• Journal of Bio-Environment Control
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• v.25 no.3
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• pp.168-172
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• 2016

The effect of different exposed length of M.9 rootstock on growth and yield was tested in the new apple cultivars. The 'Seohong', 'Summer Dream', and 'Hongguem' grafted on M.9 rootstock were planted in March 2010. The trees were planted in such a way that the exposed length of the rootstock to be 10, 20 and 30 cm. The result showed that as decreasing exposure length, TCA of 'Seohong', 'Summer Dream', and 'Hongguem' was increased between $3^{rd}$ and $6^{th}$ year after planting. The TCA of 20 cm and 30 cm exposure length showed respectively 70% and 60% in 'Seohong', 88% and 66% in 'Summer Dream', and 55% and 41% in 'Hongguem' of the TCA with 10 cm exposure length on 6-year-old trees. Tree height, canopy width, shoot length and terminal shoot length were also increased according to decreased exposure length in 6-year-old trees. The cumulative yield of three cultivars was higher in the tree with a lower exposure length between $4^{th}$ and $6^{th}$ year after planting. The cumulative yield of 20 cm and 30 cm exposure length showed respectively 77% and 63% in 'Seohong', 85% and 76% in 'Summer Dream', and 73% and 58% in 'Hongguem' of the cumulative yield with 10 cm exposure length in 6-year-old trees. Considering tree growth and yield, the optimum exposure length of M.9 was 10 cm for 'Seohong', 'Summer Dream' and 'Hongguem'.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.238.2-238.2
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• 2015

Surface modification of vertically-aligned carbon nanotube (VACNT) is essential in order to meet specific demands for particular applications such as field emission displays, heat dissipation device and potential sun energy conversion due to their superior electrical and thermal conductivity and strong light absorption. In this study, we observe the effect of exposure to water vapor on a different lengths of the surfaces of VACNT. The study was conducted on three different lengths of the VACNT: short length around $200{\mu}m$, medium-length around $500{\mu}m$, and high length around 1 mm. Water exposure time ranges between 2-10 min and temperature of the water ranges from 60 to 120 oC. The result of water vapor exposure mainly show that increasing the exposure time and water temperature give rise to increase of the speed of change on the surface of the VACNT. Especially, the shorter VACNT change their surface morphology most rapidly.

• Journal of Korean society of Dental Hygiene
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• v.12 no.2
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• pp.345-353
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• 2012

Objectives : The author has studied about correlation of gingival exposure upon smiling and oral facial status that reduce facial aesthetic. Methods : The subjects in this study are 91 female vulunteers who were in aged $21.4{\pm}1.89$ in Suwon. Objectives should be normal oral and facial status without the prosthodontic, orthodontic appliance or conqenital missing tooth, and agree to be examined the oral status and impression taking. 1.Measure the length of gingival exposure upon smiling. 2.Measure of the size on central incisor. 3.Measure of Facial. SPSS(SPSS 10.0 for windows, SPSS Inc, Chicago, USA) was utilized for calculating the correlation coefficient between gingival exposure upon smiling and facial status. Regression analysis was calculated in order to predict the R square for gingival exposure upon smiling. Results : 1.Correlation coefficient between the gingival exposure and length of maxillary central incisor was calculated as reversed correlation(r=-.302, p<0.01), and between the gingival exposure and the ratio of the length of central incisor/width of central incisor was revealed as reversed correlation(r=-.250, p<0.05) on smiling. 2.There was correlation between the gingival exposure and the facial height(r=.351, p<0.01), the lower facial height(r=.454, p<0.01) and the upper lip height(r=.274, p<0.01) upon smiling. 3.There was correlation between the gingival exposure and the ratio of the facial height/facial width(r=.358, p<0.05), the ratio of the upper facial height/facial width(r=.214, p<0.05), and the ratio of the lower facial height/facial height(r=.383, p<0.01) upon smiling. 4.The equation of the regression analysis for gingival exposure upon smiling could be estimated as gingival exposure upon smiling=-5.139+.279${\times}$lower facial height-.615${\times}$maxillary central incisal length-.05${\times}$nasolabial angle. Conclusions : Considering these results, it recommended that treatment planning should be designed in consideration of such factors as the length of maxillary central incisor, facial height, upper lip height and lower facial height, in order to promote the easthetic problems of face on smiling.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2003.11a
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• pp.7-11
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• 2003

Interactions of both feminizing and masculinizing chemicals inducing imposex in gastropod were investigated with a long-term exposure experiment. Imposex-free rock shell(Thais-clavigera)was exposed to TBT and other antagonistic chemicals (nonylphenol and DDT), P450 inducer (phenobarbital) and natural sex hormone (estrogen) mixtures for 60 days. None of imposexed-females were found in control, sham (ethanol) and testosterone exposure group, on the other hand imposex was induced in the TBT and all the TBT+antagonist mixture groups. After 60-day exposure, frequency of imposexed-female ranged from 31-68%. Female mean penis length (FMPL) of imposexed-female ranged from 0.87-2.58 mm, and relative penis length indices were from 7.2 to 21.2%. However, the degrees of imposex were different among the exposure groups. The FMPLS of three exposure groups (TBT+estrogen, + DDT and +nonylphe- not) were less than that of the TBT exposure group. Ethoxyresorufin-O-deethylase (EROD) activities in gastropod decreased in the TBT and all the TBT+antagonist ekposure groups compared to the control group. A negative correlation was abtained between TBT body residue and EROD activity, while a positive relationship was obtained between 737 body residue and the degree of imposex except for the TBT +DDT exposure group. Although 737 concentration was relatively high in the TBT+DDT exposure group, the TBT +DDT exposure group demonstrated low EROD activity and low degree of imposex. These results indicate that a certain antagonistic effect of DDT occurred in induction of imposex by TBT.

