• International Journal of Fluid Machinery and Systems
• /
• 제6권2호
• /
• pp.105-112
• /
• 2013

The application of contra-rotating rotors for higher specific speed pump has been proposed in our studies, which is in principle effective for reducing the rotational speed and/or the pump size under the same specification of conventional axial flow pump. In the previous experiments of our prototype, the cavitation inception at the tip region of the rear rotor rather than that of the front rotor and the strong potential interaction from the suction surface of the rear rotor blade to the pressure surface of the front one were observed, indicating the possibility to further improve the pump performance by optimizing rotational speed combination between the two rotors. The present research aims at the design of rear rotor with lower rotational speed. Considering the fact that the incoming flow velocity defects at the tip region of the rear rotor, an integrated inflow model of 'forced vortex' and 'free vortex' is employed. The variation of maximum camber location from hub to tip as well as other related considerations are also taken into account for further performance improvement. The ideas cited above are separately or comprehensively applied in the design of three types of rear rotor, which are subsequently simulated in ANSYS CFX to evaluate the related pump performance and therefore the whole low speed design idea. Finally, the experimental validation is carried out on one type to offer further proofs for the availability of the whole design method.

• 지역사회간호학회지
• /
• 제19권2호
• /
• pp.157-166
• /
• 2008

This study was conducted with whole home care nurses nationwide to provide secondary analyzed data to understand on their usage of medical equipments and their need of them for a month. This study found that treatments given by home care nurses were nelaton catheterization, bladder washing/urethral washing, newborn care, exchange and care for nasogastric tube and suction in that order of frequency. Second, instruments and equipments used for home care were reported to be stethoscope, patient monitor, blood pressure measuring equipment, air flotation mattresses, beds for patients, mattresses, suctioning device sets, enteral feeding equipment and dressing set in that oder of frequency. Moreover, need assessment of medical instruments and equipments showed renal dialysis was most needed and patient monitor, blood pressure measuring equipment, enteral feeding equipment, solution and other supplies for renal dialysis and beds for patient were necessary in that order. In conclusion, the results of this study investigating special treatments and medical instruments and equipments used for home care patients and analyzing patients' need, were expected to be useful for expansion of application of long-term care insurance for the elderly and health insurance as well as for quality control of home care and development of medial instruments and equipments used at home.

• 한국지역지리학회지
• /
• 제9권4호
• /
• pp.534-545
• /
• 2003

한국의 화강암 풍화층은 한냉하고도 습윤한 환경에서 사용하는 결빙과 융해에 의한 특이한 구조들이 잘 발달되어 있다. 이들의 구조들은 일반적인 풍화가 진전된 상황에서만 발견된다. 조사지역인 대관령의 풍화층은 두껍지는 않지만 결빙된 특색이 현미경관찰에서 파쇄되지 않은 채로 보존되어 있다. 특히 조립의 모래알에는 미립의 운모류와 실트 중심의 물질들이 압축되어 치밀하게 덮여 있고 풍화층 상층부에 미립물질이 더욱 많아지고 있다. 결빙에 의한 이동현상도 뚜렷하여 현미경하의 토립들은 미약하게 원마되어 공극과 더불어 화석화되었다. 풍화단면층에서는 사면경사를 따라 커브를 나타낸 적색의 band현상도 관찰되었다. 본 연구결과 풍화층은 냉각과 결빙정도가 오늘날과 달랐던 한냉습윤한 환경이 시차를 두고 존재했음을 시사한 고환경 즉 주빙하 조건에서 형성되었고 동시에 결빙포행이 이루어졌다고 추정된다.

