• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2006년도 학술발표회 논문집
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• pp.487-494
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• 2006

The ultimate capacities of a rubber bearing are defined by compressive stress, shear strain, and stabilized roster ing force. The experiments were conducted with parameters of shesr elasticity(G) and first shape factor(S1), second shape factor(S2) for rubber bearing. Considering with test results, the ultimate capacities were verified, and furthermore the influence of those parameters were clarified. Using test results stable deformation of rubber bearings for designing was proposed.

• Journal of Microbiology and Biotechnology
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• 제24권7호
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• pp.987-997
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• 2014

The mature landfill leachate, which is characterized by a high concentration of ammonia nitrogen ($NH_3$-N) and humic acid (HA), poses a challenge to biotreatment methods, due to the constituent toxicity and low biodegradable fraction of the organics. In this study, we applied bioaugmentation technology in landfill leachate degradation by introducing a domesticated $NH_3$-N and HA resistant bacteria strain, which was identified as Bacillus cereus (abbreviated as B. cereus Jlu) and Enterococcus casseliflavus (abbreviated as E. casseliflavus Jlu), respectively. The isolated strains exhibited excellent tolerant ability for $NH_3$-N and HA and they could also greatly improved the COD (chemical oxygen demand), $NH_3$-N and HA removal rate, and efficiency of bioaugmentation degradation of landfill leachate. Only 3 days was required for the domesticated bacteria to remove about 70.0% COD, compared with 9 days' degradation for the undomesticated (autochthonous) bacteria to obtain a similar removal rate. An orthogonal array was then used to further improve the COD and $NH_3$-N removal rate. Under the optimum condition, the COD removal rate in leachate by using E. casseliflavus Jlu and B. cereus Jlu increased to 86.0% and 90.0%, respectively after, 2 days of degradation. The simultaneous removal of $NH_3$-N and HA with more than 50% and 40% removal rate in leachate by employing the sole screened strain was first observed.

• 한국직업건강간호학회지
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• 제15권2호
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• pp.133-143
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• 2006

Purpose: The purpose of this study was to examine the relationship between perceived job stress and work environmental factors related with socioeconomics factors and physical burden in the golf caddies. Methods: Job stress in golf caddies was estimated by using the Karasek's job content questionnaire (JCQ) and work environmental factors were estimated by self-reported questionnaire and interview. Results: The subjects were 316 woman caddies who had never been occupationally exposed to hazardous chemicals, was mean age 31.1 years. Mean work duration was 6.44 years and working hours per day on low- and high-demand season were 6.16 and 10.51, respectively. The golf caddies displayed higher scores of job stress due to multiple factors such as working hours and frequency of rounding per week, physical burden, confliction, income satisfaction and employment stability. We found that high strain group was positive correlation with age, career, working hour (including frequency of rounding) and job demand, however, showed negative correlation with job decision latitude and support of supervisor and coworker. Conclusion: In conclusion, we suggest that the golf caddies be regard divided into high strain group as appropriate. Thus, stress management and health promotion program for golf caddies should be developed.

• Structural Engineering and Mechanics
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• 제76권3호
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• pp.279-291
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• 2020

The seismic design of conventional frame structures is meant to enhance plastic deformations at beam ends and prevent yielding in columns. To this end, columns are made stronger than beams. Yet yielding in columns cannot be avoided with the column-to-beam strength ratios (about 1.3) prescribed by seismic codes. Preventing plastic deformations in columns calls for ratios close to 4, which is not feasible for economic reasons. Furthermore, material properties and the rearrangement of geometric shapes inevitably make the distribution of damage among stories uneven. Damage in the i-th story can be characterized as the accumulated plastic strain energy (W_pi) normalized by the product of the story shear force (Q_yi) and drift (δ_yi) at yielding. Past studies showed that the distribution of the plastic strain energy dissipation demand, W_pi/ΣW_pj, can be evaluated from the deviation of Q_yi with respect to an "optimum value" that would make the ratio W_pi/(Q_yiδ_yi) -i.e. the damage- equal in all stories. This paper investigates how the soil type and ductility demand affect the optimum lateral strength distribution. New optimum lateral strength distributions are put forth and compared with others proposed in the literature.

• 한국토양비료학회지
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• 제17권4호
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• pp.314-318
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• 1984

China has made rapid strides in agricultural production during the past few years. Although the absence of any serious climatic disturbances is a contributing factor, implementation of the responsibility system to reward peasant families for their initiatives has been by far the most significant. This has resulted in increased specialization, a greater requirement for technical adivsory services, and a much higher demand for farm equipment and production inputs. The revamped system has brought with it some problems such as differences in income between the most progressive producers and their less successful neighbours and urban workers, a shortage of storage, transport and processing facilities, and a strain on the national treasury to continue to subsidize farm prices. Demand for fertilizers has been increasing at a fast rate, especially for nitrogen. This has led to a serious imbalance in nutrient use which must be corrected if the current momentum in improving crop yields is to be maintained. Following a decade of total stagnation during the Cultural Revolution, agricultural research and education facilities are being strengthened. Younger scientists, many with overseas training, are being placed in key positions. China is still a developing country, and much remains to be done; however, progress in the last decade, and especially in the past five years, has been remarkable.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.491-496
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• 2001

