• The Journal of the Petrological Society of Korea
• /
• v.25 no.1
• /
• pp.85-88
• /
• 2016

The new rocks of the oceanic crust, like basalt, are created in the mid-oceanic ridge, and the magnetic polarities of the rocks are supposed to be oriented as following the Earth's magnetic field. An extensive magnetic survey of total field at sea level reveals mainly unusual north-south magnetic stripes parallel to the axis of the mid-oceanic ridge, especially in the Atlantic Ocean. From this stripes the Earth's magnetic field is considered as repeatedly 'flipped'(the N pole becoming the S pole, and vice versa) and many times over geological time. The discovery of stripes of alternately normal and reversed-magnetized rocks forming the ocean floor has been a key evidence for the sea-floor spreading, continental drift, and plate tectonics. This study introduces a simple apparatus to explain a possible mechanism of the magnetic reversal in the new oceanic crust, which makes a magnetic stripe adjacent to the mid-oceanic ridge. The apparatus shows a bar magnet effect of adjoined stripes to have a special magnetic polarity on the rocks in the center of the mid-oceanic ridge. The new magnetic stripe seems to be generated not only by Earth's magnetic field, but also by neighbored stripes in the mid-oceanic ridge, acting as a bar magnet.

• Journal of the Korean Institute of Gas
• /
• v.23 no.4
• /
• pp.10-18
• /
• 2019

The Interior finishing materials tried to evaluate the combustion characteristics and the dangerous characteristic of Floor finish and Wall finish. We often use, conducting the experiment ISO 5660-1, Cone Calorimeter method, and ISO-TR-9122 FT-IR. According to the result of Cone calorimeter experiment, the tile carpet FF3 of Floor material had the highest THR $74.6mj/m^2$ because of the highest risk, and the PHRR of FF1 was $726kW/m^2$, which was easy to bum. As a result FT-IR test, The CO, $CO_2$ ratio was 8,146 PPM for roll carpet FF1 than tile carpet FF2, FF3 5,996, 5,171 PPM, which was a carpet with a high toxicity risk. In the case of wall finishes, The MDF plate(WF3) was THR $86.7mj/m^2$ with a high risk, PHRR $384kW/m^2$ was easy to ignite and toxicity index was 5.5. The CO, $CO_2$ ratio was 1,340~8,596 PPM, But the WF4 was the most toxic with 8,596 PPM.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.24 no.5
• /
• pp.111-118
• /
• 2020

The U-shaped composite beam used in this study consist of a reinforced concrete structure, a beam steel structure supporting the slab, a reinforced concrete structure, and a U-shaped steel plate. The U-shaped composite beam was developed for the purpose of using it as a parking lot because it is highly constructible and has low floor height and long span. For the improvement of constructivity, the U-shaped composite beam ends are planned with standardized H-shaped steel and connected directly to the columns, and the middle of the U-shaped composite beam consists of U-shaped steel plates folded in U-shaped form using thin steel plates (t=6) instead of H-shaped steel. In the middle of the composite beam, where U-shaped steel plates are located, the depth of U-shaped beam may be planned to be small so as to satisfy the height limit of the parking lot. It is important to grasp the structural performance according to the change of depth because low beam depth is advantageous for the reduction of the floor height, but it is a inhibitor to the structural behaviors of U-shaped composite beam. In addition, since U-shaped composite beams are a mixture of steel frame structures, reinforced concrete structures and U-shaped steel plates, securing unity has a great influence on securing structural performance. Therefore, in this study, a structural experiment was conducted to understand the structural performance according to the depth change for U-shaped composite beam. A total of three specimens were planned, including two specimens that changed the depth using a criteria specimen planned for a general parking lot. The results of the experiment showed that the specimens who planned the depth greatly had better structural performance such as yield strength, maximum strength, and energy than the standard specimen.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2008.11a
• /
• pp.93-98
• /
• 2008

