• Journal of the Korean Magnetic Resonance Society
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• v.5 no.2
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• pp.73-90
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• 2001

Vanadium-doped H-SAPO-34 samples were prepared by a high-temperature solid-state reaction between SAPO-34 and the paramagnetic V(Ⅳ) species and characterized carefully by EPR and Electron Spin-Echo Modulation(ESEM) studies. The paramagnetic vanadium species generated in both V$_2$O$\_$5/ and VOSO$\_$4/ of SAPO-34 have the same narrow range of g value fur vanadium species assigned to VO$\^$2+/ inferred from the isotropic EPR spectrum at 293 K. The EPR and ESEM data indicate that the V(Ⅳ) species exist as a vanadyl ion either as [V(Ⅳ)]O$\^$2+/ or V$\^$4+/. The [V(Ⅳ)]O$\^$2+/ species seems to be more probable because SAPO-34 having a low negative framework charged and more positively charged species like V$\^$4+/can not be easily stabilized. Tetravalent vanadium ion in vadium-doped H- SAPO-34 can only be observed at the temperature lower than 77 K, while the vanadyl ion, VO$\^$2+/in the activated sample of VH-SAPO-34 can produce the ion even at room temperature. After the adsorption of methanol, ethanol, propanol or ethene to the VH-SAPO-34, only one molecule coordinate to [V(Ⅳ)]O$\^$2+/ was observed in EPR and ESEM spectra.

• Journal of the Korean Chemical Society
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• v.30 no.1
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• pp.76-83
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• 1986

Four oxovandium(IV) complexes with carboxylate ligands, $VO(picn)_2$, $VO(htmq)_2$, $VO(quin)_2$ and $VO(pyra)_2{\cdot}2H_2O)$ have been prepared and studied. Infrared spectral data coupled with the results of magnetic susceptibility study strongly suggest that there are relatively strong intermolecular interactions in $VO(picn)_2$ and $VO(htmq)_2$. In all oxovanadium(IV) complexes studied in this work, the carboxylate ligand coordinates to the metal ion in the unidentated fashion. Some fundamental vibration modes of oxovanadium(IV) complexes were empirically assigned from the difference in the spectrum of metal complex with free ligand.

• Journal of the Korean Society for Railway
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• v.15 no.2
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• pp.135-140
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• 2012

Interior Permanent Magnet Synchronous motors (IPMSM) with concentrated winding are superior to distributed winding in the power density point of view. But it causes huge amount of eddy current losses on the permanent magnet. This paper presents the optimal permanent magnet V-shape on the rotor of an interior permanent magnet synchronous motor to reduce the core losses and improve the performance. Each eddy current loss on permanent magnet has been investigated in detail by using FEM (Finite Element Method) instead of equivalent magnetic circuit network method in order to consider saturation and non-linear magnetic property. Simulation-based design of experiment is also applied to avoid large number of analyses according to each design parameter and consider expected interactions among parameters. Consequently, the optimal design to reduce the core loss on the permanent magnet while maintaining or improving motor performance is proposed by an optimization algorithm using regression equation derived and lastly, it is verified by FEM.

• Clinical Psychopharmacology and Neuroscience
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• v.16 no.4
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• pp.449-460
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• 2018

