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Institution

Pusan National University

EducationBusan, South Korea
About: Pusan National University is a education organization based out in Busan, South Korea. It is known for research contribution in the topics: Population & Catalysis. The organization has 24124 authors who have published 45054 publications receiving 819356 citations. The organization is also known as: Busan National University & Pusan University.


Papers
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Journal ArticleDOI
01 Sep 2000
TL;DR: In this paper, the authors investigated reduction of cogging torque and acoustic noise in permanent magnet motors with larger stator slot opening using an energy method with Fourier series expansion, using an analytically determined with airgap MMF function and airgap permeance function.
Abstract: This paper investigates reduction of cogging torque and acoustic noise in permanent magnet motors with larger stator slot opening. Using an energy method with Fourier series expansion, cogging torque is analytically determined with airgap MMF function and airgap permeance function. It shows that there exist several tooth widths which minimize the cogging torque. It also proposes a teeth pairing with two different types of tooth width which can effectively reduce the cogging torque and thus the acoustic noise. Experimental results show that the proposed teeth pairing reduces the cogging torque by 85% and the acoustic noise by 3.1 dB.

170 citations

Journal ArticleDOI
TL;DR: Oligomers rather than polymers from proanthocyanidins of persimmon peel may be expected to be a more promising antioxidative and antidiabetic agent in relation to utilization in biological systems and their inhibitory activities on digestive enzymes and advanced glycation endproduct (AGE) formation were evaluated.
Abstract: The present study was carried out to evaluate the promising potential of polymers and oligomers from proanthocyanidins of persimmon peel as antioxidants and therapeutic agents for diabetes. Both polymers and oligomers showed the scavenging effect of 2,2-diphenyl-l-picrylhydrazyl, with IC50 values of 4.35 and 2.41 microg/mL, respectively, and they also showed a protective activity against protein oxidation induced by 2,2'-azobis (2-amidinopropane) dihydrochloride. In particular, oligomers exerted a stronger activity against free radicals than polymers. In addition, to investigate their protective potential against diabetes-related pathological conditions, their inhibitory activities on digestive enzymes and advanced glycation endproduct (AGE) formation were evaluated. Polymers showed a strong inhibitory activity against alpha-amylase, while oligomers had a relatively weak effect. This suggests that the inhibition of alpha-amylase activity would probably depend on the degree of polymerization. On the other hand, against alpha-glucosidase activity and AGE formation, oligomers exerted a stronger protective effect than polymers. The present study suggests that polymers and oligomers from proanthocyanidins of persimmon peel could play a role as antidiabetic agents with antioxidative effects. Moreover, oligomers rather than polymers from proanthocyanidins of persimmon peel may be expected to be a more promising antioxidative and antidiabetic agent in relation to utilization in biological systems.

170 citations

Journal ArticleDOI
TL;DR: Oxygen stress successfully inhibited methanogens, while slightly suppressing the exoelectrogens, and is believed to be a practical option due to its low operating cost.

170 citations

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the potential for improvements in conductivity properties of polymers after 2 MeV electron and 62 MeV proton irradiation and found that the shift in optical absorption edges as observed by UV-VIS spectra of the irradiated polymers has been correlated to the optical band-gap using Tauc's expression.
Abstract: Ion beam treatment studies have been carried out to investigate the potential for improvements in conductivity properties of the polymers Polytetrafluroethylene (PTFE), Polyimide (PI), Polyethyleneterepthalate (PET) and Polypropylene (PP), after 2 MeV electron and 62 MeV proton irradiation. The shift in optical absorption edges as observed by UV–VIS spectra of the irradiated polymers has been correlated to the optical band-gap using Tauc’s expression. A decrease in the optical band-gap has been observed in irradiated PP and PTFE, but no considerable change was found for the optical band-gaps of PET and PI. Further AC conductivity measurements confirmed an increase in conductivity in electron irradiated PP.

170 citations

Journal ArticleDOI
TL;DR: In this paper, high nitrogen-enriched mesoporous carbon nitride materials with 2D and 3D mesostructures (3D-meso-CN) were synthesized using mesoporus silica as a hard template and cyanamide as a precursor via the incipient wetness process without using any solvent.
Abstract: Highly nitrogen-enriched mesoporous carbon nitride materials with 2-dimensional (2-D) (2D-meso-CN) and 3-dimensional (3-D) mesostructures (3D-meso-CN) were synthesized using mesoporous silica as a hard template and cyanamide as a precursor via the incipient wetness process without using any solvent. The materials were characterized by small-angle X-ray scattering (SAXS), X-ray diffraction (XRD), and transmission electron microscopy (TEM) for the mesostructure analysis, N2 adsorption–desorption isotherms for surface area and pore size distribution, and X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared (FT-IR) spectroscopy for the composition analysis of frameworks. The mesoporous carbon nitride replicas have graphitic-like stacking of carbon nitride sheets in mesopore walls. The N/C ratio of the mesoporous carbon nitride replicas is 1.13 after the carbonization at 550 °C for 3 h. 2D-meso-CN and 3D-meso-CN have the BET surface area of 361 and 343 m2 g−1, large pore volume of 0.50 and 0.67 cm3 g−1, and pore diameter of 27.8 A (for 2D-meso-CN), 24.5 and 80.3 A (for 3D-meso-CN), respectively. It was found that the 3D-meso-CN has higher capacity of hydrogen uptake of 0.25 wt% than the pure mesoporous carbon FDU-15 (0.16 wt%) at 50 bar under room temperature (298 K).

170 citations


Authors

Showing all 24296 results

NameH-indexPapersCitations
Hyun-Chul Kim1764076183227
Taeghwan Hyeon13956375814
George C. Schatz137115594910
Darwin J. Prockop12857687066
Mark A. Ratner12796868132
Csaba Szabó12395861791
David E. McClelland10760272881
Yong Sik Ok10285441532
C. M. Mow-Lowry10137866659
I. K. Yoo10143732681
Haijun Yang10040335114
Buddy D. Ratner9950135660
Dong Jo Kim9849736272
Shuzhi Sam Ge9788340865
B. J. J. Slagmolen9634962356
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202391
2022302
20213,260
20203,069
20193,039
20182,718