• 한국토양비료학회지
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• 제49권6호
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• pp.819-825
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• 2016

Monitoring of soil fertility and crop productivity in long-term application of silicate fertilizers is necessary to use fertilizers efficiently. This study was conducted to investigate effects of continuous application of silicate fertilizer for rice cultivation from 1969 to 2014. The treatments were no silicate fertilizer treatments (N, NC, NPK, and NPKC) and silicate fertilizer treatments (N+S, NC+S, NPK+S, and NPKC+S). The 46-yr input of $2\;ton\;ha^{-1}yr^{-1}$ of silicate fertilizer increased pH 0.6 ~ 1.1 and exchangeable Ca $2.0{\sim}2.4cmol_c\;kg^{-1}$ in silicate fertilizer treatments (N+S, NC+S, NPK+S, and NPKC+S) compared with no silicate fertilizer treatments (N, NC, NPK, and NPKC) because silicate fertilizer included Ca component. Also, available silicate concentrations of silicate fertilizer treatments (N+S, NC+S, NPK+S, and NPKC+S) increased $169mg\;kg^{-1}$ compared to no silicate fertilizer treatments. In Period II ('90~'14), the mean annual Si field balance varied from 62 to $175kg\;ha^{-1}yr^{-1}$ in silicate fertilizer treatments, indicating continuous accumulation of soil Si. Silicon uptake and grain yield of rice had greater differences between N treatment and N+S treatment than other treatments. This showed that the application of silicate fertilizer had greater effect in nutrient-poor soils than in proper nutrient soils. Thus the application of silicate fertilizer led to improvement the fertility of soil and increasement of rice production for the lack of soil nutrients.

• 한국잡초학회지
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• 제32권3호
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• pp.230-239
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• 2012

Coconut (Cocos nucifera L) is one of the predominant plantation crops in Sri Lankan economy which is known to have existed for over thousands of years. During the past decades coconut production had been reduced by a significant quantity. The usage of poor quality planting materials is a major reason for the low coconut production. Thus much attention needs to be paid in coconut nurseries. Weed management is a critical management practice in the nursery. Though glyphosate application is becoming popular in nurseries it can affect weeds as well as coconut seedlings growth. Therefore the effects of glyphosate were evaluated by determining the growth of shoot and root of coconut seedlings. Poly bag nursery was prepared and three treatments were used. Treatments were no glyphosate and manual weeding ($T_1$), application of glyphosate 1.08 ai kg $ha^{-1}$ at 2 monthly interval ($T_2$) and application of glyphosate 1.44 ai kg $ha^{-1}$ at 2 monthly interval ($T_3$). Application of glyphosate at early stage of seedling growth had a no significant effect on growth parameters tested. However, the concentrations of glyphosate negatively affected numbers, volumes and dry weights of secondary, tertiary and quaternary roots at the latter stage of seedling growth. The leaf area and the height of seedling were significantly reduced by the highest concentration of glyphosate. Among the growth parameters tested, seedling girth and shoot dry weight were not affected by the application of glyphosate. These results revealed that the usage of glyphosate at both concentrations negatively affected root growth of coconut seedlings. Based on these results, the both concentration levels of glyphosate should be applied to coconut nurseries before sprouting the seed nuts.

• 한국초지조사료학회지
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• 제17권1호
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• pp.43-50
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• 1997

The aim of the study is to describe the fate and transformation of nitrogen in grassland ecosystems. Field experiments were conducted using sandyloam soil under variabling conditions: Zen, fertilization, reduced slurry application(l20kg N $ha^{-1}\;yr^{-1}$), usual sluny application (240 kg N $ha^{-1}\;yr^{-1}$).Soil water samples were gathered with 120cm ceramic cups with initial pressure of 0.5 bar. Samples were collected twice a month and analysed for NO, colormetrically. Percolation was calculated as the difference between precipitation and potential evapotranspiration, and leaching as the product of percolation and nitrate content of the water h m the ceramic cups. The N$H_4$-N content in soil had no significant effect on slurry application, but high slurry application on grassland resulted in high N$O_3$-N content in soil. The NO, concentration in soil water was remarkably variable during the year. The average N$O_3$, concentration during experiment became the lowest(8.5 mg/e ) without slurry application and highest with 240kOa cattle sluny(25.3 mg4 ). For each of the three different amounts of cattle sluny applied (0, 120, and 240kOa), the amount of N$O_3$-N leached per year were 12, 23 and 29kg/ha respectively. On grassland under the climatic conditions of Allgau showed enormous nitrate leaching, which has a p a t potential of polluting the ground water. The high pool of mineral N in the soil are the source for N$O_3$ leaching. The leaching of N$O_3$ cannot be avoided completely, but minimized by optimizing N fertilization rate.

