• Journal of the Semiconductor & Display Technology
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• v.10 no.1
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• pp.1-6
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• 2011

In this paper, the air flow induced by the rotating flat disk is numerically investigated in a hope to better understand the air flow structures inside the wax spin coater for a silicon wafer polishing station. Due to the complex inner geometry of actual spin coater such as the casing around the rotating ceramic block and servo motor, recirculation of air flow is inevitably found on the coating target if the internal space of spin coater is closed at the bottom and it could be the possible source of contamination on the wax coating. By numerical flow simulation, we found that it is necessary to install the air vent at the bottom and to apply the sufficient air suction in order to control the path of air flow and to eliminate the air recirculation zone above the spinning surface of coating target.

• Journal of Chest Surgery
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• v.27 no.6
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• pp.489-493
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• 1994

Our patient was a 2.3 kg, male of 33 weeks gestation and spontaneous vaginal delivery. Copious salivary secretion, mild aspiration pneumonia episode due to tracheoesophageal fistula and intermittent cyanotic appearance due to hypoxia were noted shortly after birth. Head up position, frequent upper pouch suction, and adequate fluid and antibiotic therapy were done in incubator. Combined Chest and abdominal film was revealed gas in the stomach and an haziness in right chest with mediastinal shift to the right side. Esophagogram revealed markedly dilated proximal esophagus as blind pouch, and Two dimensional echocardiography showed the Ventricular Septal Defect. The conclusion was congenital esophageal atresia with tracheoesophageal fistula, Vogt-Gross type C, Waterston Risk Category B. Surgical correction with Beardmore anastomosis was performed extrapleurally through 3rd rib bed after the cannulation of umbilical vein and preliminary gastrostomy. The fistula was closed by triple ligation and the upper pouch was then brought down to the presenting surface of the lower esophageal segment that incised, and end to side anastomosis was underwent using interrupt suture placed through the full thickness of both upper pouch and lower esophageal segment. The postoperative patient was well tolerated and recovered uneventfully, permitted feeding on 7th postoperative day after esophagogram.

• Journal of Chest Surgery
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• v.8 no.1
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• pp.37-44
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• 1975

Authors have reviewed the records of seven patients of multiple rib fractures with severe flail chest who were admitted to Hanyang University Hospital during the 3 years period from 1972 through 1975. Of the seven patients studied, automobile accidents led to the injuries in 4 cases, two patients were injured in fall from a tree and on the ox-heading. All who had a blunt trauma without any open wound on the chest. The numbers of the fractured ribs accounted for 6 to 9 of the ribs including double fractures from 3 to 5 ribs. The left side fractures occurred in the 6 patients and in the right only one patient. Thus the flail segment was more often located in the left antero-lateral position than in the right lateral position [the ratio was 6:1].. All cases had associated injuries. The injuries and multiple fractures were the most common associated injuries occurring in four and five of the patients respectively. The patients were classified as having associated head injuries when they were admitted in comatose or semicomatose state. When a major degree of instability of the thoracic cage exists, adequate respiratory change is not possible. For this reason the tracheostomy was performed in five patients in an acutely injured patient with flail chest only after an endotracheal tube has been inserted or after an endotracheal suction. All patients had secondary complications in the pleural cavity, such as hemothorax or hemopneumothorax with or without intrapulmonary hemorrhage and subcutaneous emphysema. Therefore, closed thoracostomy was performed in five patients in the emergency room. The thoracotomy was required in four patients: immediate operation without closed thoracostomy was performed in two patients and the thoracotomy was indicated in two patients after closed thoracostomy, because of increasing intrathoracic hemorrhage. As to the fixation of the flail segments, authors employed two techniques; one was towel clip traction of the flail segments and the other was intramedullary insertion of Kirschner`s wire in to the double fractured rib fragments for the fixation of the flail segments [Kirschner`s wire fixation]. Because` of an different results in the course of treatment between two techniques, data from patients with towel clip traction was compared with those from patients with thoracotomy and Kirschner`s wire fixation of the flail segments. Of the three patients with towel clip traction, two patients required bronchoscopic toilet due to lung atelectasis which developed because of inadequate motion of thoracic cage and poor expectoration. This was in contrast to the four patients with thoracotomy and Kirschner`s wire fixation, who didn`t these complication because of adequate motion of the thoracic cage and subsequent good expectoration.

