검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 211

        22.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        OBJECTIVES : The objective of this research is to determine the moisture resistance of the freeze-thaw process occurring in low-noise porous pavement using either hydrated-lime or anti-freezing agent. Various additives were applied to low-noise porous asphalt, which is actively paved in South Korea, to overcome its disadvantages. Moreover, the optimum contents of hydrated-lime and anti-freezing agent and behavior properties of low-noise porous asphalt layer are determined using dynamic moduli via the freeze-thaw test. METHODS: The low-noise porous asphalt mixtures were made using gyratory compacters to investigate its properties with either hydratedlime or anti-freezing agent. To determine the dynamic moduli of each mixture, impact resonance test was conducted. The applied standard for the freeze-thaw test of asphalt mixture is ASTM D 6857. The freeze-thaw and impact resonance tests were performed twice at each stage. The behavior properties were defined using finite element method, which was performed using the dynamic modulus data obtained from the freezethaw test and resonance frequencies obtained from non-destructive impact test. RESULTS: The results show that the coherence and strength of the low-noise porous asphalt mixture decreased continuously with the increase in the temperature of the mixture. The dynamic modulus of the normal low-noise porous asphalt mixture dramatically decreased after one cycle of freezing and thawing stages, which is more than that of other mixtures containing additives. The damage rate was higher when the freeze-thaw test was repeated. CONCLUSIONS : From the root mean squared error (RMSE) and mean percentage error (MPE) analyses, the addition rates of 1.5% hydrated-lime and 0.5% anti-freezing agent resulted in the strongest mixture having the highest moisture resistance compared to other specimens with each additive in 1 cycle freeze-thaw test. Moreover, the freeze-thaw resistance significantly improved when a hydrated-lime content of 0.5% was applied for the two cycles of the freeze-thaw test. Hence, the optimum contents of both hydrated-lime and anti-freezing agent are 0.5%.
        4,000원
        23.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A nineteen years old male patient showed a cystic lesion in left maxillary canine to premolar area (#23-#25). This lesion was asymptomatic, and found during his routine radiological check in local clinic. In the radiological observation the cystic lesion showed round radiolucent image containing many calcified bodies which were usually small but irregular in shape, expanding tumorously and resulted in the displacement of canine and second premolar in the absence of first premolar. The lesion was surgically enucleated, and a cystic fibrous tissue containing abnormal teeth was removed and examined pathologically. With the histological observation of tumorous odontogenic epithelium including many ghost cells, which were closely associated with abortive teeth, the lesion was finally diagnosed as CCOT associated with complex odontoma. The ghost cells of CCOT was strongly positive for β-catenin, GADD45, and LC3, and slightly positive for MMP-9, while they were rarely positive for BCL2, Wnt1, HSP-70, and p38. Therefore, it was presumed that the ghost cells of CCOT might undergo dormant cell state through altered cytodifferentiation stimulated by severe growth arrest, DNA damage signaling, and abundant autophage formation.
        4,000원
        24.
        2016.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        중심부 석회화를 동반한 간내 담관암은 국외에서 1예 보고 되었을 정도로 매우 드문 증례이며, 담관내 석회화 소견을 보이는 환자의 감별진단에 있어서 간내 담도암에 대한 고려 와 조직검사가 필요할 것으로 판단되어 중심부 석회화가 동반된 간내 담관암 증례를 보고하는 바이다.
        4,000원
        25.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was to investigate the firing method of limestone in Joseon Dynasty, and analyze the physical·chemical properties of lime mortars in Joseon Dynasty. This study was to manufacture and evaluate the firing experiment and mortar of Limestone by each sort in order to reproduce the traditional lime mortars in Joseon Dynasty, and investigate the behavior to improve physical properties according to the firing method of Limestone. This study has found out that there were screening criteria and standard of appropriate firing temperature about the Limestone in Joseon Dynasty. Accordingly, this study was to improve its strength through various additives and mixture. In particular, in case of Limestone, the black and blue Limestone were preferred, and most of domestic Limestones were low grade Limestone including the clay and took ivory white or blue with low whiteness. This study has shown that the low grade Limestone was mined by the surface mining compared with the high grade Limestone as underground mining method, and could be used because it was easy to mine relatively and there was possibility that Natural Hydraulic Lime(NHL) was used with the traditional lime mortars in Joseon Dynasty.
        4,000원
        26.
