• 제목/요약/키워드: Differential erosion

검색결과 47건 처리시간 0.188초

Tenosynovial Giant Cell Tumor Showing Severe Bone Erosion in the Finger: Case Report and Review of the Imaging Findings and Their Significance

  • Lee, Kyung Ryeol;Hyun, Chang Lim
    • Investigative Magnetic Resonance Imaging
    • /
    • 제20권2호
    • /
    • pp.127-131
    • /
    • 2016
  • We report a case of tenosynovial giant cell tumor with severe bone erosion in the right fifth finger of a 46-year-old man. Throughout this case review, we describe the imaging findings of tenosynovial giant cell tumor with severe bone erosion and review the literatures regarding osseous lesions caused by tenosynovial giant cell tumor and their significance related to the differential diagnosis and patient treatment.

Dishing and Erosion in Chemical Mechanical Polishing of Electroplated Copper

  • Yoon, In-Ho;Ng, Sum Huan;Hight, Robert;Zhou, Chunhong;Higgs III, C. Fred;Yao, Lily;Danyluk, Steven
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
    • /
    • 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
    • /
    • pp.435-437
    • /
    • 2002
  • Polishing of copper, a process called copper chemical mechanical polishing, is a critical, intermediate step in the planarization of silicon wafers. During polishing, the electrodeposited copper films are removed by slurries: and the differential polishing rates between copper and the surrounding silicon dioxide leads to a greater removal of the copper. The differential polishing develops dimples and furrows; and the process is called dishing and erosion. In this work, we present the results of experiments on dishing and erosion of copper-CMP, using patterned silicon wafers. Results are analyzed for the pattern factors and properties of the copper layers. Three types of pads - plain, perforated, and grooved - were used for polishing. The effect of slurry chemistries and pad soaking is also reported.

  • PDF

Topographical Landscapes and their Controlling Geological Factors in the Cheongryangsan Provincial Park: Lithologic Difference and Faults (청량산 도립공원의 지형경관과 지질학적 지배 요인: 암질차이와 단층)

  • Hwang, Sang Koo;Son, Young Woo;Son, Jin Dam
    • The Journal of the Petrological Society of Korea
    • /
    • 제26권3호
    • /
    • pp.167-181
    • /
    • 2017
  • Cheongryangsan area ($49.51km^2$) has been designated as the Provincial Park in 1982, because it has magnificent aspect and seasonally spectacular landscapes. Especially, Cheongryangsa sitey ($4.09km^2$) has been designated as Noted Scenery No. 23 in 2007, because it has the same topographical landscape as rock cliffs, rock peaks and caves. The most spectacular landscapes are exhibited in the Cheongryangsan Conglomerate and Osipbong Basalt. There are twelve rock peaks on the ridges of the two strata, and many rock cliffs in the several valleys of strata, in which a few caves are formed by differential weathering and erosion. The valleys, in which flow Cheongryang, Bukgok and Cheonae streams, are classified as fault valleys along WNW-ESE faults. The rock cliffs were generated from vertical joints parallel to WNW-ESE faults in the two strata, and the caves were formed by differential weathering and erosion along bedding of sandstones and shales intercalated in the conglomerates. The rock peaks are landscapes formed by differential erosion along crossed vertical joints in the ridges. The vertical joints are developed subparallel to two WNW-ESE faults and a NNE-WWS fault. Therefore the topographical features are caused by existence of the faults and Lithologic difference in the Cheongryangsan Conglomerate and Osipbong Basalt, and by differential weathering and erosion along them.

Diagnosis on performance of turbine flowmeter using differential pressure in the meter (차압을 이용한 터빈유량계 성능 진단)

  • Ha, Young-cheol;Her, Jae-young
    • 유체기계공업학회:학술대회논문집
    • /
    • 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
    • /
    • pp.153-159
    • /
    • 2004
  • We have investigated the feasibility of using differential pressure(pressure drop) of gas turbine meter to diagnose turbine performance degradation caused by mechanical wearing damage and/or dirt buildup or erosion. If the differential pressure between the upstream piping and the throat of a turine meter can be correlated to meter flow rate over the operating range of the meter, then a relatively simple differential pressure measurement in the filed might be used to detect meter performance changes. To test this method, we have conducted two experimental simulation on Straightener Integrated Type(SIT) turbine meter. One is fur dirt buildup on turbine blade, the other is for eccentricity of the blade. Results show that this method provide a reliable measure of performance degradation and is useful maintenance indicator.

  • PDF

MULTI-SCALE DERIVATIVE OF IRREGULAR FUNCTIONS

  • Kim, Tae-Sik
    • Journal of applied mathematics & informatics
    • /
    • 제13권1_2호
    • /
    • pp.393-404
    • /
    • 2003
  • In general, a differential operator can be used as a tool of treating the local properties of given function. However, when the given function is varied with high frequency and has irregular form with non-stationary evolution it may not act its role sufficiently as in case of nowhere differentiable curves. In this paper we introduce a multi-scale derivative as a form of weakened global derivative so that it may explain its semi global diffusion properties as well as local ones for the various irregular diffusion phenomena.

Diagnon of Sjogren Syndrome from a Xerotomia with Multiple Dental Hard Tissue Loss(Case Report) (다발성 치아경조직 결손을 동반한 구강 건조증에서 Sjogren syndrome으로 진단한 증례)

  • Seo, Deok-Gyu;Kim, Jin;Lee, Chan-Yeong;Park, Seong-Ho
    • The Journal of the Korean dental association
    • /
    • 제42권6호통권421호
    • /
    • pp.414-421
    • /
    • 2004
  • Sjogren syndrome is a chronic systemic autoimmune disorder that chiefly involves the salivary gland and the lacrimal gland, resulting in xerostomia and xerophthalmia. Although the exact cause of the disease is not early diagnosis, treatment and observation must be emphasized because of its poor prognosis, such as the high occurrence of malignant lymphoma and other autoimmune disease that may be accompanied. In the present case, a twenty-year-old woman whose chief complaint was multiple dental hard tissue loss and xerostomia, which was misdiagnosed as iron deficiency anemia at first, but through re-evaluation and differential diagnosis it was Sjogren syndrome. the diagnosis approach was discussed in this report, suggesting that Sjogren syndrome should be considered as a differential diagnosis in a with xerostomia.

