• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.2
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• pp.33-38
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• 2014

Purpose Auto exposure control (AEC) in SPECT/CT automatically controls the exposure dose (mA) according to patient's shape and size. The aim of this study was to evaluate the effect of AEC in SPECT/CT on exposure dose reduction and image quality. Materials and Methods The model of SPECT/CT used in this study was Discovery 670 (GE, USA), Smart mA for AEC; and $^{99m}Tc$ as a radioisotope. To compare SPECT and CT images by CT exposure dose variation, we used a standard technique set at 80, 100, 120, 140 kVp, 10, 30, 50, 100, 150, 200, 250 mA, and AEC at 80, 100, 120, 140 kVp, 10-250 mA. To evaluate resolution and contrast of SPECT images, triple line phantom and flangeless Esser PET phantom were used. For CT images, noise and uniformity were checked by anthropomrphic chest phantom. For dose evaluation to find DLP value, anthropomorphic chest phantom was used and the CT protocol of torso was applied by standard technique (120 kVp, 100 mA) and AEC (120 kVp, 10-250 mA). Results When standard and AEC were applied, the resolutions at SPECT images with attenuation correction (AC) were the same as FWHM by center 3.65 mm, left 3.48 mm, right 3.61 mm. Contrasts of standard and AEC showed no significant difference: standard 53.5, 29.8, 22.5, 15.8, 6.0, AEC 53.5, 29.6, 22.4, 15.7, 6.1 In CT images, noise values at standard and AEC were 15.4 and 18.5 respectively. The application of AEC increases noise but the value of coefficient variation were 33.8, 24.9 respectively, obtaining uniform noise image. The values of DLP at standard and AEC were 426.78 and 352.09 each, which shows that the application of AEC decreases exposure dose more than standard by approximately 18%. Conclusion The results of our study show that there was no difference of AC in SPECT images based on the CT exposure dose variation at SPECT/CT images. It was found that the increased CT exposure dose leads to the improvement of CT image quality but also increases the exposure dose. Thus, the use of AEC in SPECT/CT contributes to obtaining equal AC SPECT images, and uniform noise in CT images while reducing exposure dose.

• Journal of Bio-Environment Control
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• v.26 no.2
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• pp.72-77
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• 2017

This study was conducted to examine the effect by application method and concentration of plant growth regulator (PGR) on the growth and runner production of strawberry (Fragaria ${\times}$ ananassa Duch. cv. Maehyang) in a velno-type greenhouse. The seedlings of strawberry were transplanted in pot ($64{\times}27{\times}18cm$) filled with commercial mixed medium (Tosilee) on February 22nd, 2016. The 6-benzylaminopurine (6-BAP) was applied with foliar spray or drench, respectively as 900, 1,200 or $1,500mg{\cdot}L^{-1}$ (50 mL per plant) at 3 weeks after transplanting. Nutrient solution was sufficiently supplied by the drip irrigation as EC $0.65dS{\cdot}m^{-1}$ for rooting during 7 days. After rooting, the 450 mL nutrient solution supplied per pot twice a day (10 min). Plant height and crown diameter of 'Maehyang' mother plant appeared no significantly difference. The other growth characteristics, such as root length, number of primary roots, leaf length, leaf width, leaf area and fresh and dry weights of the shoot or root, were significantly the greatest in the control. And, the SPAD value of strawberry was the highest as 44.2 in the drench with $900mg{\cdot}L^{-1}$. The foiler spray was more effective in runner production than drench, and the number of runners appeared high values at the 900 and $1,500mg{\cdot}L^{-1}$. Whereas, the number of strawberry plantlets was effective in the drench. The results indicate that both growth and the number of runners of strawberry plant were the best achieved by foliar spray application at the $900mg{\cdot}L^{-1}$.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.77-101
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• 2009

