• KSBB Journal
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• v.9 no.3
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• pp.272-278
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• 1994

Attenuated varicella-zoster virus(VZV) was cultured in human embryonic lung cells. The effects of serum type and its concentration on the production of VZV were studied. Regardless of cell culture conditions, VZV yield was increased with multiplicity of infection, and the total cell concentration was decreased after virus infection. The newborn calf serum, calf serum, or horse serum was not as good as the fetal bovine serum or calf serum supplemented with iron for the propagation of VZV in the human embryonic lung cells. The yields of total VZV(cell-associated virus and cell-free virus) in the medium with calf serum containing iron were comparable to those in the medium supplemented with fetal bovine serum. Furthermore, some components of serum appear to be important for the maintenance of VZV infectivity.

• Computational Structural Engineering
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• v.10 no.4
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• pp.195-203
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• 1997

The interaction between cracks and stress wave due to impact and explosive loads is numerically calculated in the study. The interaction and the effects of stress wave are numerically examined with the application of Bicharacteristic Method. This method has been used with confidence for its reliability in reproducing the realistic and physical wave pattern in the complete solution domain. The dynamic stress intensity factor, K/sub I/(t) for cracks under impact loads are numerically simulated and its results are compared favorably with Kalthoff's experimental output. Also the influence of stress wave to the dynamic stress intensity factor for the case of two symmetric holes around cracks are investigated. The results of study are also compared favorably with the experiment and proven to be applied to the structures exposed to impact and explosive loads.

• International Journal of Railway
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• v.6 no.3
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• pp.95-106
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• 2013

Earthborne vibrations are induced by construction operation such as pile driving, roadbed compaction, and blasting and also by transit activities such as truck and trains. The earthborne vibration creates the stress waves traveling outward from the source and can structurally damage nearby buildings and structures in the forms of direct damage to structure and damage due to dynamic settlement. The wave propagation characteristics depends on impact or vibration energy, distance from the source, and soil characteristics. The aim of this paper is to provide a comprehensive review on the mechanistic of earthborne vibration and the current practice of vibration control and mitigation measures. The paper describes the state of knowledge in the areas of: (1) mechanics of earthborne vibration, (2) damage mechanism by earthborne vibration, (3) calculation, prediction of ground vibration, (4) the criteria of vibration limits, (5) vibration mitigation measures and their performance, and (6) the current practice of vibration control and mitigation measures.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.2
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• pp.108-115
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• 2003

Two types of one-dimensional dispersion-correction scheme are developed to take into account the dispersion effects for the simulation of tsunami propagation using ADCIRC finite element model based on shallow-water equations The first is an implicit scheme, and the dispersion-correction is accomplished by controlling the weighting factor assigned to each spatial derivative term of different time levels. The other scheme is explicit and the dispersion is considered by adjusting the element size. The validity of the dispersion-correction scheme proposed in this study is confirmed through the comparison of numerical solutions calculated using the new schemes with analytical ones considering dispersion effect of waves.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.6
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• pp.464-467
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• 2001

In order to establish a in vitro propagation system for gold tree[Dendropanax morbifera $L_{EV}$], the effects of auxins and cytokinins on shoot multiplication and rooting were investigated. Germination rate was the best in MS medium. The fresh weight and number of shoot were the best on the medium containing 0.1 or 1.0 mg/l BAP and 0.5 or 1.0 mg/l NAA. Shoots were successfully rooted in MS medium with 1.0 mg/l NAA. Roots were easily formed by the addition of auxins, especially 0.1 or 1.0 mg/l BAP.P.

• Journal of Astronomy and Space Sciences
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• v.33 no.4
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• pp.273-278
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• 2016

December 2009 was one of the quietest (monthly Ap=2) months over the last eight decades. It provided an excellent opportunity to study the day-to-day variability of the F2 layer with the smallest contribution due to geomagnetic activity. With this aim, we analyze hourly values of the F2-layer critical frequency (foF2) recorded at 18 ionosonde stations during the magnetically quietest (Ap=0) days of the month. The foF2 variability is quantified as the relative standard deviation of foF2 about the mean of all the "zero-Ap" days of December 2009. This case study may contribute to a more clear vision of the F2-layer variability caused by sources not linked to geomagnetic activity. In accord with previous studies, we find that there is considerable "zero-Ap" variability of foF2 all over the world. At most locations, foF2 variability is presumably affected by the passage of the solar terminator. The patterns of foF2 variability are different at different stations. Possible causes of the observed diurnal foF2 variability may be related to "meteorological" disturbances transmitted from the lower atmosphere or/and effects of the intrinsic turbulence of the ionosphere-atmosphere system.

