• Title/Summary/Keyword: Expansion effect

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A Case Study on the Effect of Damaged Expansion Joint for Safety Assessment of Highway Bridges

  • Kim, Kwang-Il;Chai, Won-Kyu;Lee, Myeong-Gu;Son, Young-Hyun
    • International Journal of Safety
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    • v.9 no.2
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    • pp.16-21
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    • 2010
  • In this study, the variations of transformed impact factors and load carrying capacity of highway bridges measured from the state of expansion joint are evaluated. the field loading tests were performed on the highway bridge with damaged expansion joint to investigate the variation of the load carrying capacity. From the field loading tests in case that damaged expansion joint exist or do not exist, the static displacements and dynamic displacements were measured, and TIF were calculated, respectively. dynamic test is performed in order to estimate dynamic displacement and TIF according to the level of damage of expansion joint. From the results of TIF, the load carrying capacity of highway bridges with damaged expansion joint were estimated.

A Study on the Reactivity Effect due to Expansion of Diagrid and Pad (Diagram와 Pad의 팽창에 의한 반응도 효과에 대한 연구)

  • Young In Kim;Keun Bae Oh;Kun Jong Yoo;Mann Cho
    • Nuclear Engineering and Technology
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    • v.16 no.2
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    • pp.70-79
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    • 1984
  • With the help of the nuclear computational system for a large LMFBR (KAERI-26 group cross section library/1DX/2DB), the reactivity coefficients for the diagrid expansion and the pad expansion at the beginning of cycle of the equilibrium core of SUPER-PHENIX I are calculated and reviewed. the core is described using R-Z geometry model, and a two-dimensional multigroup diffusion theory is used. For reference cases, reactivity calculations for radial and axial uniform expansion are performed, and also calculated are reactivity variations due to changes in material density and core volume. The reactivity coefficient for the diagrid expansion is calculated to be -0.553pcm/mil. The temperature coefficient corresponding to the above value is -1.0766pcm/$^{\circ}C$ and is well in accord with the French datum of -1.09pcm/$^{\circ}C$ within 1.2% difference. With the use of 4he calculational method for the diagrid expansion effect, reactivity calculations for the pad expansion bringing about nonuniform expansion are performed, which show that the calculational method is very useful in the analysis of the pad expansion effect. The reactivity coefficients for the pad expansion are calculated to be -0.2743 pcm/mil and -0.2786pcm1mi1 for the averaged expansion model and for the integrated pancake model, respectively. Under the assumption of the free expanding core the temperature reactivity coefficients for each model are obtained to be -0.5766pcm/$^{\circ}C$ and -0.5858pcm/$^{\circ}C$, both of which agree with the French datum of -0.574pcm/$^{\circ}C$ within 2% difference.

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Effect of Market-Wholesaler System on Market Expansion, Re-transaction Intention, and Recommendation Intention

  • ROH, Gye-Ho;YI, Jong-Hyun;CHO, Young-Sam
    • Journal of Distribution Science
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    • v.18 no.5
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    • pp.99-109
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    • 2020
  • Purpose: This study aims to develop and empirically analyze a research model in order to comprehend the relationship among the service quality of market-wholesaler system, re-transaction intention, and recommendation intention of forwarder. Further, we suggest new six factors reflecting the service quality of market-wholesaler system and highlight market expansion of forwarder as a mechanism in the relationship. Research design, data and methodology: The authors developed the new scales measuring the service quality of market-wholesaler system (i.e. trade price, price fluctuation, payment receipt, settlement period, trade information, and customer service) and conducted a cross-sectional survey for 439 forwarders in a wholesale market. And then we performed a series of path analyses to test hypotheses. The hypotheses are as follows. [H1] The service quality of market-wholesaler system will positively affect forwarders' market expansion, [H2] Forwarders' market expansion will positively affect their re-transaction intention, [H3] Forwarders' market expansion will positively affect their recommendation intention, [H4] Forwarders' re-transaction intention will positively affect their recommendation intention. Results: The results showed that all the six factors for the service quality of market-wholesaler system were positively related to market expansion of forwarders. There was a differential effectiveness in the six factors of the service quality. More specifically, the positive effect of customer service factor was the strongest on market expansion of forwarders. And the respective effects of trade price, price fluctuation, settlement period, trade information factors were followed in order. The positive effect of payment receipt factor was the weakest on market expansion of forwarders. Also, market expansion of forwarders was positively related to their re-transaction intention and recommendation intention. Furthermore, market expansion of forwarders was indirectly related to recommendation intention through re-transaction intention as well. Conclusions: The research findings provide important theoretical and practical implications. This study is the first to attempt to test the perception of forwarders for the service quality of market-wholesaler system by developing and using the new scales. Also, there has been a sharp controversy about the effectiveness of market-wholesaler system. The findings support that market-wholesaler system would be activated by empirically verifying the effectiveness of the service quality on the various outcomes.

