• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.490-494
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• 2019

Abutment teeth supporting removable partial denture could be faced a number of problems including development of dental caries. If the existing removable partial denture is in clinically acceptable state and the patient does not want to replace the existing removable partial denture, then a new prosthesis for abutment teeth need to be made. The procedure of fabricating a new prosthesis of abutment teeth for existing removable partial denture is complicate and technically challenging. To fabricate the abutment crown, the original cast of patient obtained before any complication to the abutment teeth is required. The original cast should also contain teeth other than the abutment teeth as a reference point. Once the cast is prepared, CAD/CAM could be used to produce retrofitting prosthesis effortlessly and efficiently. This clinical report presents fabricating a crown to fit existing removable partial denture using CAD/CAM for a patient with post and core failure and dislodged prosthesis. The prosthesis had high stability with minimum adjustment yielding satisfying result.

• Computers and Concrete
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• v.29 no.1
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• pp.15-29
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• 2022

Concrete-filled steel tubes (CFSTs) are increasingly used as composite sections in structures owing to their excellent load bearing capacity. Therefore, predicting the mechanical behavior of CFST sections under axial compression loading is vital for design purposes. This paper presents the first study on the nonlinear analysis of heated CFSTs with high-strength concrete core containing steel fiber and waste tire rubber under axial compression loading. CFSTs had steel fibers with 0, 1, and 1.5% volume fractions and 0, 5, and 10% rubber particles as sand alternative material. They were subjected to 20, 250, 500, and 750℃ temperatures. Using flow rule and analytical analysis, a model is developed to predict the load bearing capacity of steel tube, and hoop strain-axial strain relationship, and axial stress-volumetric strain relationship of CFSTs. An elastic-plastic analysis method is applied to determine the axial and hoop stresses of the steel tube, considering elastic, yield, and strain hardening stages of steel in its stress-strain curve. The axial stress in the concrete core is determined as the difference between the total experimental axial stress and the axial stress of steel tube obtained from modeling. The results show that steel tube in CFSTs under 750℃ exhibits a higher load bearing contribution compared to those under 20, 250, and 500℃. It is also found that the ratio of load bearing capacity of steel tube at peak point to the load bearing capacity of CFST at peak load is noticeable such that this ratio is in the ranges of 0.21-0.33 and 0.31-0.38 for the CFST specimens with a steel tube thickness of 2 and 3.5 mm, respectively. In addition, after the steel tube yielding, the load bearing capacity of the tube decreases due to the reduction of its axial stiffness and the increase of hoop strain rate, which is in the range of about 20 to 40%.

• Proceedings of the Korean Society of Grassland Science Conference
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• 2002.09b
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• pp.103-127
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• 2002

The main problem of the forage-based livestock farming in Germany at the moment is the high yielding cow requiring high energy concentration in feed which can be obtained lot easier with corn and grain than with grass. Therefore milk production tends out of the grassland region and into the forage crop region. Nutrient surplus due to concentrates in milk production in future probably will be limited by the government. The problem can only be solved by using best swards and optimal silage techniques as well as optimisation of manure utilization. Most important steps of sustainable forage production are care of grassland as well as regular resowing, especially of silage meadows. About 40% of Hessian grassland is managed in agri-environmental problems to keep it in use and to protect the natural resources. Selective measures are realized, to solve special problmes of nature and landscape conservation.

• Journal of Periodontal and Implant Science
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• v.54 no.3
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• pp.189-204
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• 2024

Purpose: This pilot study was conducted to develop a novel test setup for the in vitro assessment of the primary stability of dental implants. This was achieved by characterising their long-term behaviour based on the continuous recording of micromotions resulting from dynamic and cyclic loading. Methods: Twenty screw implants, each 11 mm in length and either 3.8 mm (for premolars) or 4.3 mm (for molars) in diameter, were inserted into the posterior region of 5 synthetic mandibular models. Physiological masticatory loads were simulated by superimposing cyclic buccal-lingual movement of the mandible with a vertically applied masticatory force. Using an optical 3-dimensional (3D) measuring system, the micromotions of the dental crowns relative to the alveolar bone resulting from alternating off-centre loads were concurrently determined over 10,000 test cycles. Results: The buccal-lingual deflections of the dental crowns significantly increased from cycle 10 to cycle 10,000 (P<0.05). The deflections increased sharply during the first 500 cycles before approaching a plateau. Premolars exhibited greater maximum deflections than molars. The bone regions located mesially and distally adjacent to the loaded implants demonstrated deflections that occurred synchronously and in the same direction as the applied loads. The overall spatial movement of the implants over time followed an hourglass-shaped loosening pattern with a characteristic pivot point 5.5±1.1 mm from the apical end. Conclusions: In synthetic mandibular models, the cyclic reciprocal loading of dental implants with an average masticatory force produces significant loosening. The evasive movements observed in the alveolar bone suggest that its anatomy and yielding could significantly influence the force distribution and, consequently, the mechanical behaviour of dental implants. The 3D visualisation of the overall implant movement under functional cyclic loading complements known methods and can contribute to the development of implant designs and surgical techniques by providing a more profound understanding of dynamic bone-implant interactions.

