• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.3
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• pp.171-178
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• 2008

Metal filter elements were newly introduced to the high temperature filter(HTF) system in the low- and intermediate-level radioactive waste vitrification plant. In order to evaluate the performance of various metal materials as filter media, elements made of AISI 316L, AISI 904L, and Inconel 600 were included to the test set of filter elements. At the visual inspection to the elements performed after completion of each test, a few dark spots were observed on the surface of some elements. Especially they were found much more at the AISI 316L elements than others. To check the dark spots are the corrosion phenomena or not, two kinds of analyses were performed to the tested filter elements. Firstly, the surfaces or the cross sections of filter specimens cut out from both normal area and dark spot area of elements were analyzed by SEM/EDS. The results showed that the dark spots were not evidences of corrosion but the deposition of sodium, sulfur and silica compounds volatilized from waste or molten glass. Secondly, the ring tensile strength were analyzed for the ring-shape filter specimens cut out from each kind of element. The result obtained from the strength tested showed no evidence of corrosion as well. Conclusionally, depending on the two kinds of analysis, no evidences of corrosion were found at the tested metal filter elements. But the dark spots formed on the surface could reduce the effective filtering area and increase the overall pressure drop of HTF system. Thus, continuous heating inside filter housing up to dew point will be required normally. And a few long-period test should be followed for the exact evaluation of corrosion of the metal filter elements.

• Clinical and Experimental Pediatrics
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• v.51 no.4
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• pp.383-390
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• 2008

Purpose : This study was aimed to analyze the clinical characteristics of patients with acute interstitial pneumonia who had presented similar clinical patterns from March to June, 2006 and to describe our experience of treatment and to identify risk factors associated with prognosis. Methods : The clinical characteristics, radiologic and histopathologic findings and response to steroids of 15 patients (non-survival group [n=7] and survival group [control, n=8]) with acute interstitial pneumonia were investigated through the review of medical records. Results : The mean age of the patients was 26 (range: 3-48) months. Cough, cyanosis and fever were frequent symptoms. The most frequent radiologic findings on admission were pneumomediastium and extensive ground glass opacity. Surgical lung biopsy was performed on 8/15 (53.3%) patients and diffuse alveolar damage was found. Mechanical ventilation was applied for 9/15 (60.0%) patients for 40 (range: 1-99) days. Five patients in survival group received steroid treatment and 7 patients in non-survivial group (P=0.20). One patient in survival group received steroid pulse treatment and 4 patients in non-survival group (P=0.12). Seven patients died all of respiratory failure. The survival rate was 53.4%. Conclusion : The patients with acute interstitial pneumonia which occurred on spring 2006 showed high mortality because of rapidly and extensively progressing pulmonary fibrosis and air leakage. Therefore, we should consider surgical lung biopsy and steroid application earlier. We should recognize this acute interstitial pneumonia occurring on spring in domestics and need to investigate the cause and treatment in large scale.

• The Korean Journal of Physiology
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• v.21 no.2
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• pp.241-257
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• 1987

