• Title/Summary/Keyword: Field Environment

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Effects of Supplementary Composts on Microbial Communities and Rice Productivity in Cold Water Paddy Fields

  • Xie, Kaizhi;Xu, Peizhi;Yang, Shaohai;Lu, Yusheng;Jiang, Ruiping;Gu, Wenjie;Li, Wenying;Sun, Lili
    • Journal of Microbiology and Biotechnology
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    • v.25 no.5
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    • pp.569-578
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    • 2015
  • Cold water paddy field soils are relatively unproductive, but can be ameliorated by supplementing with inorganic fertilizer from animal waste-based composts. The yield of two rice cultivars was significantly raised by providing either chicken manure or cow dung-based compost. The application of these composts raised the soil pH as well as both the total nitrogen and ammonium nitrogen content, which improved the soil's fertility and raised its nitrification potential. The composts had a measurable effect on the abundance of nitrogencycling-related soil microbes, as measured by estimating the copy number of various bacterial and archaeal genes using quantitative real-time PCR. The abundance of ammonia oxidizing archaea and bacteria was markedly encouraged by the application of chicken manure-based compost. Supplementation with the composts helped promote the availability of soil nitrogen in the cold water paddy field, thereby improving the soil's productivity and increasing the yield of the rice crop.

Scanning Rayleigh Doppler Lidar for Wind Profiling Based on Non-polarized Beam Splitter Cube Optically Contacted FPI

  • Zheng, Jun;Sun, Dongsong;Chen, Tingdi;Zhao, Ruocan;Han, Yuli;Li, Zimu;Zhou, Anran;Zhang, Nannan
    • Current Optics and Photonics
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    • v.2 no.2
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    • pp.195-202
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    • 2018
  • A Scanning Rayleigh Doppler lidar for wind profiling based on a non-polarized beam splitter cube optically contacted FPI is developed for wind measurement from high troposphere to low stratosphere in 5-35 km. Non-polarized beam splitter cube optically contacted to the FPI are used for a stable optical receiver. Zero Doppler shift correction is used to correct for laser or FPI frequency jitter and drift and the timing sequence is designed. Stability of the receiver for Doppler shift discrimination is validated by measuring the transmissions of FPI in different days and analyzed the response functions. The maximal relative wind deviation due to the stability of the optical receiver is about 4.1% and the standard deviation of wind velocity is 1.6% due to the stability. Wind measurement comparison experiments were carried out in Jiuquan ($39.741^{\circ}N$, $98.495^{\circ}E$), Gansu province of China in 2015, showing good agreement with radiosonde result data. Continuous wind field observation was performed from October 16th to November 12th and semi-continuous wind field of 19 nights are presented.

LES of wind environments in urban residential areas based on an inflow turbulence generating approach

  • Shen, Lian;Han, Yan;Cai, C.S.;Dong, Guochao;Zhang, Jianren;Hu, Peng
    • Wind and Structures
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    • v.24 no.1
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    • pp.1-24
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    • 2017
  • Wind environment in urban residential areas is an important index to consider when evaluating the living environment. However, due to the complexity of the flow field in residential areas, it is difficult to specify the correct inflow boundary conditions in the large eddy simulation (LES). In this paper, the weighted amplitude wave superposition (WAWS) is adopted to simulate the fluctuating velocity data, which satisfies the desired target wind field. The fluctuating velocity data are given to the inlet boundary of the LES by developing an UDF script, which is implemented into the FLUENT. Then, two numerical models - the empty numerical wind tunnel model and the numerical wind tunnel model with spires and roughness elements are established based on the wind tunnel experiment to verify the present method. Finally, the turbulence generation approach presented in this paper is used to carry out a numerical simulation on the wind environment in an urban residential area in Lisbon. The computational results are compared with the wind tunnel experimental data, showing that the numerical results in the LES have a good agreement with the experimental results, and the simulated flow field with the inlet fluctuations can generate a reasonable turbulent wind field. It also shows that strong wind velocities and turbulent kinetic energy occur at the passageways, which may affect the comfort of people in the residential neighborhood, and the small wind velocities and vortexes appear at the leeward corners of buildings, which may affect the spreading of the pollutants.

