• Current Photovoltaic Research
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• v.6 no.4
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• pp.94-101
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• 2018

Light elevated temperature induced degradation (LeTID) was noted as an issue in multi-crystalline silicon solar cells (MSSC) by Ram speck in 2012. In contrast to light induced degradation (LID), which has been researched in silicon solar cells for a long time, research about both LeTID and the mechanism of LeTID has been limited. In addition, research about LeTID in single-crystalline silicon solar cells (SSSC) is even more limited. In order to improve understanding of LeTID in SSSC with a passivated emitter rear contact (PERC) structure, we fabricated four group samples with boron and oxygen factors and evaluated the solar cell characteristics, such as the cell efficiency, $V_{oc}$, $I_{sc}$, fill factor (FF), LID, and LeTID. The trends of LID of the four group samples were similar to the trend of LeTID as a function of boron and oxygen.

• Geomechanics and Engineering
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• v.18 no.1
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• pp.71-83
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• 2019

This investigation presented conventional triaxial and creep-permeability tests on sandstones considering thermally-induced damage (TID). The TID had no visible effects on rock surface color, effective porosity and permeability below $300^{\circ}C$ TID level. The permeability enlarged approximately two orders of magnitude as TID increased to $1000^{\circ}C$ level. TID of $700^{\circ}C$ level was a threshold where the influence of TID on the normalized mass and volume of the specimen can be divided into two linear phases. Moreover, no prominent variations in the deformation moduli and peak strength and strain appeared as TID< $500^{\circ}C$ level. It is interesting that the peak strength increased by 24.3% at $700^{\circ}C$ level but decreased by 11.5% at $1000^{\circ}C$ level. The time-related deformation and steady-state creep rate had positive correlations with creep loading and the TID level, whereas the instantaneous modulus showed the opposite. The strain rates under creep failure stresses raised 1-4 orders of magnitude than those at low-stress levels. The permeability was not only dependent on the TID level but also dependent on creep deformation. The TID resulted in large deformation and complexity of failure pattern for the sandstone.

• Journal of the Korean Magnetic Resonance Society
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• v.16 no.1
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• pp.22-33
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• 2012

Tid1, belonging to the Hsp40/DnaJ family of proteins, functions as a cochaperone of cytosolic and mitochondrial Hsp70 proteins. In particular, the N-terminal J-domain of Tid1 (Tid1-JD) constitutes the major binding sites for proteinprotein interactions with client proteins, including p53, as well as its partner chaperone, Hsp70. In the present study, soluble, recombinant protein of Tid1-JD could be obtained by using the pCold vector system, and backbone NMR assignments were completed using the isotope $[^{13}C/^{15}N]$-enriched protein. Far-UV CD result implied that Tid1-JD is an ${\alpha}$-helical protein and the secondary structure determined using chemical shift data sets indentified four ${\alpha}$-helices with a loop region containing the HPD (conserved tripeptide of His, Pro and Asp) motif. Additionally, NMR spectra under different conditions implied that the HPD motif, which is a critical region for protein-protein interactions of Tid1-JD, would possess dynamic properties.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.1
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• pp.79-84
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• 2013

DC/DC switching power converters are commonly used to generate a regulated DC output voltage with high efficiency. The DC/DC converter is composed of a PWM-IC (pulse width modulation-integrated circuit) controller, a MOSFET (metal-oxide semiconductor field effect transistor), inductor, capacitor, etc. It is shown that the variation of threshold voltage and the offset voltage in the electrical characteristics of PWM-IC increase by radiation effects in TID (Total Ionizing Dose) testing at the low energy ${\gamma}$ rays using $^{60}Co$, and 4 heavy ions applied for SEL (Single Event Latch-up) make the PWM pulse unstable. Also, the output waveform for the given input in the DC/DC converter is observed by the simulation program with integrated circuit emphasis (SPICE). TID testing on PWM-IC is accomplished up to the total dose of 30 krad, and the cross section($cm^2$) versus LET($MeV/mg/cm^2$) in the PWM operation is studied at SEL testing after implementation of the controller board.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.11
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• pp.981-987
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• 2014

DC/DC switching power converters are commonly used to generate a regulated DC output voltage with high efficiency. The DC/DC converter is composed of a MOSFET (metal-oxide semiconductor field effect transistor), a PWM-IC (pulse width modulation-integrated circuit) controller, inductor, capacitor, etc. It is shown that the variation of threshold voltage and the breakdown voltage in the electrical characteristics of MOSFET occurs by radiation effects in TID (Total Ionizing Dose) testing at the low energy ${\gamma}$ rays using $^{60}Co$, and 5 heavy ions make the gate of MOSFET broken in SEGR (Single Event Gate Rupture) testing. TID testing on MOSFET is accomplished up to the total dose of 40 krad, and the cross section($cm^2$) versus LET(MeV/mg/$cm^2$) in the MOSFET operation is studied at SEGR testing after implementation of the controller board.

