• Journal of Animal Environmental Science
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• v.13 no.2
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• pp.97-104
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• 2007

This study was carried out to develop the modified cyclone dust collector in windowless broiler building measuring 12 m wide, 46 m long, with a side wall height of 3 m and a capacity of 12,800 birds. Ventilation rate in windowless broiler building was $0.014{\sim}0.015\;and\;0.158{\sim}0.181cmm$ in second weeks and fifth weeks of age, respectively. Ammonia concentration was $13{\sim}16\;and\;20{\sim}24\;ppm$ in first and second weeks of age, respectively. Amount of dust collected in dust collector each week was 104.1, 274.7 and 388.6g in first, second and third weeks of age. But it was decreased from fourth weeks of age because of the increased ventilation rate. Total suspended particulate(TSP) of polluted air was $3,111.7{\sim}8,745.2{\mu}g/m^3$, but it was decreased to $530.8{\sim}2,264.4{\mu}g/m^3$ when it passed through the dust collector. Collecting efficiency was $54.2{\sim}82.9%$ in TSP. But collecting efficiency of Particulate matter smaller than $1{\mu}g$ (PM1.0) was $7.6{\sim}33.8%$, and lower than TSP. TSP concentration in control broiler house was 1,387.6 and $4,210.1{\mu}g/m^3$ in first and fourth weeks of age, respectively. But it was decreased to 876.3 and $2,535.3{\mu}g/m^3$ in broiler house operated dust collector in first and fourth weeks of age, respectively. Dust collecting efficiency for TSP was $36.8{\sim}39.8%$, and it was decreased to $11.4{\sim}39.8%$ in smaller dust size.

• Tuberculosis and Respiratory Diseases
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• v.44 no.5
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• pp.1072-1082
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• 1997

Background : To characterize the clinical features and determine the prognostic factors of severe community-acquired pneumonia. This study is the first of its kind in Korea. Methods : Recruited were 40 patients diagnosed as severe community-acquired pneumonia in Hallym University Hospital from January 1, 1989 through July 31, 1996. Patients were analysed retrospectively for age, sex, underlying disease, respiration rate, hypoxemia, requirement of mechanical ventilation, involvement on chest radiograph, shock, and the serum concentration of BUN and albumin. All parameters were compared between survived and dead group. Results : Male to female ratio was 2.07 : 1. The mean age was $63.1{\pm}17.5$years(range 25~90years) with 65% of patients aged equal to or more than 60. The major underlying diseases were old pulmonary tuberculosis(12.5%), chronic obstructive pulmonary disease(7.5%), bronchial asthma(5%), bronchiectasis(2.5%), and diabetes mellitus(22.5%). Microbiologic diagnosis was made in 26 out of 40 patients(65%). The most common causative organism was S. pneumoniae(17.5%, 7/40) followed by S. aureus(15.0%, 6/40), K. Pneumoniae(12.5%, 5/40), M. tuberculosis(7.5%, 3/40), H. influenzae(2.5%, 1/40), coagulase negative staphylococcus(2.5%, 1/40), P. aeruginosa(2.5%. 1/40), E. cloaceae(2.5%, 1/40), and E. coli(2.5%, 1/40). M. pneumoniae was detected in no patient. The most frequent drugs administered in single or combination therapy were aminoglycosides(75%, 30/40), second- and third-generation cephalosporin(40%, 16/40 and 27.5%, 11/40), macrolides(27.5%, 11/40), and amoxicillin/clavulanic acid(22.5%, 9/40). Of the 40 patients, 14 died of severe community-acquired pneumonia(37.5%). Among them, seven patients (50%) expired within 72h of hospital arrival. According to multivariate analysis, mortality was significantly associated with requirement of mechanical ventilation, bilateral pulmonary involvement, and serum albumins$\leq$3.0g/dl. Conclusion : An understanding of the clinical characteristics and prognostic factors in severe community-acquired pneumonia identified in this study will optimize therapeutic approach in this disease and help decreasing its notorious mortality rate.

