Space to Space Advanced EMU Radio

NASA Technical Reports Server (NTRS)

Maicke, Andrew

2016-01-01

The main task for this project was the development of a prototype for the Space to Space Advanced EMU Radio (SSAER). The SSAER is an updated version of the Space to Space EMU Radio (SSER), which is the current radio used by EMUs (Extravehicular Mobility Unit) for communication between suits and with the ISS. The SSER was developed in 1999, and it was desired to update the design used in the system. Importantly, besides replacing out-of-production parts it was necessary to decrease the size of the radio due to increased volume constraints with the updated Portable Life Support System (PLSS) 2.5, which will be attached on future space suits. In particular, it was desired to fabricate a PCB for the front-end of the prototype SSAER system. Once this board was manufactured and all parts assembled, it could then be tested for quality of operation as well as compliancy with the SSER required specifications. Upon arrival, a small outline of the target system was provided, and it was my responsibility to take that outline to a finished, testable board. This board would include several stages, including frequency mixing, amplification, modulation, demodulation, and handled both the transmit and receive lines of the radio. I developed a new design based on the old SSER system and the outline provided to me, and found parts to fit the tasks in my design. It was also important to consider the specifications of the SSER, which included the system noise figure, gain, and power consumption. Further, all parts needed to be impedance matched, and spurious signals needed to be avoided. In order to fulfill these two requirements, it was necessary to perform some calculations using a Smith Chart and excel analysis. Once all parts were selected, I drew the schematics for the system in Altium Designer. This included developing schematic symbols, as well as layout. Once the schematic was finished, it was then necessary to lay the parts out onto a PCB using Altium. Similar to the schematic design, in order to accomplish this it was necessary to develop component land patterns and add component 3D models. All of this was achieved, and the PCB is currently in review. After it is finished being reviewed, this board will be sent out for manufacture. All electronic components used in the PCB have been acquired, and once the board arrives they will be soldered onto the board using a machine in building 44. Finally, the board will be tested for performance on-site. This will likely be accomplished by the end of the internship.

Chemical and biological processes for multi-metal extraction from waste printed circuit boards of computers and mobile phones.

PubMed

Shah, Monal B; Tipre, Devayani R; Dave, Shailesh R

2014-11-01

E-waste printed circuit boards (PCB) of computers, mobile-phones, televisions, LX (LongXiang) PCB in LED lights and bulbs, and tube-lights were crushed to ≥250 µm particle size and 16 different metals were analysed. A comparative study has been carried out to evaluate the extraction of Cu-Zn-Ni from computer printed circuit boards (c-PCB) and mobile-phone printed circuit boards (m-PCB) by chemical and biological methods. Chemical process showed the extraction of Cu-Zn-Ni by ferric sulphate was best among the studied chemical lixiviants. Bioleaching experiments were carried out with the iron oxidising consortium, which showed that when E-waste and inoculum were added simultaneously in the medium (one-step process); 60.33% and 87.50% Cu, 75.67% and 85.67% Zn and 71.09% and 81.87% Ni were extracted from 10 g L(-1) of c-PCB and m-PCB, respectively, within 10-15 days of reaction time. Whereas, E-waste added after the complete oxidation of Fe(2+) to Fe(3+) iron containing medium (two-step process) showed 85.26% and 99.99% Cu, 96.75% and 99.49% Zn and 93.23% and 84.21% Ni extraction from c-PCB and m-PCB, respectively, only in 6-8 days. Influence of varying biogenerated Fe(3+) and c-PCB concentrations showed that 16.5 g L(-1) of Fe(3+) iron was optimum up to 100 g L(-1) of c-PCB. Changes in pH, acid consumed and redox potential during the process were also studied. The present study shows the ability of an eco-friendly process for the recovery of multi-metals from E-waste even at 100 g L(-1) printed circuit boards concentration. © The Author(s) 2014.

Packaging printed circuit boards: A production application of interactive graphics

NASA Technical Reports Server (NTRS)

Perrill, W. A.

1975-01-01

The structure and use of an Interactive Graphics Packaging Program (IGPP), conceived to apply computer graphics to the design of packaging electronic circuits onto printed circuit boards (PCB), were described. The intent was to combine the data storage and manipulative power of the computer with the imaginative, intuitive power of a human designer. The hardware includes a CDC 6400 computer and two CDC 777 terminals with CRT screens, light pens, and keyboards. The program is written in FORTRAN 4 extended with the exception of a few functions coded in COMPASS (assembly language). The IGPP performs four major functions for the designer: (1) data input and display, (2) component placement (automatic or manual), (3) conductor path routing (automatic or manual), and (4) data output. The most complex PCB packaged to date measured 16.5 cm by 19 cm and contained 380 components, two layers of ground planes and four layers of conductors mixed with ground planes.

Life cycle assessment of a printed circuit board manufacturing plant in Turkey.

PubMed

Ozkan, Elif; Elginoz, Nilay; Germirli Babuna, Fatos

2017-09-29

The objective of this study is to investigate the environmental impacts of a printed circuit board (PCB) manufacturing plant through streamlined life cycle assessment approach. As a result, the most effective recommendations on minimizing the environmental impacts for the mentioned sector are revealed and first steps towards establishing a country specific database are taken. The whole PCB production consists of two consecutive stages: namely board fabrication followed by the manufacturing of PCB. Manufacturing of PCB contributes the highest shares to freshwater aquatic ecotoxicity potential (FAETP) and ozone layer depletion potential (ODP). Eighty-nine percent of FAETP is found to be generated from the manufacturing of PCB. Almost all of this contribution can be attributed to the disposal of copper containing wastewater treatment sludge from etching operations to incineration. On the other hand, PCB manufacturing has 73% share in total ODP. Within the manufacturing of PCB, as etching operations are found to be of importance for all the impact categories except eutrophication potential (EP), it is recommended to focus further studies on in-plant control of etching.

The DMON2: A Commercially Available Broadband Acoustic Monitoring Instrument

DTIC Science & Technology

2015-09-30

the need for a new system design. o Seamless integration of the DMON2 with multiple platforms: Slocum and Wave Gliders, moored real-time buoys and...and robustness (stainless steel design). Transducer Head Printed Circuit Board (PCB): We have completed the design and fabrication of the DMON2

Microfluidic networks embedded in a printed circuit board

NASA Astrophysics Data System (ADS)

Dong, Liangwei; Hu, Yueli

2017-07-01

In order to improve the robustness of microfluidic networks in printed circuit board (PCB)-based microfluidic platforms, a new method was presented. A pattern in a PCB was formed using hollowed-out technology. Polydimethylsiloxane was partly filled in the hollowed-out fields after mounting an adhesive tape on the bottom of the PCB, and solidified in an oven. Then, microfluidic networks were built using soft lithography technology. Microfluidic transportation and dilution operations were demonstrated using the fabricated microfluidic platform. Results show that this method can embed microfluidic networks into a PCB, and microfluidic operations can be implemented in the microfluidic networks embedded into the PCB.

Command and Data Handling Branch Internship

NASA Technical Reports Server (NTRS)

Billings, Rachel Mae

2016-01-01

Modular Integrated Stackable Layers (MISL) is a computer system designed for simple, fast, and cost effective flexible reconfiguration in space environments such as the ISS and Orion projects for various uses. Existing applications include wireless and wired communications, data acquisition and instrumentation, and camera systems, and potential applications include bus protocol converters and subsystem control. MISL is based on Texas Instruments (TI)' MSP430 16-bit ultra-low-power microcontroller device. The purpose of my project was to integrate the MISL system with a liquid crystal display (LCD) touchscreen. The LCD, manufactured by Crystalfontz and part number CFAF320240F-035T-TS, is a 320 by 240 RGB resistive color screen including an optional carrier board. The vast majority of the project was done with Altium Designer, a tool for printed circuit board (PCB) schematic capture, 3D design, and FPGA (Field Programmable Gate Array) development. The new PCB was to allow the LCD to directly stack to the rest of MISL. Research was done with datasheets for the TI microcontroller and touchscreen display in order to meet desired hardware specifications. Documentation on prior MISL projects was also utilized. The initial step was to create a schematic for the LCD, power bus, and data bus connections between components. A layout was then designed with the required physical dimensions, routed traces and vias, power and ground planes, layer stacks, and other specified design rules such as plane clearance and hole size. Multiple consultation sessions were held with Hester Yim, the technical discipline lead for the Command and Data Handling Branch, and Christy Herring, the lead PCB layout designer in the Electronic Design and Manufacturing Branch in order to ensure proper configuration. At the moment, the PCB is awaiting revision by the latter-mentioned branch. Afterwards, the board will begin to undergo the manufacturing and testing process. Throughout the internship at Johnson Space Center, I gained several technical and professional skills. I gained proficiency in Altium Designer and experience using subversion clients, as well as knowledge in PSpice with OrCAD and battery design for spaceflight from on-site. I also gained networking, organization, and communication skills throughout meetings with coworkers and other interns. This internship at Johnson Space Center has impacted my future aspirations by further inspiring me to follow a career path into space rated engineering technology and human spaceflight applications. After graduation, I plan to attend graduate Modular Integrated Stackable Layers (MISL) is a computer system designed for simple, fast, and cost effective flexible reconfiguration in space environments such as the ISS and Orion projects for various uses. Existing applications include wireless and wired communications, data acquisition and instrumentation, and camera systems, and potential applications include bus protocol converters and subsystem control. MISL is based on Texas Instruments’ MSP430 16 bit ultra-low power microcontroller device. The purpose of my project was to integrate the MISL system with a liquid crystal display touchscreen. The LCD, manufactured by Crystalfontz and part number CFAF320240F-035T-TS, is a 320x240 RGB resistive color screen including an optional carrier board.The vast majority of the project was done with Altium Designer, a tool for printed circuit board (PCB) schematic capture, 3D design, and FPGA development. The new PCB was to allow the LCD to directly stack to the rest of MISL. Research was done with datasheets for the TI microcontroller and touchscreen display in order to meet desired hardware specifications. Documentation on prior MISL projects was also utilized. The initial step was to create a schematic for the LCD, power bus, and data bus connections between components. A layout was then designed with the required physical dimensions, routed traces and vias, power and ground planes, layer stacks, and other specified design rules such as plane clearance and hole size. Multiple consultation sessions were held with Hester Yim, the technical discipline lead for the Command and Data Handling Branch, and Christy Herring, the lead PCB layout designer in the Electronic Design and Manufacturing Branch in order to ensure proper configuration. At themoment, the PCB is awaiting revision by the latter-mentioned branch. Afterwards, the board will begin to undergo the manufacturing and testing process.Throughout the internship at Johnson Space Center, I gained several technical and professional skills. I gained proficiency in Altium Designer and experience using subversion clients, as well as knowledge in PSpice with OrCAD and battery design for spaceflight from on-site. I also gained networking, organization, and communication skills throughout meetings with coworkers and other interns. This internship at Johnson Space Center has impacted my future aspirations by further inspiring me to follow a career path into space rated engineering technology and human spaceflight applications. After graduation, I plan to attend graduate school for a master's or doctorate degree in electrical or computer engineering.

Electrochemical Migration Behavior of Copper-Clad Laminate and Electroless Nickel/Immersion Gold Printed Circuit Boards under Thin Electrolyte Layers

PubMed Central

Yi, Pan; Xiao, Kui; Ding, Kangkang; Dong, Chaofang; Li, Xiaogang

2017-01-01

The electrochemical migration (ECM) behavior of copper-clad laminate (PCB-Cu) and electroless nickel/immersion gold printed circuit boards (PCB-ENIG) under thin electrolyte layers of different thicknesses containing 0.1 M Na2SO4 was studied. Results showed that, under the bias voltage of 12 V, the reverse migration of ions occurred. For PCB-Cu, both copper dendrites and sulfate precipitates were found on the surface of FR-4 (board material) between two plates. Moreover, the Cu dendrite was produced between the two plates and migrated toward cathode. Compared to PCB-Cu, PCB-ENIG exhibited a higher tendency of ECM failure and suffered from seriously short circuit failure under high relative humidity (RH) environment. SKP results demonstrated that surface potentials of the anode plates were greater than those of the cathode plates, and those potentials of the two plates exhibited a descending trend as the RH increased. At the end of the paper, an electrochemical migration corrosion failure model of PCB was proposed. PMID:28772497

Theoretic model and computer simulation of separating mixture metal particles from waste printed circuit board by electrostatic separator.

PubMed

Li, Jia; Xu, Zhenming; Zhou, Yaohe

2008-05-30

Traditionally, the mixture metals from waste printed circuit board (PCB) were sent to the smelt factory to refine pure copper. Some valuable metals (aluminum, zinc and tin) with low content in PCB were lost during smelt. A new method which used roll-type electrostatic separator (RES) to recovery low content metals in waste PCB was presented in this study. The theoretic model which was established from computing electric field and the analysis of forces on the particles was used to write a program by MATLAB language. The program was design to simulate the process of separating mixture metal particles. Electrical, material and mechanical factors were analyzed to optimize the operating parameters of separator. The experiment results of separating copper and aluminum particles by RES had a good agreement with computer simulation results. The model could be used to simulate separating other metal (tin, zinc, etc.) particles during the process of recycling waste PCBs by RES.

Electrostatic separation for recycling waste printed circuit board: a study on external factor and a robust design for optimization.

PubMed

Hou, Shibing; Wu, Jiang; Qin, Yufei; Xu, Zhenming

2010-07-01

Electrostatic separation is an effective and environmentally friendly method for recycling waste printed circuit board (PCB) by several kinds of electrostatic separators. However, some notable problems have been detected in its applications and cannot be efficiently resolved by optimizing the separation process. Instead of the separator itself, these problems are mainly caused by some external factors such as the nonconductive powder (NP) and the superficial moisture of feeding granule mixture. These problems finally lead to an inefficient separation. In the present research, the impacts of these external factors were investigated and a robust design was built to optimize the process and to weaken the adverse impact. A most robust parameter setting (25 kv, 80 rpm) was concluded from the experimental design. In addition, some theoretical methods, including cyclone separation, were presented to eliminate these problems substantially. This will contribute to efficient electrostatic separation of waste PCB and make remarkable progress for industrial applications.

Integrated Advanced Microwave Sounding Unit-A (AMSU-A). As-Designed Parts List: Electrical, Electronic and Electromechanical (EEE) As-Designed Parts List

NASA Technical Reports Server (NTRS)

Lorenz, E.

1999-01-01

This report comprises the Electrical, Electronic, and Electromechanical (EEE) As Designed Parts List to be used in the Integrated Advanced Microwave Sounding Unit-A (AMSU-A) instrument. The purpose of the EEE As-Designed Parts List is to provide a listing of EEE parts identified for use on the Integrated AMSU-A. All EEE parts used on the AMSU-A must meet the parts control requirements as defined in the Parts Control Plan (POP). All part applications are reviewed by the Parts Control Board (PCB) and granted approval if POP requirements are met. The "As Designed Parts Lists" indicates PCB approval status, and thus also serves as the Program Approved Parts List.

Simple fabricating PCB-based inter digital capacitor for glucose biosensor

NASA Astrophysics Data System (ADS)

Jamaluddin, Anif; Taufik, Usman; Iriani, Yofentina; Budiawanti, Sri; Suyitno

2017-01-01

This paper presents the simple fabrication of interdigital capacitor (IDC) using print circuit board (PCB) for glucose biosensor. PCB type FR04 laminated with Cu as electrode was used as sensor base. The IDC pattern of sensor was designed by computer aided design program and printed with a laser printer on plastic polymers. Then, the IDC pattern was transferred into PCB by a laminating machine. The etching process of PCB was done by immersing in ferric chloride liquid to form Cu pattern. There were five patterns of sensors including 5, 10, 15, 20 and 25 patterns. The capacitance value of PCB was measured with RCL meter when IDC biosensor was put in air, aquades, and glucose liquid with various moles of glucose (0.02, 0.04, 0.06, 0.08, 0.1M). In air medium, the increase of pattern number of IDC sensor (from 5 to 25) caused the sensor capacitance rose from 22 pf to 46 pf. In addition, the capacitance of sensor was dramatically increased until 0.36 µf while IDC sensor with 25 patterns was put in aquades medium. In liquid glucose medium, the capacitance of IDC biosensor with 25 patterns increased until 0.58 µf on 0.1 M glucose liquid.

Lead phytoextraction from printed circuit computer boards by Lolium perenne L. and Medicago sativa L.

PubMed

Díaz Martínez, María Esther; Argumedo-Delira, Rosalba; Sánchez Viveros, Gabriela; Alarcón, Alejandro; Trejo-Téllez, Libia Iris

2018-04-16

This work assessed the ability of Lolium perenne and Medicago sativa for extracting lead (Pb) from particulate printed circuit computer boards (PCB) mixed in sand with the following concentrations: 0.5, 1.0 and 1.5 g of PCB, and including a control treatment without PCB. The PCB were obtained from computers, and grinded in two particle sizes: 0.0594 mm (PCB1) and 0.0706 mm (PCB2). The PCB particle sizes at their corresponding concentrations were applied to L. perenne and M. sativa by using three experimental assays. In assay II, PCB2 affected the biomass production for both plants. For assay III, the PCB1 increased the biomass of M. sativa (236.5%) and L. perenne (142.2%) when applying either 0.5 or 1.0 g, respectively. In regards to phytoextraction, assay I showed the highest Pb-extraction by roots of L. perenne (4.7%) when exposed to 1.5 g of PCB1. At assay I, L. perenne showed a Pb-bioconcentration factor higher than 1.0 when growing at 0.5 g of PCB1, and when HNO 3 was used as digestion solution; moreover, in assay III both plants showed a Pb-translocation factor higher than 1.0. Therefore, Lolium perenne and Medicago sativa are able to recover Pb from electronic wastes (PCB).

Automatic extraction of via in the CT image of PCB

NASA Astrophysics Data System (ADS)

Liu, Xifeng; Hu, Yuwei

2018-04-01

In modern industry, the nondestructive testing of printed circuit board (PCB) can prevent effectively the system failure and is becoming more and more important. In order to detect the via in the PCB base on the CT image automatically accurately and reliably, a novel algorithm for via extraction based on weighting stack combining the morphologic character of via is designed. Every slice data in the vertical direction of the PCB is superimposed to enhanced vias target. The OTSU algorithm is used to segment the slice image. OTSU algorithm of thresholding gray level images is efficient for separating an image into two classes where two types of fairly distinct classes exist in the image. Randomized Hough Transform was used to locate the region of via in the segmented binary image. Then the 3D reconstruction of via based on sequence slice images was done by volume rendering. The accuracy of via positioning and detecting from a CT images of PCB was demonstrated by proposed algorithm. It was found that the method is good in veracity and stability for detecting of via in three dimensional.

Direct-referencing Two-dimensional-array Digital Microfluidics Using Multi-layer Printed Circuit Board

PubMed Central

Gong, Jian; Kim, Chang-Jin “CJ”

2008-01-01

Digital (i.e. droplet-based) microfluidics, by the electrowetting-on-dielectric (EWOD) mechanism, has shown great potential for a wide range of applications, such as lab-on-a-chip. While most reported EWOD chips use a series of electrode pads essentially in one-dimensional line pattern designed for specific tasks, the desired universal chips allowing user-reconfigurable paths would require the electrode pads in two-dimensional pattern. However, to electrically access the electrode pads independently, conductive lines need to be fabricated underneath the pads in multiple layers, raising a cost issue especially for disposable chip applications. In this article, we report the building of digital microfluidic plates based on a printed-circuit-board (PCB), in which multilayer electrical access lines were created inexpensively using mature PCB technology. However, due to its surface topography and roughness and resulting high resistance against droplet movement, as-fabricated PCB surfaces require unacceptably high (~500 V) voltages unless coated with or immersed in oil. Our goal is EWOD operations of aqueous droplets not only on oil-covered but also on dry surfaces. To meet varying levels of performances, three types of gradually complex post-PCB microfabrication processes are developed and evaluated. By introducing land-grid-array (LGA) sockets in the packaging, a scalable digital microfluidics system with reconfigurable and low-cost chip is also demonstrated. PMID:19234613

Printed Circuit Board Assembly for Use in Space Missions

NASA Technical Reports Server (NTRS)

Petrick, David J. (Inventor); Vo, Luan (Inventor); Albaijes, Dennis (Inventor)

2017-01-01

An electronic assembly for use in space missions that includes a PCB and one or more multi-pin CGA devices coupled to the PCB. The PCB has one or more via-in-pad features and each via-in-pad feature comprises a land pad configured to couple a pin of the one or more multi-pin CGA devices to the via. The PCB also includes a plurality of layers arranged symmetrically in a two-halves configuration above and below a central plane of the PCB.

Effects of mould on electrochemical migration behaviour of immersion silver finished printed circuit board.

PubMed

Yi, Pan; Xiao, Kui; Dong, Chaofang; Zou, Shiwen; Li, Xiaogang

2018-02-01

The role played by mould in the electrochemical migration (ECM) behaviour of an immersion silver finished printed circuit board (PCB-ImAg) under a direct current (DC) bias was investigated. An interesting phenomenon is found whereby mould, especially Aspergillus niger, can preferentially grow well on PCB-ImAg under electrical bias and then bridge integrated circuits and form a migration path. The cooperation of the mould and DC bias aggravates the ECM process occurring on PCB-ImAg. When the bias voltage is below 15V, ECM almost does not occur for Ag coating. Mechanisms that explain the ECM processes of PCB-ImAg in the presence of mould and DC bias are proposed. Copyright © 2017. Published by Elsevier B.V.

Converting non-metallic printed circuit boards waste into a value added product.

PubMed

Muniyandi, Shantha Kumari; Sohaili, Johan; Hassan, Azman; Mohamad, Siti Suhaila

2013-01-01

The aim of this study was to investigate the feasibility of using nonmetallic printed circuit board (PCB) waste as filler in recycled HDPE (rHDPE) in production of rHDPE/PCB composites. Maleic anhydride modified linear low-density polyethylene (MAPE) was used as compatibilizer. In particular, the effects of nonmetallic PCB and MAPE on mechanical properties of the composites were assessed through tensile, flexural and impact testing. Scanning electron microscope (SEM) was used to study the dispersion of nonmetallic PCB and MAPE in the matrix. Nonmetallic PCB was blended with rHDPE from 0-30 wt% and prepared by counter-rotating twin screw extruder followed by molding into test samples via hot press for analysis. A good balance between stiffness, strength and toughness was achieved for the system containing 30 wt% PCB. Thus, this system was chosen in order to investigate the effect of the compatibilizer on the mechanical properties of the composites. The results indicate that MAPE as a compatiblizer can effectively promote the interfacial adhesion between nonmetallic PCB and rHDPE. The addition of 6 phr MAPE increased the flexural strength, tensile strength and impact strength by 71%, 98% and 44% respectively compared to the uncompatibilized composites.

Converting non-metallic printed circuit boards waste into a value added product

PubMed Central

2013-01-01

The aim of this study was to investigate the feasibility of using nonmetallic printed circuit board (PCB) waste as filler in recycled HDPE (rHDPE) in production of rHDPE/PCB composites. Maleic anhydride modified linear low-density polyethylene (MAPE) was used as compatibilizer. In particular, the effects of nonmetallic PCB and MAPE on mechanical properties of the composites were assessed through tensile, flexural and impact testing. Scanning electron microscope (SEM) was used to study the dispersion of nonmetallic PCB and MAPE in the matrix. Nonmetallic PCB was blended with rHDPE from 0–30 wt% and prepared by counter-rotating twin screw extruder followed by molding into test samples via hot press for analysis. A good balance between stiffness, strength and toughness was achieved for the system containing 30 wt% PCB. Thus, this system was chosen in order to investigate the effect of the compatibilizer on the mechanical properties of the composites. The results indicate that MAPE as a compatiblizer can effectively promote the interfacial adhesion between nonmetallic PCB and rHDPE. The addition of 6 phr MAPE increased the flexural strength, tensile strength and impact strength by 71%, 98% and 44% respectively compared to the uncompatibilized composites. PMID:24764542

PCB tester selection for future systems. Volume 2. Final report, August 1989-June 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmitt, W.

1992-06-01

This report describes a computer program (to run on an IBM compatible PC) designed to aid in the selection of a PCB tester, given the characteristics of the PC board to be tested. The program contains a limited data base of PCB testers, and others may be added easily. This report also provides a specification for a limited family of PCB testers to fill the gap between what the U.S. Air Force is expected to need and what is expected to be available within the next four to six years. The parameters used in the computer program and the specificationmore » are based on a survey of military and commercial PCBs - both those now available and those expected to come on line within the next four to six years. The results of the survey are covered in volume 2 - available from DTIC. Automatic Test Equipment, Technology Forecast, Air Force Avionics.« less

PCB tester selection for future systems. Volume 1. Final report, August 1989-June 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmitt, W.

1992-06-01

This report describes a computer program (to run on an IBM compatible PC) designed to aid in the selection of a PCB tester, given the characteristics of the PC board to be tested. The program contains a limited data base of PCB testers, and others may be added easily. This report also provides a specification for a limited family of PCB testers to fill the gap between what the U.S. Air Force is expected to need and what is expected to be available within the next four to six years. The parameters used in the computer program and the specificationmore » are based on a survey of military and commercial PCBs - both those now available and those expected to come on line within the next four to six years. The results of the survey are covered in volume 2 - available from DTIC. Automatic Test Equipment, Technology Forecast, Air Force Avionics.« less

4 channels x 10-Gbps optoelectronic transceiver based on silicon optical bench technology

NASA Astrophysics Data System (ADS)

Chen, Chin T.; Hsiao, Hsu L.; Chang, Chia. C.; Shen, Po K.; Lu, Guan F.; Lee, Yun C.; Chang, Shou F.; Lin, Yo S.; Wu, Mount L.

2012-01-01

In this paper, a bi-directional 4-channel x 10-Gbps optoelectronic transceiver based on this silicon optical bench (SiOB) technology is developed. A bi-directional optical sub-assembly (BOSA), fiber ribbon assembly, PCB with high frequency trace design, transmitter driver, and receiver TIA IC are included in this transceiver. The BOSA and PCB also have some specific design for conventional chip-on-board (COB) process. In eye diagram measurement, the transmitter can pass 10-G Ethernet eye mask with 25% margin at room temperature; Bit-error-rate (BER) performance from the transmitter to receiver via 10-meter fiber can achieve 10-12 order, which confirm the transceiver's ability of 10-Gbps data transmission per a channel.

Flexible Packaging by Film-Assisted Molding for Microintegration of Inertia Sensors

PubMed Central

Hera, Daniel; Berndt, Armin; Günther, Thomas; Schmiel, Stephan; Harendt, Christine; Zimmermann, André

2017-01-01

Packaging represents an important part in the microintegration of sensors based on microelectromechanical system (MEMS). Besides miniaturization and integration density, functionality and reliability in combination with flexibility in packaging design at moderate costs and consequently high-mix, low-volume production are the main requirements for future solutions in packaging. This study investigates possibilities employing printed circuit board (PCB-)based assemblies to provide high flexibility for circuit designs together with film-assisted transfer molding (FAM) to package sensors. The feasibility of FAM in combination with PCB and MEMS as a packaging technology for highly sensitive inertia sensors is being demonstrated. The results prove the technology to be a viable method for damage-free packaging of stress- and pressure-sensitive MEMS. PMID:28653992

In-situ, Nanosecond, High Resolution TEM Instrumentation for Multi-Disciplinary Research and Education in Nanomaterials

DTIC Science & Technology

2014-10-30

rotation of the tilt table (Figure 3b). A torsion spring pushes the tilt table against the push bar, so that contact is maintained (Figure 3a). The tilt...designed flexible circuit board (Figure 3a), composed of copper conductors patterned on top of vacuum-compatible kapton polymer. The flexibility of...this board is important so that it does not hinder rotation of the tilt-table. The flexible PCB extends into the hollow holder shaft, and interfaces

An Approach for Practical Use of Common-Mode Noise Reduction Technique for In-Vehicle Electronic Equipment

NASA Astrophysics Data System (ADS)

Uno, Takanori; Ichikawa, Kouji; Mabuchi, Yuichi; Nakamura, Atsushi; Okazaki, Yuji; Asai, Hideki

In this paper, we studied the use of common-mode noise reduction technique for in-vehicle electronic equipment in an actual instrument design. We have improved the circuit model of the common-mode noise that flows to the wire harness to add the effect of a bypass capacitor located near the LSI. We analyzed the improved circuit model using a circuit simulator and verified the effectiveness of the noise reduction condition derived from the circuit model. It was also confirmed that offsetting the impedance mismatch in the PCB section requires to make a circuit constant larger than that necessary for doing the impedance mismatch in the LSI section. An evaluation circuit board comprising an automotive microcomputer was prototyped to experiment on the common-mode noise reduction effect of the board. The experimental results showed the noise reduction effect of the board. The experimental results also revealed that the degree of impedance mismatch in the LSI section can be estimated by using a PCB having a known impedance. We further inquired into the optimization of impedance parameters, which is difficult for actual products at present. To satisfy the noise reduction condition composed of numerous parameters, we proposed a design method using an optimization algorithm and an electromagnetic field simulator, and confirmed its effectiveness.

Surface and Electrical Characterization of Ag/AgCl Pseudo-Reference Electrodes Manufactured with Commercially Available PCB Technologies

PubMed Central

Moschou, Despina; Trantidou, Tatiana; Regoutz, Anna; Carta, Daniela; Morgan, Hywel; Prodromakis, Themistoklis

2015-01-01

Lab-on-Chip is a technology that could potentially revolutionize medical Point-of-Care diagnostics. Considerable research effort is focused towards innovating production technologies that will make commercial upscaling financially viable. Printed circuit board manufacturing techniques offer several prospects in this field. Here, we present a novel approach to manufacturing Printed Circuit Board (PCB)-based Ag/AgCl reference electrodes, an essential component of biosensors. Our prototypes were characterized both structurally and electrically. Scanning Electron Microscopy (SEM) and X-Ray Photoelectron Spectroscopy (XPS) were employed to evaluate the electrode surface characteristics. Electrical characterization was performed to determine stability and pH dependency. Finally, we demonstrate utilization along with PCB pH sensors, as a step towards a fully integrated PCB platform, comparing performance with discrete commercial reference electrodes. PMID:26213940

75 FR 73080 - Science Advisory Board Staff Office; Request for Nominations of Experts for the SAB...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-29

... are IRIS reference doses (RfDs) for two commercial PCB mixtures: Aroclor 1016 and Aroclor 1254 that... developing a draft assessment of the potential noncancer health hazards of complex PCB mixtures for inclusion... with the goal of establishing an RfD for application to complex PCB mixtures. The EPA's National Center...

Low-Cost Wireless Temperature Measurement: Design, Manufacture, and Testing of a PCB-Based Wireless Passive Temperature Sensor.

PubMed

Yan, Dan; Yang, Yong; Hong, Yingping; Liang, Ting; Yao, Zong; Chen, Xiaoyong; Xiong, Jijun

2018-02-10

Low-cost wireless temperature measurement has significant value in the food industry, logistics, agriculture, portable medical equipment, intelligent wireless health monitoring, and many areas in everyday life. A wireless passive temperature sensor based on PCB (Printed Circuit Board) materials is reported in this paper. The advantages of the sensor include simple mechanical structure, convenient processing, low-cost, and easiness in integration. The temperature-sensitive structure of the sensor is a dielectric-loaded resonant cavity, consisting of the PCB substrate. The sensitive structure also integrates a patch antenna for the transmission of temperature signals. The temperature sensing mechanism of the sensor is the dielectric constant of the PCB substrate changes with temperature, which causes the resonant frequency variation of the resonator. Then the temperature can be measured by detecting the changes in the sensor's working frequency. The PCB-based wireless passive temperature sensor prototype is prepared through theoretical design, parameter analysis, software simulation, and experimental testing. The high- and low-temperature sensing performance of the sensor is tested, respectively. The resonant frequency decreases from 2.434 GHz to 2.379 GHz as the temperature increases from -40 °C to 125 °C. The fitting curve proves that the experimental data have good linearity. Three repetitive tests proved that the sensor possess well repeatability. The average sensitivity is 347.45 KHz / ℃ from repetitive measurements conducted three times. This study demonstrates the feasibility of the PCB-based wireless passive sensor, which provides a low-cost temperature sensing solution for everyday life, modern agriculture, thriving intelligent health devices, and so on, and also enriches PCB product lines and applications.

Low-Cost Wireless Temperature Measurement: Design, Manufacture, and Testing of a PCB-Based Wireless Passive Temperature Sensor

PubMed Central

Yan, Dan; Yang, Yong; Hong, Yingping; Liang, Ting; Yao, Zong; Chen, Xiaoyong; Xiong, Jijun

2018-01-01

Low-cost wireless temperature measurement has significant value in the food industry, logistics, agriculture, portable medical equipment, intelligent wireless health monitoring, and many areas in everyday life. A wireless passive temperature sensor based on PCB (Printed Circuit Board) materials is reported in this paper. The advantages of the sensor include simple mechanical structure, convenient processing, low-cost, and easiness in integration. The temperature-sensitive structure of the sensor is a dielectric-loaded resonant cavity, consisting of the PCB substrate. The sensitive structure also integrates a patch antenna for the transmission of temperature signals. The temperature sensing mechanism of the sensor is the dielectric constant of the PCB substrate changes with temperature, which causes the resonant frequency variation of the resonator. Then the temperature can be measured by detecting the changes in the sensor’s working frequency. The PCB-based wireless passive temperature sensor prototype is prepared through theoretical design, parameter analysis, software simulation, and experimental testing. The high- and low-temperature sensing performance of the sensor is tested, respectively. The resonant frequency decreases from 2.434 GHz to 2.379 GHz as the temperature increases from −40 °C to 125 °C. The fitting curve proves that the experimental data have good linearity. Three repetitive tests proved that the sensor possess well repeatability. The average sensitivity is 347.45 KHz/°C℃ from repetitive measurements conducted three times. This study demonstrates the feasibility of the PCB-based wireless passive sensor, which provides a low-cost temperature sensing solution for everyday life, modern agriculture, thriving intelligent health devices, and so on, and also enriches PCB product lines and applications. PMID:29439393

Recovery of metals from waste printed circuit boards by a mechanical method using a water medium.

PubMed

Duan, Chenlong; Wen, Xuefeng; Shi, Changsheng; Zhao, Yuemin; Wen, Baofeng; He, Yaqun

2009-07-15

Research on the recycling of waste printed circuit boards (PCB) is at the forefront of environmental pollution prevention and resource recycling. To effectively crush waste PCB and to solve the problem of secondary pollution from fugitive odors and dust created during the crushing process, a wet impacting crusher was employed to achieve comminution liberation of the PCB in a water medium. The function of water in the crushing process was analyzed. When using slippery hammerheads, a rotation speed of 1470 rpm, a water flow of 6m(3)/h and a sieve plate aperture of 2.2mm, 95.87% of the crushed product was sized less than 1mm. 94.30% of the metal was in this grade of product. Using smashed material graded -1mm for further research, a Falcon concentrator was used to recover the metal from the waste PCB. Engineering considerations were the liberation degree, the distribution ratio of the metal and a way to simplify the technology. The separation mechanism for fine particles of different densities in a Falcon concentrator was analyzed in detail and the separation process in the segregation and separation zones was deduced. Also, the magnitude of centrifugal acceleration, the back flow water pressure and the feed slurry concentration, any of which might affect separation results, were studied. A recovery model was established using Design-Expert software. Separating waste PCB, crushed to -1mm, with the Falcon separator gave a concentrated product graded 92.36% metal with a recovery of 97.05%. To do this the reverse water pressure was 0.05 MPa, the speed transducer frequency was set at 30 Hz and the feed density was 20 g/l. A flow diagram illustrating the new technique of wet impact crushing followed by separation with a Falcon concentrator is provided. The technique will prevent environmental pollution from waste PCB and allow the effective recovery of resources. Water was used as the medium throughout the whole process.

PCB Fault Detection Using Image Processing

NASA Astrophysics Data System (ADS)

Nayak, Jithendra P. R.; Anitha, K.; Parameshachari, B. D., Dr.; Banu, Reshma, Dr.; Rashmi, P.

2017-08-01

The importance of the Printed Circuit Board inspection process has been magnified by requirements of the modern manufacturing environment where delivery of 100% defect free PCBs is the expectation. To meet such expectations, identifying various defects and their types becomes the first step. In this PCB inspection system the inspection algorithm mainly focuses on the defect detection using the natural images. Many practical issues like tilt of the images, bad light conditions, height at which images are taken etc. are to be considered to ensure good quality of the image which can then be used for defect detection. Printed circuit board (PCB) fabrication is a multidisciplinary process, and etching is the most critical part in the PCB manufacturing process. The main objective of Etching process is to remove the exposed unwanted copper other than the required circuit pattern. In order to minimize scrap caused by the wrongly etched PCB panel, inspection has to be done in early stage. However, all of the inspections are done after the etching process where any defective PCB found is no longer useful and is simply thrown away. Since etching process costs 0% of the entire PCB fabrication, it is uneconomical to simply discard the defective PCBs. In this paper a method to identify the defects in natural PCB images and associated practical issues are addressed using Software tools and some of the major types of single layer PCB defects are Pattern Cut, Pin hole, Pattern Short, Nick etc., Therefore the defects should be identified before the etching process so that the PCB would be reprocessed. In the present approach expected to improve the efficiency of the system in detecting the defects even in low quality images

Ultrasonic recovery of copper and iron through the simultaneous utilization of Printed Circuit Boards (PCB) spent acid etching solution and PCB waste sludge.

PubMed

Huang, Zhiyuan; Xie, Fengchun; Ma, Yang

2011-01-15

A method was developed to recover the copper and iron from Printed Circuit Boards (PCB) manufacturing generated spent acid etching solution and waste sludge with ultrasonic energy at laboratory scale. It demonstrated that copper-containing PCB spent etching solution could be utilized as a leaching solution to leach copper from copper contained PCB waste sludge. It also indicated that lime could be used as an alkaline precipitating agent in this method to precipitate iron from the mixture of acidic PCB spent etching solution and waste sludge. This method provided an effective technique for the recovery of copper and iron through simultaneous use of PCB spent acid solution and waste sludge. The leaching rates of copper and iron enhanced with ultrasound energy were reached at 93.76% and 2.07% respectively and effectively separated copper from iron. Followed by applying lime to precipitate copper from the mixture of leachate and rinsing water produced by the copper and iron separation, about 99.99% and 1.29% of soluble copper and calcium were settled as the solids respectively. Furthermore the settled copper could be made as commercial rate copper. The process performance parameters studied were pH, ultrasonic power, and temperature. This method provided a simple and reliable technique to recover copper and iron from waste streams generated by PCB manufacturing, and would significantly reduce the cost of chemicals used in the recovery. Copyright © 2010 Elsevier B.V. All rights reserved.

Studies on the reuse of waste printed circuit board as an additive for cement mortar.

PubMed

Ban, Bong-Chan; Song, Jong-Yoon; Lim, Joong-Yeon; Wang, Soo-Kyoon; An, Kwang-Guk; Kim, Dong-Su

2005-01-01

The recent development in electronic industries has generated a drastic increase in production of printed circuit boards (PCB). Accordingly, the amount of waste PCB from electronic productions and waste electronics and its environmental impact such as soil and groundwater contamination have become a great concern. This study aims to propose a method for reuse of waste PCB as an additive for cement mortar. Although the expansibility of waste PCB powder finer than 0.08 mm in water was observed to be greater than 2.0%, the maximum expansion rates in water for 0.08 to approximately 0.15 and 0.15 to approximately 0.30 mm sized PCB powders were less than 2.0%, which satisfied the necessary condition as an alternative additive for cement mortar in place of sand. The difference in the compressive strength of standard mortar and waste PCB added mortar was observed to be less than 10% and their difference was expected to be smaller after prolonged aging. The durability of waste PCB added cement mortar was also examined through dry/wet conditioning cyclic tests and acidic/alkaline conditioning tests. From the tests, both weight and compressive strength of cement mortar were observed to be recovered with aging. The leaching test for heavy metals from waste PCB added mortar showed that no heavy metal ions such as copper, lead, or cadmium were detected in the leachate, which resulted from fixation effect of the cement hydrates.

New Discrete Fibonacci Charge Pump Design, Evaluation and Measurement

NASA Astrophysics Data System (ADS)

Matoušek, David; Hospodka, Jiří; Šubrt, Ondřej

2017-06-01

This paper focuses on the practical aspects of the realisation of Dickson and Fibonacci charge pumps. Standard Dickson charge pump circuit solution and new Fibonacci charge pump implementation are compared. Both charge pumps were designed and then evaluated by LTspice XVII simulations and realised in a discrete form on printed circuit board (PCB). Finally, the key parameters as the output voltage, efficiency, rise time, variable power supply and clock frequency effects were measured.

Electro-optical backplane demonstrator with integrated multimode gradient-index thin glass waveguide panel

NASA Astrophysics Data System (ADS)

Schröder, Henning; Brusberg, Lars; Pitwon, Richard; Whalley, Simon; Wang, Kai; Miller, Allen; Herbst, Christian; Weber, Daniel; Lang, Klaus-Dieter

2015-03-01

Optical interconnects for data transmission at board level offer increased energy efficiency, system density, and bandwidth scalability compared to purely copper driven systems. We present recent results on manufacturing of electrooptical printed circuit board (PCB) with integrated planar glass waveguides. The graded index multi-mode waveguides are patterned inside commercially available thin-glass panels by performing a specific ion-exchange process. The glass waveguide panel is embedded within the layer stack-up of a PCB using proven industrial processes. This paper describes the design, manufacture, assembly and characterization of the first electro-optical backplane demonstrator based on integrated planar glass waveguides. The electro-optical backplane in question is created by laminating the glass waveguide panel into a conventional multi-layer electronic printed circuit board stack-up. High precision ferrule mounts are automatically assembled, which will enable MT compliant connectors to be plugged accurately to the embedded waveguide interfaces on the glass panel edges. The demonstration platform comprises a standardized sub-rack chassis and five pluggable test cards each housing optical engines and pluggable optical connectors. The test cards support a variety of different data interfaces and can support data rates of up to 32 Gb/s per channel.

Design and fabrication of embedded micro-mirror inserts for out-of-plane coupling in PCB-level optical interconnections

NASA Astrophysics Data System (ADS)

Van Erps, Jurgen; Hendrickx, Nina; Bosman, Erwin; Van Daele, Peter; Debaes, Christof; Thienpont, Hugo

2010-05-01

Optical interconnections have gained interest over the last years, and several approaches have been presented for the integration of optics to the printed circuit board (PCB)-level. The use of a polymer optical waveguide layer appears to be the prevailing solution to route optical signals on the PCB. The most difficult issue is the efficient out-of-plane coupling of light between surface-normal optoelectronic devices (lasers and photodetectors) and PCB-integrated waveguides. The most common approach consists of using 45° reflecting micro-mirrors. The micro-mirror performance significantly affects the total insertion loss of the optical interconnect system, and hence has a crucial role on the system's bit error rate (BER) characteristics. Several technologies have been proposed for the fabrication of 45° reflector micro-mirrors directly into waveguides. Alternatively, it is possible to make use of discrete coupling components which have to be inserted into cavities formed in the PCB-integrated waveguides. In this paper, we present a hybrid approach where we try to combine the advantages of integrated and discrete coupling mirrors, i.e. low coupling loss and maintenance of the planararity of the top surface of the optical layer, allowing the lamination of additional layers or the mounting of optoelectronic devices. The micro-mirror inserts are designed through non-sequential ray tracing simulations, including a tolerance analysis, and subsequently prototyped with Deep Proton Writing (DPW). The DPW prototypes are compatible with mass fabrication at low cost in a wide variety of high-tech plastics. The DPW micro-mirror insert is metallized and inserted in a laser ablated cavity in the optical layer and in a next step covered with cladding material. Surface roughness measurements confirm the excellent quality of the mirror facet. An average mirror loss of 0.35-dB was measured in a receiver scheme, which is the most stringent configuration. Finally, the configuration is robust, since the mirror is embedded and thus protected from environmental contamination, like dust or moisture adsorption, which makes them interesting candidates for out-of-plane coupling in high-end boards.

Initial Corrosion Behavior and Mechanism of PCB-HASL in Typical Outdoor Environments in China

NASA Astrophysics Data System (ADS)

Ding, Kangkang; Xiao, Kui; Dong, Chaofang; Zou, Shiwen; Yi, Pan; Li, Xiaogang

2015-11-01

A long-term (1, 3, and 6 months) outdoor exposure test was performed for lead-free hot air solder leveling printed circuit boards (PCB-HASL) in typical environments in China and the corrosion behavior and mechanism of outdoor PCB-HASL were investigated. In a dry environment PCB-HASL corroded slightly, because of the protective effect of surface oxide films. Corrosion spread from places where dust particles were deposited or mold spores were adsorbed. Under the combined effects of humidity and contamination, large amounts of granular corrosion products with a loose structure were generated, greatly reducing the protective effect of the Sn layer. Furthermore, protection of the edges of the plates was poor, and corrosion products from these regions migrated rapidly on the FR-4 board. When a 12 V electrical bias was applied, Sn and Cu migrated simultaneously. In the electrochemical migration process the effect of humidity was much more critical than that of contamination.

Two-step bioleaching of copper and gold from discarded printed circuit boards (PCB).

PubMed

Işıldar, Arda; van de Vossenberg, Jack; Rene, Eldon R; van Hullebusch, Eric D; Lens, Piet N L

2016-11-01

An effective strategy for environmentally sound biological recovery of copper and gold from discarded printed circuit boards (PCB) in a two-step bioleaching process was experimented. In the first step, chemolithotrophic acidophilic Acidithiobacillus ferrivorans and Acidithiobacillus thiooxidans were used. In the second step, cyanide-producing heterotrophic Pseudomonas fluorescens and Pseudomonas putida were used. Results showed that at a 1% pulp density (10g/L PCB concentration), 98.4% of the copper was bioleached by a mixture of A. ferrivorans and A. thiooxidans at pH 1.0-1.6 and ambient temperature (23±2°C) in 7days. A pure culture of P. putida (strain WCS361) produced 21.5 (±1.5)mg/L cyanide with 10g/L glycine as the substrate. This gold complexing agent was used in the subsequent bioleaching step using the Cu-leached (by A. ferrivorans and A. thiooxidans) PCB material, 44.0% of the gold was mobilized in alkaline conditions at pH 7.3-8.6, and 30°C in 2days. This study provided a proof-of-concept of a two-step approach in metal bioleaching from PCB, by bacterially produced lixiviants. Copyright © 2015 Elsevier Ltd. All rights reserved.

PCB-Based Break-Out Box

NASA Technical Reports Server (NTRS)

Lee, Jason H.

2011-01-01

Break-out boxes (BOBs) are necessary for all electrical integration/cable checkouts and troubleshooting. Because the price of a BOB is high, and no work can be done without one, often the procedure stops, simply waiting for a BOB. A less expensive BOB would take less time in the integration, testing, and troubleshooting process. The PCB-based BOB works and looks the same as a standard JPL BOB, called Gold Boxes. The only differences between the old BOB and the new PCB-based BOB is that the new one has 80 percent of its circuitry in a printed circuit board. This process reduces the time for fabrication, thus making the BOBs less expensive. Moreover, because of its unique design, the new BOBs can be easily assembled and fixed. About 80 percent of the new PCB-based BOB is in a $22 (at the time of this reporting) custom-designed, yet commercially available PCB. This device has been used successfully to verify that BOB cables were properly made. Also, upon completion, the BOB was beeped out via a multimeter to ensure that all sockets on the connectors were properly connected to the respective banana jack. When compared to the Gold Box BOBs, the new BOB has many advantages. It is much more cost efficient, it delivers equal usability at substantially lower cost of the BOB, and the Gold Box is much heavier when compared to the new BOB. The new BOB is also a bit longer and much more versatile in that connectors are easily changeable and if a banana jack is broken, it can be replaced instead of throwing away an entire BOB.

Simulation of high SNR photodetector with L-C coupling and transimpedance amplifier circuit and its verification

NASA Astrophysics Data System (ADS)

Wang, Shaofeng; Xiang, Xiao; Zhou, Conghua; Zhai, Yiwei; Quan, Runai; Wang, Mengmeng; Hou, Feiyan; Zhang, Shougang; Dong, Ruifang; Liu, Tao

2017-01-01

In this paper, a model for simulating the optical response and noise performances of photodetectors with L-C coupling and transimpedance amplification circuit is presented. To verify the simulation, two kinds of photodetectors, which are based on the same printed-circuit-board (PCB) designing and PIN photodiode but different operational amplifiers, are developed and experimentally investigated. Through the comparisons between the numerical simulation results and the experimentally obtained data, excellent agreements are achieved, which show that the model provides a highly efficient guide for the development of a high signal to noise ratio photodetector. Furthermore, the parasite capacitances on the developed PCB, which are always hardly measured but play a non-negligible influence on the photodetectors' performances, are estimated.

Simulation of high SNR photodetector with L-C coupling and transimpedance amplifier circuit and its verification.

PubMed

Wang, Shaofeng; Xiang, Xiao; Zhou, Conghua; Zhai, Yiwei; Quan, Runai; Wang, Mengmeng; Hou, Feiyan; Zhang, Shougang; Dong, Ruifang; Liu, Tao

2017-01-01

In this paper, a model for simulating the optical response and noise performances of photodetectors with L-C coupling and transimpedance amplification circuit is presented. To verify the simulation, two kinds of photodetectors, which are based on the same printed-circuit-board (PCB) designing and PIN photodiode but different operational amplifiers, are developed and experimentally investigated. Through the comparisons between the numerical simulation results and the experimentally obtained data, excellent agreements are achieved, which show that the model provides a highly efficient guide for the development of a high signal to noise ratio photodetector. Furthermore, the parasite capacitances on the developed PCB, which are always hardly measured but play a non-negligible influence on the photodetectors' performances, are estimated.

Design of inductive sensors for tongue control system for computers and assistive devices.

PubMed

Lontis, Eugen R; Struijk, Lotte N S A

2010-07-01

The paper introduces a novel design of air-core inductive sensors in printed circuit board (PCB) technology for a tongue control system. The tongue control system provides a quadriplegic person with a keyboard and a joystick type of mouse for interaction with a computer or for control of an assistive device. Activation of inductive sensors was performed with a cylindrical, soft ferromagnetic material (activation unit). Comparative analysis of inductive sensors in PCB technology with existing hand-made inductive sensors was performed with respect to inductance, resistance, and sensitivity to activation when the activation unit was placed in the center of the sensor. Optimisation of the activation unit was performed in a finite element model. PCBs with air-core inductive sensors were manufactured in a 10 layers, 100 microm and 120 microm line width technology. These sensors provided quality signals that could drive the electronics of the hand-made sensors. Furthermore, changing the geometry of the sensors allowed generation of variable signals correlated with the 2D movement of the activation unit at the sensors' surface. PCB technology for inductive sensors allows flexibility in design, automation of production and ease of possible integration with supplying electronics. The basic switch function of the inductive sensor can be extended to two-dimensional movement detection for pointing devices.

Compact Radar Transceiver with Included Calibration

NASA Technical Reports Server (NTRS)

McLinden, Matthew; Rincon, Rafael

2013-01-01

The Digital Beamforming Synthetic Aperture Radar (DBSAR) is an eight-channel phased array radar system that employs solid-state radar transceivers, a microstrip patch antenna, and a reconfigurable waveform generator and processor unit. The original DBSAR transceiver design utilizes connectorized electronic components that tend to be physically large and heavy. To achieve increased functionality in a smaller volume, PCB (printed circuit board) transceivers were designed to replace the large connectorized transceivers. One of the most challenging problems designing the transceivers in a PCB format was achieving proper performance in the calibration path. For a radar loop-back calibration path, a portion of the transmit signal is coupled out of the antenna feed and fed back into the receiver. This is achieved using passive components for stability and repeatability. Some signal also leaks through the receive path. As these two signal paths are correlated via an unpredictable phase, the leakage through the receive path during transmit must be 30 dB below the calibration path. For DBSAR s design, this requirement called for a 100-dB isolation in the receiver path during transmit. A total of 16 solid-state L-band transceivers on a PCB format were designed. The transceivers include frequency conversion stages, T/R switching, and a calibration path capable of measuring the transmit power-receiver gain product during transmit for pulse-by-pulse calibration or matched filtering. In particular, this calibration path achieves 100-dB isolation between the transmitted signal and the low-noise amplifier through the use of a switching network and a section of physical walls achieving attenuation of radiated leakage. The transceivers were designed in microstrip PCBs with lumped elements and individually packaged components for compactness. Each transceiver was designed on a single PCB with a custom enclosure providing interior walls and compartments to isolate transceiver subsystems from radiated interference. The enclosure also acts as a heat sink for the voltage regulators and power amplifiers inside the system. The PCB transceiver design produces transmit pulses of 2 W with an arbitrary duty cycle. Each transceiver is fed by an external 120-MHz signal transmit and two 1,140-MHz local oscillator signals. The received signal is amplified and down-converted to 120 MHz and is fed to the data processor. The transceiver dimensions are approximately 3.5 11.5 0.6 in. (9 29 1.5 cm). The PCB transceiver design reduces the volume and weight of the DBSAR instrument while maintaining the functionality found in the original design. Both volume and weight are critical for airborne and flight remote sensing instrumentation.

Advantages and Challenges of 10-Gbps Transmission on High-Density Interconnect Boards

NASA Astrophysics Data System (ADS)

Yee, Chang Fei; Jambek, Asral Bahari; Al-Hadi, Azremi Abdullah

2016-06-01

This paper provides a brief introduction to high-density interconnect (HDI) technology and its implementation on printed circuit boards (PCBs). The advantages and challenges of implementing 10-Gbps signal transmission on high-density interconnect boards are discussed in detail. The advantages (e.g., smaller via dimension and via stub removal) and challenges (e.g., crosstalk due to smaller interpair separation) of HDI are studied by analyzing the S-parameter, time-domain reflectometry (TDR), and transmission-line eye diagrams obtained by three-dimensional electromagnetic modeling (3DEM) and two-dimensional electromagnetic modeling (2DEM) using Mentor Graphics HyperLynx and Keysight Advanced Design System (ADS) electronic computer-aided design (ECAD) software. HDI outperforms conventional PCB technology in terms of signal integrity, but proper routing topology should be applied to overcome the challenge posed by crosstalk due to the tight spacing between traces.

Development of a high-sensitivity strain measurement system based on a SH SAW sensor

NASA Astrophysics Data System (ADS)

Oh, Haekwan; Lee, Keekeun; Eun, Kyoungtae; Choa, Sung-Hoon; Yang, Sang Sik

2012-02-01

A strain measurement system based on a shear horizontal surface acoustic wave (SH SAW) was developed. The developed system is composed of a SAW microsensor, a printed circuit board (PCB), an adhesive and a strain gauge. When a compression force is applied to the PCB by the strain gauge, the PCB is bent so that external strain energy can be evenly delivered to the microsensor without any detachment of the sensor from the board. When a stretching force is applied to the PCB under the condition that one side of the PCB is fixed and the other side is modulated, the actual length of the SAW delay line between the two interdigital transducers (IDTs) is increased. The increase in the delay line length causes a change in the time for the propagating SAW to reach the output IDT. If strain energy is applied to the piezoelectric substrate, the substrate density is changed, which then changes the propagation velocity of the SAW. Coupling-of-modes modeling was conducted prior to fabrication to determine the optimal device parameters. Depending on the strain, the frequency difference was linearly modulated. The obtained sensitivity for stretching was 17.3 kHz/% for the SH wave mode and split electrode. And the obtained sensitivity for bending was 46.1 kHz/% for the SH wave mode and split electrode. The SH wave showed about 15% higher sensitivity than the Rayleigh wave, and the dog-bone PCB showed about 8% higher sensitivity than the rectangular PCB. The obtained sensitivity was about five times higher than that of existing SAW-based strain sensors.

Modular integration of electronics and microfluidic systems using flexible printed circuit boards.

PubMed

Wu, Amy; Wang, Lisen; Jensen, Erik; Mathies, Richard; Boser, Bernhard

2010-02-21

Microfluidic systems offer an attractive alternative to conventional wet chemical methods with benefits including reduced sample and reagent volumes, shorter reaction times, high-throughput, automation, and low cost. However, most present microfluidic systems rely on external means to analyze reaction products. This substantially adds to the size, complexity, and cost of the overall system. Electronic detection based on sub-millimetre size integrated circuits (ICs) has been demonstrated for a wide range of targets including nucleic and amino acids, but deployment of this technology to date has been limited due to the lack of a flexible process to integrate these chips within microfluidic devices. This paper presents a modular and inexpensive process to integrate ICs with microfluidic systems based on standard printed circuit board (PCB) technology to assemble the independently designed microfluidic and electronic components. The integrated system can accommodate multiple chips of different sizes bonded to glass or PDMS microfluidic systems. Since IC chips and flex PCB manufacturing and assembly are industry standards with low cost, the integrated system is economical for both laboratory and point-of-care settings.

Impedance Discontinuity Reduction Between High-Speed Differential Connectors and PCB Interfaces

NASA Technical Reports Server (NTRS)

Navidi, Sal; Agdinaoay, Rodell; Walter, Keith

2013-01-01

High-speed serial communication (i.e., Gigabit Ethernet) requires differential transmission and controlled impedances. Impedance control is essential throughout cabling, connector, and circuit board construction. An impedance discontinuity arises at the interface of a high-speed quadrax and twinax connectors and the attached printed circuit board (PCB). This discontinuity usually is lower impedance since the relative dielectric constant of the board is higher (i.e., polyimide approx. = 4) than the connector (Teflon approx. = 2.25). The discontinuity can be observed in transmit or receive eye diagrams, and can reduce the effective link margin of serial data networks. High-speed serial data network transmission improvements can be made at the connector-to-board interfaces as well as improving differential via hole impedances. The impedance discontinuity was improved by 10 percent by drilling a 20-mil (approx. = 0.5-mm) hole in between the pin of a differential connector spaced 55 mils (approx. = 1.4 mm) apart as it is attached to the PCB. The effective dielectric constant of the board can be lowered by drilling holes into the board material between the differential lines in a quadrax or twinax connector attachment points. The differential impedance is inversely proportional to the square root of the relative dielectric constant. This increases the differential impedance and thus reduces the above described impedance discontinuity. The differential via hole impedance can also be increased in the same manner. This technique can be extended to multiple smaller drilled holes as well as tapered holes (i.e., big in the middle followed by smaller ones diagonally).

Designing an Electronics Data Package for Printed Circuit Boards (PCBs)

DTIC Science & Technology

2013-08-01

finished PCB flatness deviation should be less than 0.010 inches per inch. 4  The minimum copper wall thickness of plated-thru holes should be...Memory Card International Association)  IPC-6015 MCM-L (Multi-Chip Module – Laminated )  IPC-6016 HDI (High Density Interconnect)  IPC-6018...Interconnect ICT In Circuit Tester IPC Association Connecting Electronics Industries MCM-L Multi-Chip Module – Laminated MIL Military NEMA National

Theory, Design, and Measurement of Novel Uniform Circular Antenna Arrays for Direction of Arrival Estimation

DTIC Science & Technology

2015-01-01

generously offering the use of the printed circuit board (PCB) milling machine at the Royal Military College of Canada (RMC) as well as other lab... military research for over a century. However, continual technological advances in wireless communications along with widespread proliferation of...several decades, motivated initially by military applications. Over the past 10–15 years however, this topic has received widespread interest due in

Genetic Algorithm (GA)-Based Inclinometer Layout Optimization.

PubMed

Liang, Weijie; Zhang, Ping; Chen, Xianping; Cai, Miao; Yang, Daoguo

2015-04-17

This paper presents numerical simulation results of an airflow inclinometer with sensitivity studies and thermal optimization of the printed circuit board (PCB) layout for an airflow inclinometer based on a genetic algorithm (GA). Due to the working principle of the gas sensor, the changes of the ambient temperature may cause dramatic voltage drifts of sensors. Therefore, eliminating the influence of the external environment for the airflow is essential for the performance and reliability of an airflow inclinometer. In this paper, the mechanism of an airflow inclinometer and the influence of different ambient temperatures on the sensitivity of the inclinometer will be examined by the ANSYS-FLOTRAN CFD program. The results show that with changes of the ambient temperature on the sensing element, the sensitivity of the airflow inclinometer is inversely proportional to the ambient temperature and decreases when the ambient temperature increases. GA is used to optimize the PCB thermal layout of the inclinometer. The finite-element simulation method (ANSYS) is introduced to simulate and verify the results of our optimal thermal layout, and the results indicate that the optimal PCB layout greatly improves (by more than 50%) the sensitivity of the inclinometer. The study may be useful in the design of PCB layouts that are related to sensitivity improvement of gas sensors.

Genetic Algorithm (GA)-Based Inclinometer Layout Optimization

PubMed Central

Liang, Weijie; Zhang, Ping; Chen, Xianping; Cai, Miao; Yang, Daoguo

2015-01-01

This paper presents numerical simulation results of an airflow inclinometer with sensitivity studies and thermal optimization of the printed circuit board (PCB) layout for an airflow inclinometer based on a genetic algorithm (GA). Due to the working principle of the gas sensor, the changes of the ambient temperature may cause dramatic voltage drifts of sensors. Therefore, eliminating the influence of the external environment for the airflow is essential for the performance and reliability of an airflow inclinometer. In this paper, the mechanism of an airflow inclinometer and the influence of different ambient temperatures on the sensitivity of the inclinometer will be examined by the ANSYS-FLOTRAN CFD program. The results show that with changes of the ambient temperature on the sensing element, the sensitivity of the airflow inclinometer is inversely proportional to the ambient temperature and decreases when the ambient temperature increases. GA is used to optimize the PCB thermal layout of the inclinometer. The finite-element simulation method (ANSYS) is introduced to simulate and verify the results of our optimal thermal layout, and the results indicate that the optimal PCB layout greatly improves (by more than 50%) the sensitivity of the inclinometer. The study may be useful in the design of PCB layouts that are related to sensitivity improvement of gas sensors. PMID:25897500

Use of large pieces of printed circuit boards for bioleaching to avoid ‘precipitate contamination problem’ and to simplify overall metal recovery

PubMed Central

Adhapure, N.N.; Dhakephalkar, P.K.; Dhakephalkar, A.P.; Tembhurkar, V.R.; Rajgure, A.V.; Deshmukh, A.M.

2014-01-01

Very recently bioleaching has been used for removing metals from electronic waste. Most of the research has been targeted to using pulverized PCBs for bioleaching where precipitate formed during bioleaching contaminates the pulverized PCB sample and making the overall metal recovery process more complicated. In addition to that, such mixing of pulverized sample with precipitate also creates problems for the final separation of non metallic fraction of PCB sample. In the present investigation we attempted the use of large pieces of printed circuit boards instead of pulverized sample for removal of metals. Use of large pieces of PCBs for bioleaching was restricted due to the chemical coating present on PCBs, the problem has been solved by chemical treatment of PCBs prior to bioleaching. In short,•Large pieces of PCB can be used for bioleaching instead of pulverized PCB sample.•Metallic portion on PCBs can be made accessible to bacteria with prior chemical treatment of PCBs.•Complete metal removal obtained on PCB pieces of size 4 cm × 2.5 cm with the exception of solder traces. The final metal free PCBs (non metallic) can be easily recycled and in this way the overall recycling process (metallic and non metallic part) of PCBs becomes simple. PMID:26150951

Use of large pieces of printed circuit boards for bioleaching to avoid 'precipitate contamination problem' and to simplify overall metal recovery.

PubMed

Adhapure, N N; Dhakephalkar, P K; Dhakephalkar, A P; Tembhurkar, V R; Rajgure, A V; Deshmukh, A M

2014-01-01

Very recently bioleaching has been used for removing metals from electronic waste. Most of the research has been targeted to using pulverized PCBs for bioleaching where precipitate formed during bioleaching contaminates the pulverized PCB sample and making the overall metal recovery process more complicated. In addition to that, such mixing of pulverized sample with precipitate also creates problems for the final separation of non metallic fraction of PCB sample. In the present investigation we attempted the use of large pieces of printed circuit boards instead of pulverized sample for removal of metals. Use of large pieces of PCBs for bioleaching was restricted due to the chemical coating present on PCBs, the problem has been solved by chemical treatment of PCBs prior to bioleaching. In short,•Large pieces of PCB can be used for bioleaching instead of pulverized PCB sample.•Metallic portion on PCBs can be made accessible to bacteria with prior chemical treatment of PCBs.•Complete metal removal obtained on PCB pieces of size 4 cm × 2.5 cm with the exception of solder traces. The final metal free PCBs (non metallic) can be easily recycled and in this way the overall recycling process (metallic and non metallic part) of PCBs becomes simple.

Deposition and thermal characterization of nano-structured aluminum nitride thin film on Cu-W substrate for high power light emitting diode package.

PubMed

Cho, Hyun Min; Kim, Min-Sun

2014-08-01

In this study, we developed AlN thick film on metal substrate for hybrid type LED package such as chip on board (COB) using metal printed circuit board (PCB). Conventional metal PCB uses ceramic-polymer composite as electrical insulating layer. Thermal conductivities of such type dielectric film are typically in the range of 1~4 W/m · K depending on the ceramic filler. Also, Al or Cu alloy are mainly used for metal base for high thermal conduction to dissipate heat from thermal source mounted on metal PCB. Here we used Cu-W alloy with low thermal expansion coefficient as metal substrate to reduce thermal stress between insulating layer and base metal. AlN with polyimide (PI) powder were used as starting materials for deposition. We could obtain very high thermal conductivity of 28.3 W/m · K from deposited AlN-PI thin film by AlN-3 wt% PI powder. We made hybrid type high power LED package using AlN-PI thin film. We tested thermal performance of this film by thermal transient measurement and compared with conventional metal PCB substrate.

Wearable Inset-Fed FR4 Microstrip Patch Antenna Design

NASA Astrophysics Data System (ADS)

Zaini, S. R. Mohd; Rani, K. N. Abdul

2018-03-01

This project proposes the design of a wireless body area network (WBAN) microstrip patch antenna covered by the jeans fabric as the outer layer operating at the center frequency, fc of 2.40 GHz. Precisely, the microstrip patch antenna with the inset-fed edge technique is designed and simulated systematically by using the Keysight Advanced Design System (ADS) software where the FR4 board with the dielectric constant, ɛr of 4.70, dissipation factor or loss tangent, tan δ of 0.02 and height, h of 1.60 mm is the chosen dielectric substrate. The wearable microstrip patch antenna design is then fabricated using the FR4 printed circuit board (PCB) material, hidden inside the jeans fabric, and attached to clothing, such as a jacket accordingly. Simulation and fabrication measurement results show that the designed microstrip patch antenna characteristics can be applied significantly within the industrial, scientific, and medical (ISM) radio band, which is at fc = 2.40 GHz.

Altered fine motor function at school age in Inuit children exposed to PCBs, methylmercury, and lead.

PubMed

Boucher, Olivier; Muckle, Gina; Ayotte, Pierre; Dewailly, Eric; Jacobson, Sandra W; Jacobson, Joseph L

2016-10-01

Motor deficits have frequently been reported in methylmercury (MeHg) poisoning in adults. However, whether exposure to neurotoxic contaminants from environmental sources early in life is associated with neuromotor impairments has received relatively little attention. This study examines the relation of developmental exposure to MeHg, polychlorinated biphenyls (PCBs), and lead to motor function in school-age Inuit children exposed through their traditional diet. In a prospective study in Nunavik, children (mean age=11.3years) were assessed on a battery of fine motor tasks, namely the Stanford-Binet Copying subtest (N=262), the Santa Ana Form Board, and the Finger Tapping Test (N=215). The relation of mercury (Hg; as an index of MeHg exposure), PCB congener 153 (PCB153), and lead concentrations in cord and current blood samples to task performance was examined using linear regression analyses. After adjustment for potential confounders and control for the other contaminants, higher current PCB concentrations were associated with poorer Santa Ana Form Board and Finger Tapping performance. Results were virtually identical when PCB153 was replaced by other PCB congeners. Higher current Hg levels were independently associated with poorer Finger Tapping performance. This is the first prospective longitudinal study in children to provide evidence of neuromotor impairments associated with postnatal exposure to seafood contaminants from environmental sources. Fine motor speed appears particularly sensitive to the effects of postnatal PCB exposure, which is unusually high in this population. Results with postnatal MeHg are concordant with previous cross-sectional studies with children and adults. Copyright © 2016 Elsevier Ltd. All rights reserved.

Design and Application of a Collocated Capacitance Sensor for Magnetic Bearing Spindle

NASA Technical Reports Server (NTRS)

Shin, Dongwon; Liu, Seon-Jung; Kim, Jongwon

1996-01-01

This paper presents a collocated capacitance sensor for magnetic bearings. The main feature of the sensor is that it is made of a specific compact printed circuit board (PCB). The signal processing unit has been also developed. The results of the experimental performance evaluation on the sensitivity, resolution and frequency response of the sensor are presented. Finally, an application example of the sensor to the active control of a magnetic bearing is described.

Electrostatic separation for recovering metals and nonmetals from waste printed circuit board: problems and improvements.

PubMed

Wu, Jiang; Li, Jia; Xu, Zhenming

2008-07-15

Electrostatic separation is an effective and environmentally friendly method for recycling comminuted waste printed circuit boards (PCB). As a classical separator, the roll-type corona-electrostatic separator (RTS) has some advantages in this field. However, there are still some notable problems, such as the middling products and their further treatment, impurity of nonconductive products because of the aggregation of fine particles, and stability of the separation process and balance between the production capacity and the separation quality. To overcome these problems, a conception of two-step separation is presented, and a new two-roll type corona-electrostatic separator (T-RTS) was built As compared to RTS, the conductive products increase by 8.9%, the middling products decrease by 45%, and the production capacity increases by 50% in treating comminuted PCB wastes by T-RTS. In addition, the separation process in T-RTS is more stable. Therefore, T-RTS is a promising separator for recycling comminuted PCB.

Soldering mask laser removal from printed circuit boards aiming copper recycling.

PubMed

Raele, Marcus Paulo; De Pretto, Lucas Ramos; Zezell, Denise Maria

2017-10-01

Management of waste of electric and electronic equipment (WEEE) is a key issue for modern societies; furthermore, it contains valuable materials that can be recycled, especially in printed circuit boards (PCB), which have approximately one-third of their weight in copper. In this study we demonstrated the use of laser to strip the covering soldering mask on PCB's, thus exposing the copper underneath so that extraction techniques may take place. Using a Q-Switched Nd:YAG laser operating at 1064nm and 532nm we tested the procedure under different energy conditions. The laser stripping of the soldering mask was achieved with satisfactory results by irradiation with 225mJ at 1064nm. However, when using similar parameters at 532nm the process of the coating ejection was not promoted properly, leading to a faulty detachment. Infrared laser PCB stripping presents itself to be technically viable and environmental friendly, since it uses no chemicals inputs, offering one more option to WEEE treatment and recycling. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ethernet-Enabled Power and Communication Module for Embedded Processors

NASA Technical Reports Server (NTRS)

Perotti, Jose; Oostdyk, Rebecca

2010-01-01

The power and communications module is a printed circuit board (PCB) that has the capability of providing power to an embedded processor and converting Ethernet packets into serial data to transfer to the processor. The purpose of the new design is to address the shortcomings of previous designs, including limited bandwidth and program memory, lack of control over packet processing, and lack of support for timing synchronization. The new design of the module creates a robust serial-to-Ethernet conversion that is powered using the existing Ethernet cable. This innovation has a small form factor that allows it to power processors and transducers with minimal space requirements.

Amperometric IFN-γ immunosensors with commercially fabricated PCB sensing electrodes.

PubMed

Moschou, Despina; Greathead, Louise; Pantelidis, Panagiotis; Kelleher, Peter; Morgan, Hywel; Prodromakis, Themistoklis

2016-12-15

Lab-on-a-Chip (LoC) technology has the potential to revolutionize medical Point-of-Care diagnostics. Currently, considerable research efforts are focused on innovative production technologies that will make commercial upscaling of lab-on-chip products financially viable. Printed circuit board (PCB) manufacturing techniques have several advantages in this field. In this paper we focus on transferring a complete IFN-γ enzyme-linked immune-sorbent assay (ELISA) onto a commercial PCB electrochemical biosensing platform, We adapted a commercially available ELISA to detect the enzyme product TMB/H2O2 using amperometry, successfully reproducing the colorimetry-obtained ELISA standard curve. The results demonstrate the potential for the integration of these components into an automated, disposable, electronic ELISA Lab-on-PCB diagnostic platform. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of Bypass Capacitor in Common-mode Noise Reduction Technique for Automobile PCB

NASA Astrophysics Data System (ADS)

Uno, Takanori; Ichikawa, Kouji; Mabuchi, Yuichi; Nakamura, Atushi

In this letter, we studied the use of common mode noise reduction technique for in-vehicle electronic equipment, each comprising large-scale integrated circuit (LSI), printed circuit board (PCB), wiring harnesses, and ground plane. We have improved the model circuit of the common mode noise that flows to the wire harness to add the effect of by-pass capacitors located near an LSI.

Preparation of hierarchical porous carbon from waste printed circuit boards for high performance electric double-layer capacitors

NASA Astrophysics Data System (ADS)

Du, Xuan; Wang, Li; Zhao, Wei; Wang, Yi; Qi, Tao; Li, Chang Ming

2016-08-01

Renewable clean energy and resources recycling have become inevitable choices to solve worldwide energy shortages and environmental pollution problems. It is a great challenge to recycle tons of waste printed circuit boards (PCB) produced every year for clean environment while creating values. In this work, low cost, high quality activated carbons (ACs) were synthesized from non-metallic fractions (NMF) of waste PCB to offer a great potential for applications of electrochemical double-layer capacitors (EDLCs). After recovering metal from waste PCB, hierarchical porous carbons were produced from NMF by carbonization and activation processes. The experimental results exhibit that some pores were formed after carbonization due to the escape of impurity atoms introduced by additives in NMF. Then the pore structure was further tailored by adjusting the activation parameters. Roles of micropores and non-micropores in charge storage were investigated when the hierarchical porous carbons were applied as electrode of EDLCs. The highest specific capacitance of 210 F g-1 (at 50 mA g-1) and excellent rate capability were achieved when the ACs possessing a proper micropores/non-micropores ratio. This work not only provides a promising method to recycle PCB, but also investigates the structure tailoring arts for a rational hierarchical porous structure in energy storage/conversion.

