• Journal of Korean Society of Forest Science
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• v.30 no.1
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• pp.19-29
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• 1976

The fiberboard and paper mills in this country are much affected by the price hikes and shortage of phenolic resins, since phenolic acid as a raw material depends on imported good. It is prerequisite to fiberboard industry to help replace with other sized and stabilize the prices and supply of them, improving the quality of boards. Thus, the present study was carried out to examine the effect of strength increasing sized such as urea formaldehyde resin (anion and cation type) and urea melamine copolymer resin, on the quality of the wet forming hardboard, and comparing them with two types of proprietary modified melamine resins, and ordinary size, phenol resin. The Asplund pulp was prepared from wood wastes mixed with 20 percent of lauan and 80 percent of pines as a fibrous material. After sizing agents were added at a pH of 4.5 for 10 minutes with alum in the beater, the stock was made in the form of wet sheet, prepared, and then performed by hot pressing cycle: $180^{\circ}C$, $50-6-5kg/cm^2$, 1-2-7 minutes. The properties of hardboard were examined after air conditioning. The results obtained are summarized as follows: 1. There is a significant difference in specific gravity among hardboards that were treated with strength increasing resins, but no difference is effected by the increase in the resin content. In the case of modified melamine resin, its specific gravity is highest. The middle group comprises cation type of urea resin, anion type of urea resin, and acid colloid of urea-melamine copolymer resin. The lowest is phenolic resin. 2. The difference of the moisture content of hardboard both by the resins and by the amount of each resin applied is significant. The moisture content of hardboard becomes lower along with the increase of each resin content, but there is no difference between 2 and 3 percent. 3. For water absorption, there is a significant difference both in the adhesives used and in the amount of paraffin wax emulsion. The water resistance becomes higher inn proportion to the content of the paraffin wax emulsion. To satisfy KS F standards of the water resistance, a proprietary modified melamine resin (p-6100) and modified cation type of urea resin (p-1500) do not require any paraffin wax emulsion, but in the case of anion type of urea resin, cation type of urea resin, and urea-melamine copolymer resin, 1 percent of paraffin wax emulsion is needed, and 2 percent of paraffin wax emulsion in the case of phenolic resin. 4. The difference of flexural strength of hardboard both by the resins and by the amount of each resin is significant. Modified melamine resin shows the highest degree of flexural strength. Among the middle group are urea-melamine copolymer resin, p-1500, anion type of urea resin, and cation type of urea resin. Phenolic resin is the lowest. The cause may be attributable to factors combined with the pressing temperature, sizing effect, and thermal efficiency of press platens heated electrically. 5. Considering the economic advantages and properties of hardboard, it is proposed that urea-melamine copolymer resin and cation type of urea resin be used for the development of the fiberboard industry. It is desirable to further develop the modified urea-melamine copolymer resin and cation type of urea resin through continuous study.

• Journal of Korean Society of Forest Science
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• v.77 no.4
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• pp.429-444
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• 1988

Considering the recent trent toward the development of multiple-use of forest trees, investigations for comprehensive information on these young stands of Hinoki cypress are necessary for rational forest management. From this point of view, 83 sample trees were selected and cut down from 23-ear old stands of Hinoki cypress at Changsung-gun, Chonnam-do. Various stem growth factors of felled trees were measured and canonical correlaton analysis, principal component analysis and factor analysis were applied to investigate the stem growth characteristics, relationships among stem growth factors, and to get potential information and comprehensive information. The results are as follows ; Canonical correlation coefficient between stem volume and quality growth factor was 0.9877. Coefficient of canonical variates showed that DBH among diameter growth factors and height among height growth factors had important effects on stem volume. From the analysis of relationship between stem-volume and canonical variates, which were linearly combined DBH with height as one set, DBH had greater influence on volume growth than height. The 1st-2nd principal components here adopted to fit the effective value of 85% from the pincipal component analysis for 12 stem growth factors. The result showed that the 1st-2nd principal component had cumulative contribution rate of 88.10%. The 1st and the 2nd principal components were interpreted as "size factor" and "shape factor", respectively. From summed proportion of the efficient principal component fur each variate, information of variates except crown diameter, clear length and form height explained more than 87%. Two common factors were set by the eigen value obtained from SMC (squared multiple correlation) of diagonal elements of canonical matrix. There were 2 latent factors, $f_1$ and $f_2$. The former way interpreted as nature of diameter growth system. In inherent phenomenon of 12 growth factor, communalities except clear length and crown diameter had great explanatory poorer of 78.62-98.30%. Eighty three sample trees could he classified into 5 stem types as follows ; medium type within a radius of ${\pm}1$ standard deviation of factor scores, uniformity type in diameter and height growth in the 1st quadrant, slim type in the 2nd quadrant, dwarfish type in the 3rd quadrant, and fall-holed type in the 4 th quadrant.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.464-477
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• 2013

