• Nuclear Engineering and Technology
• /
• v.34 no.2
• /
• pp.154-164
• /
• 2002

Neutron cross section data on Dy-160, Dy-161, Dy-162, Dy-163 and Dy-164 were calculated and evaluated in the energy range of 1 keV to 20 MeV using a spherical optical model, statistical model and pre-equilibrium model. The energy dependent optical model potential parameters were obtained based on the recent experimental data. The width fluctuation correction in Hauser-Feshbach particle decay and the quantum mechanical approach in pre-equilibrium analysis were introduced and gave a better cross section calculation in EMPIRE-II. The total, elastic scattering and threshold reaction cross sections were evaluated and compared with the evaluated files. The model calculated (n, tot), (n, ${\gamma}$) and (n, p) cross sections were in good agreement with the experimental data in the measured energy range. The results will be applied to ENDF/B-VI for data improvement.

• Bulletin of the Korean Chemical Society
• /
• v.29 no.6
• /
• pp.1131-1136
• /
• 2008

The electrical repulsive energy between two model cylinders was calculated by solving nonlinear Poission- Boltzmann (P-B) equation under Derjaguin approximation. Effects of the surface potential, Debye screening length, and configuration of cylinders on the repulsive interaction energy were examined. Due to the anisotropy of the shape of cylinder, the interaction repulsive energy showed dependence to the configuration of particles; cylinders aligned in end-to-end configuration showed largest repulsive energy and crossed particles had lowest interaction energy. The configuration effect is originated from the curvature effect of the interacting surfaces. The curved surfaces showed less repulsive energy than flat surfaces at the same interacting surface area. The configuration dependency of interaction energy agreed with the previous analytical solution obtained under the linearized P-B equation. The approach and results present in this report would be applicable in predicting colloidal behavior of cylindrical particles.

• Nutrition Research and Practice
• /
• v.10 no.4
• /
• pp.404-410
• /
• 2016

BACKGROUND/OBJECTIVE: Malnutrition and inflammation are reported as the most powerful predictors of mortality and morbidity in hemodialysis (HD) patients. Diet has a key role in modulating inflammation and dietary inflammatory index (DII) is a new tool for assessment of inflammatory potential of diet. The aim of this study was to evaluate the application of DII on dietary intake of HD patients and examine the associations between DII and malnutrition-inflammation markers. SUBJECTS/METHODS: A total of 105 subjects were recruited for this cross-sectional study. Anthropometric measurements, 3-day dietary recall, and pre-dialysis biochemical parameters were recorded for each subject. Subjective global assessment (SGA), which was previously validated for HD patients, and malnutrition inflammation score (MIS) were used for the diagnosis of protein energy wasting. DII was calculated according to average of 3-day dietary recall data. RESULTS: DII showed significant correlation with reliable malnutrition and inflammation indicators including SGA (r = 0.28, P < 0.01), MIS (r = 0.28, P < 0.01), and serum C-reactive protein (CRP) (r = 0.35, P < 0.001) in HD patients. When the study population was divided into three subgroups according to their DII score, significant increasing trends across the tertiles of DII were observed for SGA score (P = 0.035), serum CRP (P = 0.001), dietary energy (P < 0.001), total fat (P < 0.001), saturated fatty acids (P < 0.001), polyunsaturated fatty acids (P = 0.006), and omega-6 fatty acids (P = 0.01) intakes. CONCLUSION: This study shows that DII is a good tool for assessing the overall inflammatory potential of diet in HD patients.

• Applied Chemistry for Engineering
• /
• v.30 no.6
• /
• pp.667-672
• /
• 2019

As a non-renewable energy source, fossil fuel causes environment problems, numerous efforts have been made for a global decarbonization, for example, the realization of Power 2 Gas (P2G) system as a definitive research goal. In particular, ammonia is regarded as an emerging source since it can be used as a hydrogen carrier and production alongside for fuel cell applications. In this mini-review, we summarized the properties of ammonia and further highlighted the worldwide research trend for its superb potential in hydrogen energy supply industries.

• ETRI Journal
• /
• v.45 no.6
• /
• pp.996-1006
• /
• 2023

Renewable energy is promoted massively to overcome problems that fossil fuel power plants generate. One popular renewable energy type that offers easy installation is a photovoltaic (PV) system. However, the energy harvested through a PV system is not optimal because influenced by exposure to solar irradiance in the PV module, which is constantly changing caused by weather. The maximum power point tracking (MPPT) technique was developed to maximize the energy potential harvested from the PV system. This paper presents the MPPT technique, which is operated on a new high-gain voltage DC/DC converter that has never been tested before for the MPPT technique in PV systems. Fuzzy logic (FL) was used to operate the MPPT technique on the converter. Conventional and adaptive perturb and observe (P&O) techniques based on variables step size were also used to operate the MPPT. The performance generated by the FL algorithm outperformed conventional and variable step-size P&O. It is evident that the oscillation caused by the FL algorithm is more petite than variables step-size and conventional P&O. Furthermore, FL's tracking speed algorithm for tracking MPP is twice as fast as conventional P&O.

