• Journal of the Korean Chemical Society
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• v.33 no.6
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• pp.662-668
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• 1989

The decomposition reaction of hydrogen peroxide was carried out by using metal-4,4',4",4"'-tetraaminophthalocyanine [Mt-$PcNH_2$, Mt = Fe(III), Co(II)] supported on poly (styrene-co-methacrylic acid), in heterogeneous aqueous system. These catalysts showed a catalse-like activity and Fe(III)-$PcNH_2$ supported on the copolymer was particularly effective for the decomposition of hydrogen peroxide. It was found that the rate of decomposition increased smoothly in the higher pH region and catalytic reaction was interfered by adding $CN^-,\;CNS^-,\;{C_2O_4}^{-2},\;I^-$ ions. The kinetics of the catalytic reaction was also investigated and the reaction proceeds according to the Michaelis-Menten type mechanism.

• Journal of the Korea Society for Simulation
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• v.20 no.1
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• pp.51-59
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• 2011

This paper is concerned with locomotion of dog-like quadruped robots that can adapt to various terrains, mainly dealing with implementation methods and characteristics of static and dynamic gaits. To this end, a 12-DOF robot is built in house, motional trajectories of its body and feet are generated mimicking biological life, and the corresponding leg joint angles are analytically obtained by inverse kinematics. Such joint angle data are then applied to the robot's ADAMS model for computer simulations so that the planned walk and trot gaits are both confirmed dynamically stable. However, contrary to the simulation results, previous trot patterns showed unstable behavior during experiments. This problem led us to analyze the reason, and in the course we discovered the importance of maximally utilizing the concept of WSM rather than ZMP and therefore reducing the gait period to secure the stability of dynamic gaits such as trot.

• Journal of Navigation and Port Research
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• v.34 no.5
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• pp.383-388
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• 2010

Lab scale experiment study was carried out for biological process development on cruise. SBR(Sequence Batch Reactor), MBR(Membrane Bioreactor), and MSBR(Membrane Sequence Batch Reactor) system were investigated for practical application on shipboard sewage treatment. From the results it was suggested that MSBR system might be suitable process for cruise in terms of pollutant removal efficiency, maintenance and special environmental conditions of cruise. About 99% of BOD, 98% of COD and 99% of SS were removed in MSBR system. In addition, about 76% of total nitrogen was reduced and the total phosphorus reduction averaged 59%.

• Analytical Science and Technology
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• v.34 no.3
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• pp.128-133
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• 2021

During titration, several chemical reactions result in changes not only in the potential of chemicals, but also in the colors of the indicator. In a potentiometric titration, a titration curve is obtained by measuring the abrupt change in the potential at the endpoint. Generally, acid-base titration is performed by observing the color change caused by an indicator to determine the endpoint. The method of determining the endpoint by measuring the potential difference has been well established and commercialized; however, the devices that can obtain the endpoint by observing the color change are limited. Consequently, in this study, a simple and precise spectral endpoint detector was manufactured using a drop-counter comprising an infrared emitter and a phototransistor, a white light LED as the light source and photodetector, and an analog-to-digital converter (Arduino). Spectrator, a new named, showed excellent results in terms of the reproducibility of acid-base titration using thymol blue as an indicator. Herein, we present the results of the Spectrator-manufacturing process as well as the experimental results.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.3
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• pp.127-137
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• 2007

To confirm whether or not the Electrochemical Disinfection System (EDS) meet with the D-2 regulation established by IMO (International Maritime Organization), the biological treatment efficacy of the EDS was assessed using three groups of natural marine plankton (bacteria, $10-50\;{\mu}m$ and $>50\;{\mu}m$ sized organisms). Influent water was passed through the EDS under the flow velocity ($23.8\;m^3/hr$) and test design was consisted of control (no treatment) and experimental (10 ppm and 30 ppm) condition for total residual chlorine (TRC). And the biological condition of the influent water followed the standards established by the guidelines for the approval of ballast water management systems. The disinfection efficacy of the $10-50\;{\mu}m$ sized organisms (phytoplankton) was assessed by three kinds of measurements using photomicroscope, epifluorescence microscope and fluorometer (fumer Designs 10-AU). After being passed through the EDS, all motile phytoplankton lost their motility under photomicroscope, the colour of chlorophyll fluorescence fumed from red into green under epifluorescence, and the high chlorophyll fluorescence (Expt. 1: 6.95, Expt. 2: 7.11) detected by fluorometer decreased into value not detected. These results indicated phytoplankton community was totally killed after electrochemical disinfection treatment. Survivorship of the larger organisms than $50\;{\mu}m$ was determined based on the appendage's movement under a stereomicroscope. Natural assemblage collected from ambient seawater was killed shortly after being passed through the EDS, whereas some Artemia remained alive. However, no live Artemia was found after 24 hour further exposure to each TRC concentration (10 and 30 ppm) under darkness. After electrochemical treatment, the target bacteria such as aerobes, coliform and Escherichia coli were completely killed on the basis of CFU (colony forming unit) on Petrifilm plate ($3\;M^{TM}$) after 48 hr incubation. Moreover, no regrowth was found in the three groups of plankton during five days under additional exposure to the treated water. These results indicated that the disinfection efficiency of the EDS on the three groups of plankton satisfy D-2 regulation.

