• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.1
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• pp.65-74
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• 2023

This study compared the surface roughness and microbial adhesion characteristics of Omnichroma, a novel composite resin developed using "smart chromatic technology", with those of two other conventional composite resins with different filler compositions. A total of 144 specimens were fabricated using 3 types of composite resins: Omnichroma (nano-spherical), Filtek Z350XT (nanofill), and Tetric N-Ceram (nanohybrid) and, divided into 3 groups of 48. Finishing was performed using tungsten carbide burs. Specimens were then divided into 3 subgroups using different polishing methods: Control, SofLex, and PoGo. Surface roughness was analyzed quantitatively and qualitatively using an atomic force microscope and a scanning electron microscope. Microbial adhesion was assessed by culturing Streptococcus mutans on the specimens for 24 hours and then measuring colony-forming units attached to the upper surface. The surface roughness (Ra) of Omnichroma was 0.123 ㎛ after finishing, and it exhibited a smooth surface compared to the other resins. However, after polishing, there were no significant differences in the surface roughness between the three composite groups, regardless of the polishing methods. The surfaces of the Control subgroups were significantly rougher than those of the SofLex subgroups in all 3 composite groups. However, except for Tetric N-Ceram, there were no significant differences between the Control and PoGo subgroups in the other composite groups. Microbial adhesion assessment showed no significant differences between any of the 3 composite resin subgroups; however, Omnichroma exhibited higher microbial adhesion than the other two composites. No significant correlation was observed between surface roughness and microbial adhesion.

• The korean journal of orthodontics
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• v.27 no.6 s.65
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• pp.979-995
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• 1997

The purpose of this study was to identify the preventive and the progressive inhibitory effects of enamel demineralization with fluoride releasing light-and self-cured orthodontic sealants(FluoroBond), in vitro, under the polarizing light microscope and the scanning electon microscope. The polarizing light microscopic group was subdivided into seven groups(Group A-Group G). The scanning electron microscopic group was also subdivided into seven groups(Group A'-Goup G'). For polarizing light microscopic evaluation, longitudinal sections were made longitudinally by Maruto cutter(Maruto Co., Japan) and Maruto grinding machine(Maruto Co., Japan). Sections were examined and photographed by the polarizing light microscope(Olympus Optical Co., Japan) using crossed polars and with the enamel rod longitudinal axis oriented at $45^{\circ}$ to the extinction position. For scanning electron microscopic evaluation, the specimens were coated with a highly conducting layer of gold palladium in a model Hus-4 high-vacuum evaporator and examined in an ISI-100B scanning electron microcope operated at 20kV. The results of this study were as follows : 1. The mean depths of artificial carious lesions under a polarized light microscope were $Group\;A(5.08{\mu}m),\;Group\;B(47.82{\mu}m,\;Group\;C(8.42{\mu}m),\;Group\;D(7.20{\mu}m),\;Group\;E(85.41{\mu}m),\;Group\;F(60.38{\mu}m),\;Group\;G(60.13{\mu}m)$. 2. There were statistically significant differences in Group B compared with Group A, C, and D(p<0.05), and also, in Group I compared with Group F and Group G(p<0.05). 3. Light-and self-cured orthodontic sealants had the preventive effects of enamel demineralization. 4. Light-and self-cured orthodontic sealants had the progressive inhibitory effects of enamel demineralization. 5. The time progress of demineralizing agent had no influence on the samples of light-and self-cured orthodontic sealants under the scanning electron microscope. 6. There was no difference between the specimens of light-and self-cured orthodontic sealants both in the polarized light microscopic group and in the scanning electron microscopic group.

• Radiation Oncology Journal
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• v.21 no.4
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• pp.299-305
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• 2003