Organic farming in Korea has mainly focused on producing vegetables in plastic film house and cereals in paddy field. For high productivity of vegetables and cereals, most Korean farmers have not applied crop rotation in the cropping system. Thus, this study was carried out to evaluate the effects of crop rotation on the yield of red pepper and green onion, the changes in soil fertility and the potential as green manure of rye and hairy vetch. Rye and hairy vetch were cultivated for winter season every year, and directly incorporated into the soil. The yield of red pepper fruits in organic farming using crop rotation (OFCR) decreased 23 to 36% compared with conventional farming system (CFS). Whereas, green onion showed the increased yield of about 13%. In OFCR, total carbon content of soil was higher, however available phosphate content lower than conventional farming. As a result of measuring the bulk density of soil, OFCR and CFS were 1.26 to $1.35Mg/m^3$ and 1.37 to $1.42Mg/m^3$, respectively. Carbon and nitrogen contents of microbial biomass in OFCR were obviously higher compared with the CFS. In the plot cultivated rye for winter season, the weed germination was strongly reduced (about 52 %). Balance of macro nutrient elements, nitrogen and phosphate, in the application of rye and hairy vetch had a minus value. For potassium, the output value was higher than the input one, therefore organic farming under red pepper-rye or hairy vetch systems requires applying additional potassium input. Also, we selected two hairy vetch varieties of cv. Hungvillosa and Ostsaat which can be adapt at Korea climate. In order to estimate a yield of green manures, the weight of shoot and root was measured. The ratio of shoot and root between rye and hairy vetch showed 0.88 and 1.91, respectively. The potential levels of nitrogen, phosphate and potassium which could be supplied from rye were 7.7, 7.8 and 21.9 kg/10a and from hairy vetch were 17.0, 8.6 and 22.9 kg/10a, respectively. So we recommend that cultivating hairy vetch, as a nutrient supplier, and rye, as an amendment to enhance the soil physical property, for winter season be practical method in Korea organic farming system.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.2
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• pp.123-130
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• 2002

A field experiment was carried out to determine the effect of application level of animal manure on the nitrate nitrogen concentration, sugar content and animal intake of forage sorghum $\times$ sudangrass hybrid (Sorghum bicolor (L.) Moench, cv. Pionee. 988) in 1995. The application amount of animal manure were 50, 100 and 150MT in cattle manure, 20, 40 and 80MT in swine manure, and 10, 20 and 40MT/ha in poultry manure. Non-application plot(control) was involved. The nitrate nitrogen concentration was increased with increasing of application level of animal manure(P<0.05). Average nitrate nitrogen concentration was 397, 512, and 609mg/kg at low, medium and high application level of animal manure. The nitrate nitrogen concentration by plant height was 438mg/kg at 50~60m of plant height, 454mg at 100~120cm, and 418mg at 200~220cm. The nitrate nitrogen concentration of stems was 376mg, and significantly higher than that(135mg) of leaves(P<0.05) regardless of animal manure type, and lower parts of stems and leaves were significantly higher than those of upper parts of plants(P<0.05). Average nitrate nitrogen concentration of leaves was 151mg at lower, and 58mg at upper parts of plants, and the concentration of stems was 357mg at lower, 511mg at middle, and 610mg at upper parts of plants. The sugar contents of sorghum $\times$ sudangrass hybrid was decreased with increasing of application level of animal manure(P<0.05). Average sugar content was 4.9, 4.4, and 4.3。 at low, medium and high application level of animal manure. The sugar content by plant height was 3.9。 at 50~60 and 100~120cm of plant height, and 6.1。 at 200~220cm of plant height. Animal intake of sorghum $\times$ sudangrass hybrid was decreased greatly with increasing of application level of animal manure. Average intake was 73.9, 55.7, and 52.3% at low, medium and high application level of animal manure. The intake by animal manure type was 73.7% in cattle, 59.7% in swine and 62.5% in poultry manure.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.628-635
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• 2014