• The Korean Journal of Physiology
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• v.13 no.1_2
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• pp.1-12
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• 1979

To evaluate the present status of physical fittness of Korean long distance runners, body fat, pulmonary functions, maximal oxygen intake and oxygen debt were measured in 5 elite marathoners (A group), 6 college student runners (B group) and 3 middle school student runners (C group). After laboratory tests, full course marathon running was performed in 2 elite marathoners during which their heart rates were monitored continuously. The results are summerized as follows: 1) Total body fat in all three groups are in the range of 13-15% of their body weight. 2) In all three groups, average values of various pulmonary functions were within the normal limits, but those of tidal volume were higher and respiratory rate were lower in comparison to normal values. These phenomena may represent respiratory adaptations against training. The average resting oxygen consumptions in A,B and C were $322{\pm}23$, $278{\pm}14$ and $287{\pm}16$m1/min, respectively. 3) In all three groups, resting blood pressures were in the normal range, but the resting heart rate was slightly lower in groups A $(56{\pm}3\;beats/min)$ and B $(64{\pm}2\;beats/min)$ and higher in group C $(82{\pm}9\;beats/min)$ in comparison to normal values. These changes in cardiovascular functions in marathoners may also represent adaptive phenomena. 4) During treadmill running the minute ventilation and oxygen consumption of the runners increased lineally with work load in all three groups. When the oxygen consumption was related to heart rate, it appeared to be a exponential function of the heart rate in all three groups. 5) The average maximal heart rates during maximal work were $196{\pm}3$, $191{\pm}3$ and $196{\pm}5\;beats/min$ for groups A,B and C, respectively. Maximal oxygen intakes were $84.2{\pm}3.3\;ml/min/kg$ in group A, $65.2{\pm}1.1\;ml/min/kg$ in group B and $58.7{\pm}0.4\;ml/min/kg$ in group C. 6) In all three groups, oxygen debts and the rates of recovery of heart rate after treadmill running were lower than those of long ditsance runners reported previously. 7) The 40 km running time in 2 elite marathoners was recorded to be $2^{\circ}42'25'$, and their mean speed was 243 m/min (ranged 218 to 274 m/min). The heart rate appeared to increase lineally with running speed, and the total energy expenditure during 40 km running was approximately 1360.2 Calories. From these it can be speculated that if their heart rates were maintained at 166 beats/min during the full course of marathon running, their records would be arround $2^{\circ}15'$. Based on these results, we may suspect that a successful long distance running is, in part, dependent on the economical utilization of one's aerobic capacity.

• Journal of Chest Surgery
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• v.44 no.5
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• pp.348-354
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• 2011

Background: Traumatic rupture of the diaphragm is an unusual type of trauma. In addition, it is difficult to diagnose because it can be accompanied by injuries to other organs. If it is not detected early, the mortality rate can increase due to serious complications. Diaphragmatic rupture is an important indicator of the severity of the trauma. The aim of this study was to investigate the factors affecting the incidence of complications and mortality in patients who had surgery to treat traumatic rupture of the diaphragm. Materials and Methods: The subjects were patients who had undergone a diaphragmatic rupture by blunt trauma or stab wounds except patients who were transferred to other hospitals within 3 days of hospitalization, from January 2000 to December 2007. This study was a retrospective study. 43 patients were hospitalized, and 40 patients were included during the study period. Among them, 28 were male, 12 were female, and the average age was 42 (from 18 to 80). Outcome predictive factors including hypoxia, ventilator application days, revised trauma score (RTS), injury severity score (ISS), age, herniated organs, complications, and the mortality rate were investigated. Results: Causes of trauma included motor vehicle crashes for 20 patients (50%), falls for 10 (25%), stab wounds for 8 (20%), and agricultural machinery accidents for 2 (5%). Most of the patients (36 patients; 90%) had wound sites on the left. Diagnosis was performed within 12 hours for most patients. The diaphragmatic rupture was diagnosed preoperatively in 27 patients (70%) and in 12 patients (30%) during other surgeries. For surgical treatment, thoracotomy was performed in 14 patients (35%), laparotomy in 11 (27.5%), and a surgery combining thoracotomy and laparotomy in 15 patients (37.5%). Herniated organs in the thoracic cavity included the stomach for 23 patients (57.5%), the omentum for 15 patients (37.5%), the colon for 10 patients (25%), and the spleen for 6 patients (15%). Accompanying surgeries included splenectomy for 13 patients (32.5%), lung suture for 6 patients (15%), and liver suture for 5 patients (12.5%). The average hospital stay was $47.80{\pm}56.72$ days, and the period of ventilation was $3.90{\pm}5.8$ days. The average ISS was $35.90{\pm}16.81$ (11~75), and the average RTS was $6.46{\pm}1.88$ (1.02~7.84). The mortality rate was 17.5% (7 patients). Factors affecting complications were stomach hernia and age. Factors affecting the mortality rate were ISS and RTS. Conclusion: There are no typical symptoms of the traumatic rupture of the diaphragm by blunt trauma. Nor are there any special methods of diagnosis; in fact, it is difficult to diagnose because it accompanies injuries to other organs. Stab wounds are also not easy to diagnose, though they are relatively easy to diagnose compared to blunt trauma because the accompanying injuries are more limited. Suture of the diaphragm can be performed through the chest, the abdomen, or the thoracoabdomen. These surgical methods are chosen based on accompanying organ injuries. When there are many organ injuries, there are a great number of complications. Significant factors affecting the complication rate were stomach hernia and age. ISS and RTS were significant as factors affecting the mortality rate. In the case of severe trauma such as pelvic fractures, frequent physical examinations and chest X-rays are necessary to confirm traumatic rupture of the diaphragm because it does not have specific symptoms, and there are no clear diagnosis methods. Complications and the mortality rate should be reduced with early diagnosis and with treatment by confirming diaphragmatic rupture in the thoracic cavity and the abdomen during surgery.