• Journal of Biosystems Engineering
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• v.21 no.4
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• pp.429-435
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• 1996

A wind tunnel consisting of two air flow conditioners with polycarbonate pipes, a plant growth room, a suction fan and fan controller, and fluorescent lamps, was designed to investigate the interactions between the growth of plug seedlings under artificial light and their Physical environments. Light transmissivities in the plant growth room based on the photosynthetic photon flux density and photosynthetically active radiation was appeared to be 96.3% and 96.8%, respectively. Measurement showed a uniformity in the vertical profiles of air current speed at the middle and rear regions of plug trays in wind tunnel. This result indicated that the development of a wind tunnel based on the design criteria of the American Society of Mechanical Engineers was adequate. Air current speed inside the plug stand was significantly decreased due to the resistance by the leaves of plug seedlings and boundary layer developed over and below the plug stand. Driving force to facilitate the diffusion of gas inside the plug stand might be regarded as extremely low. Aerodynamic characteristics above the plug stand under artificial light were investigated. As the air current speed increased, zero plane displacement decreased but roughness length and frictional velocity increased. Zero plane displacement linearly increased with the average height of plug seedlings. The wind tunnel developed in this study would be useful to investigate the effects of air current speed on the microclimate over and inside the plug stand and to collect basic data for a large-scale plug production under artificial light in a semi-closed ecosystem.

• Archives of Plastic Surgery
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• v.40 no.5
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• pp.621-626
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• 2013

Background Ever since lipoabdominoplasty was first developed to achieve better aesthetic outcomes and less morbidity, the rate of seroma formation, especially in obese patients, has disturbed plastic surgeons. The aim of this study was to evaluate the effect of fibrin sealant in the prevention of seroma formation after lipoabdominoplasty in obese patients. Methods Sixty patients with a body mass index (BMI) between 30 and 39.9 were assigned randomly to 1 of 2 groups (30 patients each). Group A underwent lipoabdominoplasty with fibrin glue, while group B underwent traditional lipoabdominoplasty; both had closed suction drainage applied to the abdomen. The patients' demographics and postoperative complications were recorded. Seroma was detected using abdominal ultrasound examinations at two postoperative periods: between postoperative days 10 and 12 and, between postoperative days 18 and 21. Results The age range was 31 to 55 years ($38.5{\pm}9.5$ years) in group A and 25 to 58 years ($37.8{\pm}9.1$ years) in group B, while the mean BMI was 31.4 to 39.9 $kg/m^2$ (32.6 $kg/m^2$) in group A and 32.7 to 37.4 $kg/m^2$ (31.5 $kg/m^2$) in group B. In group A, the patients had a complication rate of 10% in group A versus 43% in group B (P<0.05). The incidence of seroma formation was 3% in the fibrin glue group but 37% in the lipoabdominoplasty-alone group (P<0.05). Conclusions Lipoabdominoplasty with the use of autologous fibrin sealant is a very effective method that significantly reduces the rate of postoperative seroma.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.6
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• pp.140-147
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• 2011