Haeundae Doosan We've The Zenith project is adjacent to Suyoung-bay, now it is in the process of excavation and foundation work. The main use of the tower is residence which height is 300m and 80 floor, the highest residential reinforced concrete building through the Orient. It is comprised of 3 high- rised buildings and 1 low-rised building, the basement is 230m wide and 200m length sized mass structure. The lateral resistance system is acted effectively against the lateral load and satisfactorily against the wind vibration by the 4 direction extension of the center core wall($700{\sim}800mm$ thickness) and reinforced concrete column set around the slab. Flat-plate slab system(250mm thickness) is adjusted for the slab system and it enables effective work process and shortening the working term by minimizing the ceiling height and not needing to install perimeter beam and drop panel. The strength and serviceability of the structure is able to be monitored and estimated constantly through the health monitoring system during the construction and after the construction.

• Economic and Environmental Geology
• /
• v.24 no.4
• /
• pp.447-463
• /
• 1991

Petrological and chemical studies of Precambrian dikes in the southern Lake Superior region were conducted with the objects of evaluating magma source and constraining models for the paleo-tectonic environment. Forty-six samples were analyzed for major, trace, and rare earth elements. Chemical data of the studied dikes are typical of continental tholeiites and showing iron-enrichment fractionation trend. With wallrock contamination carefully evaluated, a series of tectonic discriminating methods utilizing immobile trace elements indicate that the source magma was a high-Ti tholeiitic basalt similar to present-day T-type MORB. Effect of chemical contamination from wallrock assimilation accmulates with increasing differentiation. Evolved rocks show LREE enriched patterns and have enhanced levels of LIL elements (e.g., Rb, K, Ba, Th), but low levels of high field strength elements (e.g., Nb, P, Ti) with respect to their neighboring elements. It is suggested from this study that this enrichment possibly due to a combination of a feature inherited from the subcontinental lithosphere and crustal contamination. Geochemical signatures of these rocks are distinctively different from those of arc-related volcanics. Comparisons with chemistries of modern magmas show a pattern of overlap between Within-plate and ocean-floor characteristics, and chemical signatures of these rocks favor a model of intrusion into a crustal environment undergoing lithospheric attenuation.

• Land and Housing Review
• /
• v.2 no.3
• /
• pp.287-297
• /
• 2011

This paper presents the results of performance verification tests of the isolated flat plate apartment building with the laminated rubber bearings. The shaking table test is carried out in CABR(China Academy of Building Research) with two 1/10 scale isolation and non-isolation models under 4 excitation waves. The shaking table test is proceeding from x axis, y axis and x+y axis with different amplitude of acceleration values. The results show that, to non-isolated model, the natural vibration period is remarkably decreased and entered non-linear condition after moderate earthquake. Its accelerations become lager with increasing storey number and completely collapsed under large earthquake. The inter-storey shifts largely exceed the limit values of regulated displacement angles. But to isolated model, the natural vibration period of isolated modal is almost the same in all conditions and still in its elastic condition. The earthquake loading is greatly reduced and the accelerations of superstructure are greatly reduced. The inter-storey drifts are very small and can be neglected. The isolated model is in translational state and can be seen as a rigid whole. The displacements of isolation layer are in the allowable range. This experiment demonstrates that the seismic isolation is very effective to mitigate the influence of earthquake on structures and it is possible to increase the serviceability due to decrease the floor acceleration. facilities from their good states that is superior to non-isolated structure.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.27 no.2
• /
• pp.135-144
• /
• 1997

The primary intra-osseous carcinoma (PIOC) is a very rare lesion. PIOC is an odontogenic carcinoma defined as a squamous cell carcinoma arisinig within a jaw having no initial connection with the oral mucosa, and presumably developing from residues of the odontogenic epithelium. The authors diagnosed a 51-year-old female as primary intra-osseous carcinoma after undergoing clinical, radiological and histological examinations. The characteristics were as followed : 1. The patient complained of gingival bleeding on the premolar area in the left maxilla 2. The conventional radiograms showed a relatively well-defined unilocular radiolucent lesion from the mesial aspect of the upper left canine to the mesial aspect of the upper left 1st molar. The 2nd premolar was separated from the 1st molar and the floor of the maxillary sinus was elevated by the lesion. There was a external root resorption of the upper left canine, the 1st premolar, and the 2nd premolar. 3. On the computed tomograms, the osteolytic bony lesion expanded the cortical plate of the left maxilla and displaced the margin of the left maxillary sinus upwards. But the bony lesion was separated from the maxillary sinus by a bony septum. 4. Bone scintigram with /sup 99m/Tc demonstrated the increased uptake in the left maxilla. Sonograms in the neck area and chest P-A radiogram didn't show any abnormalities. 5. Histologically, the tumor islands infiltrating into the surrounding bone increased in alveolar pattern, composed of the malignant cells, and there was a necrosis in the center of the tumor islands.

