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1.
Ahn Kyu-Hong Hwang Jong-Hyuk Song Kyung-Guen Jung Yong-Ho Cho Eul-Saeng Lim Byung-Ran Kim Kwang-Soo 《Metals and Materials International》2004,10(2):167-170
The performance of an attached growth wastewater treatment process was investigated in an effort to improve nitrogen removal
efficiency. Recycled Yakult (lactic acid fermentation drink) bottles made of polystyrene were used as a biofilm media. The
use of Yakult bottles as a biofilm media has been attempted by numerous researchers in Japan for the removal of solids and
organics. However, these studies focused only on the removal of solids and organics. This study extended their application
to the removal of nitrogen for domestic sewage treatment. Yakult media was placed in a reactor with 70% apparent reactor volume
in a conventional A/O process. The bottom of the Yakult media was removed, and randomly filled Yakult media were effectively
able to reduce the flow in tanks, resulting in an increase in the contact time between pollutants and microorganisms. With
higher HRT, the nitrogen removal efficiency was increased by up to 83% with 12 hr of HRT. Nitrification appeared to be the
limiting factor of nitrogen removal at an HRT that is less than 12 hr, indicating that the Yakult process requires more retention
time to achieve nitrification compared to other biofilm processes. The removal efficiencies of organics and solids were high
regardless of the change of operational parameters.
This article is based on a presentation in “The 7th Korea-China Workshop On Advanced Materials” organized by the Korea-China
Advanced Materials Cooperation Center and the China-Korea Advanced Materials Cooperation Center, held at Ramada Plaza Jeju
Hotel, Jeju Island, Korea on August 24–27, 2003. 相似文献
2.
VoIP (Voice over Internet Protocol), which provides voice calls as well as additional services at cheaper prices than PSTN (Public Switched Telephone Network), is gaining ground over the latter, which had been the dominant telephone network in the past. This kind of a VoIP service is evolving into a dedicated mVoIP service for the smartphone which allows calls to be made at cheap prices using a WiFi network, as the number of smartphone users is skyrocketing as of late. While an increase in the user base is expected for mVoIP, a packet network is an open network which means anyone can easily gain access and so there can be various problems. To mitigate this, in this paper an authentication system is designed which has an AA (Attribute Authority) server added to VoIP in order to increase security and discriminate user access. In this paper a system for addressing security vulnerabilities from the increase in the use of VoIP services and providing differentiated services according to user access privileges is designed. This paper is organized as follows: Chapter 1 gives the introduction; Chapter 2 is on related research; Chapter 3 describes the proposed technique and system; Chapter 4 implements the system and analyzes its the performance; and Chapter 5 gives the conclusions. 相似文献
3.
Jong-Hwan Park Jong-Hyun Lee Yong-Ho Lee Yong-Seog Kim 《Journal of Electronic Materials》2002,31(11):1175-1180
The reaction characteristics of molten Au/Sn eutectic solder with potential diffusion-barrier materials of optoelectronic
packages were investigated. The characteristics were studied by reflowing the solder on Pt, Ni, and Co plates, respectively,
and by measuring the thickness of the reaction product. In addition, the dissolution rate of Pt into the solder was measured.
The results indicated that Pt, which is commonly used as the diffusion-barrier layer in the under-bump metallurgy (UBM) of
optoelectronic packages, reacts readily with the molten solder, resulting in discontinuous reaction products at the solder/Pt
interface. Cobalt, on the other hand, reacted with the solder at an order of magnitude slower rate than that of Pt and provided
an effective barrier against the reaction with the solder. 相似文献
4.
En-Hai Sun Yong-Ho Choa Tohru Sekino Tomohiko Adachi Koichi Niihara 《Materials Research Innovations》2002,6(3):105-111
Cordierite/ZrO2 composites with 5 to 25 wt% ZrO2 were fabricated by conventional powder mixing and pressureless sintering method. Their densification behavior, microstructure,
mechanical and thermal properties were studied. By dispersing 25 wt% (9.57 vol%) ZrO2, densified cordierite/ZrO2 composite with a relative density of 98.5% was obtained at an optimum sintering condition of 1440 °C and 2 h. ZrO2 particles were homogenously dispersed within matrix grains and at the grain boundaries. The intragranular particles were
finer than 100 nm and the intergranular particles were coarser. Both fracture strength and toughness could be enhanced more
than two times higher, compare to those of monolithic cordierite, by dispersing 25 wt% ZrO2 into the cordierite matrix. The toughening mechanism in the present composites was mainly attributed to martensitic transformation
due to ZrO2 dispersion.
