• 한국농공학회논문집
• /
• 제51권5호
• /
• pp.19-24
• /
• 2009

This study was conducted to provide fundamental data for design of air inflating apparatus of air-inflated double-layer plastic greenhouse. The variation of static pressure in air tube for different fans and filters, filtering performance for various kinds of filters and destruction phase of experimental greenhouse collapsed by excessive static pressure in air space were analyzed. The general type of forward centrifugal fan was recommended for inflating air space in air-inflated double-layer plastic greenhouse. The experimental greenhouse was collapsed down by excessive static pressure just like fallen by heavy snow load acting on it. The static pressure in air tube without filter decreased linearly as the number of outlet openings increased. But the pressure in air tube with filter declined quadratically, the decremental ratio diminished by the increase of outlet openings. The higher filtering efficiency and the greater decrements of static pressure in air tube, the larger capacity fan was required for maintaining proper static pressure in air space. Because the porosities of filter were blocked by dust as time goes by, the static pressure in air tube with filter decreased. The higher filtering efficiency, the less decremental ratio of static pressure in air tube as time passes by. Considering the filtering efficiency, decrement of static pressure and thickness of filter, the 5mm thickness filter of 75% efficiency was recommended for air inflating filter of air-inflated double-layer plastic greenhouse.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
• /
• pp.73-76
• /
• 2002

In this paper we present an integrated Hail sensor It for fan motors, fabricated in industrial bipolar process. As a discrete Hall sensor and signal processing circuitry In the fan motor system were Integrated into single chip a temperature dependence of Hall sensitivity and Hall offset voltage can be compensated and cancelled by on-chip circuitry. We Propose a novel temperature compensation of Hall sensitivity with negative temperature coefficient (TC) using the differential amplifier gain with Positive TC. After a package of the chip was sealed using a plastic Package 20 Pins, the thermal and magnetic characteristics were investigated. The obtained experimental results are in agreement with analytical predictions and have more excellent performance than\ulcorner conventional the fan motor system using discrete Hall sensor.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2000년도 추계학술대회 논문집
• /
• pp.767-770
• /
• 2000

In order to reduce lean-time and cost, recently the technology of Rapid Prototyping and Manufacturing(PR/M) has been used widely. So various RP/M methods have been developed and these systems commercialized several years ago. The machining process is one of these methods. It also offers advantages such as precision and versatility. But there are some considerations during machining. The most important problem among them is the fixturing. So we have to overcome the limitation because the fixturing time is depend on the complexity of geometry to be machined. In this paper, we have developed the fixturing technique using filling process that can be widely useful for rapid products within a short time. So we have carried out some kinds of rapid products such as plastic knob and metal fan using our fixturing process. In fixturing step, the filling material might chosen a resin or a alloy according to wether the work material is plastic or metal respectively. Also we developed the set-up equipment attachable on the table of the milling machine that provided practicable quality during a series of machining operations, named by two step milling process.

• Archives of Plastic Surgery
• /
• 제36권2호
• /
• pp.242-246
• /
• 2009

Purpose: The majority of nasal bone fractures have been managed by routine procedure of closed reduction and intranasal packing. However, nasal packing can cause nasal injury, hypoxia and patient's discomfort. And, synechiae formation is a frequently occurred after the nasal surgery. Various methods are used to reduce the incidence of synechiae formation. The purpose of this study was to compare routine procedure and nasal packing with reverse "U" shaped silicone sheet with respect to postoperative nasal synechiae formation and final outcome. Methods: We analyzed the medical records of 100 patients with nasal bone fracture who were operated by closed reduction in the last one year. The silicone sheet was designed in reverse "U" fan - shape and inserted between the middle turbinate and the septal wall. Nasal packing was removed at two days after the operation, and silicone sheet was removed at 10 to 14 days. Results: Synechiae in the middle meatus developed in 2 of 75 patients. Although synechiae between the middle meatus and nasal septum occurred in patients, the patients did not complaint of any olfactory disturbance and nasal obstruction. Conclusion: The reverse "U" fan - shape silicone sheet caused less pain for patients and no significant differences in outcome were found. The results of this study suggest that insertion of silicone sheet between the middle meatus and septum can be a useful method in the prevention of intranasal synechiae formation. The reverse "U" silicone sheet is a good alternative for routine packing methods.