Optimization of Cvd Diamond Coating Type on Micro Drills in Pcb Machining

NASA Astrophysics Data System (ADS)

Lei, X. L.; He, Y.; Sun, F. H.

2016-12-01

The demand for better tools for machining printed circuit boards (PCBs) is increasing due to the extensive usage of these boards in digital electronic products. This paper is aimed at optimizing coating type on micro drills in order to extend their lifetime in PCB machining. First, the tribotests involving micro crystalline diamond (MCD), nano crystalline diamond (NCD) and bare tungsten carbide (WC-Co) against PCBs show that NCD-PCB tribopair exhibits the lowest friction coefficient (0.35) due to the unique nano structure and low surface roughness of NCD films. Thereafter, the dry machining performance of the MCD- and NCD-coated micro drills on PCBs is systematically studied, using diamond-like coating (DLC) and TiAlN-coated micro drills as comparison. The experiments show that the working lives of these micro drills can be ranked as: NCD>TiAlN>DLC>MCD>bare WC-Co. The superior cutting performance of NCD-coated micro drills in terms of the lowest flank wear growth rate, no tool degradation (e.g. chipping, tool tipping) appearance, the best hole quality as well as the lowest feed force may come from the excellent wear resistance, lower friction coefficient against PCB as well as the high adhesive strength on the underneath substrate of NCD films.

Liberation characteristic and physical separation of printed circuit board (PCB).

PubMed

Guo, Chao; Wang, Hui; Liang, Wei; Fu, Jiangang; Yi, Xin

2011-01-01

Recycling of printed circuit board (PCB) is an important subject and to which increasing attention is paid, both in treatment of waste as well as recovery of valuable material terms. Precede physical and mechanical method, a good liberation is the premise to further separation. In this study, two-step crushing process is employed, and standard sieve is applied to screen crushed material to different size fractions, moreover, the liberation situation and particles shape in different size are observed. Then metal of the PCB is separated by physical methods, including pneumatic separation, electrostatic separation and magnetic separation, and major metal contents are characterized by inductively coupled plasma emission spectrometry (ICP-AES). Results show that the metal and nonmetal particles of PCB are dissociated completely under the crush size 0.6mm; metal is mainly enriched in the four size fractions between 0.15 and 1.25 mm; relatively, pneumatic separation is suitable for 0.6-0.9 mm size fraction, while the electrostatic separation is suitable for three size fractions that are 0.15-0.3mm, 0.3-0.6mm and 0.9-1.25 mm. The whole process that involves crushing, electrostatic and magnetic separation has formed a closed cycle that can return material and provide salable product. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Copper extraction from coarsely ground printed circuit boards using moderate thermophilic bacteria in a rotating-drum reactor.

PubMed

Rodrigues, Michael L M; Leão, Versiane A; Gomes, Otavio; Lambert, Fanny; Bastin, David; Gaydardzhiev, Stoyan

2015-07-01

The current work reports on a new approach for copper bioleaching from Printed Circuit Board (PCB) by moderate thermophiles in a rotating-drum reactor. Initially leaching of PCB was carried out in shake flasks to assess the effects of particle size (-208μm+147μm), ferrous iron concentration (1.25-10.0g/L) and pH (1.5-2.5) on copper leaching using mesophile and moderate thermophile microorganisms. Only at a relatively low solid content (10.0g/L) complete copper extraction was achieved from the particle size investigated. Conversely, high copper extractions were possible from coarse-ground PCB (20mm-long) working with increased solids concentration (up to 25.0g/L). Because there was as the faster leaching kinetics at 50°C Sulfobacillus thermosulfidooxidans was selected for experiments in a rotating-drum reactor with the coarser-sized PCB sheets. Under optimal conditions, copper extraction reached 85%, in 8days and microscopic observations by SEM-EDS of the on non-leached and leached material suggested that metal dissolution from the internal layers was restricted by the fact that metal surface was not entirely available and accessible for the solution in the case of the 20mm-size sheets. Copyright © 2015 Elsevier Ltd. All rights reserved.

Using the Fuzzy DEMATEL to Determine Environmental Performance: A Case of Printed Circuit Board Industry in Taiwan

PubMed Central

Tsai, Sang-Bing; Chien, Min-Fang; Xue, Youzhi; Li, Lei; Jiang, Xiaodong; Chen, Quan; Zhou, Jie; Wang, Lei

2015-01-01

The method by which high-technology product manufacturers balance profits and environmental performance is of crucial concern for governments and enterprises. To examine the environmental performance of manufacturers, the present study applied Fuzzy-DEMATEL model to examine environmental performance of the PCB industry in Taiwan. Fuzzy theory was employed to examine the environmental performance criteria of manufacturers and analyse fuzzy linguistics. The fuzzy-DEMATEL model was then employed to assess the direction and level of interaction between environmental performance criteria. The core environmental performance criteria which were critical for enhancing environmental performance of the PCB industry in Taiwan were identified and presented. The present study revealed that green design (a1), green material procurement (a2), and energy consumption (b3) constitute crucial reason criteria, the core criteria influencing other criteria, and the driving factors for resolving problems. PMID:26052710

DC coupled Doppler radar physiological monitor.

PubMed

Zhao, Xi; Song, Chenyan; Lubecke, Victor; Boric-Lubecke, Olga

2011-01-01

One of the challenges in Doppler radar systems for physiological monitoring is a large DC offset in baseband outputs. Typically, AC coupling is used to eliminate this DC offset. Since the physiological signals of interest include frequency content near DC, it is not desirable to simply use AC coupling on the radar outputs. While AC coupling effectively removes DC offset, it also introduces a large time delay and distortion. This paper presents the first DC coupled IQ demodulator printed circuit board (PCB) design and measurements. The DC coupling is achieved by using a mixer with high LO to RF port isolation, resulting in a very low radar DC offset on the order of mV. The DC coupled signals from the PCB radar system were successfully detected with significant LNA gain without saturation. Compared to the AC coupled results, the DC coupled results show great advantages of less signal distortion and more accurate rate estimation.

Using the Fuzzy DEMATEL to Determine Environmental Performance: A Case of Printed Circuit Board Industry in Taiwan.

PubMed

Tsai, Sang-Bing; Chien, Min-Fang; Xue, Youzhi; Li, Lei; Jiang, Xiaodong; Chen, Quan; Zhou, Jie; Wang, Lei

2015-01-01

The method by which high-technology product manufacturers balance profits and environmental performance is of crucial concern for governments and enterprises. To examine the environmental performance of manufacturers, the present study applied Fuzzy-DEMATEL model to examine environmental performance of the PCB industry in Taiwan. Fuzzy theory was employed to examine the environmental performance criteria of manufacturers and analyse fuzzy linguistics. The fuzzy-DEMATEL model was then employed to assess the direction and level of interaction between environmental performance criteria. The core environmental performance criteria which were critical for enhancing environmental performance of the PCB industry in Taiwan were identified and presented. The present study revealed that green design (a1), green material procurement (a2), and energy consumption (b3) constitute crucial reason criteria, the core criteria influencing other criteria, and the driving factors for resolving problems.

High-Temperature Storage Testing of ACF Attached Sensor Structures

PubMed Central

Lahokallio, Sanna; Hoikkanen, Maija; Vuorinen, Jyrki; Frisk, Laura

2015-01-01

Several electronic applications must withstand elevated temperatures during their lifetime. Materials and packages for use in high temperatures have been designed, but they are often very expensive, have limited compatibility with materials, structures, and processing techniques, and are less readily available than traditional materials. Thus, there is an increasing interest in using low-cost polymer materials in high temperature applications. This paper studies the performance and reliability of sensor structures attached with anisotropically conductive adhesive film (ACF) on two different organic printed circuit board (PCB) materials: FR-4 and Rogers. The test samples were aged at 200 °C and 240 °C and monitored electrically during the test. Material characterization techniques were also used to analyze the behavior of the materials. Rogers PCB was observed to be more stable at high temperatures in spite of degradation observed, especially during the first 120 h of aging. The electrical reliability was very good with Rogers. At 200 °C, the failures occurred after 2000 h of testing, and even at 240 °C the interconnections were functional for 400 h. The study indicates that, even though these ACFs were not designed for use in high temperatures, with stable PCB material they are promising interconnection materials at elevated temperatures, especially at 200 °C. However, the fragility of the structure due to material degradation may cause reliability problems in long-term high temperature exposure. PMID:28793735

Environmental risk assessment of wastewaters from printed circuit board production: A multibiomarker approach using human cells.

PubMed

Gerić, Marko; Gajski, Goran; Oreščanin, Višnja; Domijan, Ana-Marija; Kollar, Robert; Garaj-Vrhovac, Vera

2017-02-01

Since the production of printed circuit boards (PCBs) generates wastewater contaminated with heavy metals and organic matter, PCB factories represent potential pollution sites. The wastewater toxicologically tested in this study contained several metals and the most abundant were copper and iron. At two exposure times tested (4 and 24 h) PCB wastewater (PCBW) proved to be cytotoxic (decreased cell viability) and genotoxic (increased comet assay tail intensity and tail moment) to human blood peripheral lymphocytes in vitro, and the oxidative stress parameter (malondialdehyde concentration) was also found to be higher. After application of combined treatment by waste base, ozone and waste sludge methods, concentrations of metals in purified PCBW were below the upper permitted levels and all tested toxicological parameters did not differ compared to the negative control. Taken together, similar methods could be implemented in PCB factories before discharging potentially toxic wastewater into the environment because purified PCBW does not represent a threat from the aspect of cytotoxicity and genotoxicity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Focal Plane Alignment Utilizing Optical CMM

NASA Technical Reports Server (NTRS)

Liebe, Carl Christian; Meras, Patrick L.; Clark, Gerald J.; Sedaka, Jack J.; Kaluzny, Joel V.; Hirsch, Brian; Decker, Todd A.; Scholtz, Christopher R.

2012-01-01

In many applications, an optical detector has to be located relative to mechanical reference points. One solution is to specify stringent requirements on (1) mounting the optical detector relative to the chip carrier, (2) soldering the chip carrier onto the printed circuit board (PCB), and (3) installing the PCB to the mechanical structure of the subsystem. Figure 1 shows a sketch of an optical detector mounted relative to mechanical reference with high positional accuracy. The optical detector is typically a fragile wafer that cannot be physically touched by any measurement tool. An optical coordinate measuring machine (CMM) can be used to position optical detectors relative to mechanical reference points. This approach will eliminate all requirements on positional tolerances. The only requirement is that the PCB is manufactured with oversized holes. An exaggerated sketch of this situation is shown in Figure 2. The sketch shows very loose tolerances on mounting the optical detector in the chip carrier, loose tolerance on soldering the chip carrier to the PCB, and finally large tolerance on where the mounting screws are located. The PCB is held with large screws and oversized holes. The PCB is mounted loosely so it can move freely around. The optical CMM measures the mechanical reference points. Based on these measurements, the required positions of the optical detector corners can be calculated. The optical CMM is commanded to go to the position where one detector corner is supposed to be. This is indicated with the cross-hairs in Figure 2(a). This figure is representative of the image of the optical CMM monitor. Using a suitable tapping tool, the PCB is manually tapped around until the corner of the optical detector is at the crosshairs of the optical CMM. The CMM is commanded to another corner, and the process is repeated a number of times until all corners of the optical detector are within a distance of 10 to 30 microns of the required position. The situation is sketched in Figure 2(b) (the figure also shows the tapping tool and where to tap). At this point the fasteners for the PCB are torqued slightly so the PCB can still move. The PCB location is adjusted again with the tapping tool. This process is repeated 3 to 4 times until the final torque is achieved. The oversized mounting holes are then filled with a liquid bonding agent to secure the board in position (not shown in the sketch). A 10- to 30-micron mounting accuracy has been achieved utilizing this method..

Recycling of WEEE: characterization of spent printed circuit boards from mobile phones and computers.

PubMed

Yamane, Luciana Harue; de Moraes, Viviane Tavares; Espinosa, Denise Crocce Romano; Tenório, Jorge Alberto Soares

2011-12-01

This paper presents a comparison between printed circuit boards from computers and mobile phones. Since printed circuits boards are becoming more complex and smaller, the amount of materials is constantly changing. The main objective of this work was to characterize spent printed circuit boards from computers and mobile phones applying mineral processing technique to separate the metal, ceramic, and polymer fractions. The processing was performed by comminution in a hammer mill, followed by particle size analysis, and by magnetic and electrostatic separation. Aqua regia leaching, loss-on-ignition and chemical analysis (inductively coupled plasma atomic emission spectroscopy - ICP-OES) were carried out to determine the composition of printed circuit boards and the metal rich fraction. The composition of the studied mobile phones printed circuit boards (PCB-MP) was 63 wt.% metals; 24 wt.% ceramics and 13 wt.% polymers; and of the printed circuit boards from studied personal computers (PCB-PC) was 45 wt.% metals; 27 wt.% polymers and ceramics 28 wt.% ceramics. The chemical analysis showed that copper concentration in printed circuit boards from personal computers was 20 wt.% and in printed circuit boards from mobile phones was 34.5 wt.%. According to the characteristics of each type of printed circuit board, the recovery of precious metals may be the main goal of the recycling process of printed circuit boards from personal computers and the recovery of copper should be the main goal of the recycling process of printed circuit boards from mobile phones. Hence, these printed circuit boards would not be mixed prior treatment. The results of this paper show that copper concentration is increasing in mobile phones and remaining constant in personal computers. Copyright © 2011 Elsevier Ltd. All rights reserved.

A compact linear accelerator based on a scalable microelectromechanical-system RF-structure

DOE PAGES

Persaud, A.; Ji, Q.; Feinberg, E.; ...

2017-06-08

Here, a new approach for a compact radio-frequency (RF) accelerator structure is presented. The new accelerator architecture is based on the Multiple Electrostatic Quadrupole Array Linear Accelerator (MEQALAC) structure that was first developed in the 1980s. The MEQALAC utilized RF resonators producing the accelerating fields and providing for higher beam currents through parallel beamlets focused using arrays of electrostatic quadrupoles (ESQs). While the early work obtained ESQs with lateral dimensions on the order of a few centimeters, using a printed circuit board (PCB), we reduce the characteristic dimension to the millimeter regime, while massively scaling up the potential number ofmore » parallel beamlets. Using Microelectromechanical systems scalable fabrication approaches, we are working on further red ucing the characteristic dimension to the sub-millimeter regime. The technology is based on RF-acceleration components and ESQs implemented in the PCB or silicon wafers where each beamlet passes through beam apertures in the wafer. The complete accelerator is then assembled by stacking these wafers. This approach has the potential for fast and inexpensive batch fabrication of the components and flexibility in system design for application specific beam energies and currents. For prototyping the accelerator architecture, the components have been fabricated using the PCB. In this paper, we present proof of concept results of the principal components using the PCB: RF acceleration and ESQ focusing. Finally, ongoing developments on implementing components in silicon and scaling of the accelerator technology to high currents and beam energies are discussed.« less

A compact linear accelerator based on a scalable microelectromechanical-system RF-structure

NASA Astrophysics Data System (ADS)

Persaud, A.; Ji, Q.; Feinberg, E.; Seidl, P. A.; Waldron, W. L.; Schenkel, T.; Lal, A.; Vinayakumar, K. B.; Ardanuc, S.; Hammer, D. A.

2017-06-01

A new approach for a compact radio-frequency (RF) accelerator structure is presented. The new accelerator architecture is based on the Multiple Electrostatic Quadrupole Array Linear Accelerator (MEQALAC) structure that was first developed in the 1980s. The MEQALAC utilized RF resonators producing the accelerating fields and providing for higher beam currents through parallel beamlets focused using arrays of electrostatic quadrupoles (ESQs). While the early work obtained ESQs with lateral dimensions on the order of a few centimeters, using a printed circuit board (PCB), we reduce the characteristic dimension to the millimeter regime, while massively scaling up the potential number of parallel beamlets. Using Microelectromechanical systems scalable fabrication approaches, we are working on further reducing the characteristic dimension to the sub-millimeter regime. The technology is based on RF-acceleration components and ESQs implemented in the PCB or silicon wafers where each beamlet passes through beam apertures in the wafer. The complete accelerator is then assembled by stacking these wafers. This approach has the potential for fast and inexpensive batch fabrication of the components and flexibility in system design for application specific beam energies and currents. For prototyping the accelerator architecture, the components have been fabricated using the PCB. In this paper, we present proof of concept results of the principal components using the PCB: RF acceleration and ESQ focusing. Ongoing developments on implementing components in silicon and scaling of the accelerator technology to high currents and beam energies are discussed.

A compact linear accelerator based on a scalable microelectromechanical-system RF-structure.

PubMed

Persaud, A; Ji, Q; Feinberg, E; Seidl, P A; Waldron, W L; Schenkel, T; Lal, A; Vinayakumar, K B; Ardanuc, S; Hammer, D A

2017-06-01

A new approach for a compact radio-frequency (RF) accelerator structure is presented. The new accelerator architecture is based on the Multiple Electrostatic Quadrupole Array Linear Accelerator (MEQALAC) structure that was first developed in the 1980s. The MEQALAC utilized RF resonators producing the accelerating fields and providing for higher beam currents through parallel beamlets focused using arrays of electrostatic quadrupoles (ESQs). While the early work obtained ESQs with lateral dimensions on the order of a few centimeters, using a printed circuit board (PCB), we reduce the characteristic dimension to the millimeter regime, while massively scaling up the potential number of parallel beamlets. Using Microelectromechanical systems scalable fabrication approaches, we are working on further reducing the characteristic dimension to the sub-millimeter regime. The technology is based on RF-acceleration components and ESQs implemented in the PCB or silicon wafers where each beamlet passes through beam apertures in the wafer. The complete accelerator is then assembled by stacking these wafers. This approach has the potential for fast and inexpensive batch fabrication of the components and flexibility in system design for application specific beam energies and currents. For prototyping the accelerator architecture, the components have been fabricated using the PCB. In this paper, we present proof of concept results of the principal components using the PCB: RF acceleration and ESQ focusing. Ongoing developments on implementing components in silicon and scaling of the accelerator technology to high currents and beam energies are discussed.

Design of light-small high-speed image data processing system

NASA Astrophysics Data System (ADS)

Yang, Jinbao; Feng, Xue; Li, Fei

2015-10-01

A light-small high speed image data processing system was designed in order to meet the request of image data processing in aerospace. System was constructed of FPGA, DSP and MCU (Micro-controller), implementing a video compress of 3 million pixels@15frames and real-time return of compressed image to the upper system. Programmable characteristic of FPGA, high performance image compress IC and configurable MCU were made best use to improve integration. Besides, hard-soft board design was introduced and PCB layout was optimized. At last, system achieved miniaturization, light-weight and fast heat dispersion. Experiments show that, system's multifunction was designed correctly and worked stably. In conclusion, system can be widely used in the area of light-small imaging.

Advanced Atmospheric Water Vapor DIAL Detection System

NASA Technical Reports Server (NTRS)

Refaat, Tamer F.; Elsayed-Ali, Hani E.; DeYoung, Russell J. (Technical Monitor)

2000-01-01

Measurement of atmospheric water vapor is very important for understanding the Earth's climate and water cycle. The remote sensing Differential Absorption Lidar (DIAL) technique is a powerful method to perform such measurement from aircraft and space. This thesis describes a new advanced detection system, which incorporates major improvements regarding sensitivity and size. These improvements include a low noise advanced avalanche photodiode detector, a custom analog circuit, a 14-bit digitizer, a microcontroller for on board averaging and finally a fast computer interface. This thesis describes the design and validation of this new water vapor DIAL detection system which was integrated onto a small Printed Circuit Board (PCB) with minimal weight and power consumption. Comparing its measurements to an existing DIAL system for aerosol and water vapor profiling validated the detection system.

Dose-mortality assessment upon reuse and recycling of industrial sludge.

PubMed

Lin, Kae-Long; Chen, Bor-Yann

2007-09-05

This study provides a novel attempt to put forward, in general toxicological terms, quantitative ranking of toxicity of various sources of sludge for possible reusability in further applications. The high leaching concentrations of copper in printed circuit board (PCB) sludge and chromium in leather sludge apparently exceeded current Taiwan's EPA regulatory thresholds and should be classified as hazardous wastes. Dose-mortality analysis indicated that the toxicity ranking of different sources of sludge was PCB sludge>CaF(2) sludge>leather sludge. PCB sludge was also confirmed as a hazardous waste since the toxicity potency of PCB sludge was nearly identical to CdCl(2). However, leather sludge seemed to be much less toxic than as anticipated, perhaps due to a significant decrease of toxic species bioavailable in the aqueous phase to the reporter bacterium Escherichia coli DH5alpha. For possible reusability of sludge, maximum concentrations allowable to be considered "safe" (ca. EC(100)/100) were 9.68, 42.1 and 176 mgL(-1) for CaF(2) sludge, PCB sludge and leather sludge, respectively.

Reliability Assessment of Critical Electronic Components

DTIC Science & Technology

1992-07-01

Failures FLHP - Full Horse Power FSN - Federal Stock Number I Current IC - Integrated Circuit IPB - Illustrated Parts Breakdown K - Boltzmans Constant L...Classified P - Power PC - Printed Circuit PCB - Printed Circuit Board PGA - Pin Grid Array PPM - Parts Per Million PWB - Printed Wiring Board 0...4-59 4.4.3.2.3 Circuit Brcakers ......................................................... 4-59 4.4.3.2.4 Thermal

Microwave Temperature Profiler Mounted in a Standard Airborne Research Canister

NASA Technical Reports Server (NTRS)

Mahoney, Michael J.; Denning, Richard F.; Fox, Jack

2009-01-01

Many atmospheric research aircraft use a standard canister design to mount instruments, as this significantly facilitates their electrical and mechanical integration and thereby reduces cost. Based on more than 30 years of airborne science experience with the Microwave Temperature Profiler (MTP), the MTP has been repackaged with state-of-the-art electronics and other design improvements to fly in one of these standard canisters. All of the controlling electronics are integrated on a single 4 5-in. (.10 13- cm) multi-layer PCB (printed circuit board) with surface-mount hardware. Improved circuit design, including a self-calibrating RTD (resistive temperature detector) multiplexer, was implemented in order to reduce the size and mass of the electronics while providing increased capability. A new microcontroller-based temperature controller board was designed, providing better control with fewer components. Five such boards are used to provide local control of the temperature in various areas of the instrument, improving radiometric performance. The new stepper motor has an embedded controller eliminating the need for a separate controller board. The reference target is heated to avoid possible emissivity (and hence calibration) changes due to moisture contamination in humid environments, as well as avoiding issues with ambient targets during ascent and descent. The radiometer is a double-sideband heterodyne receiver tuned sequentially to individual oxygen emission lines near 60 GHz, with the line selection and intermediate frequency bandwidths chosen to accommodate the altitude range of the aircraft and mission.

Recycling of WEEE: Characterization of spent printed circuit boards from mobile phones and computers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamane, Luciana Harue, E-mail: lucianayamane@uol.com.br; Tavares de Moraes, Viviane, E-mail: tavares.vivi@gmail.com; Crocce Romano Espinosa, Denise, E-mail: espinosa@usp.br

Highlights: > This paper presents new and important data on characterization of wastes of electric and electronic equipments. > Copper concentration is increasing in mobile phones and remaining constant in personal computers. > Printed circuit boards from mobile phones and computers would not be mixed prior treatment. - Abstract: This paper presents a comparison between printed circuit boards from computers and mobile phones. Since printed circuits boards are becoming more complex and smaller, the amount of materials is constantly changing. The main objective of this work was to characterize spent printed circuit boards from computers and mobile phones applying mineralmore » processing technique to separate the metal, ceramic, and polymer fractions. The processing was performed by comminution in a hammer mill, followed by particle size analysis, and by magnetic and electrostatic separation. Aqua regia leaching, loss-on-ignition and chemical analysis (inductively coupled plasma atomic emission spectroscopy - ICP-OES) were carried out to determine the composition of printed circuit boards and the metal rich fraction. The composition of the studied mobile phones printed circuit boards (PCB-MP) was 63 wt.% metals; 24 wt.% ceramics and 13 wt.% polymers; and of the printed circuit boards from studied personal computers (PCB-PC) was 45 wt.% metals; 27 wt.% polymers and ceramics 28 wt.% ceramics. The chemical analysis showed that copper concentration in printed circuit boards from personal computers was 20 wt.% and in printed circuit boards from mobile phones was 34.5 wt.%. According to the characteristics of each type of printed circuit board, the recovery of precious metals may be the main goal of the recycling process of printed circuit boards from personal computers and the recovery of copper should be the main goal of the recycling process of printed circuit boards from mobile phones. Hence, these printed circuit boards would not be mixed prior treatment. The results of this paper show that copper concentration is increasing in mobile phones and remaining constant in personal computers.« less

Passive front-ends for wideband millimeter wave electronic warfare

NASA Astrophysics Data System (ADS)

Jastram, Nathan Joseph

This thesis presents the analysis, design and measurements of novel passive front ends of interest to millimeter wave electronic warfare systems. However, emerging threats in the millimeter waves (18 GHz and above) has led to a push for new systems capable of addressing these threats. At these frequencies, traditional techniques of design and fabrication are challenging due to small size, limited bandwidth and losses. The use of surface micromachining technology for wideband direction finding with multiple element antenna arrays for electronic support is demonstrated. A wideband tapered slot antenna is first designed and measured as an array element for the subsequent arrays. Both 18--36 GHz and 75--110 GHz amplitude only and amplitude/phase two element direction finding front ends are designed and measured. The design of arrays using Butler matrix and Rotman lens beamformers for greater than two element direction finding over W band and beyond using is also presented. The design of a dual polarized high power capable front end for electronic attack over an 18--45 GHz band is presented. To combine two polarizations into the same radiating aperture, an orthomode transducer (OMT) based upon a new double ridge waveguide cross section is developed. To provide greater flexibility in needed performance characteristics, several different turnstile junction matching sections are tested. A modular horn section is proposed to address flexible and ever changing operational requirements, and is designed for performance criteria such as constant gain, beamwidth, etc. A multi-section branch guide coupler and low loss Rotman lens based upon the proposed cross section are also developed. Prototyping methods for the herein designed millimeter wave electronic warfare front ends are investigated. Specifically, both printed circuit board (PCB) prototyping of micromachined systems and 3D printing of conventionally machined horns are presented. A 4--8 GHz two element array with integrated beamformer fabricated using the stacking of PCB boards is shown, and measured results compare favorably with the micromachined front ends. A 3D printed small aperture horn is compared with a conventionally machined horn, and measured results show similar performance with a ten-fold reduction in cost and weight.

40 CFR 761.210 - Manifest discrepancies.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROHIBITIONS PCB Waste Disposal Records and Reports § 761.210 Manifest discrepancies. (a) Manifest discrepancies are differences between the quantity or type of PCB waste designated on the manifest or shipping paper and the quantity or type of PCB waste actually delivered to and received by a designated facility...

40 CFR 761.208 - Use of the manifest.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PROHIBITIONS PCB Waste Disposal Records and Reports § 761.208 Use of the manifest. (a)(1) The generator of PCB... dilution. (ii) The PCB waste is accepted by the transporter for transport only to a storage or disposal... disposal facility listed on the manifest. (ii) The next designated transporter of PCB waste. (8) If the PCB...

40 CFR 761.208 - Use of the manifest.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROHIBITIONS PCB Waste Disposal Records and Reports § 761.208 Use of the manifest. (a)(1) The generator of PCB... dilution. (ii) The PCB waste is accepted by the transporter for transport only to a storage or disposal... disposal facility listed on the manifest. (ii) The next designated transporter of PCB waste. (8) If the PCB...

Anvil for Flaring PCB Guide Pins

NASA Technical Reports Server (NTRS)

Winn, E.; Turner, R.

1985-01-01

Spring-loaded anvil results in fewer fractured pins. New anvil for flaring guide pins in printed-circuit boards absorbs approximately 80 percent of press force. As result fewer pins damaged, and work output of flaring press greatly increased.

3-D Packaging: A Technology Review

NASA Technical Reports Server (NTRS)

Strickland, Mark; Johnson, R. Wayne; Gerke, David

2005-01-01

Traditional electronics are assembled as a planar arrangement of components on a printed circuit board (PCB) or other type of substrate. These planar assemblies may then be plugged into a motherboard or card cage creating a volume of electronics. This architecture is common in many military and space electronic systems as well as large computer and telecommunications systems and industrial electronics. The individual PCB assemblies can be replaced if defective or for system upgrade. Some applications are constrained by the volume or the shape of the system and are not compatible with the motherboard or card cage architecture. Examples include missiles, camcorders, and digital cameras. In these systems, planar rigid-flex substrates are folded to create complex 3-D shapes. The flex circuit serves the role of motherboard, providing interconnection between the rigid boards. An example of a planar rigid - flex assembly prior to folding is shown. In both architectures, the interconnection is effectively 2-D.

40 CFR 761.215 - Exception reporting.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PROHIBITIONS PCB Waste Disposal Records and Reports § 761.215 Exception reporting. (a) A generator of PCB waste... the designated PCB commercial storage or disposal facility within 35 days of the date the waste was... commitments or other factors affecting the facility's disposal capacity, the disposer of PCB waste could not...

40 CFR 761.215 - Exception reporting.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROHIBITIONS PCB Waste Disposal Records and Reports § 761.215 Exception reporting. (a) A generator of PCB waste... the designated PCB commercial storage or disposal facility within 35 days of the date the waste was... commitments or other factors affecting the facility's disposal capacity, the disposer of PCB waste could not...

Novel Ultrahigh Vacuum System for Chip-Scale Trapped Ion Quantum Computing

NASA Astrophysics Data System (ADS)

Chen, Shaw-Pin; Trapped Team

2011-05-01

This presentation reports the experimental results of an ultrahigh vacuum (UHV) system as a scheme to implement scalable trapped-ion quantum computers that use micro-fabricated ion traps as fundamental building blocks. The novelty of this system resides in our design, material selection, mechanical liability, low complexity of assembly, and reduced signal interference between DC and RF electrodes. Our system utilizes RF isolation and onsite-filtering topologies to attenuate AC signals generated from the resonator. We use a UHV compatible printed circuit board (PCB) material to perform DC routing, while the RF high and RF ground received separated routing via wire-wrapping. The standard PCB fabrication process enabled us to implement ceramic-based filter components adjacent to the chip trap. The DC electrodes are connected to air-side electrical feed through using four 25D adaptors made with polyether ether ketone (PEEK). The assembly process of this system is straight forward and in-chamber structure is self-supporting. We report on initial testing of this concept with a linear chip trap fabricated by the Sandia National Labs.

PARduino: A Simple Device Measuring and Logging Photosynthetically Active Radiation

NASA Astrophysics Data System (ADS)

Barnard, H. R.; Findley, M. C.

2013-12-01

Photosynthetically Active Radiation (PAR, 400 to 700 nm) is one of the primary controls of forest carbon and water relations. In complex terrain, PAR has high spatial-variability. Given the high cost of commercial datalogging equipment, spatially-distributed measurements of PAR have been typically modeled using geographic coordinates and terrain indices. Here, we present a design for a low cost, field-deployable device for measuring and logging PAR built around an Arduino microcontroller (we named it PARduino). PARduino provides for widely distributed sensor arrays and tests the feasibility of using hobbyist-grade electronics for collecting scientific data. PARduino components include a LiCor quantum sensor, EME Systems signal converter/amplifier, and Sparkfun's Arduino Pro Mini microcontroller. Additional components include a real time clock, a microSD flash memory card, and a custom printed circuit board (PCB). We selected the components with an eye towards ease of assembly. Everything can be connected to the PCB using through-hole soldering techniques. Since the device will be deployed in remote research plots that lack easy access to line power, battery life was also a consideration in the design. Extended deployment is possible because PARduino's software keeps it in a low-power sleep mode until ready to make a measurement. PARduino will be open-source hardware for use and improvement by others.

Modeling and characteristic of the SMT Board Plug connector in high speed optical communication system

NASA Astrophysics Data System (ADS)

Wu, Haoran; Dong, Zhenzhen; Wang, Tanglin; Zhao, Heng; Feng, Junbo; Cui, Naidi; Teng, Jie; Guo, Jin

2015-04-01

Modeling and characteristic of the SMT Board Plug connector, which is used to connect micro optical transceiver to the main board, are proposed and analyzed in this paper. When the high speed signal transfers from the PCB of transceiver to main board through SMT Board Plug connector, the structure and material discontinuity of the connector causes insertion losses and impedance mismatches. This makes the performance of high speed digital system exacerbated. So it is essential to analyze the signal transfer characteristics of the connector and find out what factors affected the signal quality at the design stage of the digital system. To solve this problem, Ansoft's High Frequency Structure Simulator (HFSS), based on the finite element method, was employed to build accurate 3D models, analyze the effects of various structure parameters, and obtain the full-wave characteristics of the SMT Board Plug connectors in this paper. Then an equivalent circuit model was developed. The circuit parameters were extracted precisely in the frequency range of interests by using the curve fitting method in ADS software, and the result was in good agreement with HFSS simulations up to 8GHz with different structure parameters. At last, the measurement results of S-parameter and eye diagram were given and the S-parameters showed good coincidence between the measurement and HFSS simulation up to 4GHz.

High-Sensitivity Low-Noise Miniature Fluxgate Magnetometers Using a Flip Chip Conceptual Design

PubMed Central

Lu, Chih-Cheng; Huang, Jeff; Chiu, Po-Kai; Chiu, Shih-Liang; Jeng, Jen-Tzong

2014-01-01

This paper presents a novel class of miniature fluxgate magnetometers fabricated on a print circuit board (PCB) substrate and electrically connected to each other similar to the current “flip chip” concept in semiconductor package. This sensor is soldered together by reversely flipping a 5 cm × 3 cm PCB substrate to the other identical one which includes dual magnetic cores, planar pick-up coils, and 3-D excitation coils constructed by planar Cu interconnections patterned on PCB substrates. Principles and analysis of the fluxgate sensor are introduced first, and followed by FEA electromagnetic modeling and simulation for the proposed sensor. Comprehensive characteristic experiments of the miniature fluxgate device exhibit favorable results in terms of sensitivity (or “responsivity” for magnetometers) and field noise spectrum. The sensor is driven and characterized by employing the improved second-harmonic detection technique that enables linear V-B correlation and responsivity verification. In addition, the double magnitude of responsivity measured under very low frequency (1 Hz) magnetic fields is experimentally demonstrated. As a result, the maximum responsivity of 593 V/T occurs at 50 kHz of excitation frequency with the second harmonic wave of excitation; however, the minimum magnetic field noise is found to be 0.05 nT/Hz1/2 at 1 Hz under the same excitation. In comparison with other miniature planar fluxgates published to date, the fluxgate magnetic sensor with flip chip configuration offers advances in both device functionality and fabrication simplicity. More importantly, the novel design can be further extended to a silicon-based micro-fluxgate chip manufactured by emerging CMOS-MEMS technologies, thus enriching its potential range of applications in modern engineering and the consumer electronics market. PMID:25196107

High-sensitivity low-noise miniature fluxgate magnetometers using a flip chip conceptual design.

PubMed

Lu, Chih-Cheng; Huang, Jeff; Chiu, Po-Kai; Chiu, Shih-Liang; Jeng, Jen-Tzong

2014-07-30

This paper presents a novel class of miniature fluxgate magnetometers fabricated on a print circuit board (PCB) substrate and electrically connected to each other similar to the current "flip chip" concept in semiconductor package. This sensor is soldered together by reversely flipping a 5 cm × 3 cm PCB substrate to the other identical one which includes dual magnetic cores, planar pick-up coils, and 3-D excitation coils constructed by planar Cu interconnections patterned on PCB substrates. Principles and analysis of the fluxgate sensor are introduced first, and followed by FEA electromagnetic modeling and simulation for the proposed sensor. Comprehensive characteristic experiments of the miniature fluxgate device exhibit favorable results in terms of sensitivity (or "responsivity" for magnetometers) and field noise spectrum. The sensor is driven and characterized by employing the improved second-harmonic detection technique that enables linear V-B correlation and responsivity verification. In addition, the double magnitude of responsivity measured under very low frequency (1 Hz) magnetic fields is experimentally demonstrated. As a result, the maximum responsivity of 593 V/T occurs at 50 kHz of excitation frequency with the second harmonic wave of excitation; however, the minimum magnetic field noise is found to be 0.05 nT/Hz(1/2) at 1 Hz under the same excitation. In comparison with other miniature planar fluxgates published to date, the fluxgate magnetic sensor with flip chip configuration offers advances in both device functionality and fabrication simplicity. More importantly, the novel design can be further extended to a silicon-based micro-fluxgate chip manufactured by emerging CMOS-MEMS technologies, thus enriching its potential range of applications in modern engineering and the consumer electronics market.

Development of two-step process for enhanced biorecovery of Cu-Zn-Ni from computer printed circuit boards.

PubMed

Shah, Monal B; Tipre, Devayani R; Purohit, Mamta S; Dave, Shailesh R

2015-08-01

Metal pollution due to the huge electronic waste (E-waste) accumulation is widespread across the globe. Extraction of copper, zinc and nickel from computer printed circuit boards (c-PCB) with a two-step bleaching process using ferric sulphate generated by Leptospirillum ferriphilum dominated consortium and the factors influencing the process were investigated in the present study. The studied factors with 10 g/L pulp density showed that pH 2.0 was optimum which resulted in 87.50-97.80% Cu-Zn-Ni extraction. Pre-treatment of PCB powder with acidified distilled water and NaCl solution showed 3.80-7.98% increase in metal extraction corresponding to 94.08% Cu, 99.80% Zn and 97.99% Ni extraction. Particle size of 75 μm for Cu and Zn while 1680 μm for Ni showed 2-folds increase in metal extraction, giving 97.35-99.80% Cu-Zn-Ni extraction in 2-6 days of reaction time. Whereas; 2.76-3.12 folds increase in Cu and Zn extraction was observed with the addition of 0.1% chelating agents. When the studies were carried out with high pulp density, ferric iron concentration of 16.57 g/L was found to be optimum for metal extraction from 75 g/L c-PCB and c-PCB addition in multiple installments resulted in 8.81-26.35% increase in metal extraction compared to single addition. The studied factors can be implemented for the scale-up aimed at faster recovery of multimetals from E-waste and thereby providing a secondary source of metal in an eco-friendly manner. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

40 CFR 761.35 - Storage for reuse.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Manufacturing, Processing, Distribution in Commerce, and Use of PCBs and PCB Items § 761.35 Storage for reuse. (a) The owner or operator of a PCB Article may store it for reuse in an area which is not designed... applicable to the PCB Article. (2) Maintains records starting at the time the PCB Article is removed from use...

The bar PANDA Barrel-TOF Detector at FAIR

NASA Astrophysics Data System (ADS)

Zimmermann, S.; Suzuki, K.; Steinschaden, D.; Chirita, M.; Ahmed, G.; Dutta, K.; Kalita, K.; Lehmann, A.; Böhm, M.; Schwarz, K.; Orth, H.; Brinkmann, K.-Th.

2017-08-01

The barrel-Time-of-Flight subdetector is one of the outer layers of the multi-layer design of the \\panda target spectrometer. It is designed with a minimal material budget in mind mainly consisting of 90×30×5 mm3 thin plastic scintillator tiles read out on each end by a serial connection of 4 SiPMs. 120 such tiles are placed on 16 2460 × 180 mm2 PCB boards forming a barrel covering an azimuthal angle from 22.5o to 150o. The detector is designed to achieve a time resolution below σ< 100 ps which allows to distinguish events in the constant stream of hits, as well as particle identification below the Cherenkov threshold via the time-of-flight; simultaneously providing the interaction times of events. The current prototype achieved a time resolution of ~54 ps, well below the design goal.

The Infrared Automatic Mass Screening (IRAMS) System For Printed Circuit Board Fault Detection

NASA Astrophysics Data System (ADS)

Hugo, Perry W.

1987-05-01

Office of the Program Manager for TMDE (OPM TMDE) has initiated a program to develop techniques for evaluating the performance of printed circuit boards (PCB's) using infrared thermal imaging. It is OPM TMDE's expectation that the standard thermal profile (STP) will become the basis for the future rapid automatic detection and isolation of gross failure mechanisms on units under test (UUT's). To accomplish this OPM TMDE has purchased two Infrared Automatic Mass Screening ( I RAMS) systems which are scheduled for delivery in 1987. The IRAMS system combines a high resolution infrared thermal imager with a test bench and diagnostic computer hardware and software. Its purpose is to rapidly and automatically compare the thermal profiles of a UUT with the STP of that unit, recalled from memory, in order to detect thermally responsive failure mechanisms in PCB's. This paper will review the IRAMS performance requirements, outline the plan for implementing the two systems and report on progress to date.

Corrosion Behavior of Silver-Plated Circuit Boards in a Simulated Marine Environment with Industrial Pollution

PubMed Central

Xiao, Kui; Yi, Pan; Yan, Lidan; Bai, Ziheng; Dong, Chaofang; Dong, Pengfei; Gao, Xiong

2017-01-01

The electrochemical corrosion behavior of a silver-plated circuit board (PCB-ImAg) in a polluted marine atmosphere environment (Qingdao in China) is studied through a simulated experiment. The morphologies of PCB-ImAg show some micropores on the surface that act as the corrosion-active points in the tests. Cl− mainly induces microporous corrosion, whereas SO2 causes general corrosion. Notably, the silver color changes significantly under SO2 influence. EIS results show that the initial charge transfer resistance in the test containing SO2 and Cl− is 9.847 × 103, while it is 3.701 × 104 in the test containing Cl− only, which demonstrates that corrosion accelerates in a mixed atmosphere. Polarization curves further show that corrosion potential is lower in mixed solutions (between −0.397 V SCE and −0.214 V SCE) than it in the solution containing Cl− only (−0.168 V SCE), indicating that corrosion tendency increases with increased HSO3− concentration. PMID:28773121

Sensor fusion of phase measuring profilometry and stereo vision for three-dimensional inspection of electronic components assembled on printed circuit boards.

PubMed

Hong, Deokhwa; Lee, Hyunki; Kim, Min Young; Cho, Hyungsuck; Moon, Jeon Il

2009-07-20

Automatic optical inspection (AOI) for printed circuit board (PCB) assembly plays a very important role in modern electronics manufacturing industries. Well-developed inspection machines in each assembly process are required to ensure the manufacturing quality of the electronics products. However, generally almost all AOI machines are based on 2D image-analysis technology. In this paper, a 3D-measurement-method-based AOI system is proposed consisting of a phase shifting profilometer and a stereo vision system for assembled electronic components on a PCB after component mounting and the reflow process. In this system information from two visual systems is fused to extend the shape measurement range limited by 2pi phase ambiguity of the phase shifting profilometer, and finally to maintain fine measurement resolution and high accuracy of the phase shifting profilometer with the measurement range extended by the stereo vision. The main purpose is to overcome the low inspection reliability problem of 2D-based inspection machines by using 3D information of components. The 3D shape measurement results on PCB-mounted electronic components are shown and compared with results from contact and noncontact 3D measuring machines. Based on a series of experiments, the usefulness of the proposed sensor system and its fusion technique are discussed and analyzed in detail.

Effects of PCB Substrate Surface Finish, Flux, and Phosphorus Content on Ionic Contamination

NASA Astrophysics Data System (ADS)

Bacior, M.; Sobczak, N.; Siewiorek, A.; Kudyba, A.; Homa, M.; Nowak, R.; Dziula, M.; Masłoń, S.

2015-02-01

The ionic contamination on printed circuit boards (PCB) having different surface finishes was examined using ionograph. The study was performed at the RT on three types of PCBs covered with: (i) hot air solder leveling (HASL LF), (ii) electroless nickel immersion gold (ENIG), and (iii) organic surface protectant (OSP), all on Cu substrates, as well as two types of fluxes, namely EF2202 and RF800. In the group of boards without soldered components, the lowest average value of contamination was for the ENIG 18 µm surface (0.01 μg NaCl/cm2). Boards with soldered components were more contaminated (from 0.29 μg NaCl/cm2 for the HASL LF 18 µm surface). After spraying boards with fluxing agents, the values of contaminants were the highest. The influence of phosphorus content in Ni-P layer of ENIG finish on ionic contamination was examined. In the group of PCBs with Au coating, the smallest amount of surface contaminants (0.32 μg NaCl/cm2) was for Ni-2-5%P layer. PCBs with Ni-11%P layer were higher contaminated (0.47 μg NaCl/cm2), and another with Ni-8%P layer had 0.81 μg NaCl/cm2. PCBs without Au coating, had the lowest contamination (0.48 μg NaCl/cm2) at phosphorous content equal 11%P. Higher contamination (0.67 μg NaCl/cm2) was at 2-5%P, up to 1.98 μg NaCl/cm2 for 8% of P. Boards with Au finish have lower value of contamination than identical boards without Au layer thus contributing to better reliability of electronic assemblies, since its failures due to current leakage and corrosion can be caused by contaminants.

40 CFR 761.208 - Obtaining manifests.

Code of Federal Regulations, 2014 CFR

2014-07-01

... PROHIBITIONS PCB Waste Disposal Records and Reports § 761.208 Obtaining manifests. (a)(1) A generator may use... 761.208 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL...) Commercial printer; (iii) PCB waste generator, transporter or, designated facility; or (iv) PCB waste broker...

40 CFR 761.208 - Obtaining manifests.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PROHIBITIONS PCB Waste Disposal Records and Reports § 761.208 Obtaining manifests. (a)(1) A generator may use... 761.208 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL...) Commercial printer; (iii) PCB waste generator, transporter or, designated facility; or (iv) PCB waste broker...

Residual Strain in PCBs with Cu-Plated Holes

NASA Astrophysics Data System (ADS)

Rudajevova, A.; Dušek, K.

2017-12-01

The residual strain in pure printed circuit boards (PCBs) and PCBs with Cu-plated holes has been obtained by measurement of the temperature dependence of their dilatational characteristics in the x, y, and z directions up to 240°C. Shrinkage in all directions was observed for all samples of both materials in the first thermal cycle. No permanent length changes were observed in the second or subsequent thermal cycles. The residual strain was determined from the difference in relative elongation between the first and second thermal cycles. Relaxation of residual strain occurred only in the first thermal cycle, as a thermally activated process. The highest value of relaxed residual strain was found in the z direction for both materials. Relaxation of residual strain in the z direction of the pure PCB occurred only in the negative strain range, whereas relaxation of the PCB with Cu-plated holes occurred in both the positive and negative strain ranges. The relaxation of the positive strain in the PCB with Cu-plated holes in the z direction implies that this part of the PCB was under pressure during its preparation. This relaxation is a consequence of the high coefficient of thermal expansion of PCB laminate in this direction, which can also lead to cracks in Cu holes when the material is heated above the glass-transition temperature.

Optical printed circuit board (O-PCB) and VLSI photonic integrated circuits: visions, challenges, and progresses

NASA Astrophysics Data System (ADS)

Lee, El-Hang; Lee, S. G.; O, B. H.; Park, S. G.; Noh, H. S.; Kim, K. H.; Song, S. H.

2006-09-01

A collective overview and review is presented on the original work conducted on the theory, design, fabrication, and in-tegration of micro/nano-scale optical wires and photonic devices for applications in a newly-conceived photonic systems called "optical printed circuit board" (O-PCBs) and "VLSI photonic integrated circuits" (VLSI-PIC). These are aimed for compact, high-speed, multi-functional, intelligent, light-weight, low-energy and environmentally friendly, low-cost, and high-volume applications to complement or surpass the capabilities of electrical PCBs (E-PCBs) and/or VLSI electronic integrated circuit (VLSI-IC) systems. These consist of 2-dimensional or 3-dimensional planar arrays of micro/nano-optical wires and circuits to perform the functions of all-optical sensing, storing, transporting, processing, switching, routing and distributing optical signals on flat modular boards or substrates. The integrated optical devices include micro/nano-scale waveguides, lasers, detectors, switches, sensors, directional couplers, multi-mode interference devices, ring-resonators, photonic crystal devices, plasmonic devices, and quantum devices, made of polymer, silicon and other semiconductor materials. For VLSI photonic integration, photonic crystals and plasmonic structures have been used. Scientific and technological issues concerning the processes of miniaturization, interconnection and integration of these systems as applicable to board-to-board, chip-to-chip, and intra-chip integration, are discussed along with applications for future computers, telecommunications, and sensor-systems. Visions and challenges toward these goals are also discussed.

Experimental study on the heat transfer characteristics of waste printed circuit boards pyrolysis.

PubMed

Ma, Hongting; Du, Na; Lin, Xueyin; Li, Chen; Lai, Junwen; Li, Zihao

2018-08-15

In order to study the appropriate and advanced technology for recycling waste printed circuit boards (PCBs), a fixed bed pyrolysis device with stirring function has been designed and developed. The effect of rotating speed on the temperature distribution and mass change in the pyrolysis process of FR-4 PCB has been analyzed. The heat transfer and pyrolysis characteristics of different granular layers with and without stirring have been investigated. The results indicate that the stirring can change the main way of heat transfer from conduction to convection in the PCB layers. As the increase of rotating speed, the temperature rising rate of material at the bottom of the pyrolysis furnace gradually decreases, while the heating rate is increasing at the upper layer, and the temperature difference between the upper and bottom layers is gradually reduced. When the rotating speed varies from 0r/min to 18r/min, the weight loss of the material increases from 3.97% to 6.76%, and the overall pyrolysis degree is improved. During the pyrolysis process, the material layer can be divided into three zones along the vertical direction, namely complete pyrolysis zone, partial pyrolysis zone and non-pyrolysis zone. As the rotating speed is 0r/min, the thickness of each zones is 6cm, 6cm and 3cm, respectively. However, when the rotating speed is increased to 18r/min, the non-pyrolysis zone disappears, and the thickness of complete pyrolysis zone and partial pyrolysis zone increase to 9cm and 6cm, respectively. Copyright © 2018 Elsevier B.V. All rights reserved.

Schiff Base modified on CPE electrode and PCB gold electrode for selective determination of silver ion

NASA Astrophysics Data System (ADS)

Leepheng, Piyawan; Suramitr, Songwut; Phromyothin, Darinee

2017-09-01

The schiff base was synthesized by 2,5-thiophenedicarboxaldehyde and 1,2,4-thiadiazole-3,5-diamine with condensation method. There was modified on carbon paste electrode (CPE) and Printed circuit board (PCB) gold electrode for determination silver ion. The schiff base modified electrodes was characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM), respectively. The electrochemical study was reported by cyclic voltammetry method and impedance spectroscopy using modified electrode as working electrode, platinum wire and Ag/AgCl as counter electrode and reference electrode, respectively. The modified electrodes have suitable detection for Ag+. The determination of silver ions using the modified electrodes depended linearly on Ag+ concentration in the range 1×10-10 M to 1×10-7 M, with cyclic voltammetry sensitivity were 2.51×108 μAM-1 and 1.88×108 μAM-1 for PCB gold electrode and CPE electrode, respectively, limits of detection were 5.33×10-9 M and 1.99×10-8 M for PCB gold electrode and CPE electrode, respectively. The modified electrodes have high accuracy, inexpensive and can applied to detection Ag+ in real samples.

Radiation patterns of dual concentric conductor microstrip antennas for superficial hyperthermia.

PubMed

Stauffer, P R; Rossetto, F; Leoncini, M; Gentilli, G B

1998-05-01

The finite difference time domain (FDTD) method has been used to calculate electromagnetic radiation patterns from 915-MHz dual concentric conductor (DCC) microwave antennas that are constructed from thin and flexible printed circuit board (PCB) materials. Radiated field distributions are calculated in homogeneous lossy muscle tissue loads located under variable thickness coupling bolus layers. This effort extends the results of previous investigations to consider more realistic applicator configurations with smaller 2-cm-square apertures and different coupling bolus materials and thicknesses, as well as various spacings of multiple-element arrays. Results are given for practical applicator designs with microstrip feedlines etched on the backside of the PCB antenna array instead of previously tested bulky coaxial-cable feedline connections to each radiating aperture. The results demonstrate that for an optimum coupling bolus thickness of 2.5-5 mm, the thin, flexible, and lightweight DCC antennas produce effective heating to the periphery of each aperture to a depth of approximately 1 cm, and may be combined into arrays for uniform heating of large area superficial tissue regions with the 50% power deposition contour conforming closely to the outer perimeter of the array.

A compact muon tracking system for didactic and outreach activities

NASA Astrophysics Data System (ADS)

Antolini, R.; Candela, A.; Conicella, V.; De Deo, M.; D` Incecco, M.; Sablone, D.; Arneodo, F.; Benabderrahmane, M. L.; Di Giovanni, A.; Pazos Clemens, L.; Franchi, G.; d`Inzeo, M.

2016-07-01

We present a cosmic ray telescope based on the use of plastic scintillator bars coupled to ASD-RGB1S-M Advansid Silicon Photomultipliers (SiPM) through wavelength shifter fibers. The system is comprised of 200 electronic channels organized into 10 couples of orthogonal planes allowing the 3D reconstruction of crossing muons. Two monolithic PCB boards have been designed to bias, readout all the SiPMs enclosed in the system, to monitor the working parameters and to remotely connect the detector. To make easier the display of muon tracks to non-expert users, two LED matrices, triggered by particle interactions, have been implemented. To improve the usability of the muon telescope, a controller board unit permits to select different levels of trigger and allows data acquisition for refined analyses for the more proficient user. A first prototype, funded by INFN and deployed in collaboration with NYUAD, is operating at the Toledo Metro station of Naples, while two further detectors will be developed and installed in Abu Dhabi in the next few months.

Experimental results on the influence of fluxes on partial discharge onset in PCB solder joints

NASA Astrophysics Data System (ADS)

Bulletti, Andrea; Capineri, Lorenzo; Materassi, Maurizio

2003-09-01

This work concerns the development of an experimental set-up for assessing the influence of fluxes on Partial Discharge (PD) onset in High Voltage (HV) devices soldered on Printed Circuit Boards (PCBs). In particular, the work considered the effects of three types of fluxes chosen in agreement with the directions of the Materials and Processes Division at ESA/ESTEC. Contaminated samples are formed by a standard FR-4 PCB board with a pair of copper electrodes and a protocol of contamination has been applied for all samples. The measuring system is placed inside a shielded chamber and provides measurements of Corona Inception Voltage (CIV), Corona Extinction Voltage (CEV) and PD amplitudes collected in a vacuum chamber with controlled temperature fixture. The results shows that flux Alpha 850-33 has the mean CIV smaller than other types of fluxes and the same result is observed for the mean CEV. Also the PD amplitudes are greater for samples contaminated with flux Alpha 850-33 than the other two types and similar in value for samples without flux.

Impact of Data Transmission over 10 Gbps on High-Density and Low-Cost Optoelectronic Module with Polynorbornene Waveguides

NASA Astrophysics Data System (ADS)

Ito, Yuka; Terada, Shinsuke; Arai, Shinya; Fujiwara, Makoto; Mori, Tetsuya; Choki, Koji; Fukushima, Takafumi; Koyanagi, Mitsumasa

2012-04-01

We proposed a rigid/flex optoelectronic (O/E) module with 48-channel polymeric waveguides for short-distance board-level optical interconnection. A flexible O/E test module was fabricated in the following two steps by using standard packaging processes. First, two vertical cavity surface emitting laser diodes (VCSELs) and one VCSEL driver (VD) were flip-chip bonded to a completed flexible printed circuit board (PCB), and two photodiodes (PDs) and one transimpedance amplifier/limiting amplifier (TIA/LA) to another flexible PCB. Second, the two flexible PCBs were attached with a polynorbornene (PNB) sheet in which high-density PNB waveguides were formed by UV exposure. Active areas of VCSELs and PDs on the flexible PCBs were aligned to micromirrors of the waveguides with -6 µm offset toward the signal propagation direction. We successfully demonstrated data transmission over 10 Gbps and low inter-channel crosstalk of less than -20 dB was achieved in the flexible O/E test module with 120-mm-long and 62.5-µm-pitch waveguides.

The ultrasonically assisted metals recovery treatment of printed circuit board waste sludge by leaching separation.

PubMed

Xie, Fengchun; Li, Haiying; Ma, Yang; Li, Chuncheng; Cai, Tingting; Huang, Zhiyuan; Yuan, Gaoqing

2009-10-15

This paper provides a practical technique that realized industrial scale copper and iron separation from printed circuit board (PCB) waste sludge by ultrasonically assisted acid leaching in a low cost, low energy consumption and zero discharge of wastes manner. The separation efficiencies of copper and iron from acid leaching with assistance of ultrasound were compared with the one without assistance of ultrasound and the effects of the leaching procedure, pH value, and ultrasonic strength have been investigated in the paper. With the appropriate leaching procedure, a final pH of 3.0, an ultrasonic generator power of 160 W (in 1l tank), leaching time of 60 min, leaching efficiencies of copper and iron had reached 97.83% and 1.23%, respectively. Therefore the separation of copper and iron in PCB waste sludge was virtually achieved. The lab results had been successfully applied to the industrial scaled applications in a heavy metal recovery plant in city of Huizhou, China for more than two years. It has great potentials to be used in even the broad metal recovery practices.

Use of high-radiant flux, high-resolution DMD light engines in industrial applications

NASA Astrophysics Data System (ADS)

Müller, Alexandra; Ram, Surinder

2014-03-01

The field of application of industrial projectors is growing day by day. New Digital Micromirror Device (DMD) - based applications like 3D printing, 3D scanning, Printed Circuit Board (PCB) board printing and others are getting more and more sophisticated. The technical demands for the projection system are rising as new and more stringent requirements appear. The specification for industrial projection systems differ substantially from the ones of business and home beamers. Beamers are designed to please the human eye. Bright colors and image enhancement are far more important than uniformity of the illumination or image distortion. The human eye, followed by the processing of the brain can live with quite high intensity variations on the screen and image distortion. On the other hand, a projector designed for use in a specialized field has to be tailored regarding its unique requirements in order to make no quality compromises. For instance, when the image is projected onto a light sensitive resin, a good uniformity of the illumination is crucial for good material hardening (curing) results. The demands on the hardware and software are often very challenging. In the following we will review some parameters that have to be considered carefully for the design of industrial projectors in order to get the optimum result without compromises.

Evaluation of a recycling process for printed circuit board by physical separation and heat treatment.

PubMed

Fujita, Toyohisa; Ono, Hiroyuki; Dodbiba, Gjergj; Yamaguchi, Kunihiko

2014-07-01

Printed circuit boards (PCBs) from discarded personal computer (PC) and hard disk drive were crushed by explosion in water or mechanical comminution in order to disintegrate the attached parts. More parts were stripped from PCB of PC, composed of epoxy resin; than from PCB of household appliance, composed of phenol resin. In an attempt to raise the copper grade of PCB by removing other components, a carbonization treatment was investigated. The crushed PCB without surface-mounted parts was carbonized under a nitrogen atmosphere at 873-1073 K. After screening, the char was classified by size into oversized pieces, undersized pieces and powder. The copper foil and glass fiber pieces were liberated and collected in undersized fraction. The copper foil was liberated easily from glass fiber by stamping treatment. As one of the mounted parts, the multi-layered ceramic capacitors (MLCCs), which contain nickel, were carbonized at 873 K. The magnetic separation is carried out at a lower magnetic field strength of 0.1T and then at 0.8 T. In the +0.5mm size fraction the nickel grade in magnetic product was increased from 0.16% to 6.7% and the nickel recovery is 74%. The other useful mounted parts are tantalum capacitors. The tantalum capacitors were collected from mounted parts. The tantalum-sintered bodies were separated from molded resins by heat treatment at 723-773 K in air atmosphere and screening of 0.5mm. Silica was removed and 70% of tantalum grade was obtained after more than 823K heating and separation. Next, the evaluation of Cu recycling in PCB is estimated. Energy consumption of new process increased and the treatment cost becomes 3 times higher comparing the conventional process, while the environmental burden of new process decreased comparing conventional process. The nickel recovery process in fine ground particles increased energy and energy cost comparing those of the conventional process. However, the environmental burden decreased than the conventional one. The process for recovering tantalum used more heat for the treatment and therefore the energy consumption increased by 50%, when comparing with conventional process. However, the market price for tantalum is very large; the profit for tantalum recovery is added. Also the environmental burden decreased by the recycling of tantalum recovery. Therefore, the tantalum recovery is very important step in the PCB recycling. If there is no tantalum, the consumed energy and treatment cost increase in the new process, though the environmental burden decreases. Copyright © 2014 Elsevier Ltd. All rights reserved.

Laser-induced breakdown spectroscopy (LIBS) combined with hyperspectral imaging for the evaluation of printed circuit board composition.

PubMed

Carvalho, Rodrigo R V; Coelho, Jomarc A O; Santos, Jozemir M; Aquino, Francisco W B; Carneiro, Renato L; Pereira-Filho, Edenir R

2015-03-01

In this study, laser-induced breakdown spectroscopy (LIBS) was combined with chemometric strategies (PCA, Principal Component Analysis) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) to investigate the metal composition of a printed circuit board (PCB) sample from a mobile phone. Scanning electron microscopy-EDS was used for two main reasons: it was possible at the same time to visualize the sample surface, craters (made by the laser pulses) and also the chemical composition of the samples. A 30 mm×40 mm area of the mobile phone PCB sample, which was manufactured in 2011, was investigated. In this case, a matrix with 30 rows and 40 columns (1200 points) was analyzed, and 10 pulses were performed at each point. A total of 12,000 emission spectra were recorded in the wavelength range from 186 to 1040 nm. After an initial exploratory investigation using PCA, 18 emission lines were selected (representing the elements Al, Au, Ba, Ca, Co, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Sb, Si, Sn, Ti and Zn) and then normalized by the relative intensities, and a new PCA was calculated with the autoscaled data. For example, Au and Si were mainly observed in the superficial electrical contacts and in the bulk of the PCB, respectively. A second sample (a mouse PCB) was also analyzed and Pb (emission lines 357.273, 363.956, 368.346, 373.994 and 405.780 nm) was identified in the solders. In addition, this element was determined using FAAS (flame atomic absorption spectrometry) and the Pb concentration was around 25% (w/w). This study opens the possibility for improved recycling processes and the chemical investigation of solid samples measuring a few millimeters in dimension without sample preparation. Copyright © 2014 Elsevier B.V. All rights reserved.

Atmospheric occurrence, transport and gas-particle partitioning of polychlorinated biphenyls over the northwestern Pacific Ocean

NASA Astrophysics Data System (ADS)

Wu, Zilan; Lin, Tian; Li, Zhongxia; Li, Yuanyuan; Guo, Tianfeng; Guo, Zhigang

2017-10-01

Ship-board air samples were collected during March to May 2015 from the East China Sea (ECS) to the northwestern Pacific Ocean (NWP) to explore the atmospheric occurrence and gas-particle partitioning of polychlorinated biphenyls (PCBs) when the westerly East Asian Monsoon prevailed. Total PCB concentrations in the atmosphere ranged from 56.8 to 261 pg m-3. Higher PCB levels were observed off the coast and minor temperature-induced changes showed that continuous emissions from East Asia remain as an important source to the regional atmosphere. A significant relationship between Koa (octanol-air partition coefficient) and KP (gas-particle partition coefficient) for PCBs was observed under continental air masses, suggesting that land-derived organic aerosols affected the PCB gas-particle partitioning after long-range transport, while an absence of this correlation was identified in marine air masses. The PCB partitioning cannot be fully explained by the absorptive mechanism as the predicted KP were found to be 2-3 orders of magnitude lower than the measured Kp, while the prediction was closely matched when soot adsorption was considered. The results suggested the importance of soot carbon as a transport medium for PCBs during their long-range transport and considerable impacts of continental outflows on PCBs across the downwind area. The estimated transport mass of particulate PCBs into the ECS and NWP totals 2333 kg during the spring, constituting ca. 17% of annual emission inventories of unintentionally produced PCB in China.

355 nm UV laser patterning and post-processing of FR4 PCB for fine pitch components integration

NASA Astrophysics Data System (ADS)

Dupont, F.; Stoukatch, S.; Laurent, P.; Dricot, S.; Kraft, M.

2018-01-01

Laser direct patterning of fine pitch features on standard PCB (Printed Circuit Board) was investigated. As a feasibility study, eight parameter sets were selected and the smallest achievable grooves and tracks were determined. Three regular FR4 (Flame Resistant 4) PCB substrates have been experimented with. The first two have respectively 18 μm and 35 μm bare copper conductive layer without finish while the third one has a 18 μm copper layer with ENIG (Electroless Nickel Immersion Gold) finish. Laser patterning of PCB conductive structure is a single step, maskless and purely dry operation expected to allow reaching fine pitch features, even on thick copper layers (≥ 18 μm) for which the traditional chemical wet processes encounter underetch problems. Aside PCB complete structuring, a second objective is to evaluate laser post-processing of standard patterned PCB as an economically viable technique to integrate a few fine pitch components on low cost PCBs. This process is suitable for prototyping and for small and medium series. The widths of the smallest grooves and tracks that we achieved were measured about 11 μm and 19 μm on 18 μm thick cooper layer, 13 μm and 39 μm on 35 μm thick cooper layer, and 11 μm and 38 μm on 18 μm cooper layer with ENIG finish. These values are well below what can be achieved with a wet process. Etching results are presented at high magnification both from the top and from a cross-sectioning perspective. The latter allows observation of the TAZ (Thermal Affected Zone) in the conductive layer and the damages in the FR4.

Design and evaluation of a SiPM-based large-area detector module for positron emission imaging

NASA Astrophysics Data System (ADS)

Alva-Sánchez, H.; Murrieta-Rodríguez, T.; Calva-Coraza, E.; Martínez-Dávalos, A.; Rodríguez-Villafuerte, M.

2018-03-01

The design and evaluation of a large-area detector module for positron emission imaging applications, is presented. The module features a SensL ArrayC-60035-64P-PCB solid state detector (8×8 array of tileable silicon photomultipliers by SensL, 7.2 mm pitch) covering a total area of 57.4×57.4 mm2. The detector module was formed using a pixelated array of 40×40 lutetium-yttrium oxyorthosilicate (LYSO) scintillator crystal elements with 1.43 mm pitch. A 7 mm thick coupling light guide was used to allow light sharing between adjacent SiPM. A 16-channel symmetric charge division (SCD) readout board was designed to multiplex the number of signals from 64 to 16 (8 columns and 8 rows) and a center-of-gravity algorithm to identify the position. Data acquisition and digitization was accomplished using a custom-made system based on FPGAs boards. Crystal maps were obtained using 18F-positron sources and Voronoi diagrams were used to correct for geometric distortions and to generate a non-uniformity correction matrix. All measurements were taken at a controlled room temperature of 22oC. The crystal maps showed minor distortion, 90% of the 1600 total crystal elements could be identified, a mean peak-to-valley ratio of 4.3 was obtained and a 10.8% mean energy resolution for 511 keV annihilation photons was determined. The performance of the detector using our own readout board was compared to that using two different commercially readout boards using the same detector module arrangement. We show that these large-area SiPM arrays, combined with a 16-channel SCD readout board, can offer high spatial resolution, excellent energy resolution and detector uniformity and thus, can be used for positron emission imaging applications.

Reliability of CGA/LGA/HDI Package Board/Assembly (Final Report)

NASA Technical Reports Server (NTRS)

Ghaffaroam. Reza

2014-01-01

Package manufacturers are now offering commercial-off-the-shelf column grid array (COTS CGA) packaging technologies in high-reliability versions. Understanding the process and quality assurance (QA) indicators for reliability are important for low-risk insertion of these advanced electronics packages. The previous reports, released in January of 2012 and January of 2013, presented package test data, assembly information, and reliability evaluation by thermal cycling for CGA packages with 1752, 1517, 1509, and 1272 inputs/outputs (I/Os) and 1-mm pitch. It presented the thermal cycling (-55C either 100C or 125C) test results for up to 200 cycles. This report presents up to 500 thermal cycles with quality assurance and failure analysis evaluation represented by optical photomicrographs, 2D real time X-ray images, dye-and-pry photomicrographs, and optical/scanning electron Microscopy (SEM) cross-sectional images. The report also presents assembly challenge using reflowing by either vapor phase or rework station of CGA and land grid array (LGA) versions of three high I/O packages both ceramic and plastic configuration. A new test vehicle was designed having high density interconnect (HDI) printed circuit board (PCB) with microvia-in-pad to accommodate both LGA packages as well as a large number of fine pitch ball grid arrays (BGAs). The LGAs either were assembled onto HDI PCB as an LGA or were solder paste print and reflow first to form solder dome on pads before assembly. Both plastic BGAs with 1156 I/O and ceramic LGAs were assembled. It also presented the X-ray inspection results as well as failures due to 200 thermal cycles. Lessons learned on assembly of ceramic LGAs are also presented.

Design of Low Inductance Switching Power Cell for GaN HEMT Based Inverter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gurpinar, Emre; Iannuzzo, Francesco; Yang, Yongheng

Here in this paper, an ultra-low inductance power cell is designed for a three-Level Active Neutral Point Clamped (3LANPC) based on 650 V gallium nitride (GaN) HEMT devices. The 3L-ANPC topology with GaN HEMT devices and the selected modulation scheme suitable for wide-bandgap (WBG) devices are presented. The commutation loops, which mainly contribute to voltage overshoots and increase of switching losses, are discussed. The ultra-low inductance power cell design based on a fourlayer Printed Circuit Board (PCB) with the aim to maximize the switching performance of GaN HEMTs is explained. The design of gate drivers for the GaN HEMT devicesmore » is presented. Parasitic inductance and resistance of the proposed design are extracted with finite element analysis and discussed. Common mode behaviours based on the SPICE model of the converter are analyzed. Experimental results on the designed 3L-ANPC with the output power of up to 1 kW are presented, which verifies the performance of the proposed design in terms of ultra-low inductance.« less

Magneto-impedance in Multilayered [Ni80Fe20/Cu]4 with modification of the line-length pattern on Cu printed circuit board

NASA Astrophysics Data System (ADS)

Eko Prastyo, Wahyu; Maulana, F.; Nuryani, N.; Purnama, B.

2017-11-01

Magneto-impedance of multilayer [Ni80Fe20/Cu]4 on Cu PCB substrate has successfully studied. To enhance the magneto-impedance we modify the geometry the Cu PCB substrate. The multilayer is made by electro-deposition with Pt (Platinum) as elctrodes. Electro-deposition is made at room temperature. Magneto-impedance total is evaluated under the external magnetic field. The results shows that magneto-impedance curve is symmetry. The difference of line-length result in the difference of the magneto-impedance. The samples is with the longest line-length has the largest magneto-impedance ratio. The homogeneity of the samples is on account estimated the increase magneto-impedance ratio.

Evaluation of a recycling process for printed circuit board by physical separation and heat treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fujita, Toyohisa, E-mail: tfujita@sys.t.u-tokyo.ac.jp; Ono, Hiroyuki; Dodbiba, Gjergj

Highlights: • The parts mounted on printed circuit board (PCB) were liberated by underwater explosion and mechanical crushing. • The crushed PCB without surface-mounted parts was carbonized under inert atmosphere at 873 K to recover copper. • The multi-layered ceramic capacitors including nickel was carbonized at 873 K to recover nickel by the magnetic separation. • The tantalum powders were recovered from the molded resins by heat treatment at 723 and 823 K in air atmosphere and screening. • Energy and treatment cost of new process increased, however, the environmental burden decreased comparing conventional one. - Abstract: Printed circuit boardsmore » (PCBs) from discarded personal computer (PC) and hard disk drive were crushed by explosion in water or mechanical comminution in order to disintegrate the attached parts. More parts were stripped from PCB of PC, composed of epoxy resin; than from PCB of household appliance, composed of phenol resin. In an attempt to raise the copper grade of PCB by removing other components, a carbonization treatment was investigated. The crushed PCB without surface-mounted parts was carbonized under a nitrogen atmosphere at 873–1073 K. After screening, the char was classified by size into oversized pieces, undersized pieces and powder. The copper foil and glass fiber pieces were liberated and collected in undersized fraction. The copper foil was liberated easily from glass fiber by stamping treatment. As one of the mounted parts, the multi-layered ceramic capacitors (MLCCs), which contain nickel, were carbonized at 873 K. The magnetic separation is carried out at a lower magnetic field strength of 0.1 T and then at 0.8 T. In the +0.5 mm size fraction the nickel grade in magnetic product was increased from 0.16% to 6.7% and the nickel recovery is 74%. The other useful mounted parts are tantalum capacitors. The tantalum capacitors were collected from mounted parts. The tantalum-sintered bodies were separated from molded resins by heat treatment at 723–773 K in air atmosphere and screening of 0.5 mm. Silica was removed and 70% of tantalum grade was obtained after more than 823 K heating and separation. Next, the evaluation of Cu recycling in PCB is estimated. Energy consumption of new process increased and the treatment cost becomes 3 times higher comparing the conventional process, while the environmental burden of new process decreased comparing conventional process. The nickel recovery process in fine ground particles increased energy and energy cost comparing those of the conventional process. However, the environmental burden decreased than the conventional one. The process for recovering tantalum used more heat for the treatment and therefore the energy consumption increased by 50%, when comparing with conventional process. However, the market price for tantalum is very large; the profit for tantalum recovery is added. Also the environmental burden decreased by the recycling of tantalum recovery. Therefore, the tantalum recovery is very important step in the PCB recycling. If there is no tantalum, the consumed energy and treatment cost increase in the new process, though the environmental burden decreases.« less

Wideband Array for C, X, and Ku-Band Applications with 5.3:1 Bandwidth

NASA Technical Reports Server (NTRS)

Novak, Markus H.; Volakis, John L.; Miranda, Felix A.

2015-01-01

Planar arrays that exploit strong intentional coupling between elements have allowed for very wide bandwidths in low-profile configurations. However, such designs also require complex impedance matching networks that must also be very compact. For many space applications, typically occurring at C-, X-, Ku-, and most recently at Ka-band, such designs require specialized and expensive fabrication techniques. To address this issue, a novel ultra-wideband array is presented, using a simplified feed network to reduce fabrication cost. The array operates from 3.5-18.5 GHz with VSWR less than 2.4 at broadside, and is of very low profile, having a total height of lambda/10 at the lowest frequency of operation. Validation is provided using a 64-element prototype array, fabricated using common Printed Circuit Board (PCB) technology. The low size, weight, and cost of this array make it attractive for space-borne applications.

