• Title/Summary/Keyword: water deficiency

Search Result 294, Processing Time 0.026 seconds

Simulation of Water Quality Changes in the Saemangeum Reservoir Induced by Dike Completion (방조제 완공에 따른 호내부 수질변화 모의)

  • Suh, Seung-Won;Lee, Hwa-Young;Yoo, Sang-Cheol
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.22 no.4
    • /
    • pp.258-271
    • /
    • 2010
  • In order to figure out hydrodynamic and water quality changes after completion of dike construction of the Saemangeum, which behaves as a semi-enclosed estuarine lake, numerical simulations based on fine grid structure by using EFDC were intensively carried out. In this study some limitations of precedent study has been improved and gate operation were considered. Also 3 phases such as air-water-sediment interaction modeling was considered. It is clear that inner mixing of the Saemangeum is dominated by Mankyeong and Dongjin riverine discharges rather than the gate opening influence through the Lagrangian particle tracking simulations. Vertical DO structure after the dike completion shows steep gradient especially at Dongjin river estuary due to lessen of outer sea water exchange. Increasing SOD at stagnantly changed man-made reservoir might cause oxygen deficiency and accelerating degradation of water quality. According to TSI evaluation test representing eutrophication status, it shows high possibility of eutrophication along Mankyeong waterway in spite of dike completion, while the index is getting high after final closing along Dongjin waterway. Numerical tests with gate operations show significant differences in water quality. Thus it should be noted that proper gate operation plays a major role in preserving target water quality and management for inner development plan.

Characteristics and management of citrus orchard soils in Jeju (제주도(濟州道) 감귤원토양(柑橘園土壤)의 특성(特性)과 관리(管理))

  • Park, Hoon;Yoo, Sun-Ho;Hong, Soon Beum
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.8 no.3
    • /
    • pp.135-152
    • /
    • 1975
  • The following informations are known from physical and chemical characteristics of orchard soils and nutritional diagnosis of orange leaves in Jeju. 1. Most orange orchards are located on terrace and cindercone thus soil moisture and microclimate of an orchard will greatly be affected by its topography. 2. Excessive well drainage, shallow soil depth, high content of gravels, low solid phase ratio and strong wind will give severe problem of soil moisture and wind errosion, thus the exte- nsion of soil depth is necessary for maintain nutrients, water and sufficient root volume. 3. Available soil water was significantly and positively correlated with organic matter content and clay content also contributes to available soil water. Vinyl mulching was greatly helpful for soil water conservation, wind errosion prevention, soil temperature increases during winter. 4. Abundant amphoteric amorphous allophane take a key role to fix phosphorus and also rations and thus it is the major factor to determine fertilizer efficiency. Lime and phosphorus must be applied in deeper soil layer. Release of filed phosphorus must be reevluated for availability. 5. Organic matter such as see weeds will greatly increase fertilizer efficiency and low fertilizer efficiency during spring may be related to available soil water. 6. Nitrogen was in superoptimum and Mg was enough but P and Ca were somewhat deficient according to leaf analysies while K was deficient according to fruit analysis. Phosphorus application increased sugar/acid ratio and potassium decreases rind percentage. 7. Manganese deficiency and toxicity appeared in a few places. Iron and boron were enough. Most places showed tendency of copper excess but some places showed copper deficiency. 8. Soiling after elimination of rock base, application of slow release fertilizer and abundant organic matter, vinyl mulching and drip irrigation will increase fertilizer efficiency greatly and fruit yield drastically.

  • PDF

The Effect of Salt Contents in Diet and Water on Performance and Physiological Changes in Broiler Chicks (염분 수준이 육계 병아리의 생산성과 생리적인 변화에 미치는 영향)

  • HwangBo J.;Hong E.C.;Lee B.S.;Lee H.J.;Jo Seong-Baek;Bae H.D.;Lee S.J.;Nho W.G.
    • Korean Journal of Poultry Science
    • /
    • v.33 no.2
    • /
    • pp.159-164
    • /
    • 2006
  • To investigate the effects of salt contents in diet and water on the growth of broiler chicks, 288 heads of Hubbards strain chicks, were fed with com-soybean meal diets containing 0, 0.25, 0.5, 0.75 1.0, 2.0, 3.0, or 4.0% salt from 1d to l4d posthatching. And 180 chicks were also supplemented with salt to their water at 0, 0.1, 0.2, 0.5 or 1.0%. Feed intake and weight gain tended to decrease as the salt levels in diets increased and those were the lowest in 4% group as 481 g and 168 g, however, mortality was the highest in 4% group as 75.0%. As for the salt levels in water, feed intake and weight gain were low as 427 g and 162 g in 1% group, while mortality was 77.8%. Salt poisoning chicks were shown with thirsty, appetite deficiency, rising impossibility, sleepiness, or convulsions, and in autopsy, were shown with ascites, hydropericardium, cardiac hypertrophy, hemorrhage of eyelid, hemorrhage of trachea, hemorrhage of intestine, etc. Conclusively, salt content above 4% in diet or 1% in water could reduce the performance in broiler chicks.