• ALGAE
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• v.26 no.3
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• pp.243-251
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• 2011

Environmental conditions can influence the morphology of local biota through phenotypic plasticity or local adaptation. Macroalgal morphologies are often associated with wave-exposure conditions. We investigated the relationship between morphology and wave exposure in two common endemic subtidal macroalgae, Carpophyllum angustifolium and C. maschalocarpum, from the East Cape of New Zealand. Morphological comparisons were made between individuals from two sites and four different wave-exposure zones, as defined by fetch and barnacle composition. Of the seven morphological traits measured in C. angustifolium, only total length varied, and individuals were longer in more wave-exposed environments between the two exposure zones where the species were found. In contrast, total length, stipe thickness and vesicle presence all varied significantly between exposure zones in C. maschalocarpum. C. maschalocarpum specimens were shorter with thinner stipes, and fewer individuals had vesicles in the more wave-exposed zones. Morphological traits of both species also varied between sites, suggesting that other influences are important for determining species morphology. Further study is needed to investigate the role of phenotypic plasticity and genetic variability for driving morphological variation in C. angustifolium and C. maschalocarpum.

• Journal of Environmental Health Sciences
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• v.22 no.2
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• pp.43-57
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• 1996

To characterize worker's exposure to glass fibers, to find the correlation between airborne total dust concentrations and fiber concentrations and to recommend an appropriate evaluation method for worker's exposure to fibrous dusts in glass wool industry, we carried out this study. Average respirable fiber levels at five factories were 0.013-0.056 f/cc, and fairly below the OSHA PEL, 1 f/cc. A factory showed the lowest airborne fiber level, 0.013 f/cc, which was different significantly from those of other factories of which average fiber concentration was 0.046 f/cc. The cutting and grinding operations of insulation products resulted in higher airborne fiber cocentrations than any other processes(p<0.05). To characterize airborne fiber dimension, fiber length and diamter were determined using phase contrast microscope. The geometric means of airborne fiber lengths were $42-105 \mu m$. One factory had airborne fibers whose length distribution(GM = $105 \mu m$) was different from those of other factories(GM = $42-50 \mu m$). The percentages of respirable fibers less thinner than 3 gm were 38.9-90.9% at four factories, and two factories of them had the higher percentages than others. The findings explain for variation of airborne fiber diameters between factories. On the other hand, between the processes were the difference of fiber-length distributions observed. The cutting and grinding operations showed shorter fiber-length distributions than the fiber forming one. However, fiber-diameter distributions or respirable fiber contents were similar in all processes. The airborne fiber concentrations and the dust concentrations had relatively weak correlation(r=0.25), thus number of fibers couldn't be expected reliably from dust amount. Fiber count is appropriate for assessing accurate exposures and health effects caused by fibrous dusts including glass fibers. Ministry of Labor have established occupational exposure limit to glass fibers as nuisiance dust, but should establish it on the basis of respirable fiber concentration to provide adequate protection for worker's health

• Structural Engineering and Mechanics
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• v.69 no.2
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• pp.193-204
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• 2019

This paper presents results from experimental and numerical studies on the response of steel-concrete composite box bridge girders under certain localized fire exposure conditions. Two composite box bridge girders, a simply supported girder and a continuous girder respectively, were tested under simultaneous loading and fire exposure. The simply supported girder was exposed to fire over 40% of its span length in the middle zone, and the two-span continuous girder was exposed to fire over 38% of its length of the first span and full length of the second span. A measurement method based on comparative rate of deflection was provided to predict the failure time in the hogging moment zone of continuous composite box bridge girders under certain localized fire exposure condition. Parameters including transverse and longitudinal stiffeners and fire scenarios were introduced to investigate fire resistance of the composite box bridge girders. Test results show that failure of the simply supported girder is governed by the deflection limit state, whereas failure of the continuous girder occurs through bending buckling of the web and bottom slab in the hogging moment zone. Deflection based criterion may not be reliable in evaluating failure of continuous composite box bridge girder under certain fire exposure condition. The fire resistance (failure time) of the continuous girder is higher than that of the simply supported girder. Data from fire tests is successfully utilized to validate a finite element based numerical model for further investigating the response of composite box bridge girders exposed to localized fire. Results from numerical analysis show that fire resistance of composite box bridge girders can be highly influenced by the spacing of longitudinal stiffeners and fire severity. The continuous composite box bridge girder with closer longitudinal stiffeners has better fire resistance than the simply composite box bridge girder. It is concluded that the fire resistance of continuous composite box bridge girders can be significantly enhanced by preventing the hogging moment zone from exposure to fire. Longitudinal stiffeners with closer spacing can enhance fire resistance of composite box bridge girders. The increase of transverse stiffeners has no significant effect on fire resistance of composite box bridge girders.