Flexible circuits with integrated switches for robotic shape sensing

NASA Astrophysics Data System (ADS)

Harnett, C. K.

2016-05-01

Digital switches are commonly used for detecting surface contact and limb-position limits in robotics. The typical momentary-contact digital switch is a mechanical device made from metal springs, designed to connect with a rigid printed circuit board (PCB). However, flexible printed circuits are taking over from the rigid PCB in robotics because the circuits can bend while carrying signals and power through moving joints. This project is motivated by a previous work where an array of surface-mount momentary contact switches on a flexible circuit acted as an all-digital shape sensor compatible with the power resources of energy harvesting systems. Without a rigid segment, the smallest commercially-available surface-mount switches would detach from the flexible circuit after several bending cycles, sometimes violently. This report describes a low-cost, conductive fiber based method to integrate electromechanical switches into flexible circuits and other soft, bendable materials. Because the switches are digital (on/off), they differ from commercially-available continuous-valued bend/flex sensors. No amplification or analog-to-digital conversion is needed to read the signal, but the tradeoff is that the digital switches only give a threshold curvature value. Boundary conditions on the edges of the flexible circuit are key to setting the threshold curvature value for switching. This presentation will discuss threshold-setting, size scaling of the design, automation for inserting a digital switch into the flexible circuit fabrication process, and methods for reconstructing a shape from an array of digital switch states.

Method for reworkable packaging of high speed, low electrical parasitic power electronics modules through gate drive integration

DOEpatents

Passmore, Brandon; Cole, Zach; Whitaker, Bret; Barkley, Adam; McNutt, Ty; Lostetter, Alexander

2016-08-02

A multichip power module directly connecting the busboard to a printed-circuit board that is attached to the power substrate enabling extremely low loop inductance for extreme environments such as high temperature operation. Wire bond interconnections are taught from the power die directly to the busboard further enabling enable low parasitic interconnections. Integration of on-board high frequency bus capacitors provide extremely low loop inductance. An extreme environment gate driver board allows close physical proximity of gate driver and power stage to reduce overall volume and reduce impedance in the control circuit. Parallel spring-loaded pin gate driver PCB connections allows a reliable and reworkable power module to gate driver interconnections.

Detection of Banned and Restricted Ozone-Depleting Chemicals in Printed Circuit Boards

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Richard N.; Wright, Bob W.

2008-12-01

A study directed toward the detection of halogenated solvents in the matrix of circuit boards has recently been completed. This work was undertaken to demonstrate the potential for reliable detection of solvents used during the fabrication of printed circuit boards (PCB). Since many of these solvents are now, or soon will be, restricted under the terms of legislation enacted in response to the Montreal Protocol and other international agreements, the work described here, conducted over a period of more that 4 years, has provided guidance for the development of chromatographic system and analytical protocol to assure compliance with regulations introducedmore » to control, or ban, industrial solvents associated with adverse environmental impact.« less

Study on Subgrain Rotation Behavior at Different Interfaces of a Solder Joint During Thermal Shock

NASA Astrophysics Data System (ADS)

Han, Jing; Tan, Shihai; Guo, Fu

2016-12-01

In order to investigate subgrain rotation behavior in the recrystallized region of lead-free solder joints, a ball grid array (BGA) specimen with a cross-sectioned edge row was thermally shocked. Electron backscattered diffraction (EBSD) was used to obtain the microstructure and orientations of Sn grains or subgrains in as-reflowed and thermally shocked conditions. Orientation imaging microscopy (OIM) showed that several subgrains were formed at the tilted twin grain boundaries, near the chip side and near the printed circuit board (PCB) side after 200 thermal shocks due to a highly mismatched coefficient of thermal expansion (CTE) of twin grains. Also, subgrains formed at the chip side and PCB side in the solder joint were selected to research the grain rotation behavior in lead-free solder joints. The analysis of subgrain rotation also indicated that the rotation behavior of subgrains was different between the chip side and PCB side. It was closely related with the large different crystal orientations between the chip side and PCB side. Furthermore, electron backscattered patterns (EBSPs) at several parts of the joint were not obtained after 300 thermal shocks due to the serious deformation caused by mismatched CTE during thermal shock. But 4 subgrains were selected and compared with that of the initial state and 200-thermal shock conditions. The results showed that the subgrains at the chip side were also rotated around the Sn [101] and [001] axes and the subgrains at the PCB side were also rotated around the Sn [100] axis, which indicated a continuous process of subgrain rotation.

Transmit/receive 3-20 GHz 1.2 mW packaged double-pole-16-throw switching matrix for radar-based target detection

NASA Astrophysics Data System (ADS)

Azhari, Afreen; Kuwano, Yuki; Xiao, Xia; Kikkawa, Takamaro

2018-01-01

A 3-20 GHz transmit/receive (T/R) double-pole-16-throw (DP16T) switching matrix has been developed on a printed circuit board (PCB) to control sixteen antennas in a radar-based portable breast-cancer detection system. The DP16T switch consists of four 65 nm CMOS 0.01-20 GHz double-pole-four-throw (DP4T) switches. The proposed switch increase the number of T/R combinations to 224 from the 196 of a conventional switching matrix in order to construct high-resolution images. Using this switch and a 4 × 4 slot antenna array, a 10 × 10 mm2 aluminum target was detected with an 8-GHz-center-frequency Gaussian monocycle pulse. The power consumption of the switch is only 1.2 mW. To the best of the authors’ knowledge, this is the first T/R radio frequency (RF) DP16T switching matrix, which was realized with four CMOS DP4T switches on a PCB and was measured with RF PCB connectors.

Automated Visual Inspection Of Integrated Circuits

NASA Astrophysics Data System (ADS)

Noppen, G.; Oosterlinck, Andre J.

1989-07-01

One of the major application fields of image processing techniques is the 'visual inspection'. For a number of rea-sons, the automated visual inspection of Integrated Circuits (IC's) has drawn a lot of attention. : Their very strict design makes them very suitable for an automated inspection. : There is already a lot of experience in the comparable Printed Circuit Board (PCB) and mask inspection. : The mechanical handling of wafers and dice is already an established technology. : Military and medical IC's should be a 100 % failproof. : IC inspection gives a high and allinost immediate payback. In this paper we wil try to give an outline of the problems involved in IC inspection, and the algorithms and methods used to overcome these problems. We will not go into de-tail, but we will try to give a general understanding. Our attention will go to the following topics. : An overview of the inspection process, with an emphasis on the second visual inspection. : The problems encountered in IC inspection, as opposed to the comparable PCB and mask inspection. : The image acquisition devices that can be used to obtain 'inspectable' images. : A general overview of the algorithms that can be used. : A short description of the algorithms developed at the ESAT-MI2 division of the katholieke Universiteit Leuven.

Recovering metallic fractions from waste electrical and electronic equipment by a novel vibration system.

PubMed

Habib, Muddasar; Miles, Nicholas J; Hall, Philip

2013-03-01

The need to recover and recycle valuable resources from Waste Electrical and Electronic Equipment (WEEE) is of growing importance as increasing amounts are generated due to shorter product life cycles, market expansions, new product developments and, higher consumption and production rates. The European Commission (EC) directive, 2002/96/EC, on WEEE became law in UK in January 2007 setting targets to recover up to 80% of all WEEE generated. Printed Wire Board (PWB) and/or Printed Circuit Board (PCB) is an important component of WEEE with an ever increasing tonnage being generated. However, the lack of an accurate estimate for PCB production, future supply and uncertain demands of its recycled materials in international markets has provided the motivation to explore different approaches to recycle PCBs. The work contained in this paper focuses on a novel, dry separation methodology in which vertical vibration is used to separate the metallic and non-metallic fractions of PCBs. When PCBs were comminuted to less than 1mm in size, metallic grades as high as 95% (measured by heavy liquid analysis) could be achieved in the recovered products. Copyright © 2012 Elsevier Ltd. All rights reserved.

A cytokine immunosensor for Multiple Sclerosis detection based upon label-free electrochemical impedance spectroscopy using electroplated printed circuit board electrodes.

PubMed

Bhavsar, Kinjal; Fairchild, Aaron; Alonas, Eric; Bishop, Daniel K; La Belle, Jeffrey T; Sweeney, James; Alford, T L; Joshi, Lokesh

2009-10-15

A biosensor for the serum cytokine, Interleukin-12 (IL-12), based upon a label-free electrochemical impedance spectroscopy (EIS) monitoring approach is described. Overexpression of IL-12 has been correlated to the diagnosis of Multiple Sclerosis (MS). An immunosensor has been fabricated by electroplating gold onto a disposable printed circuit board (PCB) electrode and immobilizing anti-IL-12 monoclonal antibodies (MAb) onto the surface of the electrode. This approach yields a robust sensor that facilitates reproducible mass fabrication and easy alteration of the electrode shape. Results indicate that this novel PCB sensor can detect IL-12 at physiological levels, <100 fM with f-values of 0.05 (typically <0.0001) in a label-free and rapid manner. A linear (with respect to log concentration) detectable range was achieved. Detection in a complex biological solution is also explored; however, significant loss of dynamic range is noted in the 100% complex solution. The cost effective approach described here can be used potentially for diagnosis of diseases (like MS) with known biomarkers in body fluids and for monitoring physiological levels of biomolecules with healthcare, food, and environmental relevance.

MEMS Technology for Space Applications

NASA Technical Reports Server (NTRS)

vandenBerg, A.; Spiering, V. L.; Lammerink, T. S. J.; Elwenspoek, M.; Bergveld, P.

1995-01-01

Micro-technology enables the manufacturing of all kinds of components for miniature systems or micro-systems, such as sensors, pumps, valves, and channels. The integration of these components into a micro-electro-mechanical system (MEMS) drastically decreases the total system volume and mass. These properties, combined with the increasing need for monitoring and control of small flows in (bio)chemical experiments, makes MEMS attractive for space applications. The level of integration and applied technology depends on the product demands and the market. The ultimate integration is process integration, which results in a one-chip system. An example of process integration is a dosing system of pump, flow sensor, micromixer, and hybrid feedback electronics to regulate the flow. However, for many applications, a hybrid integration of components is sufficient and offers the advantages of design flexibility and even the exchange of components in the case of a modular set up. Currently, we are working on hybrid integration of all kinds of sensors (physical and chemical) and flow system modules towards a modular system; the micro total analysis system (micro TAS). The substrate contains electrical connections as in a printed circuit board (PCB) as well as fluid channels for a circuit channel board (CCB) which, when integrated, form a mixed circuit board (MCB).

A learning-based autonomous driver: emulate human driver's intelligence in low-speed car following

NASA Astrophysics Data System (ADS)

Wei, Junqing; Dolan, John M.; Litkouhi, Bakhtiar

2010-04-01

In this paper, an offline learning mechanism based on the genetic algorithm is proposed for autonomous vehicles to emulate human driver behaviors. The autonomous driving ability is implemented based on a Prediction- and Cost function-Based algorithm (PCB). PCB is designed to emulate a human driver's decision process, which is modeled as traffic scenario prediction and evaluation. This paper focuses on using a learning algorithm to optimize PCB with very limited training data, so that PCB can have the ability to predict and evaluate traffic scenarios similarly to human drivers. 80 seconds of human driving data was collected in low-speed (< 30miles/h) car-following scenarios. In the low-speed car-following tests, PCB was able to perform more human-like carfollowing after learning. A more general 120 kilometer-long simulation showed that PCB performs robustly even in scenarios that are not part of the training set.

Critical rotational speed model of the rotating roll electrode in corona electrostatic separation for recycling waste printed circuit boards.

PubMed

Li, Jia; Lu, Hongzhou; Xu, Zhenming; Zhou, Yaohe

2008-06-15

Waste printed circuit board (PCB) is increasing worldwide. The corona electrostatic separation (CES) was an effective and environmental protection way to recycle resource from waste PCBs. The aim of this paper is to analyze the main factor (rotational speed) that affects the efficiency of CES from the point of view of electrostatics and mechanics. A quantitative method for analyzing the affection of rotational speed was studied and the model for separating flat nonmetal particles in waste PCBs was established. The conception of "charging critical rotational speed" and "detaching critical rotational speed" were presented. Experiments with the waste PCBs verified the theoretical model, and the experimental results were in good agreement with the theoretical model. The results indicated that the purity and recycle percentage of materials got a good level when the rotational speed was about 70 rpm and the critical rotational speed of small particles was higher than big particles. The model can guide the definition of operator parameter and the design of CES, which are needed for the development of any new application of the electrostatic separation method.

Integrated Forensics Approach to Fingerprint PCB Sources in Sediments using Rapid Sediment Characterization (RSC) and Advanced Chemical Fingerprinting (ACF). (Environmental Security Technology Certification Program)

DTIC Science & Technology

2012-06-01

23 5 TEST DESIGN ... research project, ORD will continue to focus on only the PCB inventory in the test zone and selected areas of the river as further defined in subsequent...1,000 500 50 25 5 TEST DESIGN This section of the report provides the detailed description of the experimental design and testing

Efficient Heat Dissipation of Uncooled 400-Gbps (16×25-Gbps) Optical Transceiver Employing Multimode VCSEL and PD Arrays

NASA Astrophysics Data System (ADS)

Shih, Tien-Tsorng; Chi, Yu-Chieh; Wang, Ruei-Nian; Wu, Chao-Hsin; Huang, Jian-Jang; Jou, Jau-Ji; Lee, Tai-Cheng; Kuo, Hao-Chung; Lin, Gong-Ru; Cheng, Wood-Hi

2017-04-01

An effective heat dissipation of uncooled 400-Gbps (16×25-Gbps) form-factor pluggable (CDFP) optical transceiver module employing chip-on-board multimode 25-Gbps vertical-surface-emitting-laser (VCSEL) and 25-Gbps photodiode (PD) arrays mounted on a brass metal core embedded within a printed circuit board (PCB) is proposed and demonstrated. This new scheme of the hollow PCB filling with thermally-dissipated brass metal core was simulated and used for high temperature and long term stability operation of the proposed 400-Gbps CDFP transceiver. During one-hour testing, a red-shift of central wavelength by 0.4-nm corresponding temperature increment of 6.7 °C was observed with the brass core assisted cooler module. Such a temperature change was significantly lower than that of 28.3 °C for the optical transceiver driven with conventional circuit board. After 100-m distance transmission over a multimode fiber (OM4), the 400-Gbps CDFP transceiver exhibited dispersion penalty of 2.6-dB, power budget of ≧ 3-dB, link loss of ≦ 0.63-dB, mask margin of 20%, and bit error rate (BER) of <10-12 with maintained stability more than one hour. The developed 400-Gbps CDFP transceiver module employing low-power consumption VCSEL and PD arrays, effective coupling lens arrays, and well thermal-dissipation brass metal core is suitable for use in the low-cost and high-performance data center applications.

Effect of Ground Patterns Size on FM-Band Cross-Talks between Two Parallel Signal Traces of Printed Circuit Boards for Vehicles

NASA Astrophysics Data System (ADS)

Iida, Michihira; Maeno, Tsuyoshi; Fujiwara, Osamu

It is well known that electromagnetic disturbances in vehicle-mounted radios are mainly caused by conducted noise currents flowing through wiring-harnesses from vehicle-mounted printed circuit boards (PCBs) with common ground patterns containing slits. To suppress the noise currents outflow from PCBs of these kinds, we previously measured noise currents outflow from simple two-layer PCBs having two parallel signal traces and different ground patterns with/without slits to reveal that making slits with open ends on the ground patterns in parallel with the traces can reduce the conducted noise currents. In the present study, with FDTD simulation, we investigated reduction effects of ground patterns size on the FM-band cross-talk noise levels between two parallel signal traces, by using four types of simple PCB models having different ground patterns formed in different numbers but containing the same planar dimension slits parallel to the traces, in addition to two types of PCB models with different ground patterns divided into two parts parallel to the traces. As a result, we found that the cross-talk noise currents for the above six types of PCBs decrease by 6.9-8.5dB compared to the PCB which has a plain ground with no slits. From this study, we got the finding that the contributing factor for the above mentioned cross-talk reduction relies on the reduction of mutual inductance between the two parallel traces. In addition, in case of this study, it is interesting to note that the noise currents outflow from PCBs can rather be suppressed when the size of the return ground of each signal trace is small.

Demonstration of glass-based photonic interposer for mid-board-optical engines and electrical-optical circuit board (EOCB) integration strategy

NASA Astrophysics Data System (ADS)

Schröder, H.; Neitz, M.; Schneider-Ramelow, M.

2018-02-01

Due to its optical transparency and superior dielectric properties glass is regarded as a promising candidate for advanced applications as active photonic interposer for mid-board-optics and optical PCB waveguide integration. The concepts for multi-mode and single-mode photonic system integration are discussed and related demonstration project results will be presented. A hybrid integrated photonic glass body interposer with integrated optical lenses for multi-mode data communication wavelength of 850 nm have been realized. The paper summarizes process developments which allow cost efficient metallization of TGV. Electro-optical elements like photodiodes and VCSELs can be directly flip-chip mounted on the glass substrate according to the desired lens positions. Furthermore results for a silicon photonic based single-mode active interposer integration onto a single mode glass made EOCB will be compared in terms of packaging challenges. The board level integration strategy for both of these technological approaches and general next generation board level integration concepts for photonic interposer will be introductorily discussed.

Meta-analysis of pemetrexed plus carboplatin doublet safety profile in first-line non-squamous non-small cell lung cancer studies.

PubMed

Okamoto, Isamu; Schuette, Wolfgang H W; Stinchcombe, Thomas E; Rodrigues-Pereira, José; San Antonio, Belén; Chen, Jian; Liu, Jingyi; John, William J; Zinner, Ralph G

2017-05-01

This meta-analysis compared safety profiles (selected drug-related treatment-emergent adverse events [TEAEs]) of first-line pemetrexed plus carboplatin (PCb) area under the concentration-time curve 5 mg/min•mL (PCb5) or 6 mg/min•mL (PCb6), two widely used regimens in clinical practice for advanced non-squamous non-small cell lung cancer. All patients received pemetrexed 500 mg/m 2 every 21 days with either of two carboplatin doses for up to 4-6 cycles. Safety profiles of PCb doses were compared using three statistical analysis methods: frequency table analysis (FTA), generalized linear mixed effect model (GLMM), and the propensity score method. Efficacy outcomes of PCb5 and PCb6 regimens were summarized. A total of 486 patients mainly from the US, Europe, and East Asia were included in the analysis; 22% (n = 105) received PCb5 in one trial and 78% (n = 381) received PCb6 in four trials. The FTA comparison demonstrated that PCb5 vs PCb6 was associated with a statistically significantly lower incidence of TEAEs, including all-grade thrombocytopenia, anemia, fatigue, and vomiting, and grade 3/4 thrombocytopenia. In the GLMM analysis, PCb5 patients were numerically less likely to experience all-grade and grade 3/4 neutropenia, anemia, and thrombocytopenia. The propensity score regression analysis showed PCb5 group patients were significantly less likely than PCb6 group patients to experience all-grade hematologic TEAEs and grade 3/4 thrombocytopenia and anemia. After applying propensity score 1:1 matching, FTA analysis showed that the PCb5 group had significantly less all-grade and grade 3/4 hematologic toxicities. Overall efficacy outcomes, including overall survival, progression-free survival, and response rate, were similar between the two carboplatin doses. Acknowledging the limitations of this meta-analysis of five trials, heterogeneous in patient's characteristics and trial designs, the results show that the PCb5 regimen was generally associated with a better safety profile than PCb6 across three statistical approaches, with no apparent impact on survival outcomes.

Continuous, Wireless Monitoring of Sediment Flux within Streams on Military Installations

DTIC Science & Technology

2013-10-17

2.2.1.3.2 Voltage Regulation ...................................................................................... 14 2.2.1.3.3 Mote and Data...components are: A. PCB board; B. Suspended sediment sensor; C. MDA300; D. Crossbow mote (not in the picture); E. Rain gauge; F. Two solenoid valves...wireless mote (MICA2, Crossbow Technology), a rechargeable battery, and a mounting structure. The exact configuration of the wireless sensor node

Evaluation of gold and silver leaching from printed circuit board of cellphones

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petter, P.M.H., E-mail: patymhp@yahoo.com.br; Veit, H.M.; Bernardes, A.M.

2014-02-15

Highlights: • Printed circuit boards (PCB) of mobile phones have large amounts of metals with high economic value such as gold and silver. • Dissolution of gold was done with a cyanide-based reagent and silver with nitric acid. • Leaching of PCB with Na{sub 2}S{sub 2}O{sub 3} and (NH{sub 4}){sub 2}S{sub 2}O{sub 3} to examine the feasibility of using these reagents was done. - Abstract: Electronic waste has been increasing proportionally with the technology. So, nowadays, it is necessary to consider the useful life, recycling, and final disposal of these equipment. Metals, such as Au, Ag, Cu, Sn and Nimore » can be found in the printed circuit boards (PCB). According to this, the aims of this work is to characterize the PCBs of mobile phones with aqua regia; obtaining “reference” values of leaching, to gold and silver, with cyanide and nitric acid, respectively; and study the process of leaching of these metals in alternative leaching with sodium thiosulfate and ammonium thiosulfate. The metals were characterized by digesting the sample with aqua regia for 1 and 2 h at 60 °C and 80 °C. The leaching of Au with a commercial reagent (cyanide) and the Ag with HNO{sub 3}were made. The leaching of Au and Ag with alternative reagents: Na{sub 2}S{sub 2}O{sub 3,} and (NH{sub 4}){sub 2}S{sub 2}O{sub 3} in 0.1 M concentration with the addition of CuSO{sub 4}, NH{sub 4}OH, and H{sub 2}O{sub 2}, was also studied. The results show that the digestion with aqua regia was efficient to characterize the metals present in the PCBs of mobile phones. However, the best method to solubilize silver was by digesting the sample with nitric acid. The leaching process using sodium thiosulfate was more efficient when an additional concentration of 0.015 and 0.030 M of the CuSO{sub 4} was added.« less

A Physics-Based Approach for Power Integrity in Multi-Layered PCBs

NASA Astrophysics Data System (ADS)

Zhao, Biyao

Developing a power distribution network (PDN) for ASICs and ICs to achieve the low-voltage ripple specifications for current digital designs is challenging with the high-speed and low-voltage ICs. Present methods are typically guided by best engineering practices for low impedance looking into the PDN from the IC. A pre-layout design methodology for power integrity in multi-layered PCB PDN geometry is proposed in the thesis. The PCB PDN geometry is segmented into four parts and every part is modelled using different methods based on the geometry details of the part. Physics-based circuit models are built for every part and the four parts are re-assembled into one model. The influence of geometry details is clearly revealed in this methodology. Based on the physics-based circuit mode, the procedures of using the pre-layout design methodology as a guideline during the PDN design is illustrated. Some common used geometries are used to build design space, and the design curves with the geometry details are provided to be a look up library for engineering use. The pre-layout methodology is based on the resonant cavity model of parallel planes for the cavity structures, and parallel-plane PEEC (PPP) for the irregular shaped plane inductance, and PEEC for the decoupling capacitor connection above the top most or bottom most power-return planes. PCB PDN is analyzed based on the input impedance looking into the PCB from the IC. The pre-layout design methodology can be used to obtain the best possible PCB PDN design. With the switching current profile, the target impedance can be selected to evaluate the PDN performance, and the frequency domain PDN input impedance can be used to obtain the voltage ripple in the time domain to give intuitive insight of the geometry impact on the voltage ripple.

Ultra-Wideband Array in PCB for Millimeter-Wave 5G and ISM

NASA Technical Reports Server (NTRS)

Novak, Markus H.; Volakis, John L.; Miranda, Felix A.

2017-01-01

Growing mobile data consumption has prompted the exploration of the millimeter-wave spectrum for large bandwidth, high speed communications. However, the allocated bands are spread across a wide swath of spectrum: Fifth generation mobile architecture (5G): 28, 38, 39, 6471 GHz; Industrial, Scientific, and Medical bands (ISM): 24, 60 GHz. Moreover, high gain phased arrays are required to overcome the significant path loss associated with these frequencies. Further, it is necessary to incorporate several of these applications in a single, small size and low cost platform. To this end, we have developed a scanning, Ultra-Wideband (UWB) array which covers all 5G, ISM, and other mm-W bands from 2472 GHz. Critically, this is accomplished using mass-production Printed Circuit Board (PCB) fabrication. The results of this work are presented in this poster.

Ion Trapping, Storage, and Ejection in Structures for Lossless Ion Manipulations

DOE PAGES

Zhang, Xinyu; Garimella, Sandilya V. B.; Prost, Spencer A.; ...

2015-06-14

Here, a structure for lossless ion manipulation (SLIM) module was constructed with electrode arrays patterned on a pair of parallel printed circuit boards (PCB) separated by 5 mm and utilized to investigate capabilities for ion trapping at 4 Torr. Positive ions were confined by application of RF having alternating phases on a series of inner rung electrodes and by positive DC potentials on surrounding guard electrodes on each PCB. An axial DC field was also introduced by stepwise varying the DC potential of the inner rung electrodes so as to control the ion transport and accumulation inside the ion trap.more » We show that ions could be trapped and accumulated with 100% efficiency, stored for at least 5 hours with no losses, and could be rapidly ejected from the SLIM trap.« less

1060-nm VCSEL-based parallel-optical modules for optical interconnects

NASA Astrophysics Data System (ADS)

Nishimura, N.; Nagashima, K.; Kise, T.; Rizky, A. F.; Uemura, T.; Nekado, Y.; Ishikawa, Y.; Nasu, H.

2015-03-01

The capability of mounting a parallel-optical module onto a PCB through solder-reflow process contributes to reduce the number of piece parts, simplify its assembly process, and minimize a foot print for both AOC and on-board applications. We introduce solder-reflow-capable parallel-optical modules employing 1060-nm InGaAs/GaAs VCSEL which leads to the advantages of realizing wider modulation bandwidth, longer transmission distance, and higher reliability. We demonstrate 4-channel parallel optical link performance operated at a bit stream of 28 Gb/s 231-1 PRBS for each channel and transmitted through a 50-μm-core MMF beyond 500 m. We also introduce a new mounting technology of paralleloptical module to realize maintaining good coupling and robust electrical connection during solder-reflow process between an optical module and a polymer-waveguide-embedded PCB.

40 CFR 761.215 - Manifest discrepancies.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PROHIBITIONS PCB Waste Disposal Records and Reports § 761.215 Manifest discrepancies. (a) Manifest... Section 761.215 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES... quantity or type of PCB waste designated on the manifest or shipping paper, and the quantity and type of...

40 CFR 761.215 - Manifest discrepancies.

Code of Federal Regulations, 2014 CFR

2014-07-01

... PROHIBITIONS PCB Waste Disposal Records and Reports § 761.215 Manifest discrepancies. (a) Manifest... Section 761.215 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES... quantity or type of PCB waste designated on the manifest or shipping paper, and the quantity and type of...

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - RAPID ASSAY SYSTEM FOR PCB ANALYSIS - STRATEGIC DIAGNOSTICS INC.

EPA Science Inventory

In July 1997, the U.S. Environmental Protection Agency (EPA) conducted a demonstration of polychlorinated biphenyl (PCB) field analytical techniques. The demonstration design was subjected to extensive review and comment by EPA's National Exposure Research Laboratory (NERL) Envi...

Enhanced accumulation of PCB congeners by Baltic Sea blue mussels, Mytilus edulis, with increased algae enrichment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilek, M.; Bjoerk, M.; Broman, D.

The objective of this study was to examine if natural variations in the quantity of phytoplankton-derived particulate and dissolved organic carbon influences the accumulation of polychlorinated biphenyls (PCBs) in the tissues of Baltic Sea blue mussels (Mytilus edulis L.). In a laboratory flow-through experiment the authors exposed M. edulis to the technical PCB mixture Aroclor{reg_sign} 1248 for 21 d at three different enrichments of the unicellular green algae Chlamydomonas sp., 0.10, 0.16, and 0.32 mg particulate organic carbon (POC)/L. Tissue and water concentrations were determined for seven PCB congeners and 21-d bioaccumulation factors were calculated against total water concentrations. Contrarymore » to what would be expected, an increase in algae enrichment from 0.10 to 0.32 mg POC/L resulted in an enhanced PCB accumulation by a factor of approx. 2. This increase in PCB accumulation was more pronounced for PCB congeners with lower hydrophobicity. These observations have implications for the design of laboratory accumulation studies and potentially for PCB accumulation and cycling in field populations of suspension-feeding mussels in response to changes in eutrophication status.« less

EPA (ENVIRONMENTAL PROTECTION AGENCY) METHOD STUDY 28, PCB'S (POLYCHLORINATED BIPHENYLS) IN OIL

EPA Science Inventory

This report describes the experimental design and the results of the validation study for two analytical methods to detect polychlorinated byphenyls in oil. The methods analyzed for four PCB Aroclors (1016, 1242, 1254, and 1260), 2-chlorobiphenyl, and decachlorobiphenyl. The firs...

PVC-based composite material containing recycled non-metallic printed circuit board (PCB) powders.

PubMed

Wang, Xinjie; Guo, Yuwen; Liu, Jingyang; Qiao, Qi; Liang, Jijun

2010-12-01

The study is directed to the use of non-metallic powders obtained from comminuted recycled paper-based printed circuit boards (PCBs) as an additive to polyvinyl chloride (PVC) substrate. The physical properties of the non-metallic PCB (NMPCB) powders were measured, and the morphological, mechanical and thermal properties of the NMPCB/PVC composite material were investigated. The results show that recycled NMPCB powders, when added below a threshold, tended to increase the tensile strength and bending strength of PVC. When 20 wt% NMPCB powders (relative to the substrate PVC) of an average diameter of 0.08 mm were added, the composite tensile strength and bending strength reached 22.6 MPa and 39.83 MPa, respectively, representing 107.2% and 123.1% improvement over pure PVC. The elongation at break of the composite material reached 151.94% of that of pure PVC, while the Vicat softening temperature of the composite material did not increase significantly compared to the pure PVC. The above results suggest that paper-based NMPCB powders, when used at appropriate amounts, can be effective for toughening PVC. Thus, this study suggests a new route for reusing paper-based NMPCB, which may have a significant beneficial environmental impact. Copyright © 2010 Elsevier Ltd. All rights reserved.

Size Effect of Ground Patterns on FM-Band Cross-Talks between Two Parallel Signal Traces of Printed Circuit Boards for Vehicles

NASA Astrophysics Data System (ADS)

Iida, Michihira; Maeno, Tsuyoshi; Wang, Jianqing; Fujiwara, Osamu

Electromagnetic disturbances in vehicle-mounted radios are mainly caused by conducted noise currents flowing through wiring-harnesses from vehicle-mounted printed circuit boards (PCBs) with common slitting ground patterns. To suppress these kinds of noise currents, we previously measured them for simple two-layer PCBs with two parallel signal traces and slitting or non-slitting ground patterns, and then investigated by the FDTD simulation the reduction characteristics of the FM-band cross-talk noise levels between two parallel signal traces on six simple PCB models having different slitting ground or different divided ground patterns parallel to the traces. As a result, we found that the contributory factor for the FM-band cross-talk reduction is the reduction of mutual inductance between the two parallel traces, and also the noise currents from PCBs can rather be suppressed even if the size of the return ground becomes small. In this study, to investigate this finding, we further simulated the frequency characteristics of cross-talk reduction for additional six simple PCB models with different dividing dimensions ground patterns parallel to the traces, which revealed an interesting phenomenon that cross-talk reduction characteristics do not always decrease with increasing the width between the divided ground patterns.

Digital Signal Processing Based Biotelemetry Receivers

NASA Technical Reports Server (NTRS)

Singh, Avtar; Hines, John; Somps, Chris

1997-01-01

This is an attempt to develop a biotelemetry receiver using digital signal processing technology and techniques. The receiver developed in this work is based on recovering signals that have been encoded using either Pulse Position Modulation (PPM) or Pulse Code Modulation (PCM) technique. A prototype has been developed using state-of-the-art digital signal processing technology. A Printed Circuit Board (PCB) is being developed based on the technique and technology described here. This board is intended to be used in the UCSF Fetal Monitoring system developed at NASA. The board is capable of handling a variety of PPM and PCM signals encoding signals such as ECG, temperature, and pressure. A signal processing program has also been developed to analyze the received ECG signal to determine heart rate. This system provides a base for using digital signal processing in biotelemetry receivers and other similar applications.

An electron-beam dose deposition experiment: TIGER 1-D simulation code versus thermoluminescent dosimetry

NASA Astrophysics Data System (ADS)

Murrill, Steven R.; Tipton, Charles W.; Self, Charles T.

1991-03-01

The dose absorbed in an integrated circuit (IC) die exposed to a pulse of low-energy electrons is a strong function of both electron energy and surrounding packaging materials. This report describes an experiment designed to measure how well the Integrated TIGER Series one-dimensional (1-D) electron transport simulation program predicts dose correction factors for a state-of-the-art IC package and package/printed circuit board (PCB) combination. These derived factors are compared with data obtained experimentally using thermoluminescent dosimeters (TLD's) and the FX-45 flash x-ray machine (operated in electron-beam (e-beam) mode). The results of this experiment show that the TIGER 1-D simulation code can be used to accurately predict FX-45 e-beam dose deposition correction factors for reasonably complex IC packaging configurations.

A Universal Portable Appliance for Stellarator W7-X Power Supply Controlling

NASA Astrophysics Data System (ADS)

Xu, Wei-hua; Wolfgang, Foerster; Guenter, Mueller

2001-06-01

In the project Wendelstein 7-X (W7-X), the popular fieldbus Profibus has been determined as a uniform connection between the central control system and all the subordinate systems. A universal embedded control system has been developed for W7-X power supply controlling. Siemens 80C167CR microcontroller is used as the central control unit of the system. With a user-defined printed circuit board (PCB) several control buses, i.e., Profibus, CAN, IEEE 488, RS485 and RS 232 have been connected to the microcontroller. The corresponding hardware interfaces for the control buses have been designed. A graphic liquid crystal display(LCD) and a user-defined keyboard are used as user interface. The control software will be developed with a C-like language, i.e., C166 for the controller.

Simple-1: Development stage of the data transmission system for a solid propellant mid-power rocket model

NASA Astrophysics Data System (ADS)

Yarce, Andrés; Sebastián Rodríguez, Juan; Galvez, Julián; Gómez, Alejandro; García, Manuel J.

2017-06-01

This paper presents the development stage of a communication module for a solid propellant mid-power rocket model. The communication module was named. Simple-1 and this work considers its design, construction and testing. A rocket model Estes Ventris Series Pro II® was modified to introduce, on the top of the payload, several sensors in a CanSat form factor. The Printed Circuit Board (PCB) was designed and fabricated from Commercial Off The Shelf (COTS) components and assembled in a cylindrical rack structure similar to this small format satellite concept. The sensors data was processed using one Arduino Mini and transmitted using a radio module to a Software Defined Radio (SDR) HackRF based platform on the ground station. The Simple-1 was tested using a drone in successive releases, reaching altitudes from 200 to 300 meters. Different kind of data, in terms of altitude, position, atmospheric pressure and vehicle temperature were successfully measured, making possible the progress to a next stage of launching and analysis.

Nanogranular soft magnetic material and on-package integrated inductors

NASA Astrophysics Data System (ADS)

Li, Liangliang

2007-12-01

Integrated inductors used in electronic circuits are mainly spiral-shaped aluminum devices fabricated on Si chip. They have several disadvantages---large silicon area consumption, high DC resistance and high cost. An attractive approach to address these issues is directly integrating inductors into package substrates, which provide plenty of usage area, low resistance and low cost. The goals of this dissertation are designing and fabricating magnetic and air-core inductors with characteristic low resistance and high quality factor on package substrates. The research work includes three parts which are summarized below. First, the CoFeHfO nanogranular magnetic material developed on Si wafers and package substrates by pulsed DC reactive sputtering were investigated. On Si wafers, the optimized CoFeHfO film has soft magnetic properties. On printed circuit board (PCB) substrates, these magnetic properties degrade due to the rough surface. Surface planarization such as chemical-mechanical polishing can be applied on PCB substrates to reduce the surface roughness and hence improve these properties. Second, on-package inductors with small resistances and high quality factors were designed, fabricated, measured and analyzed. Air-core and magnetic inductors (20 design variations) were built on 8-inch PCB substrates. The DC resistances of these inductors are less than 12 mO, one of the lowest values ever reported. The maximum quality factors can be as large as ˜80 at around 1 GHz for the air-core inductors and ˜25 at 200 MHz for the magnetic inductors. Third, inductor simulation was carried out to study the effects of magnetic materials on the properties of inductors using the Ansoft HFSS software package. The measurement data for the permeability spectra of the CoFeHfO film and the tensor nature of the permeability were taken into account in the simulation. The simulation results matched the experimental data for the inductances, resistances and quality factors. This established an accurate method for modeling high-frequency magnetic devices. Using this method, an inductor with a closed magnetic core was studied by varying the geometry of the core and copper coil. It has been found that the inductance of this inductor depends strongly on whether the permeability of the magnetic core is isotropic or anisotropic.

An application protocol for CAD to CAD transfer of electronic information

NASA Technical Reports Server (NTRS)

Azu, Charles C., Jr.

1993-01-01

The exchange of Computer Aided Design (CAD) information between dissimilar CAD systems is a problem. This is especially true for transferring electronics CAD information such as multi-chip module (MCM), hybrid microcircuit assembly (HMA), and printed circuit board (PCB) designs. Currently, there exists several neutral data formats for transferring electronics CAD information. These include IGES, EDIF, and DXF formats. All these formats have limitations for use in exchanging electronic data. In an attempt to overcome these limitations, the Navy's MicroCIM program implemented a project to transfer hybrid microcircuit design information between dissimilar CAD systems. The IGES (Initial Graphics Exchange Specification) format is used since it is well established within the CAD industry. The goal of the project is to have a complete transfer of microelectronic CAD information, using IGES, without any data loss. An Application Protocol (AP) is being developed to specify how hybrid microcircuit CAD information will be represented by IGES entity constructs. The AP defines which IGES data items are appropriate for describing HMA geometry, connectivity, and processing as well as HMA material characteristics.

Digital Signal Processing by Virtual Instrumentation of a MEMS Magnetic Field Sensor for Biomedical Applications

PubMed Central

Juárez-Aguirre, Raúl; Domínguez-Nicolás, Saúl M.; Manjarrez, Elías; Tapia, Jesús A.; Figueras, Eduard; Vázquez-Leal, Héctor; Aguilera-Cortés, Luz A.; Herrera-May, Agustín L.

2013-01-01

We present a signal processing system with virtual instrumentation of a MEMS sensor to detect magnetic flux density for biomedical applications. This system consists of a magnetic field sensor, electronic components implemented on a printed circuit board (PCB), a data acquisition (DAQ) card, and a virtual instrument. It allows the development of a semi-portable prototype with the capacity to filter small electromagnetic interference signals through digital signal processing. The virtual instrument includes an algorithm to implement different configurations of infinite impulse response (IIR) filters. The PCB contains a precision instrumentation amplifier, a demodulator, a low-pass filter (LPF) and a buffer with operational amplifier. The proposed prototype is used for real-time non-invasive monitoring of magnetic flux density in the thoracic cage of rats. The response of the rat respiratory magnetogram displays a similar behavior as the rat electromyogram (EMG). PMID:24196434

Digital signal processing by virtual instrumentation of a MEMS magnetic field sensor for biomedical applications.

PubMed

Juárez-Aguirre, Raúl; Domínguez-Nicolás, Saúl M; Manjarrez, Elías; Tapia, Jesús A; Figueras, Eduard; Vázquez-Leal, Héctor; Aguilera-Cortés, Luz A; Herrera-May, Agustín L

2013-11-05

We present a signal processing system with virtual instrumentation of a MEMS sensor to detect magnetic flux density for biomedical applications. This system consists of a magnetic field sensor, electronic components implemented on a printed circuit board (PCB), a data acquisition (DAQ) card, and a virtual instrument. It allows the development of a semi-portable prototype with the capacity to filter small electromagnetic interference signals through digital signal processing. The virtual instrument includes an algorithm to implement different configurations of infinite impulse response (IIR) filters. The PCB contains a precision instrumentation amplifier, a demodulator, a low-pass filter (LPF) and a buffer with operational amplifier. The proposed prototype is used for real-time non-invasive monitoring of magnetic flux density in the thoracic cage of rats. The response of the rat respiratory magnetogram displays a similar behavior as the rat electromyogram (EMG).

40 CFR 761.214 - Retention of manifest records.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PROHIBITIONS PCB Waste Disposal Records and Reports § 761.214 Retention of manifest records. (a)(1) A generator... Section 761.214 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES... receives a signed copy from the designated facility which received the PCB waste. This signed copy must be...

40 CFR 761.214 - Retention of manifest records.

Code of Federal Regulations, 2014 CFR

2014-07-01

... PROHIBITIONS PCB Waste Disposal Records and Reports § 761.214 Retention of manifest records. (a)(1) A generator... Section 761.214 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES... receives a signed copy from the designated facility which received the PCB waste. This signed copy must be...

Integrated Printed Circuit Board (PCB) Active Cooling With Piezoelectric Actuator

DTIC Science & Technology

2012-09-01

The cooler substrate is a laminated multilayer FR-4 substrate. Individual layers are patterned to support the active element, form a resonant...prepreg epoxy. Individual FR-4 lamina were mechanically machined to pattern each layer. The layers were aligned, stacked, and laminated to form the... laminated with 70/30 copper-nickel alloy or 80/20 nickel-chrome alloy and patterned by means of photolithographic techniques and wet etching in a ferric

Direct Power Injection of Microcontrollers in PCB Environments (Postprint)

DTIC Science & Technology

2012-09-01

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Air Force Research Laboratory 8. PERFORMING ORGANIZATION REPORT...and model development. The Atmel AT89LP2052, 8-bit microcontroller has been programmed to complete a binary count from 20 to 28. A 20 pin SOIC has...onto the custom board ( SOIC ). LabVIEW has been used to control the power level and timing of the RF source (MXG), and data acquisition using the

Dietary Manganese Modulates PCB126 Toxicity, Metal Status, and MnSOD in the Rat

PubMed Central

Wang, Bingxuan; Klaren, William D.; Wels, Brian R.; Simmons, Donald L.; Olivier, Alicia K.; Wang, Kai; Robertson, Larry W.; Ludewig, Gabriele

2016-01-01

PCB126 (3,3′,4,4′,5-pentachlorobiphenyl) is a potent aryl hydrocarbon receptor agonist and induces oxidative stress. Because liver manganese (Mn) levels decrease in response to PCB126, a Mn dietary study was designed to investigate the role of Mn in PCB126 toxicity. Male Sprague Dawley rats received diets containing 0, 10, or 150 ppm added Mn for 3 weeks, followed by a single ip injection of corn oil or PCB126 (5 µmol/kg body weight). After 2 weeks, Mn, Cu, Zn, and Fe levels in the heart, liver, and liver mitochondria, and Mn-containing superoxide dismutase (MnSOD) and metallothionein mRNA, MnSOD protein, and MnSOD activity were determined. Mn levels in liver, heart, and liver mitochondria were strongly decreased by the Mn-deficient diet. Small effects on Fe levels and a stepwise increase in MnSOD activity with dietary Mn were also visible. PCB126 caused profound changes in Cu (up), Zn, Fe, and Mn (down) in liver, but not in heart, and differing effects (Cu, Zn, and Fe up, Mn down) in liver mitochondria. Liver MnSOD and metallothionein mRNA levels and MnSOD protein were increased but MnSOD activity was decreased by PCB126. PCB126-induced liver enlargement was dose-dependently reduced with increasing dietary Mn. These changes in metals homeostasis and MnSOD activity in liver but not heart may be a/the mechanism of PCB126 liver-specific toxicity. Specifically, transport of Fenton metals (Cu, Fe) into and Mn out of the mitochondria, a probable mechanism for lower MnSOD activity, may be a/the cause of PCB126-induced oxidative stress. The role of metallothioneins needs further evaluation. Dietary Mn slightly alleviated PCB126-induced toxicities. PMID:26660635

Transformer oils as a potential source of environmental exposure to polychlorinated biphenyls (PCBs): an assessment in three central provinces of Iran.

PubMed

Saeedi, Reza; Khakzad, Saeed; Koolivand, Ali; Dobaradaran, Sina; Khaloo, Shokooh Sadat; Jorfi, Sahand; Abtahi, Mehrnoosh

2017-08-01

Polychlorinated biphenyl (PCB) contamination of oils from all transformers of the national electrical grid in Tehran, Qom, and Alborz, three central provinces of Iran, was assessed. The concentration of PCBs in transformer oils was determined by gas chromatography. At the national level, the proportions of transformers with oil PCB contents of <5, 5-49, 50-499, 500-4999, and >5000 ppm were determined to be 85.7, 12.4, 1.6, 0.1, and 0.1%, respectively. About 0.5% of transformer oils (66,000 kg out of 13,342,000 kg) exhibited PCB levels higher than 50 ppm that based on the Stockholm Convention should be phased out before 2025. The contaminated oils contained 91.4% of detected PCBs (132 kg PCBs out of 144 kg PCBs) and were located in 1.9% of transformers (27 transformers out of 1449 transformers). Statistical analysis indicated that the year of manufacture and manufacturing company provided significant effects on PCB contamination (p value <0.001). PCB contamination of transformer oils in Tehran was higher than that of the other provinces that could be mainly caused by the older average year of manufacture. PCB levels higher than 499 ppm were also observed only in Tehran. This study provided valuable information for future studies on identification of PCB-contaminated transformers as well as planning and design of waste management facilities for PCB-contaminated oils at the national level.

Development of the micro pixel chamber based on MEMS technology

NASA Astrophysics Data System (ADS)

Takemura, T.; Takada, A.; Kishimoto, T.; Komura, S.; Kubo, H.; Matsuoka, Y.; Miuchi, K.; Miyamoto, S.; Mizumoto, T.; Mizumura, Y.; Motomura, T.; Nakamasu, Y.; Nakamura, K.; Oda, M.; Ohta, K.; Parker, J. D.; Sawano, T.; Sonoda, S.; Tanimori, T.; Tomono, D.; Yoshikawa, K.

2018-02-01

Micro pixel chambers (μ-PIC) are gaseous two-dimensional imaging detectors originally manufactured using printed circuit board (PCB) technology. They are used in MeV gamma-ray astronomy, medicalimaging, neutron imaging, the search for dark matter, and dose monitoring. The position resolution of the present μ-PIC is approximately 120 μm (RMS), however some applications require a fine position resolution of less than 100 μm. To this end, we have started to develop a μ-PIC based on micro electro mechanical system (MEMS) technology, which provides better manufacturing accuracy than PCB technology. Our simulation predicted the gains of MEMS μ-PICs to be twice those of PCB μ-PICs at the same anode voltage. We manufactured two MEMS μ-PICs and tested them to study their behavior. In these experiments, we successfully operated the fabricatedMEMS μ-PICs and we achieved a maximum gain of approximately 7×103 and collected their energy spectra under irradiation of X-rays from 55Fe. However, the measured gains of the MEMS μ-PICs were less than half of the values predicted in the simulations. We postulated that the gains of the MEMS μ-PICs are diminished by the effect of the silicon used as a semiconducting substrate.

Packaging Technologies for High Temperature Electronics and Sensors

NASA Technical Reports Server (NTRS)

Chen, Liang-Yu; Hunter, Gary W.; Neudeck, Philip G.; Beheim, Glenn M.; Spry, David J.; Meredith, Roger D.

2013-01-01

This paper reviews ceramic substrates and thick-film metallization based packaging technologies in development for 500 C silicon carbide (SiC) electronics and sensors. Prototype high temperature ceramic chip-level packages and printed circuit boards (PCBs) based on ceramic substrates of aluminum oxide (Al2O3) and aluminum nitride (AlN) have been designed and fabricated. These ceramic substrate-based chip-level packages with gold (Au) thick-film metallization have been electrically characterized at temperatures up to 550 C. A 96% alumina based edge connector for a PCB level subsystem interconnection has also been demonstrated recently. The 96% alumina packaging system composed of chip-level packages and PCBs has been tested with high temperature SiC devices at 500 C for over 10,000 hours. In addition to tests in a laboratory environment, a SiC JFET with a packaging system composed of a 96% alumina chip-level package and an alumina printed circuit board mounted on a data acquisition circuit board was launched as a part of the MISSE-7 suite to the International Space Station via a Shuttle mission. This packaged SiC transistor was successfully tested in orbit for eighteen months. A spark-plug type sensor package designed for high temperature SiC capacitive pressure sensors was developed. This sensor package combines the high temperature interconnection system with a commercial high temperature high pressure stainless steel seal gland (electrical feed-through). Test results of a packaged high temperature capacitive pressure sensor at 500 C are also discussed. In addition to the pressure sensor package, efforts for packaging high temperature SiC diode-based gas chemical sensors are in process.

Packaging Technologies for High Temperature Electronics and Sensors

NASA Technical Reports Server (NTRS)

Chen, Liangyu; Hunter, Gary W.; Neudeck, Philip G.; Beheim, Glenn M.; Spry, David J.; Meredith, Roger D.

2013-01-01

This paper reviews ceramic substrates and thick-film metallization based packaging technologies in development for 500degC silicon carbide (SiC) electronics and sensors. Prototype high temperature ceramic chip-level packages and printed circuit boards (PCBs) based on ceramic substrates of aluminum oxide (Al2O3) and aluminum nitride (AlN) have been designed and fabricated. These ceramic substrate-based chiplevel packages with gold (Au) thick-film metallization have been electrically characterized at temperatures up to 550degC. A 96% alumina based edge connector for a PCB level subsystem interconnection has also been demonstrated recently. The 96% alumina packaging system composed of chip-level packages and PCBs has been tested with high temperature SiC devices at 500degC for over 10,000 hours. In addition to tests in a laboratory environment, a SiC JFET with a packaging system composed of a 96% alumina chip-level package and an alumina printed circuit board mounted on a data acquisition circuit board was launched as a part of the MISSE-7 suite to the International Space Station via a Shuttle mission. This packaged SiC transistor was successfully tested in orbit for eighteen months. A spark-plug type sensor package designed for high temperature SiC capacitive pressure sensors was developed. This sensor package combines the high temperature interconnection system with a commercial high temperature high pressure stainless steel seal gland (electrical feed-through). Test results of a packaged high temperature capacitive pressure sensor at 500degC are also discussed. In addition to the pressure sensor package, efforts for packaging high temperature SiC diode-based gas chemical sensors are in process.

Automation of a high-speed imaging setup for differential viscosity measurements

NASA Astrophysics Data System (ADS)

Hurth, C.; Duane, B.; Whitfield, D.; Smith, S.; Nordquist, A.; Zenhausern, F.

2013-12-01

We present the automation of a setup previously used to assess the viscosity of pleural effusion samples and discriminate between transudates and exudates, an important first step in clinical diagnostics. The presented automation includes the design, testing, and characterization of a vacuum-actuated loading station that handles the 2 mm glass spheres used as sensors, as well as the engineering of electronic Printed Circuit Board (PCB) incorporating a microcontroller and their synchronization with a commercial high-speed camera operating at 10 000 fps. The hereby work therefore focuses on the instrumentation-related automation efforts as the general method and clinical application have been reported earlier [Hurth et al., J. Appl. Phys. 110, 034701 (2011)]. In addition, we validate the performance of the automated setup with the calibration for viscosity measurements using water/glycerol standard solutions and the determination of the viscosity of an "unknown" solution of hydroxyethyl cellulose.

Automation of a high-speed imaging setup for differential viscosity measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hurth, C.; Duane, B.; Whitfield, D.

We present the automation of a setup previously used to assess the viscosity of pleural effusion samples and discriminate between transudates and exudates, an important first step in clinical diagnostics. The presented automation includes the design, testing, and characterization of a vacuum-actuated loading station that handles the 2 mm glass spheres used as sensors, as well as the engineering of electronic Printed Circuit Board (PCB) incorporating a microcontroller and their synchronization with a commercial high-speed camera operating at 10 000 fps. The hereby work therefore focuses on the instrumentation-related automation efforts as the general method and clinical application have beenmore » reported earlier [Hurth et al., J. Appl. Phys. 110, 034701 (2011)]. In addition, we validate the performance of the automated setup with the calibration for viscosity measurements using water/glycerol standard solutions and the determination of the viscosity of an “unknown” solution of hydroxyethyl cellulose.« less

Hierarchical planning for a surface mounting machine placement.

PubMed

Zeng, You-jiao; Ma, Deng-ze; Jin, Ye; Yan, Jun-qi

2004-11-01

For a surface mounting machine (SMM) in printed circuit board (PCB) assembly line, there are four problems, e.g. CAD data conversion, nozzle selection, feeder assignment and placement sequence determination. A hierarchical planning for them to maximize the throughput rate of an SMM is presented here. To minimize set-up time, a CAD data conversion system was first applied that could automatically generate the data for machine placement from CAD design data files. Then an effective nozzle selection approach implemented to minimize the time of nozzle changing. And then, to minimize picking time, an algorithm for feeder assignment was used to make picking multiple components simultaneously as much as possible. Finally, in order to shorten pick-and-place time, a heuristic algorithm was used to determine optimal component placement sequence according to the decided feeder positions. Experiments were conducted on a four head SMM. The experimental results were used to analyse the assembly line performance.

Sexual difference in polychlorinated biphenyl accumulation rates of walleye (Stizostedion vitreum)

USGS Publications Warehouse

Madenjian, Charles P.; Noguchi, George E.; Haas, Robert C.; Schrouder, Kathrin S.

1998-01-01

Adult male walleye (Stizostedion vitreum) exhibited significantly higher polychlorinated biphenyl (PCB) concentrations than similarly aged female walleye from Saginaw Bay (Lake Huron). To explain this difference, we tested the following three hypotheses: (i) females showed a considerably greater reduction in PCB concentration immediately following spawning than males, (ii) females grew at a faster rate and therefore exhibited lower PCB concentrations than males, and (iii) males spent more time in the Saginaw River system than females, and therefore received a greater exposure to PCBs. The first hypothesis was tested by comparing PCB concentration in gonadal tissue with whole-body concentration, the second hypothesis was tested via bioenergetics modeling, and we used mark-recapture data from the Saginaw Bay walleye fishery to address the third hypothesis. The only plausible explanation for the observed difference in PCB accumulation rate was that males spent substantially more time in the highly contaminated Saginaw River system than females, and therefore were exposed to greater environmental concentrations of PCBs. Based on the results of our study, we strongly recommend a stratified random sampling design for monitoring PCB concentration in Saginaw Bay walleye, with fixed numbers of females and males sampled each year.

Experimental investigation on sandwich structure ring-type ultrasonic motor.

PubMed

Peng, Taijiang; Shi, Hongyan; Liang, Xiong; Luo, Feng; Wu, Xiaoyu

2015-02-01

This paper presents a manufacture method for a sandwich structure Ultrasonic Motor (USM) and experiment. Two pieces of rotor clamped on a stator, and a stainless steel disk-spring is bonded on the hollow rotor disk to provide the press by a nut assembled on the shaft. The stator is made of a double-side Printed-Circuit Board (PCB) which is sawed out the ring in the center and connected on the board with three legs. On each side of the ring surface, there are electrodes connected at the same position via through hole. The three layer drive circuit for sine, cosine, and ground signal is connected on the board through each leg. There are many piezoelectric components (PZT) bonded between two electrodes and fill soldering tin on each electrode. Then PZT is welded on PCB by reflow soldering. Finally, rub the gibbous soldering tin down to the position of PZT surface makes sure the surface contacts with rotor evenly. The welding process can also be completed by Surface Mounted Technology (SMT). A prototype motor is manufactured by this method. Two B03 model shapes of the stator are obtained by the finite element analysis and the optimal frequency of the motor is 56.375 kHz measured by impedance instrument. The theoretical analysis is conducted for the relationship between the revolving speed of the USM and thickness of stator ring, number of the travelling waves, PZT amplitude, frequency and the other parameters. The experiment result shows that the maximum revolving speed is 116 RPM and the maximum torque is 25 N mm, when the actuate voltage is 200 VAC. Copyright © 2014 Elsevier B.V. All rights reserved.

Demonstrating the Effect of Particle Impact Dampers on the Random Vibration Response and Fatigue Life of Printed Wiring Assemblies

NASA Technical Reports Server (NTRS)

Knight, Brent; Montgomery, Randall; Geist, David; Hunt, Ron; LaVerde, Bruce; Towner, Robert

2013-01-01

In a recent experimental study, small Particle Impact Dampers (PID) were bonded directly to the surface of printed circuit board (PCB) or printed wiring assemblies (PWA), reducing the random vibration response and increasing the fatigue life. This study provides data verifying practicality of this approach. The measured peak strain and acceleration response of the fundamental out of plane bending mode was significantly attenuated by adding a PID device. Attenuation of this mode is most relevant to the fatigue life of a PWA because the local relative displacements between the board and the supported components, which ultimately cause fatigue failures of the electrical leads of the board-mounted components are dominated by this mode. Applying PID damping at the board-level of assembly provides mitigation with a very small mass impact, especially as compared to isolation at an avionics box or shelf level of assembly. When compared with other mitigation techniques at the PWA level (board thickness, stiffeners, constrained layer damping), a compact PID device has the additional advantage of not needing to be an integral part of the design. A PID can simply be bonded to heritage or commercial off the shelf (COTS) hardware to facilitate its use in environments beyond which it was originally qualified. Finite element analysis and test results show that the beneficial effect is not localized and that the attenuation is not due to the simple addition of mass. No significant, detrimental reduction in frequency was observed. Side-by-side life testing of damped and un-damped boards at two different thicknesses (0.070" and 0.090") has shown that the addition of a PID was much more significant to the fatigue life than increasing the thickness. High speed video, accelerometer, and strain measurements have been collected to correlate with analytical results.

A Distributed Operating System Design and Dictionary/Directory for the Stock Point Logistics Integrated Communications Environment.

DTIC Science & Technology

1983-11-01

transmission, FM(R) will only have to hold one message. 3. Program Control Block (PCB) The PCB ( Deitel 82] will be maintained by the Executive in...and Use of Kernel to Process Interrupts 35 10. Layered Operating System Design 38 11. Program Control Block Table 43 12. Ready List Data Structure 45 13...examples of fully distributed systems in operation. An objective of the NPS research program for SPLICE is to advance our knowledge of distributed

High Speed Imaging using Nanoprobe Arrays

DTIC Science & Technology

2010-06-23

Gotsmann and U. Dürig, Appl. Phys. Lett. 87, 194102 2005. 9 W. P. King, S. Saxena, B. A. Nelson, R. Pitchimani, and B. L. Weeks, Nano Lett. 6, 2145...microcantilevers with selective coatings has been applied as an artificial nose to recognize and characterize alcohol vapors either in a static mode...doped resistive heater. Fig. 4(c) shows a custom printed circuit board (PCB) to mount the array chip and a flexible ribbon cable for the electrical

Plant protection by the recombinant, root-colonizing Pseudomonas fluorescens F113rifPCB strain expressing arsenic resistance: improving rhizoremediation.

PubMed

Ryan, R P; Ryan, D; Dowling, D N

2007-12-01

The present study was designed to evaluate the stable insertion and expression of an arsenic resistance operon in the rhizosphere competent, PCB degrading strain Pseudomonas fluorescens F113rifPCB (F113rifPCB) and to investigate its ability to protect plants from arsenic. Introduction of the clone pUM3 (arsRDABC) into F113rifPCB was carried out by triparental conjugation. The resultant arsenic resistant strain was screened through a number of phenotypic tests including ability to grow on biphenyl, its rhizosphere competence and plant protection potential. Insertion and expression of arsenic resistant operon arsRDABC (from plasmid R773) into F113rifPCB strain has allowed this strain to grow, colonize the root and degrade biphenyl (100 mmol l(-1)) in the presence of sodium arsenate concentrations of up to 11.5 mmol l(-1). The strain retains its ability to colonize the rhizosphere of plants and appears to provide seed germination protection to arsenic which is not seen by the wild type. Owing to the significantly improved growth characteristics of both this rhizobacterium and plant species, the use of F113rifPCB-ars endowed with arsenic resistance capabilities may be a promising strategy to remediate mixed organic metal-contaminated sites. These types of strain could be used in the inoculation of metal accumulation plants for phytoremediation.

Effects on development, growth responses and thyroid-hormone systems in eyed-eggs and yolk-sac larvae of Atlantic salmon (Salmo salar) continuously exposed to 3,3',4,4'-tetrachlorobiphenyl (PCB-77).

PubMed

Arukwe, Augustine; Olufsen, Marianne; Cicero, Nicola; Hansen, Marianne D

2014-01-01

Thyroid hormones (triiodothyronine, T3; and thyroxine, T4) play significant roles in development, metamorphosis, metabolism, homeostasis, cellular proliferation, and differentiation, for which the effects are mediated through thyroid hormone receptors (TRα and TRβ). Similarly, the insulin-like growth factor (IGF) is involved in growth and development through regulation of somatic growth. This study was designed to examine the effects of the dioxin-like 3,3',4,4'-tetrachlorobiphenyl (PCB-77) on responses related to growth and thyroid hormone system in eyed eggs and yolk-sac larvae of Atlantic salmon. Salmon eggs were continuously exposed to two waterborne concentrations of PCB-77 (1 or 10 ng/L) over a period of 50 d covering hatching and through yolk-sac absorption stages. Sampling was performed regularly throughout the exposure period and at different time intervals. Gene expression patterns were performed on whole-body homogenate at age 500, 548, 632, 674, and 716 dd (dd: day degrees) using quantitative polymerase chain reaction (PCR). Total T3 (TT3) and total T4 (TT4) were measured using radioimmunoassay (RIA). Data showed that 10 ng PCB-77 increased dioiodinase 2 (Dio2) at 500 dd and both PCB-77 concentrations decreased dio2 expression at 548 dd. PCB-77 elevated cellular TT3 at 500 dd and was lowered at 548 dd only at 10 ng. Otherwise, time-related reduction was not affected by PCB-77 exposure as observed for the rest of the exposure period. For TT4, 1 ng PCB-77 produced a rise at 500 dd, and an apparent concentration decrease at 548 dd, before a total inhibition at 632 dd. The IGF-1 and IGF-1R were variably affected by PCB-77. For IGF-2, PCB-77 produced a concentration-dependent increase at 548 dd, and thereafter an elevation (1 ng) and fall (10 ng) at 632 dd. TRβ mRNA demonstrated PCB-77 related increases during the exposure period, and this effect returned to control levels at 716 dd. For TRα, a rise was noted only after exposure to 10 ng PCB-77 at 500 dd. Overall, the present study demonstrates some possible growth and developmental consequences following exposure to PCB-77 during early life stages of Atlantic salmon.

A high-precision miniaturized rotating coil transducer for magnetic measurements

DOE PAGES

Arpaia, P.; Buzio, M.; De Oliveira, R.; ...

2018-02-08

A miniaturized Printed Circuit Board (PCB) sensing coil, jointly developed by CERN and Fermilab for measuring the field of small-gap (less than 10 mm) accelerator magnets, is illustrated. A sensing coil array, with a scheme for compensating the main field when measuring the harmonic error components, hosted on a synthetic sapphire-based transducer, is presented. Key innovating features are (i) very-small size, both for the sensing coil array (thickness of 1.380 mm) and for the transducer (overall diameter of 7.350 mm), (ii) metrological performance, namely accuracy (more than five times better than state of the art), and 1-sigma repeatability (ten timesmore » better on harmonics with amplitude less than 100 ppm), and (iii) manufacturing technology of both the coil array (13 double layers aligned within 10 μm), and the sapphire support (concentricity, the most important uncertainty source for rotating coils, 3 μm of uncertainty, namely one order of magnitude better than fiberglass support). After stating the measurement problem, the design of the transducer and a case study of a two-layer PCB sensor array are also illustrated. Then, the prototyping and quality control of both the sensor and the transducer are discussed. Furthermore, the calibration and the results obtained with a prototype setup at Fermilab are presented. Finally, in the appendix, the theory of the rotating coil, the sensor geometry, and the harmonic compensation are briefly reviewed for the reader easiness.« less

A high-precision miniaturized rotating coil transducer for magnetic measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arpaia, P.; Buzio, M.; De Oliveira, R.

A miniaturized Printed Circuit Board (PCB) sensing coil, jointly developed by CERN and Fermilab for measuring the field of small-gap (less than 10 mm) accelerator magnets, is illustrated. A sensing coil array, with a scheme for compensating the main field when measuring the harmonic error components, hosted on a synthetic sapphire-based transducer, is presented. Key innovating features are (i) very-small size, both for the sensing coil array (thickness of 1.380 mm) and for the transducer (overall diameter of 7.350 mm), (ii) metrological performance, namely accuracy (more than five times better than state of the art), and 1-sigma repeatability (ten timesmore » better on harmonics with amplitude less than 100 ppm), and (iii) manufacturing technology of both the coil array (13 double layers aligned within 10 μm), and the sapphire support (concentricity, the most important uncertainty source for rotating coils, 3 μm of uncertainty, namely one order of magnitude better than fiberglass support). After stating the measurement problem, the design of the transducer and a case study of a two-layer PCB sensor array are also illustrated. Then, the prototyping and quality control of both the sensor and the transducer are discussed. Furthermore, the calibration and the results obtained with a prototype setup at Fermilab are presented. Finally, in the appendix, the theory of the rotating coil, the sensor geometry, and the harmonic compensation are briefly reviewed for the reader easiness.« less

Modified modular imaging system designed for a sounding rocket experiment

NASA Astrophysics Data System (ADS)

Veach, Todd J.; Scowen, Paul A.; Beasley, Matthew; Nikzad, Shouleh

2012-09-01

We present the design and system calibration results from the fabrication of a charge-coupled device (CCD) based imaging system designed using a modified modular imager cell (MIC) used in an ultraviolet sounding rocket mission. The heart of the imaging system is the MIC, which provides the video pre-amplifier circuitry and CCD clock level filtering. The MIC is designed with standard four-layer FR4 printed circuit board (PCB) with surface mount and through-hole components for ease of testing and lower fabrication cost. The imager is a 3.5k by 3.5k LBNL p-channel CCD with enhanced quantum efficiency response in the UV using delta-doping technology at JPL. The recently released PCIe/104 Small-Cam CCD controller from Astronomical Research Cameras, Inc (ARC) performs readout of the detector. The PCIe/104 Small-Cam system has the same capabilities as its larger PCI brethren, but in a smaller form factor, which makes it ideally suited for sub-orbital ballistic missions. The overall control is then accomplished using a PCIe/104 computer from RTD Embedded Technologies, Inc. The design, fabrication, and testing was done at the Laboratory for Astronomical and Space Instrumentation (LASI) at Arizona State University. Integration and flight calibration are to be completed at the University of Colorado Boulder before integration into CHESS.

Condition monitoring of Electric Components

NASA Astrophysics Data System (ADS)

Zaman, Ishtiaque

A universal non-intrusive model of a flexible antenna array is presented in this paper to monitor and identify the failures in electric machines. This adjustable antenna is designed to serve the purpose of condition monitoring of a vast range of electrical components including Induction Motor (IM), Printed Circuit Board (PCB), Synchronous Reluctance Motor (SRM), Permanent Magnet Synchronous Machine (PMSM) etc. by capturing the low frequency magnetic field radiated around these machines. The basic design and specification of the proposed antenna array for low frequency components is portrayed first. The design of the antenna is adjustable to fit for an extensive variety of segments. Subsequent to distinguishing the design and specifications of the antenna, the ideal area of the most delicate stray field has been identified for healthy current streaming around the machineries. Following this, short circuit representing faulty situation has been introduced and compared with the healthy cases. Precision has been found recognizing the faults using this one generic model of Antenna and the results are presented for three different machines i.e. IM, SRM and PMSM. Finite element method has been used to design the antenna and detect the optimum location and faults in the machines. Finally, a 3D Printer is proposed to be employed to build the antenna as per the details tended to in this paper contingent upon the power segments.

Conformal and Spectrally Agile Ultra Wideband Phased Array Antenna for Communication and Sensing

NASA Technical Reports Server (NTRS)

Novak, M.; Alwan, Elias; Miranda, Felix; Volakis, John

2015-01-01

There is a continuing need for reducing size and weight of satellite systems, and is also strong interest to increase the functional role of small- and nano-satellites (for instance SmallSats and CubeSats). To this end, a family of arrays is presented, demonstrating ultra-wideband operation across the numerous satellite communications and sensing frequencies up to the Ku-, Ka-, and Millimeter-Wave bands. An example design is demonstrated to operate from 3.5-18.5 GHz with VSWR2 at broadside, and validated through fabrication of an 8 x 8 prototype. This design is optimized for low cost, using Printed Circuit Board (PCB) fabrication. With the same fabrication technology, scaling is shown to be feasible up to a 9-49 GHz band. Further designs are discussed, which extend this wideband operation beyond the Ka-band, for instance from 20-80 GHz. Finally we will discuss recent efforts in the direct integration of such arrays with digital beamforming back-ends. It will be shown that using a novel on-site coding architecture, orders of magnitude reduction in hardware size, power, and cost is accomplished in this transceiver.

Recycling of lead solder dross, Generated from PCB manufacturing

NASA Astrophysics Data System (ADS)

Lucheva, Biserka; Tsonev, Tsonio; Iliev, Peter

2011-08-01

The main purpose of this work is to analyze lead solder dross, a waste product from manufacturing of printed circuit boards by wave soldering, and to develop an effective and environmentally sound technology for its recycling. A methodology for determination of the content and chemical composition of the metal and oxide phases of the dross is developed. Two methods for recycling of lead solder dross were examined—carbothermal reduction and recycling using boron-containing substances. The influence of various factors on the metal yield was studied and the optimal parameters of the recycling process are defined. The comparison between them under the same parameters-temperature and retention time, showed that recycling of dross with a mixture of borax and boric acid in a 1:2 ratio provides higher metal yield (93%). The recycling of this hazardous waste under developed technology gets glassy slag and solder, which after correction of the chemical composition can be used again for production of PCB.

A Study on the Effect of Ageing and Intermetallic Compound Growth on the Shear Strength of Surface Mount Technology Solder Joints

NASA Astrophysics Data System (ADS)

Nath, Jyotishman; Mallik, Sabuj; Borah, Anil

2015-04-01

The effect of ageing and intermetallic compound formation on the surface mount solder joints and its shear strength behavior under extreme mechanical and thermal conditions have been discussed in this paper. The specimens used are solder paste (Sn3.8Ag0.7Cu), bench marker II printed circuit boards (PCB), resistors 1206 and the fabrication of solder joints makes use of conventional surface mount technology (SMT). Reflow process was carried out at a peak temperature of 250 °C and the test samples were exposed to isothermal ageing at a constant temperature of 150 °C for a period of 600 h. Shear test was conducted on the PCB's. The shear strength of the solder joints rapidly increased during isothermal ageing to a certain time period and then started decreasing. Field emission scanning electron microscopy (FESEM) micrograph of the solder joint and energy dispersive X-ray (EDX) was performed on the solder sample to verify the formation of intermetallic compounds.

Sampling of BTX in Hat Yai city using cost effective laboratory-built PCB passive sampler.

PubMed

Subba, Jas Raj; Thammakhet, Chongdee; Thavarungkul, Panote; Kanatharana, Proespichaya

2016-08-23

A laboratory-built printed circuit board (PCB) passive sampler used for the monitoring of xylene and styrene in copy print shops was re-validated for detecting benzene, toluene and xylene (BTX) and applied for the sampling of ambient air from Hat Yai city, Songkhla, Thailand, in the month of November 2014. For monitoring, the PCB passive samplers were exposed to target analytes in 16 locations covering high to low exposure areas. After sampling, the samplers were thermally desorbed and the analytes were trapped by multi-walled carbon nanotubes packed into a micro-preconcentrator coupled to a gas chromatograph (GC) equipped with a flame ionization detector. At the optimum GC operating conditions, the linear dynamic ranges for BTX were 0.06-5.6 µg for benzene, 0.07-2.2 µg for toluene and 0.23-2.5 µg for xylene with R(2) > 0.99 with the limits of detection being 6.6, 6.8 and 19 ng for benzene, toluene and xylene, respectively. The concentrations of BTX in the 16 sampling sites were in the range of N.D.-1.3 ± 1.6, 4.50 ± 0.76-49.6 ± 3.7 and 1.00 ± 0.21-39.6 ± 3.1 µg m(-3), respectively. When compared to past studies, there had been an increase in the benzene concentration.

Evaluation and interconversion of various indicator PCB schemes for ∑PCB and dioxin-like PCB toxic equivalent levels in fish.

PubMed

Gandhi, Nilima; Bhavsar, Satyendra P; Reiner, Eric J; Chen, Tony; Morse, Dave; Arhonditsis, George B; Drouillard, Ken G

2015-01-06

Polychlorinated biphenyls (PCBs) remain chemicals of concern more than three decades after the ban on their production. Technical mixture-based total PCB measurements are unreliable due to weathering and degradation, while detailed full congener specific measurements can be time-consuming and costly for large studies. Measurements using a subset of indicator PCBs (iPCBs) have been considered appropriate; however, inclusion of different PCB congeners in various iPCB schemes makes it challenging to readily compare data. Here, using an extensive data set, we examine the performance of existing iPCB3 (PCB 138, 153, and 180), iPCB6 (iPCB3 plus 28, 52, and 101) and iPCB7 (iPCB6 plus 118) schemes, and new iPCB schemes in estimating total of PCB congeners (∑PCB) and dioxin-like PCB toxic equivalent (dlPCB-TEQ) concentrations in sport fish fillets and the whole body of juvenile fish. The coefficients of determination (R(2)) for regressions conducted using logarithmically transformed data suggest that inclusion of an increased number of PCBs in an iPCB improves relationship with ∑PCB but not dlPCB-TEQs. Overall, novel iPCB3 (PCB 95, 118, and 153), iPCB4 (iPCB3 plus 138) and iPCB5 (iPCB4 plus 110) presented in this study and existing iPCB6 and iPCB7 are the most optimal indicators, while the current iPCB3 should be avoided. Measurement of ∑PCB based on a more detailed analysis (50+ congeners) is also overall a good approach for assessing PCB contamination and to track PCB origin in fish. Relationships among the existing and new iPCB schemes have been presented to facilitate their interconversion. The iPCB6 equiv levels for the 6.5 and 10 pg/g benchmarks of dlPCB-TEQ05 are about 50 and 120 ng/g ww, respectively, which are lower than the corresponding iPCB6 limits of 125 and 300 ng/g ww set by the European Union.