The injection nozzle of an electro-hydraulic injector for the common rail Diesel fuel injection system is being opened and closed by movement of a injector's needle which is balanced by pressure at the nozzle seat and at the needle control chamber, at the opposite end of the needle. In this study, the slenoid actuator was considered as a prime movers in high pressure Diesel injector. Namely a solenoid-driven Diesel injector with different driving current types, as a general method driven by solenoid coil energy, has been applied with a purpose to develop the analysis model of the solenoid actuator to predict the dynamics characteristics of the hydraulic component (injector) by using the AMESim code. Aimed at simulating the hydraulic behavior of the solenoid-driven injector, the circuit model has been developed as a unified approach to mechanical modeling in this study. As this analytic results, we know the suction force and first order time lag for driving force can be endowed in solenoid-driven injector in controlling the injection rate. Also it can predict that the input current wave exerted on solenoid coil is the dominant factor which affects on the initial needle behavior of solenoid-driven injector than the hydraulic force generated by the constant injection pressure.

• Child Health Nursing Research
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• v.5 no.2
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• pp.198-210
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• 1999

The goal of respiratory management in high risk infants is to maintain proper oxygenation by supporting respiration, therefore to minimize the secondary complications and to promote the maximum growth and development. While on artificial ventilator to achieve this goal, the infants require endotracheal suctioning(ETS) to remove lung secretions. However, the negative effects of ETS in neoates have been documented and include hypoxia, bradycardia, mucosal damage, increased intracranial pressure, and death result. The purpose of the study was to investigate how ETS is currently performed in NICU, which would be beneficial to develop the standardized ETS protocol and to apply it to these population. A national-wide survey on clinical protocol of ETS was performed to 149 neonatal nurses with the average of 3 years and 6 months experience in neonatal nursing, 34.2% of whom was bachelor in nursing. The results showed that about 89% of the nurses initiate En primarily based on the need of the subjects. The aseptic regulation on ETS was used in 83.9% of the subjects. There was no regulation on the length of catheter in 32.9% and on ID/OD ratio in 17.4%. Many nurses administered hyperoygenation/hyperinflation/hyperventilation based on personal knowhow, rather than scientific rationals (77.2%, 40.9%, 75.2%, retrospectively). About 41% of the nurse regulate subjectively the suction power, while 73.8% of them rotate the sub ject's head during suctioning and the half of the nurses was favorable in adapting the closed-suctioning protocol. With the findings of the study, the current clinical application of E% in neonates appears to be based on adult care practices, or personal preference, rather than scientific validation of the safety and effectiveness of the procedure. This study support the needs for developing and applying the standardized ETS protocolin conjunction with the consideration given to the physiologic characteristics of the neonates in respiratory distress.

• Archives of Plastic Surgery
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• v.47 no.1
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• pp.33-41
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• 2020

Background Closed-suction drains are widely used in expander-based breast reconstruction. These drains are typically removed using a volume-based criterion. The drainage volume affects the hospital stay length and the recovery time. However, few studies have analyzed the factors that influence drainage volume after expander-based breast reconstruction. Methods We retrospectively analyzed data regarding daily drainage from patients who underwent expander-based breast reconstruction between April 2014 and January 2018 (159 patients, 176 expanders). Patient and operative factors were analyzed regarding their influence on total drainage volume and drain placement duration using univariate and multivariate analyses and analysis of variance. Results The mean total drainage volume was 1,210.77±611.44 mL. Univariate analysis showed correlations between total drainage volume and age (B=19.825, P<0.001), body weight (B=17.758, P<0.001), body mass index (B=51.817, P<0.001), and specimen weight (B=1.590, P<0.001). Diabetes history (P<0.001), expander type (P<0.001), and the surgical instrument used (P<0.001) also strongly influenced total drainage. The acellular dermal matrix type used did not affect total drainage (P=0.626). In the multivariate analysis, age (B=11.907, P=0.004), specimen weight (B=0.927, P<0.001), and expander type (B=593.728, P<0.001) were significant predictors of total drainage. Conclusions Our findings suggest that the total drainage and the duration of drain placement needed after expander-based breast reconstruction can be predicted using preoperative and intraoperative data. Patient age, specimen weight, and expander type are important predictors of drainage volume. Older patients, heavier specimens, and use of the Mentor rather than the Allergan expander corresponded to a greater total drainage volume and a longer duration of drain placement.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.271-278
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• 2021

