• Title/Summary/Keyword: 조기 강도

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A Study on the Impervious Effect of Middle Pressure Grouting Techniques in Using the Environmentally Friendly Impregnation Materials (친환경 주입재를 사용한 중압그라우팅 기법의 차수효과에 관한 연구)

  • Chun, Byung-Sik;Kim, Byung-Hong;Do, Jong-Nam
    • Journal of the Korean Geotechnical Society
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    • v.22 no.12
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    • pp.25-31
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    • 2006
  • This paper studies the field applicability of the Special Chemical grouting Method (SCM) in reinforcing and reducing permeability of the back of an existing continuous wall. SCM uses double rod which imposes intermediate pressure ($981{\sim}9,810kPa$) to disturb, cut, discharge, and mix the ground. It is observed that a bulb is formed by using cement paste and environmentally friendly injection materials with minimal alkali leaching. Uniaxial compression tests, test for chemical properties and fish poison test are performed. Test results indicate that the method results in higher durability, less leaching through the use of the environmentally friendly injection material and faster mobilization of the strength. In addition, field tests confirm the formation of the bulb and the seepage cutoff wall.

Characteristics of early strength development of blended cement according to the addition of C-S-H based Hardening acceleration (C-S-H계 조강제 첨가에 따른 혼합시멘트의 조기 강도 발현 특성)

  • An, Tae-Yun;Ra, Jeong-Min;Park, Jun-Hyung;Kim, Jin-Man
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.11a
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    • pp.127-128
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    • 2022
  • In order to realize carbon neutrality in the international society, research on supplementary cementitious materials(SCMs) has been actively conducted as a way to reduce carbon dioxide emissions in the cement industry. However, the use of SCMs causes problems of initial hydration delay and strength reduction due to the reduction of tricalcium silicate(C3S) in the cement clinker. Therefore, in this study, the initial hydration and basic characteristics of cement mortar were confirmed by adding a C-S-H based hardening acceleration to blended cement mixed with Portland cement, blast furnace slag, fly ash, and limestone power. As a result of the heat of hydration and compressive strength test, it was confirmed that when hardening acceleration was added, the initial reactivity was high, so the heat of hydration was promoted, and the initial strength was increased. It is considered to be due to C-S-H seeding effect. Therefore, it is judged that the use of C-S-H based hardening acceleration can supplement the problem of initial hydration delay of blended cement in Korea.

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Avascular Necrosis of Femoral Head on Bone Scan (대퇴골두 무혈성 괴사의 뼈스캔상의 병기)

  • Yang, Hyung-In;Kim, Eui-Jong;Kim, Deog-Yoon;Ryu, Kyung-Nam;Cho, Kyung-Sam
    • The Korean Journal of Nuclear Medicine
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    • v.28 no.2
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    • pp.206-213
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    • 1994
  • We studied 90 patients(179 femoral heads) with avascular necrosis of femoral head, who had been performed X-ray, bone scan and MRI to compare of the findings of AVN on bone scan between each other, retrospectively. The patients were 82 males and 9 females, their mean age was 45 years. Radiographic stages were classified by Steinberg modification, radionuclide stages were classified as followed; stage o(or type 0) : normal, stage 1 : faint ring like uptake around the femoral head, stage 2: intense ring like uptake, stage 3: irregular increased uptake with central photon defect, stage 4 : Intense diffuse increased uptake at femoral head and stage 5 : hip joint deformity with relatively mild increased uptake. The findings of MRI were classified according to extent, location, early or advanced lesion, signal intensity of the lesion and joint effusion. 156(87%) of 179 femoral heads had avascular necrosis, 68(75.5%) of 90 patients had bilateral AVN, 35 femoral heads had early stage and 120 had advanced stage. The detection rate of AVN by X-ray and bone scan were 85% (134), 91.6% (143), respectively. Early AVN with atypical types of bone scan showed larger extent, moderate to large amount of joint effusion, soft tissue hypertrophy within joint, and secondary degenerative changes. Bone scan had relatively high detection rate in the diagnosis of AVN of femoral head, and demonstrated various types depending on the disease stage.

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Early Changes after Death of Plaice, Paralichthys olivaceus Muscle -4. Effect of Killing Methods on Rigor Index and Breaking Strength of Muscle- (넙치(Paralichthys olivaceus)육의 사후 조기 변화 -4. 치사 방법이 육의 사후 경직도와 파괴 강도에 미치는 영향-)

