• 한국농공학회논문집
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• 제57권5호
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• pp.51-60
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• 2015

In Korea, 69.4 % of duck farms had utilized conventional plastic greenhouses. In this facilities, there are difficulties in controlling indoor environments for raising duck. High rearing density in duct farms also made the environmental control difficult resulting in getting more stressed making their immune system weaker. Therefore, a facility is needed to having structurally enough solidity and high efficiency on the environmental control. So, new design plans of duck house have recently been conducted by National Institute of Animal Science in Korea. As a study in advance to establish standard, computational fluid dynamics (CFD) was used to estimate the aerodynamic problems according to the designs by means of overall and regional ventilation efficiencies quantitatively and qualitatively. Tracer gas decay (TGD) method was used to calculate ventilation rate according to the structural characteristics of duck houses including installation of indoor circulation fan. The results showed that natural ventilation rate was averagely 164 % higher than typically designed ventilation rate, 1 AER ($min^{-1}$). Meanwhile, mechanically ventilated duck houses made 81.2 % of summer ventilation rate requirement. Therefore, it is urgent to develop a new duck house considering more structural safety as well as higher efficiency of environmental control.

• 한국대기환경학회지
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• 제19권5호
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• pp.551-560
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• 2003

Particle deposition in human lungs was investigated theoretically by using asymmetric five-lobe lung model. The volumes of each of the five lobes were different, thereby forming an asymmetric lung structure. The tidal volume and flow rate of each lobe were scaled according to lobar volume. The total and regional deposition with various breathing patterns were calculated by means of tracking volume segments and accounting for particle loss during inhalation and exhalation. The deposition fractions were obtained for each airway generation and lung lobe, and dominant deposition mechanisms were investigated for different size particles. Results show that the tidal volume and flow rate have a characteristic influence on particle deposition. The total deposition fraction increases with an increase in tidal volume for all particle sizes. However, flow rate has dichotomous effects: a higher flow rate results in a sharp increase in deposition for large size particles, but decreases deposition for small size particles. Deposition distribution within the lung shifts proximally with higher flow rate whereas deposition peak shifts to the deeper lung region with larger tidal volume. Deposition fraction in each lobe was proportional to its volume. Among the three main deposition mechanisms, diffusion was dominant for particles < 0.5 ${\mu}{\textrm}{m}$ whereas sedimentation and impaction were most influential for larger size particles. Impaction was particularly dominant for particles> 8 ${\mu}{\textrm}{m}$. The results may prove to be useful for estimating deposition dose of inhaled pollutant particles at various breathing conditions.

• 한국농공학회논문집
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• 제62권5호
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• pp.27-37
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• 2020

As domestic meat consumption increases, the broiler production industry has been larger and denser. The concentration of particulate matter (PM) and harmful gases generated is also increasing inside livestock house. However, the current research status of PM exposed to farm workers and the health effects are in the early stage. To understand PM concentration affecting workers in the broiler house, field monitoring was conducted according to its size distributions. Concentrations of PM₁₀, PM_2.5, and TD (Total Dust) were monitored using personal air samplers with teflon filter during working and moving periods considering the ventilation systems of 6 broiler houses. The purpose of this study is to monitor the PM concentration in the experimental broiler houses operated by forced ventilation system generally used in Korea and to evaluate the regional concentrations through airflow pattern. The PM concentrations were increased from inlet to outlet vents resulting in 1,872 of TD, 1,385 of PM₁₀, and 209 ㎍/㎥ of PM_2.5, respectively. The TD and PM₁₀ concentrations were increased when the workers and broilers were moving. Among them, the particle size that occupied the largest amount of PM was 13.75 ㎛. These results suggest that personal protection equipments are important to reduce the health effect from PM inhalation.

• 대기
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• 제30권4호
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• pp.377-390
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• 2020

Not only emissions, but also atmospheric circulation is a key factor that affects local particulate matters (PM) concentrations in Korea through ventilation effects and transboundary transports. As part of the atmospheric circulation, air stagnation especially adversely affects local air quality due to weak ventilation. This study investigates the large-scale circulation related to air stagnation over Korea during winter and projects the climate change impacts on atmospheric patterns, using observed PM data, reanalysis and regional climate projections from HadGEM3-RA with Modified Korea Particulate matter Index. Results show that the stagnation affects the PM concentration, accompanied by pressure ridge at upper troposphere and weaken zonal pressure gradient at lower troposphere. Downscaling using HadGEM3-RA is found to yield Added-Value in the simulated low tropospheric winds. For projection of future stagnation, SSP5-8.5 and SSP1-2.6 (high and low emission) scenarios are used here. It has been found that the stagnation condition occurs more frequently by 11% under SSP5-8.5 and by 5% under SSP1-2.6 than in present-day climate and is most affected by changes in surface wind speed. The increase in the stagnation conditions is related to anticyclonic circulation anomaly at upper troposphere and weaken meridional pressure gradient at lower troposphere. Considering that the present East Asian winter monsoon is mainly affected by change in zonal pressure gradient, it is worth paying attention to this change in the meridional gradient. Our results suggest that future warming condition increase the frequency of air stagnation over Korea during winter with response of atmospheric circulation and its nonlinearity.