• Journal of Korean Society of Steel Construction
• /
• v.25 no.1
• /
• pp.47-59
• /
• 2013

This study that is a successive secondary study right after the primary bending strength test of a new form of U-shape hybrid composite beam is a cyclic seismic test of U-shape hybrid composite beam and column conncetion. Three specimens are built for the variables which are kinds of columns, depth of beam, continuity or discontinuity of upper plate of beam, and a number of steel bars of end-beam. Kinds of columns are a reinforcement concrete column and a ACT column of CFT shape, and beam depth are 300, and 500 mm. Detail of connection is bolt connection with using a short bracket that is commonly use. As the result, deformability of 2~4% is ensured the floor displacement angle. If it is the negative moment, the maximum moment shows that its capacity is above the nominal moment.

• Korean Institute of Interior Design Journal
• /
• v.23 no.6
• /
• pp.195-203
• /
• 2014

This study selects factors affecting form type of hospital architecture by considering studies and references on hospital architecture type in korea and other countries in general. Also this study classifies general hospitals chronologically and analyzes type change of general hospitals in relation with periodic change of healthcare environment. Through this, this study aims to analyze chronological change of general hospitals' form type and provide the current of hospital architecture's general type. The form type classification of this study is classification according to the form of ward, classification according to the relationship between ward and D.T.D(Diagnostic and Treatment department), classification according to the relationship between O.P.D(Out Patient department) and D.T.D, classification according to the rate of centralization, classification according to the circulation system. The form type of ward changed from plate type to tower type, and the circulation system of ward changed from middle corridor to double corridor, the number of Team Nursing chaged from 1 to 2 in 1990. On the other hand the chage of others classifications took place from 1990' to 2010'. It is judged that this overall change is appeared by a change from an inpatien-oriented system to an outpatient-oriented system followed by an increase in number of outpatients, an increase in amenities in ground floor and adoption of healing environment for patients and visitors.

• Korean Journal of Applied Biomechanics
• /
• v.27 no.3
• /
• pp.189-195
• /
• 2017

Objective: The aim of this study was to examine the effect of foot landing type (forefoot vs. rearfoot landing) on kinematics, kinetics, and energy absorption of hip, knee, and ankle joints. Method: Twenty-five healthy men performed single-leg landings with two different foot landing types: forefoot and rearfoot landing. A motion-capture system equipped with eight infrared cameras and a synchronized force plate embedded in the floor was used. Three-dimensional kinematic and kinetic parameters were compared using paired two-tailed Student's t-tests at a significance level of .05. Results: On initial contact, a greater knee flexion angle was shown during rearfoot landing (p < .001), but the lower knee flexion angle was found at peak vertical ground reaction force (GRF) (p < .001). On initial contact, ankles showed plantarflexion, inversion, and external rotation during forefoot landing, while dorsiflexion, eversion, and internal rotation were shown during rearfoot landing (p < .001, all). At peak vertical GRF, the knee extension moment and ankle plantarflexion moment were lower in rearfoot landing than in forefoot landing (p = .003 and p < .001, respectively). From initial contact to peak vertical GRF, the negative work of the hip, knee, and ankle joint was significantly reduced during rearfoot landing (p < .001, all). The contribution to the total work of the ankle joint was the greatest during forefoot landing, whereas the contribution to the total work of the hip joint was the greatest during rearfoot landing. Conclusion: These results suggest that the energy absorption strategy was changed during rearfoot landing compared with forefoot landing according to lower-extremity joint kinematics and kinetics.