

Purpose: The purpose of this research is to provide basic informations for the encouragements of premature infants' breast feeding. Method: From August 10 to October 9, 2002, we have carried out a statical research which surveyed 148 mothers of premature infants registered in NICU. The sample had generated cluster-randomly from 25 General Hospitals, all over the Korea peninsula and being surveyed with 74 questionnaires. Result: Mean hospitalized day of premature infants was 27.9 days. The mean total feeding period was 19.1 days and continuous breast feeding period 12.4days. They were interested in breast feeding education-they answered that they would join the breast feeding education if they were given the chance 87.8％. There was significant relation between babies fed only breast milk and the body weight of birth(p<.05). The reasons why mother gave the baby her breast milk include 'for her baby's health' and 'people said breast milk is good for babies' with a portion of 99％. The main reason why mothers could not execute breast feeding was 'the deficit of breast milk volume' 50.0％ and other reason were 'because of start to support more nutritions '18.2％, 'difficulty to carry out the breast milk to hospital'13.6％. The reasen why mothers could not try breast feeding at first were 'deficit of breast milk volume'37.0％, 'not to be prepared for breast feeding because of unexpected delivery'32.6％. Conclusion: We need a program to inform importance and excellent of the breast feeding and a plan to increase the premature infants' breast feeding through the importation of fortifier.

• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.1327-1331
• /
• 2004

In this paper constant power models for electric trains have been used to analyze the steady states of the AT feeding systems. There are some previous studies utilizing constant impedance models or constant current models. These mentioned models are easy to use, but even so they don't yield exact results because of the innate restraints of the models since linear models cannot represent the characteristic of constant power in inverter-driven trains. It is reasonable that the train be considered as a constant load model when it drives or as a constant source model when it applies regenerative brake. Nonlinear equations which reflect constant power model for train have been developed by considering mutual impedances between wires and AT's turn-ratio of 1:1, then these equations have been solved by N-R iterative method. The proposed method doesn't need any specific assumptions through either the process of developing equations or the process of acquiring solutions, so it can be said to be stricter than other conventional methods.

• Proceedings of the KIEE Conference
• /
• 2001.04a
• /
• pp.449-451
• /
• 2001

This study presents a study on modified algorithm to operating train simulation of AT feeding systems. In this study equivalent impedance is constructed by $Z_c,\;Z_r,\;Z_f,\;Z_{cr},\;Z_{rf},\;Z_{fc}$. The train current flows through the all auto-transformer corresponding to track impedance. To calculate train voltage from analyzing the railway systems, the algorithm is based on the K. C. L, K. V. L, superposition and circuit separation method. Multi-train's voltages are determined by calculating the catenary voltage at each train's position and adding up these train's voltage drop. Case studies use a field operational data, show that the proposed method is easily applied.

• Korean Journal of Poultry Science
• /
• v.35 no.2
• /
• pp.171-176
• /
• 2008

Animal welfare advocates, claim that the induced molting by fasting be avoided. This study was conducted to evaluate the effect of molting induced by various feeding methods on productivity and egg quality in laying hens. We used 400 flocks of 60-week-old leghorn laying hens in four treatments(five replicates of 20 hens each): fasting method (C), feeding single corn grain diet (T1), feeding single wheat bran diet (T2) and feeding single alfalfa meal diet (T3). As the result of the experiment, egg production and daily egg mass significantly decreased only in T1 compared with the control during the $1{\sim}4th$ week after the secondary egg laying (P<0.05). Although the amount of feed intake was significantly less in T1 group during the $1{\sim}4th$ week compared to the control, no significant difference was detected during the total period (P>0.05). In addition, no significant difference of feed conversion was observed between treatment groups. In terms of egg quality, the egg shell thickness was significantly improved in T1 group than the control group by feeding only corn at the 10th and 14th week after the secondary egg laying (P<0.05), but the significant decrease was observed at the corn (T1) and wheat bran (T2) fed treatment groups than the control group at the 26th week of the experiment (P<0.05). The eggshell strength and haugh unit did not show any difference by the molting methods. Egg yolk color was significantly decreased in T1 and T2 group than the control group at the 6th week (P<0.05). However, T1 and T2 group resulted to show significantly high egg yolk color at the 18th week of the experiment (P<0.05). As the result of the experiment, no large difference was observed in the productivity by the feeding molting method and by the fasting induced molting method. In addition, the single diet fed feeding induced molting method by using alfalfa revealed to show more satisfactory trend than the corn or wheat bran single diet fed feeding induced molting methods even if no statistically significant difference was found in terms of egg productivity.

