• Journal of the Korean Society of Radiology
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• v.16 no.4
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• pp.427-434
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• 2022

Atrial fibrillation treatment includes 3D RFCA and Cryo-balloon ablation. Both procedures have in common that they enter after understanding the structure of the heart using angiography equipment. Therefore, there is a disadvantage that the effect of exposure according to the procedure time can be a threat to both the patient and the operator, so this study aims to confirm the relationship between the total ablation time and the effect of radiation exposure. We used follow-up data (retrospective) from 41 patients who underwent coronary angiography and arrhythmia at the same time from March 2019 to July 2022. The range for total ablation time was based on the recorded data from the start to the end of the total ablation. The end point of 3D RFCA was when the ablation was completed for 4 pulmonary veins, and in the case of Cryo-balloon ablation, the data that succeeded in electrical insulation were included. As a result of analyzing the total ablation time, the time taken for Cryo-balloon ablation was 1037.29±103.66 s, which was 2448.61 s faster than 3D RFCA using 3485.9±405.71 s, and was statistically significant. (p<0.05) As a result of analyzing the total fluoroscopy time, the exposure time for 3D RFCA was 2573.75±239.08 s, which was less by 1717.15 s than the exposure time for Cryo-balloon ablation, 4290.9±420.42 s, and was statistically significant. In the case of total area dose product, 3D RFCA was 59.04±13.1 uGy/m², which was lower than Cryo-balloon ablation 980.6±658.07 uGy/m² by 921.56 uGy/m², which was statistically significant. As the insulation time of the Cryo-balloon ablation is shorter than that of the 3D RFCA, the method using the Cryo-balloon ablation is considered to be effective when the patient's condition is not good and a quick procedure is required. However, in patients with permanent Atrial fibrillation, there is a high probability of structural changes in the heart, so it is considered that 3D RFCA is better than Cryo-balloon ablation, which is difficult to manipulate.

• Economic and Environmental Geology
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• v.56 no.6
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• pp.847-870
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• 2023

The safe disposal of high-level radioactive waste requires accurate predictions of the long-term geochemical behavior of radionuclides. To achieve this, the present study was conducted to model geochemical behaviors of uranium (U), plutonium (Pu), and palladium (Pd) under different hydrogeochemical conditions that represent deep groundwater in Korea. Geochemical modeling was performed for five types of South Korean deep groundwater environment: high-TDS saline groundwater (G1), low-pH CO₂-rich groundwater (G2), high-pH alkaline groundwater (G3), sulfate-rich groundwater (G4), and dilute (fresh) groundwater (G5). Under the pH and Eh (redox potential) ranges of 3 to 12 and ±0.2 V, respectively, the solubility and speciation of U, Pu, and Pd in deep groundwater were predicted. The result reveals that U(IV) exhibits high solubility within the neutral to alkaline pH range, even in reducing environment with Eh down to -0.2 V. Such high solubility of U is primarily attributed to the formation of Ca-U-CO₃ complexes, which is important in both G2 located along fault zones and G3 occurring in granitic bedrocks. On the other hand, the solubility of Pu is found to be highly dependent on pH, with the lowest solubility in neutral to alkaline conditions. The predominant species are Pu(IV) and Pu(III) and their removal is predicted to occur by sorption. Considering the migration by colloids, however, the role of colloid formation and migration are expected to promote the Pu mobility, especially in deep groundwater of G3 and G5 which have low ionic strengths. Palladium (Pd) exhibits the low solubility due to the precipitation as sulfides in reducing conditions. In oxidizing condition, anionic complexes such as Pd(OH)₃^-, PdCl₃(OH)₂^-, PdCl₄^2-, and Pd(CO₃)₂^2- would be removed by sorption onto metal (hydro)oxides. This study will improve the understanding of the fate and transport of radionuclides in deep groundwater conditions of South Korea and therefore contributes to develop strategies for safe high-level radioactive waste disposal.