• Tuberculosis and Respiratory Diseases
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• v.43 no.6
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• pp.987-996
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• 1996

Background : We prospectively evaluated the applicability and effect of noninvasive ventilation (NIV) in acute respiratory failure and tried to find out the parameters that could predict successful application of NIV. Methods : Twenty-six out of 106 patients with either acute ventilatory failure (VF: $PaCO_2$ > 43 mm Hg with pH < 7.35) or oxygenation failure (OF: $PaO_2/AO_2$ < 300 mm Hg with $pH{\geq}7.35$) requiring mechanical ventilation were managed by NIV (CPAP + pressure suppon, or BiPAP) with face mask. Eleven out of 19 cases with VF (57.9%) (M : F=7 : $55.4{\pm}14.6$ yrs) and 15 out of 87 cases with OF (17.2%) (M : F=12 : 3, $50.6{\pm}15.6$ yrs) were s uilable for NIY. Respiratory rates, arterial blood gases and success rate of NIV were analyzed in each group. Results: 81.8% (9/11) of YF and 40% (6/15) of OF were successfully managed on NIV and were weruled from mechanical ventilator without resorting to endotracheal intubation. Complications were noted in 2 cases (nasal skin necrosis 1, gaseous gastric distension 1). In NIV for ventilatory failure, the respiration rate was significantly decreased at 12 hour of NIV ($34{\pm}9$ /min pre-NIV, $26{\pm}6$ /min at 12 hour of NIV, p=0.045), while $PaCO_2$ ($87.3{\pm}20.6$ mm Hg pre-NIV, $81.2{\pm}9.1$ mm Hg at 24 hour of NIV) and pH ($7.26{\pm}0.04$, $7.32{\pm}0.02$, respectively, p <0.05) were both significantly decreased at 24 hour of NIV In NIV for oxygenation failure, $PaCO_2$ were not different between the successful and the failed cases at pre-NIV and till 12 hours after NIV. The $PaO_2/FIO_2$ ratio, however, significantly improved at 0.5 hour of NIV in successful cases and were maintained at around 200 mm Hg (n=6 : at baseline, 0.5h, 6h, 12h : $120.0{\pm}19.6$, $218.9{\pm}98.3$, $191.3{\pm}55.2$, $232.8{\pm}17.6$ mm Hg, respectively, p=0.0211), but it did not rise in the failed cases (n=9 : $127.9{\pm}63.0$, $116.8{\pm}24.4$, $100.6{\pm}34.6$, $129.8{\pm}50.3$ mm Hg, respectively, p=0.5319). Conclusion : From the above results we conclude that NIV is effective for hypercapnic respiratory failure and its success was heralded by reduction of respiration rale before the reduction in $PaCO_2$ level. In hypoxic respiratory failure, NIV is much less effective, and the immediate improvement of $PaO_2/FIO_2$ ratio at 0.5h after application is thought to be a predictor of successful NIV.

