• Journal of the Semiconductor & Display Technology
• /
• v.19 no.1
• /
• pp.79-84
• /
• 2020

Unlike a printing process, it is difficult to pattern organic thin films in the longitudinal (coating) direction using a coating process. In this paper, we have investigated the feasibility of patterning organic thin films using needles. To this end, we have slot-coated an aqueous poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) solution in the form of a fine stripe or large area and then applied the dual needle; one for discharging the main solvent of the underlying thin film and the other for sucking the dissolved thin film. We have found that the pattern width and depth increase as the moving speed of the plate decreases. However, it is observed that the sidewall slope is very gentle (the length of the slope is of the order of 200 ㎛) due to the fact that the discharged main solvent is widely spread and then isotropic etching occurs. With this scheme, we have also demonstrated that a fine stripe can be obtained by scanning the dual needle closely. To demonstrate its applicability to solution-processable organic light-emitting diodes (OLEDs), we have also fabricated OLED with the patterned PEDOT:PSS stripe and observed the insulation property in the strong light-emitting stripe.

• Journal of Biosystems Engineering
• /
• v.28 no.5
• /
• pp.395-402
• /
• 2003

Standard ginseng seedling, selected after one year's rearing in the seedling bed has been conventionally transplanted in Korea. Recently, the direct seeding areas have been increasing to product high quality ginsengs for red-ginseng processing. Reciprocating push-rod brush, holed-roller and vacuum suction seeders, planting with 30 ${\times}$ 30mm spacings and adjustable to the folds were designed and theirs performances were evaluated. The developed three types of seeders reliably performed at the success rate over 95% with less than 10% in slip rate, and could be used a seeder for the greater spacings by adjusting metering parts. The research concluded that the vacuum suction seeder was the most feasible and practical with the greatest metering success and the least slip among three type seeders of the reciprocating push-rod brush, holed-roller and vacuum suction seeders. The vacuum suction seeder holds a seed with each needle nozzle using the negative pressure created by a vacuum pump. The capacity was 24.5 times greater than a man power at the speed of 5 m/min.

• Journal of Biosystems Engineering
• /
• v.36 no.6
• /
• pp.434-443
• /
• 2011

A large scale seeding system was stable in terms of techniques but a convenient seeding system of small size was unsettled. This study was performed to develop a semi-automatic seeder for small and medium sized scale farm. To investigate optimum needle diameter and vacuum pressure was used vacuum suction needle seeder. Although the needle diameter according to the kinds of seed was different, the needle diameter for salvia and lettuce seed was suitable for 0.34 mm needle nozzle and 0.4 mm taper nozzle. The prototype consisted a seeding frame attached with needle nozzle, seed hopper, vibrating device, seeding part, vacuum ejector, seed tube etc.. As the result with the experiments, the seeding rate of the seeder was 92% and more at 0.34 mm diameter needle nozzle and 0.4 mm taper nozzle. Eccentric weight for seed hopper vibration was suitable that weight is 11 g and eccentric distance is 0.5 mm. Vibration acceleration of upward direction was 0.363 m/$s^2$. Working capacity of the seeder was possible 160 trays per hour. It was possible for sowing small seeds but it was required to make compact and simple model.

• Journal of Environmental Science International
• /
• v.19 no.12
• /
• pp.1447-1454
• /
• 2010

In this study, the detection limits of lower fatty acids in air were investigated by using Dynamic SPME(Solid Phase Micro-Extraction), i.e. improved Head Space - SPME method(HS-SPME). This Dynamic SPME, called SPDE(Solid Phase Dynamic Extraction), is the analytical method for volatile compounds in air with the extraction by using a stainless steel needle of which inner surface is coated with adsorption material and following the gas chromatographic analysis by inserting the needle into a injection port of GC and subsequently, desorption of the volatile compounds into a gas-chromatographic column. Extraction was carried out by passing the sample air through the needle with a suction pump which has been used for a detection tube. The result of measurement for the 6 lower fatty acids showed that the detection limits ranged from 0.10 ppm to 0.44 ppm and the linear correlation coefficients were over 0.99. Relative standard deviations obtained from 5 analytical repetition of a ca. 1.6 ppm standard mixture were in the range of 1.87%~2.47%. This method has been shown to be a adequate for the measuring C2~C5 fatty acids in air in the concentrations of over several hundreds ppb.

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

• Journal of Chest Surgery
• /
• v.1 no.1
• /
• pp.25-30
• /
• 1968

Fifty-two cases of spontaneous pneumothorax encountered in Seoul National University Hospital during the period from 1961 to 1968 were reviewed. The incidence was highest in the adult between 21 and 40 years of age, showing 50%. Four cases of bilateral spontaneous pneumothorax [7.7%] were noted. Pulmonary tuberculosis was the most common cause, 50% of the cases. Non-tuberculous group was 26 cases [50%], of which 15 cases were idiopathic, 5 emphysematous bullae or blebs, 5 inflammatory lung disease, mostly pneumonia, and one pulmonary paragonimiasis. Among 52 cases, the lung expanded completely with absolute bed rest in 7 cases, 3 out of 9 with needle aspiration and bed rest, 34 out of 41 with closed thoracotomy and underwater seal Stedman suction, and 7 cases were treated with open thoracotomy with resection of the lesions without complication. Among these cases treated with closed thoracotomy it took about 3 days in non-tuberculous group to expand the collapsed lung and more than 2 weeks in tuberculous group.