• Korean Journal of Heritage: History & Science
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• v.56 no.4
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• pp.192-214
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• 2023

Wooden architectural cultural heritages are one of the visible legacies that show the national's identity. Even when the concept of 'the original' of cultural heritages was not accurately understood, the emphasis of preservation and management of cultural heritages was placed on 'preservation of the original form' or 'maintenance of the original form'. Moreover, these days, following the trend of international preservation principles, cultural heritages are considered important as "values as historical objects." This paper is the result of an attempt to determine the scope and content of what parts should be monitored to maintain the original form of wooden architectural cultural heritage. The first thing to be done in monitoring wooden architectural cultural heritage is to check the condition of the ground and foundation. The second is the column. This is because the instability of the column causes damage to the joint with each member and the fitting part, resulting in physical changes leading to damage to the wall. The third is monitor the roof tiles. If the leak continues into the building due to the separation or damage of the roof, the defect should be partially dismantled and repaired, so it should be monitored to maintain its original shape as much as possible. The monitoring range of the base, column, and roof serves as a reference point for identifying what damage is being done to the relevant cultural heritages. In other words, the data at the time when monitoring began becomes the 'original' for the year. Alternatives based on the analysis of monitoring for the preservation of original cultural heritages should be actively introduced. In addition, by sharing the current state and situation of cultural heritages as a result of monitoring with various related organizations, preventive preservation should be established rather than preservation of cultural heritages by "intervention."

• Journal of Korean Elementary Science Education
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• v.43 no.1
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• pp.48-63
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• 2024

This study aims to develop a class procedure for the application of classrooms that value context and to conduct science classes using this procedure to examine the effects. Among various contexts related to scientific knowledge, the study develops a teaching procedure for designing classes that focus on the contexts of discovery and real life. After verifying the content validity of the context-based design and the program to which it was applied, a class was conducted, and the responses of the children were checked. The final draft of the lesson design completed after revision and supplementation is as follows: context-based design was presented in four stages, namely, presenting, exploring the context, adapting the context, and organizing (share and synthesizing; PEAS). The goal is to enable people to experience the overall flow of scientific knowledge instead of focusing on the acquisition of fragmentary knowledge by covering a wide range of topics from the social and historical contexts in which scientific knowledge was created to its use in real life. To aid in understanding the newly proposed class procedure and verifying its effectiveness, we developed a program by selecting the "My Fun Exploration," 2. Biology and Environment unit of the second semester of the fifth grade. The result indicated that the elementary science program that applied the context-centered design effectively improved the self-directed learning ability of students. In addition, the effect was especially notable in terms of intrinsic motivation. As the students experienced the contexts of discovery and real life related to scientific knowledge, they developed the desire to actively participate in science learning. As this becomes an essential condition for deriving active learning effects, a virtuous cycle in which meaningful learning can occur has been created. Based on the implications, developing programs that apply context-based design to various areas and contents will be possible.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.2
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• pp.102-117
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• 2009

This study was carried out to investigate the extent to which benthic environment of Ulsan Bay was disturbed by organic materials and trace metals from the megacity and industrial complex. Field survey for benthic environment and macroinvertebrate community was seasonally conducted from February to November 2006 at nine stations covering the inside and outside of the bay. TOC was on average 1.7% while four (As, Cu, Pb, Zn) out of seven trace metals measured exceeded the Effects Range Low (ERL) in most of the stations. Total number of species sampled was 199 and mean density was 4,578 ind./$m^2$, both of which were greatly dominated by the polychaetes. Dominant species were Aphelochaeta monilaris (22.6%), Ruditapes philippinarum (17.1%), Magelona japonica (12.2%), Lumbrineris longifolia (9.9%) and their distribution was ruled by the difference in the benthic environmental condition of each station. From the multivariate analyses, four stational groups were identified: northern part of the bay, middle and lower part of the bay, the intersection of Taewha River and Gosa stream and outside of the bay. As a result, the community heterogeneity of inner bay was much more greater than that of outer bay. SIMPER analysis showed that four groups were represented by R. philippinarum-Capitella capitata, A. monilaris-Balanoglossus carnosus, Sinocorophium sinensis-Cyathura higoensis and M. japonica-Ampharete arctica, respectively. Spatio-temporal changes of macroinvertebrate communities in Ulsan Bay were closely related to those of depth, mean grain size and organic content, and Zn was also a meaningful factor in that context.