The large amount of $CO_2$ emitted from mushrooms during incubation and developmental stages can be utilized in plant production systems as a $CO_2$ source. The objectives of this study were to measure the $CO_2$ emission and absorption rates of mushroom and lettuce, respectively, and to analyze the $CO_2$ concentrations at various ratios of mushroom and lettuce in a closed production system. The $CO_2$ emission rate of king oyster mushrooms (Pleurotus eryngii ( DC.) Qu$\acute{e}$l) and $CO_2$ absorption rate of lettuces (Lactuca sativa L. cv. Asia Heuk Romaine) were measured by using two closed acryl chambers ($1.0m{\times}0.8m{\times}0.5m$) in which indoor temperatures were maintained at $18^{\circ}C$ and $22^{\circ}C$, respectively. The lettuce was grown at a light intensity of PPF $340mol{\cdot}m^{-2}{\cdot}s^{-1}$ and with nutrient solution at EC $1.2dS{\cdot}m^{-1}$. The air was periodically circulated between the two chambers using a diaphragm pump. The $CO_2$ emission rate of the mushroom increased until the $15^{th}$ day after scratching (DAS) and then decreased. The rate also increased with increased indoor temperature. In particular, the $CO_2$ emission rate per fresh weight of fruit body increased by about 3.1 times after thinning compared to before thinning. In terms of $CO_2$ balance, the $CO_2$ emission rates from a bottle (950 mL) of the mushroom at 9, 12, and 14 DAS were equivalent to those of 3, 4.5, and 5.5 lettuce plants at 7, 10, and 12 DAT (days after transplanting), respectively. This work shows that balance in $CO_2$ concentration could be achieved using an appropriate ratio of the two crops in a closed production system.

• Asian Journal of Turfgrass Science
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• v.22 no.2
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• pp.185-196
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• 2008

This Study was conducted to evaluate the effect of liquid fertilizer containing medium of on growth of shoot and root in creeping bentgrass (Agrostis palustris Huds. cv. Pennlixs). According to application method of liquid fertilizer, the experiment plot was designed as follows; NF : non-fertilizer; CF : compound fertilizer(21-17-17) only; T500, T300, T100 : compound fertilizer +liquid fertilizer solution diluted 500, 300, 100 folds, respective; L500 : only liquid fertilizer solution which contained the medium of Lactobacillus confusa and Pichia anomala diluted 500 folds. The every treatments was arranged by a completely randomized complete block designs with three replications. The order of turf qualities like leaf color index and chlorophyll content in treatments showed T500 T300 T100 $\geq$ CF > NF. In treatment applied with compound fertilizer, the dry weight of shoot increased by about 13% in T500, T300 and T100 than CF, and that of root about 25% in just T300. Dry weight of shoot and root increased by 88% and 44% in L500 than NF, respectively. As compared with CF, T/R ratio in T500, T300 and T100 increased by 20%, 11% and 21%, respectively and root length 7%, 8% and 3%. In comparison with NF, T/R ratio and root length in L500 increased by 39% and 74%. These results suggested that the application of liquid fertilizer containing medium of Lactobacillus confusa and Pichia anomala induced the development of turf quality and growth by promoting root growth in creeping bentgrass.

• Food Science and Preservation
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• v.24 no.8
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• pp.1103-1112
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• 2017

This study was performed to investigate the effects of different cooking methods (boiling, roasting, stir-frying, and deep-frying) on folate retention in 6 kinds of mushrooms (Beech-, button-, Juda's ear-, oak-, oyster-, and winter-mushrooms) frequently consumed in Korea. In order to assure reliability of analytical data, trienzyme extraction-L casei method was verified and analytical quality control was also evaluated. Folate contents of mushrooms varied by 6.04-64.82 g/100 g depending on the type of mushrooms. and were significantly affected by cooking methods. Depending on cooking methods, folate contents of mushrooms decreased by 22-48%, 2-31%, and 17-56% for Juda's ear-, oak- and oyster-mushrooms, respectively, while 17-90% of folate was increased in Beech mushroom. Overall, the largest weight loss was found in boiled mushrooms, but the lowest one in deep-fried samples. True folate retention rates considering processing factor were less than 100% for all cooked mushrooms except for Beech samples. Overall, folate loss was the largest by boiling with water but the smallest by deep-frying. Both accuracy and precision of trienzyme extraction-L-casei method were excellent based on a recovery close to 100% and coefficient variations less than 3%. Quality control chart of folate analysis (n=26) obtained during the entire study and an international proficiency test (z-score=-0.5) showed that trienzyme extraction-L casei method is reliable enough for production of national folate database.

