• The Korea Journal of Herbology
• /
• v.27 no.4
• /
• pp.25-31
• /
• 2012

Objectives : The purpose of this study is searching for grounds of new regulations about submerging properties of Aquilariae Lignum described in the Korean Herbal Pharmacopoeia. Methods : Through the investigation of the various Chinese histories and herbal classics, the definitions of Aquilariae Lignum and documents on actual trade and discrimination methods by sinking under water. Results : In Jiaozhouyiwuzhi(交州異物志) written in the early 2nd century, Aquilariae Lignum was defined as heart wood part or knots sinking under water due to hard and dark deposition of resins. Also, which are not sinking were defined as zhan xiang(棧香), and which are floating were named as qian xiang(槧香). The definitions of Aquilariae Lignum had not been changed till Ching Dynasty era, but the classification and the names about not-sinking and floating Lignum materials were a little changed. Conclusions : These results indicate that it is reasonable to make a regulation that "Aquilariae Lignum sinks under water" in the property description of The Korean Herbal Pharmacopoeia.

• Journal of the Korean Geophysical Society
• /
• v.6 no.2
• /
• pp.49-56
• /
• 2003

Under the attack of storm waves, there are many destructions of coastal structures in the forms of sinking and sliding. There types of destructions will be in close relation to the dynamic behavior of sand bed around the structures. Form this point of view, in this pear, we investigate the characteristics of the pore water pressure and effective stresses in the highly saturated sand bed under oscillating water pressure theoretically. The results indicate that the oscillating water pressure induce the notable drop of strength of and bed around the structure under certain condition.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.31 no.4
• /
• pp.362-371
• /
• 1995

This study describes with the sinking behaviour for the purse seine. The experiment was carried out using three model purse seines of knotless netting. The nettings were woven in same leg length(10.5mm) of polypropylene 170 denier, polyamide 210 denier and polyester 250 denier two thread ply twine, each of the seines were named PP seine, PA seine and PES seine. Dimension of Purse seine models were 420cm for corkline and 85cm for seine depth, each models rigged 65.8g, 50.6g and 35.8g(weight in water) of lead for a leadline, seine models will have the same weight in water. Experiments carried out in the observation channel in a flume tank under still water conditions. Sinking motion was recorded by the one set of TV-camera for VTR, and reading coordinate carried out by the video digitization system. The results obtained were as follows: 1) Netting bundle for PP seine was existence on the surface of the water, spread out a netting by sinking force of sinkers. 2) Netting bundle for PES seine was existence in the middle of corkline and leadline. 3) Average sinking speed of seine margin was fastest for 10.7cm/s of PP seine, followed by 9.7cm/s of PA and 9.2cm/s of PES seines. 4) In all seines, the force of horizontal movement for the seine setting was values of ranged in disregard.

• Reproductive and Developmental Biology
• /
• v.37 no.3
• /
• pp.97-102
• /
• 2013

The objective of this study was to develop of semen transport system for cryopreservation and fertility in bull sperm. The ejaculated semen were diluted with Triladyl containing 20% egg-yolk for transportation. Diluted semen was transported by three methods that there were wrapping tissue (Tissue), sinking under $30^{\circ}C$ water (Water) and sinking between warm water and air (Air) methods. Semen was transported within 2 hours in $0.3^{\circ}C$. For this study, the freezing of diluted semen were added with Triladyl containing 20% egg-yolk. And frozen-thawed sperm were estimated with SYBR14/PI double stain for viability, FITC-PNA/PI double stain for acrosome reaction analysis and Rhodamine123 double stain for mitochondrial intact assessment. In results, live sperm (SYBR+/PI-) in Air treatment group ($43.3{\pm}4.7%$) was significantly (p<0.05) higher than other treatment groups (Tissue: $16.3{\pm}2.7%$ and Water: $27.5{\pm}3.1%$), dying sperm (SYBR+/PI+) in Air treatment group ($55.6{\pm}4.7%$) was significantly lower than other treatment groups (Tissue: $77.6{\pm}3.2%$ and Water: $67.6{\pm}3.3%$) (p<0.05). Acrosome reaction in Air treatment group ($0.2{\pm}0.1%$) within live sperm (PI negative region) was significantly (p<0.05) lower than other treatment groups (Tissue: $0.7{\pm}0.2%$ and Water: $0.5{\pm}0.1%$), the acrosome reaction in Air treatment group ($28.6{\pm}2.8%$) within all sperm also was significantly lower than other treatment groups (Tissue: $44.2{\pm}1.8%$ and Water: $36.2{\pm}2.0%$) (p<0.05). And mitochondrial intact in Air treatment group within live ($97.1{\pm}0.4%$) and all ($61.9{\pm}3.3%$) sperm were significantly higher than other treatment groups (Tissue: $85.2{\pm}3.3%$, Water: $87.8{\pm}2.9%$ within live sperm and Tissue: $49.28{\pm}3.7%$, Water: $42.0{\pm}3.1%$ within all sperm) (p<0.05). Therefore, we suggest that transportation by sinking method between warm water and air was beneficial to improvement of fertility in frozen-thawed in bull semen.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.40 no.1
• /
• pp.29-36
• /
• 2004

