• Archives of Reconstructive Microsurgery
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• v.20 no.1
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• pp.38-42
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• 2011

Purpose: To evaluate the effect of intermittent bleeding method in the distal phalanx replantation. Materials and Methods: From January 2007 through June 2009, authors have replanted 117 cases of distal phalangeal amputation in adults at Soo Hospital and Chonbuk National University Hospital. Cases of zone II were 60 cases and zone III 57 according to Allen classification. Male to female ratio was 8.7:1.3. The most common cause was machinery injury in the factory, 98 cases(83.8%), next one was belt injury of the machine, 11 cases(9.4%) and others, 8(6.8%). At least one digital artery and digital nerve were anastomosed under the operating microscope, but vein was impossible to anastomosis as unable to find out in the zone II and III. After anastomosis of one or more digital arteries and nerves, heparine(6,000-10,000 units) was kept to intravenous injection for 24 hours and at the same time fish mouth incision in 2-3 millimeter diameter was made in the distal radial and ulnar margin of the replanted distal phanlanx. From the first 30 minutes to an hour after replantation, incision site was swabbed with heparinized cotton ball for 5 minutes in every 30 to 40 minutes to make sure perfusion for 24 hours, every an hour at the second day, every two hours at the postoperative third to fifth day. Results: 92 cases(78.6%) was completely survived at average postoperative third week follow-up and satisfied with preservation of the finger nail, digit length, good range of motion of the distal interphalangeal joint and acceptable sensibility at average 1.2 years follow-up. Conclusions: Intermittant bleeding method in replantation of crushed distal phalanx impossible to anastomosis of vein at zone II and III of Allen classification was regarded as one of the notable salvage procedure.

• Journal of Mechanical Science and Technology
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• v.16 no.7
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• pp.986-998
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• 2002

Flow and spray characteristics are critical factors that affect the performance and exhaust emissions of a direct injection diesel engine. It is well known that the swirl control system is one of the useful ways to improve the fuel consumption and emission reduction rate in a diesel engine. However, until now there have only been a few studies on the effect of flow on spray. Because of this, the relationship between the flow pattern in the cylinder and its influence on the behavior of the spray is in need of investigation. First, in-cylinder flow distributions for 4-valve cylinder head of DI (Direct Injection) Diesel engine were investigated under steady-state conditions for different SCV (Swirl Control Valve) opening angles using a steady flow rig and 2-D LDV (Laser Doppler Velocimetry). It was found that swirl flow was more dominant than that of tumble in the experimented engine. In addition, the in-cylinder flow was quantified in terms of swirl/tumble ratio and mean flow coefficient. As the SCV opening angle was increased, high swirl ratios more than 3.0 were obtained in the case of SCV -70° and 90°. Second, spray characteristics of the intermittent injection were investigated by a PDA (Phase Doppler Anemometer) system. A Time Dividing Method (TDM) was used to analyze the microscopic spray characteristics. It was found that the atomization characteristics such as velocity and SMD (Sauter Mean Diameter) of the spray were affected by the in-cylinder swirl ratio. As a result, it was concluded that the swirl ratio improves atomization characteristics uniformly.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.5
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• pp.73-80
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• 2002

Dimethyl ether (DM) is one of the most attractive alternative fuel far compression ignition engine. Its main advantage in diesel engine application is high efficiency of diesel cycle with soot free combustion though conventional fuel injection system has to be modified due to the intrinsic properties of DME. Experimental study of DME and conventional diesel spray employing a common-rail type fuel injection system with a 5-holes sac type injector (hole diameter 0.168 ㎜/hole) was performed in a high pressure chamber pressurized with nitrogen gas. A CCD camera was employed to capture time series of spray images followed by spray cone angles and penetrations of DME were characterized and compared with those of diesel. Under atmospheric pressure condition, regardless of injection pressure, spray cone angles of the DME were wider than those of diesel and penetrations were shorter due to flash boiling effect. Tip of the DME spray was farmed in mushroom like shape at atmospheric chamber pressure but it was disappeared in higher chamber pressure. On the contrary, spray characteristics of the DME became similar to that of diesel under 3MPa of chamber pressure. Hole-to-hole variation of the DME spray was lower than that of diesel in both atmospheric and 3MPa chamber pressures. At 25MPa and 40MPa of DME injection pressures, regardless of chamber pressure, intermittent DME spray was observed. It was thought that vapor lock inside the injector was generated under the two injection pressures.

• The Korean Journal of Pain
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• v.1 no.2
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• pp.211-213
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• 1988

Efforts from many different approaches have been made to cure Raynaud's phenomenon using dosal sympathectomy and topical injection of nitroglycerine, phentolamine or procaine and oral or parenteral administration of various drugs. However, there has been no successful management proven yet. In recent years, it was reported that intra-arterial adminstriation of various drugs in normal subjects as well as patients with Raynaud's syndrome, had emonstrated a significant increase in blood flow to the hands. We used an intermittent stellate ganglion block in conjunction with intra-arterial injection of reserpine and procaine in the patient suffering from finger necrosis caused by accidental intraarterial antibiotic (cephamezine) injection. The stellate ganglion block was performed via a paratracheal approach by injection of 0.5% bupivacaine 6 ml, and 1% lidocaine 6 ml, and followed by administration of reserpine 1 mg and procaine 50 mg through a butterfly needle inserted in the radial artery. The administration of reserpine and procaine was done twice. The stellate ganglion block was performed every day for about 3 days, then once every a 5 days as needed for 15 days. As the procedure was carried out, the discolored tissue improved and the pain was progressively relieved. In conclusion, it was suggested that the intra-arterial administration of reserpine and procaine helped initiate and accelerate the increasing blood flow to the hand and the stellate ganglion block continued to help revascularization by dilating the peripheral beds.

