• Bulletin of the Korean Chemical Society
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• v.35 no.4
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• pp.1195-1201
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• 2014

Atomic layer deposition (ALD) of $TiO_2$ thin film from $TiCl_4$ and $H_2O$ has been intensively studied since the invention of ALD method to grow thin films via chemical adsorptions of two precursors. However the role of HCl which is a gaseous byproduct in ALD chemistry for $TiO_2$ growth is still intriguing in terms of the growth mechanism. In order to investigate the role of HCl in $TiO_2$ ALD, HCl pulse and its purging steps are inserted in a typical sequence of $TiCl_4$ pulse-purge-$H_2O$ pulse-purge. When they are inserted after the first-half reaction (chemisorption of $TiCl_4$), the grown thickness of $TiO_2$ becomes thinner or thicker at lower or higher growth temperatures than $300^{\circ}C$, respectively. However the insertion after the second-half reaction (chemisorption of $H_2O$) results in severely reduced thicknesses in all growth temperatures. By using the result, we explain the growth mechanism and the role of HCl in $TiO_2$ ALD.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.13 no.1
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• pp.89-110
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• 2009

Background : Eight-Constitution Medicine (ECM) devides the human body into eight constitutions. Up until now, checking the pulse types is only way to classify the eight constitution. Recently we try to make a questionnaire that is based on the Eight-Constitution characters and analyze the answer from patients who were classified into one of the eight constitutions according to their pulse types and their responses to constitution-acupuncture therapy. Objective : This study intends to analyze each answer of the Eight-Constitution Questionnaire with independent sample t-test. Methods : Participants of this study were outpatients in ECM clinics located in Korea. The resources were collected from 925 patients who were classified into one of the eight constitutions according to their pulse types and their responses to constitution-acupuncture therapy. SPSS 13.0 for Windows was used for independent sample t-test. Results and Conclusions : 1. The proportion of participants' constitutions is in the order of Pancreotonia (28.0%), Colonotonia (17.3%), Pulmotonia (18.1%), Hepatonia (18.1%), Vesicotonia (8.5%), Cholecystotonia (7.0%), Renotonia (2.6%) and Gastrotonia (0.4%). 2. Eight-Constitution Questionnaire consists of 5 parts; Appearance, Character, Body reaction, Physiology & Pathology and Food reaction. 3. 18 items were chosen among 81 question about Character. 4. Due to the deficiency of Gastrotonia examples, useful items have to be given up. If we can gather Gastrotonia examples, we can use meaningful items more than 18.

• The Journal of the Acoustical Society of Korea
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• v.25 no.1E
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• pp.14-19
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• 2006

Ultrasonic absorption and velocity spectra in bovine serum albumin (BSA) aqueous solutions have been measured at $20^{\circ}C$ over the frequency range 0.2-3 MHz in the pH range 1.5-13.2. The high-Q ultrasonic resonator and pulse-echo overlap methods were used. At acid pH's, excess absorption over that of pH 7 was explained by double relaxation. The pH dependences of the relaxation frequency and maximum absorption per wavelength, showed that the relaxation at about 200 kHz was related to the expansion of molecules and that about 3 MHz resulted from the proton transfer reaction of carboxyl group. At alkaline pH's, the excess absorption was explained by double relaxation. The relaxation at about 300 kHz was associated with a helix-coil transition, and that about 3 MHz was attributed to the proton transfer reaction of phenolic group. The rate constants and volume changes associated with these processes were estimated.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.2 s.25
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• pp.77-86
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• 2006

Usually, a tracking-gate of the tracker is used to track the target radar signal in the active ECM system. In this paper, we propose the feed-back tracking-gate filtering method. The designed method applies a tracking-gate of the tacker to the ECM system's receiver as a rejection or pass filter selected by the receiver's purpose, and the specific target signals can be passed or rejected though this tracking-gate filter. Thus, the number of input signals within the receiver's search band is minimized owing to this filter except the target signals. In conclusion, the EW equipment's reaction time can be reduced and the error value about the target signals can be lower than the previous methods'.

• Journal of Surface Science and Engineering
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• v.57 no.4
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• pp.331-337
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• 2024

Platinum has been utilized as an excellent electrocatalyst with low overpotential for the hydrogen evolution reaction (HER) in water splitting, despite of its high cost. In this study, platinum particles were produced using pulsed laser technology as a HER catalyst for water splitting. The colloidal platinum particles were synthesized by nanosecond pulsed laser irradiation (PLI) without reducing agents, not traditional polyol processes including reducing agents. The crystal structure, shape and size of the synthesized platinum particles as a function of pulsed laser irradiation time were investigated by XRD and SEM analysis. Additionally, the electrochemical properties for the HER in water splitting of the irradiation time-dependent platinum electrocatalysts were studied with the analysis of overpotentials in linear sweep voltammetry and Tafel slope.

• The Journal of Korean Physical Therapy
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• v.23 no.4
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• pp.53-58
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• 2011

Purpose: This study aims to examine the effects of pulsed ultrasound on skin inflammatory reaction induced by ultraviolet irradiation. Methods: Twenty subjects were selected for this study. Inflammatory reaction was induced by ultraviolet irradiation in two areas of the lumbar region of the subjects. Pulsed ultrasound (3 MHz) was applied to one of the two areas of inflammatory reaction at a pulse ratio of 1:4, intensity of $0.5W/cm^2$, once a day for 5 min, and pulsed ultrasound was not applied to the other area. Wound color (chromatic red), luminance (gray) and wound contraction (area) were measured using digital imaging processing method. Results: There was a significant difference in wound color (chromatic red) in the interaction between time and area. There was a significant difference in luminance in the interaction between time and area. There was a significant difference in wound contraction between the two areas. Conclusion: These results indicate that pulsed ultrasound increased the wound contraction rate and reduced the inflammatory reaction activity such as erythema induced by ultraviolet irradiation.