• 대한건축학회연합논문집
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• 제21권4호
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• pp.139-146
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• 2019

The purpose of this study is to propose the building design guideline considering photovoltaic panel installation through the analysis of relevant guidelines from home and abroad in terms of building design and solar panel installation. Conclusions can be summarized as followings; Considerations in building design : selection of the site with high solar accessibility, avoidance of the shade from the adjacent building & trees, south facing orientation of solar panel in building design, removal of shade on the solar panel from the part of building itself, load consideration of solar panel & fixing materials, safe passage securement for solar system maintenance, and planning of piping and mechanical room for solar system. Considerations in solar panel installation : harmonizing of solar panel with surrounding environment, unity of solar panel orientation & slope, regular maintenance of solar system, (in case of flat roof installation) solar panel installation afloat over the roof, installation area within the roof floor, and lower than parapet height, (in case of sloped roof installation) solar panel installation parallel with the roof slope, ventilation space securement below the panel, installation area within the roof surface, and similar material installation in empty space.

• 한국산학기술학회논문지
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• 제18권4호
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• pp.21-26
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• 2017

본 연구에서는 이중관형 열회수 환기장치의 제품 적용 가능성을 검토하기 위해 성능 시험을 수행하였으며 이중관의 내측관의 재질에 변경에 따른 검토를 하기 위해 종이관, 알루미늄관, 폴리머관을 제작하여 동일한 급/배기 풍량을 인가하여 측정하였다. 온도 교환 효율은 모든 경우에서 알루미늄관의 경우가 가장 큰 값을 나타냈으며 종이관과 폴리머관은 비슷한 결과를 보였다. 이는 내측관으로 사용된 재료의 열전도율과 두께의 차이 때문인 것으로 판단된다. 습도 교환 효율은 모든 경우에서 종이관의 경우가 가장 큰 값을 나타냈으며 알루미늄관과 폴리머관은 비슷한 결과를 보였다. 이는 종이 재질은 습도 교환이 가능하지만 알루미늄과 폴리머재질은 습도 교환이 불가능하기 때문인 것으로 판단된다. 습도 교환과 온도 교환의 두 값을 포함하는 전열 교환 효율은 종이관의 경우가 가장 큰 값을 나타냈으며 알루미늄관과 폴리머관은 비슷한 결과를 보였다. 에너지계수(COE)는 현열과 잠열교환이 동시에 일어나는 종이관의 경우 전열에너지계수 값을 현열교환만 일어나는 알루미늄관과 폴리머관은 현열에너지계수를 비교해 보면 종이관의 에너지계수가 가장 큰 값을 나타냄을 알 수 있었다. 본 연구를 통하여 이중관형 열회수 환기장치의 내부관 재질에 따른 성능을 비교 분석 하였으며 환기장치로 적용이 가능한 것을 알 수 있었다.

• Journal of Korean Biological Nursing Science
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• 제23권2호
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• pp.138-150
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• 2021

Purpose: This retrospective study aimed to investigate nursing interventions in patients with severe thoracic injury in trauma bay of a regional trauma center. Methods: Of the 1,780 patients admitted to the trauma bay of a regional trauma center in a university hospital in the Gyeonggi Province between January 1, 2019 and December 31, 2019, 120 adult patients with severe thoracic injury who met the inclusion criteria were enrolled. Participants' clinical characteristics and nursing interventions were collected from electronic medical records after receiving ethical approval. Nursing interventions were classified using the terminology in the Nursing Intervention Classification. Results: The mean age of participants was 52.25 years and 72.5% of participants were male. The main areas of thoracic injury included lung parenchyma and pleura (95.8%). The mean Abbreviated Injury Scale (AIS) for thoracic injury was 3.13 and the mean Injury Severity Score (ISS) was 17.81. Fluid resuscitation, invasive hemodynamic monitoring, chest tube care, respiratory monitoring, artificial airway management, gastrointestinal tube care, mechanical ventilation management: airway insertion and stabilization, blood product administration, allergy management, and surgical preparation were performed significantly more frequently in thoracic injury patients with unstable vital signs or a higher AIS score. Conclusion: This study is significant as it investigated the types of nursing interventions given to patients with severe thoracic injury in the trauma bay. These results would contribute to developing more detailed educational materials for initial nursing interventions in trauma bay.

