• Title, Summary, Keyword: pcb

Search Result 1,955, Processing Time 0.051 seconds

The removal characteristics of PCB by catalyzed fabric filter (촉매 처리된 여과재에 의한 PCB 처리특성)

  • Kim, Moon-Chan
    • Analytical Science and Technology
    • /
    • v.21 no.3
    • /
    • pp.167-173
    • /
    • 2008
  • In order to solve the reproduction problem of PCB, we carried out poly chlorinated biphenyl (PCB) removal at low temperature (< $220^{\circ}C$), which could not take place reproduction of PCB by over 90% on catalyst. We coated catalyst to commercial bag filter for simultaneous removal of PCB and particle. It was found that PCB could be not reproducible due to it's decomposition of benzene ring. The coating method of spray type was more useful than that of precipitation one. PCB removal conversion was highest on the Pt-Co catalyzed bag filter. The data of this study can be well used in order to remove PCB and particle simultaneously for incinerator process by substituting commercial bag filter to catalyzed bag filter.

The Characteristics of PCBs Deposition on Plants (PCBs의 식물에 대한 침착 특성)

  • Kim, Tae-Wook;Yeo, Hyun-Gu;Choi, Min-Kyu;Chun, Man-Young
    • Korean Journal of Environmental Agriculture
    • /
    • v.20 no.2
    • /
    • pp.99-107
    • /
    • 2001
  • PCBs(Polychlorinated biphenyls) in air and plants were measured every two weeks at Hankyong University located in Ansung, Kyoung ki province from July to November in 1999. The percentage of tri-CBs(PCB 28) and tetra-CBs(PCB 52) is 49% of the total PCBs in air, which shows these two components are the major congeners. A correlation coefficient(r) of PCB congeners detected in two plants is 0.83 (p<0.01), indicating that the plants can be used as a passive sampler to indirectly estimate the pollution levels of residual PCBs in the environmental even if they have different physicochemical properties. The average ratio of PCB 110/PCB 52 is higher in plants as 0.5, 2.9 and 2.5 respectively in the air and mulberry leaves as well as scallions, which comes from the higher lipophilicity of PCB 110 rather than the ratio of PCB 110/PCB 52 in the air.

  • PDF

Analysis of SMPS Characteristics applying Ground Plane Layer (Ground Plane레이어를 적용한 SMPS 특성분석)

  • Park, Jin-Hong
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.15 no.1
    • /
    • pp.436-440
    • /
    • 2014
  • To verity the effect of PCB plane layer to the output characteristics of the Switched Mode Power Supply (SMPS), this paper compared with a generic one-layer PCB and a double-side PCB. This paper specially focused on the voltage, the current and the high frequency noise of the output characteristic of the SMPS, using a double-side PCB which has same layout and was installed a ground plane on the opposite side. This double-side PCB was assembled by all same components which used on the SMPS using the single-side PCB. The experiment results show the SMPS using the ground plan PCB can efficiently reduce the high frequency noise to 50mV at 100MHz from 150mV in the single-side PCB. And the results also show the high harmonics frequency was reduced as well.

Data Transformation System Implementation for the Automation of PCB Product (PCB 생산 자동화를 위한 데이터 변환 시스템 구현)

  • Lee Seung-Hyuk;Kim Gui-Jung;Han Jung-Soo
    • The Journal of the Korea Contents Association
    • /
    • v.5 no.5
    • /
    • pp.17-25
    • /
    • 2005
  • In this paper, we design data transformation interface for the automation of PCB product. The data designed to CAD does not exchange itself for the assembly line, so we construct an automation system which is exchangeable. To do this, we analyze the information of PCB components and construct the Information of IC components as database. We also develope two kinds of algorithm; one is to detect human error and another is to exchange itself for the data which is suitable for PCB assembly line. We design data transformation interface to do addition and revision of the information for PCB assembly line. By automating existing manual processing, we are able to shorten access time and enhance reliability of the data and the efficient assembly line of PCB.

  • PDF

Development of Cutting Jig using Separation of PCB component (PCB소자 분리용 컷팅지그 개발)

  • Lee, Seung-Chul;Park, Suk-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.15 no.5
    • /
    • pp.2567-2572
    • /
    • 2014
  • In the present study, we aimed to obtain multi jig that PCB sheet with several PCB component can cut in a short time as to the Separation of PCB component. PCB supporter designed safely at the base frame and each model can be separable. it completed the neodium magnet for the fixing of the upper part laser transmission hole of the both. One of the development, the cutting working with one base frame which PCB component of various standard, fixing of module and bridge connected to PCB component could be possible. and it reduced the inconvenience which has to replace the base frame and PCB sheet fixed member. It compared to other press up about 70% of accuracy and a reduction in investment cost was about 400%.

