• New & Renewable Energy
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• v.16 no.4
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• pp.76-82
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• 2020

Soiling on the surface of a PV module reduces the amount of light reaching the solar cells, decreasing power performance. The performance of the PV module is generally restored after contaminants on the module surface are washed away by rain, but it accumulates at the bottom of the module owing to the thickness of the module frame, causing an output mismatch on the PV module. Since PV modules are usually installed horizontally or vertically outdoors, soiling can occur at the bottom of the PV module, depending on the installation direction due to external environmental factors. This paper is analyzed the output characteristics of a PV module considering its installation direction and the soiling area. The soiling was simulated to use transparent films with 5% transmittance, and the transmission film was attached to the bottom part of the PV module horizontally and vertically. When the soiling area was 33% of the string at the bottom of the PV module, the power output decreased similarly regardless of installation direction. However, when the soiling area was 66% of the string at the bottom of the PV module, it was confirmed that the output performance decreased sharply when installed vertically rather than horizontally.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.23 no.1
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• pp.26-34
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• 2020

Purpose: To compare the clinical features, diagnostic findings, and medications of children with infrequent bowel movements or fecal soiling. Methods: This study enrolled 333 children (189 male; age range, 1 month to 18 years) diagnosed with functional constipation by Rome III or IV criteria. We classified them into 3 groups (infrequent bowel movement without fecal soiling [G3-a], infrequent bowel movement with fecal soiling [G3-b], and fecal soiling only [G3-c]) and into 2 subgroups of fecal soiling (G2-b) or not (G2-a). Retrospective data on clinical characteristics, colon transit time (CTT) test results, and medications were collected. The Wilcoxon rank-sum test, Kruskal-Wallis test, Chi-square test, and Fisher's exact test were used for the statistical analysis. Results: The median age (months) and interquartile range (IQR) was 33 (45) in G3-a, 54 (40) in G3-b, and 73 (48) in G3-c (p<0.0001). G3-c had the latest onset (median, 18; IQR, 18; p=0.0219) and longest symptom duration (24 [24], p=0.0148). PEG 4000 was used in 60.6% (G3-a), 96.8% (G3-b), and 83.2% (G3-c) of patients (p<0.0001). The median age (months) and IQR were 33.0 (45.0) in G2-a and 63.5 (52.5) in G2-b (p<0.0001). G2-b had later onset (median, 12; IQR, 19.5; p=0.0062) and longer symptom duration than G2-a (24 [12], p=0.0070). PEG 4000 was used in 60.6% (G2-a) and 88.3% (G2-b) of children (p<0.0001). No statistically significant intergroup differences were seen in maintenance laxative dose, CTT, or CTT type. Conclusion: Infrequent bowel movement and fecal soiling represent the advanced stage of chronic functional constipation.

• Journal of the Korean Solar Energy Society
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• v.35 no.2
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• pp.63-71
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• 2015

Soiling is the accumulation of dirt on photovoltaic (PV) modules and can reduce the performance of the PV power plant depending on the site location. Nevertheless, the reason which can not be the great interest to researchers of PV reliability is the phenomenon of performance loss caused by external environmental factors, not the internal degradation of the PV module. In this paper, we provide the phenomenon, history, research overview and mitigation method in order to help understanding of the soiling.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.170-171
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• 2008

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.2
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• pp.112-117
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• 1995

