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Geology of Athabasca Oil Sands in Canada (캐나다 아사바스카 오일샌드 지질특성)

  • Kwon, Yi-Kwon
    • The Korean Journal of Petroleum Geology
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    • v.14 no.1
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    • pp.1-11
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    • 2008
  • As conventional oil and gas reservoirs become depleted, interests for oil sands has rapidly increased in the last decade. Oil sands are mixture of bitumen, water, and host sediments of sand and clay. Most oil sand is unconsolidated sand that is held together by bitumen. Bitumen has hydrocarbon in situ viscosity of >10,000 centipoises (cP) at reservoir condition and has API gravity between $8-14^{\circ}$. The largest oil sand deposits are in Alberta and Saskatchewan, Canada. The reverves are approximated at 1.7 trillion barrels of initial oil-in-place and 173 billion barrels of remaining established reserves. Alberta has a number of oil sands deposits which are grouped into three oil sand development areas - the Athabasca, Cold Lake, and Peace River, with the largest current bitumen production from Athabasca. Principal oil sands deposits consist of the McMurray Fm and Wabiskaw Mbr in Athabasca area, the Gething and Bluesky formations in Peace River area, and relatively thin multi-reservoir deposits of McMurray, Clearwater, and Grand Rapid formations in Cold Lake area. The reservoir sediments were deposited in the foreland basin (Western Canada Sedimentary Basin) formed by collision between the Pacific and North America plates and the subsequent thrusting movements in the Mesozoic. The deposits are underlain by basement rocks of Paleozoic carbonates with highly variable topography. The oil sands deposits were formed during the Early Cretaceous transgression which occurred along the Cretaceous Interior Seaway in North America. The oil-sands-hosting McMurray and Wabiskaw deposits in the Athabasca area consist of the lower fluvial and the upper estuarine-offshore sediments, reflecting the broad and overall transgression. The deposits are characterized by facies heterogeneity of channelized reservoir sands and non-reservoir muds. Main reservoir bodies of the McMurray Formation are fluvial and estuarine channel-point bar complexes which are interbedded with fine-grained deposits formed in floodplain, tidal flat, and estuarine bay. The Wabiskaw deposits (basal member of the Clearwater Formation) commonly comprise sheet-shaped offshore muds and sands, but occasionally show deep-incision into the McMurray deposits, forming channelized reservoir sand bodies of oil sands. In Canada, bitumen of oil sands deposits is produced by surface mining or in-situ thermal recovery processes. Bitumen sands recovered by surface mining are changed into synthetic crude oil through extraction and upgrading processes. On the other hand, bitumen produced by in-situ thermal recovery is transported to refinery only through bitumen blending process. The in-situ thermal recovery technology is represented by Steam-Assisted Gravity Drainage and Cyclic Steam Stimulation. These technologies are based on steam injection into bitumen sand reservoirs for increase in reservoir in-situ temperature and in bitumen mobility. In oil sands reservoirs, efficiency for steam propagation is controlled mainly by reservoir geology. Accordingly, understanding of geological factors and characteristics of oil sands reservoir deposits is prerequisite for well-designed development planning and effective bitumen production. As significant geological factors and characteristics in oil sands reservoir deposits, this study suggests (1) pay of bitumen sands and connectivity, (2) bitumen content and saturation, (3) geologic structure, (4) distribution of mud baffles and plugs, (5) thickness and lateral continuity of mud interbeds, (6) distribution of water-saturated sands, (7) distribution of gas-saturated sands, (8) direction of lateral accretion of point bar, (9) distribution of diagenetic layers and nodules, and (10) texture and fabric change within reservoir sand body.

