• Journal of the Korean Recycled Construction Resources Institute
• /
• v.12 no.3
• /
• pp.281-289
• /
• 2024

In this study, CO₂-immobilized desulfurized gypsum(CFDG) was applied to ground granulated blast furnace slag to examine the basic properties of mortar and concrete, and to evaluate its responsiveness through field demonstration test. CFDG had a relatively circular composition compared to desulfurized gypsum(DG), and its main components were CaO 47.6 % and SO₃ 22.1 %. As a result of mortar and concrete tests, the flow tended to increase and the compressive strength was at the same level. In addition, the target properties of concrete for application to farm roads, which were a slump of 120±25 mm and a compressive strength of 24 MPa, were satisfied with a slump of 135 mm and a compressive strength of 42.1 MPa at 28 days. In February 2024, an on-site demonstration of a farm road was conducted in Seongmun-myeon, Dangjin-si, and as a result of reviewing the compressive strength according to curing conditions, the physical properties and durability of unhardened concrete, the target results were satisfied, expanding the use of CFDG by applying fine powder of blast furnace slag and carbon reduction can be expected.

• The Journal of Engineering Geology
• /
• v.34 no.3
• /
• pp.447-457
• /
• 2024

This study investigated a cut-slope surface containing Tertiary faults, representing a conical-shaped slope with strike varying from N44°E to NS, N50°W, and finally N70°E. The slope consists mainly of basalt, with discontinuities in the slope including faults, fault zones, fracture zones, shear joints, and extension joints. The type and scale of failure vary with the strike of the slope and the strikes of discontinuities, with plane and wedge failure predominating. Based on face-mapping data, SMR (slope mass rating), rock physical and mechanical properties, analysis of stereonet projections and geological cross-sections, and critical equilibrium analysis, optimal slope stability determination was found to involve the countermeasure method, the slope gradient relief method, the green soil surface treatment method, and a fall prevention measure. After application of the countermeasure method, both dry and wet slope conditions exceeded allowable safety factors. It is expected that the preparation of geological cross-sections of various representative sections perpendicular to the surface of the slope, and the application of corresponding countermeasure methods, will be reasonable tools for three-dimensional analysis of slope stability. If the strike of the slope varies widely, it is necessary to prepare geological cross-sections, and the section used for critical equilibrium analysis must be established as the basic section.

• Ocean and Polar Research
• /
• v.46 no.1
• /
• pp.31-42
• /
• 2024

Due to physical processes varying in space and time, regional sea-level rise (SLR) significantly deviates from the global mean. Thus, understanding and quantifying the contribution of each process to regional sea-level change is crucial to prevent low-lying inundation in preparation for future ocean conditions. In this study, we assessed to what degree sterodynamic (SD) effects (i.e., density-driven steric expansion and mass redistribution due to ocean circulation), contemporary mass redistribution (CMR), and glacial isostatic adjustment (GIA) contribute relative sea-level rise around the Korean coast from 1993 to 2018, with independent observations and reanalysis datasets. The assessment showed that the tide gauge-observed SLR trend can be explained by the sum of each component at 16 of 19 locations. The major contributors to relative SLR are SD effects of 2.03±0.27 mm/yr and CMR components of 1.31±0.05 mm/yr, while GIA drives sea-level decreasing of -0.27±0.15 mm/yr on the Korean coast. It was also found that the spatial deviations of SLR are primarily caused by the SD effects. In addition, the evaluation of vertical land motion (VLM) based on altimetry and tide gauge indicates that most tide gauge locations have experienced uplift during at least altimetry period, whereas Wido station has experienced particularly high rate of subsidence that contributed to the SLR acceleration. Further examination of the impact of earth deformation due to CMR, GIA, and local process on the VLM trends demonstrated that the GIA and CMR contribute to land uplift with the average of 0.35±0.15 mm/yr and 0.17±0.05 mm/yr, respectively. On the other hand, the local processes like groundwater depletion and sediment compaction showed a wide range of variability, from -1.61 to 0.58 mm/yr, indicating a significant contribution to regional differences in vertical land motion.