• Economic and Environmental Geology
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• v.57 no.2
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• pp.143-159
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• 2024

Natural aggregate is an essential resource for human activities, closely related to construction. The aggregate demand has been increasing annually, and due to the nature of the resource, it is difficult to procure from distant locations. This study identifies the distribution and characteristics of aggregate-bearing areas as part of a municipal-level aggregate resource survey conducted in Nonsan City, Korea, in 2023. Nonsan City is located approximately 35 km straight distance from the Geum River estuary and lies at the passageway of the main stream of the Geum River. The topography of Nonsan City features eastern mountainous areas and western plains, creating an east-high-west-low geomorphic setting, with 33 streams distributed across the city, including tributaries of the Geum River like Nonsan Stream, Noseong Stream, and Ganggyeong Stream. All streams originate from the highlands in the north and east, converge with Nonsan Stream, and then join the west bank of the main stream of the Geum River at the western boundary of Nonsan City. Drilling core results show shallow depths in the highlands to the north and east, deepening towards the west, reaching a maximum depth of 25 m near the main stream of the Geum River. The total reserve of land aggregates is calculated to be 246,789,000 m³, with a developable amount of 172,750,000 m³. The total reserve of river aggregates is 5,236,000 m³, with a developable amount of 3,765,000 m³. The distribution of aggregates varies according to the geomorphic, geologic, and development pattern of the river system. Reserves are scarce in mountainous areas but are abundant in regions with rivers and wide alluvial plains, although reserves appear at depths greater than 4m. The distribution of aggregate resources in Nonsan City is influenced by stream activities and sea level changes, with the tidal range of the Yellow Sea acting as an unfavorable condition for the preservation of aggregate resources.

• Journal of Aquaculture
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• v.2 no.2
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• pp.53-90
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• 1989

