• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.6 no.4
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• pp.439-452
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• 1994

One of the chlorofluorocarbon compounds. R-12 deplete atmospheric ozone. It leads to international agreement to reduce CFC production. R-134a has similar thermodynamic properties to CFC-12. It has zero ODP(Ozone Depletion Potential). This Paper focuses on the lubricating oils for using with R-134a PAGs(Polyalkylene Glycol's) and esters are primary lubricants that are now being tested for use with R-134a Because of extreme polarity of R-134a. there are many problems in the selection of lubricating oil. This investigation analyzes compressor working conditions and calculates wear parts friction for simulation testing. Miscibility and material compatibility is proved by sealed glass tests. Friction was tested on the closed type pin on disk wear tester. This equipment simulates actual refrigerating compressor. Environment controlled test made more reliable result than field test Conventional oils(mineral oils, Alkylbenzene, PAO(Polyalpha Olefin) are immiscible with R-134a. PAGs and ester oils are miscible with R-134a. Friction coefficient is similar to conventional system(mineral oil/R-12 systems) at operating condition. At start & stop condition, PAGs/R-134a system has high friction coefficient. It provide reliable result on the lubricity, miscibility, material compatibility of R-134a with these new lubricants. It suggests proper selection of refrigeration oil that may improve compressor durability of performance.

• Economic and Environmental Geology
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• v.41 no.2
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• pp.253-265
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• 2008

Sustainable resource management(SRM) is regarded as the core strategy to achieve Dematerialisation and Decoupling of economic growth from the use of natural resources and environmental degradation. This paper presents status SRM policy and research in worldwide, and analyzes decoupling of economic activity from energy consumption of domestic manufacturing, using decoupling factor. Also This paper suggests methodologies and strategies of SRM in Korea. SRM is established through various analysis and survey as following; forecasting of resource demand, material flow analysis and value chain analysis, resource market structure analysis. Through these analysis, we can obtain hot-spot and solution of environmental burden, recycling market management, recycling technology and best-optimal supply rate of primary and secondary resource. In Korea, resource management system must be linked with national and regional material flow analysis, and it is necessary to make SRM-law of national dimension for effective run of sustainable resource management system.

• The Journal of the Petrological Society of Korea
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• v.26 no.3
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• pp.183-200
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• 2017

Alkali rhyolites in the Cheonmunbong of the Mt. Baekdu stratovolcano show porphyritic texture in the glassy or aphanic groundmass. Major phenocryst is alkali-feldspar, pyroxene, and amphibole, and small amount of microphenocryst is olivine, quartz, opaque mineral (ilmenite). The content of $Fe^{2+}/(Fe^{2+}+Mg^{2+})$ and alkali elements in the mafic minerals is high. Alkali feldspar is classified as sanidine or anorthclase, olivine as fayalite, and pyroxene as ferro-hedenbergite of ferro-augite area. Amphibole belongs to alkali amphibole group, but FeO and $Fe_2O_3$ were not separated, so it is required future studies. Nb(-) anomaly suggesting that slab-derived materials might have played a primary role in the genesis of the rhyolite magma, is not observed. It is noted that they originated in the within plate environment which is not related to subduction zone of the convergent plate boundary. The Mt. Baekdu alkaline rocks are classified into the comendite series. The alkali rhyolites of the summit at Mt. Baekdu shows the disequilibrium mineral assemblages, suggesting that it evolved from thrachytic magma with experience of magma mixing as well as fractional crystallization.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.3
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• pp.363-368
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• 2010

Artemisia princeps has been utilized as a traditional medicine for a variety of diseases in Korea. In this study, we investigated the effects of Artemisia princeps extract (APE) on bone metabolism both in vitro using primary mouse bone marrow-derived macrophage and in vivo using ovariectomized rats. APE decreased the number of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells and TRAP activity. Also, APE inhibited bone resorptive activity of differentiated osteoclasts. In ovariectomized rats, APE alleviated the decrease in the trabecular bone mineral density. These results showed that APE might be useful for the prevention of postmenopausal bone loss.

• Research in Community and Public Health Nursing
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• v.20 no.3
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• pp.285-295
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• 2009

Purpose: This study was to examine the effectiveness of exercise for bone mineral density (BMD). Methods: Four investigators reviewed English articles from Pub Med and CINAHL, selecting randomized controlled trials on exercise programs for middle-aged and older women. Out of 25 studies identified, 14 that satisfied with the inclusion criteria were included in the meta-analysis. The quality of the studies was assessed using recognized methods and the effect size was calculated as a Hedges'g using Comprehensive Meta-analysis Version 2.0. Primary outcomes were changes in BMD at femoral neck, trochanter, and lumbar spine. Subgroup analysis included changes in BMD according to exercise style. Results: Weight bearing exercise was effective(Q=20.1, p>.05, ES=0.32), and resistance exercise was effective in case of comparing to pre and post intervention (Q=4.15, p=.98, ES=0.14). At the femoral neck, 9 study groups were homogeneous and the experimental groups demonstrated a positive effect on BMD (Q=19.5, p>.05, ES=0.33). In contrast, marked heterogeneity (Q=33.3, p<0.01) was apparent in 7 study groups evaluating trochanter. Conclusion: These findings suggest that weight bearing is effective for BMD of the femoral neck, and is relevant to the non-pharmacological treatment of bone loss for middle-aged and older women.