• Journal of Chest Surgery
• /
• 제28권6호
• /
• pp.542-548
• /
• 1995

The goal of this study is to develop an effective control system for cardiac output regulation based upon the preload and afterload conditions without any transducers and compliance chambers in the moving actuator type total artificial heart. Motor current waveforms during the actuator movement are used as an input to the automatic control algorithm. While the current waveform analysis is performed, the stroke length and velocity of the actuator are gradually increased up to the maximum pump output level. If the diastolic filling rate of either right or left pump begins to exceed the venous return, atrial collapse will occur. Since the diastolic suction acts as a load to the motor, this critical condition can be detected by analyzing the motor current waveforms. Every time this detection criterion is met, the control algorithm decreases the stroke velocity and length of the actuator step by step just below the critical detection level. Then, they start to increase. In this way the maximum pump output under given venous return can be achieved. Additionally the control algorithm provides some degree of afterload sensitivity. If the aortic pressure is detected to exceed 120 mmHg, the stroke length and velocity decrease in the same way as the response to the preload. Left-right pump output balance is maintained by proper adjustment of the asymmetry of the stroke angle. In the mock circulatory test, this control system worked well and there was a considerable range of stroke volume difference with adjustment of the asymmetry value. Two ovine experiments were performed. It was confirmed that the required cardiac output regulation according to the venous return could be achieved with adequate detection of diastolic function, at least in the in vivo short-term survival cases[2-3 days . We conclude that this control algorithm is a promising method to regulate cardiac output in the moving actuator type total artificial heart.

• Advances in pediatric surgery
• /
• 제1권1호
• /
• pp.68-72
• /
• 1995

Segmental dilatation of the colon is a very rare disease entity of unknown etiology and may mimic Hirschsprung's disease. It is characterized by dilatation of a segment of the colon of variable length with obstruction due to lack of peristalsis in a normally innervated intestine. Recently authors experienced a case of segmental dilatation of the sigmoid colon in a 6 month-old male, who presented with severe constipation, abdominal distention, and abdominal mass since 2 months of age. Down's syndrome and congenital nystagmus were associated. Barium enema demonstrated focal dilatation of the sigmoid colon, but the rectum and descending colon proximal t o the affected colon were of normal caliber. Rectal suction biopsy with acetylcholinesterase staining was normal and anorectal manometry showed normal rectosphincteric reflex. At operation, there was a massively dilated and hypertrophied sigmoid colon with increased tortuous serosal vessels, measuring 15 cm in length and 10 cm in width. Teniae coli were identifiable in the affected segment. Frozen section biopsies at the proximal, affected, and distal colon showed ganglion cells. Descending loop colostomy was constructed initially and segmental resection and end to end colocolostomy were carried out 3 months later. Final histologic examination showed 1) normal colonic mucosa with ganglion cells, 2) prominent submucosal fibrosis and marked muscular hypertrophy, 3) unremarkable acetylcholinesterase activity and immunohistochemical findings against S-100 protein. On 8 months follow-up, he has been doing well and moves bowels 1-2 times daily.

• 대한치과마취과학회지
• /
• 제7권1호
• /
• pp.1-5
• /
• 2007

Background: It is well known that nasotracheal intubation is comfort for patient compared to oral intubation. We sometimes delay extubation when it is thought that the patient can not maintain airway, or there may be other emergency associated with airway. And we sometimes experience complaint of discomfort of nasotracheal tube. But, we could not find any report on degree of discomfort of delayed nasotracheal intubation. Methods: Eighteen patients in whom extubation of nasotraceal tube was delayed after operation because of difficulties of airway mamagement were selected. We surveyed the discomfort of nasotracheal tube with 0 to 10 visual analogue scale (VAS) and compared with the pain of operation site (VAS). Result: The VAS of nasotracheal intubation was $6.7{\pm}3.4$, and VAS of the primary operation site was $3.5{\pm}2.4$, and VAS of flap harvest site was $5.5{\pm}2.7$. 10 of the patients complained of nasotracheal suction extremely and 6 patients complained of respiratory difficulties. Conclusions: Nasotracheal intubation was discomfort and there must be intervention.

• 대한기계학회논문집
• /
• 제12권3호
• /
• pp.520-527
• /
• 1988

본 연구에서는 액체용 이젝터의 성능을 결정하는 여러가지 제약인자중 특히 레이놀즈수 변화에 따른 구동노즐의 면적비 및 목부길이가 액체용 이제터성능에 미치 는 영향을 체계적인 실험을 통하여 연구함으로써 기 개발된 CAD용 전산프로그램의 타 당성을 보다 세밀히 검토하고 이에 보완을 가하는데 연구의 목적이 있다.