There is a great need to develop a training program proven to change behavior and improve knowledge. The purpose of this study was to evaluate employee hygiene knowledge, hygiene practice, and cleanliness, before and after HACCP system implementation at one small-size restaurant. The efficiency of the system was analyzed using time-temperature control after implementation of u-HACCP$^{(R)}$. The employee hygiene knowledge and practices showed a significant improvement (p<0.05) after HACCP system implementation. In non-heating processes, such as seasoned lettuce, controlling the sanitation of the cooking facility and the chlorination of raw ingredients were identified as the significant CCP. Sanitizing was an important CCP because total bacteria were reduced 2~4 log CFU/g after implementation of HACCP. In bean sprouts, microbial levels decreased from 4.20 logCFU/g to 3.26 logCFU/g. There were significant correlations between hygiene knowledge, practice, and microbiological contamination. First, personnel hygiene had a significant correlation with 'total food hygiene knowledge' scores (p<0.05). Second, total food hygiene practice scores had a significant correlation (p<0.05) with improved microbiological qualities of lettuce salad. Third, concerning the assessment of microbiological quality after 1 month, there were significant (p<0.05) improvements in times of heating, and the washing and division process. On the other hand, after 2 months, microbiological was maintained, although only two categories (division process and kitchen floor) were improved. This study also investigated time-temperature control by using ubiquitous sensor networks (USN) consisting of an ubi reader (CCP thermometer), an ubi manager (tablet PC), and application software (HACCP monitoring system). The result of the temperature control before and after USN showed better thermal management (accuracy, efficiency, consistency of time control). Based on the results, strict time-temperature control could be an effective method to prevent foodborne illness.

• The Korean Journal of Nuclear Medicine
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• v.39 no.6
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• pp.481-488
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• 2005

Purpose: Functional imaging of dopamine transporter (DAT) defines integrity of the dopaminergic system, and DAT is the target site of drugs of abuse such as cocaine and methamphetamine. Functional imaging the DAT may be a sensitive and selective indicator of neurotoxic change by the drug. The aim of the present study is to evaluate the clinical implications of qualitative/quantitative analyses of dopamine transporter imaging in methamphetamine abusers. Materials and Methods: Six detoxified methamphetamine abusers (abuser group) and 4 volunteers (control group) were enrolled in this study. Brain MRI was performed in all of abuser group. Abuser group underwent psychiatric and depression assessment using brief psychiatric rating scale (BPRS) and Hamilton depression rating scale (HAMD), respectively. All of the subjects underwent I-123 IPT SPECT (IPT SPECT). IPT SPECT image was analysed with visual qualitative method and quantitative method using basal ganglia dopamine transporter (DAT) specific/non-specific binding ratio (SBR). Comparison of DAT SBR between abuser and control groups was performed. We also performed correlation tests between psychiatric and depression assessment results and DAT SBR in abuser group. Results: All of abuser group showed normal MRI finding, but had residual psychiatric and depressive symptoms, and psychiatric and depressive symptom scores were exactly correlated (r=1.0, p=0.005) each other. Five of them showed abnormal finding on qualitative visual I-123 IPT SPECT Abuser group had lower basal ganglia DAT SBR than that of control ($2.38{\pm}0.20\;vs\;3.04{\pm}0.27$, p=0.000). Psychiatric and depressive symptoms were negatively well correlated with basal ganglia DAT SBR (r=-0.908, p=0.012, r=-0.924, p=0.009). Conclusion: These results suggest that dopamine transporter imaging using I-123 IPT SPECT may be used to evaluate dopaminergic system of the basal ganglia and the clinical status in methamphetamine abusers.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.3
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• pp.241-246
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• 2007