Purpose: In order to develop the national guide-lines for the standardization of radiotherapy we are planning to establish a web-based, on-line data-base system for laryngeal cancer. As a first step this study was performed to accumulate the basic clinical information of laryngeal cancer and to determine the items needed for the data-base system. Materials and Methods: We analyzed the clinical data on patients who were treated under the diagnosis of laryngeal cancer from January 1998 through December 1999 In the South-west area of Korea. Eligiblity criteria of the patients are as follows: 18 years or older, currently diagnosed with primary epithelial carcinoma of larynx, and no history of previous treatments for another cancers and the other laryngeal diseases. The items were developed and filled out by radiation oncologlst who are members of forean Southwest Radiation Oncology Group. SPSS vl0.0 software was used for statistical analysis. Results: Data of forty-five patients were collected. Age distribution of patients ranged from 28 to 88 years(median, 61). Laryngeal cancer occurred predominantly In males (10 : 1 sex ratio). Twenty-eight patients (62$\%$) had primary cancers in the glottis and 17 (38$\%$) in the supraglottis. Most of them were diagnosed pathologically as squamous cell carcinoma (44/45, 98$\%$). Twenty-four of 28 glottic cancer patients (86$\%$) had AJCC (American Joint Committee on Cancer) stage I/II, but 50$\%$ (8/16) had In supraglottic cancer patients (p=0.02). Most patients(89$\%$) had the symptom of hoarseness. indirect laryngoscopy was done in all patients and direct laryngoscopy was peformed in 43 (98$\%$) patients. Twenty-one of 28 (75$\%$) glottic cancer cases and 6 of 17 (35$\%$) supraglottic cancer cases were treated with radiation alone, respectively. The combined treatment of surgery and radiation was used in 5 (18$\%$) glottic and 8 (47$\%$) supraglottic patients. Chemotherapy and radiation was used in 2 (7$\%$) glottic and 3 (18$\%$) supraglottic patients. There was no statistically significant difference in the use of combined modality treatments between glottic and supraglottic cancers (p=0.20). In all patients, 6 MV X-ray was used with conventional fractionation. The iraction size was 2 Gy In 80$\%$ of glottic cancer patients compared with 1.8 Gy in 59$\%$ of the patients with supraglottic cancers. The mean total dose delivered to primary lesions were 65.98 ey and 70.15 Gy in glottic and supraglottic patients treated, respectively, with radiation alone. Based on the collected data, 12 modules with 90 items were developed or the study of the patterns of care In laryngeal cancer. Conclusion: The study Items for laryngeal cancer were developed. In the near future, a web system will be established based on the Items Investigated, and then a nation-wide analysis on laryngeal cancer will be processed for the standardization and optimization of radlotherapy.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.12 no.1
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• pp.94-102
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• 2001

Bullying has recently become a serious social problem in Korean society. Bullying, which is defined as a phenomenon that one particular student is intensively and continuously harassed or ostracized by a group of students, is apt to produce harmful effects on bullies as well as victims. Bullying has many causes including those originated from the personality of victims and bullies. This study is designed to investigate the difference in personality trait between victims, bullies, victims/bullies, and neither. The subjects of this study were 215(115 male and 100 female) 6th-grade students in the primary school in Seoul. Questionnares were distributed to the students and their carers. The student carers were also asked to answer the questions for a survey called the Korean Personality Invertory for Children(KPI-C). SPSS was used for the statistical analysis of the collected test information；ANOVA, post hoc scheffe test, and T-test were used to analyze the differences between the tested groups. The result of the study is as follows. 1) The victims, bullies, victims/bullies and neither totaled respectively 11(5.1%), 56(26.0%), 11(5.1%) and 137(63.7%). 115 were male and 100 were female. 2) The frequency of victimized is as follows：1 time is 15(7.0%), 2 times is 4(1.9%) and more than 3 times is 3(1.4%). The frequency of bullying is as follows；1 time is 40(18.6%), 2 times is 17 (7.9%) and more than 3 times is 10(4.7%). 3) The differences between froups in KPI-C test is as follows. (1) The ESR(p=.00) scale was significantly lower in the victims group than in the neither group and the HPR(p=.00) scale and PSY(p<.01) scale were significantly higher in the former than in the latter. (2) The ESR(p=.00) scale was significantly lower in the victims/bullies group than in the neither group and the SOM(p=.00) scale and HPR(p=.00) scale were significantly higher in the formaer than in the latter. (3) The SOC(p=.00) scale, PSY(p<.01) scale and AUT(p=.00) scale were significantly higher in the victims group than in the bullies group. (4) There is statistically no difference between the bullies group and the neither group. To conclusion, Victims need to learn how to cope with harsh situations, or they will have to face difficulties in relationships. Even after they experience bullying, they may not realize why they have been bullied, or speak out for themselves.