This study deals with an analysis on the sinking resistance for the model purse seine, in the case of different netting material and sinkers. The experiment was carried out using rune simplified model seines of knotless nettings. Dimension of model seines 420cm for corkline and 85cm for seine depth, three groups of models rigged 25, 45 and 60g with the same weighted sinkers in water were used. These were named PP-25, PA-25, PES-25, PP-45, PA-45, PES-45, PP-60, PA-60 and PES-60 seine. The densitie($\rho$) of netting materials were 0.91g/cm$cm^3$, 1.14g/cm$cm^3$ and 1.38g/cm$m^3$. Experiments carried out in the observation channel in a flume tank under still water conditions. Sinking motion was recorded by the one set of TV-camera for VTR, and reading coordinate carried out by the video digitization system. Differential equations were derived from the conservation of momenta of the model purse seines and used to determine the sinking speeds of the depths of leadline and the other portions of the seines. An analysis carried out by simultaneous differential equations for numerical method by sub-routine Runge-Kutta-Gill The results obtained were as follows : 1. Average sinking speed of leadline for the model seines rigged 60g with the same weighted sinkers in water was fastest for 12.2cm/sec of PES seine, followed by 11.4cm/sec of PA and 10.7cm/sec of PP seines. 2. The coefficient of resistance for netting of seine was estimated to be $K_D=0.09(\frac{\rho}{\rho_w})^4$ 3. The coefficient of resistance for netting bundle of seine was estimated to be $C_R=0.91(\frac{\rho}{\rho_w})$ 4. In all seines, the calculated depths of leadline closely agreed with the measured ones, each 25g, 45g, 60g of weighted sinkers were put into formulas meas.=1.04cal., meas.=0.99cal. and meas.=0.98 cal.

• Journal of Biosystems Engineering
• /
• v.38 no.4
• /
• pp.240-247
• /
• 2013

Purpose: This study was conducted to develop a rubber-crawler type vehicle as a traveling device for harvesting water-dropwort cultivated in water contained paddy rice field in winter season. Methods: A commercial rubber-crawler type vehicle was used to investigate application of rubber crawler to the paddy rice field as preliminary test. As the result of the preliminary test, a both prototype traveling device with rubber crawlers for a water-dropwort harvest was designed with inclination of $45^{\circ}$ at the front-end and rear-end of crawler under the basic water depth of 0.6 m in the paddy rice field. The device was fabricated and attached to the experimental harvesting test devices on the front of the prototype vehicle. The size of the prototype crawler vehicle with a harvesting part is $2,800{\times}1,460{\times}1,040 $ (mm) ($L{\times}W{\times}H$) with weight of 9.21 kN (maximum). Sizes of the crawler of prototype vehicle are ground contact length of 900 mm, width of 180 mm, height of 1,070 mm and distance between center to center of crawlers of 720 mm. The side-overturn angle of the prototype was $26.4^{\circ}$. Results: Driving performance of the prototype vehicle in water contained paddy field were good at both forward and reverse (backward) directions as weights were applied. The drawbar pull and the maximum sinking depth of the prototype vehicle were 3.5 kN and 0.13 m respectively at water depth of 0.5 m, when the weight and bearing capacity of the prototype rubber crawler in the paddy field were 8.51 kN and 26.3 $kN/m^2$, respectively. Conclusions: Results of the driving test performance of the prototype crawler in paddy rice field at the water depth of 0.5 m were satisfactory. The prototype had enough drawbar pull and driving ability in the deep water contained paddy field.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.31 no.4
• /
• pp.372-378
• /
• 1995

