• Archives of Reconstructive Microsurgery
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• v.1 no.1
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• pp.51-55
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• 1992

Problems of composite tissue transfer commonly arise when a single indispensable recipient vessel receives the graft vssel, and the graft vessel must be sutured in end-to-side fashion so as not todisturb the vascularity of the recipient vessel. The triangular flap in the recipient vessel wall gives an intact endothelial surface when the flow of blood stream is presented and may reduce the chance of anastomosis. We selected mature Wistar rats weighing over 450 grams to compare the conventional longitudinal slit from the triangular flap in the recipient carotid artery over bloood pressure and blood flow when the donor carotid artery was anastomosed in end-to-side fashion. In 30 minutes after anastomosis, maximum blood pressure measured in the donor carotid arterial side when the recipient arterial wall was fasioned with the longitudinal slit was recorded 114 mmHg and with the triangular flap 100mmHg. Minimum blood pressure with the longitudinal slit was 98mmHg and with the triangular flap 88mmHg. The amount of blood collected for 30 seconds in the conventional longitudinal slit was 1.18mg and in the triangular flap 0.78mg. Histology study in 30 minutes, the conventional longitudinal slit demonstrated the more hemorrhagic features around the suture material compared to that of the triangular. flap and, in the 7th day, the conventional longitudinal slit demonstrated the more prominent granulomatous reactions and vascular proliferations around the suture material compared to that of the triangular flap.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.4
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• pp.484-491
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• 1999

Air side heat transfer and pressure drop for ø9.52 fin-tube heat exchanger with various types of slit and louver fins were measured, and compared with wave-slit fin. Longitudinal and transverse tube spacings of the heat exchangers are 21.65mm and 25mm respectively. Actual heat exchanger was tested using water, and the tests were performed for 2 row heat exchangers with 3 different fin spacings, 1.3, 1.5 and 1.7mm. The overall performance of the enhanced fins was evaluated by comparing heat transfer coefficient with respect to fan power.

• International Journal of Air-Conditioning and Refrigeration
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• v.8 no.2
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• pp.29-38
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• 2000

Air side heat transfer and pressure drop for f 9.52 fin-tube heat exchanger with various types of slit and louver fins were measured, and compared with wave-slit fin. Longitudinal and transverse tube spacings of the heat exchangers are 21.65 mm and 25mm respectively. Actual heat exchanger was tested using water, and the tests were performed for 2 row heat exchangers with 3 different fin spacings, 1.3, 1.5 and 1.7 mm. The overall performance of the enhanced fins was evaluated by comparing heat transfer coefficient with respect to fan power

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.627-632
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• 2006

An experimental study is conducted to investigate the effect of the tube row and fin spacing on the air-side heat transfer and friction characteristics of fin-tube heat exchangers with slit fin pattern. A total of twelve samples of fin-tube heat exchangers with the nominal tube diameter of 7 mm, transverse tube pitch of 19 mm and longitudinal tube pitch of 12.5 mm are tested. The thermal fluid measurements are made using a psychometric calorimeter. The raw data are reduced to the desired heat transfer coefficient in terms of j-factor and friction factor of f for various frontal air velocities, fin pitches and number of tube rows.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.10 no.5
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• pp.589-599
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• 1998

Air side heat transfer and pressure drop for fin-tube heat exchanger with wave and wave-slit fins were measured for various fin spacings and number of tube rows. Outer diameter of the tube including fin collar is 10.07mm, and experiments were done with dry surface condition. Longitudinal and transverse tube spacings of the heat exchangers are 21.65mm and 25mm respectively, and wave depth of the wave fin is 2mm. Experiments were conducted for 1, 2 and 3 rows and 3 different fin spacings, 1.3, 1.5 and 1.7mm. An attempt was made to demonstrate advantage of the enhanced fins over the plane fin by introducing the concept of fan power, Effect of the number of tube rows on heat transfer was discussed in connection with general mechanisms of heat transfer enhancement for fin-tube heat exchanger. Also the effect of hydrophilic coating was investigated. Lastly, correlations for Colburn j-factor and friction factor were developed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.6 s.261
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• pp.547-557
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• 2007

This study was conducted to investigate the flow and combustion characteristic of the experimental burner which was manufactured for the reflection of the oven and broil burner features. As slot shape, spacing between slots, and slot arrangement of the exit area which emits the mixing gas are different in case of oven burners and broil turners, the purpose of this study is to know the affection of the flame interaction and combustion characteristic according to the change of shape factors such as slot shape, slot arrangement, and slot-to-slot spacing. With no relation of the slot shape, as the spacing between slots became narrow, the occurrence of a lift-flame was delayed. So the combustion was possible in the leaner region, but the appearance of yellow-tip became a little fast. Slit slot port had the broadest operating range among the other slot shapes. Specially, from the side of lift-flame, as the jet that spreads downstream in the longitudinal slot was nearly circular just a few slot lengths away from the orifice, slot-to-slot spacing of the Slit port was closer than the other ports. These results could be expected through the computer numerical method and had a good agreement. As the spacing between slots increased, in case of Slit and Mix port, NOx emission rate was constant or decreased, but the NOx emission of Hole port was increased. CO emission rate of Slit and Hole port was increased as the slot-to-slot spacing was broadened.

