• Economic and Environmental Geology
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• v.55 no.3
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• pp.219-229
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• 2022

Bentonite is being considered as a candidate for buffer material in geological disposal systems for high-level radioactive wastes. In this study, the effect of cement-bentonite interactions on bentonite alteration was investigated by reviewing the literature on studies of cement-bentonite interactions. The major bentonite alteration by hyperalkaline fluids produced by the interaction of cementitious materials with groundwater includes cation exchange, montmorillonite dissolution, secondary mineral precipitation, and illitization. When the hyperalkaline leachate from the reaction of the cementitious material with the groundwater comes into contact with bentonite, montmorillonite, the main component of bentonite, is dissolved and a small amount of secondary minerals such as zeolite, calcium silicate hydrate, and calcite is produced. When montmorillonite is continuously dissolved, the physicochemical properties of bentonite may change, which may ultimately causes changes in bentonite performance as a buffer material such as adsorption capacity, swelling capacity, and hydraulic conductivity. In addition, the bentonite alteration is affected by various factors such as temperature, reaction period, pressure, composition of pore water, bentonite constituent minerals, chemical composition of montmorillonite, and types of interlayer cations. This study can be used as basic information for the long-term stability verification study of the buffer material in the geological disposal system for high-level radioactive wastes.

• Clean Technology
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• v.15 no.1
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• pp.60-66
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• 2009

Adsorptive removal of tetrahydrothiophene (THT) and tert-butylmercaptan (TBM) that were widely used sulfur odorants in pipeline natural gas was studied using various ion-exchanged NaY zeolites at ambient temperature and atmospheric pressure. In order to improve the adsorption ability, ion exchange was performed on NaY zeolites with alkali metal cations of $Li^+,\;Na^+,\;K^+$ and transition metal cations of $Cu^{2+},\;Ni^{2+},\;Co^{2+},\;Ag^+$. Among the adsorbents tested, Cu-NaY and Ag-NaY showed good adsorption capacities for THT and TBM. These good behaviors of removal of sulfur compound for Cu-NaY and Ag-NaY zeolites probably was influenced by their acidity. The adsorption capacity for THT and TBM on the best adsorbent Cu-NaY-0.5, which was ion exchanged with 0.5 M copper nitrate solution, was 1.85 and 0.78 mmol-S/g at breakthrough, respectively. It was the best sulfur capacity so far in removing organic sulfur compounds from fuel gas by adsorption on zeolites. While the desorption activation energy of TBM on the Cu-NaY-0.5 was higher than NaY zeolite, the difference of THT desorption activation energy between two zeolites was comparatively small.

• Design & Manufacturing
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• v.17 no.3
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• pp.21-27
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• 2023

The mold industry in Japan, an advanced country in the mold industry, is also at a point of great change. The main causes are the Ukraine crisis and the collapse of the global supply chain (parts supply chain) caused by COVID-19. In addition, the prices of overseas products are rising sharply due to rapid exchange rate fluctuations (decrease in the value of the yen). Until now, Japan's monotsukuri industry has been actively pursuing overseas expansion, riding the trend of globalization. However, the trend began to rapidly reverse, and now the monotsukuri industry that had expanded overseas is showing a tendency to return to Japan. Another factor of change is the change in the automobile industry, which is the most demanded product in the mold industry. As the automobile industry evolves from gasoline cars to electric cars, the number of parts that make up a car will drastically decrease. This trend is expected to increase the demand for small-scale production of a variety of products in the mold industry, and furthermore, it is expected that short delivery times will be required in parts development. As in Korea, the production population working in the mold industry is rapidly decreasing in Japan as well. Even if you add up the total population working in manufacturing in Japan, it only accounts for about 15%. Even in Japan, it is judged that it will be difficult to sustain the monotsukuri industry with this small production population. Therefore, since improvement in production efficiency cannot be expected with the same manual dexterity as before, the mold industry is also demanding the development of mold technology at a different level than before to increase productivity. In this paper, I would like to introduce new Japanese mold technology collected through attending the Intermold exhibition. This is an example of applying a dedicated pin (Gastos) to a mold to prevent an increase in internal pressure during plastic injection molding, and a deep drawing press molding technology with an inherent hydraulic function.

