Geological Survey by Electrical Resistivity Prospecting in Landslide Area

Park, Sam-Gyu,Kim, Jung-Ho 한국암반공학회 2005 Geosystem engineering Vol.8 No.2

This paper examines the applicability of electrical resistivity prospecting to landslide investigations based on the effect of the physical properties of rock on resistivity. Resistivity data measured in the laboratory shows that the resistivity of rock depends mostly on its porosity, water saturation, pore fluid resistivity, and intrinsic matrix resistivity with weathering and alteration. In the case of water-saturated rock, resistivity is mainly affected by porosity, pore fluid resistivity, and intrinsic matrix resistivity, but the resistivity of unsaturated rock is mostly affected by the degree of water saturation. Based on these results, the distribution of slip surfaces, geological structure, and regions of landslide was estimated by combining existing borehole logs and underground observation data with resistivity distribution in a Tertiary landslide area. Therefore, it was confirmed that the application of electrical resistivity prospecting to landslide investigations is an effective research method.

콘크리트내 염소이온량이 전기저항에 미치는 영향

윤인석,남진원 한국구조물진단유지관리공학회 2014 한국구조물진단유지관리공학회 논문집 Vol.18 No.6

The electrical resistivity of concrete can be related to two processes involved in corrosion of reinforcement: initiation (chloridepenetration) and propagation (corrosion rate). The resisistivity of concrete structure exposed to chloride indicates the risk of earlycorrosion damage, because a low resistivity is related to rapid chloride penetration and to high corrosion rate. Concrete resistivityis a geometry-independent material property that describes the electrical resistance, which is the ratio between applied voltage andresulting current in a unit cell. In previous study, it was realized that the resistivity of concrete depended on the moisture contentin the concrete, microstructural properties, and environmental attack such as carbonation. The current is carried by ions dissolvedin the pore liquid. While some data exist on the relationship between moisture content on electrical resistivity of concrete, verylittle research has been conducted to evaluate the effect of chloride on the conduction of electricity through concrete. The purpose of this study is to examine and quantify the effect of chloride content on surface electrical resistivity measurementof concrete. It was obvious that chloride content had influenced the resistivity of concrete and the relationship showed a linearfunction. That is, concrete with chloride ions had a comparatively lower resistivity. Decreasing rate of resistivity of concrete wasclear at early time, however, after 50 days resistivity was constant irrespective of chloride concentration. Conclusively, this papersuggested the quantitive solution to depict the electrical resistivity of concrete with chloride content. 콘크리트의 전기저항은 철근부식 개시 이전인 잠복기와 철근부식되는 진전기 두과정과 유관된다. 염소이온에 노출된 콘크리트 구조물의전기저항은 초기 부식율의 위험도를 표현할 수 있는데, 낮은 전기저항은 빠른 염소이온 침투와 높은 부식속도를 의미하기 때문이다. 콘크리트의 전기저항은 인가된 전압과 전류간의 비율인 전기저항으로 표현된다. 이전의 연구에 의하면 콘크리트의 전기저항은 콘크리트내 수분량, 미세구조 및 탄산화 등에 크게 의존하였다. 습윤량과 전기저항의 관계를 다룬 연구가 적지만 존재하는 반면, 염소이온이 전기저항에 미치는연구를 행한 연구는 매우 드물다. 본 연구의 목적은 염소이온이 콘크리트의 전기저항에 미치는 영향을 고찰하는 것이다. 실험결과에 의하면 염소이온량은 전기저항을 떨어뜨리는 것으로 나타났으며 이는 선형의 관계가 성립되었다. 초기 양생 50일 이전까지 전기저항의 감소추세는 뚜렷하였으며, 이후로는 염소이온량과 상관없이 일정하였다. 결과적으로 본 연구는 염소이온량을 함유한 콘크리트의 전기저항을 표현하는데 결정적인 방법을 제안하였다.