A field experiment was canied out to determine the effects of harvest time (grazing, soiling and hay stage) on the grass growth, dry matter (DM) yield, nutritive value, and weed development in reed canarygrass (Phalaris arundinacea L.) pasture. The cultivars of reed canarygrass used in this study were Palaton, Venture, Castor, and Frontier (control). The grass was harvested 3 times at hay stage, 4 times at soiling stage, and 6 times at grazing stage in 1992. The average plant height was 31-41cm at grazing, 47-59cm at soiling, and 76-86cm at hay stage. Similar DM yield was observed in Palaton(12,567 kglha), Venture(l2,435kg), and Frontier(12,762kg), and the yields of 3 cultivars were significantly higher than that of Castor(ll,025kg) (P<0.05). Total yields affected by harvest time were lO,O6 1, 1 1,832, and 14,699 kg/ha at grazing, soiling, and hay stage, respectively(P<0.05). The content of crude protein (CP) was not significantly different among cultivars. CP contents by harvest time were 21.6% at grazing, 19.3% at soiling, and 18.8% at hay stage, regardless of cultivm(P<0.05). The contents of neutral detergent fiber (NDF) and acid detergent fiber (ADF) were similar among cultivars and harvest time. However, slightly higher NDF and ADF contents were found in Frontier. The contents of Ca, P, K, and Mg were not affected by cultivars and harvest time. The appearance of weeds was high in Castor, and low in Frontier. The weeds at grazing stage(33.3-60.0%) were remarkably higher than those at soiling and hay astage (ca 10%). In conclusion, it is suggested that 3-4 times (soiling and hay stage) of harvest was recommended for grass production, nutritive value, and weed control in reed canarygrass pasture, regradless of cultivars of Palation, Venture and Frontier, except Castor.

• Textile Coloration and Finishing
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• v.13 no.2
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• pp.18-18
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• 2001

This study has examined the removal of mixed soil of protein and fat by protease. Cotton and PET fabrics were soiled by spotting of hemoglobin and triolein, respectively. The soiling order and soil concentration were changed in this procedure. The soiled fabrics were aged at 130℃ for 20 minutes. Protease was added in the alcohol ethoxylate(AE) detergent solution. The removal effciency was evaluated by analysis of protein and/or fat on the fabrics before and after washing, respectively. The detergency of PET fabrics was higher than that of cotton fabrics. The removal efficiency of hemoglobin was improved by protease from cotton and PET fabrics. Especially the removal efficiency of hemoglobin was remarkably improved from cotton fabrics. With the increase of hemoglobin and triolein (1:1) mixed soil, the removal of mixed soil was increased in proportion to mixed soil content up to a certain point. but it began to decrease above the point from cotton fabrics, while it was generally increased from PET fabrics. The detergency of total mixed soil from cotton fabrics was higher in case of soiling order with triolein after hemoglobin than in case of soiling order with triolein before hemoglobin. But the soiling order was not greatly effected in the detergency of total mixed soil from PET fabrics.

• Textile Coloration and Finishing
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• v.13 no.2
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• pp.104-113
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• 2001

This study has examined the removal of mixed soil of protein and fat by protease. Cotton and PET fabrics were soiled by spotting of hemoglobin and triolein, respectively. The soiling order and soil concentration were changed in this procedure. The soiled fabrics were aged at $130^\circ{C}$ for 20 minutes. Protease was added in the alcohol ethoxylate(AE) detergent solution. The removal effciency was evaluated by analysis of protein and/or fat on the fabrics before and after washing, respectively. The detergency of PET fabrics was higher than that of cotton fabrics. The removal efficiency of hemoglobin was improved by protease from cotton and PET fabrics. Especially the removal efficiency of hemoglobin was remarkably improved from cotton fabrics. With the increase of hemoglobin and triolein (1:1) mixed soil, the removal of mixed soil was increased in proportion to mixed soil content up to a certain point. but it began to decrease above the point from cotton fabrics, while it was generally increased from PET fabrics. The detergency of total mixed soil from cotton fabrics was higher in case of soiling order with triolein after hemoglobin than in case of soiling order with triolein before hemoglobin. But the soiling order was not greatly effected in the detergency of total mixed soil from PET fabrics.

• Journal of The Korean Society of Grassland and Forage Science
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• v.9 no.1
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• pp.1-6
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• 1989

This field experiment was carried out to determine the effects of fertilizer application time in spring on the growth, crude protein(CP) content and dry matter(DM) yield of grasses for soiling. Application times of fertilizer were March 10, 20, 30, April 9 and 19, and control (non-fertilized) plot was involved. All fertilized plots were also treated with single- and compound fertilizer. The first harvesting date for soiling was May 12, and the regrowth soiling yield was investigated on June 9, 1988. In all fertilized plots, the growth, DM yield, CP, CP yield and regrowth yield of gasses were significantly increased compared with control, and the best grass growth, DM yield, CP, CP yield and N recovery were observed on March 30 and April 9 among all fertilized plots. And there were not significant differences between singleand compound fertilizer treatment in grass growth, DM yield and CP content. On March 30 and April 9 in this experiment, the accumulated temperature was 120 and 200^{\circ}C.$ and the subsoil temperature at 10 cm depth was 8 and 10^{\circ}C.$. Considering the average meteorological condition in Suwon area, the optimum application time of spring fertilizer for soiling may be recommended from April 3 to April 10.