The Effect of Treadmill Training with Elastic Bands on the Chest Expansion and Pulmonary Functions of Young Adults

  • Lim, Sang-Wan;Seo, Kyo-Chul
    • Journal of International Academy of Physical Therapy Research
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    • v.2 no.2
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    • pp.301-307
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    • 2011
  • The purpose of this study was an determine whether elastic band on treadmill training might effect the chest expansion and pulmonary function of the 20's men. 40 subjects with experimental group(male: 20) and control group(male: 20) was participated in experiment. During four weeks, each group participated thirty minutes for three times per week. Subjects were assessed using pre-value and post-value measurement chest length(chest length for resting, chest expansion) and pulmonary function(forced vital capacity, forced expiratory volume at one second, FEV1/FVC, peak expiratory flow, vital capacity, tidal volume, expiratory reserve volume, inspiratory reserve volume) by the CardioTouch 3000S(BIONET, USA). These findings suggest that experimental group can be used to improve chest expansion, pulmonary function than control group. In comparison of both groups, post-test was more improved in experimental group. In conclusion, experimental group helped improving function of pulmonary volume and respiratory muscle, and thus it indicates that the functions will be more improved through the continued respiratory exercise program.

Development of the technique for prediction of the hub-hole crack with the punching effect (펀칭 효과를 고려한 허브홀의 파단 예측기법 개발)

  • Lee J. S.;Ko Y. K.;Huh H.;Kim H. K.;Park S. H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2005.10a
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    • pp.362-365
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    • 2005
  • The hub hole is usually formed with a flanging process followed by a blanking process of a ]tole. Since the hole is made by blanking, the blanked surface is so rough that the formability in the region is rather poor. The emerging task is to identify the formability of the blanked region in the forming simulation and to relate the criterion to the real forming process by experiments. In this paper, hole expansion tests are carried out with respect to various hole conditions to verify the hole condition effect on the hole expansion ratio. The hole of specimens is made by machining or punching. In the case of punching, two different punching clearances are used for making the hole. From the results of test, fracture mechanism of the hole expansion is explained.

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The Effect of Fly Ash Replacement on Alkali - Silica Reaction (플라이 애쉬 치환에 따른 알칼리-실리카 반응의 팽창저감 효과)

  • Kim Jung Eun;Jun Ssang Sun;Seo Ki Young;Jin Chi Sub
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.185-188
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    • 2004
  • The effect of fly ash to prevent detrimental expansion due to alkali -silica reaction was investigated through the ASTM C 1260 method that is one of the most commonly used method because results can be obtained within about 16 days. Reactive aggregate used is a netamorphic rock and sedimentary rock. The replacement proportions of portland cement by fly ash were respectively 0, 5, 10, 15, 25 and 35 percent. Expansion of mortar bars due to alkali-silica reaction decreased with the increase of fly ash content. The results show that the expansion due to alkali-silica reaction is dramatically reduced in the presence of high volume fly ash. When the fly ash content examine from all angles (strength and a flow), the replacement proportions of fly ash is about $25\%$ in order to control on expansion.

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Effect of Carbon on the Coefficient of Thermal Expansion of As-Cast Fe-3 0 wt.%Ni-12.5wt.% Co-xC Invar Alloys

  • 김봉서;유경재;김병걸;이희웅
    • Transactions of Materials Processing
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    • v.8 no.3
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    • pp.247-247
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    • 1999
  • The segregation (distribution) of nickel and the composition of its constituents influence the low thermal expansion characteristics (Invar effect) in Fe-30 wt.% Ni-12.5 wt.% Co-xC Invar alloy. The change of coefficient of the thermal expansion and magnetic properties were studied as an aspect of carbon addition causing the segregation of Ni in primary austenite of as-cast Fe-30 wt.% Ni-12.5 wt.% Co Invar alloy. The coefficient of thermal expansion of Fe-30 wt.% Ni-12.5 wt.% Co-xC Invar alloy showed its lowest value at 0.08 wt.% carbon, increased with increasing carbon content in the range of 0.08-1.0 wt.%C, kept constant at 1.0-2.0 wt.%C and decreased at carbon higher than 2.0 wt.%. The effective distribution of the coefficient of nickel in as-cast Fe-30 wt.% Ni-12.5 wt.% Co-xC Invar alloy increased with increasing carbon content. The volume fraction of they phase of Fe-30 wt.% Ni-12.5 wt.% Co-xC alloy increased with increasing carbon content. The microstructure of Fe-30 wt.% Ni-12.5 wt.% Co-xC alloy changed with the carbon content was independent of the coefficient of thermal expansion. The Curie temperature changed linearly with the carbon content and was similar to the change of the coefficient of thermal expansion. Moreover, the coefficient of thermal expansion decreased when the ratio of saturation magnetization to Curie temperature ($\sigma_s/T_c$) increased, decreasing the Curie temperature and showed a specific relationship with the magnetic properties of the Fe-30 wt.% Ni-12.5 wt.% Co-xCInvar alloy.