  • PDF

Geomorphological Environment of Suwon Basin (수원 분지의 지형 환경)

  • Kee, Keun-Doh;Lee, Sang-Whan
    • Journal of the Korean association of regional geographers
    • /
    • 제10권2호
    • /
    • pp.300-312
    • /
    • 2004
  • The geomorphological environment of Suwon Basin consists of two great elements: mountains which surround the basin and plains and low relief hills by differential erosion of granitic area. Nothern and eastern parts of the basin surround with gneissic mountains(Mt. Kwangkyo), southern and western parts of the basin with granitic mountains(Mt. Chilbo, etc). The basin developed on granitic saprolites is composed of two types of sub-order geomorphic elements: flood plains alongside four river(Whangkuji-chon, Seoho-chon, Suwon-chon, Wonchonri-chon) and aligned hills and mounts between the river side plains. While the low down lands provided the spatial condition for the extention of downtown of Suwon, the gneissic mountains have played the positive roles by high ecological dam effects with stable supply of water and purification of air, etc.

  • PDF

Differential antioxidation activities in two alfalfa cultivars under chilling stress

  • Wang, Wen-Bin;Kim, Yun-Hee;Lee, Haeng-Soon;Deng, Xi-Ping;Kwak, Sang-Soo
    • Plant Biotechnology Reports
    • /
    • 제3권4호
    • /
    • pp.301-307
    • /
    • 2009
  • To understand the adaptability of alfalfa (Medicago sativa L.) to chilling stress, we analyzed the antioxidative mechanism during seed germination. The germination rates of six alfalfa cultivars were studied comparatively at $10^{\circ}C$. Xinmu No. 1 and Northstar were selected as chilling stress-tolerant and stress-sensitive cultivars for further characterization. After chilling treatment, Xinmu No. 1 showed higher seedling growth than Northstar. Xinmu No. 1 exhibited low levels of hydrogen peroxide and lipid peroxidation compared with Northstar. In addition, shoots in Xinmu No. 1 treated with chilling showed higher activities of the superoxide dismutase, ascorbate peroxidase (APX), and catalase than those of Northstar, whereas Xinmu No. 1 showed higher APX activity in roots that Northstar. These results indicated that high antioxidation activity in Xinmu No. 1 under chilling stress is well associated with tolerance to chilling condition during germination.

Investigation and Analysis of Shoreline Change using DGPS - Focusing on the Gangnung City Shore in Gangwondo - (DGPS를 이용한 해안선 변화 조사 및 분석 - 강원도 강릉시 연안을 중심으로 -)

  • Lee, Hyung-Seok;Kim, In-Ho
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • 제10권2호
    • /
    • pp.1-10
    • /
    • 2007
  • The tendency of erosion and accretion of the coast has occurred by the wanton development of a shore so that establishing the plans of nature preservation and development according to shoreline change is in demand. In this study, six DGPS positioning are executed in the periodic interval of about 2 months to choose coastal area of Gangnung, Gangwon-do and the observation data which is post-processed about 50cm accuracies on the Gangnung regular service is compared with digital map in 1998 and digital chart in 2006. Comparing DGPS values with shoreline of digital map, we know that erosion has occurred locally around training dike placed in Gangmun harbor and in southern Namhangjin, many accretions has happened near the breakwater of Namhangjin region and partial accretion is occurring in the other area. Therefore DGPS which is an acquisition method suitable for GIS data input is in use to collect the horizontal data and it could be used effectively to measure the shoreline change of time series through the long-term continuous observation by the coastal development.

  • PDF

A study on the relationship between Schmidt Hammer's 'R' and bedrock microforms (기반암 하상 미지형과 슈미트 해머 반발 값과의 관계에 대한 연구)

  • KIM, Jong Yeon
    • Journal of The Geomorphological Association of Korea
    • /
    • 제19권3호
    • /
    • pp.51-69
    • /
    • 2012
  • Physical strength of the rock is the most important factor of resistance to erosion and has been measured through various way. Bedrock microforms, like potholes and grooves, are the forms sculpted by the erosional processes of flow and the location and morphology are strongly affected by the differential erosion. It also assumed that the physical strength of the rock controls the erosion rate and mode of erosion. The schmidt hammer has been used to measure the rock strength in the field for the geomorphological research. To find the relationship between the rock strength and microforms, Schmidt hammer's R(rebound) were measured in the Baeksuktan, middle reach of Gilancheon, Cheongsong, Gyungsangbuk do. The overall values of rebound of the local sandstone showed over 65 in most cases, so it can be regarded as 'very strong'. It is found that the rebound values of the rock surface decreased towards current water level. It also, however, found that there was no systematic differences in rebound values among the topographically high and lows in the bedrock surface. There was no statistically significant difference in rebound values of the area with well developed microforms and others. The values of R from the exposed faces and inside of the microforms are similar. In the case of conglomerate, the part with the gravel showed higher values that the parts with sands. The rebound values are decreased near of(<1cm) the geological discontinuities(including joint and faults), so this line of weakness could be the point of initiation of active erosion to form microforms. However there is large variations in rebound values within this part. It also should be mentioned that topological relation between the strike of the geologic discontinuities and flow direction looks control the mode of erosional processes.