• Bulletin of the Korean Chemical Society
• /
• v.23 no.2
• /
• pp.337-345
• /
• 2002

The equilibrium structures for the ground and transition states of $C_7H_7^+$ isomers have been investigated using sophisticated ab initio quantum mechanical techniques with various basis sets. The structures of tropyrium and benzyl cations have been fully optimized at the DZP CCSD(T) levels of theory. And the structures of o-, m-and p-tolyl cations are optimized fully up to the DZ CCSD(T) levels of theory. The geometries for the transition states between three isomers of tolyl cations have been optimized up to DZP CISD level of theory. The SCF harmonic vibrational frequencies for tropylium, benzyl, and three isomers of tolyl cations are all real numbers, which confirm the potential minima and each unique imaginary vibrational frequencies for TS1 and TS2 confirm the true transition states. The relative energy of the benzyl cation with respect to the tropyrium cation is predicted to be 28.5 kJ/mol and is in good agreement with the previous theoretical predictions. The 0 K heats of formation, ${\Delta}H^{\circ}_{f0}$, have been predicted to be 890, 1095, 1101, and 1110 kJ/mol for tropylium, ortho-, meta-, and para-tolyl cations by taking the experimental value of 919 kJ/mol for the benzyl cation as the base level. The relative stability between tolyl cations is in the order of ortho

• Journal of the East Asian Society of Dietary Life
• /
• v.22 no.1
• /
• pp.1-8
• /
• 2012

We compared the dietary behaviors and living habits of Han Children living in both China and Korea to find any influences from the different living environments. Three hundred $5^{th}$ and $6^{th}$ -grade children in China and two hundred thirty three $5^{th}$ and $6^{th}$ -grade children in a Chinese school in Korea were surveyed via questionnaire. Mean BMI was higher and sleeping hours were lower in the children living in Korea compared to the children living in China. Mean age and education level of the parents were higher in the children living in Korea. Most of the dietary behaviors discovered via the questionnaire showed similar tendencies in the two groups. However, in terms of skipping breakfast, deviating in food habits, snacking before sleeping, and snacking right after eating a meal, the children living in Korea showed significantly higher frequencies. Also, children living in Korea showed significantly lower frequencies of overeating, snacking while watching TV or using the computer, and eating food when stressed, than children living in China. In living habits, children living in Korea do less regular exercise and use buses or cars more frequently for short distance transportation and spend more time to watch TV or computer than the children living in China. Therefore, it seems that different living environments may somewhat influence the dietary behaviors and living habits of children even if they have the same ethnic background.

• Korean Journal of Environmental Biology
• /
• v.21 no.4
• /
• pp.368-376
• /
• 2003

The UV-B sensitivity was tested for the intertidal species Chondrus ocellatus from Korea, by measuring photosynthesis estimated as effective quantum yield ($\Phi_{PSII}$) of photosystem II (PS II), growth and content and composition of photosynthetic pigments and UV-absorbing pigments (UVAPs). The $$\Phi_{PSII}$ of the alga decreased with increasing time of exposure to UV-B radiation, followed by fast and nearly full recovery indicating dynamic photoinhibiton. Fresh weight-based growth and pigment contents of C. ocellatus were not seriously affected by UV-B radiation. A single broad peak at 327 nm was obtained from methanol extracts of C. ocellatus, and the absorbance peak increased with increasing UV. The single peak was resolved into three peaks (311, 330 and 336 nm) by the fourth -derivative, and quantitative change in response to UV-B radiation occurred only at 330 nm. High performance liquid chromatography (HPLC) analysis of purified extracts indicated that three MAAs (mycosporine-like amino acids) are present, asterina 330, palythine and shinorine. Field observations during three growing months showed that C. ocellatus exhibit the highest amount of UVAPs in May followed by July and little trace in September, coinciding with the species' phenology. In an ecological context, dynamic photoinhibition as well as accumulation of UVAPs may enable the shallow water red alga C. ocellatus to be well adapted to high UV-B environments.

• Archives of Reconstructive Microsurgery
• /
• v.4 no.1
• /
• pp.16-22
• /
• 1995

We analyzed 11 children who underwent epiphyseal transplantation to the forearm for manage growing deformity ranged from 2 years 6 months to years(average 5 years 10 months) follow-up period. Etiologies of the functional impairment of the eleven were five traumatic, three congenital and three tumorous conditions. Lesions of epiphysis were distal radius in eight patients and distal ulna in three patients. Operation was performed with removal of non-functioning or deformed epiphysis followed by transplantation of free vascularized proximal fibular epiphysis with microvascular anastomesis. Evaluation was performed radiologically and functionally. The 9(81.8%) patients showed growth of transplanted epiphysis by radiological examination during follow up. At the last follow up, average growth rate was 0.86cm per year excepts 2 cases of no growth. Active wrist motion near normal to contralateral joint was achieved in 7 patients. In other 2 patients, active joint motion was improved but weaker than contralateral joint. Complications on donor site were two transient peroneal nerve palsy which have been resolved after 2 and 5 months post operation and one valgus ankle deformity. The ankle deformity was corrected with $Langenski\"{o}ld$ operation of the dital tibiofibular fusion. At recipient site, there was one superficial infection and it was easily controlled by systemic antibiotics. Many subsequent reports have described successful nonvascularized epiphyseal transplante, but overall results have been inconsistent and unsatisfactory. Other experimental and clinical studies in the transfer of vascularized epiphyses has encourage its clinical application. We also could gel successful growth in several cases with free vascularized epiphyseal transplantation.