Method for contact resistivity measurements on highly phosphorus-doped silicon using a multiline transmission line model

Shin Hyunsu,Park Seran,Park Heungsoo,Ko Dae-Hong 한국물리학회 2021 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.78 No.4

As the size of a transistor decreases, the parasitic resistances of the transistor become dominant for contact resistance. In-situ phosphorus-doped epitaxial silicon with high doping concentrations has been used to reduce contact resistivity. In this study, we measured the contact resistivity of in-situ phosphorus-doped silicon using a circular transmission line model (CTLM). The distribution of the contact resistivity for films with high phosphorus concentrations was found to be about 400 times larger than that for films with low phosphorus concentrations. To explain the large distribution of the measured contact resistivity, the potential distribution and current flow in phosphorus-doped silicon films with various phosphorus concentrations were simulated using the CTLM and a transmission line model (TLM). In silicon films with high phosphorus doping concentrations, the greater effects of metal resistance and the vertical current reduced the accuracy of the extracted contact resistivity. A multiline transmission line model (ML–TLM) was proposed to improve the accuracy of the extracted contact resistivity at a given phosphorous concentration. The use of the ML–TLM increased the ratio of the contact resistance to the total resistance; thus, the effect of metal resistance was significantly reduced, and the accuracy of contact resistivity was improved.

콘크리트내 염소이온량이 전기저항에 미치는 영향

윤인석,남진원 한국구조물진단유지관리공학회 2014 한국구조물진단유지관리공학회 논문집 Vol.18 No.6

콘크리트의 전기저항은 철근부식 개시 이전인 잠복기와 철근부식되는 진전기 두과정과 유관된다. 염소이온에 노출된 콘크리트 구조물의전기저항은 초기 부식율의 위험도를 표현할 수 있는데, 낮은 전기저항은 빠른 염소이온 침투와 높은 부식속도를 의미하기 때문이다. 콘크리트의 전기저항은 인가된 전압과 전류간의 비율인 전기저항으로 표현된다. 이전의 연구에 의하면 콘크리트의 전기저항은 콘크리트내 수분량, 미세구조 및 탄산화 등에 크게 의존하였다. 습윤량과 전기저항의 관계를 다룬 연구가 적지만 존재하는 반면, 염소이온이 전기저항에 미치는연구를 행한 연구는 매우 드물다. 본 연구의 목적은 염소이온이 콘크리트의 전기저항에 미치는 영향을 고찰하는 것이다. 실험결과에 의하면 염소이온량은 전기저항을 떨어뜨리는 것으로 나타났으며 이는 선형의 관계가 성립되었다. 초기 양생 50일 이전까지 전기저항의 감소추세는 뚜렷하였으며, 이후로는 염소이온량과 상관없이 일정하였다. 결과적으로 본 연구는 염소이온량을 함유한 콘크리트의 전기저항을 표현하는데 결정적인 방법을 제안하였다. The electrical resistivity of concrete can be related to two processes involved in corrosion of reinforcement: initiation (chloridepenetration) and propagation (corrosion rate). The resisistivity of concrete structure exposed to chloride indicates the risk of earlycorrosion damage, because a low resistivity is related to rapid chloride penetration and to high corrosion rate. Concrete resistivity is a geometry-independent material property that describes the electrical resistance, which is the ratio between applied voltage andresulting current in a unit cell. In previous study, it was realized that the resistivity of concrete depended on the moisture contentin the concrete, microstructural properties, and environmental attack such as carbonation. The current is carried by ions dissolvedin the pore liquid. While some data exist on the relationship between moisture content on electrical resistivity of concrete, verylittle research has been conducted to evaluate the effect of chloride on the conduction of electricity through concrete. The purpose of this study is to examine and quantify the effect of chloride content on surface electrical resistivity measurement of concrete. It was obvious that chloride content had influenced the resistivity of concrete and the relationship showed a linear function. That is, concrete with chloride ions had a comparatively lower resistivity. Decreasing rate of resistivity of concrete wasclear at early time, however, after 50 days resistivity was constant irrespective of chloride concentration. Conclusively, this papersuggested the quantitive solution to depict the electrical resistivity of concrete with chloride content.