Feeding proper level of ration matchable with the appetite of fish will enhance production and also prevent waste of food and its consequence, side effects such as pollution of culture medium. To pursue this goal, elaborate studies on dissolved oxygen concentrations- as the major force in inducing appetite and the growth outcome are necessary. The growth of common carp of 67, 200, 400, 600, and 800 gram size groups was studied at oxygen concentrations ranging from 2.0 to 6 mg/$\iota$ in relation to rations from 1 to as many percent of the initial body weight as could be consumed under constant temperature of $25^{\circ}C$. The results from the experiments are summarized as followings; 1. Appetite: The smaller fish exhibited higher degree of appetite than the bigger ones at the same oxygen concentrations. The bigger the fish the less tolerant it was to the lower oxygen thersholds, and the degree of tolerence decreased as ration level increased. 2. Growth : Growth rate (percent per day) increased - unless consumption was suppressed by low oxygen levels- as the ration was increased to maximum. In case of 67 g fish, it reached the highest point of $5.05\%$ / day at $7\%$ ration under 5.0 mg/$\iota$ of oxygen. In case of 200 g fish, the maximum growth rate of $3.75\%$/day appeared at the maximum ration of $6\%$ under 5.5 mg/$\iota$ of oxygen. In 400 g fish, the highest growth of $3.37\%$/day occurred at the maximum ration of $5\%$ and 6.0 mg/$\iota$ of oxygen. In 600 g fish, the highest growth rate of $2.82\%$ /day was at the maximum ration of $4\%$ under 5.5 mg/$\iota$ oxygen. In case of 800g fish, the highest growth rate of $1.95\%$/day was at maximum tested ration of $3\%$ under 5.0 mg/$\iota$ oxygen. 3. Food Conversion Efficiency: Food conversion efficiency ($\%$ dry feed converted into the fish tissue) first increased as the ration was increased, reached maximum at certain food level, then started decreasing with further increase in the ration. The maximum conversion efficiency stood at higher feeding rate for the smaller fish than the larger ones. In case of 67 g fish, the maximum food conversion efficiency was at $4\%$ ration within 3.0-4.0 mg/$\iota$ oxygen. In 200g fish, the maximum efficiency was at $3\%$ ration within 4.0-4.5 mg/$\iota$ oxygen. In 400g fish, the maximum efficiency was at $2\%$ ration within 4.0 - 4.5 mg/$\iota$ oxygen. In 600 and 800g fish, the maximum conversion efficiency shifted to the lowest ration ($1\%$) and lower oxygen ranges. 4. Behaviour: The fish within uncomfortably low oxygen levels exhibited suppressed appetite and movements and were observed to pass feces quicker and in larger quantity than the ones in normal condition; in untolerably low oxygen the fish were lethargic, vomited, and had their normal skin color changed into pale yellow or grey patches. All these processes contributed to reducing food conversion efficiency. On the other hand, the fish within relatively higher oxygen concentrations exhibited higher degree of movement and their food conversion tended to be depressed when compared with sister groups under corresponding size and ration within relatively low oxyen level. 5. Suitability of Oxygen Ranges to Rations: The oxygen level of 2.0- 2.5 mg/$\iota$ was adequate to sustain appetite at $1\%$ ration in all size groups. As the ration was increased higher oxygen was required to sustain the fish appetite and metabolic activity, particularly in larger fish. In 67g fish, the $2\%$ ration was well supported by 2.0-2.5 mg/$\iota$ range; as the ration increased to $5\%$, higher range of 3.0-4.0 mg/$\iota$ brought better appetite and growth; from 5 till $7\%$ (the last tested ration for 67 g fish) oxygen levels over 4.0 mg/$\iota$ could sustain appetite. In 200 g fish, the 2 and $3\%$ rations brought the best growth and conversion rates at 3.5-4.5 mg/$\iota$ oxygen level; from 3 till $6\%$ (the last tested ration at 200 g fish) oxyge groups over 4.5 mg/$\iota$ were matchable with animal's appetite. In 400, 600, and 800 g fish, all the rations above $2\%$ had to be generally supported with oxygen levels above 4.5 mg/$\iota$.

• Journal of Animal Science and Technology
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• v.45 no.1
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• pp.69-78
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• 2003

This experiment was carried out to evaluate the value of total mixed fermentation feeds(TMFF) as completely mixed ration and to observe the effect of various kinds of TMFF on the palatability, feed intake, and milk performance in Holstein cows. The dry matter (DM) content of TMFF used in the experiment was 23.98-28.42% range, and CP, TDN, ADF and NDF were 16.2${\sim}$19.2%, 58.3-65.1%, 34.4-39.6% and 46.9${\sim}$49.9% levels, respectively. The relative feed value (RFV) in rape-, alfalfa-, grass-, oat-, corn-TMFF groups were 138.6, 133.9, 116.5, 111.8, 111.4 and 108.1, respectively. Among these groups, RFV of rye-TMFF group was lowest. Dry matter disappearance(DMD) showed 0.8${\sim}$.9% to the all kinds of TMFF groups. The pH was 3.89${\sim}$.87 and $NH_3$-N concentration was 6.93-8.66 mg/$d\ell$. The acetic acid concentration in the raw material of TMFF showed low level of 0.19${\sim}$0.57%, lactic acid showed high level of 1.17${\sim}$3.21% and butyric acid was very high as 0.03${\sim}$0.32%. Therefore, these results provide evidence that the quality of TMFF was not so bad. In the daily fresh matter intake on the alfalfa-, grass-, rape-, corn-, oats- and rye-TMFF were showed 62.85, 60.48, 58.04, 57.11, 54.61 and 45.74 kg respectively. All TMFF showed high palatability as daily dry matter intake of 1.95 to 2.90% by body weight of experimental cows. Body condition score(BCS) was gradually increased in during 60 days of the experiment term. Average daily gain(ADG) showed about 140.0${\sim}$326.7g. In alfalfa-TMFF group, the ADG was higher than in the other groups (p<0.05). Also, the increase in BCS was observed in grass-TMFF group (3.07 to 3.34) and rye-TMFF group was decreased in 3.07 to 3.34 (p<0.05). The milk yield appropriately showed a range of 16.16${\sim}$18.95 kg in all groups. Among these groups, alfalfa-TMFF group was highest(P<0.05). Average milk fat contents showed high levels of 4.06${\sim}$4.79% and the level was high in order of rape-, grass-, corn-, alfalfa-, rye- and oats-TMFF. Milk protein was highest in forage-TMFF and level of lactose in milk was approximately 4.56% in overall groups. Solid non fat(SNF) and total solid(TS) contents were 8.75% and 12.8%, respectively. However, milk composition was not significantly affected by TMFF.