• Transactions on Electrical and Electronic Materials
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• v.18 no.5
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• pp.287-297
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• 2017

Novel power system stabilizers (PSSs) have been proposed to effectively dampen low frequency oscillations (LFOs) in multi-machine power systems and have attracted increasing research interest in recent years. Due to this attention, recently, fractional order controllers (FOCs) have found new applications in power system stability issues. Here, a tilt-integral-derivative power system stabilizer (TID-PSS) is proposed to enhance the dynamic stability of a multi-machine power system by providing additional damping to the LFOs. The TID is an extended version of the classical proportional-integral-derivative (PID) applying fractional calculus. The design of the proposed three-parameter tunable TID-PSS is systematized as a nonlinear time domain optimization problem in which the tunable parameters are adjusted concurrently using a modified group search optimization (MGSO) algorithm. An integral of the time multiplied squared error (ITSE) performance index is considered as the objective function. The proposed stabilizer is simulated in the MATLAB/SIMULINK environment using the FOMCON toolbox and the dynamic performance is evaluated on a 3-machine 6-bus power system. The TID-PSS is compared with both classical PID-PSS (PID-PSS) and conventional PSS (CPSS) using eigenvalue analysis and time domain simulations. Sensitivity analyses are performed to assess the robustness of the proposed controller against large changes in system loading conditions and parameters. The results indicate that the proposed TID-PSS provides the better dynamic performance and robustness compared with the PID-PSS and CPSS.

• Journal of the Korean Society of Radiology
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• v.11 no.3
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• pp.101-108
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• 2017

DC/DC switching power converters are commonly used to generate a regulated DC output voltage with high efficiency. The advanced DC/DC converter uses a PWM-IC with OP-Amp. (Operational Amplifier) to control a MOSFET (metal-oxide semiconductor field effect transistor), which is a switching component, efficiently. In this paper, it is shown that the electrical characteristics of OP-Amp. are affected by radiations of ${\gamma}$ rays using $^{60}Co$ for TID (Total Ionizing Dose) testing and 5 heavy ions for SEL (Single Event Latch-up) testing. TID testing on OP-Amp. is accomplished up to the total dose of 30 krad, and the cross section($cm^2$) versus LET($MeV/mg/cm^2$) in the OP-Amp. operation is evaluated SEL testing after implementation of the controller board.

• BMB Reports
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• v.55 no.10
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• pp.488-493
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• 2022

The specific pair of heat shock protein 70 (Hsp70) and Hsp40 constitutes an essential molecular chaperone system involved in numerous cellular processes, including the proper folding/refolding and transport of proteins. Hsp40 family members are characterized by the presence of a conserved J-domain (JD) that functions as a co-chaperone of Hsp70. Tumorous imaginal disc 1 (Tid1) is a tumor suppressor protein belonging to the DNAJA3 subfamily of Hsp40 and functions as a co-chaperone of the mitochondrial Hsp70, mortalin. In this work, we performed nuclear magnetic resonance spectroscopy to determine the solution structure of JD and its interaction with the glycine/phenylalanine-rich region (GF-motif) of human Tid1. Notably, Tid1-JD, whose conformation was consistent with that of the DNAJB1 JD, appeared to stably interact with its subsequent GF-motif region. Collectively with our sequence analysis, the present results demonstrate that the functional and regulatory mode of Tid1 resembles that of the DNAJB1 subfamily members rather than DNAJA1 or DNAJA2 subfamily proteins. Therefore, it is suggested that an allosteric interaction between mortalin and Tid1 is involved in the mitochondrial Hsp70/Hsp40 chaperone system.

• Journal of the Korean Magnetic Resonance Society
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• v.22 no.3
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• pp.64-70
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• 2018

Human Tid1, belonging to the family of the Hsp40/DnaJ, functions as a co-chaperone of cytosolic and mitochondrial Hsp70 proteins. In addition, the conserved J-domain and G/F-rich region of Tid1 has been suggested to interact with the p53 tumor suppressor protein, to translocate it to the mitochondria. Here, backbone NMR assignments were achieved for the putative p53-binding domain of Tid1. The obtained chemical shift information identified five ${\alpha}$-helices including four helices characteristic of J-domain, which are connected to a short ${\alpha}$-helix in the G/F-rich region via a flexible loop region. We expect that this structural information would contribute to our progressing studies to elucidate atomic structure and molecular interaction of the domain with p53.

• Journal of Astronomy and Space Sciences
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• v.18 no.2
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• pp.153-162
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• 2001

In this paper, space radiation environment and total ionizing dose(TID) effect have been analyzed for the KOMPSAT-2 operational orbit. It has been revealed that the trapped protons are concentrated in the SAA(South Atlantic Anomaly) area and that the trapped protons and electrons, and solar protons are main factors affecting TID. It turned out that low energy Particles can be effectively blocked by aluminum shielding thickness, but high energy Particles can not be effectively blocked by increasing aluminum shielding thickness. KOMPSAT-2 total radiation dose which is accumulated continuously to spacecraft electronics has been expressed as the function of aluminum thickness. These values ran be used as the criteria for the selection of electronic parts and shielding thinkness of the KOMPSAT-2 structure or electronic box.