• Clinical and Experimental Reproductive Medicine
• /
• v.48 no.1
• /
• pp.91-94
• /
• 2021

A 28-year-old woman presented with a 1-year history of severe progressive dysmenorrhea following suction evacuation and tubal ligation. Sonography showed a bicornuate uterus with hematometra in the left horn. Hysteroscopy ruled out a diagnosis of a congenital Müllerian anomaly, as both ostia appeared normal. Under laparoscopy, a mass was seen on the left fundal region near the insertion of the round ligament, and needle aspiration of a chocolate-colored fluid confirmed the diagnosis of an adenomyotic cyst. The cyst was excised. The patient recovered well and has been symptom-free since surgery. Adenomyotic cyst is a rare entity in young women and must be differentiated from obstructive Müllerian anomaly. Laparoscopy is the preferred minimally invasive modality for managing this rare disorder.

• Journal of Yeungnam Medical Science
• /
• v.21 no.1
• /
• pp.108-113
• /
• 2004

A 23 years old single nulligravida woman underwent laparoscopic removal of a huge cystic adnexal mass that occupied her entire abdomen, giving the appearance of a full term pregnancy. After anesthesia, a vertical infra-umbilical incision, 1 cm long, was made and a telescope was introduced through the port to determine the status of the intra-abdomen and the surface contour of the mass. A needle tipped with a laparoscopic suction apparatus was inserted into the cyst through the infra-umbilical port, directly under the mass. Subsequently, 3,200 ml of cystic fluid was aspirated without spillage. A huge cyst, reaching to the level of the xyphoid process was effectively excised through the operative laparoscopy after prelaparoscopic drainage. Operation time was 140 minutes and hospital stay was 2 days. There were no complications during hospital stay and after discharge. It seems the size of the cyst is not a criteria for the contraindication of laparoscopic surgery.

• Journal of The Korean Society of Emergency Medicine
• /
• v.29 no.6
• /
• pp.641-648
• /
• 2018

Objective: This study examined the incidence and amount of air inflow during central venous catheter (CVC) insertion. Methods: This study was an experimental study aimed at designing an apparatus to implement blood vessel and blood flow in the human body. A 1.5-m long core tube with a Teflon tube, suction rubber tube, and polyvinyl chloride tube were made. This core tube was assumed to be the blood vessel of the human body. Blood was replaced with a saline solution. The saline solution was placed higher than the core tube and flowed into the inside of the tube by gravity. The CVC was injected 15-cm deep into the core tube. The air was collected through a 3-way valve into the upper tube. The experiments were carried out by differentiating the pressure in the tube, CVC insertion step, and diameter of the end of the catheter. The experiment was repeated 10 times under the same conditions. Results: The amount of air decreased with increasing pressure applied to the tube. Air was not generated when the syringe needle was injected, and the amount of air increased with increasing size of the distal end catheter. Conclusion: To minimize the possibility of air embolism, it is necessary to close the distal end catheter at the earliest point as soon as possible.

• Korean Journal of Animal Reproduction
• /
• v.21 no.2
• /
• pp.147-156
• /
• 1997

Ultrasound-guided follicular aspiration was performed in Holstein heifers once weekly with or without pretreatment of single or multiple decreasing doses using a total of 400 mg FSH. Oocytes were aspirated with a 6.5 MHz convex-array ultrasound trasducer designed for intravaginal use. All the visible follicles larger than 4 mm in diameter were punctured with a 17 gauge, 55 cm needle at each aspiration session and the follicular fluids containing oocytes were obtained by vacuum suction. The results obtained were as follows: As a preliminary experiment, the recovery rates of folicular oocytes by ultrasound-guided aspiration from the isolated ovaries of Korean native cows were compared between suction methods using manual syringe or vacuum pump. The recovery rate of oocytes using vacuum pump (80.7%) was significantly (P<0.05) higher than that using manual syringe (47.1%). The follicles were counted by their size in diameter with ultrasound image, and recovery rates and grades of follicular oocytes collected by ultrasound-guided aspiration were investigated in Holstein heifers pretreated with or without FSH. A group of heifiers were injected with multiple decreasing doses (twice a day for 3 days) of a total of 400 mg FSH. The other 2 groups were injected with a single dose of 400 mg FSH mixed with 25% PVP. Ultrasound observation of follicle population and/or ultrasound-guided transvaginal oocyte aspiration were performed 12 hrs following the last FSH injection in the multiple dose group, and 48 or 60 hrs after FSH injection in the single dose groups. Most of the visible follicles had small size of less than 3 mm in diameter in unstimulated heifers (71.0%), but medium size in all the heifers treated with FSH. (70.5 to 92.8%). The number of OPU follicles per session (4.6$\pm$1.9) were much less, compared to the vilsible follicle counts (9.7$\pm$2.2), in the nustimulated heifers due to the small dominant follicles. Among 4 goups of heifers the most visible as well as OPU follicles were observed in the heifers at 60 hrs following treatment of a single dose of 400 mg FSH (21.2$\pm$2.3 and 21.0$\pm$2.0), and the differences in both the follicle counts between the groups was found significant (P<0.05) The rates of oocyte recovery from the follicles by ultrasound-guilded aspiration were varied 46.3 to 75.0% in the heifers unstimulated and treated with a single dose of 400 mg FSH, but the group difference was not significant. The number of recovered oocytes per session a, pp.ared to be highest at aspiration at 60 hrs following single FSH (10.6$\pm$2.2) than at aspiration at 48 hrs after single FSH (7.8$\pm$2.7) or in the unstimulated heifers (3.4$\pm$3.0). The proportion of grade I and II oocytes to all oocytes collected was varied 31.8 to 64.0% between the groups. However, there was found no significant difference in both the number of oocytes recovered per session and the percentage and the percentage of grade I and II oocytes. From the above results it was concluded that the more oocytes of superior quality might be recovered economically by ultrasound-guided aspiration at 60 hrs following the pretreatment of a single dose of 400 mg FSH and by suction using a vacuum pump system of about negative pressure of 75 to 85 mmHg.