The effects of external $Ca^{2+}$ and $Ca^{2+}-antagonists$ on the spontaneous contractions and electrical activities were investigated in guinea-pig stomach in order to clarify the mechanism for the generation of slow waves. Electrical responses of circular smooth muscle cells were recorded using glass capillary microelectrodes filled with 3 M KCl. All experiments were performed in tris-buffered Tyrode solution which was aerated with 100% $O_2$ and kept at $35^{\circ}C$. The results obtained were as follows: 1) The amplitude of spontaneous contractions was maximal at around 2-4 mM $Ca^{2+}$, whereas their frequency was inversely related with external $Ca^{2+}$ within the range of 0.5 to 16 mM $Ca^{2+}$. 2) Verapamil suppressed the amplitude of spontaneous contraction in a dose-dependent manner, while the frequency of spontaneous contractions was almost not changed over the whole concentration of verapamil $(0.01{\sim}5\;mg/l)$. 3) Manganese increased both the amplitude and the frequency of spontaneous contractions dose-dependently in low $Mn^{2+}$ (below 0.05 mM $Mn^{2+}$), while their amplitude and frequency were decreased in high $Mn^{2+}$ (above 0.1 mM $Mn^{2+}$). 4) The ampltude and maximum rate of rise of slow waves were incrased in high $Ca^{2+}$ solution. In $Ca^{2+}-free$ solution, the spontaneous contractions recorded simultaneously with slow waves ceased and tonic contraction ($Ca^{2+}-free$ contracture) was developed in parallel with membrane depolarization and the disappearance of slow waves. 5) Verapamil (1 mg/1) decreased the amplitude and maximum rate of rise of slow waves and it depolarized the membrane by about 6 mV, whereas the frequency of slow waves was not affected by verapamil. 6) Manganese showed different characteristic effects between low and high $Mn^{2+}$ on the slow waves: In low $Mn^{2+}$ (0.05 mM $Mn^{2+}$), the initial rapid increases and the subsequent gradual decreases in three parameters of slow waves (amplitude, rate of rise, and frequency of slow waves) till a new steady state were observed. However, in high $Mn^{2+}$ (0.5 mM $Mn^{2+}$) slow waves disappeared and membrane was depolarized. From the above results, the following conclusions could be made: 1) $Ca^{2+}$ is necessary for a generation of the slow waves, even though it is small amount. 2) Verapamil suppresses the spontaneous contractions of gastric antral strip by the decreases in amplitude and maximum rate of rise of slow waves, while this drug does not block the $Ca^{2+}-channel$ involved in the generation of slow waves. 3) Manganese has dual actions on the $Ca^{2+}-channels$; the $Ca^{2+}-channel$ involved in the generation of slow waves (or Na-Ca exchange system) or the channel for the generation of spike potentials are stimulated by a low concentration of $Mn^{2+}$, while both the $Ca^{2+}$. Channels are blocked by high concentration of $Mn^{2+}$.

• The Korean Journal of Physiology
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• v.24 no.1
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• pp.1-13
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• 1990

The effects of electrolytes, adenosine, ATP, 5-hydroxytryptamine (5-HT, serotonin) and ketanserin on the inhibitory junction potentials (IJPs) were investigated to clarify the interactions of these drugs with the neurotransmitters released from non-adrenergic, non-cholinergic nerves in the antrum of guinea-pig stomach. Electrical responses of antral circular muscle cells were recorded intracellularly using glass capillary microelectrode filled with 3 M KCI. All experiments were performed in Tris-buffered Tyrode soluition which was aerated with 100% $O_{2}$ and kept at $35^{\circ}C$. The results obtained were as follows: 1) Inhibitory junction potential (IJP) was recorded in antral strip, while excitatory junction potential (EJP) was recorded in fundic strip. 2) IJP recorded in antral strip was not influenced by atropine $(10^{-6}\;M)$ and guanethidine $(5{\times}10^{-6})$. 3) The amplitude of IJP increased in high $Ca^{2+}$ solution, while that of IJP decreased in high $Mg^{2+}$ solution or by $Ca^{2+}$ antagonist (verapamil). Apamin, $Ca^{2+}$-activated $K^{+}$ channel blocker blocked IJP completely. 4) ATP and adenosine decreased the amplitude of IJP. 5) 5-HT decreased the amplitude of IJP with no change of the amplitude of slow waves, while ketanserin (5-HT type 2 blocker) decreased the amplitude of slow waves markedly with no change in that of IJP. From the above results, the following conclusions could be made. 1) IJP recorded in antral strip is resulted from neurotransmitters released from non-adrenergic, non-cholinergic nerves. 2) An increase in the concentration of external $Ca^{2+}$ enhances the release of neurotransmitters from non-adrenergic, non-cholinergic nerves which activate the $Ca^{2+}$-dependent $K^{+}$ channel.