        2016.06 구독 인증기관·개인회원 무료
        The effect of hydrated lime (HL) as an antioxidant (AO) for retarding aging of asphalt mixture using the large molecular size (LMS) of gel-permeation chromatogram (GPC) technique. A HL were used for preparing dense-graded asphalt (DGA) mixes to examine the effect of the HL on age retardation. The asphalt mixtures prepared with and without HL were aged artificially in two stages; the short-term aging (SA) for 1, 2, 4 hour at 160℃ and 180℃ on the loose mixes, and the long-term aging (LA) for 68 hours at 110℃ on the specimen. The specimen ( =100mm) of SA-treated mix was compacted to the air void of 7% using a gyratory compactor. The LMS values were used for estimating absolute viscosity (AV) for evaluating aging level and age- retardation effect in terms of viscosity. It was observed that the asphalt mixes which were short-term aged at 180℃ for over 2 hours were significantly aged, compared with the mix which was short-term aged for 1 hour at 160℃. It was also found that the use of 1.5% HL by wt. of mix resulted in a significant reduction of binder aging of SA and LA treated mixes. It was concluded that the HL did apparently have an effect of reducing aging of asphalt in the mixes after SA and LA. This result will be an applicable information for retarding aging of the field HMA mixture which is carried in the dump truck at hot temperature for 2-4 hours.
        27.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: It is theoretically well known all over the world, that porous hot mixed asphalt (HMA) with hydrated Lime improves moisture and rutting resistance, and reduces pothole occurrence frequency, as well as the life cycle cost (LCC). METHODS : Addictive in the two different formations of the liquid anti-stripping Agent and powder Hydrated-Lime was applied in this investigation in order to obtain relatively clear results according to their types and conditions. Firstly, the moisture conditions were set, and applied to the porous HMA mixtures with hydrated lime (anti-stripping agent). Next, it was followed by a non-destructive test with the application of three freeze-thaw cycles, which were individually carried out thrice to compare the results of the dynamic moduli. Lastly, the hydrated lime effect related to moisture sensibility to porous HMA has been verified through the analysis of the modulus results regarding the change rate of dynamic modulus per n-cycle. RESULTS: It is clear from this investigation, that the dynamic modulus is inversely proportional to the change in temperature, as the graph representing the rigidity of the thermorheologically simple (TRS) material showed gradual decline of the dynamic modulus with the increase in temperature. CONCLUSIONS: The porous HMA mixture with the anti-stripping agent (hydrated Lime) has been found to be more moisture resistant to freezing and thawing than the normal porous HMA mixture. It is clear that the hydrated lime helps the HMA mixture to improve its fatigue resistance.
        4,200원
        28.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The hydrated lime-modified asphalt, which improves moisture resistance, is normally used for pavements to reduce the number of potholes. However, the method of applying the material properties of the lime-modified asphalt mixture for use in pavements is not covered in the Korean Pavement Research Program (KPRP). The objective of this research is to find a method for the design application of lime-modified asphalt’s material properties to the KPRP. METHODS: The section for test design is selected in some conditions which are related to the level of design regarding Annual Average Daily Traffic (AADT). To define the application methods of hydrated lime in the KPRP, the models of fatigue, rut and international roughness index (IRI) are determined based on the M-EPDG test results from some earlier research results. Moreover, it is well known that dynamic moduli of the unmodified mixture are not different from those of the lime-modified mixture. RESULTS: The performance results of hydrated lime-modified asphalt pavement were not very much different from those of the unmodified pavement, which meant the limited design regulations regarding fatigue failure, rutting deformation and IRI. CONCLUSIONS: The KPRP uses the weather model from the data for previous 10 years. It implies that the KPRP cannot predict abnormal climate changes accurately. Hence, the predictive weather data regarding the abnormal climate changes are unreliable. Secondly, the KPRP cannot apply the moisture resistance of asphalt mixtures. Therefore, a second level of design study will have to be performed to reflect the influence of moisture. It means that the influence on pavement performance can be changed by the application of hydrated lime in asphalt mixture design.
        4,000원
        29.
        2015.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Calcifying cystic odontogenic tumor (CCOT), also known as calcifying odontogenic cyst or Gorin cyst is a rare developmental lesion which arises from odontogenic epithelium. It has been classified as a benign odontogenic neoplasm related to odontogenic apparatus by the World Health Organization. CCOT may be associated with other odontogenic tumors, most frequently odontoma, a finding that is a rare event in other types of odontogenic cysts or tumors. This report describes a case of hybrid odontogenic tumor composed of CCOT and ameloblastic fibroma-odontoma of the impacted right maxillary canine region that occurred in a 14-year-old female.
