• Title/Summary/Keyword: ground characterization

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A Study on Assessment of Biochar Adsorption Applicability by Physical and Chemical Characterization with Livestock Manure (가축분뇨 Biochar의 물리·화학적 특성분석을 통한 흡착제 적용성 평가 연구)

  • Lee, Youngjin;Oh, Minah;Park, Kyoungjoo;Lee, Jai-young
    • Journal of Soil and Groundwater Environment
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    • v.22 no.2
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    • pp.52-57
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    • 2017
  • As livestock husbandry has broadened from family-scale to enterprise-scale, the number of farming families has decreased in contrast to the increase of the number of livestock, and the amount of livestock manure discharged per household has increased. Livestock manure is difficult to handle and its disposal in the ocean is prohibited. Moreover, facilities that compost and liquefy manure are blamed as sources of soil, ground water, and surface water pollution because the amount of manure generated from husbandry farms causes eutrophication. In this study, livestock manure was utilized as a feedstock of hydrothermal carbonization (HTC) process to produce biochar for use as an environmental medium. The biochar was tested for iodine adsorption capability and its performance was compared with other adsorbent materials.

A study on the Optimum Design of an Inverted-F Antenna for the Bluetooth system (블루투스용 역-F형 안테나 최적 설계에 관한 연구)

  • Kim, Kab-Ki;Park, Gyei-Kark
    • Journal of Navigation and Port Research
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    • v.28 no.1
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    • pp.31-36
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    • 2004
  • In this paper, the characteristics of an inverted-F antenna for the 2.4GHz(ISM) Bluetooth system have been analysed in terms of the variation of design parameters. The antenna can be integrated on printed circuit board, and the characteristics in terms of the variation of the gap between feed line and shorting stub, gap between antenna's leg and ground plane, antenna leg's width, substrate's height and dielectric constant are analysed By using these characterization plot of design parameter, the tuning techniques are proposed to design optimum antenna. The designed antenna has 6.3%(150MHz) frequency bandwidth for VSWR under 1.5, and 3dBi gain.

Synthesis and Characterization of Gallium Nitride Powders and Nanowires Using Ga(S2CNR2)3(R = CH3, C2H5) Complexes as New Precursors

  • Jung, Woo-Sik;Ra, Choon-Sup;Min, Bong-Ki
    • Bulletin of the Korean Chemical Society
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    • v.26 no.1
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    • pp.131-135
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    • 2005
  • Gallium nitride (GaN) powders and nanowires were prepared by using tris(N,N-dimethyldithiocarbamato)gallium(III) (Ga(DmDTC)$_3$) and tris(N,N-diethyldithiocarbamato)gallium(III) (Ga(DeDTC)$_3$) as new precursors. The GaN powders were obtained by reaction of the complexes with ammonia in the temperature ranging from 500 to 1100 ${^{\circ}C}$. The process of conversion of the complexes to GaN was monitored by their weight loss, XRD, and $^{71}$Ga magic-angle spinning (MAS) NMR spectroscopy. Most likely the complexes decompose to $\gamma$ -Ga$_2$S$_3$ and then turn into GaN via amorphous gallium thionitrides (GaS$_x$N$_y$). The reactivity of Ga(DmDTC)$_3$ with ammonia was a little higher than that of Ga(DeDTC)$_3$. Room-temperature photoluminescence spectra of asprepared GaN powders exhibited the band-edge emission of GaN at 363 nm. GaN nanowires were obtained by nitridation of as-ground $\gamma$ -Ga$_2$S$_3$ powders to GaN powders, followed by sublimation without using templates or catalysts.

Effects of Surface Deformation on Intergranular Oxidation of Alloy 600 (Alloy 600의 결정립계 산화에 대한 표면 변형의 영향)