• Restorative Dentistry and Endodontics
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• v.27 no.2
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• pp.158-174
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• 2002

The aim of this study was to investigate the effect of light irradiation modes on polymerization shrinkage, degree of cure and microleakage of a composite resin. VIP$^{TM}$ (Bisco Dental Products, Schaumburg, IL, USA) and Optilux 501$^{TM}$ (Demetron/Kerr, Danbury, CT, USA) were used for curing Filtek$^{TM}$ Z-250 (3M Dental Products, St. Paul., MN, USA) composite resin using following irradiation modes: VIP$^{TM}$ (Bisco) 200mW/$\textrm{cm}^2$ (V2), 400mW/$\textrm{cm}^2$ (V4), 600mW/$\textrm{cm}^2$ (V6), Pulse-delay (200 mW/$\textrm{cm}^2$ 3 seconds, 5 minutes wait, 600mW/$\textrm{cm}^2$ 30seconds, VPD) and Optilux 501$^{TM}$ (Demetron/Kerr) C-mode (OC), R-mode (OR). Linear polymerization shrinkage of the composite specimens were measured using Linometer (R&B, Daejeon, Korea) for 90 seconds for V2, V4, V6, OC, OR groups and for up to 363 seconds for VPD group (n=10, each). Degree of conversion was measured using FTIR spectrometer (IFS 120 HR, Bruker Karlsruhe, Germany) at the bottom surface of 2 mm thick composite specimens V2, Y4, V6, OC groups were measured separately at five irradiation times (5, 10, 20, 40, 60 seconds) and OR, VPD groups were measured in the above mentioned irradiation modes (n=5 each). Microhardness was measured using Digital microhardness tester (FM7, Future-Tech Co., Tokyo, Japan) at the top and bottom surfaces of 2mm thick composite specimens after exposure to the same irradiation modes as the test of degree of conversion(n=3, each). For the microleakage test, class V cavities were prepared on the distal surface of the ninety extracted human third molars. The cavities were restored with one of the following irradiation modes : V2/60 seconds, V4/40 seconds, V6/30 seconds, VPD , OC and OR. Microleakage was assessed by dye penetration along enamel and dentin margins of cavities. Mean polymerization shrinkage, mean degree of conversion and mean microhardness values for all groups at each time were analyzed using one-way ANOVA and Duncan's multiple range test, and using chi-square test far microleakage values. The results were as follows : . Polymerization shrinkage was increased with higher light intensity in groups using VIP$^{TM}$ (Bisco) : the highest with 600mW/$\textrm{cm}^2$, followed by Pulse-delay, 400mW/$\textrm{cm}^2$ and 200mW/$\textrm{cm}^2$ groups, The degree of polymerization shrinkage was higher with Continuous mode than with Ramp mode in groups using Optilux 501$^{TM}$ (Demetron/Kerr). . Degree of conversion and microhardness values were higher with higher light intensity. The final degree of conversion was in the range of 44.7 to 54.98% and the final microhardness value in the range of 34.10 to 56.30. . Microleakage was greater in dentin margin than in enamel margin. Higher light intensity showed more microleakage in dentin margin in groups using VIP$^{TM}$ (Bisco). The microleakage was the lowest with Continuous mode in enamel margin and with Ramp mode in dentin margin when Optilux 501$^{TM}$ (Demetron/Kerr) was used.

• Journal of Korean Home Economics Education Association
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• v.19 no.4
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• pp.37-56
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• 2007

The purpose of this study is to provide basic resources to the first-grade Home Economics Regular Teacher Qualification Program (FGHERTQP) in order to improve its operation plans. For the study, the three methods were carried out: an analysis on the curricula of FGHERTQP over six years since 2000, a questionnaire asking their satisfaction degrees and needs on the programs which was answered by the home economics teachers who were the participants of FGHERTQP, and several statistical analyses such as a descriptive-test, a $X^2$-test, a t-test, and one way ANOVA by using SPSS Win ver 10.0. The results of the study were as follows; Firstly, FGHERTQP has been operated ten times by five training centers during resent six years. Subject matters ($1{\sim}7$), whole numbers of lectures ($11{\sim}29$), and their allotted working hours ($111{\sim}136$) vary with individual training centers and operation years. Secondly, when using 5 point likert scales, Contents and Methods of evaluation marked 3.08 which were the lowest scores, and Qualification Training in General marked 3.72 which was the highest score among five fields of Qualification Training in General, Contents, Organizations, Methods and Evaluation. The overall scores were low. Thirdly, in needs analysis on offering subject matters, the participants wanted to study the field of home economics education more than that of subject contents. Looking about the highest needs classified by domains, Food Principles & Meal Management showed the highest in Foods. And Consumer Issues in Clothing & Textiles in Textiles, Upcoming Housing Cultures in Housing, Family Relationship in Child Development & Family Relationship, Juveniles and their daily life as a consumer in Family & Consumer Resources Management. Fourthly, training centers' lectures available had a significant influence on the satisfaction degrees according to general characteristic variations of the participants. That is, as a training center offers more lectures in the field of subject education than those of subject contents, the participants showed higher satisfaction degrees (p<.05).

