• Title/Summary/Keyword: Reduction process

Search Result 6,043, Processing Time 0.037 seconds

Multi-point Dynamic Displacement Measurements of Structures Using Digital Image Correlation Technique (Digital Image Correlation기법을 이용한 구조물의 다중 동적변위응답 측정)

  • Kim, Sung-Wan;Kim, Nam-Sik
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.13 no.3
    • /
    • pp.11-19
    • /
    • 2009
  • Recently, concerns relating to the maintenance of large structures have been increased. In addition, the number of large structures that need to be evaluated for their structural safety due to natural disasters and structural deterioration has been rapidly increasing. It is common for the structural characteristics of an older large structure to differ from the characteristics in the initial design stage, and changes in dynamic characteristics may result from a reduction in stiffness due to cracks on the materials. The process of deterioration of such structures enables the detection of damaged locations, as well as a quantitative evaluation. One of the typical measuring instruments used for the monitoring of bridges and buildings is the dynamic measurement system. Conventional dynamic measurement systems require considerable cabling to facilitate a direct connection between sensor and DAQ logger. For this reason, a method of measuring structural responses from a remote distance without the mounted sensors is needed. In terms of non-contact methods that are applicable to dynamic response measurement, the methods using the doppler effect of a laser or a GPS are commonly used. However, such methods could not be generally applied to bridge structures because of their costs and inaccuracies. Alternatively, a method using a visual image can be economical as well as feasible for measuring vibration signals of inaccessible bridge structures and extracting their dynamic characteristics. Many studies have been conducted using camera visual signals instead of conventional mounted sensors. However, these studies have been focused on measuring displacement response by an image processing technique after recording a position of the target mounted on the structure, in which the number of measurement targets may be limited. Therefore, in this study, a model experiment was carried out to verify the measurement algorithm for measuring multi-point displacement responses by using a DIC (Digital Image Correlation) technique.

Selective Oxidation of 2,6-di-tert-butylphenol and Electrochemical Properties by Oxygen Adducted Tetradentate Schiff Base Cobalt (Ⅲ) Activated Catalysts in Aprotic Solvents (비수용매에서 산소 첨가된 네자리 Schiff Base Cobalt(Ⅲ) 활성 촉매들에 의한 2,6-di-tert-butylphenol의 선택 산화와 전기화학적 성질)

  • Jo, Gi Hyeong;Choe, Yong Guk;Ham, Hui Seok;Kim, Sang Bok;Seo, Seong Seop
    • Journal of the Korean Chemical Society
    • /
    • v.34 no.6
    • /
    • pp.569-581
    • /
    • 1990
  • It is generated in DMF by activated catalysts of superoxo cobalt(III) complex, such as [Co(III)(Schiff base)(L)]O$_2$ (Schiff base; SED, SOPD and o-BSDT, L; DMF and Py) which mole ratio of oxygen to metal is 1:1 that oxidation major product of 2,6-di-tert-butylphenol by homogeneous oxidatve catalysts of oxygen adducted tetradentate Schiff base cobalt(III) is 2,6-ditert-butylbenzoquinone (BQ). And oxidation product of 3,3',5,5'-tetra-tert-butyldiphenoquinone (DPQ) is generated by activated catalysts such as $\mu$-peroxo cobalt(III) complex; $[Co(III)(SND)(L)]_2$$O_2$ (L; DMF and Py) which mole ratio of oxygen to metal is 1:2. It is difficult to identify these homogeneous activated catalysts such as superoxo and $\mu$-peroxo cobalt(III) complexes in DMF and DMSO solvents. But we can identify by P.V.T method of the oxygen absorption in pyridine solvent and by the reduction process occurred to four steps including prewave of O$_2$- in 1:1 oxygen adducted superoxo cobalt(III) complexes and three steps not including prewave of O$_2$- in 1:2 oxygen adducted $\mu$-peroxo cobalt(III) complexes by the cyclic voltammetry with glassy carbon electrode in 0.1 M TEAP as supporting electrolyte solutidn.

  • PDF

Blood Vessel Regeneration using Human Umbilical Cord-derived Endothelial Progenitor Cells in Cyclophosphamide-treated Immune-deficient Mice