• Structural Engineering and Mechanics
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• v.76 no.4
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• pp.491-503
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• 2020

This study extends previous experimental research on the shear behaviour of macrosynthetic fibre-reinforced concrete beams and compares them to steel fibre-reinforced concrete beams with similar mechanical and geometrical properties. This work employed two fibre types: 60/0.9 (long/diameter) double hooked-end steel fibre and 60/85 monofilament polypropylene fibre. Beams were tested by shear loading covering parameters, such as two different cross-section widths, two shear-span-to-effective-depth ratios, two fibre types and using repetitions with and without transverse reinforcement. For quantitative comparison purposes, crack pattern evolution was studied along increasing loads levels. Effects were studied by photogrammetry, including influence of fibres on crack propagation in uncracked and dowel zones, influence of fibres on stirrup behaviour, and shear deformation or kinematics of critical shear cracks. The results evidenced similar effectiveness for both fibre types in controlling shear crack propagation and horizontal dowel cracking. Both fibres provided similar shear ductility and shear deflections. Consequently, the authors confirm that residual flexural tensile strengths are a convenient parameter for characterising the shear behaviour of fibre-reinforced concrete beams.

• Earthquakes and Structures
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• v.3 no.3_4
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• pp.203-230
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• 2012

This paper presents results for impedance (and compliance) functions and input motions of foundations in a layered half-space computed on the basis of a procedure that combines a consistent transmitting boundary with continued-fraction absorbing boundary conditions which are accurate and effective in modeling wave propagation in various unbounded domains. The effects of obliquely incident seismic waves in a layered half-space are taken into account in the formulation of the transmitting boundary. Using the numerical model, impedance (and compliance) functions and input motions of rigid circular foundations on the surface of or embedded in a homogeneous half-space are computed and compared with available published results for verification of the procedure. Extrapolation methods are proposed to improve the performance in the very-low-frequency range and for the static condition. It is concluded from the applications that accurate analysis of foundation dynamics and soil-structure interaction in a layered half-space can be carried out using the enhanced consistent transmitting boundary and the proposed extrapolations.

• Advances in concrete construction
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• v.7 no.1
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• pp.39-50
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• 2019

This study presents a comprehensive experimental investigation on mostly encountered types of Reinforced Concrete Haunched Beams (RCHBs) where three modes of RCHBs investigated; the diversity of studied beams makes it a pioneer in this topic. The experimental study consists of twenty RCHBs and four prismatic beams. Effects of important parameters including beam type, the inclination angle, flexure and compressive reinforcement, shear reinforcement on mechanical behavior and failure mode of each mode of RCHBs were examined in detail. Furthermore crack propagation at certain load levels were inspected and visualized for each RCHB mode. The results confirm that RCHBs have different behavior in shear as compared to the prismatic beams. At the same time, different mechanical behavior was observed between the modes of RCHBs. Therefore, RCHBs were classified into three modes according to the inclination shape and mode of failure (Modes A, B and C). However, it was observed that there is no significant difference between RCHBs and prismatic beams regarding flexural behavior. Moreover, a new and unified formula was proposed to predict the critical effective depth of all modes of RCHBs that is very useful to predict the critical section for failure.

• Journal of Forest and Environmental Science
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• v.36 no.4
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• pp.267-273
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• 2020

Diospyros mespiliformis is a highly valued and threatened tree species within the Sahelo-Sudanian zone of Africa, but its seed germination requirements under cultivation are not well researched. In a first experiment which aimed at determining germination response of seeds to dehydration, fresh seeds were dried at room temperature for 26 days during which their moisture content, their germinability, and their viability were monitored at two-day intervals. In the second experiment, 14 pre-germination treatments were tested for their effect on the germination of dried seeds. Results showed that fresh seeds had 52.7% moisture and achieved 97.7% germination. As seeds were dried, percentage germination gradually decreased with decreasing moisture content and reached 0% when moisture content had dropped to 18%. Meanwhile, seed viability remained at 100% over drying duration. Seeds that were not germinated after air dry also recorded 100% viability. The most effective treatment for inducing germination of dried seeds was scarification using 98% sulfuric acid for 30 min which resulted in 96.6% germination. This study reports for the first time in D. mespiliformis seeds a desiccation-induced dormancy which can be efficiently alleviated by acid scarification. This study provides useful information that will contribute to efficient management of D. mespiliformis seed resources for propagation.