Studies of application of artificial ground freezing for a subsea tunnel under high water pressure - focused on case histories - (고수압 해저터널 건설을 위한 동결공법 적용성에 관한 연구 - 사례를 중심으로 -)

  • Son, Young-Jin;Lee, Kyu-Won;Ko, Tae Young
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.16 no.5
    • /
    • pp.431-443
    • /
    • 2014
  • In this paper case studies of artificial ground freezing, which have not been applied in Korea, have been investigated for the water cut-off in a subsea tunnel under high water pressure and the most commonly used cooling mediums of brine and liquid nitrogen are examined. Since sea water with pressure has the lower freezing point than pure water, the lower temperature cooling medium is required in the application of subsea tunnel. Also, the cooling medium must have refrigeration safety and is able to reduce executing time. Brine freezing system can reuse cooling medium and is safer than liquid nitrogen freezing. But it takes more time to freeze ground and needs complex circulation plants. On the other hand, liquid nitrogen freezing system can't recycle cooling medium and may cause breathing problems or asphyxiation through oxygen deficiency. But, freezing with liquid nitrogen is fast and requires simple refrigeration equipment. Principal elements of design for ground freezing in subsea tunnel have been extracted and these elements are needed further research.

Biological Significance of Essential Fatty Acids/Prostanoids/Lipoxygenase-Derived Monohydroxy Fatty Acids in the Skin

  • Ziboh, Vincent-A.;Cho, Yunhi;Mani, Indu;Xi, Side
    • Archives of Pharmacal Research
    • /
    • v.25 no.6
    • /
    • pp.747-758
    • /
    • 2002
  • The skin displays a highly active metabolism of polyunsaturated fatty acids (PUFA). Dietary deficiency of linoleic acid (LA), an 18-carbon (n-6) PUFA, results in characteristic scaly skin disorder and excessive epidermal water loss. Although arachidonic acid (AA), a 20-carbon (n6) PUFA, is metabolized via cyclooxygenase pathway into predominantly prostaglandin $E_2(PGE_2)$ and $PGF_{2{\alpha}}$, the metabolism of AA via the 15-lipoxygenase (15-LOX) pathway, which is very active in skin epidermis and catalyzes the transformation of M into predominantly 15S-hydroxyeicosatetraenoic acid (15S-HETE). Additionally, the 15-LOX also metabolizes the 18-carbon LA into 13S-hydroxyoctadecadienoic acid (13S-HODE), respectively. Interestingly, 15-LOX catalyzes the transformation of $dihomo-{\gamma}-linolenic$ acid (DGLA), derived from dietary gamma-linolenic acid, to 15S-hydroxyeicosatrienoic acid (15S-HETrE). These monohydroxy fatty acids are incorporated into the membrane inositol phospholipids which undergo hydrolytic cleavage to yield substituted-diacylglycerols such as 13S-HODE-DAG from 13S-HODE and 15S-HETrE-DAG from 15S-HETrE. These substituted-monohydroxy fatty acids seemingly exert anti-inflammatory/antiproliferative effects via the modulation of selective protein kinase C as well as on the upstream/down-stream nuclear MAP-kinase/AP-1/apoptotic signaling events.

On-the-go Nitrogen Sensing and Fertilizer Control for Site-specific Crop Management

  • Kim, Y.;Reid, J.F.;Han, S.
    • Agricultural and Biosystems Engineering
    • /
    • v.7 no.1
    • /
    • pp.18-26
    • /
    • 2006
  • In-field site-specific nitrogen (N) management increases crop yield, reduces N application to minimize the risk of nitrate contamination of ground water, and thus reduces farming cost. Real-time N sensing and fertilization is required for efficient N management. An 'on-the-go' site-specific N management system was developed and evaluated for the supplemental N application to com (Zea mays L.). This real-time N sensing and fertilization system monitored and assessed N fertilization needs using a vision-based spectral sensor and controlled the appropriate variable N rate according to N deficiency level estimated from spectral signature of crop canopies. Sensor inputs included ambient illumination, camera parameters, and image histogram of three spectral regions (red, green, and near-infrared). The real-time sensor-based supplemental N treatment improved crop N status and increased yield over most plots. The largest yield increase was achieved in plots with low initial N treatment combined with supplemental variable-rate application. Yield data for plots where N was applied the latest in the season resulted in a reduced impact on supplemental N. For plots with no supplemental N application, yield increased gradually with initial N treatment, but any N application more than 101 kg/ha had minimal impact on yield.

