• Title/Summary/Keyword: and resonance

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Experimental Study on Sloshing Characteristics of a Ferrofluid in the Spherical Container (구형 용기 내 자성유체의 슬로싱 특성에 관한 실험적 연구)

  • Kim, Dae-Wan;Lee, Moo-Yeon;Seo, Lee-Soo
    • Journal of the Korean Magnetics Society
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    • v.23 no.5
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    • pp.173-177
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    • 2013
  • This work describes the experimental investigations on sloshing characteristics of water and ferrofluid as working fluids in the spherical container with the horizontal oscillation motion and compared the results obtained by two working fluids. In order to Investigate the sloshing characteristics of the sphere container with the horizontal oscillation, experiments are performed with the magnetic intensities from 0 mT to 50 mT and horizontal oscillation motions from 5 mm to 15 mm. As results, Ferrofluid without magnetic field in the sphere container showed a similar liquid surface movement with water. The resonance point of the ferrofluid in the sphere container happened at higher value than that of the theoretical resonance frequency with the rise of the magnetic field. In addition, the sloshing characteristics of the ferrofluid in the sphere container can be controlled with the resonance frequency with the magnetic intensity and the liquid surface displacement could be also controlled.

Synthesis and Evaluation of Oleanolic Acid-Conjugated Lactoferrin for β-Amyloid Plaque Imaging

  • Kim, Sung-Min;Kim, Dongkyu;Chae, Min Kyung;Jeong, Il-Ha;Cho, Jee-Hyun;Choi, Naeun;Lee, Kyo Chul;Lee, Chulhyun;Ryu, Eun Kyoung
    • Bulletin of the Korean Chemical Society
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    • v.33 no.11
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    • pp.3671-3675
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    • 2012
  • ${\beta}$-Amyloid accumulation in the brain is a pathological hallmark of Alzheimer's disease (AD). Since early detection of ${\beta}$-amyloid may facilitate more successful and timely therapeutic interventions, many investigators have focused on developing AD diagnostic reagents that can penetrate the blood-brain barrier (BBB). Oleanolic acid (OA) is a substance found in a variety of plants that has been reported to prevent the progression of AD in mice. In this study, we synthesized and evaluated a new radioligand in which OA was conjugated to lactoferrin (Lf, an iron-binding glycoprotein that crosses the BBB) for the diagnosis of AD. In an in vitro study in which OA-Lf was incubated with ${\beta}$-amyloid (1-42) aggregates for 24 h, we found that OA-Lf effectively inhibited ${\beta}$-amyloid aggregation and fibril formation. In vivo studies demonstrated that $^{123}I$-OA-Lf brain uptake was higher than$^{123}I$-Lf uptake. Therefore, radiolabeled OA-Lf may have diagnostic potential for ${\beta}$-amyloid imaging.

133Cs Nuclear Magnetic Resonance Relaxation Study of the Phase Transition of Cs2MnCl4·2H2O Single Crystals

  • Heo, Cheol;Lim, Ae-Ran
    • Journal of the Korean Magnetic Resonance Society
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    • v.14 no.2
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    • pp.76-87
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    • 2010
  • The structural phase transition of $Cs_2MnCl_4{\cdot}2H_2O$ single crystals was investigated by determining the $^{133}Cs$ spin-lattice relaxation time $T_1$. The number of resonance lines in the $^{133}Cs$ spectrum changes from seven to one near 375 K, which means that above 375 K the Cs sites are symmetric. Further, the $T_1$ of the $^{133}Cs$ nucleus undergoes a significant change near 375 K, which coincides with the change in the splitting of the $^{133}Cs$ resonance lines. The change in $T_1$ near $T_C$ is related to the loss of $H_2O$, and means that the forms of the octahedra of water molecules surrounding $Cs^+$ are disrupted.