• Journal of the Korean Vacuum Society
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• v.8 no.2
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• pp.102-110
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• 1999

The LIGA X-ray exposure step was modelled into three inequalities, by assuming that the X-ray energy attenuated within a resist is deposited only in the localized range of the resist. From these inequalities, equations for the minimum and maximum exposure times required for a good quality microstructure were obtained. Also, an equation for the thickness of an X-ray mask absorber was obtained from the exposure requirement of threshold dose deposition. The calculation method of the synchrotron radiation power from a synchrotron radiation source was introduced and applied to an X-ray exposure step. A power from a synchrotron radiation source was introduced and applied to an X-ray exposure step/ A power function of photon energy, approximating the attenuation length of the representative LIGA resist, PMMA, and the mean photon energy of the XZ-rays incident upon an X-ray mask absorber were applied to the above mentioned equations. Consequently, the tendencies of the minimum and maximum exposure and with respect to mean photon energy and thick ness of PMMA was obtained. Additionally, the tendencies of the necessary thickness of PMMA and photon energy of the X-ray mask absorber with respect to thickness of PMMA and photon energy of the X-rays incident upon an X-ray mask absorber were examined. The minimum exposure time increases monotonically with increasing mean photon energy for the same total power density and is not a function of the thickness of resist. The minimum exposure time increases with increasing mean photon energy for the same total power density in the case of the general LIGA process, where the thickness of PMMA is thinner than the attenuation length of PMMA. Additionally, the minimum exposure time increases monotonically with increasing thickness of PMMA. The maximally exposable thickness of resist is proportional to the attenuation length of the resist at the mean photon energy with its proportional constant of ln $(Dd_m/D_{dv})$. The necessary thickness of a gold X-ray mask absorber due to absorption edges of gold, increases smoothly with increasing PMMA thickness ratio, and is independent of the total power density itself. The simplicity of the derived equations has made clearly understandable the X-ray exposure phenomenon and the correlation among the exposure times, the attenuation coefficient and the thickness of an X-ray mask absorber, the attenuation coefficient and the thickness of the resist, and the synchrotron radiation power density.

• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.297-310
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• 2023

M.7 rootstock is moderately resistant to fire blight. However, M.7 is generally too vigorous for high-density apple systems, but it can be grafted onto cultivars that exhibit weak tree growth, such as 'Sansa'. This study investigated the vegetative growth, yield, and fruit quality of 'Sansa' apple trees grafted on M.7 or M.9 rootstocks to assess the feasibility of establishing domestic high-density apple systems using M.7 and to determine the optimum exposure length for rootstocks. Trees were planted with exposed rootstock lengths of 5, 10, and 15 cm. The vegetative growth of apple trees grafted onto M.7 was greater than that of M.9 and vegetative growth tended to decrease as the exposed length of rootstock increased. However, the differences in yield per tree, average weights, soluble solids contents, and titratable acidity due to the rootstock and its exposure length varied. The accumulated yield over a 10 year period and the yield efficiency of M.7 were lower than that of M.9 and the yield efficiency tended to decrease as the exposed length of rootstock increased. When apple trees were grafted onto M.9, biennial bearing and tree vigor weakening occurred if the exposed length of the rootstock was over 10 cm. Conversely, when apple trees were grafted onto M.7, vegetative growth was excessive if the exposed length of rootstock was below 10 cm. Based on the results from this study, the optimum M.7 and M.9 exposure lengths for 'Sansa' were 15 cm and 5 cm, respectively.

• Wind and Structures
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• v.14 no.1
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• pp.15-34
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• 2011

Three wind-tunnel simulations of the atmospheric boundary layer (ABL) flow in suburban country exposure were generated for length scale factors 1:400, 1:250 and 1:220 to investigate scale effects in wind-tunnel simulations of the suburban ABL, to address recommended wind characteristics for suburban exposures reported in international standards, and to test redesigned experimental hardware. Investigated parameters are mean velocity, turbulence intensity, turbulent Reynolds shear stress, integral length scale of turbulence and power spectral density of velocity fluctuations. Experimental results indicate it is possible to reproduce suburban natural winds in the wind tunnel at different length scales without significant influence of the simulation length scale on airflow characteristics. However, in the wind tunnel it was not possible to reproduce two characteristic phenomena observed in full-scale: dependence of integral length scales on reference wind velocity and a linear increase in integral length scales with height. Furthermore, in international standards there is a considerable scatter of recommended values for suburban wind characteristics. In particular, recommended integral length scales in ESDU 85020 (1985) are significantly larger than in other international standards. Truncated vortex generators applied in this study proved to be successful in part-depth suburban ABL wind-tunnel simulation that yield a novel methodology in studies on wind effects on structures and air pollution dispersion.