• Journal of Korean Academy of Nursing
• /
• v.5 no.1
• /
• pp.1-16
• /
• 1975

The newborn human is the only mammalian whose mother does not have a food supply ready for it's offspring at birth. From two to four days usually elapse before the mother's supply If milk appears, and during this period, some kind of artificial feeding should be supplied to the infants. Because of this factor, there has been continued debate fog the past hundreds of years as to when the first feeding should be started Accordingly, many experiments were carried out by scholars and because of these, Pre-lateral feedings were believed to be necessary. Many types of pre-lateral feedings were tried and the conclusion was reached that glucose water was the best food for the first infants'feedings. Traditionally, This has been started 12 hours after birth. The causes for the 12 hours delay were thought to (1) provide rest for the infants: (2) prevent regurgitation ana vomiting which tended to be prevalent during this tine: (3) in cases of low weight infants, prevention of aspiration pneumonia. From recent studies of newborn physiology and as pediatric medicine has been rapidly advancing, many studies hare been carried out concerning the improvement of infant nutrition and the early feeding of infants has been emphasized. This author believes it would be very beneficial to try two different kinds of feedings for the infant. (1) experimental feedings ana (2) comparative feeding, and during this period to investigate and compare the infants blood sugar level, hematocrit, gamma globulin level weight changes and to observe the infant reaction ill order to search for a more desirable feeding program. This study was conducted from January to March 1974 with data related to 40 healthy newborn infants (male 21, female 19: weight, 2.79∼4.20㎏ : gestation, 39∼40 weeks) born at Ewha Womens University Hospital and the results obtained were as follows : 1. At time of birth the blood sugar level from the cord sample averaged 88.99㎎/100㎖, but the blood sugar level rapidly dropped after 2 to 3 hours and reached the lowest point after 10 to 11 hours (54.48㎎/100㎖) and rose again by the 24 hour time period (76.80㎎/100㎖). Changes in the blood sugar level of the experiments: groups and the compare-five group was not significantly different until the 6 to 7 hour period, but by the 10 to 11 hour period the blood sugar levels of the experimental group (49,10㎎/100㎖) and the comparative group (49.70㎎/100㎖) were lower than the remainder of the experimental groups. 9. There ware no significant weight changes between the two groups. Average weight at birth was 3.35㎏, but at the 24 hours period birth weight averaged 3.29㎏. (1.8% reduction of birth weight). It continually lowered until at 48 hours, average weight was 3.26㎏ (2.7% reduction from birth weight.) 3. Hematocrit readings showed no significant difference between the groups. Hematocrit, the average value at birth, was 28.07% and abruptly elevated to average 64.35% at the 2 to 3 hour period, then slowly lowered to an average of 59.67% at the 6 to 7 hour period, 55.10% at the 10 to 11 hour period, ana 53.70% at the 24 hour period. 4. At birth, average gamma globulin value averaged 1,39㎎/100㎖. and at the 24 hour period averaged 1,52㎎/100㎖ revealing no significant difference between the two feeding groups. 5. Such factors as voiding, passing of meconium, regurgitation and vomiting showed no significance between the two feeding groups. However, the number of infants voiding and passing meconium in the experimental groups during the first 12 hours was slightly greater. In general there was an increased tendency for regurgitation and. vomiting among a small group of the infants during the first 24 hours which thereafter decreased. 6. Fluid intake averaged 24.38cc at the first feeding and increased to average 30.48cc at the third feeding and further increased to 73. 00cc at the fifteenth feeding. Finally it was suggested that the most reasonable method of early feeding is to give less than 25cc of 5% glucose water and/or 8% powdered milk at 8 to 9 flours after birth in order to prevent hypoglycemia and dehydration.

• Journal of Electrical Engineering and Technology
• /
• v.8 no.1
• /
• pp.118-123
• /
• 2013

This paper presents performance comparison between concentrated winding and distributed winding of IPMSM (Interior Permanent Magnet Synchronous Motors) which is recently used for light-weight railway applications. Motors are designed on various schemes and analyzed by using FEM (Finite Element Method) instead of EMCNM (Equivalent Magnetic Circuit Network Method) in order to take into account saturation and non-linear magnetic property. The overall performance such as torque, torque ripple, losses, demagnetization, efficiency, power density and so on are investigated in detail at the rated and maximum operating speed. The results of the analysis found that both concentrated and distributed winding IPMSMs are promising candidates for high power railway traction motor.

• Transactions of Materials Processing
• /
• v.13 no.2
• /
• pp.142-147
• /
• 2004

Three-dimensional rigid-plastic finite element analysis has been performed to optimize open die forging process to make round bar. In the round bar forging, it is difficult to optimize process parameters in the operational environments. Therefore in this study, finite element method is used to analyze the practice of open die forging, focusing on the effects of reduction, feeding pitch and rotation angle for optimal forging pass designs. The soundness of forging process has been estimated by the smoothness and roundness of the bar at various combination of feeding pitches and rotation angles. From the test result, process conditions to make round bar having precise dimensional accuracy have been proposed.

• Journal of the Korean Society for Precision Engineering
• /
• v.7 no.3
• /
• pp.14-25
• /
• 1990

A model predicting thermal and wear crown in order to control strip crown and shape has been investigated at the hot roll mill. A basic equation of predicting wear crown was obtained experimentally whereas thermal crown was approximately analyzed by the integral method. The calculated result based on the accumulative model of basic eauation coincides with that measured under the real rolling conditions. The effect of wear corwn is also analyzed by the longitudinal feeding method of the work roll. The high frequency feeding method is recommended in removing local wear effectively.