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The Significance of 24-Hour Esophageal pH Monitoring in Children with Recurrent Vomiting or Regurgitation (반복성 구토 또는 역류증 환아에서 24시간식도 산도 측정의 의의)

  • Lee, So-Hyun;Lee, Chang-Han;Chung, Ki-Sup
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.2 no.2
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    • pp.139-146
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    • 1999
  • Purpose: The aim of this study was to evaluate the clinical significance of 24 hour pH monitoring in the pediatric patients with recurrent vomiting or regurgitation. Methods: We performed 24 hour pH monitoring on 87 pediatric patients with recurrent vomiting or regurgitation using GastrograpH with glass electrode. The pathologic GER was determined by the reflux index (RI). RIs>10% were considered positive in patients <1 year of age, whereas RIs of >5% were positive in other age groups. We evaluated the mean and standard deviation of the reflux parameters between physiologic and pathologic GER groups, and also compared the reflux indices of each group with respect to time zones of the day. Results: Pathologic GER was found in 32 of 87 patients (36.8%), and the age incidence included 32.5% in infants <6 months old, 13.3% in infants aged 6 months-1 year old, 61.5% in children aged 1~2 years old, 14.3% in children aged 2~3 years old and 66.7% in children >3 years old. In physiologic GER patients, the RI was $3.7{\pm}2.9%$ for the patients <1 year old (group A), and $1.8{\pm}1.5%$ for those ${\geq}1$ year old (group B) which was statistically significant between the 2 age groups (p=0.02). The number of long refluxes more than 5 minutes was significantly increased (p=0.03) in group A ($1.7{\pm}1.9$) than in group B ($0.8{\pm}1.0$). The duration of the longest reflux was significantly longer (p=0.007) in group A ($604{\pm}551$ sec) than in group B ($275{\pm}296$ sec). In pathologic GER patients, the RI was $17.7{\pm}11.6%$ for the patients <1 year old and $7.8{\pm}2.9$ for those ${\geq}1$ year old. The number of long refluxes of more than 5 minutes were $8.9{\pm}4.6$ and $3.2{\pm}1.8$, and the duration of the longest reflux were $1955{\pm}2190$ sec and $1093{\pm}706$ sec for each age group. In both physiologic and pathologic GER patients, there was no significant difference of RI among the time zones of the day. Conclusion: Pathologic GER was found in 36.8% of patients. There was significant difference of RI between those <1 year old and those ${\geq}1$ year old in physiologic GER patients. There was no significant difference of RI among the time zones of the day in both pathologic and physiologic groups. In our study, the frequency of pathplogic GER was too much higher in age group of 1~2 years old (61.5%) than in group of 6 months-1 year old (13.3%), which means that further study is needed to determine the pathologic criteria of RI (Vandenplas criteria is >5%) in the age group of 1~2 years old.

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Incidence of Hypertension in a Cohort of an Adult Population (성인코호트에서 고혈압 발생률)

  • Kam, Sin;Oh, Hee-Sook;Lee, Sang-Won;Woo, Kook-Hyeun;Ahn, Moon-Young;Chun, Byung-Yeol
    • Journal of Preventive Medicine and Public Health
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    • v.35 no.2
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    • pp.141-146
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    • 2002
  • Objectives : This study was peformed in order to assess the incidence of hypertension based on two-years follow-up of a rural hypertension-free cohort in Korea. Methods : The study cohen comprised 2,580 subjects aged above 20 (1,107 men and 1,473 women) of Chung-Song County in Kyungpook Province judged to be hypertensive-free at the baseline examination in 1996. For each of two examinations in the two-year follow-up, those subjects free of hypertension were followed for the development of hypertension to the next examination one year (1997) and two years later (1998). The drop-out rate was 24.7% in men and 19.6% in women. Hypertension was defined as follows 1) above mild hypertension as a SBP above 140 mmHg or a DBP above 90 mmMg,2) above moderate hypertension as a SBP above 160 mmHg or a DBP above 100 mmHg or when the participant reported having used antihypertensive medication after beginning this survey. Results : The age-standardized incidence of above mild hypertension was 6 per 100 person years (PYS) in men and that of above moderate hypertension was 1.2. In women, the age-standardized rate for above mild hypertension was 5.7 and 1.5 for above mild and moderate hypertension, respectively. However, the rates of incidence as calculated by the risk method were 4.8% and 1.0% in men and 4.6%, 1.2% in women, respectively. In both genders, incidence was significantly associated with advancing age(p<0.01), In men, the incidences of above moderate hypertension by age group were 0.5 per 100 PYS aged 20-39, 0.7 aged 40-49, 1.7 aged 50-59, 3.6 aged 60-69, and 5.8 aged above 70(p<0.01). In women, those the incidence measured 0.6 per 100 PYS aged 20-39, 1.8 aged 40-49, 1.3 aged 50-59, 3.3 aged 60-69, and 5.6 aged above 70(p<0.01). After age 60, the incidence of hypertension increased rapidly. Conclusions : The incidence data of hypertension reported in this study may serve as a reference data for evaluating the impact of future public efforts in the primary prevention of hypertension in Korea.