  • CHO Young-Je;LEE Nam-Geoul;KIM Yuck-Yong;KIM Jae-Hyun;CHOI Young-Joon;KIM Geon-Bae;LEE Keun-Woo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.27 no.1
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    • pp.41-46
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    • 1994
  • This study was undertaken to clarify the effect of killing methods on physical and rheological changes of plaice, Paralichthys olivaceus muscle at early period after death. Plaices killed by the four different methods(1. spiking at the brain instantly. 2. drowning in air. 3. dipping in 1,000ppm ethylaminobenzoate dissolved sea water as an anesthetic. 4. electrifying in sea water.) were stored at $5^{\circ}C$, and the rigor-index and breaking strength through storage were monitored. The longest onset time of rigor-mortis and full rigor was in the samples killed by dipping in sea water with dissolved anesthetic among all samples, where rigor-mortis began at 20hrs after killing and maximum tension was attained after 56hrs. However, in the cases of plaice electrified in sea water or drowned in air, the onset of rigor-mortis began just after killing and maximum tensions were attained after 9hrs and 13hrs, respectively. The level of breaking strength in the muscle of fish killed by spiking the brain instantly was $950.30{\pm}50.23g$, immediately after killing. The value and time reached around the maximum breaking strength for each of the samples were $1,230.60{\pm}30.32g$ and Ohr (immediately after killing) for samples killed by electrifying in sea water, $1,235.83{\pm}35.37g$ and 2.5hrs for drowning samples, $1,186.29{\pm}55.90g$ and 10hrs for spiking samples, and $1,189.67{\pm}50.32g$ and 15hrs for samples dipped in anesthetic, respectively. From the results above, it could be concluded that electrification in sea water is the most effective method in accelerating rigor-mortis and shortening times of reaching the maximum breaking strength of fresh plaice flesh of all the killing methods at early periods after death, whereas dipping in sea water treated with anesthetic was the most effective way in delaying those changes.

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Nutritional and Sensory of Green Leafy Vegetables Cultivated from Medicinal Plant Seed (약용식물 종자로 재배된 쌈잎채소의 영양학 및 관능적 평가)

  • Park, So-I;Kim, Tae-Su;Park, Chun-Geon;Kang, Myung-Hwa
    • Journal of the East Asian Society of Dietary Life
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    • v.22 no.2
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    • pp.271-277
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    • 2012
  • Ten green leafy vegetables were cultivated from medicinal plant seed. Their nutritional content, taste, appearance and texture were evaluated. Moisture content was $91.23{\pm}0.00%$ in $Saururus$ $chinensis$ (Sc), $90.39{\pm}0.05%$ in $Perilla$ $frutescens$ (Pa) and $66.78{\pm}0.05%$ in $Agastache$ $rugosa$ (Ar). The fat content was 8.89% in $Salvia$ $plebeia$ (Sp) and 0.13% in $Peucedanum$ $japonicum$ (Pj). The protein content was $11.1{\pm}0.00%$ in Ar and $0.54{\pm}0.03%$ in Pj. Total sugar content was $20.06{\pm}0.03%$ in $Geum$ $japonicum$ (Gj), $12.73{\pm}0.03%$ in $Coixlacry$ $majobi$ (Cm) and $1.04{\pm}0.03%$ in $Atractylodes$ $japonica$ (Aj). Medicinal leafy vegetables had higher glucose, sucrose and fructose, but lower maltose. Ascorbic acid content was $33.67{\pm}1.40$ mg% in Sc, $27.91{\pm}2.91$ mg% in Pa and $15.68{\pm}1.09$ mg% in At. Chlorophyll content was higher in $Perilla$ $frutescens$ var. $acuta$ Kudo than other leafy vegetables. The evaluation also showed that Cm, Pa and Aj tasted sweeter and had low acidity.

Analysis of Sensors' Behavior and Its Utility for Shallow Landslide Early Warning through Model Slope Collapse Experiment (붕괴모의실험을 통한 산사태 조기경보용 계측센서의 반응성 분석 및 활용성 고찰)

  • Kang, Minjeng;Seo, Junpyo;Kim, Dongyeob;Lee, Changwoo;Woo, Choongshik
    • Journal of Korean Society of Forest Science
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    • v.108 no.2
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    • pp.208-215
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    • 2019
  • The goal of this study was to analyze the reactivity of a volumetric water content sensor (soil moisture sensor) and tensiometer and to review their use in the early detection of a shallow landslide. We attempted to demonstrate shallow and rapid slope collapses using three different soil ratios under artificial rainfall at 120 mm/h. Our results showed that the measured value of the volumetric water-content sensor converged to 30~37%, and that of the tensiometer reached -3~-5 kPa immediately before the collapse of the soil under all three conditions. Based on these results, we discussed a temporal range for early warnings of landslides using measurements of the volumetric water content sensors installed at the bottom of the soil slope, but could not generalize and clarify the exact timing for these early warnings. Further experiments under various conditions are needed to determine how to use both sensors for the early detection of shallow landslides.