        3,000원
        30.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        16 water treatment plants(WTPs) in Jeju province were investigated to evaluate the corrosivity of tap water. In addition, the impacts of lime and carbon dioxide on LI changes at ES WTP were analyzed. The average of LI in Jeju tap was -1.78 which was similar to that of in-land multi-regional WTPs. The recommended process to improve LI of ES WTP which has high corrosivity(i.e., LI = -2.61) was to combine lime and carbon dioxide with the dosages of 20 mg/L and 5 mg/L respectively to meet LI of -1.0 ~ 0. pH was confirmed to be a major water quality parameter that determined LI based on the correlation results among LI and water quality parameters. Precaution on turbidity increase by lime addition should given to minimize particle breakthrough in the distribution system. Turbidity increase can be controlled by the addition of lime prior to filters.
        4,000원
        32.
        2014.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 석회암이 나출되어 있는 덕항산지역 주요 산림식생을 중심으로 그 유형을 분류하고 군락지리적 특성을 분석하였다. 덕항산 능선부 일대 산림식생의 유형은 1개 군락군(신갈나무군락군), 3개 군락(개회나무-조록싸리군락, 소나무-철쭉군락, 소사나무-솔체꽃군락), 2개 군(소사나무-회양목군, 까치박달-사창분취군), 2개 소군(들메나무-부채마소군, 털댕강나무-솔나리소군)으로 총 5개 유형으로 구분되었다. 덕항산 군락지리형은 지형적 특이성, 아고산지대와의 인접성, 석회암 지대 등의 특징을 잘 나타내고 있다. 그리고 배수가 잘되는 약건조지에 출현하는 털대사초, 가는잎그늘 사초 등의 고상재도는 석회암지대의 토양환경을 잘 대변해 주고 있으며 북방계 식물인 싸라기사초, 돌좀고사리 등은 인접한 아고산 식생의 특성을 보여주고 있다. 그리고 소사나무의 출현은 서식지 특이성에 의한 피난식생 특징을 나타내고 있는 것으로 생각된다. 본 연구 지역의 군락지리학적 특이성은 서식지 및 식물지리적 특이성이 결합되어 나타나고 있다. 그리고 식생학적 측면에서 한반도 군락 및 서식지 유형의 다양성 증진에 기여할 것으로 생각된다.
        4,000원
        33.
        2014.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to investigate the association between carotid artery calcification (CAC) on panoramic radiograph and intima-media thickeness (IMT) measured on ultrasound. Panoramic radiographs which were taken from dental patients aged 50 years and older who visited for dental treatment were screened for the presence of CAC. The study group was composed of seven patients (four males and three females, average age 74.4±4.2 yrs) with CAC detected on panoramic radiographs, and the control group eleven patients (seven males and four females, average age 64.5±10.1 yrs) without CAC. All the patients underwent carotid ultrasonography to measure carotid IMT. The IMT was compared between the groups by nonparametric analysis of covariance (ANCOVA). The range of IMT of the study group was 1.10~2.0 mm, while that of the control group 0.60~1.10 mm. The mean of IMT was 1.50±0.34 mm in the study group and 0.85±0.14 mm in the control group, and there was statistically significant difference between the two groups (p<.01). In conclusion, CAC detected on panoramic radiograph might have an association with atherosclerosis
        4,000원
        34.
        2013.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        담낭신경내분비종은 드물게 발생하는 일차성 담낭암이며, 전산화단층촬영이나 초음파와 같은 통상적인 영상검사로 쉽게 발견되지 않는다. 석회화담낭 역시 드물기 때문에 석회화담낭을 동반하는 신경내분비종은 매우 희귀하다. 명치부위 통증을 주소로 내원한 75세 여자환자가 전산화단층촬영에서 석회화담낭과 다엽성 종괴가 발견되어 확대 담낭절제술을 시행하였고, 최종 병리소견으로 담낭신경내분비종과 석회화담낭이 확진되었다. 석회화담낭을 동반하는 담낭신경내분비종은 이전에 보고된 바 없기에 저자들은 이를 문헌고찰과 함께 보고하는 바이다.
        3,000원
        37.