Trends of Study and Classification of Reference on Occupational Health Management in Korea after Liberation (해방 이후 우리나라 산업보건관리에 관한 문헌분류 및 연구동향)

  • Ha, Eun-Hee;Park, Hye-Sook;Kim, Young-Bok;Song, Hyun-Jong
    • Journal of Preventive Medicine and Public Health
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    • v.28 no.4 s.51
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    • pp.809-844
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    • 1995
  • The purposes of this study are to define the scope of occupational health management and to classify occupational management by review of related journals from 1945 to 1994 in Korea. The steps of this study were as follows: (1) Search of secondary reference; (2) Collection and review of primary reference; (3) Survey; and (4) Analysis and discussion. The results were as follows ; 1. Most of the respondents majored in occupational health(71.6%), and were working in university (68.3%), males and over the age 40. Seventy percent of the respondents agreed with the idea that classification of occupational health management is necessary, and 10% disagreed. 2. After integration of the idea of respondents, we reclassified the scope of occupational health management. It was defined 3 parts, that is , occupational health system, occupational health service and others (such as assessment, epidemiology, cost-effectiveness analysis and so on). 3. The number of journals on occupational health management was 510. It was sightly increased from 1986 and abruptly increased after 1991. The kinds of journals related to occupational health management were The Korean Journal of Occupational Medicine(18.2%), Several Kinds of Medical Colloge Journal(17.0%), The Korean Journal Occupational Health(15.1%), The Korean Journal of Preventive Medicine(15.1%) and others(34.6%). As for the contents, the number of journals on occupational health management systems was 33(6.5%) and occupational health services 477(93.5%). Of the journals on occupational health management systems, the number of journals on the occupational health resource system was 15(45.5%), occupational finance system 8(24.2%), occupational health management system 6(18.2%), occupational organization 3(9.1%) and occupational health delivery system 1 (3.0%). Of the journals on occupational health services, the number of journals on disease management was 269(57.2%), health management 116(24.7%), working environmental management 85(18.1%). As for the subjects, the number of journals on general workers was 185(71.1%), followed by women worker, white coiler workers and so on. 4. Respondents made occupational health service(such as health management, working environmental management and health education) the first priority of occupational health management. Tied for the second are quality analysis(such as education, training and job contents of occupational health manager) and occupational health systems(such as the recommendation of systems of occupational and general disease and occupational health organization). 5. Thirty seven respondents suggested 48 ideas about the future research of occupational health management. The results were as follows: (1) Study of occupational health service 40.5%; (2) Study of organization system 27.1%; (3) Study of occupational health system (e.g. information network) 8.3%; (4) Study of working condition 6.2%; and (5) Study of occupational health service analysis 4.2%.

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Quantitative Differences between X-Ray CT-Based and $^{137}Cs$-Based Attenuation Correction in Philips Gemini PET/CT (GEMINI PET/CT의 X-ray CT, $^{137}Cs$ 기반 511 keV 광자 감쇠계수의 정량적 차이)

