• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.229-234
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• 2002

Under the hostile influence of the extreme space environmental conditions due to the deep space and direct solar flux, the thermal control in space applications is especially of major importance. There are tight temperature range restrictions for electro-optical elements while on the other hand there are low power consumption requirements due to the limited energy sources on the spacecraft. So, we usually have strong requirement of thermal and power control module in space applications. In this paper, the design concept of a thermal and power control module in the MSC(Multi-Spectral Camera) system which will be a payload on KOMPSATII is described in terms of H/W & S/W. This thermal and power control module, called THTM(Thermal and Telemetry Module) in MSC, resides inside the PMU(Payload Management Unit) which is responsible for the proper management of the MSC payload for controlling and monitoring the temperature insides the EOS(Electro-Optic System) and gathering all the analog telemetry from all the MSC sub-units, etc. Particularly, the designed heater controller has the special mode of "duty cycle" in addition to normal closed loop control mode as usual. THTM controls heaters in open loop according to on/off set time designed through analysis in duty cycle mode in case of all thermistor failure whereas it controls heaters by comparing the thermistor value to temperature based on closed loop in normal mode. And a designed THTM provides a checking and protection method against the failure in thermal control command using the test pulse in command itself.

• Korean Journal of Applied Biomechanics
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• v.28 no.1
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• pp.55-60
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• 2018

Objective: This study aimed to analyze the effects of computer game exposure on pathological musculoskeletal symptoms in adolescents. Method: This study included 10 male junior high school students who used computers less than 3 times a week for 1 hr per day. The subjects were asked to play computer games for 4 hr. Magnetic resonance imaging of the hand and wrist, from the distal radius and ulnar head to the distal phalanges, and radiography of the cervical vertebrae were performed before and after playing computer games. For each dependent variable, a paired t-test was performed to identify significant changes before and after a 4-hr active computer game (p<.05). Results: The horizontal diameters of the flexor tendons in the index and middle fingers were significantly reduced after playing computer games. The horizontal diameters of the flexor tendons of other fingers did not show any significant differences, but there was a tendency toward a decrease after playing computer games. There was no significant change in the cervical lordosis angle before and after playing computer games. However, the cervical lordosis angle was relatively decreased. Conclusion: The results of this study showed that computer game exposure had direct and indirect effects on morphological changes of flexor tendons. In addition, playing computer games for long periods of time can have a negative effect on normal functioning of the musculoskeletal system, with the possible development of abnormalities. However, computer game exposure in adolescents cannot be decisively identified as a factor causing pathological symptoms, based on the results of this study alone. Thus, longterm longitudinal studies on the overall musculoskeletal system are necessary.

• Journal of Soil and Groundwater Environment
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• v.19 no.2
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• pp.16-24
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• 2014

To test the potential effects of extracellular electron shuttles (EES) on the rate and extent of heavy metal release from contaminated soils during microbial iron reduction, we created anaerobic batch systems with anthraquinone-2,6-disulfonate (AQDS) as a surrogate of EES, and with contaminated soils as mixed iron (hydr)oxides and microbial sources. Two types of soils were tested: Zn-contaminated soil A and As/Pb-contaminated soil B. In soil A, the rate of iron reduction was fastest in the presence of AQDS and > 3500 mg/L of total Fe(II) was produced within 2 d. This suggests that indigenous microorganisms can utilize AQDS as EES to stimulate iron reduction. In the incubations with soil B, the rate and extent of iron reduction did not increase in the presence of AQDS likely because of the low pH (< 5.5). In addition, less than 2000 mg/L of total Fe(II) was produced in soil B within 52 d suggesting that iron reduction by subsurface microorganisms in soil B was not as effective as that in soil A. Relatively high amount of As (~500 mg/L) was released to the aqueous phase during microbial iron reduction in soil B. The release of As might be due to the reduction of As-associated iron (hydr)oxides and/or direct enzymatic reduction of As(V) to As(III) by As-reducing microorganisms. However, given that Pb in liquid phase was < 0.3 mg/L for the entire experiment, the microbial reduction As(V) to As(III) by As-reducing microorganisms has most likely occurred in this system. This study suggests that heavy metal release from contaminated soils can be strongly controlled by subsurface microorganisms, soil pH, presence of EES, and/or nature of heavy metals.