A study on the reduction of noise and vibration by acoustic resonance in the tube bank of a circulating fluidized bed combustion boiler (순환 유동층 보일러 관군의 음향공진에 의한 이상소음 발생 및 저감 연구)

  • Park, Eung-Kyu;Song, Keun-Bok;Kim, Won-Hyun;Joo, Won-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.10a
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    • pp.101-106
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    • 2011
  • In the present paper, the phenomena of abnormal noise and vibration due to acoustic resonance of CFBC(Circulating Fluidized Bed Combustion) boiler was presented. The acoustic resonance which occurred in the gas path of CFBC boiler system was caused by coincidence of vortex shedding frequency of tube bank and acoustic natural frequency of duct and hopper. And, the phenomena of beating arose from the interference of two closed resonant waves at 66.4Hz and 70.8Hz. There are two control methods for acoustic resonance in this system. The first method is to change the vortex shedding frequency from the structural alterations on the tube bank. And the second method is to change the acoustic natural frequency of the gas path with the installation of anti-noise baffles. The second one which is relatively easy to apply, was adapted in this study. As a result, the noise and vibration level have been decreased by 41dB and 94% at 66.4Hz, respectively. And the improvement of noise and vibration at 70.8Hz was identified by sensory evaluation.

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Celebrity Endorser and Purchase Intention: The Mediating Role of Resonance-Based Self-Attitude and Brand Credibility

  • GUNAWAN, Stephanie Angelina;HERMAWAN, Asep;WIDJAJA, Anton Wachidin;BERNARTO, Innocentius
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.7
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    • pp.603-611
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    • 2021
  • This study aims to analyze the mediating influences of resonance-based self-attitude and brand credibility in a relationship between celebrity endorser credibility and celebrity endorser congruity toward brand purchase intention in the current dynamic business environment. It employs a quantitative research method and reports on a survey, using a questionnaire, including the population of consumers of various instant coffee brands in several cities in Indonesia. The number of respondents in this study was 432 people. The analysis was performed using Partial Least Square Structural Equation Modeling and SmartPLS software. The analysis consisted of descriptive statistics, evaluation of the measurement model, evaluation of the structural model, and hypothesis testing. The results partially support the model developed. The findings suggest that the instant coffee product advertising in Indonesia needs to create brand messages focusing on the formation of resonance-based self-attitude from consumers to increase the influence of celebrity endorser credibility and celebrity endorser congruity, as well as the brand credibility towards the brand purchase intention. This study contributes to the marketing literature and the theory of planned behavior by providing empirical evidence on the relationship between celebrity endorser credibility, celebrity endorser congruity, resonance-based self-attitude, brand credibility, and brand purchase intention.

Vibration Characteristics of Packaged Freight and Packaged Apples by Random Vibration Input (랜덤 진동에 의한 포장화물 및 포장된 사과의 진동특성)

  • Kim, Ghi-Seok;Jung, Hyun-Mo;Kim, Ki-Bok;Kim, Man-Soo
    • Journal of Biosystems Engineering
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    • v.33 no.1
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    • pp.45-50
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    • 2008
  • Shock and vibration inputs are transmitted from the transporting vehicle through the packaging box to the fruit. The vibration causes sustained bouncing of fruits against each other and the container wall. The steady state vibration input may cause serous fruit injury, and the damage is particularly severe if the fruits are bounced at its resonance frequency. The determination of the resonance frequencies of the fruits and vegetables may help the packaging designer to design the proper packaging system providing adequate protection of the fruits from external impact or shock. In this study, to analyze the vibration properties of the apples for optimum packaging design during transportation, the random vibration tests were carried out. From the results of random vibration test, the resonance frequency and power spectral density (PSD) of the packaged freight of apples in the test were in the range of 82 to 97 Hz and 0.0013 to 0.0021 $G^2/Hz$ respectively and the resonance frequency and PSD of the packaged apples were in the range of 13 to 71 Hz and 0.0143 to 0.0923 $G^2/Hz$ respectively.

Broadband Piezoelectric Energy Harvesting Technology (광대역 압전 에너지 하베스팅 기술)

  • Lee, Dong-Gyu;Yee, Yeon-Jeong;Song, Hyun-Cheol
    • Ceramist
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    • v.22 no.1
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    • pp.56-69
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    • 2019
  • Recent advances in low-power sensors and transmitters are driving the search for standalone power sources that utilize unused ambient energy. These energy harvesters can alleviate the issues related to the installation and maintenance of sensors. Particularly piezoelectric energy harvesters, with the ability to convert ambient mechanical energy into useful electricity, have received significant attention due to their high energy density, low cost and operational stability over wide temperature and pressure conditions. In order to maximize the generated electrical power, the natural frequency of the piezoelectric energy harvester should be matched with the dominant frequency of ambient vibrations. However, piezoelectric energy harvesters typically exhibit a narrow bandwidth, thus, it becomes difficult to operate near resonance under broadband ambient vibration conditions. Therefore, the resonating of energy harvesters is critical to generate maximum output power under ambient vibration conditions. For this, energy harvesters should have broadband natural frequency or actively tunable natural frequency with ambient vibrations. Here, we review the most plausible broadband energy harvesting techniques of the multi-resonance, nonlinearity, and self-resonance tuning. The operation mechanisms and recent representative studies of each technique are introduced and the advantages and disadvantages of each method are discussed. In addition, we look into the future research direction for the broadband energy harvester.

