• 한국광물학회지
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• 제11권2호
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• pp.97-105
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• 1998

Weathering of biotite in Palgonsan granite was studied by using X-ray diffraction, optical microscopy, scanning electron microscopy, and electron probe micro analysis. Biotite altered to biotite/vermiculite regular mixed layer mineral (B/V) in the early stage of weathering. Although partially replaced by kaolinite with the progress of weathering. B/V is the major weathering product of biotite throughout the profile. During the formation of B/V, Mg, Fe and K are removed from a biotite layer to form a vermiculite layer by about 28%, 44% and 88%, respectively, whereas the Ti content is not changed. Considerable volume increase after the kaolinitization of B/V suggests that Al and Si are largely introduced from the external weathering solution. The silicate lattice templet of a weathering biotite facilitated the nucleation and growth of kaolinite. In the Palgongsan granite weathering profile, plagioclase weathered mostly into halloysite whereas biotite greatly contributes to the kaolinite crystallization though its small content in fresh rock.

• 자원환경지질
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• 제55권6호
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• pp.597-616
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• 2022

The Chungnam basin is a crucial area for studying the Mesozoic crustal evolutionary history of the Korean Peninsula. This study reports the revised geology and new isotopic ages from the northeastern Chungnam Basin based on detailed geological mapping and LA-ICP-MS zircon U-Pb analysis. Our renewed geologic map defines intra-basin, basin-bounding, and basement fault systems closely related to hydrothermal gold-bearing quartz vein injections. Here, we propose the directions of (micro)structural and geochronological future work to address issues on the relationship between the tectonic process, basin evolution, and hydrothermal fluid migration in the southwestern Korean Peninsula.

• Computers and Concrete
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• 제33권6호
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• pp.725-738
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• 2024

This study presents a macro-modeling procedure for nonlinear finite element analysis of reinforced and prestressed concrete panels under blast loading. The analysis procedure treats cracked concrete as an orthotropic material based on a smeared rotating crack model within the context of total-load secant stiffness-based formulation. A direct time integration method compatible with the analysis formulation is adapted to solve the dynamic equation of motion. Considerations are made to account for strain rate effects. The analysis procedure is verified by modeling 14 blast tests from various sources reported in the literature including a blast simulation contest. The analysis results are compared against those obtained from experiments, simplified single-degree-of-freedom (SDOF) methods, and sophisticated hydrocodes. It is demonstrated that the smeared crack macro-modeling approach is a viable alternative analysis procedure that gives more information about the structural behavior than SDOF methods, but does not require detailed micro-modeling and extensive material characterization typically needed with hydrocodes.

• 한국수산과학회지
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• 제28권1호
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• pp.49-59
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• 1995

Nine species of edible seaweed [green laver (Monostroma nitidium) and sea staghorn ( Codium fragile) of green algae; sea mustard (Undaria pinnatifida), seaweed fusiforme(Hizikia fusiforme), gulf weed (Sargassum fulvellium), and sea tangle (Laminaria japonica) of brown algae; seaweed dilatata (Halimeniopsis dilatata), seaweed furcata (Gloiopeltis furcata), and laver (Porphyra tenera) of red algae] collected from Kijang, Chungmu, and Yosu in Korea, were examined and compared on their chemical and mineral composition depending on their harvesting season. Crude protein $(N\pm6.25)$ showed about $45\%$ on moisture free basis (the contents of every components described below are shown as moisture free basis) for laver and $30\%$ for green laver collected from ever seasons and sites. Sea tangle showed the highest content in crude lipid $(10\%)$ among brown seaweeds and green laver had $6\%$ of crude lipid regardless their habitats. Ash and carbohydrate in sea staghorn hold about $90\%$ of total solids but those levels were only $50\%$ in laver. The relationship between ash and carbohydrate content showed a tendency with reverse correlation. Mineral compositions were examined on green laver, sea mustard, and seaweed furcata collected from Kijang. Sodium was eminent element (1,798-7,334mg/l00g) followed by potassium. Magnesium and calcium content were low level compared with sodium and potassium. As a micro-element iron was appraised the highest status (165-330mg/100g) in green laver, however, iron in sea mustard and seaweed furcata was comparatively low amount (2.7-47.4mg/100g). The level of zinc was also comparatively high and that was varied on habitats. In conclusion, chemical compositions of these algae were distinctively varied on species and habitats, and mineral compositions were notably changed by the harvesting season.

