• KIEAE Journal
• /
• v.5 no.1
• /
• pp.43-49
• /
• 2005

People grow up and build up most of their character through living in dwelling space and have relax and refresh at home. Creating healthy dwelling space is being considered very important in architectural planning and design for providing comfortable living environment and improving quality of life. One of the properties of the earth is that the earth has a magnetic field associated with it- the Geomagnetic field. The geomagnetic field is produced by a combination of crustal rocks, external electric current systems that surround the earth that surround the earth and currents induced in the outer layers of the earth by magnetic field variations. Human beings have evolved with the background of magnetic field, they are accustomed to living in its presence. Geopathic stress occurs at geopathic zones where the geomagnetic field is disturbed. Geopathic zones exhibit magnetic charges. Geopathic zones are characterized by variations in geomagnetism, for the geomagnetic field is not uniform but exhibits many highly localized distortions, some random, some fairly regular. These occur in geological faults, caves and underground water channel. Many research papers and experiments of the western countries indicates that the geomagnetic field affects the people and living organism in dwellings. Therefore, it is necessary to investigate the geomagnetic field and people's response in living space. In this study the Health Hazard of geomagneic field in dwelling are studied through literature survey of related science field.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.39 no.10
• /
• pp.805-815
• /
• 2015

The present study numerically investigated two-dimensional dielectrophoretic motions of a pair of particles suspended freely in a viscous fluid, interacting with a nearby nonconducting planar wall, under an external uniform electric field. The results show that the motions depend strongly on the set of two electric conductivity signs and the particles-wall separation gap. When both particles have the same sign, they revolve and finally align parallel to the electric field. In contrast, with different signs, they revolve in the opposite direction and finally align perpendicular to the field. Simultaneously, they are repelled to move farther away from the wall regardless of their conductivity set. With further separation from the wall, the particles-wall interaction effect diminishes and tthe particle-particle effect dominates.

• Journal of Magnetics
• /
• v.2 no.1
• /
• pp.28-33
• /
• 1997

Very large in electrical resistivity by several orders of magnitude is obtained when an external magnetic field is applied to the colossal magnetoresistnace (CMR) materials such as La-Ca-Mn-O. The magnetoresistance is strongly temperature-dependent, and exhibits a sharp peak below room temperature, which can be shifted by adjusting the composition or processing parameters. The control of lattice geometry or strain, e.g., by chemical substitution, epitaxial growth or post-deposition anneal of thin films appears to be crucial in obtaining the CMR properties. The orders of magnitude change in electrical resistivity could be useful for various magnetic and electric device applications. .

• Proceedings of the Korean Fiber Society Conference
• /
• 2002.04a
• /
• pp.203-205
• /
• 2002

poly(ethylene oxide)(PEO)와 Poly(methyl methacrylate)(PMMA)는 상용성이 있는 고분자 블렌드계로서, 혼합되는 PMMA의 함량과 사용하는 용매 등에 의해서 PEO의 결정화 거동은 많은 영향을 받는다[l-3]. 비결정성 고분자인 PMMA의 함량이 증가할 수록 PEO의 결정 성장은 제약을 받게 되어 결정화 속도가 느려진다. 한편, PEO는 전기활성을 나타내는 고분자로서 외부전장을 가한 상태에서 용응 결정화시키면 전장의 영향을 받아 결정화가 늦어진다[4]. (중략)

• Proceedings of the Korean Fiber Society Conference
• /
• 2002.04a
• /
• pp.439-442
• /
• 2002

나일론 m형의 폴리아미드계 고분자의 경우 m의 수가 홀수일 때 N-H와 C=O 사이의 dipole 배열에 의하여 거대한 dipole moment가 나타나기 때문에 극성 결정구조를 나타내게 되며(1), 그 중에서도 특히 나일론 7과 11은 압전성을 나타낸다. 한편, 나일론 11[poly(undecanolactam)]은 $\alpha$, $\beta$, ν, $\delta$, $\delta$' 형과 같이 적어도 다섯 개의 결정형태를 갖는데[2-3], 이러한 여러 가지의 결정형태는 시료의 제조조건과 열처리 조건 등에 따라서 달라진다. (중략)