• Journal of Pharmacopuncture
• /
• v.21 no.2
• /
• pp.98-103
• /
• 2018

Objective: DIt is need to evaluate he changes of the bio-signals through the hot-cold stimulation in the CV4. Methods: The 30 healthy participants were enrolled and randomly allocated, to one of three groups(10 participants for each group): the hot stone therapy(HST) group, or the cold stone therapy(CST) group or no treatment group(NT). All the participants took a rest for 10 minutes for stability before the test. And additional 10 minute rest after measurements of skin test and sEMG. After that two group received hot or cold stone therapy for 30 minutes and one group treated nothing with HRV test. Results: HRV LF value showed a significant increase over time in all three groups, but there was no significant difference between groups but HRV HF value did not show any significant difference with time in all three groups and there was no significant difference between groups. sEMG value showed a significant increase in the left side of the masseter muscle of the HST group and sebum levels was a significant decreased in HST group but no significant meaning was found. Conclusion: There was no objective evidence that hot-cold stimulation produced bio-signals changes in comparison to the control group, but additional studies are needed as the subjects were limited.

• Korean Journal of Environment and Ecology
• /
• v.29 no.4
• /
• pp.564-569
• /
• 2015

In order to discover materials that can be used for OLED, extractions of marine microalgae was screened for photoluminescence(PL) properties and analyzed using gas chromatography-mass spectrometry(GC-MS). The extractions of Nitzschia denticula, Navicula cancellata and Nannochloropsis salina showed PL spectroscopy among fourteen marine microalgae species. The selected three fractions from three microalgae were analyzed by GC-MS. According to the results, it was found that the identified organic light-emitting materials can be subdivided into three functional groups based on imidazole, purine and quinoline. These chemicals are considered to have a strong relationship with PL spectroscopy for OLED materials.

• Journal of Radiation Protection and Research
• /
• v.28 no.2
• /
• pp.97-108
• /
• 2003

A three-dimensional wind field model based on the variational technique has been developed for estimating the overall wind patterns over a complex terrain. The three-dimensional elliptic partial differential equations on Cartesian and terrain-following coordinates have been established to obtain the Lagrangian multiplier and the adjusted wind velocity. The simulations were performed to evaluate the variations of the velocity vectors on the hemisphere, half-cylinder, and saddle type obstacles. Also, the wind field model in the terrain-following coordinate has been applied for evaluating the characteristics of wind patterns according to the variations of Gauss precision moduli on the hemispheric topography. The results showed that the horizontal and vertical wind components were strongly governed by the selection of the values of Gauss precision moduli.

• Proceedings of the KIEE Conference
• /
• 1999.07d
• /
• pp.1680-1682
• /
• 1999

In this study, three kinds of Mn-Zn ferrite/Ni-Zn ferrite/$Ni_2Y$ ferroxplana prepared by the coprecipitation method were compounded with the silicon rubber, and the ring-shaped specimens with various compositional ratio were made. The material constant of ferrite/rubber composite absorbers was obtained by the 2-port method. The material constants of the ferrite/rubber composite microwave absorber made of three kinds of ferrite with various compositional ratio were utilized in design the matching conditions (frequency and thickness) on the impedance matching map. We were able to predict the matching condition from the matching map. On all three kinds of ferrite/rubber composite microwave absorber with less than compositional ratio 60[wt.%] of ferroxplana, we have found that the reflection losses were over than 20[dB] at the S-Band $(2\sim4[GHz])$ and C-Band$(4\sim8[GHz])$.

• Journal of Korean Society of Steel Construction
• /
• v.17 no.3 s.76
• /
• pp.317-324
• /
• 2005

The specially orthotropic plate theory is used to analyse three-span continuous composite slab bridges with elastic intermediate supports. A method of calculating the natural frequency corresponding to the first mode of vibration of beams and tower structures, with irregular cross sections and with arbitrary boundary conditions, was developed and the result of application of this method to the three-span continuous composite slab bridges with elastic intermediate supports is presented. This type of bridge represents either concrete or sandwich type three-span bridge on polymeric supports for passive control or on actuators for active control. Any method may be used to obtain the deflection influence surfaces needed for this vibration analysis. The finite difference method is used for this purpose in this paper. The influence of flexural stiffnesses and the modulus of the foundation are studied.

• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.3156-3159
• /
• 2011

In case of the continuous welded rail(CWR) track is supported by the railway bridge, the additional axial force is occurred in the CWR due to the track-bridge interaction. In the various design codes such as Korean code, European code, UIC code, etc, three important loads(temperature variation in the bridge-deck, braking/acceleration and the bending of the bridge-deck resulted from the passing train) are treated as the independent loading case. In other words, the additional axial force can be obtained by summing up the three different values calculated by the three independent analysis. However, this analysing method may have an error because the behavior of the longitudinal resistance between the rail and the bridge-deck is under the highly nonlinear. Therefore, in order to exactly analyse the track-bridge interaction, nonlinear loading history and the change of the longitudinal resistance owing to the loading history must be considered in the analysis process. In this study, the loading history effect on the track-bridge interaction is investigated considering the resonable combination of three loads and the longitudinal resistance change.