Purpose: $[^{11}C]6-OH-BTA-1$ ([N-methyl-$^{11}C$]2-(4'-methylaminophenyl)-6-hydroxybenzothiazole, 1), a -amyloid imaging agent for the diagnosis of Alzheimer's disease in PET, can be labeled with higher yield by a simple loop method. During the synthesis of $[^{11}C]1$, we found the formation of by-products in various solvents, e.g., methylethylketone (MEK), cyclohexanone (CHO), diethylketone (DEK), and dimethylformamide (DMF). Materials and Methods: In Automated radiosynthesis module, 1 mg of 4-aminophenyl-6-hydroxybenzothiazole (4) in 100 l of each solvent was reacted with $[^{11}C]methyl$ triflate in HPLC loop at room temperature (RT). The reaction mixture was separated by semi-preparative HPLC. Aliquots eluted at 14.4, 16.3 and 17.6 min were collected and analyzed by analytical HPLC and LC/MS spectrometer. Results: The labeling efficiencies of $[^{11}C]1$ were $86.0{\pm}5.5%$, $59.7{\pm}2.4%$, $29.9{\pm}1.8%$, and $7.6{\pm}0.5%$ in MEK, CHO, DEK and DMF, respectively. The LC/MS spectra of three products eluted at 14.4, 16.3 and 17.6 mins showed m/z peaks at 257.3 (M+1), 257.3 (M+1) and 271.3 (M+1), respectively, indicating their structures as 1, 2-(4'-aminophenyl)-6-methoxybenzothiazole (2) and by-product (3), respectively. Ratios of labeling efficiencies for the three products $([^{11}C]1:[^{11}C]2:[^{11}C]3)$ were $86.0{\pm}5.5%:5.0{\pm}3.4%:1.5{\pm}1.3%$ in MEK, $59.7{\pm}2.4%:4.7{\pm}3.2%:1.3{\pm}0.5%$ in CHO, $9.9{\pm}1.8%:2.0{\pm}0.7%:0.3{\pm}0.1%$ in DEK and $7.6{\pm}0.5%:0.0%:0.0%$ in DMF, respectively. Conclusion: The labeling efficiency of $[^{11}C]1$ was the highest when MEK was used as a reaction solvent. As results of mass spectrometry, 1 and 2 were conformed. 3 was presumed.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.3
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• pp.234-240
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• 2007

Purpose: In this study we propose a block-iterative method for reconstructing Compton scattered data. This study shows that the well-known expectation maximization (EM) approach along with its accelerated version based on the ordered subsets principle can be applied to the problem of image reconstruction for Compton camera. This study also compares several methods of constructing subsets for optimal performance of our algorithms. Materials and Methods: Three reconstruction algorithms were implemented; simple backprojection (SBP), EM, and ordered subset EM (OSEM). For OSEM, the projection data were grouped into subsets in a predefined order. Three different schemes for choosing nonoverlapping subsets were considered; scatter angle-based subsets, detector position-based subsets, and both scatter angle- and detector position-based subsets. EM and OSEM with 16 subsets were performed with 64 and 4 iterations, respectively. The performance of each algorithm was evaluated in terms of computation time and normalized mean-squared error. Results: Both EM and OSEM clearly outperformed SBP in all aspects of accuracy. The OSEM with 16 subsets and 4 iterations, which is equivalent to the standard EM with 64 iterations, was approximately 14 times faster in computation time than the standard EM. In OSEM, all of the three schemes for choosing subsets yielded similar results in computation time as well as normalized mean-squared error. Conclusion: Our results show that the OSEM algorithm, which have proven useful in emission tomography, can also be applied to the problem of image reconstruction for Compton camera. With properly chosen subset construction methods and moderate numbers of subsets, our OSEM algorithm significantly improves the computational efficiency while keeping the original quality of the standard EM reconstruction. The OSEM algorithm with scatter angle- and detector position-based subsets is most available.