  • Kim, Jin-Su;Lee, Jae-Sung;Lee, Dong-Soo;Park, Eun-Kyung;Kim, Jong-Hyo;Kim, Jae-Il;Lee, Hong-Jae;Chung, June-Key;Lee, Myung-Chul
    • The Korean Journal of Nuclear Medicine
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    • v.39 no.3
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    • pp.182-190
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    • 2005
  • Purpose: There are differences between Standard Uptake Value (SUV) of CT attenuation corrected PET and that of $^{137}Cs$. Since various causes lead to difference of SUV, it is important to know what is the cause of these difference. Since only the X-ray CT and $^{137}Cs$ transmission data are used for the attenuation correction, in Philips GEMINI PET/CT scanner, proper transformation of these data into usable attenuation coefficients for 511 keV photon has to be ascertained. The aim of this study was to evaluate the accuracy in the CT measurement and compare the CT and $^{137}Cs$-based attenuation correction in this scanner. Methods: For all the experiments, CT was set to 40 keV (120 kVp) and 50 mAs. To evaluate the accuracy of the CT measurement, CT performance phantom was scanned and Hounsfield units (HU) for those regions were compared to the true values. For the comparison of CT and $^{137}Cs$-based attenuation corrections, transmission scans of the elliptical lung-spine-body phantom and electron density CT phantom composed of various components, such as water, bone, brain and adipose, were performed using CT and $^{137}Cs$. Transformed attenuation coefficients from these data were compared to each other and true 511 keV attenuation coefficient acquired using $^{68}Ge$ and ECAT EXACT 47 scanner. In addition, CT and $^{137}Cs$-derived attenuation coefficients and SUV values for $^{18}F$-FDG measured from the regions with normal and pathological uptake in patients' data were also compared. Results: HU of all the regions in CT performance phantom measured using GEMINI PET/CT were equivalent to the known true values. CT based attenuation coefficients were lower than those of $^{68}Ge$ about 10% in bony region of NEMA ECT phantom. Attenuation coefficients derived from $^{137}Cs$ data was slightly higher than those from CT data also in the images of electron density CT phantom and patients' body with electron density. However, the SUV values in attenuation corrected images using $^{137}Cs$ were lower than images corrected using CT. Percent difference between SUV values was about 15%. Conclusion: Although the HU measured using this scanner was accurate, accuracy in the conversion from CT data into the 511 keV attenuation coefficients was limited in the bony region. Discrepancy in the transformed attenuation coefficients and SUV values between CT and $^{137}Cs$-based data shown in this study suggests that further optimization of various parameters in data acquisition and processing would be necessary for this scanner.

Evaluation of Radiation Exposure to Nurse on Nuclear Medicine Examination by Use Radioisotope (방사성 동위원소를 이용한 핵의학과 검사에서 병동 간호사의 방사선 피폭선량 평가)

  • Jeong, Jae Hoon;Lee, Chung Wun;You, Yeon Wook;Seo, Yeong Deok;Choi, Ho Yong;Kim, Yun Cheol;Kim, Yong Geun;Won, Woo Jae
    • The Korean Journal of Nuclear Medicine Technology
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    • v.21 no.1
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    • pp.44-49
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    • 2017
  • Purpose Radiation exposure management has been strictly regulated for the radiation workers, but there are only a few studies on potential risk of radiation exposure to non-radiation workers, especially nurses in a general ward. The present study aimed to estimate the exact total exposure of the nurse in a general ward by close contact with the patient undergoing nuclear medicine examinations. Materials and Methods Radiation exposure rate was determined by using thermoluminescent dosimeter (TLD) and optical simulated luminescence (OSL) in 14 nurses in a general ward from October 2015 to June 2016. External radiation rate was measured immediately after injection and examination at skin surface, and 50 cm and 1 m distance from 50 patients (PET/CT 20 pts; Bone scan 20 pts; Myocardial SPECT 10 pts). After measurement, effective half-life, and total radiation exposure expected in nurses were calculated. Then, expected total exposure was compared with total exposures actually measured in nurses by TLD and OSL. Results Mean and maximum amount of radiation exposure of 14 nurses in a general ward were 0.01 and 0.02 mSv, respectively in each measuring period. External radiation rate after injection at skin surface, 0.5 m and 1 m distance from patients was as following; $376.0{\pm}25.2$, $88.1{\pm}8.2$ and $29.0{\pm}5.8{\mu}Sv/hr$, respectively in PET/CT; $206.7{\pm}56.6$, $23.1{\pm}4.4$ and $10.1{\pm}1.4{\mu}Sv/hr$, respectively in bone scan; $22.5{\pm}2.6$, $2.4{\pm}0.7$ and $0.9{\pm}0.2{\mu}Sv/hr$, respectively in myocardial SPECT. After examination, external radiation rate at skin surface, 0.5 m and 1 m distance from patients was decreased as following; $165.3{\pm}22.1$, $38.7{\pm}5.9$ and $12.4{\pm}2.5{\mu}Sv/hr$, respectively in PET/CT; $32.1{\pm}8.7$, $6.2{\pm}1.1$, $2.8{\pm}0.6$, respectively in bone scan; $14.0{\pm}1.2$, $2.1{\pm}0.3$, $0.8{\pm}0.2{\mu}Sv/hr$, respectively in myocardial SPECT. Based upon the results, an effective half-life was calculated, and at 30 minutes after examination the time to reach normal dose limit in 'Nuclear Safety Act' was calculated conservatively without considering a half-life. In oder of distance (at skin surface, 0.5 m and 1 m distance from patients), it was 7.9, 34.1 and 106.8 hr, respectively in PET/CT; 40.4, 199.5 and 451.1 hr, respectively in bone scan, 62.5, 519.3 and 1313.6 hr, respectively in myocardial SPECT. Conclusion Radiation exposure rate may differ slightly depending on the work process and the environment in a general ward. Exposure rate was measured at step in the general examination procedure and it made our results more reliable. Our results clearly showed that total amount of radiation exposure caused by residual radioactive isotope in the patient body was neglectable, even comparing with the natural radiation exposure. In conclusion, nurses in a general ward were much less exposed than the normal dose limit, and the effects of exposure by contacting patients undergoing nuclear medicine examination was ignorable.