Initial Field Deployment Results of Green PCB Removal from Sediment Systems (GPRSS)

NASA Technical Reports Server (NTRS)

Devor, Robert; Captain, James; Weis, Kyle; Maloney, Phillip; Booth, Greg; Quinn, Jacqueline

2014-01-01

Purpose of Study: (a) Develop/optimize technology capable of removing PCBs from contaminated sediments; (b) Develop design for functional GPRSS unit; (c) Produce and prove functionality of prototype units in a laboratory settings; (d) Produce fully-functional GPRSS units for testing at a demonstration site in Altavista, VA; and (e) Evaluate efficacy of GPRSS technology for the remediation of PCB-contaminated sediments.

Feasibility Test of a Liquid Film Thickness Sensor on a Flexible Printed Circuit Board Using a Three-Electrode Conductance Method

PubMed Central

Lee, Kyu Byung; Kim, Jong Rok; Park, Goon Cherl; Cho, Hyoung Kyu

2016-01-01

Liquid film thickness measurements under temperature-varying conditions in a two-phase flow are of great importance to refining our understanding of two-phase flows. In order to overcome the limitations of the conventional electrical means of measuring the thickness of a liquid film, this study proposes a three-electrode conductance method, with the device fabricated on a flexible printed circuit board (FPCB). The three-electrode conductance method offers the advantage of applicability under conditions with varying temperatures in principle, while the FPCB has the advantage of usability on curved surfaces and in relatively high-temperature conditions in comparison with sensors based on a printed circuit board (PCB). Two types of prototype sensors were fabricated on an FPCB and the feasibility of both was confirmed in a calibration test conducted at different temperatures. With the calibrated sensor, liquid film thickness measurements were conducted via a falling liquid film flow experiment, and the working performance was tested. PMID:28036000

Reliability of CGA/LGA/HDI Package Board/Assembly (Revision A)

NASA Technical Reports Server (NTRS)

Ghaffarian, Reza

2013-01-01

This follow-up report presents reliability test results conducted by thermal cycling of five CGA assemblies evaluated under two extreme cycle profiles, representative of use for high-reliability applications. The thermal cycles ranged from a low temperature of 55 C to maximum temperatures of either 100 C or 125 C with slow ramp-up rate (3 C/min) and dwell times of about 15 minutes at the two extremes. Optical photomicrographs that illustrate key inspection findings of up to 200 thermal cycles are presented. Other information presented include an evaluation of the integrity of capacitors on CGA substrate after thermal cycling as well as process evaluation for direct assembly of an LGA onto PCB. The qualification guidelines, which are based on the test results for CGA/LGA/HDI packages and board assemblies, will facilitate NASA projects' use of very dense and newly available FPGA area array packages with known reliably and mitigation risks, allowing greater processing power in a smaller board footprint and lower system weight.

Fully 3D-Integrated Pixel Detectors for X-Rays

DOE PAGES

Deptuch, Grzegorz W.; Gabriella, Carini; Enquist, Paul; ...

2016-01-01

The vertically integrated photon imaging chip (VIPIC1) pixel detector is a stack consisting of a 500-μm-thick silicon sensor, a two-tier 34-μm-thick integrated circuit, and a host printed circuit board (PCB). The integrated circuit tiers were bonded using the direct bonding technology with copper, and each tier features 1-μm-diameter through-silicon vias that were used for connections to the sensor on one side, and to the host PCB on the other side. The 80-μm-pixel-pitch sensor was the direct bonding technology with nickel bonded to the integrated circuit. The stack was mounted on the board using Sn–Pb balls placed on a 320-μm pitch,more » yielding an entirely wire-bond-less structure. The analog front-end features a pulse response peaking at below 250 ns, and the power consumption per pixel is 25 μW. We successful completed the 3-D integration and have reported here. Additionally, all pixels in the matrix of 64 × 64 pixels were responding on well-bonded devices. Correct operation of the sparsified readout, allowing a single 153-ns bunch timing resolution, was confirmed in the tests on a synchrotron beam of 10-keV X-rays. An equivalent noise charge of 36.2 e - rms and a conversion gain of 69.5 μV/e - with 2.6 e - rms and 2.7 μV/e - rms pixel-to-pixel variations, respectively, were measured.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deptuch, Grzegorz W.; Gabriella, Carini; Enquist, Paul

The vertically integrated photon imaging chip (VIPIC1) pixel detector is a stack consisting of a 500-μm-thick silicon sensor, a two-tier 34-μm-thick integrated circuit, and a host printed circuit board (PCB). The integrated circuit tiers were bonded using the direct bonding technology with copper, and each tier features 1-μm-diameter through-silicon vias that were used for connections to the sensor on one side, and to the host PCB on the other side. The 80-μm-pixel-pitch sensor was the direct bonding technology with nickel bonded to the integrated circuit. The stack was mounted on the board using Sn–Pb balls placed on a 320-μm pitch,more » yielding an entirely wire-bond-less structure. The analog front-end features a pulse response peaking at below 250 ns, and the power consumption per pixel is 25 μW. We successful completed the 3-D integration and have reported here. Additionally, all pixels in the matrix of 64 × 64 pixels were responding on well-bonded devices. Correct operation of the sparsified readout, allowing a single 153-ns bunch timing resolution, was confirmed in the tests on a synchrotron beam of 10-keV X-rays. An equivalent noise charge of 36.2 e - rms and a conversion gain of 69.5 μV/e - with 2.6 e - rms and 2.7 μV/e - rms pixel-to-pixel variations, respectively, were measured.« less

Interfacial and mechanical property analysis of waste printed circuit boards subject to thermal shock.

PubMed

Li, Jinhui; Duan, Huabo; Yu, Keli; Wang, Siting

2010-02-01

Waste printed circuit boards (PCBs) are the focal points for handling electric and electronic waste. In this paper, a thermal shock method was used to pretreat waste PCBs for the improvement of crushing performance. The influence of the thermal shock process on interfacial modification and mechanical property attenuation of PCB waste was studied. The appearance and layer spacing of the basal plane began to change slightly when the temperature reached 200 degrees C. By 250 degrees C, apparent bulging, cracking, and delamination were observed. However, pyrolysis of PCBs occurred when the temperature reached 275 degrees C, where PCBs were carbonized. The thermogravimetric analysis of PCB particles under vacuum showed that 270 degrees C was the starting point of pyrolysis. The tensile and impact strength of PCBs were reduced as shock temperature rose gradually, with a reduction by 2.6 and 16.5%, respectively, at 250 degrees C from its unheated strength. The PCBs that were heated to 250 degrees C achieved 100% liberation, increasing linearly from 13.6% for unheated PCBs through a single-level shear-crusher (2-mm mesh) and resulting in an obvious reduction of 9.5% (dB) in dust and noise at 250 degrees C. These parameters could be helpful for establishing the operational setup for industrial-scale facilities with the aim of achieving a compact process and a highly efficient recovery for waste PCBs compared with those of the traditional combination mechanical technologies.

Evaluation of Cleanliness Test Methods for Spacecraft PCB Assemblies

NASA Astrophysics Data System (ADS)

Tegehall, P.-E.; Dunn, B. D.

2006-10-01

Ionic contamination on printed-circuit-board assemblies may cause current leakage and short-circuits. The present cleanliness requirement in ECSS-Q-70-08, "The manual soldering of high-reliability electrical connections", is that the ionic contamination shall be less than 1.56 fl-glcm2 NaCI equivalents. The relevance of the method used for measurement of the ionic contamination level, resistivity of solvent extract, has been questioned. Alternative methods are ion chromatography and measurement of surface insulation resistance, but these methods also have their drawbacks. These methods are first described and their advantages and drawbacks are discussed. This is followed by an experimental evaluation of the three methods. This was done by soldering test vehicles at four manufacturers of space electronics using their ordinary processes for soldering and cleaning printed board assemblies. The experimental evaluation showed that the ionic contamination added by the four assemblers was very small and well below the acceptance criterion in ECSS-Q-70-80. Ion-chromatography analysis showed that most of the ionic contamination on the cleaned assembled boards originated from the hot-oil fusing of the printed circuit boards. Also, the surface insulation resistance was higher on the assembled boards compared to the bare printed circuit boards. Since strongly activated fluxes are normally used when printed circuit boards are hot-oil fused, it is essential that they are thoroughly cleaned in order to achieve low contamination levels on the final printed-board assemblies.

Development of testing and training simulator for CEDMCS in KSNP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nam, C. H.; Park, C. Y.; Nam, J. I.

2006-07-01

This paper presents a newly developed testing and training simulator (TTS) for automatically diagnosing and tuning the Control Element Drive Mechanism Control System (CEDMCS). TTS includes a new automatic, diagnostic, method for logic control cards and a new tuning method for phase synchronous pulse cards. In Korea Standard Nuclear Power Plants (KSNP). reactor trips occasionally occur due to a damaged logic control card in CEDMCS. However, there is no pre-diagnostic tester available to detect a damaged card in CEDMCS before it causes a reactor trip. Even after the reactor trip occurs, it is difficult to find the damaged card. Tomore » find the damaged card. ICT is usually used. ICT is an automated, computer-controlled testing system with measurement capabilities for testing active and passive components, or clusters of components, on printed circuit boards (PCB) and/or assemblies. However, ICT cannot detect a time dependent fault correctly and requires removal of the waterproof mating to perform the test. Therefore, the additional procedure of re-coating the PCB card is required after the test. TTS for CEDMCS is designed based on real plant conditions, both electrically and mechanically. Therefore, the operator can operate the Control Element Drive Mechanism (CEDM), which is mounted on the closure head of the reactor vessel (RV) using the soft control panel in ITS, which duplicates the Main Control Board (MCB) in the Main Control Room (MCR). However, during the generation of electric power in a nuclear power plant, it is difficult to operate the CEDM so a CEDM and Control Element Assembly (CEA) mock-up facility was developed to simulate a real plant CEDM. ITS was used for diagnosing and tuning control logic cards in CEDMCS in the Ulchin Nuclear Power Plant No. 4 during the plant overhaul period. It exhibited good performance in detecting the damaged cards and tuning the phase synchronous pulse cards. In addition, TTS was useful in training the CEDMCS operator by supplying detail signal information from the logic cards. (authors)« less

Piezoelectrically and triboelectrically hybridized self-powered sensor with applications to smart window and human motion detection

NASA Astrophysics Data System (ADS)

Fuh, Yiin-Kuen; Li, Shan-Chien; Chen, Chun-Yu

2017-07-01

In this paper, we demonstrate a hybrid generator, derived from the concurrent adoption of piezoelectric and triboelectric mechanisms in one press-and-release cycle, called a Hybridized Self-Powered sensor (HSPS). A new integration of print circuit board (PCB) technology-based piezoelectric generator (PG) concurrently adopted the direct-write, near-field electrospun polyvinylidene fluoride (PVDF) nano/micro-fibers as piezoelectric source materials. On the other hand, triboelectric nanogenerators have the advantages of a high output performance with a simple structure which is also concurrently combined with the PG. The working mechanism of the HSPS includes the PCB-based substrate mounted with parallel aligned piezoelectric PVDF fibers in planar configuration which first bended and generated the electric potential via the effect of piezoelectricity. In what follows, the deformation of a cylindrical rolled-up piezoelectric structure is exercised, and finally, the triboelectric contact of Cu and PTFE layers is physically rubbed against each other with a separation to induce the triboelectric potential. This hybridized generator with a double domed shape design simultaneously combines piezoelectric output and triboelectric output and offers a built-in spacer with automatically spring back capability, which produces a peak output voltage of 100 V, a current of 4 μA, and a maximum power output of 450 nW. A self-powered smart window system was experimentally driven through finger-induced strain of HSPS, showing the optical properties with reversibly tunable transmittances. This research is a substantial advancement in the field of piezoelectric PVDF fibers integration toward the practical application of the whole self-powered system.

40 CFR 433.11 - Specialized definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (BHC-hexachloro- cyclohexane) Alpha-BHC Beta-BHC Gamma-BHC Delta-BHC (PCB-polychlorinated biphenyls) PCB-1242 (Arochlor 1242) PCB-1254 (Arochlor 1254) PCB-1221 (Arochlor 1221) PCB-1232 (Arochlor 1232) PCB-1248 (Arochlor 1248) PCB-1260 (Arochlor 1260) PCB-1016 (Arochlor 1016) Toxaphene 2,3,7,8...

A Direct Spectral Domain Method for Near-ground Microwave Radiation by a Vertical Dipole above Earth in the Presence of Atmospheric Refractivity

DTIC Science & Technology

2013-08-01

G., Antenna Theory and Microstrip Antennas , CRC Press, 2010. 9. Hu, B. and W. C. Chew, “Fast inhomogeneous plane wave algorithm for electromagnetic...circuit board (PCB) structures such as transmission lines and antennas [8]. The SDGF/SI technique expresses the EM fields as SIs, which must be evaluated...Transactions on Antennas and Propagation, Vol. 53, No. 11, 3785–3791, 2005. 2. Aksun, M. and G. Dural, “Clarification of issues on the closed-form

Microwave Photonic Architecture for Direction Finding of LPI Emitters: Post-Processing for Angle of Arrival Estimation

DTIC Science & Technology

2016-09-01

mean- square (RMS) error of 0.29° at ə° resolution. For a P4 coded signal, the RMS error in estimating the AOA is 0.32° at 1° resolution. 14...FMCW signal, it was demonstrated that the system is capable of estimating the AOA with a root-mean- square (RMS) error of 0.29° at ə° resolution. For a...Modulator PCB printed circuit board PD photodetector RF radio frequency RMS root-mean- square xvi THIS PAGE INTENTIONALLY LEFT BLANK xvii

Advanced Filters and Components for Power Applications

DTIC Science & Technology

2006-08-31

PCB with a rectangular and circular coil version on each board. The printed windings are placed in an end-tapped configuration, with the winding...of fiat circular loops of various diameters in a system without magnetic material. We have found that the most accurate prediction for this...application is that of [31]. The formula for mutual inductance of circular traces is: Mt=°T f 00 S(kr2, kri)S(ka 2 , kai)Q(kh)e-k zdk (3.2) h2ln (rf) In (az) J0

MO-F-CAMPUS-J-03: Development of a Human Brain PET for On-Line Proton Beam-Range Verification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shao, Yiping

Purpose: To develop a prototype PET for verifying proton beam-range before each fractionated therapy that will enable on-line re-planning proton therapy. Methods: Latest “edge-less” silicon photomultiplier arrays and customized ASIC readout electronics were used to develop PET detectors with depth-of-interaction (DOI) measurement capability. Each detector consists of one LYSO array with each end coupled to a SiPM array. Multiple detectors can be seamlessly tiled together to form a large detector panel. Detectors with 1.5×1.5 and 2.0×2.0 mm crystals at 20 or 30 mm lengths were studied. Readout of individual SiPM or signal multiplexing was used to transfer 3D interaction position-codedmore » analog signals through flexible-print-circuit cables or PCB board to dedicated ASIC front-end electronics to output digital timing pulses that encode interaction information. These digital pulses can be transferred to, through standard LVDS cables, and decoded by a FPGA-based data acquisition of coincidence events and data transfer. The modular detector and scalable electronics/data acquisition will enable flexible PET system configuration for different imaging geometry. Results: Initial detector performance measurement shows excellent crystal identification even with 30 mm long crystals, ∼18% and 2.8 ns energy and timing resolutions, and around 2–3 mm DOI resolution. A small prototype PET scanner with one detector ring has been built and evaluated, validating the technology and design. A large size detector panel has been fabricated by scaling up from modular detectors. Different designs of resistor and capacitor based signal multiplexing boards were tested and selected based on optimal crystal identification and timing performance. Stackable readout electronics boards and FPGA-based data acquisition boards were developed and tested. A brain PET is under construction. Conclusion: Technology of large-size DOI detector based on SiPM array and advanced readout has been developed. PET imaging performance and initial phantom studies of on-line proton beam-range measurement will be conducted and reported. NIH grant R21CA187717; Cancer Prevention and Research Institute of Texas grant RP120326.« less

Sulfate Metabolites of 4-Monochlorobiphenyl in Whole Poplar Plants

PubMed Central

Zhai, Guangshu; Lehmler, Hans-Joachim; Schnoor, Jerald L.

2013-01-01

4-Monochlorobiphenyl (PCB3) has been proven to be transformed into hydroxylated metabolites of PCB3 (OH-PCB3s) in whole poplar plants in our previous work. However, hydroxylated metabolites of PCBs, including OH-PCB3s, as the substrates of sulfotransferases have not been studied in many organisms including plants in vivo. Poplar (Populus deltoides × nigra, DN34) was used to investigate the further metabolism from OH-PCB3s to PCB3 sulfates because it is a model plant and one that is frequently utilized in phytoremediation. Results showed poplar plants could metabolize PCB3 into PCB3 sulfates during 25 day exposures. Three sulfate metabolites, including 2′-PCB3 sulfate, 3′-PCB3 sulfate and 4′-PCB3 sulfate, were identified in poplar roots and their concentrations increased in the roots from day 10 to day 25. The major products were 2′-PCB3 sulfate and 4′-PCB3 sulfate. However, the concentrations of PCB3 sulfates were much lower than those of OH-PCB3s in the roots, suggesting the sequential transformation of these hydroxylated PCB3 metabolites into PCB3 sulfates in whole poplars. In addition, 2′-PCB3 sulfate or 4′-PCB3 sulfate was also found in the bottom wood samples indicating some translocation or metabolism in woody tissue. Results suggested that OH-PCB3s were the substrates of sulfotransferases which catalyzed the formation of PCB3 sulfates in the metabolic pathway of PCB3. PMID:23215248

Atmospheric non-thermal argon-oxygen plasma for sunflower seedling growth improvement

NASA Astrophysics Data System (ADS)

Matra, Khanit

2018-01-01

Seedling growth enhancement of sunflower seeds by DC atmospheric non-thermal Ar-O2 plasma has been proposed. The plasma reactor was simply designed by the composition of multi-pin electrodes bonded on a solderable printed circuit board (PCB) anode. A stable plasma was exhibited in the non-periodical self-pulsing discharge mode during the seed treatment. The experimental results showed that non-thermal plasma treatment had a significant positive effect on the sunflower seeds. Ar-O2 mixed gas ratio, treatment time and power source voltage are the important parameters affecting growth stimulation of sunflower sprouts. In this research, the sunflower seeds treated with 3:3 liters per minute (LPM) of Ar-O2 plasma at a source voltage of 8 kV for 1 min showed the best results in stimulating the seedling growth. The results in this case showed that the dry weight and average shoot length of the sunflower sprouts were 1.79 and 2.69 times higher and heavier than those of the untreated seeds, respectively.

An improved model for computing the trajectories of conductive particles in roll-type electrostatic separator for recycling metals from WEEE.

PubMed

Wu, Jiang; Li, Jia; Xu, Zhenming

2009-08-15

Electrostatic separation presents an effective and environmentally friendly way for recycling metals and nonmetals from ground waste electrical and electronic equipment (WEEE). For this process, the trajectory of conductive particle is significant and some models have been established. However, the results of previous researches are limited by some simplifying assumptions and lead to a notable discrepancy between the model prediction and the experimental results. In the present research, a roll-type corona-electrostatic separator and ground printed circuit board (PCB) wastes were used to investigate the trajectory of the conductive particle. Two factors, the air drag force and the different charging situation, were introduced into the improved model. Their effects were analyzed and an improved model for the theoretical trajectory of conductive particle was established. Compared with the previous one, the improved model shows a good agreement with the experimental results. It provides a positive guidance for designing of separator and makes a progress for recycling the metals and nonmetals from WEEE.

40 CFR 761.207 - The manifest-general requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) (2) For each PCB Article Container or PCB Container, the unique identifying number, type of PCB waste... PCB Article not in a PCB Container or PCB Article Container, the serial number if available, or other... only containing PCB waste. However, some States track PCB wastes as State-regulated hazardous wastes...

40 CFR 761.207 - The manifest-general requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) (2) For each PCB Article Container or PCB Container, the unique identifying number, type of PCB waste... PCB Article not in a PCB Container or PCB Article Container, the serial number if available, or other... only containing PCB waste. However, some States track PCB wastes as State-regulated hazardous wastes...

Estrogenicity and androgenicity screening of PCB sulfate monoesters in human breast cancer MCF-7 cells

PubMed Central

Flor, Susanne; He, Xianran; Lehmler, Hans-Joachim; Ludewig, Gabriele

2015-01-01

Recent studies identified PCB sulfate esters as a major product of PCB metabolism. Since hydroxy-PCBs (HO-PCBs), the immediate precursors of PCB sulfates and important contributors to PCB toxicity, were shown to have estrogenic activity, we investigated the estrogenicity/androgenicty of a series of PCB sulfate metabolites. We synthesized the five possible structural sulfate monoester metabolites of PCB 3, a congener shown to be biotransformed to sulfates, a sulfate ester of the paint-specific congener PCB 11, and sulfate monoesters of two HO-PCBs reported to interact with sulfotransferases (PCB 39, no ortho chlorines, and PCB 53, 3 ortho chlorines). We tested these PCB sulfates and 4’-HO-PCB 3 as positive control for estrogenic, androgenic, anti-estrogenic and anti-androgenic activity in the E- and A-screen with human breast cancer MCF7 derived cells at 100 μM – 1 pM concentrations. Only 4’-HO-PCB 3 was highly cytotoxic at 100 μM. We observed structure-activity relationships: compounds with a sulfate group in the chlorine-containing ring of PCB 3 (2PCB 3 and 3PCB 3 sulfate) showed no interaction with the estrogen (ER) and androgen (AR) receptor. The 4’-HO-PCB 3 and its sulfate ester had the highest estrogenic effect, but at 100 fold different concentrations, i.e. 1 μM and 100 μM, respectively. Four of the PCB sulfates were estrogenic (2’PCB 3, 4’PCB 3, 4PCB 39, 4PCB 53 sulfates; at 100 μM). These sulfates and 3’PCB 3 sulfate also exhibited anti-estrogenic activity, but at nM and pM concentrations. The 4’PCB 3 sulfate (para-para’ substituted) had the strongest androgenic activity, followed by 3’PCB 3, 4PCB 53, 4PCB11, and 4PCB 39 sulfates and the 4’HO-PCB 3. In contrast, anti-androgenicity was only observed with the two compounds that have the sulfate group in ortho- or meta- position in the second ring (2’PCB 3 and 3’PCB 3 sulfate). No dose-response was observed in any screen, but, with exception of estrogenic activity (only seen at 100 μM), endocrine activity was often displayed at several concentrations and even at 1 pM concentration. These data suggest that sulfation of HO-PCBs is indeed reducing their cytotoxicity and estrogenicity, but may produce other endocrine disruptive activities at very low concentrations. PMID:26300354

Estrogenicity and androgenicity screening of PCB sulfate monoesters in human breast cancer MCF-7 cells.

PubMed

Flor, Susanne; He, Xianran; Lehmler, Hans-Joachim; Ludewig, Gabriele

2016-02-01

Recent studies identified polychlorinated biphenyl (PCB) sulfate esters as a major product of PCB metabolism. Since hydroxy-PCBs (HO-PCBs), the immediate precursors of PCB sulfates and important contributors to PCB toxicity, were shown to have estrogenic activity, we investigated the estrogenicity/androgenicty of a series of PCB sulfate metabolites. We synthesized the five possible structural sulfate monoester metabolites of PCB 3, a congener shown to be biotransformed to sulfates, a sulfate ester of the paint-specific congener PCB 11, and sulfate monoesters of two HO-PCBs reported to interact with sulfotransferases (PCB 39, no ortho chlorines, and PCB 53, 3 ortho chlorines). We tested these PCB sulfates and 4'-HO-PCB 3 as positive control for estrogenic, androgenic, anti-estrogenic, and anti-androgenic activity in the E- and A-screen with human breast cancer MCF7-derived cells at 100 μM-1 pM concentrations. Only 4'-HO-PCB 3 was highly cytotoxic at 100 μM. We observed structure-activity relationships: compounds with a sulfate group in the chlorine-containing ring of PCB 3 (2PCB 3 and 3PCB 3 sulfate) showed no interaction with the estrogen (ER) and androgen (AR) receptor. The 4'-HO-PCB 3 and its sulfate ester had the highest estrogenic effect, but at 100-fold different concentrations, i.e., 1 and 100 μM, respectively. Four of the PCB sulfates were estrogenic (2'PCB 3, 4'PCB 3, 4'PCB 39, and 4'PCB 53 sulfates; at 100 μM). These sulfates and 3'PCB 3 sulfate also exhibited anti-estrogenic activity, but at nM and pM concentrations. The 4'PCB 3 sulfate (para-para' substituted) had the strongest androgenic activity, followed by 3'PCB 3, 4'PCB 53, 4PCB11, and 4PCB 39 sulfates and the 4'HO-PCB 3. In contrast, anti-androgenicity was only observed with the two compounds that have the sulfate group in ortho- or meta- position in the second ring (2'PCB 3 and 3'PCB 3 sulfate). No dose-response was observed in any screen, but, with exception of estrogenic activity (only seen at 100 μM), endocrine activity was often displayed at several concentrations and even at 1 pM concentration. These data suggest that sulfation of HO-PCBs is indeed reducing their cytotoxicity and estrogenicity, but may produce other endocrine disruptive activities at very low concentrations.

Hypoxia perturbs aryl hydrocarbon receptor signaling and CYP1A1 expression induced by PCB 126 in human skin and liver-derived cell lines.

PubMed

Vorrink, Sabine U; Severson, Paul L; Kulak, Mikhail V; Futscher, Bernard W; Domann, Frederick E

2014-02-01

The aryl hydrocarbon receptor (AhR) is an important mediator of toxic responses after exposure to xenobiotics including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and dioxin-like polychlorinated biphenyls (PCBs). Activation of AhR responsive genes requires AhR dimerization with the aryl hydrocarbon receptor nuclear translocator (ARNT), a heterodimeric partner also shared by the hypoxia-inducible factor-1α (HIF-1α) protein. TCDD-stimulated AhR transcriptional activity can be influenced by hypoxia; however, it less well known whether hypoxia interferes with AhR transcriptional transactivation in the context of PCB-mediated AhR activation in human cells. Elucidation of this interaction is important in liver hepatocytes which extensively metabolize ingested PCBs and experience varying degrees of oxygen tension during normal physiologic function. This study was designed to assess the effect of hypoxia on AhR transcriptional responses after exposure to 3,3',4,4',5-pentachlorobiphenyl (PCB 126). Exposure to 1% O2 prior to PCB 126 treatment significantly inhibited CYP1A1 mRNA and protein expression in human HepG2 and HaCaT cells. CYP1A1 transcriptional activation was significantly decreased upon PCB 126 stimulation under conditions of hypoxia. Additionally, hypoxia pre-treatment reduced PCB 126 induced AhR binding to CYP1 target gene promoters. Importantly, ARNT overexpression rescued cells from the inhibitory effect of hypoxia on XRE-luciferase reporter activity. Therefore, the mechanism of interference of the signaling crosstalk between the AhR and hypoxia pathways appears to be at least in part dependent on ARNT availability. Our results show that AhR activation and CYP1A1 expression induced by PCB 126 were significantly inhibited by hypoxia and hypoxia might therefore play an important role in PCB metabolism and toxicity. Copyright © 2013 Elsevier Inc. All rights reserved.

Hypoxia perturbs aryl hydrocarbon receptor signaling and CYP1A1 expression induced by PCB 126 in human skin and liver-derived cell lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vorrink, Sabine U.; Department of Radiation Oncology, The University of Iowa, Iowa City, IA; Severson, Paul L.

2014-02-01

The aryl hydrocarbon receptor (AhR) is an important mediator of toxic responses after exposure to xenobiotics including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and dioxin-like polychlorinated biphenyls (PCBs). Activation of AhR responsive genes requires AhR dimerization with the aryl hydrocarbon receptor nuclear translocator (ARNT), a heterodimeric partner also shared by the hypoxia-inducible factor-1α (HIF-1α) protein. TCDD-stimulated AhR transcriptional activity can be influenced by hypoxia; however, it less well known whether hypoxia interferes with AhR transcriptional transactivation in the context of PCB-mediated AhR activation in human cells. Elucidation of this interaction is important in liver hepatocytes which extensively metabolize ingested PCBs and experience varying degreesmore » of oxygen tension during normal physiologic function. This study was designed to assess the effect of hypoxia on AhR transcriptional responses after exposure to 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126). Exposure to 1% O{sub 2} prior to PCB 126 treatment significantly inhibited CYP1A1 mRNA and protein expression in human HepG2 and HaCaT cells. CYP1A1 transcriptional activation was significantly decreased upon PCB 126 stimulation under conditions of hypoxia. Additionally, hypoxia pre-treatment reduced PCB 126 induced AhR binding to CYP1 target gene promoters. Importantly, ARNT overexpression rescued cells from the inhibitory effect of hypoxia on XRE-luciferase reporter activity. Therefore, the mechanism of interference of the signaling crosstalk between the AhR and hypoxia pathways appears to be at least in part dependent on ARNT availability. Our results show that AhR activation and CYP1A1 expression induced by PCB 126 were significantly inhibited by hypoxia and hypoxia might therefore play an important role in PCB metabolism and toxicity. - Highlights: • Significant crosstalk exists between AhR and HIF-1α signaling. • Hypoxia perturbs PCB 126 induced AhR function and target gene expression. • PCB 126 mediated activation of AhR activity inhibits HIF-1α signaling. • AhR binding to CYP1A1 and CYP1B1 promoters is inhibited by hypoxia. • ARNT overexpression relieves hypoxic inhibition of AhR function.« less

Uptake and Translocation of Lesser-Chlorinated Polychlorinated Biphenyls (PCBs) in Whole Hybrid Poplar Plants after Hydroponic Exposure

PubMed Central

Liu, Jiyan; Schnoor, Jerald L.

2009-01-01

Mono-, di-, tri-, and tetra-chlorinated polychlorinated biphenyls (PCBs) are congeners with greater volatility which remain in air, soils and sediments requiring treatment. In this study, the fate of these PCBs was investigated within whole poplar plants (Populus deltoides x nigra, DN34) with application for a treatment system such as a confined disposal facility for dredged material. Whole hybrid poplars were exposed hydroponically to a mixture of five congeners, common in the environment, having one to four chlorine atoms per molecule. Results indicated that PCB 3, 15, 28, 52, and 77 were initially sorbed to the root systems. The Root Concentration Factor (RCF) of PCBs during the exposure was calculated and correlated with Kow. PCB congeners were taken up by the roots of hybrid poplar, and the translocation of PCBs to stems was inversely related to congener hydrophobicity (Log Kow). PCB 3 and 15 were translocated to the upper stem at small but significant rates. PCB 28 was translocated to the wood of the main stem but no farther; translocation from the roots was not detected for PCB 52 and 77. The distribution of PCBs within poplars was determined, and mass balances were completed to within 15% for each chemical except for PCB 3, the most volatile congener. This is the first report on the transport of PCBs through whole plants designed for use in treatment at disposal facilities. PMID:18793792

Remediation of PCB contaminated soils in the Canadian Arctic: excavation and surface PRB technology.

PubMed

Kalinovich, Indra; Rutter, Allison; Poland, John S; Cairns, Graham; Rowe, R Kerry

2008-12-15

The site BAF-5 is located on the summit of Resolution Island, Nunavut, just southeast of Baffin Island at 61 degrees 35'N and 60 degrees 40'W. The site was part of a North American military defense system established in the 1950s that became heavily contaminated with PCBs during and subsequent, its operational years. Remediation through excavation of the PCB contaminated soil at Resolution Island began in 1999 and at its completion in 2006 approximately 5 tonnes of pure PCBs in approximately 20,000 m3 of soil were remediated. Remediation strategies were based on both quantity of soil and level of contamination in the soil. Excavation removed 96% of the PCB contaminated soil on site. In 2003, a surface funnel-and-gate permeable reactive barrier was design and constructed to treat the remaining contamination left in rock crevices and inaccessible areas of the site. Excavation had destabilized contaminated soil in the area, enabling contaminant migration through erosion and runoff pathways. The barrier was designed to maximize sedimentation through settling ponds. This bulk removal enabled the treatment of highly contaminated fines and water through a permeable gate. The increased sediment loading during excavation required both modifications to the funnel and a shift to a more permeable, granular system. Granulated activated charcoal was chosen for its ability to both act as a particle retention filter and adsorptive filter. The reduction in mass of PCB and volume of soils trapped by the funnel of the barrier indicate that soils are re-stabilizing. In 2007, nonwoven geotextiles were re-introduced back into the filtration system as fine filtering could be achieved without clogging. Monitoring sites downstream indicate that the barrier system is effective. This paper describes the field progress of PCB remediation at Resolution Island.

OXIDATION OF POLYCHLORINATED BIPHENYLS BY LIVER TISSUE SLICES FROM PHENOBARBITAL-PRETREATED MICE IS CONGENER-SPECIFIC AND ATROPSELECTIVE

PubMed Central

Wu, Xianai; Duffel, Michael; Lehmler, Hans-Joachim

2013-01-01

Mouse models are powerful tools to study the developmental neurotoxicity of polychlorinated biphenyls (PCBs); however, studies of the oxidation of chiral PCB congeners to potentially neurotoxic hydroxylated metabolites (OH-PCBs) in mice have not been reported. Here we investigate the atropselective oxidation of chiral PCB 91 (2,2',3,4',6-pentachlorobiphenyl), PCB 95 (2,2',3,5',6-pentachlorobiphenyl), PCB 132 (2,2',3,3',4,6'-hexachlorobiphenyl), PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl) and PCB 149 (2,2',3,4',5',6-hexachlorobiphenyl) to OH-PCBs in liver tissue slices prepared from female mice. The metabolite profile of PCB 136 typically followed the rank order 5-OH-PCB > 4-OH-PCB > 4,5-OH-PCB, and metabolite levels increased with PCB concentration and incubation time. A similar OH-PCB profile was observed with the other PCB congeners, with 5-OH-PCB:4-OH-PCB ratios ranging from 2 to 12. More 5-OH-PCB 136 was formed in liver tissue slices obtained from animals pretreated with phenobarbital (P450 2B inducer) or, to a lesser extent, dexamethasone (P450 2B and 3A enzyme inducer) compared to tissue slices prepared from vehicle-pretreated animals. The apparent rate of 5-OH-PCBs formation followed the approximate rank order PCB 149 > PCB 91 > PCB 132 ~ PCB 136 > PCB 95. Atropselective gas chromatography revealed a congener-specific atropisomeric enrichment of major OH-PCB metabolites. Comparison of our results with published OH-PCB patterns and chiral signatures (i.e., the direction and extent of the atropisomeric enrichment) from rat liver microsomal revealed drastic differences between both species, especially following induction of P450 2B enzymes. These species differences in the metabolism of chiral PCBs should be considered in developmental neurotoxicity studies of PCBs. PMID:24107130

Waste printed circuit board recycling techniques and product utilization.

PubMed

Hadi, Pejman; Xu, Meng; Lin, Carol S K; Hui, Chi-Wai; McKay, Gordon

2015-01-01

E-waste, in particular waste PCBs, represents a rapidly growing disposal problem worldwide. The vast diversity of highly toxic materials for landfill disposal and the potential of heavy metal vapors and brominated dioxin emissions in the case of incineration render these two waste management technologies inappropriate. Also, the shipment of these toxic wastes to certain areas of the world for eco-unfriendly "recycling" has recently generated a major public outcry. Consequently, waste PCB recycling should be adopted by the environmental communities as an ultimate goal. This article reviews the recent trends and developments in PCB waste recycling techniques, including both physical and chemical recycling. It is concluded that the physical recycling techniques, which efficiently separate the metallic and nonmetallic fractions of waste PCBs, offer the most promising gateways for the environmentally-benign recycling of this waste. Moreover, although the reclaimed metallic fraction has gained more attention due to its high value, the application of the nonmetallic fraction has been neglected in most cases. Hence, several proposed applications of this fraction have been comprehensively examined. Copyright © 2014 Elsevier B.V. All rights reserved.

Sensor Functionality of Conducting Polyaniline-Metal Oxide (TiO2/SnO2) Hybrid Materials Films toward Benzene and Toluene Vapors at Room Temperature

NASA Astrophysics Data System (ADS)

Subramanian, E.; Santhanamari, P.; Murugan, C.

2018-05-01

Polyaniline-metal oxide (TiO2/SnO2) organic-inorganic hybrid materials films were fabricated in situ on a printed circuit board (PCB) via drop coating technique. The mixture of aniline and metal oxide (TiO2/SnO2) dispersed in ethanol was applied along with an oxidant for the coating process. The formed material films were characterized by Fourier transform infra-red spectroscopy, x-ray diffraction and scanning electron microscopy techniques. The sensor functionality of the prepared films on PCB was investigated individually for the detection of benzene or toluene vapor at room temperature. The promptness of sensor response to analyte vapor and its recovery to air, as well as the concentration-dependent sensor functionality of the hybrid material films were investigated. The film form of hybrid materials has shown much improved sensor efficiency even at ambient air condition compared to the pellet form of the polyaniline-SnO2 hybrid material reported earlier, which sensed the same analytes only in nitrogen atmosphere.

PCDD/F and dioxin-like PCB minimization: A 13-year experimental study along the flue gas cleaning system of a secondary aluminium refining plant.

PubMed

Collina, Elena; Bortolami, Michele; Franzoni, Francesco; Lasagni, Marina; Piccinelli, Elsa; Pitea, Demetrio

2017-08-01

A 13-years study shows that a careful design of the flue gas cleaning system of a full scale secondary aluminium refining plant results in a minimized and very stable emission of Polychlorinated Dibenzo-p-Dioxins (PCDD), Polychlorinated Dibenzo Furans (PCDF) and dioxin-like Polychlorinated Biphenyls (PCB). The value of equivalent toxicity of PCDD/F in the emission was definitely of an order of magnitude less than the regulation limit. In the initial flue gas cleaning system, the PCB mean fingerprint after the slow cooling of the flue gas was typical of de novo synthesis. Instead, in the presence of quenching, there was evidence that the fast cooling of flue gas prevented the PCB de novo synthesis. In fact, the PCB profile was similar to that in the air collected from the aspiration hoods for the quenching. The gas-phase and solid-phase partitioning of PCBs, before and after the fabric filters, highlights the predominant role of the vapor phase with respect to the total removal efficiency. The polycyclic aromatic hydrocarbons breakdown could be an additional de novo formation pathway even in industrial plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Exhaust constituent emission factors of printed circuit board pyrolysis processes and its exhaust control.

PubMed

Chiang, Hung-Lung; Lin, Kuo-Hsiung

2014-01-15

The printed circuit board (PCB) is an important part of electrical and electronic equipment, and its disposal and the recovery of useful materials from waste PCBs (WPCBs) are key issues for waste electrical and electronic equipment. Waste PCB compositions and their pyrolysis characteristics were analyzed in this study. In addition, the volatile organic compound (VOC) exhaust was controlled by an iron-impregnated alumina oxide catalyst. Results indicated that carbon and oxygen were the dominant components (hundreds mg/g) of the raw materials, and other elements such as nitrogen, bromine, and copper were several decades mg/g. Exhaust constituents of CO, H2, CH4, CO2, and NOx, were 60-115, 0.4-4.0, 1.1-10, 30-95, and 0-0.7mg/g, corresponding to temperatures ranging from 200 to 500°C. When the pyrolysis temperature was lower than 300°C, aromatics and paraffins were the major species, contributing 90% of ozone precursor VOCs, and an increase in the pyrolysis temperature corresponded to a decrease in the fraction of aromatic emission factors. Methanol, ethylacetate, acetone, dichloromethane, tetrachloromethane and acrylonitrile were the main species of oxygenated and chlorinated VOCs. The emission factors of some brominated compounds, i.e., bromoform, bromophenol, and dibromophenol, were higher at temperatures over 400°C. When VOC exhaust was flowed through the bed of Fe-impregnated Al2O3, the emission of ozone precursor VOCs could be reduced by 70-80%. Copyright © 2013 Elsevier B.V. All rights reserved.

Front-end receiver electronics for a matrix transducer for 3-D transesophageal echocardiography.

PubMed

Yu, Zili; Blaak, Sandra; Chang, Zu-yao; Yao, Jiajian; Bosch, Johan G; Prins, Christian; Lancée, Charles T; de Jong, Nico; Pertijs, Michiel A P; Meijer, Gerard C M

2012-07-01

There is a clear clinical need for creating 3-D images of the heart. One promising technique is the use of transesophageal echocardiography (TEE). To enable 3-D TEE, we are developing a miniature ultrasound probe containing a matrix piezoelectric transducer with more than 2000 elements. Because a gastroscopic tube cannot accommodate the cables needed to connect all transducer elements directly to an imaging system, a major challenge is to locally reduce the number of channels, while maintaining a sufficient signal-to-noise ratio. This can be achieved by using front-end receiver electronics bonded to the transducers to provide appropriate signal conditioning in the tip of the probe. This paper presents the design of such electronics, realizing time-gain compensation (TGC) and micro-beamforming using simple, low-power circuits. Prototypes of TGC amplifiers and micro-beamforming cells have been fabricated in 0.35-μm CMOS technology. These prototype chips have been combined on a printed circuit board (PCB) to form an ultrasound-receiver system capable of reading and combining the signals of three transducer elements. Experimental results show that this design is a suitable candidate for 3-D TEE.

41 CFR 101-42.1102-2 - Polychlorinated biphenyls.

Code of Federal Regulations, 2010 CFR

2010-07-01

... parts per million (ppm). (i) Zero through 49 ppm is classified as an excluded PCB product. (ii) Fifty through 499 ppm PCB is classified as PCB item. (iii) Five hundred or greater ppm PCB is classified as PCB. (3) Excluded PCB products (0-49 ppm PCB) are not subject to Federal restrictions and may be...

MCM Polarimetric Radiometers for Planar Arrays

NASA Technical Reports Server (NTRS)

Kangaslahti, Pekka; Dawson, Douglas; Gaier, Todd

2007-01-01

A polarimetric radiometer that operates at a frequency of 40 GHz has been designed and built as a prototype of multiple identical units that could be arranged in a planar array for scientific measurements. Such an array is planned for use in studying the cosmic microwave background (CMB). All of the subsystems and components of this polarimetric radiometer are integrated into a single multi-chip module (MCM) of substantially planar geometry. In comparison with traditional designs of polarimetric radiometers, the MCM design is expected to greatly reduce the cost per unit in an array of many such units. The design of the unit is dictated partly by a requirement, in the planned CMB application, to measure the Stokes parameters I, Q, and U of the CMB radiation with high sensitivity. (A complete definition of the Stokes parameters would exceed the scope of this article. In necessarily oversimplified terms, I is a measure of total intensity of radiation, while Q and U are measures of the relationships between the horizontally and vertically polarized components of radiation.) Because the sensitivity of a single polarimeter cannot be increased significantly, the only way to satisfy the high-sensitivity requirement is to make a large array of polarimeters that operate in parallel. The MCM includes contact pins that can be plugged into receptacles on a standard printed-circuit board (PCB). All of the required microwave functionality is implemented within the MCM; any required supporting non-microwave ("back-end") electronic functionality, including the provision of DC bias and control signals, can be implemented by standard PCB techniques. On the way from a microwave antenna to the MCM, the incoming microwave signal passes through an orthomode transducer (OMT), which splits the radiation into an h + i(nu) beam and an h - i(nu) beam (where, using complex-number notation, h denotes the horizontal component, nu denotes the vertical component, and +/-i denotes a +/-90deg phase shift). Each of these beams enters the MCM through one of two WR-22 waveguide input terminals in the lid of the MCM. The h + i(nu0 and h - i(nu) signals are amplified, then fed to a phase-discriminator hybrid designed specifically to fit the predominantly planar character of the MCM geometry and to enable determination of Q and U. The phase-discriminator hybrid generates four outputs, which are detected and used to calculate I, Q, and U.

Tailored benzoxazines as novel resin systems for printed circuit boards in high temperature e-mobility applications

NASA Astrophysics Data System (ADS)

Troeger, K.; Darka, R. Khanpour; Neumeyer, T.; Altstaedt, V.

2014-05-01

This study focuses on the development of Bisphenol-F-benzoxazine resins blended with different ratios of a trifunctional epoxy resin suitable as matrix for substrates for high temperature printed circuit board (HT-PCB) applications. With the benzoxazine blends glass transition temperatures of more than 190 °C could be achieved in combination with a coefficient of thermal expansion in thickness direction (z-CTE) of less than 60 ppm/K without adding any fillers. This shows the high potential of the benzoxazine-epoxy blend systems as substrate materials for HT-PCBs. To understand the thermal behavior of the different formulations, the apparent crosslink density was calculated based on data from Dynamic Mechanical Analysis. Laminates in laboratory scale were prepared and characterized to demonstrate the transformation of the neat resin properties into real electronic substrate properties. The produced laminates exhibit a z-CTE below 40 ppm/K.

Tailored benzoxazines as novel resin systems for printed circuit boards in high temperature e-mobility applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Troeger, K., E-mail: altstaedt@uni-bayreuth.de; Darka, R. Khanpour, E-mail: altstaedt@uni-bayreuth.de; Neumeyer, T., E-mail: altstaedt@uni-bayreuth.de

2014-05-15

This study focuses on the development of Bisphenol-F-benzoxazine resins blended with different ratios of a trifunctional epoxy resin suitable as matrix for substrates for high temperature printed circuit board (HT-PCB) applications. With the benzoxazine blends glass transition temperatures of more than 190 °C could be achieved in combination with a coefficient of thermal expansion in thickness direction (z-CTE) of less than 60 ppm/K without adding any fillers. This shows the high potential of the benzoxazine-epoxy blend systems as substrate materials for HT-PCBs. To understand the thermal behavior of the different formulations, the apparent crosslink density was calculated based on datamore » from Dynamic Mechanical Analysis. Laminates in laboratory scale were prepared and characterized to demonstrate the transformation of the neat resin properties into real electronic substrate properties. The produced laminates exhibit a z-CTE below 40 ppm/K.« less

Waste Printed Circuit Board (PCB) Recycling Techniques.

PubMed

Ning, Chao; Lin, Carol Sze Ki; Hui, David Chi Wai; McKay, Gordon

2017-04-01

With the development of technologies and the change of consumer attitudes, the amount of waste electrical and electronic equipment (WEEE) is increasing annually. As the core part of WEEE, the waste printed circuit board (WPCB) is a dangerous waste but at the same time a rich resource for various kinds of materials. In this work, various WPCB treatment methods as well as WPCB recycling techniques divided into direct treatment (landfill and incineration), primitive recycling technology (pyrometallurgy, hydrometallurgy, biometallurgy and primitive full recovery of NMF-non metallic fraction), and advanced recycling technology (mechanical separation, direct use and modification of NMF) are reviewed and analyzed based on their advantages and disadvantages. Also, the evaluation criteria are discussed including economic, environmental, and gate-to-market ability. This review indicates the future research direction of WPCB recycling should focus on a combination of several techniques or in series recycling to maximize the benefits of process.

A Study on the Thermomechanical Reliability Risks of Through-Silicon-Vias in Sensor Applications

PubMed Central

Shao, Shuai; Liu, Dapeng; Niu, Yuling; O’Donnell, Kathy; Sengupta, Dipak; Park, Seungbae

2017-01-01

Reliability risks for two different types of through-silicon-vias (TSVs) are discussed in this paper. The first is a partially-filled copper TSV, if which the copper layer covers the side walls and bottom. A polymer is used to fill the rest of the cavity. Stresses in risk sites are studied and ranked for this TSV structure by FEA modeling. Parametric studies for material properties (modulus and thermal expansion) of TSV polymer are performed. The second type is a high aspect ratio TSV filled by polycrystalline silicon (poly Si). Potential risks of the voids in the poly Si due to filling defects are studied. Fracture mechanics methods are utilized to evaluate the risk for two different assembly conditions: package assembled to printed circuit board (PCB) and package assembled to flexible substrate. The effect of board/substrate/die thickness and the size and location of the void are discussed. PMID:28208758

Effect of Ground Layer Patterns with Slits on Conducted Noise Currents from Printed Circuit Board

NASA Astrophysics Data System (ADS)

Maeno, Tsuyoshi; Unou, Takanori; Ichikawa, Kouji; Fujiwara, Osamu

Electromagnetic disturbances for vehicle-mounted radios can be caused by conducted noise currents that flows out from electronic equipment for vehicles to wire-harnesses. In this paper, for reducing the conducted noise currents from electronic equipment for vehicles, we made a simulation and experiment on how ground patterns affect the noise currents from three-layer printed circuit boards (PCBs) with slit-types and plane-type ground patterns. As a result, we could confirm that slits on a ground pattern allow conducted noise currents to flow out from PCBs to wire-harnesses. For the PCBs with plane-type ground and one of three slit-type patterns, on the other hand, both the simulation and examination showed that resonance phenomena occur at unexpected low-frequencies. A circuit analysis revealed that the above phenomena can be caused by the imbalance of a bridge circuit consisting of the trace circuits on the PCB.

24-71 GHz PCB Array for 5G ISM

NASA Technical Reports Server (NTRS)

Novak, Markus H.; Volakis, John L.; Miranda, Felix A.

2017-01-01

Millimeter-wave 5G mobile architectures need to consolidate disparate frequency bands into a single, multifunctional array. Existing arrays are either narrow-band, prohibitively expensive or cannot be scaled to these frequencies. In this paper, we present the first ultra-wideband millimeter wave array to operate across six 5G and ISM bands spanning 24-71 GHz. Importantly, the array is realized using low-cost PCB. The paper presents the design and optimized layout, and discusses fabrication and measurements.

Polychlorinated Biphenyls, Glycaemia and Diabetes in a Population Living in a Highly Polychlorinated Biphenyls-Polluted Area in Northern Italy: a Cross-sectional and Cohort Study

PubMed Central

Zani, Claudia; Donato, Francesco; Magoni, Michele; Feretti, Donatella; Covolo, Loredana; Vassallo, Francesco; Speziani, Fabrizio; Scarcella, Carmelo; Bergonzi, Roberto; Apostoli, Pietro

2013-01-01

Conflicts of interests: the authors declare no potential conflict of interests. Background Polychlorinated biphenyls (PCBs) have been found to be associated with diabetes in some, but not all, studies performed so far. The aim of this study was to assess the association between PCB serum levels and glycaemia and diabetes in people living in Brescia, a highly industrialised PCB-polluted town in Northern Italy. Design and Methods 527 subjects were enrolled in a cross-sectional population-based study: they were interviewed face-to-face in 2003 and also provided a blood sample under fasting conditions. The concentration of 24 PCB congeners was determined using gas-chromatography (GC/MS). Subsequently, all subjects were included in a follow-up (cohort) study. According to the Local Health Authority health-care database, subjects were considered to be diabetic if they had diabetes at interview time (prevalent cases) or during a 7-year follow-up (incident cases). Results A total of 53 subjects (10.0%) were diabetics: 28 had diabetes at enrolment and other 25 developed the disease subsequently. Diabetes frequency increased according to the serum concentrations of total PCBs and single PCB congeners, but no association was found when estimates were adjusted for education, body mass index, age and gender by logistic regression analysis. Accordingly, glycaemia increased with PCB serum levels, but no association was observed when multiple regression analysis, including confounding factors, was performed. Conclusions This study does not support the hypothesis that PCB environmental exposure is strictly associated with diabetes or glycaemia. PMID:25170473

Serum PCB levels and congener profiles among teachers in PCB-containing schools: a pilot study

PubMed Central

2011-01-01

Background PCB contamination in the built environment may result from the release of PCBs from building materials. The significance of this contamination as a pathway of human exposure is not well-characterized, however. This research compared the serum PCB concentrations, and congener profiles between 18 teachers in PCB-containing schools and referent populations. Methods Blood samples from 18 teachers in PCB-containing schools were analyzed for 57 PCB congeners. Serum PCB concentrations and congener patterns were compared between the teachers, to the 2003-4 NHANES (National Health and Nutrition Examination Survey) data, and to data from 358 Greater Boston area men. Results Teachers at one school had higher levels of lighter (PCB 6-74) congeners compared to teachers from other schools. PCB congener 47 contributed substantially to these elevated levels. Older teachers (ages 50-64) from all schools had higher total (sum of 33 congeners) serum PCB concentrations than age-comparable NHANES reference values. Comparing the teachers to the referent population of men from the Greater Boston area (all under age 51), no difference in total serum PCB levels was observed between the referents and teachers up to 50 years age. However, the teachers had significantly elevated serum concentrations of lighter congeners (PCB 6-74). This difference was confirmed by comparing the congener-specific ratios between groups, and principal component analysis showed that the relative contribution of lighter congeners differed between the teachers and the referents. Conclusions These findings suggest that the teachers in the PCB-containing buildings had higher serum levels of lighter PCB congeners (PCB 6-74) than the referent populations. Examination of the patterns, as well as concentrations of individual PCB congeners in serum is essential to investigating the contributions from potential environmental sources of PCB exposure. PMID:21668970

Results of Sediment Sampling and Elutriate Testing at the Proposed Indian Cave State Park Shallow Water Habitat Project Site

DTIC Science & Technology

2013-08-01

Aroclor1248 10 50 Endrin 1.0 9.9 PCB - Aroclor1268 10 50 Endrin Aldehyde 1.0 9.9 PCB - Aroclor1232 10 50 Endrin Ketone 0.8 9.9 PCB - Aroclor1254 10 50... Aldehyde 0.011 0.1 PCB - Aroclor1232 0.2 1.0 Endrin Ketone 0.006 0.1 PCB - Aroclor1254 0.2 1.0 Heptachlor 0.009 0.05 PCB - Aroclor1242 0.2 1.0 Heptachlor...9.9 PCB - Aroclor1268 10 50 Endrin Aldehyde 1.0 9.9 PCB - Aroclor1232 10 50 Endrin Ketone 0.8 9.9 PCB - Aroclor1254 10 50 Heptachlor 0.6 5.1 PCB

Atropisomers of 2,2',3,3',6,6'-hexachlorobiphenyl (PCB 136) exhibit stereoselective effects on activation of nuclear receptors in vitro.

PubMed

Pěnčíková, Kateřina; Brenerová, Petra; Svržková, Lucie; Hrubá, Eva; Pálková, Lenka; Vondráček, Jan; Lehmler, Hans-Joachim; Machala, Miroslav

2017-11-09

PCB 136 is an environmentally relevant chiral PCB congener, which has been found in vivo to be present in form of rotational isomers (atropisomers). Its atropselective biotransformation or neurotoxic effects linked with sensitization of ryanodine receptor suggest that it might interact also with other intracellular receptors in a stereospecific manner. However, possible atropselective effects of PCB 136 on nuclear receptor transactivation remain unknown. Therefore, in this study, atropselective effects of PCB 136 on nuclear receptors controlling endocrine signaling and/or expression of xenobiotic and steroid hormone catabolism were investigated. PCB136 atropisomers were found to exert differential effects on estrogen receptor (ER) activation; (+)-PCB 136 was estrogenic, while (-)-PCB 136 was antiestrogenic. In contrast, inhibition of androgen receptor (AR) activity was not stereospecific. Both PCB136 stereoisomers induced the constitutive androgen receptor (CAR)-dependent gene expression; however, no significant stereospecificity of PCB 136 atropisomers was observed. PCB136 was a partial inducer of the pregnane X receptor (PXR)-dependent gene expression. Here, (-)-PCB 136 was a significantly more potent inducer of PXR activity than (+)-PCB 136. Taken together, the present results indicate that at least two nuclear receptors participating in endocrine regulation or metabolism, ER and PXR, could be regulated in an atropselective manner by chiral PCB 136. The enantioselective enrichment of PCB atropisomers in animal and human tissues may thus have significant consequences for endocrine-disrupting effects of chiral ortho-substituted PCB congeners.

Hydroxylated polychlorinated biphenyls increase reactive oxygen species formation and induce cell death in cultured cerebellar granule cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dreiem, Anne; Norwegian Defence Research Establishment, Department for Protection, Kjeller; Rykken, Sidsel

2009-10-15

Polychlorinated biphenyls (PCBs) are persistent organic pollutants that bioaccumulate in the body, however, they can be metabolized to more water-soluble products. Although they are more readily excreted than the parent compounds, some of the metabolites are still hydrophobic and may be more available to target tissues, such as the brain. They can also cross the placenta and reach a developing foetus. Much less is known about the toxicity of PCB metabolites than about the parent compounds. In the present study, we have investigated the effects of eight hydroxylated (OH) PCB congeners (2'-OH PCB 3, 4-OH PCB 14, 4-OH PCB 34,more » 4'-OH PCB 35, 4-OH PCB 36, 4'-OH PCB 36, 4-OH PCB 39, and 4'-OH PCB 68) on reactive oxygen species (ROS) formation and cell viability in rat cerebellar granule cells. We found that, similar to their parent compounds, OH-PCBs are potent ROS inducers with potency 4-OH PCB 14 < 4-OH PCB 36 < 4-OH PCB 34 < 4'-OH PCB 36 < 4'-OH PCB 68 < 4-OH PCB 39 < 4'-OH PCB 35. 4-OH PCB 36 was the most potent cell death inducer, and caused apoptotic or necrotic morphology depending on concentration. Inhibition of ERK1/2 kinase with U0126 reduced both cell death and ROS formation, suggesting that ERK1/2 activation is involved in OH-PCB toxicity. The results indicate that the hydroxylation of PCBs may not constitute a detoxification reaction. Since OH-PCBs like their parent compounds are retained in the body and may be more widely distributed to sensitive tissues, it is important that not only the levels of the parent compounds but also the levels of their metabolites are taken into account during risk assessment of PCBs and related compounds.« less

40 CFR 750.31 - Filing of petitions for exemption.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-contaminated transformer dielectric fluid. Persons who process or distribute in commerce dielectric fluid containing 50 ppm or greater PCB (but less than 500 ppm PCB) for use in PCB-Contaminated Transformers may... dielectric fluids containing 50 ppm or greater PCB for use in PCB Transformers, railroad transformers, or PCB...

40 CFR 750.31 - Filing of petitions for exemption.

Code of Federal Regulations, 2011 CFR

2011-07-01

...-contaminated transformer dielectric fluid. Persons who process or distribute in commerce dielectric fluid containing 50 ppm or greater PCB (but less than 500 ppm PCB) for use in PCB-Contaminated Transformers may... dielectric fluids containing 50 ppm or greater PCB for use in PCB Transformers, railroad transformers, or PCB...

40 CFR 750.31 - Filing of petitions for exemption.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-contaminated transformer dielectric fluid. Persons who process or distribute in commerce dielectric fluid containing 50 ppm or greater PCB (but less than 500 ppm PCB) for use in PCB-Contaminated Transformers may... dielectric fluids containing 50 ppm or greater PCB for use in PCB Transformers, railroad transformers, or PCB...

40 CFR 750.31 - Filing of petitions for exemption.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-contaminated transformer dielectric fluid. Persons who process or distribute in commerce dielectric fluid containing 50 ppm or greater PCB (but less than 500 ppm PCB) for use in PCB-Contaminated Transformers may... dielectric fluids containing 50 ppm or greater PCB for use in PCB Transformers, railroad transformers, or PCB...

40 CFR 750.31 - Filing of petitions for exemption.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-contaminated transformer dielectric fluid. Persons who process or distribute in commerce dielectric fluid containing 50 ppm or greater PCB (but less than 500 ppm PCB) for use in PCB-Contaminated Transformers may... dielectric fluids containing 50 ppm or greater PCB for use in PCB Transformers, railroad transformers, or PCB...

Biomonitoring of Non-Dioxin-Like Polychlorinated Biphenyls in Transgenic Arabidopsis Using the Mammalian Pregnane X Receptor System: A Role of Pectin in Pollutant Uptake

PubMed Central

Bao, Lieming; Gao, Chen; Li, Miaomiao; Chen, Yong; Lin, Weiqiang; Yang, Yanjun; Han, Ning; Bian, Hongwu; Zhu, Muyuan; Wang, Junhui

2013-01-01

Polychlorinated biphenyls (PCBs) are persistent organic pollutants damaging to human health and the environment. Techniques to indicate PCB contamination in planta are of great interest to phytoremediation. Monitoring of dioxin-like PCBs in transgenic plants carrying the mammalian aryl hydrocarbon receptor (AHR) has been reported previously. Herein, we report the biomonitoring of non-dioxin-like PCBs (NDL-PCBs) using the mammalian pregnane X receptor (PXR). In the transgenic Arabidopsis designated NDL-PCB Reporter, the EGFP-GUS reporter gene was driven by a promoter containing 18 repeats of the xenobiotic response elements, while PXR and its binding partner retinoid X receptor (RXR) were coexpressed. Results showed that, in live cells, the expression of reporter gene was insensitive to endogenous lignans, carotenoids and flavonoids, but responded to all tested NDL-PCBs in a dose- and time- dependent manner. Two types of putative PCB metabolites, hydroxy- PCBs and methoxy- PCBs, displayed different activation properties. The vascular tissues seemed unable to transport NDL-PCBs, whereas mutation in QUASIMODO1 encoding a 1,4-galacturonosyltransferase led to reduced PCB accumulation in Arabidopsis, revealing a role for pectin in the control of PCB translocation. Taken together, the reporter system may serve as a useful tool to biomonitor the uptake and metabolism of NDL-PCBs in plants. PMID:24236133

Levels of PCB 126 and PCB 153 in plasma and tissues in goats exposed during gestation and lactation.

PubMed

Lyche, Jan L; Skaare, Janneche U; Larsen, Hans J S; Ropstad, Erik

2004-04-01

The aim of the present study was to gain knowledge about the disposition of the PCB congeners 126 and 153 in a goat model where pregnant does were given oral doses of PCB from day 60 of gestation until delivery. The goat kids were thus exposed to PCB during gestation and lactation. The doses of PCB 153 and PCB 126 were 98 and 49 ng/kg body wt/day, respectively. PCB levels were measured in plasma from the does at day 90 of gestation and at delivery, and in plasma from the kids at birth and four weeks post partum. Concentrations of PCB were analysed in brain, liver and fat tissue from the does six weeks after delivery and in liver and fat tissue from the kids at nine months of age. The ratio of estimated body burden to ingested dose in the does, was 0.95 +/- 0.07 for PCB 153 and 0.41 +/- 0.03 for PCB 126. Approximately 9% of PCB 153 and 6% of PCB 126 was transferred from the mothers to their kids during gestation and lactation. Prenatal exposure contributed to a much lower fraction of the body burden than postnatal PCB intake via milk, due to the fact that almost 100% of the PCB 153 transferred from the does to kids was transferred via milk, and the PCB 126 intake via milk was threefold higher than the calculated body burden. The hepatic PCB 126 concentration in both does and kids was significantly higher than the concentration in fat, in contrast to PCB 153, where the highest concentrations were found in fat. A significant difference in body burden between the does at delivery, the newborn kids, and the kids at four weeks of age, did not influence the plasma concentration of PCB 153 on a fat weight basis, which showed no difference with sampling time. Our results suggest that PCB 126 and PCB 153 have different pharmacokinetic properties. The higher levels of PCB 126 in liver tissue compared to fat tissue confirm the concept of hepatic sequestration. The similar blood concentration of PCB 153 in the does at delivery and their newborn kids despite the considerable difference in body burden, suggests a high degree of placental transfer. This supports previous observations that low molecular weight, lipid-soluble, non-polar chemicals reach the fetus to the greatest possible extent. For PCB 153, the body burden may provide the appropriate dose metric at steady state, but may give a minor underestimation of PCB 126 at low environmental exposure levels due to hepatic sequestration.

Thermal dechlorination of PCB-209 over Ca species-doped Fe₂O₃.

PubMed

Su, Guijin; Huang, Linyan; Shi, Ruifang; Liu, Yexuan; Lu, Huijie; Zhao, Yuyang; Yang, Fan; Gao, Lirong; Zheng, Minghui

2016-02-01

Degradation reaction of decachlorobiphenyl (PCB-209) was investigated over the synthesized Ca species-doped Fe2O3 at 300 °C. The 1%Ca-Fe2O3 exhibited the highest activity among the four catalysts prepared with the pseudo-first order reaction at k(obs) = 0.103 min(-1). PCB-207, PCB-197, PCB-176, PCB-184, PCB-150, PCB-136, PCB-148, PCB-104, PCB-96, PCB-54, PCB-19, PCB-4 and PCB-1 were identified as the dominant isomers in their respective nonachlorobiphenyl (NonaCB) to monochlorobiphenyl (MonoCB) homologue groups. Analysis of the hydrodechlorination products indicated that dechlorination was much more favored on meta- and para-than on ortho-positions. The formation of significantly predominant NonaCB and octachlorobiphenyl (OctaCB) isomers was attributed to lower energy principles and to the 90° dihedral angles of two aromatic rings which prevented the hydrodechlorination at ortho-positions. When the number of chlorine atoms is not more than 7, the steric effect supports the formation of predominant PCB isomers having chlorines at four ortho-positions. During the dechlorination of tetrachlorobiphenyl (TetraCB) formed to generate monochlorobiphenyl (MonoCB) isomers, the chlorine atoms fully substituted at the ortho-positions have to be successively removed, with the first two dechlorinations preferentially occurring at the two different benzene rings. This is dissimilar to that of octachloronaphthalene (PCN-75) in which the hydrodechlorination reaction happened preferentially at ortho-position due to the existence of steric effects. The opposite roles of the steric effect in ortho-position between PCB-209 and PCN-75 might be due to the difference of the π-conjugated plane caused by the dihedral angle of 90° and 0° of the two aromatic rings. Copyright © 2015 Elsevier Ltd. All rights reserved.

Quantification of all 209 PCB congeners in blood-Can indicators be used to calculate the total PCB blood load?

PubMed

Kraft, M; Rauchfuss, K; Sievering, S; Wöckner, M; Neugebauer, F; Fromme, H

2017-03-01

Polychlorinated biphenyls (PCBs) are a substance group of 209 theoretically possible compounds. The human body burden of PCBs is commonly calculated based on so-called indicator congeners such as PCB 138, PCB 153 and PCB 180, which are analyzed in human blood. The German "Human Biomonitoring (HBM) Commission" assumes that the sum of these indicator congeners multiplied by a factor of 2 represents the total PCB burden. This norm is based on data obtained from exposure studies after dietary intake. Data from indoor air shows a different congener pattern, which might lead to a relatively higher intake of lower chlorinated PCBs by inhalation. In two independent studies with adult participants from two regions in Germany, we measured all 209 PCB congeners in 44 whole blood and 42 plasma samples. Participants from the whole blood study group had additional exposure to PCBs via indoor air. With our analytical method, 141 individual PCB congeners, 27 coeluted pairs of PCB congeners and 2 records of 3 and 4 coeluted PCBs could be determined. Thus, 172 analysis results were reported per sample. In the whole blood samples, 50 congeners showed values below the limit of quantification (LOQ), whereas 94 congeners could not be detected in any of plasma samples. Total PCB concentrations (Σ 209 PCB congeners, incl. ½ LOQ) in the whole blood samples ranged from 99 to 2152ng PCB/g lipid (Median: 454ng/g lipid; 95th Percentile: 1404ng/g lipid). The sum of all 209 measured PCB (incl. ½ LOQ) in plasma samples showed levels between 52 and 933ng PCB/g lipid (Median: 226ng/g lipid; 95th Percentile: 642ng/g lipid). Our results show that the burden of PCBs on the human body is caused mainly by the three highly chlorinated indicator congeners PCB 138, PCB 153 and PCB 180. In median approximately 50% of the total PCB content in human whole blood or plasma samples can be attributed to these congeners. Total PCB, calculated by multiplying the sum of the three indicator congeners by 2, showed a strong and highly significant correlation to the sum of all 209 measured congeners for each sample. A slightly stronger correlation in the whole blood samples could be achieved by choosing six indicator congeners, including the lower chlorinated congeners (PCB 28, 52 and 101) into the calculation. Although this difference is very small, it must be considered that higher PCB levels in indoor air than those measured in the present study might be associated with a higher burden of indoor-air-related congeners in exposed individuals. For precautionary reasons, it could therefore be recommended that the assessment of individuals exposed to PCB via indoor air should be carried out based on the sum of the 6 indicator congeners PCB 28, PCB 52, PCB 101, PCB 138, PCB 153 and PCB 180 multiplied by a factor of 2. Copyright © 2016 Elsevier GmbH. All rights reserved.

Polychlorinated biphenyls in fly ashes collected from five coal-fired power plants in North China

NASA Astrophysics Data System (ADS)

Li, Zhiyong; Li, Xu; Ma, Huiqiao; Fan, Lin

2017-01-01

The 5 coal fly ash samples (CFA) were systematically collected from 5 coal-fired power plants (CFPPs) in North China for analysis of 86 PCB congeners. The predominant PCB congeners were PCB-6, -4/10, -28, -18, -19 and -16/32, which belonged to lighter molecular weight (LMW) congeners. The Σ86PCBs for 5 CFPPs ranged from 10.93 to 32.06 ng/g with the mean value as 16.01 ng/g. The PCBs in CFA were dominated by LMW-PCBs with 2-, 3- and 4-Cl PCBs contributed 34.80%, 39.18% and 9.21% to the Σ86PCBs. The TEQ concentrations for 5 CFPPs was 42.54 pg/g higher than 4 pg/g designed by Canada for soil quality, indicated the using of CFA as soil amendment should be cautioned.

Polychlorinated biphenyls and their association with survival following breast cancer

PubMed Central

Parada, Humberto; Wolff, Mary S.; Engel, Lawrence S.; Eng, Sybil M.; Khankari, Nikhil K.; Neugut, Alfred I.; Teitelbaum, Susan L.; Gammon, Marilie D.

2015-01-01

Background Polychlorinated biphenyls (PCBs) are hypothesized to influence breast carcinogenesis due to their persistence and potential to induce estrogenic and anti-estrogenic effects. Whether PCBs influence survival following breast cancer is unknown. Methods A population-based cohort of women diagnosed with first primary invasive or in situ breast cancer in 1996–1997 and with blood-measured PCBs (n=627) collected shortly after diagnosis was followed for vital status through 2011. After 5 and 15 years we identified 54 and 187 deaths, respectively, of which 36 and 74 were breast cancer-related. Using Cox regression, we estimated hazard ratios (HR) and 95% confidence intervals (CI) for mortality for baseline PCB concentrations, individually and as estrogenic (ΣGroup 1B: PCB101, PCB174, PCB177, PCB187, PCB199), anti-estrogenic (ΣGroup 2A: PCB66, PCB74, PCB105, PCB118; Σ2B: PCB138, PCB170), and cytochrome P450 enzyme-inducing (ΣGroup 3: PCB99, PCB153, PCB180, PCB183, PCB203) groups. Results The highest PCB174 tertile was associated with an increase in all-cause (HR=2.22, 95%CI: 1.14–4.30) and breast cancer-specific (HR=3.15, 95%CI: 1.23–8.09) mortality within 5 years of diagnosis and remained associated with breast cancer-specific mortality (HR=1.88, 95%CI: 1.05–3.36) at 15 years. At 5 years, the highest tertile of PCB177 was positively associated with all-cause mortality (HR=2.12, 95%CI: 1.05–4.30). At 15 years, the highest tertiles of ΣGroup 2A congeners and PCB118 were inversely associated with all-cause mortality (HR=0.60, 95%CI: 0.39–0.83; HR=0.63, 95%CI: 0.43–0.92, respectively). Conclusions In this first US study of PCBs and breast cancer survival, PCBs were associated with mortality in biologically plausible directions. The investigation of other, structurally similar, chemicals may be warranted. PMID:26798968

DEMONSTRATION BULLETIN: CLOR-N-SOIL PCB TEST KIT L2000 PCB/CHLORIDE ANALYZER - DEXSIL CORP.

EPA Science Inventory

DEXSIL CORP(Environmental Test Kits)The Dexsil Corporation (Dexsil) produces two test kits that detect polychlorinated biphenyls (PCB) in soil: the Dexsil Clor-N-Soil PCB Screening Kit, and the Dexsil L2000 PCB/Chloride Analyzer. The Dexsil Clor-N-Soil PCB Screening Kit extr...

Atmospheric PCB concentrations at Terra Nova Bay, Antarctica.

PubMed

Gambaro, Andrea; Manodori, Laura; Zangrando, Roberta; Cincinelli, Alessandra; Capodaglio, Gabriele; Cescon, Paolo

2005-12-15

Concentrations of gas-phase polychlorobiphenyls (PCBs) were studied over an austral summer at a site in Terra Nova Bay, Antarctica. Gas-phase concentrations of individual PCB congeners in the atmosphere of Terra Nova Bay ranged from below the detection limit to 0.25 pg m(-3), with a mean concentration of sigmaPCB of 1.06 pg m(-3). The PCB profile was dominated by lower-chlorinated PCB congeners; in fact >78% of the total PCB content was due to congeners with 1-4 chlorine atoms and only about 10% with 5-7 chlorines, whereas higher-chlorinated PCB congeners were below detection limits. The mean sigmaPCB concentration obtained in this study were lower than those reported in previous Antarctic studies. Temporal concentration profiles of sigmaPCB do not correspond to seasonal temperature changes. In consideration of the low PCB concentrations observed, the studies with the wind roses, the regression between In P(PCB) and T(-1), and the distribution of congeners, we can hypothesize that PCB local source contributions are not very important, whereas long-distance transport is the prevalent factor bringing PCBs to Terra Nova Bay.

Effects of perinatal exposure to low doses of PCB 153 and PCB 126 on lymphocyte proliferation and hematology in goat kids.