• Tuberculosis and Respiratory Diseases
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• v.56 no.5
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• pp.523-531
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• 2004

Background : Bronchoscopy in patients on mechanical ventilation is being performed much more frequently. However, there is little data on the changes in physiologic parameters and no established mechanical ventilation protocol during bronchoscopy. A decreasing or the removal of positive end-expiratory pressure (PEEP) during bronchoscopy may precipitate severe hypoxemia and/or derecruitment. Methods : Our standardized mechanical ventilation protocol, without changing the PEEP level, was used during bronchoscopy. The physiological parameters were measured during the bronchoscopic procedure. Results : During bronchoscopy, respiratory acidosis, elevation of peak pressure, elevation of heart rate and auto-PEEP were developed, but were reversible changes. Procedure-related gross barotraumas or other severe complications did not developed. Conclusion : No serious complications developed during bronchoscopy under our standardized mechanical ventilation protocol when the PEEP level remained unchanged. The procedure time should be kept to a minimum to decrease the exposure time to undesirable physiological changes.

• Tuberculosis and Respiratory Diseases
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• v.46 no.5
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• pp.628-635
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• 1999

Background : Maximal expiratory flow rate is determined by the size of airway, elastic recoil pressure and the collapsibility of airway in the lung. The obstruction of expiratory flow is one of the major functional impairments of emphysema, which represents COPD. Nevertheless, expiratory narrowing of upper airway may be recruited as a mechanism for minimizing airway collapse, and maintaining lung volume and hyperinflation by an endogenous positive end-expiratory pressure in patients with airflow obstruction. We investigated the physiologic role of trachea in respiration in emphysema. Method : We included 20 patients diagnosed as emphysema by radiologic and physiologic criteria from January to August in 1997 at Seoul Municipal Boramae Hospital. Chest roentgenogram, high resolution computed tomography(HRCT), and pulmonary function tests including arterial blood gas analysis and body plethysmography were taken from each patient. Cross-sectional area of trachea was measured according to the respiratory cycle on the level of aortic arch by HRCT and calibrated with body surface area. We compared this corrected area with such parameters of pulmonary function tests as $PaCO_2$, $PaO_2$, airway resistance, lung compliance and so on. Results : Expiratory cross-sectional area of trachea had significant correlation with $PaCO_2$ (r=-0.61, p<0.05), $PaO_2$ (r=0.6, p<0.05), and minute ventilation (r=0.73, p<0.05), but inspiratory cross-sectional area did not (r=-0.22, p>0.05 with $PaCO_2$, r=0.26, p>0.05 with $PaO_2$, and r=0.44, p>0.05 with minute ventilation). Minute ventilation had significant correlation with tidal volume (r=0.45, p<0.05), but it had no significant correlation with respiratory frequency (r=-0.31, p>0.05). Cross-sectional area of trachea had no significant correlation with other parameters of pulmonary function including $FEV_1$, FVC, $FEV_1$/FVC, peak expiratory flow, residual volume, diffusing capacity, airway resistance, and lung compliance, whether the area was expiratory or inspiratory. Conclusion : Cross-sectional area of trachea narrowed during expiration in emphysema, and its expiratory area had significant correlation with $PaCO_2$, $PaO_2$, and minute ventilation.

• Tuberculosis and Respiratory Diseases
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• v.43 no.5
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• pp.736-745
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• 1996

Background : It is known that pulmonary rehabilitation improves dyspnea and exercise tolerance in patient with chronic lung disease, although it does not improve pulmonary function. But there is a controversy whether this improvement after pulmonary rehabilitation is due to increased aerobic exercise capacity. We performed this study to evaluate the effect of pulmonary rehabilitation for 6 weeks on the pulmonary function, gas exchange, exercise tolerance and aerobic exercise capacity in patients with chronic lung disease. Methods : Pulmonary rehabilitations including education, muscle strengthening exercise and symptom-Umited aerobic exercise for six weeks, were performed in fourteen patients with chronic lung disease (COPD 11, bronchiectasis 1, IPF 1, sarcoidosis 1 ; mean age $57{\pm}4$ years; male 12, female 2). Pre- and post-rehabilitaion pulmonary function and exercise capacity were compared. Results: 1) Before the rehabilitation, FVC, $FEV_1$ and $FEF_{25-75%}$ of the patients were $71.5{\pm}6.4%$. $40.6{\pm}3.4%$ and $19.3{\pm}3.8%$ of predicted value respectively. TLC, FRC and RV were $130.3{\pm}9.3%$, $157.3{\pm}13.2%$ and $211.1{\pm}23.9%$ predicted respectively. Diffusing capacity and MVV were $59.1{\pm}1.1%$ and $48.6{\pm}6.2%$. These pulmonary functions did not change after pulmonary rehabilitation. 2) In the incremental exercise test using bicycle ergometer, maximum work rale ($57.7{\pm}4.9$) watts vs. $64.8{\pm}6.0$ watts, P=0.036), maximum oxygen consumption ($0.81{\pm}0.07$ L/min vs. $0.96{\mu}0.08$ L/min, P=0.009) and anaerobic threshold ($0.60{\pm}0.06$ L/min vs. $0.76{\mu}0.06$ L/min, P=0.009) were significantly increased after pulmonary rehabilitation. There was no improvement in gas exchange after rehabilitation. 3) Exercise endurances of upper ($4.5{\pm}0.7$ joule vs. $14.8{\pm}2.4$ joule, P<0.001) and lower extremity ($25.4{\pm}5.7$ joule vs. $42.6{\pm}7.7$ joule, P<0.001), and 6 minute walking distance ($392{\pm}35$ meter vs. $459{\pm}33$ meter, P<0.001) were significantly increased after rehabilitation. Maximum inspiratory pressure was also increased after rehabilitation ($68.5{\pm}5.4$ $CmH_2O$ VS. $80.4{\pm}6.4$ $CmH_2O$, P<0.001). Conclusion: The pulmonary rehabilitation for 6 weeks can improve exercise performance in patients with chronic lung disease.