• Tunnel and Underground Space
• /
• v.34 no.5
• /
• pp.421-432
• /
• 2024

Pre-fracturing, a type of pre-conditioning blast, is a method used to weaken rock masses prior to mechanical excavation. In this study, various laboratory tests were conducted on rock core samples obtained from the field to verify the effectiveness of pre-fracturing in controlling the BIDZ (Blast-Induced Damaged Zone) by measuring the physical properties of rock cores obtained from a test site and assessing changes in these properties. In the EDZ (Excavation Damaged Zone) caused by combined excavation using blasting and mechanical excavation, the effect of blasting is generally more significant than that of mechanical excavation, so BIDZ control directly leads to EDZ control. In terms of Poisson's ratio, elastic wave velocity, porosity, density, thermal conductivity, tensile strength and hydraulic conductivity, the BIDZ size in pre-fracturing was smaller than that of conventional blasting. However, no clear reduction in the BIDZ was observed in the case of Young's modulus and uniaxial compressive strength. By applying a theoretical formula predicting the range of tensile cracks caused by blasting and comparing it with the laboratory results, the BIDZ was reasonably predicted. Nonetheless, limitations in accurately predicting BIDZ size were identified due to assumptions regarding ground conditions and charge density in the formula.

• The Journal of Learner-Centered Curriculum and Instruction (JLCCI)
• /
• v.22 no.1
• /
• pp.243-276
• /
• 2018

This paper analyzes the possibilities and practical limitations of ecological welfare commons in the case of Hansalim Seoul's community care. As a commons against social-ecological crisis, the localized Salim movement in Hansalim Seoul is noteworthy as an articulation of ecological transition and socialization of care. Community care as a part of the localized Salim movement suggests the possibilities of good care by pursuing comprehensive care beyond functional(or physical) care and trying to improve the conditions of care work. In addition, Hansalim Seoul's community care is experimenting with the combination of care service and ecological transition based on a comprehensive definition of care. Of course, the scale of welfare commons in Hansalim Seoul is limited and it is not enough to fundamentally solve the undervaluation and feminization of care work. However, the tension between welfare commons and universal welfare is alleviated by pursuing open welfare commons. In the localized Salim movement, commoning focuses on experimenting with the articulation of ecological transition and socialization of care and on spreading alternatives based on its experiments. If such commoning is spread and public support is strengthened, the ecological welfare commons will be able to develope as an alternative that combines ecological welfare and good care.

• Korean Journal of Soil Science and Fertilizer
• /
• v.19 no.4
• /
• pp.283-289
• /
• 1986

To establish a suitability grouping system of paddy soils for multiple cropping of rice with other upland crops, the study was carried out after a few basic experiments. In succession to the results on basic experiment prior, the suitability system proposed and the results of application mentioned in this report were summarized as follows; 1. The factors of soil properties in the system were productivities represented by soil texture and drainage class, as well as salinity of surface and sub-soil pH of chemical properties were considered together with slope, warmth index, ground water table, parent materials etc. of soil physical or environmental conditions. The weights of the factors were combined with multiplicatively and additively so as the total marks of ideal soil to be 100. The system was composed with 5 suitability classes; over 91 mark is class I, under 60 mark class V, and each 10 point interval between classes. The limiting factors "P" (in the case that Physical properties or Productivity marks under 24), "S" (Surface slope less than 15) and "C" (Chemical condition below 15) etc. were appended up to two kinds to the classes except a part of soils in class I. 2. The areas where the warmth index exceed 110 in Yeongnam were 19% for class I, 22.7% for class II, 44.7% for class III, 11.5% for class IV, and 2.1% for class V. The rates in class I and II were slightly more than those of the whole country. 3. The points of each soil gained by the system had a positive correlation ($r=.922^{**}$) with the potential productivities.