• The Korean Journal of Physiology
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• v.27 no.2
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• pp.209-215
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• 1993

The aim of the present study was to derive regression equations for $\dot{V}o_{2max}\;vs.\;\dot{V}o_{2peak},\;and\;\dot{V}o_2\;vs.$ heart rate, exercise time, and other variables from maximal exercise tests on a treadmill using the Bruce and inclined protocols. Twelve male and 10 female Korean college students aged between 19 and 23 years voIunteered for this study. After the resting measurements, the subjects performed a maximal exercise on a treadmill according to the Bruce protocol. When the resting conditions were restored, the subjects performed another maximal exercise according to an inclined protocol where the speed was fixed at 8.05 $km{\cdot}h^{-1}$ and the grade was incremented starting from 09t by 2.5% for every 2 min. Peak $\dot{V}o_2$ observed during the Bruce exercise $(\dot{V}o_{2peak})$ was $37.7{\pm}2.4\;and\;31.7{\pm}1.8\;ml\;kg^{-1}\;min^{-1}$ in the male and female groups, respectively. Peak $\dot{V}o_2$ observed during the inclined exercise was higher than $\dot{V}o_{2peak}$ during the Bruce exercise. Maximum $\dot{V}o_2$ value observed during the tyro exercises $(\dot{V}o_{2max})$ was $43.0{\pm}2.8\;and\;36.2{\pm}1.4\;ml\;kg^{-1}\;min^{-1}$ in the male and female groups, respectively. Thus, $\dot{V}o_{2peak}$ by the Bruce protocol was about 12% (male) or 13% (female) lower than $\dot{V}o_{2max}$, and a linear relationship was found between $\dot{V}o_{2peak}$ and $\dot{V}o_{2max}$. The peak values of % $\dot{V}o_{max}$ with the Bruce protocol were $89.2{\pm}3.3\;and\;87.5{\pm}3.6%$ and those with the inclined protocol $97.7{\pm}1.8\;and\;96.9{\pm}2.0%$ in the male and female groups, respectively. In the female group, $%\dot{V}o_{2max}$ at a given workload was higher than in the male group, while $\dot{V}o_{2}$ per kg body weight was the same. Maximum HR observed during the two exercises was $204{\pm}2\;and\;195{\pm}3\;beat\;min^{-1}$ in the male and female groups, respectively. Linear relationships were found, excluding the last points, between 1) $\dot{V}o_{2}$ and exercise time, 2) $\dot{V}o_{2}$ and $%\dot{V}o_{2max}\;and\;%HR_{max}$.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.5
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• pp.739-746
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• 2016

A total of 152 pig farms were randomly selected from the five provinces in South Korea. During the experiment, the average temperature and relative humidity was $24.7^{\circ}C$ and 74% in summer and $2.4^{\circ}C$ and 53% in winter, respectively. The correlation between floor space allowance (FSA) and productivity index was analyzed, including non-productive sow days (NPD), number of weaners (NOW), survival rate (SR), appearance rate of A-grade pork (ARA), and days at a slaughter weight of 110 kg (d-SW) at different growth stages. The objectives of the present study were i) to determine the effect of FSA on the pig productivity index and ii) to suggest the minimum FSA for pigs based on scientific baseline data. For the pregnant sow, NPD could be decreased if pregnant sows were raised with a medium level (M) of FSA (3.10 to $3.67m^2/head$) while also keeping the pig house clean which improves hygiene, and operating the ventilation system properly. For the farrowing sows, the NOW tended to decrease as the FSA increased. Similarly, a high level of FSA (H) is significantly negative with weaner SR of farrowing sows (p-value = 0.017), indicating this FSA tends to depress SR. Therefore, a FSA of 2.30 to $6.40m^2/head$ (very low) could be appropriate for weaners because a limited space can provide a sense of security and protection from external interruptions. The opposite trend was observed that an increase in floor space (> $1.12m^2/head$ leads to increase the SR of growing pigs. For the fattening pigs, H level of FSA was negatively correlated with SR, but M level of FSA was positively correlated with SR, indicating that SR tended to increase with the FSA of 1.10 to $1.27m^2/head$. In contrast, ARA of male fattening pigs showed opposite results. H level of FSA (1.27 to $1.47m^2/head$) was suggested to increase productivity because ARA was most affected by H level of space allowance with positive correlation ($R^2=0.523$). The relationship between the FSA and d-SW of fattening pigs was hard to identify because of the low $R^2$ value. However, the farms that provided a relatively large floor space (1.27 to $1.54m^2/head$) during the winter period showed d-SW was significantly and negatively affected by FSA.

