• Title/Summary/Keyword: wave exposure

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Variation in morphological traits over a wave-exposure gradient in one but not in another species of the brown alga Carpophyllum (Fucales)

  • Hodge, Fiona;Buchanan, Joseph;Zuccarello, Giuseppe C.
    • ALGAE
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    • v.26 no.3
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    • pp.243-251
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    • 2011
  • Environmental conditions can influence the morphology of local biota through phenotypic plasticity or local adaptation. Macroalgal morphologies are often associated with wave-exposure conditions. We investigated the relationship between morphology and wave exposure in two common endemic subtidal macroalgae, Carpophyllum angustifolium and C. maschalocarpum, from the East Cape of New Zealand. Morphological comparisons were made between individuals from two sites and four different wave-exposure zones, as defined by fetch and barnacle composition. Of the seven morphological traits measured in C. angustifolium, only total length varied, and individuals were longer in more wave-exposed environments between the two exposure zones where the species were found. In contrast, total length, stipe thickness and vesicle presence all varied significantly between exposure zones in C. maschalocarpum. C. maschalocarpum specimens were shorter with thinner stipes, and fewer individuals had vesicles in the more wave-exposed zones. Morphological traits of both species also varied between sites, suggesting that other influences are important for determining species morphology. Further study is needed to investigate the role of phenotypic plasticity and genetic variability for driving morphological variation in C. angustifolium and C. maschalocarpum.

Exposure Does of X-ray Generator on Full Wave Rectification Method (전파정류 방식의 X선 발생장치에서 조사선량)

  • Kim, Tae-Gon;Kim, Young-Pyo;Cheon, Min-Woo;Lee, Ho-Shik;Park, Yong-Pil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.138-138
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    • 2010
  • X-ray systems for medical treatment use noninvasive procedures. I fabricated a high tension generator of a full-wave rectification type using a LC resonant inviter. It is said that a full-wave rectifying X-ray equipment such as the fabricated system can shorten initiating period and be precision control because of stable output, compared with the X-ray equipment of a half wave rectifying type used in the usual clinical medicine. In order to evaluate the capability of the fabricated high tension generator, I performed exposure dose characteristics experiments.

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Effect of electromagnetic field exposure on the reproductive system

  • Gye, Myung-Chan;Park, Chan-Jin
    • Clinical and Experimental Reproductive Medicine
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    • v.39 no.1
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    • pp.1-9
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    • 2012
  • The safety of human exposure to an ever-increasing number and diversity of electromagnetic field (EMF) sources both at work and at home has become a public health issue. To date, many in vivo and in vitro studies have revealed that EMF exposure can alter cellular homeostasis, endocrine function, reproductive function, and fetal development in animal systems. Reproductive parameters reported to be altered by EMF exposure include male germ cell death, the estrous cycle, reproductive endocrine hormones, reproductive organ weights, sperm motility, early embryonic development, and pregnancy success. At the cellular level, an increase in free radicals and $[Ca^{2+}]i$ may mediate the effect of EMFs and lead to cell growth inhibition, protein misfolding, and DNA breaks. The effect of EMF exposure on reproductive function differs according to frequency and wave, strength (energy), and duration of exposure. In the present review, the effects of EMFs on reproductive function are summarized according to the types of EMF, wave type, strength, and duration of exposure at cellular and organism levels.

Double Exposure Laser Interference Lithography for Pattern Diversity using Ultraviolet Continuous-Wave Laser

  • Ma, Yong-Won;Park, Jun Han;Yun, Dan Hee;Gwak, Cheongyeol;Shin, Bo Sung
    • Journal of the Microelectronics and Packaging Society
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    • v.26 no.2
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    • pp.9-14
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    • 2019
  • The newly discovered properties of periodic nanoscale patterns have increasingly sparked research interests in various fields. Along this direction, it is worth mentioning that there had been rare studies conducted on interference exposure, a method of creating periodic patterns. Additionally, these few studies seemed to validate the existence of only exact quadrangle shapes and dot patterns. This study asserted the formation of wavy patterns associated to using multiple exposures of the ratio of the first exposure intensity to the second exposure intensity. Such patterns were designed and constructed herein via overlapping of two Gaussian beams relative to certain rotation angles, and with a submicron structure fabricated based on a 360-nm continuous-wave laser. Results confirmed that the proposed double exposure laser interference lithography is able to create circular, elliptical and wavy patterns with no need for complex optical components.

Extracorporeal Shock Wave Therapy: Its Acoustical Aspects

  • Choi, Min-Joo;Cho, Sung-Chan;Paeng, Dong-Guk;Lee, Kang-Il
    • The Journal of the Acoustical Society of Korea
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    • v.29 no.3E
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    • pp.119-130
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    • 2010
  • Extracorporeal shock wave therapy (ESWT) is simply evolved from extracorporeal shock wave lithotripsy known as a revolutionary non-invasive technique for treating kidney stone diseases. Since ESWT was approved for treating plantar fasciitis by FDA in 2000, it has been rapidly accepted into various clinical practices. Its indication includes chronic tendinitis and pseudoarthrosis, and has been widened to various applications other than orthopeadics. Little has been reported on their acoustic properties, yet, even if a number of clinical ESWT systems are readily available. This article reviews the acoustical aspects of ESWT and discusses critical issues towards acoustic exposure optimization and shock wave dosimetry.