This paper is a study on the implementation of smart filter system that recognizes the external environment and automatically removes pollutants according to pollution level. Recently, the occurrence of various pollutants in indoor and outdoor space has adversely affected the human body. Especially, various fine dust generated in the atmosphere becomes worse in closed residential space or office space. Although air pollution can be temporary lowered through ventilation, it is difficult to respond to fine dust changes in real time, and such problems become serious in the space where many people reside, such as at home or industry. Therefore, it is necessary to measure the pollution level of fine dust inside the residential space in real time and to reduce the pollution of indoor ventilation through automatic ventilation with the outside. To improve these problems, this paper proposes the implementation of smart filter system for external environment recognition. The structure of smart filter system that automatically measures air quality inside and outside, removes pollutants, implements the function, and confirms the operability by manufacturing prototypes. Finally, the effectiveness of the smart filter system for solving fine dust problems was examined.

• Journal of Chest Surgery
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• v.8 no.1
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• pp.19-28
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• 1975

The thoracoscopic study was reported on 21 cases of spontaneous pneumothorax requiring surgical management, and clinical values of thoracoscopic examination on spontaneous pneumothorax were also discussed. patients were treated in the Department of .Thoracic Surgery, Hanyang University Hospital for the period of two Years from May 1972 to April 1974. For exact detection of etiologic factors on spontaneous pneumothorax, the thoracoscopic examination in the intrapleural space was performed in parallel with X-ray study. this study, the difference of diagnostic and therapeutic significance between radiological and thoracoscopic findings were observed and compared simultaneously. The results are summerized as follows: Patients age was distributed between 3 and 70 years old with highest incidence in the age group of sixty decade [33. 3%], and sex ratio of male to female was 5:2. The tuberculous processes which developed superficial subpleural layer in the lung parenchyme, on the pulmonary surface could be observed by thoracoscopic examination in a characteristic picture. detection ratio of pulmonary tuberculosis by the radiologic study to that by thoracoscopy was 8:2. The adhesion between the visceral and the parietal pleura which could possibly make a rupture of the alveola and the visceral pleura was found to be localized in a small area of the lung surface. The other part of the lung surface was free of the adhesion and, therefore, the movement of the lung took place completely without any difficulty. The ruptured orifice of the pleura and pathological changes surrounding the orifice can be detected by thoracoscopy, but not by other means such as radiologic examination. A single tuberculous bleb and multiple emphysematous blebs were found on 6 cases out of 21 cases of spontaneous pneumothorax. Among these cases, radiologic Study revealed the bleb only in one patient. On the other hand, the blebs were found in all the six patients by means of thoracoscopic examination. It gives the detection ratio of bleb by radiologic study to that by thoracoscopy was 1:6. By thoracoscopy, the rupture on the lung surface were visualized on the 10 patients out of a total of 21 patients [10 patients of visual rupture]. However, the rupture of the pleura was not observed on the rest of 11 patients even by thoracoscopic examination [11 patients of non visual rupture]. Five patients [50%] out of ten who had the visual rupture on the lung surface was required a surgical operation to remove pneumothorax. For the patients who were detected to have the visual rupture of the pleura by thoracoscopy, be considered in the early stage of closed thoracostomy. of 21 patients, 16 patients [11 patients of non visual rupture of the pleura and 5 patients of visual rupture of the pleura] who received no surgical management, were treated with closed thoracostomy with continuous suction, and the` pneumothorax was healed completely up in each cases. Therapeutic measures for the remaining 5 patients of visual rupture of the pleura who were subjected to surgical approach for radical treatment of spontaneous pneumothorax were accordingly complicated, and the following different procedures were properly indicated case by case, that is, rib resection thoracostomy, simple closure of ruptured visceral pleura, wedged resection of the lung, and lobectomy.