  • Kwon, Soon-Keun;Ko, Yu-Jin;Cho, Tae-Jun;Park, Eu-Gene;Kang, Byung-Chul;Lee, Gene;Cho, Jae-Jin
    • International Journal of Oral Biology
    • /
    • v.36 no.3
    • /
    • pp.117-122
    • /
    • 2011
  • Endothelial cells are a vital constituent of most mammalian organs and are required to maintain the integrity of these tissues. These cells also play a major role in angiogenesis, inflammatory reactions, and in the regulation of thrombosis. Angiogenesis facilitates pulp formation and produces the vessels which are essential for the maintenance of tooth homeostasis. These vessels can also be used in bone and tissue regeneration, and in surgical procedures to place implants or to remove cancerous tissue. Furthermore, endothelial cell regeneration is the most critical component of the tooth generation process. The aim of the present study was to stimulate endothelial regeneration at a site of acute cyclophosphamide (CP)-induced endothelial injury by treatment with human umbilical cord-derived endothelial/mesenchymal stem cells (hEPCs). We randomly assigned 16 to 20-week-old female NOD/SCID mice into three separate groups, a hEPC ($1{\times}10^5$ cells) transplanted, 300mg/kg CP treated and saline (control) group. The mice were sacrificed on days 5 and 10 and blood was collected via the abdominal aorta for analysis. The alanine transaminase (ALT), aspartate aminotransferase (AST), serum alkaline phosphatase (s-ALP), and albumin (ALB) levels were then evaluated. Tissue sections from the livers and kidneys were stained with hematoxylin and eosin (HE) for microscopic analysis and were subjected to immunohistochemistry to evaluate any changes in the endothelial layer. CP treatment caused a weight reduction after one day. The kidney/body weight ratio increased in the hEPC treated animals compared with the CP only group at 10 days. Moreover, hEPC treatment resulted in reduced s-ALP, AST, ALT levels compared with the CP only group at 10 days. The CP only animals further showed endothelial injuries at five days which were recovered by hEPC treatment at 10 days. The number of CD31-positive cells was increased by hEPC treatment at both 5 and 10 days. In conclusion, the CP-induced disruption of endothelial cells is recovered by hEPC treatment, indicating that hEPC transplantation has potential benefits in the treatment of endothelial damage.

Mechanical Properties of Recycled Powder mixing Concrete (재생미분말을 혼입한 콘크리트의 역학적 특성)

  • Lee, Seung-Hwan;Jung, Dae-Jin;Choi, Ik-Chang
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2008.04a
    • /
    • pp.769-772
    • /
    • 2008
  • The problem of disposing construction waste materials has become a national and social problem. Recycled powder generated in the process of making aggregate, and the recycled powder is land-filled in its entirety. Results of toxicity testing of recycled power show that it contains base-pair substituent mutagenicity. As recycled powder is disposed of as landfill, it can cause secondary contamination such as soil and underground water contamination. There has been very little research made on recycled powder. This study has examined the utilization of concrete mixture by using recycled powder in a mixture instead of cement and compared and analyzed the characteristics of dynamics and workability. This study has examined the application of recycled powder in concrete. Depending on the replacement rate and workability, test piece was manufactured using different mixing rate by CP, WCP, PCP. The CP was used to examine the physical property of concrete and characteristics its dynamics. The letters W of WCP and P of PCP are the initials of water and mixture. They were made using the standard mixing ratiosemphasizing the workability to determine the characteristic of dynamics of concrete based on the mixing ratio of recycled powder. With the increase in the replacement rate, CP had very little change in the strength. But with the decline of slump, the workability was not good. The result of manufacturing WCP and PCP using the standard mixing ratio showed that WCP had a drop in strength compared to the plain. PCP had almost the same value as the plain only when the replacement rate was 10%. When it was higher than that, a reduction in strength was observed.

  • PDF

A Systematic Approach to Port related Problems An Analysis on the Actual Condition of physical Distribution System of Pusan port (항만관련문제의 시스템적 고찰 부산항 물류시스템의 실태분석)

  • Lee Cheol-Yeong;Moon Seong-Hyeok
    • Journal of Korean Port Research
    • /
    • v.2 no.1
    • /
    • pp.7-28
    • /
    • 1988
  • From the viewpoint of physical distribution, the port transport process can be regarded as a system which consists of various subsystems such as navigational aids, quay handling, transfer, storage, information If management, and co-ordination with inland transport. The handling productivity of this system is determined by the production level of the least productive subsystem. So, a productivity analysis on the flow of cargoes through each subsystem should be made in order to achieve efficient port operation. The purpose of this paper is to analyze the productivity of each subsystem in Pusan port, and to bring forward problems and finally to draw up plans for their betterment. Analyzed results on the productivity of each subsystem are as follows, i) It is known that the number of tugs with low HP should be increased by a few, the number of tugs with medium HP is appropriate, and the number of tugs with high HP is in excess of that necessary. ii ) In the case of container cargoes, it is found that the transfer and storage systems in BCTOC have the lowest handling capability, with a rate of $115\%$, leading to bottle-necks in the port transport system, while the handling rate of the storage and quay handling systems in general piers is in excess of the inherent capability. iii) In the case of the principal seaborne cargoes passing through general piers, there is found to be a remarkable bottle-neck in the storage system. In the light of these findings, both the extension of storage capability and the extension of handling productivity are urgently required to meet the needs of port users. Therefore, iv) As a short-term plan, it is proposed that many measures such as the reduction of free time, the efficient application of ODCY, etc must be brought in and v) In the long-trun, even though the handling capability will accommodate an additional 960,000 TEU in 1991, the scheduled completion date of the third development plan of Pusan port, insufficiency of handling facilities in the container terminal is still expected and concrete countermeasures will ultimately have to be taken for the port's harmonious operation. In particular, the problem of co-ordination with inland transport and urban traffic should be seriously examined together in the establishment of the Pusan port development. As a method of solving this, vi) It is suggested that Pusan port (North port) should be converted into an exclusive container ternimal and overall distribution systems to the other ports for treating general cargoes must be established. vii) And finally, it is also proposed that the arrival time (cut-off time) of influx cargoes for exports such as general merchandise and steel product should be limited, with a view to securing cargoes suitable for the operational capability of BCTOC.