• Journal of Chest Surgery
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• v.40 no.9
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• pp.593-599
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• 2007

Background: The correlation between levels of brain natriuretic peptide (BNP) and the effect of pulmonary resection on the right ventricle of the heart is not yet widely known. This study aims to assess the relationship between the change in hemodynamic values of the right ventricle and increased BNP levels as a compensatory mechanism for right heart failure following pulmonary resection and to evaluate the role of the BNP level as an index of right heart failure after pulmonary resection. Material and Method: In 12 non small cell lung cancer patients that had received a lobectomy or pnemonectomy, the level of NT-proBNP was measured using the immunochemical method (Elecsys $1010^{(R)}$, Roche, Germany) which was compared with hemodynamic variables determined through the use of a Swan-Garz catheter prior to and following the surgery. Echocardiography was performed prior to and following the surgery, to measure changes in right ventricular and left ventricular pressures. For statistical analysis, the Wilcoxon rank sum test and linear regression analysis were conducted using SPSSWIN (version, 11.5). Result: The level of postoperative NT-proBNP (pg/mL) significantly increased for 6 hours, then for 1 day, 2 days, 3 days and 7 days after the surgery (p=0.003, 0.002, 0.002, 0.006, 0.004). Of the hemodynamic variables measured using the Swan-Ganz catheter, the mean pulmonary artery pressure after the surgery when compared with the pressure prior to surgery significantly increased at 0 hours, 6 hours, then 1 day, 2 days, and 3 days after the surgery (p=0.002, 0,002, 0.006, 0.007, 0.008). The right ventricular pressure significantly increased at 0 hours, 6 hours, then 1 day, and 3 days after the surgery (p=0.000, 0.009, 0.044, 0.032). The pulmonary vascular resistance index [pulmonary vascular resistance index=(mean pulmonary artery pressure-mean pulmonary capillary wedge pressure)/cardiac output index] significantly increased at 6 hours, then 2 days after the surgery (p=0.008, 0.028). When a regression analysis was conducted for changes in the mean pulmonary artery pressure and NT-proBNP levels after the surgery, significance was evident after 6 hours (r=0.602, p=0.038) and there was no significance thereafter. Echocardiography displayed no significant changes after the surgery. Conclusion: There was a significant correlation between changes in the mean pulmonary artery pressure and the NT-proBNP level 6 hours after a pulmonary resection. Therefore, it can be concluded that changes in NT-proBNP level after a pulmonary resection can serve as an index that reflects early hemodynamic changes in the right ventricle after a pulmonary resection.

• Journal of Chest Surgery
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• v.38 no.1 s.246
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• pp.44-49
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• 2005