Objective: Prior functional magnetic resonance imaging (fMRI) work has revealed that children/adolescents with disruptive behavior disorders (DBDs) show dysfunctional reward/non-reward processing of non-social reinforcements in the context of instrumental learning tasks. Neural responsiveness to social reinforcements during instrumental learning, despite the importance of this for socialization, has not yet been previously investigated. Methods: Twenty-nine healthy children/adolescents and 19 children/adolescents with DBDs performed the fMRI social/non-social reinforcement learning task. Participants responded to random fractal image stimuli and received social and non-social rewards/non-rewards according to their accuracy. Results: Children/adolescents with DBDs showed significantly reduced responses within the caudate and posterior cingulate cortex (PCC) to non-social (financial) rewards and social non-rewards (the distress of others). Connectivity analyses revealed that children/adolescents with DBDs have decreased positive functional connectivity between the ventral striatum (VST) and the ventromedial prefrontal cortex (vmPFC) seeds and the lateral frontal cortex in response to reward relative to non-reward, irrespective of its sociality. In addition, they showed decreased positive connectivity between the vmPFC seed and the amygdala in response to non-reward relative to reward. Conclusion: These data indicate compromised reinforcement processing of both non-social rewards and social non-rewards in children/adolescents with DBDs within core regions for instrumental learning and reinforcement-based decision-making (caudate and PCC). In addition, children/adolescents with DBDs show dysfunctional interactions between the VST, vmPFC, and lateral frontal cortex in response to rewarded instrumental actions potentially reflecting disruptions in attention to rewarded stimuli.

• Journal of the Korean Electrochemical Society
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• v.22 no.2
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• pp.53-59
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• 2019

To examine the solution structure of electrolytes, it is very important to understand ion-ion and ion-solvent interactions. In this review, we introduce the basic principle of dielectric relaxation spectroscopy (DRS) and studies of electrolyte structure. DRS is a type of impedance method, which measures the dielectric properties of electrolytes over a high frequency domain at levels of tens of GHz. Therefore, DRS provides information on the different polar chemical species present in the electrolyte, including the type and concentration of free solvents and ion pairs with dipole moments. The information of DRS is complementary to the information of conventional analytical techniques (Infrared/Raman spectroscopy, nuclear magnetic resonance (NMR), etc.) and thus enables a broad understanding of electrolyte structure.

• Science of Emotion and Sensibility
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• v.25 no.4
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• pp.77-94
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• 2022

Social interactions often involve encountering inconsistent information about social others. We conducted a functional magnetic resonance imaging (fMRI) study to comprehensively investigate voxel-wise temporal dynamics showing how impressions are anchored and/or adjusted in response to inconsistent social information. The participants performed a social impression task inside an fMRI scanner in which they were shown a male face, together with a series of four adjectives that described the depicted person's personality traits, successively presented beneath the image of the face. Participants were asked to rate their impressions of the person at the end of each trial on a scale of 1 to 8 (where 1 is most negative and 8 is most positive). We established two hypothetical models that represented two temporal patterns of voxel activity: Model 1 featured decreasing patterns of activity towards the end of each trial, anchoring impressions to initially presented information, and Model 2 showed increasing patterns of activity toward the end of each trial, where impressions were being adjusted using new and inconsistent information. Our data-driven model fitting analyses showed that the temporal activity patterns of voxels within the ventral anterior cingulate cortex, medial orbitofrontal cortex, posterior cingulate cortex, amygdala, and fusiform gyrus fit Model 1 (i.e., they were more involved in anchoring first impressions) better than they did Model 2 (i.e., showing impression adjustment). Conversely, voxel-wise neural activity within dorsal ACC and lateral OFC fit Model 2 better than it did Model 1, as it was more likely to be involved in processing new, inconsistent information and adjusting impressions in response. Our novel approach to model fitting analysis replicated previous impression-related neuroscientific findings, furthering the understanding of neural and temporal dynamics of impression processing, particularly with reference to functionally segmenting each region of interest based on relative involvement in impression anchoring as opposed to adjustment.

• The korean journal of orthodontics
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• v.42 no.6
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• pp.318-328
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• 2012

Objective: To assess the position and movements of the hyoid bone during deglutition in patients with open bite. Methods: Thirty-six subjects were divided into 2 groups according to the presence of anterior open bite. The open bite group (OBG) and control group each comprised 18 patients with a mean overbite of $-4.9{\pm}1.9$ mm and $1.9{\pm}0.7$ mm. The position of the hyoid bone during the 4 stages of deglutition was evaluated by measuring vertical and horizontal movement of the bone. Results: Interactions of group and stage showed no significant effect on the measurements (p > 0.05). However, when group and stage were evaluated individually, they showed significant effects on the measurements (p < 0.001). In OBG, the hyoid bone was more inferiorly and posteriorly positioned, and this position continued during the deglutition stages. Conclusions: The hyoid bone reaches the maximum anterior position at the oral stage and maximum superior position at the pharyngeal stage during deglutition. Open bite does not change the displacement pattern of the bone during deglutition. The hyoid bone is positioned more inferiorly and posteriorly in patients with open bite because of released tension on the suprahyoid muscles.