        2013.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        논의 99Tc 오염 시 소석회와 유기질 비료의 토양 첨가가 쌀알 내 99Tc 농도 저감 대책으로서 유용한지 알아보기 위하여 온실 내에서 두 가지 논토양에 대해 포트실험을 수행하였다. 모내기 15 일 전에 약 20 cm 깊이에 해당하는 상부 토양을 상기 농용 물질과 99Tc로 처리하였다. 처리 효과는 토양 중 농도에 대한 작물체 내 농도의 비로 정의되는 전이계수(TF)로 비교하였다. 대조 작물체의 경우 두 토양에서 현미 TF 값은 4.1×10-4 및 4.3×10-4였다. 각종 유형의 첨가 중에서 한 토양에 대해 60%정도의 TF 값 감소를 나타낸 소석회 저수준 첨가(약 0.6 kg m-2)만이 대책으로서 이용 가능성이 있을 것으로 판단되었다. 다른 한 토양에서는 동 첨가의 효과가 거의 없었으므로 다수의 토양에 대한 평균적인 효과를 알아내는 것이 중요하다. 두 가지 다른 수준의 유기질 비료의 첨가는 모두 TF 값을 증가시켰다. 위보다 더 낮은 수준의 소석회 첨가에 대해 실험을 수행할 필요가 있을 것으로 사료되었다.
        4,000원
        38.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Rushton bodies are known to be the aberrant keratinization and calcification in the epithelium of odontogenic cyst, which are similar to the features of calcifying odontogenic cyst and pilomatricoma. However, the pathogenetic mechanism of keratinization and calcification of Rushton bodies has not been clearly elucidated. Here, a case of Rushton bodies found in dentigerous cyst was examined by immunohistochemical method using antisera of PCNA, pAKT, HIF, PIM1, and PARP. The globular keratinization in lamellate fashion showed weak birefringency under polarizing microscope, and the Rushton bodies frequently underwent the dystrophic calcification. The polygonal keratinocytes of Rushton bodies were strongly positive for HIF and PARP, and the cyst epithelium was diffusely positive for pAKT and PIM1. Particularly, the cyst epithelium was hyperplastic and focally invaginated into cyst wall with positive reaction of PCNA. These findings may indicate the active response of odontogenic epithelium against the apoptotic stress of the cyst, producing the globular keratinization and irregular calcification in the polygonal keratinocytes. Therefore, it is presumed that the lamellate keratinization and dystrophic calcification of Rushton bodies are aberrant products of retrograding keratinocytes slowly undergoing apoptotic progresses similar to the phenomena of the ghost cells in calcifying odontogenic cyst and pilomatricoma, and also may have a potential for oncogenic proliferation.
        4,000원
        39.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 2년간 '홍로'/M.9 및 '후지'/M.9 품종의 적과를 위한 석회유황합제 및 어유와의 혼합처리 효과를 조사하기 위해 진행하였다. '후지' 1년 차에 있어, 만개 시 석회유황합제 1% 또는 2% 처리는 대조구에 비해 정과 및 액과의 유과수를 감소시켰다. 하지만 2차년도에는 석회유황합제 1% 또는 2% 단용처리에서는 정과 유과수의 차이를 나타내지 않았다. 다만 석회유황합제 1%의 3회 처리에서는 1차년도와 2차년도 모두 유의적인 적과효과를 나타내었다. 석회유황합제 1%의 다중처리는 '홍로'에서 가장 효율적인 적과효과를 나타내었다. 1차년도의 경우, 석회유황합제 1%의 2회 또는 3회 살포가 효과적인 적과효과를 보였으며, 2차년도에서는 석회유황합제 1% 1회처리를 제외하고는 모두 유의적인 적과효과를 나타내었다. 첨가된 어유의 경우 대부분의 경우 석회유황합제의 적과효과를 강화하지 않았다. 본 시험에 사용된 모든 처리구는 과실의 동녹 형성에 악영향을 미치지 않았으며, 또한 '후지' 및 '홍로'의 과실 중량, 경도, 가용성고형물 및 적정산도와 같은 과실품질에 영향을 미치지 않았다.
        4,000원
        40.
        2012.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Although the mechanism of the abnormal calcification in the calcifying odontogenic cyst (COC) was not elucidated so far, it has been known that the ghost cells are closely related to the calcification, producing dystrophic globular cementum-like materials, comparable to pilomatricoma in epithelium1). Here, we presented a case of COC occurred in left maxillary canine area of 23 years old female, exhibiting a collection of aberrant ossification admixed with basophilic ghost cells in comparison with seven cases of COC. In the polarizing microscope observation with Masson trichrome stain the present case clearly disclosed the typical birefringence of bony tissue, stained red in von Gieson stain, indicating the collagenous backbone. Some ghost cells showed the features of interdigitating epithelial attachments, empty spaces of nuclei, and reticular basophilic cytoplasms, which were similar to the basophilic ghost cells of philomatricoma. The present case demonstrated the aberrant ossification by basophilic ghost cells in COC similar to the ossification of pilomatricoma
        4,000원
        1 2 3 4 5