  • Ha, Dong Woog;Lim, Yun Soo;Kim, Dong Jin
    • Corrosion Science and Technology
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    • v.19 no.3
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    • pp.138-145
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    • 2020
  • Immersion tests of Alloy 600 were conducted in simulated primary water environments of a pressurized water reactor at 325 ℃ for 10, 100, and 1000 h to obtain insight into effects of surface deformation on internal and intergranular (IG) oxidation behavior through precise characterization using various microscopic equipment. Oxidized samples after immersion tests were covered with polyhedral and filamentous oxides. It was found that oxides were abundant in mechanically ground (MG) samples the most. The number density of surface oxides increased with time irrespective of the method of surface finish. IG oxidation occurred in mechanically polished (MP) and chemically polished (CP) samples with thin internal oxidation layers. However, IG oxidation was suppressed with relatively thick internal oxidation layers in MG samples compared to MP and CP samples, suggesting that MG treatment could increase resistance to primary water stress corrosion cracking (PWSCC) from the standpoint of IG oxidation. As a result, appropriate surface treatment for Alloy 600 could prevent oxygen diffusion into grain boundaries, inhibit IG oxidation, and finally induce its high PWSCC resistance.

Evaluation of Shear Wave Velocity Profiles by Performing Uphole Test Using SPT (표준관입시험을 이용한 업홀시험에서 전단파 속도 주상도의 도출)

  • 김동수;방은석;서원석
    • Journal of the Korean Geotechnical Society
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    • v.19 no.2
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    • pp.135-146
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    • 2003
  • Uphole test is a seismic field test using receivers on ground surface and a source in depth. In this paper, the uphole test using SPT(standard penetration test) which is economical and reliable for obtaining shear wave velocity profile was introduced. In the proposed uphole test, SPT sampler which is common in site investigation, was used as a source and several 1Hz geophones in line were used as receivers. Test procedures in field and interpretation methods for obtaining interval times and for determining shear wave velocity profile considering refracted ray path were introduced. Finally, uphole test was performed at three sites, and the applicability of the proposed uphole test was verified by comparing wave velocity profiles determined by the uphole test with the profiles determined by downhole test, SASW test and SPT-N values.

A Study on space organization of the SeongBo(聖寶)Museum's of The Buddhist Temple (사찰 성보박물관의 공간구성에 관한 연구)

  • Park, Hyun-Jeong;Kim, Kai-Chun
    • Korean Institute of Interior Design Journal
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    • v.16 no.6
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    • pp.205-212
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    • 2007
  • It is a world wide tread for museums to become specialized museums emphasizing their characteristics, but Seongbo museums(museums that preserve Buddhist artifacts) are more general and show no specialization or characterization. The purpose of this study is to emphasize the special character of the Seongbo museum which manages and maintains sacred Buddhist cultural artifacts, and to understand the architectural characteristics of the building distribution and interior composition to implement a more systematic spatial composition plan. For our analysis we selected 6 currently operating museums as our subjects, and analyzed the characteristics of their spatial composition through their plans including the plot plans and ground plans. As a result, we found that most of them were small scale museums, and that the character and rank of each building changed according to its positioning. In terms of areas, the museums consisted of exhibition areas, storage areas, maintenance areas, and other miscellaneous areas and were lacking areas for research and education. It is necessary for these museums to possess facilities for managing these cultural artifacts as well as adequate exhibition and storage spaces. Seongbo museums, which are connected with Buddhist temples, must possess differentiated preservation and maintenance methods unlike museums dealing with artifacts that need only be preserved, and must have an area plan suitable to the characteristics of the various artifacts near and around the temple so as to help build our Buddhist cultural heritage in a systematic and continuous matter.

Footprint extraction of urban buildings with LIDAR data

  • Kanniah, Kasturi Devi;Gunaratnam, Kasturi;Mohd, Mohd Ibrahim Seeni
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.113-119
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    • 2003
  • Building information is extremely important for many applications within the urban environment. Sufficient techniques and user-friendly tools for information extraction from remotely sensed imagery are urgently needed. This paper presents an automatic and manual approach for extracting footprints of buildings in urban areas from airborne Light Detection and Ranging (LIDAR) data. First a digital surface model (DSM) was generated from the LIDAR point data. Then, objects higher than the ground surface are extracted using the generated DSM. Based on general knowledge on the study area and field visits, buildings were separated from other objects. The automatic technique for extracting the building footprints was based on different window sizes and different values of image add backs, while the manual technique was based on image segmentation. A comparison was then made to see how precise the two techniques are in detecting and extracting building footprints. Finally, the results were compared with manually digitized building reference data to conduct an accuracy assessment and the result shows that LIDAR data provide a better shape characterization of each buildings.