• Bulletin of the Korean Chemical Society
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• v.25 no.4
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• pp.529-532
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• 2004

Cesium-133 NMR spectra of a single crystal of tetragonal $Cs^+ (15-crown-5)_2I^-$ were obtained as a function of crystal orientation in an applied magnetic field of 9.40T and analyzed to provide the magnitudes and orientations of the $^{133}Cs$ chemical shift and quadrupolar tensors for two magnetically nonequivalent and symmetry related sites. Chemical shift tensor components and parameters of quadrupolar interactions are obtained as ${\delta}_{11}=46(1),\;{\delta}_{22}=60(1),\;{\delta}_{33}=-30(1)$ ppm, quadrupole coupling constant QCC = 581(1) kHz, and asymmetry parameter ${\eta}$ = 0.481(1), respectively. The nonaxially symmetric NMR parameters imply that the local environment of the cesium nuclei is nonaxially symmetric. The DANTE experiment burned holes in the $^{133}Cs$ NMR line of the title compound. The hole burning of the single crystal and powder $^{133}Cs$ NMR lines showed that the NMR lines are not homogeneously broadened.

• Journal of Magnetics
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• v.21 no.3
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• pp.476-489
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• 2016

In the present study, squeezing flow of micropolar nanofluid between parallel infinite disks in the presence of magnetic field perpendicular to plane of the disks is taken into account. The constitutive equations that govern the flow configuration are converted into nonlinear ordinary differential with the help of suitable similarity transforms. HAM package BVPh2.0 has been employed to solve the nonlinear system of ordinary differential equations. Effects of different emerging parameters like micropolar parameter K, squeezed Reynolds number R, Hartmann number M, Brownian motion parameter Nb, thermophoresis parameter Nt, Lewis number Le for dimensionless velocities, temperature distribution and concentration profile are also discussed graphically. In the presence of strong and weak interaction (i.e. n = 0 and n = 0.5), numerical values of skin friction coefficient, wall stress coefficient, local Nusselt number and local Sherwood number are presented in tabulated form. To check the validity and reliability of the developed algorithm BVPh2.0 a numerical investigation is also a part of this study.

• Journal of The Korean Astronomical Society
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• v.37 no.5
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• pp.455-460
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• 2004

There have been many speculations about the presence of cosmic ray protons (CRps) in galaxy clusters over the past two decades. However, no direct evidence such as the characteristic $\gamma$-ray signature of decaying pions has been found so far. These pions would be a direct tracer of hadronic CRp interactions with the ambient thermal gas also yielding observable synchrotron and inverse Compton emission by additionally produced secondary electrons. The obvious question concerns the type of galaxy clusters most likely to yield a signal: Particularly suited sites should be cluster cooling cores due to their high gas and magnetic energy densities. We studied a nearby sample of clusters evincing cooling cores in order to place stringent limits on the cluster CRp population by using non-detections of EGRET. In this context, we examined the possibility of a hadronic origin of Coma-sized radio halos as well as radio mini-halos. Especially for mini-halos, strong clues are provided by the very plausible small amount of required CRp energy density and a matching radio profile. Introducing the hadronic minimum energy criterion, we show that the energetically favored CRp energy density is constrained to $2\%{\pm}1\%$ of the thermal energy density in Perseus. We also studied the CRp population within the cooling core region of Virgo using the TeV $\gamma$-ray detection of M 87 by HEGRA. Both the expected radial $\gamma$-ray profile and the required amount of CRp support this hadronic scenario.