• Title/Summary/Keyword: stone age

Search Result 179, Processing Time 0.023 seconds

Physical and Mechanical Properties of Plantable Block (식생블럭의 물리.역학적 특성)

  • Youn, Joon-No;Noh, Kyung-Hee;Nam, Ki-Sung;Sung, Chan-Yong
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 2001.10a
    • /
    • pp.181-184
    • /
    • 2001
  • This study is performed to examine the development of the plantable concrete using excellent soil compound, crushed stone, stone dust and superplasticizer. The following conclusions are drawn ; The void ratio is in the range of $25.10{\sim}31.40%$ and the compressive strength is in the range of $69{\sim}113kgf/cm^{2}$ at the curing age 28days, respectively. The plant length was showed higher block by 10% stone dust than 20%.

  • PDF

A Study on the Properties of High Fluidity Concrete Incorporating Lime Stone Powder and Fly Ash (석회석 미분말 및 플라이애쉬 치환율 변화에 따른 고유동 콘크리트의 특성에 관한 연구)

  • 조병영;윤길봉;황인성;한민철;윤기원;한천구
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2001.11a
    • /
    • pp.287-292
    • /
    • 2001
  • This paper investigates the properties of high fluidity concrete incorporating lime stone powder and fly ash. Lime stone powder(LSP) and fly ash(FA) contents are varied with. According to test results, as LSP and FA contents increase, fluidity, air content and placeability shows a declining tendency. For the temperature history, both LSP and FA have favorable effects on reducing hydration heat, moreover, LSP reduces hydration heat more than FA. LSP shows undesirable strength loss as its content increases. FA also decreases the strength at early age, but it enhances later age strength. Accordingly LSP is expected to improve the quality at fresh concrete and reduce hydration heat, while it causes strength loss.

  • PDF

A Study on the Attrition Pattern of Posterior Teeth in Adult (성인구치의 교모형태에 관한 연구)

  • 박영식;김영구
    • Journal of Oral Medicine and Pain
    • /
    • v.6 no.1
    • /
    • pp.57-82
    • /
    • 1981
  • The author had collected the full mouth stone model of 277 persons from 20 ages to 60 ages and studied the attrition pattern of posterior teeth paying attention to the teeth cusps on the stone model. All of the attrition patterns were classified by age, sex and analyzed. The results are followings : 1. Attrition patterns of posterior teeth were divided into 64 forms.(expept 3rd molar) 2. There was no significant difference between right & left. 3. Generally early attrition pattern of younger age and late attriction pattern of older age were more prominent in men being compared with sexual difference. 4. Being compared with age group, early attrition pattern showed decreasing tendency and late attrition pattern showed increasing tendency by aging.

  • PDF

Assessment of Relapsing Urolithiasis from K43 with Erosive Gastritis (미란성 위염 환자 K43에서 재발성 요로 결석에 관한 연구)

  • 김재웅
    • The Korean Journal of Food And Nutrition
    • /
    • v.10 no.1
    • /
    • pp.44-52
    • /
    • 1997
  • Nephrolithiasis is the most common disorder of the urinary tract in hospitalized patients, more frequently increased in 30~50 years of age, more common in males than in females, prior right stone to left side, and than upper ureteral stone is found in cultural country, while lower ureteral stone is increased in uncultural country. Stone components are classified as calcium oxalate, calcium phosphate, magnesium ammonium phosphate, uric acid, cystine, and their mixed stone, respectively. According to the pathophysiology of urinary stones, supersaturation/crystalization of inorganic salt concentration in urine, organic matrix, inhibitor deficiency, and epitaxy theory could be based on the stone formation. Not only hypercalciuria, hyperparathyroidism, hyperoxaluria, hyperuricosuria, and cystinuria, but also renal tubular acidosis, hypervitaminosis D, and peptic ulcer, are significantly associated with nephrolithiasis. In this study upper ureteral stone component were analyzed with chemical analysis, infrared spectrum, and image analyzer from K43 patient wit erosive gastritis. As the results, mixed stone of calcium oxalate dihydrate and calcium phosphate apatite was identified, the values of clinical test in blood and urine maintained normal revels. The relapsing urinary stone from K43 have no correlation between factors for stone formation reported early, also have no evidence for risk from erosive gastritis.