• Journal of Chest Surgery
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• 제55권5호
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• pp.417-421
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• 2022

Minimally invasive strategies are increasingly popular in patients with myasthenia gravis (MG)-associated thymomas. Within the context of video-assisted thoracoscopic surgery (VATS) as a widely known minimally invasive option, the most recent achievement is uniportal subxiphoid VATS. In MG patients, it is mandatory (1) to minimize perioperative interference with administered anesthetics to avoid complications and (2) to achieve a complete surgical resection, as the prognosis essentially depends on radical tumor resection. In order to fulfill these criteria, we merged this surgical technique with its anesthesiologic counterpart: regional anesthesia with the maintenance of spontaneous ventilation via a laryngeal mask. Non-intubated uniportal subxiphoid VATS for extended thymectomy allowed radical thymectomy in all MG patients with both rapid symptom control and fast recovery.

• Tuberculosis and Respiratory Diseases
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• 제83권3호
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• pp.248-254
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• 2020

Background: Although few studies have reported improved clinical outcomes with the administration of vitamin B1 and C in critically ill patients with septic shock or severe pneumonia, its clinical impact on patients with sepsis-related acute respiratory distress syndrome (ARDS) remains unclear. The purpose of this study was to evaluate the association with vitamin B and C supplementation and clinical outcomes in patients with ARDS. Methods: Patients with ARDS requiring invasive mechanical ventilation, admitted to the medical intensive care unit (ICU) were included in this study. Clinical outcomes were compared between patients administered with vitamin B1 (200 mg/day) and C (2 g/day) June 2018-May 2019 (the supplementation group) and those who did not receive vitamin B1 and C administration June 2017-May 2018 (the control group). Results: Seventy-nine patients were included. Thirty-three patients received vitamin B1 and C whereas 46 patients did not. Steroid administration was more frequent in patients receiving vitamin B1 and C supplementation than in those without it. There were no significant differences in the mortality between the patients who received vitamin B1 and C and those who did not. There were not significant differences in ventilator and ICU-free days between each of the 21 matched patients. Conclusion: Vitamin B1 and C supplementation was not associated with reduced mortality rates, and ventilator and ICU-free days in patients with sepsis-related ARDS requiring invasive mechanical ventilation.

• Journal of Trauma and Injury
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• 제35권2호
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• pp.76-83
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• 2022

Purpose: Ventilator-associated pneumonia is the most common nosocomial infection in patients with mechanical ventilation. In 2013, the new concept of ventilator-associated events (VAEs) replaced the traditional concept of ventilator-associated pneumonia. We analyzed risk factors for VAE occurrence and in-hospital mortality in trauma patients who received mechanical ventilatory support. Methods: In this retrospective review, the study population comprised patients admitted to the Jeju Regional Trauma Center from January 2020 to January 2021. Data on demographics, injury characteristics, and clinical findings were collected from medical records. The subjects were categorized into VAE and no-VAE groups according to the Centers for Disease Control and Prevention/National Healthcare Safety Network VAE criteria. We identified risk factors for VAE occurrence and in-hospital mortality. Results: Among 491 trauma patients admitted to the trauma center, 73 patients who received ventilator care were analyzed. Patients with a chest Abbreviated Injury Scale (AIS) score ≥3 had a 4.7-fold higher VAE rate (odds ratio [OR], 4.73; 95% confidence interval [CI], 1.46-17.9), and those with a glomerular filtration rate (GFR) <75 mL/min/1.73 m² had 4.1-fold higher odds of VAE occurrence (OR, 4.15; 95% CI, 1.32-14.1) and a nearly 4.2-fold higher risk for in-hospital mortality (OR, 4.19; 95% CI, 1.30-14.3). The median VAE-free duration of patients with chest AIS ≥3 was significantly shorter than that of patients with chest AIS <3 (P=0.013). Conclusions: Trauma patients with chest AIS ≥3 or GFR <75 mL/min/1.73 m² on admission should be intensively monitored to detect at-risk patients for VAEs and modify the care plan accordingly. VAEs should be closely monitored to identify infections early and to achieve desirable results. We should also actively consider modalities to shorten mechanical ventilation in patients with chest AIS ≥3 to reduce VAE occurrence.