• 한국환경농학회지
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• 제17권2호
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• pp.170-173
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• 1998

신천하수종말처리장에서 발생한 슬러지를 처리별로 시용한 다음 토양의 이화학성(理化學性)과 중금속 함량변화를 조사하였다. 슬러지 시용량이 증가함에 따라 질소, 인산 및 무기염류의 함량이 증가하는 것으로 나타 났으며, 토양의 입단화, 공극률 및 투수성이 증가하였으며 경도는 감소하였다. 중금속 함량은 Cr, Zn의 경우 약간의 증가를 보였으며,함류량이 적어 시용량이 증가하여도 함량에 차이가 없으며, 하층으로 이동하거나 용탈하지 않는 것으로 나타났다. Sludge중 중금속 함량이 매우 낮음으로 sludge의 처리가 토양 중금속 함량에 별다른 영향을 주지 않았다.따라서 토양의 하부(下部)로 이동하는 현상도 나타나지 않았다.

• 센서학회지
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• 제10권6호
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• pp.273-278
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• 2001

혈중 헤모글로빈 농도를 비침습적으로 측정하기 위하여 가시광선부터 근적외선 영역인 $400{\sim}2500\;nm$ 영역에서 주요 혈중 성분들의 스펙트럼의 분석에 관하여 연구하였다. 근적외선 영역에서는 물이 주 흡수 성분이 되는데 특정성분의 농도 변화에 따라 물의 상대적인 흡수변화가 수반되므로(water displacement effect) 특정성분의 농도 변화에 따른 물의 농도변화를 고려해줌으로써 보정된 스펙트럼을 얻었고 이로부터 각 흡수 peak을 정확히 얻어내었고 농도변화에 따른 선형적인 증가를 보여주었다 비침습적으로 헤모글로빈 측정을 위한 조직의 산란효과와 타 성분의 영향을 고려하여 파장대역의 선정하였다.

• 한국치위생학회지
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• 제16권1호
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• pp.77-83
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• 2016

Objectives: This study was carried out to investigate the effect of fluoride application after dental prophylaxis by the type of dental floss. Methods: Artificial caries lesion was made on the surface of cow's permanent teeth having sound enamel surface and vickers hardness number(VHN) was measured. Specimens were classified into APF gel group and artificial saliva group. Each group was divided into waxed floss group and unwaxed flossed group. All specimens were immersed into the artificial saliva for one minute and dental flossing was applied to waxed or unwaxed floss. After washing and drying, APF gel groups were applied with fluoride for four minutes and artificial saliva groups were immersed into the artificial saliva for four minutes. After treatment, specimens were measured by VHN and surface conditions of enamel were confirmed by scanning electron microscopy(SEM). Results: VHN of waxed flossing and fluoride application group increased to $6.78{\pm}2.75$. VHN of unwaxed flossing and fluoride application group increased to $7.36{\pm}2.51$. There was no significant difference between waxed and unwaxed groups(p>0.05). VHN of waxed flossing and artificial saliva group increased to $1.07{\pm}2.84$. VHN of waxed flossing and artificial saliva group increased to $1.05{\pm}3.13$. There was no significant difference between waxed and unwaxed groups(p>0.05). There was significant increase in VHN between waxed/unwaxed flossing and fluoride application. However, waxed/unwaxed flossing with artificial saliva showed no significant VHN increase. SEM demonstrated no residue on the enamel surface in the waxed flossing groups. Conclusions: No difference was found in the remineralization of enamel by waxed flossing or unwaxed flossing.

• 생물환경조절학회지
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• 제15권1호
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• pp.35-46
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• 2006

Objective of this research was to determine the effect of application rate of a slow release fertilizer (SRF) in three root media, peatmoss+vermiculite (1:1, v/v; PV), peatmoss+composted rice hall (1:1, v/v; PR), and peatmoss+composted pine bark (1:1, v/v; PB), on growth and nutrient contents of potted chrysanthemum 'Lima Honey'. All media contained polyacrylic acid sodium salt at a rate of $4.5g L^{-1}$. The fresh and dry weights at 43 days after transplanting did not show statistical differences among treatments in each root media. Elevated application rate of SRF increased fresh and dry weights at 80 days after transplanting in PV and PB media, but not in PR medium. Elevated application rates of SRF resulted in the increase of tissue phosphorus content and decrease of tissue Ca, Na, and Zn contents at both 43 and 80 days after transplanting. Elevated application rates of SRF resulted in the decrease of pH and increase of EC and concentrations of ${NO_3}^-$ and ${P_2O_5}^{3-}$, K, Ca, and Mg in the soil solution of PV and PR media. The trends of those in PR media were also similar except ${NO_3}^-$. The differences among treatments in EC at 80 days after transplanting were less significant as compared to those at 43 days after transplanting in three media.