In recent years, the research and development about the new material proceed rapidly and actively in the building industry. As building structures become bigger, higher and more specialized, so does the demand for material with higher strength. In the future, we will need to research repair and rehabilitation to make high strength concrete mixed steel fibrous building safe. The carbon fiber reinforced plastic bonding method is widely used in reinforcing the existing concrete structure among the various methods. The repair of initiate loaded reinforced high-strength concrete beams mixed steel fibrous with epoxy bonded Carbon Fiber Sheets(CFS) was investigated experimentally. The CFS thickness and length were varied to assess the peel failure at the curtailment of CFS, The behaviour of the repaired beams was represented by load-longitudinal steel strain relation and failure modes were discussed. The test results indicate that CFS is very effective for strengthening the demand beams and controlling deflections of reinforced high strength concrete beams mixed steel fibrous happen diagonal crack, the increase in the number of CFS layers over two layers didn't effect the increase in the strength of beams.

• 한국지하수토양환경학회지:지하수토양환경
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• 제24권5호
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• pp.17-30
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• 2019

Intensive agricultural development in Mexicali valley, Baja-California, Mexico, has induced tremendous strain on the limited water resources. Agricultural water consumption in the valley mainly relies on diversions of the Colorado River, but their water supply is far less than the demand. Hence, the use of groundwater for irrigation purposes has gained considerable attention. To account for these changes, it is important to evaluate surface water and groundwater conditions based on historical water use. This study identified the effects of agricultural activities on groundwater levels and groundwater recharge in the Mexicali valley (in irrigation unit 16) by a comprehensive MODFLOW Farm process (MF-FMP) numerical modeling. The MF-FMP modeling results showed that the water table in the study area is drawn downed, more in eastern areas. The inflow-outflow analysis demonstrated that recharge to the aquifer occurs in response to agricultural supplies. In general, the model provides MF-FMP simulations of natural and anthropogenic components of the hydrologic cycle, the distribution and dynamics of supply and demand in the study area.

• 콘크리트학회논문집
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• 제11권5호
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• pp.119-130
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• 1999

Recently, as the building structure has been larger, higher, longer and more specialized, the demand of material with high-strength concrete for building has been increasing. In this research, silica-fume was used as an admixture in order to get a high-strength concrete. From the test result, High-strength concrete with cylinder strength of 1,200kgf/$\textrm{cm}^2$ in 28-days was produced and tested. The static test was carried out to measure the ultimate load, the initial load of flexural and diagonal cracking, crack patterns and fracture modes. The load versus strain and load versus deflection relations were obtained from the static test. The relation of cycle loading to deflections on the mid-span, the crack propagation and the modes of failure according to cycle number, fatigue life and S-N curve were observed through the fatigue test. Based on the fatigue test results, high-strength reinforced concrete beams failed to 57~66 percent of the static ultimate strength. Fatigue strength about two million cycles from S-N curves was certified by 60 percent of static ultimate strength.

• Journal of Microbiology and Biotechnology
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• 제5권2호
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• pp.100-104
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• 1995

Production of $poly-{\beta}-hydroxybutyrate$ (PHB) in a strain of Azotobacter chroococcum, a nitrogen-fixing bacteria, was investigated at various levels of nitrogen and oxygen. Feeding nitrogen source increased both cell growth and PHB accumulation. Oxygen supply appeared to be one of the most important operating parameters for PHB production. Both cell growth and PHB accumulation increased with the sufficient supply of air in the fed-batch fermentation of the strain. However, it was also noted that keeping the oxygen level under limited condition was critical to achieve high PHB productivity. A high titer of PHB (52 g/l) with a high cellular content (60%) was obtained after 48 hr of fed-batch operation by controlling the oxygen supply. Dual limitation of nitrogen and oxygen did not further increase the PHB accumulation probably due to the greater demand for reducing power and ATP for nitrogen fixation.

• Interdisciplinary Bio Central
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• 제2권4호
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• pp.15.1-15.5
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• 2010

RIKEN BioResource Center (BRC) has collected, preserved, conducted quality control of, and distributed mouse resources since 2002 as the core facility of the National BioResource Project by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. Our mouse resources include over 5,000 strains such as humanized disease models, fluorescent reporters, and knockout mice. We have developed novel mouse strains such as tissue-specific Cre-drivers and optogenetic strains that are in high demand by the research community. We have removed all our specified pathogens from the deposited mice and used our quality control tests to examine their genetic modifications and backgrounds. RIKEN BRC is a founding member of the Federation of International Mouse Resources and the Asian Mouse Mutagenesis and Resource Association, and provides mouse resources to the one-stop International Mouse Strain Resource database. RIKEN BRC also participates in the International Gene Trap Consortium, having registered 713 gene-trap clones and their sequences in a public library, and is an advisory member of the CREATE (Coordination of resources for conditional expression of mutated mouse alleles) consortium which represents major European and international mouse database holders for the integration and dissemination of Cre-driver strains. RIKEN BRC provides training courses in the use of advanced technologies for the quality control and cryopreservation of mouse strains to promote the effective use of mouse resources worldwide.