• Korean Journal of Environmental Biology
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• v.35 no.2
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• pp.198-206
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• 2017

From June 2007 to May 2008, seasonal variations of bacterial abundance and heterotrophic nanoflagellate (HNF), together with environmental factors, were investigated at weekly and monthly intervals in Kyeonggi Bay. During the study period, the water temperature and salinity varied from $1.9^{\circ}C{\sim}29.0^{\circ}C$ and 31~35.1 psu, respectively. The concentration of ammonia, nitrate+nitrite, phosphate, and silicate ranged from 0.01 to $3.22{\mu}M$, 2.03 to $15.34{\mu}M$, 0.06 to $1.82{\mu}M$, and 0.03 to $18.3{\mu}M$, respectively. The annual average concentration of Chl. a varied from $0.86{\mu}g\;L^{-1}$ to $37.70{\mu}g\;L^{-1}$; the concentration was twice as much at the surface than at the deeper layers. The abundance of bacteria and HNF ranged from $0.29{\times}10^6$ to $7.62{\times}10^6cells\;mL^{-1}$ and $1.00{\times}10^2$ to $1.26{\times}10^3cells\;mL^{-1}$, respectively. In particular, there were significant correlations between bacteria and HNF abundance (p<0.05), and then the high abundance of HNF was frequently observed with an increase of bacterial abundance in summer (p<0.001). Our results therefore indicate that bacterial abundance in the bay was mainly controlled by resources supplied as organic and inorganic substances from Lake Shihwa due to the daily water exchange after dike construction. Also, the bacterial abundance was significantly controlled by HNF grazing pressure (top-down) in the warm seasons, i.e. excluding winter, in the Kyeonggi Bay.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.6
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• pp.327-340
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• 2017

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2016. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of flow, heat and mass transfer, the reduction of pollutant exhaust gas, cooling and heating, the renewable energy system and the flow around buildings. CFD schemes were used more for all research areas. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results of the long-term performance variation of the plate-type enthalpy exchange element made of paper, design optimization of an extruded-type cooling structure for reducing the weight of LED street lights, and hot plate welding of thermoplastic elastomer packing. In the area of pool boiling and condensing, the heat transfer characteristics of a finned-tube heat exchanger in a PCM (phase change material) thermal energy storage system, influence of flow boiling heat transfer on fouling phenomenon in nanofluids, and PCM at the simultaneous charging and discharging condition were studied. In the area of industrial heat exchangers, one-dimensional flow network model and porous-media model, and R245fa in a plate-shell heat exchanger were studied. (3) Various studies were published in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, subjects include mobile cold storage heat exchanger, compressor reliability, indirect refrigeration system with $CO_2$ as secondary fluid, heat pump for fuel-cell vehicle, heat recovery from hybrid drier and heat exchangers with two-port and flat tubes. In the alternative refrigeration/energy system category, subjects include membrane module for dehumidification refrigeration, desiccant-assisted low-temperature drying, regenerative evaporative cooler and ejector-assisted multi-stage evaporation. In the system control category, subjects include multi-refrigeration system control, emergency cooling of data center and variable-speed compressor control. (4) In building mechanical system research fields, fifteenth studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, renewable energies, etc. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which could be help for improving the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the analyses of indoor thermal environments controlled by portable cooler, the effects of outdoor wind pressure in airflow at high-rise buildings, window air tightness related to the filling piece shapes, stack effect in core type's office building and the development of a movable drawer-type light shelf with adjustable depth of the reflector. The subjects of building energy were worked on the energy consumption analysis in office building, the prediction of exit air temperature of horizontal geothermal heat exchanger, LS-SVM based modeling of hot water supply load for district heating system, the energy saving effect of ERV system using night purge control method and the effect of strengthened insulation level to the building heating and cooling load.