• 한국유기농업학회지
• /
• 제20권4호
• /
• pp.655-668
• /
• 2012

유기농 토마토 생산에 있어 지상부 잎에 발생하는 병은 수량을 감소시키는 중요한 요인이다. 특히 흰가루병, 잎곰팡이병, 잿빛곰팡이병이 유기농 토마토 포장에서 심각한 문제가 되고 있다. 본 연구는 저항성 품종, 환기장치, 난황유 및 미생물 농약 등 친환경적인 방제방법을 이용하여 유기농 토마토 생산 기술을 증대시키기 위해서 수행되었다. 시설하우스에 환기장치를 작동시키면 환기장치를 설치하지 않은 하우스에 비해 최고온도와 최저온도의 편차가 $2{\sim}7^{\circ}C$ 줄어들고, 평균상대습도도 1~5% 감소되었다. 그 결과 토마토 잎곰팡이병 발생이 55.0%, 그리고 토마토 잿빛곰팡이병 발생이 24.4% 억제되었다. 미생물 농약 2종을 시설하우스에서 잿빛곰팡이병과 잎곰팡이병을 대상으로 방제시험을 실시한 결과, 잿빛곰팡이병은 49.0~55.9%, 잎곰팡이병은 39.2~58.2%의 방제효과가 있는 것으로 조사되었다. 또한 난황유를 제조하여 흰가루병을 대상으로 시설하우스에서 처리한 결과 97.6%의 우수한 방제효과가 확인되었다. 잎곰팡이병과 흰가루병을 대상으로 병저항성 품종 선발시험을 실시한 결과 15품종 중 슈퍼탑을 포함한 7품종이 잎곰팡이병에 대해 저항성을 가지는 것으로 확인되었으며, 흰가루병의 경우에는 15품종 중 파워킹만이 저항성을 나타내었다.

• Archives of Plastic Surgery
• /
• 제48권2호
• /
• pp.231-236
• /
• 2021

Mucormycosis is an invasive, rapidly progressive, life-threatening fungal infection, with a propensity for diabetic, immunosuppressed, and trauma patients. The classic rhinocerebral variation is most common in diabetic patients. While the cutaneous form is usually caused by direct inoculation in immunocompetent patients. Cutaneous mucormycosis manifests in soft tissue and risks involvement of underlying structures. Tibial osteomyelitis can also occur secondary to cutaneous mucormycosis but is rare. Limb salvage is typically successful after lower extremity cutaneous mucormycosis even when the bone is involved. Herein, we report two cases of lower extremity cutaneous mucormycosis in diabetic patients that presented as acute worsening of chronic pretibial ulcers. Despite aggressive antifungal therapy and surgical debridement, both ultimately required amputation. Such aggressive presentation has not been reported in the absence of major penetrating trauma, recent surgery, or burns.

• 설비공학논문집
• /
• 제17권2호
• /
• pp.117-124
• /
• 2005

Aluminum plate heat exchanger, rotary wheel heat exchanger, and heat pipe heat exchanger have been used (or ventilation heat recovery in the air-conditioning system. The purpose of this research is to develop high efficiency plastic plate heat exchanger which can substitute aluminum plate heat exchanger. Because thermal conductivity of plastic is quite small compared to that of aluminum, various heat transfer enhancement techniques are applied in the design of plastic plates. Five types of heat exchanger model are designed and manufactured, which are plate type, plate-fin type, turbulent promoter type, corrugate type, and dimple type. Thermal performance and pressure loss of each heat exchangers are measured in various operating conditions, and compared each other. Test results show that heat transfer performance of corrugate type, turbulent promoter type, and dimple type are increases about $43\%$, $14\%$, and $33\%$ at the equivalent fan power compared to those of plate type, respectively. On the other hand, the heat transfer performance of plate-fin type decreases $9\%$ because fins can not play their own role.