• Journal of Korean Society of Steel Construction
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• v.20 no.1
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• pp.105-119
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• 2008

In steel deck bridges suffering directly on wheel load according to the number of serviced years, the occurrence of fatigue cracks increases in structural details, which includes the cross section parts of the longitudinal rib and transversal rib, and so on. Through the control method for these fatigue cracks the increased thickness of the steel deck plate or the application of retrofit detail to the inside of the longitudinal rib was observed to be effective. This study suggests structural details for the retrofitted and non-retrofitted longitudinal rib. The target details in this study are the connection parts of the lo ngitudinal and transversal rib, and the slit parts of transverse rib where fatigue cracks were frequently reported in previous studies. In the analyses, detailed structural analyses were performed as parameters, which include the shape, change of size and attached position. From the results the stress reduction in the target details was observed to be larger in the retroffited details. Also, the improvement of fatigue strength is more effective in the retrofitted details with the vertical rib than the bulkhead plate.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.11
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• pp.1555-1563
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• 1998

Heat transfer and pressure drop for ${\phi}10.07$ dry surface fin-tube heat exchanger with wave and wave-slit fins were measured for different fin spacings and number of tube rows. Longitudinal and transverse tube spacings of the heat exchangers are 21.65mm and 25mm respectively, and wave depth of wave fin is 1.5mm. The experiments were performed for 4 different fin spacings, 1.3, 1.5, 1.7 and 2.0mm, and the number of tube rows were 1,2 and 3 rows. The present results were compared with the previous results for the wave depth of 2mm. Also hydrophilic coated and bare fins were tested. Correlations for Colburn j-factor and friction factor were developed.

• Journal of Korean Society of Steel Construction
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• v.18 no.4
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• pp.417-426
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• 2006

Various fatigue damages have been reported in orthotropic steel deck structures put upon girders. These damages are caused by complex behaviors of the deck, which is directly subjected to vehicle loads. To estimate the causes of fatigue cracks at the welded connected parts of the trough rib and the flor beam, and the trough rib and the deck plate, in orthotropic steel deck structures, FE analyses were first, performed in this study. Parameter studies were carried out to suggest effective structural details that consider fatigue, in which the main parameters are the thickness of the deck plate, the shape of the connection of the trough rib and the flor beam such as the slit form, and the welding length. This study suggests that the effective structural details improved the fatigue strength and discusses.

• Asian Journal of Turfgrass Science
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• v.13 no.2
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• pp.101-112
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• 1999

Four major scarab beetles, Ectinohoplia rufipes, Adoretus tenuimaculatus, Exomala orientalis and Popillia quadriguttata were obserbved in golf courses. Morphological characters of adults and larvae, feeding habit, mounds by grubs, and outbreak time were inbestigated. Body lengths of E. rufipes and A. tenuimaculatus were 11.5mm and 9.7-11.3mm, respectively and those of E. orientalis and P. quadriguttata were 8.0-13.5mm and 7.6-12.7mm, respectively. Adult of E. rufipes had a tendency to raise hind legs during the feeding and mating but showed no death feigning. On the contrary, A. tenuimaculatus adult did not raise its hind legs during the feding and showed death feigning and dropped to earth when disturbed. E. orientalis adults were mainly found from the flowers of chestnut trees in the daytime and P. quadriguttata adults were chiefly found from soft leaves of herbaceous plants in golf courses. White grubs of E. rufipes and A. tenuimaculatus did not have longitudinal and transversal seatae on anal part but setae on the raster were hooked. The shape of anal slit was Y-shape in E. rufipes and crescent-shape in A. tenuimaculatus. White grubs of E. orientalis had ten to sixteen longitudinal setae on raster and those of P. quadriguttata had medially two conspicuous rows of six or seven shorter straight setae forming a V. Adults of E. rufipes mainly fed on front part of leaves but those of A. tenuimaculatus fed on hind part of leaves. Mounds by earthworms and white grubs were different depending on species. Earthworm piled up sticky soil around exit hole but E. orientalis adult scattered soil one part of exit hole and A. tenuimaculatus adult scattered soil evenly around exit hole. Outbreak time of E. rufipes and A. tenuimaculatus was early May and that of E. orientalis and P. quadriguttata was late May.