Reidentification of Comamonas sp. Strain DJ-12 and Analysis of its pcbABC2D2 Genes Responsible for Degradation of 4-Chlorobiphenyl. (Comamonas sp. Strain DJ-12 의 재동정 및 4-Chlorobiphenyl 분해유전자 pcbABC2D2 의 분석)

  • 이준훈;박동우;강철희;채종찬;이동훈;김치경
    • Korean Journal of Microbiology
    • /
    • v.40 no.2
    • /
    • pp.121-126
    • /
    • 2004
  • Comamonas sp. strain DJ-12 is a 4-chlobiphenyl(4CB)-degrading bacterium that was reidentified from Pseudomonas sp. DJ-12. The genomic DNA was isolated from the strain DJ-12 and amplified by PCR with primers for cloning pcbABCD genes responsible for degradation of 4CB. The amino acid sequences deduced from the nucleotide sequences of pcbA1, pcbA2, pcbA3, pcbA4, pcbB, pcbC2, and pcbD2 genes showed 91, 87, 99, 87, 97, 90 and 87% homologies with those of Pseudomonas sp. KKS102, respectively. The pcbC1D1 genes that are involved in the degradation of (4-chloro)1,2-dihydroxybiphenyl produced from 4CB by pcbAB gene products were previously reported in the recombinant plasmid pCU1 from Pseudomonas sp. DJ-12. However, the pcbC2D2 genes in the plasmid pCT4 and pCT5 cloned from Comamonas sp. DJ-12 in this study showed 51 and 62% homologies with those of pcbC1D1 in their nucleotide sequences. The pcbC1D1 and pcbC2D2 genes were found by Southern hybridization to be located at different loci on the chromosome of DJ-12 strain. These results indicate that Comamonas sp. strain DJ-12 has two different sets of pcbCD genes responsible for deg-radation of (4-chloro)1,2-dihydroxybiphenyl.

Numerical Study on Package Warpage as Structure Modeling Method of Materials for a PCB of Semiconductor Package (반도체 패키지용 PCB의 구조 모델링 방법에 따른 패키지의 warpage 수치적 연구)

  • Cho, Seunghyun;Ceon, Hyunchan
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.25 no.4
    • /
    • pp.59-66
    • /
    • 2018
  • In this paper, we analyzed the usefulness of single-structured printed circuit board (PCB) modeling by using numerical analysis to model the PCB structure applied to a package for semiconductor purposes and applying modeling assuming a single structure. PCBs with circuit layer of 3rd and 4th were used for analysis. In addition, measurements were made on actual products to obtain material characteristics of a single structure PCB. The analysis results showed that if the PCB was modeled in a single structure compared to a multi-layered structure, the warpage analysis results resulting from modeling the PCB structure would increase and there would be a significant difference. In addition, as the circuit layer of the PCB increased, the mechanical properties of the PCB, the elastic coefficient and inertia moment of the PCB increased, decreasing the package's warpage.

Evaluation of human exposure to polychlorinated biphenyls using human serum by congener-specific analysis (혈액 중 PCBs 이성질체별 분석에 의한 인체 노출 평가)

  • Park, Hyo-Keun;Lee, Se-Jin;Jin, Guang-Zhu;Kang, Jung-Ho;Baek, Song-E;Chang, Yoon-Seok
    • Analytical Science and Technology
    • /
    • v.19 no.1
    • /
    • pp.73-85
    • /
    • 2006
  • Blood serum concentrations of polychlorinated biphenyls (PCBs) were measured in employees who worked at a municipal solid waste incinerator (MSWI), members of residential community who lived near the MSWI (<0.3km) and members of residential community lived far from the MSWI (>10 km). Human blood serum samples were analyzed for all PCB congeners using high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS). The mean levels of total PCBs and dioxin-like PCBs in 87 serum samples were 242.77 ng/g lipid and 8.83 TEQ pg/g lipid, respectively. The PCB homologue profiles showed that penta-, hexa-, hepta-chlorinated biphenyls contributed more than 80% of the total PCBs concentration. The most abundant congeners were PCB153, PCB138, PCB180, PCB187, PCB118. A statistical analysis was performed to determine whether there were significant correlations between PCB concentrations and specific variables such as age, gender, smoking habits, occupation, BMI (Body Mass Index) and time of residence. As a result, the age was found to be strongly correlated with serum PCB concentrations. In addition, there were strong correlations between total PCBs and PCB153 (r=0.93, p<.0001), dioxin-like PCBs and PCB118 (r=0.98, p<.0001). So these two congeners are satisfactory indicators for total PCB concentrations and dioxin-like PCBs in human blood respectively.