• The Korean Society of Law and Medicine
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• v.20 no.3
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• pp.47-79
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• 2019

The Korean Society of Law and Medicine has faithfully played the role of professional academic organizations last 20 years in terms of academic activities, accumulated achievements, diversity, professionalism, and influence on academic circles. The Korean Society of Law and Medicine and the Journal of Medical Law serve as a platform for academic information and exchange of opinions on medical law. Medical law began in the midst of increasing conflicts and disputes caused by medical malpractice and the enactment and legal coercion of medical care as pressure on medical workers. It tried to find a way to coexist with each other through the encounter and convergence of medicine and law. Medical criminal law extends from traditional crimes in the realm of life and body protection to bioethics violations caused by the development of biomedical technology, corruption and economic crime in the medical field. Medical law has evolved into a comprehensive legal area dealing with legal issues raised in medical treatment, healthcare, bioethics, and life sciences technology. On the legal side, medical law is not independent legal areas. It is overlapping with traditional law areas such as civil law, administrative law, criminal law, social law, civil and criminal procedure law. However, it is now established as a convergence study in medicine, bioethics, life science, as well as in various fields of law. It has become an area where collaboration is needed with the field of law, medicine, ethics, sociology and economics. Medical criminal law has undergone a dynamic development over the last two decades. The development of medicine and medical technology provides new and innovative methods of diagnosis and treatment. The achievements and risks of revolutionary developments in biotechnology, genetic engineering and medicine coexist. While there is a dazzling achievement that mankind has hoped for: combating disease and improving health, it also creates unwanted side effects and risks to humans. There is a need to reconsider ethical and legal principles. The discovery and development of patient identity and autonomy has changed the medical doctor-patient relationship. Furthermore, it was complicated by the triangle relationship of patients, medical doctors and insurance. Legal matters are also complicated. This is why the necessity of legislation is emerging. Criminal punishment provisions are also required. The Medical Law and Biomedical Law are systematically and coherently deformed as mosaic-based legislation that takes place whenever there are social issues, citizens' needs, and medical organizations' interests, rather than sufficient enactment and revision procedures. It needs a complete overhaul, and this is possible through interdisciplinary collaboration which is the strength of The Korean Society of Law and Medicine.

• Tuberculosis and Respiratory Diseases
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• v.46 no.5
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• pp.645-653
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• 1999

Introduction : Although myocardial ischemia tends to occur more frequently than can he documented in ventilated patients, it has not been well studied on the factors related to the occurrence of the ischemia. Methods : To investigate the related factors to ischemia development, a prospective study was done in 95 cases with consecutive 73 patients who had received mechanical ventilation(MV) in MICU. In addition to 24 h holter monitoring, echocardiogram, electrolytes, cardiac enzymes, hemodynamic, and gas exchange measurements were done within 24 h after initiation of MV in 69 cases. The measurements were repeated at weaning period in 26 cases. The ischemia was defined by the ST segment changes; up-sloping depression more than 1.5 mm or down-sloping or horizontal depression more than 1.0 mm from isoelectric baseline for 80 ms following J point. Results : Twelve patients(12.6% in 95 cases) developed ischemia in total. The incidence of ischemia development showed an increased tendency in the initial 24 hr after MV (15.9%) and in patients with left-sided heart failure found by echocardiogram (18.2%) compared with that of the weaning period (3.8%) and patients without heart failure (10.9%) (P=0.12, P=0.09, in each). There were no differences in APACHE III score, baseline ECG findings, electrolytes abnormalities, use of inotropics or bronchodilators, presence of sepsis or shock, mode of ventilation, and survival rate according to the development of ischemia. Maximal heart rates and mean arterial pressure also were not different between patients with ($137.2{\pm}30.9/min$, $82.5{\pm}15.9$ mm Hg) and without ischemia ($l29.5{\pm}29.7/min$, $83.8{\pm}17.6$ mm Hg). Conclusion : Although the incidence of myocardial ischemia was 12.6% in total, there were no clinically predictable factors to the development of ischemia during mechanical ventilation.