• Asian-Australasian Journal of Animal Sciences
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• 제16권5호
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• pp.719-725
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• 2003

An experiment was conducted to study the requirement of calcium (Ca) and non-phytin phosphorus (NPP) in commercial broilers during starter phase. Seven hundred and twenty day-old Vencob male broiler chicks were randomly distributed into 144 stainless steel battery brooders, 5 birds in each. Four levels each of Ca (6, 7, 8, and 9 g/kg) and NPP (3, 3.5, 4, and 4.5 g/kg diet) were fed in a factorial design in a corn-soya basal diet. Levels of dicalcium phosphate and oyster shell grit were adjusted to obtain the desired levels of Ca and NPP. Each diet was fed ad libidum to chicks in 9 battery brooders from one d to 21 d of age. Body weight gain and feed intake were depressed (p<0.01) by increasing the dietary Ca level (8 and 9 g/kg) at lower levels of NPP (3 and 3.5 g/kg diet). The growth depression observed at lower NPP level was alleviated by reducing the Ca content to 6 g/kg diet. The tibia ash content and tibia breaking strength increased with increase in both Ca (>6 g/kg) and NPP (>3 g/kg) levels. The leg abnormality score decreased (p<0.01) with increase in NPP content in the diet at all levels of Ca tested. The serum Ca and inorganic P levels were increased with increase in the level of the respective mineral in the diet, but the serum concentration of Ca and P were inversely related to the level of NPP and Ca, respectively /kg diet. In general, the excretion of macro minerals (Ca, and P), and micro minerals {zinc (Zn), manganese (Mn), iron (Fe), and copper (Cu)} was significantly lower at lower levels of Ca and NPP tested (6 and 3 g/kg diet, respectively). The mineral excretion increased with increase in dietary Ca and NPP levels, more conspicuously at the disproportionate ratio of these minerals (>2:1, Ca and NPP). Similarly, the retention of Zn, Mn, and Fe in liver was significantly higher (p<0.01) at lower levels of Ca and NPP tested. Results from this study indicate that the commercial broilers do not require more than 3 g NPP and 6g Ca/kg diet during starter phase (up to 21 d of age) for optimum weight gain, feed efficiency and utilization of Ca, P, Zn, Mn, Fe and Cu. However, the requirements of these minerals for optimum bone mineralization were higher than the levels suggested above.

• 지구물리와물리탐사
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• 제22권4호
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• pp.210-224
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• 2019

표면파 탐사는 매우 작은 규모의 초음파 분석부터 지질공학 규모의 분석까지 다양한 분야에서 활용하고 있으며, 특히 천부 지질의 지반 안정성을 평가하는 데 활발히 이용되고 있다. 표면파 탐사는 기본적으로 지표면을 따라 전파하는 표면파의 분산 특성에 기초하여 매질의 전단 속도 분포를 파악하는 탐사법이다. 즉, 지하 구조가 1차원 구조라는 가정 하에 탐사를 수행하는 표면파 탐사는, 진동수와 전파 속도의 관계인 분산곡선을 분석하고 1차원적 역산을 통해 층서구조 속도를 계산하게 된다. 이 논문에서는 천부 지질 조사를 위한 표면파 탐사법의 기초적인 이론부터 전반적인 자료처리 과정을 기술보고를 통해 설명하고자 한다. 먼저, 표면파에 대한 개략적인 설명과 가장 큰 특징 중 하나인 분산 특성에 대하여 설명한 후 일반적인 표면파 자료처리 순서에 대하여 설명하였다. 표면파 탐사법은 인공적인 송신원의 유무에 따라 능동 표면파 탐사법과 수동 표면파 탐사법으로 나눌 수 있으나 이 논문에서는 능동 표면파 탐사법인 CSW, SASW, MASW에 대하여 집중적으로 기술하였다. 수동 표면파 탐사법에 대해서는 다음 기술보고에서 다루고자 한다.

• 대한영양사협회학술지
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• 제10권4호
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• pp.407-416
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• 2004

The purpose of this study was to examine the comparison of growth development, bone mineral density and nutrient intakes between double income families' preschool children(DIFPC) and full-time housewives' preschool children(FHPC). Subjects were 111 preschool children. Anthropometric characteristics and bone mineral density in right forearm were measured. The questionnaire was composed of health status, life style, dietary behaviors, and dietary intakes and was completed by the children's mothers. The average age of the DIFPC(n=60) was 53.02 months and that of the FHPC(n=51) was 54.80 months. The birth height and weight of the subjects were 50.47㎝ and 3.27㎏ for DIFPC and 50.85㎝ and 3.36㎏ for FHPC, respectively. The average height, weight, % body fat, and obesity index were 108.50㎝, 18.35㎏, 15.35%, 96.71% in DIFPC and 111.46㎝, 19.64㎏, 16.80%, 97.31% in FHPC, respectively. The bone mineral density in forearm of two groups were 0.24g/㎠ in all. The infant feeding method was significantly different between DIFPC and FHPC; 58.9% of DIFPC was fed formula, while 44.4% of FHPC was fed breast milk(p<0.05). Proportions of children for their regular meal were 59.4%, 89.6%, and 61.0% for breakfast, lunch, and dinner, respectively. The major reasons for irregular meal were lack of time and poor appetite for breakfast and snacks for lunch and dinner. Most of the children answered they have snack over once a day, and 60.0% have unbalanced diet. The intakes of energy, calcium, iron, zinc, vitamin A, vitamin B1, niacin, and vitamin C did not meet the Korean RDAs. The intakes of K and vitamin A for DIFPC were significantly higher than those of FHPC(p<0.05, p<0.05). In conclusion, double income families' preschool children more have a low frequency of breast feeding and low intakes of micro nutrients, such as K and vitamin A than full-time housewives' ones.