  • PDF

Physical Effect of Adding Stone Dust Sludge on the Properties of Cement Mortar (석분슬러지 혼입이 시멘트 모르타르 특성에 미치는 물리적 영향)

  • Seo, Jun-Yeong;Choi, Seon-Jong;Kang, Su-Tae
    • Journal of the Korean Recycled Construction Resources Institute
    • /
    • v.3 no.2
    • /
    • pp.152-158
    • /
    • 2015
  • In order to investigate the feasibility of stone dust sludge as fine aggregate, an experimental study was performed on cement mortar with stone dust sludge. fresh mortar properties and strength with various stone dust sludge replacement ratios were estimated. the replacement ratio adopted in this study was 0, 10, 20, 30%. Flow, air content, and rheological properties were considered as properties of fresh mortar. Compressive strength and flexural tensile strength were measured for strength. The results are as follows. Higher amount of stone dust sludge caused reduction in slump and air content. In the rheological properties, both yield stress and plastic viscosity increased as stone dust sludge content increased up to 20% replacement ratio, but there were no remarkable difference between 20 and 30%. Yield stress increased drastically between 10 and 20%. Compressive and flexural tensile strength results indicated that the strength variation was not significant according to stone dust sludge content, but the strength gain in the early age by adding stone dust sludge was evident. the strength at the age of 28 days however did not show noticeable effect of adding stone dust sludge.

Material Characteristics and Provenance Presumption for Stone Artifacts of Bronze Age from the Hyocheon Site in Gwangju, Korea (광주 효천유적 출토 청동기시대 석기의 재질특성과 원산지 추정)

  • Park, Sung-Mi;Lee, Chan-Hee;Kim, Ji-Young;Jeong, Il
    • Journal of Conservation Science
    • /
    • v.21
    • /
    • pp.5-20
    • /
    • 2007
  • The stone artifacts in Bronze age from the Hyocheon sites in the Gwangju, Korea were studied on the basis of material characteristics and provenance presumptions. The use and rock names of the artifacts are a stone shovel by andesite, the stone grinding pestle by pyrophyllite, the stone sickle by schist and four stone semifinished artifacts by slates. Andesitic stone shovel could be observed easily around the Hyocheon relic site. But, rocks of the stone grinding pestle, the stone sickle, the stone arrowhead and the stone semifinished artifacts could be confirmed typical occurrences of the all kinds of rocks around the Hwasun coal mine area above 10km from the site. These are made the coupled samples with each stone artifact to the same kinds of raw material rocks based on analysis of the lithology and geochemistry. As a result a geochemical evolution trends of both a stone artifact and the rock showed very similar patterns based on normalization using the behavior, enrichment, compatibility and incompatibility of the elements. Therefore, the source rock of the stone shovel was convey from Mudeung mountain possible interpreted that the domestic-type artifacts are distributed in the vicinity of the Hyocheon site. On the other hand, the stone grinding pestle, the stone sickle, the stone arrowhead and the stone semifinished artifacts were convey from the Hwasun coal mine area possible foreign-type stone artifacts interpreted that the source rocks. Consequently, in the foreign-type stone artifacts are should archaeologic research which it can examine various possibilities clearly that the possibility to coming the introduction with the mankind migration, diffusion to dealings of tribe, the captured enemy equipment through the war and the trade with the behavior of the materials.

  • PDF

A Study on the Characteristics of Building the Japanese Castle at the Period of Japanese Invasion of Korea in 1592 and in 1597 (임진왜란과 정유재란시기 왜성 축조방법에 대한 연구)

  • Lee, Hyung-Jae
    • Journal of architectural history
    • /
    • v.18 no.1
    • /
    • pp.31-49
    • /
    • 2009
  • Periodically, the Japanese Castle was created in the domestic of Japan and then 2 Invasions into Chosun was started. The Japanese Castle in the domestic of Japan was repaired several times by the building boom of castle before & after 2 invasions and so the initially-built type of castles was changed. Accordingly, there are much difficulties to understand the original shape of Japanese Castle. Through the Japanese Castle within Korea called as the fossil of Japanese Castle, I would like to examine & consider its building period and characteristics. The terminology called as [Two Side Stone's Wall] is that of castle which is not acknowledged in the Japanese Academic Circles. However, it means the two-fold wall of Japanese Castle which was widely applied to the fortification way in the Age of Japan Edo. The terminology of [Sori] says the stonework curve in the corner of Japanese Castle which is indicated best in the Japanese Castle. It calls the curve as like the fan frame. [Curb Stone's Wall] says the type of castle wall constructed with over 1 face in wall body of Japanese Castle. (1) About classifying the construction period of Japanese Castle, the curb stone's wall and the castle having no two side stone's wall must consider the building period as that of Japanese Invasion of Korea in 1592. If there was [Sori], the two-side stone's wall was used and the place which supported the documentary data, in particular, the place having the record of contraction is considered to be confirmed as the castle constructed in the period of Japanese Invasion of Korea in 1597. (2) The two-side-type stone's wall shown in the Modern Japanese Stone Castle is difficultly considered to be generated from the Japanese Castle at the period of Japanese Invasion of Korea in 1592 and in 1597. (3) The beautiful [Sori] shown in the Modern Japanese Stone Castle was started from the Japanese Castle of Korea at the period of Japanese Invasion of Korea in 1597. It is difficultly considered which its indication was firstly generated by the Chaesung-Folded Segment Structure.

