• Molecules and Cells
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• 제24권3호
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• pp.394-408
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• 2007

Several genes/QTLs governing resistance/tolerance to abiotic and biotic stresses have been reported and mapped in rice. A QTL for submergence tolerance was found to be co-located with a major QTL for broad-spectrum bacterial leaf blight (bs-blb) resistance on the long arm of chromosome 5 in indica cultivars FR13A and IET8585. Using the Nipponbare (japonica) and 93-11 (indica) genome sequences, we identified, in silico, candidate genes in the chromosomal region [Kottapalli et al. (2006)]. Transcriptional profiling of FR13A and IET8585 using a rice 22K oligo array validated the above findings. Based on in silico analysis and arraying we observed that both cultivars respond to the above stresses through a common signaling system involving protein kinases, adenosine mono phosphate kinase, leucine rich repeat, PDZ/DHR/GLGF, and response regulator receiver protein. The combined approaches suggest that transcription factor EREBP on long arm of chromosome 5 regulates both submergence tolerance and blb resistance. Pyruvate decarboxylase and alcohol dehydrogenase, co-located in the same region, are candidate downstream genes for submergence tolerance at the seedling stage, and t-snare for bs-blb resistance. We also detected up-regulation of novel defense/stress-related genes including those encoding fumaryl aceto acetate (FAA) hydrolase, scramblase, and galactose oxidase, in response to the imposed stresses.

• 한국농공학회지
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• 제19권4호
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• pp.4533-4543
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• 1977

The purpose of this study was to investigate and compare flow discharges of rectangular, V-notch and trapezoidal type of cutthrooat flumes, and the published data for trapezoidal parshall flumes. And the trapezoidal cutthroat flumes were also compared in their accuracy of discharge measurements for various convergence ratios in the inlet section and divergence ratios in the outlet section. Five flumes were studied, and all the flumes were 45cm long with flat-bottom and were made of well-finished transparent acryl plate of 3mm thickness. One rectangular, one V-notch and three trapezoidal types were numbered 1 to 5 as shown in Fig. III-1. The measured depth of water was ranged from 5 to 20cm. The results obtained in this study are summarized as follows: 1. The general discharge equations for tested prototypes are listed for free flow in Table IV-1 and for submergence flow in Table IV-4. 2. In both free and submerged flow, the accuracy of the discharge formula obtained by this test is highly significant at 1% level as shown in Table IV-2 and Table IV-6. The accuracy of disharges measured depends upon the convergence and divergence ratios in the trapezoidal types: the less the ratios of convergence as well as divergence, the lower the accuracy. 3. Submergence ratios tend to increase in the order of flume number except flume No. 4. This implies that trapezoidal cutthroat flumes are more acceptable than rectangular or V-notch ones for free flow. 4. The transition submergence for the trapezoidal Parshall flumes ranges from 80-85 percent, which is slightly higher than the tested flume. However, the trapezoidal cutthroat flume No. 5 has higher transition submergence ratio, ranging from 73-78 percent, than other trapezoidal ones. The difference between the trapezoidal Parshall flumes and the trapezoidal cutthroat flumes in transition submergence seems small enough to be ignored in their field use. 5. Trapezoidal cutthroat flume is simple and economical to construct in existing openchannels whose shapes are generally trapezoidal. In order to obtain the best rating accuracy, flume No. 3 among the tested trapezoidal types is recommended, because it shows the highest accuracy for both free and submerged flow.

• 구강회복응용과학지
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• 제36권4호
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• pp.289-295
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• 2020

비심미적인 임플란트유지형 보철물의 심미성 개선은 매우 어려운 문제이며 특히, 상악 전치부 임플란트와 관련되어 있는 경우는 더욱 그러하다. 본 증례는 상악전치부 임플란트의 주기적 배농과 비심미성을 주소로 보철과의사로부터 의뢰된 69세 남자 환자의 심미성 개선에 관한 보고이다. 임플란트는 다소 깊게 식립되어 긴 임상치관길이를 보였으며, 주변 연조직 양도 부족하였다. 임상 검사와 방사선검사 후, 깊게 식립된 임플란트의 제거 대신 예후가 불량한 인접 치아의 발치 후 임플란트를 추가 식립하여 임플란트 유지형 고정성보철물을 제작하고, 깊게 식립된 임플란트는 제거 대신 치조제 증대에 도움을 주기 위해 침수(submergence)시켜 치조제를 증대시키는 방식을 선택하였다. 적절한 진단이 동반된 임플란트 침수가 전치부의 임플란트 비심미성을 개선시킬 수 있는 또다른 대안이 될 수 있을 것이다.