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Effects of Fermented Diets Including Liquid By-products on Nutrient Digestibility and Nitrogen Balance in Growing Pigs (착즙부산물을 이용한 발효사료가 육성돈의 영양소 소화율 및 질소균형에 미치는 영향)

  • Lee, Je-Hyun;Jung, Hyun-Jung;Kim, Dong-Woon;Lee, Sung-Dae;Kim, Sang-Ho;Kim, In-Cheul;Kim, In-Ho;Ohh, Sang-Jip;Cho, Sung-Back
    • Journal of Animal Environmental Science
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    • v.16 no.1
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    • pp.81-92
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    • 2010
  • This study was conducted to evaluate the effects of fermented diets including liquid by-products on nutrient digestibility and nitrogen balance in growing pigs. Treatments were 1) CON (basal diet), 2) F (fermented diet with basal diet), 3) KF (fermented diet with basal diet including 30% kale pomace), 4) AF (fermented diet with basal diet including 30% angelica keiskei pomace), 5) CF (fermented diet with basal diet including 30% carrot pomace) and 6) OF (fermented diet with basal diet including 30% grape pomace). A total of 24 pigs (41.74kg average initial body weight, Landrace $\times$ Yorkshire $\times$ Duroc), were assigned to 6 treatments, 4 replicates and 1 pig per metabolic cage in a randomized complete block (RCB) design. Pigs were housed in $0.5\times1.3m$ metabolic cage in a 17d digestibility trial. During the entire experimental period, Digestibility of dry matter (p<0.05) of treatment CON, F and CF were higher than other treatments. In crude protein digestibility, treatment F was higher than treatment AF and GF (p<0.05). Treatment GF showed the lowest digestibility of crude fiber among all treatments (p<0.05). In ether extract digestibility, treatment AF and CF showed higher than other treatments (p<0.05) except KF treatment. CF treatment showed the best digestibility of ash among all treatments (p<0.05). Whereas, For Ca and P digestibility, CF and OF treatments were improved than other treatments (p<0.05). Energy digestibility (p<0.05) of CON, F and CF treatments were higher than KF, AF and GF treatments. In total essential amino acid digestibility, F treatment was improved than AF, CF and GF treatments (p<0.05). In total non-essential amino acid digestibility, F treatment was higher than CON, AF and GF treatments (p<0.05). In total amino acid digestibility, F treatment was higher than AF and CF treatments (p<0.05) and GF treatment showed the lowest digestibility (p<0.05). In fecal nitrogen excretion ratio, GF treatment was greatest among all treatments (p<0.05) and F treatment was decreased than other treatments (p<0.05). In urinary nitrogen excretion ratio, CON and GF treatments showed the lowest among all treatments (p<0.05). In nitrogen retention ratio, CON treatment showed the high and KF treatment showed the lost among all treatments (p<0.05). Therefore, this experiment suggested that fermented diet could improve nutrient and amino acid digestibilities of growing pigs.

