• Title/Summary/Keyword: growth environments

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Effect of Trinexapac-ethyl on Zoysiagrass Quality under a Shade Condition (그늘 지역에서의 Zoysiagrass에 미치는 Trinexapac-ethyl의 효과)

  • Ok, Chang-Ho
    • Asian Journal of Turfgrass Science
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    • v.20 no.1
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    • pp.25-31
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    • 2006
  • 'Meyer' zoysiagrass(Zoysia japonica Steud.) is a popular turfgrass species used for transition zone golf course fairways and tees in mfd U.S.A golf courses because it is generally winter hardy while providing an excellent playing surface with minimal chemical and irrigation inputs. However, its functionality declines easily in many of the shaded areas of these courses. Reduced irradiance causes excessive shoot elongation, reduced tillering, and weak plants that are poorly suited to tolerate or recover from traffic and devoting. Trinexapac-ethyl (TE) effectively reduces gibberellic acid (GA) biosynthesis and subsequent shoot cell elongation. This study was initiated to evaluate TE effect on shoot elongation and stand persistence under two levels of shade in 'Meyer' zoysiagrass. A mature stand of 'Meyer' was treated with all combinations of three levels of shade(0%, 79%, and 92%) and three levels of monthly TE [0, 48 $g{\cdot}ha^{-1}$ a.i(0.5x) and 96 $g{\cdot}ha^{-1}$ a.i(1x)]. In full sun, the TE at 48 $g{\cdot}ha^{-1}$ a.i reduced clipping yield by 18% over a four-week period and, whereas the TE at 96 $g{\cdot}ha^{-1}$ a.i by 30% to 38%. Monthly application of TE at the 96 $g{\cdot}ha^{-1}$ a.i increased 'Meyer' tiller density in full sun and under 79% shade. Both rates of TE consistently reduced shoot growth under shade relative to the shaded control. Only the monthly applications of the TE at 96 $g{\cdot}ha^{-1}$ a.i consistently delayed loss of quality under 79% shade. Our results indicate TE can be an effective management practice to increase 'Meyer' zoysiagrass persistence in shaded environments.

Analysis of Threats and Countermeasures on Mobile Smartphone (스마트폰 보안위협과 대응기술 분석)

  • Jeon, Woong-Ryul;Kim, Jee-Yeon;Lee, Young-Sook;Won, Dong-Ho
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.2
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    • pp.153-163
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    • 2011
  • Smartphone is a mobile device which can perform better than feature phone. Recently, growth in demand for advanced mobile devices boasting powerful performance, market share of smartphone is increasing rapidly in mobile device market, for example, iphone and android phone. Smartphone can provide many functionalities, e-mail, scheduler, word-processing, 3D-game, and etc, based on its powerful performance. Thus, various secret information is integrated in smartphone. To provide service, sometimes, smartphone transmits informations to outside via wireless network. Because smartphone is a mobile device, user can lose his/her smartphone, easily, and losing smartphone can cause serious security threats, because of integrated information in smartphone. Also data which is transmitted in wireless network can be protected for privacy. Thus, in present, it is very important to keep secure smartphone. In this paper, we analyze threats and vulnerabilities of smartphone based on its environments and describe countermeasures against threats and vulnerabilities.

Comparison of nutrition, anti-nutritional factors of rice straw and microbial composition in soil according to GM and non-GM rice field

  • Im, Seon yeong;Jeon, Young ji;Mun, Se young;Han, Kyu dong;Ahn, Tae young;Lee, Dong jin
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.350-350
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    • 2017
  • The study was conducted to evaluate differences of growth characteristics of rice cultivated in two different regions (Cheonan and Jeonju). It focused on nutritional composition and anti-nutritional factors of rice straw produced from 21 rice varieties including GM rice (Iksan 483). The range of general nutrition ingredient is that crude was 0.97 ~ 3.2 %, carbohydrate was 67.45 ~ 80.01 %, crude protein was 1.46 ~ 4.81 %, crude ash was 6.52 ~ 18.96 %, crude fiber was 25.77 ~ 40.02 %, NDF was 51.84 ~ 67.77 %, ADF was 27.11 ~ 40.44 %, calcium was 0.49 ~ 5.18 mg/g and phosphorous was 0.26 ~ 2.77 mg/g. The general nutritional contents of GM rice were included above range. The range of phytic acid of rice straws cultivated in Cheonan and Jeonju was 0 ~ 0.056 mg/ml and 0 ~ 0.059 mg/ml, respectively. The phytic acid content of GM was 0.033 mg/ml, which was in the range of the content of rice straw in Cheonan and Jeonju. The range of trypsin inhibitor of rice straws cultivated in Cheonan and Jeonju was 0.061 ~ 0.461 TIU/mg and 0 ~ 1.278 TIU/mg, respectively. The trypsin acid content of GM was 0.461 TIU/mg, which was in the range of the content of rice straw in Cheonan and Jeonju. In addition, we investigated microbial community from each soil sample by using metagenomics sequencing based on rRNA microbial diversity in order to inspect indirect changes of soil environment with cultivation of GM rice. Metagenomics analysis was carried out using soil samples cultivated with GM and non-GM rice for before transplanting, young panicle differentiation stage, heading stage, and ripening stage. Beta diversity of microbial community in both soil environments were calculated by using Bray-Curtis distance method and showed low value with an average of 0.24 (dissimilarity = 1). As a result, it was confirmed that the cultivation of GM does not give a significant effect on the change of microbial composition in soil. Therefore, Our study demonstrates that there is no difference in the composition of soil microorganism due to GM and non-GM rice.