Effect of Die Geometry on Expansion of Corn Flour Extrudate (사출구 구조에 따른 옥수수가루 압출성형물의 팽화특성)

  • Gu, Bon-Jae;Ryu, Gi-Hyung
    • Food Engineering Progress
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    • v.15 no.2
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    • pp.148-154
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    • 2011
  • The objective of this study was to determine the effect of die geometry on expansion index of extruded corn flour. Water solubility index, water absorption index and specific mechanical energy (SME) input were analyzed to observe the relationship with die geometry. The feed moisture content was 20 and 25%. Die dimensions were tapered angle (57, 95o) and length/diameter (L/D) ratio of die land (0.67, 1.67 and 2.67). The SME input was the highest at 20% moisture content and 2.23E-10 m3 die constant. The sectional and volumetric expansion indices at 20% moisture were increased with increase in die constant. However, die constant did not influence sectional expansion index of corn flour extrudate at 25% moisture content. The extruded corn flour at 25% moisture content had higher longitudinal expansion index than those of extruded corn flour at 20% moisture content. Sectional expansion and longitudinal expansion index were negatively correlated. The water absorption index and water solubility index were not affected with the die constant.

The Effect of Breathing Technique with Aerobic Exercise on the Respiratory Function of Adults (유산소 운동 시 호흡 기법에 따라 호흡 기능에 미치는 영향)

  • Ji-Won Han;Keon-Cheol Lee;In-Seob Kim
    • Journal of The Korean Society of Integrative Medicine
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    • v.11 no.4
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    • pp.135-145
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    • 2023
  • Purpose : The purpose of this study was to discover which breathing technique is more effective in improving respiratory function by applying different breathing techniques-the chest expansion respiratory technique and the abdominal expansion respiratory technique-to adults in the same aerobic exercise situation. Methods : In this study, 30 people were randomly assigned to two groups: chest expansion respiratory technique with aerobic exercise (A group) and abdominal expansion respiratory technique with aerobic exercise (B group). Group A was asked to breathe after wrapping their rib cage with an elastic band, and Group B was asked to breathe after wrapping their abdomen with an elastic band. A total of 3 sets of 30 breaths were performed, 3 times a week for 6 weeks. For statistical processing, an independent t-test was used to verify homogeneity between the two groups, and a repeated measure analysis of variance (ANOVA) was used to compare differences according to the period for each group. Results : The changes in FVC and FEV1 for each group following 6 weeks of intervention are as follows. In comparison according to the intervention period, there was a significant increase in all groups depending on the timing of measurement (p<.05), and as a result of the inter-subject effect test, there was no significant difference between groups (p>.05). In addition, there was no interaction effect between period and group (p>.05). Conclusion : The conclusion of this study is that FVC and FEV1 values increased according to the intervention period in both groups; therefore, it can be suggested that flexible breathing techniques can be applied depending on the patient's physical situation when applying a breathing program to improve respiratory function.

An Experimental Study on Evaporative Heat Transfer Characteristics in Micro-Fin Tubes Before and After Expansion Process (마이크로핀관의 확관 전후 증발열전달 특성에 관한 실험적 연구)

  • 전상희;황윤욱;윤석호;김민수
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.10
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    • pp.932-940
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    • 2000
  • An experimental study on evaporative heat transfer characteristics in micro-fin tubes before and after expansion process has been performed with R-22. Single-grooved micro-fin tubes with outer diameter of 9.52 mm were used as test sections, and it was uniformly heated by applying direct current to the test tubes. Experiments were conducted at mass flow rates of 20 and 30 kg/hr. For each mass flow rate condition, evaporation temperature was set at 5 and $15^{\circ}C$and heat flux was changed from 6 to 11 kW/$m^2$ The evaporative heat transfer coefficient of micro-fin tubes after expansion is decreased because of the crush of fins and enlargement of inner diameter compared to that before expansion. Convective boiling effect decreased remarkably at higher quality range in the micro-fin tube after expansion, and the difference of the heat transfer coefficient in micro-fin tubes before and after expansion was greater for higher quality region. The evaporative heat transfer coefficient of the micro-fin tube after expansion was 19.9% smaller on the average than that before expansion.

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