• Journal of the Korean Society of Radiology
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• v.9 no.7
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• pp.529-533
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• 2015

VCUG(Voiding Cystourethrography) study is being performed to check urinary reflex symptom from bladder to ureter or kidney in the method of filling the bladder with radiation opaque contrast agent. However, VCUG study have been performed impersonally, patients have to be naked and open their legs and then void. This method is so impersonal that it is immediately needed to improve the way of testing and crete new aid. Therefore, this study through producing underwear for VCUG, analysis and compares the test time of VCUG, patient radiation dose and patient satisfaction. The target of this study was 79 Male and Female patients who visited genitourinary clinic of PNUYH for their VCUG tests AXIUM Iconos R200(Siemens Medical System : Germany) and self-produced plastic underwears made by vinyl and plasic molding machine were used. The 79 patient were divided into two groups : experiment of patient and comparison group of we patient (using aid) in order to compare, testing time, DAP (dose area product) and patient satisfaction. There was time reduction, from 35.3min of comparison group to 27.8min experimentation group by 7.5min decrease. And comparison group of $4566.6{\mu}Gym^2$(DAP) decreased experimental group (using aid) of $3411.9{\mu}Gym^2$ by $1154.7{\mu}Gym^2$. In the case of patients satisfaction study, anxiety had a drop by 3.45 of comparison group to 2.51 experimentation group by 0.94 decrease. in experimental group. And shame had a drop by 4.02 of comparison group to 3.08 experimentation group by 0.94 increase. in experimental group. Difference of the smooth voiding had a drop by 1.90 of comparison group to 2.84 experimentation group by 0.94 increase. in experimental group. In addition satisfaction had a rise by 1.19 in experimental group. There were also other opinions of uncomfortableness on it and troublesome to wear. VCUG is one of the sensitive care required test. Therefore staff and the aid can give patients such comfortable and the aid can consentive on voiding. As a result test time and DAP can be reduced. It is needed to make testing at more comfortable for patients.

• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.563-567
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• 2009

This study compared the instrument performance and tissue healing of a steel scalpel with a $CO_2$ laser in an animal uterine surgery model. Five Landrace and Yorkshire mixed breed pigs were used. Two symmetrical incisions were made in the uterine of each pig. One incision was made on the left side of the uterine horn using a steel scalpel, while the other incision was performed on the right side using a $CO_2$ laser with an 8W output power. Each instrument was evaluated clinically for speed, ease of incision, and extent of bleeding. An ovariohysterectomy was performed at 21 days after the surgical procedure for a histological examination. The scalpel was an easier instrument to use in the confines of the uterine tissue, compared with the laser. However, there is no significant difference between the two groups. The amount of bleeding was less in the laser group but the time of the incisions was shorter with the scalpel. Postoperative uterus adhesion in the $CO_2$ laser incisions was lower than the scalpel incisions. Scalpel incisions showed complete restoration of the epithelium and endometrial gland. On the other hand, the laser incisions showed incomplete restoration of the epithelium and endometrial gland. Although the scalpel produced less damage to the uterine tissue and was easier to handle than the $CO_2$ laser, it did not provide hemostasis that was helpful for use on highly vascular tissue. The $CO_2$ laser provided good hemostasis but delayed wound healing.