• 한국환경농학회지
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• 제1권1호
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• pp.65-70
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• 1982

담수토양(湛水土壤)에 IBP 입제(粒劑)를 반부처리(反復處理)하고 후처리(後處理)한 약제(藥劑)의 분해(分解)에 미치는 영향(影響)을 시험(試驗)한 결과(結果) 1) IBP의 반부처리(反復處理)로 후처리(後處理)한 IBP의 분해(分解)가 촉진(促進)되었으며 그 효과(效果)는 약 53일간지속(日間 持續)되었으나 diazinon의 분해(分解)에는 영향(影響)이 없었다. 2) 토양살균(土壤殺菌)으로 IBP의 분해(分解)가 크게 억제(抑制)되어 분해속도(分解速度)는 무살균토양(無殺菌土壤)에 비해 3배(倍)이상 지연(遲延)되었으며 반부처리(反復處理)에 의해 생성(生成)된 IBP 분해촉진능력(分解促進能力)도 소실(消失)되었다. 3) IBP 반부처리(反復處理)로 인(因)한 토양미생물(土壤微生物)의 전체 colony수(數)는 변하지 않았다.

• Journal of Periodontal and Implant Science
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• 제31권2호
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• pp.333-344
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• 2001

The present study was performed to evaluate the effect of tetracycline - HCl on the change of implant surface microstructure according to application time. Implants with pure titanium machined surface and titanium plasma-sprayed surface were utilized. Implant surface was rubbed with 50mg/ml tetracycline - HCl solution for 1 min., $1\frac{1}{2}\;min$., 2 min., $2\frac{1}{2}\;min$. and 3min. respectively in the test group and with saline for 1 min. in the control group. Then, the specimens were processed for scanning electron microscopic observation. The following results were obtained. 1. Pure titanium machined surfaces conditioned with saline for 1 min., showed a few shallow grooves and ridges and were less irregular. 2. Pure titanium machined surfaces conditioned with 50mg/ml tetracycline - HCl solution showed more irregular and corrosive surfaces compared to the control group irrespective of the application time of tetracycline - HCl solution. 3. Titanium plasma-sprayed surfaces conditioned with saline for 1 min., were deposited with round amorphous particles and showed round or irregular pores that can be connected to each other. 4. The irregularity of titanium plasma-sprayed surfaces conditioned with 50mg/ml tetracycline - HCl solution was lessened and the flattened areas were wider relative to the application time of tetracycline - HCl solution. 5. Titanium plasma-sprayed surfaces conditioned with tetracycline - HCl solution for 1 min. and $1\frac{1}{2}\;min$. were very similar to that of the control group, but the surfaces conditioned for 2 min., $2\frac{1}{2}\; min$. and 3 min. were changed. In conclusion, pure titanium machined surfaces were changed irrespective of the application time of tetracycline - HCl solution. And titanium plasma-sprayed surfaces conditioned with tetracycline - HCl solution began to be changed from $1\frac{1}{2}\;min$. This results will be applicable to the regenerative procedures for peri-implantitis treatment.

• Restorative Dentistry and Endodontics
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• 제20권2호
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• pp.527-537
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• 1995

The effect of calcitonin gene-related peptide (CGRP), substance P (SP) and electrical stimulation of the tooth on the intradental nerve activtiy (INA) was investigated in anesthetized cats. The INA was recorded from single pulp nerve units dissected from the inferior alveolar nerve under stereomicroscope. The INA elicited by 3 minute application of 4M NaCl in deep dentinal cavity was compared before and after stimulation at 10 minute intervals. The magnitude of INA was calculated as the total number of nerve impulses produced in given period, and the changes of INA are expressed as % of control INA. The results obtained were as follows. 1. 16 single pulp nerve units were classified as 14 $A{\delta}$-fibers (3.4~19.4m/sec) and 2-fibers (1.5~1.7m/sec) according to the conduction velocity. 2. 4M NaCl evoked an irregular bursts of spikes which continued until washing out. Isotonic saline did not affect INA to subsequent applications of the hypertonic NaCl solution (P>0.05). 3. Local application of CGRP ($200{\mu}g$/ml) in deep dentinal cavity reduced the INA induced by 4M NaCl in $A{\delta}$-fiber units (P<0.01) and some units of those responded to CGRP during application. 4. Local application of SP ($100{\mu}g$/ml) in deep dentinal cavity reduced the INA induced by 4M NaCl in AS-fiber units (p<0.05), but increased the INA in C-fiber unit coincided with large reduction of the INA of $A{\delta}$-fiber units. 5. Monopolar electrical stimulation applied to the crown at intensities high enough to excite C-fibers (12V, 5ms, 10Hz, 10~30min) decreased the INA in $A{\delta}$-fiber units (P<0.01) and systemic pretreatment with phenoxybenzamine (3mg/kg, i.v.) enhanced this inhibitory effect (P<0.01). On the contrary, electrical stimulation increased the INA in C-fiber unit.