Monitoring Occurrence Status of Thrips Populations on Field-Cultivated Pepper at Major Cultivated Region in West Coast, Korea (서해안 주요 고추 주산지에서 발생하는 총채벌레의 발생현황)

  • Seo, Mi Hye;Lee, Seong Chan;Yang, Chang Yeol;Yoon, Jung Beom;Park, Jung-Joon
    • Korean Journal of Environmental Biology
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    • v.36 no.4
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    • pp.544-549
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    • 2018
  • Thrips populations were monitored in field-cultivated pepper at Gochang, Jeonbuk province, Cheongyang, Chungnam province, and Goesan, Chungbuk province during the field growing seasons of 2017 to 2018, respectively. We classified and quantified thrips population in each plot and year. Most of the monitored thrips were composed of three species: Frankliniella intonsa, F. occidentalis, and Thrips tabaci, respectively. F. intonsa was the dominant species in all the monitoring season. The density of thrips was increased from late June in each field and year with the highest density being recorded in mid-July. Based on the results, management strategy of thrips in red peppers should be evaluated from early June with monitoring and appropriate controls.

Parameter Mismatches and its Biases in Ocean Matched Field Processing (해양 정합장처리에서 매개변수 오정합과 바이어스)

  • Park Jae-Eun;Kim Jea-Soo;Shin Kee-Cheol
    • The Journal of the Acoustical Society of Korea
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    • v.24 no.2
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    • pp.87-96
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    • 2005
  • In matched field processing (MEP), the observed acoustic field data is basically correlated with the replica produced by the modeling. therefore the results of source localization and correlation is limited by the mismatch of the environment and sensor location. In this paper. the effects of mismatch in environment and system on the bias in estimating the source location are investigated in the context of source localization. In the Pekeris waveguide, the simulation shows that the mismatches in environment and system, can cause a significant biases in the source localization and a degradation in MFP correlation. Mismatch caused by uncertainties in array tilt and depth, bottom depth, bottom sound speed, etc. causes degradation in source localization performance.

Near-field Target Localization Using Bottom-mounted Linear Sensor Array in Multipath Environment (다중경로환경에서 바닥고정형 선배열센서를 이용한 근거리표적의 위치추정기법)

  • 이수형;류창수;이균경
    • The Journal of the Acoustical Society of Korea
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    • v.19 no.7
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    • pp.7-14
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    • 2000
  • In this paper, we propose a near-field target localization algorithm using a bottom-mounted linear sensor amy in a multipath environment. In a multipath environment, the conic angles of a target signals through each path are different, and the position of the target can be estimated using these conic angles and the time difference of these signals. We derive equations on the relation of time-difference of signals and conic angles estimates under the far-field assumption, and estimate the position of target by simultaneously solving these equations. For a certain geometry of a target and the sensor array, there exist cases when the conic angles are very close. In such a case, we estimate the position of the target using an additional 1-D search.

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An Analysis of Wind Field around the Air Quality Monitoring Station in the Urban Area by Using the Envi-met Model (Envi-met 모델을 이용한 도심지역 대기오염측정망 주변의 바람장 분석)

  • Kim, Min-Kyoung;Lee, Hwa Woon;Dou, Woo-Gon;Jung, Woo-Sik
    • Journal of Environmental Science International
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    • v.18 no.9
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    • pp.941-952
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    • 2009
  • The urban microscale wind field around the air quality monitoring station was investigated in order to check how a building complex influences it. For this study as the high density areas Jwa-dong and Yeonsan-dong monitoring sites in Busan were chosen. As the direction of inflow which is perpendicular to the building of the monitoring station was expected to cause the considerable variation of the wind field, that direction was selected. The model Envi-met was used as the diagnostic numerical model for this study. It is suitable for this investigation because Envi-met has the microscale resolution. After simulating it, on the leeward side around a building complex the decrease of flow velocity and some of vortexes or circulation area were discovered. In addition, on the edge of the top at the building and at the back of the building the upward flow was developed. If the sampling hole of monitoring site were located in this upward flow, it would be under the influence of upward flow from the near street.