• The Korean Journal of Mycology
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• v.43 no.1
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• pp.33-39
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• 2015

In filamentous fungi, velvet complex associated with the veA gene plays pivotal roles in development and secondary metabolism. In a model fungus Aspergillus nidulans, many proteins that can interact with VeA, including two methyltransferases VipB and VipC, have been isolated and characterized. In this study, we isolated homologs of the vipB and vipC genes in the human opportunistic pathogenic fungus Aspergillus fumigatus and named AfuvipB and AfuvipC. The AfuvipB gene, annotated as Afu3g14920 in the Aspergillus Genome Database (AspGD) database, consists of 1,510 bp interrupted with 10 introns yielding 336 amino acid-long putative methyltransferase protein. Similarly, AfuvipC, which is Afu8g01930, has 10 introns and encodes a polypeptide with 339 amino acids having a methyltransferase domain in the middle of the protein. To characterize the function of the genes in A. fumigatus, knock-out mutants were generated and the phenotypes were observed. Deletion of AfuvipB gene caused no obvious phenotypic change on point inoculation but showed smaller colony than wild-type when the mutant was subjected to culture on single spore-driven culture condition. However, AfuvipC deletion mutant demonstrated no phenotypic difference from wild type both in point inoculation and streaking cultures. These results indicate that the two methyltransfereases might have a redundant role and could be dispensable in normal culture conditions.

• The Journal of Engineering Geology
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• v.20 no.3
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• pp.311-318
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• 2010

We performed laboratory measurements of the mechanical properties and slake durability of Cretaceous shale from the Hwasun area, Korea, including highly weathered and fresh samples, yielding ranges of specific gravity of 2.14-2.88, dry density of 1.86-2.83(g/$cm^3$), water content of 0.12-6.36 (%), porosity of 1.33-20.49 (%), and absorption ratio of 0.51-8.5 (%). The absorption ratio shows a strong linear relation with porosity, expressed as Ab = 0.44P-0.09 (Ab: absorption ratio, P: porosity). Values of the slake durability index ($Id_2$) and point load intensity index ($Is_{(50)}$) of highly weathered to fresh shale are 90.07-99.33 (%) and 10.8-90.2(kg/$cm^2$), respectively. $Id_2$ is linearly related to $Is_{(50)}$, expressed as $Is(50)=1E-07e^{0.2033Id_2}$(kg/$cm^2$)($r^2=0.69$). This equation is a useful tool for estimating the $Id_2$ value for shale in the Hwasun area.

• Applied Biological Chemistry
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• v.25 no.4
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• pp.232-238
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• 1982

From ^{15}N$ labelled nitrogen experiments on 13 fields use efficiency by difference method was higher than that by labelling method in 80% of fields tested indicating augmentation of soil nitrogen uptake by fertilizer nitrogen. Both methods showed very similar trend among fields. Sulfur coated urea(SCU) and point application increased fertilization efficiency(yield increment per fertilizer nitrogen applied, Fe) to 23 from 15 of split application through the increase of fertilizer use efficiency from 29(Eu) to 50 but tended to decrease efficiency of absorbed fertilizer nitrogen(yield increment per nitrogen derived from fertilizer, Ef) from 50. to 46 High yielding capacity of Tongil line appears to be attributed to the higher Ef, translocation efficiency and soil nitrogen preference index(soil nitrogen increment in plant per the increment of fertilizer nitrogen in plant, PI). This studies confirmed that yield under fertilizer application system depends on Fe which is the multiplication of Eu and Ef and that the improvement of fertilizer management(form, application method and time) increases principally Eu, the limit of which is controlled by Ef that is attributed mainly to varietal characteristics.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.2
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• pp.134-142
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• 1991