  • PDF

Effects of dietary taurine supplementation on plasma and liver lipids in OVX rats fed calcium-deficient diet

  • Choi, Mi-Ja
    • Nutrition Research and Practice
    • /
    • v.2 no.1
    • /
    • pp.13-16
    • /
    • 2008
  • Taurine supplementation has been shown to have an effect on lowering blood lipids in ovariectomized (OVX) rats. It therefore seemed desirable to find out whether the beneficial effect of taurine on OVX rats fed calcium-deficient diet could also be reproduced. Forty female Sprague-Dawley rats were divided into two groups. One group was OVX and the other group received a sham operation (Sham). Each rat group was further divided into the control diet and the taurine supplemented (2.0g/100g diet) diet group. All rats were fed on calcium-deficient diet and deionized water ad libitum for 6 weeks. Plasma and liver lipids were determined by using commercial kits. LDL-cholesterol concentrations were estimated with the equation of Friedewald et al. (1972). There were no significant differences in body weight gain and food intake between the control and taurine group within Sham and OVX groups, but body weight gain, food intake, and food efficiency ratio was higher in the OVX group. Concentrations of plasma total cholesterol, triglyceride, LDL-cholesterol were significantly lower in the taurine fed group of OVX rats fed Ca deficient diet, while HDL-cholesterol concentration was increased in the taurine fed group. Therefore, in this study, we examined whether taurine also prevented hypercholesterolemia induced by ovarian hormone deficiency in ovariectomized rats when they were fed a calcium-deficient diet. These results indicate that taurine may have some beneficial effects on hypercholesterolemia and hypertriglyceridemia in OVX rats fed calcium-deficient diet.

Study on Suk Gock's Fortify Yang Theory (석곡 이규준의 부양이론에 관한 연구)

  • Hwang Won Duek
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.18 no.3
    • /
    • pp.713-723
    • /
    • 2004
  • With regard of YinYang and Five Elements Theory, predominance of Yin or Yang is a key point to discuss Nourishin Ying or Reinforcing Yang. There are two major branches about studying predominance of Yin or Yang. Zhu Danxi advocated the theory that Yang was always in excess while Yin was often deficient, and thus belonged to the School for Nourishing the Yin. Zhang Jie-bin advocated that Yang is easily deficient while Yin is easily sufficient. It seems that they studied Wang Bing's 'Ministerial fire rule on all thing instead of Imperial Fire' and right Kidney Mingmen theory in Nan Jing, which are both related to the First Yang in the Book of Changes and say Mingmen fire is the host of the body. Zhu Danxi insisted that Mingmen fire was easily in excess and likely to become pathogenic fire while Water phase was easily in deficiency, so the doctors should nourish Yin and suppress Yang. Zhang Jie-bin said that Mingmen fire is vulnerable so the doctors should fortify yang and reinforce Mingmen fire. Suk Gock Master Lee thought that the Book of Changes and Nei Jing had a viewpoint of Fortify Yang as regards of some distinguished Physicians' articles about predominance of YinYang. The author's going to discribe Suk Gock's Fortify Yang Theory with viewpoints of Nei Jing and the Book of Changes.

Frequent Urination of Old People and Hyungsang Medicine (노인(老人) 소변단소(小便短少)의 형상의학적(形象醫學的) 고찰(考察))

  • Kang, Kyung-Hwa;Song, Moon-Sung;Lee, Yong-Tae
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.19 no.1
    • /
    • pp.38-43
    • /
    • 2005
  • The following conclusions are drawn from the review on the frequent urination of old people in perspective of Hyungsang medicine: Frequent urination is a difficulty in urination that is often common to old people. Frequent urination is one of the symptoms occurred when the nine body orifices do not operate normally because Jung(精) and Blood(血) are exhausted with ages. Frequent urination is brought by the deficiency of kidney, bladder and lung's Ki. In six meridian type persons, Yangmyung meridian type persons are most often afflicted with frequent urination because earth checks water(土克水). Persons with big cheek bones are easy to be caught by frequent urination due to the consumption of Jung(精) and Blood(血). Frequent urination is the source of geriatric diseases so that it should be treated preferentially. Frequent urination of old people should be treated with tonic prescription(補劑).

The Effect of Dietary Calcium Level on Bone Mineral Density and Bone Mineral Content in Ovariectomized Female Rats (난소절제한 흰쥐에서 식이칼슘량이 골밀도에 미치는 영향)

  • 김경희
    • Journal of Nutrition and Health
    • /
    • v.29 no.6
    • /
    • pp.590-593
    • /
    • 1996
  • This study was done to evaluate the effect of dietary calcium level (a diet which met 100% or twice the calcium level in AIN-76 diet) on preventing bone loss in ovariectomized rats. Forty Sprauge-Dawley female rats(body weight 200$\pm$5g)were divided into two groups. One group were ovariecotomized (Ovx) while the others received sham operation(Sham). Thereafter, each rat group was further divided into normal calcium diet(0.52%) and high calcium diet(1.04%) subgroups. All rats were fed on experimental diet and deionized water ad libitum for 8 weeks. The total body, spine and femur bone mineral densities and bone mineral contents were measured by Dual Energy X-ray Absorptiometry, Eight weeks following operation, ovariectomized rats fed a high calcium diet had a significantly higher total bone mineral content, total bone calcium content, spine bone mineral density, spine bone mineral content and femur bone mineral content than ovariectomized rats fed control calcium diet. The correlation between dietary calcium intake level and spine bone mineral density were positive, but there was no correlation between dietary calcium intake and femur bone mineral density. The findings from the present study demonstrated that bone loss due to ovarian hormonal deficiency can be partially prevented by a high calcium diet. Futhermore, these findings support the strategy of the use of a high calcium diet in the prevention of estrogen depleted bone loss(postmenopausal osteoporosis)

  • PDF