• Asian Journal of Turfgrass Science
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• v.21 no.2
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• pp.137-146
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• 2007

Traffic causes more and more stress and injury to grasses on golf course green in Korea due to the increased playing. This study compared the effect of fertilizer component (Nitrate, Phosphate, Potassium) on turfgrass growth and quality golf course green under traffic stress during early winter. Experiment was conducted by using different fertilizer components for 2 months(Oct. 1 to Nov. 30, 2005). Turfgrass leaf color, leaf texture, density and traffic tolerance were evaluated visually, and the root length(cm) and tiller density(tiller/$cm^2$) were measured. Creeping bentgrass(Agrostis palustris cv. 'Seaside II') fromthe nursery of Incheon Grand Golf Club was used. Results of this study are as followings: 1). Turfgrass color was the best in A6(20-15-10) and A5(15-15-10) treatments in the N study. Leaf texture was not different among treatments. Turf quality and traffic tolerance were the highest In A5 and A6. Root length was the longest(15.8cm) in A6 (20-15-10). Root length increased with nitrogen levels. 2). Turf color of A9(5-7.5-5) and A10(15-22.5-15) was darkest in the comparison of P study. Leaf texture was the best in A4(10-15-10) and A9. Turf quality was the best in A10. A7(10-0-10). 3). In general, to recover turfgrass damage on the putting greens during low temperature period, fertilizer amount need to be increased; and nitrogen is better than phosphate and potassium for that purpose.

• Korean Journal of Weed Science
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• v.17 no.3
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• pp.288-294
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• 1997

Field and pot expeiments were carried out to evaluate the interaction between quinclorac and bensulfuron-methyl on growth of the rice plants(Oryza sativa L. cv. Choocheongbyeo) at 20, 45, 65 days-old stages. Quinclorac and bensulfuron-methyl showed antagonistic interaction at both stages, which were detected by the Chisaka's method at isobles of 10% growth inhibition. The antagonism indices were -0.63 and -1.67 at 20 and 65 days-old seedling stages, respectively. Leaf-rolling of rice occurred when quinclorac was applied at 600g ai/ha or more at 20 days-old seedling stage, while it occured at the dose of 900g ai/ha at 65 days-old stage. Bensulfuron-methyl reduced plant height and dry weight as well as tiller production at both stages. Leaf-rolling of rice was reduced when mixture of quinclorac and bensulfuron-methyl was applied due to antagonism of the two herbicides. High temperatures increased the phytotoxicity of bensulfuron-methyl, while the phytotoxicity caused by quinclorac alone was not responsive to temperature. The antagonistic effect between quinclorac and bensulfuron-methyl increased at low temperature as tested by the Colby's method.

• Horticultural Science & Technology
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• v.34 no.4
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• pp.596-606
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• 2016

The growth and contents of anthocyanins and ascorbic acid in lettuce(Lactuca sativa L., 'Jeokchima') as affected by supplemental UV-A LED irradiation under different light quality and photoperiod conditions were analyzed in this study. Five light qualities, namely B (blue LED), R (red LED), BUV (blue LED+UV-A LED), RUV (red LED+UV-A LED) and Control (white fluorescent lamps) with photoperiods of 12/12 hours (day/night), 16/8 hours, or 20/4 hours were provided to investigate the effects of light quality and photoperiod on the growth and accumulation of anthocyanins and ascorbic acid in lettuce leaves. As measured 28 days after transplanting, the number of leaves, leaf length, leaf width, leaf area, shoot fresh weight and dry weight of lettuce were significantly affected by light quality and photoperiod. The number of leaves, leaf length, leaf width, leaf area, shoot fresh weight and dry weight of lettuce grown under R treatment increased with increasing light period. By contrast, leaf development was inhibited, but chlorophyll content increased, under B treatment. Supplemental UV-A irradiation significantly decreased leaf length, leaf width, leaf area and shoot fresh weight. Anthocyanins in lettuce increased significantly with decreasing dark period under B treatment. A synergistic effect of supplemental UV-A LED irradiation on anthocyanins accumulation was found for lettuce leaves grown under R treatment but not B treatment. Ascorbic acid in lettuce was greatly affected by photoperiod. Ascorbic acid content at BUV and RUV treatments increased by 20-30% compared to without UV-A LED irradiation. From these results, it was concluded that growth and contents of anthocyanins and ascorbic acid in lettuce are significantly affected by supplemental UV-A LED irradiation. The results obtained in this study will be informative for efforts to improve the nutritional value of leafy vegetables grown in plant factories.