• International Journal of Highway Engineering
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• v.9 no.4
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• pp.117-127
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• 2007

The exposed aggregate PCC(EAP) pavements have been successfully used in Europe and Japan as low-noise pavements. Coarse aggregate are exposed on the pavement surface texture of EAP by removing mortar of surface. The pavement surface texture should maintain not only low-noise characteristic but also adequate skid resistance level during the performance period. Skid resistance decreased with wearing and polishing of tire and pavement surface due to the repetition of tire-pavement contact. Since the tires mainly contact the exposed coarse aggregate, the shape and rock type of coarse aggregate significantly influence wearing and polishing of EAP pavements. The test for resistance to abrasion coarse aggregate by use of the Los Angeles machine(KS F 2508) and the method of test for resistance to abrasion coarse aggregate by use of the Accelerated Polishing Machine(ASTM D 3319-90) are generally used to evaluate polishing characteristics of aggregate. In this study, polishing of coarse aggregate of different five rock types were evaluated by KS F 2508(LA abrasion test) and ASTM D 3319-90(PSV method). The results of LA abrasion test and PSV method were contrary to each other. Since LA abrasion test is estimated the quantity of abrasion by the impact of aggregate, it may not be adequate to evaluate the polishing of aggregate by the repetition of tire. In the case of PSV method, the resistance of polishing is estimated the skid resistance variation of polished aggregate after repetition of tire. The PSV method is adequate for the evaluation on polishing of coarse aggregate. From the test results of PSV method, it was founded that rock type, specific gravity, coarse aggregate angularity, flat or elongated particles in coarse aggregate are significant to the resistance characteristic of coarse aggregate.

• Journal of Life Science
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• v.29 no.9
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• pp.996-1001
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• 2019

Edible insects are reported to be rich in protein, minerals and vitamins, and much attention has been paid to them as a future food source. In Korea, they were massively reared and sold. In order to enhance the market value of edible insects for industrialized mass production, it is important to develop the safe and nutritious feed sources for rearing them are needed. In this study, a chlorella-free control feed (Exp1) and six experimental feeds supplemented with 0.5~2.0% liquid or powder types of chlorella were formulated. Protaetia brevitarsis and Allomyrina dichotoma, registered as food ingredients in Korea, were fed with the designed feeds and parameters of growth including larval survivorship, larval body weight, and larval period were analyzed. When chlorella added, larval survivorship was increased 2~13%(p>0.05) and 9~22%(p<0.05) in each beetle compared to the control. Interestingly, the larval period of chlorella powder-added groups was shortened by 24 days (Exp3, p<0.05) in P. brevitarsis and 19 days (Exp4, p<0.01) in A. dichotoma. Meanwhile, some parameters, crude protein, crude fiber, copper, zinc, potassium, magnesium, and phosphorous, in chlorella-added groups of P. brevitarsis were also higher than the control group. Therefore, chlorella could promote the larval growth performance of these two beetles and be used as a feed additive in rearing them.

• Journal of radiological science and technology
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• v.32 no.4
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• pp.419-426
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• 2009

Purpose : The aim of this study was to evaluate the difference of bone mineral density according to distal radius rotation and to develop the supporting tool to measure rotation angles. Materials and Methods : CT scanning and the measurement of BMD by DXA of the appropriate position of the forearm were performed on 20 males. Twenty healthy volunteers without any history of operations, anomalies, or trauma were enrolled. The CT scan was used to evaluate the cross sectional structure and the rotation angle on the horizontal plane of the distal radius. The rotational angle was measured by the m-view program on the PACS monitor. The DXA was used in 20 dried radii of cadaveric specimens in pronation and supination with five and ten degrees, respectively, including a neutral position (zero degrees) to evaluate the changes of BMD according to the rotation. Results : The mean rotation angle of the distal radius on CT was 7.4 degrees of supination in 16 cases (80%), 3.3 degrees of pronation in three cases (15%), and zero degree of neutral in one case (9%), respectively. The total average rotation angle in 20 people was 5.4 degrees of supination. In the cadaveric study, the BMD of the distal radius was different according to the rotational angles. The lowest BMD was obtained at 3.3 degrees of supination. Conclusion : In the case of the measurement of BMD in the distal radius with a neutral position, the rotational angle of the distal radius is close to supination. Pronation is needed for the constant measurement of BMD in the distal radius with the rotation angle measuring at the lowest BMD and about five degrees of pronation of the distal radius is recommended.