• Archives of Plastic Surgery
• /
• 제48권6호
• /
• pp.599-606
• /
• 2021

Background Postoperative dehiscence and surgical site infection after spinal surgery can carry serious morbidity. Multidisciplinary involvement of plastic surgery is essential to minimizing morbidity and achieving definitive closure. However, a standardized approach is lacking. The aim of this study was to identify effective reconstructive interventions for the basis of an evidence-based management protocol. Methods A retrospective review was performed at a single tertiary institution for 45 patients who required 53 reconstruction procedures with plastic surgery for wounds secondary to spinal surgery from 2010 to 2019. Statistical analysis was performed for demographics, comorbidities, and treatment methods. Primary outcomes were postoperative complications, including dehiscence, seroma, and infection. The secondary outcome was time to healing. Results The overall complication rate was 32%, with dehiscence occurring in 17%, seroma in 15% and infection in 11% of cases. Median follow-up was 10 months (interquartile range, 4-23). Use of antibiotic beads did not affect rate of infection occurrence after wound closure (P=0.146). Use of incisional negative pressure wound therapy (iNPWT) was significant for reduced time to healing (P=0.001). Patients treated without iNPWT healed at median of 67.5 days while the patients who received iNPWT healed in 33 days. Demographics and comorbidities between these two groups were similar. Conclusions This data provides groundwork for an evidence-based approach to soft tissue reconstruction and management of dehiscence after spinal surgery. Timely involvement of plastic surgery in high-risk patients and utilization of evidence-based interventions such as iNPWT are essential for improving outcomes in this population.

• 대한두경부종양학회지
• /
• 제12권1호
• /
• pp.52-57
• /
• 1996

Since the upper lip does not receive direct actinic radiation, only 5% of lip tumors develop in the upper lip, while the lower lip is the site of the remainder. Among the lower lip cancer, squamous cell carcinoma is the most common tumor, especially the vermillion border of lower lip is the most common site. The aims of reconstruction of the lip are both aesthetic effect and functional restoration and the ideal procedure must produce a aesthetically normal, not-tao-tight lip and a good sensation and muscle tone of the lip. We have a satisfactory reconstruction of a subtotal loss of lower lip after squamous cell carcinoma extirpation using Gillies fan flap and the case is presented with reviewing a many published reports.

• Archives of Plastic Surgery
• /
• 제46권6호
• /
• pp.544-549
• /
• 2019

Background As the indications for postmastectomy radiotherapy expand, innovative solutions are required to reduce operative complications and reconstructive failure after prosthetic breast reconstruction. In this study, we investigated the effectiveness of acellular dermal matrix (ADM) inlay grafts in preventing postoperative wound dehiscence of irradiated breasts in the context of prosthetic breast reconstruction. Methods A retrospective analysis was conducted of 45 patients who received two-stage prosthetic reconstruction and radiotherapy following mastectomy. An ADM graft was placed beneath the incisional site during the second-stage operation in 19 patients using marionette sutures, whereas the control group did not receive the ADM reinforcement. Patient demographics and complications such as wound dehiscence, capsular contracture, peri-prosthetic infection, cellulitis, and seroma were compared between the two groups. Results During an average follow-up period of 37.1 months, wound dehiscence occurred significantly less often in the ADM-reinforced closure group (0%) than in the non-ADM group (23.1%) (P=0.032). There was no significant difference between the two groups in relation to other complications, such as capsular contracture, postoperative infection, or seroma. Conclusions The ADM inlay graft is a simple and easily reproducible technique for preventing incisional dehiscence in the setting of radiotherapy after prosthetic breast reconstruction. The ADM graft serves as a buttress to offload tension during healing and provides a mechanical barrier against pathogens. Application of this technique may serve to reduce complications in prosthetic breast reconstruction after radiotherapy.