• Proceedings of the Korean Society of Grassland Science Conference
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• 2005.06a
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• pp.168-169
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• 2005

• Journal of Korean Society of Forest Science
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• v.19 no.1
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• pp.1-23
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• 1973

The results of ground vegetation experiment conducted at completely denuded forestland in the mudstone region are summerized as follows: On the reaults of soiling quantity the effect of soiling was observed where depth of soiling over 10 cm was practiced, and a plot where treated with 15cm soiling and without fertilizer showed poor growth and it was even worser than the plot where soiling was practiced only 1 cm in thikness but applied adequate amount of fertilizers. The depth of slits between 30cm and 40cm showed no significant difference in the effect. A plot where covered with vegetation bag showed somewhat better results in seed loss and early growth but no differences observed in the fall result over the none covered plot. And then, it is recommendable to have soiling over 10cm in thikness with slit of 30cm and 30cm in depth and to apply 30 gram of fertilizer (22;22:11, 50 gram) per slit. On various soiling materials trial there were no striking differences in the effect of soiling between weathered granite soil, wheathered tuffs soil and weathered mudstone soil. In the treatment with various green materials, a plot treated with straw mat showed a significant difference at 1 percent. The results show that weathered mudstone soil is effective to use as soiling materials and straw mat treatment was better. On forest fertilization trial, in the mudstone region where red and black pine trees already existing at a rate of 2,000-3,000 trees per hectare had applied 110kg of compound fertilizers (9:12:3 and 22:22:11) per hectare basis in terms of plant nutrient. As a result, the difference in effect between the compound fertilizers was not found however the leaf color and leaf length of the fertilizer added plot showed darker and longer at 30 percent over the no fertilizer received plot. Compound fertilizers, 14:37:12 and 9:12:3 were applied to alder trees at a rate of 20 gram and 40 gram per tree in terms of plant nutrient and a remarkable growth accelerantion was observed where 40 grams of plant nutrient applied. The effect difference between the compound fertilizers was not found. On investigation of tree root elongation, forty years old red pine trees showed only 15cm tap root elongation through mudstone while black pine had 23 cm tap root elongation. The total length of supporting root elongtion of red and black pines showed 20 and 13 meters, respectively. The tap roots of Black locusts were not able to elongate through mudstone, however, the supporting roots tended to develop to the underneath of pine tree where some moisture content is available. Black locusts And grown on the residual soil of mudstone normally die between 8 to 10 years. The red pine trees show flat in tree shape while black pine had triangle in the shape. With the results it can be said that in an artificial reforestation in denuded forest land of the mudstone region the adequate slit and enough amount of fertiliizer application must be provided for the succesful performance of the program. On integrated experimental results of 1972. for the establishment of ground vegetation on the completely denuded forest land in mudstone region, soiling could be effectively practiced with weathered mudstone soil and it would not specially necessiate to have either weathered granite or tuffssoil for the soiling. And the soiling depth should be more than 10 cm in thickness. Among green materials used the straw mat proved to be the most effective reatment. Three major factors which enable to establish ground vegetation by the shortest period of time: A. Physical improvement of soil is necessary to breakdown of the horizontal cracks sushas Slit, contour line plot, seeding hole and etc., and soiling with weathered mudstone soil. B. Chemical improvement of soil: is needed sufficient amount of fertilizer application 300~400kg ha, $N+P_2O_5+K_2O$), and increased production of ground covering and expedite resolution of the vegetation (ground vegetation, fallen leaves and twigs). C. Complete establishment of the basic structure for the erosion control (Prevention of surface soil erosion)