This study describes an analysis on the sinking characteristics in purse seine. The experiment was carried out using three simplified model seines in a flume tank under still water condition. The densities($\rho$) of netting materials were 0.91g/$cm^3$ for PP seine, 1.14g/$cm^3$ for PA seine and 1.38g/$cm^3$ for PES seine. Differential equations were derived from the conservation of momenta of the model seines and used to determine the sinking speeds of the depths of leadline and the other portions of seines. An analysis carried out by simultaneous differential equations for numerical method by subroutine Runge-Kutta-Gill. The results obtained were as follows: 1) Sinking speed of net margin was fastest for PP seine, followed by PA and PES seines. 2) The coefficient of resistance for netting of seine was estimated to be $K_D=0.061({\frac{\rho}{{\rho}_w}})^4$. 3) The coefficient of resistance for netting bundle of seine was estimated to be $C_R=0.91({\frac{\rho}{{\rho}_w}}$. 4) In all seines, the calculated depths of leadline closely agreed with the measured ones(meas.=0.99cal.).

• Journal of the Korean Professional Engineers Association
• /
• v.43 no.1
• /
• pp.26-31
• /
• 2010

The changes of climate and earth environment caused by Global Warming has seriously occurred recently. For instance, the water in the Chad Lake in Africa has continuously disappeared and Tuvalu in the South Pacific is facing a serious natural disaster with that the entire country is sinking under the sea. These natural disasters become a serious risk threatening the existence of the human-race. Therefore, we needs a fundamental measure to prevent Global Warming. That is a natural phenomenon that makes the earth warmer by 6 types a greenhouse gas including $CO_2So$ we look for an answer from the 'Green Growth' movement.

• Journal of the Korean Institute of Navigation
• /
• v.25 no.4
• /
• pp.417-422
• /
• 2001

Every ship might be exposed to collision, grounding and/or various accidents. They may make some underwater holes on the hull. An underwater damage would cause her loss of buoyancy, trim, and inclination. Although a ship has some provisions against these accidents, if the circumstance is serious, she would be sunk or upsetted. Because of varieties of type of accidents, one could not prepare all of them. Many subdivision could prevent them, but it is difficult to realize it due to rising costs. This paper deals with physical phenomena of sinkage and an application on box type ship, and some results are earned as follows； 1. sinkage speed up to the level of the damage hole is increased proportionally, and is decreased proportionally after filling the level. 2. the curve of draft shows cup type of second order polynomial up to the damage hole level, and shows cap type of second order polynomial after filling the level. 3. if damage occurs beneath half of the draft, changes of head and displacement, and sinking speed follow almost straight lines. 4. by careful observation, sinkage speed could be predicted.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.23 no.4
• /
• pp.267-279
• /
• 1990

The temporal and spatial distribution of the coastal cold waters which was formed due to winter colling in the South Sea of Korea was analyzed by IR images from satellite and in situ data from shipboard observations. The coastal waters are known to be consisted of the Yellow Sea Coastal Waters(YSCW) and the South Korean Coastal Waters(SKCW). The former is driven around the Chuja-do and drifted into the Cheju Strait by residual currents, while the latter expands toward offsea by southward wind forcing. The expansion patterns of the SKCW were observed as sinking expansion or drifting expansion such that both were strongly dependent on the surface heat flux conditions. Under the condition of positive heat flux(warmer sea surface) or when the sea surface heat is lost to the atmosphere, the surface water started sinking and eventually expanded toward the open sea causing the cooling of the water column. For the negative heat flux the surface water was just drifted horizontally and expanded seaward and in this case only the surface layer of water was cooled.