• Journal of Periodontal and Implant Science
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• 제35권2호
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• pp.335-343
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• 2005

Inorganic bovine bone mineral has been widely researched as bone substitution materials in orthopedic and oral and maxillofacial application. OCS-B(NIBEC, Korea) is newly-developed inorganic bovine bone mineral. The aim of this study is to evaluate the safety and efficacy of bovine bone-derived bone graft material(OCS-B). Micro-structure of newly-developed inorganic bovine bone mineral(OCS-B) was analyzed by scanning electron microscope(SEM). Round cranial defects with eight mm diameter were made and filled with OCS-B in rabbits. OCS-B was inserted into femoral quadrant muscle in mouse. In scanning electron microscope, OCS-B was equal to natural hydroxyapatite. Rabbits were sacrificed at 2 weeks and 4 weeks after surgery and mice were sacrificed at 1 week and 2 weeks after surgery. Decalcified specimens were prepared and observed by microscope. In calvarial defects, osteoid and new bone were formed in the neighborhood of OCS-B at 2 weeks after surgery. And at 4 weeks after surgery osteoid and new bone bridge formed flourishingly. No inflammatory cells were seen on the surface of OCS-B at 1 week and 2 weeks in mouse experimental group. It is concluded that newly-developed inorganic bovine bone mineral(OCS-B) is a flourishing bone-forming material and biocompatible material.

• 한국식생활문화학회지
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• 제22권2호
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• pp.246-253
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• 2007

참나물의 잎과 줄기부위에서 가장 많이 함유하고 있는 무기 성분은 K, P, Ca, Mg 순이었으며 잎 부위가 줄기부위보다 Ca, P, Mg함유량이 약 4배 정도 많았다 전자코를 이용한 휘발성 향기성분 패턴은 신선한 참나물의 경우 제1주성분 값이 +값을, 음건한 건조 참나물은 - 값을 나타내어서 신선한 참나물과 건조한 참나물 사이에는 뚜렷한 차이를 보였고 건조방법에 따른 시료간의 구별이 가능하였다. SDE법에 의해 신선한 참나물은 aldehydes 3종, alcohols 9종, ester 4종, hydrocarbons 5종, terpen hydrocarbons 34종, ketone 1종, 기타 2종의 총 58 종이 확인되었고, 음건한 참나물은 aldehydes 4종, alcohols 7종, hydrocarbon 1종, terpen hydrocarbons 17종, ketone 1종, 기타 1종의 총 31종이 확인되었다. SDE법에 의한 신선, 음건한 참나물 모두 ${\alpha}$-selinene(37.89%, 12.59%)가 가장 많이 확인되었는데 신선할 때보다 음건한 경우 휘발성향기성분의 peak수와 peak area%가 적었다. CAR/PDMS fiber HS-SPME법에 의해 34종이 확인되었는데 aldehydes 2종, alcohols 2종, hydrocarbons 7종, terpen hydrocarbons 23종이며 myrcene(15.50%)가 가장 많이 확인되었다. PDMS fiber HS-SPME법에 의해 aldehydes 1종, alcohols 1종, hydrocarbons 2종, terpen hydrocarbons 17종으로 총 21종이 확인되었고 germacrene D(16.84%)가 가장 많았다. SDE법에 의한 경우가 SPME법보다 향기성분의 종류와 양이 많았고 HS-SPME법의 경우 CAR/PDMS fiber가 PDMS fiber 보다 더 많은 종류의 향기가 확인되었다.

• 한국광물학회지
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• 제18권3호
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• pp.147-153
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• 2005

최근 캐나다 퀘벡주 운가바 지역의 메사맥스 노스웨스트광상에서 발견된 신종광물인 날드렛타이트(naldrettite)의 광물학적 성질 중 이 광물의 이상화학성분이 $Pd_2Sb$인 것으로 발표되었다. 따라서 이 연구에서는 순수한 $Pd_2Sb$성분의 화합물을 합성한 후 천연 및 합성 물질간의 광학적 성질, 화학조성, 결정구조, 미경도 등의 자료를 비교하여 두 물질의 일치성 여부를 확인하고자 하였다. 합성 $Pd_2Sb$는 공기 및 오일 속에서 밝은 백색에 옅은 노란색이 곁들여 있는 것으로 관찰되며, 복반사가 미약하게 관찰된다. 이방성이 강하며, 회갈색으로부터 녹청색으로 변한다. 미경도 측정값은 $VHN_{100}=293(242-322)$이다. 화학성분은 Pd가 $63.7\~64.3wt.\%,\;Sb\;가\;36.4\~36.8\;wt.\%$로 매우 일정하다. 합성 $Pd_2Sb$의 결정구조는 사방정계의 공간군 $Cmc2_1$에 속하며, $510^{\circ}C$에서 합성한 물질의 경우 단위포 상수는 a=3.366(1), b=17.523(3), c=6.929(2) ${\AA}$이다. 이와 같은 합성 $Pd_2Sb$의 광물학적 자료는 날드렛타이트의 자료와 잘 일치하며, 이로부터 naldrettite가 합성 $Pd_2Sb$의 천연산 광물임을 알 수 있다.