• The Journal of Engineering Geology
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• v.18 no.4
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• pp.501-509
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• 2008

It is very important in designing civil engineering structures that the quantification of geological informations must be carried out in terms of importance. In this study, the geological informations are quantified and evaluated using analytic hierarchy process (AHP). A professional group was organized with 30 people in the field of civil engineering, transport, and geology. On the assumption that the civil engineering structure is linear such as highway or railroad, a survey of the group in terms of geological and hydro-geological elements has found that the hierarchy structure is composed of four levels. And fault structure is a primary factor which causes the stability of a linear civil engineering structure. The importance of geological items are arranged with fault (0.456), foliation/bedding plane(0.l65), lineation(0.144), ground water(0.124), and rock type(0.111).

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.9
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• pp.1423-1429
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• 2019

Objective: In this study, we evaluated the nutritional value and antioxidant activity of black goat loin (BGL) and black goat rump (BGR) meat. Methods: We evaluated the proximate compositions, collagen and mineral contents, and fatty acid compositions of BGL and BGR with respect to their nutritional value. The levels of bioactive compounds such as L-carnitine, creatine, creatinine, carnosine, and anserine were also measured. The ferric reducing antioxidant power (FRAP), 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, and oxygen radical absorption capacity (ORAC) were assessed to evaluate the antioxidant activity of BGL and BGR. Results: BGR showed higher collagen, Fe, Ca, P, and Na contents than did BGL (p<0.05). Notably, the Ca/P ratio was high in both BGR and BGL (1.82 and 1.54, respectively), thus satisfying the recommendation that the Ca/P ratio is between 1 and 2. BGL showed a significantly higher content of desirable fatty acids (stearic acid and total unsaturated fatty acids) than did BGR. In addition, the levels of creatine, carnosine, and anserine in BGL were higher than those in BGR (p<0.05). There was no significant difference in the antioxidant activity between BGL and BGR, as assessed by FRAP (both $15.92{\mu}mol$ Trolox equivalent [TE]/g of dry matter [DM]), ABTS (12.51 and $12.90{\mu}mol\;TE/g\;DM$, respectively), and ORAC (101.25 and $99.06{\mu}mol\;TE/g\;DM$, respectively) assays. Conclusion: This was a primary study conducted to evaluate the differences in nutritional value and antioxidant activity between loin and rump cuts of black goat meat. Our results provide fundamental knowledge that can help understand the properties of black goat meat.

• Ocean and Polar Research
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• v.44 no.3
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• pp.221-233
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• 2022

A sediment trap had been deployed at 1250 m depth in the Eastern Tropical Pacific (ETP) from September 2009 to July 2010, with the aim of understanding the temporal and vertical variability of particle flux. During the monitoring period, total particle flux varied from 12.4 to 101.0 mg m^-2day^-1, with the higher fluxes in January-March 2010. Biogenic particle flux varied in phase with the total particle flux. The increase in total particle flux during January-March 2010 was attributed to the enhanced biological production in the surface layer caused by wind-driven mixing in response to the seasonal shifts in the location of the Intertropical convergence zone. The export ratio (e-ratio) was estimated using the particulate organic carbon flux and satellite-derived net primary production data. The estimated e-ratios changed between 0.8% and 2.8% (1.4±0.6% on average). The ratio recorded in the negative phase of Pacific decadal oscillation (PDO) was similar to the previous results obtained from the ETP during the 1992/93 periods in the positive phase of PDO. This suggests that the regime shift of the PDO is not related to the carbon export ratio.

• Korean Journal of Clinical Pharmacy
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• v.33 no.2
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• pp.128-134
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• 2023

Background: This systematic review and meta-analysis aimed to evaluate the efficacy and cardiovascular safety of romosozumab compared with placebo. Methods: Randomized controlled trials (RCTs) were searched from Medline, EMBASE, Cochrane Central, and Web of Science until July 2022. Primary outcomes included the change in bone mineral density (BMD) from baseline at month 6. The secondary outcomes were the change of bone turnover markers (N-terminal propeptide of type 1 procollagen (P1NP); C-terminal telopeptide of type 1 collagen (CTX)) from baseline at month 3, and the incidence of cardiovascular adverse events for the total follow-up period. Results: A total of 7 RCTs on 8,370patients were included. Romosozumab showed better effects in improving BMD in both lumbar spine and femoral neck at month 6 (standardized mean difference, SMD 2.20 [95% CI: 1.89-2.52], SMD 0.63 [95% CI: 0.41-0.86]). In contrast to placebo, romosozumab significantly increased PINP levels and reduced CTX levels at month 3 (SMD 0.93 [95% CI: 0.65-1.22], SMD -1.03 [95% CI: -1.23~ -0.82]. However, there was no significant difference in the composite incidence of cardiovascular adverse events and major adverse cardiovascular events (OR 1.16 [95% CI: 0.82-1.65], OR 1.08 [95% CI: 0.75-1.56]). Conclusion: This analysis showed that romosozumab significantly improved BMD compared to placebo and was beneficial for change in bone turnover markers. There is no significant difference in the incidence of cardiovascular adverse events compared to placebo.

• Journal of the Korean Geotechnical Society
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• v.40 no.1
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• pp.39-46
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• 2024

Artificial recharge systems have been employed to solve drought problems due to global climate change. Despite the increased usage, the applications of artificial recharge systems are limited by clogging problems, which reduce recharge rates. In this study, the soil texture and mineral characteristics of alluvial soil in a planned artificial recharge system area were investigated to evaluate the possibility of chemical clogging during the injection of stream water. The primary minerals contained in the clastic particles are quartz, K-feldspar, plagioclase, and biotite, and the secondary minerals filling the pore space are illite, kaolinite and Fe-oxide. The fact that carbonate and sulfate are observed as secondary minerals in the pore space suggests that chemical clogging has not occurred by the interaction between the groundwater and surface water in the study area. Thus, monitoring soil properties, e.g., the formation and growth of secondary minerals in the pore space, is required to investigate the possibility of chemical clogging in artificial recharge systems.