• Archives of Plastic Surgery
• /
• 제35권2호
• /
• pp.169-173
• /
• 2008

Purpose: Sacrococcygeal pilonidal sinus is a chronic inflammatory disease that mostly affects young people, which warrants surgical intervention. Although many surgical methods have been suggested, an optimal surgical method remains controversial because of high recurrence rates and postoperative complications. The objective of this study is to evaluate the results of wide excision and coverage with fasciocutaneous advancement flap for the treatment of sacrococcygeal pilonidal sinus, and to assess the usefulness of this method Methods: From May 1995 to October 2006, the authors treated 19 patients with the use of coverage with fasciocutaneous flap after wide excision. The results were evaluated regarding recurrence rates, complications, and the change in sensitivity of the gluteal region after surgery. The follow-up period was 7 to 142 months (mean, 76 months). All patients were male. Results: Postoperative complications were wound infection at the suction drain insertion site and skin necrosis around the suture margin in one case, respectively. During the follow up period, only one recurrence (5.3%) was seen in fifth postoperative month, which was successfully treated by the same operative procedure. There was no other complications such as seroma, hematoma, wound dehiscence and flap loss. Extensive scarring and anatomic distortion did not occur in the reconstructed area. In addition, sensitivity of the gluteal region did not diminish. The aesthetic results were satisfactory for all patients as well. Conclusion: The authors advocate that fasciocutaneous flap closure be a good alternative method to cover defects after the excision of sacrococcygeal pilonidal sinus.

• Journal of Chest Surgery
• /
• 제30권4호
• /
• pp.453-456
• /
• 1997

기관삽관 및 인공호흡으로 발생하는 후천성 기관식도루는 드물고, 치료하기 힘든 질환이다. 57세 여자 환자로 교통사고후 장기간의 기관상관 및 기관절개 관 상관을 하고있던 환자로, 지속적인 흉인 있어 시행한 식도조영술과 기관지 내시경 검사에서 성문하 협착이 동반된 기관식도루로 진단되 었 다. 수술은 기관식도루 절제 후 4-0 vicryl로 두층으로 식도를 봉합하였으며, 4-0 PDS로 기관을 봉합였 고, 기관과 식도사이 에 흉골설골근(sternohyoid muscle)을 거치 시켜 재발을 방지하였다. T-자관을 기존 의 기 관절개술 부위 에 거치 하여 좁아진 부위가 내경을 유지할 수 있도록 할 뿐아니라 기 관내 분비물 흡 인제거를 용이하게 하였다. 환자는 술후 14일째 T-자관 제거하였으며 이후 좋은 경과를 보이고 있다.

• Archives of Plastic Surgery
• /
• 제35권4호
• /
• pp.393-399
• /
• 2008

Purpose: Chronic infected wounds sustained over 4 weeks with exposed tendon or bone are difficult challenges to plastic surgeons. Vacuum assisted closure (VAC) device has been well used for the management of chronic wounds diminishing wound edema, reducing bacterial colonization, promoting formation of granulation tissue and local blood flow by negative pressure to wounds. But Commercial ready-made VAC device might have some difficulties to use because of its high expenses and heavy weight. So we modified traditional VAC device with silver dressing materials as topical therapeutic agents for control of superimposed bacterial wound infection such as MRSA, MRSE and peudomonas. Methods: We designed the modified VAC device using wall suction, 400 cc Hemovac and combined slow release silver dressing materials. We compared 5 consecutive patients' data treated by commercial ready-made VAC device(Group A) with 11 consecutive patients' data treated by modified VAC device combined with silver dressing materials(group B) from September 2004 to June 2007. Granulation tissue growth, wound discharge, wound culture and wound dressing expenses were compared between the two groups. Results: In comparison of results, no statistical differences were identified in reducing rate of wound size between group A and B. Wound discharge was significantly decreased in both groups. Modified VAC device with silver dressing materials showed advantages of convenience, cost effectiveness and bacterial reversion. Conclusion: In combination of modified VAC device and silver dressing materials, our results demonstrated the usefulness of managing chronic open wounds superimposed bacterial infection, cost effectiveness compared with traditional VAC device and improvement of patient mobility.