• Journal of Korean Academy of Nursing
• /
• v.30 no.6
• /
• pp.1488-1502
• /
• 2000

This study, based on current home nursing services, aims at promoting measures for establishing a community-based home nursing system derived from the pilot home nursing demonstration project conducted by the Seoul Nurses Association. The study was based on an analysis of home nursing records from march 1993 to December 1999. The following is a summary analysis, based on individual characteristics of the patients, the organization, which recommended the service for their patients and personnel services. 1. The service has been used by many elderly people 60years of age or older(66.4%). and married people(60.9%). The average number of visits by service personnel for patients of city government was 23.5. This is 2.5 times as many visits by general patients. General patients(20.2%) had only one visit from service personnel, while 65.5% of patients of city government had 10 or more visits. Particularly, for government recommended patients, 72.7% of the patients were recommended by nurses, while only 21.9% where referred to the services by doctors. The main focus of a home nursing service was to maintain present health status (53.4%), and hospice(11.6%). Also to increase hospital-based home nursing services focused on recovery(55.9%) and maintain present health conditions (19.0%). 2. For general patients, 42.0% of patients were suffering from problems related to CVA, 11.3% from high blood pressure, and for patients referred from city, 21.2% from skeletal muscular disease. Results of home nursing services 29.4% of patients were able to recover or maintain their health status, but 48.9% of the patients died. Another main point of community-based home nursing services is medication(6.7%), other basic nursing services(6.1%), special treatment, instructions on how to use medical devices(5.9%), change of physical posture(4.6%), and training on changing physical positions(4.7%). As mentioned above there were some differences between the characteristics of patients who used the pilot home nursing service conducted by the Seoul Nurses Association and those hospital-based service users. The results are believed to be useful to support a community-based home nursing service model. Particularly, patients under medical supervision and patients recommended by government-run health clinics show a higher frequency and longer use of home nursing services compared to general patients or hospital-based home nursing service users. According to the study, nurses accounted for a large number of recommendations for home nursing services. Many patients with CVA, high blood pressure, skeletal muscular disease and bedsores used community-based home nursing services, while others used the service for minor treatments or maintaining their current health status. Based on the study, the researchers make several suggestions to establish a community- based home nursing service system. First, different ways of setting up a community-based home nursing system have to be mapped out based on the evaluation of the pilot home nursing service conducted by the Seoul Nurses Association. Secondly, a new, community-based, home health care nursing service model, and reimbursement payment system have to be developed. This is based on the outcome of the analysis, and implemented policy. Accordingly, efforts are needed to develop a community- based home nursing system with an intermediary role to promote the visiting nursing services of government-run health centers.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.32 no.4
• /
• pp.232-246
• /
• 2018

The purpose of this research is to contribute to clinical researches on neck pain and cervical spondylosis by reviewing the latest research trends and evaluation tools through the analyses of clinical studies on neck pain and cervical spondylosis over the last 5 years. 70 papers satisfying the selection conditions among the RCT papers that had been searched as "neck pain" or "cervical spondylosis" at Pubmed(https://www.ncbi.nlm.nih.gov/pubmed) from March 2011 to February 2016 were targeted. Papers were numbered in order of their publication dates and analyzed by classifying their contents into 1) pain classification, 2) treatment type, 3) treatment duration, 4) treatment time, 5) number of participants, 6) evaluation tools and methods of research, and 7) evaluation duration. 55 papers targeted chronic neck pain, 6 papers acute and subacute neck pain, and 2 papers subacute and chronic neck pain. In comparison by intervention, 43 papers corresponded to physical therapy, 3 papers to acupuncture, 1 to herbal fomentation, 5 to medication, and 18 papers corresponded to multilateral comparisons comparing the efficacy by various interventions. In research period, there were 50 papers based on treatment period, 16 papers based on the number of treatments, and 4 papers based on different periods depending on each group. In treatment duration, the cases from 1 month or more to less than 3 months were most, followed by the cases of less than 1 month, and the cases from 3 months or more to less than 6 months. In treatment frequency, the number of treatments of the treatment group was the same as that of the control group in 51 papers, and many treatments were conducted by the methods of acupuncture, manual therapy, and injection therapy in cases of once or twice of treatments, and physical therapy and electroacupuncture corresponded mainly to the cases from 3 times or more to less than 10 times of treatments, and retrospective observation and exercise programs corresponded mainly to the cases of more than 30 times of treatments. In the number of subjects of the researches, the cases from 50 or more to less than 100 were most, followed by the cases from 20 or more to less than 50. There were 7 evaluation tools cited 10 times or more: VAS, NRS, PPT, NDI, NPQ, CROM, and SF-36. In evaluation period, 37 papers evaluated only during the treatment period, and 33 papers conducted follow-up. In follow-up period, the cases of less than 3 months were most, followed by the cases from 6 months or more to less than 1 year, and the cases from 3 months or more to less than 6 months. When planning clinical researches on cervical pain in the future, appropriate intervention methods, frequency and duration of treatment, period of follow-up, appropriate number of subjects and selection of evaluation tools for objective validity will have to be considered. In addition, randomization, double-blind, etc. will have to be considered for researches with high basis level.