• 한국해양공학회지
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• 제25권1호
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• pp.1-7
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• 2011

The radiation of water waves by a heaving truncated circular cylinder with damping plate is solved in the frame of the three-dimensional linear potential theory. The damping plate has a distinct advantage in reducing the motion response of a floating circular cylinder by increasing the added mass and the damping coefficient. Using the matched eigenfunction expansion method, the characteristics of hydrodynamic added mass and the damping coefficient are investigated with various system parameters, such as the radius and submergence depth of the damping plate. It is found that both added mass and the damping coefficient are significantly increased due to the arranged features of the larger damping plate with shallow submergence, which are positive factors as a motion reduction device of the floating offshore platform. Also the numerical results for an oscillating submerged disk show that the added mass is negative and that the damping coefficient has a peak value at resonant frequency when submergence depth is sufficiently small.

• Journal of Advanced Marine Engineering and Technology
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• 제23권2호
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• pp.252-258
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• 1999

As an effective means to convey crushed materials from seabed to on board ship and to raise hazardous or abrasive liquids air-lift pump provides a reliable mechanism due to its simple config-uration and easy-to-operate principle. The present study is focused on fundamental investigation of related performance by the analysis program based on the gas-liquid two-phase flow in circular pipes. The program covers pump operating in isothermal and vertical two-phase flow with Newto-nian liquids. it is summarized as important result that an optimum air mass flow rate exists for the maximum lifted liquid mass flow rate in terms of a given submergence rates and furthermore attachment of downcomer gives little effects on riser performance the conveyed liquid flow rate increases with larger submergence rate.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.147-147
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• 2017

Rice is one of the major staple food in Asia, covering around half of the world population. More than 40% of rice cultivation area are subject to abiotic stresses such as drought, submergence and phosphate deficiency. Pyramiding useful genes into elite variety is a promising strategy to develop tolerance varieties to multiple abiotic stresses. However, some genes are not functionally compatible when they are introgressed into the same elite variety. Here, we tested the functional compatibility of Sub1 and Pup1, major QTLs for tolerance to submergence and phosphate (P)-deficiency conditions, respectively. Phenotypic analysis revealed that IR64-Sub1 Pup1(SP1) plants harboring both Sub1 and Pup1 QTLs showed significant tolerance to submerged conditions, similarly in IR64-Sub1 (Sub1) plant, while SP1 plants failed to tolerate to P-deficiency conditions; only IR64-Pup1 (Pup1) showed strong P-deficiency tolerance phenotype. In submerged conditions, the expression levels of Sub1A and PSTOL1, major genes for Sub1 and Pup1 QTLs, respectively, were not significantly different in between Pup1 and SP1 plants. On the other hand, the expression of both Sup1A and PSTOL1 was significantly downregulated in P-deficiency conditions, suggesting that Sub1 and Pup1 repressed gene expression each other in P-deficiency conditions. These results suggest Pup1 does not compromise the Sub1 function in submerged conditions while Sub1 suppresses the function of Pup1 in (P)-deficient condition, possibly by regulating transcript level of Pup1. In conclusion, Sub1 and Pup1 are functionally compatible in terms of submergence tolerance but not in P-deficiency conditions. Further analysis need to be performed to elucidate how Sup1 suppresses the function of Pup1 in P-deficiency conditions.

• 대한조선학회논문집
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• 제34권1호
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• pp.50-59
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• 1997