Effects of Combined Micronutrient(Fe, Mn, Cu, Zn, Mo and B) Application on Forage Traits in Pure and Mixed Swards of Orchardgrass and White Clover I. Changes in the growth, summer depression, and flowering of forage plants (Orchardgrass 및 White Clover의 단파 및 혼파 재배에서 미량요소(Fe, Mn, Cu, Zn, Mo, B)의 조합시비가 목초의 여러 특성에 미치는 영향 I. 목초의 생육, 하고 및 개화 등의 특성 변화)

  • Jung, Yeun-Kyu
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.23 no.4
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    • pp.229-236
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    • 2003
  • This pot experiment was conducted in order to observe the effects of application of combined micronutrients(T$_1$: control. T$_2$; Fe, T$_3$; Fe+Mn, T$_4$; Fe+Mn+Cu, T$_{5}$; Fe+Mn+Cu+Zn, T$_{6}$;Fe+Mn+Cu+Zn+Mo, T$_{7}$; Fe+Mn+Cu+Zn+Mo+B) on forage performance of pure and mixed cultures of orchardgrass and white clover. The first part was concerned with the changes in the growth, summer depression, and flowering of forage plants. The results obtained are summarized as follows: 1. The T$_3$and T$_{6}$ resulted in a wide chlorosis induced by the Fe-deficiency on orchardgrass. Chlorosis was significantly reduced by the T$_4$and T$_{5}$, whereas the T$_{7}$, T$_2$, and T$_1$showed normal growth without chlorosis symptoms. The T$_{7}$ resulted in the best growth of orchardgrass both in the pure and mixed swards. There was no chlorosis symptom on white clover. whereas the T$_1$, T$_2$and T$_{7}$ showed a relatively good growth with deep green leaf-colour compared with the other treatments in the pure culture. 2. In summer, a summer depression occurred in orchardgrass: this was significantly reduced by the T$_1$and T$_{7}$. The treatments with chlorosis symptoms in orchardgrass partly induced a lodging. Summer depression in white clover did not occur. 3. In the pure culture, the T$_{7}$ and T$_2$in white clover resulted in many flowers and flower-buds compared with the other treatments. The T$_{7}$, especially, showed a long blooming period and an early full bloom compared with the other treatments, whereas the T$_{6}$ and is showed inferior numbers of them. Only the T$_{7}$ resulted in more flowers than flower-buds, and above 1 in the flower/flower-bud ratio except the T$_{6}$ in the mixed culture. 4. It was recognized that the chlorosis of Fe-deficiency occurred not only from the unsuitable ratios of Fe/Mn and Fe/Mo but also from the unsuitable mutual ratios among the cations(Fe, Mn, Cu and Mn), between the anions(Mo and B), and their total ion concentration. It was observed the multiple interactions of Fe${\times}$Mn${\times}$Mo${\times}$B, and the distinct role of B as a regulator.

Effects of Nitrogen , Phosphorus and Potassium Application Rates on Oversown Hilly Pasture under Different Levels of Inclination II. Changes on the properties, chemical composition, uptake and recovery of mineral nutrients in mixed grass/clover sward (경사도별 3요소시용 수준이 겉뿌림 산지초지에 미치는 영향 II. 토양특성 , 목초의 무기양분함량 및 3요소 이용율의 변화)

  • 정연규;이종열
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.5 no.3
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    • pp.200-206
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    • 1985
  • This field experiment was undertaken to assess the effects of three levels of inclination ($10^{\circ},\;20^{\circ},\;and\;30^{\circ}$) and four rates of $N-P_2O_5-K_2O$ (0-0-0-, 14-10-10, 28-25-25, and 42-40-40kg/10a) on establishment, yield and quality, and botanical compositions of mixed grass-clover sward. This second part is concerned with the soil chemical properties, concentrations and uptake of mineral nutrients, and percent recovery and efficiency of NPK. The results obtained after a two-year experiment are summarized as follows: 1. The pH, exchangeable Mg and Na, and base saturation in the surface soils were decreased by increasing the grade of inclination, whereas organic matter and available $P_2O_5$ tended to be increased. However, the changes in the Ca content and equivalent ratio of $K\sqrt{Ca+Mg}$ were not significant. The pH, exchangeable Ca and Mg, and base saturation were reduced by increasing the NPK rate, whereas available $P_2O_5$, exchangeable K, and equivalent ratio of $K\sqrt{Ca+Mg}$ tended to be increased. 2. The concentrations of mineral nutrients in grasses and weeds were not significantly affected by increasing the grade of slope in hilly pasture, whereas the concentrations of N, K, and Mg in legume were the lowest with the steep slope, which seemed to be related to the low legume yield. The Mg concentrations of all forage species were below the critical level for good forage growth and likelihood of grass tetany. 3. The increase of NPK rate resulted in the increment of N, K and Na concentrations, and the decrease of Mg and Ca in grasses. The P concentration was increased with P application, but there were no differences in that among the P rates applied. It resulted also in a slight increase of K, and a decrease of Mg in legume, but the contents of N, Ca, and Na were not affected by that. On the other hand, it has not affected the mineral contents in weeds except a somewhat increase of N. The mixed forages showed a increase of N and K contents, a decrease of Ca and Mg, and a slight change in P and Na. 4. The percent recovery of N, P and K by mixed forages were greatly decreased by increasing the grade of inclination and NPK rate. They were high in the order; K>N>P. The efficiency of mixed NPK applications was decreased by that. The efficiency of mixed NPK fertilizers absorbed was slightly decreased by the increased rate of NPK, but it was not affected by the grade of inclination.