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Model Development on the Fate and Transport of Chemical Species in Marsh Wetland Sediments Considering the Effects of Plants and Tides (식생과 조석의 영향을 고려한 연안습지 퇴적물 내 물질거동 모형의 개발)

  • Park, Do-Hyun;Wang, Soo-Kyun
    • Journal of Soil and Groundwater Environment
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    • v.14 no.6
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    • pp.53-64
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    • 2009
  • Wetlands can remove organic contaminants, metals and radionuclides from wastewater through various biogeochemical mechanisms. In this study, a mathematical model was developed for simulating the fate and transport of chemical species in marsh wetland sediments. The proposed model is a one-dimensional vertical saturated model which is incorporated advection, hydrodynamic dispersion, biodegradation, oxidative/reductive chemical reactions and the effects from external environments such as the growth of plants and the fluctuation of water level due to periodic tides. The tidal effects causes periodic changes of porewater flow in the sediments and the evapotranspiration and oxygen supply by plant roots affect the porewater flow and redox condition on in the rhizosphere along with seasonal variation. A series of numerical experiments under hypothetical conditions were performed for simulating the temporal and spatial distribution of chemical species of interests using the proposed model. The fate and transport of a trace metal pollutant, chromium, in marsh sediments were also simulated. Results of numerical simulations show that plant roots and tides significantly affect the chemical profiles of different electron acceptors, their reduced species and trace metals in marsh sediments.

Nutrient Environments of Japanese Cedar(Cryptomeria japonica) Forests in Cheju Island II. Nutrient Characteristics of Different Site Quality (제주도(濟州道) 삼나무(Cryptomeria japonica) 조림지(造林地)의 영양환경(營養環境)에 관한 연구(硏究) II. 지위(地位)에 따른 토양(土壤) 및 임목(林木)의 양분(養分) 특성(特性))

  • Jin, Hyun-O
    • Korean Journal of Soil Science and Fertilizer
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    • v.25 no.3
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    • pp.255-262
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    • 1992
  • For the purpose of investigation the local characteristics of the nutrient status in the Japanese cedar in Cheju island, the author have carried out chemical analysis of the soils and needles of established Japanese ceder forests in four site quality classified by height growth. Results were summarized as follows. 1. Site quality was related closely to exch. Ca, exch. Mg in the surface soil and to N, K and Ca concentrations in the needle. 2. Appropriate concentration of nutrients in the surface soil and current year's needles are exch. Ca>4.0(me/100g), exch. Mg>2.0(me/100g) and N>1.5(%), K>0.8(%), Ca>1.5(%). 3. In addition, the Ca : Mg : Na ratio of the exch. cation(me/100g) may be useful as an indicator in the assesment of site quality of Japanese cedar forests in Cheju island.

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Growth of SiC Oxidation Protective Coating Layers on graphite substrates Using Single Source Precursors

