• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.4
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• pp.478-483
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• 2011

Cast mold has low wear-resistance comparing with other alloyed molds which result in lower production rate and high cost of products. Recently, various weld methods are being applied to increase the wear-resistance of molds and to extend mold life. Among them, nickel alloy weld process increases the hardness irrelevant to its machinability and creates very uniform structures. In addition, it causes better wear-resistance and reduces shrinkage defects. In this paper, we analyze the mold surface cracks welded by nickel alloy and propose the methods to improve the mold surface and its wear-resistance. It has been found that nickel alloy weld does not affect the inside crack of mold but has an influence on the surface crack seriously. Results show that the start and growth of fatigue cracks have been delayed about 3 times and reduced approximately 75%, respectively, and the mold surface cracks are decreased about 5.7 times.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.12
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• pp.66-72
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• 1997

This paper aims at reviewing the possibility application over normal or abnormal, detection used by AE and the wear characteristics of grinding process. In this study, when diamond bur in dentistry with chosen grinding conditions were tuned at grinding. The variation of grinding resistance and AE signal is detected by the use of AE measuring system. The tests are carried out in accordance with diamond burs and workpiece: arcyl and bovine. According to the experiment results, the following can be expected: AE has the possibility to detect the state normality and abnormality. Hpwever, the grinding resistance measuring can find it difficult to detect it. It can be accurately excepted from AE occurrence pattern in contact start point of diamond bur and bovine, grinding condition and derailment point. It is known that AErms is well compatible with grinding resistance. According to the increase of the material removal rate, the specific energy of the diamond bur is inclined to dectease and the grinding resistance has a tendency to increase.

• Journal of The Korean Society of Integrative Medicine
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• v.1 no.1
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• pp.11-22
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• 2013

Purpose : The purpose of this study was to investigate the effects of music intervention upon lighting on stress. Method : The participants 60 college students, were divided three groups. Two groups were apply each music and bright lighting(bright lighting groups) and music and dark lighting(dark lighting groups) during 13minutes at Snozelen and the other group was control group. Each groups were assessed stress resistance, activity of parasympathetic nerve, activity of sympathetic nerve, balance of ANS, physical arousal by EKG of CANS 3000, at before and after other each intervention. The analyses were performed using version of SPSS 17. Result : The change rate of bright lighting group was showed statistically significant decrease in stress resistance compared to control group. And the change rate of dark lighting group was showed statistically significant decrease in resistance stress, activity of parasympathetic nerve, and balance of ANS compared to control group and statistically significant increase in stress resistance and activity of parasympathetic nerve compared to bright lighting group. Conclusion : The results of this study indicate that music intervention on dark lighting is more effective on decrease of stress than application of bright lighting and general lighting.

• Journal of Chest Surgery
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• v.9 no.1
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• pp.20-26
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• 1976

Author has performed experimental study on hemodynamic changes of lung following radical hilar stripping and contralateral pulmonary artery ligation. In view of hemodynamic changes in group 1 (right pulmonary artery ligation only) and group 2(left hilar stripping+right pulmonary artery ligation). group 2 showed remarkable decrease rate in oxygen uptake (P<0.001) and total pulmonary blood flow(P<0.001), and the more increase rate in mean pulmonary artery pressure(P<0.02) and total pulmonary vascular resistance (P<0.001). Meanwhile, the decrease percent of left lung vascular resistance was lower than group 1(P<0.001). The hemodynamic changes in group 1 returned to control range two weeks later. In the group 2, two dogs were expired as a result of atelectasis and pulmonary hypertension. Among allying 8 dogs, five months after operation, follow up studies performed in two dogs, which showed normal pulmonary hemodynamics similar to preoperative data. The altered blood gas values and decreased oxygen uptake are more remarkable in denervated lung, which may due to pulmonary hypertension and partly retained more secretion in bronchial trees than usual. Important factors of raising pulmonary vascular resistance and pulmonary artery pressure are considered as the increased blood flow to remaining left lung and dysfunction of pulmonary vascular bed to accept the increased blood flow after denervation. Loss of nerve innervation had a influence, to some extent, to the decrease of oxygen uptake and the increase of pulmonary vascular resistance and pulmonary artery pressure. There can be little question that denervation does impair the pulmonary hemodynamics, however, intact pulmonary nerve innervation is not absolutely essential for survival of the animal.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.886-895
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• 1993

Experimental were conducted to obtain information on the effect of airflow rates and bed depths on the resistance of coffee cherries and coffee beans available locally (Coffea Liberica). The airflow used were in the range of 0.06 to 0.6 cu. m/s-sq.m. The moisture content of the coffee cherries ranged from 10 % to 50% (wet basis) and that of coffee beans ranged from 12% to 30% )wet basis). Two methods of filling were used i.e. loose fill and packed fill. Pressure drops across the material bed in a vertical column were measured at several depths using inclined manometer. The pressure drop increased directly with air flow rate as well as bed depths. The effects of air flowrates and moisture contents on the resistance in terms of pressure drip per unit bed depth were analysed. The pressure drop per unit depth across the material bed varied slightly due to different depth. The resistance to airflow decreased with the increase in moisture content for loose fill. However, the effect of moisture content is not apparent for packed fill.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.163-172
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• 2022