• The Korean Journal of Physiology
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• v.18 no.1
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• pp.19-35
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• 1984

Since the first report of Drury and $Szent-Gy{\ddot{o}}rgyi$ in 1929, the inhibitory influences of adenosine on the heart have repeatedly been described by many investigators. These studies have shown that adenosine and adenine nucleotides have overall depressant effects, similar to those of acetylcholine. Heart beats become slow and weak. It is also well known that adenosine is a potent endogenous coronary vasodilator. Many investigations on the working mechanisms of adenosine have been focused mainly on the effects of the coronary blood flow. However, the cellular mechanisms underlying the inhibitory action of adenosine on sinus node are not well understood yet. Thus, this study was undertaken to examine the behavior of rabbit SA node under influence of adenosine. In these series of experiments three kinds of preparations were used: whole atrial pair, left atrial strip, and isolated SA node preparations. The electrical activity of SA node was recorded with conventional glass microelectrodes 30 to 50 $M{\Omega}$. The preparations were superfused with bicarbonate-buffered Tyrode solution of pH 7.35 and aerated with a gas mixture of $3%\;CO_2-97%\;O_2$ at $35^{\circ}C$. In whole atrial pair, adenosine suppressed sinoatrial rhythm in a dose-dependent manner. Effect of adenosine on atrial rate appeared at the concentration of $10^{-5}M$ and was enhanced in parallel with the increase in adenosine concentration. Inhibitory action of adenosine on pacemaker activity was more prominent in the preparation pretreated with norepinephrine, which can steepen the slope of pacemaker potential by increasing permeability of $Ca^{+2}$. Calcium ions in perfusate slowly produced a marked change in sinoatrial rhythm. Elevation of the calcium concentration from 0.3 to 8 mM increased the atrial rate from 132 to 174 beats/min, but over 10 mM $Ca^{+2}$ decreased. The inhibitory effect of adenosine on sinoatrial rhythm developed very rapidly. Atrial rate was recovered promptly from the adenosine-induced suppression by the addition of norepinephrine, but extra $Ca^{+2}$ was less suitable to restore the suppression of atrial rate. Adenosine suppressed also atrial contractility in the same dosage range that restricted pacemaker activity, even in the reserpinized preparation. In isolated SA node preparation, spontaneous firing rate of SA node at $35^{\circ}C$(mean{\pm}SEM, n=16) was $154{\pm}3.3\;beats/min. The parameters of action potentials were: maximum diastolic potential(MDP), $-73{\pm}1.7\;mV: overshoot(OS), $9{\pm}1.4\;mV: slope of pacemaker potential(SPP), $94{\pm}3.0\;mV/sec. Adenosine suppressed the firing rate of SA node in a dose-dependent manner. This inhibitory effect appeared at the concentration of $10^{-6}M$ and was in parallel with the increase in adenosine concentration. Changes in action potential by adenosine were dose-dependent increase of MDP and decrease of SPP until $10^{-4}M$. Above this concentration, however, the amplitude of action potential decreased markedly due to the simultaneous decrease of both MDP and OS. All these effects of adenosine were not affected by pretreatment of atropine and propranolol. Lowering extra $Ca^{2+}$ irom 2 mM to 0.3 mM resulted in a marked decrease of OS and SPP, but almost no change of MDP. However, increase of perfusate $Ca^{2+}$ from 2 mM to 6 or 8 mM produced a prominent decrease of MDP and a slight increase of OS and SPP. Dipyridamole(DPM), which is known to block the adenosine transport across the cell membrane, definately potentiated the action of adenosine. The results of this experiment suggest that adenosine suppressed pacemaker activity and atrial contractility simultaneously and directly, by decreasing $Ca^{2+}-permeability$ of nodal and atrial cell membranes.