Recurrent Early Gastric Cancer with Liver Metastasis Mimicking Pancreaticobiliary Cancer (조기위암으로 위 절제술 후 갑자기 발생한 췌담도암으로 오인되었던 재발성 위암 1례)

  • Byung Hoo Lee;Joo Young Cho
    • Journal of Digestive Cancer Research
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    • v.1 no.1
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    • pp.48-51
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    • 2013
  • We report an unusual case of postoperative early gastric cancer with liver metastasis mimicking pancreaticobiliary carcinoma. A 73-year-old man with early gastric cancer was transferred for endoscopic treatment. The patient underwent endoscopic submucosal dissection for the treatment of the early gastric cancer. The pathological diagnosis was adenocarcinoma with extension to the deep submucosa and some lymphatic invasion. Therefore, subsequent a subtotal gastrectomy was performed. The histological results demonstrated residual adenocarcinoma confined to the mucosa. The resection margin and lymph node metastasis were negative. Thus, he was closely monitored for recurrence every 6 months. After 2 years, he was suddenly suspected of developing liver metastasis and local recurrence. He received a liver biopsy, and the pathological result was poorly differentiated adenocarcinoma. Immunohistochemical staining suggested pancreaticobiliary carcinoma rather than metastatic adenocarcinoma from the stomach or colon, but primary focus was not found. We were sure that the recurrent stomach cancer metastasized to the liver because stomach cancer can show heterogeneous cytokeratin (CK) expression pattern with various histological features. Therefore, no single CK expression pattern has diagnostic value for distinguishing gastric carcinoma. The patient underwent chemotherapy for metastatic stomach cancer.

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Early Prediction of Concrete Strength Using Ground Granulated Blast Furnace Slag by Hot-Water Curing Method (열수양생법에 의한 고로슬래그미분말 혼합 콘크리트의 강도 추정)

  • Moon Han-Young;Choi Yun-Wang;Kim Yong-Gic
    • Journal of the Korea Concrete Institute
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    • v.16 no.1 s.79
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    • pp.102-110
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    • 2004
  • Recently, production cost of ready mixed concrete(remicon) has been increased due to the rising cost of raw materials such as cement and aggregate etc. cause by the upturn of oil price and increase of shipping charge. The delivery cost of remicon companies, however, has been decreased owing to their excessive competition in sale. Consequently, remicon companies began to manufacture the concrete by mixing ground granulated blast furnace slag(GGBF) in order to lower the production cost. Therefore, the objective of this study was to predict 28-day strength of GGBF slag concrete by early strength(1 day-strength, 7 day-strength) for the sake of managing with ease the quality of remicon. In experimental results, the prediction equation for 28 day-strength of GGBF slag concrete could be produced through the linear regression analysis of early strength and 28 day-strength. In order to acquire the reliability, all mixture were repeated as 3 times and each mixture order was carried out by random sampling. The prediction equation for 28 day-strength of GGBF slag concrete by 1-day strength(hot-water method) won the good reliability.

The Performance of Concrete Used High Strength Development Polycarboxylate Superplasticizer (고강도용 폴리카르본산계 고성능 감수제가 사용된 콘크리트의 성능)

  • Lee, Wan-Jo;Kang, Sung-Gu;Hwang, In-Dong;Lee, Jae-Yong;Park, Sung;Chug, Yun-Joong
    • Journal of the Korean Ceramic Society
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    • v.42 no.3 s.274
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    • pp.182-187
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    • 2005
  • There are many kinds of polycarboxylate superplasticizer as a functional classification which are introduced to domestic; Water Reducer, Retention, Ultra High Strength Superplasicizer. These are showed different physical behaviors because of the difference in the chemical system and the manners after cement mixing. In the case of water reducer, when $1.2\% of cement weight used, water reducing which is over $30\% is observed, but it take with segregation and the reduction of slump flow shows over 30 cm after 45 min of concrete produce. In the case of retention, when the same quantity used, water reducing which is about $25\% is observed and slump flow which is up to 45 min shows under 15 cm. And in the case of ultra high strength, when $1.2\% of cement weight used, water reducing which is over $30\% is observed, and slump flow which is up to 45 min recorded fewer than 15 cm. Compressive strength of ultra high strength superplasticizer has take effect of early age strength, and in the condition of specific mixing, 18 h-compressive strength is insured for more than $60\;Kgf/cm^2$ and 24 h-compressive strength is insured for more than $80\;Kgf/cm^2$.

A Case of Heterotopic Pregnancy in a Natural Cycle (자연 생리주기에서 발생된 병합임신 1예)

  • Bae, Sung Jun;Kim, Ju Sun;Kim, Jin Hak;Yun, Yeon Jung;lee, Shin Ae
    • Clinical and Experimental Reproductive Medicine
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    • v.33 no.1
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    • pp.69-69
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    • 2006
  • Heterotopic pregnancy is the coexistency of intrauterine and extrauterine pregnancy. The incidence of heterotopic pregnancy is about 1 to 30,000 pregnancy in a natural cycle. However, the frequency of heterotopic pregnancy has steadily increased because of rising incidence of pelvic inflammatory disease, pelvic surgery and the development of ovulation induction and assisted reproduction. Because heterotopic pregnancy is difficult due to diagnose and it has high morbidity and mortality rate, one should always take this into consideration and should conduct careful and thorough gynecologic evaluation. We have experienced a case of heterotopic pregnancy in a 29-year old woman who presented with acute abdominal pain in a natural cycle and report this case with a brief review of literature.