  • Kim, Myung-Chan;Heo, Cheol-Ho;Park, Jin-Hyo;Park, Seung-Jun;Han, Jeon-Geon
    • Proceedings of the Korean Vacuum Society Conference
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    • 1999.07a
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    • pp.122-122
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    • 1999
  • Graphite with its advantages of high thermal conductivity, low thermal expansion coefficient, and low elasticity, has been widely used as a structural material for high temperature. However, graphite can easily react with oxygen at even low temperature as 40$0^{\circ}C$, resulting in CO2 formation. In order to apply the graphite to high temperature structural material, therefore, it is necessary to improve its oxidation resistive property. Silicon Carbide (SiC) is a semiconductor material for high-temperature, radiation-resistant, and high power/high frequency electronic devices due to its excellent properties. Conventional chemical vapor deposited SiC films has also been widely used as a coating materials for structural applications because of its outstanding properties such as high thermal conductivity, high microhardness, good chemical resistant for oxidation. Therefore, SiC with similar thermal expansion coefficient as graphite is recently considered to be a g행 candidate material for protective coating operating at high temperature, corrosive, and high-wear environments. Due to large lattice mismatch (~50%), however, it was very difficult to grow thick SiC layer on graphite surface. In theis study, we have deposited thick SiC thin films on graphite substrates at temperature range of 700-85$0^{\circ}C$ using single molecular precursors by both thermal MOCVD and PEMOCVD methods for oxidation protection wear and tribological coating . Two organosilicon compounds such as diethylmethylsilane (EDMS), (Et)2SiH(CH3), and hexamethyldisilane (HMDS),(CH3)Si-Si(CH3)3, were utilized as single source precursors, and hydrogen and Ar were used as a bubbler and carrier gas. Polycrystalline cubic SiC protective layers in [110] direction were successfully grown on graphite substrates at temperature as low as 80$0^{\circ}C$ from HMDS by PEMOCVD. In the case of thermal MOCVD, on the other hand, only amorphous SiC layers were obtained with either HMDS or DMS at 85$0^{\circ}C$. We compared the difference of crystal quality and physical properties of the PEMOCVD was highly effective process in improving the characteristics of the a SiC protective layers grown by thermal MOCVD and PEMOCVD method and confirmed that PEMOCVD was highly effective process in improving the characteristics of the SiC layer properties compared to those grown by thermal MOCVD. The as-grown samples were characterized in situ with OES and RGA and ex situ with XRD, XPS, and SEM. The mechanical and oxidation-resistant properties have been checked. The optimum SiC film was obtained at 85$0^{\circ}C$ and RF power of 200W. The maximum deposition rate and microhardness are 2$mu extrm{m}$/h and 4,336kg/mm2 Hv, respectively. The hardness was strongly influenced with the stoichiometry of SiC protective layers.

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Mozi's View on Social Responsibility of Corporation (묵가적(墨家的) 입장에서 바라본 기업의 사회적 책임과 역할)

  • Seo, Yong-Mo;Kim, Ha-Yun
    • Journal of the Korea Convergence Society
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    • v.9 no.9
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    • pp.245-252
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    • 2018
  • This study interprets the corporate social responsibility and its management through analysis of philosophical view of Mozi(墨子). Mozi was a chinese philosopher during the Hundred Schools of Thought period. He advocated Universal love(兼愛), which stresses that people should care for everyone equally. This principle is in accord with the sustainable management strategy for global market environments. The realization of the value that the company pursues in the rapid growth of such enterprises is an important issue. The pursuit of corporate value in its own interest under the rapidly changing business environment is perceived very negative. And it has demanded a different philosophy as a new management philosophy. The philosophical strategies of these companies were centered around the core philosophy of the ancient Chinese philosopher, Mozi. It is not merely an outcome approach as the act or moral principle but the inner motive to love each other and the principle of sharing the profits of each other. In order to pursue the sustainable value of the enterprise, We would like to suggest a way to pursue the existing absolute value, and to suggest a philosophical strategy based on the philosophy of Mozi.

Geotechnical Characteristics of Prefabricated Vertical Drain System for Contaminated Soil Remediation (오염토양 복원을 위한 연직배수시스템의 지반공학적 특성)

  • Shin, Eunchul;Park, Jeongjun
    • Journal of the Korean GEO-environmental Society
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    • v.8 no.5
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    • pp.5-14
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    • 2007
  • The quantity of noxious wastes generated by the growth in industrialization and population in all over the world and its potential hazards in subsurface environments are becoming increasingly significant. The extraction of the contaminant from the soil and movement of the water are restricted due to the low permeability and adsorption characteristics of the reclaimed soils. Incorporated technique with PVDs have been used for dewatering from fine-grained soils for the purpose of ground improvement by means of soil flushing and soil vapor extraction systems. This paper is to evaluate several key parameters that affected to the performance of the PVDs specifically with regard to: well resistance of PVD, zone of influence, and smear effects. In the feasibility of contaminant remediation was evaluated in pilot-scale laboratory experiments. Well resistance is affected on the vertical discharge capacity of the PVDs under the various vacuum pressures. The discharge capacity increases consistently in areal extents with higher applied vacuum up to a limiting vacuum pressure. The head values for each piezometer at different vacuum pressures show that the largest head loss occurs within 14 cm of the PVD. Air flow rates and head losses were measured for the PVD placed in the model test box and the gas permeability of the silty soils was calculated. Increasing the equivalent diameter results in a decrease in the calculated gas permeability. It is concluded that the gas permeability determined over the 1,500 to 2,000 $cm^3/s$ flow rates are the most accurate values which yields gas permeability of about 3.152 Darcy.