Study of the electric and magnetic characteristics in Mn+ implanted p-GaN films

Y. Shi,P. Song,C. Z. Jiang,X. J. Fan 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.-

The magnetic doping of wurtzite p-GaN films, which are grown on sapphire substrates by MOCVD, is achieved by 90-keV Mn+ ion implantation at room temperature. The implantation doses are set between 1× 10 15 cm-2 and 5×10 16 cm-2 After an annealing step at 800 ℃ for 0 - 90 s in flowing N₂, the magnetic and electric characteristics of the Mn+ implanted p-GaN films are studied. With relatively low implantation doses (leq 1× 10 16 cm-2), the dose-dependent ferromagnetism is proportional to resistivity, i.e., the sample with strong ferromagnetism has high resistivity, while the sample with weak ferromagnetism shows low resistivity. However, such regularity does not hold for p-GaN films with 5×10 16 cm-2 Mn+ implantation. By the study of annealing conditions, it is found that the sample annealed for 45 s has both strong ferromagnetism and low resistivity, while the sample annealed for 90 s has decreased ferromagnetism and increased resistivity. The magnetic doping of wurtzite p-GaN films, which are grown on sapphire substrates by MOCVD, is achieved by 90-keV Mn+ ion implantation at room temperature. The implantation doses are set between 1× 10 15 cm-2 and 5×10 16 cm-2 After an annealing step at 800 ℃ for 0 - 90 s in flowing N₂, the magnetic and electric characteristics of the Mn+ implanted p-GaN films are studied. With relatively low implantation doses (leq 1× 10 16 cm-2), the dose-dependent ferromagnetism is proportional to resistivity, i.e., the sample with strong ferromagnetism has high resistivity, while the sample with weak ferromagnetism shows low resistivity. However, such regularity does not hold for p-GaN films with 5×10 16 cm-2 Mn+ implantation. By the study of annealing conditions, it is found that the sample annealed for 45 s has both strong ferromagnetism and low resistivity, while the sample annealed for 90 s has decreased ferromagnetism and increased resistivity.

지반 오염도 조사를 위한 전기비저항/정전용량 측정콘의 적용성 평가

오명학,김용성,박준범 한국지반공학회 2006 한국지반공학회논문집 Vol.22 No.7

Resistivity cone penetrometer test (RCPT) can be employed at a relatively low cost for in-situ delineation of subsurface contamination. While the resistivity measurement has a potential to investigate the subsurface contamination, resistivity measurements alone will lead to some degree of ambiguity in the results. In this study, capacitance measurement was incorporated into the RCPT to overcome the ambiguity inherent in electrical resistivity measurements. This study is focused on verifying the applicability of resistivity and capacitance measurements of CPT module to provide information on subsurface contaminated by heavy metal and petroleum hydrocarbon. Laboratory model tests were performed to evaluate the sensitivity of the measured resistivity and relative capacitance on the water content and different types of contaminants. Test results show that simultaneous measurement of electrical resistivity and capacitance can give more reliable information on subsurface contamination. Electrical measurements of the CPT module showed high applicability to be used in detecting saturated soils contaminated by heavy metal and diesel plume floating above the groundwater table.

현장측정에 의한 대지 저항률 변화에 대한 접지전극의 저항계산의 보정계수 계산

조영철 ( Young-chul Cho ),윤경석 ( Gyeong-seok Yoon ),박정민 ( Jeong-min Park ) 조선대학교 공학기술연구원 2017 공학기술논문지 Vol.10 No.2

The formula for calculating the ground resistance for the ground electrode is already well known as the formula for calculating the soil resistivity and the type of ground electrode. However, it is a reality that the equation of resistance of the ground electrode is insufficient from the viewpoint of calculating the accurate ground resistance value according to the deformation of the ground electrode or the variation of the soil resistivity. Although some grounding resistance equations are provided for some ground electrode materials, it is suggested to apply a constant value irrespective of changes in soil resistivity, although other correction factors should be applied according to changes in soil resistivity, which is an important variable of grounding resistance. However, there are difficulties in practical application in the field. Therefore, in this paper, to solve these problems, we installed a ground electrode directly in the field test, and proposed a correction factor for the calculation of ground resistance according to the variation of soil resistivity through measurement. The proposed equation of ground resistance is a formula of ground resistance applying the correction factor which is a variable of soil resistivity.