Acquisition and Interpretation Guidelines of Breast Diffusion-Weighted MRI (DW-MRI): Breast Imaging Study Group of Korean Society of Magnetic Resonance in Medicine Recommendations

  • Kang, Bong Joo;Kim, Min Jung;Shin, Hee Jung;Moon, Woo Kyung
    • Investigative Magnetic Resonance Imaging
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    • v.26 no.2
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    • pp.83-95
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    • 2022
  • The purpose of this study was to establish and provide guidelines for the standardized acquisition and interpretation of diffusion-weighted magnetic resonance imaging (DW-MRI) to improve the image quality and reduce the variability of the results interpretation. The standardized protocol includes the use of high-resolution DW-MRI with advanced techniques and post-processing. The aim of the protocol is to increase the effectiveness of the medical image information exchange involved in the construction, activation, and exchange of clinical information for healthcare use. An organized interpretation form could make DW-MRIs' interpretation easier and more familiar. Herein, the authors briefly review the basic principles, optimized image acquisition, standardized interpretation guidelines, false negative and false positive cases of DW-MRI, and provide a standard interpretation form and examples of various cases to help users become more familiar with the DW-MRI.

Backbone NMR assignments of the anti-CRISPR AcrIIA5 from phages infecting Streptococcus thermophilus

  • An, So Young;Kim, Eun-Hee;Bae, Euiyoung;Suh, Jeong-Yong
    • Journal of the Korean Magnetic Resonance Society
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    • v.24 no.3
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    • pp.70-76
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    • 2020
  • The CRISPR-Cas system provides an adaptive immunity for bacteria and archaea against invading phages or foreign plasmids. In the type II CRISPR-Cas system, a single effector protein Cas9 and a guide RNA form an RNA-guided endonuclease complex that can degrade DNA targets of foreign origin. To avoid the Cas9-mediated destruction, phages evolved anti-CRISPR (Acr) proteins that neutralize the host bacterial immunity by inactivating the CRISPR-Cas system. Here we report the backbone 1H, 15N, and 13C resonance assignments of AcrIIA5 that inhibits the endonuclease activity of type II-A Streptococcus thermophilus Cas9 and also Streptococcus pyogenesis Cas9 using triple resonance nuclear magnetic resonance spectroscopy. The backbone chemical shifts of AcrIIA5 predict a disordered region at the N-terminus, followed by an αββββαβββ fold.

Experience with the Application of Magnetic Resonance Diagnostic $Analyser^{(R)}$ -A case of idiopathic hyperhidrosis- (자기 공명분석기에 의한 특발성 다한증의 치험)

  • Kim, Jin-Soo;Kim, Jin-Ho;Kim, Il-Ho;Park, Wook;Kim, Sung-Yell
    • The Korean Journal of Pain
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    • v.6 no.2
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    • pp.280-283
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    • 1993
  • Idiopathic hyperhidrosis is a physically and emotionally distressing symptom, which lacks a precise definition. Although operative and nonoperative methods have been shown to be effective in the treatment of idiopathic hyperhidrosis, limitations, cautions and complications are inherent in their extended use. The purpose of this report is to describe the theraputetic effects of magnetic resonance for managing idiopathic hyperhidrosis. A 28 years old woman had been suffering from profuse sweating on both planter and palmar sides for 15 years. We successfully treated this symptom with the 6 magnetic resonance treatments without any complications. Now she lives well in a condition of normal sweating after the applications. It suggest that short daily periods of exposure to appropriate magnetic resonance can beneficially modulate the balance of autonomic nervous system that are responsible for sympathetic overflow, and that there is an effective window of induced electrical magnetism in which sympathetic function can be controlled in the absence of side effects.

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