• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2003.11a
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• pp.313-323
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• 2003

The sliding wear behaviors of Zircaloy-4 nuclear fuel rod were investigated using two support springs with convex and concave shapes in room temperature air and water. The main focus is to compare the wear behavior of various test variables such as slip amplitude, environment, contact contours with different spring shape and a number of cycles. The results indicated that wear volume and maximum wear depth increased with slip amplitude in both air and water, but their trends tended to change according to the spring shapes and test environments. In air condition, the wear volume was controlled by wear debris behavior generated on worn surface. As a result, final wear volume and maximum wear depth decreased if a ratio of protruded wear volume to worn area $(D_p)$ would be saturated to specific value. This is because wear particle layer could accommodate large strain by accumulating and transforming wear particle layer. However, in water condition, metal-to metal contact was more dominant and wear volume was greatly affected by changed mechanical behavior between contact surfaces since wear debris should be generated after repeated plastic deformation and fracture. After wear test, worn surfaces were examined using optical microscope and SEM and details of wear mechanism were discussed using a ratio of wear volume to worn area $(D_e)$ at each test condition.

• The International Journal of Costume Culture
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• v.7 no.2
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• pp.135-150
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• 2004

The purpose of this study is to explicate the contemporary concept of the term 'sportswear' by studying the history of sportswear tradition in America where sportswear was first established and developed. American sportswear originated from some functional clothes made for specific sports during the 19th century. Early in 20th century, there occurred many significant events in America while Americans were undergoing two successive world wars. First of all, due to the wars, women's role in labor force became so significant that their social status was enhanced remarkably. With economy growing every decade, the amount of leisure time for American people substantially increased and, therefore they could develop their leisure activity culture. All these changes made Americans demand the need for comfortable and functional clothes suitable for their changed way of life. In response to this demand, the sportswear tradition became mature due to the contribution by many creative All-American designers, most of whom have made their active contributions since 1970s. Now the sportswear, which used to be designed for specific sports, developed into casual wear in general with its extended definition. The contemporary concept of sportswear is no longer limited to those clothes for specific sports. Sportswear has now become more like a casual activity wear which all classes of people can enjoy in their life. Since the concept and scope of sportswear is extended to a great degree today, we need a new professional term to correctly express the extended nature of these contemporary clothes.

• Advances in biomechanics and applications
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• v.1 no.3
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• pp.159-167
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• 2014

The aim of this study was to evaluate the influence of disc thickness on the normal behavior of the temporomandibular joint. Based on a specific patient case, CT scan images showing accentuated wear in the right disc were reconstructed and the geometrical and finite element model of the temporomandibular joint structures (cranium, mandible, articular cartilages and articular discs) was developed. The loads applied in this study were referent to the five most relevant muscular forces acting on the temporomandibular joint during daily tasks such as talking or eating. We observed that the left side structures of the temporomandibular joint (cranium, mandible and articular disc) were the most affected as a consequence of the wear on the opposite articular disc (right side). From these results, it was possible to evaluate the differences in the two sides of the joint and understand how a damaged articular disc influences the behavior of this joint and the possible consequences that can arise without treatment.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.11a
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• pp.78-87
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• 2001

The friction and wear behaviors of WC/C multilayer coating were investigated by using a pin on disk type tester. The experiment was conducted by using silicon nitride (S $i_{3}$ $N_{4}$) as a pin material and WC/C multilayer coating on bearing steel (STB2) as a disk material, under various environments that are atmospheric conditions of high vacuum( 1,3$\times$10$^{-4}$ Pa), medium vacuum( 1.3$\times$10$^{-l}$Pa). ambient air( 10$^{5}$ pa)(3 types) and relative humidity(2~98%) conditions. The results showed that WC/C coating fracture was suddenly increased with increasing degree of vacuum, because of high adhesion. So, WC/C coating could not be displayed their ability as solid lubricant. WC/C coating could be displayed better abilitv as solid lubricant with increasing relative humidity. because of oxide film, size and shape of wear debris. The friction coefficient and specific wear rate became better about RH 50%.%.

• The Research Journal of the Costume Culture
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• v.10 no.5
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• pp.518-531
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• 2002

The purpose of this study was to research specific dimensional increments of grading and to support to establish a grading system according to the targets of women's wear manufacturers in Korea. For the questionnaire, 91 women's wear brands, which were in higher ranking of sales, were selected, and the age groups were separated into 3: 20's, 30's, and 40's & 50's, according to their customers. The graders of each brand were questioned about specific dimensional increments of grading fur this research. The results of the study were as follows: 1. Using the most common dimensional increments, 3.81cm(1 f inch) and 5.08cm(2 inch) for upper garments and lower garments, the modes of increments and reference increments for each garment section were suggested. 2. For upper garments, the brands for older women made larger increments of waist girth than for bust girth. This was to cover abdominal obesity. Also, the brands made larger increments of girth than for shoulder breadth. 3. For lower garments, the brands for older women made larger increments of waist girth than fur hip girth. It meant the drop value of hip girth minus waist girth was smaller. The breadths of front and back crotch were also wider.