• Journal of the Microelectronics and Packaging Society
• /
• v.26 no.3
• /
• pp.75-80
• /
• 2019

Silicon solar cells have been widely used as a most promising renewable energy source due to eco-friendliness and high efficiency. As modules of silicon solar cells are connected in series for a practical electricity generation, a large voltage of 500-1,500 V is applied to the modules inevitably. Potential-induced degradation (PID), a deterioration of the efficiency and maximum power output by the continuously applied high voltage between the module frames and solar cells, has been regarded as the major cause that reduces the lifetime of silicon solar cells. In particular, the migration of the $Na^+$ ions from the front glass into Si through the anti-reflection coating and the accumulation of $Na^+$ ions at stacking faults inside Si have been reported as the reason of PID. In this research, the thickness effect of $SiO_x$ layer that can block the migration of $Na^+$ ions on the reduction of PID is investigated as it is incorporated between anti-reflection coating and p-n junction in p-type PERC solar cells. From the measurement of shunt resistance, efficiency, and maximum power output after the continuous application of 1,000 V for 96 hours, it is revealed that the thickness of $SiO_x$ layer should be larger than 7-8 nm to reduce PID effectively.

• Journal of the Korean Ceramic Society
• /
• v.32 no.11
• /
• pp.1262-1268
• /
• 1995

Photoelectrochemical properties of p-GaAs electrode have been investigated. I-V characteristic shows that the cathodic photocurrent is observed at -0.7 V vs. SCE. The photoresponse at near 870~880nm wavelength indicates that the photogenerated carriers contibuted to the observed current. The maximum converson efficiency of 35% is obtained for a Xe lamp light source at 400nm. In C-V relation, capacitance peaks appeared at the frequencies of 100Hz and 300Hz due to the activation of the interfacial states which exist at the energy level corresponding to the one-third of the GaAs band gap. The difference of about 1.1V between flatband potential (Vfb) from the Mott-Schottky method and onset voltage from I-V curve is observed due to the trap of carriers at the interfacial states in the boundary between GaAs and electrolyte. In case of WO3 deposited p-GaAs electrode, higher positive onset current and photocurent density are obtained. This can be explained by the fact that carriers are generated by light penetrated into the WO3 thin flm as well as p-GaAs substrate and then move into the electrolyte effectively.

• Journal of the Korean Ceramic Society
• /
• v.35 no.11
• /
• pp.1182-1189
• /
• 1998

Crystal structure and structural stability of needle-shaped maghemite(${\gamma}$-{{{{ { {Fe }_{2 }O }_{3 } }}) have been studied by the computation and estimation of lattice energies interionic distances and site potentials. The refined struc-tures analyzed with cubic system(space group P4332) and tetragonal system(space group P4332) were used for these computations. The lattice energy of tetragonal system is -143.10eV/molecule. The maghemite structure with tetragonal system is more stable than that with cubic system. The ordering energy of the FE and cation vacancy within the octahedral site the 4b site of the structure with cubic system(space group P4332) is -0.95eV/molecule but this Fe has larger interionic distance and is very unstable.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.11 no.3
• /
• pp.181-187
• /
• 1998

The ionization energy and degree of ionization for p-type $Si_{1-x}Ge_x$ with boron doping are calculated taking into account the screening and broadening effects. The drift and Hall mobilities are then calculated using the relaxation time approximation and compared with the previously reported measurement data for relaxed and strained $Si_{1-x}Ge_x$ alloys to estimate the alloy scattering potential. From a fit, the alloy scattering potential is found to be 0.5 eV. The in-plane drift mobility for p-type strained $Si_{1-x}Ge_x$ grown on (001) Si substrate is approximately 1+$10x^2$ times higher than that for bulk Si in the high doping range.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.19 no.5
• /
• pp.765-773
• /
• 1995

Effect of interfacial electrical conditions such as, the f potential of PET fiber and u-Fe203 particles, the stability parameter and potential energy of interaction on adhesion of a-Fe903 particles to PET fabric and their removal from the fabric, were investigated as functions of pH, electrolyte and ionic strength. The stability parameter, potential energy of interaction between a-Fe2O3 particles and PET fabric were calculated by using the heterocoagulation theory for a sphere-plate model The adhesion of a-Fe2O3 particles to PET fabric and their removal from PET fabric were carried out by using water bath shaker and Terg-O-Tometer under various solution conditions. The adhesion of a-Fe2O3 particles to the PET fabric and the removal of a-Fe2O3 particles from the PET fabric were biphasic and were maximum and minimum at pH 7~8, respectively. With high pH and polyanion electrolytes in solution, the adhesion of a-Fe2O3 particles to the PET fabric was low but effects of electrolytes on the removal of a-Fe2O3 particles from the PET fabric was small. The adhesion of a-Fe2O3 particles to the PET fabric and the removal of a-Fe2O3 Particles from the PET fabric were biphasic, and were lowest and highest at the ionic strength 1$\times$10-3, respectively. The adhesion of a-Fe2O3 particles to PET fabric was well related with the interfacial electrical conditions; it was negatively correlated with the f potentials of a-Fe2O3 Particles of its absolute value, the stability parameter and the maximum of total potential energy, while, the adhesion was not related with the t potentials of PET fiber itself. Therefore, the primary factor determining the adhesion of a-Fe203 particles to PET fabric may be the stability of dispersed particles caused by the electrical repulsion of particles. The removal of a-Fe203 particles from PET fabric was not related to such interfacial electrical conditions as the t potentials of PET fiber, the stability parameter and the maximum of total potential energy but removal was related to t potential of a-Fe203 particles.