• Polymer(Korea)
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• v.26 no.5
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• pp.670-679
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• 2002

1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU, carmustine) is one of the effective chemotherapeutic agents which has been used clinically for treating malignant glioma. Poly(D,L-lactide-co-glycolide) (PLGA, molecular weight: 20000 g/mole. mole ratio of lactide to glycolide 75 : 15) is a well known biodegradable polymer used as a drug carrier for drug delivery system. In this study, we investigated the BCNU release behaviour of BCNU-loaded PLGA wafers containing poly (N-vinylpyrrolidone) (PVP) or polyethyleneoxide (PEO) and the effect of hydrophilic polymers incoporated in the wafers. BCNU-loaded PLGA microparticles with or without hydrophilic polymers were prepared by a spray drying method and fabricated into wafers by direct compression. Encapsulation efficiency of BCNU-loaded PLGA microparticles containing PVP and PEO was 85 ∼ 97% and crystallinity of BCNU encapsulated in PLGA decreased significantly initial release amount and release rate of BCNU increased with the increasing PVP or PEO amount. Morphological change and mass loss of wafers during the release test were confirmed that hydration and degradation of PLGA would be facilitated with an increase of hydrophilic polymers.

• The Plant Pathology Journal
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• v.31 no.4
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• pp.414-420
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• 2015

Antifungal activities of crude extractum of Nanshancha Seed Cake (NSC), to inactivate postharvest pathogens were investigated. Highest inhibitory rate was found against C. musae, C. gloeosporioides and C. papaya P.Henn, which was much stronger than that by tea saponin. Compared to tea saponin, effects of NSC extractum was relatively weak and similar on C. gloeosporioides Penzig and P. italicum. In an in vivo study, best controlling effects by NSC extractum was found with banana anthracnose disease development, which showed no inhibitory effects by tea saponin. NSC extractum controlled in vitro C. musae growth through directly inhibiting germination rate and germ tube elongation, and causing distortation, rupture and indentation of C. musae mycelium. In banana fruit subject to C. musae inoculation, higher PAL, POD, GLU and CHT activity was observed in banana fruit treated with crude NSC extractum than that of water control fruits. Current study proved the best controlling effects of crude NSC extractum in C. musae in vitro and in vivo development, which through direct inhibition of C. musae growth and increasing defense system of the banana fruit.

• Journal of Chest Surgery
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• v.25 no.7
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• pp.693-701
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• 1992

Extracorporeal cardiopulmonary bypass[CPB] has been associated with a wide variety of hematologic derangements, including a transient deformation and hemolysis of red blood cells[RBCs], which is supposed to be due to mechanical trauma and/or metabolic alterations. Since membrane integrity is, in part, maintained by energy requiring process, inadequate function of erythrocyte glycolytic pathway, which is inevitalble during CPB, may cause depletion of high energy phosphate pool and result in hemolysis. The authors performed an investigation to assess whether administration of Fructose-l, 6-diphsphate [FDP], which has been known to enhance intracellular glycolytic activities, could counteract erythrocyte hemolytic events caused by CPB. Sixty pateints with cyanotic congenital heart diseases, who underwent open heart surgery under CPB longer than 60 minutes, were randomly divided into two groups depending on whether use of FDP[Group FDP] or not[Group Control]. The age, sex, CPB time, preoperative hemoglobin level, disease entities were all similar[Table 1], and membrane type oxygenators were used in all patients. In Group, FDP, a dose of 250mg/kg body weight of FDP was administered by intravenous dripping every 12 hours from the morning of the operation to postoperative 48 hours, To demonstrate the degree and pattern of hemolysis of erythrocyte, reticulocyte count, indirect /direct bilirubin, haptoglobin, plasma hemoglobin, lactate dehydrogenase were measured every 12 hours from the time of cessation of CPB to 48 hours and RBC morphologic study, osmotic fragility test were done every 24 hours. All parameters revealed less hemolytic in group FDP [Fig. 1~5], though the differences between two groups were not significant, except plasma hemoglobin, lactate dehydrogenase changes. A pattern of sequential changes of plasma hemoglobin, lactate deh-ydrogenase showed the highest level at the time of CPB stop and abrupt decrease in following 24 hours in both groups, and statistically significant differences were demonstrated in group FDP at least for the first 12 hours postoperatively[p<0.05]. The authors conclude that they can expect the benificial effect of FDP on the maintenance of membrane stability of RBC probably by energy enhancement during the shock status of CPB, but FDP could not completely prevent the damaging effect on RBC by cardiopulmonary bypass

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.101-101
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• 2010