• The korean journal of orthodontics
• /
• v.33 no.2 s.97
• /
• pp.121-130
• /
• 2003

The purpose of this study was to evaluate the possibile clinical application of electroplating to increase diameter of an orthodontic wire, through examining the change of physical properties. The diameter of stainless steel orthodontic wire was increased from 0.016 inch to 0.018 inch by electroplating in a bath of nickel sulfate 100g/L, nickel chloride 60g/L, boric acid 30g/L, and sodium chloride 50g/L, under the conditions of 1.7V, $25\~29^{\circ}C\;and\;3.1\~3.3pH$. During the electroplating, the rate of diameter increase was measured every minute. To investigate uniformity, the diameter was measured at three different locations of each wire specimen aster electroplating. An X-ray diffraction test was performed to analyze the nature of the electroplated metal. Following heat treatment to improve adhesion between the wire and electroplated metal, a three-point bending test was conducted to compare stiffness, field strength, and ultimate strength among four wire groups; 0.016 inch, electroplated 016, electroplated and heat-treated 016, and 0.018 inch wires. Through the comparison of each wire group, following results were obtained. 1. In the load-deflection graph, the curve of the electroplated group was Placed between that of the 0.016 inch group and the 0.018 inch group, and the owe was closer to the 0.018 inch group by heat treatment. 2. In the electroplated and heat-treated 016 wire group, the values of stiffness, yield strength and ultimate strength showed higher tendency than in the original 0.016 Inch group. Stiffness and ultimate strength showed statistically significant differences between two groups. 3. Stiffness, yield strength, and ultimate strength of electroplated wire presented lower values than those of 0.018 inch wire group. 4. Stiffness, yield strength, and ultimate strength of electroplated and heat-treated wire showed higher tendency than those of electroplated wire group, and ultimate strength showed statistically significant difference between two groups. 5. After electroplating, the difference in diameter between the three locations was within $0.1\~0.3\%$ variation, and showed no statistical significance.

• Elastomers and Composites
• /
• v.46 no.4
• /
• pp.277-283
• /
• 2011

In this study, engineering grade and high intensity reflective sheets were prepared with glass beads and their reflection performance and physical properties were investigated. The reflective sheets prepared by using glass beads are divided into enclosed or encapsulated lens type, depending on whether the glass beads are open in air or not. Because of an extra layer on the glass bead surface, the enclosed lens type reflective sheets show very little change in the properties by bad weather conditions, compared to encapsulated lens type reflective sheets. Optimization of the amount of glass beads on the surface was carried out, which determines the retroreflective properties. Enclosed and encapsulated lens type reflective sheets with various colors were prepared and their coefficients of retroreflection were determined. The encapsulated type reflective sheet with white color shows a coefficient of retroreflection of $210.4cd/1x{\cdot}m^2$, which is higher than the enclosed type ($74cd/1x{\cdot}m^2$). Effect of washing on the reflective property and adhesive power of the reflective sheets was investigated, and it is found that the number of glass beads decreased with washing and the aluminum layer deposited was damaged extensively in the encapsulated lens type reflective sheets.