PubMed

Lyche, Jan; Larsen, Hans; Skaare, Janneche Utne; Tverdal, Aage; Dahl, Ellen; Johansen, Grethe; Ropstad, Erik

2004-06-11

Pregnant does (10 goats/group) were dosed orally with either PCB 153 or PCB 126 dissolved in corn oil or only corn oil (control group) from day 60 of gestation until delivery. Effects on in vitro mitogen-induced lymphocyte proliferation and blood cell counts in their goat kids exposed to low levels of PCB 153 and PCB 126 during gestation and lactation were assessed. The concentrations of PCB 153 and PCB 126 in adipose tissue in the goat kids 9 mo postpartum were 5800 ng/g (fat weight) and 0.49 ng/g (fat weight), respectively. Kids exposed to PCB 153 had a significantly higher number of white blood cells, neutrophils, and lymphocytes at 2 wk of age compared to controls. In the kids exposed to PCB 126 there was a significantly lower concentration of monocytes at 2, 4, and 8 wk of age. The mean lymphocyte response to phytohemagglutinin (PHA) and to concanavalin A (Con A) was significant lower in the PCB 153 compared to the control group at wk 2, 4, and 8 postnatally. The results of the present study support previous reports on immunotoxic effects of PCB exposure in animals. However, this is the first report to demonstrate immunotoxicity in animals by using low doses of PCB 153. The difference in results between PCB 126 and PCB 153 treatment groups may strengthen the hypothesis that PCBs mediate immunotoxic effects through both AhR-dependent and -independent mechanisms.

2,2',3,3',6,6'-Hexachlorobiphenyl (PCB 136) is Enantioselectively Oxidized to Hydroxylated Metabolites by Rat Liver Microsomes

PubMed Central

Wu, Xianai; Pramanik, Ananya; Duffel, Michael W.; Hrycay, Eugene G.; Bandiera, Stelvio M.; Lehmler, Hans-Joachim; Kania-Korwel, Izabela

2011-01-01

Developmental exposure to multiple-ortho substituted polychlorinated biphenyls (PCBs) causes adverse neurodevelopmental outcomes in laboratory animals and humans by mechanisms involving the sensitization of Ryanodine receptors (RyRs). In the case of PCB 136, the sensitization of RyR is enantiospecific, with only (-)-PCB 136 being active. However, the role of enantioselective metabolism in the developmental neurotoxicity of PCB 136 is poorly understood. The present study employed hepatic microsomes from phenobarbital (PB-), dexamethasone (DEX-) and corn oil (VEH-)treated male Sprague-Dawley rats to investigate the hypothesis that PCB 136 atropisomers are enantioselectively metabolized by P450 enzymes to potentially neurotoxic, hydroxylated PCB 136 metabolites. The results demonstrated the time- and isoform-dependent formation of three metabolites, with 5-OH-PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl-5-ol) being the major metabolite. The formation of 5-OH-PCB 136 increased with the activity of P450 2B enzymes in the microsomal preparation, which is consistent with PCB 136 metabolism by rat P450 2B1. The minor metabolite 4-OH-PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl-4-ol) was produced by a currently unidentified P450 enzymes. An enantiomeric enrichment of (-)-PCB 136 was observed in microsomal incubations due to the preferential metabolism of (+)-PCB 136 to the corresponding 5-OH-PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl-5-ol) atropisomer. 4-OH-PCB 136 displayed an enrichment of the atropisomer formed from (-)-PCB 136; however, the enrichment of this metabolite atropisomer didn't affect the enantiomeric enrichment of the parent PCB because 4-OH-PCB 136 is only a minor metabolite. Although the formation of 5- and 4-OH-PCB 136 atropisomers increased with time, the enantioselective formation of the OH-PCB metabolites resulted in constant enantiomeric enrichment, especially at later incubation times. These observations not only demonstrate that the chiral signatures of PCBs and their metabolites in wildlife and humans are due to metabolism by P450 enzymes, but also suggest that the enantioselective formation of neurotoxic PCB 136 metabolites, such as 4-OH-PCB 136, may play a role in the developmental neurotoxicity of PCBs. PMID:22026639

2,2′,3,5′,6-PENTACHLOROBIPHENYL (PCB 95) AND ITS HYDROXYLATED METABOLITES ARE ENANTIOMERICALLY ENRICHED IN FEMALE MICE

PubMed Central

Kania-Korwel, Izabela; Barnhart, Christopher D.; Stamou, Marianna; Truong, Kim M.; El-Komy, Mohammed H.M.E.; Lein, Pamela J.; Veng-Pedersen, Peter; Lehmler, Hans-Joachim

2012-01-01

Epidemiological and laboratory studies link polychlorinated biphenyls and their metabolites to adverse neurodevelopmental outcomes. Several neurotoxic PCB congeners are chiral and undergo enantiomeric enrichment in mammalian species, which may modulate PCB developmental neurotoxicity. This study measures levels and enantiomeric enrichment of PCB 95 and its hydroxylated metabolites (OH-PCBs) in adult female C57Bl/6 mice following subchronic exposure to racemic PCB 95. Tissue levels of PCB 95 and OH-PCBs increased with increasing dose. Dose-dependent enantiomeric enrichment of PCB 95 was observed in brain and other tissues. OH-PCBs also displayed enantiomeric enrichment in blood and liver, but were not detected in adipose and brain. In light of data suggesting enantioselective effects of chiral PCBs on molecular targets linked to PCB developmental neurotoxicity, our observations highlight the importance of accounting for PCB and OH-PCB enantiomeric enrichment in the assessment of PCB developmental neurotoxicity. PMID:22974126

40 CFR 761.347 - First level sampling-waste from existing piles.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Purposes of Characterization for PCB Disposal in Accordance With § 761.62, and Sampling PCB Remediation... a cone; that is, having a circular base with PCB bulk product waste or PCB remediation waste... one pile. If the PCB bulk product waste or PCB remediation waste consists of more than one pile or...

Modular Pulsed Plasma Electric Propulsion System for Cubesats

NASA Technical Reports Server (NTRS)

Perez, Andres Dono; Gazulla, Oriol Tintore; Teel, George Lewis; Mai, Nghia; Lukas, Joseph; Haque, Sumadra; Uribe, Eddie; Keidar, Michael; Agasid, Elwood

2014-01-01

Current capabilities of CubeSats must be improved in order to perform more ambitious missions. Electric propulsion systems will play a key role due to their large specific impulse. Compared to other propulsion alternatives, their simplicity allows an easier miniaturization and manufacturing of autonomous modules into the nano and pico-satellite platform. Pulsed Plasma Thrusters (PPTs) appear as one of the most promising technologies for the near term. The utilization of solid and non-volatile propellants, their low power requirements and their proven reliability in the large scale make them great candidates for rapid implementation. The main challenges are the integration and miniaturization of all the electronic circuitry into a printed circuit board (PCB) that can satisfy the strict requirements that CubeSats present. NASA Ames and the George Washington University have demonstrated functionality and control of three discrete Micro-Cathode Arc Thrusters (CAT) using a bench top configuration that was compatible with the ARC PhoneSat Bus. This demonstration was successfully conducted in a vaccum chamber at the ARC Environmental Test Laboratory. A new effort will integrate a low power Plasma Processing Unit and two plasma thrusters onto a single printed circuit board that will utilize less than 13 U of Bus volume. The target design will be optimized for the accommodation into the PhoneSatEDISON Demonstration of SmallSatellite Networks (EDSN) bus as it uses the same software interface application, which was demonstrated in the previous task. This paper describes the design, integration and architecture of the proposed propulsion subsystem for a planned Technology Demonstration Mission. In addition, a general review of the Pulsed Plasma technology available for CubeSats is presented in order to assess the necessary challenges to overcome further development.

Does living near a Superfund site contribute to higher polychlorinated biphenyl (PCB) exposure?

PubMed

Choi, Anna L; Levy, Jonathan I; Dockery, Douglas W; Ryan, Louise M; Tolbert, Paige E; Altshul, Larisa M; Korrick, Susan A

2006-07-01

We assessed determinants of cord serum polychlorinated biphenyl (PCB) levels among 720 infants born between 1993 and 1998 to mothers living near a PCB-contaminated Superfund site in Massachusetts, measuring the sum of 51 PCB congeners (capital sigmaPCB) and ascertaining maternal address, diet, sociodemographics, and exposure risk factors. Addresses were geocoded to obtain distance to the Superfund site and neighborhood characteristics. We modeled log10(capital sigmaPCB) as a function of potential individual and neighborhood risk factors, mapping model residuals to assess spatial correlates of PCB exposure. Similar analyses were performed for light (mono-tetra) and heavy (penta-deca) PCBs to assess potential differences in exposure pathways as a function of relative volatility. PCB-118 (relatively prevalent in site sediments and cord serum) was assessed separately. The geometric mean of capital sigmaPCB levels was 0.40 (range, 0.068-18.14) ng/g serum. Maternal age and birthplace were the strongest predictors of capital sigmaPCB levels. Maternal consumption of organ meat and local dairy products was associated with higher and smoking and previous lactation with lower capital sigmaPCB levels. Infants born later in the study had lower capital sigmaPCB levels, likely due to temporal declines in exposure and site remediation in 1994-1995. No association was found between capital sigmaPCB levels and residential distance from the Superfund site. Similar results were found with light and heavy PCBs and PCB-118. Previously reported demographic (age) and other (lactation, smoking, diet) correlates of PCB exposure, as well as local factors (consumption of local dairy products and Superfund site dredging) but not residential proximity to the site, were important determinants of cord serum PCB levels in the study community.

Construction and quality assurance of large area resistive strip Micromegas for the upgrade of the ATLAS Muon Spectrometer at LHC/CERN

NASA Astrophysics Data System (ADS)

Lösel, P.

2017-06-01

Large area Micromegas detectors will be employed for the first time in high-energy physics experiments. To cope with increasing background rates, associated with the steadily increasing luminosity of LHC to 10 times design luminosity, the present detector technology in the current innermost stations of the muon endcap system of the ATLAS experiment (the Small Wheel), will be replaced in 2019/2020 by resistive strip Micromegas and small strip TGC detectors. Both technologies will provide tracking and trigger information. In the "New Small Wheel" the Micromegas will be arranged in eight detection layers built of trapezoidally shaped quadruplets of four different sizes covering in total about 1200 m2 of detection plane. In order to achieve 15 % transverse momentum resolution for 1 TeV muons, a challenging mechanical precision is required in the construction of each active plane, with an alignment of the readout strips at the level of 30 μm RMS along the precision coordinate and 80 μm RMS perpendicular to the plane. Each individual Micromegas plane must achieve a spatial resolution better than 100 μm at background rates up to 15 kHz/cm2 while being operated in an inhomogeneous magnetic field (B <= 0.3 T). The required mechanical precision for the production of the components and their assembly, on such large area detectors, is a key point and must be controlled during construction and integration. Particularly the alignment of the readout strips within a quadruplet appears to be demanding. The readout strips are etched on PCB boards using photolithographic processes. Depending on the type of the module, 3 or 5 PCB boards need to be joined and precisely aligned to form a full readout plane. The precision in the alignment is reached either by use of precision mechanical holes or by optical masks, both referenced to the strip patterns. Assembly procedures have been developed to build the single panels with the required mechanical precision and to assemble them in a module including the four metallic micro-meshes. Methods to confirm the precision of components and assembly are based on precise optical devices and X-ray or cosmic muon investigations. We will report on the construction procedures for the Micromegas quadruplets, on the quality control procedures and results, and on the assembly and calibration methods.

Polybrominated diphenyl ethers and indicator polychlorinated biphenyls in human milk from China under the Stockholm Convention.

PubMed

Zhang, Lei; Yin, Shuaixing; Zhao, Yunfeng; Shi, Zhixiong; Li, Jingguang; Wu, Yongning

2017-12-01

Seven congeners of polybrominated diphenyl ethers (PBDEs) (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153,BDE-154 and BDE-183) and six indicator polychlorinated biphenyls (PCBs) (PCB-28, PCB-52, PCB-101, PCB-138, PCB-153 and PCB-180) were measured in 32 regional pooled human milk samples originating from 1760 volunteering primiparous mothers to evaluate the current human body burden of general population and the temporal trend in China. Individual human milk samples were collected following a WHO-designed procedure. This work is one of parts of the evaluation of effectiveness of Stockholm Convention performance. The concentration of ∑ 7 PBDEs ranged from 0.3 ng g -1 lipid to 4.0 ng g -1 lipid with a mean of 1.5 ng g -1 lipid. The concentration of ∑ 6 PCBs ranged from 2.3 ng g -1 lipid to 19.0 ng g -1 lipid with a mean of 6.6 ng g -1 lipid. By comparing with background determination in 2007, there was no significance for ∑ 7 PBDEs. However, BDE-47, BDE-99, and BDE-100 significantly decreased with an average of 45%, 48%, and 46%, respectively, from 2007 to 2011, and an increase of BDE-183 was founded in most regions. For ∑ 6 PCBs, there was a significant decline with an average reduction of 41% from 2007 to 2011. These results indicate the effectiveness of reduction and elimination of POPs in China. Future national human milk biomonitoring is worthy to be done to further evaluate the time trend and effectiveness of the Convention performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Qualitative and quantitative metals liberation assessment for characterization of various waste printed circuit boards for recycling.

PubMed

Priya, Anshu; Hait, Subrata

2017-12-01

Metals liberation and composition are decisive attributes in characterization of e-waste for metal recycling. Though end-of-life printed circuit board (PCB) is an integral part of e-waste as secondary resource reservoir, yet no standardized procedure exists for metals liberation and dissolution for its characterization. Thus, the paper aims at assessment of metals liberation upon comminution employing scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) followed by comparative assessment of the existing United States Environmental Protection Agency (USEPA) digestion procedures, viz., USEPA 3050B, USEPA 3051A, and USEPA 3052, in effective dissolution of metals from comminuted particles of waste PCBs of computer, laptop, mobile phone, and television. Effect of comminution and digestion conditions was assessed to have significant role in metal liberation and dissolution from PCBs. The SEM-EDS analysis demonstrated partial release of metals from the silica matrix of PCBs. The USEPA digestion methods showed statistically significant (P < 0.05) difference with greater dissolution of metals complexed to PCB matrix by the USEPA 3052 method owing to use of strong acid like hydrofluoric acid. Base metals like Cu and Zn and toxic metals such as Pb and Cd were present in abundance in PCBs and in general exceeded the total threshold limit concentration (TTLC). The maximum contents of Cu (20.13 ± 0.04 wt.%) and Zn (1.89 ± 0.05 wt.%) in laptop PCBs, Pb (2.26 ± 0.08 wt.%) in TV PCBs, and Cd (0.0812 ± 0.0008 wt.%) in computer PCBs were observed.

Monitoring OH-PCBs in PCB transport worker's urine as a non-invasive exposure assessment tool.

PubMed

Haga, Yuki; Suzuki, Motoharu; Matsumura, Chisato; Okuno, Toshihiro; Tsurukawa, Masahiro; Fujimori, Kazuo; Kannan, Narayanan; Weber, Roland; Nakano, Takeshi

2018-06-01

In this study, we analyzed hydroxylated polychlorinated biphenyls (OH-PCBs) in urine of both PCB transport workers and PCB researchers. A method to monitor OH-PCB in urine was developed. Urine was solid-phase extracted with 0.1% ammonia/ methanol (v/v) and glucuronic acid/sulfate conjugates and then decomposed using β-glucuronidase/arylsulfatase. After alkaline digestion/derivatization, the concentration of OH-PCBs was determined by HRGC/HRMS-SIM. In the first sampling campaign, the worker's OH-PCB levels increased several fold after the PCB waste transportation work, indicating exposure to PCBs. The concentration of OH-PCBs in PCB transport workers' urine (0.55~11 μg/g creatinine (Cre)) was higher than in PCB researchers' urine (< 0.20 μg/g Cre). However, also a slight increase of OH-PCBs was observed in the researchers doing the air sampling at PCB storage area. In the second sampling, after recommended PCB exposure reduction measures had been enacted, the worker's PCB levels did not increase during handling of PCB equipment. This suggests that applied safety measures improved the situation. Hydroxylated trichlorobiphenyls (OH-TrCBs) were identified as a major homolog of OH-PCBs in urine. Also, hydroxylated tetrachlorobiphenyls (OH-TeCBs) to hydroxylated hexachlorobiphenyls (OH-HxCBs) were detected. For the sum of ten selected major indicators, a strong correlation to total OH-PCBs were found and these can possibly be used as non-invasive biomarkers of PCB exposure in workers managing PCB capacitors and transformer oils. We suggest that monitoring of OH-PCBs in PCB management projects could be considered a non-invasive way to detect exposure. It could also be used as a tool to assess and improve PCB management. This is highly relevant considering the fact that in the next 10 years, approx. 14 million tons of PCB waste need to be managed. Also, the selected populations could be screened to assess whether exposure at work, school, or home has taken place.

Biotransformation of 2,2',5,5'-tetrachlorobiphenyl (PCB 52) and 3,3',4,4'-tetrachlorobiphenyl (PCB 77) by liver microsomes from four species of sea turtles.

PubMed

Richardson, Kristine L; Schlenk, Daniel

2011-05-16

The rates of oxidative metabolism of two tetrachlorobiphenyl congeners were determined in hepatic microsomes from four species of sea turtles, green (Chelonia mydas), olive ridley (Lepidochelys olivacea), loggerhead (Caretta caretta), and hawksbill (Eretmochelys imbricata). Hydroxylation of 3,3',4,4'-tetrachlorobiphenyl (PCB 77), an ortho-meta unsubstituted rodent cytochrome P450 (P450) 1A substrate PCB, was not observed in sea turtle microsomes. Sea turtle microsomes hydroxylated 2,2',5,5'-tetrachlorobiphenyl (PCB 52), a meta-para unsubstituted rodent P450 family 2 substrate PCB, at rates ranging from less than 0.5 to 53 pmol/min/mg protein. The P450 inhibitor ketoconazole inhibited hydroxylation of PCB 52, supporting the role of P450 catalysis. Sea turtle PCB 52 hydroxlyation rates strongly correlated with immunodetected P450 family 2-like and less so with P450 family 3-like hepatic proteins. Testosterone 6β-, 16α-, 16β-hydroxylase activities were also significantly correlated with the expression of these enzymes, indicating that P450 family 2 or P450 family 3 proteins are responsible for PCB hydroxylation in sea turtles. This study indicated species-specific PCB biotransformation in sea turtles and preferential elimination of meta-para unsubstituted PCB congeners over ortho-meta unsubstituted PCB congeners consistent with PCB accumulation patterns observed in tissues of sea turtles.

Low temperature Zn diffusion for GaSb solar cell structures fabrication

NASA Technical Reports Server (NTRS)

Sulima, Oleg V.; Faleev, Nikolai N.; Kazantsev, Andrej B.; Mintairov, Alexander M.; Namazov, Ali

1995-01-01

Low temperature Zn diffusion in GaSb, where the minimum temperature was 450 C, was studied. The pseudo-closed box (PCB) method was used for Zn diffusion into GaAs, AlGaAs, InP, InGaAs and InGaAsP. The PCB method avoids the inconvenience of sealed ampoules and proved to be simple and reproducible. The special design of the boat for Zn diffusion ensured the uniformality of Zn vapor pressure across the wafer surface, and thus the uniformity of the p-GaSb layer depth. The p-GaSb layers were studied using Raman scattering spectroscopy and the x-ray rocking curve method. As for the postdiffusion processing, an anodic oxidation was used for a precise thinning of the diffused GaSb layers. The results show the applicability of the PCB method for the large-scale production of the GaSb structures for solar cells.

High speed displacement measurement based on electro-magnetic induction applied to electromagnetically driven ring expansion

NASA Astrophysics Data System (ADS)

Han, Xiaotao; Wu, Jiawei; Huang, Lantao; Qiu, Lei; Chen, Qi; Cao, Quanliang; Herlach, Fritz; Li, Liang

2017-11-01

Investigating the mechanism of electromagnetic forming (EMF) becomes a hot topic in the field of metal forming. The high speed up to 200 m/s in EMF makes it a real challenge to capture the forming process. To this end, a new method for measuring displacement at high speed based on electromagnetic induction has been developed. Specifically this is used to measure the displacement of an expanding metal ring driven by a pulsed magnetic field; this is one of the basic EMF processes. The new method is simple and practical, and it combines high-speed response with adequate precision. The new measurement system consists of a printed circuit board (PCB) and a Rogowski probe. Eleven coaxial annular detecting probes are arranged in the PCB plate to acquire induced voltage at different positions, and a Rogowski probe is used to measure the current in the driving coil. The displacement of the ring is deduced by analyzing the output voltages of the detecting probes and the Rogowski probe. The feasibility of the method is verified by comparing the results with pictures from a high speed camera taken simultaneously.

Environmental risk assessment of CRT and PCB workshops in a mobile e-waste recycling plant.

PubMed

Song, Qingbin; Zeng, Xianlai; Li, Jinhui; Duan, Huabo; Yuan, Wenyi

2015-08-01

The mobile e-waste recycling equipment was chosen as the object of this study, including manual dismantling, mechanical separation of cathode ray tubes (CRTs), and printed circuit boards (PCBs) in the two independent workshops. To determine the potential environmental contamination, the noise, the heavy metals (Cu, Cd, Pb), and the environmental impacts of the e-waste recycling processes in the two workshops of the mobile plant have been evaluated in this paper. This study determined that when control measures are employed, the noise within the two workshops (<80 dB) will meet the national standards. In the CRT workshop, Pb was the most polluting metal, with 2.3 μg/m(3) and 10.53 mg/g in the air and floor dust, respectively. The result of a health risk assessment shows that noncancerous effects are possible for Pb (hazard index (HI) = 3.54 in the CRT workshop and HI = 1.27 in the PCB workshop). The carcinogenic risks to workers for Cd are relatively light in both the workshops. From the results of life cycle assessment (LCA), it can be seen that there was an environmental benefit from the e-waste recycling process as a whole.

Electrical Design and Evaluation of Asynchronous Serial Bus Communication Network of 48 Sensor Platform LSIs with Single-Ended I/O for Integrated MEMS-LSI Sensors.

PubMed

Shao, Chenzhong; Tanaka, Shuji; Nakayama, Takahiro; Hata, Yoshiyuki; Muroyama, Masanori

2018-01-15

For installing many sensors in a limited space with a limited computing resource, the digitization of the sensor output at the site of sensation has advantages such as a small amount of wiring, low signal interference and high scalability. For this purpose, we have developed a dedicated Complementary Metal-Oxide-Semiconductor (CMOS) Large-Scale Integration (LSI) (referred to as "sensor platform LSI") for bus-networked Micro-Electro-Mechanical-Systems (MEMS)-LSI integrated sensors. In this LSI, collision avoidance, adaptation and event-driven functions are simply implemented to relieve data collision and congestion in asynchronous serial bus communication. In this study, we developed a network system with 48 sensor platform LSIs based on Printed Circuit Board (PCB) in a backbone bus topology with the bus length being 2.4 m. We evaluated the serial communication performance when 48 LSIs operated simultaneously with the adaptation function. The number of data packets received from each LSI was almost identical, and the average sampling frequency of 384 capacitance channels (eight for each LSI) was 73.66 Hz.

A novel miniaturized PCR multi-reactor array fabricated using flip-chip bonding techniques

NASA Astrophysics Data System (ADS)

Zou, Zhi-Qing; Chen, Xiang; Jin, Qing-Hui; Yang, Meng-Su; Zhao, Jian-Long

2005-08-01

This paper describes a novel miniaturized multi-chamber array capable of high throughput polymerase chain reaction (PCR). The structure of the proposed device is verified by using finite element analysis (FEA) to optimize the thermal performance, and then implemented on a glass-silicon substrate using a standard MEMS process and post-processing. Thermal analysis simulation and verification of each reactor cell is equipped with integrated Pt temperature sensors and heaters at the bottom of the reaction chamber for real-time accurate temperature sensing and control. The micro-chambers are thermally separated from each other, and can be controlled independently. The multi-chip array was packaged on a printed circuit board (PCB) substrate using a conductive polymer flip-chip bonding technique, which enables effective heat dissipation and suppresses thermal crosstalk between the chambers. The designed system has successfully demonstrated a temperature fluctuation of ±0.5 °C during thermal multiplexing of up to 2 × 2 chambers, a full speed of 30 min for 30 cycle PCR, as well as the capability of controlling each chamber digitally and independently.

BEHAVIORAL ASSESSMENTS OF ADULTS RATS EXPOSED PERINATALLY TO PCB153.

EPA Science Inventory

Ortho-substituted polychlorinated biphenyl (PCB) congeners are more neurotoxic in vitro than are non-ortho-substituted PCB congeners. We selected PCB153, a common ortho-substituted PCB congener, to evaluate the neurobehavioral toxicity of this class of PCBs in vivo. Pregnant fema...

77 FR 12293 - PCBs Bulk Product v. Remediation Waste

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-29

.... Remediation Waste AGENCY: Environmental Protection Agency (EPA). ACTION: Request for Public Comment. SUMMARY... biphenyl (PCB) disposal regulations regarding PCB bulk product and PCB remediation waste. The proposed... regarding PCB bulk product and PCB remediation waste under regulations promulgated at 40 CFR part 761. The...

Associations between plasma concentrations of PCB 28 and possible indoor exposure sources in Danish school children and mothers.

PubMed

Egsmose, Emilie Lund; Bräuner, Elvira Vaclavik; Frederiksen, Marie; Mørck, Thit Aarøe; Siersma, Volkert Dirk; Hansen, Pernille Winton; Nielsen, Flemming; Grandjean, Philippe; Knudsen, Lisbeth E

2016-02-01

Polychlorinated biphenyls (PCBs) are ubiquitously present in the environment and are suspected of carcinogenic, neurotoxic and immunotoxic effects. Significantly higher plasma concentrations of the congener PCB 28 occur in children compared to adults. Exposure in schools may contribute to this difference. To determine whether increased blood plasma concentrations of PCB 28 in Danish school children and mothers are associated with living in homes or attending schools constructed in the PCB period (1959-1977). PCB 28 was analyzed in plasma samples from 116 children aged 6-11years and 143 mothers living in an urban and a rural area in Denmark and participating in the European pilot project DEMOCOPHES (Demonstration of a study to COordinate and Perform Human Biomonitoring on a European Scale). In Denmark, PCBs were used in construction in the period 1950-1977, and year of construction or renovation of the homes and schools was used as a proxy for indoor PCB exposure. Linear regression models were used to assess the association between potential PCB exposure from building materials and lipid adjusted concentrations of PCB 28 in plasma, with and without adjustment for potential confounders. Among the 116 children and 143 mothers, we were able to specify home construction period in all but 4 children and 5 mothers leaving 111 children and 138 mothers for our analyses. The median lipid adjusted plasma PCB 28 concentration was 3 (range: 1-28) ng/g lipid in the children and 2 (range: 1-8) ng/g lipid in the mothers. Children living in homes built in the PCB period had significantly higher lipid adjusted plasma PCB 28 concentrations compared to children living in homes built before or after the PCB period. Following adjustment for covariates, PCB 28 concentrations in children were 40 (95% CI: 13; 68) percent higher than concentrations of children living in homes constructed at other times. Furthermore, children attending schools built or substantially refurbished in the PCB period also had significantly higher (46%, 95% CI: 22; 70) PCB 28 concentrations compared to children attending schools constructed before or after the PCB period, while their mothers had similar concentrations. Adjustment for the most prevalent congener, PCB 153, did not change this effect of home or school construction. When both home and school construction year were included in the models, the increase in lipid adjusted plasma PCB 28 for children living in or attending schools from the PCB period was no longer statistically significant. The individual effect of home and school construction periods could not be evaluated further with the available data. Our results suggest that PCB exposure in the indoor environment in schools and homes constructed during the PCB period may contribute significantly to children's plasma PCB 28 concentration. Efforts to minimize PCB exposure in indoor environments should be considered. Copyright © 2015 Elsevier Ltd. All rights reserved.

PCB dechlorination hotspots and reductive dehalogenase genes in sediments from a contaminated wastewater lagoon.

PubMed

Mattes, Timothy E; Ewald, Jessica M; Liang, Yi; Martinez, Andres; Awad, Andrew; Richards, Patrick; Hornbuckle, Keri C; Schnoor, Jerald L

2017-08-12

Polychlorinated biphenyls (PCBs) are a class of persistent organic pollutants that are distributed worldwide. Although industrial PCB production has stopped, legacy contamination can be traced to several different commercial mixtures (e.g., Aroclors in the USA). Despite their persistence, PCBs are subject to naturally occurring biodegradation processes, although the microbes and enzymes involved are poorly understood. The biodegradation potential of PCB-contaminated sediments in a wastewater lagoon located in Virginia (USA) was studied. Total PCB concentrations in sediments ranged from 6.34 to 12,700 mg/kg. PCB congener profiles in sediment sample were similar to Aroclor 1248; however, PCB congener profiles at several locations showed evidence of dechlorination. The sediment microbial community structure varied among samples but was dominated by Proteobacteria and Firmicutes. The relative abundance of putative dechlorinating Chloroflexi (including Dehalococcoides sp.) was 0.01-0.19% among the sediment samples, with Dehalococcoides sp. representing 0.6-14.8% of this group. Other possible PCB dechlorinators present included the Clostridia and the Geobacteraceae. A PCR survey for potential PCB reductive dehalogenase genes (RDases) yielded 11 sequences related to RDase genes in PCB-respiring Dehalococcoides mccartyi strain CG5 and PCB-dechlorinating D. mccartyi strain CBDB1. This is the first study to retrieve potential PCB RDase genes from unenriched PCB-contaminated sediments.

PCB concentrations of lake whitefish (Coregonus clupeaformis) vary by sex

USGS Publications Warehouse

Madenjian, Charles P.; Ebener, Mark P.; Sepulveda, Maria S.

2015-01-01

We determined whole-fish polychlorinated biphenyl (PCB) concentrations in 26 female lake whitefish (Coregonus clupeaformis) and 34 male lake whitefish from northern Lake Huron. In 5 of the 26 female lake whitefish, we also determined PCB concentrations in the somatic tissue and ovaries. In addition, bioenergetics modeling was used to determine the contribution of the growth dilution effect to the observed difference in PCB concentrations between the sexes. Whole-fish PCB concentrations for females and males averaged 60 ng/g and 80 ng/g, respectively; thus males were 34% higher in PCB concentration compared with females. Based on the PCB determinations in the somatic tissue and ovaries, we predicted that PCB concentration of females would increase by 2.5%, on average, immediately after spawning due to release of eggs. Thus, the change in PCB concentration due to release of eggs did not explain, to any degree, the higher PCB concentrations observed in males compared with females. Bioenergetics modeling results indicated that the growth dilution effect could account for males being only 0.7% higher in PCB concentration compared with females. Thus, the growth dilution effect contributed very little to the observed difference in PCB concentrations between the sexes. We conclude that males were higher than females in PCB concentration most likely due to a higher rate of energy expenditure, stemming from greater activity and a greater resting metabolic rate. A higher rate of energy expenditure leads to a higher rate of food consumption, which, in turn, leads to a higher PCB accumulation rate.

Polychlorinated biphenyls exposure-induced insulin resistance is mediated by lipid droplet enlargement through Fsp27.

PubMed

Kim, Hye Young; Kwon, Woo Young; Kim, Yeon A; Oh, Yoo Jin; Yoo, Seung Hee; Lee, Mi Hwa; Bae, Ju Yong; Kim, Jong-Min; Yoo, Young Hyun

2017-06-01

Although epidemiological and experimental studies demonstrated that polychlorinated biphenyls (PCBs) lead to insulin resistance, the mechanism underlying PCBs-induced insulin resistance has remained unsolved. In this study, we examined in vitro and in vivo effects of PCB-118 (dioxin-like PCB) and PCB-138 (non-dioxin-like PCB) on adipocyte differentiation, lipid droplet growth, and insulin action. 3T3-L1 adipocytes were incubated with PCB-118 or PCB-138 during adipocyte differentiation. For in vivo studies, C57BL/6 mice were administered PCB-118 or PCB-138 (37.5 mg/kg) by intraperitoneal injection and we examined adiposity and whole-body insulin action. PCB-118 and PCB-138 significantly promoted adipocyte differentiation and increased the lipid droplet (LD) size in 3T3-L1 adipocytes. In mice, both PCBs increased adipose mass and adipocyte size. Furthermore, both PCBs induced insulin resistance in vitro and in vivo. Expression of fat-specific protein 27 (Fsp27), which is localized to LD contact sites, was increased in PCB-treated 3T3-L1 adipocytes and mice. Depletion of Fsp27 by siRNA resulted in the inhibition of LD enlargement and attenuation of insulin resistance in PCB-treated 3T3-L1 adipocytes. An anti-diabetic drug, metformin, attenuated insulin resistance in PCB-treated 3T3-L1 adipocytes through the reduced expression of Fsp27 protein and LD size. This study suggests that PCB exposure-induced insulin resistance is mediated by LD enlargement through Fsp27.

Effect of PCB and DES on rat monoamine oxidase, acetylcholinesterase, testosterone, and estradiol ontogeny

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vincent, D.R.; Bradshaw, W.S.; Booth, G.M.

1992-06-01

Diethylstilbestrol (DES) and polychlorinated biphenyl (PCB) have been documented as potentially hazardous environmental agents. In utero exposure to DES produces human vaginal adenocarcinoma, male reproductive tract lesions in mice, and has been correlated with personality changes in human males. PCB (Kanechlor) was found to be the major toxin in the {open_quotes}Yusho{close_quotes} rice oil poisoning in Japan in 1968. Other investigators have shown in rats that PCB (Arochlor) causes liver adenofibrosis, thyroid dysfunction, atypical mitochondria, and dilation of both smooth and rough endoplasmic reticulum. Matthews et al. (1978) also reported that 4, 4{prime} chlorinated biphenyl was the most potent inducer ofmore » monooxygenases, irrespective of chlorination at other sites. Although these compounds have been studied extensively in mammals, there is a paucity of data examining their effects when non-fetotoxic amounts are administered chronically and orally during gestation. The present study is part of a larger effort designed to establish a protocol for testing the developmental effects of xenobiotics such as DES and PCB. Levels of acetylcholinesterase (AChE) were measured as an indicator of the integrity of nerve transmission in the central nervous system. Monoamine oxidase (MAO) is a marker for the outer mitochondrial membrane and is an important amine metabolizing enzyme. Testosterone and estradiol are important sex steroids in mammals, and effects upon levels of the two hormones may signal anomalies in development of sex characteristics. 35 refs., 3 figs., 1 tab.« less

Field application of activated carbon amendment for in-situ stabilization of polychlorinated biphenyls in marine sediment.

PubMed

Cho, Yeo-Myoung; Ghosh, Upal; Kennedy, Alan J; Grossman, Adam; Ray, Gary; Tomaszewski, Jeanne E; Smithenry, Dennis W; Bridges, Todd S; Luthy, Richard G

2009-05-15

We report results on the first field-scale application of activated carbon (AC) amendment to contaminated sediment for in-situ stabilization of polychlorinated biphenyls (PCBs). The test was performed on a tidal mud flat at South Basin, adjacent to the former Hunters Point Naval Shipyard, San Francisco Bay, CA. The major goals of the field study were to (1) assess scale up of the AC mixing technology using two available, large-scale devices, (2) validate the effectiveness of the AC amendment at the field scale, and (3) identify possible adverse effects of the remediation technology. Also, the test allowed comparison among monitoring tools, evaluation of longer-term effectiveness of AC amendment, and identification of field-related factors that confound the performance of in-situ biological assessments. Following background pretreatment measurements, we successfully incorporated AC into sediment to a nominal 30 cm depth during a single mixing event, as confirmed by total organic carbon and black carbon contents in the designated test plots. The measured AC dose averaged 2.0-3.2 wt% and varied depending on sampling locations and mixing equipment. AC amendment did not impact sediment resuspension or PCB release into the water column over the treatment plots, nor adversely impactthe existing macro benthic community composition, richness, or diversity. The PCB bioaccumulation in marine clams was reduced when exposed to sediment treated with 2% AC in comparison to the control plot Field-deployed semi permeable membrane devices and polyethylene devices showed about 50% reduction in PCB uptake in AC-treated sediment and similar reduction in estimated pore-water PCB concentration. This reduction was evident even after 13-month post-treatment with then 7 months of continuous exposure, indicating AC treatment efficacy was retained for an extended period. Aqueous equilibrium PCB concentrations and PCB desorption showed an AC-dose response. Field-exposed AC after 18 months retained a strong stabilization capability to reduce aqueous equilibrium PCB concentrations by about 90%, which also supports the long-term effectiveness of AC in the field. Additional mixing during or after AC deployment, increasing AC dose, reducing AC-particle size, and sequential deployment of AC dose will likely improve AC-sediment contact and overall effectiveness. The reductions in PCB availability observed with slow mass transfer under field conditions calls for predictive models to assess the long-term trends in pore-water PCB concentrations and the benefits of alternative in-situ AC application and mixing strategies.

Laboratory study of PCB transport from primary sources to settled dust

EPA Science Inventory

Transport of house dust and Arizona Test Dust on polychlorinated biphenyl (PCB)-containing panels and PCB-free panels was investigated in a 30-m3 stainless steel chamber. The PCB-containing panels were aluminum sheets coated with a PCB-spiked, oil-based primer or two-part polysul...

40 CFR 761.40 - Marking requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... illustrated in Figure 1 is referred to as ML throughout this subpart. (1) PCB Containers; (2) PCB Transformers...) Equipment containing a PCB Transformer or a PCB Large High Voltage Capacitor at the time of manufacture, at... this section); (8) Heat transfer systems (other than PCB Transformers) using PCBs (See also paragraph...

40 CFR 761.40 - Marking requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... illustrated in Figure 1 is referred to as ML throughout this subpart. (1) PCB Containers; (2) PCB Transformers...) Equipment containing a PCB Transformer or a PCB Large High Voltage Capacitor at the time of manufacture, at... this section); (8) Heat transfer systems (other than PCB Transformers) using PCBs (See also paragraph...

40 CFR 761.40 - Marking requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... illustrated in Figure 1 is referred to as ML throughout this subpart. (1) PCB Containers; (2) PCB Transformers...) Equipment containing a PCB Transformer or a PCB Large High Voltage Capacitor at the time of manufacture, at... this section); (8) Heat transfer systems (other than PCB Transformers) using PCBs (See also paragraph...

40 CFR 761.40 - Marking requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... illustrated in Figure 1 is referred to as ML throughout this subpart. (1) PCB Containers; (2) PCB Transformers...) Equipment containing a PCB Transformer or a PCB Large High Voltage Capacitor at the time of manufacture, at... this section); (8) Heat transfer systems (other than PCB Transformers) using PCBs (See also paragraph...

40 CFR 761.40 - Marking requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... illustrated in Figure 1 is referred to as ML throughout this subpart. (1) PCB Containers; (2) PCB Transformers...) Equipment containing a PCB Transformer or a PCB Large High Voltage Capacitor at the time of manufacture, at... this section); (8) Heat transfer systems (other than PCB Transformers) using PCBs (See also paragraph...

Distribution and transport of polychlorinated biphenyls in Little Lake Butte des Morts, Fox River, Wisconsin, April 1987-October 1988

USGS Publications Warehouse

House, L.B.

1995-01-01

The mass of PCB's transported from the lake in streamflow during 1987-88 was calculated to be 110 kilograms annually. The PCB's transport rate decreased 50 percent from 1987 to 1988, for the period April through September. Transport of PCB's was greatest during April and May of each year. The average flux rate of PCB's into the water column from the bottom sediment in the lake was estimated to be 1.2 milligrams per square meter per day. The PCB's load seems to increase at river discharges greater than 212 cubic meters per second. This increase in PCB's load might be caused by resuspension of PCB's-contaminated bottom-sediment deposits. There was little variation in PCB's load at flows less than 170 cubic meters per second. The bottom sediments are a continuing source of PCB's to Little Lake Butte des Morts and the lower Fox River.

Comparison of the in vitro effects of TCDD, PCB 126 and PCB 153 on thyroid-restricted gene expression and thyroid hormone secretion by the chicken thyroid gland.

PubMed

Katarzyńska, Dorota; Hrabia, Anna; Kowalik, Kinga; Sechman, Andrzej

2015-03-01

The aim of this study was to compare the in vitro effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3,3',4,4',5-pentachlorobiphenyl (PCB 126; a coplanar PCB congener) and 2,2'4,4',5,5'-hexachlorobiphenyl (PCB153; non-coplanar PCB) on mRNA expression of thyroid-restricted genes, i.e. sodium iodide symporter (NIS), thyroid peroxidase (TPO) and thyroglobulin (TG), and thyroid hormone secretion from the thyroid gland of the laying chicken. Relative expression levels of NIS, TG and TPO genes and thyroxine (T4) and triiodothyronine (T3) secretion from the thyroidal explants were quantified by the real-time qPCR and RIA methods, respectively. In comparison with the control group, TCDD and PCB 126 significantly increased mRNA expression of TPO and TG genes. TCDD did not affect NIS mRNA levels, but PCB 126 decreased its expression. No effect of PCB 153 on the expression of these genes was observed. TCDD and PCB 126 significantly decreased T4 and T3 secretion. There was no significant effect of PCB 153 on these hormone secretions. In conclusion, the results obtained show that in comparison with non-coplanar PCB 153, TCDD and coplanar PCB 126 can directly affect thyroid hormone synthesis and secretion, and in consequence, they may disrupt the endocrine function of the thyroid gland of the laying chicken. Copyright © 2015 Elsevier B.V. All rights reserved.

Microsomal Metabolism of Prochiral Polychlorinated Biphenyls Results in the Enantioselective Formation of Chiral Metabolites

PubMed Central

2016-01-01

Polychlorinated biphenyl (PCB) congeners with multiple ortho chlorine substituents and their metabolites exist as stable rotational isomers, or atropisomers, that are nonsuperimposable mirror images of each other. Additionally, the oxidation of certain axially prochiral PCBs, such as 2,2′,4,6′-tetrachlorobiphenyl (PCB 51) and 2,2′,4,5,6′-pentachlorobiphenyl (PCB 102), in the meta position of the symmetrically substituted phenyl ring is expected to form axially chiral hydroxylated metabolites (OH-PCBs); however, the formation of chiral OH-PCBs from prochiral PCBs has not been demonstrated experimentally. Here, we investigate if the oxidation of PCB 51 and PCB 102 by different microsomal preparations results in the formation of chiral OH-PCBs. Gas chromatographic analysis revealed that PCB 51 and PCB 102 were metabolized to 2,2′,4,6′-tetrachlorobiphenyl-3′-ol (OH-PCB 51) and 2,2′,4,5,6′-pentachlorobiphenyl-3′-ol (OH-PCB 102), respectively, by liver microsomes from male rats pretreated with different inducers; untreated male monkeys, guinea pigs, rabbits, and hamsters; and female dogs. The formation of both metabolites was inducer- and species-dependent. Both OH-PCB 51 and OH-PCB 102 were chiral and formed enantioselectively by all microsomal preparations investigated. These findings demonstrate that axially chiral PCB metabolites are formed from axially prochiral PCB congeners, a fact that should be considered when studying the environmental fate, transport, and toxicity of OH-PCBs. PMID:28038482

Developing tools for risk assessment in protected species: relative potencies inferred from competitive binding of halogenated aromatic hydrocarbons to aryl hydrocarbon receptors from beluga (Delphinapterus leucas) and mouse

PubMed Central

Jensen, Brenda A.; Reddy, Christopher M.; Nelson, Robert K.; Hahn, Mark E.

2011-01-01

Persistent organic pollutants such as halogenated aromatic hydrocarbons (HAHs) biomagnify in food webs and accumulate to high concentrations in top predators like odontocete cetaceans (toothed whales). The most toxic HAHs are the 2,3,7,8-substituted halogenated dibenzo-p-dioxins and furans, and non-ortho-substituted polychlorinated biphenyls (PCBs), which exert their effects via the aryl hydrocarbon receptor (AHR). Understanding the impact of HAHs in wildlife is limited by the lack of taxon-specific information about the relative potencies of toxicologically important congeners. To assess whether Toxic Equivalency Factors (TEFs) determined in rodents are predictive of HAH relative potencies in a cetacean, we used beluga and mouse AHRs expressed in vitro from cloned cDNAs to measure the relative AHR-binding affinities of ten HAHs from five different structural classes. The rank order of mean IC50s for competitive binding to beluga AHR was: TCDD

Developing tools for risk assessment in protected species: Relative potencies inferred from competitive binding of halogenated aromatic hydrocarbons to aryl hydrocarbon receptors from beluga (Delphinapterus leucas) and mouse.

PubMed

Jensen, Brenda A; Reddy, Christopher M; Nelson, Robert K; Hahn, Mark E

2010-11-01

Persistent organic pollutants such as halogenated aromatic hydrocarbons (HAHs) biomagnify in food webs and accumulate to high concentrations in top predators like odontocete cetaceans (toothed whales). The most toxic HAHs are the 2,3,7,8-substituted halogenated dibenzo-p-dioxins and furans, and non-ortho-substituted polychlorinated biphenyls (PCBs), which exert their effects via the aryl hydrocarbon receptor (AHR). Understanding the impact of HAHs in wildlife is limited by the lack of taxon-specific information about the relative potencies of toxicologically important congeners. To assess whether Toxic Equivalency Factors (TEFs) determined in rodents are predictive of HAH relative potencies in a cetacean, we used beluga and mouse AHRs expressed in vitro from cloned cDNAs to measure the relative AHR-binding affinities of ten HAHs from five different structural classes. The rank order of mean IC(50)s for competitive binding to beluga AHR was: TCDD

Analog signal processing for optical coherence imaging systems

NASA Astrophysics Data System (ADS)

Xu, Wei

Optical coherence tomography (OCT) and optical coherence microscopy (OCM) are non-invasive optical coherence imaging techniques, which enable micron-scale resolution, depth resolved imaging capability. Both OCT and OCM are based on Michelson interferometer theory. They are widely used in ophthalmology, gastroenterology and dermatology, because of their high resolution, safety and low cost. OCT creates cross sectional images whereas OCM obtains en face images. In this dissertation, the design and development of three increasingly complicated analog signal processing (ASP) solutions for optical coherence imaging are presented. The first ASP solution was implemented for a time domain OCT system with a Rapid Scanning Optical Delay line (RSOD)-based optical signal modulation and logarithmic amplifier (Log amp) based demodulation. This OCT system can acquire up to 1600 A-scans per second. The measured dynamic range is 106dB at 200A-scan per second. This OCT signal processing electronics includes an off-the-shelf filter box with a Log amp circuit implemented on a PCB board. The second ASP solution was developed for an OCM system with synchronized modulation and demodulation and compensation for interferometer phase drift. This OCM acquired micron-scale resolution, high dynamic range images at acquisition speeds up to 45,000 pixels/second. This OCM ASP solution is fully custom designed on a perforated circuit board. The third ASP solution was implemented on a single 2.2 mm x 2.2 mm complementary metal oxide semiconductor (CMOS) chip. This design is expandable to a multiple channel OCT system. A single on-chip CMOS photodetector and ASP channel was used for coherent demodulation in a time domain OCT system. Cross-sectional images were acquired with a dynamic range of 76dB (limited by photodetector responsivity). When incorporated with a bump-bonded InGaAs photodiode with higher responsivity, the expected dynamic range is close to 100dB.

An Optimization System with Parallel Processing for Reducing Common-Mode Current on Electronic Control Unit

NASA Astrophysics Data System (ADS)

Okazaki, Yuji; Uno, Takanori; Asai, Hideki

In this paper, we propose an optimization system with parallel processing for reducing electromagnetic interference (EMI) on electronic control unit (ECU). We adopt simulated annealing (SA), genetic algorithm (GA) and taboo search (TS) to seek optimal solutions, and a Spice-like circuit simulator to analyze common-mode current. Therefore, the proposed system can determine the adequate combinations of the parasitic inductance and capacitance values on printed circuit board (PCB) efficiently and practically, to reduce EMI caused by the common-mode current. Finally, we apply the proposed system to an example circuit to verify the validity and efficiency of the system.

The Design and Optimization of a Highly Sensitive and Overload-Resistant Piezoresistive Pressure Sensor

PubMed Central

Meng, Xiawei; Zhao, Yulong

2016-01-01

A piezoresistive pressure sensor with a beam-membrane-dual-island structure is developed for micro-pressure monitoring in the field of aviation, which requires great sensitivity and overload resistance capacity. The design, fabrication, and test of the sensor are presented in this paper. By analyzing the stress distribution of sensitive elements using the finite element method, a novel structure incorporating sensitive beams with a traditional bossed diaphragm is built up. The proposed structure proved to be advantageous in terms of high sensitivity and high overload resistance compared with the conventional bossed diaphragm and flat diaphragm structures. Curve fittings of surface stress and deflection based on ANSYS simulation results are performed to establish the sensor equations. Fabricated on an n-type single crystal silicon wafer, the sensor chips are wire-bonded to a printed circuit board (PCB) and packaged for experiments. The static and dynamic characteristics are tested and discussed. Experimental results show that the sensor has a sensitivity as high as 17.339 μV/V/Pa in the range of 500 Pa at room temperature, and a high overload resistance of 200 times overpressure. Due to the excellent performance, the sensor can be applied in measuring micro-pressure lower than 500 Pa. PMID:27005627

Serum levels of environmental pollutants is a risk factor for breast cancer in Inuit: a case control study.

PubMed

Wielsøe, Maria; Kern, Peder; Bonefeld-Jørgensen, Eva Cecilie

2017-06-13

Environmental Persistent Organic Pollutants (POPs) can alter the hormone homeostasis by mimicking, interfering or blocking the function of hormones; moreover POPs are hypothesized to modify the risk of breast cancer. The association between POPs and breast cancer has been widely studied but the conclusions are inconsistent. The present study examined the associations between serum levels of POPs and breast cancer with focus on the highly exposed Greenlandic Inuit population. The study design was a case-control study of Inuit women from Greenland. The participants were asked to complete a questionnaire with information on reproductive history and lifestyle and to provide a blood sample. The sampling was carried out in two time periods (2000-2003 and 2011-2014). The serum levels were determined of 14 polychlorinated biphenyls (PCBs), 11 organochlorine pesticides (OCPs), 16 perfluoroalkyl acids (PFAAs), 1 polybrominated biphenyl (PBB), and 9 polybrominated diphenyl ethers (PBDEs). Independent samples t-test was used to compare differences between cases and controls and odds ratios (OR) adjusted for identified confounders were obtained using logistic regression. The study population included 77 breast cancer cases and 84 controls. The majority of the measured compounds declined significantly from 2000 - 2003 to 2011-2014. However, for the perfluorinated carboxylic acids (PFCAs) an increase was observed. The serum levels were significantly higher in cases compared to controls for the majority of the compounds, and after adjusting for age the difference was maintained for ∑OCP, dichlorodiphenyldichloroethylene (p,p'-DDE), ∑PFAA, ∑perfluorinated sulfonic acids (PFSA), perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS). For the lipophilic POPs, high serum levels (middel/highest vs. lowest tertile) of ∑PCB, ∑estrgoenicPCB, PCB99, PCB138, PCB153, PCB170, PCB170, and PCB183 was associated with breast cancer risk; for the amphiphilic PFAAs, high serum levels of ∑PFAA, ∑PFCA, ∑PFSA, perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), PFHxS, and PFOS were associated with breast cancer risk. Significant, positive associations between breast cancer risk and PCBs and PFAAs were observed. The associations indicate that environmental exposure to POPs can be a factor increasing the risk for breast cancer in Inuit women.

Differences in energy expenditures and growth dilution explain higher PCB concentrations in male summer flounder

USGS Publications Warehouse

Madenjian, Charles P.; Jensen, Olaf P.; Rediske, Richard R.; O'Keefe, James P.; Vastano, Anthony R.; Pothoven, Steven A.

2016-01-01

Comparison of polychlorinated biphenyl (PCB) concentrations between the sexes of mature fish may reveal important behavioral and physiological differences between the sexes. We determined whole-fish PCB concentrations in 23 female summer flounder Paralichthys dentatus and 27 male summer flounder from New Jersey coastal waters. To investigate the potential for differences in diet or habitat utilization between the sexes, carbon and nitrogen stable isotope ratios were also determined. In 5 of the 23 female summer flounder, PCB concentrations in the somatic tissue and ovaries were determined. In addition, we used bioenergetics modeling to assess the contribution of the growth dilution effect to the observed difference in PCB concentrations between the sexes. Whole-fish PCB concentrations for females and males averaged 87 and 124 ng/g, respectively; thus males were 43% higher in PCB concentration compared with females. Carbon and nitrogen stable isotope ratios did not significantly differ between the sexes, suggesting that diet composition and habitat utilization did not vary between the sexes. Based on PCB determinations in the somatic tissue and ovaries, we predicted that PCB concentration of females would increase by 0.6%, on average, immediately after spawning due to release of eggs. Thus, the change in PCB concentration due to release of eggs did not explain the higher PCB concentrations observed in males. Bioenergetics modeling results indicated that the growth dilution effect could account for males being 19% higher in PCB concentration compared with females. Thus, the bulk of the observed difference in PCB concentrations between the sexes was not explained by growth dilution. We concluded that a higher rate of energy expenditure in males, stemming from greater activity and a greater resting metabolic rate, was most likely the primary driver for the observed difference in PCB concentrations between the sexes.

Differences in Energy Expenditures and Growth Dilution Explain Higher PCB Concentrations in Male Summer Flounder.

PubMed

Madenjian, Charles P; Jensen, Olaf P; Rediske, Richard R; O'Keefe, James P; Vastano, Anthony R; Pothoven, Steven A

2016-01-01

Comparison of polychlorinated biphenyl (PCB) concentrations between the sexes of mature fish may reveal important behavioral and physiological differences between the sexes. We determined whole-fish PCB concentrations in 23 female summer flounder Paralichthys dentatus and 27 male summer flounder from New Jersey coastal waters. To investigate the potential for differences in diet or habitat utilization between the sexes, carbon and nitrogen stable isotope ratios were also determined. In 5 of the 23 female summer flounder, PCB concentrations in the somatic tissue and ovaries were determined. In addition, we used bioenergetics modeling to assess the contribution of the growth dilution effect to the observed difference in PCB concentrations between the sexes. Whole-fish PCB concentrations for females and males averaged 87 and 124 ng/g, respectively; thus males were 43% higher in PCB concentration compared with females. Carbon and nitrogen stable isotope ratios did not significantly differ between the sexes, suggesting that diet composition and habitat utilization did not vary between the sexes. Based on PCB determinations in the somatic tissue and ovaries, we predicted that PCB concentration of females would increase by 0.6%, on average, immediately after spawning due to release of eggs. Thus, the change in PCB concentration due to release of eggs did not explain the higher PCB concentrations observed in males. Bioenergetics modeling results indicated that the growth dilution effect could account for males being 19% higher in PCB concentration compared with females. Thus, the bulk of the observed difference in PCB concentrations between the sexes was not explained by growth dilution. We concluded that a higher rate of energy expenditure in males, stemming from greater activity and a greater resting metabolic rate, was most likely the primary driver for the observed difference in PCB concentrations between the sexes.

PCB 136 Atropselectively Alters Morphometric and Functional Parameters of Neuronal Connectivity in Cultured Rat Hippocampal Neurons via Ryanodine Receptor-Dependent Mechanisms

PubMed Central

Yang, Dongren; Kania-Korwel, Izabela; Ghogha, Atefeh; Chen, Hao; Stamou, Marianna; Bose, Diptiman D.; Pessah, Isaac N.; Lehmler, Hans-Joachim; Lein, Pamela J.

2014-01-01

We recently demonstrated that polychlorinated biphenyl (PCB) congeners with multiple ortho chlorine substitutions sensitize ryanodine receptors (RyRs), and this activity promotes Ca2+-dependent dendritic growth in cultured neurons. Many ortho-substituted congeners display axial chirality, and we previously reported that the chiral congener PCB 136 (2,2′,3,3′,6,6′-hexachlorobiphenyl) atropselectively sensitizes RyRs. Here, we test the hypothesis that PCB 136 atropisomers differentially alter dendritic growth and other parameters of neuronal connectivity influenced by RyR activity. (−)-PCB 136, which potently sensitizes RyRs, enhances dendritic growth in primary cultures of rat hippocampal neurons, whereas (+)-PCB 136, which lacks RyR activity, has no effect on dendritic growth. The dendrite-promoting activity of (−)-PCB 136 is observed at concentrations ranging from 0.1 to 100nM and is blocked by pharmacologic RyR antagonism. Neither atropisomer alters axonal growth or cell viability. Quantification of PCB 136 atropisomers in hippocampal cultures indicates that atropselective effects on dendritic growth are not due to differential partitioning of atropisomers into cultured cells. Imaging of hippocampal neurons loaded with Ca2+-sensitive dye demonstrates that (−)-PCB 136 but not (+)-PCB 136 increases the frequency of spontaneous Ca2+ oscillations. Similarly, (−)-PCB 136 but not (+)-PCB 136 increases the activity of hippocampal neurons plated on microelectrode arrays. These data support the hypothesis that atropselective effects on RyR activity translate into atropselective effects of PCB 136 atropisomers on neuronal connectivity, and suggest that the variable atropisomeric enrichment of chiral PCBs observed in the human population may be a significant determinant of individual susceptibility for adverse neurodevelopmental outcomes following PCB exposure. PMID:24385416

Editor's Highlight: Congener-Specific Disposition of Chiral Polychlorinated Biphenyls in Lactating Mice and Their Offspring: Implications for PCB Developmental Neurotoxicity.

PubMed

Kania-Korwel, Izabela; Lukasiewicz, Tracy; Barnhart, Christopher D; Stamou, Marianna; Chung, Haeun; Kelly, Kevin M; Bandiera, Stelvio; Lein, Pamela J; Lehmler, Hans-Joachim

2017-07-01

Chiral polychlorinated biphenyl (PCB) congeners have been implicated by laboratory and epidemiological studies in PCB developmental neurotoxicity. These congeners are metabolized by cytochrome P450 (P450) enzymes to potentially neurotoxic hydroxylated metabolites (OH-PCBs). The present study explores the enantioselective disposition and toxicity of 2 environmentally relevant, neurotoxic PCB congeners and their OH-PCB metabolites in lactating mice and their offspring following dietary exposure of the dam. Female C57BL/6N mice (8-weeks old) were fed daily, beginning 2 weeks prior to conception and continuing throughout gestation and lactation, with 3.1 µmol/kg bw/d of racemic 2,2',3,5',6-pentachlorobiphenyl (PCB 95) or 2,2',3,3',6,6'-hexachlorobiphenyl (PCB 136) in peanut butter; controls received vehicle (peanut oil) in peanut butter. PCB 95 levels were higher than PCB 136 levels in both dams and pups, consistent with the more rapid metabolism of PCB 136 compared with PCB 95. In pups and dams, both congeners were enriched for the enantiomer eluting second on enantioselective gas chromatography columns. OH-PCB profiles in lactating mice and their offspring were complex and varied according to congener, tissue and age. Developmental exposure to PCB 95 versus PCB 136 differentially affected the expression of P450 enzymes as well as neural plasticity (arc and ppp1r9b) and thyroid hormone-responsive genes (nrgn and mbp). The results suggest that the enantioselective metabolism of PCBs to OH-PCBs may influence neurotoxic outcomes following developmental exposures, a hypothesis that warrants further investigation. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Differences in Energy Expenditures and Growth Dilution Explain Higher PCB Concentrations in Male Summer Flounder

PubMed Central

Madenjian, Charles P.; Jensen, Olaf P.; Rediske, Richard R.; O’Keefe, James P.; Vastano, Anthony R.; Pothoven, Steven A.

2016-01-01

Comparison of polychlorinated biphenyl (PCB) concentrations between the sexes of mature fish may reveal important behavioral and physiological differences between the sexes. We determined whole-fish PCB concentrations in 23 female summer flounder Paralichthys dentatus and 27 male summer flounder from New Jersey coastal waters. To investigate the potential for differences in diet or habitat utilization between the sexes, carbon and nitrogen stable isotope ratios were also determined. In 5 of the 23 female summer flounder, PCB concentrations in the somatic tissue and ovaries were determined. In addition, we used bioenergetics modeling to assess the contribution of the growth dilution effect to the observed difference in PCB concentrations between the sexes. Whole-fish PCB concentrations for females and males averaged 87 and 124 ng/g, respectively; thus males were 43% higher in PCB concentration compared with females. Carbon and nitrogen stable isotope ratios did not significantly differ between the sexes, suggesting that diet composition and habitat utilization did not vary between the sexes. Based on PCB determinations in the somatic tissue and ovaries, we predicted that PCB concentration of females would increase by 0.6%, on average, immediately after spawning due to release of eggs. Thus, the change in PCB concentration due to release of eggs did not explain the higher PCB concentrations observed in males. Bioenergetics modeling results indicated that the growth dilution effect could account for males being 19% higher in PCB concentration compared with females. Thus, the bulk of the observed difference in PCB concentrations between the sexes was not explained by growth dilution. We concluded that a higher rate of energy expenditure in males, stemming from greater activity and a greater resting metabolic rate, was most likely the primary driver for the observed difference in PCB concentrations between the sexes. PMID:26794728

Photo-assisted electrochemical degradation of polychlorinated biphenyls with boron-doped diamond electrodes.

PubMed

Gutiérrez-Hernández, Rubén F; Bello-Mendoza, Ricardo; Hernández-Ramírez, Aracely; Malo, Edi A; Nájera-Aguilar, Hugo A

2017-09-19

The capacity of the photo electro-Fenton (PEF) process to degrade a mixture of seven polychlorinated biphenyl (PCB) congeners was studied. Boron-doped diamond (BDD) sheets were used as anode and cathode in the experimental electrolytic cell that contained Na 2 SO 4 0.05 M at pH 3 as supporting electrolyte for the electro generation of H 2 O 2 at the cathode. The effects of UV light intensity (254 and 365 nm), current density (8, 16 and 24 mA cm -2 ) and ferrous ion dosage (0.1, 0.2 and 0.3 mM) on PCB (C 0 = 50 μg L -1 ) degradation were evaluated. The highest level of PCB degradation (97%) was achieved with 16 mA cm -2 of current density, 0.1 mM of ferrous ion and UV light at 365 nm as irradiation source after 6 h of reaction. PCB28, PCB52 and PCB101 were not detected after 0.5, 1.5 and 3 h of reaction, respectively. The degradation of PCB138, PCB153, PCB180 and PCB209 was also high (>95%). The PEF system outperformed other oxidation processes (electro-Fenton, anodic oxidation, Fenton, photo-Fenton and UV photolysis) in terms of reaction rate and degradation efficiency. These results demonstrate for the first time the degradation of PCB209, the most highly chlorinated PCB congener, by an advanced electrochemical oxidation process.

An overlooked environmental issue? A review of the inadvertent formation of PCB-11 and other PCB congeners and their occurrence in consumer products and in the environment.

PubMed

Vorkamp, Katrin

2016-01-15

Polychlorinated biphenyls (PCBs) are banned from production and use in most countries as they are persistent organic pollutants (POPs) of concern for environment and health. Recent research has pointed at a new environment issue resulting from the inadvertent formation of PCBs in certain processes, in particular the pigment production. PCB-11 is a major by-product in these processes, but PCB-28, PCB-52, PCB-77 as well as the nonachlorinated PCBs and PCB-209 have been found in pigments and consumer products as well. In addition to environmental emissions via point sources, in particular related to industrial and municipal wastewater, atmospheric transport seems to be important for the global distribution of PCB-11. Thus, PCB-11 has also been detected in the polar regions. Worldwide air concentrations appear relatively uniform, but maxima have been found in urban and industrialised areas. Data on the uptake and accumulation of PCB-11 in the food chain are still inconclusive: Although food web studies do not show biomagnification, PCB-11 has been detected in humans. The human exposure might originate from the direct contact to consumer products as well as from the omnipresence of PCB-11 in the environment. Copyright © 2015 Elsevier B.V. All rights reserved.

Laboratory study of PCB transport from primary sources to ...

EPA Pesticide Factsheets

Transport of house dust and Arizona Test Dust on polychlorinated biphenyl (PCB)-containing panels and PCB-free panels was investigated in a 30-m3 stainless steel chamber. The PCB-containing panels were aluminum sheets coated with a PCB-spiked, oil-based primer or two-part polysulfide caulk. The PCB-free panels were coated with the same materials but they were not spiked with PCBs. The dust was weighed and spread on the panels as evenly as possible. The dust on each panel was collected at different times to determine its PCB content. The dust data collected from the PCB panels were used to evaluate the PCB migration from the source to the dust through direct contact, and the data from the PCB-free panels were used to evaluate the sorption of PCBs through the dust/air partition. Settled dust can adsorb PCBs from air. The sorption concentration was dependent on the congener concentration in the air and favored less volatile congeners. When the house dust was in direct contact with a primary source, PCBs migrated into the dust at a much faster rate than the PCB transfer rate due to the dust/air partition. Unlike the dust/air partition, the dust/source partition was not significantly affected by the volatility of the congener. This research is important to decision makers, environmental engineers, and researchers who are concerned with risk assessment and risk management for PCB contamination.

40 CFR 761.180 - Records and monitoring.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PCBs contained in PCB Container(s), or one or more PCB Transformers, or 50 or more PCB Large High or...., transformer or capacitor), the weight in kilograms of the PCB waste in each transformer or capacitor, the date... the calendar year. (iv) The total number of PCB Transformers and total weight in kilograms of PCBs...

40 CFR 761.180 - Records and monitoring.

Code of Federal Regulations, 2014 CFR

2014-07-01

... PCBs contained in PCB Container(s), or one or more PCB Transformers, or 50 or more PCB Large High or...., transformer or capacitor), the weight in kilograms of the PCB waste in each transformer or capacitor, the date... the calendar year. (iv) The total number of PCB Transformers and total weight in kilograms of PCBs...

40 CFR 761.180 - Records and monitoring.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PCBs contained in PCB Container(s), or one or more PCB Transformers, or 50 or more PCB Large High or...., transformer or capacitor), the weight in kilograms of the PCB waste in each transformer or capacitor, the date... the calendar year. (iv) The total number of PCB Transformers and total weight in kilograms of PCBs...

40 CFR 761.180 - Records and monitoring.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PCBs contained in PCB Container(s), or one or more PCB Transformers, or 50 or more PCB Large High or...., transformer or capacitor), the weight in kilograms of the PCB waste in each transformer or capacitor, the date... the calendar year. (iv) The total number of PCB Transformers and total weight in kilograms of PCBs...

40 CFR 761.180 - Records and monitoring.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PCBs contained in PCB Container(s), or one or more PCB Transformers, or 50 or more PCB Large High or...., transformer or capacitor), the weight in kilograms of the PCB waste in each transformer or capacitor, the date... the calendar year. (iv) The total number of PCB Transformers and total weight in kilograms of PCBs...

40 CFR 761.208 - Use of the manifest.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROHIBITIONS PCB Waste Disposal Records and Reports § 761.208 Use of the manifest. (a)(1) The generator of PCB... accompany the shipment of PCB waste. (2) For bulk shipments of PCB waste within the United States... PCB waste within the United States which originate at the site of generation, the generator shall send...

40 CFR 761.359 - Reporting the PCB concentrations in samples.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Reporting the PCB concentrations in... COMMERCE, AND USE PROHIBITIONS Sampling Non-Liquid, Non-Metal PCB Bulk Product Waste for Purposes of Characterization for PCB Disposal in Accordance With § 761.62, and Sampling PCB Remediation Waste Destined for Off...

40 CFR 761.63 - PCB household waste storage and disposal.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false PCB household waste storage and..., AND USE PROHIBITIONS Storage and Disposal § 761.63 PCB household waste storage and disposal. PCB... to manage municipal or industrial solid waste, or in a facility with an approval to dispose of PCB...

40 CFR 761.358 - Determining the PCB concentration of samples of waste.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Determining the PCB concentration of..., DISTRIBUTION IN COMMERCE, AND USE PROHIBITIONS Sampling Non-Liquid, Non-Metal PCB Bulk Product Waste for Purposes of Characterization for PCB Disposal in Accordance With § 761.62, and Sampling PCB Remediation...

Serum concentrations of persistent organic pollutants (POPs) in the inhabitants of a Sicilian city.

PubMed

Amodio, Emanuele; Turci, Roberta; Massenti, Maria Fatima; Di Gaudio, Francesca; Minoia, Claudio; Vitale, Francesco; Firenze, Alberto; Calamusa, Giuseppe

2012-11-01

Polychlorinated biphenyls (PCBs) and organochlorine pesticides are common environmental contaminants that have been associated with human health problems. To assess serum concentrations of several organochlorine contaminants in general population living in a city with an ancient agricultural tradition and to identify possible exposure sources in Sicily. A cross-sectional study was conducted on 101 individuals. Each participant answered a face-to-face questionnaire submitted by well-trained personnel and provided a serum sample which was analyzed for the concentrations of PCBs, HCB, HCHs and DDTs by using gas-chromatography coupled with mass spectrometry. HCB, p,p'-DDE, PCB 138, PCB 153 and PCB 180 were detected in more than 80% of the study participants. The ng g(-1) lipid median concentrations were: 18.6 for HCB; 175.1 for p,p'-DDE; 22. for PCB 138; 32.5 for PCB 153 and 23.0 for PCB 180. PCB 153 and PCB 138, PCB 138 and PCB 180, PCB 153 and PCB 180, and p,p'-DDE and HCB showed a high correlation each other (p<0.05). HCB and p,p'-DDE concentrations were significantly higher in subjects >49 years old (adj-p=0.03 in 50-69 years old and adj-p<0.001 in >69 years old, respectively) whereas PCB 138, PCB 153 and PCB 180 concentrations were higher in males (adj-p=0.03), in subjects >69 years old (adj-p=0.04) and in current smokers (adj-p=0.04). The present study shows that serum concentrations of organochlorine compounds detected in subjects living in a small Sicilian city with ancient agricultural tradition are similar to those found in subjects living in urban areas of other countries. However, further investigations are needed to compare data from rural/urban areas in the same country, assessing correlations between serum concentrations of several chemical compounds and potential health effects in general population. Copyright © 2012 Elsevier Ltd. All rights reserved.

40 CFR 761.65 - Storage for disposal.

Code of Federal Regulations, 2011 CFR

2011-07-01

... storage of non-liquid PCB/ radioactive wastes must be designed to prevent the buildup of liquids if such... conditions: (i) The waste is placed in a pile designed and operated to control dispersal of the waste by wind...) A run-on control system designed, constructed, operated, and maintained such that: (1) It prevents...

Determination of the partition coefficient between dissolved organic carbon and seawater using differential equilibrium kinetics.

PubMed

Kim, Du Yung; Kwon, Jung-Hwan

2018-05-04

Because the freely dissolved fraction of highly hydrophobic organic chemicals is bioavailable, knowing the partition coefficient between dissolved organic carbon and water (K DOCw ) is crucial to estimate the freely dissolved fraction from the total concentration. A kinetic method was developed to obtain K DOCw that required a shorter experimental time than equilibrium methods. The equilibrium partition coefficients of four polychlorinated biphenyls (PCBs) (2,4,4'-trichlorobiphenyl (PCB 28), 2,2',3,5'-tetrachlorobiphenyl (PCB 44), 2,2',4,5,5'-pentachlorobiphenyl (PCB 101), and 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153)) between dissolved organic carbon and seawater (K DOCsw ) were determined using seawater samples from the Korean coast. The log K DOCsw values of PCB 28 were measured by equilibrating PCB 28, the least hydrophobic congener, with seawater samples, and the values ranged from 6.60 to 7.20. For the more hydrophobic PCBs (PCB 44, PCB 101, and PCB 153), kinetic experiments were conducted to determine the sorption rate constants (k 2 ) and their log K DOCsw values were obtained by comparing their k 2 with that of PCB 28. The calculated log K DOCsw values were 6.57-7.35 for PCB 44, 6.23-7.44 for PCB 101, and 6.35-7.73 for PCB 153. The validity of the proposed method was further confirmed using three less hydrophobic polycyclic aromatic hydrocarbons. This kinetic method shortened the experimental time to obtain the K DOCsw values of the more hydrophobic PCBs, which did not reach phase equilibrium. Copyright © 2018 Elsevier Ltd. All rights reserved.

Identification of a sulfate metabolite of PCB 11 in human serum

PubMed Central

Grimm, Fabian A.; Lehmler, Hans-Joachim; Koh, Wen Xin; DeWall, Jeanne; Teesch, Lynn M.; Hornbuckle, Keri C.; Thorne, Peter S.; Robertson, Larry W.; Duffel, Michael W.

2016-01-01

Despite increasing evidence for a major role for sulfation in the metabolism of lower-chlorinated polychlorinated biphenyls in vitro and in vivo, and initial evidence for potential bioactivities of the resulting sulfate ester metabolites, the formation of PCB sulfates in PCB exposed human populations had not been explored. The primary goal of this study was to determine if PCB sulfates, and potentially other conjugated PCB derivatives, are relevant classes of PCB metabolites in the serum of humans with known exposures to PCBs. In order to detect and quantify dichlorinated PCB sulfates in serum samples of 46 PCB-exposed individuals from either rural or urban communities, we developed a high-resolution mass spectrometry-based protocol using 4-PCB 11 sulfate as a model compound. The method also allowed the preliminary analysis of these 46 human serum extracts for the presence of other metabolites, such as glucuronic acid conjugates and hydroxylated PCBs. Sulfate ester metabolites derived from dichlorinated PCBs were detectable and quantifiable in more than 20 % of analyzed serum samples. Moreover, we were able to utilize this method to detect PCB glucuronides and hydroxylated PCBs, albeit at lower frequencies than PCB sulfates. Altogether, our results provide initial evidence for the presence of PCB sulfates in human serum. Considering the inability of previously employed analytical protocols for PCBs to extract these sulfate ester metabolites and the concentrations of these metabolites observed in our current study, our data support the hypothesis that total serum levels of PCB metabolites in exposed individuals may have been underestimated in the past. PMID:27816204

Identification of a sulfate metabolite of PCB 11 in human serum.