• Journal of Hospice and Palliative Care
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• v.8 no.2
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• pp.143-151
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• 2005

Purpose: Bereavement Memorial Service has been held every year by the hospice team at St. Vincent's Hospital for the purpose of supporting the bereaved family who feel grief and mourning. The purpose of this study is to find out the attitude of the bereaved attending at bereavement memorial service (BMS) and to find out the areas needing improvements to set up better memorial service. Methods: Hospice team sent invitation card to 180 families of patients who admitted and passed away at hospice ward Nov., 2003${\sim}$Oct., 2004. Among them 22 families attended the BMS meeting, which was held on 26th Nov., 2004. The researcher collected data from 22 families with 'Questionnaire' survey. Except identifying data and 2 dichotomy questions, we used open-ended questionnaire. 1 researcher conducted a telephone interview survey in 18 families who couldn't attend at BMS meeting. Results: The median age was 56 (range $16{\sim}19$) and there were 37 females and 3 males. They were patient's wife (22), mother (4), husband (5), daughter (4), mother-in-law (1), siblings (1), brothers wife (1). Duration after bereavement, $1{\sim}3$ months (17) was the highest frequency. 36 families agreed 'the dead experienced the death with dignity'. The reason of agreement to the death with dignity was 'the patient died in preparation' (16). 'the patient died in well-being condition spiritually' (9), 'the patient died in comfort physically (7). 4. persons thought the dead died with indignity. The bereaved defined 'the death with dignity' as follows: 'acceptance of death & death in spiritual well-being' (9), 'death in physical comfort condition' (7), 'the death in psycho-social well-being' (3), non-respondents (10). Most families (21) were still in difficulty to overcome bereavement grief. The answer regarding the method to overcome the difficulty was 'with spiritual sublimation' (13), 'with devotion of oneself in daily life' (10), 'with devotion to mourning as it is' (3). With regard to their attitude to invitation, 'having joy and thanks from hospice team' (21), 'grief' (4), 'suffering' (4). Toward the existence of hesitation about attendance at BMS meeting, the result as follows. Nonexistence of hesitation respondent (34), existence respondent (6), the reason for hesitation was various; 'the meeting reminds me of the suffering times', 'the meeting makes me to recall, and it will be likely to cry', and so on. The needs and feelings to memorial service meeting were various; 'it was meaningful time', 'it was good to recall about the dead', 'more meeting annually' and so on. In respect of the most difficulty after bereavement, in attendant family, 'depression' (10) was the highest frequency, whereas, in non-attendant family, the most difficult thing was 'financial problem/role difficulty (6). Conclusion: This study shows the rate of attendance was high in bereaved whose bereavement duration $1{\sim}3$ month. Most of bereaved were still suffering from bereavement grief within 1 year. Although most families didn't hesitate and felt positive mood to invitation, the rate of attendance was low. Comparing with two groups between attendant family and non-attendant, the latter felt more difficulty in 'financial problem/role difficulty, on the other hand, the former felt difficulty in 'depression'. Hereafter, the additional study about the factor relating to these attitude and needs of the bereaved relating to memorial service will be necessary.