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Direct-fed Microbials for Ruminant Animals

  • Seo, Ja-Kyeom;Kim, Seon-Woo;Kim, Myung-Hoo;Upadhaya, Santi D.;Kam, Dong-Keun;Ha, Jong-K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.12
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    • pp.1657-1667
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    • 2010
  • Direct-fed microbials (DFM) are dietary supplements that inhibit gastrointestinal infection and provide optimally regulated microbial environments in the digestive tract. As the use of antibiotics in ruminant feeds has been banned, DFM have been emphasized as antimicrobial replacements. Microorganisms that are used in DFM for ruminants may be classified as lactic acid producing bacteria (LAB), lactic acid utilizing bacteria (LUB), or other microorganisms including species of Lactobacillus, Bifidobacterium, Enterococcus, Streptococcus, Bacillus and Propionibacterium, strains of Megasphaera elsdenii and Prevotella bryantii and yeast products containing Saccharomyces and Aspergillus. LAB may have beneficial effects in the intestinal tract and rumen. Both LAB and LUB potentially moderate rumen conditions and improve feed efficiency. Yeast DFM may reduce harmful oxygen, prevent excess lactate production, increase feed digestibility, and improve fermentation in the rumen. DFM may also compete with and inhibit the growth of pathogens, stimulate immune function, and modulate microbial balance in the gastrointestinal tract. LAB may regulate the incidence of diarrhea, and improve weight gain and feed efficiency. LUB improved weight gain in calves. DFM has been reported to improve dry matter intake, milk yield, fat corrected milk yield and milk fat content in mature animals. However, contradictory reports about the effects of DFM, dosages, feeding times and frequencies, strains of DFM, and effects on different animal conditions are available. Cultivation and preparation of ready-to-use strict anaerobes as DFM may be cost-prohibitive, and dosing methods, such as drenching, that are required for anaerobic DFM are unlikely to be acceptable as general on-farm practice. Aero-tolerant rumen microorganisms are limited to only few species, although the potential isolation and utilization of aero-tolerant ruminal strains as DFM has been reported. Spore forming bacteria are characterized by convenience of preparation and effectiveness of DFM delivery to target organs and therefore have been proposed as DFM strains. Recent studies have supported the positive effects of DFM on ruminant performance.

Effects of Hot Environment and Dietary Protein Level on Growth Performance and Meat Quality of Broiler Chickens

  • Gu, X.H.;Li, S.S.;Lin, H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.11
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    • pp.1616-1623
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    • 2008
  • This study was conducted to determine the effect of hot environment and dietary crude protein level (CP) on performance, carcass characteristics, meat visual quality, muscle chemical composition and malondialdehyde (MDA) concentration of tissues in broilers. Two hundred and sixteen 21-d old Arbor Acre broilers were used in a $4\times3$ factorial arrangement and randomly reared in 4 environmental chambers and fed on 3 diets with different CP levels for 3 weeks. The results showed: (1) when air temperature (AT) rose to $33^{\circ}C$, average daily feed intake, average daily gain, carcass weight, right breast meat weight, left thigh and drumstick meat weight decreased (p<0.05) and feed conversion rate decreased (p<0.05), but the ratio of carcass to live weight and of left thigh and drumstick meat weight to carcass weight increased (p<0.05). (2) There were significant differences in pH and shear force in breast meat, and shear force, L* and a* in thigh meat (p<0.01 or 0.05) among hot environments. Dietary CP level tended to affect breast meat pH and pH and L* of thigh meat (p<0.06 or 0.09). Compared to the normal temperature ($22^{\circ}C$), low temperature ($15^{\circ}C$) and hot humid (AT $33^{\circ}C$, relative humidity (RH) 80%) treatments significantly (p<0.05) decreased the tenderness of thigh meat. L* and a* value in thigh meat under high temperature treatments, regardless of RH, were higher (p<0.05) than those under normal temperature. (3) Protein content in breast and thigh meat of broilers fed under high temperature ($33^{\circ}C$) was lower (p<0.05) than that under $22^{\circ}C$, but fat content had an adverse change. High temperature ($33^{\circ}C$) increased the moisture of breast meat significantly (p<0.05). Protein content in breast meat increased significantly (p<0.05), in which fat content had an adverse change (p<0.05), when the dietary protein rose. (4) MDA concentration in liver and breast meat under hot humid (AT $33^{\circ}C$, RH 80%) treatment increased markedly (p<0.05). (5) High humidity could sharpen the bad effect of high temperature on performance, carcass yield and choice cuts, crude protein and moisture content in breast meat. It was concluded that a hot environment could affect the performance and meat quality of broiler chicks more significantly than CP level and that high humidity would aggravate the bad influence of high temperature on the broiler.