Since IR8, the first high-yielding rice cultivar characterised by semidwarf and high-tillering, was released in 1966, rice yields during the last two decades have apparently reached a plateau and subsequent efforts to further improve yielding ability have not resulted in visible gains. At this point of time, a new ideotype of rice plant would be necessary to increase grain yield potential. This experiment was conducted to investigate the yield contribution of different tillers within a plant in relation to an ideo type of rice plant. A low-tillering, large panicled IR25588 was compared with a high-tillering, small panicled IR58. Based on spikelet number and grain weight per panicle, the top six panicles in both low- and high-tillering cultivarswere significantly bigger than those in the other panicles. The top six panicles were M, PI, P2, P3, P4 and S1P2 in both cultivars. Their tillers had 100% probability of occurring. The top six tillers were characterised by earlier initiation and heading, longer growth duration, greater leaf area. and heavier culm and total dry weight per tiller. The top six panicles, based on grain weight was mainly due to higher spikelet number per panicle with little differences in 1,000 grain weight and percent fertility. They had also a greater number of high -density grains. The top six panicles were significantly bigger than the rest of the panicles in both low- and high-tilliering types suggesting that a new rice ideotype having six or fewer potential tillers or panicles per paint with 200 to 250 spikelets per panicle (a low-tillering, paicle weight type) may help increase grain yield potential since they have been shown to be superior physio-morphologically to the rest of the tillers.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.1
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• pp.31-35
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• 1975

In order to gain information on the plant characteristics of high yielding paddy from the point of view of mineral nutrition and to learn more about soil conditions under which high yields are produced a number of soil samples collected from the field experiment carried out in The City College of Seoul were analysed. In addition, a laboratory experiment carried out to support the field experiment was also analysed. Results obtained are as follows: 1. Generally, the higher the yield of paddy, the higher is the potassium content in flag leaves, whereas the reverse is true for the content of Ca and Mg in the leaves. From these facts it can conceivably be said that the high yielding paddy should absorb a large quantity of potassium and a lesser quantity of calcium and magnesium in the reproductive stage. 2. Leaves of paddy which produced yields over 600kg/10a (a comparatively high yield in the experiment) contained 30-35mg/100g of potassium, less than 25me/100g of calcium, and 10me/100g of magnesium which brings the ratio of $K/{\sqrt{Ca+Mg}}$ over 5. 3. Correlation studies indicated a remarkable relationship between the paddy yield and exchangeable potassium in soil samples taken after harvesting. A similar relationship was observed between the yield of paddy and $K/{\sqrt{Cae+Mge}}$ ratio of the soil samples. 4. A regression between yield of padcy (Y) and exchangeable potassium (Ke) or $K/{\sqrt{Ca+Mg}}$ in soil samples taken after harvesting was shown to be; Y=183.95+2135.86Ke $$Y=352.45+3114.454\;K/{\sqrt{Ca+Mg}}$$ 5. The regression between exchangeable potassium (Ke) in soil samples taken after harvesting and the amount of lime (L) and potassium (P) to be applied is; $$Ke=0.1246+0.00007037L+0.004444P+0.000004444L{\cdot}P$$.

• Korean Journal of Soil Science and Fertilizer
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• v.7 no.1
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• pp.35-42
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• 1974

From the results of countrywide two year N. P. K simple trial with newly bred IR 667-Suwon 214 and leading local varieties for comparison soil productivity (yield without fertilizer) and fertilization productivity (yield increase with fertilizer) were investigated. 1. IR667 showed higher yield than leading local by 19% in 1971 and by 12% in the year of low temperature stress, 1972. High yielding capacity of IR667 was attributed to greater number of spikelet per panicle. The coefficient of variation in yield was smaller in IR667 but the leading locals showed higher yield in 23(1971) and 30% (1972) of the fields. 2. IR667 required more nitrogen, especially phosphorus and potassium. Fertilization efficiency (yield increment per unit fertilizer) in IR667 was-about 4kg higher in nitrogen but smaller in phosphorus and almost the same in potassium. 3. Soil productivity was higher in IR667 but percent contribution of soil productivity to total productivity (field productivity) was lower. 4. Percent contribution of fertilization productivity to field productivity was 19 to 33, of which 5 was due to phosphorus and potassium. 5. The greater the soil productivity, the greater the field productivity becomes, but the much greater the percentage contribution of soil productivity becomes. 6. Fertility saturation point at which fertilization efficiency is nil, was propoesd as a soil productivity (or field productivity) limit.