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Influence of Fertilizer Type on Physiological Responses during Vegetative Growth in 'Seolhyang' Strawberry (생리적 반응이 다른 비료 종류가 '설향' 딸기의 영양생장에 미치는 영향)

  • Lee, Hee Su;Jang, Hyun Ho;Choi, Jong Myung;Kim, Dae Young
    • Horticultural Science & Technology
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    • v.33 no.1
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    • pp.39-46
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    • 2015
  • Objective of this research was to investigate the influence of compositions and concentrations of fertilizer solutions on the vegetative growth and nutrient uptake of 'Seolhyang' strawberry. To achieve this, the solutions of acid fertilizer (AF), neutral fertilizer (NF), and basic fertilizer (BF) were prepared at concentrations of 100 or $200mg{\cdot}L^{-1}$ based on N and applied during the 100 days after transplanting. The changes in chemical properties of the soil solution were analysed every two weeks, and crop growth measurements as well as tissue analyses for mineral contents were conducted 100 days after fertilization. The growth was the highest in the treatments with BF, followed by those with NF and AF. The heaviest fresh and dry weights among treatments were 151.3 and 37.8 g, respectively, with BF $200mg{\cdot}L^{-1}$. In terms of tissue nutrient contents, the highest N, P and Na contents, of 3.08, 0.54, and 0.10%, respectively, were observed in the treatment with NF $200mg{\cdot}L^{-1}$. The highest K content was 2.83%, in the treatment with AF $200mg{\cdot}L^{-1}$, while the highest Ca and Mg were 0.98 and 0.42%, respectively, in BF $100mg{\cdot}L^{-1}$. The AF treatments had higher tissue Fe, Mn, Zn, and Cu contents compared to those of NF or BF when fertilizer concentrations were controlled to equal. During the 100 days after fertilization, the highest and lowest pH in soil solution of root media among all treatments tested were 6.67 in BF $100mg{\cdot}L^{-1}$ and 4.69 in AF $200mg{\cdot}L^{-1}$, respectively. The highest and lowest ECs were $5.132dS{\cdot}m^{-1}$ in BF $200mg{\cdot}L^{-1}$ and $1.448dS{\cdot}m^{-1}$ in BF $100mg{\cdot}L^{-1}$, respectively. For the concentrations of macronutrients in the soil solution of root media, the AF $200mg{\cdot}L^{-1}$ treatment gave the highest $NH_4$ concentrations followed by NF $200mg{\cdot}L^{-1}$ and AF $100mg{\cdot}L^{-1}$. The K concentrations in all treatments rose gradually after day 42 in all treatments. When fertilizer concentrations were controlled to equal, the highest Ca and Mg concentrations were observed in AF followed by NF and BF until day 84 in fertilization. The BF treatments produced the highest $NO_3$ concentrations, followed by NF and AF. The trends in the change of $PO_4$ concentration were similar in all treatments. The $SO_4$ concentrations were higher in treatments with AF than those with NF or BF until day 70 in fertilization. These results indicate that compositions of fertilizer solution should to be modified to contain more alkali nutrients when 'Seolhyang' strawberry is cultivated through inert media and nutri-culture systems.