Electronic Publication 相似文献
5.
6.
Chong Hyun Chang Yong-Ho Choa Deok-Yong Park Nosang V. Myung 《Electrochimica acta》2010,55(3):743-9109
Bismuth (Bi) and tellurium (Te) thin films were formed by galvanic displacement of different sacrificial iron group thin films [i.e. nickel (Ni), cobalt (Co) and iron (Fe)] where the formation was systematically investigated by monitoring the change of open circuit potential (OCP), surface morphology and microstructure. The surface morphologies and crystal structures of galvanically displaced Bi or Te thin films strongly depended on the type and thickness of the sacrificial materials. Continuous Bi thin films were successfully deposited with the sacrificial Co. However, dendrites and nanoplatelets were formed from the Ni and Fe thin films. Te thin films were synthesized with all the three sacrificial thin films. Chemical dissolution rate of the sacrificial thin films and mixed potential strongly influenced formation of Bi or Te thin films. 相似文献
7.
Regarding the assessment of the terrestrial food chain dose to man, radioecology may be the field that is focused on the transfer of radionuclides from environmental media to food crops. In Korea, the environmental transfer of radionuclides to staple food crops have been investigated at Korea Atomic Energy Research Institute (KAERI) for the last 25 y mainly through radiotracer experiments in greenhouses. As a result, several hundreds of parameter values for the prediction of the radionuclide transfer have been produced. Many of them appear in two recent publications of International Atomic Energy Agency. This paper outlines the KAERI's past radioecological work and introduces the ongoing research and future plans. 相似文献
8.
Sung-Min Hwang Youn-Yi Jo Cinder Faith Cohen Yong-Ho Kim Temugin Berta Chul-Kyu Park 《International journal of molecular sciences》2022,23(10)
The transient receptor potential vanilloid 1 (TRPV1) ion channel plays an important role in the peripheral nociceptive pathway. TRPV1 is a polymodal receptor that can be activated by multiple types of ligands and painful stimuli, such as noxious heat and protons, and contributes to various acute and chronic pain conditions. Therefore, TRPV1 is emerging as a novel therapeutic target for the treatment of various pain conditions. Notably, various peptides isolated from venomous animals potently and selectively control the activation and inhibition of TRPV1 by binding to its outer pore region. This review will focus on the mechanisms by which venom-derived peptides interact with this portion of TRPV1 to control receptor functions and how these mechanisms can drive the development of new types of analgesics. 相似文献
9.
Emmanuel Perez Yong-Ho Sohn Dennis D. Keiser Jr. 《Metallurgical and Materials Transactions A》2013,44(1):584-595
U-Mo dispersions in Al-alloy matrix and monolithic fuels encased in Al-alloy are under development to fulfill the requirements for research and test reactors to use low-enriched molybdenum stabilized uranium alloy fuels. Significant interaction takes place between the U-Mo fuel and Al during manufacturing and in-reactor irradiation. The interaction products are Al-rich phases with physical and thermal characteristics that adversely affect fuel performance and result in premature failure. Detailed analysis of the interdiffusion and microstructural development of this system was carried through diffusion couples consisting of U-7 wt pct Mo, U-10 wt pct Mo and U-12 wt pct Mo in contact with pure Al, Al-2 wt pct Si, and Al-5 wt pct Si, annealed at 823 K (550 °C) for 1, 5 and 20 hours. Scanning electron microscopy and transmission electron microscopy were employed for the analysis. Diffusion couples consisting of U-Mo in contact with pure Al contained UAl3, UAl4, U6Mo4Al43, and UMo2Al20 phases. Additions of Si to the Al significantly reduced the thickness of the interdiffusion zone. The interdiffusion zones developed Al- and Si-enriched regions, whose locations and size depended on the Si and Mo concentrations in the terminal alloys. In these couples, the (U,Mo)(Al,Si)3 phase was observed throughout the interdiffusion zone, and the U6Mo4Al43 and UMo2Al20 phases were observed only where the Si concentrations were low. 相似文献
10.
This paper presents an improved sensorless driving method for switched reluctance motor (SRM) using a phase-shift circuit technique. The conventional method consists of impressing short voltage pulses during unenergized phases, measuring the phase current pulses, and finding the correlation between the filtered current signals and rotor position. However, the filtering process causes a signal phase delay which varies with motor speed. This delay must be compensated for in providing the sensorless signal which is proper to the rotor position. A solution for this phase delay compensation, based on a simple analog and digital circuit, is proposed in this paper. 相似文献