  • PDF

Comparison of three different endoscopic approaches in the treatment of bladder calculi

  • Jang, Jae Youn;Ko, Young Hwii;Song, Phil Hyun;Choi, Jae Young
    • Journal of Yeungnam Medical Science
    • /
    • v.36 no.1
    • /
    • pp.16-19
    • /
    • 2019
  • Background: This study compared the following three endoscopic techniques used to treat bladder stones: transurethral cystoscope used with a pneumatic lithoclast or nephroscope used with a pneumatic lithoclast and nephroscope used with an ultrasonic lithoclast. Methods: Between January 2013 and May 2016, 107 patients with bladder stones underwent endoscopic treatment. Patients were classified into three groups based on the endoscopic techniques and energy modalities used in each group as: group 1 (transurethral stone removal using a cystoscope with pneumatic lithoclast), group 2 (transurethral stone removal using a nephroscope with pneumatic lithoclast), and group 3 (transurethral stone removal using a nephroscope with ultrasonic lithoclast). Baseline and perioperative data were retrospectively compared between three groups. Results: No statistically significant intergroup differences were observed in age, sex ratio, and stone size. A statistically significant intergroup difference was observed in the operation time-group 1, $71.3{\pm}46.6min$; group 2, $33.0{\pm}13.7min$; and group 3, $24.6{\pm}8.0min$. All patients showed complete stone clearance. The number of urethral entries was higher in group 1 than in the other groups. Significant complications did not occur in any patient. Conclusion: Nephroscopy scores over cystoscopy for the removal of bladder stones with respect to operation time. Ultrasonic lithoclast is a safe and efficacious modality that scores over a pneumatic lithoclast with respect to the operation time.

A Study on the Age Estimation Based upon Attrition of Molars (증령에 따른 구치의 학모면적비에 관한 연구)

  • 양무도;이승우
    • Journal of Oral Medicine and Pain
    • /
    • v.6 no.1
    • /
    • pp.91-100
    • /
    • 1981
  • The author collected 146 men's stone models and 175 women;s stone models over the age of twenties, and studied area ratio of attrition of molars. Area ratio of attrition = (area of attrition / area of occlusal surface)*100(%) All data were analyzed by means of statistical method, and following results were obtained. 1. There was correlation between age and area ratio of attrition, that is, area ratio of attrition was increased with aging process. 2. Regression equtions and coefficients of correlation showed a significant meaning. 3. Generally, upper teeth showed higher tendency of area ratio of attrition, being compared with lowers. 4. Being compared with male and female, there was no uniform difference.

  • PDF

Study on the Characteristics of the Stone-Cultural Properties and Weathering Phenomena of the Rocks for Conservation( I ) - Yongin-gun and Eechon-gun, Gyeonggi-do - (보존을 위한 석조문화재의 특징과 암석에 대한 연구( I ) -경기도 용인군과 이천군-)

  • Park, Kyung Rip;Lee, Sang Hun;Shin, Jong Won
    • Journal of Conservation Science
    • /
    • v.5 no.1 s.5
    • /
    • pp.41-68
    • /
    • 1996
  • Stone-cultural-properties, distributed In the area, have been investigated and studied on the characteristics and the rock phases in the geological and conservational point of view. Stone-Buddhas in the area can be subdivided into Maebul-, General -, and Massive rock-types according to their styles. The rocks used in these stone-cultural-properties are mainly massive, coarse grained biotite granite of the Jurassic age, which is widely distributed around the Reckon-gun area. However, quartz-feldspathic banded gneiss, marble, phyllite and hornblendite are also used. These rocks are mainly distributed in the Yongin-gun area. This suggests that the rocks used. These rocks are strongly influenced by chemical weathering so that the rock surface is very irregular with $2\~3mm$ relief. Biotite granite used shows generally weathered surface of brown color due to chemical weathering of feldspars. Moss are pervasive partly on the surface to show black and/or green colors. The strong weathering may induce secondarily to appear the igneous lineation, onion-structure, and/or minor cracks latent in the rocks. The cultural properties In the area are relatively well conserved except Maebuls and one(Duchangri 3-story) pagoda. However, one stone-buddha may be grinded recently by machine to take off the weathered surface resulting in the loss of its age and the original detailed shape. For conservation, they must be scientifically considered on the shape, kind of the rock phase and characteristics of the weathered phenomena.

  • PDF