• Proceedings of the Korean Society of Potoscience Conference
• /
• spring
• /
• pp.99-100
• /
• 1999

• Proceedings of the Korean Fiber Society Conference
• /
• 2001.10a
• /
• pp.271-274
• /
• 2001

최근 압전성 및 유전성, 비선형 광학전도성 등과 같은 특성을 갖는 전기전자 및 광기능성 고분자에 대한 연구가 많이 이루어지고 있다[1-2]. 그 중에서 압전 및 초전성을 나타내는 대표적 유기 고분자인 poly(vinylidene fluoride)(PVDF)의 경우 압전성을 향상시키기 위하여 vinylidene. fluoride(VDF)나 vinyl fluoride(VF), trifluoroethylene(TrFE) 등과 공중합시킨 고분자들에 대한 연구가 활발히 진행되어 왔다[3-4]. (중략)

• Journal of the Korean Society of Safety
• /
• v.8 no.4
• /
• pp.101-106
• /
• 1993

The streaming current of insulating oil increases with increasing oil velocity and oil amount, A contact potential difference as an energetic state exits in the polymer thin film, both sides of which are contacted by two different metals having different work functions. Accordingly, the potential difference may be a cause for the short circuited transient current flowing through the external circuit. The polymers are electrificated as the electric field Is supplied, and the currents flow with increasing temperature.

• Proceedings of the KIEE Conference
• /
• 1997.07d
• /
• pp.1317-1319
• /
• 1997

This paper is to study and develope a measurement apparatus for ferroelectricity. The apparatus consists of wave generation part, high voltage amplifier part, measurement part, data acquisition part and the related controll circuits. Single or double excitation wave is digitalized and sent to the external RAM of wave generation part by personal computer. These datas saved in the RAM are converted to analog excitation wave through D/A converter. The frequency of excitation wave is depend on the read-out speed of the RAM by clock pulse. Such generated wave is applied to high voltage amplifier as a input voltage. The output of high voltage amplifier is applied to ferroelectrics and the response is obtained from the charge amplifier of measurement part. The response is sampled and converted to digital datas through AID converter. These digital datas are automatically saved in the external RAM of acquisition part. The computer takes the digital datas and calculates the electric displacement D, the electric field and the dielectric constant $\varepsilon$. We tested for PZT ceramic sample and could observed the D-E hysteresis lops and ${\varepsilon}_s$-E hysteresis loops with good forms.

• Structural Engineering and Mechanics
• /
• v.91 no.4
• /
• pp.417-426
• /
• 2024

Nanotechnology has emerged as a promising avenue for enhancing musical structures. In this study, we analyze the static behavior of laser harp (i.e., electronic musical instrument) reinforced with Zinc Oxide (ZnO) nanoparticles. Leveraging the piezoelectric properties of ZnO nanoparticles, the structure is subjected to an electric field for intelligent control. The electronic musical structure is situated in a foundation with vertical springs and shear modulus constants. We employ the exponential Shear Deformation Beam Theory (ESDBT) to mathematically model the structure. A micro-electro-mechanical model is employed to determine the equivalent properties of the system. By utilizing nonlinear stress-strain relations, energy methods, and Hamilton's principle, we derive the motion equations. The buckling load of the electronic musical beam is calculated using the Difference Quadrature Method (DQM). The primary objective of this study is to present a mathematical model for electronic musical beams and determining the buckling load of the structure and to investigate the influence of nanotechnology and electric fields on its buckling behavior. The buckling is the case when the structure becomes deforms and unstable. Our findings reveal that the application of negative external voltage to the electronic musical structure increases both the stiffness and the buckling load of the musical system. Furthermore, reinforcing the electronic musical structure with ZnO nanoparticles results in an increased buckling load. Notably, the maximum enhancement in the 28-day compressive and tensile strengths of samples containing zinc oxide nanoparticles compared to the control sample resulting in increases of 18.70% and 3.77%, respectively.