Effects of the Pelvic Compression Belt on Trunk Muscles Activities During Sit-to-Stand, and Stand-to-Sit Tasks (골반압박벨트가 앉아서 일어서기와 일어서서 앉기 동작 시 체간근육 근활성도에 미치는 영향)

  • Jang, Hyun-Jeong;Kim, Suhn-Yeop;Park, Hyun-Ju
    • Physical Therapy Korea
    • /
    • v.20 no.1
    • /
    • pp.1-9
    • /
    • 2013
  • The purpose of this study was to determine the effect of the pelvic compression belt (PCB) on the electromyography (EMG) activities of trunk muscles during sit-to-stand (SitTS), and stand-to-sit (StandTS) tasks. Twenty healthy subjects (7 men and 13 women) were recruited for this study. The subjects performed SitTS, and StandTS tasks, with and without a PCB. Surface EMG was used to record activity of the internal oblique (IO), external oblique (EO), rectus abdominis (RA), erector spinae (ES), and multifidus (MF) of the dominant limb. EMG activity significantly decreased in the RA (without the PCB, $8.34{\pm}6.04$ %maximal voluntary isometric contraction [%MVIC]; with the PCB, $7.64{\pm}5.11$ %MVIC), EO (without the PCB, $14.83{\pm}11.82$ %MVIC; with the PCB, $11.98{\pm}7.60$ %MVIC), MF (without the PCB, $21.74{\pm}7.76$ %MVIC; with the PCB, $18.50{\pm}8.04$ %MVIC), and ES (without the PCB, $18.39{\pm}7.16$ %MVIC; with the PCB, $16.63{\pm}6.31$ %MVIC) during the SitTS task and in the IO (without the PCB, $20.58{\pm}15.60$ %MVIC; with the PCB, $17.27{\pm}12.32$ %MVIlC), RA (without the PCB, $8.04{\pm}5.68$ %MVIC; with the PCB, $7.40{\pm}4.71$ %MVIC), EO (without the PCB, $13.29{\pm}8.80$ %MVIC; with the PCB, $11.24{\pm}6.14$ %MVIC), MF (without the PCB, $18.59{\pm}7.64$ %MVIC; with the PCB, $15.86{\pm}6.48$ %MVIC), and ES (without the PCB, $17.14{\pm}6.44$ %MVIC; with the PCB, $15.46{\pm}5.62$ %MVIC) during the StandTS task when a PCB was used (p<.05). In men the EMG activity of the MF significantly decreased during the SitTS task when a PCB was used (p<.05): in women, the EMG activity of the RA, EO, MF, and ES during the SitTS task and that of the EO, MF, and ES during the SitTS task significantly decreased when a PCB was used (p<.05). In addition, the rates of change in the EMG activity of each muscle differed significantly during the SitTS and StandTS tasks before and after the use of the PCB. However, the EMG activity did not significantly differ between the male and female subjects. These findings suggest that the PCB may contribute to the modification of activation patterns of the trunk muscles during SitTS, and StandTS tasks.

Effects of PCB Patterns on EMI Measurement in TEM Cell and Proposal of PCB Design Guidelines (TEM 셀에서 PCB 패턴이 EMI 측정에 미치는 영향 및 PCB 설계 가이드라인 제시)

  • Choi, Minkyoung;Shin, Youngsan;Lee, Seongsoo
    • Journal of IKEEE
    • /
    • v.21 no.3
    • /
    • pp.272-275
    • /
    • 2017
  • Recently, semiconductor integration density enormously increases and its interconnection width is significantly narrowed, which leads to EMI (electromagnetic interference) problems on chip level. Chip manufacturer exploits TEM cell (transverse electromagnetic cell) to measure EMI on chip level, which requires PCB (printed circuit board) for measurement purpose. However, it is often neglected to consider that PCB patterns and other factors can affect on EMI measurement. In this paper, several test patterns are designed for different PCB design variables, and effects of PCB patterns on EMI measurement in TEM cell are analyzed. Based on these analyses, PCB design guidelines are also proposed to minimize the effects on EMI measurements.