• Korean Journal of Optics and Photonics
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• v.13 no.3
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• pp.197-203
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• 2002

The TiO$_2$ coating solutions were synthesized with different concentrations (T1-0.7N, T2-2.0N) of hydrochloric acid used as catalyst. and TiO$_2$ thin films were prepared by sol-gel dip coating. Their structural and optical properties were examined as a function of calcination temperature. XRD results showed that T1 thin films calcined at 400~80$0^{\circ}C$ had the anatase phase, while those calcined at 100$0^{\circ}C$ had the rutile phase. T2 thin films calcined at 40$0^{\circ}C$ and $600^{\circ}C$ had the anatase phase, with the rutile phase for calcination at 80$0^{\circ}C$. Crystallinity of T2 thin films was superior to that of T1 thin films. The crystallite size of TiO$_2$ thin films increased with increasing calcination temperature, and the crystallite size of anatase phase in T2 thin films was larger than that in T1 thin films, but the crystallite size of rutile phase in T2 thin films was smaller. The surface morphology of the films showed that the films were formed more densely in the rutile phase than in the anatase phase, this phenomenon appeared conspicuously in T2 thin films. The transmittance of the samples with thin films on quartz glass calcined at 100$0^{\circ}C$ was significantly reduced at wavelength range about 300-700 nm due to the increased absorption originating from the change of crystallite phase and composition of the films and the scattering effect originating from increasing crystallite size. The refractive index of TiO$_2$ thin films increased, and hence the film thickness as well as the porosity of TiO$_2$ thin films decreased with increasing calcination temperature. Furthermore, the refractive index of T2 thin films was higher than T1 thin films, and porosity of T2 films was lower.

• The korean journal of orthodontics
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• v.28 no.4 s.69
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• pp.517-531
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• 1998

The purpose of this study was to investigate the changes in the craniofacial skeleton subsequent to chincap therapy in the juvenile skeletal Class III malocclusion with more appropriate control samples. The experimental group consisted of 29 Korean children(14 males, 15 females) who had skeletal Class III malocclusion with prognathic mandible and were undergone chincap thorny from the beginning of treatment. The control group was composed of 21 Korean children(10 males, 11 females) who had no orthodontic treatment, but with similar skeletal discrepancies to experimental group. Lateral cephalometric radiographs at the age of 7, and 2 years later were analyized and compared with student's t-test(p<0.05). The results of this study were as follows; 1. The control group without chincap therapy had not shown any improvement of the skeletal discrepancies, but had grown to be much severe. This means that the untreated Class III patient with prognathic mandible would not be corrected by growth. For the experimental group with chincap therapy, the anterior-posterior skeletal discrepancies and mandibular prognathism were both improved. 2. Neither significant restraint nor acceleration of growth was found in the cranial base and maxilla by chincap treatment. 3. The inhibition of mandibular growth could not be accepted, but the changes of the direction of growth and morphological changes were found. 4. Vertical growth tendency was increased with chincap therapy. 5. When Putting together the results of the analyses , it seems to be the rotation and displacement of the mandible that the major treatment effects of chincap we. The changes of the direction of growth and the morphological changes also seems to contibute to the treatment effect partly. In summary, the chincap doesn't restrain the mandibular growth. But, it is considered as a useful treatment modality for correction of skeletal discrepancies and reduction of mandibular prognathism in growing Class III patients with madibular prognathism.

• The korean journal of orthodontics
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• v.28 no.4 s.69
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• pp.533-546
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• 1998

A Skeletal Class III malocclusion may be the result of a large mandible, a small maxilla or combination of the two. Protraction devices for the maxilla are used to promote the growth of a deficient maxilla by applying extraoral force to actively growing patients. This study has been performed to determine whether there are significant differences in skeletal and dental changes between FH/Pal 1 and FH/Pal 2 group, SNA 1 and SNA 2 group, SNB 1 and SNB 2 group, and LFH 1 and LFH 2 group after RME and facial mask therapy. The results of this study can be summarized and concluded as follows ; 1. In all patients after maxillary protraction, the maxilla and maxillary dentitions moved forward, and the mandible rotated backward and downward. In most of them, palatal plane is tends to have an upward inclination. 2. The FH/Pal group 1, having an upward inclination of the palatal plane as a result of Facial mast showed statistically significant maxillary forward movement compared to the FH/Pal group 2. 3. The SNA group 1 showed significantly less mandibular backward movement and there was a tendency for the palatal plane to upward inclination compared to SNA group 2. 4. The SNB group 1 showed significantly less maxillary forward movement, but the vertical dimension, especially the lower facial height increased by mandibular downward rotation compared to SNB group 2. 5. LFH group 1, which had large saddle angle and posterior positioned mandible in the pre-treatment stage, showed maxillary protraction effect without significant increase in lower facial height compared to LFH group 2.