  • PDF

An effective transform hardware design for real-time HEVC encoder (HEVC 부호기의 실시간처리를 위한 효율적인 변환기 하드웨어 설계)

  • Jo, Heung-seon;Kumi, Fred Adu;Ryoo, Kwang-ki
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2015.10a
    • /
    • pp.416-419
    • /
    • 2015
  • In this paper, we propose an effective design of transform hardware for real-time HEVC(High Efficiency Video Coding) encoder. HEVC encoder determines the transform mode($4{\times}4$, $8{\times}8$, $16{\times}16$, $32{\times}32$) by comparing RDCost. RDCost require a significant amount of computation and time because it is determined by bit-rate and distortion which is computated via transform, quantization, dequantization, and inverse transform. This paper therefore proposes a new method for transform mode determination using sum of transform coefficient. Also, proposed hardware architecture is implemented with multiplexer, recursive adder/subtracter, and shifter only to derive reduction of the computation. Proposed method for transform mode determination results in an increase of 0.096 in BD-PSNR, 0.057 in BD-Bitrate, and decrease of 9.3% in encoding time by comparing HM 10.0. The hardware which is proposed is implemented by 256K logic gates in TSMC 130nm process. Its maximum operation frequency is 200MHz. At 140MHz, the proposed hardware can support 4K Ultra HD video encoding at 60fps in real time.

  • PDF

Gas Permeation Properties of Carbon Dioxide and Methane for $PEBAX^{TM}$/TEOS Hybrid Membranes ($PEBAX^{TM}$/TEOS 하이브리드 분리막을 통한 이산화탄소와 메탄의 기체투과특성)

  • Kim, Hyunjoon
    • Korean Chemical Engineering Research
    • /
    • v.49 no.4
    • /
    • pp.460-464
    • /
    • 2011
  • Poly(ether-block-amide)(PEBA, $PEBAX^{TM}$) resin is a thermoplastic elastomer combining linear chains of hard-rigid polyamide block interspaced soft-flexible polyether block. It was believed that the hard polyamide block provides the mechanical strength and permeation selectivity, whereas gas transport occurs primarily through the soft polyether block. The objective of this work was to investigate the gas permeation properties of carbon dioxide and methane for $PEBAX^{TM}$-1657 membrane and compare with those obtained for other grade of $PEBAX^{TM}$, $PEBAX^{TM}$-2533. And the organic/inorganic hybrid membranes were prepared using $PEBAX^{TM}$ and TEOS(tetraethoxysilane) by sol-gel process, and gas permeation properties were studied. $PEBAX^{TM}$-2533 membrane exhibited higher gas permeability coefficients than $PEBAX^{TM}$-1657 membrane. This was explained by the increase of chain mobility. The permeability coefficients for $PEBAX^{TM}$/TEOS hybrid membranes were higher than pure $PEBAX^{TM}$ membranes. This results were explained by the reduction of crystallinity of polyamide block by the introduction of TEOS. Ideal separation factor of hybrid membranes does not change much. This might be due to the increase of solubility selectivity.

Effect of Sludge Digestion on Removal Efficiency of Heavy Metals from Sewage Sludge Using Thiobacillus thiooxidans MET (Thiobacillus thiooxidans MET를 이용한 중금속 제거 효율에 미치는 슬러지 성상의 영향)