• Korean Journal of Environmental Agriculture
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• v.18 no.4
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• pp.310-315
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• 1999

The feasibility of an absorbent biofilter system was examined for rural wastewater treatment. Hydraulic loading rates varied from 50 to 250 cm/day. Effluent of the septic tank was fed into the absorbent biofilter, and small ventilation fan was provided to supply air at the rate of 250 L/min to aerate the biofilter. The biofilter system demonstrated high removal rates for $BOD_5$ and TSS at the loading rate of 150 cm/day, generally meeting the Korean effluent water quality standard of 20 mg/L applicable to both. The nutrient removal was less satisfactory than the results of $BOD_5$ and TSS, but it was within the expected range of biological treatment processes. Considering the abnormally high influent concentration of nutrients during the experiment, better performance results could have been obtained if ordinary domestic wastewater was used. The system performance was not significantly affected by the hydraulic loading up to 150 cm/day, which is far more than the loading limit of the sand filter systems. Maintenance requirement was minimal, and no problems with noise, odor, flies or sludge arose. Since the biofilter system can be operated at a distance, operation in remote rural area and multi-system connected to one control office might be advantageous to the rural area. Overall, considering the cost-effectiveness, stable performance, and minimum maintenance, the biofilter system was thought to be a competitive alternative to treat wastewater in Korean rural communities.

• Fire Science and Engineering
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• v.27 no.6
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• pp.32-37
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• 2013

For The performance based fire design of the buildings, the fire characteristic such as proceeding and scale of the fire should be figured out but, there is lack of relevant information because of different conditions and difficulties of mock-up test like type of division space, ventilation condition, etc, in buildings. Therefore, in the study, a heal release rate etc, the engineering characteristic data value on the fire is proposed by mock-up fire test for division space in buildings. The mock-up fire test is carried out in a bedroom with 2.4 (L) ${\times}$ 3.6 (W) ${\times}$ 2.4 (H) m model. Initial ignition was started from trash box and the test was carried out for 30 min. As a result of the fire test, flame was broken to outside within 7 min and 50 s after starting the test and the maximum heat release rate was measured as 3,810.6 kW at 9 min and 34 s.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.1
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• pp.54-62
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• 2015

Small scale paint overspray booths are being operated nationwidely, for repair of passenger car body parts. paint aerosols are emitted from the paint overspray booth in operations. In paint overspray booth operations without ventilation system and air pollutants collection unit, it may land on nearby equipment. In this study a removal of sticky paint aerosol for application of the small-scale overspray paint booth. it's cause the surface of filter bag from generated sticky paint aerosol. To remove adhesion of paint aerosol the agglomerating agents are injected and mixed with sticky paint aerosols prior to reach the filter bag. The paint spray rate was set as $10{\pm}5g/min$ from air-atomized spray guns in the spray booth, injection rate of agglomerating was $10{\pm}5g/min$ in the mixing chamber. The filtration velocity including air pollutants varied from 0.2 m/min to 0.4 m/min. Bag cleaning air pressure was set as $5.0kg_f/min$ for detaching dust cake from surface of filter bag. Bag cleaning interval at the filtration velocity of 0.2 m/min was around 3 times longer than that of the 0.4 m/min. The residual pressure drop maintained highest value at the highest filtration velocity. Fractional efficiency of 99.952%~99.971% was possible to maintain for the particle size of 2.5 microns. Total collection efficiency at the filtration velocity of 0.2 m/min was 99.42%. During this study we could confirm high collection efficiency and long cleaning intervals for the test with filtration velocity of 0.2 m/min indicating an optimal value for the given dimensions of the test unit and test operating conditions.