• Journal of the Korean Society of Radiology
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• v.11 no.5
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• pp.361-370
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• 2017

In the Brain MRI, RF Pulse is irradiated on the human body in order to acquire an image. At this time, a considerable part of the irradiated RF Pulse energy is absorbed as it is in our body. This will raise the temperature of the human body, but depending on the extent of exposure, it will affect the human body. The change of the SAR and the temperature of the head according to the change of the magnetic field strength is examined. And to investigate the difference in results depending on the use of dental implant. In the human head model, 64 MHz RF Pulse frequency generated from 1.5 T, 128 MHz RF Pulse frequency generated from 3.0 T, and 298 MHz RF Pulse frequency generated from 7.0 T send a frequency and experiment was performed using dental implant using the XFDTD program, we measured the SAR and body temperature changes around the head. The SAR value showed up to about 5800 times the difference at the RF Pulse frequency of 256 MHz, when with dental implant than without dental implant and as the frequency increased, the use of the dental implant increased difference in the SAR value. The change of the temperature of the head showed a temperature rise nearly 2 to 4 times when with dental implant than without dental implant. As the RF Pulse frequency increase, the SAR value increase, but the change of the temperature of the head decrease. Because of as the frequency increase, wavelength is smaller and the more the amount absorbed by the surface of the human. Physiological and biochemical studies of the human body ar necessary through studies of the presence of dental implant and the cause of reaction caused by change in the RF Pulse frequency.

• Journal of Korean Academy of Nursing
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• v.17 no.2
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• pp.137-144
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• 1987

The main purpose of this study was to examine the validity of the vital sign as an instrument of stress reaction measurement. From July to August 1986, stress reaction was evaluated by the difference of endoscopic vital sign on 93 G-I troubled out-patients who underwent endoscopy for the first time and did not have any evidence of cardiovascular disease. The data were analysed by x$^2$-test, Paired . t-test, ANCOVA and Multiple Comparison Test. The result of study were as follows: 1. The frequency of gastric disease was differed by the family type, and the mobility of gastritis and gastric cancer were more increased in nuclear family than in large family (p=0.019). 2. In a comparison of before with after 5 minutes endoscopic vital sign, and a Pulse rate (P=0.0001), respiration rate (p=0.0001), systolic blood pressure (p=0.0002) and diastolic blood Pressure (P=0.006) were significantly increased after 5minutes by endoscopy in contrast with before 5minutes. 3. The control of before 5 minutes of endoscopic vital sign, after 5 minutes of endoscopic systolic (p=0.024) and diastolic blood pressure (p=0.0146) were more elevated in biopsyed group than in non-biopsyed, group. And after 5minutes of endoscopic respiration rate was more increased in gastric cancer than in gastritis (p=0.0406) or gastric ulcer (p=0.0073). And after 5 minutes of endoscopic systolic blood pressure was elevated over 50years old men (P=0.0238). In short, the increase of a pulse rate af ter 5 minutes of endoscopy was not influenced by general characteristics of samples in this experiment. And systolic blood pressure over 50years old men must be considered of physiological hypertension.

• Journal of the Semiconductor & Display Technology
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• v.20 no.4
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• pp.157-160
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• 2021

As an insulator for a thin film transistor(TFT) and an encapsulation material of organic light emitting diode(OLED), aluminum oxide (Al₂O₃) has been widely studied using several technologies. Especially, in spite of low deposition rate, atomic layer deposition (ALD) has been used as a process method of Al₂O₃ because of its low process temperature and self-limiting reaction. In the Al₂O₃ deposition by ALD method, Ar Purge had some crucial effects on the film properties. After reaction gas is injected as a formation of pulse, an inert argon(Ar) purge gas is injected for gas desorption. Therefore, the process parameter of Ar purge gas has an influence on the ALD deposited film quality. In this study, Al₂O₃ was deposited on glass substrate at a different Ar purge time and its structural characteristics were investigated and analyzed. From the results, the growth rate of Al₂O₃ was decreased as the Ar purge time increases. The surface roughness was also reduced with increasing Ar purge time. In order to obtain the high quality Al₂O₃ film, it was known that Ar purge times longer than 15 sec was necessary resulting in the self-limiting reaction.

• Journal of the Korean Society of Propulsion Engineers
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• v.1 no.1
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• pp.64-72
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• 1997

An analytical study has been performed to investigate the unsteady ignition characteristics of pulse combustion. In many combustion applications, strain rate of the flow can significantly affect the combustion features; ignition, extinction, and reignition. In the pulse combustion, two jets (hot combustion gases and fresh mixtures) coming from the opposite side of the combustor will collide in the combustor forming a stagnation region where the chemical reaction is suppressed by the strain rate until this becomes below the critical value. In this research, the method of large activation energy asymptotic is adopted with one step irreversible kinetics to examine the ignition response to the periodic variation of the strain rate of flow. The results show the variation of the maximum value of strain rate can determine whether the ignition or extinction occur.