A Study on the Characteristics of Elastic Wave Propagation in Plates Using Double Pulsed Laser Holographic Interferometry (이중펄스레이저 홀로그래픽 간섭법을 이용한 평판의 탄성파 전파특성에 관한 연구)

  • Lee, Ki-Baik;Na, Jong-Moon;Kim, Jeong-Hun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.10
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    • pp.3211-3223
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    • 1996
  • In this paper, the propagation of elastic wave generated by loading impact to plates made of isotropic of anisotropic material was studied. And the influence of boundary conditions (free or clamped edge) upon the reflection of elastic wave was anlyzed. Also, double exposure holographic interferometer using ruby pulse laser was formed in order to investigate transient waves. Before the elasitc wave was reflected from the edges, the elastic wave of isotropic plate such as aluminum plate showed circular interferometric fringe pattern, whereas that of anisotropic plate such as epoxy composite laminates showed elliptical one. And the transverse displacement curves obtained from experiment and theory for both plates agreed well. Also, the waves reflected from the boundary edges showed much differences according to the boundary condition of edges.

Input Power Determination of TEM Cell Due to SAR for Mobile Phone Wave Blood Exposure (휴대폰 전자파의 혈액 조사를 위한 SAR별 TEM 셀의 입력 전력 산출)

  • Youn Ji-Hun;Son Tae-Ho
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.8 s.99
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    • pp.810-814
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    • 2005
  • Input power for TEM cell apparatus due to SAR(Specific Absorption Rate) for culture blood cell is determined by the transmission and reflection measurement of blood into the TEM cell. Blood cell with skin cell are reference culture cells for the study of EM wave effect. Exposure RF power from exposure apparatus to culture cell should not only exact for SAR value, but also should be based on the theoretical theory. In this paper, insertion loss of 50 g blood was measured to know exposure power per gram for culture blood cell, and input power of TEM cell due to SAR 0.8, 1.6, 3, 4 mW/g using the measured data are delivered. This study is for applying to EM wave exposure apparatus to culture cell.

A Study on the Comparision of Performance between Three-phase Full-wave and Single-phase Full-wave X-ray Generators (삼상(三相)12펄스 전파정류장치(全波整流裝置)와 단상(單相) 전파정류장치(全波整流裝置)의 성능(性能) 비교(比較))

  • Kim, Young-Ill;Kim, Chang-Kyun;Huh, Joon
    • Journal of radiological science and technology
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    • v.3 no.1
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    • pp.81-86
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    • 1980
  • To compare three-phase 12-pulse full-wave X-ray generators with single-phase full-wave X-ray generators on their performance of outputs, authors studied the generating X-ray by means of exposure dose and radiographic density. The results were as follows; 1. The exposure doses of three-phase full-wave X-ray generators showed a 30%-60% increase as compared against of single-phase full-wave generators. 2. The transmitted doses of three-phase full-wave generators were more increased than single-phase full-wave X-ray generators. 3. To obtain the same density, 60kVp in three-phase full-wave generators were equivalent to $60{\sim}65kVp$ in single-phase full-wave generators, and 100kVp in those generators were equivalent to $100{\sim}125kVp$ in these generators.

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Implementation of an in vitro exposure system for 28 GHz

  • Lee, Young Seung;Dzagbletey, Philip Ayiku;Chung, Jae-Young;Jeon, Sang Bong;Lee, Ae-Kyoung;Kim, Nam;Song, Seong Jong;Choi, Hyung-Do
    • ETRI Journal
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    • v.42 no.6
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    • pp.837-845
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    • 2020
  • The objective of this study was to implement an in vitro exposure system for 28 GHz to investigate the biological effects of fifth-generation (5G) communication. A signal source of 28 GHz for 5G millimeter-wave (MMW) deployment was developed, followed by a variable attenuator for antenna input power control. A power amplifier was also customized to ensure a maximum output power of 10 W for high-power 28-GHz exposure. A 3-dB uniformity over the 80 mm × 80 mm area that corresponds to four Petri dishes of three-dimensional cell cultures can be obtained using a customized choke-ring-type antenna. An infrared camera is employed for temperature regulation during exposure by adjusting the airflow cooling rate via real-time feedback to the incubator. The reported measurement results confirm that the input power control, uniformity, and temperature regulation for 28-GHz exposure were successfully accomplished, indicating the possibility of a wide application of the implemented in vitro exposure system in the fields of various MMW dose-response studies.

Measurement of electro-physiological changes in the brain exposed to eletromagnetic wave radiation (전자파에 노출된 생체두부의 전기생리적 변화의 측정에 관한 연구)

  • 이준하;신현진;이상학;유동수;이무영;김성규
    • Progress in Medical Physics
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    • v.5 no.2
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    • pp.35-43
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    • 1994
  • Electromagnetic wave may induce effect and damage on the bio-body, either by electric fields of magnetic fields. We measure electrophysiological changs in rabbit's brain exposed to 2.45GHz micro wave(power density 40mW/cm$^2$) which distance 30cm from the source. In order to process the bio-electrical signal (EEG), used pre-amplifier module with self-made and Digtal analyzer computer system. Spectal analysis of the EEG showed variable power in the frequency range(1~30Hz) through each exposure time(10min, 20min, 30min) before and after. In effectively measured by the bio-electrical signal processing and can found threshold of minmal permissible exposure and lethal exposure.

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