PubMed

Grimm, Fabian A; Lehmler, Hans-Joachim; Koh, Wen Xin; DeWall, Jeanne; Teesch, Lynn M; Hornbuckle, Keri C; Thorne, Peter S; Robertson, Larry W; Duffel, Michael W

2017-01-01

Despite increasing evidence for a major role for sulfation in the metabolism of lower-chlorinated polychlorinated biphenyls in vitro and in vivo, and initial evidence for potential bioactivities of the resulting sulfate ester metabolites, the formation of PCB sulfates in PCB exposed human populations had not been explored. The primary goal of this study was to determine if PCB sulfates, and potentially other conjugated PCB derivatives, are relevant classes of PCB metabolites in the serum of humans with known exposures to PCBs. In order to detect and quantify dichlorinated PCB sulfates in serum samples of 46 PCB-exposed individuals from either rural or urban communities, we developed a high-resolution mass spectrometry-based protocol using 4-PCB 11 sulfate as a model compound. The method also allowed the preliminary analysis of these 46 human serum extracts for the presence of other metabolites, such as glucuronic acid conjugates and hydroxylated PCBs. Sulfate ester metabolites derived from dichlorinated PCBs were detectable and quantifiable in more than 20% of analyzed serum samples. Moreover, we were able to utilize this method to detect PCB glucuronides and hydroxylated PCBs, albeit at lower frequencies than PCB sulfates. Altogether, our results provide initial evidence for the presence of PCB sulfates in human serum. Considering the inability of previously employed analytical protocols for PCBs to extract these sulfate ester metabolites and the concentrations of these metabolites observed in our current study, our data support the hypothesis that total serum levels of PCB metabolites in exposed individuals may have been underestimated in the past. Copyright © 2016 Elsevier Ltd. All rights reserved.

Contamination by polychlorinated biphenyls (PCBs) in striped dolphins (Stenella coeruleoalba) from the Southeastern Mediterranean Sea.

PubMed

Storelli, Maria Maddalena; Barone, Grazia; Giacominelli-Stuffler, Roberto; Marcotrigiano, Giuseppe Onofrio

2012-09-01

Concentrations of polychlorinated biphenyls (PCBs) including dioxin-like PCBs (non-ortho, PCB 77, PCB 126, and PCB 169 and mono-ortho, PCB 105, PCB 118, and PCB 156) were measured in different organs and tissues (melon, blubber, liver, kidney, lung, heart, and muscle tissue) of striped dolphins (Stenella coeruleoalba) from the Eastern Mediterranean Sea (Adriatic Sea). The mean highest levels were in blubber and melon, followed by liver, kidney, lung, heart, and muscle tissue. PCB profiles were similar in all tissues and organs being dominated by the higher chlorinated homologues (hexa-CBs, 55.8-62.1%; penta-CBs, 15.4-20.0%; and hepta-CB PCB 180, 12.7-16.5%). Major PCBs in all tissues were congeners 138 and 153 collectively accounting for 50.6-58.3% of the total PCB concentrations, followed by PCB 101, 105, 118, and 180 constituting from 27.0% to 31.0%. PCB levels were higher in adult males than in adult females. The estimated 2,3,7,8-TCDD toxic equivalents of non- and mono-ortho PCBs were much higher than the threshold level above which adverse effects have been observed in other marine mammals species, suggesting that striped dolphins in this region are at risk for toxic effects.

Organochlorine contaminant concentrations in multiple tissues of free-ranging Steller sea lions (Eumetopias jubatus) in Alaska.

PubMed

Beckmen, Kimberlee B; Keogh, Mandy J; Burek-Huntington, Kathleen A; Ylitalo, Gina M; Fadely, Brian S; Pitcher, Kenneth W

2016-01-15

The relationships of selected organochlorine (OC) contaminants between blubber, blood, feces, and milk of young, free-ranging Steller sea lions (Eumetopias jubatus) were examined. Both between and within each tissue there was considerable individual variation. In spite of the variation, similar patterns were observed across the tissues for most of the selected PCB congeners. In all four tissues, the major PCB congeners were PCB101, PCB118, PCB138, and PCB153. The most prominent congener, both as a weight (ng/g lipid) and as a percentage of summed PCBs (∑PCBs), was PCB 153. Comparisons between paired tissues showed that ∑DDTs in blubber samples were related to concentrations in blood, feces, and milk. The ∑PCBs in blubber were related to concentrations in milk and fecal samples, though the relationship with feces was weak. Our findings show milk samples, in particular, are useful for assessing OCs in young sea lions. Blubber concentrations of PCB101, PCB118, and PCB138 were an order of magnitude higher than those in milk, supporting the biomagnification of these PCB congeners in SSL tissues. The findings indicate alternative tissues may be used as indicators of relative contaminant exposure in lieu of surgical blubber biopsy. Copyright © 2015 Elsevier B.V. All rights reserved.

Enantio-alteration of gene transcription associated with bioconcentration in adult zebrafish (Danio rerio) exposed to chiral PCB149

NASA Astrophysics Data System (ADS)

Chai, Tingting; Cui, Feng; Mu, Pengqian; Yang, Yang; Xu, Nana; Yin, Zhiqiang; Jia, Qi; Yang, Shuming; Qiu, Jing; Wang, Chengju

2016-01-01

Enantioselective enrichment of chiral PCB149 (2,2’,3,4’,5’,6-hexachlorobiphenyl) was analysed in adult zebrafish (Danio rerio) exposed to the racemate, (-)-PCB149, and (+)-PCB149. Greater enrichment of (-)-PCB149 compared to (+) PCB149 was observed following 0.5 ng/L exposure; however, as the exposure time and concentration increased, racemic enrichment was observed in adult fish exposed to the racemate. No biotransformation between the two isomers was observed in fish exposed to single enantiomers. When zebrafish were exposed to different forms of chiral PCB149, enantioselective expression of genes associated with polychlorinated biphenyls (PCBs) was observed in brain and liver tissues and enantioselective correlations between bioconcentration and target gene expression levels were observed in brain and liver tissues. The strong positive correlations between expression levels of target genes (alox5a and alox12) and PCB149 bioconcentration suggest that prolonged exposure to the racemate of chiral PCB149 may result in inflammation-associated diseases. Prolonged exposure to (-)-PCB149 may also affect metabolic pathways such as dehydrogenation and methylation in the brain tissues of adult zebrafish. Hepatic expression levels of genes related to the antioxidant system were significantly negatively correlated with bioconcentration following exposure to (+)-PCB149.

New CYP1 genes in the frog Xenopus (Silurana) tropicalis: Induction patterns and effects of AHR agonists during development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joensson, Maria E., E-mail: maria.jonsson@ebc.uu.se; Biology Department, Redfield 3-42 MS 32, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543; Berg, Cecilia

2011-01-15

The Xenopus tropicalis genome shows a single gene in each of the four cytochrome P450 1 (CYP1) subfamilies that occur in vertebrates, designated as CYP1A, CYP1B1, CYP1C1, and CYP1D1. We cloned the cDNAs of these genes and examined their expression in untreated tadpoles and in tadpoles exposed to waterborne aryl hydrocarbon receptor agonists, 3,3',4,4',5-pentachlorobiphenyl (PCB126), {beta}-naphthoflavone ({beta}NF), or indigo. We also examined the effects of PCB126 on expression of genes involved in stress response, cell proliferation, thyroid homeostasis, and prostaglandin synthesis. PCB126 induced CYP1A, CYP1B1, and CYP1C1 but had little effect on CYP1D1 (77-, 1.7-, 4.6- and 1.4-fold induction versusmore » the control, respectively). {beta}NF induced CYP1A and CYP1C1 (26- and 2.5-fold), while, under conditions used, indigo tended to induce only CYP1A (1.9-fold). The extent of CYP1 induction by PCB126 and {beta}NF was positively correlated to the number of putative dioxin response elements 0-20 kb upstream of the start codons. No morphological effect was observed in tadpoles exposed to 1 nM-10 {mu}M PCB126 at two days post-fertilization (dpf) and screened 20 days later. However, in 14-dpf tadpoles a slight up-regulation of the genes for PCNA, transthyretin, HSC70, Cu-Zn SOD, and Cox-2 was observed two days after exposure to 1 {mu}M PCB126. This study of the full suite of CYP1 genes in an amphibian species reveals gene- and AHR agonist-specific differences in response, as well as a much lower sensitivity to CYP1 induction and short-term toxicity by PCB126 compared with in fish larvae. The single genes in each CYP1 subfamily may make X. tropicalis a useful model for mechanistic studies of CYP1 functions.« less

Compound- and sex-specific effects on programming of energy and immune homeostasis in adult C57BL/6JxFVB mice after perinatal TCDD and PCB 153

DOE Office of Scientific and Technical Information (OSTI.GOV)

Esterik, J.C.J. van, E-mail: joantine.van.esterik@rivm.nl; Department of Chemistry and Biology, Institute for Environmental Studies; Verharen, H.W., E-mail: henny.verharen@rivm.nl

Early life exposure to endocrine disrupting compounds has been linked to chronic diseases later in life, like obesity and related metabolic disorders. We exposed C57BL/6JxFVB hybrid mice to the aryl hydrocarbon receptor agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and the constitutive androstane receptor/pregnane X receptor agonist polychlorinated biphenyl 153 (PCB 153) in an experimental design relevant for human exposure. Exposure occurred during gestation and lactation via maternal feed to a wide dose range (TCDD: 10–10,000 pg/kg body weight/day; PCB 153: 0.09–1406 μg/kg body weight/d). Then exposure was ceased and offspring were followed up to 1 year of age. Metabolic parameters like body weight,more » fat pad weights, glucose tolerance, endocrine serum profile, and neurobehavioral and immunological parameters were determined. Body weight was transiently affected by both compounds throughout the follow-up. TCDD-exposed males showed decreased fat pad and spleen weights and an increase in IL-4 production of splenic immune cells. In contrast, females showed increased fat pad weights and production of IFNγ. PCB 153-exposed males showed an increase in glucose, whereas females showed an increase in glucagon, a decrease in pancreas weight, and an increase in thymus weight. In conclusion, early life exposure to TCDD appears to affect programming of energy and immune homeostasis in offspring, whereas the effects of perinatal PCB 153 were mainly on programming of glucose homeostasis. Both compounds act sex-specifically. Lowest derived BMDLs (lower bounds of the (two sided) 90%-confidence interval for the benchmark dose) for both compounds are not lower than current tolerable daily intakes. - Highlights: • Early life exposure to TCDD affects programming of energy and immune homeostasis. • Early life exposure to PCB 153 affects programming of energy homeostasis. • Both compounds act sex-specifically. • Lowest derived BMDLs for both TCDD and PCB 153 are not lower than current tolerable daily intakes.« less

Ultra-Wideband Array in PCB for Millimeter-Wave 5G and ISM

NASA Technical Reports Server (NTRS)

Novak, Markus H.; Volakis, John L.; Miranda, Felix A.

2017-01-01

Next generation 5G mobile architectures will take advantage of the millimeter-wave spectrum to deliver unprecedented bandwidth. Concurrently, there is a need to consolidate numerous disparate allocations into a single, multi-functional array. Existing arrays are either narrow-band, prohibitively expensive or cannot be scaled to these frequencies. In this paper, we present the first ultra-wideband millimeter-wave array to operate across the six 5G and ISM bands spanning 24-71 GHz. Critically, the array is realized using low-cost PCB. The design concept and optimized layout are presented, and fabrication and measurement considerations are discussed.

Impact of nonconductive powder on electrostatic separation for recycling crushed waste printed circuit board.

PubMed

Wu, Jiang; Qin, Yufei; Zhou, Quan; Xu, Zhenming

2009-05-30

The electrostatic separation is an effective and environmentally friendly method for recycling metals and nonmetals from crushed printed circuit board (PCB) wastes. However, it still confronts some problems brought by nonconductive powder (NP). Firstly, the NP is fine and liable to aggregate. This leads to an increase of middling products and loss of metals. Secondly, the stability of separation process is influenced by NP. Finally, some NPs accumulate on the surface of the corona and electrostatic electrodes during the process. These problems lead to an inefficient separation. In the present research, the impacts of NP on electrostatic separation are investigated. The experimental results show that: the separation is notably influenced when the NP content is more than 10%. With the increase of NP content, the middling products sharply increase from 1.4 g to 4.3g (increase 207.1%), while the conductive products decrease from 24.0 g to 19.1g (decrease 20.4%), and the separation process become more instable.

Structural Dynamics of Electronic Systems

NASA Astrophysics Data System (ADS)

Suhir, E.

2013-03-01

The published work on analytical ("mathematical") and computer-aided, primarily finite-element-analysis (FEA) based, predictive modeling of the dynamic response of electronic systems to shocks and vibrations is reviewed. While understanding the physics of and the ability to predict the response of an electronic structure to dynamic loading has been always of significant importance in military, avionic, aeronautic, automotive and maritime electronics, during the last decade this problem has become especially important also in commercial, and, particularly, in portable electronics in connection with accelerated testing of various surface mount technology (SMT) systems on the board level. The emphasis of the review is on the nonlinear shock-excited vibrations of flexible printed circuit boards (PCBs) experiencing shock loading applied to their support contours during drop tests. At the end of the review we provide, as a suitable and useful illustration, the exact solution to a highly nonlinear problem of the dynamic response of a "flexible-and-heavy" PCB to an impact load applied to its support contour during drop testing.

Determination of polychlorinated biphenyls in marine fish obtained from tsunami-stricken areas of Japan.

PubMed

Uekusa, Yoshinori; Takatsuki, Satoshi; Tsutsumi, Tomoaki; Akiyama, Hiroshi; Matsuda, Rieko; Teshima, Reiko; Hachisuka, Akiko; Watanabe, Takahiro

2017-01-01

We determined the polychlorinated biphenyl (PCB) congeners in 101 marine fish obtained from tsunami-stricken areas following the Great East Japan Earthquake in 2011. In particular, to determine the degree of PCB contamination in the fish, we investigated the concentration of total PCB (∑PCB) and the proportions of 209 individual PCB congeners by high-resolution gas chromatography/high-resolution mass spectrometry. The ∑PCB concentration was 1.7-33 ng/g in fat greenling (n = 29), 0.44-25 ng/g in flounder (n = 36), and 1.6-86 ng/g in mackerel (n = 36), all values being much lower than the provisional regulatory limit in Japan. In the congener analysis, tetra-, penta-, hexa-, and hepta-chlorinated PCB congeners dominated in all samples (comprising over 86% of the ∑PCB). The proportions of the chlorinated PCB congeners were similar to the contamination patterns derived from Kanechlor in the environment, implying that the marine fish were not contaminated with fresh PCBs.

Reduced cytotoxicity in PCB-exposed Chinese Hamster Ovary (CHO) cells pretreated with vitamin E.

PubMed

Murati, Teuta; Šimić, Branimir; Pleadin, Jelka; Vukmirović, Maja; Miletić, Marina; Durgo, Ksenija; Kniewald, Jasna; Kmetič, Ivana

2017-01-01

The aim of this study was to evaluate protective effects of vitamin E (50 -150 μM) in ovary cells upon cytotoxic effects induced by two structurally distinct PCB congeners - planar "dioxin-like" PCB 77 and non-planar di-ortho-substituted PCB 153 with an emphasis on identifying differences in the mechanism of vitamin E action depending on the structure of congeners. Application of three bioassays confirmed that PCBs decrease ovarian cell proliferation with slightly profound effects of PCB 77. PCB - induced ROS production and lipid peroxidation were significant for both congeners with also more noticeable effect for PCB 77. Vitamin E pre-incubation has improved viability of cells, reduced ROS formation and lipid peroxidation induced by PCBs' treatment. Preincubation with vitamin E was more effective when cells where treated with non-planar PCB 153. Altogether, vitamin E action was protective, congener specific and more effective when ovary cells were exposed to ortho-substituted PCB congener. Copyright © 2016 Elsevier Ltd. All rights reserved.

Study of penetration behavior of PCB-DNAPL in a sand layer by a column experiment.

PubMed

Okuda, Nobuyasu; Shimizu, Takaaki; Muratani, Masaru; Terada, Akihiko; Hosomi, Masaaki

2014-11-01

To better understand the infiltration performances of high concentration PCB oils (KC-300 and KC-1000 polychlorinated biphenyl (PCB) mixtures), representative dense non-aqueous phase liquid (DNAPL), under both saturated and unsaturated conditions, we conducted experiments on a sand column filled with Toyoura Standard Sand. When PCB oil with the volume comparable to the total porosity in the column was supplied, the residual PCB concentrations under PCB-water conditions were 4.9×10(4)mgkg(-1) in KC-300 and 3.9×10(4)mgkg(-1) in KC-1000. Under PCB-air conditions, residual PCB concentrations were 6.0×10(4)mgkg(-1) and 2.4×10(5)mgkg(-1) in the upper and lower parts for KC-300 and 3.6×10(4)mgkg(-1) and 1.5×10(5)mgkg(-1) in those for KC-1000, respectively, while the rest of the PCBs were infiltrated. On the other hand, when a small amount of PCB oil with the volume far smaller than the total porosity in the column was supplied, the original PCBs were not transported via water permeation. However, lower-chlorinated PCB congeners-e.g., di- or tri-chlorinated biphenyls-preferentially dissolved and were infiltrated from the bottom of the column. These propensities on PCB oil infiltration can be explained in conjunction with the degree of PCB saturation in the sand column. Copyright © 2014 Elsevier Ltd. All rights reserved.

BILSAT-1: a Low-Cost Agile Earth Observation Microsatellite for Turkey

NASA Astrophysics Data System (ADS)

Bradford, Andy; Gomes, Luis M.; Sweeting, Martin, , Sir

TUBITAK-BILTEN has initiated a project to develop and propagate small satellite technologies in Turkey. As part of this initiative, TUBITAK-BILTEN is working with SSTL (UK) to develop a 100kg class microsatellite, BILSAT-1. With the successful completion of this project, TUBITAK-BILTEN will be capable of producing its own satellites, covering all phases from design to production. It is hoped that acquisition of these technologies will stimulate Turkish industry into greater involvement in space related activities. The project was started in August 2001 and will run through to launch scheduled for February 2003. BILSAT-1 will be one of the most capable microsatellites built by SSTL and features several technologies normally only found on larger satellites. Specifically, the Attitude Determination and Control System of BILSAT-1 will include dual-redundant star cameras, sun sensors and rate gyros to provide precise attitude information allowing very accurate attitude knowledge. Actuators on board will make the satellite extremely agile, allowing fast slew manoeuvres about its roll and pitch axes enabling the satellite to reduce imaging revisit times compared to fixed nadir-pointing gravity gradient stabilized satellites, and will allow novel and complex operations scenarios to be undertaken with the satellites prime payloads; a 26-metre GSD 4-band multispectral and a 12-metre GSD panchromatic imaging system. Stereoscopic imaging, target tracking and multiple attitude imaging are all operational scenarios that feature in the mission plan. Also on board the satellite are additional payloads, including a state-of-the-art Digital Signal Processing Board payload that will enable real time image compression in JPEG2000 format using a high performance floating point DSP, and a low resolution 9-band multispectral camera. BILSAT-1 will join the other 5 microsatellites in the SSTL-led international Disaster Monitoring Constellation (DMC), providing the ability to enhance the imaging capabilities of the constellation whose objective is to provide EO with daily revisit worldwide. In parallel with the Satellite design and build activities at the Surrey Space Centre &SSTL in the UK, all the infrastructure required to design, produce and operate a satellite, is being constructed at BILTEN's premises in Turkey. This infrastructure includes assembly and integration rooms, a PCB prototyping workshop, research and development laboratories, and a satellite mission control ground station.

Effects of PCB contamination on the reproduction of the DAB Limanda limanda L. under laboratory conditions

NASA Astrophysics Data System (ADS)

Fonds, Mark; Casal, Elizabeth; Schweizer, Dominik; Boon, Jan P.; Van der Veer, Henk W.

The effect of PCB contamination on the reproduction of female dab was studied under laboratory conditions. Females were contaminated during gonad maturation by multiple oral administration of capsules containing the technical PCB mixture Clophen A40. PCB contamination resulted in increased levels in the eggs, with concentrations of selected PCB congeners of 35 to 86 μg·g -1 lipid for PCB-exposed fish, 10 μg·g -1 lipid for eggs from fish fed with mussel meat and fish fed with shrimp. A statistically significant dose-effect relationship was found between the PCB content of the eggs and the PCB dose ingested by the fish. For eggs from the PCB-treated fish the mean fertilization rate was 61% and mean hatching 45%, compared to 67% fertilization and 59% hatching for eggs from untreated fish. Rate of development and survival of the eggs and mortality of the larvae after hatching were mainly related to incubation temperature. No statistically significant differences between untreated and PCB-treated fish could be found in egg production, egg quality, fertilization rate, hatching rate and survival of larvae.

Variation in net trophic transfer efficiencies among 21 PCB congeners

USGS Publications Warehouse

Madenjian, C.P.; Schmidt, L.J.; Chernyak, S.M.; Elliott, R.F.; Desorcie, T.J.; Quintal, R.T.; Begnoche, L.J.; Hesselberg, R.J.

1999-01-01

We tested the hypothesis that the efficiency with which fish retain polychlorinated biphenyl (PCB) congeners from their food strongly depends on Kow and degree of chlorination of the congener. We used diet information, determinations of concentrations of individual PCB congeners in both coho salmon (Oncorhynchus kisutch) and their prey, and bioenergetics modeling to estimate the efficiencies with which Lake Michigan coho salmon retain various PCB congeners from their food. The retention efficiency for the tetrachloro congeners averaged 38%, whereas retention efficiencies for higher chlorinated congeners ranged from 43 to 56%. Not including tetrachloro congeners, we found neither decreasing nor increasing trends in the efficiencies with which the coho salmon retained the PCB congeners from their food with either increasing Kow or increasing degree of chlorination of the PCB congeners. We concluded that (a) for PCB congeners with 5−8 chlorine atoms/molecule, Kow and degree of chlorination had little influence on the efficiency with which coho salmon retained the various PCB congeners in their food, and (b) the efficiency with which coho salmon retained tetrachloro PCB congeners in their food appeared to be slightly lower than that for higher chlorinated PCB congeners.

Sexual difference in PCB concentrations of lake trout (Salvelinus namaycush) from Lake Ontario

USGS Publications Warehouse

Madenjian, Charles P.; Keir, Michael J.; Whittle, D. Michael; Noguchi, George E.

2010-01-01

We determined polychlorinated biphenyl (PCB) concentrations in 61 female lake trout (Salvelinus namaycush) and 71 male lake trout from Lake Ontario (Ontario, Canada and New York, United States). To estimate the expected change in PCB concentration due to spawning, PCB concentrations in gonads and in somatic tissue of lake trout were also determined. In addition, bioenergetics modeling was applied to investigate whether gross growth efficiency (GGE) differed between the sexes. Results showed that, on average, males were 22% higher in PCB concentration than females in Lake Ontario. Results from the PCB determinations of the gonads and somatic tissues revealed that shedding of the gametes led to 3% and 14% increases in PCB concentration for males and females, respectively. Therefore, shedding of the gametes could not explain the higher PCB concentration in male lake trout. According to the bioenergetics modeling results, GGE of males was about 2% higher than adult female GGE, on average. Thus, bioenergetics modeling could not explain the higher PCB concentrations exhibited by the males. Nevertheless, a sexual difference in GGE remained a plausible explanation for the sexual difference in PCB concentrations of the lake trout.

Polychlorinated biphenyls in the atmosphere of an urban city: levels, distribution, and emissions.

PubMed

Chen, Laiguo; Peng, Xiaochun; Huang, Yumei; Xu, Zhencheng; Mai, Bixian; Sheng, Guoying; Fu, Jiamo; Wang, Xinhua

2009-10-01

Polychlorinated biphenyl (PCB) concentrations, profiles, and possible sources were determined in the atmosphere of Guangzhou, the largest city in south China. summation operator PCB concentrations ranged from 160 to 2720 pg/m(3), which is comparable with values found by similar studies in North America, Europe, and Asia. The highest PCB concentrations were found in the old industrial district, suggesting it to be the principal emission source. The most important PCB homologue group was tetra-PCB, followed by tri- and penta-PCB. The PCBs' homologue composition differs from that found in Chinese transformer oils: Chinese PCB products (no. 1 PCB and no. 2 PCB), Aroclor1242, and Aroclor1254. However, it is similar in composition to that found in sediments and soils subjected to arbitrary disposal of used electronic appliances in this region. Our results suggest that volatilization from PCB-contaminated soils in the old urban center may be the major source of PCBs in the atmosphere of Guangzhou. Additional studies will be required to characterize the geochemical cycles of PCBs from the contaminated environmental "hot spots" during the typical subtropical climate conditions in the study regions.

Gender difference in walleye PCB concentrations persists following remedial dredging

USGS Publications Warehouse

Madenjian, Charles P.; Jude, David J.; Rediske, Richard R.; O'Keefe, James P.; Noguchi, George E.

2009-01-01

Eleven male walleyes (Sander vitreus) and 10 female walleyes from the Saginaw Bay (Lake Huron) population were caught during the spawning run at Dow Dam (Midland, Michigan) in the Tittabawassee River during April 1996, and individual whole-fish polychlorinated biphenyl (PCB) determinations were made. Total PCB concentrations averaged 7.95 and 3.17??mg/kg for males and females, respectively. As part of the Natural Resource Damage Assessment remediation process, contaminated sediments from the Saginaw River, the main tributary to Saginaw Bay, were removed during 2000 and 2001. Total PCB concentrations of 10 male and 10 female walleyes caught at Dow Dam during April 2007 averaged 1.58 and 0.55??mg/kg, respectively. Thus, dredging of the Saginaw River appeared to be effective in reducing PCB concentrations of Saginaw Bay adult walleyes, as both males and females decreased in PCB concentration by more than 80% between 1996 and 2007. However, the ratio of male PCB concentration to female PCB concentration did not decline between 1996 and 2007. This persistent gender difference in PCB concentrations was apparently due to a gender difference in habitat utilization coupled with a persistent spatial gradient in prey fish PCB concentrations from the Saginaw River to Lake Huron.

Sulfated Metabolites of Polychlorinated Biphenyls Are High-Affinity Ligands for the Thyroid Hormone Transport Protein Transthyretin

PubMed Central

Grimm, Fabian A.; Lehmler, Hans-Joachim; He, Xianran; Robertson, Larry W.

2013-01-01

Background: The displacement of l-thyroxine (T4) from binding sites on transthyretin (TTR) is considered a significant contributing mechanism in polychlorinated biphenyl (PCB)-induced thyroid disruption. Previous research has discovered hydroxylated PCB metabolites (OH-PCBs) as high-affinity ligands for TTR, but the binding potential of conjugated PCB metabolites such as PCB sulfates has not been explored. Objectives: We evaluated the binding of five lower-chlorinated PCB sulfates to human TTR and compared their binding characteristics to those determined for their OH-PCB precursors and for T4. Methods: We used fluorescence probe displacement studies and molecular docking simulations to characterize the binding of PCB sulfates to TTR. The stability of PCB sulfates and the reversibility of these interactions were characterized by HPLC analysis of PCB sulfates after their binding to TTR. The ability of OH-PCBs to serve as substrates for human cytosolic sulfotransferase 1A1 (hSULT1A1) was assessed by OH-PCB–dependent formation of adenosine-3´,5´-diphosphate, an end product of the sulfation reaction. Results: All five PCB sulfates were able to bind to the high-affinity binding site of TTR with equilibrium dissociation constants (Kd values) in the low nanomolar range (4.8–16.8 nM), similar to that observed for T4 (4.7 nM). Docking simulations provided corroborating evidence for these binding interactions and indicated multiple high-affinity modes of binding. All OH-PCB precursors for these sulfates were found to be substrates for hSULT1A1. Conclusions: Our findings show that PCB sulfates are high-affinity ligands for human TTR and therefore indicate, for the first time, a potential relevance for these metabolites in PCB-induced thyroid disruption. PMID:23584369

Alterations in geometry, biomechanics, and mineral composition of juvenile rat femur induced by nonplanar PCB-155 and/or planar PCB-169.

PubMed

Brankovič, Jana; Jovanovski, Sašo; Jevnikar, Peter; Hofmeister, Alexander; Reininger-Gutmann, Birgit; Jan, Janja; Grošelj, Maja; Osredkar, Joško; Uršič, Matjaž; Fazarinc, Gregor; Pogačnik, Azra; Vrecl, Milka

2017-04-01

Exposure to widespread lipophilic and bioaccumulative polychlorinated biphenyls (PCBs) induces diverse biochemical and toxicological responses in various organs, including the bone. The aim of this study was to evaluate the changes in growth rate, geometry, serum, and bone biochemical parameters and biomechanics of juvenile rat femur induced by lactational exposure to nonplanar PCB-155 and planar PCB-169 individually and in combination. Fifteen lactating Wistar rats were divided into four groups (PCB-169, PCB-155, PCB-155+169, and control), and PCBs were administered intraperitoneally at different time points after delivery. Femurs from 22-day-old offspring were analyzed by microCT, three-point bending test and inductively coupled plasma-mass spectrometry (ICP-MS) to obtain data on bone geometry, biomechanics and mineral composition. The serum levels of calcium, phosphate and alkaline phosphatase were also determined. Lactational exposure to planar PCB-169 resulted in shorter and thinner femurs, reduced endosteal and periosteal perimeters, smaller total cross-sectional and medullary areas, and lowered serum bone marker levels and calcium levels in the bone, while femur mechanical properties were not significantly altered. The changes observed in the combination exposure (PCB-155+169) group were similar to those observed in the PCB-169 group but were less pronounced. In summary, our results demonstrate that alterations in lactationally exposed offspring were primarily induced by planar PCB-169. The milder outcome in the combined group suggested that the PCB-169-mediated toxic effects on the bone might be reduced by a nonplanar PCB-155 congener. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1135-1146, 2017. © 2016 Wiley Periodicals, Inc.

Enantioselectivity of 2,2',3,5',6-Pentachlorobiphenyl (PCB 95) Atropisomers toward Ryanodine Receptors (RyRs) and Their Influences on Hippocampal Neuronal Networks.

PubMed

Feng, Wei; Zheng, Jing; Robin, Gaëlle; Dong, Yao; Ichikawa, Makoto; Inoue, Yoshihisa; Mori, Tadashi; Nakano, Takeshi; Pessah, Isaac N

2017-12-19

Nineteen ortho-substituted PCBs are chiral and found enantioselectively enriched in ecosystems. Their differential actions on biological targets are not understood. PCB 95 (2,2',3,5',6-pentachlorobiphenyl), a chiral PCB of current environmental relevance, is among the most potent toward modifying ryanodine receptors (RyR) function and Ca 2+ signaling. PCB 95 enantiomers are separated and assigned aR- and aS-PCB 95 using three chiral-column HPLC and circular dichroism spectroscopy. Studies of RyR1-enriched microsomes show aR-PCB 95 with >4× greater potency (EC 50 = 0.20 ± 0.05 μM), ∼ 1.3× higher efficacy (B max = 3.74 ± 0.07 μM) in [ 3 H]Ryanodine-binding and >3× greater rates (R = 7.72 ± 0.31 nmol/sec/mg) of Ca 2+ efflux compared with aS-PCB 95, whereas racemate has intermediate activity. aR-PCB 95 has modest selectivity for RyR2, and lower potency than racemate toward the RyR isoform mixture in brain membranes. Chronic exposure of hippocampal neuronal networks to nanomolar PCB 95 during a critical developmental period shows divergent influences on synchronous Ca 2+ oscillation (SCO): rac-PCB 95 increasing and aR-PCB 95 decreasing SCO frequency at 50 nM, although the latter's effects are nonmonotonic at higher concentration. aS-PCB95 shows the greatest influence on inhibiting responses to 20 Hz electrical pulse trains. Considering persistence of PCB 95 in the environment, stereoselectivity toward RyRs and developing neuronal networks may clarify health risks associated with enantioisomeric enrichment of PCBs.

Effects of thiol antioxidants on the atropselective oxidation of 2,2',3,3',6,6'-hexachlorobiphenyl (PCB 136) by rat liver microsomes.

PubMed

Wu, Xianai; Lehmler, Hans-Joachim

2016-02-01

Chiral polychlorinated biphenyl (PCB) congeners, such as PCB 136, are atropselectively metabolized to various hydroxylated PCB metabolites (HO-PCBs). The present study investigates the effect of two thiol antioxidants, glutathione and N-acetyl-cysteine (NAC), on profiles and chiral signatures of PCB 136 and its HO-PCB metabolites in rat liver microsomal incubations. Liver microsomes prepared from rats pretreated with phenobarbital were incubated with PCB 136 (5 μM) in the presence of the respective antioxidant (0-10 mM), and levels and chiral signatures of PCB 136 and its HO-PCB metabolites were determined. Three metabolites, 5-136 (2,2',3,3',6,6'-hexachlorobiphenyl-5-ol), 4-136 (2,2',3,3',6,6'-hexachlorobiphenyl-4-ol), and 4,5-136 (2,2',3,3',6,6'-hexachlorobiphenyl-4,5-diol), were detected in all incubations, with 5-136 being the major metabolite. Compared to microsomal incubations without antioxidant, levels of 4,5-136 increased with increasing antioxidant concentration, whereas levels of PCB 136 and both mono-HO-PCBs were not affected by the presence of either antioxidant. PCB 136, 4-136, and 5-136 displayed significant atropisomeric enrichment; however, the direction and extent of the atropisomeric enrichment was not altered in the presence of an antioxidant. Because 4,5-136 can either be conjugated to a sulfate or glucuronide metabolite that is readily excreted or further oxidized a potentially toxic PCB 136 quinone, the effect of both thiol antioxidants on 4,5-136 formation suggests that disruptions of glutathione homeostasis may alter the balance between both metabolic pathways and, thus, PCB 136 toxicity in vivo.

EFFECTS OF THIOL ANTIOXIDANTS ON THE ATROPSELECTIVE OXIDATION OF 2,2′,3,3′,6,6′-HEXACHLOROBIPHENYL (PCB 136) BY RAT LIVER MICROSOMES

PubMed Central

Wu, Xianai; Lehmler, Hans-Joachim

2015-01-01

Chiral polychlorinated biphenyl (PCB) congeners, such as PCB 136, are atropselectively metabolized to various hydroxylated PCB metabolites (HO-PCBs). The present study investigates the effect of two thiol antioxidants, glutathione and N-acetyl-cysteine (NAC), on profiles and chiral signatures of PCB 136 and its HO-PCB metabolites in rat liver microsomal incubations. Liver microsomes prepared from rats pretreated with phenobarbital were incubated with PCB 136 (5 μM) in the presence of the respective antioxidant (0–10 mM), and levels and chiral signatures of PCB 136 and its HO-PCB metabolites were determined. Three metabolites, 5-136 (2,2′,3,3′,6,6′-hexachlorobiphenyl-5-ol), 4-136 (2,2′,3,3′,6,6′-hexachlorobiphenyl-4-ol) and 4,5-136 (2,2′,3,3′,6,6′-hexachlorobiphenyl-4,5-diol), were detected in all incubations, with 5-136 being the major metabolite. Compared to microsomal incubations without antioxidant, levels of 4,5-136 increased with increasing antioxidant concentration, whereas levels of PCB 136 and both mono-HO-PCBs were not affected by the presence of either antioxidant. PCB 136, 4-136 and 5-136 displayed significant atropisomeric enrichment; however, the direction and extent of the atropisomeric enrichment was not altered in the presence of an antioxidant. Because 4,5-136 can either be conjugated to a sulfate or glucuronide metabolite that is readily excreted or further oxidized a potentially toxic PCB 136 quinone, the effect of both thiol antioxidants on 4,5-136 formation suggests that disruptions of glutathione homeostasis may alter the balance between both metabolic pathways and, thus, PCB 136 toxicity in vivo. PMID:26155892

Individual Polychlorinated Biphenyl (PCB) Congeners Produce Tissue- and Gene-Specific Effects on Thyroid Hormone Signaling during Development

PubMed Central

Giera, Stefanie; Bansal, Ruby; Ortiz-Toro, Theresa M.; Taub, Daniel G.

2011-01-01

Polychlorinated biphenyls (PCB) are industrial chemicals linked to developmental deficits that may be caused in part by disrupting thyroid hormone (TH) action by either reducing serum TH or interacting directly with the TH receptor (TR). Individual PCB congeners can activate the TR in vitro when the metabolic enzyme cytochrome P4501A1 (CYP1A1) is induced, suggesting that specific PCB metabolites act as TR agonists. To test this hypothesis in vivo, we compared two combinations of PCB congeners that either activate the TR (PCB 105 and 118) or not (PCB 138 and 153) in the presence or absence of a PCB congener (PCB 126) that induces CYP1A1 in vitro. Aroclor 1254 was used as a positive control, and a group treated with propylthiouracil was included to characterize the effects of low serum TH. We monitored the effects on TH signaling in several peripheral tissues by measuring the mRNA expression of well-known TH-response genes in these tissues. Aroclor 1254 and its component PCB 105/118/126 reduced total T4 to the same extent as that of propylthiouracil but increased the expression of some TH target genes in liver. This effect was strongly correlated with CYP1A1 expression supporting the hypothesis that metabolism is necessary. Effects were gene and tissue specific, indicating that tissue-specific metabolism is an important component of PCB disruption of TH action and that PCB metabolites interact in complex ways with the TR. These are essential mechanisms to consider when evaluating the health risks of contaminant exposures, for both PCB and other polycyclic compounds known to interact with nuclear hormone receptors. PMID:21540284

Polychlorinated biphenyl contamination of nursing mothers' milk in Michigan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wickizer, T.M.; Brilliant, L.B.; Copeland, R.

As part of an effort to assess the extent and distribution of PCB contamination in the human population of Michigan, PCB levels in the breast milk of Michigan nursing mothers were investigated. All of the 1057 samples collected from 68 counties contained PCB residues ranging from trace amounts to 5.1 ppm. The mean PCB level was 1.496 ppm. The public health significance of PCB contamination in human populations and the implications of PCB contamination of human milk for current breast-feeding practices are discussed. Several precautionary measures for nursing mothers are recommended.

Identification of a novel hydroxylated metabolite of 2,2′,3,5′,6-pentachlorobiphenyl formed in whole poplar plants

PubMed Central

Ma, Cunxian; Zhai, Guangshu; Wu, Huimin; Kania-Korwel, Izabela; Lehmler, Hans-Joachim; Schnoor, Jerald L

2015-01-01

Polychlorinated biphenyls (PCBs) are a group of persistent organic pollutants consisting of 209 congeners. Oxidation of several PCB congeners to hydroxylated PCBs (OH-PCBs) in whole poplar plants has been reported before. Moreover, 2,2′,3,5′,6-pentachlorobiphenyl (PCB95), as a chiral congener, has been previously shown to be atropselectively taken up and transformed in whole poplar plants. The objective of this study was to determine if PCB95 is atropselectively metabolized to OH-PCBs in whole poplar plants. Two hydroxylated PCB95s were detected by high performance liquid chromatography-mass spectrometry in the roots of whole poplar plants exposed to racemic PCB95 for 30 days. The major metabolite was confirmed to be 4′-hydroxy-2,2′,3,5′,6-pentachlorobiphenyl (4′-OH-PCB95) by gas chromatography-mass spectrometry (GC-MS) using an authentic reference standard. Enantioselective analysis showed that 4′-OH-PCB95 was formed atropselectively, with the atropisomer eluting second on the Nucleodex β-PM column (E2-4′-OH-PCB95) being slightly more abundant in the roots of whole poplar plants. Therefore, PCB95 can at least be metabolized into 4′-OH-PCB95 and another unknown hydroxylated PCB95 (as a minor metabolite) in whole poplar plants. Both atropisomers of 4′-OH-PCB95 are formed, but E2-4′-OH-PCB95 has greater atropisomeric enrichment in the roots of whole poplar plants. A comparison with mammalian biotransformation studies indicates a distinctively different metabolite profile of OH-PCB95 metabolites in whole poplar plants. Our observations suggest that biotransformation of chiral PCBs to OH-PCBs by plants may represent an important source of enantiomerically enriched OH-PCBs in the environment. PMID:26676542

Impact of Paclitaxel Dose on Tissue Pharmacokinetics and Vascular Healing: A Comparative Drug-Coated Balloon Study in the Familial Hypercholesterolemic Swine Model of Superficial Femoral In-Stent Restenosis.

PubMed

Gongora, Carlos A; Shibuya, Masahiko; Wessler, Jeffrey D; McGregor, Jenn; Tellez, Armando; Cheng, Yanping; Conditt, Gerard B; Kaluza, Greg L; Granada, Juan F

2015-07-01

This study sought to compare the effect of paclitaxel-coated balloon (PCB) concentration on tissue levels and vascular healing using 3 different PCB technologies (In.Pact Pacific = 3 μg/mm(2), Lutonix = 2 μg/mm(2) and Ranger = 2 μg/mm(2)) in the experimental setting. The optimal therapeutic dose for PCB use has not been determined yet. Paclitaxel tissue levels were measured up to 60 days following PCB inflation (Ranger and In.Pact Pacific) in the superficial femoral artery of healthy swine (18 swine, 36 vessels). The familial hypercholesterolemic swine model of superficial femoral artery in-stent restenosis (6 swine, 24 vessels) was used in the efficacy study. Two weeks following bare-metal stent implantation, each in-stent restenosis site was randomly treated with a PCB or an uncoated control balloon (Sterling). Quantitative vascular analysis and histology evaluation was performed 28 days following PCB treatment. All PCB technologies displayed comparable paclitaxel tissue levels 4 h following balloon inflation. At 28 days, all PCB had achieved therapeutic tissue levels; however, the In.Pact PCB resulted in higher tissue concentrations than did the other PCB groups at all time points. Neointimal inhibition by histology was decreased in all PCB groups compared with the control group, with a greater decrease in the In.Pact group. However, the neointima was more mature and contained less peri-strut fibrin deposits in both 2-μg/mm(2) PCB groups. Compared with the clinically established PCB dose, lower-dose PCB technologies achieve lower long-term tissue levels but comparable degrees of neointimal inhibition and fewer fibrin deposits. The impact of these findings in restenosis reduction and clinical outcomes needs to be further investigated. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Serum PCB levels and congener profiles among US construction workers

PubMed Central

Herrick, Robert F; Meeker, John D; Hauser, Russ; Altshul, Larisa; Weymouth, George A

2007-01-01

Background The presence of PCB in caulking (sealant) material found in masonry buildings has been well-documented in several countries. A recent investigation of 24 buildings in the greater Boston area found that 8 buildings had high PCB levels in caulking materials used around window frames and in joints between masonry blocks. Workers removing caulking material have been shown to have elevated serum PCB levels. Methods This project compared serum PCB levels among male workers who installed and/or removed PCB-containing caulking material from buildings in the greater Boston area with reference serum PCB levels from 358 men from the same area. Serum PCB levels were measured in the same laboratory by liquid-liquid extraction, column chromatography clean-up and dual capillary column GC/microECD analysis. Results When the congener profiles were compared between the reference population and the construction workers, the serum levels of the more volatile, lighter PCBs (di-, tri-and tetrachloro, sum of IUPAC# 6–74) were substantially higher among the construction workers. One of the youngest workers had the lowest total serum PCB levels (sum of 57 congeners) of all 6 workers, but the contribution of more volatile (less chlorinated) PCB congeners (#16, 26,28,33,74,66, and 60) was markedly higher than in other 5 workers and reference men. Only this worker was working on a job that involved removing PCB caulking at the time of the blood sampling. Conclusion While the results of this pilot study are based upon small numbers (6 construction workers who handled PCB caulking), the serum PCB levels among the construction workers exceed the referents. Comparison of the congener profiles suggests that there are substantial differences between the construction workers and the general population samples. These differences, and the similarities of profiles among the construction workers strongly suggest that occupational contact with caulking material can be a major source of PCB exposure for construction workers. PMID:17764566

Metabolism of 2,2′,3,3′,6,6′-Hexachlorobiphenyl (PCB 136) Atropisomers in Tissue Slices from Phenobarbital or Dexamethasone-Induced Rats is Sex-Dependent

PubMed Central

Wu, Xianai; Kania-Korwel, Izabela; Chen, Hao; Stamou, Marianna; Dammanahalli, Karigowda J.; Duffel, Michael; Lein, Pamela J.; Lehmler, Hans-Joachim

2013-01-01

Chiral polychlorinated biphenyls (PCBs) such as PCB 136 enantioselectively sensitize the ryanodine receptor (RyR). In light of recent evidence that PCBs cause developmental neurotoxicity via RyR-dependent mechanisms, this suggests that enantioselective PCB metabolism may influence the developmental neurotoxicity of chiral PCBs. However, enantioselective disposition of PCBs has not been fully characterized.The effect of sex and cytochrome P450 (P450) enzyme induction on the enantioselective metabolism of PCB 136 was studied using liver tissue slices prepared from naïve control (CTL), phenobarbital (PB; CYP2B inducer) or dexamethasone (DEX; CYP3A inducer) pretreated adult Sprague-Dawley rats. PCB 136 metabolism was also examined in hippocampal slices derived from untreated rat pups.In liver tissue slices, hydroxylated PCB (OH-PCB) profiles depended on sex and inducer pretreatment, and OH-PCB levels followed the rank orders male > female and PB > DEX > CTL. In contrast, the enantiomeric enrichment of PCB 136 and its metabolites was independent of sex and inducer pretreatment. Only small amounts of PCB 136 partitioned into hippocampal tissue slices and no OH-PCB metabolites were detected.Our results suggest that enantioselective metabolism, sex and induction status of P450 enzymes in the liver may modulate the neurotoxic outcomes of developmental exposure to chiral PCBs. PMID:23581876

ENANTIOSELECTIVITY IN THE BIODEGRADATION OF PCB ATROPISOMERS

EPA Science Inventory

Microcosms inoculated with sediment from two locations in a contaminated reservoir, Lake Hartwell, SC, USA, degraded certain PCB atropisomers enantioselectively while other atropisomers were degraded in racemic proportions. The microcosms were spiked with either 234-236 PCB (PCB...

[Indoor air pollution by polychlorinated biphenyl compounds in permanently elastic sealants].

PubMed

Burkhardt, U; Bork, M; Balfanz, E; Leidel, J

1990-10-01

A common cause for indoor pollution by polycholorinated biphenyls (PCB) are defective capacitors of luminous discharge lamps. This paper describes elastic sealing compounds as another source of PCB pollution in buildings. In several rooms of a large school building indoor concentrations of 1000 ng PCB/m3 and more were registered. The total PCB concentration in sealing compounds ranged between 124,000 and 327,000 ppm. Blood specimens drawn from the school's personnel did not show elevated PCB concentrations, but additional incorporation of PCB via the respiratory tract cannot be excluded. We do not presume that any impairment of the health has been caused by this pollutant, but we think that reduction of the PCB indoor concentrations would be advisable for prophylactic purposes. Attention should be given to so-called open PCB systems such as elastic sealing compounds. Although they have been prohibited 1978, there might be a widespread use in older buildings.

Leopard frog PCB levels and evaluation of EROD as a biomarker in Green Bay ecosystem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Y.W.; Karasov, W.H.; Patnode, K.P.

1995-12-31

The induction of mixed function oxidases has been shown to be a promising biomarker in many taxa of wildlife, though not yet tested for amphibians. The three hypotheses tested in this study were (1) activities of hepatic EROD of leopard frog (Rana pipiens) are induced following exposure to planar chlorinated PCBs, (2) tissue PCB residue levels of leopard frogs are positively correlated with their wetland sediment PCB levels, and (3) EROD activities are positively correlated with tissue PCB concentrations and sediment PCB. In the laboratory, EROD was increased 2--3 times seven days after i.p. injection with PCB 126 at dosesmore » {ge} 2.3 ppm (wet mass basis). Leopard frogs from seven sites along the Lower Fox River and Green Bay in 1994--1995 were assayed for hepatic EROD activities and total PCB levels in carcasses. Tissue PCB levels ranged from 3 to 152 ppb (including coplanar congeners) and were highest from sites with higher sediment PCB. EROD activity in frogs collected in August--September was not significantly correlated with frog body mass and was similar among sites with one exception. There was no significant correlation between EROD activity and tissue PCB concentration. This result was consistent with the fact that the frogs collected from the Green Bay ecosystem had relatively low PCB levels compared with what was required for induction in the laboratory. The authors conclude that EROD activity is not a sensitive biomarker of PCB exposure in leopard frogs in this ecosystem.« less

Relationships between Atmospheric Transport Regimes and PCB Concentrations in the Air at Zeppelin, Spitsbergen.

PubMed

Ubl, Sandy; Scheringer, Martin; Hungerbühler, Konrad

2017-09-05

Polychlorinated biphenyls (PCBs) are persistent hazardous chemicals that are still detected in the atmosphere and other environmental media, although their production has been banned for several decades. At the long-term monitoring site, Zeppelin at Spitsbergen, different PCB congeners have been continuously measured for more than a decade. However, it is not clear what factors determine the seasonal and interannual variability of different (lighter versus heavier) PCB congeners. To investigate the influence of atmospheric transport patterns on PCB-28 and PCB-101 concentrations at Zeppelin, we applied the Lagrangian Particle Dispersion Model FLEXPART and calculated "footprints" that indicate the potential source regions of air arriving at Zeppelin. By means of a cluster analysis, we assigned groups of similar footprints to different transport regimes and analyzed the PCB concentrations according to the transport regimes. The concentrations of both PCB congeners are affected by the different transport regimes. For PCB-101, the origin of air masses from the European continent is primarily related to high concentrations; elevated PCB-101 concentrations in winter can be explained by the high frequency of this transport regime in winter, whereas PCB-101 concentrations are low when air is arriving from the oceans. For PCB-28, in contrast, concentrations are high during summer when air is mainly arriving from the oceans but low when air is arriving from the continents. The most likely explanation of this finding is that local emissions of PCB-28 mask the effect of long-range transport and determine the concentrations measured at Zeppelin.

Acute alteration of cardiac ECG, action potential, I{sub Kr} and the human ether-a-go-go-related gene (hERG) K{sup +} channel by PCB 126 and PCB 77

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Mi-Hyeong; Park, Won Sun; Jo, Su-Hyun, E-mail: suhyunjo@kangwon.ac.kr

2012-07-01

Polychlorinated biphenyls (PCBs) have been known as serious persistent organic pollutants (POPs), causing developmental delays and motor dysfunction. We have investigated the effects of two PCB congeners, 3,3′,4,4′-tetrachlorobiphenyl (PCB 77) and 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126) on ECG, action potential, and the rapidly activating delayed rectifier K{sup +} current (I{sub Kr}) of guinea pigs' hearts, and hERG K{sup +} current expressed in Xenopus oocytes. PCB 126 shortened the corrected QT interval (QTc) of ECG and decreased the action potential duration at 90% (APD{sub 90}), and 50% of repolarization (APD{sub 50}) (P < 0.05) without changing the action potential duration at 20% (APD{submore » 20}). PCB 77 decreased APD{sub 20} (P < 0.05) without affecting QTc, APD{sub 90}, and APD{sub 50}. The PCB 126 increased the I{sub Kr} in guinea-pig ventricular myocytes held at 36 °C and hERG K{sup +} current amplitude at the end of the voltage steps in voltage-dependent mode (P < 0.05); however, PCB 77 did not change the hERG K{sup +} current amplitude. The PCB 77 increased the diastolic Ca{sup 2+} and decreased Ca{sup 2+} transient amplitude (P < 0.05), however PCB 126 did not change. The results suggest that PCB 126 shortened the QTc and decreased the APD{sub 90} possibly by increasing I{sub Kr}, while PCB 77 decreased the APD{sub 20} possibly by other modulation related with intracellular Ca{sup 2+}. The present data indicate that the environmental toxicants, PCBs, can acutely affect cardiac electrophysiology including ECG, action potential, intracellular Ca{sup 2+}, and channel activity, resulting in toxic effects on the cardiac function in view of the possible accumulation of the PCBs in human body. -- Highlights: ► PCBs are known as serious environmental pollutants and developmental disruptors. ► PCB 126 shortened QT interval of ECG and action potential duration. ► PCB 126 increased human ether-a-go-go-related K{sup +} current and I{sub Kr}. ► PCB 77 decreased action potential duration and increased intracellular Ca{sup 2+} content. ► PCBs acutely change cardiac electrophysiology and rhythmicity.« less

Microbial community analysis of switchgrass planted and unplanted soil microcosms displaying PCB dechlorination

PubMed Central

Liang, Yi; Meggo, Richard; Hu, Dingfei; Schnoor, Jerald L.; Mattes, Timothy E.

2015-01-01

Polychlorinated biphenyls (PCBs) pose potential risks to human and environmental health because they are carcinogenic, persistent and bioaccumulative. In this study we investigated bacterial communities in soil microcosms spiked with PCB 52, 77 and 153. Switchgrass (Panicum virgatum) was employed to improve overall PCB removal and redox cycling (i.e. sequential periods of flooding followed by periods of no flooding) was performed in an effort to promote PCB dechlorination. Lesser chlorinated PCB transformation products were detected in all microcosms, indicating the occurrence of PCB dechlorination. Terminal restriction fragment length polymorphism (T-RFLP) and clone library analysis showed that PCB spiking, switchgrass planting and redox cycling affected the microbial community structure. Putative organohalide-respiring Chloroflexi populations, which were not found in unflooded microcosms, were enriched after two weeks of flooding in the redox-cycled microcosms. Sequences classified as Geobacter sp. were detected in all microcosms, and were most abundant in the switchgrass-planted microcosm spiked with PCB congeners. The presence of possible organohalide-respiring bacteria in these soil microcosms suggests they play a role in PCB dechlorination therein. PMID:25820643

Microbial community analysis of switchgrass planted and unplanted soil microcosms displaying PCB dechlorination.

PubMed

Liang, Yi; Meggo, Richard; Hu, Dingfei; Schnoor, Jerald L; Mattes, Timothy E

2015-08-01

Polychlorinated biphenyls (PCBs) pose potential risks to human and environmental health because they are carcinogenic, persistent, and bioaccumulative. In this study, we investigated bacterial communities in soil microcosms spiked with PCB 52, 77, and 153. Switchgrass (Panicum virgatum) was employed to improve overall PCB removal, and redox cycling (i.e., sequential periods of flooding followed by periods of no flooding) was performed in an effort to promote PCB dechlorination. Lesser chlorinated PCB transformation products were detected in all microcosms, indicating the occurrence of PCB dechlorination. Terminal restriction fragment length polymorphism (T-RFLP) and clone library analysis showed that PCB spiking, switchgrass planting, and redox cycling affected the microbial community structure. Putative organohalide-respiring Chloroflexi populations, which were not found in unflooded microcosms, were enriched after 2 weeks of flooding in the redox-cycled microcosms. Sequences classified as Geobacter sp. were detected in all microcosms and were most abundant in the switchgrass-planted microcosm spiked with PCB congeners. The presence of possible organohalide-respiring bacteria in these soil microcosms suggests that they play a role in PCB dechlorination therein.

Results of Sediment Sampling and Elutriate Testing at the Proposed Desoto Shallow Water Habitat Project Site

DTIC Science & Technology

2013-08-01

50 Endrin Aldehyde 1.0 9.9 PCB - Aroclor1232 10 50 Endrin Ketone 0.8 9.9 PCB - Aroclor1254 10 50 Heptachlor 0.6 5.1 PCB - Aroclor1242 10 50...Endosulfan (Beta) 0.22 0.056 ----- Endosulfan sulfate ----- 89 89 Endrin 0.086 0.036 ----- Endrin aldehyde ----- 0.30 0.30 Heptachlor 0.52...2.0 Endosulfan Sulfate 0.010 0.1 PCB - Aroclor1248 0.3 1.0 Endrin 0.003 0.1 PCB - Aroclor1268 0.3 1.0 Endrin Aldehyde 0.011 0.1 PCB - Aroclor1232

Polychlorinated Biphenyls Water Pollution along the River Nile, Egypt

PubMed Central

Megahed, Ayman Mohamed; Dahshan, Hesham; Abd-El-Kader, Mahdy A.; Abd-Elall, Amr Mohamed Mohamed; Elbana, Mariam Hassan; Nabawy, Ehab; Mahmoud, Hend A.

2015-01-01

Ten polychlorinated biphenyl (PCB) congeners were determined in water samples collected along the River Nile using gas chromatography-electron capture detector (GC-ECD). PCB concentrations ranged from 14 to 20 μg/L, which were higher than those reported in previous studies, indicating serious PCB pollution in the River Nile. PCB congener profiles varied depending on the sampling sties. PCB-138 was the predominant congener accounting for more than 18% of total PCBs. The composition of PCB congeners in the water revealed that highly chlorinated PCB technical mixtures such as Aroclor 1254 was the main PCB production historically used in Egypt. An increasing trend in PCB levels from the upper stream to the Nile estuaries was observed. The calculated flux of PCBs indicated that 6.8 tons of PCBs is dumped into the Mediterranean Sea each year from the River Nile. The hazard quotients and carcinogenic risk caused by PCB pollution in the River Nile were above the acceptable level indicating that PCBs in the River Nile water pose adverse health effects for all age groups. Our findings revealed that PCBs possess a serious risk to the Egyptian population that depends mainly on the River Nile as a source of water. Thus, stricter legislation and regulatory controls should be applied to reduce the risk of PCBs in Egypt. PMID:26798844

Uptake and depuration of PCB-153 in edible shrimp Palaemonetes varians and human health risk assessment.

PubMed

Grilo, T F; Cardoso, P G; Pato, P; Duarte, A C; Pardal, M A

2014-03-01

A medium-term mesocosm exposure study was conducted to elucidate bioaccumulation and depuration of polychlorinated biphenyl congener 153 (PCB-153) in edible shrimp Palaemonetes varians. Over the 15-day exposure period, shrimp under different exposure concentrations exhibited a significant increase in PCB-153 concentration compared with control organisms. Distinct bioaccumulation patterns and uptake rates were observed depending on the exposure concentrations. For low PCB-153 exposure levels (0.25μgL(-1)), accumulation followed a saturation model, reaching an apparent steady state after fifteen days exposure. For intermediate (2.5μgL(-1)) and high PCB-153 levels (25μgL(-1)), accumulation was faster and linear. In addition, the bioaccumulation rate was not proportional to PCB-153 concentration, and the bioaccumulation was higher at intermediate exposure concentrations. Regarding the depuration phase, P. varians lost up to 30% of PCB-153 after 72h and levels continued slowly to decrease until the end of the 30-d experimental period. However, PCB-153 levels in shrimp did not reach background values, and those exposed to moderate and high PCB-153 concentrations presented contamination levels much higher than the regulatory limit for human food consumption (75ngg(-1) ww for Σ6 PCB). Copyright © 2013 Elsevier Inc. All rights reserved.

Historical record of polychlorinated biphenyls (PCBs) and special occurrence of PCB 209 in a shallow fresh-water lake from eastern China.

PubMed

Huo, Shouliang; Li, Chaocan; Xi, Beidou; Yu, Zhiqiang; Yeager, Kevin M; Wu, Fengchang

2017-10-01

Concentrations of polychlorinated biphenyls (PCBs) were measured in dated sediment cores collected from the fifth largest freshwater lake in China, Lake Chaohu, to investigate PCB temporal trends, accumulation, and environmental fate. Total PCB concentrations in Lake Choahu sediments ranged from 0.03 to 24.11 ng g -1 (d.w.). PCB 209 was the dominant congener, accounting for 45.5%-83.9% of total PCBs detected after the mid-20th century. All PCB congeners were positively correlated with total organic carbon (TOC) concentrations. TOC-normalized PCB concentrations exhibited three stages of variation over time: a slight increase from their emergence in the early 20th century, followed by a rapid increase since the late 1950s (peaking in the late 1980s), before a general decrease to the present. Both compositional PCB patterns and principal component analysis (PCA) indicated a source switch from commercial PCBs to other sources. Major contributions of PCB209 to total PCBs in Lake Chaohu sediments is a highlight of this study, with results showing that PCB209 was derived from the upstream city of Hefei, and the production of phthalocyanine-type pigments is the likely source of PCB209. Copyright © 2017 Elsevier Ltd. All rights reserved.

Graphene Oxide Attenuates the Cytotoxicity and Mutagenicity of PCB 52 via Activation of Genuine Autophagy.

PubMed

Liu, Yun; Wang, Xinan; Wang, Juan; Nie, Yaguang; Du, Hua; Dai, Hui; Wang, Jingjing; Wang, Mudi; Chen, Shaopeng; Hei, Tom K; Deng, Zhaoxiang; Wu, Lijun; Xu, An

2016-03-15

Graphene oxide (GO), owing to its large surface area and abundance of oxygen-containing functional groups, is emerging as a potential adsorbent for polychlorinated biphenyls (PCBs), which accumulate over time and are harmful to both natural ecosystems and human health. However, the effect of GO against PCB-induced toxicity remains largely unexplored. The present study aimed to investigate the protective effect of GO against PCB 52 induced cytotoxic and genotoxic response in mammalian cells at various exposure conditions and clarify the protective role of autophagy. Pretreatment with GO dramatically decreased PCB 52 induced cytotoxicity and CD59 gene mutation in human-hamster hybrid (AL) cells. The toxic response in cells either pretreated with PCB 52 and then treated with GO or concurrently treated with GO and PCB 52 did not differ significantly from the toxic response in the cells treated with PCB 52 alone. Using autophagy inhibitors (3-methyladenine and wortmannin) and inducers (trehalose and rapamycin), we found that genuine autophagy induced by GO was involved in decreasing PCB 52 induced toxicity. These findings suggested that GO has an antagonistic effect against the toxicity of PCB 52 mainly by triggering a genuine autophagic process, which might provide new insights into the potential application of GO in PCB disposal and environmental and health risk assessment.

Absolute configuration of 2,2',3,3',6-pentachlorinatedbiphenyl (PCB 84) atropisomers.

PubMed

Li, Xueshu; Parkin, Sean R; Lehmler, Hans-Joachim

2017-05-23

Nineteen polychlorinated biphenyl (PCB) congeners, such as 2,2',3,3',6-pentachlorobiphenyl (PCB 84), display axial chirality because they form stable rotational isomers, or atropisomers, that are non-superimposable mirror images of each other. Although chiral PCBs undergo atropselective biotransformation and atropselectively alter biological processes, the absolute structure of only a few PCB atropisomers has been determined experimentally. To help close this knowledge gap, pure PCB 84 atropisomers were obtained by semi-preparative liquid chromatography with two serially connected Nucleodex β-PM columns. The absolute configuration of both atropisomers was determined by X-ray single-crystal diffraction. The PCB 84 atropisomer eluting first and second on the Nucleodex β-PM column correspond to (aR)-(-)-PCB 84 and (aS)-(+)-PCB 84, respectively. Enantioselective gas chromatographic analysis with the β-cyclodextrin-based CP-Chirasil-Dex CB gas chromatography column showed the same elution order as the Nucleodex β-PM column. Based on earlier reports, the atropisomers eluting first and second on the BGB-172 gas chromatography column are (aR)-(-)-PCB 84 and (aS)-(+)-PCB 84, respectively. An inversion of the elution order is observed on the Cyclosil-B gas chromatography and Cellulose-3 liquid chromatography columns. These results advance the interpretation of environmental and human biomonitoring as well as toxicological studies.

Habitat-based PCB environmental quality criteria for the protection of endangered killer whales (Orcinus orca).

PubMed

Alava, Juan José; Ross, Peter S; Lachmuth, Cara; Ford, John K B; Hickie, Brendan E; Gobas, Frank A P C

2012-11-20

The development of an area-based polychlorinated biphenyl (PCB) food-web bioaccumulation model enabled a critical evaluation of the efficacy of sediment quality criteria and prey tissue residue guidelines in protecting fish-eating resident killer whales of British Columbia and adjacent waters. Model-predicted and observed PCB concentrations in resident killer whales and Chinook salmon were in good agreement, supporting the model's application for risk assessment and criteria development. Model application shows that PCB concentrations in the sediments from the resident killer whale's Critical Habitats and entire foraging range leads to PCB concentrations in most killer whales that exceed PCB toxicity threshold concentrations reported for marine mammals. Results further indicate that current PCB sediment quality and prey tissue residue criteria for fish-eating wildlife are not protective of killer whales and are not appropriate for assessing risks of PCB-contaminated sediments to high trophic level biota. We present a novel methodology for deriving sediment quality criteria and tissue residue guidelines that protect biota of high trophic levels under various PCB management scenarios. PCB concentrations in sediments and in prey that are deemed protective of resident killer whale health are much lower than current criteria values, underscoring the extreme vulnerability of high trophic level marine mammals to persistent and bioaccumulative contaminants.

How to Make Reliable, Washable, and Wearable Textronic Devices

PubMed Central

Tao, Xuyuan; Koncar, Vladan; Huang, Tzu-Hao; Shen, Chien-Lung; Ko, Ya-Chi; Jou, Gwo-Tsuen

2017-01-01

In this paper, the washability of wearable textronic (textile-electronic) devices has been studied. Two different approaches aiming at designing, producing, and testing robust washable and reliable smart textile systems are presented. The common point of the two approaches is the use of flexible conductive PCB in order to interface the miniaturized rigid (traditional) electronic devices to conductive threads and tracks within the textile flexible fabric and to connect them to antenna, textile electrodes, sensors, actuators, etc. The first approach consists in the use of TPU films (thermoplastic polyurethane) that are deposited by the press under controlled temperature and pressure parameters in order to protect the conductive thread and electrical contacts. The washability of conductive threads and contact resistances between flexible PCB and conductive threads are tested. The second approach is focused on the protection of the whole system—composed of a rigid electronic device, flexible PCB, and textile substrate—by a barrier made of latex. Three types of prototypes were realized and washed. Their reliabilities are studied. PMID:28338607

Hepatic metabolism affects the atropselective disposition of 2,2',3,3',6,6'-hexachlorobiphenyl (PCB 136) in mice.

PubMed

Wu, Xianai; Barnhart, Christopher; Lein, Pamela J; Lehmler, Hans-Joachim

2015-01-06

To understand the role of hepatic vs extrahepatic metabolism in the disposition of chiral PCBs, we studied the disposition of 2,2',3,3',6,6'-hexachlorobiphenyl (PCB 136) and its hydroxylated metabolites (HO-PCBs) in mice with defective hepatic metabolism due to the liver-specific deletion of cytochrome P450 oxidoreductase (KO mice). Female KO and congenic wild type (WT) mice were treated with racemic PCB 136, and levels and chiral signatures of PCB 136 and HO-PCBs were determined in tissues and excreta 3 days after PCB administration. PCB 136 tissue levels were higher in KO compared to WT mice. Feces was a major route of PCB metabolite excretion, with 2,2',3,3',6,6'-hexachlorobiphenyl-5-ol being the major metabolite recovered from feces. (+)-PCB 136, the second eluting PCB 136 atropisomers, was enriched in all tissues and excreta. The second eluting atropisomers of the HO-PCBs metabolites were enriched in blood and liver; 2,2',3,3',6,6'-hexachlorobiphenyl-5-ol in blood was an exception and displayed an enrichment of the first eluting atropisomers. Fecal HO-PCB levels and chiral signatures changed with time and differed between KO and WT mice, with larger HO-PCB enantiomeric fractions in WT compared to KO mice. Our results demonstrate that hepatic and, possibly, extrahepatic cytochrome P450 (P450) enzymes play a role in the disposition of PCBs.

DEMONSTRATION BULLETIN: ENVIROGARD™ PCB TEST KIT - MILLIPORE, INC.

EPA Science Inventory

The EnviroGard™ polychlorinated biphenyl (PCB) immunoassay test kit rapidly analyzes for PCB concentrations in soils. Soil sample extracts are added to test tubes coated with antibodies that bind PCB molecules. The excess soil extracts are washed out of the tubes after incubat...

Olive tree, Olea europaea L., leaves as a bioindicator of atmospheric PCB contamination.

PubMed

Sofuoglu, Sait C; Yayla, Burak; Kavcar, Pınar; Ates, Duygu; Turgut, Cafer; Sofuoglu, Aysun

2013-09-01

Olive tree leaf samples were collected to investigate their possible use for biomonitoring of lipophilic toxic substances. The samples were analyzed for 28 polychlorinated biphenyls (PCB) congeners. Twelve congeners were detected in the samples. PCB-60, 77, 81, 89, 105, 114, and 153 were the most frequently detected congeners ranging from 32 % for PCB-52 to 97 % for PCB-81. Σ12PCBs concentration varied from below detection limit to 248 ng/g wet weight in the sampling area, while the mean congener concentrations ranged from 0.06 ng/g (PCB-128 + 167) to 64.2 ng/g wet weight (PCB-60). Constructed concentration maps showed that olive tree leaves can be employed for the estimation of spatial distrubution of these congeners.

Excretion pattern of co-planar and non-planar tetra- and hexa-chlorobiphenyls in ovine milk and faeces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vrecl, Milka; Ursic, Matjaz; Pogacnik, Azra

This study employed the gas chromatography with electron capture detection to determine residual levels and excretion patterns of two pairs of structurally diverse polychlorinated biphenyl (PCB) congeners (IUPAC Nos. 54, 80, 155, and 169) administered to lactating sheep by intramuscular injection. PCB levels and excretion patterns in blood, milk, and faeces were time-dependent and differed from the composition of PCB congeners administered. Lactational transfer substantially exceeded the faecal transfer. Between days 3 and 7, the amount of PCB congeners 54 and 169 excreted in milk was around 50- and 800-fold higher than the amount of these two congeners excreted viamore » faeces. During the same period, the relative contribution of co-planar PCB congeners (80 and 169) in PCB pattern decreased in blood and increased in milk and faeces compared with non-planar PCBs (54 and 155). On day 3, the ratio PCB 169 to 54 was 7-fold higher in milk than in faeces. PCB congeners with log K{sub ow} values under 6.5 reached peaks of their excretion in milk within the first three days after administration, while the super-lipophilic PCB 169 congener with log K{sub ow} value of over 7 has not reached the plateau until day 10, but afterwards, its level remained relatively high throughout the observation period. During the 57-day follow-up period, the excretion of PCB 80, 155, and 169 in milk was 4.5-, 14-, and 46-fold greater compared with PCB 54. Differences in levels and patterns were explained with some physico-chemical properties of individual PCB congeners, such as lipophilicity, planarity, metabolic stability, sorption/diffusion properties.« less

Hydroxylated and methyl sulfone PCB metabolites in adipose and whole blood of polar bear (Ursus maritimus) from East Greenland.

PubMed

Sandala, G M; Sonne-Hansen, C; Dietz, R; Muir, D C G; Valters, K; Bennett, E R; Born, E W; Letcher, R J

2004-09-20

Persistent methyl sulfone (MeSO2-) and hydroxylated (HO-) polychlorinated biphenyl (PCB) metabolites have emerged as important classes of environmental contaminants in vertebrate, aquatic biota and humans. In the present study, PCB, MeSO2-PCB and HO-PCB concentrations and congener patterns were determined in the whole blood and adipose tissue of male (n = 7) and female (n = 12) polar bears (Ursus maritimus) of random age (3-25 years of age), and collected in 1999-2001 from the Ittoqqortoormiit/Scoresby Sound area in central East Greenland. There was no significant difference (P < 0.05) between males and females with respect to PCB or PCB metabolite concentrations in either tissue. The mean sum (Sigma) PCB concentrations were 7020+/-3366 ng/g lipid weight (lw) (range 2708-18148 ng/g lw) and 46.1+/-44.6 ng/g wet weight (ww) (range 12.6-204.2 ng/g ww) in adipose and blood, respectively. The mean Sigma-HO-PCB concentration in whole blood was 182.3+/-72.1 ng/g ww (range 93.8-382.1 ng/g ww). The mean Sigma-HO-PCB to Sigma-PCB concentration ratios in whole blood were 4.59+/-3.58 (range 1.03-11.88) and 8.30+/-5.56 (range 2.16-19.47) in females and males, respectively, which are the highest ratios reported so far for polar bears from any population, or for any free-ranging animal. Sigma-HO-PCB concentrations were greater than all other major classes of organochlorines (i.e. Sigma-PCBs, Sigma-MeSO2-PCBs, Sigma-chlordanes (CHLs), Sigma-hexachlorocyclohexanes (HCHs) and Sigma-chlorobenzenes (CBzs). The mean Sigma-MeSO2-PCB concentrations were 699+/-836 ng/g lw (range 127-3920 ng/g lw) and 10.9+/-9.6 ng/g ww (range 4.3-52.1 ng/g ww) in the adipose and blood, respectively. Regardless of age and sex, in both adipose and whole blood the MeSO2-PCB congener pattern was dominated by 3'- and 4'-MeSO2-CB101 and -CB87, and 4-MeSO2-CB149 (approx. 70% of the Sigma-MeSO2-PCBs). Minor differences in the MeSO2-PCB congener pattern were observed between blood and adipose, which suggests the possible influence of metabolite structure on mobilization and/or deposition to the adipose tissue. Sixteen HO-PCB congeners and one di-HO-PCB congener were identified, and five HO-PCB isomers and one di-HO-PCB isomer were detected. However, congener patterns were dominated by 4'-OH-CB120, 4-HO-CB146/3-HO-CB153, 4-OH-CB187, 4'-HO-CB172, 4-HO-CB193 and 4,4'-di-HO-CB202 (> 10 ng/g ww). HO-PCB congener patterns in whole blood were not significantly different (P < 0.05) between males and females. Other chlorinated phenolic contaminants, pentachlorophenol (0.3+/-0.3 ng/g ww) and 4-HO-heptachlorostyrene (7.5+/-2.9 ng/g ww) were also detected in blood. To our knowledge, this is to first report comparing PCBs, MeSO2-PCBs and HO-PCBs in whole blood and adipose tissue in a free-ranging wildlife species. HO-PCBs and MeSO2-PCBs are both important circulating contaminants in polar bears from this eastern Greenland population. Given the known toxicities of PCB metabolites, this population of polar bear may be experiencing health risks due to exposure to a complex loading of organohalogen contaminants that include HO-PCB and MeSO2-PCB metabolites.

Study on polychlorobiphenyl serum levels in French consumers of freshwater fish.