• KSBB Journal
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• v.8 no.4
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• pp.328-335
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• 1993

A flow injection analysis(FIA) system was developed for the determination of cholesterol using immobilized cholesterol oxidase and cholesterol ester hydrolase. The enzymes were immobilized on controlled pore galas(CPG) by the glutaraldehyde method. The glass colunms packed with immobilized enzymes were found to contain 3-5 I.U. for each enzyme. A hydrogen peroxide sensitive electrode was contructed and applied to the FIA system. The operational conditions for FIA response were investigated and optimized with variation of sampling volume, flow rate and composition of carrier solution. The FIA response were linear upto 60 and 400mg/m1 for free cholesterol and cholesterol ester, respectively. All samples were analyzed with a good precision (<2.5% CV) and accuracy. 23 samples were mea sured succesively within about an hour. Intermittent assays of more than 500 times caused 50% decrease in response sensitivity.

• Journal of ILASS-Korea
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• v.7 no.1
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• pp.14-20
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• 2002

It is well known that the flow and spray characteristics is critical factor on the performance and emission of a direct injection diesel engine. So this study aims to investigate the interaction of flow and spray characteristics. At first, in cylinder flow distributions in swirl adaptor for 4-valve cylinder head of DI Diesel engine were investigated under steady conditions for different SCV angles mounted on the cylinder head with steady rig test and 2-D LDV. And the in-cylinder flow was quantified in terms of mean flow coefficient and swirl ratio/tumble ratio. It was found that the swirl ratio is controlled between 2.3 and 3.8. Then spray characteristics of the intermittent injection were investigated. PDA system was utilized for measurement of a droplet size and velocity. The analyses of the PDA results are carried out with Time Dividing Method. It was found that there is a correlation between the swirl flow and SMD. The droplet size and the velocity were nearly constant value with each SCV angle. And the swirl ratio is higher, SMD smaller. The swirl ratio was helpful factor to the atomization of droplet.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.5
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• pp.64-74
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• 2005

The effect of fuel injection spray on engine performance has been known as one of the major concerns for improving fuel economy and reducing emissions. In general, reducing the spray droplet size could prevent HC emission in gasoline engine. As far as PFI gasoline engine is concerned, the mixture of air and fuel may not be uniform under a certain condition, because breakup and production of spray droplets are made in a short distance between the fuel injector and intake valve. This study, by constituting PFI gasoline spray system, was performed to study the transient spray characteristics and dynamic behavior of droplets from two-holes two-sprays type injector used in DOHC gasoline engine. Mean droplet size and optical concentration in accordance with various conditions were measured by LDPA and CCD camera. Through this study, the variation of drop size and optical concentration could be used for understanding the behavior of unsteady spray was declared and the existing the small droplets between each pulse spray could be estimated caused to the development of wall film was conformed.

• Journal of Power Electronics
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• v.16 no.6
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• pp.2173-2181
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• 2016

Permanent magnet synchronous motors (PMSMs) have higher torque and superior output power per volume than other types of AC motors. They are commonly used for applications that require a large output power and a wide range of speed. For precise control of PMSMs, knowing the accurate position of the rotor is essential, and normally position sensors such as a resolver or an encoder are employed. On the other hand, the position sensors make the driving system expensive and unstable if the attached sensor malfunctions. Therefore, sensorless algorithms are widely researched nowadays, to reduce the cost and cope with sensor failure. This paper proposes a sensorless algorithm that can be applied to a wide range of speed. The proposed method features a robust operation at low-speed as well as high-speed ranges by employing a gain adjustment scheme and intermittent voltage pulse injection method. In the proposed scheme the position estimation gain is tuned by a closed loop manner to have stable operation in tough driving environment. The proposed algorithm is fully verified by various experiments done with a 1 kW outer rotor-type PMSM.

• Archives of Plastic Surgery
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• v.49 no.4
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• pp.527-530
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• 2022

Lupus panniculitis (LP) often presents with tender nodules and intermittent ulcers that then heal with scarring and lipoatrophy. The current mainstay of treatment is medical treatment. Research regarding the treatment of lipoatrophy from LP with autologous fat grafting is limited. We would like to share our experience in this rare case, which was treated with autologous fat transfer. A 48-year-old female presented with erythematous plaque, tender nodules, and ulcers following by a depression of the lesion at the left temporal area. The patient also had indurated erythematous plaque at her left cheek. Both lesions were aggravated by sunlight exposure. After several investigations, she was diagnosed as LP with secondary lipoatrophy and tumid lupus erythematosus at her left temporal and left cheek, respectively. She received antimalarial drug and topical steroids. The patient underwent two sessions of autologous fat transfer. She was satisfied with the volume and contour improvement in the scar following the injection of 8 and 3.7 mL of fat. Furthermore, the patient reported the remission of tender nodules and ulcers since the first fat graft injection. In conclusion, the autologous fat transfer is a simple and effective treatment for lipoatrophy and scar secondary to LP with promising results.

• Journal of Biosystems Engineering
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• v.21 no.3
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• pp.306-314
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• 1996

A seeder monitoring system was developed to solve the problems of mis-sowing and tube clogging in direct seeding machines, which have been one of the factors that reduce the performance of sowing operations. The system consisted of photo sensors, air nozzles, an air compressor, and a one-chip micro-computer based controller. The system was also equipped with the devices that perform the functions of self-checking and intermittent air injection for cleaning seed tubes. The performance of the system was tested in the laboratory and field. Using the well-cleaned rice seed, the average time for checking the mis-sowing was 1.37 seconds in the field and 1.2 seconds in the laboratory without any malfunction. Overall evaluation of the system indicated that the system can be utilized for seeding machines not only for paddies but beans and corns.