  • 임설희;이소은;이인숙;조경숙;류희욱
    • KSBB Journal
    • /
    • v.16 no.4
    • /
    • pp.389-397
    • /
    • 2001
  • The effect of sludge digestion on the leaching efficiency of heavy metals from sludge by bioleaching with Thiobacillus thiooxidans MET was investigated. The used sludges were a non- and anaerobically digested. The leaching efficiency of heavy metals was strongly dependent on the pH of the sludge solution rather than the sludge condition and stolid concentration. The lower the pH the more heavy metal was leached from 3.0 of pH. The sequent orders of leaching heavy metals were Zn, Cu, and Cr. Although the buffering capacity of non-digested sludge was similar to anaerobically digested sludge, the pH decrease rate of the anaerobically digested sludge solution was faster than that of the non-digested sludge solution due to the higher sulfur oxidation rate of T. thiooxidans MET in the anaerobically digested sludge. The amount of leached heavy metals from the anaerobically digested sludge showed higher than that of non-digested sludge at the same pH value. This result might be caused by the difference of the insoluble metal types, which were contained in the sludge. An increase in sludge solids concentration decreased the leaching efficiency of heavy metals in the range of solids concentration 10 g/L to 70 g/L. The optimum ratio of S° to sludge stolid was 0.1 in both the sludge. The bioleaching process of heavy metals with T. thiooxidans MET showed the disinfecting effect over 90% as well as the reduction effect in sludge weight of 20%.

  • PDF

Electrochemical Characteristics of Ru Added Li4Ti5O12 as an Anode Material (Ru를 첨가한 음극활물질 Li4Ti5O12의 전기화학적 특성)

  • Cho, Woo-Ram;Na, Byung-Ki
    • Clean Technology
    • /
    • v.20 no.4
    • /
    • pp.433-438
    • /
    • 2014
  • There is an increasing interest in the development of rechargeable batteries suitable for use in both hybrid electric vehicles and energy storage systems that require higher charge & discharge rates, bigger battery sizes and increased safety of the batteries. Spinel-type lithium titanium oxide ($Li_4Ti_5O_{12}$) as a potential anode for lithium ion batteries has many advantages. It is a zero-strain materials and it experiences no structural change during the charge/discharge precess. Thus, it has long cycle life due to its structural integrity. It also offers a stable operation voltage of approximately 1.55 V versus $Li^+/Li$, above the reduction potential of most organic electrolyte. In this study, Ru added $Li_4Ti_5O_{12}$ composites were synthesized by solid state process. The characteristics of active material were investigated with TGA-DTA, XRD, SEM and charge/discharge test. The capacity was reduced when Ru was added, however, the polarization decreased. The capacity rate of $Li_4Ti_5O_{12}$ with Ru (3%, 4%) addition was reduced during the charge/discharge precess with 10 C-rate as a high current density.

The Meaning of P50 Suppression : Interaction of Gamma and Alpha Waves

  • Lee, Kyungjun;Kang, Ung Gu
    • Korean Journal of Biological Psychiatry
    • /
    • v.21 no.4
    • /
    • pp.168-174
    • /
    • 2014
  • Objectives Sensory gating dysfunctions in patients with schizophrenia and bipolar disorder have been investigated through two similar methods ; P50 suppression and prepulse inhibition paradigms. However, recent studies have demonstrated that the two measures are not correlated but rather constitute as distinct neural processes. Recent studies adopting spectral frequency analysis suggest that P50 suppression reflects the interaction between gamma and other frequency bands. The aim of the present study is to investigate which frequency component shows more significant interaction with gamma band. Methods A total of 108 mood disorder patients and 36 normal subjects were included in the study. The P50 responses to conditioning and test stimuli with an intra-pair interval of 500 msec were measured in the study population. According to P50 ratio (amplitude to the test stimulus/amplitude to the conditioning stimulus), the subjects with P50 ratio less than 0.2 were defined as suppressed group (SG) ; non-suppressed group (NSG) consisted of P50 ratio more than 0.8. Thirty-five and 25 subjects were included in SG and NSG, respectively. Point-to-point correlation coefficients (PPCCs) of both groups were calculated between two time-windows : the first window (S1) was defined as the time-window of one hundred millisecond after the conditioning auditory stimulus and the second window (S2) was defined as the time-window of 100 msec after the test auditory stimulus. Spectral frequency analysis was performed to investigate which frequency band results in the difference of PPCC between SG and NSG. Results Significant reduction of PPCC between S1 and S2 was observed in the SG (Pearson's r = 0.24), compared to PPCC of the NSG (r = 0.58, p < 0.05). In spectral frequency analysis, gamma band showed "phase-reset" and similar responses after the two auditory stimuli in suppressed and non-suppressed group. However in the case of alpha band, comparison showed significantly low PPCC in SG (r = -0.14) compared to NSG (r = 0.36, p < 0.05). This may be reflecting "phase-out" of alpha band against gamma band at approximately 50 msecs after the test stimulus in the SG. Conclusions Our study suggests that normal P50 suppression is caused by phase-out of alpha band against gamma band after the second auditory stimulus. Thus it is demonstrated that normal sensory gating process is constituted with attenuated alpha power, superimposed on consistent gamma response. Implications of preserved gamma and decreased alpha band in sensory gating function are discussed.


(34141) Korea Institute of Science and Technology Information, 245, Daehak-ro, Yuseong-gu, Daejeon
Copyright (C) KISTI. All Rights Reserved.