On the Potential of Tungsten as Next-generation Semiconductor Interconnects

최두호,Katayun Barmak 대한금속·재료학회 2017 ELECTRONIC MATERIALS LETTERS Vol.13 No.5

The continuous scaling of copper (Cu) interconnects produced two majorshortcomings – a severe resistivity size effect and material reliability issues. Tungsten (W), with the expected reduction in resistivity size effect due to itsshorter electron mean free path and improved reliability due to its highactivation energy for diffusion, is a worthwhile candidate to replace Cu. Inthis article, the potential of W for future interconnects is critically discussedby reviewing the current status of W technology, including various Wprocessing methods and the resulting phases, resistivity and microstructure. The compatibility of W with the back-end-of-line processes in CMOSdevices is also discussed. The resistivity of W and Cu wires at similar nanoscaleis compared based on the Fuchs-Sondheimer surface scattering modeland Mayadas-Shatzkes grain boundary scattering model using the reportedscattering parameters (p = 0.11 and R = 0.42 for W, and p = 0.52 andR = 0.43 for Cu), which shows that the resistivity of W wires is predicted toexhibit lower resistivity than that of Cu wires at line-widths below ~15 nm. Finally, anisotropy in the resistivity size effect in W wires is discussed, witha suggested method to reduce wire resistivity.

A Fast Calculation of Apparent Soil Resistivity Using Exponential Sampling Method

Min-Jae Kang,Ho-Chan Kim 국제문화기술진흥원 2019 International Journal of Advanced Culture Technolo Vol.7 No.4

The apparent soil resistivity is used for estimating multilayer soil parameters, such as, layer’s depth and soil resistivity. The soil parameters are estimated by continuously revising those parameters until the error between the measured and calculated apparent soil resistivity reaches to allowable level. The equation for calculating the apparent soil resistivity is complicated and time consumed, because it is composed of an infinite integral which includes a zero order Bessel’s function of the first kind. In this paper, a fast algorithm for calculating the apparent soil resistivity of horizontal multilayer earth structure is proposed using exponential sampling method.

Use of Two Dimensional Electrical Resistivity Tomography to Identify Soil Water Dynamics and the Effective Plant Root Zone

Yoon, Sung-Won,Zhang, Yong-Seon,Han, Kyung-Hwa,Jo, Hee-Rae,Ha, Sang-Keun,Park, Sam-Kyeu,Sonn, Yeon-Kyu Korean Society of Soil Science and Fertilizer 2012 한국토양비료학회지 Vol.45 No.3

The identification of effective root zone would clarify dynamics of plant available water and soil water balance. Using the relationship between soil properties and electrical resistivity (ER) the purpose of this research is to identify soil zone affected by a plant root activity using electrical resistivity tomography (ERT) technique. Four plastic containers were prepared for two different soil textures (clay and sandy loam) and one container for each texture was selected for planting four corn seedlings (Zea mays L.) and the others were prepared for the blank. For ERT monitoring, we prepared 0.8 m plastic sticks with 17 electrodes installed with 5 cm space. The Ministing (AGI Inc., Texas) instrument for electrical resistivity measurement and semi-auto converter of electrode arrangement were set up for dipole-dipole array. During 2 months of the corns growing, ERT monitoring was made 3 to 4 days after the irrigation practice. Despite of the same amount water supplied into soils, two textures showed very different apparent resistivity values due to different clay content. The apparent electrical resistivity is consistently lower in clay loam comparing to sandy loam soil implying that plant root does not significantly alter the overall trend of resistivity. When plant root system, however, is active both soils with plants showed 2-7 times higher electrical resistivity and higher coefficient variation than soils without plant, implying the effect of root system on the resistivity, in which may caused by. This result suggests plant root activities regulating the soil water dynamics mainly control the variation of electrical resistivity over soil textural difference. Therefore the identification of water uptake zone would highly be correlated to plant root activities, thus ERT will be feasible approach to identify spatial characteristics of a plant root activity.