• Korean Journal of Environmental Agriculture
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• v.13 no.3
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• pp.321-337
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• 1994

The garbage from the dwelling houses was composted in two kinds of small composter in laboratory to investigate the possibility of garbage composting. They were general small composters. One (type 1) was insullated but the other (type 2) was not. Because it was found that type 2 was not available for composting under our meteorological conditions through winter experiment, only type 1 was tested in spring and summer. The experiment was performed for 8 weeks in each season. The seasonal variation of several compounds in compost was evaluated and discussed. The result summarized belows are those taken at the end of the experiment, if the time was not specified. 1) The maximum temperature was $58^{\circ}C$ in spring, $57^{\circ}C$ in summer and $41^{\circ}C$ in winter. This temperature was enough to destroy the pathogen except for winter. 2) The mass was reduced to average 62.5% and the volume reduction was avergae 74%. 3) The density was estimated as 0.7kg/l in spring, 0.8kg/l in summer and 1.1kg/l in winter. 4) The water content was not much changed for composting periods. It had 75.6% in spring and 76.6% in summer and winter. 5) There was a great seasonal difference in pH value. It was reached to pH 6.13 in spring, pH 8.62 in summer and pH 4.75 in winter. 6) The faster organic matter was decomposed, the greater ash content was increased. Cellulose and lignin content were increased, but hemicellulose content was reduced during composting period. 7) Nitrogen contents were in the range of 3.1-5.6% and especially high in summer. After ammonium nitrogen contents were increased at the early stage of composting period, they were decreased. The maximum ammonium nitrogen content was 3,243mg/kg after 2 weeks in winter, 6,053mg/kg after 3 weeks in spring and 30,828mg/kg after 6 weeks in summer. C/N-ratios were not much changed. Nitrification occurred actively in spring and summer. 8) The contents of volatile and higher fatty acids were increased in early stage of composting and reduced after that. The maximum content of total fatty acid was 10.1% after 2 weeks in winter, 5.8% after 2 weeks in spring and 15.7% after 4 weeks in summer. 9) The contents of inorganic compounds were not accumulated as composting was proceeded. They were in the range of 0.9-4.4% $P_2O_5$, 1.6-2.9% $K_2O$, 2.4-4.6% CaO and 0.30-0.80% MgO. 10) CN and heavy metal contents did not show any tendency. They were in the range of 0.11-28.99mg/kg CN, 24-166mg/kg Zn, 5-129mg/kg Cu, 0.8-14.3mg/kg Cd, 7-42mg/kg Pb, ND-30mg/kg Cr and $ND-132.16\;{\mu}g/kg$ Hg.

• Korean Journal of Animal Reproduction
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• v.22 no.4
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• pp.425-435
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• 1998

To improve the efficiency of nuclear transplantation in bovine, in this study the development in vitro of nuclear transferred (NT) embryos was compared by different activation regimens of the enucleated oocytes. The effect of developmental stage and culture system of donor nuclei on fusion and development in vitro of NT embryos were also evaluated. Oocytes were collected from Hanwoo ovaries obtained from slaughterhouse and matured in Ham's F-10 supplemented with hormones. After 20~22 h maturation, the oocytes were vortexed to be free from cumulus cells and subsequently their nucleus and the first polar body were removed. Enucleated oocytes were divided into 3 groups for activation; the oocytes of group I were activated with ionomycin for 5 min and subsequently incubated in 6-dimetylarninopurine (DMAP) for 4 h, Those of group II were treated with DMAP for 4 h at 39 h after onset of in vitro maturation (IVM) and those of group III were kept in room temperature ($25^{\circ}C$) for 3 h at 39 h after onset of IVM. After in vitro fertilization (IVF) the embryos for muclear donor were cultured either by group culture (20 embryos /50 ${mu}ell$ drop) or individually (1 embryo /50 ${mu}ell$ drop) for 4 day and 5 day. At day 4 and 5 after IVF, blastomeres were separated in calcium-magnesium free medium, and then classified into small (day 5: $\leq$ 38 ${\mu}{\textrm}{m}$, day 4: $\leq$ 46 ${\mu}{\textrm}{m}$) and large (day 5 : $\geq$ 38 ${\mu}{\textrm}{m}$, day 4 ; $\geq$ 46 ${\mu}{\textrm}{m}$). The separated blastomeres were replaced into enucleated and activated recipient cytoplasm. The blastomere-oocyte complexes were fused by electrically. The NT embryos were cultured in TCM-199 containing 10% FCS in 39$^{\circ}C$, 5% $CO_2$ incubator for 7 day. The results obtained were summarized as follows; There were no differences in fusion and development to blastocyst between groups as group I (68%, 10%), group II (75%, 14%) and group III (73%, 9%), respectively. However, the cell number in blastocyst of NT embryos in group III were significantly fewer than in the other groups (P＜0.05). No differences in fusion and development to blastocyst were found between individual or group cultured and between small or large blastomeres of day 4 and day 5 donor embryos. From these results, it was concluded that the combination of ionomycin and DMAP, or treatment of DMAP at 39 h after onset of IVM were useful for the efficient of production of NT bovine embryos, and the individual cultured embryos could be simply used as donor nuclei for NT bovine embryo.