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Photoluminescence Characteristics of InAs Quantum Dots Grown on AlAs Epitaxial Layer (AlAs 에피층 위에 성장된 InAs 양자점의 Photoluminescence 특성연구)

  • Kim, Ki-Hong;Sim, Jun-Hyoung;Bae, In-Ho
    • Korean Journal of Materials Research
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    • v.19 no.7
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    • pp.356-361
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    • 2009
  • The optical characterization of self-assembled InAs/AlAs Quantum Dots(QD) grown by MBE(Molecular Beam Epitaxy) was investigated by using Photoluminescence(PL) spectroscopy. The influence of thin AlAs barrier on QDs were carried out by utilizing a pumping beam that has lower energy than that of the AlAs barrier. This provides the evidence for the tunneling of carriers from the GaAs layer, which results in a strong QD intensity compared to the GaAs at the 16 K PL spectrum. The presence of two QDs signals were found to be associated with the ground-states transitions from QDs with a bimodal size distribution made by the excitation power-dependent PL. From the temperature-dependent PL, the rapid red shift of the peak emission that was related to the QD2 from the increasing temperature was attributed to the coherence between the QDs of bimodal size distribution. A red shift of the PL peak of QDs emission and the reduction of the FWHM(Full Width at Half Maximum) were observed when the annealing temperatures ranged from 500 $^{\circ}C$ to 750 $^{\circ}C$, which indicates that the interdiffusion between the dots and the capping layer was caused by an improvement in the uniformity size of the QDs.

Design and characterization of a compact array of MEMS accelerometers for geotechnical instrumentation

  • Bennett, V.;Abdoun, T.;Shantz, T.;Jang, D.;Thevanayagam, S.
    • Smart Structures and Systems
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    • v.5 no.6
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    • pp.663-679
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    • 2009
  • The use of Micro-Electro-Mechanical Systems (MEMS) accelerometers in geotechnical instrumentation is relatively new but on the rise. This paper describes a new MEMS-based system for in situ deformation and vibration monitoring. The system has been developed in an effort to combine recent advances in the miniaturization of sensors and electronics with an established wireless infrastructure for on-line geotechnical monitoring. The concept is based on triaxial MEMS accelerometer measurements of static acceleration (angles relative to gravity) and dynamic accelerations. The dynamic acceleration sensitivity range provides signals proportional to vibration during earthquakes or construction activities. This MEMS-based in-place inclinometer system utilizes the measurements to obtain three-dimensional (3D) ground acceleration and permanent deformation profiles up to a depth of one hundred meters. Each sensor array or group of arrays can be connected to a wireless earth station to enable real-time monitoring as well as remote sensor configuration. This paper provides a technical assessment of MEMS-based in-place inclinometer systems for geotechnical instrumentation applications by reviewing the sensor characteristics and providing small- and full-scale laboratory calibration tests. A description and validation of recorded field data from an instrumented unstable slope in California is also presented.

Spatial interpolation of geotechnical data: A case study for Multan City, Pakistan

  • Aziz, Mubashir;Khan, Tanveer A.;Ahmed, Tauqir
    • Geomechanics and Engineering
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    • v.13 no.3
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    • pp.475-488
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    • 2017
  • Geotechnical data contributes substantially to the cost of engineering projects due to increasing cost of site investigations. Existing information in the form of soil maps can save considerable time and expenses while deciding the scope and extent of site exploration for a proposed project site. This paper presents spatial interpolation of data obtained from soil investigation reports of different construction sites and development of soil maps for geotechnical characterization of Multan area using ArcGIS. The subsurface conditions of the study area have been examined in terms of soil type and standard penetration resistance. The Inverse Distance Weighting method in the Spatial Analyst extension of ArcMap10 has been employed to develop zonation maps at different depths of the study area. Each depth level has been interpolated as a surface to create zonation maps for soil type and standard penetration resistance. Correlations have been presented based on linear regression of standard penetration resistance values with depth for quick estimation of strength and stiffness of soil during preliminary planning and design stage of a proposed project in the study area. Such information helps engineers to use data derived from nearby sites or sites of similar subsoils subjected to similar geological process to build a preliminary ground model for a new site. Moreover, reliable information on geometry and engineering properties of underground layers would make projects safer and economical.