Although thymomas are relatively common mediastinal tumors, to date not only has a universal system of pathologic classification not been established but neither has a clearly defined predictable relationship between treatment and prognosis been made. Recently, a new guideline for classification was reported by WHO, and efforts, based on this work, have been made to better define the relationship between treatment and pro­gnostic outcome. In the present study a comparative analysis between the WHO classification and Masaoka stage system with the clinical disease pattern was conducted. Material and Method: A total of 98 patients undergoing complete resection for mediastinal thymoma between Juanuary 1993 and June 2003 were included in the present study. The male female ratio was 48 : 50 and the mean age at operation was $49.6{\pm}13.9\;years.$ A retrospective analytic comparison studying the relationship between the WHO classification and the Masaoka stage system with the clinical disease pattern of thymoma was conducted. Pathologic slide specimens were carefully examined, details of postoperative treatment were documented, and a relationship with the prognostic outcome and recurrence was studied. Result: There were 7 patients in type A according to the WHO system of classification, 14 in AB, 28 in B 1, 23 in B2, 18 in B3, and 9 in type C. The study of the relationship between the Masaoka stage and WHO classification system showed 4 patients to be in WHO system type A, 7 in type AB, 22 in B 1, 17 in B2, and 3 in type B3 among 53 $(54{\%})$ patients shown to be in Masaoka stage I. Among 28 $(28.5{\%})$ patients in Masaoka stage II system, there were 2 patients in type A, 7 in AB, 4 in B 1, 2 in B2, 8 in B3, and 5 in type C. Among 15 $(15.3{\%})$ in Masaoka stage III, there were 1 patient in type B1, 3 in B2, 7 in B3, and 4 in type C. Finally, among 2 $(2{\%})$ patients found to be in Masaoka stage IV there was 1 patient in type B1, and 1 in type B2. The mean follow up duration was $28{\pm}6.8$ months. There were 3 deaths in the entire series of which 2 were in type B2 (Masaoka stages III and IV), and 1 was in type C (Masaoka stage II). Of the patients that experienced relapse, 6 patients remain alive of which 2 were in type B2 (Masaoka III), 2 in type B3 (Masaoka I and III) and 2 in type C (Masaoka stage II). The 5 year survival rate by the Kaplan-Meier method was $90{\%}$ for those in type B2 WHO classification system, $87.5{\%}$ for type C. The 5 year freedom from recurrence rate was $80.7{\%}$ for those in WHO type B2, $81.6{\%}$ for those in type B3, and $50{\%}$ for those in type C. By the Log-Rank method, a statistically significant correlation between survival and recurrence was found with the WHO system of classification (p<0.05). An analysis of the relationship between the WHO classification and Masaoka stage system using the Spearman correction method, showed a slope=0.401 (p=0.023), showing a close correlation. Conclusion: As type C of the WHO classification system is associated with a high postoperative mortality and recurrence rate, aggressive treatment postoperatively and meticulous follow up are warranted. The WHO classification and Masaoka stage system were found to have a close relationship with each other and either the WHO classification method or the Masaoka stage system may be used as a predict prognostic outcome of Thymoma.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.7 no.1
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• pp.1-29
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• 1969