The purpose of this study is to investigate the changes in the number of repetitions and the repetition rate according to the exercise mode when performing 65%1RM resistance exercise at the 1-minute rest interval and the 3-minute rest interval. Sixteen healthy male subjects were treated with Bench press and Biceps curl of 65%1RM intensity at 1 and 3 minute rest intervals. The number of repetitions for each set of 1 minute rest interval showed a significant decrease from 1set to 5set in bench press. biceps curl showed a significant decrease from 1set to 4set. The repetition rate according to the exercise mode with a 1-minute rest interval showed a significant difference from 2sets to 4sets. In the repetition rate for each set, bench press showed a significant decrease from 1set to 5set. biceps curl showed a significant decrease from set 1 to set 4. The number of repetitions according to the exercise mode with a 3-minute rest interval showed a significant difference from 2sets to 5sets. In the number of repetitions for each set, bench press showed a significant decrease from 1set to 5set. biceps curl showed a significant decrease from 1set to 4set. The repetition rate according to the exercise mode with a 3-minute rest interval showed a significant difference from 2sets to 5sets. In the repetition rate for each set, bench press showed a significant decrease from 1 set to 5 sets. biceps curl showed a significant decrease from 1set to 4set. In summary, the decrease in the number of repetitions according to the set progression in the resistance exercise of the endurance depends on the exercise mode, and the increase of the rest interval or the decrease of the weight-intensity should be considered when aiming for more exercise.

• Journal of the Korean Geotechnical Society
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• v.19 no.1
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• pp.173-180
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• 2003

In spite of its potential importance in the assessment of geosynthetic-related dynamic problems, no serious attempt has yet been made to investigate a probable dependence of dynamic friction resistance of the geosynthetic interface on shear displacement rate. Hence, an experimental study of geosynthetics was carried out on a shaking table, and the relationship between dynamic friction resistance and shear displacement rate of geosynthetic interfaces was investigated. A cyclic, displacement rate-controlled experimental setup was used. The subsequent multiple rate tests showed that interfaces that involve geotextiles have such unique shearing characteristics that shear strengths tend to increase with displacement rate. In contrast, once submerged with water, the shear strength appears to be no longer dependent on the displacement rate, partly due to lubrication effect of water trapped inside the interface. The results of the experimental study can be used in the seismic safety assessment of a landfill cover and slope where the geosynthetic materials are exposed to a relatively low normal stress.

• Food Science and Preservation
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• v.20 no.3
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• pp.289-295
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• 2013

The capacity of a pressure fan can be designed based on the air flow resistance of containers packed with fruits and vegetables in a pressure cooling system. This study was conducted to develop an air flow resistance model that was dependent on changes in the air flow rate and the method of stacking containers. The air flow resistance of a container packed with uniformly shaped balls was 1.5 times greater than the sum of the air flow resistance of a vacant container and that of a wire net container packed with only balls. In addition, the air flow resistance increased exponentially as the width of the stacks increased; however, the air flow resistance did not increase greatly as the length and height of the stacks increased, which indicates that the air flow resistance is primarily influenced by the width of the stack in the air flow direction. The air flow resistance in two lines of stacking was up to 17% less than that of the width of the stack. It was also possible to determine the air flow resistance using a function of the air flow resistance through a single container and develop a prediction model. A prediction model of air flow resistance that is dependent on the stacking method and the air flow resistance of a single container was developed.

• Journal of the Korean institute of surface engineering
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• v.24 no.4
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• pp.179-186
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• 1991

The effects of silicone contents and flow rates(agitation rates) of electrolyte on the formation and mechanical properties of hard anodized film of Al-Si alloy have been studied in 12% H2SO4 + 1% Oxalic acid with varying the silicone contents in the rance of 0 to 11.6% and the flow rates of electrolyte in the range of 0 to 90cm/sec. The film forming voltage required to maintain an equivalent current density significantly increase with the silicone content of Al-Si alloys due to a low conductivity of silicone. Hardness and wear resistance of the anodized film of Al-Si alloys decreases wit increasing the silicone content. The increase in the flow rate of electrolyte has a similar influence on the formation and mechanical properties of anodized film as does the decrease in bath temperature. Hardness of anodized film is rapidly increased with the flow rate being increased from 10cm/sec. It is observed that the increase in the flow rate from 11cm/sec. It is observed that the increase in the flow from 11cm/sec to 48cm/sec is more effective in enhancing the hardness of film than is the decrease in bath temperature from 1$0^{\circ}C$ to $0^{\circ}C$.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.6
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• pp.645-652
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• 2016

A membrane module including grid was designed and introduced to MBR (membrane bio-reactor) for the purpose of better control of membrane fouling. It could be anticipated that the grid enhances the shear force of fluid-air mixture into the membrane surface by even-distributing the fluid-air to the membrane module. As MLSS concentration, packing density which is expressed in the ratio of the housing and the cross-sectional area of membrane fibers ($A_m/A_t$) and air-flow rate were changed, membrane foulings were checked by monitoring fouling resistances. The total fouling resistance ($R_c+R_f$) without grid installation (i.e., control) was $2.13{\times}10^{12}m^{-1}$, whereas it was reduced to $1.69{\times}10^{12}m^{-1}$ after the grid was installed. Regardless of the grid installation, the $R_c+R_f$ increased as the packing density increased from 0.09 to 0.28, however, the increment of resistance for the grid installation was less than that of the control. Increase in the air flow rate did not always guarantee the reduction of fouling resistance, indicating that the higher air flow rate can partially de-flocculate the activated sludge flocs, which led to severer membrane fouling. Consequently, installation of grids inside the housing have brought a beneficial effect on membrane fouling and optimum air flow rate is important to keep the membrane lowering fouling.