ZnO shows a direct band gap of 3.37eV, large exciton binding energy (~60 meV), high oxidation ability, high sensitivity to many gases, and low cost, and it has been used in various applications such as transparent electrodes, light emitting diodes (LEDs), gas sensors and photocatalysts. Among these applications ZnO as photocatalyst has considerably attracted attention over the past few years because of its high activities in removing organic contaminants generated from industrial activities. In this research, ZnO nanoparticles were synthesized by spray-pyrolysis method using the zinc acetate dihydrate as starting material at synthesis temperature of $900^{\circ}C$ with concentration varied from 0.01 to 1.0M. The physical and chemical properties of the synthesized ZnO nanoparticles were examined by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transformation Infrared (FT-IR), and UV-vis spectroscopy. The Miller indices of XRD patterns indicate that the synthesized ZnO nanoparticles showed a hexagonal wurtzite structure. With increased precursor concentration, a primary, secondary particle sizes of ZnO nanoparticles increased by 0.8 to $1.5{\mu}m$ and 15 to 35nm, and their crystallinity was improved. Methyleneblue (MB) solution ($1{\mu}M$) as a test comtaminant was prepared for evaluating the photocatalytic activities of ZnO nanoparticles synthesized in different precursor concentration. The results show that the photocatalytic efficiency of ZnO nanoparticles was gradually enhanced by increased precursor concentration.

• Tunnel and Underground Space
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• v.21 no.1
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• pp.20-32
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• 2011

Failure aspects of cut-slope, which induce the sequential collapses during the excavation stage, have been analyzed. Slope rock structures are investigated by examining the orientations and positions of discontinuity planes calculated based on the BIPS image inside the boreholes. Drilled core log has been also used to identify the structural defects. Clay minerals of swelling potentials are detected through XRD analysis. Numerical analysis for slope stability has been performed by utilizing the joint shear strength acquired from the direct joint shear test. Cut-slope collapse characteristics have been studied by investigating the posture of failure-prawn joint planes and the stability of tetrahedral blocks of different sizes. Cross-section analysis has been also performed to analyze the cut-slope behavior and to estimate the amount of reinforcement required to secure the stability of cut-slope. Behavior of reinforced cut-slope is also investigated by analyzing the slope monitoring data.

• Biomolecules & Therapeutics
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• v.3 no.4
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• pp.316-321
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• 1995

All the pharmacological studies of LB17522 described here were carried out with high doses (fifteen to sixty times of the therapeutic dose) to determine an indication of potential side effects in clinical use in terms of the acute clinical signs, cardiovascular and central nervous system. LB10522 does not produce any observable clinical signs except for the symptoms such as moist eye, skin rash, slight salivation, vomitting, and slightly reduced activity. The effects of LB10522 on the hemodynamics and cardiac function of anesthetized beagle dogs are as follows; heart rates and mean arterial blood pressure had a tendency to increase mildly, which is a normal finding in anesthetized dogs. All the animals except for one showed relatively stable respiratory rates throughout the observation period. Each animal treated with LB10522 showed slight increase in the left cardiac work and left ventricular stroke work which are mainly related to corresponding increases in cardiac output. Femoral blood flow were shown to be increased in some animals treated with LB10522. The epileptogenic activities of various cephalosporins were assessed by a direct intracerebral injection of appropriate concentration of test articles. The CD$_{50}$ values (nmol) obtained from the analysis of the dose-response data are as follows; 78.2, 175.3, 156.3, and 53.5 for cefazolin, cephaloridine, ceftazidime, and LB 10522, respectively. LB10522 seems to be equipotent with cefazolin or to be three times more potent than cephaloridine and ceftazidime in causing adverse CNS stimulation. Taken into consideration all the information obtained, LB10522 is not supposed to induce much changes in the functions examined in these studies in man at therapeutic doses.s.

• Biomolecules & Therapeutics
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• v.3 no.4
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• pp.322-326
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• 1995

General pharmacology of LB20304, a quinolone antibiotic, were examined in terms of general behaviour, cardiovascular, and central nervous system. LB20304 at oral dose of 2,000 mg/kg did not induce significant behavioural changes in mice. In contrast with ciprofloxacin, LB20304 at dose of 20 mg/kg, iv. did not show any observable effects on the blood pressure in rats. Displacement of [$^3$H]muscimol binding to the rat brain synaptic membranes was measured. LB20304 was shown to be about five times less potent than ciprofloxacin in specific GABA receptor binding. Drug interaction between LB20304 and 4-biphenyl acetic acid, an active metabolite of fenbufen, was assessed in mice by measuring convulsion and/or subsequent death. A single oral pretreatment with 4-BPA at 400 mg/kg increased the incidence of convulsion and death after oral administration of ciprofloxacin at the doses of 25, 50, and 100 from zero of five to three of five, two of five, and four of five, respectively, whereas LB20304 alone or combination with 4-BPA caused neither convulsions nor death at the doses of 12.5, 25, 50, and 100 mg/kg, respectively. Quinolones-induced epileptogenic activities were assessed by a direct intracerebral injection of test articles. The CD$_{50}$ values (nmole) are as follows; 169.47, 35.36, 105.29, and 88.67 for LB20304, ciprofloxacin, of loxacin, and lomefloxacin, respectively. From these data, LB 20304 at therapeutic doses seems to be much more safe than any other quinolones tested.d.