• Korean journal of food and cookery science
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• v.26 no.5
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• pp.636-648
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• 2010

Two types of wild grape extracts(WGE) prepared by different methods were added into butter-top bread at different concentrations(0, 5, 10, 15, 20% of water). Then, the resulting breads were analyzed for their physicochemical and sensory properties in order to identify whether or not the WGE-enriched breads were comparable to control bread in terms of qualities and preferences. Wild grape sugar mixture(WGS), which was prepared by osmotic dehydration of wild grape fruits with the same amounts of sugar, presented significantly lower moisture content and titratable acidity as well as higher pH and sugar content compared to wild grape juice(WGJ), which was produced by boiling the fruits in a vacuum jar and squeezing. The pH of the doughs and breads containing WGE tended to decrease with increasing amounts of WGE, and this phenomenon was more appreciable in those containing WGJ than WGS. This was presumably due to the higher contents of tartaric acid in WGJ. For both types of extracts, hardness, gumminess, and chewiness of the doughs decreased with the addition of WGE, nevertheless, which properties were not remained in the resulting breads. This could be partially attributed to the relatively high degree of baking loss and lower pH of the WGE-enriched breads than those of control bread. Contrary to the mechanical analyses, the sensory properties of the breads were dependent on the WGE type. That is, WGJ-enriched bread showed lower consistency and moistness than control bread, which consequently led to relatively lower overall acceptability. However, WGS addition did not adversely affect the sensory properties of the bread. In particular, addition of 5% WGS somewhat improved the physical and sensory qualities of the bread. Thus, WGE-enriched bread could be produced without loss of bread quality when prepared with 5% WGS.

• Journal of Preventive Medicine and Public Health
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• v.33 no.3
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• pp.285-298
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• 2000

Objectives : To investigate the positive rate of Helicobacter pylori in patients with dyspepsia; medical compliance and related factors; the eradication rate a year after screening and related factors; the relationship between the eradication of Helicobacter pylori and the improvement of symptoms; and the estimated cost of three alternative approaches to treat Helicobacter pylori in the community. Methods : A total of 510 subjects with dyspeptic symptoms were selected and given the serological test in March 1998. The subjects were all adults over 30 years of age residing in Kyongju city. Results : Of the 510 selected subjects, 375 (73.5%) subjects proved positive for Helicobacter pylori on serological testing. Of these 304 (81.1%) who consented to an endoscopic examination, underwent a Campylobacter-like organism (CLO) test. Of these 304 subjects, 204 (67.1%), who had positive CLO test results, were given the triple therapy - tripotassium dicitrato bismuthate, amoxicillin, and metronidazole. To determine the eradication rate of Helicobacter pylori, 181 (88.1%) out of the 204 subjects who were given the triple therapy completed a follow-up urea breath test one year later. Of these, the Helicobacter pylori of 87(48.1%) subjects was eradicated. Among the 122 subjects who were medication compliant, the Helicobacter pylori eradication rate was 57.4% (70 subjects), while the eradication rates was only 28.8% (17subjects) in the non-compliant group. The Helicobacter pylori eradication was significantly related to compliance (p<0.01), but not to other characteristics and habits. The symptom improvement rate tended to be higher 62.1%), in the Helicobacter pylori eradicated group than in the non-eradicated group (59.6%). Conclusions : When the advantages and disadvantages of each alternative treatment were considered in the light of cost, antibiotic tolerance and the number of patients to be treated, alternative II was favorable in terms of cost. Alternative III was favorable in terms of the number of patients to be treated, antibiotic tolerance and early detection of gastric cancer. Further long-term research analyzing the cost-benefit and cost-effectiveness of each treatment will be needed as supporting material in creating new policies.