• Journal of the Korean Magnetics Society
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• v.13 no.2
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• pp.53-58
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• 2003

Annealing effects of exchange bias fields ($H_{2ex}$(top), $H_{lex}$ (bottom)) on composite type NiFe/[FeMn/Mn]$_{80}$/NiFe multilayers have been studied. Three samples with ultra-thin Mn inserted layers on glass/Ta(50 $\AA$)/NiFe(150 $\AA$)/[F $e_{53}$M $n_{47}$(1.25 $\AA$)/Mn(0 $\AA$, 0.11 $\AA$, 0.3 $\AA$)]$_{80}$/NiFe(90 $\AA$)/Ta(50 $\AA$) were prepared by ion beam sputtering. The average x-ray diffraction peak ratios NiFe(111) of FeMn (111) fcc textures for the Mn inserted total thicknesses of 0 $\AA$, 9 $\AA$, and 24 $\AA$ were about 0.65, 0.90, and 1.5, respectively. For the sample without Mn inserted layer, the $H_{2ex}$ of 260 Oe up to 300 $^{\circ}C$ disappeared at 350 $^{\circ}C$. For two multilayer samples with ultra-thin Mn layers of 0.11 $\AA$ and 0.3 $\AA$, the $H_{2exs}$ of 310 Oe and 180 Oe up to 300 $^{\circ}C$ endured of 215 Oe and 180 Oe at 350 $^{\circ}C$, respectively. The $H_{ex}$ (bottom)s of three samples decreased from 100 Oe to 70 Oe up to 250 $^{\circ}C$, while these values increased beyond 300 $^{\circ}C$. This observation can be attributed to less diffusive path of Mn atoms in bottom NiFe than top NiFe layer. The top and bottom coercive fields slightly varied about 5 Oe∼10 Oe. From these results, we could obtain the enhancement of exchange coupling intensity and thermal stability by an ultra-thin Mn inserted layer on NiFe/[FeMn/Mn]$_{80}$/NiFe Multilayers.

• Korean journal of applied entomology
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• v.26 no.4 s.73
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• pp.221-228
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• 1987

The optimum temperature range for conidial germination of Pyriculacia oryzae on a slide glass was $26{\sim}30^{\circ}C$, at which at least four hours of leaf wetness period was required to germinate. Conidial germination was significantly reduced under dry conditions (relative humidity<85%) at $34^{\circ}C$ but not at lower temperature (18, 22, 26, $30^{\circ}C$). Number of lesions developed were greater at $26^{\circ}C$ than at other temperature tested. The average leaf wetness period required for production of a lesion per plant was 22 hours at $18^{\circ}C$, 16 hours at $22^{\circ}C$, 10 hours at $26^{\circ}C$, and 8 hours at $30^{\circ}C$. Less than one lesion per plant occurred at $34^{\circ}C$ even under 24 hours of leaf wetness period. The time period between inoculation and lesion appearance was $7{\sim}8$ days at $18^{\circ}C$, $4{\sim}5$ days at $22^{\circ}C$ and $26^{\circ}C$, and $3{\sim}4$ days at $30^{\circ}C$. The time period required for lesion appearance after inoculation was not affected by leaf wetness period and relative humidity. Lesion length increased most rapidly at $30^{\circ}C$ during the first four days after lesion appearance. Thereater, the rate of increase in lesion length was geratest at $26^{\circ}C$. The average increment of lesion length per day when relative humidity was greater than 90% was 0.7mm at $18^{\circ}C\;and\;22^{\circ}C$, 1mm at $26^{\circ}C$, and 0.8mm at $30^{\circ}C$. When relative humidity was less than 85%, the increments of lesion length per day were approximately $50{\sim}60%$ of those under humid conditions (relative humidity>90%) at all temperature regimes except $30^{\circ}C$. Relative humidity did not significantly affected lesion length at $30^{\circ}C$.