Experiments on rice concerning it s varieties, fertilization, seedling dates and herbicides have been conducted to determine the most desirable method of direct sowing cultivation on dry paddy field land in the middle part of Korea. The results obtained at the Office of Rural Development of Choongnam Province are as follows:. 1. Sixteen different derivatives from the main varieties of low land rice were cultivated on a dry paddy field by the direct sowing method; at the same time, a few varieties were tried adopting the common transplanting cultivation method. The yield and yield factors from these two groups were examined to give the following results: a) Compared to the common transplanting cultivation, the direct sowing method showed remarkably increased number of panicles while the number of flowers per panicle was shown to be significantly decreased. The maturing ratio was detected to be lowered. The yield horn them differed according to the different varieties : good yield was obtained from Hokwang while Norin ＃25 proved poor when compared with the common transplanting cultivation method. b) Among sixteen varieties tested, Sunsou, Norin ＃25, Jaigou, Hokwang, Palkueng and Gosi showed comparatively high yields, their yield being more than 325 kilograms per 10 Are, but Nampoong, Paldal, Nongkwang, Norin ＃29, Eunbangju ＃101 and Shiro gane showed less yield, their yield being less than 271 kilograms per 10 Are, the relations between the yield and the yield factors can be summarized as follows; Number of varieties and their rice yield. 1) The varieties which were great in the, number of panicles and high in yield=Jaigoun, Hokwang Palkueng and Gosi. 2) The varieties which were low in the number of panicles and high in yield=Sounsou and Norin ＃25. 3) The varieties which were great in the number of panicles and poor in yield=Eunbangju ＃101 and Sirogane. 4) The varieties which were poor in the number of panicles and poor in yield: Nampung, Paldal and Norin ＃29. Number of flowers per panicle and yield. 1) The varieties which were great in the number of flowers per panicle and high in yield: Sounsou, Norin ＃25 and Gosi. 2) The varieties which were poor in the number of flowers per panicle and high in yield ; Jaigoun, Hokwang and Palkueng. 3) The varieties which were great in the number of flowers per panicle and poor in yield: Paldal and Nampung. 4) The varieties which were poor in the number of flowers per panicle and poor in yield: Norin ＃29. Eunbangju ＃101 and Sirogane. Maturing ratio and yield. 1) The varieties which were high in the maturing ratio and high in yield: Jaigoun, Sounsou, Norin ＃25 and Palkueng. 2) The varieties which were low in the maturing ratio and high in yield: Hokwang and Gosi. 3) The varieties which were early maturing rat io and low in yield: Hokwang and Gosi. 4) The varieties which were late maturing ratio and poor in yield: Eunbangju ＃101, Nampungand Sirogane 1, 000 grain weight and yield. 1) The varieties which were heavy in 1, 000 grains weight and high in yield=Norin ＃25 and Hokwang. 2) The varieties which were light in 1, 000 grains weight and high in yield=Sounsou and Jaigoun. 3) The varieties which were heavy in 1, 000 grains weight and poor in yield=Nongkwang and Eunbanju. 4) The varieties which were light in 1, 000 grains weight and poor in yield=Norin ＃29 and Sirogane. 2. The experiment on fertilization showed that the most desirable amount to be given per 10 Are was 10 kilograms of Nitrogen, 5 kilograms of phosphate and 6 kilograms of potassium; and when the Nitrogen given exceeded 8 kilograms, its effect was better when given in amsll consecutive (split) amounts, while the maturing ratio and the number of the flowers per panicle increased when Nitrogen was given in large amount during the later stage of growth of rice. 3. The experiment on the date and amount of seedling showed that the tested variety, Sunsou gave the best results when planted on the days between 25 April and 10 May. Eight liters per 10 Are were preferable if planted early and 12 liters per 10 Are if planted late. The reason why the later planting gave a lower yield was that the number of flowers per panicle was fewer. 4. The experiment on the irrigation for rice with direct sowing cultivation immersed in water showed that it was the most satisfactory when irrigated on 25th June, 55 days after its seedling, its plot giving the best yield. The plots 10th June and 15th July showed just as good results. However, irrigated later, than 15th July it showed lower yields. 5. Compared to the yield of the plot controlled by the common method, the yield from the plots treated with chemical herbicide such as LOROX, TOK, PCP, SWEP, Mo-338 on dry condition soil seemed poorer, but significant difference was not found statistically. On the other hand in the case where chemical herbicides such as TOK, Mo-338, Stam F-34 or ORDRAM were used after irrigation, the yield from the ORDRAM and TOK treated plots did not show significant differences compared to the common hand weed controling method, but those treated with chemicals other than the above showed a lower yield.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.6
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• pp.642-652
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• 2008

The aim of our research was to apply experimental design methodology in the optimization condition of Photo-Fenton oxidation of the residual livestock wastewater after the coagulation process. The reactions of Photo-Fenton oxidation were mathematically described as a function of parameters amount of Fe(II)($x_1$), $H_2O_2(x_2)$ and pH($x_3$) being modeled by the use of the Box-Behnken method, which was used for fitting 2nd order response surface models and was alternative to central composite designs. The application of RSM using the Box-Behnken method yielded the following regression equation, which is an empirical relationship between the removal(%) of livestock wastewater and test variables in coded unit: Y = 79.3 + 15.61x$_1$ - 7.31x$_2$ - 4.26x$_3$ - 18x$_1{^2}$ - 10x$_2{^2}$ - 11.9x$_3{^2}$ + 2.49x$_1$x$_2$ - 4.4x$_2$x$_3$ - 1.65x$_1$x$_3$. The model predicted also agreed with the experimentally observed result(R$^2$ = 0.96) The results show that the response of treatment removal(%) in Photo-Fenton oxidation of livestock wastewater were significantly affected by the synergistic effect of linear terms(Fe(II)($x_1$), $H_2O_2(x_2)$, pH(x$_3$)), whereas Fe(II) $\times$ Fe(II)(x$_1{^2}$), $H_2O_2$ $\times$ $H_2O_2$(x$_2{^2}$) and pH $\times$ pH(x$_3{^2}$) on the quadratic terms were significantly affected by the antagonistic effect. $H_2O_2$ $\times$ pH(x$_2$x$_3$) had also a antagonistic effect in the cross-product term. The estimated ridge of the expected maximum response and optimal conditions for Y using canonical analysis were 84 $\pm$ 0.95% and (Fe(II)(X$_1$) = 0.0146 mM, $H_2O_2$(X$_2$) = 0.0867 mM and pH(X$_3$) = 4.704, respectively. The optimal ratio of Fe/H$_2O_2$ was also 0.17 at the pH 4.7.