• Journal of Hospice and Palliative Care
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• v.9 no.1
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• pp.17-29
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• 2006

Purpose: This research aimed to investigate the actual condition and satisfaction of volunteer activity in Australian hospital. Methods: Data was collected by self reported questionnaire from 101 volunteers and analyzed by frequency and percentage, t-test, ANOVA and Sheffe and Pearson's correlation coefficients using SPSS 12.0. Results: 1. Years involved in volunteer work were $5{\sim}10$ years (32.7%), above 10 years (30.7%), $2{\sim}3$ years (11.9%) and $3{\sim}5$ years (10.9%). Types of volunteer work were physical care (32.7%), physical and emotional care (14.9%), and others (18.8%). Types of allocation of tasks were by volunteer coordination (55.7%), and by volunteer preference and consent between volunteer and coordinator (both respectively, 20.5%). Main reasons for volunteer work were to help sick people (61.4%) and to make good use of leisure time (22.8%). Routes to start volunteer work were from his (her) own inquiries (43.4%), from hearing from other volunteers (30.7%) and from mass media (13.1%). 80.2% of volunteers had received some kinds of training or preparation for volunteer work. Suitability of volunteer's skill and ability to voluntary work were 'very well' (74.0%) and 'mostly well' (18.0%). Reimbursements or benefits received for volunteer work were token or lunch or group outing (31.7%), and token and lunch or group outing (19.8%). Evaluation frequency for volunteer work was occasionally (372%), frequently (30.9%), always (17.0%) and never (14.9%). Relationship with volunteer work coordinator was very good (85.0%). The relationship with other volunteers was very good (81.2%). The relationship with hospital staffs was very good (69.7%) and mostly good (21.2%). Family and friend's support for volunteer work was very good (83.2%). 2 The mean score of satisfaction for the hospital volunteer activity was $3.09{\pm}0.49\;(range:\;1{\sim}4)$. The highest score domain was 'social contact', $3.48{\pm}0.61$, and the lowest was 'social exchange', $1.65{\pm}0.63$. An item of the highest score was 'I have an opportunity to help other people' ($3.83{\pm}0.40$), and the lowest score item was 'I will receive compensation for volunteer work I have done ($1.10{\pm}0.78$).' 3. The satisfaction from hospital volunteer activity was shown by significant difference according to sex (t=2.038, P=0.044), marital status (F=3.806, P=0.013), years involved in volunteer work (F=3.326), nam reason to do volunteer work (F=2.707, P=0.035), receive any training or preparation for volunteer work (t=-1.982, 0=0.050), frequency of evaluation for volunteer work (F=7.877, P=0.000), suitability of volunteer's skill and ability to voluntary work (t=2.712, P=0.049), relationship with volunteer work coordinators (F=-2.517, P=0.013), relation with hospital staffs (F=5.202, P=0.007), and support of their volunteer work by their family and friends (t=-3.394, P=0.001). Conclusion: The satisfaction of hospice volunteer activity was moderate. The satisfaction for hospice volunteer activity was shown by significant difference according to sex (t=2.038, P=0.044), marital status (F=3.806, P=0.013), years involved in volunteer work (F=3.326), main reason to do volunteer work (F=2.707, P=0.035), receive any training or preparation for volunteer work (t=-1.982, 0=0.050), frequency of evaluation for volunteer work (F=7.877, P=0.000), suitability of volunteer's skill and ability to voluntary work (t=2.712, P=0.049), relationship with volunteer work coordinator (F=-2.517, P=0.013), relation with hospital staffs (F=5.202, P=0.007), and family and friend's support for volunteer work (t=-3.394, P=0.001). Therefore, it is necessary to consider various factors to improve the satisfaction of voluntary work.