PubMed

Desvignes, Virginie; Volatier, Jean-Luc; de Bels, Frédéric; Zeghnoun, Abdelkrim; Favrot, Marie-Christine; Marchand, Philippe; Le Bizec, Bruno; Rivière, Gilles; Leblanc, Jean-Charles; Merlo, Mathilde

2015-02-01

Polychlorobiphenyls (PCBs) are persistent pollutants that are widespread in the environment and in foodstuffs, particularly in freshwater fish, which frequently exceed the maximum levels set by European regulations. First, we describe the consumption of freshwater fish and serum PCB levels in French anglers, a population expected to have the highest level of dietary PCB exposure. Second, we investigated whether there is a statistical relationship between serum PCB levels and the angler consumption of freshwater fish with high PCB bioaccumulation potential (PCB-BP(+) freshwater fish) in order to make recommendations with regard to safe consumption of freshwater fish. We conducted a survey of anglers from six sites with contrasting PCB contamination levels. The survey included a food consumption frequency questionnaire and blood samples were taken to assess serum PCB levels. We used a regression model to determine the main factors contributing to serum PCB levels. Consumption of PCB-BP(+) freshwater fish was relatively infrequent. Serum PCB levels of the study population and of women of childbearing age were in the same range as those observed in the French population and in neighbouring European countries, but higher than in the North American population. The two factors with the highest positive association with serum PCB levels were age (R(2)=61%) and the consumption of PCB-BP(+) freshwater fish (R(2)=2%). Using the regression model, we calculated, for several scenarios depending on the age and gender of the population, the maximum annual frequencies for PCB-BP(+) freshwater fish consumption that do not exceed the critical body burden threshold. Following the results of this study, the French agency for food, environmental and occupational health and safety (ANSES) issued an opinion and recommended some specific maximum freshwater fish consumption frequencies to protect the French general population. Copyright © 2014 Elsevier B.V. All rights reserved.

DISTRIBUTION OF PCB 84 ENANTIOMERS IN C57BL/6 MICE

EPA Science Inventory

Nineteen of the 209 possible PCB congeners exist as pairs of stable rotational isomers that are enantiomeric to each other. A racemic mixture of PCB atropisomers is present in technical PCB mixtures, thus raising concerns about enantioselective distribution, metabolism, and dispo...

In vitro effects of polychlorinated biphenyls on human platelets.

PubMed Central

Raulf, M; König, W

1991-01-01

Incubation of human platelets with polychlorinated biphenyls (PCB) induced and modulated cellular responses to a different degree. 3,3',4,4'-tetrachlorobiphenyl (TCB) was a more potent inducer of platelet aggregation, serotonin release and 12-HETE generation compared to the other PCB [2,2',3,3'-TCB,3,3'-dichlorobiphenyl (DCB),2,2',4,5,5'-pentachlorobiphenyl (PCB)]. 3,3',4,4'-TCB showed synergistic effects, in combination with other PCB, such as an enhanced formation of 12-HETE, when 3,3'-DCB and 2,2',3,3'-TCB were applied simultaneously. The combined incubation of platelets with PCB and sodium fluoride (NaF), an activator of G-proteins, resulted in synergistic 12-HETE generation compared to stimulation with NaF or PCB alone. Furthermore, when platelets were incubated with the PCB the enzymatic steps controlling the metabolism of the platelet-activating factor (PAF) were modulated. A direct relationship between the extent of platelet activation and the chloro-substitution pattern of PCB exists. PMID:1901832

Incubation stage and polychlorinated biphenyl (PCB) congener patterns in an altricial and precocial bird species

USGS Publications Warehouse

Custer, Christine M.; Custer, Thomas W.; Thyen, Stefan; Becker, Peter H.

2014-01-01

The composition of polychlorinated biphenyl (PCB) congeners was compared between non-incubated and embryonated eggs of tree swallows (Tachycineta bicolor) and little terns (Sterna albifrons) to determine if measurable changes in PCB congeners occurred during the embryonic period. There was no indication of changes in PCB congener patterns over the incubation period in tree swallows in 1999 and 2000 at a site with very high PCB exposure or a site with more modest PCB exposure. Additionally, congeners known to be either quickly metabolized or conserved based on experimental studies did not generally respond as predicted. Similarly, PCB congener patterns in eggs of little terns from Bottsand, Schleswig-Holstein, Germany, did not differ between non-incubated and embryonated eggs. The results from both species suggest that the stage of incubation is not an important consideration when evaluating PCB congener patterns; comparisons and assessments can be made with eggs collected at all stages of incubation.

Incubation stage and polychlorinated biphenyl (PCB) congener patterns in an altricial and precocial bird species.

PubMed

Custer, Christine M; Custer, Thomas W; Thyen, Stefan; Becker, Peter H

2014-12-01

The composition of polychlorinated biphenyl (PCB) congeners was compared between non-incubated and embryonated eggs of tree swallows (Tachycineta bicolor) and little terns (Sterna albifrons) to determine if measurable changes in PCB congeners occurred during the embryonic period. There was no indication of changes in PCB congener patterns over the incubation period in tree swallows in 1999 and 2000 at a site with very high PCB exposure or a site with more modest PCB exposure. Additionally, congeners known to be either quickly metabolized or conserved based on experimental studies did not generally respond as predicted. Similarly, PCB congener patterns in eggs of little terns from Bottsand, Schleswig-Holstein, Germany, did not differ between non-incubated and embryonated eggs. The results from both species suggest that the stage of incubation is not an important consideration when evaluating PCB congener patterns; comparisons and assessments can be made with eggs collected at all stages of incubation. Published by Elsevier Ltd.

Novel Air Flow Meter for an Automobile Engine Using a Si Sensor with Porous Si Thermal Isolation

PubMed Central

Hourdakis, Emmanouel; Sarafis, Panagiotis; Nassiopoulou, Androula G.

2012-01-01

An air flow meter for measuring the intake air of an automobile engine is presented. It is based on a miniaturized silicon thermal mass flow sensor using a thick porous Si (Po-Si) layer for local thermal isolation from the Si substrate, on which the sensor active elements are integrated. The sensor is mounted on one side of a printed circuit board (PCB), on the other side of which the readout and control electronics of the meter are mounted. The PCB is fixed on a housing containing a semi-cylindrical flow tube, in the middle of which the sensor is situated. An important advantage of the present air flow meter is that it detects with equal sensitivity both forward and reverse flows. Two prototypes were fabricated, a laboratory prototype for flow calibration using mass flow controllers and a final demonstrator with the housing mounted in an automobile engine inlet tube. The final demonstrator was tested in real life conditions in the engine inlet tube of a truck. It shows an almost linear response in a large flow range between –6,500 kg/h and +6,500 kg/h, which is an order of magnitude larger than the ones usually encountered in an automobile engine. PMID:23202189

Personal electronics printing via tapping mode composite liquid metal ink delivery and adhesion mechanism

NASA Astrophysics Data System (ADS)

Zheng, Yi; He, Zhi-Zhu; Yang, Jun; Liu, Jing

2014-04-01

Printed electronics is becoming increasingly important in a variety of newly emerging areas. However, restricted to the rather limited conductive inks and available printing strategies, the current electronics manufacture is usually confined to industry level. Here, we show a highly cost-effective and entirely automatic printing way towards personal electronics making, through introducing a tapping-mode composite fluid delivery system. Fundamental mechanisms regarding the reliable printing, transfer and adhesion of the liquid metal inks on the substrate were disclosed through systematic theoretical interpretation and experimental measurements. With this liquid metal printer, a series of representative electronic patterns spanning from single wires to desired complex configurations such as integrated circuit (IC), printed-circuits-on-board (PCB), electronic paintings, or more do-it-yourself (DIY) devices, were demonstrated to be printed out with high precision in a moment. And the total machine cost already reached personally affordable price. This is hard to achieve by a conventional PCB technology which generally takes long time and is material, water and energy consuming, while the existing printed electronics is still far away from the real direct printing goal. The present work opens the way for large scale personal electronics manufacture and is expected to generate important value for the coming society.

Effects of Solder Temperature on Pin Through-Hole during Wave Soldering: Thermal-Fluid Structure Interaction Analysis

PubMed Central

Abdul Aziz, M. S.; Abdullah, M. Z.; Khor, C. Y.

2014-01-01

An efficient simulation technique was proposed to examine the thermal-fluid structure interaction in the effects of solder temperature on pin through-hole during wave soldering. This study investigated the capillary flow behavior as well as the displacement, temperature distribution, and von Mises stress of a pin passed through a solder material. A single pin through-hole connector mounted on a printed circuit board (PCB) was simulated using a 3D model solved by FLUENT. The ABAQUS solver was employed to analyze the pin structure at solder temperatures of 456.15 K (183°C) < T < 643.15 K (370°C). Both solvers were coupled by the real time coupling software and mesh-based parallel code coupling interface during analysis. In addition, an experiment was conducted to measure the temperature difference (ΔT) between the top and the bottom of the pin. Analysis results showed that an increase in temperature increased the structural displacement and the von Mises stress. Filling time exhibited a quadratic relationship to the increment of temperature. The deformation of pin showed a linear correlation to the temperature. The ΔT obtained from the simulation and the experimental method were validated. This study elucidates and clearly illustrates wave soldering for engineers in the PCB assembly industry. PMID:25225638

Novel air flow meter for an automobile engine using a Si sensor with porous Si thermal isolation.

PubMed

Hourdakis, Emmanouel; Sarafis, Panagiotis; Nassiopoulou, Androula G

2012-11-02

An air flow meter for measuring the intake air of an automobile engine is presented. It is based on a miniaturized silicon thermal mass flow sensor using a thick porous Si (Po-Si) layer for local thermal isolation from the Si substrate, on which the sensor active elements are integrated. The sensor is mounted on one side of a printed circuit board (PCB), on the other side of which the readout and control electronics of the meter are mounted. The PCB is fixed on a housing containing a semi-cylindrical flow tube, in the middle of which the sensor is situated. An important advantage of the present air flow meter is that it detects with equal sensitivity both forward and reverse flows. Two prototypes were fabricated, a laboratory prototype for flow calibration using mass flow controllers and a final demonstrator with the housing mounted in an automobile engine inlet tube. The final demonstrator was tested in real life conditions in the engine inlet tube of a truck. It shows an almost linear response in a large flow range between –6,500 kg/h and +6,500 kg/h, which is an order of magnitude larger than the ones usually encountered in an automobile engine.

Effects of solder temperature on pin through-hole during wave soldering: thermal-fluid structure interaction analysis.

PubMed

Aziz, M S Abdul; Abdullah, M Z; Khor, C Y

2014-01-01

An efficient simulation technique was proposed to examine the thermal-fluid structure interaction in the effects of solder temperature on pin through-hole during wave soldering. This study investigated the capillary flow behavior as well as the displacement, temperature distribution, and von Mises stress of a pin passed through a solder material. A single pin through-hole connector mounted on a printed circuit board (PCB) was simulated using a 3D model solved by FLUENT. The ABAQUS solver was employed to analyze the pin structure at solder temperatures of 456.15 K (183(°)C) < T < 643.15 K (370(°)C). Both solvers were coupled by the real time coupling software and mesh-based parallel code coupling interface during analysis. In addition, an experiment was conducted to measure the temperature difference (ΔT) between the top and the bottom of the pin. Analysis results showed that an increase in temperature increased the structural displacement and the von Mises stress. Filling time exhibited a quadratic relationship to the increment of temperature. The deformation of pin showed a linear correlation to the temperature. The ΔT obtained from the simulation and the experimental method were validated. This study elucidates and clearly illustrates wave soldering for engineers in the PCB assembly industry.

Personal electronics printing via tapping mode composite liquid metal ink delivery and adhesion mechanism.

PubMed

Zheng, Yi; He, Zhi-Zhu; Yang, Jun; Liu, Jing

2014-04-04

Printed electronics is becoming increasingly important in a variety of newly emerging areas. However, restricted to the rather limited conductive inks and available printing strategies, the current electronics manufacture is usually confined to industry level. Here, we show a highly cost-effective and entirely automatic printing way towards personal electronics making, through introducing a tapping-mode composite fluid delivery system. Fundamental mechanisms regarding the reliable printing, transfer and adhesion of the liquid metal inks on the substrate were disclosed through systematic theoretical interpretation and experimental measurements. With this liquid metal printer, a series of representative electronic patterns spanning from single wires to desired complex configurations such as integrated circuit (IC), printed-circuits-on-board (PCB), electronic paintings, or more do-it-yourself (DIY) devices, were demonstrated to be printed out with high precision in a moment. And the total machine cost already reached personally affordable price. This is hard to achieve by a conventional PCB technology which generally takes long time and is material, water and energy consuming, while the existing printed electronics is still far away from the real direct printing goal. The present work opens the way for large scale personal electronics manufacture and is expected to generate important value for the coming society.

Personal electronics printing via tapping mode composite liquid metal ink delivery and adhesion mechanism

PubMed Central

Zheng, Yi; He, Zhi-Zhu; Yang, Jun; Liu, Jing

2014-01-01

Printed electronics is becoming increasingly important in a variety of newly emerging areas. However, restricted to the rather limited conductive inks and available printing strategies, the current electronics manufacture is usually confined to industry level. Here, we show a highly cost-effective and entirely automatic printing way towards personal electronics making, through introducing a tapping-mode composite fluid delivery system. Fundamental mechanisms regarding the reliable printing, transfer and adhesion of the liquid metal inks on the substrate were disclosed through systematic theoretical interpretation and experimental measurements. With this liquid metal printer, a series of representative electronic patterns spanning from single wires to desired complex configurations such as integrated circuit (IC), printed-circuits-on-board (PCB), electronic paintings, or more do-it-yourself (DIY) devices, were demonstrated to be printed out with high precision in a moment. And the total machine cost already reached personally affordable price. This is hard to achieve by a conventional PCB technology which generally takes long time and is material, water and energy consuming, while the existing printed electronics is still far away from the real direct printing goal. The present work opens the way for large scale personal electronics manufacture and is expected to generate important value for the coming society. PMID:24699375

Management of Bottom Sediments Containing Toxic Substances. Proceedings of the U.S./Japan Experts Meeting (8th) Held at Tokyo, Japan on 8-10 November 1982

DTIC Science & Technology

1984-07-01

curtain has a peripheral length of 300 m). The spraying is done by a pump and 32 I 0 0. 00 0 -O4 No..14 NO.3 0 𔃺O 7 No.2N 14o.9 of Disrio No.4 0 04 0...Erosion Board, Washington, D.C., May 1950. HALL, J.V. and WATTS, G.M.,, Beach Rehabilitation by Fill and Nourishment. TYazactionz o6 the AmeAican...Demonstration Project 9J a statistically significant 1ioaccumulation of PCB. The capping exercise was based upon two premises: (1) that the capped mound would

Wideband Array for C, X, and Ku-Band Applications with 5.3:1 Bandwidth

NASA Technical Reports Server (NTRS)

Novak, Markus H.; Volakis, John L.; Miranda, Félix A.

2015-01-01

Satellite communication has largely been accomplished using reflector antennas. However, such antennas are inherently bulky, and rely on mechanical steering. For this reason, ultra-wideband (UWB) and beam forming arrays have received strong interest. These lower weight, size,and cost arrays can combine many satellite applicationsspread throughout the C–Ka bands (4–40 GHz).To this end, we seek to develop an UWB Tightly-Coupled Dipole Array (TCDA) with the following attributes: UWB band operation (3.5–18.5 GHz) with low loss; 45° or more scanning in all planes; Low-cost Printed Circuit Board (PCB) fabrication; Scalable to Ka-band and above.

Results of Sediment Sampling and Elutriate Testing at the Proposed Little Sioux Bend Shallow Water Habitat Project Site

DTIC Science & Technology

2013-04-01

Aroclor1248 10 50 Endrin 1.0 9.9 PCB - Aroclor1268 10 50 Endrin Aldehyde 1.0 9.9 PCB - Aroclor1232 10 50 Endrin Ketone 0.8 9.9 PCB - Aroclor1254 10 50...1.0 Endrin Aldehyde 0.011 0.1 PCB - Aroclor1232 0.2 1.0 Endrin Ketone 0.006 0.1 PCB - Aroclor1254 0.2 1.0 Heptachlor 0.009 0.05 PCB - Aroclor1242...Found Endosulfan I n.d. Endosulfan II n.d. Endosulfan sulfate n.d. Endrin n.d. Endrin aldehyde n.d. Endrin ketone n.d. Heptachlor n.d. Heptachlor

Results of Sediment Sampling and Elutriate Testing at the Proposed Middle Decatur Shallow Water Habitat Project Site

DTIC Science & Technology

2013-07-01

0.1 PCB - Aroclor1268 0.3 1.0 Endrin Aldehyde 0.011 0.1 PCB - Aroclor1232 0.2 1.0 Endrin Ketone 0.006 0.1 PCB - Aroclor1254 0.2 1.0 Heptachlor...0.056 ----- Endosulfan sulfate ----- 89 89 Endrin 0.086 0.036 ----- Endrin aldehyde ----- 0.30 0.30 Heptachlor 0.52 0.00079 0.00079 Heptachlor...Aroclor1221 10 50 Endosulfan Sulfate 1.0 9.9 PCB - Aroclor1248 10 50 Endrin 1.0 9.9 PCB - Aroclor1268 10 50 Endrin Aldehyde 1.0 9.9 PCB - Aroclor1232

Sexual difference in PCB concentrations of walleyes (Sander vitreus) from a pristine lake

USGS Publications Warehouse

Madenjian, C.P.; Hanchin, P.A.; Chernyak, S.M.; Begnoche, L.J.

2009-01-01

We determined polychlorinated biphenyl (PCB) concentrations in 15 adult female walleyes (Sander vitreus) and 15 adult male walleyes from South Manistique Lake (Michigan, United States), a relatively pristine lake with no point source inputs of PCBs. By measuring PCB concentration in gonads and in somatic tissue of the South Manistique Lake fish, we also estimated the expected change in PCB concentration due to spawning for both sexes. To determine whether gross growth efficiency differed between the sexes, we applied bioenergetics modeling. Results showed that, on average, adult males were 34% higher in PCB concentration than adult females in South Manistique Lake. Results from the PCB determinations of the gonads and somatic tissues revealed that shedding of the gametes led to 1% and 5% increases in PCB concentration for males and females, respectively. Therefore, shedding of the gametes could not explain the higher PCB concentration in adult male walleyes. Bioenergetics modeling results indicated that the sexual difference in PCB concentrations of South Manistique Lake walleyes was attributable, at least in part, to a sexual difference in gross growth efficiency (GGE). Adult female GGE was estimated to be up to 17% greater than adult male GGE.

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in Cyprinidae fish: Towards hints of their arrangements using advanced classification methods.

PubMed

Romanić, Snježana Herceg; Vuković, Gordana; Klinčić, Darija; Sarić, Marijana Matek; Župan, Ivan; Antanasijević, Davor; Popović, Aleksandar

2018-05-18

To tackle the ever-present global concern regarding human exposure to persistent organic pollutants (POPs) via food products, this study strived to indicate associations between organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in lake-fish tissue depending on the species and sampling season. Apart from the monitoring initiatives recommended in the Global Monitoring Plan for POPs, the study discussed 7 OCPs and 18 PCB congeners determined in three Cyprinidae species (rudd, carp, and Prussian carp) from Vransko Lake (Croatia), which are widely domesticated and reared as food fish across Europe and Asia. We exploit advanced classification algorithms, the Kohonen self-organizing maps (SOM) and Decision Trees (DT), to search for POP patterns typical for the investigated species. As indicated by SOM, some of the dioxin-like and non-dioxin-like PCBs (PCB-28, PCB-74, PCB-52, PCB-101, PCB-105, PCB-114, PCB-118, PCB-156 and PCB-157), α-HCH and β-HCH caused dissimilarities among fish species, but regardless of their weight and length. To support these suggestions, DT analysis sequenced the fish species and seasons based on the concentration of heavier congeners. The presented assumptions indicated that the supplemental application of SOM and DT offers advantageous features over the usually rough interpretation of POPs pattern and over the single use of the methods. Copyright © 2018 Elsevier Inc. All rights reserved.

[Blood PCB concentrations and their tendencies examined in Fukuoka 2007-2010 annual inspections for Yusho].

PubMed

Hori, Tsuguhide; Yasutake, Daisuke; Ashizuka, Yuki; Takahashi, Koji; Kajiwara, Jumboku; Hirata, Teruaki; Uchi, Hiroshi; Furue, Masutaka

2011-04-01

We performed PCB congener specific analysis using HRGC/HRMS and determined their concentrations and blood chromatogram classifications in 275 individual blood samples collected during annual Yusho examinations between 2007 and 2010. When both blood total PCB concentrations and blood chromatogram classifications were compared among eleven Yusho patients undergoing examinations between 2007 and 2010, the longitudinal concentrations and classifications in the respective individuals hardly changed over these years. In a subset of persons suspected of Yusho, it was found that the mean total blood concentrations of three index congeners, that is, 2, 3', 4, 4', 5-pentaCB (PCB118), 2, 2', 4, 4', 5, 5'-hexaCB (PCB153), 2, 3, 3', 4, 4', 5-hexaCB (PCB156) and mean blood total PCB concentrations gradually decreased between 2007 and 2010. Mean concentration of PCB118 in blood from persons suspected of Yusho was calculated as 0.035 ng/g in the 2010 examination, which was 36% lower than the mean value of 0.054 ng/g in the 2007 examination: the concentration of PCB118 showed the highest degree of decrease among the three index congeners. Among persons suspected of Yusho, occupational rates of persons with blood PCB concentrations below one ppb in the entire population increased from approx. 50% in 2007 to approx. 70% in 2010. The lowest concentration of PCB156 in blood of persons suspected of Yusho in 2010 was 0.43 pg/g, which was almost equivalent to the limit of the determination value on HRGC/HRMS, S/N = 10.

Hepatic Metabolism Affects the Atropselective Disposition of 2,2′,3,3′,6,6′-Hexachlorobiphenyl (PCB 136) in Mice

PubMed Central

2015-01-01

To understand the role of hepatic vs extrahepatic metabolism in the disposition of chiral PCBs, we studied the disposition of 2,2′,3,3′,6,6′-hexachlorobiphenyl (PCB 136) and its hydroxylated metabolites (HO-PCBs) in mice with defective hepatic metabolism due to the liver-specific deletion of cytochrome P450 oxidoreductase (KO mice). Female KO and congenic wild type (WT) mice were treated with racemic PCB 136, and levels and chiral signatures of PCB 136 and HO-PCBs were determined in tissues and excreta 3 days after PCB administration. PCB 136 tissue levels were higher in KO compared to WT mice. Feces was a major route of PCB metabolite excretion, with 2,2′,3,3′,6,6′-hexachlorobiphenyl-5-ol being the major metabolite recovered from feces. (+)-PCB 136, the second eluting PCB 136 atropisomers, was enriched in all tissues and excreta. The second eluting atropisomers of the HO-PCBs metabolites were enriched in blood and liver; 2,2′,3,3′,6,6′-hexachlorobiphenyl-5-ol in blood was an exception and displayed an enrichment of the first eluting atropisomers. Fecal HO-PCB levels and chiral signatures changed with time and differed between KO and WT mice, with larger HO-PCB enantiomeric fractions in WT compared to KO mice. Our results demonstrate that hepatic and, possibly, extrahepatic cytochrome P450 (P450) enzymes play a role in the disposition of PCBs. PMID:25420130

LONG-TERM RECOVERY OF PCB-CONTAMINATED SEDIMENTS AT THE LAKE HARTWELL SUPERFUND SITE: PCB DECHLORINATION. 2. RATES AND EXTENT

EPA Science Inventory

This paper reports on extensive polychlorinated biphenyl (PCB) dechlorination measured in Lake Hartwell (Pickens County, SC) sediments. Vertical sediment cores were collected from 18 locations in Lake Hartwell (Pickens County, SC) and analyzed in 5-cm increments for PCB congeners...

40 CFR 761.359 - Reporting the PCB concentrations in samples.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) TOXIC SUBSTANCES CONTROL ACT POLYCHLORINATED BIPHENYLS (PCBs) MANUFACTURING, PROCESSING, DISTRIBUTION IN COMMERCE, AND USE PROHIBITIONS Sampling Non-Liquid, Non-Metal PCB Bulk Product Waste for Purposes of Characterization for PCB Disposal in Accordance With § 761.62, and Sampling PCB Remediation Waste Destined for Off...

40 CFR 761.359 - Reporting the PCB concentrations in samples.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) TOXIC SUBSTANCES CONTROL ACT POLYCHLORINATED BIPHENYLS (PCBs) MANUFACTURING, PROCESSING, DISTRIBUTION IN COMMERCE, AND USE PROHIBITIONS Sampling Non-Liquid, Non-Metal PCB Bulk Product Waste for Purposes of Characterization for PCB Disposal in Accordance With § 761.62, and Sampling PCB Remediation Waste Destined for Off...

40 CFR 761.359 - Reporting the PCB concentrations in samples.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) TOXIC SUBSTANCES CONTROL ACT POLYCHLORINATED BIPHENYLS (PCBs) MANUFACTURING, PROCESSING, DISTRIBUTION IN COMMERCE, AND USE PROHIBITIONS Sampling Non-Liquid, Non-Metal PCB Bulk Product Waste for Purposes of Characterization for PCB Disposal in Accordance With § 761.62, and Sampling PCB Remediation Waste Destined for Off...

40 CFR 761.359 - Reporting the PCB concentrations in samples.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) TOXIC SUBSTANCES CONTROL ACT POLYCHLORINATED BIPHENYLS (PCBs) MANUFACTURING, PROCESSING, DISTRIBUTION IN COMMERCE, AND USE PROHIBITIONS Sampling Non-Liquid, Non-Metal PCB Bulk Product Waste for Purposes of Characterization for PCB Disposal in Accordance With § 761.62, and Sampling PCB Remediation Waste Destined for Off...

77 FR 13603 - Anniston PCB Superfund Site; Anniston, Calhoun County, AL; Correction

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-07

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9644-2; CERCLA-04-2012-3763] Anniston PCB Superfund Site... FR 11533 (FRL-9637-7), EPA posted a Notice of Amended Settlement concerning the Anniston PCB... the settlement are available from Ms. Paula V. Painter. Submit your comments by Site name Anniston PCB...

40 CFR 761.61 - PCB remediation waste.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false PCB remediation waste. 761.61 Section... PROHIBITIONS Storage and Disposal § 761.61 PCB remediation waste. This section provides cleanup and disposal options for PCB remediation waste. Any person cleaning up and disposing of PCBs managed under this section...

Compound- and sex-specific effects on programming of energy and immune homeostasis in adult C57BL/6JxFVB mice after perinatal TCDD and PCB 153.

PubMed

van Esterik, J C J; Verharen, H W; Hodemaekers, H M; Gremmer, E R; Nagarajah, B; Kamstra, J H; Dollé, M E T; Legler, J; van der Ven, L T M

2015-12-01

Early life exposure to endocrine disrupting compounds has been linked to chronic diseases later in life, like obesity and related metabolic disorders. We exposed C57BL/6JxFVB hybrid mice to the aryl hydrocarbon receptor agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and the constitutive androstane receptor/pregnane X receptor agonist polychlorinated biphenyl 153 (PCB 153) in an experimental design relevant for human exposure. Exposure occurred during gestation and lactation via maternal feed to a wide dose range (TCDD: 10-10,000 pg/kg body weight/day; PCB 153: 0.09-1406 μg/kg body weight/d). Then exposure was ceased and offspring were followed up to 1 year of age. Metabolic parameters like body weight, fat pad weights, glucose tolerance, endocrine serum profile, and neurobehavioral and immunological parameters were determined. Body weight was transiently affected by both compounds throughout the follow-up. TCDD-exposed males showed decreased fat pad and spleen weights and an increase in IL-4 production of splenic immune cells. In contrast, females showed increased fat pad weights and production of IFNγ. PCB 153-exposed males showed an increase in glucose, whereas females showed an increase in glucagon, a decrease in pancreas weight, and an increase in thymus weight. In conclusion, early life exposure to TCDD appears to affect programming of energy and immune homeostasis in offspring, whereas the effects of perinatal PCB 153 were mainly on programming of glucose homeostasis. Both compounds act sex-specifically. Lowest derived BMDLs (lower bounds of the (two sided) 90%-confidence interval for the benchmark dose) for both compounds are not lower than current tolerable daily intakes.

The M68HC11 gripper controller electronics

NASA Technical Reports Server (NTRS)

Kelley, Robert B.; Bethel, Jeffrey

1991-01-01

This document describes the instrumentation, operational theory, circuit implementation, calibration procedures, and general notes for the CIRSSE general purpose pneumatic hand. The mechanical design and the control software are discussed. The circuit design, PCB layout, hand instrumentation, and controller construction described in detail in this document are the result of a senior project.

Results of Sediment Sampling and Elutriate Testing at the Proposed Middle Decatur Revetment Shallow Water Habitat Project Site

DTIC Science & Technology

2014-07-01

Aroclor1248 10 50 Endrin 1.0 9.9 PCB - Aroclor1268 10 50 Endrin Aldehyde 1.0 9.9 PCB - Aroclor1232 10 50 Endrin Ketone 0.8 9.9 PCB - Aroclor1254...1.0 Endrin Aldehyde 0.011 0.1 PCB - Aroclor1232 0.2 1.0 Endrin Ketone 0.006 0.1 PCB - Aroclor1254 0.2 1.0 Heptachlor 0.009 0.05 PCB - Aroclor1242...Composite Endrin aldehyde ɘ.009 ug/kg U EPA 8081 496.524 0.009 10 20-May-14 1401161-01 MDR-S1 8-May-14 9:30 AM 0 -10 Composite Endrin ketone ɘ.02

Assessment of questionnaire-based PCB exposure focused on food frequency in birth cohorts in Japan.

PubMed

Eguchi, Akifumi; Otake, Masae; Hanazato, Masamichi; Suzuki, Norimichi; Matsuno, Yoshiharu; Nakaoka, Hiroko; Todaka, Emiko; Mori, Chisato

2017-02-01

We investigated the relationship between food frequency questionnaire (FFQ) responses and serum polychlorinated biphenyl (PCB) levels of mothers and fathers recruited from the Chiba Regional Center, which is one of the 15 regional centers of the Japan Environment and Children's Study (mothers: n = 1477, fathers: n = 219). The expected PCB values were estimated from the participants' FFQ answers and medical records (age, body mass index and number of deliveries). Based on the stepwise forward selection results of Bayesian regression models, age and fish and egg consumption were positively associated with PCB concentrations and a number of deliveries were negatively associated with PCB concentrations in mothers, whereas only age was positively associated with PCB concentrations in fathers.These findings indicated that the estimation of daily dietary intake may be useful for the prediction of PCB concentration for mothers.

Design of a Miniaturized Langmuir Plasma Probe for the QuadSat/PnP

NASA Astrophysics Data System (ADS)

Landavazo, M.; Jorgensen, A. M.; Del Barga, C.; Ferguson, D.; Guillette, D.; Huynh, A.; Klepper, J.; Kuker, J.; Lyke, J. C.; Marohn, B.; Mason, J.; Quiroga, J.; Ravindran, V.; Yelton, C.; Zagrai, A. N.; Zufelt, B.

2011-12-01

We have developed a miniaturized Langmuir plasma probe for measuring plasma density in low-earth orbit. Measuring plasma density in the upper ionosphere is important as a diagnostic for the rest of the ionosphere and as an input to space weather forecasting models. Developing miniaturized instrumentation allows easier deployment of a large number of small satellites for monitoring space weather. Our instrument was designed for the Swedish QuadSat/PnP, with the following constraints: A volume constraint of 5x5x1.25cm for the electronics enclosure, a mass budget 100 g, and a power budget of 0.5 W. We met the volume and mass constraints and where able to use less power than budgeted, only 0.25 W. We designed the probe for a bias range of +/-15V and current measurements in the 1 nA to 1 mA range (6 orders of magnitude). Necessary voltage of +/- 15 V and 3.3 V were generated on-board from a single 5 V supply. The electronics suite is based off carefully selected yet affordable commercial components that exhibit low noise, low leakage currents and low power consumption. Size constraints, low noise and low leakage requirements called for a carefully designed four layer PCB with a properly guarded current path using surface mount components on both sides. An ultra-low power microcontroller handles instrument functionality and is fully controllable over i2c using SPA-1 space plug and play. We elected for a probe launched deployed, which required careful design to survive launch vibrations while staying within the mass budget. The QuadSat/PnP has not been launched at the time of writing. We will present details of the instrument design and initial calibration data.

Aroclor 1248 exposure leads to immunomodulation, decreased disease resistance and endocrine disruption in the brown bullhead, Ameiurus nebulosus.

PubMed

Iwanowicz, Luke R; Blazer, Vicki S; McCormick, Stephen D; Vanveld, Peter A; Ottinger, Christopher A

2009-06-04

The brown bullhead Ameiurus nebulosus is a species of the family Ictaluridae commonly used as a sentinel of environmental contamination. While these fish have been utilized for this purpose in areas contaminated with polychlorinated biphenyls (PCBs), few controlled, laboratory-based studies have been designed to document the effects of PCB mixtures in this species. Here, brown bullhead were exposed to the PCB mixture, Aroclor 1248, via intraperitoneal injection and the effects on immune function, plasma hormones and disease resistance were evaluated. Exposure to this mixture led to a decrease in bactericidal activity and circulating antibodies to Edwardsiella ictaluri present from a previous exposure to this pathogen. A subsequent E. ictaluri disease challenge led to significantly higher mortality in A1248 treated fish compared to vehicle-control fish. The mitogenic response to the T-cell mitogen, phytohemaglutinin-P, was increased compared to vehicle-control fish. The steroid hormone, cortisol, and the thyroid hormone, T3, were also significantly lower in A1248 exposed fish. In summary, we have validated a number of functional immune assays for application in brown bullhead immunotoxicity studies. Additionally, we have demonstrated that the PCB mixture (A1248) modulates both immune function and endocrine physiology in brown bullhead. Such data may compliment the interpretation of data yielded from applied field studies conducted in PCB contaminated aquatic ecosystems.

Aroclor 1248 exposure leads to immunomodulation, decreased disease resistance and endocrine disruption in the brown bullhead, Ameiurus nebulosus

USGS Publications Warehouse

Iwanowicz, L.R.; Blazer, V.S.; McCormick, S.D.; Van Veld, P.A.; Ottinger, C.A.

2009-01-01

The brown bullhead Ameiurus nebulosus is a species of the family Ictaluridae commonly used as a sentinel of environmental contamination. While these fish have been utilized for this purpose in areas contaminated with polychlorinated biphenyls (PCBs), few controlled, laboratory-based studies have been designed to document the effects of PCB mixtures in this species. Here, brown bullhead were exposed to the PCB mixture, Aroclor 1248, via intraperitoneal injection and the effects on immune function, plasma hormones and disease resistance were evaluated. Exposure to this mixture led to a decrease in bactericidal activity and circulating antibodies to Edwardsiella ictaluri present from a previous exposure to this pathogen. A subsequent E. ictaluri disease challenge led to significantly higher mortality in A1248 treated fish compared to vehicle-control fish. The mitogenic response to the T-cell mitogen, phytohemaglutinin-P, was increased compared to vehicle-control fish. The steroid hormone, cortisol, and the thyroid hormone, T3, were also significantly lower in A1248 exposed fish. In summary, we have validated a number of functional immune assays for application in brown bullhead immunotoxicity studies. Additionally, we have demonstrated that the PCB mixture (A1248) modulates both immune function and endocrine physiology in brown bullhead. Such data may compliment the interpretation of data yielded from applied field studies conducted in PCB contaminated aquatic ecosystems.

40 CFR 761.63 - PCB household waste storage and disposal.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false PCB household waste storage and..., AND USE PROHIBITIONS Storage and Disposal § 761.63 PCB household waste storage and disposal. PCB household waste, as defined at § 761.3, managed in a facility permitted, licensed, or registered by a State...

40 CFR 761.63 - PCB household waste storage and disposal.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false PCB household waste storage and..., AND USE PROHIBITIONS Storage and Disposal § 761.63 PCB household waste storage and disposal. PCB household waste, as defined at § 761.3, managed in a facility permitted, licensed, or registered by a State...

40 CFR 761.63 - PCB household waste storage and disposal.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false PCB household waste storage and..., AND USE PROHIBITIONS Storage and Disposal § 761.63 PCB household waste storage and disposal. PCB household waste, as defined at § 761.3, managed in a facility permitted, licensed, or registered by a State...

40 CFR 761.63 - PCB household waste storage and disposal.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false PCB household waste storage and..., AND USE PROHIBITIONS Storage and Disposal § 761.63 PCB household waste storage and disposal. PCB household waste, as defined at § 761.3, managed in a facility permitted, licensed, or registered by a State...

21 CFR 509.15 - Use of polychlorinated biphenyls (PCB's) in establishments manufacturing food-packaging materials.

Code of Federal Regulations, 2012 CFR

2012-04-01

...-packaging materials shall: (i) Have the heat exchange fluid used in existing equipment for manufacturing... manufacturing practices be replaced with a heat exchange fluid that does not contain PCB's. (ii) Eliminate to... (Japan). PCB's are highly stable, heat resistant, and nonflammable chemicals. Industrial uses of PCB's...

21 CFR 509.15 - Use of polychlorinated biphenyls (PCB's) in establishments manufacturing food-packaging materials.

Code of Federal Regulations, 2013 CFR

2013-04-01

...-packaging materials shall: (i) Have the heat exchange fluid used in existing equipment for manufacturing... manufacturing practices be replaced with a heat exchange fluid that does not contain PCB's. (ii) Eliminate to... (Japan). PCB's are highly stable, heat resistant, and nonflammable chemicals. Industrial uses of PCB's...

21 CFR 109.15 - Use of polychlorinated biphenyls (PCB's) in establishments manufacturing food-packaging materials.

Code of Federal Regulations, 2012 CFR

2012-04-01

...-packaging materials shall: (i) Have the heat exchange fluid used in existing equipment for manufacturing... manufacturing practices be replaced with a heat exchange fluid that does not contain PCB's. (ii) Eliminate to... (Japan). PCB's are highly stable, heat resistant, and nonflammable chemicals. Industrial uses of PCB's...

21 CFR 109.15 - Use of polychlorinated biphenyls (PCB's) in establishments manufacturing food-packaging materials.

Code of Federal Regulations, 2014 CFR

2014-04-01

...-packaging materials shall: (i) Have the heat exchange fluid used in existing equipment for manufacturing... manufacturing practices be replaced with a heat exchange fluid that does not contain PCB's. (ii) Eliminate to... (Japan). PCB's are highly stable, heat resistant, and nonflammable chemicals. Industrial uses of PCB's...

40 CFR 261.8 - PCB wastes regulated under Toxic Substance Control Act.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 26 2011-07-01 2011-07-01 false PCB wastes regulated under Toxic... (CONTINUED) SOLID WASTES (CONTINUED) IDENTIFICATION AND LISTING OF HAZARDOUS WASTE General § 261.8 PCB wastes regulated under Toxic Substance Control Act. The disposal of PCB-containing dielectric fluid and electric...

40 CFR 761.211 - Unmanifested waste report.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROHIBITIONS PCB Waste Disposal Records and Reports § 761.211 Unmanifested waste report. (a) After April 4, 1990, if a PCB commercial storage or disposal facility receives any shipment of PCB waste from an off...), and any part of the shipment consists of any PCB waste regulated for disposal, then the owner or...

40 CFR 761.207 - The manifest-general requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., AND USE PROHIBITIONS PCB Waste Disposal Records and Reports § 761.207 The manifest—general..., the earliest date of removal from service for disposal, and the weight in kilograms of the PCB waste..., the date of removal from service for disposal, and weight in kilograms of the PCB waste in each PCB...

40 CFR 761.219 - One-year exception reporting.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PROHIBITIONS PCB Waste Disposal Records and Reports § 761.219 One-year exception reporting. (a) A disposer of... affecting the facility's disposal capacity, the disposer of PCB waste could not dispose of the affected PCBs... PCB Items within 1 year from the date of removal from service for disposal. (d) PCB/radioactive waste...

40 CFR 261.8 - PCB wastes regulated under Toxic Substance Control Act.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 27 2013-07-01 2013-07-01 false PCB wastes regulated under Toxic... (CONTINUED) SOLID WASTES (CONTINUED) IDENTIFICATION AND LISTING OF HAZARDOUS WASTE General § 261.8 PCB wastes regulated under Toxic Substance Control Act. The disposal of PCB-containing dielectric fluid and electric...

40 CFR 761.219 - One-year exception reporting.

Code of Federal Regulations, 2014 CFR

2014-07-01

... PROHIBITIONS PCB Waste Disposal Records and Reports § 761.219 One-year exception reporting. (a) A disposer of... affecting the facility's disposal capacity, the disposer of PCB waste could not dispose of the affected PCBs... PCB Items within 1 year from the date of removal from service for disposal. (d) PCB/radioactive waste...

40 CFR 761.211 - Unmanifested waste report.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PROHIBITIONS PCB Waste Disposal Records and Reports § 761.211 Unmanifested waste report. (a) After April 4, 1990, if a PCB commercial storage or disposal facility receives any shipment of PCB waste from an off...), and any part of the shipment consists of any PCB waste regulated for disposal, then the owner or...

40 CFR 761.207 - The manifest-general requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., AND USE PROHIBITIONS PCB Waste Disposal Records and Reports § 761.207 The manifest—general..., the earliest date of removal from service for disposal, and the weight in kilograms of the PCB waste..., the date of removal from service for disposal, and weight in kilograms of the PCB waste in each PCB...

40 CFR 261.8 - PCB wastes regulated under Toxic Substance Control Act.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 27 2012-07-01 2012-07-01 false PCB wastes regulated under Toxic... (CONTINUED) SOLID WASTES (CONTINUED) IDENTIFICATION AND LISTING OF HAZARDOUS WASTE General § 261.8 PCB wastes regulated under Toxic Substance Control Act. The disposal of PCB-containing dielectric fluid and electric...

40 CFR 261.8 - PCB wastes regulated under Toxic Substance Control Act.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 26 2014-07-01 2014-07-01 false PCB wastes regulated under Toxic... (CONTINUED) SOLID WASTES (CONTINUED) IDENTIFICATION AND LISTING OF HAZARDOUS WASTE General § 261.8 PCB wastes regulated under Toxic Substance Control Act. The disposal of PCB-containing dielectric fluid and electric...

77 FR 11533 - Anniston PCB Superfund Site, Anniston, Calhoun County, Alabama; Notice of Amended Settlement

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-27

... ENVIRONMENTAL PROTECTION AGENCY [CERCLA-04-2012-3763; FRL 9637-7] Anniston PCB Superfund Site... past response costs concerning the Anniston PCB Superfund Site located in Anniston, Calhoun County.... Submit your comments by Site name Anniston PCB by one of the following methods: www.epa.gov/region4...

40 CFR 261.8 - PCB wastes regulated under Toxic Substance Control Act.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 25 2010-07-01 2010-07-01 false PCB wastes regulated under Toxic... (CONTINUED) SOLID WASTES (CONTINUED) IDENTIFICATION AND LISTING OF HAZARDOUS WASTE General § 261.8 PCB wastes regulated under Toxic Substance Control Act. The disposal of PCB-containing dielectric fluid and electric...

40 CFR 761.211 - Unmanifested waste report.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROHIBITIONS PCB Waste Disposal Records and Reports § 761.211 Unmanifested waste report. (a) After April 4, 1990, if a PCB commercial storage or disposal facility receives any shipment of PCB waste from an off...), and any part of the shipment consists of any PCB waste regulated for disposal, then the owner or...

40 CFR 761.265 - Sampling bulk PCB remediation waste and porous surfaces.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sampling bulk PCB remediation waste..., DISTRIBUTION IN COMMERCE, AND USE PROHIBITIONS Cleanup Site Characterization Sampling for PCB Remediation Waste in Accordance with § 761.61(a)(2) § 761.265 Sampling bulk PCB remediation waste and porous surfaces...

40 CFR 761.269 - Sampling liquid PCB remediation waste.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sampling liquid PCB remediation waste..., AND USE PROHIBITIONS Cleanup Site Characterization Sampling for PCB Remediation Waste in Accordance with § 761.61(a)(2) § 761.269 Sampling liquid PCB remediation waste. (a) If the liquid is single phase...

Methodological refinements in the determination of 146 polychlorinated biphenyls (PCBs), including non-ortho, and mono-ortho-substituted PCBs and 26 organochlorine pesticides in eggs as demonstrated in heron eggs

USGS Publications Warehouse

Chu, S.; Hong, C.-S.; Rattner, B.A.; McGowan, P.C.

2003-01-01

A method for the determination of 146 polychlorinated biphenyls (PCBs), including 4 non-ortho and 8 mono-ortho substituted congeners and 26 chlorinated pesticides is described. The method consists of ultrasonic extraction, Florisilcleanup, HPLC fractionation over porous graphitic carbon (PGC), and final determination with GC/ECD and/or GC/MS. Two PCB congeners (PCB 30 and PCB 161) and two polybromo-biphenyls (2,4?,5-tribromobiphenyl and 3,3?,4,4?-tetrabromobiphenyl) were used as surrogate standards to evaluate the analytical efficiency. Four PCB congeners, PCB 14 and PCB 159 for the first fraction, PCB 61 for the second fraction, and PCB 204 for the third fraction, were used as internal standards to monitor the GC performance. The retention behavior of PCBs and pesticides on porous-graphitic-carbon column were discussed. The method was found to be effective and reliable under the operational conditions proposed and was applied successfully to the analysis of individual PCBs and chlorinated pesticides in heron egg samples.

Chiral PCB 91 and 149 Toxicity Testing in Embryo and Larvae (Danio rerio): Application of Targeted Metabolomics via UPLC-MS/MS

NASA Astrophysics Data System (ADS)

Chai, Tingting; Cui, Feng; Yin, Zhiqiang; Yang, Yang; Qiu, Jing; Wang, Chengju

2016-09-01

In this study, we aimed to investigate the dysfunction of zebrafish embryos and larvae induced by rac-/(+)-/(-)- PCB91 and rac-/(-)-/(+)- PCB149. UPLC-MS/MS (Ultra-performance liquid chromatography coupled with mass spectrometry) was employed to perform targeted metabolomics analysis, including the quantification of 22 amino acids and the semi-quantitation of 22 other metabolites. Stereoselective changes in target metabolites were observed in embryos and larvae after exposure to chiral PCB91 and PCB149, respectively. In addition, statistical analyses, including PCA and PLS-DA, combined with targeted metabolomics were conducted to identify the characteristic metabolites and the affected pathways. Most of the unique metabolites in embryos and larvae after PCB91/149 exposure were amino acids, and the affected pathways for zebrafish in the developmental stage were metabolic pathways. The stereoselective effects of PCB91/149 on the metabolic pathways of zebrafish embryos and larvae suggest that chiral PCB91/149 exposure has stereoselective toxicity on the developmental stages of zebrafish.

Absorption of PCB126 by upper airways impairs G protein-coupled receptor-mediated immune response

NASA Astrophysics Data System (ADS)

Shimada, Ana Lúcia B.; Cruz, Wesley S.; Loiola, Rodrigo A.; Drewes, Carine C.; Dörr, Fabiane; Figueiredo, Natália G.; Pinto, Ernani; Farsky, Sandra H. P.

2015-10-01

PCB126 is a dioxin-like polychlorinated biphenyl (PCB) environmental pollutant with a significant impact on human health, as it bioaccumulates and causes severe toxicity. PCB126-induced immune toxicity has been described, although the mechanisms have not been fully elucidated. In this study, an in vivo protocol of PCB126 intoxication into male Wistar rats by intranasal route was used, which has not yet been described. The intoxication was characterised by PCB126 accumulation in the lungs and liver, and enhanced aryl hydrocarbon receptor expression in the liver, lungs, kidneys, and adipose tissues. Moreover, an innate immune deficiency was characterised by impairment of adhesion receptors on blood leukocytes and by reduced blood neutrophil locomotion and oxidative burst activation elicited by ex vivo G protein-coupled receptor (GPCR) activation. Specificity of PCB126 actions on the GPCR pathway was shown by normal burst oxidative activation evoked by Toll-like receptor 4 and protein kinase C direct activation. Moreover, in vivo PCB180 intoxication did not alter adhesion receptors on blood leukocytes either blood neutrophil locomotion, and only partially reduced the GPCR-induced burst oxidative activation on neutrophils. Therefore, a novel mechanism of in vivo PCB126 toxicity is described which impairs a pivotal inflammatory pathway to the host defence against infections.

Efficiencies of polychlorinated biphenyl assimilation from water and algal food by the blue mussel (Mytilus edulis)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bjoerk, M.; Gilek, M.

1999-04-01

A novel method was used to estimate assimilation efficiencies (AEs) of dissolved and food associated PCBs (IUPAC 31, 49, and 153) by the Baltic Sea blue mussel (Mytilus edulis). Mussels were exposed to radiolabeled PCBs in a series of short-term toxicokinetic experiments at different algal food concentrations, both at apparent steady-state (ASS) and non-steady-state (NSS) conditions in respect to PCB partitioning between water and algae. The PCB AEs were calculated using a physiologically based bioaccumulation model where experimentally determined uptake and exposure rates at ASS and NSS conditions were combined into linear equation systems, which were solved for PCB AEmore » from water and food. A positive relationship between PCB uptake and algae clearance by the mussels was observed for all three PCBs. The PCB AEs from both water and food increased with congener hydrophobicity (octanol/water partition coefficient [K{sub ow}]), but AEs decreased with increases in water pumping and filtration rate of the mussels, respectively. The average contribution of food-associated PCB to the total uptake also increased with K{sub ow} from approximately 30% for PCB 31 and PCB 49 to 50% for PCB 153, mainly as a consequence of increased sorption to the algal food.« less

Determination of the human cytochrome P450 monooxygenase catalyzing the enantioselective oxidation of 2,2',3,5',6-pentachlorobiphenyl (PCB 95) and 2,2',3,4,4',5',6-heptachlorobiphenyl (PCB 183).

PubMed

Nagayoshi, Haruna; Kakimoto, Kensaku; Konishi, Yoshimasa; Kajimura, Keiji; Nakano, Takeshi

2017-10-17

2,2',3,5',6-Pentachlorobiphenyl (PCB 95) and 2,2',3,4,4',5',6-heptachlorobiphenyl (PCB 183) possess axial chirality and form the aS and aR enantiomers. The enantiomers of these congeners have been reported to accumulate in the human body enantioselectively via unknown mechanisms. In this study, we determined the cytochrome P450 (CYP) monooxygenase responsible for the enantioselective oxidization of PCB 95 and PCB 183, using a recombinant human CYP monooxygenase. We evaluated 13 CYP monooxygenases, namely CYP1A1, CYP1A2, CYP1B1, CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2E1, CYP2J2, CYP3A4, CYP3A5, CYP4F2, and aromatase (CYP19), and revealed that CYP2A6 preferably oxidizes aS-PCB 95 enantioselectively; however, it did not oxidize PCB 183. The enantiomer composition was elevated from 0.5 (racemate) to 0.54. In addition, following incubation with CYP2A6, the enantiomer fraction (EF) of PCB 95 demonstrated a time-dependent increase.

An improved inventory of polychlorinated biphenyls in China: A case study on PCB-153

NASA Astrophysics Data System (ADS)

Xu, Yue; Tian, Chongguo; Wang, Xiaoping; Ma, Jianmin; Tang, Jianhui; Chen, Yingjun; Li, Jun; Zhang, Gan

2018-06-01

Emission inventory of pollutants is essential for the environmental fate study and management of the pollutant. To construct a reasonable PCB (polychlorinated biphenyls) inventory in China, this study estimates PCB usage and emission using power generating capacity, installed capacity of power plants and transformer substations, population density and GDP as surrogates. Inventory of representative PCB (PCB-153) with a resolution of 1/4° latitude × 1/4° longitude in China from 1952 to 2005 was generated and assessed as an example. Totally, about 20.3 kt PCBs were applied in China, of which 179 t were PCB-153. By the end of 2005, most of them (56.4%) were emitted into the soil, 2.7% entered the air, and about 20.8% was sealed in storage site or still in service. Historical emissions exhibited increasing trends after 1968, 1984 and 1994, which were mainly associated with usage or disposal processes. Although primary emission has been declined since 2005, the influence of secondary emission from soils, unintentionally produced PCBs (UP-PCB), and reemission from storage sites could be a long-lasting issue in the future. This new emission inventory improves previous PCB emission inventory significantly, which underestimated PCB emission in China considerably.

Enrichment of marine sediment colloids with polychlorinated biphenyls: Trends resulting from PCB solubility and chlorination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burgess, R.M.; McKinney, R.A.; Brown, W.A.

1996-08-01

In this study, the three phase distributions (i.e., dissolved, colloidal, and particulate) of approximately 75 PCB congeners were measured in a marine sediment core from New Bedford Harbor, M.A. These distributions are the first report of colloid-PCB interactions in an environmentally contaminated sediment. Colloids <1.2 {mu}m in size were isolated from interstitial waters using reverse-phase chromatography with size-selected C{sub 18}. Regardless of solubility or chlorination, the majority of PCBs were associated with the particulate phase. PCBs were distributed in filtered interstitial waters between colloidal and dissolved phases as a function of solubility and degree of chlorination. Interstitial dissolved PCB concentrationsmore » generally agreed with literature-reported solubilities. The magnitude of colloid-PCB interactions increased with decreasing PCB solubility and increasing PCB chlorination. Di- and trichlorinated PCBs were approximately 40% and 65% colloidally bound, respectively, while tetra-, penta-, hexa-, hepta-, and octachlorinated PCBs were about 80% colloidally bound. As core depth increased, the magnitude of PCB-colloid interactions also increased. The relationships of organic carbon-normalized colloidal partitioning coefficient(K{sub coc}) to K{sub ow} for several PCB congeners were not linear and suggest that interstitial waters were not equilibrated. 62 refs., 8 figs., 3 tabs.« less

Use of plasma exchange or double filtration plasmapheresis to reduce body burden of polychlorinated biphenyls: A pilot trial.

PubMed

Gube, Monika; Schettgen, Thomas; Kraus, Thomas; Schikowsky, Christian; Heibges, Andreas; Klingel, Reinhard; Hoffmann, Christian; Wiemeyer, Andreas; Jacobson, Jewgeni; Esser, André

2017-07-01

The aim of the study was to examine whether plasma exchange (PE) or selective double filtration plasmapheresis (DFPP) is able to reduce the internal Polychlorinated biphenyl (PCB) burden of highly exposed participants of the health effects in high-level exposure to PCB (HELPcB) cohort. HELPcB is a surveillance program for former PCB-exposed workers of a German capacitor recycling company. After comparative evaluation of PE and DFPP in a phase I, DFPP was chosen as method for further treatment. In phase II, five participants underwent DFPP at weekly intervals for the duration of 12 weeks. Six PCB species were selected as indicators and were analyzed in the plasma before and after each treatment and 4 weeks after the last treatment. The PCB levels before and after each DFPP treatment showed a significant reduction in PCB blood levels; however, there was no significant change in PCB levels within the samples collected before each treatment as compared with the samples collected in the following week before treatment. Even the difference between PCB levels at the onset of the study and 4 weeks after the last treatment was not significant. The results of this pilot trial do not encourage further investigations in using therapeutic apheresis to reduce the PCB body burden.

The effect of activated carbon on partitioning, desorption, and biouptake of native polychlorinated biphenyls in four freshwater sediments.

PubMed

Sun, Xueli; Ghosh, Upal

2008-11-01

The present study evaluated the effect of activated carbon amendment in four freshwater sediments from the Great Lakes (North America) areas of concern with a wide range of sediment geochemical characteristics (0.83-5.1% total organic carbon) and polychlorinated biphenyl (PCB) concentrations (0.33-84.7 microg/g). The work focused on understanding the impact of activated carbon amendment on PCB aqueous partitioning, PCB desorption characteristics, and PCB biouptake in a freshwater oligochaete (Lumbriculus variegatus). The results showed that PCB aqueous equilibrium concentrations, rapid desorption fractions, and biouptake by the oligochaete were reduced after activated carbon amendment. Addition of activated carbon at a dose of 0.5-fold native organic carbon reduced PCB bioaccumulation by 42% for Niagara River sediment, 85% for Grasse River sediment, 74% for Milwaukee River sediment 1, and 70% for Milwaukee River sediment 2. A linear relationship was observed between log biota-sediment accumulation factor and the first 6-h desorption fractions for each PCB homologue for treated and untreated sediments. Water-lipid bioconcentration factors for PCB congeners were largely conserved after amendment with activated carbon. Our present results suggest that at steady state, changes in the aqueous PCB concentrations can be used to predict changes in PCB bioaccumulation in deposit-feeding organisms. Thus, use of advanced pore-water measurement techniques, such as solid-phase extraction passive samplers, may be suitable for long-term monitoring of treatment performance.

Evidence that PCBs are approaching stable concentrations in Lake Michigan fishes

USGS Publications Warehouse

Stow, Craig A.; Carpenter, Stephen R.; Eby, Lisa A.; Amrhein, James F.; Hesselberg, Robert J.

1995-01-01

We examined PCB concentration data for seven species of Lake Michigan fishes to determine what trends were apparent °20 yr after PCB restrictions became effective. Total PCB concentrations in all seven species, lake trout (Salvelinus namaycush), rainbow trout (Oncorhynchus mykiss), brown trout (Salmo trutta), chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch), alewife (Alosa pseudoharengus), and bloater chub (Coregonus hoyi) declined and appeared to stabilize in the mid-to-late 1980s. Concentrations in two species, chinook and coho salmon, appear to have increased slightly since the late 1980s. All species are currently well below the high PCB levels that existed when PCB use was curtailed in the 1970s. We believe stabilizing concentrations are the result of large pools of PCBs that are being recycled in the environment. Atmospheric and sediment PCB inputs to the lake probably constitute current PCB sources. Increasing concentrations in chinook and coho salmon are likely the result of changing growth dynamics caused by alterations in the mid-trophic levels of the food web. Median stable PCB concentrations estimated in this analysis are below the current FDA action level of 2 mg/kg, but not appreciably below this threshold. Improvements beyond these levels may result if management practices that maximize fish growth rates are implemented. Detection of future improvements in PCB levels may require samples in the range of 1000-2000 fish because of the high variability in PCB concentrations among individuals.

A modeling approach to compare ΣPCB concentrations between congener-specific analyses

USGS Publications Warehouse

Gibson, Polly P.; Mills, Marc A.; Kraus, Johanna M.; Walters, David M.

2017-01-01

Changes in analytical methods over time pose problems for assessing long-term trends in environmental contamination by polychlorinated biphenyls (PCBs). Congener-specific analyses vary widely in the number and identity of the 209 distinct PCB chemical configurations (congeners) that are quantified, leading to inconsistencies among summed PCB concentrations (ΣPCB) reported by different studies. Here we present a modeling approach using linear regression to compare ΣPCB concentrations derived from different congener-specific analyses measuring different co-eluting groups. The approach can be used to develop a specific conversion model between any two sets of congener-specific analytical data from similar samples (similar matrix and geographic origin). We demonstrate the method by developing a conversion model for an example data set that includes data from two different analytical methods, a low resolution method quantifying 119 congeners and a high resolution method quantifying all 209 congeners. We used the model to show that the 119-congener set captured most (93%) of the total PCB concentration (i.e., Σ209PCB) in sediment and biological samples. ΣPCB concentrations estimated using the model closely matched measured values (mean relative percent difference = 9.6). General applications of the modeling approach include (a) generating comparable ΣPCB concentrations for samples that were analyzed for different congener sets; and (b) estimating the proportional contribution of different congener sets to ΣPCB. This approach may be especially valuable for enabling comparison of long-term remediation monitoring results even as analytical methods change over time. 

Polychlorinated Biphenyl (PCB) Bioaccumulation in Fish: A Look at Michigan's Upper Peninsula

NASA Astrophysics Data System (ADS)

Sokol, E. C.; Urban, N. R.; Perlinger, J. A.; Khan, T.; Friedman, C. L.

2014-12-01

Fish consumption is an important economic, social and cultural component of Michigan's UpperPeninsula, where safe fish consumption is threatened due to polychlorinated biphenyl (PCB)contamination. Despite its predominantly rural nature, the Upper Peninsula has a history of industrialPCB use. PCB congener concentrations in fish vary 50-fold in Upper Peninsula lakes. Several factors maycontribute to this high variability including local point sources, unique watershed and lakecharacteristics, and food web structure. It was hypothesized that the variability in congener distributionscould be used to identify factors controlling concentrations in fish, and then to use those factors topredict PCB contamination in fish from lakes that had not been monitored. Watershed and lakecharacteristics were acquired from several databases for 16 lakes sampled in the State's fishcontaminant survey. Species congener distributions were compared using Principal Component Analysis(PCA) to distinguish between lakes with local vs. regional, atmospheric sources; six lakes were predictedto have local sources and half of those have confirmed local PCB use. For lakes without local PCBsources, PCA indicated that lake size was the primary factor influencing PCB concentrations. The EPA'sbioaccumulation model, BASS, was used to predict PCB contamination in lakes without local sources as afunction of food web characteristics. The model was used to evaluate the hypothesis that deep,oligotrophic lakes have longer food webs and higher PCB concentrations in top predator fish. Based onthese findings, we will develop a mechanistic watershed-lake model to predict PCB concentrations infish as a function of atmospheric PCB concentrations, lake size, and trophic state. Future atmosphericconcentrations, predicted by modeling potential primary and secondary emission scenarios, will be usedto predict the time horizon for safe fish consumption.

Males exceed females in PCB concentrations of cisco (Coregonus artedi) from Lake Superior

USGS Publications Warehouse

Madenjian, Charles P.; Yule, Daniel L.; Chernyak, Sergei M.; Begnoche, Linda J.; Berglund, Eric K.; Isaac, Edmund J.

2014-01-01

We determined whole-fish polychlorinated biphenyl (PCB) concentrations of 25 male and 25 female age-7 ciscoes (Coregonus artedi) captured from a spawning aggregation in Thunder Bay, Lake Superior, during November 2010. We also determined PCB concentrations in the ovaries and somatic tissue of five additional female ciscoes (ages 5–22). All 55 of these ciscoes were in ripe or nearly ripe condition. Bioenergetics modeling was used to determine the contribution of the growth dilution effect toward a difference in PCB concentrations between the sexes, as females grew substantially faster than males. Results showed that the PCB concentration of males (mean = 141 ng/g) was 43% greater than that of females (mean = 98 ng/g), and this difference was highly significant (P < 0.0001). Mean PCB concentrations in the ovaries and the somatic tissue of the five females were 135 and 100 ng/g, respectively. Based on these PCB determinations for the ovaries and somatic tissue, we concluded that release of eggs by females at previous spawnings was not a contributing factor to the observed difference in PCB concentrations between the sexes. Bioenergetics modeling results indicated that the growth dilution effect could explain males being higher than females in PCB concentration by only 3–7%. We concluded that the higher PCB concentration in males was most likely due to higher rate of energy expenditure, originating from greater activity and a higher resting metabolic rate. Mean PCB concentration in the cisco eggs was well below the U. S. Food and Drug Administration and Ontario Ministry of Environment guidelines of 2000 and 844 ng/g, respectively, and this finding may have implications for the cisco roe fishery currently operating in Lake Superior.

Males exceed females in PCB concentrations of cisco (Coregonus artedi) from Lake Superior.

PubMed

Madenjian, Charles P; Yule, Daniel L; Chernyak, Sergei M; Begnoche, Linda J; Berglund, Eric K; Isaac, Edmund J

2014-09-15

We determined whole-fish polychlorinated biphenyl (PCB) concentrations of 25 male and 25 female age-7 ciscoes (Coregonus artedi) captured from a spawning aggregation in Thunder Bay, Lake Superior, during November 2010. We also determined PCB concentrations in the ovaries and somatic tissue of five additional female ciscoes (ages 5-22). All 55 of these ciscoes were in ripe or nearly ripe condition. Bioenergetics modeling was used to determine the contribution of the growth dilution effect toward a difference in PCB concentrations between the sexes, as females grew substantially faster than males. Results showed that the PCB concentration of males (mean = 141 ng/g) was 43% greater than that of females (mean = 98 ng/g), and this difference was highly significant (P<0.0001). Mean PCB concentrations in the ovaries and the somatic tissue of the five females were 135 and 100 ng/g, respectively. Based on these PCB determinations for the ovaries and somatic tissue, we concluded that release of eggs by females at previous spawnings was not a contributing factor to the observed difference in PCB concentrations between the sexes. Bioenergetics modeling results indicated that the growth dilution effect could explain males being higher than females in PCB concentration by only 3-7%. We concluded that the higher PCB concentration in males was most likely due to higher rate of energy expenditure, originating from greater activity and a higher resting metabolic rate. Mean PCB concentration in the cisco eggs was well below the U. S. Food and Drug Administration and Ontario Ministry of Environment guidelines of 2000 and 844 ng/g, respectively, and this finding may have implications for the cisco roe fishery currently operating in Lake Superior. Published by Elsevier B.V.

A numerical study on the seasonal variability of polychlorinated biphenyls from the atmosphere in the East China Sea.

PubMed

Ono, Jun; Takahashi, Daisuke; Guo, Xinyu; Takahashi, Shin; Takeoka, Hidetaka

2012-10-01

A three-dimensional/high-resolution transport model for persistent organic pollutants (POPs) has been developed for the East China Sea (ECS). The POPs model has four compartments (gaseous, dissolved, phytoplankton-bound, and detritus-bound phases) and includes processes for diffusive air-water exchange, phytoplankton uptake/depuration to POPs, decomposition of dissolved phase, vertical sinking of phytoplankton, detritus production by phytoplankton mortality, and vertical sinking and decomposition of detritus. The POPs model is coupled with an ocean circulation model that can reproduce the seasonal variation in physical variables to represent the advection and diffusion of POPs. We applied the POPs model to the polychlorinated biphenyl congener 153 (PCB 153) from the atmosphere and examined the behavior of PCB 153 in the ocean. The model showed a remarkable seasonal variability of PCB 153. Concentrations in the dissolved and particulate phases are high in winter (January-March) and low in summer (July-September). In coastal regions, where chlorophyll a concentration is high, horizontal and vertical distributions in the dissolved and particulate PCB 153 concentrations are strongly affected by phytoplankton uptake. The sensitivity experiments on the dynamics of PCB 153 suggested that a change of Henry's law constant associated with water temperature is the major factor controlling the seasonal variability of PCB 153. The model-based yearly mass balance of PCB 153 in the ECS indicated that most of the atmospheric input (35.5 kg year(-1)) is removed by the horizontal advection outside the ECS (19.0 kg year(-1)) and accumulates to the sea bottom by vertical sinking (15.7 kg year(-1)). For comparison with PCB 153, we also conducted simulations for PCB 52, 101, and 180. The seasonal variations are similar to that of PCB 153. The mass balance of PCB 52 that has short half-life time and less hydrophobic property shows the different results compared with PCB 101, 153, and 180. Copyright © 2012 Elsevier Ltd. All rights reserved.

Persistent organic pollutants and diabetes among Inuit in the Canadian Arctic.

PubMed

Singh, Kavita; Chan, Hing Man

2017-04-01

Type 2 diabetes is a chronic metabolic disease that is of increasing concern in Inuit communities. Behavioural factors such as physical inactivity and poor diet are well-known risk factors. Exposure to persistent organic pollutants (POPs) has emerged as an additional factor in the pathogenesis of diabetes. In this study, association between polychlorinated biphenyls (PCBs) and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) with diabetes in Canadian Inuit was examined. Data from the Adult Inuit Health Survey (2007-2008) of Inuit participants from the Canadian Arctic were analyzed. Self-reported diabetes (excluding gestational diabetes) and clinical measurement of fasting glucose were examined as outcomes. Association with individual PCB congeners, sum of dioxin-like PCBs (∑DL-PCB), non-dioxin-like PCBs (∑NDL-PCB), total PCBs (∑PCB), and p,p'-DDE were investigated using multiple regression models adjusted for confounding factors. Using different methods to incorporate serum lipids, highest vs. lowest quartile exposures to PCB-105, PCB-118, PCB-153, PCB-156, PCB-170, PCB-180, PCB-183, ∑PCB, and p,p'-DDE were associated with increased risk of diabetes. For these PCBs, odds ratios (ORs) ranged from 1.9-3.5 (lower 95% CI: 0.8-1.4, upper 95% CI: 4.4-9.0) and for p,p'-DDE the OR was 2.5 (lower 95% CI: 1.1-1.2, upper 95% CI: 5.9-6.0). The highest vs. lowest quartile exposure to most PCBs and p,p'-DDE were associated with an increase of fasting glucose by 3-7%. PCBs and p,p'-DDE were associated with increased risk of diabetes and higher fasting glucose level in a cross-sectional survey of Canadian Inuit. Cause-effect relationships of PCBs and p,p'-DDE with diabetes and diabetes-related outcomes need to be further investigated in a cohort study. Copyright © 2017 Elsevier Ltd. All rights reserved.

Interacting influence of potassium and polychlorinated biphenyl on cortisol and aldosterone biosynthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, L.-A.; Lin, Tsu-Chun Emma

Giving human adrenocortical H295R cells 14 mM KCl for 24 h significantly induced not only aldosterone biosynthesis but also cortisol biosynthesis. Pre-treating the cells with polychlorinated biphenyl 126 (PCB126) further increased potassium-induced aldosterone and cortisol productions in a dose-dependent manner, but all examined concentrations of PCB126 had little effect on the yields of precursor steroids progesterone and 17-OH-progesterone. Subsequent examinations revealed that CYP11B1 and CYP11B2 genes, responsible for the respective final steps of the cortisol and aldosterone biosynthetic pathways, exhibited increased responsiveness to PCB126 under high potassium. While 10{sup -5} M PCB126 was needed to induce a significant increase inmore » the basal mRNA abundance of either gene, PCB126 could enhance potassium-induced mRNA expression of CYP11B1 at 10{sup -7} M and CYP11B2 at 10{sup -9} M. Actually, potassium and PCB126 synergistically upregulated mRNA expression of both genes. Potassium raised the transcriptional rates of CYP11B1 and CYP11B2 probably through a conserved Ad5 cis-element, whereas PCB126 appeared to regulate these two genes at the post-transcriptional level. Positive potassium-PCB126 synergism was also detected in CYP11B2 enzyme activity estimated by aldosterone/progesterone ratio. In contrast, potassium and PCB126 increased CYP11B1 enzyme activity or cortisol/17-OH-progesterone ratio additively. Moreover, potassium improved the time effect of PCB126 on gene expression and enzyme activity of CYP11B2, but not the PCB126 time response of CYP11B1. These data demonstrated that potassium differentially enhanced the potency of PCB126 to induce CYP11B1- and CYP11B2-mediated steroidogenesis.« less

Experimental feeding of DDE and PCB to female big brown bats (Eptesicus fuscus)

USGS Publications Warehouse

Clark, D.R.; Prouty, R.M.

1977-01-01

Twenty-two female big brown bats (Eptesicus fuscus) were collected in a house attic in Montgomery County, Maryland. Seventeen were fed mealworms (Tenebrio molitor larvae) that contained 166 ppm DDE; the other five were fed uncontaminated mealworms. After 54 days of feeding, six dosed bats were frozen and the remaining 16 were starved to death. In a second experiment, 21 female big brown bats were collected in a house attic in Prince Georges County, Maryland. Sixteen were fed mealworms that contained 9.4 ppm Aroclor 1254 (PCB). After 37 days, two bats had died, four dosed bats were frozen, and the remaining 15 were starved to death. Starvation caused mobilization of stored residues. After the feeding periods, average weights of all four groups (DDE-dosed, DDE control, PCB-dosed, PCB control) had increased. However, weights of DDE-dosed bats had increased significantly more than those of their contols, whereas weights of PCB-dosed bats had increased significantly less than those of their controls. During starvation, PCB-dosed bats lost weight significantly more slowly than controls. Because PCB levels in dosed bats resembled levels found in some free-living big brown bats, PCBs may be slowing metabolic rates of some free-living bats. It is not known how various common organochlorine residues may affect metabolism in hibernating bats. DDE and PCB increased in brains of starving bats as carcass fat was metabolized. Because the tremors and/or convulsions characteristic of neurotoxicity were not observed, we think even the maximum brain levels attained (132 ppm DDE, 20 ppm PCB) were sublethal. However, extrapolation of our DDE data predicted lethal brain levels when fat reserves declined sufficiently. PCB-dosed bats were probably in no danger of neurotoxic poisoning. However, PCB can kill by a nonneurotoxic mode, and this could explain the deaths of two bats on PCB dosage.

Characterization of a vertically movable gate field effect transistor using a silicon-on-insulator wafer

NASA Astrophysics Data System (ADS)

Song, In-Hyouk; Forfang, William B. D.; Cole, Bryan; You, Byoung Hee

2014-10-01

The vertically movable gate field effect transistor (VMGFET) is a FET-based sensing element, whose gate moves in a vertical direction over the channel. A VMGFET gate covers the region between source and drain. A 1 μm thick air layer separates the gate and the substrate of the VMGFET. A novel fabrication process to form a VMGFET using a silicon-on-insulator (SOI) wafer provides minimal internal stress of the gate structure. The enhancement-type n-channel VMGFET is fabricated with the threshold voltage of 2.32 V in steady state. A non-inverting amplifier is designed and integrated on a printable circuit board (PCB) to characterize device sensitivity and mechanical properties. The VMGFET is mechanically coupled to a speaker membrane to apply mechanical vibration. The oscillated drain current of FET are monitored and sampled with NI LabVIEW. The frequency of the output signal correlates with that of the input stimulus. The resonance frequency of the fabricated VMGFET is measured to be 1.11 kHz. The device sensitivity linearly increases by 0.106 mV/g Hz in the range of 150 Hz and 1 kHz.