선박의 시운전 수행 이전에 엔진 및 프로펠러의 작동상태를 체크하기 위하여 때때로 안벽계류 중에서 주기 및 발전기의 성능시험을 수행하는 데, 이때 주기관을 100% 작동시키는 것은 계류용 로프 및 안벽 비트의 강도 문제등의 여러가지 위험 부담을 갖게 된다. 본 연구는 이러한 시험에 대한 안전성 검토를 위해 필요한 프로펠러의 추력의 추정을 목적으로 하고 있다. 대상선은 최근에 건조한 대형 컨테이너선이며, 실선시험은 안벽계류 상태에서 수행되었기 때문에 프로펠러는 수면위로 노출되어 있는 상태에서 작동되었다. 이러한 낮은 프로펠러 축 몰수 수심에서 작동하는 안벽계류 상태에서의 프로펠러의 특성을 조사하기 위해 모형시험을 수행하였으며, 이들 시험결과로부터 안벽계류 시험중의 프로펠러의 추력에 관한 약산식이 도출되었다. 그 결과 프로펠러의 특성은 축 수심에 따라 크게 달라지는 것을 알 수 있으며, 특히 축 수심이 작아 프로펠러가 수면위에 노출되어 있는 경우에는, 같은 축 수성에서도 프로펠러 회전수에 지배되는 특성이 파악되었다. 한편 심수 중에서 작동하는 프로펠러에 대해서도 추력에 대한 추정식을 도출하여 실선 시험 담당자가 사용하기 쉽게 하였으며, bollard pull에서의 FPSO(Floating Production Storage and Offloading tanker based system) 의 프로펠러의 추력 계측값과 비교 검토 하였다.

• 한국해양공학회지
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• 제36권2호
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• pp.83-90
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• 2022

This paper presents the minimum submergence depth of an underwater vehicle that can remove the effect of free surface on the resistance of the underwater vehicle. The total resistance of the underwater vehicle in fully submerged modes comprises only viscous pressure and friction resistances, and no wave resistance should be present, based on the free surface effect. In a model test performed in this study, the resistance is measured in the range of 2 to 10 kn (1.03-5.14 m/s) under depth conditions of 850 mm (2.6D) and 1250 mm (3.8D), respectively, and the residual resistance coefficients are compared. Subsequently, resistance analysis is performed via computational fluid dynamics (CFD) simulation to investigate the free surface effect based on various submergence depths. First, the numerical analysis results in the absence of free surface conditions and the model test results are compared to show the tendency of the resistance coefficients and the reliability of the CFD simulation results. Subsequently, numerical analysis results of submergence depth presented in a reference paper are compared with the model test results. These two sets of results confirm that the resistance increased due to the free surface effect as the high speed and depth approach the free surface. Therefore, to identify a fully submerged depth that is not affected by the free surface effect, case studies for various depths are conducted via numerical analysis, and a correlation for the fully submerged depth based on the Froude number of an underwater vehicle is derived.

• Journal of Applied Biological Chemistry
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• 제44권4호
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• pp.159-162
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• 2001

Plant stress incurred by flooding was studied in terms of oxidative stress, using greened rice seedlings subjected to a complete submergence followed by re-exposure to air under illumination ($30W/m^2$). It appeared that shoot tissues of the seedlings suffered oxygen deficiency during the flooding treatment, pertinent to the general concept. Interestingly enough, however, membrane peroxidation in shoots was enhanced by the submergence, as assessed by the content of 2-thiobarbituric acid-reactive substances (TBARS), and the re-aeration resulted in a rapid reduction of TBARS content. Such pattern of response was also seen in the change in the steady state level of $H_2O_2$. In contrast, superoxide dismutase and glutathione reductase that are involved in the detoxifying processes of superoxide in plant cells were significantly activated only during the re-aeration. These results allowed us to suggest the followings as a working hypothesis. Photorespiration-linked production of $H_2O_2$ may largely contribute to the increase in $H_2O_2$ level as well as TBARS production in shoots during the submergence. An abrupt re-supply of $CO_2$ by the re-aeration brings the photosynthetic apparatus back to full operation, suppressing photorespiration and probably causing a momentary, excess formation of superoxide and its dismutation product through side reaction, which gives rise to activating substrate-inducible antioxidative enzymes.

• 설비공학논문집
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• 제19권4호
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• pp.313-320
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• 2007

In this paper, the experimental study has been carried out to investigate the reliability lifetime of two bearing units based on the oil temperature. Measurements for the oil temperature as well as the bearing temperature during normal operation were performed to study the effects of oil viscosity and oil submergence percentages in the two bearing units. The optimal lubrication condition to increase the lifetime of the bearing unit A was found that its viscosity and submergence percentage were VG32 and 25%, respectively. For the bearing unit B, when the oil viscosity and submergence percent were VG32 and 75%, the lubrication condition was the most efficient. Finally, the adjusted rating times of both the bearing units were calculated to be over 28,000 h, which is greater than the minimum adjusted rating times of 25,000 h. Therefore, they satisfied the regulated lifetime of API 610.