• The Korean Journal of Ceramics
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• v.3 no.1
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• pp.47-51
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• 1997

The dense sintered bodies of Si/SiC composite with various Si contents could be fabricated by changing the green density in the forming process. The Si/SiC/graphite composites with various graphite contents could be also fabricated by changing a graphite content in the starting composition. Their mechanical and tribological properties were characterized and wear mechanism was also studided. The hardness and strength of the Si/SiC and the Si/SiC/graphite were decreased with increasing the contents of free Si and graphite, respectively. However, the friction coefficient and specific wear rate had no specific relations to their hardness and strength. Adhesion of free Si was a main factor to determine a wear resistance of the Si/SiC composite. In the case of the Si/SiC/graphite, solid lubricationl and liquid reservoir of the graphite particles played the main role of the reduction of the friction force. In the torque test to estimate the possibility of practical of practical applications, the value of torque between the Al2O3 disk and Si/SiC/graphite disk was 1/6 lower compared with two $Al_2O_3$ disks on the basis of 100,000 cycles.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1859-1863
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• 2007

A new type of a fretting wear tester has been designed and developed in order to simulate the actual vibration behavior of a nuclear fuel rod for springs/dimples in room temperature. When considering the actual contact condition between fuel rod and spring/dimple, if fretting wear progress due to the flow-induced vibration (FIV) under a specific normal load exerted on the fuel rod by the elastic deformation of the spring, the contacting force between the fuel rod and dimple that were located in the opposite side should be decreased. Consequently, the evaluation of developed spacer grids against fretting wear damage should be performed with the results of a cell unit experiments because the contacting force is one of the most important variables that influence to the fretting wear mechanism. Therefore, it is necessary to develop a new type of fretting test rig in order to simulate the actual contact condition. In this paper, the development procedure of a new fretting wear tester and its performance were discussed in detail.

• Journal of Powder Materials
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• v.11 no.6 s.47
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• pp.451-461
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• 2004

Dry sliding wear behavior of electro-pressure sintered Co-Fe and Co-Ni compacts was investigated. Pin-on-disk wear tests were performed on the sintered Co-Fe, Co-Ni disks against alumina $(Al_2O_3)$ and silica $(SiO_2)$ balls at various loads ranging from 3N to 12N. A constant sliding speed of 0.1m/sec was employed. Wear rate was calculated by dividing the weight loss of a specimen by the measured specific gravity and sliding dis-tance. Worn surfaces and cross-sections of the specimens were examined using an SEM and EDS to investigate wear mechanism of the compacts. The wear behavior of the compacts were discussed as a function of their com-position. Effects of mechancial properties of the compact as well as oxide layers formed on wearing surface on the wear were also discussed.

• Journal of the Korean Institute of Gas
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• v.12 no.4
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• pp.52-57
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• 2008

This paper studies on the wear corrosion behavior of induction hardening high strength cast iron in the acidic environments. In a variety of pH solutions, wear corrosion behavior of GC 300 with a variety of contact pressures was investigated, and corrosion wear behavior after immersion test was considered. Also, electrochemical polarization test for GC 300 was carried out in various pH solutions. The main results are as following: In the strong acidic environment, wear corrosion rate of GC 300 appears highly and in the neutral environment is stable. Also, graphitic corrosion in the strong acidic environment occurs. The corrosion current density of GC 300 becomes high in a order of pH 1 > pH 2 > pH 4 > pH 6.5.

• Journal of the Korean Society of Costume
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• v.60 no.4
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• pp.126-145
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• 2010

The purpose of this research is to classify the design features of twentieth century women's tennis wear. The specific research questions are; how tennis has developed and what is the relationship between tennis wear and modern dress? What are the important developments in women's tennis wear design in the twentieth century? What are the characteristics exhibited in each decade in women's tennis dress? This paper conducted current research by considering the women's tennis wear as a background of dress simplification. Forty pictures showing tennis wear from international tennis games' catalogues and literatures were selected for this study. Researchers employed a qualitative research method providing a systematic review of the previous studies analyzed by content. The results show that sportswear has become an important trend in contemporary fashion. Tennis wear also had influence on modern dress. Current development is concentrated on functional new materials and sports marketing.