Simple and Low-Cost Dual-Band Printed Microwave Absorber for 2.4- and 5-GHz-Band Applications

NASA Astrophysics Data System (ADS)

Khoomwong, Ekajit; Phongcharoenpanich, Chuwong

2017-10-01

In this research, a dual-band thin printed-circuit-board (PCB) microwave absorber has been proposed for applications in 2.4 and 5 GHz frequency bands. Each unit cell of the absorber consists of a square ring and a thick cross-dipole, augmented with the tuning elements. In the design process, numerical simulations were performed for the optimal characteristics of the absorber and an absorber prototype was fabricated using the simple print-transferring and etching process. The measured absorption bandwidths (50 %) of 170 MHz (2.36-2.53 GHz) and 830 MHz (5.09-5.92 GHz) were achieved for the first and second bands, respectively, with the wideband characteristic at the second operating band. The absorption rates near the center frequencies (2.45 and 5.5 GHz) were respectively 97.85 % and 97.76 %. The simulation and measured results are in good agreement. Furthermore, the incidence-angle dependencies of the absorber were of moderately wide angles with the absorption capacity of at least 50 % for both operating bands. The proposed absorber is suitable for a variety of applications requiring absorption in the 2.4/5 GHz bands.

Electrical Design and Evaluation of Asynchronous Serial Bus Communication Network of 48 Sensor Platform LSIs with Single-Ended I/O for Integrated MEMS-LSI Sensors

PubMed Central

Shao, Chenzhong; Tanaka, Shuji; Nakayama, Takahiro; Hata, Yoshiyuki

2018-01-01

For installing many sensors in a limited space with a limited computing resource, the digitization of the sensor output at the site of sensation has advantages such as a small amount of wiring, low signal interference and high scalability. For this purpose, we have developed a dedicated Complementary Metal-Oxide-Semiconductor (CMOS) Large-Scale Integration (LSI) (referred to as “sensor platform LSI”) for bus-networked Micro-Electro-Mechanical-Systems (MEMS)-LSI integrated sensors. In this LSI, collision avoidance, adaptation and event-driven functions are simply implemented to relieve data collision and congestion in asynchronous serial bus communication. In this study, we developed a network system with 48 sensor platform LSIs based on Printed Circuit Board (PCB) in a backbone bus topology with the bus length being 2.4 m. We evaluated the serial communication performance when 48 LSIs operated simultaneously with the adaptation function. The number of data packets received from each LSI was almost identical, and the average sampling frequency of 384 capacitance channels (eight for each LSI) was 73.66 Hz. PMID:29342923

[Activities of System Studies and Simulation, Inc.

NASA Technical Reports Server (NTRS)

2004-01-01

Contents include the following: 1. Launch Vehicle Interface Work Performed: a. S3 provided to KSC the new launch inclination targets needed for the April '04 launch date. 2. Prelaunch operations work performed: a. S3 updated the staffing plan for MSFC on-console personnel\\during the Final Countdown prior to launch. 3. Software Assessment Work Performed: a. S3 evaluated and recommended approval for Program Control Board (PCB) proposed change 649 for ground software changes, as well as change 650 and 650A for Stored Program Commands. 4. Education and Public Outreach Work Performed: a. S3 continues to coordinate the effort for the design and fabrication of scale models of the GP-3 for use at the launch site, education forums, and management/technical briefings. S3 also prepared a Change Request for additional funds needed for fabrication of additional scale models. S3 drafted the planned uses of these models, including the possibility of participation in the Boston, MA showings of the traveling Einstein Exhibit. 5. Program Management Support Work Performed: a. S3 prepared the input for and closed three MSFC Centerwide Action Item Tracking Systems (CAITS) actions during this period.

Polychlorinated biphenyl 77 augments angiotensin II-induced atherosclerosis and abdominal aortic aneurysms in male apolipoprotein E deficient mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arsenescu, Violeta; Arsenescu, Razvan; Parulkar, Madhura

2011-11-15

Infusion of angiotensin II (AngII) to hyperlipidemic mice augments atherosclerosis and causes formation of abdominal aortic aneurysms (AAAs). Each of these AngII-induced vascular pathologies exhibit pronounced inflammation. Previous studies demonstrated that coplanar polychlorinated biphenyls (PCBs) promote inflammation in endothelial cells and adipocytes, two cell types implicated in AngII-induced vascular pathologies. The purpose of this study was to test the hypothesis that administration of PCB77 to male apolipoprotein E (ApoE) -/- mice promotes AngII-induced atherosclerosis and AAA formation. Male ApoE-/- mice were administered vehicle or PCB77 (49 mg/kg, i.p.) during week 1 and 4 (2 divided doses/week) of AngII infusion. Bodymore » weights and total serum cholesterol concentrations were not influenced by administration of PCB77. Systolic blood pressure was increased in AngII-infused mice administered PCB77 compared to vehicle (156 {+-} 6 vs 137 {+-} 5 mmHg, respectively). The percentage of aortic arch covered by atherosclerotic lesions was increased in AngII-infused mice administered PCB77 compared to vehicle (2.0 {+-} 0.4 vs 0.9 {+-} 0.1%, respectively). Lumen diameters of abdominal aortas determined by in vivo ultrasound and external diameters of excised suprarenal aortas were increased in AngII-infused mice administered PCB77 compared to vehicle. In addition, AAA incidence increased from 47 to 85% in AngII-infused mice administered PCB77. Adipose tissue in close proximity to AAAs from mice administered PCB77 exhibited increased mRNA abundance of proinflammatory cytokines and elevated expression of components of the renin-angiotensin system (angiotensinogen, angiotensin type 1a receptor (AT1aR)). These results demonstrate that PCB77 augments AngII-induced atherosclerosis and AAA formation. -- Highlights: Black-Right-Pointing-Pointer Polychlorinated biphenyl 77 (PCB77) promotes AngII-induced hypertension. Black-Right-Pointing-Pointer PCB77 augments AngII-induced atherosclerosis. Black-Right-Pointing-Pointer PCB77 promotes AngII-induced AAA formation and rupture. Black-Right-Pointing-Pointer PCB77 promotes inflammation in periaorticadipose tissue surrounding AAAs.« less

Polychlorinated Biphenyl Congeners that Increase the Glucuronidation and Biliary Excretion of Thyroxine Are Distinct from the Congeners that Enhance the Serum Disappearance of Thyroxine

PubMed Central

Martin, L. A.; Wilson, D. T.; Reuhl, K. R.; Gallo, M. A.

2012-01-01

Polychlorinated biphenyl (PCB) congeners differentially reduce serum thyroxine (T4) in rats, but little is known about their ability to affect biliary excretion of T4. Thus, male Sprague-Dawley rats were orally administered Aroclor-1254, Aroclor-1242 (32 mg/kg per day), PCB-95, PCB-99, PCB-118 (16 mg/kg per day), PCB-126 (40 μg/kg per day), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (3.9 μg/kg per day), or corn oil for 7 days. Twenty-four hours after the last dose, [125I]T4 was administered intravenously, and blood, bile, and urine samples were collected for quantifying [125I]T4 and in bile [125I]T4 metabolites. Serum T4 concentrations were reduced by all treatments, but dramatic reductions occurred in response to Aroclor-1254, PCB-99 [phenobarbital (PB)-type congener], and PCB-118 (mixed-type congener). None of the treatments increased urinary excretion of [125I]T4. Aroclor-1254, PCB-118, TCDD, and PCB-126 (TCDD-type congener) increased biliary excretion of T4-glucuronide by 850, 756, 710, and 573%, respectively, corresponding to marked induction of hepatic UDP-glucuronosyltransferase (UGT) activity toward T4. PCB-95 and PCB-99 did not induce UGT activity; therefore, the increased biliary excretion of T4-glucuronide was related to the affinity of congeners for the aryl hydrocarbon receptor. The disappearance of [125I]T4 from serum was rapid (within 15-min) and was increased by Aroclor-1254, PCB-99 and PCB-118. Thus, reductions in serum T4 in response to PCBs did not always correspond with UGT activity toward T4 or with increased biliary excretion of T4-glucuronide. The rapid disappearance of [125I]T4 from the serum of rats treated with PB-like PCBs suggests that increased tissue uptake of T4 is an additional mechanism by which PCBs may reduce serum T4. PMID:22187485

Inhibition of the promotion of hepatocarcinogenesis by 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153) by the deletion of the p50 subunit of NF-{kappa}B in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glauert, Howard P.; Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40506; Tharappel, Job C.

Polychlorinated biphenyls (PCBs) are persistent and ubiquitous environmental chemicals that bioaccumulate and have hepatic tumor promoting activity in rodents. The present study examined the effect of deleting the p50 subunit of NF-{kappa}B on the hepatic tumor promoting activity of 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153) in mice. Both wild-type and p50-/- male mice were injected i.p. with diethylnitrosamine (DEN, 90 mg/kg) and then subsequently injected biweekly with 20 i.p. injections of PCB-153 (300 {mu}mol/kg/injection). p50 deletion decreased the tumor incidence in both PCB- and vehicle-treated mice, whereas PCB-153 slightly (P = 0.09) increased the tumor incidence in wild-type and p50-/- mice. PCB-153 increased themore » total tumor volume in both wild-type and p50-/- mice, but the total tumor volume was not affected by p50 deletion in either PCB- or vehicle-treated mice. The volume of tumors that were positive for glutamine synthetase (GS), which is indicative of mutations in the beta-catenin gene, was increased in both wild-type and p50-/- mice administered PCB-153 compared to vehicle controls, and inhibited in p50-/- mice compared to wild-type mice (in both PCB- and vehicle-treated mice). The volume of tumors that were negative for GS was increased in p50-/- mice compared to wild-type mice but was not affected by PCB-153. PCB-153 increased cell proliferation in normal hepatocytes in wild-type but not p50-/- mice; this increase was inhibited in p50-/- mice. In hepatic tumors, the rate of cell proliferation was much higher than in normal hepatocytes, but was not affected by PCB treatment or p50 deletion. The rate of apoptosis, as measured by the TUNEL assay, was not affected by PCB-153 or p50 deletion in normal hepatocytes. In hepatic tumors, the rate of apoptosis was lower than in normal hepatocytes; PCB-153 slightly (P = 0.10) increased apoptosis in p50-/- but not wild-type mice; p50 deletion had no effect. Taken together, these data indicate that the absence of the NF-{kappa}B p50 subunit inhibits the promoting activity of PCB-153 and alters the proliferative and apoptotic changes in mouse liver in the response to PCBs.« less

3D multidisciplinary numerical model of polychlorinated biphenyl dynamics on the Black Sea north-western shelf

NASA Astrophysics Data System (ADS)

Bagaiev, Andrii; Ivanov, Vitaliy

2014-05-01

The Black Sea north-western shelf plays a key role in economics of the developing countries such as Ukraine due to food supply, invaluable recreational potential and variety of the relevant maritime shipping routes. On the other hand, a shallow flat shelf is mostly affected by anthropogenic pollution, eutrophication, hypoxia and harmful algae blooms. The research is focused on modeling the transport and transformation of PCBs (PolyChlorinated Biphenyls) because they are exceedingly toxic and highly resistant to degradation, hence cumulatively affect marine ecosystems. Being lipophilic compounds, PCBs demonstrate the distinguishing sorption/desorption activity taking part in the biogeochemical fluxes via the organic matter particles and sediments. In the framework of the research, the coastal in-situ data on PCB concentration in the water column and sediments are processed, visualized and analyzed. It is concluded that the main sources of PCBs are related to the Danube discharge and resuspension from the shallow-water sediments. Developed 3D numerical model is aimed at simulation of PCB contamination of the water column and sediment. The model integrates the full physics hydrodynamic block as well as modules, which describe detritus transport and transformation and PCB dynamics. Three state variables are simulated in PCB transport module: concentration in solute, on the settling particles of detritus and in the top layer of sediments. PCB adsorption/desorption on detritus; the reversible PCB fluxes at the water-sediment boundary; destruction of detritus are taken into consideration. Formalization of PCB deposition/resuspension in the sediments is adapted from Van Rijn's model of the suspended sediment transport. The model was spun up to reconstruct the short term scenario of the instantaneous PCB release from the St. George Arm of Danube. It has been shown that PCB transport on sinking detritus represents the natural buffer mechanism damping the spreading PCB contamination in the Black Sea shelf ecosystem. Special numerical experiments were carried out to evaluate the artificial sorbent efficiency as a possible post-accidental counter-measure. End-user application is implemented to provide operational PCB forecast in order to support decision making and minimize ecological risks. The graphical user interface allows specifying instantaneous or continuous PCB release scenarios and quick updating the prediction of PCB release trajectory and temporal variability of the mass balance components. It provides visualization of PCB contamination at the sea surface, in the water column and in the upper layer of sediments over time, including the animations of PCB movement. The integrated ocean-ecosystem-sediment-pollution approach developed is applicable to any coastal area and allows further implementation related to advances in the model representation of natural processes and to improvements of PCB monitoring.

Continuous-waveform constant-current isolated physiological stimulator

NASA Astrophysics Data System (ADS)

Holcomb, Mark R.; Devine, Jack M.; Harder, Rene; Sidorov, Veniamin Y.

2012-04-01

We have developed an isolated continuous-waveform constant-current physiological stimulator that is powered and controlled by universal serial bus (USB) interface. The stimulator is composed of a custom printed circuit board (PCB), 16-MHz MSP430F2618 microcontroller with two integrated 12-bit digital to analog converters (DAC0, DAC1), high-speed H-Bridge, voltage-controlled current source (VCCS), isolated USB communication and power circuitry, two isolated transistor-transistor logic (TTL) inputs, and a serial 16 × 2 character liquid crystal display. The stimulators are designed to produce current stimuli in the range of ±15 mA indefinitely using a 20V source and to be used in ex vivo cardiac experiments, but they are suitable for use in a wide variety of research or student experiments that require precision control of continuous waveforms or synchronization with external events. The device was designed with customization in mind and has features that allow it to be integrated into current and future experimental setups. Dual TTL inputs allow replacement by two or more traditional stimulators in common experimental configurations. The MSP430 software is written in C++ and compiled with IAR Embedded Workbench 5.20.2. A control program written in C++ runs on a Windows personal computer and has a graphical user interface that allows the user to control all aspects of the device.

EFFECTS OF PCB 84 ATROPISOMERS ON [3H]-PHORBOL ESTER BINDING IN RAT CEREBELLAR GRANULE CELLS AND 45CA2+-UPTAKE IN RAT CEREBELLUM.

EPA Science Inventory

There is evidence that Polychlorinated biphenyl (PCB) congeners with ortho substituents have potential to cause neurotoxicity. Many PCB congeners implicated in these neurotoxic effects are chiral. It is currently unknown if the enantiomers of a chiral PCB congeners have differe...

40 CFR 761.298 - Decisions based on PCB concentration measurements resulting from sampling.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Decisions based on PCB concentration... Cleanup and On-Site Disposal of Bulk PCB Remediation Waste and Porous Surfaces in Accordance With § 761.61(a)(6) § 761.298 Decisions based on PCB concentration measurements resulting from sampling. (a) For...

Annotated bibliography of selected references on PCB and the Kalamazoo River Superfund Site, Michigan, 1982-2002

USGS Publications Warehouse

Simard, Andreanne

2003-01-01

Fifty six publications pertaining to the Kalamazoo River Superfund Site Publications stored in the Michigan Department of Environmental Quality Environmental Response Division site files are summarized. Publications are presented chronologically within four categories: PCB releases, PCB remediation, PCB safety, and PCB testing and cleanup. The text consists of bibliographical information and brief summaries of various published documents pertaining to PCB contamination of the Kalamazoo River. Numerous investigators such as the Michigan Department of Natural Resources, Georgia Pacific, and various contractors have demonstrated that multiple and at times continuous releases and re-releases of PCBs have occurred as a result of operations at papermill facilities owned and operated by the 'Potential Responsible Parties'.

The New Bedford Harbor Superfund site long-term monitoring program (1993-2009).

PubMed

Nelson, William G; Bergen, Barbara J

2012-12-01

New Bedford Harbor (NBH), located in southeastern Massachusetts, was designated as a marine Superfund site in 1983 due to sediment contamination by polychlorinated biphenyls (PCBs). Based on risks to human health and the environment, the first two phases of the site cleanup involved dredging PCB-contaminated sediments from the harbor. Therefore, a long-term monitoring program (LTM) was developed to measure spatial and temporal chemical and biological changes in sediment, water, and biota to assess the effects and effectiveness of the remedial activities. A systematic, probabilistic sampling design was used to select sediment sampling stations. This unbiased design allowed the three segments of the harbor to be compared spatially and temporally to quantify changes resulting from dredging the contaminated sediments. Sediment was collected at each station, and chemical (e.g., PCBs and metals), physical (e.g., grain size), and biological (e.g., benthic community) measurements were conducted on all samples. This paper describes the overall NBH-LTM approach and the results from the five rounds of sample collections. There is a decreasing spatial gradient in sediment PCB concentrations from the northern boundary (upper harbor) to the southern boundary (outer harbor) of the site. Along this same transect, there is an increase in biological condition (e.g., benthic community diversity). Temporally, the contaminant and biological gradients have been maintained since the 1993 baseline collection; however, since the onset of full-scale remediation, PCB concentrations have decreased throughout the site, and one of the benthic community indices has shown significant improvement in the lower and outer harbor areas.

Health Monitoring System Based on Intra-Body Communication

NASA Astrophysics Data System (ADS)

Razak, A. H. A.; Ibrahim, I. W.; Ayub, A. H.; Amri, M. F.; Hamzi, M. H.; Halim, A. K.; Ahmad, A.; Junid, S. A. M. Al

2015-11-01

This paper presents a model of a Body Area Network (BAN) health monitoring system based on Intra-Body Communication. Intra-body Communication (IBC) is a communication technique that uses the human body as a medium for electrical signal communication. One of the visions in the health care industry is to provide autonomous and continuous self and the remote health monitoring system. This can be achieved via BAN, LAN and WAN integration. The BAN technology itself consists of short range data communication modules, sensors, controller and actuators. The information can be transmitted to the LAN and WAN via the RF technology such as Bluetooth, ZigBee and ANT. Although the implementations of RF communication have been successful, there are still limitations in term of power consumption, battery lifetime, interferences and signal attenuations. One of the solutions for Medical Body Area Network (MBANs) to overcome these issues is by using an IBC technique because it can operate at lower frequencies and power consumption compared to the existing techniques. The first objective is to design the IBC's transmitter and receiver modules using the off the shelf components. The specifications of the modules such as frequency, data rate, modulation and demodulation coding system were defined. The individual module were designed and tested separately. The modules was integrated as an IBC system and tested for functionality then was implemented on PCB. Next objective is to model and implement the digital parts of the transmitter and receiver modules on the Altera's FPGA board. The digital blocks were interfaced with the FPGA's on board modules and the discrete components. The signals that have been received from the transmitter were converted into a proper waveform and it can be viewed via external devices such as oscilloscope and Labview. The signals such as heartbeats or pulses can also be displayed on LCD. In conclusion, the IBC project presents medical health monitoring model that operates at the range of 21 MHz frequency and reduce the power consumption for a longer battery lifetime.

Comparative developmental toxicity of planar polychlorinated biphenyl congeners in chickens, American kestrels, and common terns

USGS Publications Warehouse

Hoffman, D.J.; Melancon, M.J.; Klein, P.N.; Eisemann, J.D.; Spann, J.W.

1998-01-01

The effects of PCB congeners, PCB 126 (3,3',4,4',5-pentaCB) and PCB 77 (3,3'4,4'-tetraCB), were examined in chicken (Gallus gallus), American kestrel (Falco sparverius), and common tern (Sterna hirundo) embryos through hatching, following air cell injections on day 4. PCB 126 caused malformations and edema in chickens starting at 0.3 ppb, in kestrels at 2.3 ppb, but in terns only at levels affecting hatching success (44 ppb). Extent of edema was most severe in chickens and least in terns. Defects of the beak were common in all species, but with crossed beak most prevalent in terns. Effects on embryo growth were most apparent for PCB 126 in chickens and kestrels. The approximate LD50 for PCB 126 in chickens was 0.4 ppb, in kestrels was 65 ppb, and in terns was 104 ppb. The approximate LD50 for PCB 77 in chickens was 2.6 ppb and in kestrels was 316 ppb. Induction of cytochrome P450 associated monooxygenase activity (EROD activity) by PCB 126 in chick embryo liver was about 800 times more responsive than in tern and at least 1000 times more responsive than in kestrel. High concentrations of PCB 126 found in bald eagle eggs are nearly 20-fold higher than the lowest toxic concentration tested in kestrels. Concentrations of PCB 126 causing low level toxic effects in common tern eggs are comparable to highest levels in common terns and Forster's terns in the field, suggesting additional involvement of other compounds in the Great Lakes.

Concentration of polychlorinated biphenyl (PCB) congeners in the muscle of Clarias gariepinus and sediment from inland rivers of southwestern Nigeria and estimated potential human health consequences.

PubMed

Adeogun, Aina O; Chukwuka, Azubuike V; Okoli, Chukwunonso P; Arukwe, Augustine

2016-01-01

The distributions of polychlorinated biphenyl (PCB) congeners were determined in sediment and muscle of the African sharptooth catfish (Clarias gariepinus) from the Ogun and Ona rivers, southwest Nigeria. In addition, the effect of PCB congeners on condition factor (CF) and associated human health risk was assessed using muscle levels for a noncarcinogenic hazard quotient (HQ) calculation. Elevated concentrations of high-molecular-weight (HMW) PCB congeners were detected in sediment and fish downstream of discharge points of both rivers. A significant reduction in fish body weight and CF was observed to correlate with high PCB congener concentrations in the Ona River. A principal component (PC) biplot revealed significant site-related PCB congener distribution patterns for HMW PCB in samples from the Ogun River (71.3%), while the Ona River (42.6%) showed significant PCB congener patterns for low-molecular-weight (LMW) congeners. Biota-sediment accumulation factor (BSAF) was higher downstream for both rivers, presenting PCB congener-specific accumulation patterns in the Ona River. Significant decreases in fish body weight, length and CF were observed downstream compared to upstream in the Ona River. The non-carcinogenic HQ of dioxin-like congener 189 downstream in both rivers exceeded the HQ = 1 threshold for children and adults for both the Ogun and Ona rivers. Overall, our results suggest that industrial discharges contribute significantly to PCB inputs into these rivers, with potential for significant health implications for neighboring communities that utilize these rivers for fishing and other domestic purposes.

Prenatal and postnatal serum PCB concentrations and cochlear function in children at 45 months of age.

PubMed

Jusko, Todd A; Sisto, Renata; Iosif, Ana-Maria; Moleti, Arturo; Wimmerová, Sonˇa; Lancz, Kinga; Tihányi, Juraj; Sovčiková, Eva; Drobná, Beata; Palkovičová, L'ubica; Jurečková, Dana; Thevenet-Morrison, Kelly; Verner, Marc-André; Sonneborn, Dean; Hertz-Picciotto, Irva; Trnovec, Tomáš

2014-11-01

Some experimental and human data suggest that exposure to polychlorinated biphenyls (PCBs) may induce ototoxicity, though results of previous epidemiologic studies are mixed and generally focus on either prenatal or postnatal PCB concentrations exclusively. Our aim was to evaluate the association between pre- and postnatal PCB concentrations in relation to cochlear status, assessed by distortion product otoacoustic emissions (DPOAEs), and to further clarify the critical periods in development where cochlear status may be most susceptible to PCBs. A total of 351 children from a birth cohort in eastern Slovakia underwent otoacoustic testing at 45 months of age. Maternal pregnancy, cord, and child 6-, 16-, and 45-month blood samples were collected and analyzed for PCB concentrations. At 45 months of age, DPOAEs were assessed at 11 frequencies in both ears. Multivariate, generalized linear models were used to estimate the associations between PCB concentrations at different ages and DPOAEs, adjusting for potential confounders. Maternal and cord PCB-153 concentrations were not associated with DPOAEs at 45 months. Higher postnatal PCB concentrations at 6-, 16-, and 45-months of age were associated with lower (poorer) DPOAE amplitudes. When all postnatal PCB exposures were considered as an area-under-the-curve metric, an increase in PCB-153 concentration from the 25th to the 75th percentile was associated with a 1.6-dB SPL (sound pressure level) decrease in DPOAE amplitude (95% CI: -2.6, -0.5; p = 0.003). In this study, postnatal rather than maternal or cord PCB concentrations were associated with poorer performance on otoacoustic tests at age 45 months.

Laboratory study of PCB transport from primary sources to settled dust.

PubMed

Liu, Xiaoyu; Guo, Zhishi; Krebs, Kenneth A; Greenwell, Dale J; Roache, Nancy F; Stinson, Rayford A; Nardin, Joshua A; Pope, Robert H

2016-04-01

Dust is an important sink for indoor air pollutants, such as polychlorinated biphenyls (PCBs) that were used in building materials and products. In this study, two types of dust, house dust and Arizona Test Dust, were tested in a 30-m(3) stainless steel chamber with two types of panels. The PCB-containing panels were aluminum sheets coated with a PCB-spiked primer or caulk. The PCB-free panels were coated with the same materials but without PCBs. The dust evenly spread on each panel was collected at different times to determine its PCB content. The data from the PCB panels were used to evaluate the PCB migration from the source to the dust through direct contact, and the data from the PCB-free panels were used to evaluate the sorption of PCBs through the dust/air partition. Settled dust can adsorb PCBs from air. The sorption concentration was dependent on the congener concentration in the air and favored less volatile congeners. When the house dust was in direct contact with the PCB-containing panel, PCBs migrated into the dust at a much faster rate than the PCB transfer rate due to the dust/air partition. The dust/source partition was not significantly affected by the congener's volatility. For a given congener, the ratio between its concentration in the dust and in the source was used to estimate the dust/source partition coefficient. The estimated values ranged from 0.04 to 0.16. These values are indicative of the sink strength of the tested house dust being in the middle or lower-middle range. Published by Elsevier Ltd.

Fasting modifies Aroclor 1254 impact on plasma cortisol, glucose and lactate responses to a handling disturbance in Arctic charr

USGS Publications Warehouse

Jorgensen, E.H.; Vijayan, M.M.; Aluru, N.; Maule, A.G.

2002-01-01

Integrated effects of polychlorinated biphenyl (PCB) and nutritional status on responses to handling disturbance were investigated in the Arctic charr (Salvelinus alpinus). The fish were orally contaminated with Aroclor 1254 and held either with or without food for 5 months before they were subjected to a 10-min handling disturbance. Food-deprived fish were given 0, 1, 10 or 100 mg PCB kg−1 and the fed fish 0 or 100 mg PCB kg−1. Plasma cortisol, glucose and lactate levels were measured at 0 (pre-handling), 1, 3, 6 and 23 h after the handling disturbance. Food-deprived control fish had elevated plasma cortisol levels compared with fed fish before handling. These basal cortisol levels were suppressed by PCB in food-deprived fish, and elevated by PCB in fed fish. The immediate cortisol and glucose responses to handling disturbance were suppressed by PCB in a dose-dependent way in food-deprived fish. Although these responses were also lowered by PCB in the fed fish, the effect was much less pronounced than in food-deprived fish. There were only minor effects on plasma lactate responses. Our findings suggest that the stress responses of the Arctic charr are compromised by PCB and that the long-term fasting, typical of high-latitude fish, makes these species particularly sensitive to organochlorines such as PCB.

Geographic variation of PCB congeners in polar bears (Ursus maritimus) from Svalbard east to the Chukchi Sea

USGS Publications Warehouse

Andersen, M.; Lie, E.; Derocher, A.E.; Belikov, S.E.; Bernhoft, A.; Boltunov, Andrei N.; Garner, G.W.; Skaare, J.U.; Wiig, Øystein

2001-01-01

We present data on geographic variation in polychlorinated biphenyl (PCB) congeners in adult female polar bears (Ursus maritimus) from Svalbard eastward to the Chukchi Sea. Blood samples from 90 free-living polar bears were collected in 1987–1995. Six PCB congeners, penta to octa chlorinated (PCB-99, -118, -153, -156, -180, -194), were selected for this study. Differences between areas were found in PCB levels and congener patterns. Bears from Franz Josef Land (11,194 ng/g lipid weight) and the Kara Sea (9,412 ng/g lw) had similar ΣPCB levels and were higher than all other populations (Svalbard 5,043 ng/g lw, East Siberian Sea 3,564 ng/g lw, Chukchi Sea 2,465 ng/g lw). Svalbard PCB levels were higher than those from the Chukchi Sea. Our results, combined with earlier findings, indicate that polar bears from Franz Josef Land and the Kara Sea have the highest PCB levels in the Arctic. Decreasing trends were seen eastwards and westwards from this region. Of the congeners investigated in the present study, the lower chlorinated PCBs are increasing and the high chlorinated PCBs are decreasing from Svalbard eastward to the Chukchi Sea. Different pollution sources, compound transport patterns and regional prey differences could explain the variation in PCB congener levels and patterns between regions.

PCB 28 metabolites elimination kinetics in human plasma on a real case scenario: Study of hydroxylated polychlorinated biphenyl (OH-PCB) metabolites of PCB 28 in a highly exposed German Cohort.

PubMed

Quinete, Natalia; Esser, André; Kraus, Thomas; Schettgen, Thomas

2017-07-05

Polychlorinated biphenyls (PCBs) are suspected of carcinogenic, neurotoxic and immunotoxic effects in animals and humans. Although background levels of PCBs have been slowly decreased after their ban, they are still among the most persistent and ubiquitous pollutants in the environment, remaining the subject of great concern. PCB 28 is a trichlorinated PCB found in high concentrations not only in human plasma but also in indoor air in Europe, yet little is known about its metabolic pathway and potential metabolites in humans. The present study aims to elucidate the kinetics of metabolite formation and elimination by analyzing four hydroxylated PCBs (OH-PCBs) in human plasma as potential metabolites of the PCB 28 congener. For this purpose, the study was conducted in plasma samples of highly PCB-exposed individuals (N=268), collected from 2010 to 2014 as a representation of a real case scenario with longitudinal data. OH-PCBs have been predicted, synthesized in the course of this study and further identified and quantitated in human plasma. This is the first time that previously unknown PCB 28 metabolites have been measured in human plasma and half-lives have been estimated for PCB metabolites, which could then provide further understanding in the toxicological consequences of exposure to PCBs in humans. Copyright © 2017 Elsevier B.V. All rights reserved.

Lactational exposure to hydroxylated polychlorinated biphenyl (OH-PCB 106) causes hyperactivity in male rat pups by aberrant increase in dopamine and its receptor.

PubMed

Lesmana, Ronny; Shimokawa, Noriaki; Takatsuru, Yusuke; Iwasaki, Toshiharu; Koibuchi, Noriyuki

2014-08-01

Polychlorinated biphenyls (PCBs) are recognized as persistent environmental pollutants that may cause adverse health problems. Despite extensive investigations of PCB in neural function, little is known about behavioral traits by PCB exposure and its neurochemical mechanism. Here, we report the behavioral study of a rat pup that was exposed to hydroxylated-PCB 106 (OH-PCB 106; 4-hydroxy-2',3,3',4',5'-pentachlorobiphenyl) through maternal milk. The different groups of mothers received via gavage corn oil vehicle, 0.5, 5, or 50 mg/kg body weight of OH-PCB 106 every second day from day 3 to 13 after delivery. The exposure did not affect the body weight of the dams or the physical development of the newborn pups in both sexes. Male rats exposed to OH-PCB 106 showed hyperactivity that was characterized by increased locomotor activity in novel environment and circadian period. Interestingly, OH-PCB 106-exposed rat pups displayed abnormally high levels of dopamine and D2 dopamine receptor (D2DR), but not D1DR and D5DR, in the striatum, an important center for the coordination of behavior. These findings indicate that OH-PCB 106 has a significant neurotoxic effect on rat behavior, which may be associated with increased D2DR mediated signals. Copyright © 2012 Wiley Periodicals, Inc., a Wiley company.

Clinical and metabolic abnormalities associated with occupational exposure to polychlorinated biphenyls (PCBs)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chase, K.H.; Wong, O.; Thomas, D.

1982-02-01

A cross-sectional study of 120 male workers was conducted to determine the prevalence of increased polychlorinated biphenyl (PCB) absorption as well as the presence of potentially related clinical and metabolic abnormalities. Three exposure categories (''exposed'', ''nominally exposed'', ''nonexposed'') were defined. Complete work histories, clinical histories, physical examinations and laboratory tests, including plasma PCB determinations were obtained. In addition, fat PCB levels were determined in randomly selected subjects in each exposed group. Evidence of dermatotoxicity was observed and elevated PCB levels were noted more frequently in the exposed group (p < .00001), correlating well with age and duration of employment. Thesemore » correlations were stronger for fat (p < .001) than for plasma (p < .01) PCB levels. In the exposed group, significant correlations were found between plasma PCB and serum triglyceride (p < .00001) and serum glutamic oxaloacetic transaminase (SGOT) levels (p < .01). These correlations remained significant after controlling for either age or length of employment. No significant correlations were found between PCB levels and levels of cholesterol, high-density lipoprotein cholesterol or levels studied on liver function tests other than SGOT. Further analyses relating frequency of reported direct contact with PCB levels suggested a dermal route of exposure. An analysis by union affiliation demonstrated that those in crafts involving greater direct exposure had correspondingly higher elevations of PCB levels.« less

Clinical and metabolic abnormalities associated with occupational exposure to polychlorinated biphenyls (PCBs)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chase, K.H.; Wong, O.; Thomas, D.

1982-02-01

A cross-sectional study of 120 male workers was conducted to determine the prevalence of increased polychlorinated biphenyl (PCB) absorption as well as the presence of potentially related clinical and metabolic abnormalities. Three exposure categories (''exposed'', ''nominally exposed'', ''nonexposed'') were defined. Complete work histories, clinical histories, physical examinations and laboratory tests, including plasma PCB determinations were obtained. In addition, fat PCB levels were determined in randomly selected subjects in each exposed group. Evidence of dermatotoxicity was observed and elevated PCB levels were noted more frequently in the exposed group (p less than .0001), correlating well with age and duration of employment.more » These correlations were stronger for fat (p less than .001) than for plasma (p less than .01) PCB levels. In the exposed group, significant correlations were found between plasma PCB and serum triglyceride (p less than .0001) and serum glutamic oxaloacetic transaminase (SGOT) levels (p less than .01). These correlations remained significant after controlling for either age or length of employment. No significant correlations were found between PCB levels and levels of cholesterol, high-density lipoprotein cholesterol or levels studied on liver function tests other than SGOT. Further analyses relating frequency of reported direct contact with PCB levels suggested a dermal route of exposure. An analysis by union affiliation demonstrated that those in crafts involving greater direct exposure had correspondingly higher elevations of PCB levels.« less

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - 4100 VAPOR DETECTOR - ELECTRONIC SENSOR TECHNOLOGY

EPA Science Inventory

In July 1997, the U.S. Environmental Protection Agency conducted a demonstration of polychlorinated biphenyl (PCB) FIELD ANALYTICAL TECHNIQUES. The demonstration design was subjected to extensive review and comment by EPA's National Exposure Research Laboratory (NERL) Environmen...

40 CFR 761.345 - Form of the waste to be sampled.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Characterization for PCB Disposal in Accordance With § 761.62, and Sampling PCB Remediation Waste Destined for Off-Site Disposal, in Accordance With § 761.61 § 761.345 Form of the waste to be sampled. PCB bulk product waste and PCB remediation waste destined for off-site disposal must be in the form of either flattened...

Sex effect on polychlorinated biphenyl concentrations in fish: a synthesis

USGS Publications Warehouse

Madenjian, C.P.

2011-01-01

Polychlorinated biphenyls (PCBs) accumulate in fish primarily via food intake, and therefore, PCBs serve as a chemical tracer for food consumption. Sex differences in PCB concentrations of fish have been attributed to the following three mechanisms: (i) females losing a substantial portion of their PCB body burden during spawning and consequently their PCB concentration is considerably reduced immediately after spawning; (ii) sex differences in habitat utilization leading to sex differences in the PCB concentrations of the prey; and (iii) sex differences in gross growth efficiency, which is defined as growth divided by the amount of food consumption needed to achieve that growth. Based on my analyses and synthesis, mechanisms (i) and (ii) operate in relatively few fish populations, but can lead to mature males having PCB concentrations two to three times higher than mature female PCB concentrations. In contrast, mechanism (iii) operates in all fish populations, but typically, mechanism (iii) results in relatively modest sex differences, with mature males only between 15 and 35% higher in PCB concentration than mature females. In summary, the study of sex differences in PCB concentrations of fish has led to insights into fish behaviour and fish physiology.

Stereoselective bioaccumulation of chiral PCB 91 in earthworm and its metabolomic and lipidomic responses.

PubMed

He, Zeying; Wang, Yuehua; Zhang, Yanwei; Cheng, Haiyan; Liu, Xiaowei

2018-07-01

Stereoselective bioaccumulation, elimination, metabolomic and lipidomic responses of earthworm Eisenia fetida exposed to chiral polychlorinated biphenyl (PCB) 91 in an earthworm-soil system were investigated. Preferential bioaccumulation of (-)-PCB 91 and elimination of (+)-PCB 91 were observed following 50 and 500 μg/kg dwt exposures. Enantiomer fraction (EF) values decreased over time during the uptake and elimination periods. Metabolomics and lipidomics techniques based on ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) revealed significant changes in 108 metabolites after earthworms exposure to (+)-, (-)-, and (±)-PCB 91, compared to control groups. Forty two of these metabolites were identified as amino acids, nucleosides, fatty acids, dicarboxylic acids, vitamins or others. Lysophospholipids including six lysophosphatidylcholines (LPC), six lysophosphatidylethanolamine (LPE), eight lysophosphatidylinositol (LPI) and five lysophosphatidylserine (LPS) were also differentially expressed between exposure and control groups. Alterations in the levels of metabolites and lipids indicated stereoselective effects of chiral PCB 91 on earthworm amino acid, energy, and nucleotide metabolism, neurodevelopment and gene expression. Overall, the effects of (+)-PCB 91 were more pronounced than that of (-)- and (±)-PCB 91. Copyright © 2018 Elsevier Ltd. All rights reserved.

Chamber study of PCB emissions from caulking materials and light ballasts.

PubMed

Liu, Xiaoyu; Guo, Zhishi; Krebs, Kenneth A; Stinson, Rayford A; Nardin, Joshua A; Pope, Robert H; Roache, Nancy F

2015-10-01

The emissions of polychlorinated biphenyl (PCB) congeners from thirteen caulk samples were tested in a micro-chamber system. Twelve samples were from PCB-contaminated buildings and one was prepared in the laboratory. Nineteen light ballasts collected from buildings that represent 13 different models from five manufacturers were tested in 53-L environmental chambers. The rates of PCB congener emissions from caulking materials and light ballasts were determined. Several factors that may have affected the emission rates were evaluated. The experimentally determined emission factors showed that, for a given PCB congener, there is a linear correlation between the emission factor and the concentration of the PCB congener in the source. Furthermore, the test results showed that an excellent log-linear correlation exists between the normalized emission factor and the vapor pressure (coefficient of determination, r(2)⩾0.8846). The PCB congener emissions from ballasts at or near room temperature were relatively low with or without electrical load. However, the PCB congener emission rates increased significantly as the temperature increased. The results of this research provide new data and models for ranking the primary sources of PCBs and supports the development and refinement of exposure assessment models for PCBs. Published by Elsevier Ltd.

Trophic transfer of persistent organic pollutants through a pelagic food web: The case of Lake Como (Northern Italy).

PubMed

Mazzoni, Michela; Boggio, Emanuela; Manca, Marina; Piscia, Roberta; Quadroni, Silvia; Bellasi, Arianna; Bettinetti, Roberta

2018-05-30

Despite DDT and PCB having been banned for about 40 years, they are still detectable in the environment. In the present research we specifically investigated the trophic transfer of these organochlorine contaminants (OC) through a pelagic food web of a deep lake in Northern Italy (Lake Como) over time. Zooplankton and fish were sampled each season of a year and OC concentrations and the carbon and nitrogen isotopic ratios were measured. By using stable isotopes, the direct trophic relationship between pelagic zooplankton and zooplanktivorous fish was confirmed for Alosa agone only in summer. Based on this result, the biomagnification factor normalized on the trophic level (BMF TL ) for organic contaminants was calculated. BMF TL values were within the range 0.9-1.9 for DDT isomers and 1.6-4.9 for some PCB congeners (PCB 95, PCB 101, PCB 149, PCB 153, PCB 138 - present both in zooplankton and in fish and representing >60% of the PCB contamination), confirming the biomagnification of these compounds in one of the two zooplanktivorous fish species of the lake. Copyright © 2018. Published by Elsevier B.V.

Sexual difference in PCB concentrations of coho salmon (Oncorhynchus kisutch)

USGS Publications Warehouse

Madenjian, Charles P.; Schrank, Candy S.; Begnoche, Linda J.; Elliott, Robert F.; Quintal, Richard T.

2010-01-01

We determined polychlorinated biphenyl (PCB) concentrations in 35 female coho salmon (Oncorhynchus kisutch) and 60 male coho salmon caught in Lake Michigan (Michigan and Wisconsin, United States) during the fall of 1994 and 1995. In addition, we determined PCB concentrations in the skin-on fillets of 26 female and 19 male Lake Michigan coho salmon caught during the fall of 2004 and 2006. All coho salmon were age-2 fish. These fish were caught prior to spawning, and therefore release of eggs could not account for sexual differences in PCB concentrations because female coho salmon spawn only once during their lifetime. To investigate whether gross growth efficiency (GGE) differed between the sexes, we applied bioenergetics modeling. Results showed that, on average, males were 19% higher in PCB concentration than females, based on the 1994–1995 dataset. Similarly, males averaged a 20% higher PCB concentration in their skin-on fillets compared with females. According to the bioenergetics modeling results, GGE of adult females was less than 1% higher than adult male GGE. Thus, bioenergetics modeling could not explain the 20% higher PCB concentration exhibited by the males. Nonetheless, a sexual difference in GGE remained a plausible explanation for the sexual difference in PCB concentrations.

Distributions of PCB congeners and homologues in white sucker and coho salmon from Lake Michigan

USGS Publications Warehouse

Stapanian, Martin A.; Madenjian, Charles P.; Batterman, Stuart A.; Chernyak, Sergei M.; Edwards, William H.; McIntyre, Peter B.

2018-01-01

We tested the hypothesis of the proportion of higher chlorinated biphenyl (PCB) congeners increasing with increasing trophic level by comparing the respective PCB homologue distributions in an omnivore, white sucker (Catostomus commersoni), and a top predator, coho salmon (Oncorhynchus kisutch), from Lake Michigan. Adult females had the same congener and homologue proportions of total PCB concentration (ΣPCB) as adult males in both species. Hexachlorinated congeners comprised the largest proportion (32%) found in white sucker, followed by heptachlorinated (21%) and octochlorinated (18%) congeners. In contrast, pentachlorinated congeners comprised the largest proportion (33%) of ΣPCB found in coho salmon, followed by hexachlorinated (26%) and tetrachlorinated (24%) congeners. Coho salmon contained significantly higher proportions of tri-, tetra-, and pentachlorinated congeners, whereas white sucker contained significantly higher proportions of hexa- through decachlorinated congeners. Our results were opposite of the hypothesis of greater degree of PCB chlorination with increasing trophic level, and supported the contention that the PCB congener proportions in fish depends mainly on diet, and does not necessarily reflect the trophic level of the fish. Our results also supported the contention that diets do not vary between the sexes in most fish populations.

Soft-Matter Printed Circuit Board with UV Laser Micropatterning.

PubMed

Lu, Tong; Markvicka, Eric J; Jin, Yichu; Majidi, Carmel

2017-07-05

When encapsulated in elastomer, micropatterned traces of Ga-based liquid metal (LM) can function as elastically deformable circuit wiring that provides mechanically robust electrical connectivity between solid-state elements (e.g., transistors, processors, and sensor nodes). However, LM-microelectronics integration is currently limited by challenges in rapid fabrication of LM circuits and the creation of vias between circuit terminals and the I/O pins of packaged electronics. In this study, we address both with a unique layup for soft-matter electronics in which traces of liquid-phase Ga-In eutectic (EGaIn) are patterned with UV laser micromachining (UVLM). The terminals of the elastomer-sealed LM circuit connect to the surface mounted chips through vertically aligned columns of EGaIn-coated Ag-Fe 2 O 3 microparticles that are embedded within an interfacial elastomer layer. The processing technique is compatible with conventional UVLM printed circuit board (PCB) prototyping and exploits the photophysical ablation of EGaIn on an elastomer substrate. Potential applications to wearable computing and biosensing are demonstrated with functional implementations in which soft-matter PCBs are populated with surface-mounted microelectronics.

Identification and chemical characterization of particulate matter from wave soldering processes at a printed circuit board manufacturing company.

PubMed

Szoboszlai, Z; Kertész, Zs; Szikszai, Z; Angyal, A; Furu, E; Török, Zs; Daróczi, L; Kiss, A Z

2012-02-15

In this case study, the elemental composition and mass size distribution of indoor aerosol particles were determined in a working environment where soldering of printed circuit boards (PCB) took place. Single particle analysis using ion and electron microscopy was carried out to obtain more detailed and reliable data about the origin of these particles. As a result, outdoor and indoor aerosol sources such as wave soldering, fluxing processes, workers' activity, mineral dust, biomass burning, fertilizing and other anthropogenic sources could be separated. With the help of scanning electron microscopy, characteristic particle types were identified. On the basis of the mass size distribution data, a stochastic lung deposition model was used to calculate the total and regional deposition efficiencies of the different types of particles within the human respiratory system. The information presented in this study aims to give insights into the detailed characteristics and the health impact of aerosol particles in a working environment where different kinds of soldering activity take place. Copyright © 2011 Elsevier B.V. All rights reserved.

Roughness measurements on coupling structures for optical interconnections integrated on a printed circuit board

NASA Astrophysics Data System (ADS)

Hendrickx, Nina; Van Erps, Jürgen; Suyal, Himanshu; Taghizadeh, Mohammad; Thienpont, Hugo; Van Daele, Peter

2006-04-01

In this paper, laser ablation (at UGent), deep proton writing (at VUB) and laser direct writing (at HWU) are presented as versatile technologies that can be used for the fabrication of coupling structures for optical interconnections integrated on a printed circuit board (PCB). The optical layer, a highly cross-linked acrylate based polymer, is applied on an FR4 substrate. Both laser ablation and laser direct writing are used for the definition of arrays of multimode optical waveguides, which guide the light in the plane of the optical layer. In order to couple light vertically in/out of the plane of the optical waveguides, coupling structures have to be integrated into the optical layer. Out-of-plane turning mirrors, that deflect the light beam over 90°, are used for this purpose. The surface roughness and angle of three mirror configurations are evaluated: a laser ablated one that is integrated into the optical waveguide, a laser direct written one that is also directly written onto the waveguide and a DPW insert that is plugged into a cavity into the waveguiding layer.

Comment on linking the sex difference in PCB concentrations of fish to release of eggs at spawning: Time to jettison the dogma

USGS Publications Warehouse

Madenjian, Charles P.

2017-01-01

For the past 20 years or so, a commonly used explanation in the scientific literature for higher polychlorinated biphenyl (PCB) concentrations in male fish than in female fish has been that females lose a high proportion of their PCB body burden by releasing eggs at spawning time, and therefore the females undergo a substantial decrease in their PCB concentration immediately after spawning due to shedding of their eggs [1]. Indeed, this explanation can be viewed as the conventional wisdom used by toxicologists to account for differences in PCB concentrations between the sexes of fish. On the surface, this explanation seems plausible. PCBs are lipid soluble, and eggs are thought to be relatively high in lipid concentration. If a sufficiently high proportion of the PCB body burden within a female fish is transferred to the eggs, then the release of eggs at spawning would be expected to result in a dramatic decrease in the PCB concentration of the female.

Different carbon sources affect PCB accumulation by marine bivalves.

PubMed

Laitano, M V; Silva Barni, M F; Costa, P G; Cledón, M; Fillmann, G; Miglioranza, K S B; Panarello, H O

2016-02-01

Pampean creeks were evaluated in the present study as potential land-based sources of PCB marine contamination. Different carbon and nitrogen sources from such creeks were analysed as boosters of PCB bioaccumulation by the filter feeder bivalve Brachidontes rodriguezii and grazer limpet Siphonaria lessoni. Carbon of different source than marine and anthropogenic nitrogen assimilated by organisms were estimated through their C and N isotopic composition. PCB concentration in surface sediments and mollusc samples ranged from 2.68 to 6.46 ng g(-1) (wet weight) and from 1074 to 4583 ng g(-1) lipid, respectively, reflecting a punctual source of PCB contamination related to a landfill area. Thus, despite the low flow of creeks, they should not be underestimated as contamination vectors to the marine environment. On the other hand, mussels PCB bioaccumulation was related with the carbon source uptake which highlights the importance to consider this factor when studying PCB distribution in organisms of coastal systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparing polychlorinated biphenyl concentrations and patterns in the Saginaw River using sediment, caged fish, and semipermeable membrane devices

USGS Publications Warehouse

Echols, K.R.; Gale, R.W.; Schwartz, T.R.; Huckins, J.N.; Williams, L.L.; Meadows, J.C.; Morse, D.; Petty, J.D.; Orazio, C.E.; Tillitt, D.E.

2000-01-01

Three techniques of assessing bioavailable polychlorinated biphenyls (PCBs) in the Saginaw River, MI, were compared: sediments, caged fish, and semipermeable membrane devices (SPMDs). SPMDs and caged fish were placed in the river for 28 days at five sites where sediments were also sampled. The samples were analyzed for PCB congeners to determine concentrations and patterns. Total PCB concentrations ranged from 33 to 280 ng/g (dry weight) in sediments, 46 to 290 ng/g (wet weight) in caged fish, and 77 to 790 ng/g in SPMDs. Previously reported rates of PCB accumulation by SPMDs were used to estimate aqueous concentrations from the PCB concentrations detected in the SPMDs. Sediment-water partition coefficients were used to estimate aqueous PCB concentrations from sediment. Steady-state bioconcentration factors and depuration rate constants were used to estimate dissolved PCB concentrations from caged channel catfish. Relative PCB patterns from the SPMDs, caged fish, and sediment were compared using principal components analysis. SPMD and sediment samples provide complementary information. Sediments reflect long-term accumulation and weathering, while SPMDs integrate water concentrations only during the sampling period. Because of higher water solubilities of lower-chlorinated PCBs these predominate in the SPMDs as compared to in the fish and sediments. Contaminant profile differences between caged fish and SPMDs are likely due to metabolism and depuration of certain PCB congeners by fish.Three techniques of assessing bioavailable polychlorinated biphenyls (PCBs) in the Saginaw River, Ml, were compared: sediments, caged fish, and semipermeable membrane devices (SPMDs). SPMDs and caged fish were placed in the river for 28 days at five sites where sediments were also sampled. The samples were analyzed for PCB congeners to determine concentrations and patterns. Total PCB concentrations ranged from 33 to 280 ng/g (dry weight) in sediments, 46 to 290 ng/g (wet weight) in caged fish, and 77 to 790 ng/g in SPMDs. Previously reported rates of PCB accumulation by SPMDs were used to estimate aqueous concentrations from the PCB concentrations detected in the SPMDs. Sediment-water partition coefficients were used to estimate aqueous PCB concentrations from sediment. Steady-state bioconcentration factors and depuration rate constants were used to estimate dissolved PCB concentrations from caged channel catfish. Relative PCB patterns from the SPMDs, caged fish, and sediment were compared using principal components analysis. SPMD and sediment samples provide complementary information. Sediments reflect long-term accumulation and weathering, while SPMDs integrate water concentrations only during the sampling period. Because of higher water solubilities of lower-chlorinated PCBs these predominate in the SPMDs as compared to in the fish and sediments. Contaminant profile differences between caged fish and SPMDs are likely due to metabolism and depuration of certain PCB congeners by fish.At five sites in the Saginaw River, MI, PCB concentrations were determined in the summer of 1993 using three methods: sediment analysis, concentrations in caged fish, and concentrations in semipermeable membrane devices (SPMDs). On average, total PCB concentrations in the SPMDs were twice those found in caged fish, and the SPMD-to-fish concentration ratios of di-, tri-, tetra-, and pentaCB homologues were 10.0, 3.0, 2.5, and 1.4, respectively. Average concentrations in the sediments were approximately half those in the SPMDs, and the caged fish showed a greater preponderance of higher log octanol-water partition coefficient PCBs similar to the sediment pattern. On average, the water PCB concentrations estimated from sediment concentrations were five times higher than those calculated from SPMDs and three times higher than those estimated from caged fish. The total PCB concentrations in sediment, caged fish, and SPMDs ranged 33-280, 46-290, and 77-790 ng/g, respectiv

Long-term recovery of PCB-contaminated surface sediments at the Sangamo-westonl Twelvemile Creek/lake Hartwell Superfund Site.

PubMed

Brenner, Richard C; Magar, Victor S; Ickes, Jennifer A; Foote, Eric A; Abbott, James E; Bingler, Linda S; Crecelius, Eric A

2004-04-15

Natural recovery of contaminated sediments relies on burial of contaminated sediments with increasingly clean sediments over time (i.e., natural capping). Natural capping reduces the risk of resuspension of contaminated surface sediments, and it reduces the potential for contaminant transport into the food chain by limiting bioturbation of contaminated surface or near-surface sediments. This study evaluated the natural recovery of surface sediments contaminated with polychlorinated biphenyls (PCBs) at the Sangamo-Weston/Twelvemile Creek/Lake Hartwell Superfund Site (Lake Hartwell), Pickens County, SC. The primary focus was on sediment recovery resulting from natural capping processes. Total PCB (t-PCB), lead-210 (210Pb), and cesium-137 (137Cs) sediment core profiles were used to establish vertical t-PCB concentration profiles, age date sediments, and determine surface sedimentation and surface sediment recovery rates in 18 cores collected along 10 transects. Four upgradient transects in the headwaters of Lake Hartwell were impacted by historical sediment releases from three upgradient sediment impoundments. These transects were characterized by silt/ clay and sand layering. The highest PCB concentrations were associated with silt/clay layers (1.8-3.5% total organic carbon (TOC)), while sand layers (0.05-0.32% TOC) contained much lower PCB concentrations. The historical sediment releases resulted in substantial burial of PCB-contaminated sediment in the vicinity of these four cores; each core contained less than 1 mg/kg t-PCBs in the surface sand layers. Cores collected from six downgradient Lake Hartwell transects consisted primarily of silt and clay (0.91-5.1% TOC) and were less noticeably impacted by the release of sand from the impoundments. Vertical t-PCB concentration profiles in these cores began with relatively low PCB concentrations at the sediment-water interface and increased in concentration with depth until maximum PCB concentrations were measured at approximately 30-60 cm below the sediment-water interface, ca. 1960-1980. Maximum t-PCB concentrations were followed by progressively decreasing concentrations with depth until the t-PCB concentrations approached the detection limit, where sediments were likely deposited before the onset of PCB use at the Sangamo-Weston plant. The sediments containing the maximum PCB concentrations are associated with the period of maximum PCB release into the watershed. Sedimentation rates averaged 2.1 +/- 1.5 g/(cm2 yr) for 12 of 18 cores collected. The 1994 Record of Decision cleanup requirement is 1.0 mg/kg; two more goals (0.4 and 0.05 mg/kg t-PCBs) also were identified. Average surface sedimentation requirements to meet the three goals were 1.4 +/- 3.7, 11 +/- 4.2, and 33 +/- 11 cm, respectively. Using the age dating results, the average recovery dates to meet these goals were 2000.6 +/- 2.7, 2007.4 +/- 3.5, and 2022.7 +/- 11 yr, respectively. (The 95% prediction limits for these values also are provided.) Despite the reduction in surface sediment PCB concentrations, PCB concentrations measured in largemouth bass and hybrid bass filets continue to exceed the 2.0 mg/kg FDA fish tolerance level.

Riparian spiders indicate the magnitude and sources of polychlorinated biphenyl (PCB) contamination at a large contaminated sediment site

USGS Publications Warehouse

Walters, David M.; Otter, Ryan R.; Kraus, Johanna M.; Mills, Marc A.

2018-01-01

We investigated PCB contamination at the Ashtabula River Area of Concern (AOC) following remedial dredging using araneid and tetragnathid spiders. PCB concentrations remain elevated in the AOC compared to reference conditions. Patterns of contamination were strikingly similar between taxa, but were higher in tetragnathids at the most contaminated sites. Spider PCB homolog distributions identified two PCB sources to the AOC. Based on these findings, we recommend situations where these taxa can be used singularly, in concert, or combined into a composite “spider” sample to assess environmental contamination. 

Mineral oil certified reference materials for the determination of polychlorinated biphenyls from the National Metrology Institute of Japan (NMIJ)

PubMed Central

Aoyagi, Yoshie; Matsuo, Mayumi; Ishikawa, Keiichiro; Hanari, Nobuyasu; Otsuka, Satoko; Tsuda, Yoko; Yarita, Takashi

2008-01-01

Four mineral oil certified reference materials (CRMs), NMIJ CRM 7902-a, CRM 7903-a, CRM 7904-a, and CRM 7905-a, have been issued by the National Metrology Institute of Japan, which is part of the National Institute of Advanced Industrial Science and Technology (NMIJ/AIST), for the determination of polychlorinated biphenyls (PCBs). The raw materials for the CRMs were an insulation oil (CRM 7902-a and CRM 7903-a) and a fuel oil (CRM7904-a and CRM 7905-a). A solution of PCB3, PCB8, and technical PCB products, comprising four types of Kaneclor, was added to the oil matrices. The total PCB concentrations in the PCB-fortified oils (CRM 7902-a and CRM 7904-a) are approximately 6 mg kg−1. In addition, the mineral oils which were not fortified with PCBs were also distributed as CRMs (CRM 7903-a and CRM 7905-a). Characterization of these CRMs was conducted by the NMIJ/AIST, where the mineral oils and the PCB solution were analyzed using multiple analytical methods such as dimethylsulfoxide extraction, normal-phase liquid chromatography, gel permeation chromatography, reversed-phase liquid chromatography, and chromatography using sulfoxide-bonded silica; and/or various capillary columns for gas chromatography, and two ionization modes for mass spectrometry. The target compounds in the mineral oils and those in the PCB solution were determined by one of the primary methods of measurement, isotope dilution–mass spectrometry (ID-MS). Certified values have been provided for 11 PCB congeners (PCB3, 8, 28, 52, 101, 118, 138, 153, 180, 194, and 206) in the CRMs. These CRMs have information values for PCB homologue concentrations determined by using a Japanese official method for determination of PCBs in wastes and densities determined with an oscillational density meter. Because oil samples having arbitrary PCB concentrations between respective property values of the PCB-fortified and nonfortified CRMs can be prepared by gravimetric mixing of the CRM pairs, these CRMs can be used for validation of PCB analyses using various instruments which have different sensitivities. Figure Preparation and certification processes of the mineral oil CRMs (example shown is polychlorinated biphenyls in insulation oil, high/low concentrations) Electronic supplementary material The online version of this article (doi:10.1007/s00216-008-2010-3) contains supplementary material, which is available to authorized users. PMID:18415091

Plasma polychlorinated biphenyls (PCB) levels of workers in a transformer recycling company, their family members, and employees of surrounding companies.

PubMed

Schettgen, Thomas; Gube, Monika; Esser, Andre; Alt, Anne; Kraus, Thomas

2012-01-01

In spring 2010, high internal exposures (up to 236 μg/L plasma) for the sum of indicator polychlorinated biphenyls (PCB) were discovered in workers in a transformer recycling company in Germany, where PCB-contaminated material was not handled according to proper occupational hygiene. The release of PCB from this company raised growing concerns regarding possible adverse human health effects correlated with this exposure. This provided a basis for a large biological monitoring study in order to examine the internal exposure to PCB in individuals working in that recycling company, their family members, and relatives, as well as subjects working or living in the surroundings of this company. Blood samples from 116 individuals (formerly) employed in the transformer recycling company and 45 direct relatives of these persons were obtained. Further, blood samples of 190 subjects working in close vicinity of the recycling plant, 277 persons working in the larger area, and 41 residents of the area were investigated. Plasma samples were analyzed for the 6 indicator PCB (PCB 28, 52, 101, 138, 153, 180) and 12 dioxin-like PCB using gas chromatography/mass spectroscopy (GC/MS; limit of detection [LOD] at 0.01 μg/L). Median concentrations (maximum) for the sum of the 6 indicator PCB in blood of the employees, their relatives, individuals working in close vicinity, persons working in the larger area, and the residents were 3.68 (236.3), 1.86 (22.8), 1.34 (22.9), 1.19 (6.42), and 0.85 (7.22) μg/L plasma, respectively. The (former) employees of the transformer recycling plant partly showed the highest plasma PCB levels determined thus far in Germany. Even family members displayed highly elevated levels of PCB in blood due to contaminations of their homes by laundering of contaminated clothes. Vicinity to the recycling plant including reported contact with possibly contaminated scrap was the main contributor to the PCB levels of the workers of the surrounding companies. Residents of the area did not show significantly elevated blood PCB levels compared to the general population. Our biomonitoring results served as a basis for individual risk communication and successful risk management.

PCB Analysis Plan for Tank Archive Samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

NGUYEN, D.M.

2001-03-22

This analysis plan specifies laboratory analysis, quality assurance/quality control (QA/QC), and data reporting requirements for analyzing polychlorinated biphenyls (PCB) concentrations in archive samples. Tank waste archive samples that are planned for PCB analysis are identified in Nguyen 2001. The tanks and samples are summarized in Table 1-1. The analytical data will be used to establish a PCB baseline inventory in Hanford tanks.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Li; Guo, Linlin

Polychlorinated biphenyls (PCBs) are classic persistent organic pollutants (POPs). Many studies have found a positive association between the progression of hepatocellular carcinoma (HCC) and PCBs exposure. However, the influence of PCBs on epithelial-mesenchymal transition (EMT) of HCC remains to be unclear. In this study, we explored the effect of PCB126 on EMT in HCC cells and its underlying mechanisms. The data showed that PCB126, exposing both Bel-7402 and SMMC-7721 cells for 48 h, promoted EMT that was demonstrated by E-cadherin repression, up-regulation of N-cadherin and vimentin, and morphological alteration. We found that signal transducer and activator of transcription 3 (STAT3)/Snail1more » signaling was activated after PCB126 exposure, and the addition of STAT3 inhibitor WP1066 blocked PCB126-induced down-regulation of E-cadherin as well as up-regulation of N-cadherin and vimentin. Moreover, PCB126 exposure increased pyruvate kinase M2 (PKM2) expression and its nuclear translocation, whereas treatment with PKM2 shRNA suppressed the activation of STAT3/Snail1 signaling and the alternation of EMT-related molecules (E-cadherin, N-cadherin and vimentin). Furthermore, this study indicated estrogen receptor (ER) and aryl hydrocarbon receptor (AhR) were involved in PCB126-induced effects on PKM2, STAT3/Snail1 signaling and EMT by according treatment using ER inhibitor ICI and AhR shRNA. Notably, PCB126-increased reactive oxygen species (ROS) production via AhR is associated with activation of PKM2/STAT3/Snail1 cascades and contributes to EMT. Taken together, these results indicated that PCB126 promotes EMT process of HCC cells via PKM2/STAT3/Snail1 signaling which is mediated by ER and AhR. - Highlights: • PCB126 promotes epithelial-mesenchymal transition of HCC cells. • PCB126 regulates EMT through the activation of STAT3/Snail1 signaling. • PKM2 is responsible for PCB126-induced activation of STAT3/Snail1 signaling. • AhR-induced ROS generation regulates PKM2/STAT3/Snail1 signaling. • PCB126-induced EMT is mediated by ER and AhR.« less

Refining paracervical block techniques for pain control in first trimester surgical abortion: a randomized controlled noninferiority trial.

PubMed

Renner, Regina-Maria; Edelman, Alison B; Nichols, Mark D; Jensen, Jeffrey T; Lim, Jeong Y; Bednarek, Paula H

2016-11-01

Our objective was to evaluate two different aspects of the paracervical block (PCB) technique for first trimester surgical abortion, to compare a 3-min wait prior to cervical dilation to no wait and to compare four-site with two-site injection. We conducted two consecutive randomized, single-blinded noninferiority trials. In the first trial, women <11 weeks gestational age received a 20-mL 1% buffered lidocaine four-site PCB with either a 3-min wait between PCB injection and dilation or no wait. In the second trial, we compared a four-site with a two-site PCB. We evaluated dilation pain [100-mm visual analogue scale (VAS)] as the primary outcome. Secondary outcomes included pain at additional time points, anxiety, satisfaction and adverse events. Both trials fully enrolled (total n=332). Results were inconclusive as to whether no wait was noninferior to waiting 3-min prior to cervical dilation for dilation pain [VAS: 63 mm (SD, 24 mm) vs. 56 mm (SD, 32mm)] and as to whether a two-site PCB was noninferior to a four-site block [VAS: 68 mm (SD, 21 mm) vs. 60 mm (SD, 30 mm)]. Noninferiority analysis was inconclusive because the confidence interval of the mean pain score difference between groups included the predefined inferiority margin of 13-mm pain difference. Superiority analysis showed the four-site PCB to be superior to the two-site PCB. It remained inconclusive whether a 3-min wait time between PCB and cervical dilation provides noninferior pain control for first trimester surgical abortion. However, a four-site PCB appeared to be superior to a two-site PCB. It remained inconclusive whether a 3-min wait time between PCB and cervical dilation or using a two-site instead of a four-site PCB provided noninferior pain control for first trimester surgical abortion. This study did not assess whether the combination of the two separate factors provides additive benefit. Copyright © 2016 Elsevier Inc. All rights reserved.

Lipid rafts regulate PCB153-induced disruption of occludin and brain endothelial barrier function through protein phosphatase 2A and matrix metalloproteinase-2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eum, Sung Yong, E-mail: seum@miami.edu; Jaraki, Dima; András, Ibolya E.

Occludin is an essential integral transmembrane protein regulating tight junction (TJ) integrity in brain endothelial cells. Phosphorylation of occludin is associated with its localization to TJ sites and incorporation into intact TJ assembly. The present study is focused on the role of lipid rafts in polychlorinated biphenyl (PCB)-induced disruption of occludin and endothelial barrier function. Exposure of human brain endothelial cells to 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB153) induced dephosphorylation of threonine residues of occludin and displacement of occludin from detergent-resistant membrane (DRM)/lipid raft fractions within 1 h. Moreover, lipid rafts modulated the reduction of occludin level through activation of matrix metalloproteinase 2 (MMP-2)more » after 24 h PCB153 treatment. Inhibition of protein phosphatase 2A (PP2A) activity by okadaic acid or fostriecin markedly protected against PCB153-induced displacement of occludin and increased permeability of endothelial cells. The implication of lipid rafts and PP2A signaling in these processes was further defined by co-immunoprecipitation of occludin with PP2A and caveolin-1, a marker protein of lipid rafts. Indeed, a significant MMP-2 activity was observed in lipid rafts and was increased by exposure to PCB153. The pretreatment of MMP-2 inhibitors protected against PCB153-induced loss of occludin and disruption of lipid raft structure prevented the increase of endothelial permeability. Overall, these results indicate that lipid raft-associated processes, such as PP2A and MMP-2 activation, participate in PCB153-induced disruption of occludin function in brain endothelial barrier. This study contributes to a better understanding of the mechanisms leading to brain endothelial barrier dysfunction in response to exposure to environmental pollutants, such as ortho-substituted PCBs. - Highlights: • PCB153 disturbed human brain endothelial barrier through disruption of occludin. • Lipid raft-associated PP2A/MMP-2 induced PCB153-induced dysfunction of occludin. • Disrupted lipid rafts modulated PCB153-induced increase of permeability. • Lipid rafts act as a signaling platform for PCB153-induced dysfunction of occludin.« less

Induction of cytochrome P450 1A1 in MCF-7 human breast cancer cells by 4-chlorobiphenyl (PCB3) and the effects of its hydroxylated metabolites on cellular apoptosis

PubMed Central

Ptak, Anna; Ludewig, Gabriele; Rak, Agnieszka; Nadolna, Weronika; Bochenek, Michał; Gregoraszczuk, Ewa L

2010-01-01

Several studies suggest an involvement of PCBs in breast cancer formation, but the results are ambiguous and the mechanisms not clear. We propose that local activation of cytochrome P450 enzymes, CYP1A1 and CYP1B1 by PCB3, may generate active metabolites which affect apoptosis and thereby promote mammary carcinogenesis. To test this hypothesis MCF-7 human breast cancer cells were exposed to 300 nM PCB3 and its hydroxylated metabolites, 4OH-PCB and 3,4diOH-PCB3. The enzyme activity for CYP1A1 was assayed using the EROD assay, and CYP1A1 and CYP1B1 protein expression by western blotting. PCB3 increased CYP1A1 activity (~1.5fold) and protein levels within 6 hrs after exposure. No effect on CYP1B1 protein expression was observed. The effects of PCB3 and both its metabolites on staurosporine-induced apoptosis were determined by measuring DNA fragmentation using ELISA and TUNEL assays, and by measuring caspase-8 and caspase-9 activity. We found that PCB3 and both of its hydroxylated metabolites had no effect on caspase-8 and caspase-9 activity when cells were grown in medium deprived of estrogen, but reduced caspase-9 activity when cells were grown in medium supplemented with serum containing estradiol. Interestingly, a decrease of DNA fragmentation was observed upon treatment with 3,4diOH-PCB3 in both culture conditions, suggesting that 3,4diOH-PCB3 affects a caspase-independent pathway of cell death. In summary, interactions of PCB3 and its metabolites with estradiol by yet unknown mechanisms inhibit caspase 9-related apoptosis and additional, other death pathways are affected by the catechol metabolite 3,4diOH-PCB3. These anti-apoptotic effects and the change in metabolic activity may contribute to the carcinogenic effect of PCBs. PMID:19604582

Evaluating the behavior of polychlorinated biphenyl compounds in Lake Superior using a dynamic multimedia model

NASA Astrophysics Data System (ADS)

Khan, T.; Perlinger, J. A.; Urban, N. R.

2017-12-01

Certain toxic, persistent, bioaccumulative, and semivolatile compounds known as atmosphere-surface exchangeable pollutants or ASEPs are emitted into the environment by primary sources, are transported, deposited to water surfaces, and can be later re-emitted causing the water to act as a secondary source. Polychlorinated biphenyl (PCB) compounds, a class of ASEPs, are of major concern in the Laurentian Great Lakes because of their historical use primarily as additives to oils and industrial fluids, and discharge from industrial sources. Following the ban on production in the U.S. in 1979, atmospheric concentrations of PCBs in the Lake Superior region decreased rapidly. Subsequently, PCB concentrations in the lake surface water also reached near equilibrium as the atmospheric levels of PCBs declined. However, previous studies on long-term PCB levels and trends in lake trout and walleye suggested that the initial rate of decline of PCB concentrations in fish has leveled off in Lake Superior. In this study, a dynamic multimedia flux model was developed with the objective to investigate the observed levelling off of PCB concentrations in Lake Superior fish. The model structure consists of two water layers (the epilimnion and the hypolimnion), and the surface mixed sediment layer, while atmospheric deposition is the primary external pathway of PCB inputs to the lake. The model was applied for different PCB congeners having a range of hydrophobicity and volatility. Using this model, we compare the long-term trends in predicted PCB concentrations in different environmental media with relevant available measurements for Lake Superior. We examine the seasonal depositional and exchange patterns, the relative importance of different process terms, and provide the most probable source of the current observed PCB levels in Lake Superior fish. In addition, we evaluate the role of current atmospheric PCB levels in sustaining the observed fish concentrations and appraise the need for continuous atmospheric PCB monitoring by the Great Lakes Integrated Atmospheric Deposition Network. By combining the modeled lake and biota response times resulting from atmospheric PCB inputs, we predict the time scale for safe fish consumption in Lake Superior.

Sedimentary profile of polychlorinated biphenyls in the East China Sea: implications for the recent rising emissions from the unintentionally industrial productions

NASA Astrophysics Data System (ADS)

Zhao, T.; Guo, Z.

2017-12-01

As industrially synthesized chemicals, polychlorinated biphenyls (PCBs) with their predominant anthropogenic origins are effective proxies for the processes of industrialization and urbanization. In this study, sedimentary profiles extracted from locations in the coastal and offshore area of the East China Sea (core C0803: 27°38'N, 121°39'E; core FFJ103: 31°40'N, 125°52'E) were chosen to indicate the chronological distribution of PCB pollutions in China. The concentrations of total PCBs (ΣPCBs) were 0.17-1.21 ng g-1 and 0.19-0.71 ng g-1 respectively in core 0803 and FFj103, the range of which was in the low end of that detected in regions with long PCB application history. The timeline of PCB residues in sediments coincides with the production and use of PCB products in China. PCB concentrations leveled off at the bottoms of the both core sediments and exhibited an obvious peak in periods of 60s-70s. This period corresponds to approximately the time PCBs were first manufactured commercially since 1965 in China. A small dip of ΣPCBs was followed in the early 1980s reflecting the effect of banning on PCB usage in China, after which an exponential escalation at the surface layers was found in these cores. The time-dependent PCB input flux resembles that of PCB concentrations, suggesting a relatively stable depositional environment. As compared to the other studies at most locations, a noticeable increase of ΣPCBs fluxes was consistent with the fact that the significantly rising contributions of unintentionally produced PCBs (UP-PCB) over that made by intentionally produced emissions. Based on the compilation of UP-PCB emissions in China, the UP-PCB emissions started to increase quickly in the early 90s due to the fast and continuously developing cement and steel industries in China. This discrepancy of time pattern in PCB sedimentary profiles is a result of difference in evolution of anthropic activity pressure and economic development.

Study on the Filament Yarns Spreading Techniques and Assessment Methods of the Electronic Fiberglass Fabric

NASA Astrophysics Data System (ADS)

Wang, Xi; Chen, Shouhui; Zheng, Tianyong; Ning, Xiangchun; Dai, Yifei

2018-03-01

The filament yarns spreading techniques of electronic fiberglass fabric were developed in the past few years in order to meet the requirements of the development of electronic industry. Copper clad laminate (CCL) requires that the warp and weft yarns of the fabric could be spread out of apart and formed flat. The penetration performance of resin could be improved due to the filament yarns spreading techniques of electronic fiberglass fabric, the same as peeling strength of CCL and drilling performance of printed circuit board (PCB). This paper shows the filament yarns spreading techniques of electronic fiberglass fabric from several aspects, such as methods and functions, also with the assessment methods of their effects.